An Improved Process for Generating Combustible Gas, and in Apparatus therefor.
Year: 1894

page_text: Date of Application, 11th July, 1894
Complete Specification Left, 10th Apr., 1895-Accepted, 1st June, 1895
PROVISIONAL SPECIFICATION.
An Improved Process for Generating Combustible Gas, and in
Apparatus therefor.
1, BENJAMIN HOWARTH THWAITE of 95 Finsbury Pavement London Civil
Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to an improved process for generating combustible gas,
especially adapted for use in internal combustion engines, and permitting the
employment of bituminous slack steam coal, for all heating purposes where
a fairly pure, and permanent carbonmonoxide, and hydrocarbonic gas is a
desideratum.
The essential characteristics, and qualifications of my invention are described by
the following:
It is found by experience that in order to permanently fix the hydrocarbon
gases from semi-bituminous coal that these gases should be compelled to flow
under pressure through a column of incandescent coke or other carbonaceous
fuel.
To effect this essential condition continuously and without involving any
reversal action, I proceed as follows.
1 provide two vessels connected together in their upper portion by a flue
so arranged that the heated gases and flame from one vessel pass into the
adjoining one.
Each of these vessels has a specific function to fulfil.
In one vessel called hereinafter the first vessel, the inception of fuel combustion
and its continuance is established in such a way that part of the heating effect of
combustion is, by the passage of the flame or highly heated gases through the fuel
in the second vessel, transferred to the column of fuel in this second vessel, and the
newly fed fuel in both vessels has its hydrocarbon gases driven off or expelled and
they, along with the carbonmonoxide gases from the first vessel descend through
the incandescent fuel in this second vessel, this fuel incandescence being obtained
by the partial combustion of the gas and the complete combustion of part of the
solid fuel in the first vessel.
In descending through the incandescent fuel the following effects thermic, and
chemical take place.
First the volatile hydrocarbons are gasified and converted into a condition more
or less permanent.
The carbondioxide produced by the partial combustion of the gas, another
complete combustion if part of the solid fuel in the first vessel is converted in
contact with the incandescent carbon in the second vessel into, carbonmonoxide.
Any water-vapour or steam passing into the second vessel is decomposed in its
passage through the deep column of incandescent fuel in the second generator. The
oxygen forming with the incandescent carbon carbonmonoxide the hydrogen being
set free. In one arrangement of my invention the depth of fuel in the first vessel
may be maintained of such dimensions that when a powerful air blast is established
under the firegrate, part of the air passes through the fuel and consumes part of
the gas generated by the partial combustion of the fuel in the first vessel. The
effect of this combustion in the first vessel raises the temperature of the part of the
1st vessel above the level of the fuel as well as the fuel in the 2nd vessel (through
which the treated gases have to descensionally pass) to a high temperature the

page_text: fuel in the second vessel being raised to the equivalent temperature of visible
incandescence.
In adopting this arrangement of effecting my invention I make the first vessel
much shallower in depth than the second vessel. Indeed it may be merely a fire
grate in which the fuel is entirely consumed, relying for the production of a com-
bustible gas by the passage of the products of combustion through the incandescent
fuel in the second vessel.
Instead however of employing a shallow depth of fuel in the first vessel and in
order to obtain the necessary temperature of incandescence in the second vessel I
may provide the first vessel with such a depth of fuel as to enable a regular
character of gas to be generated in- the first vessel part of this gas I consume
by the introduction under pressure of a certain proportion of atmospheric air
either immediately over or merely under the surface of the fuel in the first
vessel.
The flame resulting from this combustion passes immediately' into the second
vessel through the fuel of which it descend's raising the temperature of such vessel,
and the fuel to a high state of incandescence.
The chemical, and thermic effects of the action of gasification are as described
for the first arrangement of my invention.
I provide fuel feeding arrangement for both vessels preferring to empty a water,
jacketted feed' hopper base.
'I also employ the usual' arrangements for removing the incombustible residuum
or clinker that gravitates to the base of the fuel for both vessels. 'For the first
one I may employ a closed water bath under the grate, but for the second vessel I
may employ a solid floor.
In order to reduce the loss of heat radiatum through the walls of the first vessel
'I jacket such vessel either with water, or air employing the steam that may be
evaporated' either for propelling a fan, or by use with a steam jet aspirator,
inducing an air blast altogether under or applied to grate of first vessel, or partly
under such grate and partly over the fuel level, in order to consume a' portion of
the gas generated.
The second air supply being exactly controllable by valvular arrangements of a
special character.
To enrich the gas produced I may inject liquid hydrocarbon over the fuel in one
'or both vessels.
Dated this 10th day of July 1894.
An Improved Process for Generating Combustible Gas, and in
Apparatus' therefor..
.
:
1, 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 :-
This invention relates to an improved process for generating combustible
gas, especially adapted för "use in internal combustion engines, and perinitting
the employment of bituminous slack steam coal, for all heating purposes,
where a fairly pure, and "permanent carbon-monoxide, and hydrocarbon gas is a
"desideratum.
The essential characteristics, and qualifications of my invention are described by
"the following
It is found by experience that in order to permanently fix the hydrocarbon

page_text: De compered
GU TOW
gases from semi-bituminous, coal, that these, gases snoutu
under pressure through a column of incandescent coke or other carbonaceous.
fuel.
To effect this. essential condition continuously and without involving any
reversal action, l'proceed as follows.
I provide two vessels connected together in their upper portion by a flue,
so arranged that the heated gases, and flame from one vessel pass. into the
adjoining one.
Each of these vessels has a specific function to fulfil.,
In one vessel, called hereinafter the first vessel, the inception of fuel com-
bustion and its continuance is established in such a way that part of the heating of
combustion is, by the passage of the flame or highly heated gases through the fuel
in the second vessel, transferred to the column of fuel in this second vessel, and
the newly fed fuel in both vessels, has its hydrocarbon gases driven off or expelled,
and they, along with the carbon-monoxide gases from the first vessel, descend
through the incandescent fuel in this second vessel, this fuel incandescence being
obtained by the partial combustion of the gas and the complete combustion of part
of the solid fuel in the first vessel.
In descending through the incandescent fuel the following effects, thermic, and
chemical take place.
First the volatile bydrocarbons are gasified and converted into a condition more
or less-permanent:
The carbon-dioxide produced by the partial combustion of the gas, as well as the
complete combustion of part of the solid. fuel in the first vessel, is converted, in
contact with the incandescent. carbon in the second vessel, into carbon-monoxide.
Any water vapour or steam, passing into the second vessel is decomposed in its
passage through the column of incandescent fuel in the second generator, the
oxygen forming, with the incandescent carbon, carbon-monoxide, the hydrogen being
set free. In one arrangement of my invention the depth of fuel in the first vessel
may be maintained of such dimensions, that when a powerful air blast is established
under the fire-grate, part of the air passes through the fuel and consumes part of
the gas generated by the partial combustion of the fuel in the first vessel. The
effect of this combustion in the first vessel, raises the temperature of the part of the
first vessel above the level of the fuel, as well as the fuel in the second vessel
(through which the treated gases have to descensionally pass) to a high temperature,
the fuel (in the second vessel) being raised to the equivalent temperature of visible
incandescence. In adopting this arrangement of effecting my invention, I make
the first vessel much shallower in depth than the second vessel. Indeed it may be
merely a fire grate, in which the fuel is entirely consumed, relying for the pro-
duction of a combustible gas by the passage of the products of combustion through
the incandescent fuel in the second vessel.
Instead however of employing a shallow depth of fuel in the first vessel and in
order to obtain the necessary temperature of incandescence in the second vessel,
I may provide the first vessel with such a depth of fuel as to enable a regular
character of gas to be generated in the first vessel, part of this gas I consume by.
the introduction under pressure of a certain proportion of atmospheric air,
introduced either immediately over or merely under the surface of the fuel
in the first vessel.. The flame resulting from this combustion, passes immediately
into the second vessel, through the fuel of which it descends, raising the
temperature of, such vessel, and the fuel contained therein to a high state of
incandescence.
The chemical and thermic, effects of the action of gasification are as described;
for the first, arrangement of my invention. I provide fuel, feeding arrangement for
both, vessels preferring to employ a water jacketted feed hopper base..
I also employ, the usual arrangements for removing the incombustible residuum.
or, clinker, that gravitates to the base of the fuel of, both vessels., For the first one
1.may, employ a closed water bath under the grate, but for the second vessel. It may,

page_text: employ a solid floor. In order to reduce the loss of heat radiatum through the
walls of the first vessel I jacket such vessel either with water, or air, employing the
steam that may be evaporated either for propelling a fan, or by use with a steam
jet aspirator, inducing an air blast altogether under or applied to grate of first
vessel, or partly under such grate and partly over the fuel level, in order to
consume a portion of the gas generated.
The second air supply being exactly controllable by valvular arrangements of a
special character.
To enrich the gas produced I may inject liquid hydrocarbon over the fuel in one
or both vessels.
The chemical principles underlying the non-reversal cycle of power-gas production
may be described as follows, neglecting the diluent nitrogen :-
First at the grate :
C + 2 O + HgO = CO, + H,O ;
011.
Before describing the drawings that accompany this Specification, I wish it to
be distinctly understood that I do not intend to be confined to the exact details
shewn therein as these may be modified without departing from the nature of my
said invention.
In the sheet of drawings,
Figure 1 is a vertical cross section through line a a of Figure 3 and
Figure 2 is a longitudinal section through line 6 of Figure 3.
Figure 3 is a plan in section taken through line c c of Figures 1 and 2.
The two vessels A and B are both formed of sheet steel or iron internally lined
with refractory material.
The fuel is fed into both vessels up to the mark C. Both vessels are preferably
provided with water baths D, the vessel A has a vertical hanging grid E formed of
loose fire bars F that can be rapidly removed for repairs, either by being vertically
withdrawn from the sockets or by the removal of the two half hoops G by which
the entire set of bars can be withdrawn. The inverted truncated cone H of sheet
or cast iron or steel, is supported by the angle iron or flange J, rivetted or bolted
to the stiffly constructed parts of shell K, that has angle irons L on to which the
super and lighter upper part of generator shell is bolted.
In the vessel A two supplies of air under considerable pressure are introduced
from the air blast main M, one, and the lower supply being conveyed through the
valve N and the branch pipe O into and around the grill E, and the other by the
upper valve Q and the branch pipe R, the air entering into the flue S from which
it obtains ingress into the fuel by means of the numerous ports T.
The blast of air introduced around the grill E establishes active combustion at
the base of the fuel, and gaseous fuel is produced, as the gases flow through the
upper masses of fuel, the introduction of the secondary air supply burns part of
this gas, as well as the hydrocarbons of the newly fed fuel. The resultant com-
bustible gases, from the first generator and the products of combustion of the

page_text: partly burnt combustible gases, and of the combustion of the hydrocarbons of the
newly introduced fuel, flow through the cross conduit U which is heavily lined
with fire brick, into the vessel B where the hydrocarbons of any newly fed fuel are
met with, and are compelled to flow downwards through the fuel in the second
generator B. The fuel in the second generator B is raised to incandescence by the
combustion occurring and due to the secondary supply of air introduced into the
first vessel A and supplied through valve R.
The final gases escape by the circular flue V, at the base of the fuel in the
vessel B by means of the one or two outlet pipes W. The oxidised gases
from the vessel' A in descending through the incandescent fuel in vessel B are
reduced or reconverted into carbonmonoxide and free hydrogen along with the
usual proportion of nitrogen that would be associated with the degree of oxidation
effect.
Both vessels A and B are supplied with coal feeding hoppers W. The top of
generators are water covered as shewn at X, a channel iron skirts the edge of the
top plates, and retains the water on the surface also providing a bearing to support
the walking planks as shewn at Y.
I may surround the vessel A with a water jacket Z in order to recover part of
the shell heat of such vessel.
-
I may introduce the gases from the first vessel to the second vessel in such a way
that they have to pass through the fuel in second vessel ascensionally, and I may
provide in this instance a blast of air to the grate or lower part of the fuel in such
vessel.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same may be performed, I declare that what I
claim is included in the following statement.
First. The process of gas making substantially, as herein shewn and described.
Second The conjunction of two gas generator vessels in one of which the flow of
the gases is ascensional and in the other descensional.
Third. The method by which the hydrocarbons of the fuel fed into the two
vessels are first oxidised or burnt, and afterwards the products of combustion are
reconverted into free hydrogen and carbonmonoxide.
Fourth. The arrangement of grate described.
Fifth. The arrangement by which the air blast introduced through a water seal
around the grate and also below and above the fuel in first generator.
Sixth. The general construction of apparatus for generating gaseous fuel
substantially as shewn in Figures 1, 2 and 3 accompanying drawings.
Seventh. I claim the method of gas production in which the combustible gases
and products of partial combustion of the fuel in one generator vessel, are made to
descend or ascend through incandescent fuel in a second and associated generator
vessel, and in which second vessel the fuel may or may not partly rely for its
incandescence upon an additional supply of air applied to the base of such fuel.
Dated this 10th day of April 1895.
B. H. THWAITE.