US1751849A - Gas-making process - Google Patents

Description

March 25, 1930. UN 1,751,849

GAS MAKING PROCESS Filed June 22. 1922 Q Q Q. Ill-II N T a i Qki m m1 IQ R a R N N DQYZiZJEZIR.

Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE DANIEL J'. YOUNG, OF TACOMA, WASHINGTON, ASSIGNOR TO YOUNG-WHITWELL GAS PROCESS COMPANY, OF TACOMA, WASHINGTON, A CORPORATION OF WASHINGTON GAS-MAKING rnocnss Application filed .Tune 22,

The invention relates to the manufacture of carbureted water gas having as a basis of the present process, the prior standard process carried out in a standard three-shell set comprising a single generator, a single carburetor and a single superheater.

The object of the invention is to improve on the former practice, resulting in increased flexibility of operation, and the production of cheaper gas. I 7

An apparatus for carrying out my process may be obtained by slightly modifying an ordinary Water gas set.

in the set is shown in vertical section. In this apparatus, 1, 2 and 3 representrespective ly a water gas generator, carburetor and superheater, these being in the main the same as are now commonly used in making water as. a The generator has the customary grate 11, an ash pit 10 to which air for the blast is supplied through a pipe as 50 and steam is supplied formaking gas, as through pipe 6, these pipes being controlled by valves 51 and 60. A gas offtake pipe 7 may also be connected to the base of the generator. A second steam' supply pipe 61 and controlling valve 60 may be connected directly with the top of the generator and gas withdrawn directly from the generator for special uses if desired. Like= Wise, gas may, if desired, be removed directly from the top of the generator as by pipe 91. Pipes 7 and 91 may be provided with valves as 70 and 92. Pipes for the admission of sec ondary air to the carburetor and superheater as 52 and 54 and controlled by the valves 53 and 55 are provided.

The carburetor 2 has the usual checkerbrick 23 and chamber 20 at the bottom and the superheater 3 has its checkerbrick 33, bottom chamber 30, andstack valve 32, as is common in Water gas sets. The bottom chambers 20 and 30 of carburetor'and superheater are connected by a pipe l3 in the usual way. The

Such an apparatus is shown by the accompanying drawing where- 1922. Serial No. 570,207.

of the generator employed in the usual water gas set are or may be omitted. The carburetor may have means, as pipe 21, through which oil may be supplied to enrich the water gas. The offtake for gas usual in water gas practice, as 31, may be provided with a valve as 34. In modifying a water gas set for carrying out my process I provide means for introducing steam at the end of the set furthest removed from the generator, that is at the point where the gas is discharged in standard water gas practice. Pipe 62 controlled by valve indicates such a steamsuppl-y. I have also shown a steam supply pipe 64 discharging into the bottom of the carburetor and at 61 discharging directlyto the top of the generator. \Vhile the location of pipe 62 is that preferred, other locations as that of pipes 64 and 61, nearer to the reactive portions of the fuel bed in the generator, may be employed.

I also modify the standard water gas set by providing means for introducing finely di vided fuel into the generator above the fuel bed. The means indicated in the drawing is to be considered only as typical and not as the only suitable means. This shows a hopper or feed bin 8, a feed screw 80 discharging into a pipe ,81 which discharges into the generator and a distributing device comprising a' disk 90 carried in the generator in position to receive thereon the discharged fuel and revoluble with its supporting shaft 9. There may also be provided a device with which the surface of the fuel bed may be rabbled or otherwise agitated so as to permit of the ready flow of gases therethrough. The fuel supplying means illustrated are recognized as being of a rudimentary character and capable of further refinement of design.

' One of the important features of the present invention it'its extreme flexibility, making use of the former standard three-shell apparatus and process, so far as possible, utilizing the valuable features of such standard apparatus, and eliminating such features as were undesirable. The old appartaus was inflexible in its operation; the present invention renders the old apparatus flexible without in any way detracting from the merits of the old process and apparatus.

In common with the old process, the first step in my process is an air blasting operation designed to heat the checkerbrick of the carburetor and superheater. In this step air 5 may be supplied beneath the fuel bed of the generator through the pipe 50 controlled by valve 51. This air passes upwardly through the fuel bed of the generator, heating the same to incandescence and producing blast gases which pass through pipe 4 to the carburetor 2, highly heating the checkerbrick 23 therein, and passing through pipe 43 from the carburetor to the superheater 3, progressing upwardly through the superheater, heating the checkerbrick 33, and passing out through the stack 32 to the atmosphere. Auxiliary air may be admitted through pipe 52 to the carbutor and through pipe 54 to the superheater for completing combustionof the blast gases. 0 The temperatures in the various parts of the apparatus may be controlled by relative quantity of auxiliary air admitted at these two locations. Preferably the temperature at the top of the carburetor is the maximum in the set, and the temperatures maintained in the superheater are somewhat lower.

In carrying out my process, the standard operation may be largely adhered to in the blasting step,except that the temperatures 3 may be somewhat higher. This may be desirable, as it permits the use of heavier oils than are ordinarily employed in the subsequent carbureting run. The process, however, is entirely flexible, and the temperatures may be regulated according to the necessities of the particular case.

The blasting step may if desired be followed by an up run, such as is employed in the standard operation. In this step, steam may be admitted through the pipe 6, passed upwardly through the fuel bed of the generator, where the steam is dissociated into its con- -stituent elements of hydrogen and oxygen, producing water gas. The water gas-passes from the top of the generator through the connecting passage 4 to the top of the carburetor. The temperature at this point may approach 2,000 F. At the top of the carburetor, oil is admitted through the spray 22, and

coming in contact with the hot checkerbrick 23 in the carburetor, oil gases are produced. The oil gases and water gas pass-through the checkerbrick of the carburetor and become in timately mixed. A gradual cooling of the oil gases preferably takes place from the top of the carburetor to the final oiftake at the top of the superheater, the mixture of gases flowing from the carburetor to the superheater through the pipe 43, and thence upwardly through the checkerbrick in the superheater and through the gas otftake 31 to a water seal, wash box or place of storage or use.

It has been found in practice that an eflicient utilization of the heat in the fuel bed necessitates a reversal in the direction of flow of gases through such fuel bed. According to the old mode of operation, the up run was followed by a down run in which steam was passed downwardly through the fuel bed and thence through the oiftake pipe 41 into the carburetor. As the gases leaving the bottom of the generator are at a. much lower temperature than the temperature at the top of the carburetor, it can be seen that the pouring of such cold gases into the carburetor was a very inefficient operation, and resulted in the heating up of the cold gases and a subsequent cooling of the same to lower temperatures. The worst feature of this operation, however, was the lowering of the carburetor temperatures to such a point that oil would not be cracked efiicientl and consequently much heat would have to e employed in again heating up the checkerbrick in the carburetor in a subsequent blasting operation.

.Lccording to my improved operation, steam is passed downwardly through the fuel bed, resulting in the production of water gas, but instead of introducing this cool gas into the carburetor with the attendant disadvantages, I withdraw such gas directly from the generator through the pipe 7 and pass it preferably to the same seal or Wash box to which the pipe 31 leads.

Steam may be admitted to the set at a number of places for use in this down steam run, according to the necessities of the particular case. Three such locations are shown in the drawings, namely the pipe 61 at thetop of the generator, the pipe 64 at the bottom of the carburetor, and the pipe 62 at the top of the superheater. These locations are intended as illustrative only, as obviously other points of admission-may be employed; lVhere carbon has been deposited upon the checkerbrick of both the carburetor and superheater, it is desirable to admit steam through the inlet 62 to carry out a complete reversal of flow through the set as a whole, such steam in passing through the checkerbrick 33 and 23 removing the carbon therefrom and utilizing such carbon in the making of water gas. Moreover, the steam and gases become highly heated in passing through this heated checkerbrick, and this heat is beneficially utilized in assing downwardly through the fuel bed 0 the generator to make water gas. Where no carbon has been deposited in the superheater, it is unnecessary to cool the checkerbrick 33 therein by passing steam through this shell, and accordingly steam may be admitted at the bottom of the carburetor through the pipe 64, passing upwardly through the checkerbrick 23, thence from the top of the carburetor through the passage 4 to the enerator and downwardly through the fuel ed, water gas being withdrawn through the pipe 7.

Both of the operations just described, wlnle serving to eliminate carbon and to pre- 13 heat the steam prior to its entrance to the fuel bed, nevertheless exert a cooling action on the checkerbrick in the superheater or carburetor or both. Consequently where there is no necessity for cleaning the checkerbrick or for superheating the steam within the set, steam may be admitted through the pipe 61 directly to the generator and passed downwardly through the fuel bed, the result ing gas being removed through the offtake 7. The superheating of the steam is particularly desirable where fuel containing volatile matter is admitted at the top of the generator, and the superheated steam from the top of the carburetor passing through the pipe 4 is employed for distilling such volatiles from the fuel as it is being admitted. Where coke or other fuel low in volatiles is employed, it is evident that this distilling operation does not take place. 3

Thus it is obvious that my process is inherently flexible, since proper temperature conditions may be maintained at any particular point in the set by admitting steam or other gas to the set at the proper location and in the proper proportion to efliciently react with the fuel in the generator. The mode of operation is dependent on the type of fuel employed in the generator, the type of carbureting material employed in the carburetor and the quality of gas desired as an ultimate product. While the use of steam during this down run has been specifically referred to, sincesteam is thought to possess the most favorable qualities, nevertheless other gases may be employed, as will be more fully set forth hereinafter.

While I has described a cycle of operation consisting in first blasting, then making an up run and lastly making a down run, the order of the up and down runs maybe varied and such runs may continue as long as the temperature conditions within the set are sufficiently high to eficiently produce gas.

- Thus the blasting operation may be followed directly b a down run and then by an up run, whic in turn is followed by another blasting operation, or there may be several short up and down steam runs following J each blasting step. The order of cycles is not of the essence of my invention, except that in initiating the operation-of a cold generator the first step must be a blasting operation to introduce the necessary heat into the set. .By regulating the relative periods of the carbureting cycle as compared with the cycle in which no carbureting material is admitted. it is evident that the quality of the gas may be varied, as desired, or to comply with the requirements of the particular municipalities to which gas is furnished.

While I have described carloureting with oil during the forward run, the oil being admitted through nozzle 22, and the carbureting with the volatiles from bituminous coal admitted at 9.0 during the back run, it is evident that oilmight be admitted at 22 during a back run or that other carbureting material than oil might be admitted at 22 during either a forward or a backrun. Here again process is one of its imficial result of this action is cleaning the carburetorand superheater of carbon deposits. By the time the steam and gaseous oxides of carbon reach the generator they have become very highly heated. In entering the generator the superheated steam and gaseous oxides of carbon may travel either one of .two paths. Preferably, since the hot valve 40 and connections thereto may thereby be eliminated, they enter the top of the generator, have mixed with them the'finely divided fuel supplied through pipe 81 and pass downwardly through the fuel bed. As an alternative, however, by employing down pipe 41 and valves 40 and 42 the steam and gaseous oxides of carbon thus superheated may be caused to pass up through the fuel bed produce water gas and leave the set by pipe 9. Fuel may be added during this operation. This fuel for best results should be finely divided. It should also contain volatile hydrocarbons distillable when subjected to heat to form gases.

If the added fuel be finely divided it ab- 'sorbs heat from the superheated steam, water gas and gaseous oxides of carbon received from the carburetor giving off the volatile components in gaseous form, the remainder being deposited as coke upon the fuel bed, except that portion which may combine with the e cess steam to form water gas. I have foun that the coke supply so produced is sufficient to supply the heat needed for superheating the steam and the water and gas component of the resulting gas. I

The gas which is the ultimate product of this process possesses a higher calorific value than would a gas produced from the same fuel by any other process known to the art. The reason for this is believed to be that it contains a larger percentage of the higher hydrocarbons, of both the methane and benzene series. That is, the process is one which does not break up and degrade these higher types of hydrocarbons, but retains them in the form as originally distilled from the fuel.

It is well known that, of the higher hydrocarbons, benzene (C H a single ring compound, when heated to 600 C. condenses to solid diphenyl (G H a double ring compound eliminating hydrogen gas and, when heated to higher tem eratures, condenses further to a triple ring compound with eliminapresent initially, the action is checked as shown in connection with the formation of diphenyl from benzene. The hydrogen can, however, act directly on the toluene, reducing it to benzene by combining with the CH tion of more hydrogen until ultimately only group to form methane. Although the press ohd carbon remains. These reactions'inay once oli hydrogen lessens the torlnatlon of be indicated asfollow.:- SOlltl molecular comlensates, 1t promotes the H H H H H H H H as as as as 1 no on H0 oH Ho -c on H,

Benzene benzene 2 diphenyl hydrogen H H H H H H H H H H H H as as as a as as 2 HC/ bH H0 OH Ho b-o oo CH H1 Diphenyl benzene para-diphenylbenzene hydrogen (Double bonds are omitted from ring.)

If, however, hydrogen and, to a'less extent any other dilutinggas, as nitrogen, steam, carbon dioxide, or the like, be present the above described decomposition or dehydrogenation is practically nullified up to a temperature of at least 800 C,

It is also well known that, of the hydrocarbons, toluene (C H .CH asingle ring compound when heated to 600 C. condenses to such compounds as solid stilbii' (C H a double ring compound, eliminating hydrogen gas. At higher temperatures (800 C.) there is further condensation, the nucleus (C H giving anthracene (C I-I with elimination of hydogen gas, the latter, how ever, reacting further with toluene to give benzene and methane (CH At still higher temperatures the nucleus condenses further and ultimately yields solid carbon. These reactions may be indicated as follows H H H H H H H H as as as as (3) HO C-CHa HaCG OH HO C.CH: HC.O CH H:

-C C-0 0-0 0-0 H H H H H H H H Toluene toluene stllbene hydrogen H a e e e 1 C 110 @H, in 110 Y Y 111 H 4 U H H HflC-(il oH He J; t tH H H H H H H Toluene toluene enthracene hydrogen H H H H o-o (6) H6 7-011: H2 1* HC XE CH4 -C H H H H Toluene hydrogen 2 benzene methane (Double bonds are omitted from rings. Reversibility shown thus only where established.)

If, then, a large quantity of hydrogen is decomposition of toluene by reduction to benzene, from whence the other reactions involving the latter occur. Diluting gases, other than hydrogen, would act, in some cases, to retard toluene decomposition and, in others, to lessen the degradation of benzene. after the latter had been formed.

In like manner, the three xylenes, ortho-,

mcta-, and para-, yield, in an atmosphere of methane. Yet the decomposition occurs sufficiently slowly that, it means he provided for removing the methane from the zone of reaction, such decomposition is noticeably 1 may retarded. Any gas, either chemically active,

' such as hydrogen, steam, carbon monoxide,

carbon dioxide, and the.like, or a chemically inactive gas such as nitrogen, sweeping through the reaction zone will so retard degradation by removal of the decomposing gas. Hydrogen is particularly effective in this respect, not only because its action is chiefly chemicah but also because of its lightness, its diffusive power and the. speed with which its molecules travel. An inert gas, as nitrogen, is not without-effect, however, for although chemically inactive, it can physically sweep out the forming and reacting gases from'the'pores of the fuel, and so remove them from the zone of degradation. Particularly is this, true if the fuel be in a state of fine division. The nitrogen may be supplied by admitting air into the system, and passing it over the heated checker-brick and through the fuel bed of the generator. The oxygen in the air will be largely converted into gaseous oxides of carbon by reaction with the carbon upon the checker-brick, and these gases, together with the'nitrogen passing through the fuel bed of the generator, sweep out and car ry with them the forming and reacting gases contained in the pores of the fuel, in the manner described above. I

In summation, therefore, it may be said that dehydrogenation with resulting solid through the zone of distillation and through the fuel bed, degradation of higher hydrocarbons in the distillation gases is retarded. Such retardation of degradation is due, in part, to the presence of hydrogen, not only in the distillation gases themselves but also in the forming of water gas. Degradation of such higher hydrocarbons is further retarded because the distillation gases are uickly removed from the pores of the fine y divided fuel and from the hi h temperature zone thereby materially shortening the time during which they are exposed to the breaking down tendency of such high temperatures. in consequence, the gas produced has a higher percentage of the higher hydrocarbons than the gases of analogous character heretofore commercially produced.

As these gases pass through the fuel bed the excess steam contained therein combines with the carbon to form water gas. There also be interaction between the gases distilled from the raw fuel and the carbon of the fuel bed. There is less free hydrogen in the final gas as there is less breaking down of the higher hydrocarbons.

From the foregoing description it will be evident that any gas may serve as a carrier .of heat during the process, although'some lation operation, a nitrogen-containing gas may be preferable. Furthermore, while reference is made in the description to a gas stream it is evident that such gas stream may be produced within the set by the mtroduction of any liquid capable of being transformed into the gaseous state by theheat 1n the system, such liquids as water or oil being available for this purpose. I do not claim herein the use of any of these fluids specifical- 1y, with the exception of steam, but it is to be understood that the terms gas, gas

stream, fluid or fluid stream are to be construed broadly as covering any fluids which are capable of serving as heat carriers, no matter what their constituents, and no matter how or when they may be produced. The use of these fluids, as steam, air, nitrogen, water and oil, is broadly old in gas making operations.

The point at which the gases are introduced into the system is dependent on the amount of heat it is desired to restore to the fuel bed. The greatest amount of heat is recovered where the steam or other fluid is introduced at the end of the set most remote from the generator as at 62, this resulting in the maximum efliciency so far as utilization of waste heat is concerned. With the introduction of the steam at this oint, the maximum cleaning of thechecker rick is also effected. Where the steam or other fluid is in-- troduced at an intermediate point, as'at 64, at the bottom of the carburetor, the efliciency of the process from the standpoint of heat transfer and cleaning the checker-brick is less than in the first case, but is still effective, and a large part of the heat of the system is utilized. Where steam is introduced directly into the generator. as at 61, the only heat utilized is that existing within the generator. Thus it will be evidentthat the temperature of the steam when it reaches the fuel bed is dependent on the point at which it was introduced into the system, beinggreatest when introduced at the point most remote from the generator, less when introduced at an intermediate point, and still less when introduced directly into the top of the generator.

In each of the above mentioned cases the steam or other gas may be passed downwardly through the fuel bed, and the resultant combusti le gas is withdrawn directly from the bottom of the generator through gas offtake 7 and is passed to storage without passing through the carburetor or superheater, as in ordinary practice, which would, of course, break down the hydrocarbons. An import ant advantage of removing the gas at this point is that the gas is relatlvely cool as compared with gas taken off from the top of the generator, and thus very little heat is wasted, and the necessity for expensive hot Valves is eliminated. The gases taken off at 7 may be, and in practice generally are, combined with the gases taken off at 31 during the forward run, both ofi'takes being usually connected to a single wash box, though, if desired, the gases may be taken to separate holders.

For the purpose of fully utilizing the heat in the fuel bed it is sometimes desirable to occasionally make an uprun, steam, or other gas bein introduced at the bottom of the generator as at 6 and combustible gas withdrawn directly from the top of the generator as at 91. Such a run is not the usual run, but is made at times, and the apparatus is designed with such a run in View.

In the specification and claims I have at times used the expressions directly to the generator with reference to the admission of steam or other fluid, and the term directly from the generator with reference to the withdrawal of combustible gas. By the term directly to the generator, I mean that the steam or other fluid is admitted without being first passed through the carburetor or superheater, and by the term directly from the generator I mean that the combustible gas after being withdrawn from the generator is not passed through the carburetor or superheater, but is passed directly to storage or use after undergoing the usual purification steps to remove the undesirable constituents from the finished gas.

What I claim as my invention is:

1. An improvement in the usual two cycle process of making carbureted water gas, carried out in a plant comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, one cycle consisting in air blasting the fuel bed of the generator and storing the resulting heat successively in the carburetor and superheater, a second cycle consisting in making a forward steam run successively through the fuel bed of the generator in an upward direction, then through the carburetor and superheater, and withdrawing the resulting water gas directly from the superheater; the improvement which consists in making a third cycle in which steam is passed directly to the top of the fuel bed in the generator and the resulting water gas withdrawn directly from the bottom of the generator for storage or use.

2. 'An improvement in the usual two cycle process of making carbureted water gas, carried out in a plant comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, one cycle consisting in air blasting the fuel bed of the generator and storing the resulting heat successively in the carburetor and superheater, and the other cycle consisting in making a forward steam run successively through the fuel bed of the generator in an upward direction, then through the carburetor and superheater, and withdrawing the resulting water gas directly from the superheater; the improvement which comprises making a third cycle consisting in introducing steam into the plant at such point prior to the superheater outlet that it is heated by the time it reaches the fuel bed of the generator, passing the steam downwardly through the fuel bed of the generator, and withdrawing the resulting water gas directly from the generator for storage or use.

3. An improvement in the usual two cycle process of making carbureted water gas, carried out in a plant comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, one cycle consisting in air blasting the fuel bed of the generator and storing the resulting heat successively in the carburetor and superheater, and the other cycle consisting in making a forward steam run successively through the generator, carburetor, and superheater, and withdrawing the resulting water gas directly from the superheater; the improvement which consists in making a third cycle in which steam is passed through the fuel bed of the generator in a direction opposite to the forward run and the resulting water gas withdrawn directly from the generator for stora e or use.

4:. process as defined in claim 3 in which the water gas in the third cycle is withdrawn directly from the top of the generator.

A process for making carbureted water gas, which when carried out in an apparatus comprising a single generator containing a bed of solid fuel, a single carburetor and a single superheater, comprises air blasting the fuel bed of the generator to heat the carburetor and superheater, passing steam upwardly through the generator in a forward run, thence through the carburetor and superheater, admitting oil for carbureting to the carburetor during the forward steam run, making a down steam run through the fuel bed of the generator, introducing the steam to the set selectively at the top of the superheater, the bottom of the carburetor, and the top of the generator, withdrawing the resulting gas directly from the generator after passing through the fuel bed thereof, and with the up and down steam runs following the blasting period.

6. A process for making carbureted water gas, which when carried out in an apparatus comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, comprises first heating the apparatus by air blasting the fuel bed of the generator to incandescence and storing the heat of the resulting blast gases in the carburetor and superheater, and subsequently utilizing the stored heat in the generator, carburetor and superheater by making up and down steam runs through the fuel bed as long as temperature conditions permit, the up runs comprising introducing steam at the bottom of the generator, passing the steam upwardly through the fuel bed of the generator, then successively through the carburetor and superheater, adding carburetin material within the carburetor, and withc rawing the resulting carbureted water gas directly from the superheater, and in the down runs passing steam downwardly through the fuel bed of the generator and withdrawing the resulting water gas directly from the generator for storage or use.

7 A process for making carbureted water gas, which when carried out in an apparatus comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, comprises first heating the apparatus by air blasting the fuel bed of the generator to incandescence and storing the heat of the resulting blast gases in the car-' buretor-and superheater, and subsequently utilizing the stored heat in the generator, carburetor and superheater by making up and down steam runs through the fuel bed as long as temperature conditions permit, the

up runs comprising introducing steam at the bottom of the generator, passing the steam upwardly through the fuel bed of the genera-. tor, then successively through the carburetor and superheater, adding carbureting material within the carburetor, and withdrawing the resulting carbureted water gas directly from the superheater, and in the down runs passing steam downwardly through the fuel bed of the generator and withdrawing the resulting water gas directly from the generator for storage or use, the steam for the down run being introduced into the apparatus directly above the fuel bed of the generator.

8. A process for making carbureted water gas, which when carried out in an apparatus comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, comprises first heating the apparatus by air blasting the fuel bed of the generator to incandescence and storing the heat of the resulting blast gases in the carburetor andsuperheater, and subsequently utilizing the stored heat in the generator, carburetor and superheater by making up and down steam runs through the fuel bed as long as temperature conditions permit, the up runs comprising introducing steam at the bottom of the generator, passing the steam upwardly through the fuel bed of the generator, then successively through the carburetor and superheater, adding carbureting material with-- in the carburetor, and withdrawing the resulting carbureted water gas directly from the superheater, and in the down runs passing steam downwardly through the fuel bed of the generator and withdrawing the resulting water gas directly from the generator for storage or use, the steam for the down run being introduced into .the apparatus in the carburetor.

. 9. A process for making carbureted water gas, which when carried out in an apparatus comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, comprises first heating the apparatus by air blasting the fuel bed of the generator to incandescence and storing the heat of the resulting blast gases in the carburetor and superheater, and subsequently utilizing the stored heat in the generator,

carburetor and superheater by making up and down steam runs through the fuel bed as long as temperature conditions permit, the up runs comprising introducing steam at the bottom of the generator, passing the steam upwardly through the fuel bed of the generator, then successively through the carburetor and superheater, adding carbureting material within the carburetor, and withdrawing the resulting carbureted water gas directly from the superheater, and in the down runs passing steam downwardly through the fuel bed of the generator and withdrawing the resulting water gas directly from the generator for storage or use, the steam for the down runs being introduced into the a paratus selectively at the superheater, car uretor and generator.

10. A process for making carbureted water gas, which when carried out in an apparatus comprising a single generator having a bed of solid fuel, a single carburetor, and a single superheater, comprises first heating the apparatus by air blasting the fuel bed of the generator to incandescence and storing the heat of the resulting blast gases in the carburetor and superheater, and subsequently utilizing the stored heat in the generator, carburetor and superheater by making up and down runs through the fuel bed as long as temperature conditions permit, the up runs comprising introducing steam at the bottom-of the generator, passing the steam upwardly through the. fuel bed of the generator to make water gas, and passing the water gas successively through the carburetor and superheater, adding carbureting material within the carburetor, and withdrawing the resulting carbureted water gas directly from the generator, and in the down runs introducing into the plant a fluid which when highly heated is capable of reacting with the incandescent fuel in the generator to form gas, heating said fluid, and passin the same downwardly through the fuel bed of the generator, whereby a combustible gas is produced and withdrawing the resulting gas directly from the generator for storage or use.

11. An improvement in the usual two cycle process of making carbureted watergas, carried out in a plant comprising a single generator having a bed of solid fuel, a single carburetor and a single superheater, one cycle consisting in air blasting the fuel bed of the generator and storing the resulting heat successively in the carburetor and superheater, and the other cycle consisting in making a forward steam run successively through the generator in an upward direction, then through the carburetor and superheater, and Withdrawing the resulting Water gas directly from the superheater; the improvement which consists in introducing into the plant a fluid which when highly heated is capable of reacting with the incandescent fuel in the generator, heating said fluid, and passing the same in a downward direction through the fuel bed of the generator, whereby a combustible gas is produced, and withdrawing the resulting gas directly from the generator for storage or use.

Signed at Tacoma, Pierce County, Washington, this 14th day of June, 1922.

DANIEL J. YOUNG.

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