US 2044511 A
Description (OCR text may contain errors)
.lumev 16, 1936. E. RYscHKl-:wlTscH BURNER Filed Feb. 9, 1931 Patented `une 165, 1936 UNITED STATE PATEN BURNER v Eugen Ryschlxewitsch,` y Frankfort-on-thefMain,
Germany 14 Claims.
'Ihe essential idea of the invention is that inv l the inner space of the burner (e. g.'a gas burner or the like), in which the combustion of a. combustible gas mixed with air or oxygen takes place, the surface which accelerates catalytically the combustion process is enlarged by the arrangement of projections (e. g. by ribs running along the walls or by special built-in portions) which are arranged to run in the direction of flow of fuel stream, so that the speed of travel through the burner of the gaseous mixture is only immaterially diminished.
The favourable inuence on the combustion process arises in a particularly high measure from the fact that the enlarged surface in the burner is formed of, or is covered with, materials which produce a strong emission of electrons at high temperatures. For this, the oxides of the alkaline earths and other high temperature-Withstanding oxides, as magnesium oxide, zirconium oxide, thorium oxide and others, having proved suitable.
It has been proved that for any predetermined amount of a chosen fuel to be burnt in a unit of time a certain minimum size of contact surface in the combustion space is requisite. This depends on the temperature in the combustion space and the nature of the materials of construction.
As an example it may be given: that taking illuminating gas and a temperature of about 180020009 C., for the contact combustion of 1 cubic meter of the gas per hour a total surface in the combustion space of at least 200 square centimeters is required if the constructional material is magnesia. The gas-and air mixture should be brought into as complete a contact as possible with the contact surface.
It should be recognized from this that the narrowest possible capillary intermediate space hitherto always employed is not required, but one should provide comparatively wide passages and intermediate spaces which should be all the wider as the length of the combustion zone increases. By way of example: it is suitable for a length of combustion space of about mm. to select about 55 5 to 6 mm. for' an average distance between oppositely lying contact surfaces; for a length of 800 mm., an average distance of about 40 mm., and so on.
The size of the combustion space should be determined so that the time during which the fuel gases are in the combustion space is about 1 50 to 1/200 second when the furnace is at about 2000 C.
For the practical embodiment, then, certain limits for the ratio of the contact surface to the combustion space result from a consideration of these points, and indeed it has been demonstrated that for one litre of combustion space not less than about 15 square decimeters, preferably about 20 dmz, of contact surface, should be employed. These instructions hold good both when operating the burner with a gaseous fuel and in the case of use of finely divided liquid fuels or pulverized fuels.
The contact surface accelerates the rapidity of the combustion reaction so much that the chemicalchange takes place completely in the time specied. comparatively large intermediate spaces between suitably disposed contact surfaces, which in general should run in the direction of the gas stream, allow very low pressures to be used on the reacting gases for driving the latter through the combustion space. It is sulcient to have the usual gas pressure of about 20-40 mm. of water and the comparatively very low pressure of a centrifugal fan, as low as mm. water, in order to operate the herein-described burner. By this means temperatures can be obtained which lie far above those otherwise obtainable in like circumstances.
In the accompanying drawing different constructional forms of the invention are given by Way of example. Y
Fig. 1 shows a burner in accordance with the invention in longitudinal section,
Fig'. 2 shows a burner as in Fig. 1 but in plan view with the central inset body omitted,
Figures 3 and 4 are similar views of a further constructional form thereof.
In Figure l the reference numeral l represents a housing, made for example of cast iron, on which a gas inlet connection 2 is arranged. 'Ihe connection 2 of the gas inlet is provided with nozzles 3 which are in communication with the atmosphere so that the iniiowing gases draw in a suitable amount of air. The internal construction of the burner housing consists essentially of a refractory lining sleeve v4 and a mantle or burner body proper 5 which can be suitably constructed of a number of separate parts 1 aslcommunication through openings ID with the atmosphere, or with a' supply of compressed air under suitable pressure e. g. as low as 100 mm. water pressure, and through openings Il with the combustion space. In Fig. 2 the re proof inset body 8 is omitted, so that the interior of the burner is not covered in the illustration.
In such a gas burner, the gaseous fuel streaming into the burner through the gas connection 2 draws in a certain amount o! air and with thel air entering at Il burns completely in the combustion space lying between the ribs 1 and the inset body 8. On account of the relatively low thickness which the gas layer lling the combustion space has at every point between the ribs 1, or between these and the inset body 8, every particle is subject to the intensive action of the electron-emitting surface of the burner so that on a comparatively short passage a complete combustion even of low value gases with extraordinary high temperature increase can be obtained. The effect is enhanced owing to the air entering at 9 being intensively preheated in the circular space between the burner body 5 and the outer wall 4. Similarly the effect can be increased by high preheating of the combustible gases, e. g. to 500 C. and higher.
In Figures 3 and 4 a further constructional form is illustrated in which the internal components I1 are annular and are supported from each other by radial ribs or distance pieces I8.
Burners ofthe described kind can be employed advantageously wherever a high initial temperature with rapid combustion and complete utilization of the fuel is desired, as for example with boiler furnaces, with metal melting furnaces, and in numerous other instances. Particular advantages'ow also in the combustion of inferior fuel such as in the combustion of poor furnace gases, as` even in such cases an extraordinary high temperature can be obtained with the new burner constructions.
It may appear surprising that even withpulverized fuels such an effect is attainable; it is explained however in that, because of the high temperature in the burner-chamber, the combustion of the carbonaceous materials to carbon monoxide takes place exceptionally rapidly and completely, without Wall catalysis; and the further oxidation of the so formedcarbon-monoxide proceeds on the wall surface in 'the manner described with extreme acceleration.
, I claim:
1. A burner having a combustion chamber provided with a mantle divided into a plurality of annular sections, the interior of said mantle having inserted therein a plurality of bodies "made of catalytically acting material highly resistant to re, the inserted bodies dividing the interior of the combustion chamber into a plurality of canals whose length is at least equal to the diameter of the chamber and providing a construction, which oifers little resistance to the ow of the gaseous ,mixture and whereby the area of the catalytic contact surface of the combustion chamber is at least 15 square decimeters to one liter of combustion chamber volume.
2. A burner having a combustion chamber provided with a mantle divided into a plurality of 5 annular sections, the interior of said mantle having inserted therein a plurality of bodies made of catalytically acting material highly resistant to fire, the inserted bodies dividing the interior of the combustion chamber into a plurality of 10 canals whose length is at least equal to the width of the combustion chamber and is great relative to their transverse dimensions and providing a construction which offers little resistance to the flow of the gaseous mixture and whereby the area 15 -of the catalytic contact surface of the combuschamber into a plurality of straight channels 25 whose length is at least equal to the diameter of said chamber, whereby little resistance is oiered to the flow of the gas mixture and wherein the area of the catalytic contact surfaces is at least four hundred square decimeters for a 30 consumption of one kilogram of combustible ma terial per hour.
- 4. A burner having a catalytic combustion chamber, said chamber having a lining composed -of a plurality of readily interchangeable annular 35 sections, said annular sections carrying independent annular bodies of catalytic material highly resistant to fire and dividing the combustion chamber into a plurality of concentric passages which are at least equal in length to the diameter of the chamber, said inserted bodies oifering little resistance to the flow of fuel.
5. A construction as dened in claim 1 in which the inserted bodies are interchangeable and consist of materials of high electron emitting powers. 45
6. A construction as defined in claim 1 in which the inserted bodies are interchangeable and are composed of metallic earth oxides.
'7. A burner having a combustion chamber, said burner having a mantle composed of a. plurality of annular sections in the interior of which are inserted a plurality of bodies of catalytic material which is highlyresistant to ire, said bodies dividing the combustion chamber into a plurality of straight channels and providing a comparatively large combustion contact sin'face, the said channels having a great length relative to the transverse dimension of the chamber and oifering little resistance to the flow of the gas mixture, the width of the catalytically acting combustion channels varrying from 5 mm. to about 40 mm., where the length of the combustion chamber varies from 80 mm. to about 800 mm.
8. A burner having a combustion chamber provided with a mantle', the interior of the said man- 65 tle having inserted therein a plurality of bodies made of catalytically acting material highly resistant to fire, the inserted bodies dividing the interior of the combustion chamber into aplurality of canals whose length is great relative to the transverse dimension of the chamber and providing a construction, which offers little resistance to'the flow of the gaseous mixture and whereby the area of the catalytic contact surface of the combustion chamber is at least 15 square 75 decimeters to one liter of combustion chamber volume.
9. A burner for fluent fuel said burner having a combustion chamber provided with a refractory mantle and elongated relatively thin bodies of fire resistant material of high electron emitting power alined with the direction of fuel ow, said bodies dividing the combustion chamber into relatively straight long narrow unobstructed channels extending in the directionof flow of the fuel, said channels having relatively large catalytic wall surface as compared with the cubical contents of the chamber, substantially as set forth.
10.' A device as in claim 9, the catalytic surface being at least 15 square decimeters to l liter of space in said chamber.
11. A device as in claim 9, the width of the channel being about 1/15 to l/20 of the length of the combustion chamber.
12. A device as in claim 9, said refractory mantle being divided into annular sections each carrying independent sets of catalytic bodies.
13. A device as in claim 9, the catalytic surface being at least l5 square declmeters to 1 liter of I space in said chamber, the width of the channels being about l/15 to 1/20 of the length of said chamber, and the refractory mantle being divided into annular sections each carrying independent sets of catalytic bodies.
14. A burner for iluent fuels having a combustion chamber, a mantle in said chamber having supporting internal members of fire-resistant material acting catalytically on such fuels, said members being of relatively great length in proportion to their thickness and extending lengthwise of the combustion chamber, so as to provide long, straight narrow unobstructed channels with a large catalytic wall surface, substantially as set forth.