Improved Process and Plant for Generating Combustible Gases.
Year: 1896

page_text: Date of Application, 21st Apr., 1895
Complete Specification Left, 22nd Feb., 1897-Accepted, 17th Apr., 1897
PROVISIONAL SPECIFICATION.
Improved Process and Plant for Generating Combustible Gases.
I, BENJAMIN HOWARTH THWAITE of 29 Great George Street Westminster
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in methods of generating combustible
gas and an apparatus intended therefor, and more particularly applies to the
apparatus invented by the applicant and for which Letters Patent have already been
granted and the object of which is the production of gas intended for driving
gas engines, and the gasification of which is to be effected with inferior
hydrocarbonaceous fuel.
My former patents, to which this invention relates aro numbered and dated
respectively, No. 13,365 A.D. 1884 and No. 18,445 A.D. 1894. In one of these
specifications and that numbered 18,385 A.D. 1894 one of two associated vessels is
shewn to have an air supply applied over the surface of the fuel.
The action of final gasification in this generator is a descensional one, but the
partial and initial combustion of the fuel is effected in an associated generator, and
a secondary combustion is effected by the introduction of air above the solid fuel
level and the effect of this combustion produced for a purport clearly described in
the specification referred to, is the generation of a considerable degree of heat. In
order to reduce this loss, I preferably eucase the whole of tho gas generator sides
of both vessels, with water chambers, so constructed that they will stand a
considerable pressure; the steam thus generated I may employ as an agent to
increase the calorific intensity of the gas produced.
I may also utilise the heat thus generated to raise the temperature of the air
utilised in gaseous generation.
In a further modification of the apparatus, having a distinctive cycle, I employ
only one vessel, but provide au air connection both above the fuel level and also
below the grate.
I provide a three-way valve which diverts the air either above the fuel or below
the grate or to the base of the fuel in such generator.
The reversal of this valve also actuates the gas escape valve, this valve is fixed
on the main, lending from an aunular flue built in the refractory lining of the
generator, and connected to the inside of the generator by well distributed
connecting flues provided about 4 feet above the level of the base of fuel at the
grate or hearth.
In starting the process the air blast is turned on to the grate or to the base of
the fuel until the entire mass is raised to a condition of incandescence. Then the
air supply is directed to the upper surface of the fuel, the gas valve is opened, and
the gasification is initiated in a vertical direction, the gas escaping by the auoular
flue referred to.
During the ascensional, blowing up of the fuel, an apper valve weighted like a
safety valve is lifted, and the guses are permitted to escape until a condition of
incandescence has been established throughout the entire mass of the fuel, then this
escape valve is closed and the air is turned above the level of the fuel.
The position of the gaseous outlet will depend upon the character of the fuel to
be dealt with; I may occasionally adopt the method described in my patent

page_text: numbered and dated 18,445 A.D. 1894, in which the gases are compelled to flow
through hydraulic bath formed at the base of the fuel, before they escape into
the outlet maiu.
In order to make direct use of the heat of combustion established in the upper
part of the generator by the introduction of the high level air supply, I adopt the
following arrangement:-I provide an annular water cavity around the upper part
of the generator enclosed in except to the inside of the generator to which admission
from such a cavity is provided. I lead the air, intended for introduction into the
upper part of generator, into this water cavity, allowing the pipe that introduces
the air to dip some inches below the upper level of the water. Consequently a
certain portion of the heated water is taken over with the air and is introduced
into the fuel. A water supply pipe equipped with a seal permits the water to be
constantly replenished as fast as it is evaporated. I prefer to form the refractory
lining with a stiff slope, widening towards the base, or if I make the lining of
refractory segments or of sanitary pipes, I form successive rings of increasing size
from top to bottom, so that the tendency to clinker adherence is greatly reduced.
I may occasionally use a naked shell of steel lined externally with a water or oil
filled cavity surrounding the generator vessel.
When I employ the air blast to the base of tho fuel I use a modification of the
suspended grill described in my Patent dated and numbered 18,445-A.D. 1891.
This modification is effected as follows:-I provide a ring frame attached to the
lower ends of the bars. To this frame I hingo a grate to rotate vertically or
radially, and actuated from the outside either by a lever or by a worm gear.
I provide an upper frame formed around the grill on which to support clinker
spears.
1 may occasionally take off the gas from the centre of the base of the fuel, using
a pipe that projects above the level of the water of the bath, the outlet to be fitted
with a cone shaped cover so arrauged that the clinkers cannot block up the outlet.
1 form a slope down to the bydraulic bath, all round this central outlet, to
facilitate the removal of the cliuker, providing a water bath all round the base of
gas generator vessel, the casing of which is supported at different and equi-distant
points round the circumference.
Dated this 20th day of April 1800
1, BENJAMIN HOWARTH THWAITE, of 29 Grent George Street Westminster
Civil Engineer do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to improvements in methods of generating combustible gas
and in apparatus intended therefor, and more particularly applies to the apparatus
invented by the applicant and for which Letters Patent have already been granted
and the object of which is the production of gas intended for driving gas engines,
and the gasification of which is to be effected with inferior hydrocarbonaceous fuel.
My former patents, to which this invention relates are numbered and dated
respectively No. 13385 A.D. 189+ and No. 18445 A.D. 1894. In one of these
specifications and that numbered 13385 A.D. 1894 oue of two associated vessels is
shewn to have an air supply, applied over the surface of the fuel.
The action of final gasification in this generator is a descensional one, but the

page_text: partial and initial combustion of the fuel is effected in an associated generator, and
a second combustion is effected by the introduction of air above the solid fuel level
and the effect of this combustion, produced for a purport clearly described in the
specification referred to, is the generation of a considerable degree of heat. In
order to reduce this loss, I preferably encase the whole of the gas generator sides
of both vessels, with water chambers, so constructed that they will stand a.
considerable pressure; the steam thus generated 1 may employ as an agent to
increase the calorific intensity of the gas produced.
I may also utilise the heat thus generated to raise the temperature of the air
utilised in gaseous generation.
In a further modification of the apparatus, having a distinctive cycle, I employ
only one vessel but provide an air connection both above the fuel level and also
below the grate.
I provide a three-way valve which diverts the air either above the fuel or below
the grate or to the base of the fuel in such generator.
The reversal of this valve also actuates the gas escapo valve, this valve is fixed
on the inain, leading from an annular flue built in the refractory lining of the
generator, and connected to the inside of the generator by well distributed
connecting flues provided about 4 feet above tho level of the base of fuel at the
grate or hearth.
In starting the process, the air blast is turned on to the grate or to the base of
the fuel until the entire mass is raised to a condition of incandescence. Then the
air supply is directed to the upper surface of the fuel, the gas valve is opened, and
the gasification is initiated in a vertical direction, the gas escaping by the annular
flue referred to. -
During the ascensional blowing up of the fuel, an upper valve weighted like a
safety valve is lifted, and the gases are permitted to escape until a condition of
incandescence has been established throughout the entire mass of the fuel, then this
escape valve is closed and the air is turned above the level of the fuel.
The position of the gaseous outlet will depend upon the character of the fuel to
be dealt with; I may occasionally adopt the method described in my Patent
numbered and dated 18445 A.D. 1894 in which the gases are compelled to flow
through a hydraulic bath formed at the base of the fuel, before. they escape into
the outlet main.
In order to make direct use of the heat of combustion established in the upper
part of the generator by the introduction of the high level air supply, I adopt the
following arrangement-I provide an annular water cavity around the upper part
of the generator enclosed in except to the inside of the generator to which admission
from such a cavity is provided. I lead the air, intended for introduction into the
upper part of generator, into this water cavity, allowing the pipe that introduces
the air to dip some inches below the upper level of the water. Consequently a
certain portion of the heated water is taken over with the air and is introduced
into the fuel. A water supply pipe equipped with a seal permits the water to be
constantly replenished as fast as it is evaporated. I prefer to form the refractory
lining with a stiff slope, widening towards the base, or if I make the lining of
refractory segments or of sanitary piper, I form successive rings of increasing size
from top to bottom, or vise versa, Ro that the tendency to clinker adherence is
greatly reduced. I may occasionally use a naked shell of steel lined externally
with a water or oil filled cavity surrounding the generator vessol.
When I employ the air blast to the base of the fuel I use a modification of the
suspended grille described in my Patent dated and numbered 18445 A.D. 1894.
This modification is effected as follows:-I provide a ring frame attached to
the lower ends of the bars. To this frame I hinge a grate to rotate vertically
or radially, and actuated from the outside either by a lever or by a worm gear.
I provide an upper frame formed around the grille on which to support clinker
spears.
I may occasionally take off the gas from the centre of the base of the fuel,

page_text: using a pipe that projects above the level of the water of the bath, the outlet to
be fitted with a cone shaped cover so arranged that the clinkers cannot block up
the outlet.
I form a slope down to the hydraulic bath, all round this central outlet, to facilitate
the removal of the clinker, providing a water bath all round the base of gas
generator vessel, the casing of which is supported at different and equi-distant
points round the circumference.
Referring to the 3 sheets of drawings accompanying this specification. I wish
it to be clearly understood that I do not intend to be confined to the exact details
therein shewn as these may be modified without departing from the nature of the
said invention.
On Sheet 1 of drawings, Figure 1 shews the arrangement adopted for reducing the
thermal loss by radiant heat. The two generator vessels, A, and, B, are encased
in a jacket of water, C, made of sufficient structural strength as to withstand any
pressure of steam that may be generated, this steam is introduced into the fuel at
the position that will secure the best gasification results from such aqueous
introduction.
Figures 2 and 3 shew front aud side views of the reversal valvular connections
to gas generator, in which the cycle of operation involves ouly the employment of
one vessel and in which the gasification proceeds descensionally, and after the fuel
is blown up to a high temperature in the initiatory proceedings as fully described.
In Figures 2 & 3, D, is the air reversal valve connected by pipes, F, to the
upper part of fuel and by pipes, F, to base part of fuel. G, is the gas reversal
valve connected by pipes, H, to the upper part of geuerator, and by pipes, J, to
lower part thereof, the actuation of one reversal valve by the hand wheel, K,
simultaneously effects the reversal of the other reversal valve-such inter-
dependence of movement being obtained by the employment of sprocket wheel and
crossed link chain gear.
By the simple reversal of the valves the direction of the air can be altered from
an ascending to a descending one, in order that the cycle of operations described
can be effected. The gas whether issuing from the base of the fuel or from the
top or high level of the fuel escapes by means of the pipe, M.
On Sheet 2 of drawings Figure 4, shews the application of a water jacket encase-
ment formed around the upper part of generator vessel. The air to support the
action of gasification enters into this annular encasement and is compelled to flow
under the edges of an annular lip M by which it picks up a certain proportion of
the heated water-the overflow of the heated water escapes into the water bath
formed under the grate by means of the pipe, N, and its seal, O. The water is
introduced by means of the feed pipe, P, having the hydraulic seal, Q
Figure 5 on Sheet 2 of drawings, shews the method I adopt, of forming the
refractory lining of gas generator vessel. The sanitary or glazed fire-clay pipes, R,
of varying sizes shewn are backed up by fireclay, S. This lining is simple and
handy to construct.
Figures 6 and 7 on Sheet 2 of drawings show my improved arrangement of
hanging grate. Figure 6 is a vertical section and Figure 7 is a plan in section.
It will be noticed that the grate, T, is formed of ribs, U, some of which dip into
the water of the bath, V. The grate, T, turns on tilts, vertically around a pivot
shaft, W. This pivot shaft, W, is actuated by the worm gearing, X, located on the
outside of generator casing, Y. The worm gearing is actuated by a vertical shaft
and wheel, Z. The vertical barred grille, 2, formed around the grate, T, is placed in
the centre of an annular water trough frame, 1, this latter or annular water trough, 1,
is brought up against the lower ends of the vertical firebars 2 forming the vertical
barred grille and maintains them in a cool condition-the vertical firebars, or ribs,
are firmly inserted in upper ring, 3, that is kept by distance pieces or washer
rings, 4, up to, and within a certain distance of the lower Hange of a cope
casting, 5. The intervening space, 6, thus formed by the intervention of the
distance pieces or washer rings marked, 4, permits of the introduction of clinker

page_text: spears, 7. These spears, 7, are introduced through the casing of generator through.
perforations in the mountings, 8, which are equipped with sliding covers, 9.
The cone casting, 5, carries the rofractory lining, 10, of generator, to keep this
cool employ the water cooling method, the water being introduced by the
circular perforated pipe, 11,-as it leaves this pipe, the water flows over the
outside of cone-frame, 5, being received by the trough, 13, the water either flows
over the edges, 14, of this trough or through the hollow centre of the distance
bolts, 15, falling in a stream in front of the vertical firebars, 2, into the annular water
trough, 1, which forms the frame of the firegrate T; the shell or casing of gas
generator rests on tho edge of the water bath, V. A cross-barred door, 18, mounted
on a frame, 19, enables a workman to enter into the space around the grate, in
order to permit the cross-barred door to be readily lifted up, I provide a simple
counter-balancing arrangement, 20.
To assist the grate in supporting the fuel I employ a support bar, 21, shewn
more clearly in Figure, 7. Before the grate is rotated round, this bar must he
removed by being drawn through the mountings, 22, when the ashes and clinkers
have been tipped into the water bath by the lowering of the grate the lattor is
rotated back until it is brought up to the frame-then the support bar, 21, is
introduced across the mountings, 22, the cover-plates, 23, of this latter being
then closed. The clinker spears, 7, which have been driven into the fuel before the
grate was lowered to support the superincumbent fuel, are now withdrawn and the
fuel minus clinkers and ash fall on to the grate, and the door, 18, can now be closed
and the process of gasification can be renewed.
Figures, 8, and, 9, on Sheet, 3, shew respectively a section and plan of an.
alternative method of withdrawing the gas from the second vossel by means of a
central gas outlet pipe, 24, with its water bath arrangement, 25. The clinkers
accumulate in the water bath, 25, and they can be withdrawn by means of a rako
introduced under the edges of the shell, 26; ledges, 27, projecting from the side of
the water trough support the lower edges of the shell.
Having now particularly described the nature of my said invention and
in what manner the same may be performed, I declare that what I claim is as.
follows:-
1. The method of gasification of hydro-carbonaceous fuel in a single vessel
generator, and in which the air is introduced under pressure above the fuel, and in
which the gas escapes at the base of such fuel, the fuel being preliminarily and.
occasionally intermittently blown up to a state of thorough incandescence before
the air is introduced over or, at the high level of such fuel.
2. The reversal valvular arrangement associated with this cycle of gasification.
substantially as shewn and described.
3. The methods shewn of eucasing the upper part of a duplex gas generator
working on continuous cycle or in which part of the gas generated in the first
vessel and part of the hydrocarbons, are burnt by the introduction for this purpose.
of a secondary supply of air, with a water jacket for the purpose of, evaporation.
and, the generation of steam, substantially as shewn and described.
4. The method of building up the lining of a gas generator vessel substantially.
as shewn and described in Figure 5-Sheet 2 of drawings.
5. The moveable fire grate arrangement substantially as shewn and described in
Figures 6 & 7-Sheet 2 of drawings.
6. The gas generator central outlet pipe and its associated cooling and inclined.
water bath substantially as shewn and described in Figures 8 & 9-Sheet 3 of:
drawings.
Dated this 91st day of Enho 1907
B. H. THWAITE..