Note: Descriptions are shown in the official language in which they were submitted.
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COKING APPARATUS AND METHOD FOR PRODUCING COKE
FIELD OF INVENTION
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Distillation apparatus, retort, vertical.
OBJECTS
_
It is an aspect of the invention to provide a process
for producing coke from coal, comprising, successively charging
batches of coal into a series of side-by-side vertically
elongate pockets, coking the coal by successively forcing
opposite sides of the respective pockets inwardly to compress
the coal in the columns while heating the coal therein to coking
temperature, retaining the coal in each pocket under pressure
for a predetermined amount of time after having been charged
therein, successively discharging the coked coal from the
bottoms of the pockets into a shaft furnace disposed beneath the
pockets by successively spreading opposite sides of the pockets
so as to relieve the pressure on the column sufficient to permit
the coked coal therein to drop into the shaft furnace, and
continuously discharging the coked coal from the bottom of the
shaft furnace at a rate such as to maintain a resident mass of
the coked coal in the shaft furnace.
With this process, the type of coal is not critical as
to whether it is low, medium, or high volatile, good heat-
transfer contact between the heated walls and the coal is
maintained, and provision is made by wall pressure to
accommodate for the swelling of the coal during coking to
prevent damage to the refractory coke oven structure.
An aspect of the invention is to provide for a multi-
pocket coking system wherein the residence time of the coal in
each pocket is comparatively short, e.g., about one hour versus
17 to 19 hours for conventional ovens, and wherein the pockets
can be separately and serially charged with coal and discharged,
and wherein the charging and discharging operation can be
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automatically and computer controlled. By reducing the time
required for coking and hy serially charging and discharging the
pockets, a large throughput can be maintained, and by utilizing
a shaft furnace beneath the pockets for final devolatizatlon of
the coke and as a surge chamber, a continuous output of coke can
be maintained, nothwithstanding the batch-process
characteristics of each individual pocke-t.
More particularly, the invention comprehends an
apparatus for coking coal including a plurality of adjacent
vertically elongate side-by-side pockets each defined between
spaced parallel vertically elongate fixed side walls and a
vertically elongate fixed end wall rigidly affixed between the
side walls and defining therewith a substantially U-shaped fixed
wall structure. A movable vertically elongate end wall is
spaced oppositely from and parallel to the fixed end wall and
extends across the mouth of the "U" formed by the fixed side and
end walls wherein each pocket, save for the endmost ones, shares
a common fixed side wall with an adjacent pocket. Each pocket
has at a lower end thereof individual gate means for opening and
closing the same. Means are provided for charging coal into the
pockets via the upper ends thereof, and gas passage means extend
vertically through the side and end walls. Means feed hot
combustion gases through the passages for heating the coal in
the pockets to coking temperatures. Individual means are
respectively associated with each of the movable end walls for
moving the same towards and away from the respective opposite
end walls whereby to selectively maintain the coal in the
pockets under compression and to release the same from
compression. Shaft furnace means having an open upper end is
disposed beneath and common to the plurality of pockets for
receiving coke discharged through the lower end thereof, and
means are provided for continuously discharging coke from the
lower end of the shaft furnace means.
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With this process, the prime objective is to prevent ~-
particulate and gaseous pollution, good heat transfer
contact between heated walls and the coal is maintained,
and provision is made by wall pressure to accommodate the
u~e o~ a wide range of swelling coals during coking to
prevent damage to the refractory coke oven structure.
A further object is to coke coal without oxidizing its
fixed carbon content, while utilizing a small percentage of
its volatile content as fuel to provide heat for the pro-
cess. The movable wall coke oven can coke one type of coalwithout the need for expensive blending of low, medium and
high volatile coals. Blending is essential in conventional
coke ovens to prevent the pressure of swelling from damaging
refractory walls.
The advantage of using one type coal is made possible
by the yieldable movable walls. These and other objects will
be apparent from the following specification, claims and
drawings, which:
Figure l is a diagrammatic cross-section illustrating -
the solids and gas flows through the system;
Figure 2 is a fragmentary isometric view, partly in
cross-section, illustrating the pockets, flues, movable walls -
and gates;
Figure 3 is a fragmentary horizontal cross-section
illustrating a pocket and the adjacent wall structure;
Figure 4 is a diagrammatic top plan view of a series of
three-pocket units illustrating the layout of the movable
wall pockets and the actuating rams for the movable walls;
Figure 5 is a fragmentary and diagrammatic elevation
showing the arrangement of actuating rams for movable walls;
and
Figure 6 is a diagrammatic end elevation showing the
arrangement of the actuating rams for the movable walls.
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SPE:CIFICATION
Referring now to the drawings, in which like reference
numerals denote similar elements, the apparatus designated
2 is comprised of a movable wall coking oven 4, a shaft
furnace 6 therebeneath, and a quencher 8 beneath the shaft
furnace. The movable wall coking oven 4 has a plurality of
side-by-side vertically elongate pockets 10 each closed by
a computer controlled valve 12 at its top and a gate 14 at
its bottom. Green coal, after preheating, is fed into a
pocket 10 through valve 12, retained there until it is coked
and most of the volatiles have been driven off and then,
when gate 14 is opened, the then hot coke drops into shaft
furnace 6, from the bottom of which it is discharged on
reciprocating grate 16 after a predetermined residence time
in the shaft furnace.
The ceramic walls of the movable wall coking oven 4
have heating flues 18, 20, 22, and 24 which are heated by
hot gases from a combustion chamber 26. Part of the gaseous
volatiles which are driven off from the coal 11 in pockets
10 provide the gaseous fuel for the combustion chamber 26.
These volatile gases are supplied via valve-controlled gas
take-offs 28 to a gas main 13 which also supplies part of
the rich coal gases to a by-product utilization device.
At the top of flues 18, 20, 22 and 24 are take-offs 30 for
the hot spent gases, part of which are returned to com-
bustion chamber 26. Other of the hot spent gases are fed
via line 31 to a coal pre-dryer 32 which removes all of
the moisture from the incoming green coal. The pre-dried
coal is fed from pre-dryer 32 to a coal pre-heater 33 in
which the temperature of the coal is raised to about 400F.
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The spent gases, having given up heat in the coal pre-
heater, are drawn via a line 34 by fan 36, from which part
of the inert gas is fed into the coke near the bottom of
the shaft furnace 6 via louvers 38. The remainder of the
relatively coo] inert gas is blown into an enclosure 40
for the coke quencher 8 and passed through vents 42 in
reciprocating grates 16 and into the coke emerging from the
bottom of coal pre-heater 6 so as to reduce the temperature
of the coke to about 300F. Having collected heat in coke
quencher 8, the inert gases, then at about 950F, are
collected in a collector 44 and passed via a line 46 to a
fan 48 and thence to the coal pre-heater 33.
Referring more particularly to Figs. 2-6, the pockets
10 in movable wall coking oven 4 are bounded by a fixed
wall 50 opposite which is a movable wall 52, and on each
side is a slab 54 or 56. The sides of the pockets defined
by the movable walls are tapered as in 57 to facilitate
the fall-out of the column of hot coke when the pockets 10
and gates 14 are opened. The fixed walls are braced by
rods 58 which extend from a frame 60 to back-up plate 62
on the fixed walls. The movable walls 52 are actuated by
hydraulic rams 64 which are connected as at 66 to the frame.
Ram rods 68 drive or pull against back-up plates 70 on the
outer sides of the movable walls. Suitable seals are pro-
vided between the fixed elements of the assembly and the
movable walls, and the ram rods 68 extend through seals 72
in cover plates 74, all of these various seals being pro-
vided to deter leakage to the atmosphere of the volatile
gases driven off the coal in the pockets. -
In operation, gates 14 at the bottoms of the pockets
are closed by the action of rams 76 whose ram rods 78 are
connected to the gates. The movable walls 52 are then
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drawn away from fixed walls 50. This motion is relatively
short, being only about one inch. Valves 12 are then
opened to charge the pockets with the pre-heated coal, it
being understood that the tops of the pockets are suitably
closed except for the coal charging lines from computer
controlled valves and the gas take-off lines 28. Rams 64
are then actuated to close the pockets and compress the
coal which has been charged therein. The hot gases from
combustion chamber 26, being about 1800F, heat the coal in
the pockets so as to drive off most of the volatile gases
and coke the coal. During this process, the coal swells
and hydraulic rams 64 are suitably controlled so as to
accommodate for the swelling without causing it to fracture
the ceramic walls which define the pockets. After about 60
minutes, the coal will have coked, whereupon the gates 14
are opened to drop the columns of hot coke into the shaft
furnace 6, as previously described. Residual gases issuing
from the hot coke in shaft furnace 6 are exhausted via vents
80 into flues 18 where residual volatiles are burned.
It is contemplated that there will be a series of the
units described hereinbefore, and that the pockets will be
serially charged and discharged. Because of the residence
time in the common shaft furnace, estimated to average about
60 minutes, the coke output of the quencher will be con-
tinuous. The gas burning system is designed to prevent
build-up of moisture as the process continues.
The gas system for heating the flues is partly closed,
and it runs as follows: the hot spent gases from the flues
are passed via line 30 into combustion chamber and thence via
lines 82 and 84 to the bottoms of the flues. Rich volatile
gases from the coal 11 in pockets 10 are passed via take-off
lines 28 and main 13 into the combustion chamber 26 as make-
up fuel for this otherwise closed system.
