US1953848A - Carbureted water gas process - Google Patents

Description

April 3, 1934. H, J. CARSON CARBURETED WATER GAS PROCESS Filea April 8, 1929. 5 Sheets-Sheet 1 April 3, 1934.

H. J. CARSON CABBURETED WATER GAS PROCESS Filed April 8, 1929 s Sheets-Sheet. 2

ATTORNQY.

A ril '3, 1934.

H. J. CARSON C ARBURETED WATER GAS PROCESS Filed April 8, 3 Sheets-Shet 5 Patented Apr. 3, 1934 UNITED STATES PATENT OFFICE moval of ash and clinker forming material from a water gas generator in liquid form; introducing fluxing material into a generator fuel bed; gasi fyLng bituminous fuel in a water gas generator; the recovery of liquid hydrocarbons and ammonia from bituminous fuel; introducing and gasifying,

29 liquid hydrocarbon in a carbureting chamber;

utilizing the heat storage capacity of regeneratlve chambers in blue and carbureted water gas sets.

The invention accordingly has many objects and advantages in view which are more fully hereinafter described. Obviously any one or several of the improved methods may be applied to present day processes or all may be used in combination as described. i

As is wellknown, in the usual operation of water gas sets, the time is roughly divided into two periods; the blasting or heating up period, and the running or gas making period. The heat developed during the blasting period and stored in the generator fuel bed, is available in thegas making period for decomposing the steam admitted to the generator.

In the usual operation of carbureted water gas sets the potential and sensible heat in the blow gases leaving the generator is used to store heat in regenerative chambers known as carbureting' and gas superheating chambers, the heat so stored being used for vaporizing liquid hydrocarbons and fixing the resulting hydrocarbon gases during the gas making period.

The air for blasting usually enters the generator at about atmospheric temperature and the steam for gas making usually enters the generator with a relatively small amount of superheat, if any, and often containing moisture. The air must be heated in the generator to ignition temperature before combustion takes place and any moisture in the steam must be vaporized and the steam heated to a reaction temperature of about 1800 degrees F. for steam decomposition before water gas is formed in any appreciable amount. The blow gases from air blasting leave the apparatus containing a substantial amount of sensible heat in addition to the potential heat in any combustible gases,- therein.

-'In practice, at the beginning of a running period, the decomposition of steam is rapid and nearly complete for a short period, but falls off rapidly thereafter, owing to the lower'rate of decomposition as the generator fuel bed temperature falls. I)

It has been stated that very little steam is de composed at temperatures below 1000 deg. C. (1832 deg. F.) whenthe rate of decomposition is estimated to double with every rise of 100 deg. C. in temperature and such decomposition is very rapid at temperatures of 1200 deg. C. and above. While the temperatures in the steam decomposition zone in a generator fuel bed may vary at different levels in that zone, the minimum practical temperature of its highest temperature portion is about 1000 C. and the heat in the fuel bed useful for steam decomposition is the heat stored above that temperature.

l-leretofore insufficient account has been taken of the foregoing facts; Steam admitted to the generator is actively decomposed at first, but decomposition-is soon arrested as the fuel temperature is lowered by the cooling action of such steam decomposition. As the temperature drops, less and less of the steam'admitted is decomposed, and this increasing excess 'of undecomposed steam has the harmful effect of further cooling the fuel bed with no useful result.

To restore heat storage to the fuel bed at proper temperature levels after such cooling: fuel, air, and time are necessary, and as the fuel bed must be heated first to the temperature where steam decomposition begins at an effective rate and as the useful heat storage is that above about 1000 deg. C. the blasting and heating to bring the fuel bed temperature up to 1000 deg.

-C. may be avoided by keeping a minimum temstored and generated therein at high temperature levels for the directly useful purpose of steam decomposition and gas formation, and permitting operation at higher average temperatures in the generator.

In air blasting a generator fuel bed it is well known that more and more carbon monoxide is produced for a given rate of blasting as the temperature of the fuel rises and the high temperature zone in the fuel increases in thickness.

It is also well known that the percentage of carbon monoxide in blow gases may be limited by increasing the rate of blasting, thus reducing the time of contact of the burned gases wit-h the hot fuel.

In the usual method of air blasting water gas sets the air is blown into the bottom of the generator through grates and the entire fuel bed to the blow gas offtake. The carbon monoxide content of the blow gases is limited by shortening the air blasting and gas making periods as much as practicable and air blastingv at the highest practicable rate. Less heat is stored in the fuel in the shorter blasting period and less is needed for the short gas making period, and less carbon monoxide is produced in the blow gases.

Optimum conditions for the decomposition of steam and gas formation require the longest practicable time of contact of the steam with the fuel at the highest practicable temperature. A

thick high temperature fuel bed is desired.

The invention contemplates the maintenance of the CO content of the blow gases within the desired limits and the building up of a steam decomposition zone of greater thickness and at a higher temperature than is practicable in the usual methods of operation.

The invention contemplates the introduction of air to the fuel bed at different levels separately controllable at each level so as to limit the time of contact of the burned gases with the high temperature fuel resulting from combustion at each level.

Air may be introduced first at the lower level farthest from the blowgas offtake then discontinued as a high temperature zone is built up near that level. Airmay then be introduced at the next level so as to bypass the hot layer of fuel resulting from blasting at the first level, then discontinued at the second level, and commenced at the third level and so on until a high temperature fuel bed of the desired thickness is built up.

Theinvention also contemplates the admission of air at one level at a time or at different levels simultaneously. When air is continuously admitted at one level the carbon monoxide in the resultant gases may be burned by air simulta neously admitted at a higher level thus decreasing the carbon monoxide content of the blow gases.

The rate of blasting as in present operation. is limited by the point at which excessive amounts of fuel are blown out. of the generator.

In present operation with the air for blasting admitted under the generator grates and the fuel column not uniformly porous, the air seeks the path of least resistance through the fuel and channeling results with overheating of some por-' tions of the fuel bed and little heating of other portions. As a result a substantial part of the fuel bed is relatively inactive.

The invention contemplates that air for blasting will be supplied to the generator at relatively high velocities through a plurality of tuyeres in the generator at different levels as desired thus insuring a relatively uniform air supply to and penetration of the generator fuel bed.

In present operation the steam for gas making follows the path of least resistance through the fuel bed and often with a channeling effect.

The invention contemplates the admission of steam to the generator at relatively high velocities through tuyres in the generator at different levels as desired thus insuring the admission of steam uniformly to the different points of the fuel bed.

In present operation the steam and air enter the base of the generator relatively cold and chill the bottom zone of the fuel bed. Down steam runs are necessary from time to time to drive the heat down toward the grate as otherwise the cold zone would gradually move upwardly.

The invention contemplates that with steam superheatedabove the ignition temperature of the fuel and/or admitted above the bottom zone and with or without preheated air the bottom zone of fuel is kept sufficiently hot so that only up runs need be made.

In present practice, gas making is continued until the accumulation of ash and clinker in the lower portion of the generator fuel bed prevents further operation in a practicable manner. Gas making is then discontinued, to permit the removal of ash and clinker, after which operation may be resumed. The invention contemplates the easy removal of ash and clinker in the form of molten slag so as to permit continuous or nearly continuous operation with a uniformly clean fuel bed and without the arduous labor and loss of time usual in present operation or the use and maintenance of costly mechanical grates for continuous ash and clinker removal.

The invention further contemplates that air and steam may be admitted to the generator fuel bed selectively as desired at different levels and so the bottom zone of the generator fuel column will not be substantially exposed to the cooling action of the entering steam, will remain hot during the period of steam admission, thus permitting ready ignition at the beginning of the blasting period and keeping the underlying ash and slag substantially at and above the melting point.

The invention also contemplates the use of steam superheated near to or above the fusing temperature of the ash as desired which reduces or avoids any chilling action on the slag.

The use of preheated air for blasting facilitates the slagging operation. A flux may be charged with the fuel or introduced in the bottom zone of the fuel bed or blown in admixed with the blasting air as needed and desired. In the latter case the flux may be immediately used in liquefying the slag and the time interval required for fluxing material charged with the fuel to work down to the slagging level is avoided.

The invention contemplates the introduction of a fluxing material in the bottom zone of the fuel bed when required, also the introduction of combustible gas with the blasting air in the bottom zone in case of difliculty in slagging which may be for example occasioned by a deficiency of combustible in the fuel at the slagging level. The blasting air may also be enriched with oxygen for further hastening combustion and liquefying the slag. A limited amount of air and/or oxygen may be admitted at the lower level during the gas making period to keep the slag liquefied.

When bituminous fuel is used in a generator loll ' ture.

of the usual type having the blue water .gas'and air blow gas offtakes at the same level, volatile matter from the fuel is driven off during the gas making period and is also driven ,off during the air blasting period. Also in the usual up and down run method of operation in which steam for gas making is alternately admitted above and below the fuel bed, the hydrocarbons distilled from the fuel during the down run portion are passed through the hot zone of the generator fuel bed and broken down into mostly carbon and hydrogen.

With bituminous fuel, such as coal, used as generator fuel, the invention contemplates the use of an upper carbonizing zone and a lower incandescent o-r generating zone. The air blast gases from the lower zone, with or without the secondary combustion thereof, may be used for "externally heating the upper zone or a portion of such blast gases may, when desired, be passed through the upper carbonizing zone for internally heating the fuel therein. Part or all of the hot blue water gas from the lower incandescent zone may be passed through the fuel in the upper zone for devolatilizing the fuel and any remaining portion of the blue gas drawn off separately for enrichment with liquid hydro-carbons. With fuel containing little or no volatile matter, such as coke, the invention contemplates passing part or all of the blue water gas from the lower zone through the newly charged fuel in the upper zone to thereby preheat such fuel before it descends into the lower water gas generating zone.

In carbonizing fuel in water gas generators by internal and/or external heating as above described,,,difii'culties are experienced with some fuels which on heating swell, arch or hang in generators and form a plastic zone through which gases are passed with difficulty if at all.

The volatile matter of bituminous fuels is of varying composition and distillable at different temperatures. The volume and quality of the volatile matter given off varies with the tempera ture and time of heating.

When the volatile matter distilled off at relatively higher temperatures passes through cooler fuel, some or all of it is usually condensed on the cooler fuel. This condensate encases the lumps or particles of fuel in a liquid envelope often of a plastic nature which is not again vaporized un til the fuel passes into a zone of higher temperacontain volatile matter distillable at relatively low temperatures, which being partially or wholly Y confined within the liquid envelope causes the fuel to swell.

If the volatile matter evolved from bituminous fuel as it is heated is removed from contact therewith substantially-as it is formed under temperature and partial pressure conditions above the condensation point the time required for distilling ofi the volatile matter at any given temperature is greatly reduced; cracking of the hydrocarbons so evolved is avoided and the condensable portion of these hydrocarbons may be recovered in liquid form. With the hydrocarbons drawn off as formed and cracking avoided, the heat re quired for carbonization is substantially less.

If swelling or sticking coals are preheated for a time at 900 deg. F. more or less-the swelling properties and tend-encytoward the formation of a plastic zone is thereby reduced.

The invention contemplates the devolatilization of the fuel by the heat in the blue gas and any undecomposed steam mixed therewith pass- Meanwhile the coal lumps and particles ing through it at relatively higher temperatures than are obtained in usual practice when desired and supplemented by other methods more fully hereinafter described.

The invention also contemplates preheating the. coal to prevent sticking and the formation of a plastic zone.

The invention contemplates thedistillation of the fuel under controllable temperature conditions to permit the evolving and recovery of COI1-. densable hydrocarbons of varying qualities as desired as hereinafter more fully described.

In themanufacture of carbureted water gas the invention contemplates passing a part of the water gasthrough the carbonizing chamber and the remaining portion in desired volume through a carbureting chamber for enrichment therein by hydrocarbon vapors from liquid hydrocarbons.

The invention also contemplates the admission of steam in the lower zone of the carbonizing chamberfor the formation of ammonia and/or blue gas with such formation furthered by the presence of lime or limestone when charged with the fuel for the additional purpose of fluxing the ash.

The invention contemplates the maintenance of optimum temperatures for ammonia formation in the carbonizing chamber when ammonia recovery is desired.

The invention also contemplates the formation of methane in relatively large volume because of the catalytic effect in such production by any lime or iimestone charged with the fuel as a fluxing agent for the ash.

In the manufacture of carbureted water gas it is well known that optimum conditions for the gasification or cracking of liquid hydrocarbons in the carbureter require the maintenance of temperatures within fairly narrow limits from about 1300 to 1550 deg. F. It is also well known that in present operation the temperatures in the carbureter fluctuate widely, with a fairly rapid deterioration of the heat absorbing material, such as fire brick, because of the thermal shock incident to the temperature fluctuations. The temperatures in the top courses .of checker brick have been found to fluctuate from an average minimum of 640 degrees F. to an average maximum of 1886 degrees F. with extreme mean variations from 513 degrees F. to 2000 degrees F. Shut downs and replacement of checker brick are frequently necessary.

,jectionable compounds such as indene and styrene are formed.

The brickin the carburetor are rapidly cooled by the vaporization of the oil and in the usual up and down run methods of operation of carbureted water gas sets are further cooled by the relatively cool blue gas and undecomposed steam which enter the carbureter at temperatures sub-.

stantially lower than required for optimum oil cracking conditions. This cooling oftenprogresses to such an extent that it is difficult to ignite the blow gases and secondary air during bustion and heat absorbing chamber between the generating and carbureting chambers in which heatmay be stored during the blasting period for preheating the blue gas and undecomposed temperatures prevailing in the oil gasification zone.

The invention also contemplates the use of a mixing chamber in the oil admission zone in the carbureter to allow for the mixing therein of the highly heated entering blue gas and steam with the oil mist. The mixture of this entering hot gas and steam with the heat radiated to these oil particles from the carbureter lining 'and adjacent refractory material bring the oil particles to optimum temperatures for cracking. In the presence of a reactive gas such as hydrogen in the blue gas at optimum cracking temperatures from about 1300 to 1550 deg F. stablehydrocarbon gases'are formed and a practically complete conversion of the carbon and hydrogen in the oil into such gases is effected.

A uniform or nearly uniform descent of the mixture of oil particles or gases and blue gases 1 and steam from the generator will take place in the oil admission zone, for the hot gas and steam after passing through the supplementary heat absorbing chamber and in striking the oil particles, cool and drop out of the way of the oil .and gas and steam introduced thereafter, with the uniform descent of the mixed gas column in the chamber. The amount of secondaryv combustion and heat storage in the heat absorbing zone may be so regulated that the blue gases and steam will be heated to the required temperature for producing optimum temperature conditions for oil cracking when cooled by and mixed with the oil particles.

The relatively large volume of blue gases entering the. carbureter provides low partial pressure conditions for the oil vapors which furthers the conversion of the oil into stable hydrocarbon gases. Reduced absolute pressures further favor the conversion of the oil into stable hydrocarbon gases. When it is desired to reduce the absolute pressures the carbureter gas outlet is equipped with a vacuum pump which may be sufficiently large to handle all blue and hydrocarbon gases. The pump in such case is preferably arranged to'draw the gases through a condenser so as to reduce the gas volume and the size of pump required.

With such a vacuum pump used for drawing off the carbureted gas, and it is desired to draw coal gas 01f separately, a second vacuum pump in the coal gas outlet to draw the coal gas and any gas mixed therewith through. it or equivalent means is required.

The relative proportions of gas drawn off through each offtake may be regulated by the size and speed of each'pump.

The volume of gas withdrawn through each outlet is preferably regulated by dispensing with the pump in the coal gas outlet and providing a valve in the passageway between the generator and carbureter which may be partly closed during the gas making period to restrict the flow of gas to the carbureter as desired and to perm t higher pressures in the generator and the discharge of gas through the second outlet at pressures higher than the reduced pressures in the carbureter.

The invention contemplates the use of regenerative chambers in which heat from the blow gases is stored during the air blasting period and used for superheating steam and preheating air, and so designed that the blast gases pass downwardly and the steam and air pass upwardly through the heat absorbing material in these chambers. A practically complete utilization of the capacity of these chambers is thereby effected.

The blow gases" in passing through the passages in the heat absorbing material in the regenerator chambers are cooling and in passing downwardly the density of the cooling gas particles increases with an increasing downward velocity. Hotter particles are accordingly drawn toward the heating surfaces and the velocity of the gases is greater in the cooler passages. As a result the passagesare all heated to a relatively uniform temperature with a uniform descent therethrough of the gas column.

The air and steam are heated in passing through the passages in the heat absorbing material in the regenerative chambers and as heated the density of the gas particles decreases with an increasing upward velocity. The upward velocity and rate of heating is greater in the hotter passages and more gas passes through these than through the cooler passages.

As a result the passages reach a relatively uniform temperature with the uniform ascent therethrough of the steam and air columns.

In the preceding,I have outlined briefly certain features and disadvantages of water gas generation as heretofore commonly practised and the objects of the present invention.

Other objects of my invention will more clearly appear from the description and claims hereinafter following.

In the drawings forming a part of this specifi cation, I have illustrated suitable apparatus, with certain indicated modifications under different conditions, which may be employed in the practical carrying out of my improvements in water gas generation. In said drawings.

Fig. 1 shows a carbureted water gas plant in elevation and partly in section embodying my improvements and mainly of a familiar type.

Fig. 2 is a. partial plan view of the structure shown in Fig. 1.

Fig. 3 is an enlarged fragmentary vertical section of a carbonizing chamber in the generator shown in Fig. 1.

Fig. 4 is a sectional View of the generator on the line 44 in Fig. 1, showing a restricted and elongated base and other features.

Fig. 5 is an enlarged fragmentary vertical sectional view showing the details of construction of an air tuyere, tuyere header and air inlet valve in the lowermost air blast level of the generator in Fig. 1.

Fig. 6 is an elevation of a carbureted water gas plant partly in section with modifications as hereinafter fully set forth.

Figs. 6 and 7 are similar to Figs. 1 and 2 with the gas superheater omitted and the carbureting and gas superheating functions combined in a carbureting-gas superheating chamber, with corresponding modifications.

Fig. 8 is an elevation of a carbureted water gas plant partly in section, with generator and carbureting-gas superheating chamber as in Fig. 6, with two additional chambers each of which is used for superheating steam and preheating air. Fig. 9 is a plan view of the carbureting-gas superheating and steam superheating-air pre-- heating chambers of Fig. 8 with some details or construction.

Fig. 10 is a view in elevation and partly in section of a blue water gas plant consisting mainly of a' generator and two regenerating chambers. each of which is used for superheating steam and preheating air as in Figs. 8 and 9 with the carbureting-gas superheating chamber omitted and corresponding modifications.

Fig. 11 is a plan view showing the steam superheating-air preheating chambers and their desired through any suitable charging device as 19. Air blast inlet means are provided as shown at levels 20, 20a, 20--b, and 20--c. Steam inlet means are similarly shown at level-21. The carbonizing chamber has an annular passage around it of a relatively large area at 22 to lower the velocity of the gases ,leaving the incandescent fuel and reduce or avoid the carrying along of fine fuel particles in the gases.

ably enlarged at 24 to reduce the velocity of the gases at this pointandto further a uniform passage of the gases around the carbonizing chamber.

The gases pass from 24 into the carbureter through a conduit 25 shown with a valve therein which may be dispensed with as hereinafter described.

The wall of the carbonizing chamber 18 is preferably made of heat resisting metal to permit a relatively high rate of heat transfer therethrough but whensecondary combustion of the air blow gases is effected in 22 by air admitted as at level 20--c, that portion of the chamber wall exposed to unduly high temperatures may be made of a suitable refractory material.

The carbonizing chamber preferably contains an assembly 26 in the center thereof. This assembly is shown enlarged in Fig. 3 and is more fully described hereafter.

An inlet 127 for steam or air is shown near the bottom of the carbonizing chamber, supplied by a vertically disposed conduit 128 passing through the assembly aforesaid and fed and supported by a pipe 129. An assembly'cap or valve 30 adjustable as by a cable 31 for regulating the division of flow of gases through the assembly 26 and the also a zone of heat absorbing material 28, with I an oil admission zone 29 below with valved oil inlets as 29-a and 29-b and preferably with a lowerzone of heat absorbing. material 30.

The bottom of the carbureter is in open connection with gas superheater 14, which is of the usual type and filled with heat absorbing material such as checker brick.

The gas superheater is shown with the usual stack valve 32 and a closable gas outlet 33, and

an alternate valved gas outlet 34 leads to a condenser 35 having a gas outlet 36, with a vacuum pump 37 installed therein.

The usual stack valve 32 on the gas superheater is shown in the usual manner for use when desired.

The top of the gas superheater opens into the c steam superheating chamber 15 through a valved conduit 38 into. the combustion chamber 39.

The steam superheater is filled with heat absorbing material 40 and has a passageway 41 opening through a valved conduit 42 into the combustion chamber 43 of air preheating'chamber l6, and similarly into a similar combustion chamher in air preheater 16--a as indicated in Fig. 2. The air preheating chambers are filled with heat absorbing material 44 and have an upwardly extending passageway 45 leading to stack valves 46 and 46-a. f

The generator is shown with a solid hearth 47 preferably sloping toward a slag discharge opening 48 which is normally closed byany suitable means suchas fire clay.

A second slag di'schargeopening '48-a'is shown at a higher level for use when iron or metallic'ore metal may be drawn off at the lower level 48 with the slag drawn off at the higher'level 48a..

Theapipe 49 opening into the air inlet at level 20 indicates an admission means for combustible gas or oxygen for mixing with the air to effect combustion or raise the temperatures in the fuel bed at this level as desired for slagging the ash. This connection 49 may also be used for supplying the fiuxing material into the air blast.

Another opening into the fuel bed at any suitable level as at 50 is shown for the introduction of fluxing material as desired.

The generator is equipped with a valved gas outlet 51 in the top of the carbonizing chamber 18 for the withdrawal of the coal distillation gas and vapors and any other gases mixed therewith to such further point in the apparatus as is desired.

As further shown in Figures land 2:

An. air supply pipe 52 is connected to valved inlets 53.and 53a to the air preheaters. The valved preheated air outlets 54 and 54-a are connected into a header 55 supplying the preheated air distributing pipe56. The latter pipe supplies combustion .air to the air preheating chambers through valved inlets 57 and 57a, to the steam superheater through 53; to the carbureter through 59 and to the generator through valved inlets and air tuyere headers supplying tuyeres at levels 20, 20--a, 20-b, 20-c and air admission means 127 through valved connection 60 and pipes 129 and 12a. 1

The air preheaters may be bypassed through a pipe 56.

Steam is supplied from a source not shown through a valved inlet 61 into steam superheater 15. The valved superheated steam outlet 62 opens into the superheated steam distributing pipe 63 which supplies the carbureter when desired through valved connection 64 and the. generator through valved inlet 65 and pipes 129 and 128 leading to opening 27 and to steam tuyere open- 140 valved bypass 52-a directly into air distributing I forming a protective skirt around the upper open end of the next lower cylinder to prevent fuel falling therein and to provide annular openings 6'7 for the escape of volatile matter from the fuel into the open passage through the series of cylinders as indicated by arrows.

The assembly cap 30 is adjustable by cable 31 to regulate the division of flow of gases through the assembly and the fuel.

Figure 4 shows the restricted and elongated section at the level 44-of Figure 1 with the tuyres opening into the long sides at 6'7 and with the interior accessible through doors 68 and openings 69 which are normally filled with removable refractory material. The lowermost air blast tuyere header is indicated by 71 and the steam tuyere header at 70.

Figure 5 shows a fragmentary section of the generator wall with an air blast tuyre therein. The tuyeres at each level are supplied by tuyre header pipes 71 which are supplied by the air distributing pipe through valves 72. The tuyere nose 73 isshown projecting beyond the generator wall and Water-cooled by water entering through pipe 74 and discharging through Vi-a.

The pipe 49 is shown inserted in the tuyre through which combustible gas or oxy en may be introduced for mixing with the air an assisting in combustion at the lowermost air blast level. Fluxing material in powdered form may also be similarly admitted into the blasting air.

In Figure 6 and the partial plan view thereof in Fig. 7 a carbureted water gas plant mainly similar to that shown in Figures 1 and 2 is shown with the gas superheating chamber of Figure 1 omitted and the functions of the carbureter and gas superheater combined in one chamber as 13' 37 and thence to such other point as is desired through outlet 36.

The air and steam connections and inlet and outlet connections to the steam superheating and air preheating chambers are all substantially as shown and described in connection with Figures 1 and 2, with modifications to suit the omission of the gas superheating chamber of Figure 1 with a steam connection 61- -11 for bypassing the steam superheater when desired. These connections are all disposed so theblow gases in heating these chambers will always pass downwardly and the air and steam in being preheated will always pass upwardly through the heat absorbing material. The stack valves of Figure 1 are replaced if? the construction, of Figures 6 and '7 by valves 146 and 146a leading to a common stack 75.

In Figure 8 and the partial plan view thereof in Figure 9 a gas generator 12 with a valved connection 25 to carbureter-gas superheating chamber 13', both similar to the units in the .previous figures, are shown with the chamber 13 connected directly to two regenerative chambers, each of which are alternately heated by the air blast gases and used for superheating steam and preheating air. Valved air supply pipe 52' and steam supply pipe 61 alternately supply air and steam to chambers 16' and 16a through a common inlet header and valved inlets 53 and 53a. The preheated air leaves these chambers through valved outlets 54 and 54a connected into air distributing pipe 56 and thence to supply combustion air to these chambers and the generator in a similar manner as before described. The superheated steam leaves through outlets 62' and 62a to distributing pipe 63 and thence as before described. The gas outlet 33" leads to other apparatus or vacuum pump as before described.

Steam and air inlets 61a and 52a respectively are provided for bypassing the regenerative chambers when desired.

In Figure 10 and the partial plan view thereof in Figure 11 a generator is shown in combination with two regenerative chambers each of which are alternately heated by the blow gases and used for superheating steam and preheating air as in Figures 8 and 9. This is essentially a blue gas plant and similar to that in Figures 8 and 9 with the carbureting-gas superheating chamber 13 omitted and corresponding changes to suit this omission.

Obviously the inlet and outlet connections and passages to the different chambers in the different figures may be varied from those shown. The invention contemplates such a disposition of these that the heating gases will pass downwardly and the air and steam will pass upwardly through the heat absorbing material.

The operation of the apparatus is as follows, particular reference being had to the apparatus illustrated in Figs. 1 to 5:

A fire is kindled on the generator hearth 47 and the generator is filled with coal (preferably .coke at the start) which is replenished with preferably bituminous fuel thereafter through charging opening 19.

All valves are closed save stack valve 46a and valves 42a, 38, 25, 53, 54 and at air blast level 20. Air is admitted through 52, 53, 16, 54, 55, 56 to air blast level 20. The gases resulting from the combustion of the fuel pass upwardly through the fuel and passageways 22, 23 and 24 and successively through the carbureter, gas superheater, steam superheater and thence through air preheater 16a to the stack.

As the air blasting progresses and the fuel bed in the gas generator becomes heated, carbon monoxide is formed in increasing volume. This carbon monoxide may be burned by air admitted through the opening of valves at any level as 20a,

20b, 200, as desired, but in starting and to heat the apparatus throughout it is preferably first burned by air admitted to the carbureter through valved inlet 59. When the carbureter is sufiiciehtly heated or when it is desired to further heat the stem and air preheating chambers, combustion may be effected in these. by air admitted through 58 and 57a as desired.

The generator fuel bed is preferably continuously blasted throughout the period at level 20 and the CO content of the gas leaving the fuel bed limited by effecting combustion therewith through air admitted selectively as desired at the higher levels, thus building up a relatively thick high temperature fuel bed with a definite limitation of the CO produced, as by this method the fuel in the bottom zone is mostly consumed with a reduction to ash and slag there and the heat therefrom stored in the fuel at higher levels with less consumption of fuel and reduction to ash at the higher levels.

The fuel bed may also be blasted at the lowermost level for a certain time and then as the fuel becomes hot and CO is produced in the maximum amount desired, the blasting may be discontinued drogen or blue gas.

at this level and begun at a higher level thus bypassing the underlying zone of hot fuel, then again discontinued and begun at a still higher level V and so on until afuel bed of the desired temperature and thickness is built up.

With the fuel bed hot and the apparatus at the desired temperature the air blast is cut off and all valved outlet 62, pipe 63, through inlet valves,

tuyere header and tuyeres at level 21 to the fuel bed. The steam leaves the tuyere openings at a relatively high velocity and-through a plurality of opening so .as to penetrate the fuel bed uniformly.

The steam also enters the fuel at a sufficient distance above the lower zone of intensely hot fuel so as to bypass it without an appreciable cooling action on any liquid slag in the lower zone.

The freezing of the liquid slag at the lower level is further avoided in supplying the steam to the fuel bed superheated at a temperature relatively near to or above the freezing temperature of the slag.

The steam in passing through the relatively thick high temperature fuel bed is decomposed with the formation of carbon monoxide and hy- A portion of the blue gas so formed enters the bottom of the carbonizing chamber 18, sweeps through the fuel in the lower portion thereof and with any volatile matter therefrom a portion enters the bottom opening of the assembly 26. The remainder sweeping up through the fuel, further devolatilizes it and either entering the assembly through annularopenings as at 67 in Figure 3, or passing up through the fuel, passes out through upper offtake 51.

The cap 30 on the assembly may be. raised or lowered thus adjusting the flow through the fuel and the assembly as desired. The valve 51 is also adjustable to regulate the volume of blue gas passing through thecarbonizing chamber.

The blue gas and any, coal gas and vapors mixed therewith in passing through the cylinders of the assembly produces a vacuum effect which draws the gas from the fuel being carbonized in through the annular spaces as 67 into the stream of gas. A i

The gas and vapors are accordingly withdrawn from the fuel substantially as evolved and mixing with the blue gas leave theassembly through 30 and pass out through 51.

The heat for carbonizing the fuel is supplied by the sensible heat of the blue gas and any undecomposed steam passing through it and the assembly and is supplemented by:

(a) The heat in the blow gases passing around the carbonizing chamber with or without the secondary combustion of the blow gases efiected by air admitted at level 20C as desired for heating said chamber,

for effecting secondary combustion of any blow gases passing therethrough as described above in (c). a

(e) Admitting air and/or oxygen in the lower portion of the carbonizing chamber through 127 for combustion and the liberation of heat thereby. In this case the burned gases may be taken oil" through 51 mixed with the distillation gases but the air or oxygen is preferably admitted during the blasting period with the distillation gas outlet restricted so the burned gases will pass out through the bottom of the carbonizing chamber into 22 and mix with the blow gases, thus preventing dilution of the distillation gases. The carbonization temperature may accordingly be varied and controlled by the above methods of heating.

The hydrocarbon vapors are drawn off substantially as formed through assembly 26 and outlet 51 with a recovery of the condensible hydrocarbons in liquid form when desired, with little or no difficulty with the fuel arching or sticking during the carbonization process.

The remaining portion of blue gas and any undecomposed steam passes through 22, 23, 24, 25 into carbureter l3 and downwardly through the highly heated heat absorbing material 28 into oil admission zone 29. The hot blue gas mixes with oil sprayed into 29through 29a, and 29b, and is cooled thereby. From the drawings, particularly Figure 1, it will be observed that the nozzles or inlets 29a and 29b, through which the oil or liquid hydrocarbons are injected into the cargas will, on account of the velocity and mass of the sprayed hydrocarbon particles, cause the latterv to impinge against the downwardly moving gas and,as the hydrocarbon particles move farther and farther into the stream of the gas, said particles will be progressively heated, vaporized and cracked by the impingement upon and in contact with the gas particles successively encountered in its travel into said stream of gas, thus producing, in this reactive heated water gas, the desired mixing and formation of stable hydrocarbon gases in a short time and space as the gases continue in their downward movement.

The heat in the blue gas and steam and that radiated by the walls and refractory material adjacent to 29 brings the oil particles to the desired temperature for cracking and formation of stable hydrocarbon gases. In the passage of the gases and any uncracked oil particles through 30, and the heat absorbing material in 14, the cracking is completed and; the carbureted gas passes out through oiftake 33 with the valve therein adjusted as desired so that with valve 51, the division bureter, the valve 33 is closed or omitted with opening blanked, the valve 34 is opened and vacuum pump 37 operated.

In this case the valve 25 is partly closed to restrict and regulate the flow of gas to the carbureter. I ne oil is sprayed in as before and the resultant gas drawn olf through the condenser and vacuum pump to such further point in the apparatus as is desired.

A controllable amount of air enriched with oxygen when desired at the air blast level 20 may be admitted during the gas making period to maintain a sufficiently high temperature at this level for liquefying the slag.

As the gas making period progresses the fuel bed temperature falls and the chambers cool. When it is impracticable to continue the period, all valve; except 25 are again closed and valves 46, 42, 38 are opened.

Air is then admitted to the air preheater 16a through 53a and there preheated and then passed through 54a, 55, 56 to the generator carbureter, steam superheater, air preheater l6 and on through stack valve 46 as previously described.

During the air blasting period the valve 51 is adjusted to permit thewithdrawal of coal gases and vapors evolved meanwhile with the inclusion therein of a limited amount and preferably none of the blow gases.

Steam may be admitted through valved inlet 61a, 63, 65 and 2'? to blanket the entrance of blow gas into the carbonizing chamber and for the formation of blue gas and/or ammonia and to assist in carrying off the coal gases and vapors through oiftake 51 as previously described for the blue gas during the gas making period.

When the generator fuel bed, carbureter and regenerative chambers are suffieiently hot, the air blast is stopped and the gas making period resumed as before described.

The operation of the apparatus in Fig. 6 is carried on in a similar manner as described for Figures 1 and 2, with account taken of the omission of the gas superheater 14 of Fig. 1.

The apparatusin Figures 8 and 9 is operated in like manner with account taken of the use of each of the two regenerators 16' and 16a for superheating steam and preheating air.

In Figures 8 and 9, and assuming the apparatus to be heated and ready for continuous operation,with all valves closed except 52', 53', 54 and at level 20, and with 25, 42a and 46a" open, air passes through and is preheated in 16 thence through 54' and 56' to the generator, carbureting-superheating chamber, regenerator 16a and thence to stack through 46a". This blasting is controlled and varied at the different generator levels and in the other chambers as previously described. When the desired temperature is reached in the generator and other chambers, the air blast is discontinued and all valves except 25 are closed. Steam is now admitted to regenerator 16a through 61 and 53a and superheated therein, passes through 62a into distributing pipe 63 for use as previously described, the gas outlet 33 leading to vacuum pump or other apparatus as before described.

When the fuel bed and apparatus is cooled to such an extent that it is no longer practicable to continue the gas making period, steaming is discontinued, all valves are closed except 25. Valves 52, 53a, 54a and at level 20 in the generator and also 42, 46 are open. The air passes through and is preheated in 16a, and then passes therefrom to level 20in the generator fuel bed. The gases therefrom pass through 25 carbureter 13', 42, 16, 46" and out through stack 75. Air blasting is continued by varying the air blasting as at 20a, 20b, 20c and 2'? by opening and controlling the valves at these levels as desired and also for effecting secondary combustion in the carbureting and regenerating chambers as before described, until the fuel bed and chambers are heated to the desired temperature, when steaming is again resumed with the steam superheated in regenerator 16' as previously described.

Each regenerating chamber is accordingly heated by the blast gases and used for preheating air during alternate blasting periods and each is alternately used for superheating steam during alternate gas making periods.

The regenerators 16 and 16a preferably contain preheated air ofitake zones as 44a with valved outlet 54" for connection into preheated air distributing pipe 56 to avoid cooling the upper mass of heat absorbing material by the air so the heat therein is conserved for superheating the steam to a relatively higher temperature.

In Figures 10 and 11 a plant is shown similar to that in Figures 8 and 9 with the generator partly in section and having an additional valved gas outlet 51a to permit the withdrawal of gas from thelannular space 24 and with the carbureting gas superheating chamber 15 omitted an corresponding changes.

Air and steam admission to the generator is carried on as described for Figures 8 and 9. A portion or all or none of the blue gas may be withdrawn through the carbonizing chamber and outlet 51 with the coal gas and vapors mixed therewith, any remaining portion being discharged through gas outlet 51a.

The generatorin all the combinations may be operated as described for Figure 1 and the two regenerators shown in Figures 8, 9, 10 and 11 in which each is used for preheating air and superheating steam may be used with the plants shown in Figures 1, 2, 6 and 7 instead of the separate steam superheater 15 and air preheaters 16 and 16a.

The separate steam superheater and air preing chamber has a .blanketing effect as the steam.

entering this chamber may be at a higher pressure than the air in the air preheating chambers and prevents any air leaking through the valves as 42 and 42a, entering the carbureting chamber and mixing with the gas therein. l

With the use of two regenerators each for superheating steam and preheating air, a higher degree of superheat may be obtained in the steam by providing a sufliciently large and long passage, of heat absorbing material to permit taking the preheated air from an intermediate point in each chamber as 54 in Figure 8, thus avoiding the cooling action of the air on the hottest portion 5f the heat absorbing material 44' and conserving the heat therein for superheating the steam to a relatively higher temperature.

. tion.

The economies and advantages of the different features of by invention will be apparent to those skilled in the art from the foregoing description and may be briefly outlined asfollows:

Practically all of the otherwise waste heat in the blow gases is returned to the generator in the preheated air and superheated steam. The heat in the generator fuel bed at and above the water gas reaction temperature is thereby 'conserved for the directly useful purpose of steam decomposition. A saving in fuel, air, steam,'and time is effected with a corresponding increase ingas making capacity.

The relatively thick high temperature zone of fuel provides optimum steam decomposing con-' ditions andthe amount of undecomposed steam is substantially reduced.

The carbon monoxide content of the blow gases may be limited as desired.

The present limitation in water gas production occasioned by the fusing temperature of the fuel ash is definitely removedby removing the ash in liquid form. Cheap, abundant fuels are thereby made available for gas production.

The use of a fiuxing material such as limestone, for liquefying the ash has the additional advantages of furthering the production of ammonia and methane.

The carbonizing chamber and the assembly therein are so constructed and used that the present usual difficulties due to the stickingand hanging of the fuel are overcome and the coal gases and hydrocarbons recoverable in liquid ,form are recovered at controllable temperatures with a controllable admixture therewith of other gases. i

The heat and time for carbonizing the fuel are substantially reduced over present usual methods.

The production of ammonia is favored by the introduction of steam in the carbonizing chamber with the-temperatures therein controllable within the optimum limits for ammonia forma- The capacity of the regenerative chambers for preheating air and superheating steam is completely utilized; permitting a minimum size thereof for a given capacity and a relatively uniform temperature in the air and steam.

A practically complete conversion of the liquid hydrocarbons used for enriching water gasv into stable hydrocarbon gases is elfected, the amount required for enrichment is reduced and the formation of undesirable secondary compounds is substantially'avoided. r

In the foregoing description of the apparatus, I have entered into considerable detailed description as to the various steps andreactions under varying conditions that occur in the carrying out of" my improved method of water gas generation, but the same is to be considered merely-as illustrative'and all changes and modifications are contemplated that come within the scope of the appended claims. With respect to certain features hereinbefore set forth, particularly with reference to the apparatus and novel steps pertaining to carbonization and volatiliza absorbing material therein and a carbureting chamber below the heat-absorbing material, which comprises: blasting a column of fuel to incandescence with air; admitting air for secondary combustion to the blast gases and passing the gases downwardly through the heat-absorbing material and downwardly through the carbureting chamber in said carburetor; alternately with each air blasting period, generating water gas by admitting steam to the column of fuel; passing the water gas so formed downwardly through said heat-absorbing material and thence downwardly through said carbureting chamber;

simultaneously with the passing of the water gas through the carbureting chamber, admitting fluid hydro-carbons thereto; and maintainin the mean temperature of the mixture of water gas and hydro-carbons in the carbureting chamber within a predetermined temperature range for conversion of the hydro-carbons into'stable hydro-carbon gases, by preheating the water gas as it is passed through said heat-absorbing material.

2. The hereinvdescribed improvement in the method of carbureting water gas wherein air blasting periods are alternated with gas-making periods which includes: during each air blasting period, blasting a fuel bed to incandescence with air and passing the blast gases successively downwardly through a body of heat absorbing. material and then downwardly t ough a carbureting chamber; admitting air for secondarycombustionto the blast gases prior to the passage of the blast gases through said bodyof heat-absorbing materia1;- during each gas-making period, generating water gas by admitting steam to the incandescent fuel and passing the'water gas thereby formed also successively downwardly first through said body of heat-absorbing aterial and then downwardly through said car ureting chamber; and, simultaneously with the chamber, carbureting the water gas by injecting fluid hydro-carbons into and against the downwardly moving gas stream by spraying thereinto below the body of heat absorbing material.

3. The herein described improvement in the method of carbureting water gas wherein air blasting periods are alternated with gas-making periods, which includes: during each air blasting period, blasting a fuel bed to incandescence with air and passing the blast gases successively downwardly through a body of heat-absorbing material and then downwardly through a carbureting chamber; admitting air for secondary combustion to the blast gases prior 'to the passage of the blast gases through saidbodyof heat-absorbingmaterial; during each gas-making pe riod, generating water gas by admitting steam to the incandescent fuel and passing the water gas thereby formed also successively downwardly first through said body of heat-absorbing material to preheat the water gas and then downwardly through said carbureting chamber; and, simultaneously with the passage of the preheated water-gas through the carbureting chamber,

spraying liquid hydro-carbons into and against the gas stream at a pluralityof spaced points whereby the hydrocarbon particles in their passage into and against the gas stream are heated,

vaporized and cracked by their progressiveim pingement and contact with the gas particles in the gas stream.. I h

4.'The herein described process of manufac I ing zone and, while passing therethrough, carbureting the water gas by simultaneously injecting fluid hydrocarbons into said zone and into and against the vertically downwardly moving stream of preheated water gas.

5. In the manufacture of carbureted water gas, in an apparatus including an upright carbureter having heat-absorbing material disposed within the passage for the gases and a hydrocarbon admission zone below said heat-absorbing material; the improvement which consists in intermittently heating said heat-absorbing ma- 1 terial and hydro-carbon admission zone by the secondary combustion of air blast gases passed downwardly through the carbureter; alternately with said heating periods, passing water gas downwardly in contact with said heat-absorbing material and through said hydrocarbon admission zone; and admitting fluid hydrocarbons into the downwardly passing heated water gas and carbureting the same while passing downwardly through the hydrocarbon admission zone.

6. In the manufacture of carbureted water gas in an apparatus including a carbureter having heat-absorbing material therein and a hydrocarbon admission zone below the heat-absorbing material, the improvement which consists in: air blasting a generator fuel bed to incandescence and alternately generating water gas by admitting steam to said fuel bed; during the air blasting period, admitting air to the blast gases to burn the same; passing said'gases downwardly within the carbureter in contact with the heat absorbing material therein and thence downwardly through the hydrocarbon admission zone and, during the water gas generating period, passing the water gas downwardly in the carbureter in like manner and maintaining said heat absorbing material at a sufficiently high temperature for the ignition of the air blast gases and carbureting the water gas by injecting'fiuid hydrocarbons into the descending stream of water gas below said heat absorbing material.

' 7. In the manufacture of carbureted water gas in an apparatus including a carbureter having heat-absorbing material disposed within the passage for the gases through the carbureter and a hydrocarbon admission zone below the heat-absorbing material, the improvement which consi'sts in: blasting a generator fuel bed to incandescence with .air and alternately generating wa' 'ter gas by admitting steam to said fuel bed; during the air blasting period, admitting air to the blast gases to burn the same; passing said gases downwardly within the carbureter in contact with the heat absorbing material disposed within the passage for the gases and thereafter downwardly through the hydrocarbon admission zone; and, during the water gas generating period, passing the. water .gas similarly downwardly within the carbureter and maintaining the upper portion of said heat absorbing material free from contact with hydrocarbons by injecting fluid hydrocarbons into the descending water gas stream below said heat absorbing material, and carbureting the water gas by the injected hydrocarbons.

8. The improvement in the method of manufacturing carbureted water gas which includes: air blasting a generator fuel bed to incandescence and alternately generating water gas by admitting steam to said fuel bed; during the air blasting period, admitting air to the blast gases to burn the same; passing said blast gases after the air has been admitted thereto through passages in heat absorbing material and thence downwardly through a hydrocarbon admission zone; during the water gas making period, passing water gas through said passages in said material and preheating the water gas by contacting with said material and thence downwardly through said hydrocarbon admission zone; injecting fluid hydrocarbons into and against the preheated water gas stream while passing downwardly through said zone and vaporizing and cracking the hydrocarbons by the sensible heat of the preheated water gas and by the combination of the descending water gas current and gravity conducting the converted hydrocarbons away from the heat absorbing material.

9. The improvement in the method of manufacturing carbureted water gas which includes: air blasting a generator fuel be to incandescence and alternately generating wa er gas by admitting steam to said fuel bed; d mg the air blasting period, admitting air to the blast gases to burn the same; passing said gases through passages in heat absorbing material and thence downwardly through a. hydrocarbon admission zone; and, during the water gas generating period, passing the water gas through said passages in said heat absorbing material to be heated thereby and thence without substantial change of direction downwardly through a hydrocarbon admission zone; and injecting fluid hydrocarbons into and against the descending stream of heated water gas for vaporizing and cracking said hydrocarbons by the sensible heat of said heated water 10. In the manufacture of carbureted water gas in an apparatus including an upright carbureter having refractory material within the upper portion thereof and a hydrocarbon admission zone therebelow provided with means for injecting the hydrocarbons from the periphery inwardly, the improvement which consists in: during each air blasting period, passing the blast gases I downwardly in contact with said material and and through said zone; and carbureting the water gas during its passage through said zone by injecting liquid hydrocarbons into thedownwardly moving stream from the periphery of the carbureter.

11. In the manufacture of carbureted water gas in an apparatus including an upright carbureter having a gas inlet in the upper portion thereof, heat-absorbing material within the passage for the gases, and a gas outlet in the lower portion thereof, the improvement which consists in: intermittently heating said heat-absorbing material in said carbureter by the secondary combustion of air blast gases passed downwardly through the carbure'ter; alternately with said heating periods, passing water gas downwardly through the carbureter and simultaneously car-.

bureting the watervgas by injecting fluid hydrocarbons substantially radially into the downwardly passing water gas.

12. The herein described improvement in the method of manufacturing carbureted water gas which includes: air blasting a. fuel bed in a generator to incandescence; passing the blast gases downwardly through a carbureting chamber to a heat the latter; alternately admitting steam to HIRAM J. CARSON.

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