Improvements in Gas Producers.
Year: 1897

page_text: Date of Application, 22nd Nov., 1897-Accepted, 12th Feb.,
1898
COMPLETE SPECIFICATION.
Improvements in Gas Producers.
We, BENJAMIN TALBOT, of Pencoyd, in the County of Montgomery, Metal-
lurgical Engineer, and WILLIAM BISHOP HUGHES, of Wissahickon, in the City
and County of Philadelphia, Mechanical Engineer, both in the State of Pennsyl-
vania, one of the United States of America, 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 gas producers in which carbonic oxide is formed by
the distillation and combustion of coal or other fuel in a structure having a
determinate air supply, some of our improvements relating to producers of that
character which have a water seal, whereby the ash outlet at the bottom of the
producer is closed, air under pressure being forced into the mass of ashes in the
lower portion of the producer and rising therefrom into the superposed mass of
incandescent fuel, the water seal preventing the escape of air through the ash
cutlet or outlets, but permitting the withdrawal of the ashes therefrom.
By our improvements we simplify the construction and thereby lessen the
initial cost of the producer, permit of the removal of ashes from any point around
the producer, and without arresting the operation of the same, provide for the ready
change of the producer from forced to natural draft, or vice versa, increase the
capacity of the producer as compared with those hitherto constructed, and at
the same time provide for the effective breaking up of the clinkers in the hot
zone of the producer, using, by preference for this purpose, water cooled pokers,
or slice bars.
We also effect the breaking-up of such clinkers in the hot zone by the use of
simple mechanical devices so as to render unnecessary the employment of manual
labour for either of these purposes, and we lessen or prevent the escape of soot
from the producer, prevent the caking of ashes at the bottom of the ash hopper
and provide for the convenient removal of the said ashes by mechanical means.
In modern iron and steel works it is the practice to use as fuel in the various
furnaces, gas generated in a separate furnace or "producer," as it is usually termed,
these producers usually consisting of structures of fire brick or sheet metal casings
with fire brick linings and the coal or other solid fuel being fed into them from
the top through a bell hopper.
In order to prevent the formation of clinkers or the calking of the coal in such
producers, constant agitation or poking of the contents of the producer from the
top or sides, or both from the top and sides, is necessary, such agitation being
usually effected by means of manually operated pokers or slice bars; this labour
is extremely fatiguing and the labourers are frequently overcome by the leaking
of the gas. Furthermore, the producers must be of limited capacity in order to
permit the pokers or slice bars introduced from the top or sides to gain access
to all parts of the interior of the producer.
We will describe our invention with reference to the accompanying drawings
of which Figure 1 is a vertical section of a gas producer embodying certain
of our invention.

page_text: Figure 2 is a horizontal section of the same taken on the line a a Figure 1;
Figure 3 is a vertical section of a gas producer embodying features of our
invention in addition to those shown in Figure 1;
Figure 4 is a plan or top view, drawn to a larger scale, of the producer shown
in Figure 3, the upper portion of the producer body being shewn in section;
Figure 5 is a horizontal section taken on the line bb Figure 3;
Figure 6 is a vertical sectional view illustrating the application of our invention
to a producer of a somewhat different type from that shown in Figure 3;
Figure 7 is a vertical sectional view of another form of producer embodying our
invention;
Figure 8 is a horizontal section of the same drawn to a larger scale the section
being taken on the line d d Figure 7;
Figure 9 is an enlarged sectional view of a joint between the fixed and movable
sections of the body portion of the producer shown in Figure 7;
Figure 10 is an enlarged section of one of the pokers and its bearing on the
cover plate of the producer shown in Figure 7 ;
Figure 11 is a transverse section of the same partly in elevation and
Figure 12 is a vertical sectional view of the lower portion of the producer shown
in Figure 7, illustrating the use in connection therewith of a water-sealed ash
hopper.
In carrying out our invention we preferably make the lower portion of the
producer, that is to say, the portion containing the hot zone, where clinker is
formed, of greater diameter or lateral dimensions than the upper portion into which
the coal is fed and through which it descends to the said hot zone, so that pokers
passed vertically through this expanded portion of the producer can approach
close to the wall or lining of the said expanded lower portion and thus prevent
the formation of adhering masses of clinker on the said lining, the necessary length
of poker being only sufficient to reach to the centre of the said expanded portion
of the producer. This expansion in diameter or lateral dimensions of the lower
portion of the producer containing the hot zone, also provides for the use of water
cooled pokers which can, if desired, be operated mechanically so as to dispense
with the manual labour now required for this purpose.
In Figure 1 of the drawings, 1 represents the lower expanded portion of the
producer body which is of cylindrical cross section although it may be square or
cther polygonal shape in cross section if desired.
The portion 1 is mounted upon suitable vertical standards or legs 2 and carries
a suspended ash hopper 3, the lower portion of which extends into a sealing pit 4
containing water whereby the escape of any air or gas from the bottom of the
ash hopper is prevented.
It is advisable to use as few as possible of the supporting legs or standards in
order that free access to all parts of the bottom of the structure will be permitted.
The legs 2 which may be made in any appropriate manner, are united to the
producer body 1 and to channel bars 2 which constitute the boundary of the
water seal pit 4, the latter being preferably formed of concrete or masonry and,
for convenience, rectangular as shown in Figure 2, although this form may be
departed from to any desired extent as circumstances may suggest, without
affecting our invention.
Rising from the water seal pit 4 into and through the centre of the ash
hopper 3 is a vertical pipe 5 having a cap ring or sleeve 6 upon which is mounted
a double conical hood 7-8. Air, introduced by a steam jet, or otherwise caused
to flow under any desired degree of pressure, rises through the pipe 5 and escapes
from beneath the hood 7-8 into the mass of ashes in the lower portion of the
producer, the air rising through the ashes and entering the incandescent mass
of fuel above the same.
The water seal in the pit 4 prevents the escape of air or gas downward from the
ash hopper but permits of the withdrawal of ashes from beneath the same and
it will be observed that the ash hopper is entirely free at the bottom so that

page_text: ashes can be withdrawn at any point around the hopper, the slight amount of space
occupied by the supporting legs of the producer body constituting no practical
obstruction to such removal.
The ash hopper is, moreover, exposed on all sides to a free circulation of air
whereby the cooling of the ashes before they reach the water seal is provided for
and the formation of water vapour which occurs when hot ashes are brought into
contact with the water seal is prevented, this being a desirable result as the rise
of steam from the water seal to the incandescent fuel in volume greater than can
be readily decomposed by the latter is in practice always to be avoided.
In the depending ash hopper 3 we form, by preference, a number of poke holes
or draft openings 9 with cover plates 10 having openings closed by suitable
plugs 11, and in the ordinary working of the producer these plugs are all inserted,
any one of the plugs, however, being readily withdrawn when it is desired to
insert a poker or other implement for acting upon the ashes or clinkers contained
in the ash hopper, and all of the plugs being withdrawn when it is desired to
operate the producer by natural draft instead of by means of a forced blast
of air.
By the use of the exposed water-sealed ash hopper in combination with the
internal air-supply, the poking of the ashes by means of implements inserted
through the poke holes of the hopper can be effected without cutting off the air
supply, so that the producer is continuous in its action.
A producer of this character can be constructed without excessive initial cost,
whilst the requirements of easy removal of the ashes, proper cooling of the ashes
before they reach the water seal, and ready access to any and all parts of the
structure are provided.
Resting upon the lower portion 1 of the producer body is a ring 12, preferably
provided with one or more channels 13, for the flow of water or other cooling-fluid,
and upon this ring is supported the upper portion 14 of the producer body, which
is of considerably less diameter or lateral dimensions than the lower portion 1 of
the producer, hence there is, between the walls of the upper and lower portions
of the producer body, a portion of the said ring through which can be passed
pokers or slice bars 15, which can work close to the inner surface of the walls of
the lower portion of the producer and thereby prevent the formation, upon the
said walls, of adhering masses of clinkers. The pokers can also be moved in all
directions through the openings in the ring 12 so as to break up the clinkers
formed in the lower portion of the producer, this portion containing the hot zone
of combustion at which point the clinkers are usually formed.
To prevent leakage around the pokers the latter are properly guided in univers-
ally pivotted carriers or spheres 16, mounted upon the ring 12, and as some portion
of each poker is always embedded in the incandescent mass of fuel in the lower
portion of the producer it is advisable to use water-cooled pokers, for instance, as
Shewn in the drawing, each poker has an outer tubular casing closed at both ends
and having an internal pipe 17 extending through the outer end of the poker to
near the inner end of the same, the said pipe being of considerable less diameter
than the outer tube so that water, admitted through a flexible pipe 18 to the said
internal pipe 17, will pass down through the pipe and then rise through the annular
space between the said pipe and the outer tube 15 and escape from the upper
portion of the latter through a flexible pipe 19.
To prevent caking of the fuel in the lower portion of the upper section 14 of
the producer the latter may be provided with side poke holes 20, see Figure 2, for
the insertion of pokers or slice bars of the usual character, or the fuel in the upper
part of the producer may be broken up by pokers inserted through suitable open-
ings 21 in the top or cap plate of the producer. These openings 20 and 21 are,
however, only intended for emergency use, the pokers 15 being generally relied
upon to effect the necessary agitation of the contents of the producer.
It is advisable, however, that these pokers should be operated by mechanical
means, for, owing to the large size and increased capacity of the producer, they

page_text: will generally be too large to be operated by hand, and it is advisable on general
grounds to dispense with manual labour for the performance of such duty, because
of the heat and poisonous fumes to which the labourers would be subjected.
It is advisable also to construct the producer body with a fixed portion and a
rotating portion, the poker or pokers being carried either by the fixed or rotating
portion, as the case may be, so that the said poker or pokers may, by mechanical
means, be caused to traverse the mass of fuel and effect the desired breaking up
of the same so as to prevent the formation of masses of clinker which would other-
wise adhere to the walls of the producer.
In the producer shewn in Figures 3, 4 and 5 the ring 12 instead of being mounted
upon the lower portion 1 of the producer body, is mounted upon the fixed standards
or legs 2, and the portion 1 is surrounded by a ring 22 carrying a series of wheels
or rollers 23 which run upon an annular track 24 suitably supported upon the
standards or legs 2, so that the said lower section 1 of the producer body can be
readily rotated. The top of the said lower portion 1 of the producer body has a
trough 25 which receives a depending flange 26 on the ring 12, hence, when the
said trough is filled or partially filled with water, sand, or other suitable sealing
agent, any escape of gas from the joint between the fixed and rotating-sections
of the producer will be prevented.
The ash hopper 3 rotates with the portion 1 of the producer body and carries a
series of wings or blades 27, which serve as scrapers to scrape the ashes from the
sealing pit 4 into a conveyer trough 28 at one side of the said pit, the said trough
having an endless screw conveyer 29 which delivers the ashes into a transverse
conveyer 28 whereby they are deposited at any desired point.
The rotation of the lower section of the producer renders it unnecessary that
the pokers 15 shall have anything more than a swinging movement from and to-
wards the centre of the producer body, hence instead of the universally pivoted
block 16 shown in Figure 1, a block 16" which has trunnions adapted to suitable
bearings on the ring 12, are provided, the poker being movable vertically through
this block as it is through the block 16.
The rotation of a portion 1 of the producer body causes the pokers to traverse
through the mass of fuel into which they are projected, the swinging of the pokers
radially and the raising and lowering of them being effected by hand, if desired,
without excessive labour, and at the right hand side in Figure 3 we have shown
a poker constructed for having these movements imparted to it by hand, but for
reasons before given, we prefer to dispense with hand labour altogether in poking
the fuel, and we have therefore shewn, at the left hand side of Figure 3, and in
Figure 4, mechanical means for effecting the vertical and swinging movement
of the poker, such means comprising a shaft 30 having a pinion 31 meshing with
a spur wheel 32 on a shaft 33 on which is a pinion 34 meshing with a spur wheel 35
on a shaft 36, all of these shafts being adapted to bearings mounted upon suitable
beams forming part of the fixed framework of the producer.
On the shaft 36 is a disc 37 having a crank pin to which is connected one end
of a rod 38, the other end of the said rod being connected to an arm 39 on one
of the trunnions of the cylindrical block 16 which carries the poker, so that, as
the said shaft 36 is rotated, a rocking movement will be imparted to the said block
and to the poker carried thereby.
On the shaft 33 is a disc 40 which has a crank pin connected by a link 41 to
an arm 42, suitably hung at one end to a bracket on one of the beams of the
fixed structure, the opposite end of the said arm being forked and connected by
links 43 to a sleeve 44, which is vertically confined to the poker 15, so that rotation
of the shaft 33 will cause a reciprocating motion to be imparted to said poker.
On the shaft 30 is a bevel wheel 45 which meshes with a bevel pinion 46 on a
shaft 47, the latter having a bevel pinion 48 which meshes with a pinion 49 on a
vertical shaft 50, and this shaft 50 has a spur pinion 51 meshing with an annular
rack 52 on the lower section of the producer body, so as to effect the desired
rotation of the latter, the lower end of the shaft 50 having a bevel wheel 53 which

page_text: meshes with a bevel pinion 54 on the upper end of the shaft of the ash conveyer
screw 29.
A poker such as shown at the right hand side of Figure 3 may be used as
supplementary to the mechanically operated poker which we have just described,
ånd in this case one of the trunnions of the block 16 may have a counterbalanced
arm 55, whereby the poker may be vibrated by hand when desired, the other
trunnion having a spur wheel 56 meshing with a pinion 57 on a shaft above the
trunnion, and this latter shaft having a worm wheel 58 meshing with a worm 59
on a vertical shaft 60, the worm wheel being loose on the shaft but the latter
having a clutch 61 whereby said worm wheel may be secured to the shaft, when
desired, so that the vibration of the poker may be effected directly, by the mani-
pulation of the arm 55, or indirectly, by manipulation of the shaft 60, when a
greater amount of power is required to move the same. Normally, however, this
poker will not be vibrated but will occupy such a vertical position as to operate
close to the surface of the wall or lining of the lower section of the producer and
thereby prevent the formation of adhering masses of clinker upon said wall or lining.
Our novel form of producer having a casing partly fixed and partly rotating,
with pokers mounted upon one or other of the parts so as to act upon and break up
the fuel in the producer, permits of very many structural modifications, some of
which we have shown in the remaining figures of the drawing. In Figure 6, for
instance, we illustrate a modified construction in which the producer body 1ª is
stationary and of uniform diameter throughout, but has a rotatable water-sealed
cap 62 having wheels 63 running upon an annular rail 64 mounted exteriorly upon
the upper portion of the producer body the said rotating cap 62 constituting the
support for the poker carrying block 16 and also for the valved feed hopper 65.
The cap 62 has an annular rack 66 with which meshes a bevel pinion 67 on the
driving shaft 68.
In the producer shown in Figures 7 to 12 the lower section 1b and the upper
section 14 of the producer are of the same diameter, the upper section being
mounted upon posts or standards 2 and the lower section being rotatable, a
special form of water-sealed joint, referred to hereafter, being formed between
these two sections of the producer.
The cap plate or cover 02 carries a fuel magazine 70 with valved hopper above
the same, both the joint between the magazine casing and the cap 62 and that
between the hopper casing and the top of the magazine being, by preference,
water-scaled so that while these parts are readily detachable, one from another,
escape of gas at the joints is prevented.
The top plate 62 of the producer body has bearings for the mechanically actuated
pokers 15, whereby the agitation of the mass of fuel in the producer body is
effected, one of these bearings being shown on an enlarged scale in Figures 10
and 11, on reference to which it will be observed that the hollow poker 15 is
secured to a head 71 which has opposite trunnions 72 adapted to bearings formed
partly in the hollow boss 73, projecting upward from the top plate of the producer
body, and partly in the cap 74 which is mounted upon and secured to said hollow
boss 73. An opening 75 extends upwardly through the said cap 74 so that the
poker head and its bearings are readily accessible without removing the cap or
interfering with the operation of the poker, the said openings 75 being normally
closed by a bell 76, having a depending flange which extends down into a water-
sealed chamber 77 surrounding said opening 75, so that, in the ordinary operation
of the apparatus, the escape of gas from the poker opening is effectually prevented.
Secured to the projecting end of one of the trunnions 72 of the poker head is
an arm 78 having a pin 79 which is connected by a rod 80 to a crank pin on a
disc 81 carried by a suitable driving shaft mounted in bearings, in brackets 82
on the fixed upper section 14 of the producer body, the rotation of the disc 81
causing a rocking movement of the poker 15.
The poker head and one of its trunnions contains a chamber 83 communicating
at the outer end with a water inlet pipe 84 and at the inner end with the pipe 17

page_text: which extends down through the hollow poker 15 and discharges near the inner
end or point of the latter. The upper end of the hollow poker 15 communicates
with a chamber 85 formed in the poker head and in the other trunnion 72 of
the same and the outer end of this chamber 85 discharges through a vent pipe 86
into the water chamber formed on the top 62 of the producer body for the purpose
of cooling the same.
The fixed upper section of the producer body has, at the lower edge, an annular
channel bar 87 with depending annular flange which is comparatively close to
the inner flange of an annular channel bar 88, secured to the upper end of the
lower rotating section 1b of the producer body, as shown in Figure 9, so as to
prevent coal from working outward into the horizontal joint between the two
plates and thereby interfering with the free rotation of the lower section of the
producer.
The water trough 25 and depending flange 26 forming the water seal are sub-
atantially the same as in the structure shown in Figure 3.
The lower rotatable section 1b of the producer body has an inverted frustro-
conical ash hopper 3, but, as shown in Figure 7, this ash hopper has a horizontal
hearth plate 90 and has lateral ash discharging openings 91 which are normally
closed by swinging doors 92, and below and outwardly beyond the said hearth
plate 90 is an ash receiving plate 93 to which the ashes can be drawn from the
hearth through any one of the openings 91 when the door which normally closes
the said opening has been raised, hence an attendant, standing at one point, can,
as the ash hopper and its hearth plate are slowly rotated, draw out the ashes
through the openings 91 as they successively come into position in front of him,
the ashes being deposited upon the receiving table 93 from which they can be
removed by a fixed inclined scraper 94. whereby they are directed into a chute 95
and thence into an adjacent ash car 96.
Beneath the ash collecting plate is an annular rack 97 with which meshes a
spur wheel 98 on a short upright shaft free to turn in a bearing on the hollow
hase plate 99 of the structure, the said spur wheel meshing with a pinion 100 at
the lower end of a driving-shaft 101 whereby power is supplied for effecting the
rotation of the lower portion of the producer body and the parts connected there-
with.
On the base 99 is an annular track 102 and on the underside of the body
structure of the producer is a similar track 103 and between these two tracks are
interposed bevelled rollers 104 whereby the proper support of the rotating sections
of the producer is effected without interfering with the free rotation of the
same.
The hearth plate has a central air pipe 5 projecting up into the ash hopper but
having, instead of the double hood shown in Figures 1 and 3, a slotted head
through which the air escapes into the mass contained in the upper portion of the
ash hopper and lower portion of the producer body, a downward continuation of
the air pipe entering a water seal contained in a chamber 105 which surrounds
the fixed lower portion of the section 5 of the air pine, the latter having a
lateral branch 106 through which the air is blown and said branch having another
branch 107 for the introduction of steam.
A central pipe 108 passes up through the fixed and rotating sections of the
air pipe and has at the upper end lateral branches passing out through the said
air pipe a short distance above the hearth plate 90, the lower end of said pipe 108
being free to turn in a box 109 at the base of the air pipe, and said box 109 having
a branch 110 through which steam or water may be forced so as to be projected
into the ashes and clinkers upon the hearth plate in order to soften the same
preparatory to removal.
In Figure 12 we have illustrated a modification of our invention in which the
ash hopper has, in place of the ash receiving-plate shown in Figure 7, a flanged 5
plate or trough 111 which contains water to serve as a seal for the ash hopper,
the said water trough, however, rotating with the hopper in the same manner as

page_text: he ash receiving plate 93, so that the ashes can be drawn into the same from the
opper by an attendant standing at a fixed point, thus obviating the necessity of
ravelling around the producer in order to remove the ashes from all parts of the
opper, this being an objection to that class of gas producers which have fixed
oppers..
By the use of the magazine 70 extending down into the body of the producer,
he level of the fuel is carried at a point below the joint between the fixed and
otatable sections of the producer body, this being the preferable form when the
producer body is of the same diameter throughout and the joint is made at a
point below the top of the said body.
!
'In all of the producers constructed in accordance with our invention a large
body, of green or unignited fuel may be maintained above the hot zone, and this
acts as a screen or soot catcher and prevents, or in very large measure, lessens, the
escape of soot from the producer, the soot being gradually worked down into the
hot zone with the fuel, and there converted into gas.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is: -
.:
'
1. A water-sealed-gas producer having a body supported upon legs above the
sealing pit, an ash hopper suspended from the said body and depending into the
said sealing pit, the said, hopper being exposed to the air and having poke holes
formed in it, and an air supply pipe within the hopper, substantially, as herein-
before described.
2. A gas producer divided horizontally and having the lower portion mounted
so as to be susceptible of movement in a horizontal plane, each portion containing
a mass of fuel whereby the contents of said lower section are caused to move in
contact with those in the upper fixed section at the line of division substantially
as hereinbefore described.
3. A gas producer having a contracted upper body and an expanded lower body
with abrupt lateral connection between the two, one or more poke holes in the
said lateral connection whereby a poker can act directly upon the fuel in the
expanded lower body of the producer, and a gas outlet in the upper portion of
the contracted upper body of the producer, substantially as herein before described.
4. A gas producer having a contracted upper body with gas outlet therein, an
expanded lower body, an abrupt lateral connection between the two, and pokers
mounted in but free to pass through the said lateral connection so that they will
be outside of the upper section and inside of the lower section of the producer,
substantially as hereinbefore described.
5. A gas producer having a casing divided horizontally, one portion being re-
voluble in respect to the other, and pokers, mounted upon the upper portion of the
casing and projecting down into the lower portion of the same, whereby the said
pokers are, by the rotative movement of the casing, caused to agitate and break
up the mass into which they project, substantially as hereinbefore described.
6. A gas producer having a casing divided horizontally and having one part re-
voluble in respect to the other, the said parts of the casing being constructed to
form a sealing chamber so as to prevent the escape of the gas between the two
sections of the casing, substantially as hereinbefore described.
7. A gas producer having a casing divided horizontally at or near the top of the
hot zone and having one portion of the casing revoluble, substantially as herein-
before described.
8. A gas producer having a revoluble ash hopper and a water sealed pit into
which the lower portion of the said hopper projects, substantially as hereinbefore
described.
9. A gas producer having upper and lower sections one of which is revoluble,
5 the lower section being laterally expanded, a structure extending from one of the
said sections to the other, and movable pokers mounted in the said connecting

page_text: structure so that their action upon the contents of the producer is due partly to
the rotative movement and partly to movement imparted to them independently
of the said rotative movement, substantially as hereinbefore described.
10. A gas producer having a casing with blocks pivoted upon the upper portion
of the same, pokers free to move longitudinally through the said pivoted blocks,
and power operated mechanism for swinging the said blocks and reciprocating the
pokers therein, substantially as herein before described.
11. A gas producer having a body divided horizontally, one part being revoluble
in respect to the other, and a fuel reservoir carried by the upper portion of the
producer body, and projecting down into the gas chamber, substantially as herein-
before described.
12. The combination of the producer body having upper and lower sections, one
of which is revoluble, with joint rings having inner depending flanges whereby
the access of coal to the horizontal portion of the joint is prevented, substantially
as herein before described.
13. The combination of the body of a gas producer, with a poker carrying plate
and a hollow poker having trunnions adapted to bearings in the said plate,
one of the said trunnions having a chamber communicating directly with the
upper end of the poker and the other trunnion having a chamber communicating,
through a pipe, with the inner end or point of the poker, substantially as herein-
before described.
14. The combination of a gas producer body with a vibratable poker having
trunnions adapted to bearings on the casing of the producer, the top bearing having
an opening extending directly through it, and a sealed bell for closing the said
cpening, substantially as herein before described.
15. A gas producer having a revoluble ash hopper, and an ash receiving plate
extending outwardly beyond the said hopper and revolving therewith, whereby
it is adapted to receive the ashes as they are discharged from the hopper, sub-
stantially as herein before described.
16. A gas producer having a revoluble ash hopper, an ash receiving plate ex-
tending outwardly beyond the said hopper and revoluble therewith, so that it can
receive the ashes discharged from the hopper, and provision for removing the
ashes from the said plate as it rotates, substantially as herein before described.
17. A gas producer having a revoluble body with depending ash hopper and
hearth plate, the said hopper having lateral openings above the hearth plate, and
doors for closing the said openings, substantially as hereinbefore described.
18. The combination of the ash hopper of a gas producer, having a bottom
hearth, an air pipe projecting up into the hopper, and a pipe passing through
the said air pipe and serving to admit water or steam to the lower portion of the
hopper directly above the hearth, substantially as hereinbefore described.
Dated this 22nd day of November 1897.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Field's, London, W.C., Agents.