CA1335785C - Gas-fired radiant burner - Google Patents
Gas-fired radiant burnerInfo
- Publication number
- CA1335785C CA1335785C CA000584819A CA584819A CA1335785C CA 1335785 C CA1335785 C CA 1335785C CA 000584819 A CA000584819 A CA 000584819A CA 584819 A CA584819 A CA 584819A CA 1335785 C CA1335785 C CA 1335785C
- Authority
- CA
- Canada
- Prior art keywords
- gas
- chamber
- combustion
- burner according
- air
- 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 - Lifetime
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/12—Radiant burners
- F23D14/126—Radiant burners cooperating with refractory wall surfaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/12—Radiant burners
- F23D14/14—Radiant burners using screens or perforated plates
- F23D14/149—Radiant burners using screens or perforated plates with wires, threads or gauzes as radiation intensifying means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/46—Details, e.g. noise reduction means
- F23D14/66—Preheating the combustion air or gas
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/12—Radiant burners
- F23D14/151—Radiant burners with radiation intensifying means other than screens or perforated plates
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/20—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C3/00—Stoves or ranges for gaseous fuels
- F24C3/04—Stoves or ranges for gaseous fuels with heat produced wholly or partly by a radiant body, e.g. by a perforated plate
- F24C3/06—Stoves or ranges for gaseous fuels with heat produced wholly or partly by a radiant body, e.g. by a perforated plate without any visible flame
- F24C3/062—Stoves or ranges for gaseous fuels with heat produced wholly or partly by a radiant body, e.g. by a perforated plate without any visible flame stoves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2203/00—Gaseous fuel burners
- F23D2203/10—Flame diffusing means
- F23D2203/102—Flame diffusing means using perforated plates
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2203/00—Gaseous fuel burners
- F23D2203/10—Flame diffusing means
- F23D2203/105—Porous plates
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2212/00—Burner material specifications
- F23D2212/10—Burner material specifications ceramic
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Gas Burners (AREA)
- Air Supply (AREA)
- Combustion Of Fluid Fuel (AREA)
Abstract
A gas-fired radiant burner is essentially constituted by a plenum chamber (1) into which an air-gas mixture is injected from a mixer. One of the faces of the body (11, 12, 2) delimiting the plenum chamber (1) is constituted by at least one combustion support (2) with combustion of the air-gas mixture taking place on the surface of the combustion support, thereby raising the surface of the support (2) to a high temperature causing the support to radiate. The burner also includes a device for recovering the combustion products and comprising a recovery chamber (5) surrounding the plenum chamber (1) and delimited by a gas-tight body whose wall parallel to the combustion support (2) includes at least one radiation-passing gas-tight plate (4) constituted by a material which transmits at least a substantial portion of the infrared radiation and which withstands high temperatures. A flue (7) serves to extract the combustion products present in the recovery chamber (5) and a heat exchanger is incorporated in the burner to exchange heat between the combustion products and the oxidizing air.
Description
3~7~5 GAS-FIRED RADIANT BURNER
The present i~lv~rl~ion relates to a gas-fired radiant burner for emitting infrared heating radiation, the burner including a plenum chamber into which an air-gas mixture is injected from a mixer, with one of the faces of the body ting the pl~nllm ~h~Pr being constituted by at least one combustion support on which combustion of the air-gas mixture takes place, thereby r~ing the surface of said support to a high temperature c~ ; ng the support to radiate.
Industrial pr~mi~e~ or premises receiving the public may be heated by various techniques including, in particular, convection heating and radiant heating.
Radiant heating may be performed, in particular, by means of bright radiant panels constituting emitters and charac-terized by external combustion taking place on a ceramic sur-face which is raised to a high temperature. This surface is made up of ceramic plates or "tiles" perforated by multiple small diameter orifices. Combustion of the air-gas mixture (generally provided by an atmospheric induction mixer) begins close to the outlets of the orifices, thereby raising the surface of the tiles to a high t~m~ature. These apparatuses having high unit power are generally used for heating industrial premises which are very tall and poorly insulated.
Apparatuses of this type suffer from drawbacks insofar as the combustion products from the radiant panels are exhausted into the premises being heated. A high degree of condensation can th~n take place if the premises are sufficiently draught-proof.
Further, legislation in various countries does not allow apparatuses of this type to be used in premises receiving the public because of safety reasons related to the combustion products being exhausted into the premises being heated.
Low temperature radiant tubes are also known which are characterized by internal combustion. A gas burner provides combustion products which flow inside a tube which is raised to a relatively low temperature. This tube radiates and the radiation is directed by means of a reflector placed above the tube. An extractor fan sucks up the combustion products which may be exhausted inside or outside the premises being heated. A drawback of such apparatuses lies in the fact that their operating temperatures are relatively low which means that such apparatuses can be installed only in premises of average height.
One of the operating characteristics of radiant heaters i5 their radiation efficiency, i.e. the ratio of the power radiated to the power supplied. The radiation efficiency of bright radiant panels may be as much as 60%, whereas low temperature radiant tubes have lower radiation efficiency, of the order of 50%.
The present invention in one aspect seeks to remedy the above-mentioned drawbacks and to provide a radiant burner which, like radiant burners having perforated ceramic tiles, presents high unit radiated power, thereby enabling it to be placed in tall premises, but which does not present the drawbacks of said type of apparatus, i.e.
in particular, it does not exhaust combustion products into the premises being heated.
An object of an aspect of the invention is to provide a radiant burner capable of operating at a higher temperature and with higher radiation efficiency than radiant tubes.
An aspect of the invention is as follows:
A gas-fired radiant burner for emitting infrared heating radiation, the burner comprising a body having a plenum chamber into which an air-gas mixture is injected from a mixer, with one of the faces of the body delimiting the plenum chamber being constituted by at least one combustion support on which combustion of the air-gas mixture takes place, thereby raising the surface of said suppor~ to a high temperature causing the support to radiate, a device for recovering the combustion products comprising a recovery chamber surro~ln~i n~ the plenum chamber and delimited by a gas-tight body whose wall parallel to the combustion support includes at least one gas-tight plate made of a material which transmits at C
~ 133578~
least a substantial portion of the infrared radiation and capable of withstanding high temperatures, and a flue for extracting the combustion products present in the recovery chamber, the burner further comprising a heat exchanger between the combustion products and the oxidizing air, said heat eYch~qer including an additional chamber which surrounds the combustion product recovery chamber in gas-tight manner except for the face constituted by the radiation-passing gas-tight plate, with the oxidizing air passing through said additional chamber, and with said additional chamber being put into communication with the air-gas mixing zone of the mixer.
The walls delimiting the recovery chamber and the additional chamber are made of a material which is a good conductor of heat in order to facilitate the heating of the oxidizing air passing through the additional chamber by means of the combustion products present in the recovery chamber.
The gas-tight plate is preferably made of a glass ceramic based material which may advantageously be translucent or transparent.
The combustion support may be constituted by a porous refractory material or by refractory ceramic tiling which is pierced by multiple small-diameter orifices.
Advantageously, the radiant burner further includes a confinement screen disposed parallel to the surface of the combustion support on its side opposite from the plenum chamber in order to improve heat exchange between the flame and the support.
The confinement screen may be embodied in various different ways.
In a first embodiment, the confinement screen is constituted by a metal screen made of refractory steel in the form of a large-mesh grid.
In another embodiment, the confinement screen is .~
~ 3a 133578~
constituted by a latticework of rods.
In another embodiment, the confinement screen comprises a ceramic plate.
The walls delimiting the plenum chamber and the recovery chamber, other than the radiation-passing gas-tight plate and the optional confinement screen are made of a material which is a good conductor of heat in order to facilitate heating the air-gas mixture contained in the plenum chamber by the combustion products present in the recovery chamber.
~2 ~ 133578S
As a result, a radiant burner in accordance with the invention avoids the major drawbacks of radiant panels and of radiant tubes while still retaining the advantages of each of these types of equipment, namely:
5high unit radiated power, thereby making it possible to use the apparatus in premises which are very tall;
the combustion products can be exhausted in a controlled manner, thereby preventing them from being diluted in the atmosphere of the premises or the enclosure 10being heated; and high radiation efficiency by virtue of the ease with which the heat lost by the combustion products can be recovered.
A radiant burner in accordance with the invention is suitable for heating enclosures such as ovens, drying 15rooms, etc. and also for heating large-volume premises such as workshops, factories, exhibition halls, or sales halls.
Other characteristics and advantages of the invention appear from the following description of a particular embodiment given by way of example and with reference to 20the accompanying drawing, in which:
Figure 1 is an axial section through a gas-fired radiant burner in accordance with the invention; and Figure 2 is a cross-section on line II-II of Figure 1.
The example of a radiant burner in accordance with the 25invention which is shown in Figures 1 and 2 comprises a plenum chamber 1 into which an air-gas mixture is injected by means of a converging-diverging nozzle 9 disposed horizontally, said mixture being provided by an atmospheric induction mixer. The nozzle 9 accelerates the air-gas 30mixture and improves the quality of mixing. The mixer is essentially constituted by a pre-mixing zone 8 into which the gas is injected by an injector 81 which opens out horizontally and which lies on the axis of the nozzle 9 facing the inlet thereto. The oxidizing air is itself 35injected into the pr~r;x;ng zone 8 after flowing along an additional outer chamber 6 in contact with the wall 51, 52 of the chamber 5 for collecting the combustion products, thereby preheating the air.
The plenum chamber 1 into which the nozzle 9 opens out 40is delimited by a substantially horizontal top wall 11, two B
1~ 5 1335785 vertical side walls 12 extending in the longitudinal direction of the burner on either side of the nn~ ., a vertical end wall 13 f~i ng the outlet from the nozzle 9, a vertical end wall 14 through which the air-gas mixture in;ection nozzle 9 is mounted, and a substantially horizontal bottom face 2. The ~oL~.. face is constituted by one or more refractory ceramic tiles 2 pierced by multiple small-dia~,e~el orifices 21 with com.bustion of the air-gas mixture taking place at the outlets of the orifices, thereby raising the surface of the tile(s) 2 to a high temperature c~ ing the tile(s) 2 to radiate.
A screen 3 in the form of a large mesh grid 31 made of stainless steel is disposed parallel to and beneath the tile(s) 2, i.e. adjacent to the face looking away from the plenum ~hamb~r 1. The screen 3 confines combustion and provides i~ ~v~d heat exchange between the hot gas and the ceramic tile(s).
The com.bustion products that pass through the screen 3 are pl~v~lted from escaping into the premises being heated by vir-tue of a glass ceramic plate 4 forming a gas-tight barrier which is placed beneath the screen 3 and at a distance therefrom, and is preferably parallel to the screen 3.
Vertical side walls 52 extend in the longitudinal direction of the burner outside the side walls 12 ~elimiting the plenum ch~m~P-r 1 containing the air-gas mixture, and at a distance from said walls 12. A top horizontal wall 51 extends horizon-tally over the top horizontal wall 11 of the plenum chamber 1 at a distance therefrom. This forms a recovery chamber 5 for recovering the combustion products and surrounding the plenum chamber 1, with said recovery chamher 5 being ~Ql im;ted by a set of gas-tight walls (walls 51, 52, and vertical extensions of the end walls 13 and 14 of the plenum cham.ber 1) and the top of the recovery chamber 5 is in com.munication with a flue 7 for extracting the combustion products present in the recovery ~h~mh~ 5.
The com.bustion products are thus channelled through a recovery chamber 5 of the double-walled type which includes walls 11 and 12 for exchanging heat with the air-gas mixture in 6 133~
the plenum chamber 1. The combustion products thus give a portion of their energy to the air-gas mixture, thereby ~o.l~libuting to i~ uving ef~;r;~nr.y.
The "triple-walled" type configuration shown in Figures 1 and 2 with an additional outer chamber 6 for ~ollv~ying the ~xi ~i ~i ng air and including heat exchange walls 51 and 52 for ~xrh~ng~ng heat with the combustion products in the recovery chamber 5 serves, addi~ion~lly to preheat the oxidizing air.
The side walls 62 and the top wall 61 of the nxi~i ~ing air inlet chamber 6, and also the end walls of the burner (situated to the right and the left of Figure 1) may be coated internally or extern~lly with thermally insulating material in order to reduce heat loss via these outer walls of the apparatus.
The heat provided by the radiant burner is thus transmitted almost exclusively through the glass ceramic plate 4 which, in addition to constituting a barrier for the combus-tion products also relays the radiation emitted by the tile(s) 2 efficiently. The plate 4 is made of a glass ceramic based material and is preferably transparent or translucent.
Apparatus in accordance with the invention can thus radiate a large amount of power by virtue of its high operating t~m~Prature made possible by using a plate of glass ceramic material or the like which is capable of withstanding high t~mreratures while passing radiation.
Further, the radiation efficiency of the radiant burner is high since the energy lost to the PXh~ t is easily recovered by means of the double-walled envelope and since the ~xh~ t is not diluted with ambient air.
A radiant burner of the invention may be used for heating premises and may deliver power lying in the range about 100 kW/m2 to 150 kW/m2 of radiating ceramic tile area giving rise to a ceramic tile ~"~euature of about 900C with radiation efficiency of about 60%.
The radiant burner may also be used in like manner for heating enclosures (ovens, drying rooms, etc.) in which case it may deliver power at more than about 150 kW/m2 of radiating ceramic tile area giving rise to a ceramic tile temperature of about 1100C with radiation efficiency of about 55%.
7 133~785 Various mo~;f;~Ations and additions may be applied to the ~o~;m~nts described with reference to Figures 1 and 2.
Thus, in the event that the oxidizing air and exhaust heat exchanger (walls 51, 52) gives rise to too much p~e~sure-drop in the air supply circuit, an nX;~; ~;ng air fan may be added in order to co-operate with the premixing chamber 8 of the mixer and/or an extractor fan may be added to facilitate the extraction of combustion products via the flue 7.
The nozzle 9, and the heat exchange walls 11, 12 or 51, 52 of the double- or triple-walled enclosure may be made of st~; n 1 e~s steel, for Rxample.
In a variant, the co-mbustion support 2 may be made of a porous refractory material.
The confinement screen 3 may also have configurations other than that described with reference to Figures 1 and 2.
Thus, the screen 3 may be constituted by a lattice of rods or by a gas-passing ceramic plate or even, in some cases, by a metal grid having relatively small mesh size.
Further, it has been assumed above that the bright radiant face 4 of the radiant burner is placed beneath the burner and is horizontal. Naturally, the burner assembly may be tilted in order to direct its radiating face in a direction which is to receive most heat. In most cases, the radiating face 4 is either horizontal or else inclined to form an angle with the horizontal which is less than about 60. The burner is still capable of operating with its radiating face in a vertical position, however its efficiency is likely to be slightly reduced in comparison with operation having the radiating face horizontal or inclined at less than 60 relative to the horizontal.
The present i~lv~rl~ion relates to a gas-fired radiant burner for emitting infrared heating radiation, the burner including a plenum chamber into which an air-gas mixture is injected from a mixer, with one of the faces of the body ting the pl~nllm ~h~Pr being constituted by at least one combustion support on which combustion of the air-gas mixture takes place, thereby r~ing the surface of said support to a high temperature c~ ; ng the support to radiate.
Industrial pr~mi~e~ or premises receiving the public may be heated by various techniques including, in particular, convection heating and radiant heating.
Radiant heating may be performed, in particular, by means of bright radiant panels constituting emitters and charac-terized by external combustion taking place on a ceramic sur-face which is raised to a high temperature. This surface is made up of ceramic plates or "tiles" perforated by multiple small diameter orifices. Combustion of the air-gas mixture (generally provided by an atmospheric induction mixer) begins close to the outlets of the orifices, thereby raising the surface of the tiles to a high t~m~ature. These apparatuses having high unit power are generally used for heating industrial premises which are very tall and poorly insulated.
Apparatuses of this type suffer from drawbacks insofar as the combustion products from the radiant panels are exhausted into the premises being heated. A high degree of condensation can th~n take place if the premises are sufficiently draught-proof.
Further, legislation in various countries does not allow apparatuses of this type to be used in premises receiving the public because of safety reasons related to the combustion products being exhausted into the premises being heated.
Low temperature radiant tubes are also known which are characterized by internal combustion. A gas burner provides combustion products which flow inside a tube which is raised to a relatively low temperature. This tube radiates and the radiation is directed by means of a reflector placed above the tube. An extractor fan sucks up the combustion products which may be exhausted inside or outside the premises being heated. A drawback of such apparatuses lies in the fact that their operating temperatures are relatively low which means that such apparatuses can be installed only in premises of average height.
One of the operating characteristics of radiant heaters i5 their radiation efficiency, i.e. the ratio of the power radiated to the power supplied. The radiation efficiency of bright radiant panels may be as much as 60%, whereas low temperature radiant tubes have lower radiation efficiency, of the order of 50%.
The present invention in one aspect seeks to remedy the above-mentioned drawbacks and to provide a radiant burner which, like radiant burners having perforated ceramic tiles, presents high unit radiated power, thereby enabling it to be placed in tall premises, but which does not present the drawbacks of said type of apparatus, i.e.
in particular, it does not exhaust combustion products into the premises being heated.
An object of an aspect of the invention is to provide a radiant burner capable of operating at a higher temperature and with higher radiation efficiency than radiant tubes.
An aspect of the invention is as follows:
A gas-fired radiant burner for emitting infrared heating radiation, the burner comprising a body having a plenum chamber into which an air-gas mixture is injected from a mixer, with one of the faces of the body delimiting the plenum chamber being constituted by at least one combustion support on which combustion of the air-gas mixture takes place, thereby raising the surface of said suppor~ to a high temperature causing the support to radiate, a device for recovering the combustion products comprising a recovery chamber surro~ln~i n~ the plenum chamber and delimited by a gas-tight body whose wall parallel to the combustion support includes at least one gas-tight plate made of a material which transmits at C
~ 133578~
least a substantial portion of the infrared radiation and capable of withstanding high temperatures, and a flue for extracting the combustion products present in the recovery chamber, the burner further comprising a heat exchanger between the combustion products and the oxidizing air, said heat eYch~qer including an additional chamber which surrounds the combustion product recovery chamber in gas-tight manner except for the face constituted by the radiation-passing gas-tight plate, with the oxidizing air passing through said additional chamber, and with said additional chamber being put into communication with the air-gas mixing zone of the mixer.
The walls delimiting the recovery chamber and the additional chamber are made of a material which is a good conductor of heat in order to facilitate the heating of the oxidizing air passing through the additional chamber by means of the combustion products present in the recovery chamber.
The gas-tight plate is preferably made of a glass ceramic based material which may advantageously be translucent or transparent.
The combustion support may be constituted by a porous refractory material or by refractory ceramic tiling which is pierced by multiple small-diameter orifices.
Advantageously, the radiant burner further includes a confinement screen disposed parallel to the surface of the combustion support on its side opposite from the plenum chamber in order to improve heat exchange between the flame and the support.
The confinement screen may be embodied in various different ways.
In a first embodiment, the confinement screen is constituted by a metal screen made of refractory steel in the form of a large-mesh grid.
In another embodiment, the confinement screen is .~
~ 3a 133578~
constituted by a latticework of rods.
In another embodiment, the confinement screen comprises a ceramic plate.
The walls delimiting the plenum chamber and the recovery chamber, other than the radiation-passing gas-tight plate and the optional confinement screen are made of a material which is a good conductor of heat in order to facilitate heating the air-gas mixture contained in the plenum chamber by the combustion products present in the recovery chamber.
~2 ~ 133578S
As a result, a radiant burner in accordance with the invention avoids the major drawbacks of radiant panels and of radiant tubes while still retaining the advantages of each of these types of equipment, namely:
5high unit radiated power, thereby making it possible to use the apparatus in premises which are very tall;
the combustion products can be exhausted in a controlled manner, thereby preventing them from being diluted in the atmosphere of the premises or the enclosure 10being heated; and high radiation efficiency by virtue of the ease with which the heat lost by the combustion products can be recovered.
A radiant burner in accordance with the invention is suitable for heating enclosures such as ovens, drying 15rooms, etc. and also for heating large-volume premises such as workshops, factories, exhibition halls, or sales halls.
Other characteristics and advantages of the invention appear from the following description of a particular embodiment given by way of example and with reference to 20the accompanying drawing, in which:
Figure 1 is an axial section through a gas-fired radiant burner in accordance with the invention; and Figure 2 is a cross-section on line II-II of Figure 1.
The example of a radiant burner in accordance with the 25invention which is shown in Figures 1 and 2 comprises a plenum chamber 1 into which an air-gas mixture is injected by means of a converging-diverging nozzle 9 disposed horizontally, said mixture being provided by an atmospheric induction mixer. The nozzle 9 accelerates the air-gas 30mixture and improves the quality of mixing. The mixer is essentially constituted by a pre-mixing zone 8 into which the gas is injected by an injector 81 which opens out horizontally and which lies on the axis of the nozzle 9 facing the inlet thereto. The oxidizing air is itself 35injected into the pr~r;x;ng zone 8 after flowing along an additional outer chamber 6 in contact with the wall 51, 52 of the chamber 5 for collecting the combustion products, thereby preheating the air.
The plenum chamber 1 into which the nozzle 9 opens out 40is delimited by a substantially horizontal top wall 11, two B
1~ 5 1335785 vertical side walls 12 extending in the longitudinal direction of the burner on either side of the nn~ ., a vertical end wall 13 f~i ng the outlet from the nozzle 9, a vertical end wall 14 through which the air-gas mixture in;ection nozzle 9 is mounted, and a substantially horizontal bottom face 2. The ~oL~.. face is constituted by one or more refractory ceramic tiles 2 pierced by multiple small-dia~,e~el orifices 21 with com.bustion of the air-gas mixture taking place at the outlets of the orifices, thereby raising the surface of the tile(s) 2 to a high temperature c~ ing the tile(s) 2 to radiate.
A screen 3 in the form of a large mesh grid 31 made of stainless steel is disposed parallel to and beneath the tile(s) 2, i.e. adjacent to the face looking away from the plenum ~hamb~r 1. The screen 3 confines combustion and provides i~ ~v~d heat exchange between the hot gas and the ceramic tile(s).
The com.bustion products that pass through the screen 3 are pl~v~lted from escaping into the premises being heated by vir-tue of a glass ceramic plate 4 forming a gas-tight barrier which is placed beneath the screen 3 and at a distance therefrom, and is preferably parallel to the screen 3.
Vertical side walls 52 extend in the longitudinal direction of the burner outside the side walls 12 ~elimiting the plenum ch~m~P-r 1 containing the air-gas mixture, and at a distance from said walls 12. A top horizontal wall 51 extends horizon-tally over the top horizontal wall 11 of the plenum chamber 1 at a distance therefrom. This forms a recovery chamber 5 for recovering the combustion products and surrounding the plenum chamber 1, with said recovery chamher 5 being ~Ql im;ted by a set of gas-tight walls (walls 51, 52, and vertical extensions of the end walls 13 and 14 of the plenum cham.ber 1) and the top of the recovery chamber 5 is in com.munication with a flue 7 for extracting the combustion products present in the recovery ~h~mh~ 5.
The com.bustion products are thus channelled through a recovery chamber 5 of the double-walled type which includes walls 11 and 12 for exchanging heat with the air-gas mixture in 6 133~
the plenum chamber 1. The combustion products thus give a portion of their energy to the air-gas mixture, thereby ~o.l~libuting to i~ uving ef~;r;~nr.y.
The "triple-walled" type configuration shown in Figures 1 and 2 with an additional outer chamber 6 for ~ollv~ying the ~xi ~i ~i ng air and including heat exchange walls 51 and 52 for ~xrh~ng~ng heat with the combustion products in the recovery chamber 5 serves, addi~ion~lly to preheat the oxidizing air.
The side walls 62 and the top wall 61 of the nxi~i ~ing air inlet chamber 6, and also the end walls of the burner (situated to the right and the left of Figure 1) may be coated internally or extern~lly with thermally insulating material in order to reduce heat loss via these outer walls of the apparatus.
The heat provided by the radiant burner is thus transmitted almost exclusively through the glass ceramic plate 4 which, in addition to constituting a barrier for the combus-tion products also relays the radiation emitted by the tile(s) 2 efficiently. The plate 4 is made of a glass ceramic based material and is preferably transparent or translucent.
Apparatus in accordance with the invention can thus radiate a large amount of power by virtue of its high operating t~m~Prature made possible by using a plate of glass ceramic material or the like which is capable of withstanding high t~mreratures while passing radiation.
Further, the radiation efficiency of the radiant burner is high since the energy lost to the PXh~ t is easily recovered by means of the double-walled envelope and since the ~xh~ t is not diluted with ambient air.
A radiant burner of the invention may be used for heating premises and may deliver power lying in the range about 100 kW/m2 to 150 kW/m2 of radiating ceramic tile area giving rise to a ceramic tile ~"~euature of about 900C with radiation efficiency of about 60%.
The radiant burner may also be used in like manner for heating enclosures (ovens, drying rooms, etc.) in which case it may deliver power at more than about 150 kW/m2 of radiating ceramic tile area giving rise to a ceramic tile temperature of about 1100C with radiation efficiency of about 55%.
7 133~785 Various mo~;f;~Ations and additions may be applied to the ~o~;m~nts described with reference to Figures 1 and 2.
Thus, in the event that the oxidizing air and exhaust heat exchanger (walls 51, 52) gives rise to too much p~e~sure-drop in the air supply circuit, an nX;~; ~;ng air fan may be added in order to co-operate with the premixing chamber 8 of the mixer and/or an extractor fan may be added to facilitate the extraction of combustion products via the flue 7.
The nozzle 9, and the heat exchange walls 11, 12 or 51, 52 of the double- or triple-walled enclosure may be made of st~; n 1 e~s steel, for Rxample.
In a variant, the co-mbustion support 2 may be made of a porous refractory material.
The confinement screen 3 may also have configurations other than that described with reference to Figures 1 and 2.
Thus, the screen 3 may be constituted by a lattice of rods or by a gas-passing ceramic plate or even, in some cases, by a metal grid having relatively small mesh size.
Further, it has been assumed above that the bright radiant face 4 of the radiant burner is placed beneath the burner and is horizontal. Naturally, the burner assembly may be tilted in order to direct its radiating face in a direction which is to receive most heat. In most cases, the radiating face 4 is either horizontal or else inclined to form an angle with the horizontal which is less than about 60. The burner is still capable of operating with its radiating face in a vertical position, however its efficiency is likely to be slightly reduced in comparison with operation having the radiating face horizontal or inclined at less than 60 relative to the horizontal.
Claims (14)
1. A gas-fired radiant burner for emitting infrared heating radiation, the burner comprising a body having a plenum chamber into which an air-gas mixture is injected from a mixer, with one of the faces of the body delimiting the plenum chamber being constituted by at least one combustion support on which combustion of the air-gas mixture takes place, thereby raising the surface of said support to a high temperature causing the support to radiate, a device for recovering the combustion products comprising a recovery chamber surrounding the plenum chamber and delimited by a gas-tight body whose wall parallel to the combustion support includes at least one gas-tight plate made of a material which transmits at least a substantial portion of the infrared radiation and capable of withstanding high temperatures, and a flue for extracting the combustion products present in the recovery chamber, the burner further comprising a heat exchanger between the combustion products and the oxidizing air, said heat exchanger including an additional chamber which surrounds the combustion product recovery chamber in gas-tight manner except for the face constituted by the radiation-passing gas-tight plate, with the oxidizing air passing through said additional chamber, and with said additional chamber being put into communication with the air-gas mixing zone of the mixer.
2. A radiant burner according to claim 1, wherein the walls delimiting the recovery chamber and the additional chamber are made of a material which is a good conductor of heat in order to facilitate the heating of the oxidizing air passing through the additional chamber by means of the combustion products present in the recover chamber.
3. A radiant burner according to claim 1, further including a lining providing thermal insulation of the outer walls of the additional chamber.
4. A burner according to claim 1, wherein said radiation-passing gas-tight plate is made of a glass ceramic based material.
5. A burner according to claim 1, wherein the combustion support is made of a porous refractory material.
6. A burner according to claim 1, wherein the combustion support is made of a refractory ceramic tiling which is pierced by multiple small-diameter orifices.
7. A burner according to claim 1, further including a confinement screen disposed parallel to the surface of the combustion support on its side facing away from the plenum chamber in order to improve heat exchange between the flame and the combustion support.
8. A burner according to claim 7, wherein the confinement screen is constituted by a metal screen made of refractory steel and in the form of a large mesh grid.
9. A burner according to claim 7, wherein the confinement screen is constituted by a latticework of rods.
10. A burner according to claim 7, wherein the confinement screen comprises a ceramic plate.
11. A radiant burner according to claim 1, wherein the air-gas mixing zone of the mixer is connected to the plenum chamber by a nozzle.
12. A radiant burner according to claim 1, wherein the walls delimiting the plenum chamber and the recovery chamber, other than the radiation-passing gas-tight plate and the optional confinement screen are made of a material which is a good conductor of heat in order to facilitate heating the air-gas mixture contained in the plenum chamber by the combustion products present in the recovery chamber.
13. A radiant burner according to claim 1, wherein the radiation-passing gas-tight plate is made of a glass ceramic which is transparent or translucent.
14. A radiant burner according to claim 1, further including a fan for propelling the oxidizing air and co-operating with the mixer and/or an extractor fan co-operating with the flue for extracting the combustion products.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8716902A FR2624253B1 (en) | 1987-12-04 | 1987-12-04 | RADIANT GAS BURNER |
| FR8716902 | 1987-12-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1335785C true CA1335785C (en) | 1995-06-06 |
Family
ID=9357511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000584819A Expired - Lifetime CA1335785C (en) | 1987-12-04 | 1988-12-02 | Gas-fired radiant burner |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JP2621121B2 (en) |
| KR (1) | KR0132676B1 (en) |
| BE (1) | BE1010217A3 (en) |
| CA (1) | CA1335785C (en) |
| CH (1) | CH678222A5 (en) |
| FR (1) | FR2624253B1 (en) |
| GB (1) | GB2213254B (en) |
| IT (1) | IT1223967B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03125612A (en) * | 1989-10-11 | 1991-05-29 | Yokohama Rubber Co Ltd:The | Pneumatic tire for passenger car |
| JPH07121646B2 (en) * | 1989-11-17 | 1995-12-25 | 住友ゴム工業株式会社 | Tire and rim assembly |
| EP0457954B1 (en) * | 1990-05-25 | 1994-05-25 | Schwank GmbH | Radiant burner |
| NL9301581A (en) * | 1993-09-13 | 1995-04-03 | Gastec Nv | Compact gas-fired infrared radiator in closed design. |
| EP1016826B1 (en) * | 1998-12-28 | 2004-11-24 | Robert Bosch Gmbh | Gas burner and method of operating the same |
| ITMI20020449A1 (en) * | 2002-03-04 | 2003-09-04 | Fondital Fonderie Italiane Nuo | GAS BURNER AND GAS RADIATOR EQUIPPED WITH SUCH BURNER |
| US7116900B2 (en) * | 2003-04-01 | 2006-10-03 | Radiant Optics, Inc. | Radiant energy source systems, devices, and methods capturing, controlling, or recycling gas flows |
| US7757685B2 (en) | 2003-11-27 | 2010-07-20 | Lg Electronics Inc. | Radiation burner |
| US7721726B2 (en) | 2006-01-03 | 2010-05-25 | Lg Electronics Inc. | Gas radiation burner |
| CN104864421A (en) * | 2015-06-02 | 2015-08-26 | 天津大学 | Totally-enclosed infrared heating frying cooker |
| US11808461B2 (en) * | 2019-12-20 | 2023-11-07 | Detroit Radiant Products Company | Radiant heater assembly |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB635531A (en) * | 1948-04-28 | 1950-04-12 | Ronald Geoffrey Brocken | Improvements in or relating to gas-fired infra-red emitters |
| GB813101A (en) * | 1954-08-04 | 1959-05-06 | Hi Ro Heating Corp | Improvements in or relating to method and apparatus for infrared radiant heating |
| DE1164059B (en) * | 1957-05-07 | 1964-02-27 | Bourguignonne De Mecanique Sar | Heat radiator with flameless surface combustion, especially for space heating |
| US3237679A (en) * | 1962-01-11 | 1966-03-01 | Thermal Engr Corp | Radiant burner with vented burner surface |
| US3299938A (en) * | 1965-03-29 | 1967-01-24 | Corning Glass Works | Gas-fired radiant burner |
| DD100794A1 (en) * | 1972-12-08 | 1973-10-05 | ||
| DE3012588C2 (en) * | 1980-04-01 | 1983-09-08 | Schwank GmbH, 5000 Köln | Radiant burners, especially for gaseous fuel |
| US4639213A (en) * | 1984-12-17 | 1987-01-27 | Solaronics, Inc. | Confined spaced infrared burner system and method of operation |
| DE3516012A1 (en) * | 1985-05-03 | 1986-11-06 | Karl-Heinz 2000 Wedel Francke | HEATING UNIT WITH A BURNER AND A HEAT EXCHANGER |
| US4785552A (en) * | 1987-07-08 | 1988-11-22 | Best Willie H | Convection stabilized radiant oven |
-
1987
- 1987-12-04 FR FR8716902A patent/FR2624253B1/en not_active Expired - Lifetime
-
1988
- 1988-11-28 GB GB8827705A patent/GB2213254B/en not_active Expired - Lifetime
- 1988-11-29 JP JP63299786A patent/JP2621121B2/en not_active Expired - Lifetime
- 1988-11-30 KR KR1019880015845A patent/KR0132676B1/en not_active IP Right Cessation
- 1988-12-02 BE BE8801360A patent/BE1010217A3/en not_active IP Right Cessation
- 1988-12-02 CH CH4491/88A patent/CH678222A5/fr not_active IP Right Cessation
- 1988-12-02 IT IT68082/88A patent/IT1223967B/en active
- 1988-12-02 CA CA000584819A patent/CA1335785C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CH678222A5 (en) | 1991-08-15 |
| KR890010492A (en) | 1989-08-09 |
| FR2624253B1 (en) | 1991-11-15 |
| FR2624253A1 (en) | 1989-06-09 |
| IT1223967B (en) | 1990-09-29 |
| GB2213254B (en) | 1991-11-13 |
| BE1010217A3 (en) | 1998-04-07 |
| GB2213254A (en) | 1989-08-09 |
| KR0132676B1 (en) | 1998-04-15 |
| GB8827705D0 (en) | 1988-12-29 |
| IT8868082A0 (en) | 1988-12-02 |
| JPH0237205A (en) | 1990-02-07 |
| JP2621121B2 (en) | 1997-06-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |