US1223249A - Process for producing heat. - Google Patents

Description

w. A. BONE, 1.. w. WILSON & c. D. McCOURT. PROCESS FOR PRODUCING HEAT. APPLICATION FILED NOV. 18 I911- RENEWED FEB. 3, I91].

1,223,249. Patented Apr. 17,1917.

- g $1M 0140M ATTORNEYS BONE, of Leeds, in the county of York, JAMES WILLIAM WILSON, of Armley, Leeds,

. UNITED STATES PATENT OFFICE,

WILLIAM ARTHUR BONE, OF LEEDS, JAMES WILLIAM WILSON, OF ARMLEY, LEEDS, AND GYIRIL DOUGLAS McCOURT, OF LONDON, ENGLAND, ASSIGNORS TO RADIANT HEAT- ING LIMITED, 0]? LONDON, ENGLAND, A CORPORATION OF GREAT BRITAIN.

, rnocnss roe rnonucme HEAT.

Specification of Letters Patent.

Patented Apr. 17, 1917.

Original application filed October 8, 1910, Serial No. 586,058. Divided and this application filed November 18, 1911 Serial. No. 661,103. n Renewed February 3, 1917. Serial No. -146,514.-

To all whom it may concern:

Be it known that we, WILLIAM ARTHUR in the said county, and CYRIL DOUGLAS Mo- COURT, of Balham Hill, London, S. W., England, have made certain new and useful Inventions Relating to Processes for Producing Heat, of which the following is a specification, taken in connection with the accompanying drawings, which form part of the same.

This invention relates toprocesses for,

utilizing the accelerating influence of the incandescentsurface of a porous refractory diaphragm upon the combustion of a suitable explosive mixture of gaseous fuel and air fed through the diaphragm toward its incandescent, outer surface, so that a large proportion of the potential energy of the fuel is liberated as radiant energy from the incandescent surface so as to be available in connection with many industrial gas heating operations. When an exploslve mixture of coal gas and air, for instance, in

their: combining proportions or .with air in slight excess-thereof is forced at, a sufliciently high velocity to prevent back firing through the pores or interstices of a' suitable porous refractory diaphragm into its incandescent surface layer a many fold accelerated and substantially fiameless combustion of the gas takes place within the interstices, pores or parts of the incandescent diaphragm layer which are more or less impregnated or in contact with the gaseous mixture; and energy thus developed by this in- -tensified complete and efiicient combustion is absorbed by the adjacent surface layer of the diaphragm and maintains it in a state of incandescence, thus securin a very convenient and efiicient source 0 radiant energy. This highly accelerated or intensified surface combustion seems to be due to the emission of char ed corpuscles or electrons from such incan escent solids, and the consequent formation of layers of electrified gas in which the chemical changes incident to combustion proceed with extraordinary rapidity. It has been demonstrated that the incandescent solid plays anactive and important part in the combustion of the'explosive gaseous mlxture under these condi tions, the particles of the incandescent solid apparently forming a composite system with the adjacent molecules of the combining gases, so that'such combustion complex acts 1n a manner very different from what occurs in normal flame combustion. For example it has been proved that the presence of water vapor certalnly accelerates, if it is not essen t1a1 to, the, normal flame combustion of car bon monoxid" in air or oxygen, whereas the 1 presence of even a small quantity of water vapor such as will saturate the gases at 18 C. greatly retards the surface combustion of an explosive mixture of carbon monoxid and oxygen in contact with heated fire clay sur-' faces, the reaction constant falling from .20 to Another thing which indicates the dlstlnctive and qualitative difl'erence'between such surface combustion and normal tion of a large variety of combustible gaseous material, as for example blast furnace gas, producer gas, water gas, which may be carbureted, coke oven gas, coal. gas, petrol air gas and similar hydrocarbon gas and other combustible vapors, natural gas and mixtures thereof, all of which'are hereinafter refered to ascombustible gases, al

' though .the temperature attainable in any particular casewill naturally depend upon the calorific intensity of the gaseous material employed. The combustible gas is combined with air or other available supporter of combustion preferably in substantially the combining proportions or with a slight excess or deficiency of air, although the proportions of the constituent gaseous materials may vary considerably and still secure an explosive gaseous mixture, such as is capable of explos ve combustlon or inflammation," possibly .under, conditions of increased pressure and temperature. I

The accompanymg drawlngs show 1n a somewhat diagrammatic way certain illuspermeable diaphragm A of sufliciently re-- fractory material in conjunction with a chamber or casing C. The porous diaphragm constitutes one wall of the chamber, into which an explosive gaseous mixture is led through a pipe or from any desired injecting or mixing device such as the con nected Y pipes shown for connection with the ultimate sources of combustible gas and air or the like under the proper pressure.

' The inixture passes through the diaphragm and is caused to ignite on the face of exit E or in close proximity thereto. For instance a combustible mixture of coal gas and air in proper proportions and at various pressures, examples of which are hereinafter given, may be used for many household and industrial purposes. The supply of gas and air-in proper portions is preferably suitably regulated by ordinary means, so that the combustion may take place substantially within the diaphragm surface 'layer one eighth of an inch or so thick. The regulation' of the supply of the mixture having been adjusted, the face E of the diaphragm A becomes incandescent, and is maintained in a heated or incandescent stateby the continued flow of the combustible mixture through the porous diaphragm, and its com- .bustion within the surface layer of same. The flow can beregulated so that little or no flame appears beyond the surface of the diaphragm while the said surface ismaintained in a state of glow or incandescence. With regard to the combustible mixture the proportions of the combining gases will preferably be substantially the proportions necessary for complete combustion. In general with coal gas, we prefer to employ a little excess of air: For example, in the case of a coal gas whlch theoretically requires about five and a half times its own volume of air for complete combustion, we have obtained good results with about seven times its own volume of ail.

The joint between the diaphragm A and its seating S maybe of white lead or an asbestos paste or other suitable luting material, and any suitable retainer or ring R may be used to secure the porous diaphragm in position. The margin of the diaphragm may be glazed so as to prevent escape of gas through its edges. The diaphragm may" be arranged in various ways'de'pending on the object in view, and in some cases more vtory materials.

masses than one diaphragm may be employed. The

diaphragms may also be placedhorizontally,

vertically or at any desired angle and the diaphragm unit may be so turned that the heated external surface may be either the superior or inferior surface. Itshould be noted however that where there is, with any particular mixture of gases a tendency to heat the diaphragm so much as to cause back firing, the arrangement must be such as to utilize or convey away the heat with sufficient rapidity to prevent such back firing. For instance, in using water-gas there is always a tendency to back fire, but this may be in a large measure counteracted by employing diaphragms of a closer or less permeable texture so as to produce a steeper pressure gradient in the diaphragm, thereby increasing the-velocity of flow of the explosive gaseous mixture through the diaphragm. Accordingly it is desirable in any given case to select from a series of diaphragms 'of different permeabilities that diaphragm which on trial is found to be sufficiently impervious to prevent back firing under the given conditions. Also the tendency to back fire may be checked by mixing a larger proportion of inert gas or air with the combustible mixture. Further, where there is risk of backfiring the progressive accu- 'mulation ofheat in a'confined space must be avoided. On the other hand when using poor gases as for example blast furnace gas, the production of the glow or incandescence depends on conserving a certain amount of the lreat on the surface of the diaphragm.

The diaphragms may be produced from various materials either separately or in combination, and may vary considerably in their nature, shape and construction, exam-. ples of which are hereinafter specified. But,

it must be understood 'thatwe do not confine ourselves solely to the said examples and on the-side ofexit of the gaseous mixture as shown in Fig. 2. In the production of the diaphragms suitable refractory materials are employed and combined so as to give the desired degree of porosity and permeability somewhat in the manner usual in the production of porous refractory blocks. 'Materials of a nature to burn out and leave pores or interstices may be combined with refrac- For example we have used mixtures of fire clay with fine seed, bran and spongy plumbago produced-by acting on Ceylon flake plumbago with strong fuming nitric acid and applying heat. The degree of porosity will be determined by the quantity seed is specially suitable for this purpose.

The proportions will vary somewhat with the nature of the clay employed, some clays being by nature when burnt more porous than others, and in every case it is necessary to determine by trial the proper proportions for producing a desired degree of porosity. But the examples which we will give will serve to indicate in some measure the nature of the mixtures which are found suitable in practice. In making diaphragms suitable for working with coal gas and air at a pressure of six inches water gage, we mix 18 parts by weight of powdered Stourbridge fire clay in the dry state with 8 parts by weight of English rape-seed, and mix therewith sufiicient water to render the mixture suitable for molding. It will be found that the plasticity of the mixture becomes rapidly lost on standing owing to the absorption of the water by the dry seed. Only sufficient of the mixture should be made to suit immediate requirements, and vthe dlaphragms should be molded immediately after the mix-.

ture is made'and before it has lost its plasticity. To obviate in part the loss of plasticity hereinbefore mentioned the rape-seed may be steeped in water prior to mixing with the clay. The molded diaphragms are carefully dried, baked and burned in an oxidizing atmosphere so as to insure the complete burning out ofv the seed. After 'burning, that surface of the diaphragm which is to form the heated surface is preferably roughened with a rasp, sand blast, or

by any other known means. Or both surfaces of the diaphragm may be so roughened.

By employing the above mentioned proportions we have made diaphragms which when three quarters of an inch thickare able at a pressure .of six inches water-gage to admit of a flow per square inch of heating surface of 6.4 cu. ft. per hour of a gaseous mixture consisting of one volume of gas with 6 or 7 volumes of air. By employing a mixture consisting of 18 parts by weight of dry powdered Stourbridge fire clay with 12 parts by weight of English rape-seed we have made diaphragms which when three quarters of an inch thick admit of the same gaseousflow at a pressure of'one inch watergage.

Another method of making porous diaphragms consists in consolidating a mass of granules orfragments most desirable of porous or non-vitreous refractory material in such'a manner as to leave pores or interstic'es throughout the mass. For example burnt fire clay coarsely ground and preferably meshed to a uniform size mixed with a powder adapted to act as a cementing material when highly heated may be molded in the form of the diaphragm required, and burned. Thus for. working at a pressure of about one-quarter of an inch water gage,

with a mixture ofcoal gas and air the grade of fragments employed is that which passes through a sieve of eight meshes to the linear inch but will not pass a sieve of sixteen meshes j to the linear inch when the thickness of the diaphragm is about an inch to an inch and a half. These fragments may be moistened, mixed with onetenth of their weight of finely ground feldspar and molded or disposed into the tains subject-matter taken from our copending United States application, Serial No.

586,058, filed October 8, 1910. Having described these inventions in connection with a number of illustrative. embodiments, ar-. rangements, proportions, materials, pressures, conditions, processes and orders of steps, to the details of which disclosurethe inventions are not of course to be limited, what is claimed as new and what is desired to be secured as Letters Patent is set forth in the appendedclaims;

1. The process of producing heat which consists in combining a combustible gas and a combustion supporting gas in proportions to form an explosive gaseous mixture, maintaining a supply of the explosive mixture thus formed against one face of a porous refractory diaphragm under a pressure to cause the mixture to flow, at a speed suflicient to normally prevent back-firing, through the passages of. the diaphragm to a highly heated surface layer thereof, and effecting combustionv of the mixture within said within the surface layer of the diaphragm highly, heated surface layer ofthe dia-J phragm, whereby the combustion is localized and such surface layer is maintained in a state of incandescenc-e.

2 The process of producing heat which consists in. combining a combustible gas and a combustion supporting gas in proportions to form an explosive gaseous mixture, maintaining a supply of the explosive mixture thus formed against one face of a porous refractory diaphragm to @u'se the mixtureto flow through the passages of the dia phragm to a highly heated surface layer thereof, effecting combustion of the mixture within said highly heated surface layer of the diaphragm, and adjusting the pressure under which the mixture is supplied to maintain the combustion localized within the surface layer of the diaphragm, whereby such surface layer is maintained in a state of incandescence.

3. The process of burning explosive gaseous mixtures which consists in maintaining a supply of the explosive mixture against one face of a porous refractory diaphragm under a pressure to cause the mixture to "flow, at a speed suflicient to prevent backeous mixtures which consists in maintaining a supply of the explosive mixture against one face of a porous refractory diaphragm to cause the mixture to flow through the passages of the diaphragm to a highly heated surface layer thereof, effecting @mbus' tion of the mixture within said highly heated surface layer of the diaphragm, and adjusting the pressure under which the mixture is supplied to maintain the combustion localized within the surface layer of the diaphragm, whereby the surface layer of the diaphragm is maintained in a state of incandescence.

5. The process of producing heat which neaaaee consists in'combining a combustible gas and a combustion supporting gas in proportions to form an explosive gaseous mixture with the amount of combustion supporting gas somewhat in excess of the amount required for complete combustion of the combustible gas, maintaining a supply of the explosive mixture thus formed against one face of a porous refractory diaphragm to cause the mixture to flow through the passages of the diaphragm to a highly heated surface layer thereof, effecting combustion of the mixture within said highly heated surface layer of the diaphragm, and adjusting the pressure under which the mixture. is supplied to maintain the combustion localized within the surface layer of the diaphragm, whereby such surface layer is maintained in a state of incandescence.

6. The process of burning explosive gaseous mixtures which consists in maintaining a supply of the explosive mixture against one face of a porous refractory diaphragm of porous combustion accelerating material to cause the mixture to fiow through the passages of the diaphragm to a highly heated surface layer thereof, effecting combustion of the mixture within said highly heated surface of the diaphragm, and adjusting the pressure under which the mixture is supplied to maintain the combustion localized within the surface layer of the diaphragm, whereby the surface layer ofthe diaphragm is maintained in a state of incandescence.

WILLIAM ARTHUR BONE. JAMES WILLIAM WILSON. CYRIL DOUGLAS MGCOURT. Witnesses:

KATE BO E, PERCY GELDART.

Images