Improvements in Methods and Apparatus for Generating Gaseous Fuel from Solid Hydrocarbonaceous or Carbonaceous Material.
Year: 1894

page_text: Date of Application, 26th Jan., 1894-Accepted, 21st Apr.,
1894.
Improvements in Methods and Apparatus for Generating Gaseous
Fuel from Solid Hydrocarbonaceous or Carbonaceous Material.
We BENJAMIN HOWARTH THWAITE and GEORGE THRELFALL both
of 95 Finsbury Pavement in the City of London Civil and Mechanical Engineers
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:-
Our invention relates to improvements in apparatus for generating gaseous fuel,
but more particularly refers to apparatus for the production of that character of
gas required for internal combustion engines.
The advantageous characteristics of the improved generator, are numerous and
important, inter alia it will permit the use of a coal having in its constitution, a
high percentage of the volatile hydro-carbons and having also a high proportion
of fusible or infusible slag or incombustible matter.
These advantages permit our generator to be employed where the available
fuel is the common kind of slack or bituminous coal, having as much as 30 per
cent. of volatile matters in its constitution, or retort coke, such as "breeze" that
contains as much as 25 per cent. of incombustible matter.
The cycle of operations in our generator, that is, when using volatile hydro-
carbonaceous fuel, converts the volatile and condensable hydro-carbons into a
permanent character of gas.
The construction of the grate and means of approach to the fuel, enables the
incombustible matters and residue from combustion to be rapidly cleared away.
In our generator, the amount of carbon-dioxide in the gas produced is lower
than in ordinary gas generators of other design.
A further advantage and which may be claimed as a distinctive feature in our
generator, is the recovery of the radiated heat from the shell or casing of the type
of generator used for slack bituminous or hydro-carbonaceous fuel.
We are enabled by one modification of our apparatus, to obtain the production
of gas under considerable pressure, without involving any serious loss through
leakage of gas during the poking up of the generator.
We will now describe our improved apparatus, shewing in this description, how
we obtain the various and important characteristic advantages herein mentioned.
First the fixation of the volatile hydro-carbon gases. Two generators or vertical
cylindrical vessels are placed side by side and are connected with each other by
three specific and distinctive connections, an upper one, that joins the two vessels
above the level of the fuel or combustible matter; a lower one that connects the
two vessels below the grate and a midway or central one that connects the two
vessels at the distance of 2'6" or 3' 6" above the grate-the two lower connections
are equipped with automatically acting reversal valves of special design which
themselves form a part of our invention and which will be more specifically referred
to later on.
The cycle action of gaseous generation is as follows:-Air under pressure that
may be induced by a steam jet or a fan enters through the lower of the two
valvular connections into the ashpit space beneath one of the grates of one of the
gas generators-this ashpit space being of a specially contracted character for the
reason to be hereinafter designated. The air flows under and through the grate
into and through the fuel; that portion resting on the grate is raised to a state of
bright incandescence, and eventually this condition of incandescence for a con-
siderable height, say of five or six feet above the grate, is rapidly attained. The
newly charged fuel and that portion which has not attained a temperature

page_text: of 400° Fah., will be giving off aqueous vapour as well as some of the more
volatile gases evolved from the volatile hydro-carbons. This fuel which has
attained a temperature of 600° to 700° Fab., will be evolving the remainder of its
volatile hydro-carbonaceous constituents-the greater part of these gases, if
allowed to leave the generator directly as produced would be deposited in the
flues as tar compounds. The water vapour assisting this condensation by its
condensable characteristic.
If however, the water vapour, and the volatile hydro-carbons are compelled to
flow through a few feet of incandescent carbon, the former is decomposed into the
elementary constituents, hydrogen and oxygen, the latter combining with the carbon
to form CO or carbonmonoxide.
Now in order to effect this desirable influence on the gases generated in one of
the vessels, the gases are compelled to descend through the fuel in the other
generator vessel connected to it, and this fuel being in an incandescent state, the
chemical effects defined will follow-the hydro-carbons being rendered permanent,
and the water vapour being decomposed into its elementary constituents, as
described.
The gases in the generator in which the air blast is being applied to the underside
of the grate flow through the conduit connecting the upper parts of the vessels over
the fuel spaces and descends to a series of outlets formed in the refractory lining of
the generator from which they flow to the upper and special gas reversal valve, and
from thence to the gas flow main leading to the gas holder.
The influence of the aqueous vapour, and the hydro-carbons, in descending through
the incandescent fuel, rapidly lowers the temperature of the latter, and as a certain
range of temperature is necessary to effect the fixation producing action on the
hydro-carbons, and in order to decompose the aqueous vapour, it is requisite to
revive the condition of incandescence of the fuel, hence it is necessary to divert the
air blast into, and through the fuel of this vessel and divert the flow of the gases
resulting, in the opposite direction, in other explanatory words, the air blast is first
directed under the grate of one of the two vessels, for a period of say 50 seconds,
the products of the combustion from the introduction of air to one vessel descend
through the fuel, in the second or other vessel. The direction of the flow of the
gases is then reversed, the air entering under the grate of the vessel through the fuel
of which the gases have been descending and have been absorbing part of the
sensible heat from such fuel.
The reversal of the valves in the two lower connections compels the air to
flow through this fuel, the resulting combustion rapidly raises its temperature. The
gases flow descensionally through the fuel in the other of the two generators, in
other words, the direction of combustion and of the flow of the gases is alternated
first in one direction through the two generators and then in another and opposite
direction. By this rapid alternation of the direction of the current at comparatively
short intervals the sensible temperature of the fuel in both generators is maintained
at a temperature of visible incandescence. A depth of 8 or 9 feet from the grate of
incandescent fuel, and 4 feet above the level of the outlet openings, will be quite
adequate for the four effects, designated as follows-First, the fixation of the
hydro-carbon gases, second, decomposition of the water vapour. Third, the con-
verting of the CO, into CO and fourth, the scrubbing of the gases generated. The
reversal valves, which will be more specifically described, are automatically actuated
by a tumbling gear the mechanical arrangement of which is a special feature of our
invention.
The time period intervening between the reversals, can be exactly determined,
and will vary according to the character, chemical and physical, of the fuel.
As the gases have to flow through a thickness of from 12 to 18 feet of fuel, it
will be obvious that a very considerable pressure is required to be established to
obtain the requisite volumetric velocity, and as the lumps of some qualities of fuel
may have a tendency to amalgamate or. flux. together, and require breaking up we
provide special self closing frames or mountings that allow a poking bar to be

page_text: introduced into the vessels without permitting the escape of gas during the proce
of breaking up the fuel.
The advantage of being able to effect a rapid clearance of the incombustible
residue is obtained in our invention in the following manner.
its seat.
We provide a hinged and gridded grate at the base of the fuel chamber. This
grate is counterbalanced by means of a counterbalance weight, attached to a lever,
fixed on the end of a rocking shaft which passes in its terminals through mountings
bolted onto the casing. This circular grid is kept up in its seat by the counter-
balance weight or weights, just described. When the clinker is required to be
cleared from the fuel, the gridded grate is lowered by tipping the weighted and
external levers. At a point in the generator walls-opposite the space made by
the half opening of the gridded grate we provide a retort lid character of door,
provided with cross bars by which the door can be firmly brought into contact with
This door in the inside is provided with a refractory block-bolted to it
by means of a countersunk arrangement of bolts-this block prevents the door from
becoming overheated. To remove the clinker this door is fully opened, the
clinker clearing door is however only required to be partially opened. Bars are
inserted and driven through the fuel, the clinkers and other incombustible matters
gradually gravitate to the grate fall through it into the water trough or bath.
When the clinker is fully cleared away the grid swings back to its seat owing to the
counterbalancing weights-the door is luted with fire-clay and screwed up to contact
with its own seating. In order to allow a convenient approach to the clinker door
the air jacket does not pass entirely around or embrace the generator vessel, but is
stopped off on each side of such clinker door. Respecting the feed hopper that we
usually adopt for our generators it is of two kinds to be specifically described. In
one the base frame for carrying the truncated cone vessel that forms the chamber
for receiving the fuel, is preferably surrounded with water in order to maintain the
metal in a cool condition, and it also permits the removal of the bell part of the
hopper quite easily and without risking the burning away of the bolts. The bell
of the hopper is suspended in such a way that it is free to adjust itself and is always
in a comparatively close fit when pulled up by the counterbalance weight.
The sliding plate that is moved over the top of fuel chamber and feed hopper, is
clamped down by a cross-bar or by an excentric lever arrangement to be more
specifically described by reference to the drawings.
The reversing valves by which the direction of the gas through the bituminous
coal generator arrangement, is reversed are of the water seal type-bell shaped
steel vessels are suspended from a chain passing round a centrally placed wheel
that is fixed in the upper part of the valve casing.
The connecting pipes are of a slightly conical form, that is of a smaller diameter
at the upper end, than at the base thereof, so that when the bells are lifted, a
vacuum is not produced, by which the water is lifted over the lip into the connection
attached to the base or bottom plate of the valve casing. This reversal valve
arrangement prevents any tar or carbon or other materials carried over into the
reversal valves with the gas from obstructing the valve closures. The reversal
action is preferably effected by a special automatic gear which constitutes in its
It consists
relation to gas generators an important element in our system.
essentially of a see-saw tilting arrangement, buckets being provided at the
terminals of a balanced and rocking lever, centrally poised on a standard pivot,
over this balanced lever is a water supply arrangement, having a central three way
cock, equipped with a cross lever, attached to a spindle which is connected with
link bars to the rocking lever so that the motion of the rocking lever effects the
motion of the plug of the three way valve, from this valve casing there projects
two outlet pipes, one in one direction, the other being in an opposite one.
water pipe projecting over one of the buckets whilst the other pipe projects over
the opposite bucket. The water flows into the bucket which is held in position by
a spring until quite filled; its weight being too heavy for its retention by the
spring. The bucket falls to the full extent and at a certain distance of fall the
One

page_text: bucket comes into contact with the surface of a shoot and as the bucket is suspended
by trunnions and has an inverted pyramidal shape in section, the apex in coming
into contact with the shoot, tips the bucket, but not before the other bucket has
been lifted above the height of the spring. The water from the other bucket runs
into a receiver from which it escapes either into the valve casing or into a well to
be pumped into an overhead tank for re-use.
A small pump is constantly in action, lifting the water from the ground floor of
the gas generator house, to the overhead tank in such house.
The tilting of the lever actuates the chain wheels of the two bell reversing
valves, reversing them by lifting one and lowering the other of the two bells. It
also reverses the direction of the flow of the water through the three-way cock, so
that the empty and upper bucket is rapidly filled with water.
We may under certain circumstances, as for instance when we require the gas
generators worked on board ship, generate gas against a considerable pressure of
holder or container. In this instance we employ a pressure of air induced by
means of a special fan or air pump that will establish a pressure of at least
18 inches of water under the grate of the generator.
In order to enable the ashes and clinkers to be withdrawn from the water
trough or bath of this generator, we provide a special cross bar (of the retort lid
type) of the door entering the ashpit space under the grate, that permits the fallen
ashes to be rapidly removed, when opened, but which can be closed in such a way
as to permit without leakage what are relatively high pressures to be established
under such doors.
The lower part of the casing of this generator sits in an annular cavity the
depth of the seal required, which in this instance is 18 inches.
When gas generated under the conditions described or at high pressure of air
blast, it is necessary that the fuel feeding arrangements shall be such, as to allow
this process to be effected with the least possible escape of gas, and for this
purpose we have designed a special arrangement for feeding the fuel into the high
pressure generators that will obviate the danger and objection of gas escape.
We effect this as follows:-Instead of the ordinary bell hopper arrangement, we
employ a sliding box, which when working in another and larger casing and rotated
in one direction is ready to receive the fuel, and when rotated in the opposite
direction permits the fuel to fall into the generator vessel. As this rotation is
effected in a close fitting casing, the gas cannot easily escape. The
also acts as a measurer of the fuel and can be made to act as an automatic feed.
arrangement
Another modification of this arrangement is as follows:-The hollow cylinder is
placed in another and longer cylinder, the action is somewhat similar to the
arrangement just described, but besides the rotation there is a reciprocating
backward and forward movement as well, the cylinder moves forward to receive
the fuel being rotated through half a circle so as to receive the fuel in a hopper
placed over it. In order to allow the fuel to fall into the generators the cylinder
is then moved forward into its casing, being rotated at the same time, so that the
opening on the side of the inner cylinder comes over the opening over the generator
chamber. This arrangement tends to prevent the inner cylinder or hollow box
from becoming too hot.
Referring to the six sheets of drawings accompanying and forming part of our
Specification, we wish it to be clearly understood that although we have shown our
invention with many details, it will be obvious to everyone that a slight
modification may be made without involving any departure from such our said
invention.
We will first describe one modification of our invention that permits the use of
ordinary steam coal of a bituminous character or indeed any character of
combustible, solid fuel to be used for generating gaseous fuel.
This modification of our invention is shown by figures marked respectively 1, 2, 3,
on Sheet 1, of drawings. Figures 4, 5, 6, & 7, on Sheet 2, of drawings, and
Figures 8, 9, 10 & 11, on Sheet 3, of drawings.

page_text: Referring to Figure 1, on Sheet 1, of drawings illustrating vertical section and
part of an elevation of the arrangement of our invention; the reference letter A,
represents a vertical section of one vessel and B, an elevation of the other. The
two generator vessels are connected by the upper and refractory lined conduit C,
and by the two connections equipped with reversal valves, marked D, and E. It
will be seen that the vessel A, is internally lined with refractory or fire-brick
material F, of a special internal form. The upper part being of greater thickness
than the lower part H. An internal flue passes around the lining at J, having
openings into the interior of the vessel at K.
The lower part of the vessel A, is provided with an inverted cone-shaped
frame L, at the base of which we have provided the tilting grate M. The lower
edges of shell, or casing of vessels, penetrate into the concrete foundation N, and
into and below the water level of the bath that we form beneath the grate M. We.
support the upper refractory lining by means of brackets Q. The dotted lines P,
shew the arrangement we adopt for lining the ashpit. The water bath O, at the
base of generator is formed with concrete walls. The bottom of the bath is sloped
as shewn in Figure 3, in order to facilitate the removal of the clinkers and ashes.
The tilting grate M, is preferably circular, pivotted at one side as shewn on
Figure 3, so that it may be tilted, and by tilting the clinkers can be forced from
over the grate into the water bath either by poking or agitating with a bar from
the top or from the side of the generator.
The tilting of the grate is effected by means of the square shaft R, and the
weighed levers S, and T, fixed at the end of the shaft R. The lifting up of either
of the outside levers S, and T, actuates the tilting grate M, which assumes the
position shewn in Figure 3, in dotted lines.
The annular air jacket U, surrounding one of the generators A, is connected by
a central cross connection V, to the annular jacket of the other vessel B. In this
central cross connection we fix the head or heads of one or more steam jet air
injectors of the Thwaite or Körting type. The position of the injectors is shewn
at V. The air is aspired by the injectors through both jackets, being drawn
entirely round both vessels so that the sensible and radiated heat generally lost is
recovered, such heat being added to the air flowing to support partial combustion.
The air is forced into the lower reversal valve chamber E. This type of valve
may be described as follows:-Bell valves are suspended from a balanced wheel,
over the inlets that lead the air under one or the other of the grates M, of the two
vessels. In the valve casing D, the bell valves are marked X, and Y, and the
outlet connections Z. The reversal valves are of the water seal type. Bent pipes
surrounded with water enable the bell valves when down on their seat to form a
perfect water seal tight joint.
The projecting bent pipes Z, are slightly larger in diameter at their base than at
their summit marked 4. By this means the bell valves, when rapidly lifted have
not the same tendency to lift the water of the seal into the outlet pipes as if the
projecting pipes Z, were of equal diameter.
The inside of each of the valve bells is equipped with a disc of flexible
metal 5, in order to form flexible contact surfaces. These flexible contact pieces
prevent an imperfect connection between the bell valves and their seats; even
when by accident the water has been evaporated the valves form a perfect seal
when in contact.
The reversal gas valve D, shows one of the bell valves X, lifted, and the other
one Y, lowered on its seat. It will be seen that the valves are suspended from a
wheel 7, the chain terminals being attached to the two projections 8, formed on
the periphery of the wheel. The balancing wheel is encased by the cover 9.
The reversal valves are automatically actuated by means of a water tilting
arrangement G.
On Figure 2, the reversal valve casing is shown in plan marked 10. The numbers 11
and 12 representing the rocking lever. The central spindle 13, passes through
the rocking lever 14. The central spindle is carried by the bracket 15, on the air

page_text: trunk V, that connects the annular air jackets of the two vessels. Figure 2, shews
clearly the arrangement of the two water baths 16, of the two vessels. The gas
outlet pipe from gas reversal valve is shewn by 17.
In part of Figure 2, a plan in section shews the annular gas escape flue having
passages leading from and to the inside of the generator vessel, especially provided
by passing through these passages the gas generated finally leaves the vessel and
enters the gas reversal valve on its way to the gas holder.
Referring to Sheet 2, of drawings, in Sheet 2, Figures 5, 6, 7, & 8, shew the
automatic arrangement of reversal valves in greater detail.
At the ends of the rocking shaft R, are provided the triangular buckets 18.
The buckets 18, being pivotted above the centre of gravity require forcible means
of declension before they will tilt, and this declension is obtained by the arrange-
ment shewn. It will be seen that the buckets 18, tilt inside the special shaped
trough 19. On the side edges of this trough there slide two projections 20 attached
to the lower edge of the buckets 18. On the fall of the buckets the projections
slide on the edge with a curve of fall made by the sweep of the lever and
consequently the bucket is tilted as shewn in Figure 5.
The water from this tilted bucket flows into the trough from which it escapes,
through pipes either to replenish the water in the reversal valves or into a feed
water well, supplying the steam generators. The opposite bucket is however,
raised at the same time to the position shewn, in its upward movement it lifts the
spring 21, owing to the projection 22, fixed on the rocking lever and this projection
lifts the pivotted spring 21 that is free to move in an upward direction. The
-descent of the bucket is therefore checked by the movement of this spring, which
however, is only sufficiently strong to carry the bucket three quarters full of
water. When the bucket is entirely filled, the spring incapable of supporting
the weight, it therefore bends or becomes deflected to such an extent as to allow
the bucket to fall, tilting the opposite bucket up to, and above the opposite
.spring 25.
The tilting of the bucket sets the lever 26 in motion this lever being coupled
with the lever 27, of the three-way water valve 28, reverses the direction of the
flow of the water, which either flows into one pipe 29, or into another one
marked 30, the water only flowing into the bucket that is the uppermost.
In order to give greater effect to the downward fall of the rocking shaft, we
provide a vertical projection 31, having at its termination a weight 32. This
weight on passing over the vertical centre gives the advantage of its gravity to.
that of the water replenished bucket and the following action is much more rapid
in consequence.
The method by which the motion of the rocking lever is transmitted to the two
gas and air reversal valves, is shewn clearly in the detailed Figure 6, in which
the central pivot shaft 33 of the rocking lever is shewn supported by the
standard 34, that rests on the cross air bridge 35, that connects the annular air
jackets of the two generator vessels. This pivot shaft 33, passes through the
actuating wheel of gas valve and its bearing 33ª. On to the terminal of the shaft,
we fix the crank 39 having a connecting link 40, which actuates the crank 394, that
is attached to the pivot shaft 41, of the actuating wheel of valve casing 42, so that
the motion of the rocking shaft lever actuates simultaneously the two cranks 39
and 39ª. The spring catch bucket retention arrangement is shewn in greater
detail in Figure 7. The bridge 43, fixed on the end of the water trough, carries
the spring catches 21 and 25; it will be seen that these springs 21 and 25 are free
to move in an upward direction around a circle defined by the vertical swing of the
pivotted piece 44. Referring to Sheet 3, of drawings, Figures 8, 9, & 10,
represent respectively a plan, a longitudinal section and a cross section of the
reversal valves.
In order to save back reference, new reference numbers may be applied to
designate the respective parts of the valve.
The balance wheel 45 is mounted on the spindle shaft 46, which is in its turn

page_text: carried by the bearings and glands 47. These glands are properly bushed. The
bell valves are suspended from two projections 48. The arrangement of the
periphery being such as to obtain a positive and vertical lifting movement.
The tapering of the bent pipes towards their upper lips is clearly shewn.
The valve casing as illustrated, is built up of sheet iron or steel, rivetted up to
end plates 49, which can be rapidly bolted to a mounting fixed to the generator
vessel.
Water outlet pipes are provided at 51, and inlets at 50. We may provide in
addition, a water level gauge. The Figure 10 shews the method by which the
connecting base of steam jet air blower and connection to Roots blower or
sturtevant 52 is effected. Cover 53 is supplied with a central gland. The top.
sheet 54, of reversal valve is merely bolted to casing and not rivetted down, so
that at any time the valves can be rapidly exposed, cleaned and renewed. Figure 11,
on Sheet 3, will be hereinafter referred to. On Sheet 4, of drawings Figures 12, 13,
14, 15, 16, and 17 shew a general detail of the fuel feed hopper.
The elements of novelty in this apparatus may be summarised as follows:-
The inverted conically shaped hopper is mounted on the base frame 55, and this.
base frame is sufficiently large to allow its flange to be properly bolted or otherwise.
attached to the top of the generator, and permits the bell hopper to be renewed
without difficulty. The top plate 58, of hopper slides radially around the pin 57..
The contact surfaces being planed to permit this. In order to bring the top plate
into close contact with the hopper, we provide a cross bar hinged at one end and
equipped with an eccentrically working lever 59, the movement of which brings
a considerable strain upon the top plate 58. The cross bar 60, turns upon a hinge,
The non-gas escape-
and is held rigidly by the loop 61, pivotted to the bracket 62.
poking bar frame and balanced and automatic ball cover arrangement is shewn by
Figures 16 and 17. The principle of its action will be quite clear from the details
shewn. The ball 63, fixed at the end of the rocking lever is counterpoised by the
weight 64, that is fixed at the end of the lever bar 65. This counterpoise maintains.
the ball in intimate contact with the underside of this rim seat 66 of the conically
shaped frame inlet opening 67, into which the point of the poking bar is inserted
pressing down the ball 63. Over this opening 67, we provide a simple cover 68,.
hinged and provided with a central opening 69, into which a plug 70 can be inserted,
this plug is held by a chain 71. When a poking bar is required to be inserted the
hinged cover is lifted up by the foot or hand the point of the bar is then inserted,.
driving down the ball, the conical frame allows the poking down of the fuel and
clinker to be effected with considerable freedom. A sliding plate having a radial
movement may be substituted for the hinged cover plate shewn. These poking
frames may be bolted to the base plate of hopper at 72, see Figure 15.
In Sheet 5, Figures 18, 19 and 20 shew the modification of our invention when
applied for generating gas, with a fixed carbon fuel such as coke, charcoal, sawdust,.
or anthracite. Figure 18 represents a plan in section, Figure 19, a vertical section.
through one plane and 20, a vertical section through another plane of the gas.
generator. The general internal construction resembles that of the vessels already
described.
The generator vessel is internally lined with refractory material 73, which is.
supported by the brackets 74. These brackets carry the cone shaped frame 75,.
having at its base the gridded grate 76, hinged at one end on to a shaft 77, the
part of this shaft which passes through bearings 78 is bolted to the casing 79 and
at its terminals we fix weighted levers. The air inlet box 80 carries the steam jet
blower 81, shewn in dotted lines, its head projecting into the box 82, that is
attached to the air jacket casing 83. The air inlet box is equipped with a bent
pipe 84 that is connected up to a Sturtevant fan or Roots blower or any mechanical
contrivance for propelling air. The foot of casing 79 penetrates into the concrete
base for some distance.
The down-comer 84ª, is attached to the hydraulic seal box 85, in which there is.

page_text: a dip flange 86, that penetrates into the water to a greater extent than does the
seal flange of the gas holder.
:
The hydraulic seal box has a free opening at 87, into which the hand or a bar
can be inserted to withdraw any deposit that can accumulate therein.
In order to facilitate the clearance of the clinkers we provide the retort lid
door 88, provided with the refractory block 884, which is attached to the lid 88
with holding down bolts. The fuel charging hopper 89, is provided with a sliding
lid 90 equipped with a clamping or screwing down cross bar 91.
Figures 21, 22 and 23, 24 & 25 represent the kind of coal feeding hopper that
we may prefer to employ when generating gas under any high pressure and
when we desire to automatically feed such fuel into the generator. Figure 21,
shews a longitudinal section and Figure 22 a cross section of our arrangement.
The outer cylinder 92 forms the casing in which there slides a hollow box 93,
having an opening 94, through which the coal is introduced by means of the
hopper 95, the hopper may be left open as shewn or be closed by a sliding plate.
The hollow cylindrical box 93, is moved forward, being actuated by the
square piston rod 96, which slides through a bearing 97, and which rod may be
continually actuated by a crank or an eccentric or by the hand lever 98, it is turned
round half a circle during its forward movement owing to the fact that the edges
of the square shaft are turned on half a circle.
.
The same rotating effect can be obtained by rifling a circular piston of the
circular section employed. When the piston is moved out to the end, the
opening 94, shewn over the space 99 of generator top walls 100, by the rotating
and forward action is brought directly under the case of hopper, which being filled
with coal, this latter falls into the box 93, the return movement of this circular
hollow box 93 carries the coal over the space 99, the rotation of the box brings
the opening 94 of the box 93 over the space 99 and the coal is then deposited into
the generator vessel 100.
Figures 23, 24 and 25 on Sheet 5 of drawings illustrate a modification of this
form of coal feeding hopper adapted for the high pressure arrangement of our
invention.
The circular box 101 rotates closely in the casing 102. The coal falls from the
hopper 96, into the circular box 101. The opening 103, is brought by
a half
revolution immediately under the hopper, another half revolution brings the
opening 103, over the space 104. The coal then falls through the openings into
the generator 105. The rotation of the fuel box is effected by the helm type of
wheel handle 106. Referring back to Sheet 3 and Figure 11. This illustrates
a section of the lower part of our generator designed expressly for high pressure
work.
The ashpit part of generator 106 is provided with a retort lid 107, by which the
clinkers can be easily withdrawn from the water bath 108, and also permits the
ashpit space under the fire grate M, to be closed up very tightly or so as to resist a
pressure equivalent to 20 or 30 inches of water without escaping through the sides
of the clinker doors.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed we declare that what we
claim is included in the following statement-
1. The general arrangement of apparatus for generating gas of a character
specially adapted for motor gas plant purposes, such gas being generated from
bituminous coal.
2. The gas and air reversal valves of the hydraulic type, for the purpose and
substantially as described.
3. The automatic arrangement for effecting the reversal of such gas, air and
water valves for the purpose and substantially as described.
4. The method of aspiring air around the shell of such gas generator vessels
substantially as described.

page_text: 5. The arrangement of the aspirator foot box by which either air from a fan or
from a steam jet type of air inducer can be obtained for the purpose substantially
as described.
6. The circular tilting grate as arranged in the closed ashpit and in combination.
with or without the water trough or bath, substantially as described.
7. The external lever arrangement for actuating the tipping or tilting of the
circular gridded fire grate.
8. The cross bar retort lid arrangement of clinker clearing door as far as it
relates to our generating and arrangement.
9. The method of clamping down with the eccentric or cam arrangement the coal
feed hopper plate, substantially as described.
.
10. The poking frame arrangement for preventing the escape of gas during the
time that the poking bars are being inserted.
11. The high pressure generator in combination with the rotating coal feed, and
the retort lid type of clinker frame and tilting grate.
12. The method of encasing the connections between the reversal hydraulic
seal valves, and the generators in water, in order to maintain them in a cool
condition.
13. The general arrangement of generator, substantially as described for
generating gas from anthracite coke or a fixed character of carbon.
14. The method of obtaining a constant circulation of water through the gas
and air reversal valves and for utilising such heated water for steam generating
purposes.
Dated this 22nd day of January 1894.
B. H. THWAITE.
GEORGE THRELFALL..