Improvements in Machinery or Apparatus for Charging and Drawing Gas Retorts.
Year: 1893

page_text: Date of Application, 17th Mar., 1893-Accepted, 22nd Apr., 1893
COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Charging and Drawing
Gas Retorts.
1, JOHN WEST, of the Albion Iron Works, Miles Platting, Manchester, in the
County of Lancaster, Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:
This invention relates to improvements in machinery and apparatus for which
Letters Patent No. 789 dated 24th February 1881, No. 1226 dated 27th January
1886, and No. 723 dated 17th January 1888 were granted to me.
Power can be transmitted by compressed air to the charging and drawing
machines from an air compressor fixed in any convenient position near to or away
from the retort house in various ways according to circumstances. For instance
when convenient air under considerable pressure is carried in reservoirs attached
to the machines and supplied from a fixed reservoir by means of connecting pipes
which were detached as soon as the reservoirs on the machines are charged as
described in my aforesaid Specification No. 789 dated 24th February 1881. Or
the machines can be supplied with compressed air by means of flexible hose
coiled or uncoiled, as the case may be, automatically as the machines are moved
about to perform their work or by swinging pipes coupled and uncoupled at
intervals as may be desired, or by any other known means for accomplishing the
saine end.
In the operation of charging a retort with coal the charger was sent into
and withdrawn from the retort twice to make a complete charge as fully described
in the Specification for which Letters Patent No. 1226 dated 27th January 1886
were granted to me so that the two charges of coal were deposited in the retort
and spread therein by the scoop which turned in one case towards one side and
in the next towards the other side.
In the operation of drawing a gas retort the force required to manipulate the
rake varies greatly at different parts of the stroke on account of the varying
condition of the retort due to the effects of heat and other causes and it
frequently happens that at one moment the whole power of the machine must
be exerted to overcome an obstruction to the motion of the coke while at the
next moment a very slight force may be sufficient to keep it in motion. It may
also happen that while in one retort the coke may be very easily drawn, in the
next the force required may be several times greater; in the former case if the
machine made use of all the power which it is capable of exerting the speed of
working would be considerably accelerated and if no check were applied near
the end of the stroke the moving parts may come into violent collision with
those that are fixed and damage may result.
Also in drawing a retort it frequently happens that short strokes have to be
made near the ends, or at some intermediate part of the stroke. In such ca-es
if the work be done by a piston moving in a cylinder as in my invention the
air used may be greatly in excess of the amount actually required unless means
are provided for reducing the loss. Supposing the piston to have been arrested
when at half stroke and that it is desirable for it to move in the opposite
direction a few inches it will be understood that the greater part of the air
which was supplied to the cylinder to make the previous stroke must be exhausted
into the atmosphere and a connection must be made by means of the valves so that
pressure of the air may be made to act upon the opposite side of the piston, and

page_text: before the piston will move half a cylinder full of air must be used to fill up the
vacant space and as much air will be used to perform a stroke of a few mehes aS
would be required to make the same stroke from the commencement.
Now this invention has for its principal objects to distribute the coal from the
charger more evenly and more to the sides of the retort than when the retort is
charged by allowing the scoop to enter the retort both times in the same course;
to provide means whereby the speed of the drawing rake is effectually controlled and
gradually but surely brought to rest at the end of the drawing stroke; and to
provide means whereby the drawing rake and charging scoop can be manipulated
more economically than hitherto and consists essentially in causing the charging
scoop to move a small distance sideways after the coal from the first half of the
charge has been delivered in the retort and before the scoop goes in a second time
to complete the charge by means of a cylinder with piston and rods so fixed on the
charger frame and working between the main framework of the machine that a
sideways movement of the charger can be obtained by directing compressed air to
one side or the other of the piston: in causing the motor piston of the drawing
machine to operate a plunger or piston working in a eslinder containing water free
to escape into a reservoir through an adjustable orifice which is gradually closed
at the ml of the drawing stroke so as to prevent any damage to the rake at the
end of its outstroke and in providing an arrangement whereby before the motion
of the motor piston is reversed the pressure on the two sides of the piston is equalized
so that a certain amount of air is saved.
'
In the accompanying eight sheets of illustrative drawings:- —
Figure 1 is a side elevation of a drawing machine constructed according to this
invention and shown as arranged to work by compressed air supplied by flexible
hose or other comm ction to a fixed reservoir.
Figure 2 is an end elevation looking towards the retorts and Figure 3 is a plan
of the same.
Figures 4, 5, 6 and 7 are views of the air cylinder.
Figure 8 and 9 show two views of the valve box and Figures 10, 11 and 12
show the valve in three positions.
Figure 13 is a side elevation of the charging machine constructed according to
this invention and
Figure 11 is an end elevation looking toward the retorts and
Figure 15 is a sectional plan showing the charger frame and charger together
with the cylinders and mechanism for driving the charger in and out of the retort
of the same.
Figures 16, 17, 18 and 19 are views showing the air and check cylinders for
driving the charger.
The drawing machine consists of an upright frame supported on four wheels A
which run on rails in front of the retort stack being propelled by means of the
hand wheel B acting through the bevel gearing and D. The channel iron
hanging frame E in which the rake bar runs can be hoisted to suit the various
heights of the retorts by means of a small wine worked by the hand wheel (and
acting upon the hoist chain H which passes over pulleys on the top of the frame
and is attached to the sliding brackets supporting the channel bar hanging
frame E. The rake K is propelled into the retort or withdrawn therefrom by means
of the bar the latter being guided in a straight line by the channel guides E.
The rake K can be kept out of the coke or depressed into it at will by means of
the rocking lever M acting through the vertical rod N and causing the channel bar
hanging frame E to rock round a pivot at (). The power for drawing the coke and
working the rake is transmitted from the cylinder P through the piston rod a, the
rack R, the pinions S, the chain drum T, and the chains U and V. The latter are
fixed to the chain drum T in such a manner that when the chain drum is caused to
rotate the one chain is wound on to it while the other unwinds or pays out, and the
chain drum is made in two parts so that when the chains become slack from any
cause such as hoisting from one tier to the next they can both be tightened up.

page_text: The tank W is filled with water for the purpose of cooling the rake through the
flexible hose X and the spray pipe Y.
Up to this point the apparatus described is substantially the same as that for
which Letters Patent No. 789 dated 24th February 1881 and No. 1226 dated 27th
January 1886 were granted to me and I now proceed to describe the construction
and mechanism of those parts which are new.
ee is
The cylinder P Figures 4, 5, 6 and 7 is provided with a piston Z and a rod a
carrying a crosshead 6 near the top and being cottered to the rack R above the
crosshead. At each end of the crosshead a plunger e is attached by a nut above
and a shoulder below so that when the crosshead is moved the plungers e must
move with it. For a short distance near the bottom end of each plunger there is a
taper groove made in it as shown. The plungers do not fit the side cylinders ee
except for a short distance near the bottom. The bottom of each cylinder.
connected to the other by means of the pipe 'and each cylinder ee has an outlet !
in the side at a short distance from the bottom; this outlet is of oblong shape and
opens into a passage g which is kept full of water by the pipes & Figures 1 and 2,
the pipe opening into the bottom of the tank W. Compressed air is supplied
through the inlet to the valve box and a slide valve distributes the air as
described hereafter. When it is desired to send the rake head into the retort the
hand lever is pulled in the necessary direction and air is thereby admitted to
the underside of the piston Z and as the piston moves upwards it causes the chain
drum T to revolve through the operation of the rack R and pinion S and the
chain is wound on the drum, drawing the rake bar L forward and thus causing
the rake K to enter the retort. While this operation is going on the two
plungers ce are lifted by the crosshead band water flows out of the tank through
the pipe and passage into the cylinders ee following up the plungera until they
reach the top of their stroke. The speed of the rake is kept moderately constant
in the first place by the continually increasing leverage at which the weight of the
rake bar acts and in the second place by the action of the exhaust air from the
space above the piston it being allowed to escape only at a certain rate by adjusting
the area of the exhaust orifice.
If an obstruction to the inward motion of the rake should be met with the air
above the piston will have time to escape through the exhaust orifice, and a greater
effective load will thus come upon the piston rod until the resistance is overcome.
To draw the coke from the retort the rake bar is depressed into it by the lever M
and then the lever is moved until air is admitted above the piston, and that below
allowed to exhaust. The chain U is thus wound on the drum T and V uncoils and
the motion goes on at a predetermined speed until the plungers cc reach a point
near the bottom of the cylinders ee when they gradually cover up and partially
close the outlets so that water can only get out very slowly and as a great resis-
tance is thereby produced the motion of the plungers is gradually arrested and the
whole of the moving parts are brought quietly to rest. The pipe is for the
purpose of equalizing the load on each plunger by equalizing the pressures if
the outlet grooves d in the plungers should vary in area. The speed of stopping
can be adjusted by turning each plunger through a slight angle round its axis
whereby the grooves d in its ends are caused to overlap the outlet 1 and thus reduce
the area through which the water passes.
The arrangement of mechanism whereby the compressed air is allowed to pass
from one side of the piston to the other is as follows:-The valve box j
Figures 1, 5, 8, 9, 10, 11 and 12 has three ports mno so placed that mis
connected with the said cylinder P below the piston, n is connected with the said
cylinder above the piston, and o is in communication with the atmosphere and
forms the exhaust port. A slide valve p is used to distribute the compressed air
from the valve box to either end of the cylinder as desired, but the slide valve is
not of the ordinary kind because it has a passager formed in it in such a way that
when the valve is placed in a central position as shown in Figure 11 the compressed

page_text: air in either of the spaces m or a can flow through the passage » until the pressure
is equal and without communicating with the compressed air in the valve box or
with the exhaust. Figure 10 shows this valve in position for supplying compressed
air through the port to the space in the cylinder P above the piston in order to
make a downstroke. Figure 1 shows the valve in its central position which it
would occupy for a short space of time either during the operation of reversing the
action of the machine or when the latter is at rest. Figure 12 shows the position
of the valve when compressed air is being supplied to the underside of the piston
in order to make an upstroke. When the” port » is open to pressure the port mis
in communication with the exhaust and when the port m is open to pressure the
port a is in communication with the exhaust o during the operation of reversing
the action of the machine the valve pin its motion first closes the supply port a
or ma the case may be, closing the connection of the other port with the exhaust
at the same time; then by the continued motion of the valve the port n become
connected with m through the passage and air flows from one side of the piston
to the other until equilibrium is attained, and by the still further continued motion
of the valve the communication between ports and is cut off and then the
port m or as the case may be is opened to the pressure while the other port is
opened to exhaust and this the reversal takes place in every instance after a
communication has been made between the two sides of the piston and a saving
is effected in the manner previously described. There are two tappet levers 11
communicating through the connecting rods with the lever whereby the valve
is placed automatically in its central position when the piston approaches either
end of its stroke.
It will be understood that the same arrangement as those herein described will
accomplish the same ends whether the motive force be obtained from compressed
air or any other gas or expansive vapour under pressure and I do not limit myself
to the use of compressed air only.
The charging machine consists of an upright rectangular frame 1 Figures 13 14
and 15 supported on four wheels 2 which run on rails in front of the retort stack
being propelled by means of the motor 3 driving the vertical shaft 4 having a
sliding clutch which when put in gear with the pinion 6 drives the wheel 7 and
turns the axle S so that the machine is made to travel along the rails. The motor
is made to reverse to cause the machine to travel to the right or left as required.
The motor 3 is used for raising or lowering the coal hopper 9 and charger
frame to by putting the sliding clutch into gear with the bevel wheels 11 and 12
driving a chain barrel 13 on which the hoisting chains 14 and 15 are caused to wind
on or off according to the direction the motor 3 is running. The chains 14 and 15
lead over pulleys 16, 17, 18, 19, 20 and 21 and are anchored to the top of the main
frame 1 by the fastenings 22.
The coal hopper 9 and charger frame 10 are suspended freely from the chain
pulleys 18 and 21 and sufficient spaces are provided between the sides of the hopper
and charger frame and the uprights of the main frame 1 to permit the sideways
movement of the charger frame 10 and charger 53.
At the bottom of the charger frame 10 a cylinder 23 is fixed, this cylinder
has a piston 24 having piston rods 25 and 20 working through the stuffing boxes
and glands in the covers 27 and 28. The piston rods 25 and 26 are arranged
to slide up or down between the uprights of the main frame of the machine!
when the hopper and charger frame are raised or lowered. A valve box 29
having an ordinary three ported slide valve is fitted to the cylinder 23 the slide
valve will admit the pressure air to one side of the piston 24 while that on the
other side is exhausted into the atmosphere. The compressed air is supplied to the
valve box and cylinder through the pipe 32 and the valve is controlled by
the valve rod 30 and the hand lever 31.
On the charger frame is fixed an air cylinder 33 having two water check
cylinders 34 and 35 Figures 13, 14, 15, 16, 17, 18 and 19. The cylinder 33 is

page_text: fitted with a piston 36 and piston rod 37 having a crosshead 38 fitted at one end.
The crosshead 38 is fitted with two piston rods 39 and 40 having pistons 41 and 42
working in the check cylinders 34 and 35.
A rack 43 is also fitted at the end of the piston rod 37 driving a pinion 44 con-
nected to a chain drum 45 having chains 46 and 47 attached to it and leading over
the pulleys 48, 49, 50 and 51 to the charger and anchored to the chain barrel 52
on the charger 53.
The charger used is the same in detail and working as described in the Speci-
fication for which Letters Patent No. 1226 dated 27th January 1886 were granted
to me.
On the air cylinder 33 is fixed a slide valve box 54 fitted with a slide valve
similar to that described in detail for the drawing machine and shown in
Figures 8, 9, 10, 11 and 12 the ports leading to each end of the cylinder 33 and
effecting the same object of economy in compressed air used. The valve for the
air cylinder 33 is controlled by the hand lever 55 fitted to the side of the charger
frame 10.
When the piston 36 has nearly made a full stroke the tappet 56 on the cross-
head 38 comes in contact with the tappet lever 57 and in a similar manner to that
described for the drawing machine the air is shut off, a reverse stroke is then made
when near its completion the tappet lever 58 will again shut the air off.
The method of controlling the speed of the pisten 36 is by water displacement
the check cylinders 34 and 35 being filled with water from the water vessel 59
which automatically supplies water to the cylinders as they make an outstroke and
stores the water delivered by the displacement of the piston rods 39 and 40 when
they enter the cylinder during the return stroke. In order that the water should
follow the pistons 41 and 42 freely on the suction stroke I provide two suction
valves 60, Figures 18 and 19 in addition to the two inlet and outlet ports 61 so
that when the water is being forced out on the pressure stroke from one end of the
cylinders 34 and 35 the pressure closes the suction valve communicating with that
end and the water from that end of the cylinders is only permitted to pass to the
opposite end of the cylinders through the ports 61 though the suction valve com-
municating with the suction side is free to open to permit water from the water
vessel 59 to follow the piston freely. The ports 61 are provided with taper
pointed adjusting screws 62 for regulating the size of the ports and speed of
water flow.
Having now described the working parts of the charging machine I will describe
the cycle of operations for charging a retort. The machine having been brought
opposite a retort and the charger adjusted to the desired position for making the
charge the coal is fed to the scoop from the hopper through the feeder box 63,
Figures 13 and 14 by turning the hand wheel 64. As soon as the scoop is full
the hand lever 55 is moved in the proper direction for causing the compressed air
to enter the end of the cylinder causing the rack to go forward and operate upon
the rack pinion thereby turning the chain drum 45 and winding up the chain 46
As soon
and unwinding the other chain 47 thus driving the scoop into the retort.
as the charger approaches the end of its outstroke the tappet 56 on the cross-
head 38 comes in contact with the tappet lever 37 and causes the air supply to be
cut off preventing any further motion. The band lever 55 is then reversed and air
is thus admitted to the opposite side of the piston 36 and the return stroke is then
made the scoop being turned through a certain angle for depositing the coal in the
retort as described in the Specification for which Letters Patent No. 1226 dated
27th January 1886 were granted to me. The charger when withdrawn from the
retort comes to rest in the charger frame ready for the second supply of coal
which is provided by again turning the hand wheel 64 as described above but
before the scoop is sent forward into the retort this time the hand lever 31 is
moved to admit air to one side of the piston 24 causing one of the piston rods 25
or 26 to press against the sides of the main frame and the cylinder attached to
the charger frame is moved sideways carrying with it the charger frame 10 and the

page_text: charger 53 which are swung through a small angle round the centre of the chain
pulley 1% and 21.
The charger scoop is then propelled into the retort and the coal deposited in
the same manner as described for the first portion of the charge and as soon as the
charger is again at rest in its frame 10 the hand lever 31 is moved over so that
the air is admitted to the opposite side of the piston 24 and the charger frame 10
is then brought back to its original position. The machine is then propelled to the
next retort.
Having now particularly described and ascertamed the nature of my -nid
invention and in what manner the same is to be performed. I declare that what
I claim is -
1. In a retort drawing machine connecting the motor piston to a plunger working
in a cylinder containing water free to escape into a reservoir through an adjust-
able orifice gradually closed at the end of the outstroke of the rake substantially
as described.
2. In a retort drawing or charging machine the arrangement of the slide valve
and ports to establish a communication between the two ends of the eylinder
before reversing the machine substantially as described for the purpose specified.
3. The general arrangement of the parts constituting the drawing machine as
herein described and shown on the drawings.
4. In a charging machine the arrangement of a cylinder and piston attached to
the charger frame for giving the same sideways motion for the purpose of diss
tributing the coal more towards the sides of the retort, as herein described and
shown on the drawings.
5. The combination of parts forming the charging machine as herein described
and shown on the drawings.
Dated this 16th day of March 1893.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.