Improvements in Methods of Generating Heating and Lighting Gases from Liquid and Solid Hydrocarbons and in Apparatus therefor.
Year: 1891

page_text: e of Application, 20th Jan., 1891-Accepted, 18th Apr., 1891
COMPLETE SPECIFICATION.
Improvements in Methods of Generating Heating and Lighting
Gases from Liquid and Solid Hydrocarbons and in Apparatus
therefor.
I, BENJAMIN HOWARTH THWAITE, of 37, Victoria Street, Liverpool, in the
County of Lancaster, 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 :-
My invention relates partly to improvements in former inventions for which
Letters Patent have been granted to me, numbered 15621-1886, No. 6432-
1888, No. 10224-1888, No. 16970-1888, No. 13574-1890 and 594-1888.
This invention has for its object, improvements in methods of generating heating
and lighting gases from liquid and solid hydrocarbons and in apparatus therefor.
Such improvements also permit the production of a permanent or fixed character
of luminous gas, (from inferior grades of liquid hydrocarbons) of a high photometric
value.
In the following pages my invention is fully and adequately described.
As in my former patented inventions the numbers & dates of which I have
indicated, I employ as an essential feature, two vessels or chambers, that may be
connected together at their upper part by a refractory lined conduit, each vessel
forming a necessary element in effecting the cycle of actions or cycles of actions
hereinafter described.
In the upper part of each vessel I provide an annular cavity, the inside hanging
wall of which is supported by projecting corbels or oversailing courses and such
cavity is also loosely filled with open or checker brickwork, in such a way as to
provide a considerable heating surface and capacity for the accumulation of heat,
without such brickwork or cavity interfering with the distribution of the coals or
other fuel fed into vessel.
To the upper part of each of these vessels and connected to the annular cavity
described, I provide an air inlet arrangement for supplying air for the combustion
of part of the gas produced, by the cycle of operations hereinafter described, such
combustion taking place immediately over the fuel in each of the vessels, the flame
of combustion flows amongst the checker brickwork and raises the temperature
thereof to a degree necessary for the volatilisation and the fixing of the oil or other
liquid hydrocarbon I may inject by or with steam into the centre of such heated
chamber. In the injection of oil by steam I adopt the following arrangement :-
I place the level of the injectors in such a way, that the oil is sprayed uniformly
over the fuel, and I may use one or more injectors. If I use one, I place the
injector so that its nozzle is opposite the centre and opening of the conduit con-
necting the two vessels.
=
I may fill one of the two vessels with broken pieces of refractory material so as
to provide a great mass or capacity for the accumulation of heat, the upper part of
said vessel is however provided with the combustion chamber and the annular cavity
already described.
I also provide such upper chambers with an air inlet arrangement for the
combustion of part of the gas unconsumed in the combustion chamber of the other
vessel, each vessel has therefore its own combustion chamber, connected to the
other by a conduit, and each combustion chamber has a valvular air inlet arrange-
ment.
I provide each of the air inlets with a sliding rack valve worked with a wheel and
endless chain from the ground level, each of the air inlets is provided with a gas
ignition flame which is always kept burning and in such a way that the jet or flame

page_text: covers the opening-this ignition arrangement serves to ignite the combustible gas
when required at intervals and in such a manner as is hereinafter described.
I also provide an air inlet arrangement, attached to the conduit connecting the
two vessels, which I provide with a weighted lever safety valve, for a purpose
hereinafter described.
In order to obtain an inward aspiratory action through the air valves to consume
the whole or part of the gas pari passu or at the same time as it is being produced,
I employ under the firegrates and to produce a supply of gas, an induced draft, or
steam jet air blower arrangement, so that by this means the production of the gas is
independent of aspiratory action for its air supply, the plenum of air enabling the
gas to be produced and the aspiration or vacuum enabling the air to be supplied to
consume such gas produced. When both vessels are charged with carbonaceous
fuel the steam jet air supply is first directed to the under grate of one vessel and
then to the under grate of the other vessel at specific periods. The steam jet air
injector is equipped with an arrangement by which the air can be quickly and
effectually turned off.
The reversing valves for directing the flow of the gases and of the air and steam,
and for diverting the aspiratory action of the exhauster are similar to those described
in my Patent Specification numbered 13574-1890.
I prefer to work these valves automatically, and for this purpose I employ a
hydraulic cylinder with a free motion in its piston travel, and only a small useful
effect which is accelerated in its speed by a weight, which on falling, reverses all
the valves, by the regulation of the water feeding the hydraulic cylinder the exact
period between reversals can be accurately controlled. This automatic arrangement
may arrange so as to reverse all the valves but I generally prefer to work the
upper air inlet valves by hand. The gas exhaustion and outlet level is as shewn in
the figures illustrating my patented invention numbered 13574-A.D. 1890 or about
4 to 6 feet above the level of the firegrates.
When one of the vessels is filled with broken pieces of refractory material as
already described, the flow of the gas in combustion produced and partly consumed.
in the other vessel and completely consumed in the chamber over the refractory
material, raises such refractory material to the high temperature necessary for
rendering permanent the rich hydrocarbon gas produced by the volatilisation of the
petroleum oil or other liquid or solid hydrocarbons injected into or over the fuel in
the carbonaceous material filled vessel.
When both vessels are charged with carbonaceous fuel each of the vessels is
alternately subjected to the same conditions; serving at alternate periods for
volatilisation and fixing of the oil gas and alternately for revivifying the fuel and
restoring the temperature the products of the combustion occuring in both chambers
over the fuel alternately descend through the fuel on one side and then through
that on the other, for a period depending upon the length of time or interval between
the reversal of the valves, the gas is generated first in one vessel and consumed
partly therein and completely consumed in the second, in and by which the fuel is
raised to a high temperature the products of combustion in descending through the
mass of fuel being partly rearranged, the carbondioxide being converted into the
carbonmonoxide. The reversal of the directions of the cycle produces an identical
arrangement of reactions and new chemical combinations. When the temperature
of both chambers and the fuel in the vessels is sufficiently high, the air valves are
closed and the air is injected by steam into first one vessel, and afterwards the other,
according to the direction of the cycles of the operations. During the period of
the application of the oil the steam is introduced through the steam jet air blower
into the same vessel that the oil is being injected. The steam in passing through
the incandescent fuel is converted into the gas technically known as water gas, this
gas mixes with the vapour of oil, and water or steam in the passage through the
conduit connecting the two vessels along with the vapours named-which in the
instance of the vapours of oil, in passing descensionally through the incandescent
fuel, are converted into a permanent gas, the water vapour or superheated steam

page_text: consumed wherever required by an oxidising nature of combustion. When the second
vessel is filled with refractory material, I may, after the first cycle of operations
has been effected, and during the second cycle, direct the steam ascensionally
through the refractory material; in its passage the steam becomes highly super-
heated and flowing through the conduit into the fuel filled vessel, descends through
the latter and is decomposed and rearranged according to the following series of
reactions, including the hydrocarbons
4H₂O + 4C + 8HC + 2H₂O + 2C
th
:-
=
8H+ 200, + 2C + 8HС + 4H + CO,
+C=8H+ 200 + 8HС₁ + 4H + 2CO = 12H + 4CO + 8HC.
In the latter instance represented by the last equation, the oil is injected into the
vessel filled with refractory material, and, being vapourised, flows along the conduit
to the other or the carbonaceous charged vessel, along with the superheated steam
and descensionally flows through the fuel, the decomposition and reactions being as
shown by the equation.
When I desire to produce heating or combustible gases from carbonaceous fuel,
free from volatile hydrocarbons such as anthracite or charcoal, I employ two
vessels, but not connected together with an open conduit like the arrangements
hereinbefore described.
Each vessel has a separate outlet arrangement, but the two outlets for both
vessels are connected by a reversal valve which distributes the carbonmonoxide and
nitrogenous character of gases in one direction, and the gas technically known as
water gas in another direction, the class of valve I prefer to use is the ordinary
butterfly type.
During the time the gas, technically known as water gas is being produced in
one vessel the ordinary character of carbonic oxide and nitrogenous gas known as
generator gas, is being produced in the other vessel.
To effect these simultaneous actions, the air is directed under the firegrates of
one vessel whilst the steam is being directed under the firegrates of the other vessel.
To effect the simultaneous distribution of the air and steam 1 employ a second
butterfly valve the flap of which is actuated by the motion of the water gas and
carbonmonoxide gas reversal valve.
The cycle of action of this modification is as follows:-in one generator vessel
the gas is produced according to the following sequence of reactions
The respective gases flow along different mains and can be led independently for
different purposes or be mixed together or be partially mixed together for separate
and independent purposes.
This modification allows water gas to be produced almost continuously and the
reversal arrangements involved in effecting the processes are extremely simple.
The following is a brief recapitulation of the essential features of my invention
which will be clearly understood by the perusal of the description of and reference
to the drawings accompanying this Specification :-
1. The employment of two gas generating vessels connected together by a
conduit and acting in unison.
2. The formation of combustion chambers and heat accumulating space over
the upper level of the fuel or refractory material, as the case may be, for
the purpose of effecting the combustion of whole or part of the gaseous fuel therein
by which the temperature of such chambers and the refractory material contained
therein, is raised to a sufficiently high temperature to effect the volatilisation and
fixing of the gas produced from the solid or liquid hydrocarbon.

page_text: 3. The position and form of the annular hydraulic main and outlet blocks.
4. The employment of the following elements in their respective positions. The
air inlet valves with their ignition arrangements by which air is admitted into the
combustion chamber over the level of the fuel or the refractory material, as the
case may be, in both vessels, and by which the ingress of such air can be effected
without the production of explosive mixtures of air and gas, and by which the gas
can be ignited immediately the air is allowed to flow into both combustion
chambers. The central air ingress valve with its safety valve and ignition
system.
5. The employment of a steam jet air injector in such a way that the air supply
can be immediately shut off, and the steam supply per se can be allowed to enter
the fuel for the production of the gas technically known as water gas.
6. The method and manner employed for injecting the oil by means of steam.
7. The method of sustaining the fuel in generators, by which clinkering
operations can be accelerated and reduced in arduousness.
8. The method of effecting plenum pressure of air under the grates and a
vacuum or aspiratory action over the fuel simultaneously.
9. The automatic reversal arrangement of the valves, either effected by the
hydraulic and tumbling gear arrangement or by means of the hydraulic cylinder
hereinbefore described.
10. The arrangement of actuating the connecting rod of the feeding gear.
11. The flame jet testing arrangement by which the proper duration of the
application of the oil and steam can be rapidly determined.
12. The arrangement by which water gas and generator gas are produced
simultaneously from anthracite or from wood charcoal or coke.
My invention possesses the following prima facie advantages over other existing
systems:
1. It will enable the commoner oils or liquid hydrocarbons to be converted into a
permanent gas of a high photometric efficiency in proportion to its intrinsic
monetary value.
2. It will permit the volatile hydrocarbons evolved from the coal used to be
converted into a permanent and fixed character of gas.
3. It will allow the production of the gas technically known as water gas, along
with the production of a fixed and permanent oil gas with which it is thoroughly
and uniformly diffused.
4. It will include the injection of oil by means of steam and the partial
decomposition of the latter either by contact with the solid or liquid hydrocarbons.
5. It will enable the simultaneous production of water gas and generator gas and
by a simple arrangement of reversal valves actuated by the movement of one lever
or automatically, the direction and character of the processes can be immediately
reversed.
We will now refer to the drawings annexed, the figures illustrated elucidate mo
clearly the exact form of the structural proportions and nature of the assemblage
of parts constituting my invention.
Before doing so, I wish it to be clearly understood, that the exact details of the
figures shewn on the sheets of drawings are not to be considered as the only forms,
as they may be modified, without such modification being considered as a departure
from the nature of my said invention.
Referring to the Figure 1 on Sheet 1 of drawings:-
:-
This figure is a vertical section of the main portions or parts, that constitute my
invention, A. being one cupola shaped gas generator vessel, encased externally with
sheet iron, and internally with refractory material. B, is the other vessel, similarly
constructed in all respects, and connected to vessel A, by means of a conduit C,
lined internally with refractory material, and connected at the level of the escape
or outlet ports D, and also under the grates E, by means of connecting pipes or
flues and an assemblage of reversal valves, that may be indicated in this instance
by the letter F.

page_text: The annular and heat accumulating chambers G, are constructed in the upper
portions of each of the vessels A and B, above the level of the fuel, which level is
indicated by the line H.
The inner wall I. of the heat accumulating chambers, is supported by corbels J.
and between the outer and inner wall I fix blocks K. radiating in plan, towards the
centre of the vessel, these blocks support a mass of loosely built checker brick-
work L.
The steam jet oil injectors M, I fix and arrange at the level and positions shewn,
each injector nozzle pointing towards the centre of each generator vessel. The
injector passage in each vessel being bell mouthed, so that it will distribute the
vapour of oil and steam, well over the fuel, and diffuse it throughout the heat
accumulating chambers.
I may provide inore than one or a pair of steam oil jet injectors M.
The steam supply pipe N, and oil supply pipe O, for each of the injectors, are
connected to a central oil and steam reversal valve P. the actuation of which is
effected by the movement of the assemblage of reversal valves F, constituting this
assemblage of valves there is the gas valve Q and air valve R.
A separate regulating valve, is provided for both the oil and the steam supply in
close proximity to the injectors, so that the exact proportions of oil and of steam
can be adjusted for each injector, without interfering with the reversal arrangements.
The oil being injected by steam into the upper chamber is in its vapourous or
atomised liquid form, converted into oil gas.
The level of the top layer of fuel or refractory material as the case may be, is
shewn by the irregular line H. The level of the outlet ports D. is some 4 to 6 feet
above the level of the firegrate, the outlet ports debouch into the annular flue S.
surrounding the outer caseing.
On each side of the firegrate there is provided a water jacketted caseing T, built
up of wrought iron plates or cast in one piece as found most convenient. A
constant circulation of water is maintained in each side jacket, such circulation of
water may be connected with the hydraulic cylinder, that automatically reverses all
the valves, and which is described further on.
I also provide a constant circulation of water under the grates. In order to
maintain the top cover plates at a low temperature, I provide angle iron sides all
round them, providing ring plates around the plug holes, by which latter the fires
may be stirred.
In order to raise the temperature of the oil and steam before it is delivered
direct to the injectors, I lead the former or the oil, in coils of pipe, or any other
mechanical arrangement, by which a great heating surface is provided, such oil
heating contrivance I fix inside the main flue or funnel through which the waste
and heated gases resulting from the process of heating up or revivifying the fuel,
flow away from the generators.
In order to superheat the oil, I may also pass the steam through coils or lengths
of pipes immersed in the oil tank.
may pass the steam through a cubulous boiler placed also in the flues through
which the products of combustion flow away from the generators.
Referring to the upper conduit C, connecting the two vessels, in the centre thereof
an ignition and safety valve is provided, by which any gases resulting from an
explosive effect can harmlessly escape.
The fuel feeding arrangement P. is identical in its broad features, with the one
shewn in my Patent No. 13574, 1890, but the method by which it is actuated is
shewn on Sheet 2, of drawings.
Before leaving the description of this Figure 1. 1 will again refer to the reversal
valves Q and R. It will be observed that the upper ledges b, of ring plate
surrounding the outlets, are slightly curved inwards, this is effected for the purpose
of preventing the water from flowing into the bends c, and d, connecting the reversal
valves to the annular flues surrounding caseings.
A sight and test plug e, is provided for each of the bends to enable them to be

page_text: examined and cleaned out. Each bend is also provided with a water pressure gauge,
so that the pressure of the vacuum or plenum pressure of the gas or air as the case
may be, can be accurately determined.
Referring to Sheet 2. of drawings:-
Figure 2 represents a vertical section of one of the gas generator vessels.
In this figure the same reference numerals and letters indicated thereon, refer to
the same respective parts.
The following are the additional features of the apparatus not shewn in Figure 1.
Referring in the first instance to the firegrate arrangement, it will be seen that
there are several rails placed one over the other, like an ordinary grille, for these
rails I prefer to use those of the ordinary permanent way, rails cut to suit and
attached to the side water jacket or solidly embedded in the walls.
Beside these rails f, 1 provide two moveable L ☐ shaped bars y. that can be
slid into grooves . formed in each side of the door frames. Opposite the space i.
between the upper horizontal rail and top plate of door frame, I provide a sliding
hit and miss arrangement, by which flat clinker bars can be inserted, and be driven
through the accumulated mass of clinkers on the grate, in such a way that their
pointed ends rest on the central hollow bridge j, that supports the firebars. In
order to maintain the clinker doors in close contact with their frames, I employ a
grooved edge formed on frame or on door, in this frame I may insert or fix a roll
of asbestos or other pliable substance that will give way, when the pressure is
brought to bear upon it. In order to maintain the upper part of bridgej in a cool
condition, I maintain through it a constant circulation of water.
The air valve arrangement K is provided for the admission of air into the
annular chamber G. The air in passing through the heated nest of bricks in the
annular chamber G becomes highly heated before it meets combustible and generator
gases, the combustion of which it supports. Air valves are provided for each of
the generator vessels, and in both vessels are fixed above the level of the fuel H,
in the combustion chamber; or in such a way that the gas enters into the
annular chamber and becomes highly heated before meeting with the combustible
generator gas. I prefer, for regulating the flow of air, to use the rack slide pattern
of valve, such valve being actuatable by endless chain wheels 1, the chains of which
reach to the ground floor and can be manipulated from this level.
Over the mouth or openings of the air inlets K, I provide a flame gas ignition
jet m, by which the combustible gas can be ignited in either of the chambers, by
simply establishing an outward pressure in the gas generator vessels. On the
opening of the valve the gas escaping is ignited, by removing the outward pressure
on the generators the ignition flame is drawn into the vessel and the combustible
gases are ignited, the air flowing through the valves K. and o, and supporting
combustion in each vessel.
The ignition jets on each of the air valves are constantly kept alight. An
additional and master ignition jet n, is provided between the gas vessels on the
upper side of the refractory lined conduit C, connecting the two vessels. This
master ignition jet n, covers a valvular opening. The valve o, which is of the
safety lever pattern, has at the lower end, a suspended chain for raising the valve
when required. The master ignition jet is always kept alight.
In igniting the combustible generator gas when it is required to have the com-
bustion in both vessels all that is required is to lift the safety valve O, the gas and
air immediately meet, and are ignited by the master ignition flame, without pro-
ducing any noise or explosion.
The method of actuating the coal feed hopper p is shewn by the mechanical
arrangement q. This consists of a rack wheel, a catch lever s, and a moveable
catch bar t, which is actuated in its turn by an eccentric u.
Figure 3 is a plan in section taken through annular combustion chamber G and
partly through connecting conduit C. the latter being lined with refractory
material v. The inner wall I of annular combustion chamber G is supported by
projecting corbels J.

page_text: The steam jet oil injector is supplied with oil and steam by the supply pipes W,
each pipe having its own regulating valves N, and N', fixed near the injectors, the
main oil and steam supply reversal valve P, being fixed by the reversal of the gas
and air valves, or independently by a cross lever f. endless wheel and chain.
Figure 4 is a plan in section at the level of the annular outlet blocks D,
debouching into the annular flue S, which may be converted into a hydraulic main,
as hereinafter described. The central hollow bridge J divides the two firegrates.
The hollow bridge in its upper part is supplied with a constant flow of water by
means of the inlet and outlet pipes 3 and 4.
The gas reversal valve casing Q is shewn with the top lid removed, and with its
two valves suspended from the end of the lever which is pivoted on the centrally
placed spindle.
Referring to Sheet 3 of drawings, Figures 5 and 6 represent the methods adopted
by me for automatically actuating the valves. In the arrangement shewn by
Figure 5 the reversal of the valves is effected by the reciprocatory movement of a
piston 6, moving in a cylinder 7, by the impelling force of water introduced
alternately to one and then to the other side of the piston 6 by the fourway reversal
valve 8.
The piston rod has at each of its terminations a stiff arm 9, attached to a con-
necting link 10 in its turn coupled to a rocking piece 11 fixed behind the tilting
picce 12 or forming part thereof.
The rocking piece is thrown by the movement of the piston rod over the vertical
centre, and the rolling counter balance weight 13 then runs or rolls to the end of
the rolling surface 14, and by its momentum and the leverage the tilting piece falls
down to the full extent of its movement, reversing all the valves, the quadrant slot,
by which connection to the connecting links 15 and arms 9 is effected, is sufficiently
long to allow of the falling movement of the tilting piece.
The whole of the valves are reversed by the automatic action described; con-
necting links to the different valves being provided, marked 15.
The same reversal action also reverses the flow of the water pressure through the
fourway valve 8, to one or the other side of the piston alternately. The piston
travels free until the links moving in the quadrant slot arrive at the end of the
latter, then the tilting piece is drawn over the vertical centre in an opposite
direction and the falling weight again reverses the valves.
Figure 6 represents an elevation of another arrangement for effecting the
reversal of the valves. In this figure the weight of water at the end of the
balanced lever, throws over the balanced lever as well as a weighted lever attached
thereto and reverses the valves.
16 marks the balanced lever and attached weight 17 at each end of the lever 16
there is a bucket 18, as soon as the bucket is filled with water which falls from
pipe 19, its weight pulls over the centre the weighted lever projection 17 and the
bucket and weight fall to the full extent, reversing all the valves, including that
marked 20 for supplying the water, first to one bucket and then to the other. By
the rapid descent of the bucket the water is thrown ont, and the bucket at the
opposite end of the balanced lever is then gradually filled. Connecting links 21
are provided for distributing the movement of the balanced lever to the other valves.
Referring to Sheet 4 of drawings.
Figures 7, 8, and 9, represent a modified arrangement of apparatus intended for
the simultaneous production of water gas and carbonmonoxide gas. 22 is one
vessel and 23 the other, both vessels being identical in structural arrangements,
each having an iron casing and being internally lined with refractory material,
but the grate arrangement conforms to that shewn on Figure 1 of Sheet 1 of
drawings of my invention for which Letters Patent have been granted to me,
numbered 594-1888.
The air or air and steam or steam per se, is blown under the grate through the
mains, alternately into one vessel and then to the other, the vessel in which water
gas is being produced receives steam whilst the other vessel is receiving air or air

page_text: and steam, the two currents being directed by the reversal valve 24, which is of
the ordinary flap type, the spindle of the valve being continued through the gas
valve 25 placed alongside and which valve is of the ordinary flap type.
This latter valve directs the water gas produced in one vessel into the main 27,
and directs the flow of the other or carbonmonoxide gas, into a larger brick flue 28,
both kinds of gases are produced simultaneously, first in one vessel and then in the
other, both the water gas and carbonmonoxide always being separately led away by
the reversal valve 25.
The air is blown or forced forward by means of a fan or steam jet air injector,
through pipes 29 into and through the reversal valve 24 from which it is first
directed into one vessel for a period say of 5 minutes and then through the other
vessel for the same period, whilst the air is being forced into one vessel, steam is
introduced into the other vessel by the valve 30, the direction of the flow of steam
being controlled by the reversal valve 24. The movement of the two valves is
effected by the actuation of the lever 31, this actuation may be automatically
effected, by either of the arrangements shewn in Figures 5 and 6 on Sheet 3 of
drawings. When the air is supplied by means of a fan, the valve 32 is opened,
but when the air is injected by means of a steam jet blower 33, the valve 32 is
closed and the injector 33 is opened.
The clinker doors 34 are opposite the air inlets of both vessels.
Referring to Figure 10. This illustrates the modified arrangement of annular
flue for withdrawing the gases. In this arrangement the annular flue is converted
into a hydraulic main, in which there is a suspended plate 3 immersed an inch or
so below, the upper surface of the water, of which is kept in constant circulation.
The gases are compelled to flow through the depth of water represented by the
dip of the central plate 35. The aunular hydraulic main is connected to the
reversal valves in the usual way. By this arrangement the sensible heat of
the waste gases can be in a great measure recovered and the unfixed or condensible
hydrocarbons can be drawn away before they enter to clog the valve or mains.
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 as follows:-
:-
1st. The combination of two vessels acting in unison and working according to
the cycles herein described and set forth.
2nd. The provision and arrangement of air inlet valves over the level of the
fuel or refractory material, in both vessels as herein described.
3rd. The provision of ignition jets by which the gas can be ignited without
explosion, and in combination with the safety valve substantially as herein shewn
and for the purpose described.
4th. The injection of oil by steam and the production of water gas and oil gas,
simultaneously and their combined flow or passage through the incandescent
material in second generator vessel.
5th. The method of alternately injecting the oil by steam into one vessel and
then the other as the cycle of operations reversed.
6th. The automatic reversal arrangements of the valves, either effected by the
water tumbling gear or by the hydraulic and reciprocating piston action as herein
shewn and described.
7th. The method of connecting the gas escape belt in a hydraulic main by which
part of the sensible heat of the gases may be recovered, and by which the
temperature of the gases is considerably reduced before they enter the reversing
valves.
8th. The method of sustaining the fuel in generators by superposed rails by
which clinkering operations are simplified.
9th. The arrangement of apparatus shewn in Sheet of drawings by which
water gas and carbonmonoxide or generator gases are produced simultaneously
B

page_text: and by which the flow of the two gases is separated, substantially as shewn and
described.
10th. The arrangement in the cycle of operations, by which the generator gas is
produced by induced or forced draft and the air for combustion thereof is aspired
by an exhauster pressure at the outlet of the generators.
11th. The water top arrangement and method by which the central fire bridge is
kept cool by a circulation of water through it, substantially as described.
Dated this 12th day of January 1891.
B. H. THWAITE.