CA1161637A - Installation and process for the production of hot air - Google Patents
Installation and process for the production of hot airInfo
- Publication number
- CA1161637A CA1161637A CA000370901A CA370901A CA1161637A CA 1161637 A CA1161637 A CA 1161637A CA 000370901 A CA000370901 A CA 000370901A CA 370901 A CA370901 A CA 370901A CA 1161637 A CA1161637 A CA 1161637A
- Authority
- CA
- Canada
- Prior art keywords
- accordance
- air
- burners
- installation
- checkerwork
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B9/00—Stoves for heating the blast in blast furnaces
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Furnace Details (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Abstract
INSTALLATION AND PROCESS FOR THE PRODUCTION OF
HOT AIR
A B S T R A C T
The treatment of air, particularly raising air to a high temperature and pressure for subsequent injection into a shaft furnace, is accomplished in a manner which will enhance the reliability and service life of the heat ex-changer apparatus (10) through which the air is passed.
The heat exchanger apparatus (10) includes one or more burners (22) arranged so as to directly heat only the upper surfaces of a refractory brick checkerwork (12) which defi-nes a shaft through which the air to be heated rises. The heat exchanger may be divided into a lower chamber inclu-ding the checkerwork (12) and a hermetically sealed and cooled upper chamber defined by a partition (14) which supports the burners (22). The burners (22) and a refrac-tory lining (16) on the supporting mechanism therefor define combustion zones from which heat is radiated in a conical pattern and-the geometry of the apparatus is such that the conical patterns irradiate the upper surface of the checkerwork (12) without direct irradiation of walls (14) of the heat exchanger apparatus which extend above the checkerwork (12).
HOT AIR
A B S T R A C T
The treatment of air, particularly raising air to a high temperature and pressure for subsequent injection into a shaft furnace, is accomplished in a manner which will enhance the reliability and service life of the heat ex-changer apparatus (10) through which the air is passed.
The heat exchanger apparatus (10) includes one or more burners (22) arranged so as to directly heat only the upper surfaces of a refractory brick checkerwork (12) which defi-nes a shaft through which the air to be heated rises. The heat exchanger may be divided into a lower chamber inclu-ding the checkerwork (12) and a hermetically sealed and cooled upper chamber defined by a partition (14) which supports the burners (22). The burners (22) and a refrac-tory lining (16) on the supporting mechanism therefor define combustion zones from which heat is radiated in a conical pattern and-the geometry of the apparatus is such that the conical patterns irradiate the upper surface of the checkerwork (12) without direct irradiation of walls (14) of the heat exchanger apparatus which extend above the checkerwork (12).
Description
~nstallation and process for the Eroduction of hot air The present invention relates to an installation for the production of hot air, of the cowper type, com-prising an enclosure, mainly occupied by a checkerwork ofrefractory bric]cs, a-t least one cold air admission orifice at the base of the enclosure, at least one hot air outlet orifice situated at the top of the enclosure, ~nd one or more burners arranged in the upper part or the purpose of burning the uels and generating the heat required for the heating of the checkerwork, as well as a process to be employed with this apparatus.
Most of the known installations for the production of hot air are mainly made up of two parts. ~ first part, known as the combustion shaft, has a burner at the bottom, into which a combustible gas is injected, particularly blast furnace gas, in most cases enriched with cok:ing gas, natural gas, etc. The heat given off by the combustion of this gas rises -through the combustion shaft, is deflected by a cupola and redescends into the second part of the cowper, known as the ckeckerwork shaft, which stores the heat in its checkerwork of refrac-tory bricks. The hot air is produced by causing -the air to circulate through the checkerwork shaft in the opposite direction to the cir_ula--tion of the combustion gases, i.e. from the bottom upwards.In its passage through the ckeckerwork the air thus recu-perates the heat which was stored up in this checkerwork during the combustion of the gases.
Among these known installations a distinction must be drawn between the "separate shaft" type, in which the combustion shaft is completely separated from the checker-work shaft, and the "incorporated shaft" type, in which the combustion shaft and the checkerwork shaft, although not identical are situated next to each other in one single container.
In these known installations the part on which the ~ratest dem~nds are made an~ which is thus most subject to deterioration is the cupola. The fact is that it is directl~
exposed to the heat and -the combustion flames, since its r
Most of the known installations for the production of hot air are mainly made up of two parts. ~ first part, known as the combustion shaft, has a burner at the bottom, into which a combustible gas is injected, particularly blast furnace gas, in most cases enriched with cok:ing gas, natural gas, etc. The heat given off by the combustion of this gas rises -through the combustion shaft, is deflected by a cupola and redescends into the second part of the cowper, known as the ckeckerwork shaft, which stores the heat in its checkerwork of refrac-tory bricks. The hot air is produced by causing -the air to circulate through the checkerwork shaft in the opposite direction to the cir_ula--tion of the combustion gases, i.e. from the bottom upwards.In its passage through the ckeckerwork the air thus recu-perates the heat which was stored up in this checkerwork during the combustion of the gases.
Among these known installations a distinction must be drawn between the "separate shaft" type, in which the combustion shaft is completely separated from the checker-work shaft, and the "incorporated shaft" type, in which the combustion shaft and the checkerwork shaft, although not identical are situated next to each other in one single container.
In these known installations the part on which the ~ratest dem~nds are made an~ which is thus most subject to deterioration is the cupola. The fact is that it is directl~
exposed to the heat and -the combustion flames, since its r
- 2 - ~ 37 function is to deflect the combustion gases towards the checkerwork shaf-t. The hottest part of a cowper of this kind is thus invariably -the cupola, which is also that most exposed to stresses and therefore the most liable to suffer damage. This high temperature in the cupola reduces its mechanical strength and increases the concentration of NOX
ions, which form at high temperatures and which render the cupola particularly liable to develop what is known as "intercrystalline stress corrosion", major drawback of modern cowpers operating at high temperatures and pressures.
The cowpers with incorporated shafts also suffer from the drawback that the refractory separating wall bet-ween the combustion shaft and the checkerwork shaft is likewise exposed to an intensified risk of deterioration.
This is due to short circuits occuring between the combustion shaft and the checkerwork and manifest themselves in des-truction of the refractory material owing to the heat surges - produced by the considerable temperature differences bet-ween the two sides of the separating wall.
This last problem, inherent in the cowper of the in-corpora-ted shaft type, has been solved thanks to another type of installation known as the "Cowper without combustion shaft", in which the combustion is effected above the re-fractory checkerwork, either in the space underneath the ~5 cupola or in a separate combustion chamber above the cupola.
.
An example of an installation of this kind is described in German Patent application 2,123,552. The elimination of the combustion shaft offers the additional advantage of increasing the space available for the checkerwork or reducing the diameter required. A further advantage of this design is its symmetrical construction.
The cowpers without combus-tion shaft, however, have no-t provided any solution to the problem arising in the heating of the cupola, the wall of this latter still being the zone subjected to the most intensive heating, since either the combustion occurs immediately below it or the combustion gases are conveyed straight to the said wall.
This type of cowper therefore~invariably lnvolves the pro- ;
bl`ems of intercrystalline corrosion.
I~he purpose of the present invention is therefore to provide a new type of cowper without a com~ustion shaft and free of the drawbacks inherent in the cowpers already known.
For this purpose the invention provides an install-a-tion which is characterized by the fact that each burner is integrated into a refractory ~all provided with cavities corresponding -to each burner and forming with the front portion of the latter a "combustion dish" from which a conical flow of heat is emitted, each of these burners bein~
orientated to ensure that these heat flows act direct on the ; entire upper surface of the checkerwork without any con-tact between this surface and the flames.
In this type of burner the combustion takes place in a front "dishl' of the burner, and the combustion gases, as well as the heat given off, are conveyed direct to the upper surface of the refractory checlcerwork. The resulting advantage is that the heat is transmitted to the place where it is required and without first being reflected from the cupola. This latter therefore no longer has to function as ; a deflecting device for the combustion gases and the heat, its sole function now being that of an arch or cover serving to close the upper part of the installation. Thanks to this construction , the temperature of this arch can be reduced by 100-150 for comparable operating conditions.
Whereas in conventional cowpers the hottest point r and that subject to the greatest stress and having the least strength, was the cupola, the hottest point in the cowper according to the present invention is that subject to the minimum stress, in addition to being that of which the heat is recuperable, i.e. the upper part of the refractory checkerwork.
;- A further advantage offered by the adoption of flameless burners and the elimination of the combustion shaft is the reduction of the proportion of NOX ions for a given hot air temperature.
n the simplest version one single burner is posi-tioned in the centre of the arch of the cowper, the hot air outlet orifice being situated by the side of this burner.
i37 In another version the hot air outlet orifice is in the centre of the arch, the burners being distributed around the orifice. In this case there may be either three or four such burners, occupying the points of a triangle or square respectively.
In a further multi-burner version the burners and the hot air outlet orif$ce are arranged around the centre of the arch.
As this arch will now be subject to less stress, particularly owing to the lower temperature and the reduc-tion of the intercrystalline corrosion, a number of openings can be provided in the arch, in order to position the hot air outlet orifice and the burners without appreciably detracting from the static strenght of the assembly. The arch may be a simple brickwork structure or else a "sus-pended arch", l.e. consist of refractory bricks suspended by securing hooks from the outer metal cladding.
In another version the burner or burners are simply affixed vertically to a circular slab mounted transversely ~0 above the checkerwork and forming together with an upper casing a hermetic chamber into which the supply plpes for the burners penetrate. In this version the hot air outlet orifice may be situated between the slab and the checker-work or extend out vertically from the centre.
; 25 The invention likewise covers a process for the production of hot air in an installation of this last type, this process comprising a combustion period and an air period, and being characterized by the fact ~hat duriny the said two periods the slab and also the chamber above it are cooled. This cooling can with advantage be effected by introducing combustion air into the chamber during the combustion phase and cold air during the air phase. The cold air thus circulating in this chamber can be recycled and reintroduced at the bottom of the checkerwork in such a way as to enable its heating to be utilized in the chamber above the slab. In addition to the cooling effect, the circulation of the cold air in this chamber ensures that the pressure on the respective sides of the slab will be balanced out.
In a further embodiment of the invention a cooling system is provided in the slab, in which system a supply of water or else air which can be re-used, in the process adopted, is caused to circulate.
Further features and characteristics will become apparent to those skilled in the art from the following detailed description of certain possible embodi~ents oE the invention, by reference to the accompanying drawings wherein like reference numerals refer to like elements, and in which the respective figures are as follows :
Figure 1 : a schematic cross section of a first ; embodiment of a cowper in accordance with the present invention.
Figure la : a schematic partial plan view of the version shown in E'igure 1.
Figures 2, 2a : analogous view to the preceding figures, showing a second versi.on.
Figures 3, 3a : V:Lews corresponding to those pro~
vided by Figures 1 and la, illustrating a third embodiment.
Figures 4, 4a corresponding -to figures 1 and la respectively of the version having one single burner but provided with the suspended type of arch.
Figure 5 : a schematic vertical section through the upper part of another type of cowper according to the invention.
Figure 5a : a partial plan view of the version shown in Figure 5.
Figures 6, 6a : a variant of the version shown in Figure 5, with a schematic diagram illustrating the process adopted.
Figures 7, 7a : a schematic diagram of the process description with re~erence to Figure 6, but this applied to the version shown in Figure 5.
Figure 8 : A schematic diagram of a version similar to that shown in Figure 6, but with an air-cooled slab.
Figure 8a : a schematic horizontal sec-tion in the plane 8a-8a through the slab shown in Figure 8.
Figure 9, 9a : a variant of the process described~
by reference to Figure 6.
.
\
Figure 10 : a schematic diagram of a variant of the embodiment shown in Figure 8, but with a water-cooled slab.
Figure lOa : a schematic horizontal section in the plane lOa-lOa through the slab shown in Figure 10.
Figures 11, lla : an analogou.s embodiment to that shown in Figure 2.
Figures 12, 12a : the adaptat:ion of the sus~pension system of Figure 11 to the versions provided with a slab.
Figures 1 and la illustrate the upper part of a first embodiment of a cowper 10. This cowper comprises one single shaft 12 formed by a checkerwork of refractory bricks which are alternately heated and traversed by air from the bottom upwards in order to recuperate the heat stored up in the refractory bric]cwork. The shaft 12 is closed at the top by an arch or dome 14 consisting of an assembly of refractory bricks 16 surrounded by an external metal clad-ding 18. This arch 14 is provided with an o~ltlet 20 for the hot air rising through the refractory checkerwork of the shaft 12.
The version of the present invention shown in Figure 1 comprises a burner 22 which may be of the type described ~- ~ in French Patent 1,205,382. This is a burner essentially consisting of an enclosure 24 provided with an inlet 26 ; : :
~25 for the combustible gases and an inlet 28 for the combus-tion air, the combustion itself taking place in a "bowl" 30 also containing the tip of a pilot flame, not shown in the drawing.
The characteristic function of this burner is to prcduce a very high degree of heat radiation, thanks to a whirling flame inside the bowl 30. The burner will be simply affixed to a flange 32 of the cladding 18 of the arch 14, while an aperture 34, preferably diverging slight-ly, with an opening angle corresponding to the angle of the "cone" emitted by the burner 22, will be provided in the refractory brickwork 16. This emission cone is shown schematically by dotted lines and is marked 36.
During the phase in which the refractory brickwork ls heated up the combu~t1on gases anù co bust1on alr are ~6~7 introduced into the burner 22 at a pressure slightly above the atmospheric, in order to cause the combustion gases to be very rapidly mixed and to form a continuous flow all the way down to -the bottom of the checkerwork shaft 12. The emission of the combustion gases and that of the thermal radiation take place at a divergent angle represented b~ -the cone 36, the maximu}~ heating occurring on the upper sur~ace of the refractory checkerwork, i.e.
where the heat is really required and where it can be re-cuperated.
On the other hand, the arch 14, contrary to thearches and cupolas of all the installations known up to the present is less exposed to thermal radiations and re-mains "in the shade" from the heat given off by the burner 22.
To obtain a regulated temperature o~ 1250C for the hot air, as is the case in modern blast furnaces, the temperature of the refractory checlcerwork must be increased to 1400C, at all events in its upper part. If this temperature is -to be obtained the temperature at the outlet of the buxner must reach 1500C. Now i~ such tem-peraturesare adopted in conventional installations the temperature of a cupola, which reflects the combustion gases and the heat of the combustion shaft towards the checkerwork will be over the 1400C to which the temperature of the xefractory bricks has to be brought, i.e. the tem-perature of the cupola may rise to as much as 1450C and over. At such a temperature, needless to say, its strength is seriously reduced, in addition to which it i5 exposed to the intercrystalline corrosion phenomenon.
On the other hand, for comparable operating con-ditions, i.e~ the heatin~ of the upper part of the checker-work to 1400C and a combustion temperature of 1500C, the temperature prevailing in the arch 14 is only about 1300C, which is about 150C lower than the temperature occuring in the cupolas of conventional installations. Now it is a well known fact that a reduction of 100 or even 150C
ln the temperature is quite considerable for these thermal conditlons, particularly as re~ards the increase o~ the ~L~6~63~
statlc s-trength of the arch and the reduction of the rlsk of intercrystalline corrosion.
Furthermore, in view of the short distance between the burner and the refractory checkerwork, and in view of the fact that the burner used is operated more efficiently than the burners employed in the conventional cowpers, it is even possible to adopt less than 1500C at the outlet of the burner in order to heat the bricks to 1400C, or else, while still operating at 1500C, to raise the temperature of the upper part ~ 10 of the checkerwork to above 1400C.
: The proximity of the burner 22 of the refractory checker-work also enables the temperature of the said checkerwork to be regulated more satisfactorily, resulting in better control over the temperature of the hot air at ~he outlet of the cowper.
A further important advantage is the reduction in ~ the formation of NOX ions. The fact is tha-t experience : has shown that they :Eorm to a very considerable extent at high temperatures particularly at those exceeding 1400 C, so that, as already mentioned r it is in the cupola of conventional cowpers that the greatest concentration of NOX ions is to be found. Now if the temperature of a cupola can be reduced to below 1400C one of the causes or condi-tions which favour -the formation of NO~ ions is eliminated i.e. the concentration of NOX ions is greatly reduced, the ~ 25 risk of the intercrystalline corrosion phenomenon being ; ~ rendered far smaller at the same time.
It goes without saying that the elimination of the heating of the parts which do not require to be heated, such as teh walls of the combustion shaft and, above all, the cupola, greatly reduces the fuel required for the heating of the refractory checkerwork, or else enables it to be heated more satisfactorily with the same quantity of fuel. In either case there is naturally an energy gain.
Whereas in the case of the cupolas of conventional cowpers it was necessary, owing to the heat stresses suffered by the cupola, to adhere to certain strict condi-tions as regards its geometrical design and to avoir aper-tures as far as possible, in order to increase its static ~trength, there will hence forward be a greater degree of ~6~637 g freedom in the selection of the geometrical shape of the arch described in the foregoing, i.e. it can be given any shape which proves most suitable and the necessary aper-tures can be provided therein. It is thanks to this cir-cumstance tha-t numerous variants can he adopted, some of which will be descrlbed hereinafter, by reference to the following f:igures.
Figures 2 and 2a illustrate one embodiment ln which the hot air outlet 40 is provided in the centre of the arch, above the checkerwork shaft 12. Instead of providing one single burner, as in Figure 1, four burners 42a, 42b, 42c and 42d are provided, each of exactly the same design as the burner 22 but of a smaller size. These burners are arranged in a "square" at regular intervals around the hot air outlet 40. These burners 42a, 42b, 42c and 42d will preferably be inclined at a slight angle in relation to the longitudinal axis o~ the shaft, so that the thermal radiation cone of each burner will come in contact with the entire upper surface of the checkerwork shaft. The shape and the angle of inclination of the apertures in the brickwork of the arch 44 will naturally be in accordance with thQ angle of inclina-tion of the burners.
In the version shown in Figures 3 and 3a the arch 54 has been provided with four burners 52a, 52b, 52¢ and 52d (not shown). These burners 52a, 52b, 52c and 52d are identically similar to those of Figure 2 but arranged differently. As may be seen, the hot air outlet 50 is no longer in the centre of the arch but by the side of the latter, while the four burners 52a, 52b, 52c and 52d are arranged in a "square" around the centre of the arch 54.
Figures 4 and 4a illustrate a version analogous to that of Figures 1 and la, with a same burner 22 positioned in the centre of an arch 63 and with a hot air outlet 20 positioned adjacent to the burner 22. The difference in relation to the verslon shown in Figure l resides in the fact that the arch 63 no longer constitutes a ~rickwork assembly and that the internal refractory lining 67 is affixed by means of securing bricks 65 to the external cladding 69 of the arch 63. This enables a flatter cons-
ions, which form at high temperatures and which render the cupola particularly liable to develop what is known as "intercrystalline stress corrosion", major drawback of modern cowpers operating at high temperatures and pressures.
The cowpers with incorporated shafts also suffer from the drawback that the refractory separating wall bet-ween the combustion shaft and the checkerwork shaft is likewise exposed to an intensified risk of deterioration.
This is due to short circuits occuring between the combustion shaft and the checkerwork and manifest themselves in des-truction of the refractory material owing to the heat surges - produced by the considerable temperature differences bet-ween the two sides of the separating wall.
This last problem, inherent in the cowper of the in-corpora-ted shaft type, has been solved thanks to another type of installation known as the "Cowper without combustion shaft", in which the combustion is effected above the re-fractory checkerwork, either in the space underneath the ~5 cupola or in a separate combustion chamber above the cupola.
.
An example of an installation of this kind is described in German Patent application 2,123,552. The elimination of the combustion shaft offers the additional advantage of increasing the space available for the checkerwork or reducing the diameter required. A further advantage of this design is its symmetrical construction.
The cowpers without combus-tion shaft, however, have no-t provided any solution to the problem arising in the heating of the cupola, the wall of this latter still being the zone subjected to the most intensive heating, since either the combustion occurs immediately below it or the combustion gases are conveyed straight to the said wall.
This type of cowper therefore~invariably lnvolves the pro- ;
bl`ems of intercrystalline corrosion.
I~he purpose of the present invention is therefore to provide a new type of cowper without a com~ustion shaft and free of the drawbacks inherent in the cowpers already known.
For this purpose the invention provides an install-a-tion which is characterized by the fact that each burner is integrated into a refractory ~all provided with cavities corresponding -to each burner and forming with the front portion of the latter a "combustion dish" from which a conical flow of heat is emitted, each of these burners bein~
orientated to ensure that these heat flows act direct on the ; entire upper surface of the checkerwork without any con-tact between this surface and the flames.
In this type of burner the combustion takes place in a front "dishl' of the burner, and the combustion gases, as well as the heat given off, are conveyed direct to the upper surface of the refractory checlcerwork. The resulting advantage is that the heat is transmitted to the place where it is required and without first being reflected from the cupola. This latter therefore no longer has to function as ; a deflecting device for the combustion gases and the heat, its sole function now being that of an arch or cover serving to close the upper part of the installation. Thanks to this construction , the temperature of this arch can be reduced by 100-150 for comparable operating conditions.
Whereas in conventional cowpers the hottest point r and that subject to the greatest stress and having the least strength, was the cupola, the hottest point in the cowper according to the present invention is that subject to the minimum stress, in addition to being that of which the heat is recuperable, i.e. the upper part of the refractory checkerwork.
;- A further advantage offered by the adoption of flameless burners and the elimination of the combustion shaft is the reduction of the proportion of NOX ions for a given hot air temperature.
n the simplest version one single burner is posi-tioned in the centre of the arch of the cowper, the hot air outlet orifice being situated by the side of this burner.
i37 In another version the hot air outlet orifice is in the centre of the arch, the burners being distributed around the orifice. In this case there may be either three or four such burners, occupying the points of a triangle or square respectively.
In a further multi-burner version the burners and the hot air outlet orif$ce are arranged around the centre of the arch.
As this arch will now be subject to less stress, particularly owing to the lower temperature and the reduc-tion of the intercrystalline corrosion, a number of openings can be provided in the arch, in order to position the hot air outlet orifice and the burners without appreciably detracting from the static strenght of the assembly. The arch may be a simple brickwork structure or else a "sus-pended arch", l.e. consist of refractory bricks suspended by securing hooks from the outer metal cladding.
In another version the burner or burners are simply affixed vertically to a circular slab mounted transversely ~0 above the checkerwork and forming together with an upper casing a hermetic chamber into which the supply plpes for the burners penetrate. In this version the hot air outlet orifice may be situated between the slab and the checker-work or extend out vertically from the centre.
; 25 The invention likewise covers a process for the production of hot air in an installation of this last type, this process comprising a combustion period and an air period, and being characterized by the fact ~hat duriny the said two periods the slab and also the chamber above it are cooled. This cooling can with advantage be effected by introducing combustion air into the chamber during the combustion phase and cold air during the air phase. The cold air thus circulating in this chamber can be recycled and reintroduced at the bottom of the checkerwork in such a way as to enable its heating to be utilized in the chamber above the slab. In addition to the cooling effect, the circulation of the cold air in this chamber ensures that the pressure on the respective sides of the slab will be balanced out.
In a further embodiment of the invention a cooling system is provided in the slab, in which system a supply of water or else air which can be re-used, in the process adopted, is caused to circulate.
Further features and characteristics will become apparent to those skilled in the art from the following detailed description of certain possible embodi~ents oE the invention, by reference to the accompanying drawings wherein like reference numerals refer to like elements, and in which the respective figures are as follows :
Figure 1 : a schematic cross section of a first ; embodiment of a cowper in accordance with the present invention.
Figure la : a schematic partial plan view of the version shown in E'igure 1.
Figures 2, 2a : analogous view to the preceding figures, showing a second versi.on.
Figures 3, 3a : V:Lews corresponding to those pro~
vided by Figures 1 and la, illustrating a third embodiment.
Figures 4, 4a corresponding -to figures 1 and la respectively of the version having one single burner but provided with the suspended type of arch.
Figure 5 : a schematic vertical section through the upper part of another type of cowper according to the invention.
Figure 5a : a partial plan view of the version shown in Figure 5.
Figures 6, 6a : a variant of the version shown in Figure 5, with a schematic diagram illustrating the process adopted.
Figures 7, 7a : a schematic diagram of the process description with re~erence to Figure 6, but this applied to the version shown in Figure 5.
Figure 8 : A schematic diagram of a version similar to that shown in Figure 6, but with an air-cooled slab.
Figure 8a : a schematic horizontal sec-tion in the plane 8a-8a through the slab shown in Figure 8.
Figure 9, 9a : a variant of the process described~
by reference to Figure 6.
.
\
Figure 10 : a schematic diagram of a variant of the embodiment shown in Figure 8, but with a water-cooled slab.
Figure lOa : a schematic horizontal section in the plane lOa-lOa through the slab shown in Figure 10.
Figures 11, lla : an analogou.s embodiment to that shown in Figure 2.
Figures 12, 12a : the adaptat:ion of the sus~pension system of Figure 11 to the versions provided with a slab.
Figures 1 and la illustrate the upper part of a first embodiment of a cowper 10. This cowper comprises one single shaft 12 formed by a checkerwork of refractory bricks which are alternately heated and traversed by air from the bottom upwards in order to recuperate the heat stored up in the refractory bric]cwork. The shaft 12 is closed at the top by an arch or dome 14 consisting of an assembly of refractory bricks 16 surrounded by an external metal clad-ding 18. This arch 14 is provided with an o~ltlet 20 for the hot air rising through the refractory checkerwork of the shaft 12.
The version of the present invention shown in Figure 1 comprises a burner 22 which may be of the type described ~- ~ in French Patent 1,205,382. This is a burner essentially consisting of an enclosure 24 provided with an inlet 26 ; : :
~25 for the combustible gases and an inlet 28 for the combus-tion air, the combustion itself taking place in a "bowl" 30 also containing the tip of a pilot flame, not shown in the drawing.
The characteristic function of this burner is to prcduce a very high degree of heat radiation, thanks to a whirling flame inside the bowl 30. The burner will be simply affixed to a flange 32 of the cladding 18 of the arch 14, while an aperture 34, preferably diverging slight-ly, with an opening angle corresponding to the angle of the "cone" emitted by the burner 22, will be provided in the refractory brickwork 16. This emission cone is shown schematically by dotted lines and is marked 36.
During the phase in which the refractory brickwork ls heated up the combu~t1on gases anù co bust1on alr are ~6~7 introduced into the burner 22 at a pressure slightly above the atmospheric, in order to cause the combustion gases to be very rapidly mixed and to form a continuous flow all the way down to -the bottom of the checkerwork shaft 12. The emission of the combustion gases and that of the thermal radiation take place at a divergent angle represented b~ -the cone 36, the maximu}~ heating occurring on the upper sur~ace of the refractory checkerwork, i.e.
where the heat is really required and where it can be re-cuperated.
On the other hand, the arch 14, contrary to thearches and cupolas of all the installations known up to the present is less exposed to thermal radiations and re-mains "in the shade" from the heat given off by the burner 22.
To obtain a regulated temperature o~ 1250C for the hot air, as is the case in modern blast furnaces, the temperature of the refractory checlcerwork must be increased to 1400C, at all events in its upper part. If this temperature is -to be obtained the temperature at the outlet of the buxner must reach 1500C. Now i~ such tem-peraturesare adopted in conventional installations the temperature of a cupola, which reflects the combustion gases and the heat of the combustion shaft towards the checkerwork will be over the 1400C to which the temperature of the xefractory bricks has to be brought, i.e. the tem-perature of the cupola may rise to as much as 1450C and over. At such a temperature, needless to say, its strength is seriously reduced, in addition to which it i5 exposed to the intercrystalline corrosion phenomenon.
On the other hand, for comparable operating con-ditions, i.e~ the heatin~ of the upper part of the checker-work to 1400C and a combustion temperature of 1500C, the temperature prevailing in the arch 14 is only about 1300C, which is about 150C lower than the temperature occuring in the cupolas of conventional installations. Now it is a well known fact that a reduction of 100 or even 150C
ln the temperature is quite considerable for these thermal conditlons, particularly as re~ards the increase o~ the ~L~6~63~
statlc s-trength of the arch and the reduction of the rlsk of intercrystalline corrosion.
Furthermore, in view of the short distance between the burner and the refractory checkerwork, and in view of the fact that the burner used is operated more efficiently than the burners employed in the conventional cowpers, it is even possible to adopt less than 1500C at the outlet of the burner in order to heat the bricks to 1400C, or else, while still operating at 1500C, to raise the temperature of the upper part ~ 10 of the checkerwork to above 1400C.
: The proximity of the burner 22 of the refractory checker-work also enables the temperature of the said checkerwork to be regulated more satisfactorily, resulting in better control over the temperature of the hot air at ~he outlet of the cowper.
A further important advantage is the reduction in ~ the formation of NOX ions. The fact is tha-t experience : has shown that they :Eorm to a very considerable extent at high temperatures particularly at those exceeding 1400 C, so that, as already mentioned r it is in the cupola of conventional cowpers that the greatest concentration of NOX ions is to be found. Now if the temperature of a cupola can be reduced to below 1400C one of the causes or condi-tions which favour -the formation of NO~ ions is eliminated i.e. the concentration of NOX ions is greatly reduced, the ~ 25 risk of the intercrystalline corrosion phenomenon being ; ~ rendered far smaller at the same time.
It goes without saying that the elimination of the heating of the parts which do not require to be heated, such as teh walls of the combustion shaft and, above all, the cupola, greatly reduces the fuel required for the heating of the refractory checkerwork, or else enables it to be heated more satisfactorily with the same quantity of fuel. In either case there is naturally an energy gain.
Whereas in the case of the cupolas of conventional cowpers it was necessary, owing to the heat stresses suffered by the cupola, to adhere to certain strict condi-tions as regards its geometrical design and to avoir aper-tures as far as possible, in order to increase its static ~trength, there will hence forward be a greater degree of ~6~637 g freedom in the selection of the geometrical shape of the arch described in the foregoing, i.e. it can be given any shape which proves most suitable and the necessary aper-tures can be provided therein. It is thanks to this cir-cumstance tha-t numerous variants can he adopted, some of which will be descrlbed hereinafter, by reference to the following f:igures.
Figures 2 and 2a illustrate one embodiment ln which the hot air outlet 40 is provided in the centre of the arch, above the checkerwork shaft 12. Instead of providing one single burner, as in Figure 1, four burners 42a, 42b, 42c and 42d are provided, each of exactly the same design as the burner 22 but of a smaller size. These burners are arranged in a "square" at regular intervals around the hot air outlet 40. These burners 42a, 42b, 42c and 42d will preferably be inclined at a slight angle in relation to the longitudinal axis o~ the shaft, so that the thermal radiation cone of each burner will come in contact with the entire upper surface of the checkerwork shaft. The shape and the angle of inclination of the apertures in the brickwork of the arch 44 will naturally be in accordance with thQ angle of inclina-tion of the burners.
In the version shown in Figures 3 and 3a the arch 54 has been provided with four burners 52a, 52b, 52¢ and 52d (not shown). These burners 52a, 52b, 52c and 52d are identically similar to those of Figure 2 but arranged differently. As may be seen, the hot air outlet 50 is no longer in the centre of the arch but by the side of the latter, while the four burners 52a, 52b, 52c and 52d are arranged in a "square" around the centre of the arch 54.
Figures 4 and 4a illustrate a version analogous to that of Figures 1 and la, with a same burner 22 positioned in the centre of an arch 63 and with a hot air outlet 20 positioned adjacent to the burner 22. The difference in relation to the verslon shown in Figure l resides in the fact that the arch 63 no longer constitutes a ~rickwork assembly and that the internal refractory lining 67 is affixed by means of securing bricks 65 to the external cladding 69 of the arch 63. This enables a flatter cons-
3~
- lQ -truction to be adopted for the arch 63, i.e. the burner 22 to be positioned more closely to the upper surface of the checkerwork shaf-t 12, thus in-tensifying the advantages which result from thi~ adaptation in shape, as described in the foregoing.
Needless to say, the versions shown in Figures l to 3, can also be designed with an arch "hooked on", as shown in Figure 4. These variants, however, will no longer be described in detail.
Figures 5 and 5a illustrate a version with four burners 64a, 64b, 64c and 64d, mounted inside the head 60 of a cowper immediately above the checkerwork shaft 62.
These burners are mounted vertically on a supporting slab 66 positioned transversely above the upper surface of the lS shaft 62. The burners are arranged symmetrically in a square around a central outlet 68 which rises vertically through the slab 66.
Needless to say, the burners 64a, 64b, 64c and 64d are of the type described previously, the associated aper-2Q tures in the slab 66 being adapted to the heat radiation cone of the burners, so that the entire upper surface of the checkerwork shaft 62 will be subjected to the heating and to the combustion gas.
The supply to the four burners 64a, 64b, 64c and 64d is effected by means of two main circular pipes 70 and 72 positioned around the head 60 and conveying the combustion air and the combustible gases respectively to the said burners. Each of the four burners is connected to the two circular pipes 70 and 72 via radial pipes 74 and 76, each provided with a shut-off gate 78 and 80.
The head 60 of the cowper is closed by a hermetic casing 82 provided with the inlets 84 required for inspection and replacement of the burners and deining a chamber 86 above the slab 66~ This casing 82 thus renders the cowper head hermetic to the outside. This chamber 86 will prefer-ably be cooled by the circulation of a suitable cooling fluid, as will be described in greater detail hereinafterO
Figure 6 irst of all shows a variant of the version illustrated in Figures 5 and 5a. In this embodimen-t of the 63~
invention there are once again four burners 94a, 94b (not shown), 94c and 94d, mounted with a rim-type configuration on a slab 96, above the checkerwork shaft 92 and inside the head 90 of the cowper. The essential difference between this embodiment and trhat ~hown in F~gures 5 and Sa resides in the fac~ that the hot air outlet 98 i8 provided in the side wall between the slab 96 and the upper surface of the refractory checkerwork 92.
The supply of combustible gas to the burners is again effected by a circular pipe 102 which is provided around the head 90 and which is connected via radial pipes 104 and a shut-off gate 106 to each of the burne~ 94a, 94b, 94c and 94d. Contrary to the previous embodiment, however, the combustion air is supplied through a pipe 100 penetra-ting vertically and axially into the head 90 and connected to each oE the burners via stubs 108. The head 90 is again closed by means of a hermetic casing 110 comprising aper-tures 112 afording access to the burners, and defining a chamber 116 which can be cooled.
A casing 110 and also the casing 82 (Figure 5) are provided with one or ~ore apertures 114 as a means of regulating the pressure and circulation inside the head, in the chamber formed by the casing 110 and the supporting slab 96 of the burners.
~Figure 6 shows, likewise schematically, in thick line.s, an advantageous constructional version for the cool-ing and for the equalization cf the pressure, particularly the pressurization, of the chamber 116.
For the ventilation of the chamber 116 the apertures 114 are connected with the external atmosphere via a pipe 118 and a gate 120. The checkerwork shaft 92 is likewise connected to the exterior via a pipe 122 and a gate 124, leading into a pipe 128 provided at the base of the checker-work shaft 92, the combustion fumes normally emerging through the said gate during the heating of the shaft.
The combustion air supply pipe 100 for the burners communicates with the interior of the chamber 116 via a number of apertures 130, preferably four, these apertures 130 being preferably provided with regulating valves shown ~6~63~
schematically at 132.
The cold air inlet orifice at the base of the checkerwork shaft 92 is shown schematically by the reference number 134 and is fed from a main pipe 136 via a gate 142~
~ 5 This main pipe 136 for the cold air likewise communicates, : via a gate 149, a pipe 138 and a regulating valve 143, with the pipe 100 through which the combustion air is intro-duced into the burner.
At the beginning of each combustion phase or heating phase for the shaft 92 both the chamber 116 and the in-terior of the shaft have to be ventilated, since these en-closures, during the preliminary phase, were under pressure.
For this purpose all that is required is to open the gates 120 and 124 in order to cause the air to emerge, expanding in the process to atmospheric pressure, from the chamber 116 and the shaf-t 92, via the pipes 118 and 112 respectively.
Duriny the combustion period the interior of the chamber 116 is cool.ed by causing some of the combustion air penetrating through the pipe 100, via the apertures 130 and the regulating valve 132, to emerge through the aper-tures 114.
At the end of the combustion period and before the air period, i.e. the introduction of cold air via the ori-fice 134 at the base of the checkerwork shaft 92, the cham-ber 116 has to be pressurized in order to adapt the pressure in the said chamber 116 to that of the air in the checker-work, and the said pressure may rise to as much as 6 bars.
This equalizatlon of pressure is advantageously effected by placing the main pipe 136 in commmunication not only with the interior of the checkerwork 92, via the gate 142, for the introduction of cold air into the checkerwork 92, but also with the interior of the chamber 116, via the valve 140, the pipe 138, the pipe 100, the apertures 130 : and the regulating valves 132. The pressurization of the chamber 116 and tha-t of the shaft 92 will thus proceed : parallel with each other, and the pressure differences between one side of the slab 96 and the other will be practically nill thxoughout the entire period when the shaft 92 is being filled.
In order to prevent the cold air for the equalization o~ the pre~sure in -the chamber 11~ from penetrating the shaft 92 via the burners, valves indicated schematically by the ~eference number 133 are provided between each o~
the burners 9~a, 94b, 94c and 9~d and the admission pipe 100.
The cooling of the chamber 116 throughout the period when the cold air is being heated, this being known as the aix period, will be effected in similar fashion to the pressuri~ation and following this latter operation. In other words, during the introduction of cold air via the orifice 134 and the main pipe 136, a certain quantity of air will be deflected via the gate 149, the valve 140, open to a greater or lesser extPnt for the purpose, and the pipe 13~3, towards the interior of the chamber 116. In order to ensure the required circulation and cooling in this latter, the air, heated in this manner, in the chamber 116, is evacuated through -the apertures 114 and the pipe 118 to the atmosphere. Duriny the cooling the valves 132 are set to ensure that the circulation in the chamber 116 will maintain a substantially constant pressure equal to that obtained during the preliminary pressurization.
Instead of evacuating the air to the atmosphere via the apertures 114 and the gate 120, the pipe 118 can be connected to the pipe 122, as shown schematically by the dotted lines 144, and this air can be returned via the pipe 122 and the evacuation orifice 123 for the fumes to the interior of the checkerwork shaft 92, where this air will be mixed with the cold air introduced via the orifice 134.
This system provides a means of benefiting from the heating of the air serving to cool the chamber 116, recuperating the heat evacuated by the cooling. In this case, however, an over-pressure device must be provided in the pipe 138, in order to counteract the pressure lose oocuring in -the cooling circuit.
In order to remedy any possible failure in the cooling and pressurization circuit for the chamber 116, which may be caused by faulty operation of the valve and which may seriously aggravate the risk of accidents, the casing 110 should preferably comprise an aperture 146 connected 3L~6~6i3~
to a source of cold pressure gas such as nitrogen. A back-up circuit of this kind will normally not be in operation but will be caused to come into operation automatically as soon as the temperature in the chamber 116 exceeds a certaîn preselected threshold or the pressure in this cha~ber 116 falls below a cer-tain critical level.
The slab 96 may also be provided with a small aper-ture connecting the chamber 116 to the interior of the checkerwork shaft 92, thus providing an additional degree of safety against an accidentally excessive pressure dif-ference between the respective sides of this slab.
The process for the pressurization and cooling of the chamber 116 may also be applied to the version shown -in Figure 5, for the purpose of pressurizing and cooling the chamber 86. In particular, the apertures 130 and the regulating valve 132, provided in the pipe 100 in the case of E'igure 6, are provided on the pipes 74 where Figure S
is concerned. A slightly modified system, which will be described below by reference to E'igure 7, can likewise be adopted.
In the said Figure 7, the components discussed by reference to Figures 5 and 5a have been retained, the same reference numbers being used again. This Figure 7 likewise contains a reproduction of the general diagram provided in conjunction with Figure 6, identical components being marked with the same reference numbers. Contrary to the methodadopted in the case of Figu. 6, however, the auxiliary pipe 138 for th~e cold air leads both into the circular combustion air supply pipe 70 and into an auxiliary circular pipe 148 connected by one-or more small tubes 150 to the interior of the chamber 86.
During the combustion period so~e of the combustion air introduced into the burners via the circular pipe 70 is deflected via the regulating valve 140 into the circular auxiliary pipe 148 in order to be conveyed into the interior of the chamber 86 for cooling purposes. The evacuation of the air from the interior of the chamber 86 may on~e again be effected via the apertures 114 and the pipe 118.
During the air period the e~ualization of pressure in the chamber 86 and the cooling in the interior of this ~6~163~
latter are effected by introducing cold air via the pipe 138 into the circular auxiliary pipe 148 and conveying it from the latter to the interior of the chamber 86. Supplementary valves, not shown, can be provided in order to isolate the circular pipe 70 from the pipe 138 during the combustion period and the pipe 138 from the circular conduit 70 during the air period. More complete information will be provided by the description given with reference to Figure 6~ It should be noted, however, that in the version shown in Figure 7, a supplementary circuit 146 has likewise been provided, serving to introduce additional cooling and pressurization gas.
Needless to say, it is also possible for the example shown in Figure 6 to be provided with the system for the injection of cooling and pressurization air via a circular auxiliary pipe, as in the case of Figure 7.
Figure 8 provides a schematic diagram of the upper part of a cowper similar to that described by reference to Figure 6, comprising a similar arrangement of burners 94a, 94b, 94c and 94d, and also a similar pressurization and cooling system for the chamber 116. In order to illustrate this variant, however, the apertures connecting the pipe 100 to the interior of the chamber 116 are shown at a higher level, marked 152 in Figure 8. These apertures 152 are naturally likewise provided with regulating valves, shown schematically by the reference number 154.
Contrary to the preceding embodiment of the invention, particularly that shown in Figure 6, the embodiment illus-trated by Figures 8 and 8a comprises a slab 156 within which is provided a cooling circuit consisting of an entire series of tubes 158 sunk in the mass of the slab 156. In the diagrams these tubes 158 are position~d parallel to one another, but they can obviously be positioned differently, particularly in a circle or spiral, in order to cover the entire surface to be cooled. 'These tubes 158 are connected both to a main distributor 160 and to a mani~old 164 connected to each of the said tubes 158.
The cooling circui~ provided for the slab 156 and shown in Figures ~ and 8a is designed to function with air.
- 16 ~ 37 It is thus of advantage to connect this cooling circuit of the slab 156 to this circui-t through which combustion air is supplied to a series of cowpers. It is known, in fact, that installations for the production of hot air for blast furnaces comprise a group of cowpers, i.e. at least two cowpers operating alternately, one in the combustion period and the other in -the air period, and then vice versa. One common feed system is thus generally provided for supplying the combustion air to each of the pipes 100 and each of the cowpers. In the case of Figure 8, therefore, the `~ cooling circuit of the slab 156 can be incorporated in the ~
combustion air supply, 50 that the combustion air passes ;
through the tubes 158 before penetrating the burners.
The manifold 16~ i9 connected via two pipes 168 15and 168' (see Figure 8a) each comprising a gate 170 (see E'igure 8) to two combustlon air supply pipes 100 for two cowpers.
When the cowper shown schematically in Figure 8 is opexating during the combustion period the gate 170 is open and the cooling air circulating in the tubes 158 is introduced into the pipe 100 supplying combustion air to the burners. On the other hand, when the cowpex changes over to the air period the gate 170 is closed and the cool-ing air for the tubes 158 is conveyed through the pipe 168' to another cowper which at this moment is operating in the combustion period. Consequently, in addition to the pressurization and cooling of a chamber 116, which are carried out in the normal manner~ as in the case of Figure 6, the version shown in Figure 8 guarantees supplementary cooling of the slab 156, both during the combustion period and during the air period.
Figure 9 shows another variant applied to a cowper of the type described by reference to Figure 6, this time comprising a supplementary cooling system for the slab 96.
This supplementary cooling is effected by means of a flat cooling chamber 172 provided specially for this purpose immediately above the slab 96 and separating the latter ;from the interior o~ the chamber 116. This chamber 172 is connected via a pipe 174 and an over-pressure device 176 to -the auxiliary pipe 138, which latter, as in the version ~6~637 shown in Figure 6, connects the main pipe 136 for cold air to the combustion air supply pipe 100. The outlet of -the cooling chamber 172 is connected via a regulating valve and a pipe 178 to the exhaust orifice 128 provided for the fumes at the base of a cowper. In order to avoid a direct passage from the inlet to the outlet of the chamber 172, the latter is preferably subdivided into compartments in order to form baffles and force the cooling air to circuit throughout the chamber.
During the combustion period some of the combustion ;~ air circulating in the pipe 100 passes through the upper part of the pipe 138 and is conveyed by the over-pressure de~ice 176 into the cooling chamber 172. It is discharged from the chamber 172 to the atmosphere via the valve 130, the pipe 178 and the gate 124.
During the air period cold air is introduced into the cool.ing chamber via the pipe 138, the over-pressure device 176 and the pipe 174. Thi.s air circulating in the cooling chamber 172 is pre:Eerably recycled via the pipe 178 and the orifice 128 in order to -take advantage of the heat evacuated from the chamber 172.
n addition to the cooling of the chamber 172 the pressurization and cooling o~ the chamber 116 are effected in the same manner as in the case of Figure 6.
Needless -to say, the~cooling chamber 172 in the version shown in Figure 9 can be replaced by a system of cooling pipes as in the version shown in Figure 8. Conver-sely, the system of cooling pipes provided in the version shown in Figure 8 can be replaced by the cooling chamber provided in the case of Figure 9.
Figures I0 and 10a illustrate a version analogous ; to that of Figure 8 but with a cooling system provided inside the slab 156. As in the example shown in Figure 8, a certain number of pipes 158 are accomodated in a mass of the slab. These pipes are connected both to a distributor 182 and to a manifold 184. Contrary to the example shown in Fi~ure 8, however, i~ is only cooling water that is caused to circulate in the cooling circuit of the slab 156.
Needless to say, the pipe 158 can once again be positioned 6~;7 parallel to one another or in different configurations, particularly circular or sp.iral, in order to cover the entire surface of the slab 156. The cooling and pressur-ization of the chamber 116 are again effected as in the version shown in E'igure 6.
The different var.iants of the cooling system which are shown in Figures 8, 9 and 10 have been deseribed in eonjunetion with a eowper of the type diseussed by refer-ence to Figure 6. It is nevertheless obvious that the versions shown in Figures 8 - 10, as well as the processes employed, are equally applicable to an embodiment such as that shown in Figure 5 or in Figure 7.
Finally it should be noted that in the version shown in Figure 10 the cireuit 158 can be replaced b~ a eooling ehamber analogous to the ehamber 172 and again serving for the cireulati.on of either water or some other eooling liquid.
Figure 11 shows an advantageous example for the design of -the head of a eowper, particularly applieable to the versions shown in Figures 1-4, Figure lla being a view of the upper part of a cowper looking downwards. In this example, there are four burners 190a, l90b, l90c and l90d, mounted in a "square" around the centre of an arch 192, the hot air outle-t 194 being provided at the side. In this example the shape o~ the areh is better adapted to the burners inasmueh as for eaeh burner the areh forms a eavity 196 fitting the refraetor~v part of the burnersl and forming an extension thereto, thus eombining with them to form the eombustion bowl 198.
A set of criss-cross beams 200, 202, 204, integral with the cladding of the arch 192, supports both the latter and the burners.
Figures 12 and 12a show how the assembly illustrated in Figures 10 and lOa is adapted to the versions shown in Figures 5-10. The four burners 206a, 206b, 206e and 206d are mounted on a slab 208 whieh, like the areh 192 in Figure 11, eomprises eavities 210 which fit the shape of the refraetory portion and whieh combine with this latter to form combustion bowls 212. The slab 208 and the four burne.rs 206a, 206b, 206c and 206d are supported by beams.
These beams are supported in their turn by the external casing 214 which forms a prolongation for the external cladding of the shaft 92.
: :
.
- lQ -truction to be adopted for the arch 63, i.e. the burner 22 to be positioned more closely to the upper surface of the checkerwork shaf-t 12, thus in-tensifying the advantages which result from thi~ adaptation in shape, as described in the foregoing.
Needless to say, the versions shown in Figures l to 3, can also be designed with an arch "hooked on", as shown in Figure 4. These variants, however, will no longer be described in detail.
Figures 5 and 5a illustrate a version with four burners 64a, 64b, 64c and 64d, mounted inside the head 60 of a cowper immediately above the checkerwork shaft 62.
These burners are mounted vertically on a supporting slab 66 positioned transversely above the upper surface of the lS shaft 62. The burners are arranged symmetrically in a square around a central outlet 68 which rises vertically through the slab 66.
Needless to say, the burners 64a, 64b, 64c and 64d are of the type described previously, the associated aper-2Q tures in the slab 66 being adapted to the heat radiation cone of the burners, so that the entire upper surface of the checkerwork shaft 62 will be subjected to the heating and to the combustion gas.
The supply to the four burners 64a, 64b, 64c and 64d is effected by means of two main circular pipes 70 and 72 positioned around the head 60 and conveying the combustion air and the combustible gases respectively to the said burners. Each of the four burners is connected to the two circular pipes 70 and 72 via radial pipes 74 and 76, each provided with a shut-off gate 78 and 80.
The head 60 of the cowper is closed by a hermetic casing 82 provided with the inlets 84 required for inspection and replacement of the burners and deining a chamber 86 above the slab 66~ This casing 82 thus renders the cowper head hermetic to the outside. This chamber 86 will prefer-ably be cooled by the circulation of a suitable cooling fluid, as will be described in greater detail hereinafterO
Figure 6 irst of all shows a variant of the version illustrated in Figures 5 and 5a. In this embodimen-t of the 63~
invention there are once again four burners 94a, 94b (not shown), 94c and 94d, mounted with a rim-type configuration on a slab 96, above the checkerwork shaft 92 and inside the head 90 of the cowper. The essential difference between this embodiment and trhat ~hown in F~gures 5 and Sa resides in the fac~ that the hot air outlet 98 i8 provided in the side wall between the slab 96 and the upper surface of the refractory checkerwork 92.
The supply of combustible gas to the burners is again effected by a circular pipe 102 which is provided around the head 90 and which is connected via radial pipes 104 and a shut-off gate 106 to each of the burne~ 94a, 94b, 94c and 94d. Contrary to the previous embodiment, however, the combustion air is supplied through a pipe 100 penetra-ting vertically and axially into the head 90 and connected to each oE the burners via stubs 108. The head 90 is again closed by means of a hermetic casing 110 comprising aper-tures 112 afording access to the burners, and defining a chamber 116 which can be cooled.
A casing 110 and also the casing 82 (Figure 5) are provided with one or ~ore apertures 114 as a means of regulating the pressure and circulation inside the head, in the chamber formed by the casing 110 and the supporting slab 96 of the burners.
~Figure 6 shows, likewise schematically, in thick line.s, an advantageous constructional version for the cool-ing and for the equalization cf the pressure, particularly the pressurization, of the chamber 116.
For the ventilation of the chamber 116 the apertures 114 are connected with the external atmosphere via a pipe 118 and a gate 120. The checkerwork shaft 92 is likewise connected to the exterior via a pipe 122 and a gate 124, leading into a pipe 128 provided at the base of the checker-work shaft 92, the combustion fumes normally emerging through the said gate during the heating of the shaft.
The combustion air supply pipe 100 for the burners communicates with the interior of the chamber 116 via a number of apertures 130, preferably four, these apertures 130 being preferably provided with regulating valves shown ~6~63~
schematically at 132.
The cold air inlet orifice at the base of the checkerwork shaft 92 is shown schematically by the reference number 134 and is fed from a main pipe 136 via a gate 142~
~ 5 This main pipe 136 for the cold air likewise communicates, : via a gate 149, a pipe 138 and a regulating valve 143, with the pipe 100 through which the combustion air is intro-duced into the burner.
At the beginning of each combustion phase or heating phase for the shaft 92 both the chamber 116 and the in-terior of the shaft have to be ventilated, since these en-closures, during the preliminary phase, were under pressure.
For this purpose all that is required is to open the gates 120 and 124 in order to cause the air to emerge, expanding in the process to atmospheric pressure, from the chamber 116 and the shaf-t 92, via the pipes 118 and 112 respectively.
Duriny the combustion period the interior of the chamber 116 is cool.ed by causing some of the combustion air penetrating through the pipe 100, via the apertures 130 and the regulating valve 132, to emerge through the aper-tures 114.
At the end of the combustion period and before the air period, i.e. the introduction of cold air via the ori-fice 134 at the base of the checkerwork shaft 92, the cham-ber 116 has to be pressurized in order to adapt the pressure in the said chamber 116 to that of the air in the checker-work, and the said pressure may rise to as much as 6 bars.
This equalizatlon of pressure is advantageously effected by placing the main pipe 136 in commmunication not only with the interior of the checkerwork 92, via the gate 142, for the introduction of cold air into the checkerwork 92, but also with the interior of the chamber 116, via the valve 140, the pipe 138, the pipe 100, the apertures 130 : and the regulating valves 132. The pressurization of the chamber 116 and tha-t of the shaft 92 will thus proceed : parallel with each other, and the pressure differences between one side of the slab 96 and the other will be practically nill thxoughout the entire period when the shaft 92 is being filled.
In order to prevent the cold air for the equalization o~ the pre~sure in -the chamber 11~ from penetrating the shaft 92 via the burners, valves indicated schematically by the ~eference number 133 are provided between each o~
the burners 9~a, 94b, 94c and 9~d and the admission pipe 100.
The cooling of the chamber 116 throughout the period when the cold air is being heated, this being known as the aix period, will be effected in similar fashion to the pressuri~ation and following this latter operation. In other words, during the introduction of cold air via the orifice 134 and the main pipe 136, a certain quantity of air will be deflected via the gate 149, the valve 140, open to a greater or lesser extPnt for the purpose, and the pipe 13~3, towards the interior of the chamber 116. In order to ensure the required circulation and cooling in this latter, the air, heated in this manner, in the chamber 116, is evacuated through -the apertures 114 and the pipe 118 to the atmosphere. Duriny the cooling the valves 132 are set to ensure that the circulation in the chamber 116 will maintain a substantially constant pressure equal to that obtained during the preliminary pressurization.
Instead of evacuating the air to the atmosphere via the apertures 114 and the gate 120, the pipe 118 can be connected to the pipe 122, as shown schematically by the dotted lines 144, and this air can be returned via the pipe 122 and the evacuation orifice 123 for the fumes to the interior of the checkerwork shaft 92, where this air will be mixed with the cold air introduced via the orifice 134.
This system provides a means of benefiting from the heating of the air serving to cool the chamber 116, recuperating the heat evacuated by the cooling. In this case, however, an over-pressure device must be provided in the pipe 138, in order to counteract the pressure lose oocuring in -the cooling circuit.
In order to remedy any possible failure in the cooling and pressurization circuit for the chamber 116, which may be caused by faulty operation of the valve and which may seriously aggravate the risk of accidents, the casing 110 should preferably comprise an aperture 146 connected 3L~6~6i3~
to a source of cold pressure gas such as nitrogen. A back-up circuit of this kind will normally not be in operation but will be caused to come into operation automatically as soon as the temperature in the chamber 116 exceeds a certaîn preselected threshold or the pressure in this cha~ber 116 falls below a cer-tain critical level.
The slab 96 may also be provided with a small aper-ture connecting the chamber 116 to the interior of the checkerwork shaft 92, thus providing an additional degree of safety against an accidentally excessive pressure dif-ference between the respective sides of this slab.
The process for the pressurization and cooling of the chamber 116 may also be applied to the version shown -in Figure 5, for the purpose of pressurizing and cooling the chamber 86. In particular, the apertures 130 and the regulating valve 132, provided in the pipe 100 in the case of E'igure 6, are provided on the pipes 74 where Figure S
is concerned. A slightly modified system, which will be described below by reference to E'igure 7, can likewise be adopted.
In the said Figure 7, the components discussed by reference to Figures 5 and 5a have been retained, the same reference numbers being used again. This Figure 7 likewise contains a reproduction of the general diagram provided in conjunction with Figure 6, identical components being marked with the same reference numbers. Contrary to the methodadopted in the case of Figu. 6, however, the auxiliary pipe 138 for th~e cold air leads both into the circular combustion air supply pipe 70 and into an auxiliary circular pipe 148 connected by one-or more small tubes 150 to the interior of the chamber 86.
During the combustion period so~e of the combustion air introduced into the burners via the circular pipe 70 is deflected via the regulating valve 140 into the circular auxiliary pipe 148 in order to be conveyed into the interior of the chamber 86 for cooling purposes. The evacuation of the air from the interior of the chamber 86 may on~e again be effected via the apertures 114 and the pipe 118.
During the air period the e~ualization of pressure in the chamber 86 and the cooling in the interior of this ~6~163~
latter are effected by introducing cold air via the pipe 138 into the circular auxiliary pipe 148 and conveying it from the latter to the interior of the chamber 86. Supplementary valves, not shown, can be provided in order to isolate the circular pipe 70 from the pipe 138 during the combustion period and the pipe 138 from the circular conduit 70 during the air period. More complete information will be provided by the description given with reference to Figure 6~ It should be noted, however, that in the version shown in Figure 7, a supplementary circuit 146 has likewise been provided, serving to introduce additional cooling and pressurization gas.
Needless to say, it is also possible for the example shown in Figure 6 to be provided with the system for the injection of cooling and pressurization air via a circular auxiliary pipe, as in the case of Figure 7.
Figure 8 provides a schematic diagram of the upper part of a cowper similar to that described by reference to Figure 6, comprising a similar arrangement of burners 94a, 94b, 94c and 94d, and also a similar pressurization and cooling system for the chamber 116. In order to illustrate this variant, however, the apertures connecting the pipe 100 to the interior of the chamber 116 are shown at a higher level, marked 152 in Figure 8. These apertures 152 are naturally likewise provided with regulating valves, shown schematically by the reference number 154.
Contrary to the preceding embodiment of the invention, particularly that shown in Figure 6, the embodiment illus-trated by Figures 8 and 8a comprises a slab 156 within which is provided a cooling circuit consisting of an entire series of tubes 158 sunk in the mass of the slab 156. In the diagrams these tubes 158 are position~d parallel to one another, but they can obviously be positioned differently, particularly in a circle or spiral, in order to cover the entire surface to be cooled. 'These tubes 158 are connected both to a main distributor 160 and to a mani~old 164 connected to each of the said tubes 158.
The cooling circui~ provided for the slab 156 and shown in Figures ~ and 8a is designed to function with air.
- 16 ~ 37 It is thus of advantage to connect this cooling circuit of the slab 156 to this circui-t through which combustion air is supplied to a series of cowpers. It is known, in fact, that installations for the production of hot air for blast furnaces comprise a group of cowpers, i.e. at least two cowpers operating alternately, one in the combustion period and the other in -the air period, and then vice versa. One common feed system is thus generally provided for supplying the combustion air to each of the pipes 100 and each of the cowpers. In the case of Figure 8, therefore, the `~ cooling circuit of the slab 156 can be incorporated in the ~
combustion air supply, 50 that the combustion air passes ;
through the tubes 158 before penetrating the burners.
The manifold 16~ i9 connected via two pipes 168 15and 168' (see Figure 8a) each comprising a gate 170 (see E'igure 8) to two combustlon air supply pipes 100 for two cowpers.
When the cowper shown schematically in Figure 8 is opexating during the combustion period the gate 170 is open and the cooling air circulating in the tubes 158 is introduced into the pipe 100 supplying combustion air to the burners. On the other hand, when the cowpex changes over to the air period the gate 170 is closed and the cool-ing air for the tubes 158 is conveyed through the pipe 168' to another cowper which at this moment is operating in the combustion period. Consequently, in addition to the pressurization and cooling of a chamber 116, which are carried out in the normal manner~ as in the case of Figure 6, the version shown in Figure 8 guarantees supplementary cooling of the slab 156, both during the combustion period and during the air period.
Figure 9 shows another variant applied to a cowper of the type described by reference to Figure 6, this time comprising a supplementary cooling system for the slab 96.
This supplementary cooling is effected by means of a flat cooling chamber 172 provided specially for this purpose immediately above the slab 96 and separating the latter ;from the interior o~ the chamber 116. This chamber 172 is connected via a pipe 174 and an over-pressure device 176 to -the auxiliary pipe 138, which latter, as in the version ~6~637 shown in Figure 6, connects the main pipe 136 for cold air to the combustion air supply pipe 100. The outlet of -the cooling chamber 172 is connected via a regulating valve and a pipe 178 to the exhaust orifice 128 provided for the fumes at the base of a cowper. In order to avoid a direct passage from the inlet to the outlet of the chamber 172, the latter is preferably subdivided into compartments in order to form baffles and force the cooling air to circuit throughout the chamber.
During the combustion period some of the combustion ;~ air circulating in the pipe 100 passes through the upper part of the pipe 138 and is conveyed by the over-pressure de~ice 176 into the cooling chamber 172. It is discharged from the chamber 172 to the atmosphere via the valve 130, the pipe 178 and the gate 124.
During the air period cold air is introduced into the cool.ing chamber via the pipe 138, the over-pressure device 176 and the pipe 174. Thi.s air circulating in the cooling chamber 172 is pre:Eerably recycled via the pipe 178 and the orifice 128 in order to -take advantage of the heat evacuated from the chamber 172.
n addition to the cooling of the chamber 172 the pressurization and cooling o~ the chamber 116 are effected in the same manner as in the case of Figure 6.
Needless -to say, the~cooling chamber 172 in the version shown in Figure 9 can be replaced by a system of cooling pipes as in the version shown in Figure 8. Conver-sely, the system of cooling pipes provided in the version shown in Figure 8 can be replaced by the cooling chamber provided in the case of Figure 9.
Figures I0 and 10a illustrate a version analogous ; to that of Figure 8 but with a cooling system provided inside the slab 156. As in the example shown in Figure 8, a certain number of pipes 158 are accomodated in a mass of the slab. These pipes are connected both to a distributor 182 and to a manifold 184. Contrary to the example shown in Fi~ure 8, however, i~ is only cooling water that is caused to circulate in the cooling circuit of the slab 156.
Needless to say, the pipe 158 can once again be positioned 6~;7 parallel to one another or in different configurations, particularly circular or sp.iral, in order to cover the entire surface of the slab 156. The cooling and pressur-ization of the chamber 116 are again effected as in the version shown in E'igure 6.
The different var.iants of the cooling system which are shown in Figures 8, 9 and 10 have been deseribed in eonjunetion with a eowper of the type diseussed by refer-ence to Figure 6. It is nevertheless obvious that the versions shown in Figures 8 - 10, as well as the processes employed, are equally applicable to an embodiment such as that shown in Figure 5 or in Figure 7.
Finally it should be noted that in the version shown in Figure 10 the cireuit 158 can be replaced b~ a eooling ehamber analogous to the ehamber 172 and again serving for the cireulati.on of either water or some other eooling liquid.
Figure 11 shows an advantageous example for the design of -the head of a eowper, particularly applieable to the versions shown in Figures 1-4, Figure lla being a view of the upper part of a cowper looking downwards. In this example, there are four burners 190a, l90b, l90c and l90d, mounted in a "square" around the centre of an arch 192, the hot air outle-t 194 being provided at the side. In this example the shape o~ the areh is better adapted to the burners inasmueh as for eaeh burner the areh forms a eavity 196 fitting the refraetor~v part of the burnersl and forming an extension thereto, thus eombining with them to form the eombustion bowl 198.
A set of criss-cross beams 200, 202, 204, integral with the cladding of the arch 192, supports both the latter and the burners.
Figures 12 and 12a show how the assembly illustrated in Figures 10 and lOa is adapted to the versions shown in Figures 5-10. The four burners 206a, 206b, 206e and 206d are mounted on a slab 208 whieh, like the areh 192 in Figure 11, eomprises eavities 210 which fit the shape of the refraetory portion and whieh combine with this latter to form combustion bowls 212. The slab 208 and the four burne.rs 206a, 206b, 206c and 206d are supported by beams.
These beams are supported in their turn by the external casing 214 which forms a prolongation for the external cladding of the shaft 92.
: :
.
Claims (41)
1. - An installation for the production of hot air, of the cowper type, comprising an enclosure mainly occupied by a checkerwork of refractory bricks, at least one cold air admission orifice at the base of the enclosure, at least one hot air outlet orifice situated at the top of the en-closure, and one or more burners arranged in the upper part for the purpose of burning the fuels and generating the heat required for the heating of the checkerwork, wherein each burner is integrated into a refractory wall provided with cavities corresponding to each burner and forming with the front portion of the latter a "combustion dish" from which a conical flow of heat is omitted, each of these burners being orientated to ensure that these heat flows act direct on the entire upper surface of the checkerwork without any contact between this surface and the flames.
2. - An installation in accordance with Claim 1 comprising one single burner mounted in the centre of an arch provided above the checkerwork, the hot air outlet orifice being likewise provided, adjacent to the burner, in the said arch.
3. - An installation in accordance with Claim 1, wherein the outlet orifice is situated in the centre of an arch and wherein a number of burners are mounted in the arch in a symmetrical configuration around the outlet ori-fice and are inclined at an angle in respect of the vertical axis of the enclosure.
4. - An installation in accordance with claim 3, comprising four burners, arranged in a "square" around the orifice.
5. - An installation in accordance with claim 3, wherein the hot air outlet orifice and a number of burners are positioned around the vertical axis of an enclosure in an arch.
6. - An installation in accordance with any one of claims 2-4, wherein the arch consists of a brickwork arch formed by an assembly of refractory bricks surrounded by an external metal cladding.
7. - An installation in accordance with any one of Claims 2-4, wherein the arch consists of an arch formed by refractory bricks attached by means of securing bricks to an external metal cladding.
8. - An installation in accordance with claim 1, comprising a number of burners mounted symmetrically in rim-type configuration and affixed vertically to a circular slab mounted transversely above the checkerwork and combin-ing with an upper casing to form a hermetic chamber.
9. - An installation in accordance with claim 8, comprising a central hot air outlet pipe extending vertically out of the said casing and the slab and by external circular pipes serving to supply combustion air and combustible gases to the burners and connected to these latter by radial pipes provided with shut-off gates.
10. - An installation in accordance with Claim 9, wherein the hot air outlet orifice is provided in the lateral wall of the checkerwork, between the slab and the upper part of the checkerwork, and wherein the supply of combustion air and combustible gases to the burners is effected, res-pectively, by a pipe penetrating vertically and centrally through the casing, between the rim-shape configuration of burners, and comprising an external circular pipe connected by radial pipes and shut-off gates to each of the burners.
11. - An installation in accordance with any one of claims 8-10, wherein the chamber is cooled by means of a cooling liquid.
12. - An installation in accordance with claim 8 , wherein the external casing is provided with access apertures for the inspection and replacement of the burners.
13. - An installation in accordance with claim 8 , wherein the external casing is provided with apertures for the regulation of the pressure in the chamber.
14. - An installation in accordance with claim 10 wherein the pipes communicate via a pipe , a valve and a gate, with a main pipe connected to the cold air inlet orifice at the base of the shaft.
15. - An installation in accordance with claim 13, comprising a pipe connecting the apertures to the atmosphere via a gate.
16. An installation in accordance with claim 15, wherein the said pipe is connected to an orifice provided at the base of the shaft and serving for the evacuation of the combustion fumes.
17. An installation in accordance with claim 8, wherein the combustion air feed pipe, for each of the burners, communicate with the chamber, via apertures provided with regulating valves.
18. An installation in accordance with claim 8, comprising a circular auxiliary pipe connecting the chamber to the combustion air supply pipes, on the one hand, and via a pipe and a valve to a main pipe connected to the cold air inlet orifice at the base of the shaft, on the other hand.
19. An installation in accordance with claim 8, comprising a cooling circuit sunk in the mass of the slab.
20. An installation in accordance with claim 8, comprising a flat cooling chamber provided for the slab and positioned immediately above the latter.
21. An instillation in accordance with either of claims 19 or 20, wherein the cooling circuit or the cooling chamber is connected to a cooling water pipe.
22. An installation in accordance with claim 19, wherein the cooling circuit is connected to a cooling air pipe.
23. An installation in accordance with claim 22, wherein the inlet of the cooling circuit is connected via an over-pressure device to a main combustion air supply pipe and wherein the outlet is connected via two pipes, each provided with a gate to the two combustion air supply pipes of two cowpers operating alternately.
24. An installation in accordance with claim 22, wherein the inlet of the cooling circuit is supplied with cold air through the pipe connected to the main cold air pipe and wherein the outlet is connected via a pipe to the base of the checkerwork shaft and via a gate to the atmosphere.
25. - An installation in accordance with claim 8 , comprising an aperture in the casing of the chamber, this aperture being connected to a supplementary source for the pressurization and cooling of the chamber.
26. - An installation in accordance with claim 8 , comprising a safety aperture in the slab connecting the chamber to the interior of the checkerwork.
27. - A process for production of hot air in an installation according to claim 8 , in which process the refractory checkerwork is heated during a combustion period in which in each of the burners, a com-bustible gas in burnt in a current of combustion air, the combustion fumes being evacuated through an aperture at the base of the shaft, the combustion period being stopped and an air period being initiated, in which latter cold air is introduced at the base of the checkerwork shaft and the hot air extracted at the top of the shaft, in which process the heat stored up in the checkerwork during the combustion period is recuperated as it passes through the said checker-work, wherein during both periods the slab and also the chamber above it, containing the burners, are cooled.
28. - A process in accordance with claim 27, wherein during the combustion period the said chamber is cooled by introducing part of the combustion air.
29. - A process in accordance with claim 27, wherein during the air period the said chamber is cooled by the circulation therein of part of the cold air introduced at the base of the checkerwork shaft.
30. - A process in accordance with claim 29, wherein the cooling air is discharged from the said chamber to the atmosphere.
31. - A process in accordance with claim 29, wherein the discharge of the cooling air from the said chamber is effected in the form of a recycling operation in which this cooling air is returned to the base of the checkerwork shaft and introduced into the latter.
32. - A process in accordance with claim 27 , wherein prior to the combustion period, the said chamber and the checkerwork shaft are ventilated by con-necting them with the atmosphere.
33. - A process in accordance with claim 27 wherein, at the commencement of the air period, cold air is introduced simultaneously into the checkerwork shaft and into the said chamber, in order to increase progressively and simultaneously the pressure in each of these enclosures, for the purpose of equalizing the pressure on the two sides of the slab supporting the burners.
34. - A process in accordance with claim 27 wherein, independently of the cooling, press-urization or ventilation of the chamber, the slab is cooled during both periods by means of an auxiliary circuit provided inside the said slab or immediately above it.
35. - A process in accordance with claim 34, wherein water is used for the cooling.
36. - A process in accordance with claim 34, wherein this cooling is carried out with combustion air by in-corporating this cooling circuit into the combustion air supply pipe for the burners, and wherein the air emerging from this cooling circuit of the slab is conveyed to the burners of the cowper concerned during the combustion period of this latter, whereas during the air period this air is conveyed to the burners of another cowper which at that moment is operating in the combustion period.
37. A process in accordance with claim 34, wherein this cooling is carried out with some of the cold air and that this cooling air is recycled during the air period to the base of the checkerwork shaft for the production of hot air.
38. - A process in accordance with any one of claims 31,36,37, wherein the cooling air is compressed in an over-pressure device.
39. - A process in accordance with claim 33, wherein a supplementary cooling and pressurization source is provided, being designed to be put into operation automatically as soon as the temperature in the chamber rises above a certain preselected threshold or the pressure in the chamber differs to a certain preselected amount from that prevailing in the checkerwork.
40. - An installation in accordance with any one of claims 2-4, wherein the burners and the arch are supported by beams and wherein the arch is provided with cavities adapted to each of the burners.
41. - An installation in accordance with claim 8 , wherein the slab and the burners are suspended from beams supported by the external casing and wherein the slab is provided with cavities adapted to each of the burners.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| LU82,176 | 1980-02-15 | ||
| LU82176A LU82176A1 (en) | 1980-02-15 | 1980-02-15 | INSTALLATION FOR PRODUCING HOT WIND AND METHOD OF IMPLEMENTING |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1161637A true CA1161637A (en) | 1984-02-07 |
Family
ID=19729352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000370901A Expired CA1161637A (en) | 1980-02-15 | 1981-02-13 | Installation and process for the production of hot air |
Country Status (17)
| Country | Link |
|---|---|
| JP (1) | JPS56127716A (en) |
| AU (1) | AU6722581A (en) |
| BE (1) | BE887478A (en) |
| BR (1) | BR8100986A (en) |
| CA (1) | CA1161637A (en) |
| DE (1) | DE3104352A1 (en) |
| ES (1) | ES499323A0 (en) |
| FR (1) | FR2476134A1 (en) |
| GB (1) | GB2069677B (en) |
| IT (1) | IT1169205B (en) |
| LU (1) | LU82176A1 (en) |
| NL (1) | NL8100749A (en) |
| PL (1) | PL125908B1 (en) |
| RO (1) | RO82322A (en) |
| SE (1) | SE8101002L (en) |
| SU (1) | SU991955A3 (en) |
| ZA (1) | ZA81782B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| LU82174A1 (en) * | 1980-02-15 | 1980-05-07 | Wurth Anciens Ets Paul | METHOD AND DEVICE FOR ADJUSTING THE HOT WIND TEMPERATURE IN A HOT WIND PRODUCTION INSTALLATION |
| NL8902589A (en) * | 1989-10-19 | 1991-05-16 | Hoogovens Groep Bv | TORQUE CONNECTION HOTWIND PIPES. |
| RU2145637C1 (en) * | 1999-03-29 | 2000-02-20 | Калугин Яков Прокопьевич | Air heater |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE318068C (en) * | 1918-07-23 | 1920-01-10 | Halbergerhütte Gmbh | TOP HEATED WINDER HEATER WITHOUT CHAMBER |
| FR787888A (en) * | 1934-06-28 | 1935-09-30 | Change in gas or fluid preheating devices of any kind, particularly applicable to blast furnace hot air devices | |
| DE961284C (en) * | 1940-11-13 | 1957-04-04 | Koppers Gmbh Heinrich | Gas heater (Cowper) without a furnace |
| DE863663C (en) * | 1950-12-28 | 1953-01-19 | Otto & Co Gmbh Dr C | Wind heater with upper heating |
| FR1205382A (en) * | 1957-04-11 | 1960-02-02 | Bloom Eng Co Inc | Burner mechanism for ovens |
| DE1229567B (en) * | 1961-09-06 | 1966-12-01 | Huettenwerk Salzgitter Ag | Method of operating blast furnace hot air heaters |
| LU47700A1 (en) * | 1963-11-05 | 1965-03-02 | ||
| FR1398619A (en) * | 1964-06-15 | 1965-05-07 | Rappold & Co Gmbh Hermann | Device for hot air appliance heated by burner |
| DE2123552A1 (en) * | 1971-05-12 | 1972-11-16 | Zimmermann & Jansen GmbH, 5160 Dü- | Blast furnace wind heater burner unit - is mounted on top of heater cupola |
| JPS521794A (en) * | 1975-06-24 | 1977-01-07 | Heijiro Fukuda | Method of making artificial resinoid whetstone for cutting hard materi als |
-
1980
- 1980-02-15 LU LU82176A patent/LU82176A1/en unknown
-
1981
- 1981-02-05 ZA ZA00810782A patent/ZA81782B/en unknown
- 1981-02-07 DE DE19813104352 patent/DE3104352A1/en not_active Ceased
- 1981-02-11 GB GB8104218A patent/GB2069677B/en not_active Expired
- 1981-02-11 ES ES499323A patent/ES499323A0/en active Granted
- 1981-02-11 BE BE6/47394A patent/BE887478A/en not_active IP Right Cessation
- 1981-02-12 AU AU67225/81A patent/AU6722581A/en not_active Abandoned
- 1981-02-12 SU SU813242796A patent/SU991955A3/en active
- 1981-02-12 FR FR8102762A patent/FR2476134A1/en not_active Withdrawn
- 1981-02-13 CA CA000370901A patent/CA1161637A/en not_active Expired
- 1981-02-13 IT IT19753/81A patent/IT1169205B/en active
- 1981-02-13 JP JP2080981A patent/JPS56127716A/en active Pending
- 1981-02-13 SE SE8101002A patent/SE8101002L/en not_active Application Discontinuation
- 1981-02-14 RO RO81103414A patent/RO82322A/en unknown
- 1981-02-16 PL PL1981229708A patent/PL125908B1/en unknown
- 1981-02-16 NL NL8100749A patent/NL8100749A/en not_active Application Discontinuation
- 1981-02-16 BR BR8100986A patent/BR8100986A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| SE8101002L (en) | 1981-08-16 |
| BR8100986A (en) | 1981-08-25 |
| NL8100749A (en) | 1981-09-16 |
| GB2069677A (en) | 1981-08-26 |
| FR2476134A1 (en) | 1981-08-21 |
| ES8205864A1 (en) | 1982-07-01 |
| SU991955A3 (en) | 1983-01-23 |
| ES499323A0 (en) | 1982-07-01 |
| PL229708A1 (en) | 1981-09-18 |
| LU82176A1 (en) | 1980-05-07 |
| GB2069677B (en) | 1983-08-17 |
| RO82322A (en) | 1983-11-01 |
| PL125908B1 (en) | 1983-06-30 |
| IT1169205B (en) | 1987-05-27 |
| AU6722581A (en) | 1981-08-20 |
| DE3104352A1 (en) | 1982-01-28 |
| JPS56127716A (en) | 1981-10-06 |
| IT8119753A0 (en) | 1981-02-13 |
| BE887478A (en) | 1981-06-01 |
| ZA81782B (en) | 1982-05-26 |
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Legal Events
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| MKEX | Expiry |