CA1060778A - Method and apparatus for purifying impurity-containing gases - Google Patents
Method and apparatus for purifying impurity-containing gasesInfo
- Publication number
- CA1060778A CA1060778A CA230,982A CA230982A CA1060778A CA 1060778 A CA1060778 A CA 1060778A CA 230982 A CA230982 A CA 230982A CA 1060778 A CA1060778 A CA 1060778A
- Authority
- CA
- Canada
- Prior art keywords
- nozzles
- liquid
- conduit
- gas
- jets
- 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.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D47/00—Separating dispersed particles from gases, air or vapours by liquid as separating agent
- B01D47/06—Spray cleaning
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D47/00—Separating dispersed particles from gases, air or vapours by liquid as separating agent
- B01D47/06—Spray cleaning
- B01D47/063—Spray cleaning with two or more jets impinging against each other
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
- B05B1/26—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets
Abstract
ABSTRACT OF THE DISCLOSURE
A method and apparatus are disclosed for purifying a gas stream containing impurity particles the size of which is less than one micron, characterized by the provision of a pair of spaced generally opposed liquid jets for creating in the gas stream a liquid mist pattern which is generally normal to the gas flow, thereby to moisturize the particles for removal from the stream.
Means are provided for varying the spacing distance between the jets, the angular relationship of the jets relative to each other, or the relative pressures of the liquid jets, thereby to vary the configuration of the liquid mist pattern in the gas stream.
A method and apparatus are disclosed for purifying a gas stream containing impurity particles the size of which is less than one micron, characterized by the provision of a pair of spaced generally opposed liquid jets for creating in the gas stream a liquid mist pattern which is generally normal to the gas flow, thereby to moisturize the particles for removal from the stream.
Means are provided for varying the spacing distance between the jets, the angular relationship of the jets relative to each other, or the relative pressures of the liquid jets, thereby to vary the configuration of the liquid mist pattern in the gas stream.
Description
` ` ~0~;0778 The present invention relates to a method and apparatus for removing impurity particles on the order of one micron from a gas stream, wherein a liquid mist pattern is established in the gas normal to the direction of flow thereof, whereby the particles are moisturized for removal from the gas.
In various production processes -- such as in the steel, cement and other industries -- gases, smoke or fumes are produced which contain impurity particles of relatively small size (speci-- fically, particles less than one micron). Consequently, before 10 using the gases or fumes (in heaters or motors) or before expel-ling the smoke to atmosphere, it is necessary to purify the gases by removing the impurity particles therefrom.
Various gas purifying techniques have been proposed in the prior art, as for example, by moisturizing the gas, mechanic-al collision of the particles, condensation, diffusion in atom-, ized liquid electrostatic separation, and ultrasonic treatment ~
< of the gases. ~ -~, ' The impact processes employ mechanical collision be-tween the liquid and impurity particles. It has been established 20 that the efficiency of particle removal increases with the dif-ference in the relative speeds of the liquid drops and the parti-cles. But when the particles are very fine (for example, less -`~
than 1 ,u), the efficiency drops down to zero because the parti- -cles behave like an aerosol.
Condensation methods operate by lowering the temper-ature of the gas below its dew point. This mechanism is good for subsequent impact purification but it must be possible to bring about a strong temperature drop which can be obtained only with 1-low-temperature gas and by a strong pneumatic expansion of that gas.
In electrostatic field separation processes, the ion-ized particles are attracted by an electrode with an opposite , polarity. In order to get good purification, it is necessary to ,' ~ '- .
., - 1 - -- .: , . : .. ..
10~ 8 obtain relatively constant dust contents at the input of the electrofilters. Moreover, the cost of maintaining electrofil-ters is very high when it comes to purifying corrosive gases (for example, carbon dioxide or sulfur dioxide).
Ultrasonic procedures operate by applying resonance to the dust and the liquid droplets. ~owever, this method also re-quires a relatively heavy energy consumption.
Diffusion methods consist in mixing the impurity-contaminated gas with a liquid which is in the aerosol state.
The inconvenience of this procedure resides in the difficulty ` of pulverizing the liquid very finely. In effect, if mechanical pulverization is employed, the nozzles must be very fine and there is a risk that they might become clogged with industrial - liquids. Mechanical pulverization moreover requires very high ; liquid pressures.
In pneumatic pulverization processes, very high gas `
pulverization speeds are required, thereby resulting in a very great energy expenditure. Finally, centrifuge pulverization utilizing a centrifuge bowl revolving at great speed is a deli-cate operation because of the operating and maintenance difficul-ties.
In industrial practice, a first rough-cleaning stage employs impact purification and permits the elimination of al-most all of the coarse dust (~ 10 ~u). On the other hand, there is no way of economically achieving moist particle removal in a gas containing fine dust (< 1 ,u). The method used in the latter ~-case is the venturi washer which operates correctly at a con- ;
stant gas flow rate and with a major head loss (on theQrder of 0.3 bar) so as to give the gas the necessary speed in order to trap the fine dust.
The present invention was developed to provide a method and apparatus for removing from a gas stream impurity particles - .
iO~ 78 of less than one micron with a very low head loss.
According to a primary object of the instant invention, a mist pattern of liquid droplets is formed in the gas stream by means of a pair of generally opposed liquid jets, said liquid jets being so arranged relative to the gas stream that a liquid mist pattern is formed which extends normal to the gas stream.
It is another object of the present invention to pro-vide a method of purifying a stream of gas containing impurity particles, the size of which is less than about 1 ~. The method comprises directing a pair of spaced jets of pressure liquid in - generally opposed relation to establish a liquid mist pattern extending generally normal to the direction of flow of the gas.
In this manner the impurity particles are moisturized for removal - from the gas.
According to another object of the method and apparatus of the present invention, the generally opposed liquid jets are arranged at an obtuse angle less than 180. In the preferred embodiment, the gas stream to be purified is conducted via a conduit that contains longitudinally spaced wall openings through which the linear nozzles are introduced. In accordance with a specific feature of the invention, the liquid jet velocity rela-tive to the gas stream velocity is regulated to produce a ratio greater than 0.6.
According to another object of the invention, ~e appa-ratus which is used to carry out the method according to the in-vention comprises a conduit into which the gas stream is intro-duced for longitudinal flow in the conduit. The apparatus also comprises nozzle means connected with the conduit for introducing a pair of liquid jets in generally opposed relation into the con-duit to establish a liquid mist pattern which extends generallynormal to the flow of the gas stream. This enables the moisture particles to be moisturized for removal from the gas.
- ~' - ~ . " . '' .
10~0'~'7~
,~ In accordance with a more specific object of the inven-.
tion, the linear nozzle means for producing theliquid jets are each arranged for axial displacement (preferably by the provi-', sion of a telescopic mounting), whereby the depth of penetration of the angularly arranged nozzles into the gas conduit may be adjusted as desired.
According to another object, one or both of the linear nozzles is connected for angular adjustment relative to the gas conduit, thereby to permit variations in the liquid mist pattern produced by the liquid jets.
According to a further object, valve means and pressure gages are provided for varying the pressure of the liquid jets, '- or for varying the pressures of the jets relative to each other.
- According to anbther object, the nozzles are connected to a metal plate that is removably connected with the gas conduit, thereby to permit ready disassembly of the apparatus.
Other objects and advantages of the invention will be-come apparent from a study of the following specification when viewed in the light of the accompanying drawing, in which:-Fig. 1 is a diagrammatic view illustrating the liquid mist pattern produced by the method and apparatus of the instant invention when the liquid jets are identical and have the same pressure, Fig. 2 is a view of the spray mist pattern produced by the apparatus of Fig. 1:
Fig. 3 is a schematic illustration of the conical li-quid mist pattern produced by nozzles having orifices of differ-ent diameters:
Fig. 4 is a longitudinal sectional view of a preferred embodiment of the present invention:
~; Fig. 5 illustrates a second embodiment wherein the liquid jets have the same pressure: and , ,, i(~o7~
Fig. 6 is a modification of the apparatus of Fig. 5 wherein one of the liquid jets has a higher pressure than the other.
.j `:
Referring first more particularly to Fig. l, a pair of identical tubular injector members l and 2 terminating in nozzles la and 2a are connected with conduit means 3 that supply press-ure liquid, such as water. The injector members 1 and 2 are ^ supplied with liquid at the same pressure, whereby a planar mist pattern N is produced which is symmetrical to the liquid jets.
The nozzles are arranged at the angle ~ to the horizontal and are thus arranged at an obtuse angle which is less than 180, the liquid mist pattern N being normal to the horizontal plane P.
Since the axes of the two injectors form an angle, the mist sheet with the elliptical form shown in Fig. 2 is not homogeneous, be-cause the center G of the mist sheet is displaced to the opposite side of the obtuse angle formed by the two jets.
' If, in the case shown in Fig. 3, a pair of nozzles 4 and 5 are used one of which has an outlet orifice which is of greater diameter than the other, the mist sheet 6 produced-has the configuration of a cone whose apex is the meeting point 7 of the two jets, while the base is on the side of the jet supplied by the injector with the smaller diameter. This results from the . - . .
difference in the moments involved in these two jets. The same conical shape is obviously obtained if the two jets have the , same diameter but are supplied with liquid at different pressures.
The invention essentially consists in using the mist ~ -sheets thus produced by forming them in a conduit containing the - gas to be purified. - -- In Fig. 4 a conduit 8 is provided in which a gas to be ; 30 purified is supplied. A pair of injector members 9 and 10, equipped with nozzles 9a, lOa are provided, the axes of the in- -; jectors being inclined with respect to the axis of the conduit 8.
.
' .
.
10~iO7'7~
The injectors are attached to a plate 11 connected in a removable ` manner to the conduit 8. Telescopic devices 12 and 13 make it possible to advance and retract the injectors relative to the conduit as desired. Finally, joint connections 14 and 15 connect the injectors to an industrial liquid pipeline.
In accordance with a modification of the invention, one or both of the nozzles may be mounted for angular adjustment relative to the longitudinal axis of the conduit, thereby to vary the liquid mist pattern as desired. As shown in Fig. 4, the in-jector 10 is connected with plate 11 for pivotal movement aboutthe pivot axis 30, the injector extending in a longitudinal slot 31 that is contained in the wall of conduit 8 and that is sealed by the sliding seal 32 carried by the injector 10.
Referring now to Fig. 5, the ends of the injectors 9' and 10' which extend normal to the axis of the conduit are bent inwardly toward each other with the nozzles 9a' and lOa' being spaced longitudinally of the conduit. The nozzles have the same --orifice diameter and are supplied with liquid at the same press-ure, thereby producing the illustrated parabolic liquid mist ; 20 pattern 19. The nozzles are mounted on the plate 11 which is removably connected with the conduit by means of bolt means 16.
` Gage 17 indicates the pressure of the branch conduits leading to the nozzles, valve means 18 arranged in the main supply conduit ~connected with the source of pressure liquid, not shown) being provided for regulating the pressure of the liquid supplied to the branch conduits.
In the modification of Fig. 6,the branch conduit lead-ing to nozzle 9a" contains a valve 20 and a supplemental gage 21, said valve 20 being adjusted to cause the pressure of the liquid jet produced by nozzle 9a" to be greater than that of the jet produced by nozzle lOa". Consequently, a resulting liquid mist pattern 22 is produced having the reversely bent back configura-` lO~U7'78 tion illustrated in the figure.
;
The devices illustrated in Figs. 4, 5 and 6 each havetheir advantages and disadvantages. In the case of the devices of Figs. 5 and 6, the advantage is produced of symmetry and homo-geneousness of the mist patterns, but on the other hand, the cleaning of the conduit is not practical because, although there is a stopper in the conduit, one cannot run through a metal rod along the axis in order to break the stopper up or clean it out, owing to the hindrance produced by the bent injector tubes. In the case of the embodiment of Fig. 4, the advantage of symmetry of the mist pattern is omitted, but the cleaning of the conduit is facilitated. Moreover, one or both of the injectors may be axially slidably or pivotally mounted so as to modify the mist pattern in order to get the best result. `
To make sure that purification of blast furnace gases will be as efficient as possible, it is important that the ratio:
R = speed of water iets ."
gas speed will be as large as possible. To make the purification accep-table, we must have R >0.6 and if we have R = 0.8, then the effi-ciency of impurity removal will be 80%. But the larger we make R, the greater will be the head loss in the gas pipeline.
The following table on the other hand presents the re-sults obtained for the purification of blast furnace gas by means of the device in Fig. 4.
_ _ _ last Gas In- head Purifica- Water Ratio urnace flow jector loss, tion n q/m3 flow pres- R
~peration rate ~ mm m bar input output rate sure, i m3/hr l m3/hr bar _ 30 ~lmost about about about ormal 80/
90,000 20 160 200 7 95 13 1.4 _ ~ , ~ ... , . . - .
10~07~7~
` i:
¦~educed about - 40,000/ up to - 16,000 20 < 80 200 15/30 95 13 3/13 On the other hand, tests have been conducted on a steel conver- -ter with oxygen being blown in at the bottom, on a pilot scale, and the following results were obtained. These results evidently differ from the results for the blast furnace since the purifica-tion purpose is different.
The impurity particle concentration deriving from the purification device according to the invention was 100 mg per standard cubic meter for a head loss of less than or equal to 400mm water column, whereas on the same converter and with the same known purification processes, the same result was obtained for a head loss of 1500 mm water column. This resulted in an energy consumption gain in the smoke and fume aspiration fan or - ventilator of the impurity particle removal plant which would be very large on an industrial scale.
The advantages of the method and the device according to the invention are quite considerable. After moist purifica-tion, it is unnecessary to provide electrostatic safety filters.
~; ~he head loss due to the method is small, which reduces the - pneumatic energy losses. Finally the device is rather sturdy, requires little maintenance, and its operation is satisfactory in a wide range of gas flows to be purified.
While in accordance with the Patent Statutes, the pre-ferred forms and embodiments of the invention have been illus-trated and described, it will be apparent that changes and modi-fications may be made without deviating from the inventive con-cepts set forth above.
In various production processes -- such as in the steel, cement and other industries -- gases, smoke or fumes are produced which contain impurity particles of relatively small size (speci-- fically, particles less than one micron). Consequently, before 10 using the gases or fumes (in heaters or motors) or before expel-ling the smoke to atmosphere, it is necessary to purify the gases by removing the impurity particles therefrom.
Various gas purifying techniques have been proposed in the prior art, as for example, by moisturizing the gas, mechanic-al collision of the particles, condensation, diffusion in atom-, ized liquid electrostatic separation, and ultrasonic treatment ~
< of the gases. ~ -~, ' The impact processes employ mechanical collision be-tween the liquid and impurity particles. It has been established 20 that the efficiency of particle removal increases with the dif-ference in the relative speeds of the liquid drops and the parti-cles. But when the particles are very fine (for example, less -`~
than 1 ,u), the efficiency drops down to zero because the parti- -cles behave like an aerosol.
Condensation methods operate by lowering the temper-ature of the gas below its dew point. This mechanism is good for subsequent impact purification but it must be possible to bring about a strong temperature drop which can be obtained only with 1-low-temperature gas and by a strong pneumatic expansion of that gas.
In electrostatic field separation processes, the ion-ized particles are attracted by an electrode with an opposite , polarity. In order to get good purification, it is necessary to ,' ~ '- .
., - 1 - -- .: , . : .. ..
10~ 8 obtain relatively constant dust contents at the input of the electrofilters. Moreover, the cost of maintaining electrofil-ters is very high when it comes to purifying corrosive gases (for example, carbon dioxide or sulfur dioxide).
Ultrasonic procedures operate by applying resonance to the dust and the liquid droplets. ~owever, this method also re-quires a relatively heavy energy consumption.
Diffusion methods consist in mixing the impurity-contaminated gas with a liquid which is in the aerosol state.
The inconvenience of this procedure resides in the difficulty ` of pulverizing the liquid very finely. In effect, if mechanical pulverization is employed, the nozzles must be very fine and there is a risk that they might become clogged with industrial - liquids. Mechanical pulverization moreover requires very high ; liquid pressures.
In pneumatic pulverization processes, very high gas `
pulverization speeds are required, thereby resulting in a very great energy expenditure. Finally, centrifuge pulverization utilizing a centrifuge bowl revolving at great speed is a deli-cate operation because of the operating and maintenance difficul-ties.
In industrial practice, a first rough-cleaning stage employs impact purification and permits the elimination of al-most all of the coarse dust (~ 10 ~u). On the other hand, there is no way of economically achieving moist particle removal in a gas containing fine dust (< 1 ,u). The method used in the latter ~-case is the venturi washer which operates correctly at a con- ;
stant gas flow rate and with a major head loss (on theQrder of 0.3 bar) so as to give the gas the necessary speed in order to trap the fine dust.
The present invention was developed to provide a method and apparatus for removing from a gas stream impurity particles - .
iO~ 78 of less than one micron with a very low head loss.
According to a primary object of the instant invention, a mist pattern of liquid droplets is formed in the gas stream by means of a pair of generally opposed liquid jets, said liquid jets being so arranged relative to the gas stream that a liquid mist pattern is formed which extends normal to the gas stream.
It is another object of the present invention to pro-vide a method of purifying a stream of gas containing impurity particles, the size of which is less than about 1 ~. The method comprises directing a pair of spaced jets of pressure liquid in - generally opposed relation to establish a liquid mist pattern extending generally normal to the direction of flow of the gas.
In this manner the impurity particles are moisturized for removal - from the gas.
According to another object of the method and apparatus of the present invention, the generally opposed liquid jets are arranged at an obtuse angle less than 180. In the preferred embodiment, the gas stream to be purified is conducted via a conduit that contains longitudinally spaced wall openings through which the linear nozzles are introduced. In accordance with a specific feature of the invention, the liquid jet velocity rela-tive to the gas stream velocity is regulated to produce a ratio greater than 0.6.
According to another object of the invention, ~e appa-ratus which is used to carry out the method according to the in-vention comprises a conduit into which the gas stream is intro-duced for longitudinal flow in the conduit. The apparatus also comprises nozzle means connected with the conduit for introducing a pair of liquid jets in generally opposed relation into the con-duit to establish a liquid mist pattern which extends generallynormal to the flow of the gas stream. This enables the moisture particles to be moisturized for removal from the gas.
- ~' - ~ . " . '' .
10~0'~'7~
,~ In accordance with a more specific object of the inven-.
tion, the linear nozzle means for producing theliquid jets are each arranged for axial displacement (preferably by the provi-', sion of a telescopic mounting), whereby the depth of penetration of the angularly arranged nozzles into the gas conduit may be adjusted as desired.
According to another object, one or both of the linear nozzles is connected for angular adjustment relative to the gas conduit, thereby to permit variations in the liquid mist pattern produced by the liquid jets.
According to a further object, valve means and pressure gages are provided for varying the pressure of the liquid jets, '- or for varying the pressures of the jets relative to each other.
- According to anbther object, the nozzles are connected to a metal plate that is removably connected with the gas conduit, thereby to permit ready disassembly of the apparatus.
Other objects and advantages of the invention will be-come apparent from a study of the following specification when viewed in the light of the accompanying drawing, in which:-Fig. 1 is a diagrammatic view illustrating the liquid mist pattern produced by the method and apparatus of the instant invention when the liquid jets are identical and have the same pressure, Fig. 2 is a view of the spray mist pattern produced by the apparatus of Fig. 1:
Fig. 3 is a schematic illustration of the conical li-quid mist pattern produced by nozzles having orifices of differ-ent diameters:
Fig. 4 is a longitudinal sectional view of a preferred embodiment of the present invention:
~; Fig. 5 illustrates a second embodiment wherein the liquid jets have the same pressure: and , ,, i(~o7~
Fig. 6 is a modification of the apparatus of Fig. 5 wherein one of the liquid jets has a higher pressure than the other.
.j `:
Referring first more particularly to Fig. l, a pair of identical tubular injector members l and 2 terminating in nozzles la and 2a are connected with conduit means 3 that supply press-ure liquid, such as water. The injector members 1 and 2 are ^ supplied with liquid at the same pressure, whereby a planar mist pattern N is produced which is symmetrical to the liquid jets.
The nozzles are arranged at the angle ~ to the horizontal and are thus arranged at an obtuse angle which is less than 180, the liquid mist pattern N being normal to the horizontal plane P.
Since the axes of the two injectors form an angle, the mist sheet with the elliptical form shown in Fig. 2 is not homogeneous, be-cause the center G of the mist sheet is displaced to the opposite side of the obtuse angle formed by the two jets.
' If, in the case shown in Fig. 3, a pair of nozzles 4 and 5 are used one of which has an outlet orifice which is of greater diameter than the other, the mist sheet 6 produced-has the configuration of a cone whose apex is the meeting point 7 of the two jets, while the base is on the side of the jet supplied by the injector with the smaller diameter. This results from the . - . .
difference in the moments involved in these two jets. The same conical shape is obviously obtained if the two jets have the , same diameter but are supplied with liquid at different pressures.
The invention essentially consists in using the mist ~ -sheets thus produced by forming them in a conduit containing the - gas to be purified. - -- In Fig. 4 a conduit 8 is provided in which a gas to be ; 30 purified is supplied. A pair of injector members 9 and 10, equipped with nozzles 9a, lOa are provided, the axes of the in- -; jectors being inclined with respect to the axis of the conduit 8.
.
' .
.
10~iO7'7~
The injectors are attached to a plate 11 connected in a removable ` manner to the conduit 8. Telescopic devices 12 and 13 make it possible to advance and retract the injectors relative to the conduit as desired. Finally, joint connections 14 and 15 connect the injectors to an industrial liquid pipeline.
In accordance with a modification of the invention, one or both of the nozzles may be mounted for angular adjustment relative to the longitudinal axis of the conduit, thereby to vary the liquid mist pattern as desired. As shown in Fig. 4, the in-jector 10 is connected with plate 11 for pivotal movement aboutthe pivot axis 30, the injector extending in a longitudinal slot 31 that is contained in the wall of conduit 8 and that is sealed by the sliding seal 32 carried by the injector 10.
Referring now to Fig. 5, the ends of the injectors 9' and 10' which extend normal to the axis of the conduit are bent inwardly toward each other with the nozzles 9a' and lOa' being spaced longitudinally of the conduit. The nozzles have the same --orifice diameter and are supplied with liquid at the same press-ure, thereby producing the illustrated parabolic liquid mist ; 20 pattern 19. The nozzles are mounted on the plate 11 which is removably connected with the conduit by means of bolt means 16.
` Gage 17 indicates the pressure of the branch conduits leading to the nozzles, valve means 18 arranged in the main supply conduit ~connected with the source of pressure liquid, not shown) being provided for regulating the pressure of the liquid supplied to the branch conduits.
In the modification of Fig. 6,the branch conduit lead-ing to nozzle 9a" contains a valve 20 and a supplemental gage 21, said valve 20 being adjusted to cause the pressure of the liquid jet produced by nozzle 9a" to be greater than that of the jet produced by nozzle lOa". Consequently, a resulting liquid mist pattern 22 is produced having the reversely bent back configura-` lO~U7'78 tion illustrated in the figure.
;
The devices illustrated in Figs. 4, 5 and 6 each havetheir advantages and disadvantages. In the case of the devices of Figs. 5 and 6, the advantage is produced of symmetry and homo-geneousness of the mist patterns, but on the other hand, the cleaning of the conduit is not practical because, although there is a stopper in the conduit, one cannot run through a metal rod along the axis in order to break the stopper up or clean it out, owing to the hindrance produced by the bent injector tubes. In the case of the embodiment of Fig. 4, the advantage of symmetry of the mist pattern is omitted, but the cleaning of the conduit is facilitated. Moreover, one or both of the injectors may be axially slidably or pivotally mounted so as to modify the mist pattern in order to get the best result. `
To make sure that purification of blast furnace gases will be as efficient as possible, it is important that the ratio:
R = speed of water iets ."
gas speed will be as large as possible. To make the purification accep-table, we must have R >0.6 and if we have R = 0.8, then the effi-ciency of impurity removal will be 80%. But the larger we make R, the greater will be the head loss in the gas pipeline.
The following table on the other hand presents the re-sults obtained for the purification of blast furnace gas by means of the device in Fig. 4.
_ _ _ last Gas In- head Purifica- Water Ratio urnace flow jector loss, tion n q/m3 flow pres- R
~peration rate ~ mm m bar input output rate sure, i m3/hr l m3/hr bar _ 30 ~lmost about about about ormal 80/
90,000 20 160 200 7 95 13 1.4 _ ~ , ~ ... , . . - .
10~07~7~
` i:
¦~educed about - 40,000/ up to - 16,000 20 < 80 200 15/30 95 13 3/13 On the other hand, tests have been conducted on a steel conver- -ter with oxygen being blown in at the bottom, on a pilot scale, and the following results were obtained. These results evidently differ from the results for the blast furnace since the purifica-tion purpose is different.
The impurity particle concentration deriving from the purification device according to the invention was 100 mg per standard cubic meter for a head loss of less than or equal to 400mm water column, whereas on the same converter and with the same known purification processes, the same result was obtained for a head loss of 1500 mm water column. This resulted in an energy consumption gain in the smoke and fume aspiration fan or - ventilator of the impurity particle removal plant which would be very large on an industrial scale.
The advantages of the method and the device according to the invention are quite considerable. After moist purifica-tion, it is unnecessary to provide electrostatic safety filters.
~; ~he head loss due to the method is small, which reduces the - pneumatic energy losses. Finally the device is rather sturdy, requires little maintenance, and its operation is satisfactory in a wide range of gas flows to be purified.
While in accordance with the Patent Statutes, the pre-ferred forms and embodiments of the invention have been illus-trated and described, it will be apparent that changes and modi-fications may be made without deviating from the inventive con-cepts set forth above.
Claims (16)
1. The method of purifying a stream of gas containing impurity particles the size of which is less than about 1 µ, which comprises directing a pair of spaced jets of pressure liquid in generally opposed relation to establish a liquid mist pattern extending generally normal to the direction of flow of the gas, whereby the impurity particles are moisturized for removal from the gas.
2. The method as recited in claim 1, wherein said jets are angularly arranged to define therebetween an obtuse angle of less than 180°.
3. The method as recited in claim 1, wherein the ratio of the velocity of the jet liquid relative to the velocity of the gas is greater than 0.6.
4. Apparatus for purifying a stream of gas containing impurity particles the size of which is less than 1 µ, comprising (a) a conduit into which the gas stream is introduced for longi-tudinal flow in said conduit; and (b) nozzle means connected with said conduit for introducing a pair of liquid jets in generally opposed relation into said con-duit to establish a liquid mist pattern which extends generally normal to the flow of said gas stream, whereby the moisture particles are moisturized for removal from the gas.
5. Apparatus as defined in claim 4, wherein said nozzle means include a pair of linear nozzles, and means mounting said nozzles in longitudinally spaced relation in wall portions of said conduit.
6. Apparatus as defined in claim 5, and further including means supporting said nozzles for axial displacement, thereby to permit variation of the depths to which the outlet ends of said nozzles extend into said conduit.
7. Apparatus as defined in claim 6, wherein each of said nozzles is angularly arranged relative to the longitudinal axis of said conduit.
8. Apparatus as defined in claim 5, and further including means for varying the angular relationship of at least one of the nozzles relative to the longitudinal axis of said conduit, and a sliding seal for said nozzle.
9. Apparatus as defined in claim 5, wherein said nozzle mounting means includes a plate (11) removably connected with, and extending longitudinally of, the external surface of said conduit, said conduit containing a pair of wall openings for re-ceiving said nozzles.
10. Apparatus as defined in claim 5, and further including means for regulating the pressures of said liquid jets.
11. Apparatus as defined in claim 10, and further includ-ing a source of pressure liquid, means including a common supply conduit for connecting said pressure liquid source with said nozzles, respectively, and main valve means connected in said common supply conduit for controlling the pressure of the liquid supplied to said nozzles.
12. Apparatus as defined in claim 11, wherein said means for supplying liquid to said nozzles includes a pair of branch conduits connected with said nozzles, respectively, and further including branch valve means connected in at least one of said branch conduits for regulating the relative pressure of the li-quid supplied to said nozzles, respectively.
13. Apparatus as defined in claim 11, and further including first gage means for indicating the pressure of the liquid sup-plied to said nozzles.
14. Apparatus as defined in claim 12, and further including gage means for indicating the pressure of the liquid supplied to each of said nozzles, respectively.
15. The method as defined in claim 1, wherein the liquid jets are of unequal pressure, thereby to achieve a desired liquid mist pattern.
16. Apparatus as defined in claim 5, wherein said nozzles have orifices of different diameter, thereby to produce a spray pattern of desired configuration.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7425077A FR2278379A1 (en) | 1974-07-18 | 1974-07-18 | PROCESS AND DEVICE FOR GAS OR DUSTY FUMES CLEANING |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1060778A true CA1060778A (en) | 1979-08-21 |
Family
ID=9141457
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA230,982A Expired CA1060778A (en) | 1974-07-18 | 1975-07-08 | Method and apparatus for purifying impurity-containing gases |
Country Status (14)
| Country | Link |
|---|---|
| JP (1) | JPS5134472A (en) |
| AT (1) | AT359048B (en) |
| AU (1) | AU496923B2 (en) |
| BE (1) | BE831226A (en) |
| BR (1) | BR7504501A (en) |
| CA (1) | CA1060778A (en) |
| DE (1) | DE2530788C2 (en) |
| ES (1) | ES439284A1 (en) |
| FR (1) | FR2278379A1 (en) |
| GB (1) | GB1476265A (en) |
| IT (1) | IT1039847B (en) |
| LU (1) | LU72944A1 (en) |
| NL (1) | NL7508066A (en) |
| ZA (1) | ZA754309B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53104774A (en) * | 1977-02-23 | 1978-09-12 | Sadami Kawashima | Laver releasing machine |
| FR2503134B1 (en) * | 1981-04-02 | 1985-06-14 | Saint Gobain Isover | WASHING METHOD AND DEVICE USED IN THE MANUFACTURE OF MINERAL FIBER MATTRESSES |
| US4508555A (en) * | 1982-04-08 | 1985-04-02 | Isover Saint-Gobain | Method and apparatus for scrubbing effluent gases from mineral fiber production |
| GB2282983B (en) * | 1993-09-11 | 1997-08-20 | Atomic Energy Authority Uk | Spray generators |
| DE19909904B4 (en) * | 1999-03-06 | 2007-12-20 | Khd Humboldt Wedag Gmbh | Device for injecting a flow medium into a hot gas stream |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE533730A (en) * | 1953-11-27 | |||
| CH368926A (en) * | 1959-02-27 | 1963-04-30 | Aluminium Ind Ag | Hall exhaust air purification system |
| DE1262231B (en) * | 1963-03-21 | 1968-03-07 | Bergwerksverband Gmbh | Process for separating dust from a gas flowing in a pipeline |
| DE2243186C3 (en) * | 1972-09-01 | 1980-02-21 | Ekkehard Prof. Dr.-Ing. 4300 Essen Weber | Device for cleaning dusty gases and separating gaseous components |
-
1974
- 1974-07-18 FR FR7425077A patent/FR2278379A1/en active Granted
-
1975
- 1975-07-04 ZA ZA00754309A patent/ZA754309B/en unknown
- 1975-07-07 NL NL7508066A patent/NL7508066A/en not_active Application Discontinuation
- 1975-07-08 CA CA230,982A patent/CA1060778A/en not_active Expired
- 1975-07-09 AU AU82879/75A patent/AU496923B2/en not_active Expired
- 1975-07-10 IT IT25242/75A patent/IT1039847B/en active
- 1975-07-10 DE DE2530788A patent/DE2530788C2/en not_active Expired
- 1975-07-10 LU LU72944A patent/LU72944A1/xx unknown
- 1975-07-10 ES ES439284A patent/ES439284A1/en not_active Expired
- 1975-07-10 BE BE158176A patent/BE831226A/en not_active IP Right Cessation
- 1975-07-11 GB GB2922975A patent/GB1476265A/en not_active Expired
- 1975-07-16 BR BR7504501*A patent/BR7504501A/en unknown
- 1975-07-16 JP JP50086269A patent/JPS5134472A/ja active Pending
- 1975-07-16 AT AT548375A patent/AT359048B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE2530788A1 (en) | 1976-02-12 |
| FR2278379A1 (en) | 1976-02-13 |
| BE831226A (en) | 1975-11-03 |
| BR7504501A (en) | 1976-07-06 |
| DE2530788C2 (en) | 1984-11-22 |
| AU8287975A (en) | 1977-01-13 |
| GB1476265A (en) | 1977-06-10 |
| LU72944A1 (en) | 1976-02-04 |
| AU496923B2 (en) | 1978-11-09 |
| ES439284A1 (en) | 1977-02-16 |
| JPS5134472A (en) | 1976-03-24 |
| ZA754309B (en) | 1976-06-30 |
| IT1039847B (en) | 1979-12-10 |
| FR2278379B1 (en) | 1979-01-26 |
| AT359048B (en) | 1980-10-10 |
| NL7508066A (en) | 1976-01-20 |
| ATA548375A (en) | 1980-03-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2935375A (en) | Method of purifying a gaseous current containing an aerosol | |
| US3385030A (en) | Process for scrubbing a gas stream containing particulate material | |
| US3852409A (en) | Process for the removal of particulate matter and acidic gases from carrier gases | |
| GB655038A (en) | Improvements in and relating to method and apparatus for treating gases by means of a washing liquid | |
| EE05100B1 (en) | Apparatus and method for producing micrometric and submicrometric particles, and apparatus for use in a device | |
| JPS6048562B2 (en) | Equipment for producing spherical metal powder that is not contaminated by the atmosphere | |
| GR1000927B (en) | Method and mechanism for the supersonic separation of a flow gas and droplets | |
| CA1060778A (en) | Method and apparatus for purifying impurity-containing gases | |
| US3497194A (en) | Apparatus for the removal of dust from converter gases | |
| EP0202057B1 (en) | Low pressure misting jet | |
| FI82389C (en) | Media mixing nozzle | |
| CA1223444A (en) | Nozzle drawing process and a drawing nozzle for the separation of melts | |
| US3749377A (en) | Orifice scrubber for removing solid particles from high pressure gas | |
| CA1273283A (en) | Arrangement intended for a nozzle assembly | |
| FR2566802B1 (en) | METHOD FOR THE HEATING OF THE BLOW GAS OF A BLAST FURNACE BY A PLASMA GENERATOR | |
| JPS57157927A (en) | Soot blower equipment | |
| RU2027526C1 (en) | Method of gas cleaning from dust | |
| US3876398A (en) | Gas washing and cleaning device | |
| SU768437A1 (en) | Method of preparing and cooling gases | |
| SU656646A1 (en) | Gas-scrubbing apparatus | |
| RU2046673C1 (en) | Liquid atomizer | |
| SU1759477A1 (en) | Flotation machine aeration unit | |
| SU1103792A3 (en) | Method for forming high-velocity gas jet | |
| SU1457971A1 (en) | Apparatus for cleaning waste gases | |
| SU1279656A1 (en) | Ejection venturi tube |