Year: 1894

page_text: Date of Application, 29th Sept.; 1894
Complete Specification Left, 29th Jure, 1895-Accepted, 24th Aug., 1895
I, BENJAMIN HOWARTH THWAITE of 95 Finsbury Pavement London Civil
Engineer do hereby declare the nature of this invention to be as follows:-
In the gas generator vessel the following expedient is adopted to ensure the
approach of the air to the fuel. At the base of an inverted cone casting, which
partly acts as a support to the refractory lining and also.as a means of reducing
the area of ingress to the fuel, I provide cast iron lugs that act as a means of
suspension and support for a series of bars, of steel or wrought iron, which project
below the level of the inverted cone almost into the water of thic hydraulic batli, or
such bars may project below the inverted cone not quite to the level of the water
forming a barred grill or girdle that retains the fuel in or nearly in a vertical
column down to or near to the level of the water bath.
This barred girdle enables the air to approach and enter all round the base of
the column of fuel, and there is no danger that the accumulation of fuel becomes
such as to obstruct the passage of air through the fuel.
The arrangement of attaching the bar to the lugs is such as to permit any
damaged or distorted bar to be rapidly renewed.
The refractory lining of the gas generating vessel is of special and novel con-
struction, instead of using ordinary firebricks or blocks, I employ unglazed or
glazed fireclay pipes smaller in diameter than the iron casing, between these
fireclay pipes and casing I fill in with a grouting of fireclay, which by the heat of
the fuel is baked into a hard condition.
I employ special curved blocks for completing the fireclay pipe lining. When
I employ a fan-air-blast I prefer to lead the air, (after it has passed through a
special tubular air heating apparatus, heated by the passage through it of the
products of combustion from the gas engine into a jacket surrounding the gas
generator vessel by which the air is further heated before it enters into the base of
fuel in the gas generator.
By these means, part of the sensible heat of the gas engine exhaust gases and
the heat radiated from the side of the generator vessel is recovered.
For the purpose of catching the unvolatilized hydrocarbons that pass over with
the gases from single vessel generators I provide for these vessels a secondary
chamber which may serve for more than one gas generator.
This secondary chamber is in its general form an almost exact imitation of the
gas generator vessel, that is to say like the latter or gas generator vessel it is
provided with a bydraulic bath, and may or may not have a grate to support the
cool or coke. Such coal or coke being allowed to rest on the solid bottom of the
hydraulic bath.
The inclination of the conical base of the coal or coke column forms a space, by
which the air can enter into the base or lower part of fuel.
This second chamber is connected to the gas generator by means of refractory
lining conduits connecting the upper parts of the two vessels.
I may however for dealing with special characters of fuels provide a connection
at the hottest level of the gas generators in addition to, and independently of the
unner conduit connections.

page_text: This second chamber I fill with coke of uniform size and to enable this material
to be replenished in the event of its partial combustion reducing the level of the
coke, an ordinary gas generator feed hopper is provided, by which additional coke
can be added at any time.
In order to be able to remove the coke as rapidly as it becomes clogged or
otherwise charged with pitch tar or other hydrocarbons, the base of the column of
coke or clinker submerged beneath the water in the hydraulic bath is continually
being reduced by the removal of part of the coke, new additions being made through
the feed hopper.
The coke can be raked away from the base submerged in the water of the
hydraulic bath without in the least arresting the progress of gas making, nor does
it involve the loss of any gas, because the side plates of both the second chamber
vessels and the gas generator dips some distance into the water of, the hydraulic
bath.
The outlet gas, connection from the coke chamber is positioned at the base
thereof so that the gas produced in this, gas generator is compelled to permente
through the column of coke and becomes, thoroughly scrubbed.
Moreover the dust and, tar produced when new fuel is charged into the gas
generator does not obtain access to the gas mains or flues but is caught by the coke
in the coke, chamber which, also serves the purpose of 'a down-comer leading the
gas to the flues.
I
may or may not saturate the coke with water introduced in the usual
When
manner.
I may however introduce water midway in the height of the chamber.
Ladopt this latter arrangement I prefer to make the lower half of the chamber & 2
larger diameter thau the upper half and introduce the water over the fuel at tlie
position formed between the two diameters.
Dated this 28th day of September 1894.
Improvements in Gas Generating Plant.
I; BENJAMIN HOWARTH THWAITE of 95 Finsbury Pavement London 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:―
1
In the gas generator vessel the following expedient is adopted to ensure the
approach of the air to the fuel, At the base of an inverted cone casting, which
partly acts as a support to the refractory lining and also as a means of reducing
the area of ingress to the fuel, I provide cast iron, lugs that act as a means of
suspension and support for a series of bars, of steel or wrought iron, which project
below the level of the inverted cone almost into the water of the hydraulie-bath, or
such bars may, project below the inverted cone not quite to the level of the water
forming a barred grill or girdle that retains the fuel in or nearly in a vertical
column down to or near to the level of the, water bath.
This barred girdle enables the air to approach and enter all round-the base of
the column of fuel, and there is no danger that the accumulation of fuel becomes
such as to obstruct the passage of air through the fuel,
The arrangement of attaching the fire bars to the lugs is such as to permit any
damaged or distorted bar to be rapidly renewed. The refractory lining of the gas
generating vessel is of special and novel construction; instead of using ordinary
firebricks or blocks, I employ unglazed or glazed fireclay pipes smaller in diameter

page_text: •
than the iron casing, between these fireclay pipes, and casing I fill in with a
gronting of fireclay, which by the heat of the fuel is baked into a hard condition;
employ special curved blocks for completing the fireclay pipe lining. When
I employ a fan-air-blast I prefer to lead the air, (after it has passed through a
special tubular air heating apparatus, heated by the passage through it of the
products of combustion from the gas engine) into a jacket surrounding the gas.
generator vessel by which the air is further heated before it enters into the base
of the fuel in the gas generator.
By these means, part of the sensible heat of the gas engine-exhaust-gases and
the heat radiated from the side of the generator vessel is recovered.
For the purpose of catching the unvolatilized hydrocarbons that pass.over with
the gases from single vessel generators, I provide for these vessels a secondary
chamber which may serve for more than one gas generator. This secondary
chamber is in its general form an almost exact imitation of the gas generator vessel,
that is to say like the latter or gas generator vessel it is provided with a.hydraulic
bath, and may or may not have a grate to support the coal or coke. Such coal or
coke being allowed to rest on the solid bottom of the hydraulic bath.
The inclination of the conical base of the coal or coke column, forms a space, by
which the air can enter into the base or lower part of the fuel.
This secondary chamber is connected to the gas generator by means of refractory.
lining conduits connecting the upper parts of the two vessels.
I may howover, for dealing with special characters of fuels provide a connection
at the hottest level of the gas generators in addition to, and independently of the
upper conduit connection.
This second chamber I fill with coke of uniform size, and to enable this material
to be replenished in the event of its partial combustion lowering the level of the
coke, an ordinary gas generator feed hopper is provided, by which additional coke
can be added at any time.
In order to be able to remove the coke as rapidly as it becomes clogged or
otherwise charged with pitch tar or other hydrocarbons, the base of the column of:
coke or clinker submerged beneath the water in the hydraulic bath is being
continually reduced by the removal of part of the coke, new additions being made
through the feed-hopper.
The coke can be raked away from the base submerged in the water of the
hydraulic bath without in the least arresting the progress of gas making, nor does
it involve the loss of any gas, because the side plates of both the second chamber.
ressel and the gas generator dips some distance into the water of the hydraulic
bath. The outlet gas connection from the coke chamber is positioned at the base
thereof, so that the gas produced in this gas generator is compelled to perineate
through the column of coke and becomes thoroughly scrubbed.
Moreover the dust and tar produced when new fuel is charged into the gas
generator, does not obtain access to the gas mains or flues, but is caught by the
coke in the coke chamber which also serves the purpose of a down-comer leading
the gas to the flues. I may or may not saturate the coke with water introduced
in the usual manner.
I may however introduce water midway in the height of the chamber, when.
I adopt this latter arrangement I prefer to make the lower half of the chamber a
larger diameter than the upper half and introduce the water over the fuel at the
position formed between the two diameters.
Before referring to the 4 sheets of drawings that accompany and form part of
this Specification, I wish it to be clearly understood that I do not intend to be
confined to the exact details shown therein as they may be departed from, without
involving in such departure, a release from the rights of this invention.
In Figures 1, 2 and 3, Sheet 1 of drawings,
Figure 1 is a vertical section, Figure 2 a vertical side elevation, and Figure 3 is
a plan.
The two vessels a and b are connected together by a connecting conduit c.

page_text: a is the acting generator vessel and b 18 the scrubber, and star, dust and dirt
catcher.
The base of the generator vessel consists of the inverted cone casting & carrying the
girdle of firebars e, the lower terminations of which, dip into the water of the bath
formed of concrete, a porforated water pipe fis provided to maintain the cone io à
cool condition.
The air blast from the fan is preferably compelled to flow through the water in
the water bath gas shewn, and the air therefore carries forward with it and in
suspension part of the water, through which it penetrates.
The air and suspended moisture in passing through the column of fuel in
generator vessel a is converted into gaseous fuel, carbon-monoxide, hydrogen and
nitrogen.
The fuel is fed into the generator vessel through the usual feed hopper. The
hydrocarbons from the newly fed fuel along with the gases from the fuel in
generator vessel flow through the conduite into the second vessel b, which is coke
filled to the level marked X.
The gases in descending through the coke are thoroughly scrubbed, the dirt
from the coal being caught in the top of the coke in the second vessel.
The base of the second vessel is constituted of an inverted cone casting i,
supported by the external iron casing of the vessel: The lower liprof this cone
casting i dips beneath the surface of the water in the hydraulic bath j. By this
arrangement the gases are compelled to flow through the water before they can
escape into the outlet pipe k.
The hydraulic bath projects outside the external casing of the generator, so that
the clinker can be readily withdrawn by rake or bar from the bottom of the
hydraulic bath.
In order to prevent the gas from escaping from the second vessel the plates of
the external casing dip some 10 inches beneath the surface, level of the water in
the hydraulic bath, so that a.rake or bar can be inserted and the tar saturated
coke can be raked away without involving any escape of gas.
Figures 456 and 7 on Sheet 2 of drawings shew certain improved details
relating to the method of lining a gas generator, and shew more clearly the
improved grate construction adopted by me.
Instead of employing firebricks for lining small sized generators, I use ordinary
fireclay sanitary pipes, as shewn at m, and provide special top cover tiles, or blocks
of fireclay as shewn at n. The general construction of the lining is clearly
indicated between the sanitary pipes and the casing I provide a sand cavity o.
The hanging frebars are supported from the projection at the base of the
inverted cone, as shewn more clearly on Figures 6 and 7.. This projection is
provided with recesses p for the hanging firebars 7, which are kept in position by
the wrought iron ring r; for facility in removing the ring and to enable. the
firebars to be tightly gripped, this ring is made in two halves.
The cone casting is supported by brackets or angle irons s attached to the
casing 1 may maintain a flow of water over the surface of this casting to prevent
it from becoming overheated. This flow of water may be supplied by the pipe t
having holes on its under surface.
}
The lower points of the firebars dip into the water of the hydraulic bath u.
This water contact prevents them from becoming overheated.
On.Sheet 3 of drawings Figure 8 shews the method adopted by me for obtaining
heated air for the air blast supply to gas generator.
I employ the sensible heat of the exhaust gases. from the gas, engine as an agent
for beating the air blast to the gas generator. The method by which this heat is
transferred to the air is as follows:
A vertical cylindrical vessel is employed, in which a nest of copper or other
suitable metallic tubes are placed. The heated gases from the gas engine flow into
this cylinder and around the tubes before escaping to the outer air. The air
flowing to the gas generator passes through these tubes, being either aspired or

page_text: forced through them. Of course the heated gases from the gas engine may be led
through the tubes, the air being drawn or forced around them on its way to the
gas generator.
I may fill the vessel with fine wire gauze or coiled lengths of copper wire, in
order to increase the heat absorbing and transmitting surface.
In Figures 9 and 10 Sheet 4 of drawings, shewing respectively a vertical section
and a plan of my air heating arrangement, the exhaust gases are led into the
chamber 12 and flow through the vertical nest of tubes, transmitting its heat to
them. The heat is transferred to the air forced by fan 13 around the tube 14.
The air is compelled to encircle the tubes because of the diaphragm 15, that directs
the air supply upwards and downwards, across and around the tubes before it can
escape by the outlet 16. The wire coils are shewn at 17.
Figure 8 on Sheet 3 of drawings shews the cycle of heat production and thermo-
dynamic transformation, and the return of the heat to the generator, the general
direction of the heat, thermo, chemical and sensible is shewn by the arrows.
1 is the duplex non-reversal gas generator. 2 the hydraulic main. 3 the
condenser or gas cooler. 4 the sawdust scrubber. 5 the hydraulic valve. 6 the
gas holder. 7 the gas pipes to feed engine. 8 the gas engine. 9 the exhaust pipes
from gas engine leading the gas to the air heater. 10 the hot air maius. 11 the
high pressure fan and exhauster.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same may be performed, I declare that what I
claim is included in the following statement :-
CLAIMS.
First. The employment of a second and coke or other porous material filled
vessel in direct connection with the gas generating vessel.
Second. The suspended and vertical barred grate arrangement.
Third. The method of utilising the sensible heat of the gas engine exhaust gases
to raise the temperature of the air required for the gasification of the fuel.
Fourth. The method of internally lining the gas generator vessel, substantially
as shewn and described.
Fifth. The air heating apparatus by which the sensible heat of the gas engino
exhaust gases is transferred to the air proceeding to the gas plant.
Sixth. The method of forming a hydraulic water bath at the base of the coke in
the second vessel, and the arrangement by which the gases are compelled to force
their way through this water bath before escaping into the outlet main.
Seventh. The general arrangement of gas generating plant substantially as
shewn and described.
Dated this 25th day of June 1895.
B. H. THWAITE.