US1682264A

US1682264A - Method of generating gas

Info

Publication number: US1682264A
Authority: US
Publication date: 1928-08-28
Anticipated expiration: 1945-08-28

Description

C. W. BOTSFORD METHOD OF GENERATING GAS Aug. 28, 1928.

Original Filed Dec. 26, 1919 2 Sheets-Sheet 1 Invenfor /4 a F194 LK Aug. 28, 1928. 1,682,264

C. W. BOTSFORD METHOD OF GENERATING GAS Original Filed Dec. 26, 1919 2 Sheets-Sheet 2 Ihvenior Patented Aug. 28, 1928.

UNITED STATES PATENT OFFICE.

CLAUDE W. BOTSFOBI), OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO WILLIAM W. ODELL, OF PITTSBURGH, PENNSYLVANIA.

METHOD OF GENERATING G AS.

Original application filed December 26, 1919, Serial No. 847,566. Divided and this application fled August 30, 1923. Serial No. 660,203.

My invention relates to an improvement in a method for generating gas and more particularly to the method of manufacturing either water gas, producer gas, carburetted water gas, carburetted producer gas or com-.

binations of anyof these with coke, anthracite coal, bituminous coalor other carbonaceous fuels.

This application is a division of my application for improvements in gas generators, Serial No. 347,566 filed December 26, 1919.

Considerable difiiculty is usually met with when it is attempted to use bituminous or coking coal as generator-fuel in the manufacture of water gas, the use of such fuel resulting in reduced capacity of the generator; increased steam consumption; the roduction of excess amounts of smoke and o combustibles in the blast gas, and a decrease in the volume of incandescent fuel in the generator, due to the greater difficulty of heating coal whose temperature tends to remain below 250 degrees F. until the moisture is driven off.

The objects of my invention are to overcome the difficulties above mentioned to produce and obtain a method of generating water gas successfully from bituminous fuels and other types of fuel as well.

Other objects of my invention are to produce a greater volume of incandescent fuel from a given amount of air blast; to increase the capacity of a given size of generator; to decrease the amount-of carbon dioxide produced during-the steam run; to prevent the formation of clinkers; to reduce the amount of steam necessary for generating gas; to preent caking or sticking of the fuel when cok' ing; to maintain a more uniform temperature within the generator during the operation; and decrease the amount of poking of the fire.

The invention has among its other objects the method of generating gas reliably, efficiently and in a highly satisfactory manner.

Many other'objects and advantages of the construction herein'shown and described will be obvious to those skilled in the art from the disclosures herein given.

To this end 'my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in the claims. a In the drawings, wherein like reference characters indicate like or corresponding parts:

Fig. 1 is an elevation, partly in section, of the generator for the manufacture of gas;

2 is a top plan view of the same;

F 1g. 3 is a section taken substantially on the line YY of Fig. 1; and

Fig. 4 is a fragmentary view in vertical section showing the operation of the valve R.

In the drawings, wherein I have illustrated the preferred embodiments of my invention,

A indicates the shell of a water gas generator,-

the san'1e being of any desired size and shape and having a refractory lining B within its interior. Jonduits D and Q, are arranged adjacent the upper and lower ends of the shell, respectively as shown, and are for the admission of air blasts to the interior of the generator. of the blast air through Q. The steam ports E. H and G are arranged adjacent the upper middle and lower ends, respectively of the generator and are controlled by suitable valves I and V.

It will be noted that the inlet of the steam at G is below the grate G, upon which the body of fuel rests, while the jet E discharges into the generator above the top of the body A valve F controls the passage of fuel. A cover J is arranged to control a charging opening through the top of the generator, and cleaning and ash pit doors, K and L, are arranged adjacent the lower ends of the generator. An off-takeoutlet M, controlled by, a valve N, is arranged at the .bottom of the generator, preferably below the grate,

and an off-take O is arranged adjacent the top of the generator above the port Q, and the body of fuel and is controlled by Valves P and R. The gas taken off through the outlet M discharges into the off-take pipe W, while the gas taken off through the outlet 0 discharges into the off-take pipe X, the off-take pipe W ber V, is arranged at the lower end of the offtake X below its connection to the off-take W, as shown. l 1

The refractory lining B of the shell is of any suitable thickness and is formed with an annular recess '1 intermediate the upper and emptying into the off-take X. A dust chamlower ends, this recess being substantially angle-shaped in radial cross-section and having a sharp deflection therein. The annular recess T ends toward the lower portion of the generator at Z and thence the lining slopes taperingly outwardly and then straight down to the bottom of the generator.

Vertical ducts U are arranged through the lining B, the lower ends of said ducts opening into the generator and communicating with the fuel bed at the annular recess T preferably adjacent its upper side and extending upwardly therefrom to communicate with an annular opening or collecting chamber S within the lining adjacent the upper level of the fuel bed and emptying into or communicating with the off-take Q. Thus, air for blasting may be forced through the port Q to discharge into the fuel at its middle portion through the ducts U, or at the bottom through the port 1). or the gases from the body of fuel may .be discharged or removed upwardly through the ducts U and taken off through the off-take Q, or through the ports 0 or M.

The valve R controls the passage through both of the off-takes O and Q, and may be of any desired construction. An inlet C may be used for the introduction of the carburetting material,'such as oil or tar into the body of the fuel and in the present instancethis inlet is shown as being arranged substantially at the recess near the middle of the generator.

From the foregoing description, it is obvious that the blasts of air when conducted through the ducts U, previously heated by the outgoing blast gases, will become preheated before discharging into the mass of fuel. Steam can be discharged into the fuel at either the top or bottom or at the center, as

desired. These various methods of control give quite a range of operation, some methods being better for certain fuels than with others.

The generation of the gas may be either intermittent or continuous. When it is desired to use bituminous coal and togenerate water gas by the intermittent method, I prefer to operate as follows: I i

The ignited fuel is heated to incandescence by blasting air upwardly from the bottom of the bed of fuel through the inlet port D, the valves N, F and P being closed and the offtake Q being open so that the blast gases pass upwardly through the fines or ducts U and out through the off-take X. This blasting is continued, generally for a brief period, until the lower zone of the fuel bed becomes incandescent, but before the reaction CO +C=2CO can take place to any appreciable extent. The blast through D is then shut off, the valve F opened and the valve R lowered to close the oil-take through Q and open it through 0 and then the air blast is run through the port Q and discharges into the fuel through the ducts U having been preheated by the time it strikes the fuel. The fuel in the upper zone of the generator becomes heated, the valve P being open so that the gases are discharged upwardly from the middle of the fuel bed and pass off through the off-take O and into the main off-take X. This is continued until the fuel at the top of the fuel bed is sufliciently heated, whereupon the air blast is shut off at F and steam admitted at the bottom of the generator at G, passing upwardly through the full depth of the bed of fuel and out through the off-takes O and X to a gas holder (not shown). This is continued until the quality of the gases drops to such a point that no more good gas is passed off.

In case it is desired to carburet the water gas, the carburetting material is discharged into the fuel at C simultaneously with the discharge of the steam thereinto at G as just described above, the steam and vapors passing through the fuel together and the resulting gases and vapors discharging through the off-takes. When the fuel is no longer hot enough to generate good blue water gas, the cycle is repeated except that steam is admitted at the middle of the body of the fuel at H, and a down run made, the valves P and F being closed and N open so that the gases move downwardly and pass through the off-take M. It is to be noted that the time of contact of the steam and the incandescent fuel is generally greater than tlie time of contact of the blast gas and the fuel. Thus, during blasting, a more complete combustion of carbon takes place and the reaction C+O =CO predominates over the reaction CO +C=2CO, and more heat is liberated in the generator. During the steam run, the time of contact is so long that the reaction H O+C==CO+H takes place more completely and there is less of the reaction C 2H,O CO 2H,,.

It is to be understood that the tar'or oil'admitted through the ports C on the down run is preferably only during the latter part of the run in order to prevent the complete cracking of the hydrocarbons into hydrogen, but dur-' ing the up run I prefer to admit 'tar or oil during the entire run or during the first part of the run.

An up run may now be made by admitting steam at G and taking the resulting gases off through the preheating ducts. The steam may then be shut off and a down run made, admitting steam at E and taking the gases off through U. These cycles may be repeated, blasting from the various points and admitting steam as required.

To sum up, the first cycle consists in air blasting for ashort period upwardly from the bottom until the lower portion of the fuel fed is incandescent, then blasting for a short period with preheatedair through the center of the fuel bed upwardly, then shutting off the blast and admitting steam at the bottom (simultaneouslyadmitting the carburetting material, if desired) off at the top.

The second cycle comprises the blasting with preheated air from the center upwardly and then downwardly for the first half of the and taking the gas extent that the oxygen in blasting period, then blasting from the bottom upwardly and taking the gases off at the middle through the preheating ducts for the balance of the blasting period, then shutting off the blast and admitting steam first at the top then at the bottom while taking the gases off at the middle.

Where fresh fuel is present a third cycle may be added and comprises the air blasting upwardly from the bottom through the entire body of fuel and taking the blast gases off at the top off-take, then blasting from the center upwardly, then shutting off the air blast and admitting steam at the center downwardly (carburetting at the time if desired) for the first part of the run, taking off the gas from the bottom, then admitting steam at the bottom (carburetting if desired) while taking gas off from the middle or top, depending upon conditions.

When making water gas using coke or anthracite coal as fuel, I frequently blast up with air from D through the entire bed of fuel, taking blast gases off through 0, this being sometimes especially desirable or necessary when an increased amount of CO or other combustible is desired in the blast gas, as for instance when checker-brick chambers are to be heated. Using this kind of fuel it is sometimes necessary to blow steam in from the top of the fuel bed to prevent the top of the generator from becoming too hot, and taking the gases off at either the bottom or middle. If desired, steam may be blown through at both the bottom and top simultaneously.

When operating with a strong coking coal, the manner of operation is slightly different. The air is blasted upwardly through the entire body of fuel, taking the gas off at the top, then the air is blasted through the preheating ducts, taking the gas off at the top, then the steam is admitted at the bottom taking the gas off at the top but admitting a small quantity of air at the middle of the fuel bed during the up runs. The amount of air admitted during these up runs is not enough to cause combustion to continue, but is only sufficient to cause oxidation or incipient combustion in the coking coal.

I find that the oxidation decreases the tendency toward caking and matting together of the coal by partially destroying its strong coking tendencies. I have found that this is particularly advantageous when making carburetted gas because the tar or oil along with the blue gas reaction cools the fuel to such an the air admitted reaches the fuel at a higher level than otherwise.

The method of making producer gas is slightly different from that of making water gas. When using bituminous coal and making producer gas by a continuous process. the air is blasted upwardly through the entire body of fuel through D simultaneously with the admission of steam through H at the middle of the fuel body, taking the gas off at the top at 0, then the air is shut off at the bottom and blown in at Q becoming preheated before its admission and steam is admitted simultaneously from the bottom at G instead of through the middle at H.

If it is desired to carburet the producer gas, the same method as above described is used, except that the tar or oil is blasted in through C during a part of or during the complete run. Down runs may be made by taking the gas ofi at M and admitting the blast at U and the steam either at E or H as desired.

It will be seen that the generator is so designed and equipped that the hot air may be blasted either upwardly or downwardly, or both ways at once and the amount of such blasting can be controlled by the various valves. The alternate direction of blasting keeps the fire in more uniform condition and eliminates blow-holes therein. In addition, it keeps a more uniform temperature throughout the fuel bed and therefore operates within. a smaller maximum and minimum temperature limits, enabling one'to avoid forming clinkers, which commonly prevail when using coal having a low ash fusing point. There will be little or no tendency for the coal to coke and stick upon coking on account of the taper of the walls T. The particular shaping of the coking chamber walls causes.

the fuel to pass downwardly through the generator due to its'own weight as fast as the fuel is consumed.

Another advantage of the tapering of the coking chamber is that the fuel will not be in permanent contact with it, and leaving an annular space that will allow steam, tar and air to pass through the fuel bed evenly.

The constriction Z in the size of the fuel bed above the clinker zone tends to increase the velocity of the gases pas-sing therethrough and the ash has a better opportunity to fuse and run free from the lining during the blasting. This prevents the arching of clinkers, which is a common source of trouble, the clinker havin a special tendency to form in an umbrella formation a foot or two above the'grate.

The down run steam ports are arranged below the coking zone so that the coking is not retarded by downward steam, as it is in common practice when bituminous fuel is used.

The possibility of enabling the operator to admit steam at either top or bottom or at both simultan *ously, and blasting in any directionis especially advantageous because when the steam is admitted at either the top or bottom of the fuel bed the gas produced can be taken off at the opposite end of the generator or at the middle thereof.

The steam is more completely decomposed.

and forms less (10 when using my generator than 1n any other because a hot zone is maintained higher up in the generator than in ordinary practice. The capacity of the generator is greatly increased because I get more heat liberated for a given amount of air blasted, due tothe fact that less CO and more CO is formed. N o uncarbonized fuel reaches the grate and hence there is but a slight amount of blow holes with my fuel in the ash, with a consequent saving in operation.

The slope at the annular chamber and from.

the grate to said chamber may be varied to accommodate the various fuels used because the properties of these fuels vary to a large extent.

The coking line enables the recovery of a greater proportion of the volatiles since the blast gas need not pass through the upper bed of fresh uncoked fuel but can be taken off from substantially mid-way the generator ends. The preheating of the air for blasting enables the operator to blast at points considerably above what is usually known as the hot zone, and by avoiding the necessity of passing this air through the lower hot zone I am enabled to produce complete combustion in the middle of the fuel bed.

In common practice, during the latter part of the blast there is very little complete combustion because the CO formed combines with carbon to form CO and absorbs the heat and produces considerable CO in the blast gas.

I Little poking of the fire is necessary and greater uniformity of temperature in the fuel is obtained and less trouble is occasioned by generator, operated as described.

7 Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention;

from a point intermediate the ends hence I do not Wish to be undestood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. A method of producing carbureted water gas, consisting in air blasting from the bottom of an ignited fuel bed contained in a generator, taking off the resulting blast gas of the fuel bed, then blasting the fuel for a short period with preheated air from said intermediate point upwardly, then shutting off the.

blast and admitting steam at the bottom of the fuel bed and simultaneously admitting carbureting material intermediate the ends of the fuel bed, and taking off the gas at the top of the generator.

2. The method of consisting in ,air blasting a bed of ignited solid fuel contained in a generator from beneath, until the lower portion of the fuel is provision of the ofi'takes U below the producing water gas,

incandescent, taking off the-blast gas from a point intermediate then blasting for a period with preheated air from a pointintermediate the ends of the fuel bed upwardly, then shutting off the blast and admitting steam from beneath the fuel bed, and taking off the gas at the top.

3. A method of making carbureted water gas, which consists in air blasting a bed of ignited fuel contained in a generator from beneath the fuel bed,'taking off the resulting blast gas froma point intermediate the ends of the generator, then shutting off the blast, then admitting steam from the bottom, carbureting from an intermediate point, and taking off the resulting carbureted water gas from the top of the fuel bed, then blasting again from the bottom of the generator upwardly followed by a steam run up from the bottom for a part of the run, taking off the gas at the top, then cutting off the steam at the bottom and admitting steam from the middle, and taking off the resulting gas from the top and bottom.

4. A method of producing water gas,'consisting in air blasting ignited solid fuel contained in asingle generator from beneath the fuel bed and discharging the blast gas at the top, then stopping the blast at the bottom and blasting intermediate the ends of the fuel bed upwardly with preheated air, then shutting off the air blast and admitting steam at the bottom, passing the same upwardly for the first part of the run and discharging the gas at the. top, then shutting off the steam at the bottom and admitting steam from above the fuel bed, and taking the gas off at.

intermediate the ends of the fuel bed, then shutting off the air blast and admitting steam at the bottom and simultaneously admitting carbureting material intermediate the ends of the fuel bed, and taking the gas off at the top;rand the second cycle consisting in blasting with air from an intermediate point of the generator up and down for a period, and then from the bottom upwardly, taking the blast gases off and utilizing them for preheating purposes during the latter stage of the blasting period, then shutting off the air blast and admitting steam from the top and bottom of the generator, and taking off the gas from a' point intermediate the ends of the fuel bed.

6. A method of producing carbureted water gas, consisting in air beneath an ignited fuel bed confined in a genthe ends of the generator,

blasting from way the ends of the. fuel erator, discharging the blast gas at the top of the generator, then shutting off the blast at thebottom and blasting upwardly with preheat-ed air from a point midwa the ends of said generator, then shutting off the air blast, admitting steam at substantially midway the ends of the fuel bed and passing the same downwardly for a part of the run, discharging the gas at the bottom and carbureting at.

the time of the admission of the steam, subsequently admitting steam at the bottom of the generator, carburet-ing also during this part of the run, and taking the gas oil from the top of the generator.

7. A method of generating water gas, consisting in air blasting the ignited fuel contained in a generator from beneath the fuel bed upwardly, taking off the blast gases at an intermediate zone, and utilizing the heat of said gases for preheating air in a later stage of the blasting period, then blasting with preheated air from substantially the middle of-the fuel bed alternately up and down, then shutting off" the air blast and admitting steam at the top and bottom, and taking ofi the gas at'a point intermediate the ends of the fuel bed.

8. A method of producing water gas, consisting in air blasting ignited fuel in a generator from beneaththe fuel bed and discharging the blast gas at the top of the generator, then shutting off the blast at the bottom of the generator and blasting intermediate the ends of the fuel bed upwardly with reheated air, then shutting off the air blast and admitting steam at substantially the middle of the fuel bed, passing the steam downwardl for the first part of the run, and discharging the gas at the bottom of the generator, then admitting steam at the bottom of the generator-only, and taking off gas from the middle or top of the generator. I

9. A method of making water gas from solid fuel in a single generator, consisting in first air blasting an ignited fuel bed alternately up and down from substantially midbed, then shutting off said air blast and making a straight up steam run, introducing the steam from beneath the fuel bed, and removing the finished gas from above the fuel bed.

10. A cyclic method of making water gas from solid ignited fuel contained in a single shell, the first c ole consisting in air blasting said, fuel from beneath, and taking the blast as ofi from substantially midway the ends of the fuel bed, and removing the gas from above the fuel bed, then shutting oif said air blast, and then making a straight up steam run, introducing the steam from beneath the fuel bed; the second cycle consisting in air blasting for a period with preheated air from substantially midway the ends of the fuel bed, alternately upwardly and downwardly, and taking off the blast gas both above and below substantially the fuel bed, shutting off said air blast and making steam runs, admitting the steam altcrnately from beneath the fuel bed, and from substantially midway the ends of the fuel bed, and taking off the gas respectively from the top and from beneath the fuel bed.

.11. A method of making carbureted water gas from solid fuel contained in a single generator, consisting in first air blasting an ignited'fu'el bed alternately up and down from midway the ends of the fuel bed, then shutting off the blast and making a straight up steam run, introducing the steam from beneath the fuel bed, removing gas from above the fuel bed, and introducing carbureting material into the fuel bed midway its ends during the steam run.

12. A method of producing water gas by operating in successive cycles, the first cycle consisting in air blasting from the bottom of a confined ignited fuel bed for a short period until the lower portion of the fuel bed is incandescent, then blasting for a brief period with preheated air only upwardly from a point intermediate the ends of the fuel bed, and then shutting off the air blast and admitting steam at the bottom and taking the gas off at the top, the second cycle consisting in blasting with preheated air from a point intel-mediate the ends of the generator alternately up and down for a period, and then from below upwardly, taking the blast gases off and utilizing them for preheating purposes during the latter stage of the blasting period, then shutting off the air blast and admitting steam alternately from the top and bottom of the generator, and taking off the gas from a point intermediate the ends of the fuel bed.

13. A method of producing water gas in a generator by operating in two cycles, one cycle consisting in air blasting ignited fuel from beneath the fuel bed for a short period until the lower portion of the fuel bed is incandescen't, then air blasting for a brief period upwardly only from a point intermediate the ends of the fuel bed, then shutting off the blast and admitting steam at the bot-' tom, and taking the gas off at the top; the second cycle consisting in air blasting from a point intermediate the ends of the generator up and .down for a period, then blasting from I below upwardly, taking the blast g'ases off and utilizing them for preheating purposes during the latter stage of the blasting period, then shutting off the blast and admitting steam alternately from the top and bottom of the generator, and taking oif the gas from a point intermediate the ends of the fuel bed. 14. A method of making water gas, which consists in air blasting a bed of ignited solid fuel contained in a generator in an upward direction only, admitting air to the fuel bed from the bottom and taking off the blast gas at substantially the middle of the generator fill for the first period of blasting, then air blasting the fuel bed from both bottom and middle of the fuel bed simultaneously using preheated air at the mid point and taking oil the blast gas at the top, then making steam runs first up from the bottom, taking ofl' the yvater gas at the top, then making down steam runs from the middle of the generator, and taking the gas ofl at the bottom.

15. A method of making Water gas which consists in making successive cycles, one cycle comprising first air blasting upwardly only from beneath a bed of ignited solid fuel contained in a generator, taking off the resulting blast gas from a point adjacent the middle of the generator, then making a steam run straight up from the bottom taking off the water-gas at the top, and a subsequent cycle consisting in air blasting the fuel simul- 20 taneously from both bottom and middle of the generator upwardly, taking oil gas at the top, then making a steam run up from the middle, and taking thegas oil at the top.

16. A method of making Water gas which consists in making a series of cycles, one cycle comprising first blasting upwardly from beneath a bed of ignited solid fuel contained'in a generator, taking oil the resulting blast gas from a point adjacent the middle of the generator, then making a steam up run from the bottom taking the resulting gas off at the top, and a second cycle consisting in air blasting from the middle of the generator alternately up and down, taking, off gas from top and bottom, and then making a steam run up through the entire fuel mass.

In testimony whereof, I have hereunto signed my name.

CLAUDE W. BOTSFORD.