GB2078915A - Charging coke ovens - Google Patents

Abstract

Coal is charged into a coking chamber 1' through its extreme charging holes 9,10 while gases are withdrawn through its middle charging hole 14. At the same time the charging of a preceding chamber 1'' is being completed by charging coal through its middle charging hole 11 while withdrawing gases through that hole. The gases withdrawn are diluted with an inert diluent (comprising combustion products of gases previously withdrawn) constituting 15 to 20% of the total amount of gases withdrawn. <IMAGE>

Description

SPECIFICATION Charging coke ovens The present invention relates to a method of charging coke ovens with coal and a coal-charging machine to carry out the method.

Most advantageously this invention can be used for smokeless charging of horizontal coke ovens.

The invention provides a method of charging coke ovens with coal charge through the extreme end charging holes of the coking chambers with simultaneously withdrawing the coke-oven gas through the middle charging holes thereof, holding the coal charge over a period of time sufficient for a coalcharging machine to deliver a next batch of the coal charge for charging the next successive coking chamber, and simultaneously withdrawing, through the middle charging holes, the coke-oven gas from the coking chamber being completely charged and introducing therein a gas being inert to the cokeoven gas, the amount of the inert gas being introduced constituting from 15 to 20% of the total amount of the coke-oven gas being discharged.

The above method of charging coke ovens permits the safety of the charging operation to be improved by withdrawing the coke-oven gases from the charging zone and simultaneously introducing a gas inert to the coke-oven gas in an amount sufficient to dilute the latter to a safe concentration. At the same time the content of nitrogen oxides in the coke-oven gas is also lowered, which makes the latter suitable for the use in the nitrogen fertilizer production. Furthermore, the gases containing dust may be isolated from the gas withdrawing system of the coke-oven battery and, hence, prevented from clogging the system with dust and coal particles. With the efficiency and safety of the smokeless charging operation thus improved, the method can be used under various operating conditions, for instance, for charging both moistened coal and dried coal.

It is expedient that the coke-oven gas withdrawn be burned and the resultant combustion gas be used as an inert diluent, which will improve efficiency of the method.

The invention also provides a coal-charging machine comprising a frame with an undercarriage, hoppers for the coal charge, the number of the hoppers being equal to the member of the charging holes of the coking chamber, said hoppers being mounted on said frame and having each in the upper part a coal feed device and in the lower part a coal discharging device, the centres of the discharging holes of the discharging devices of the extreme hoppers charging the coking chamber are displaced in the direction of movement of the coal-charging machine relative the centres of the discharging holes of the coal discharging device of the middle hoppers completely charging the other coking chamber, for a distance equal to the distance between the longitudinal axis of the coking chamber being charged and the coking chamber being completely charged, a means for withdrawing coke-oven gases from the coking chamber th rough the middle charging holes thnmnf. which means beinq disposed in one row with the extreme hoppes, a blowing means connected through sleeves provided in the middle hoppers with the coking chamber each middle hopper having a gas-withdrawing sleeve connected to a gas withdrawing means for withdrawing gases from the coking chamber through the middle holes thereof.

The above coal discharging machine is simple in design and permits the fire and expiosion safety of the coal charging operation to be ensured by withdrawing the coke-oven gases from the charging zone and introducing a gas inert to the coke-oven gas into the zone of the complete charging.

It is expedient that the said means for withdrawing gases from the coking chamber through the middle charging holes thereof include ventilation gaspurifying apparatus and through a gas burner be connected with the said blowing means, which will raise the efficiency of the process at the expense of using the combustion gases resulting from burning the coke-oven gas as an inert gas.

The invention will be described further, by way of example with reference to the accompanying drawings, wherein: Figure 1 schematically represents the relative positions of a coking chamber and a three-hopper coal charging machine while charging the coking chamber through the extreme charging hole located on the coke pusher side of the coke oven battery, and withdrawing charging gases through the middle charging hole; Figure 2 is a plan view corresponding to Figure 1; Figure 3 shows the relative positions of the coking chamber and the coal-charging machine while charging the coking chamber through the extreme charging hole located on the coke discharge side of the coke oven battery, and withdrawing charging gases through the middle charging hole;; Figure 4 shows the relative positions of the coking chamber and the coal-charging machine while charging the coking chamber through the middle charging hole, withdrawing gases therethrough, and levelling the coal charge in the coking chamber; Figure 5 is a gas flow diagram of the gas withdrawal from the coking chambers through their middle charging holes with the aid of special means including a ventilation gas purifier; Figure 6 is a front view of the coal-charging machine, illustrating its position on the coke oven battery during charging; Figure 7 is a side view of the coal-charging machine under the coal bin while it is being loaded with coal; Figure 8 is a plan view of the gas withdrawing means mounted on the coal-charging machine; Figure 9 shows the coal feed device of the coal-charging-machine hopper, and the closing device of the coal bin, side view;; Figure 10 is a top view of the hopper of Figures; Figure 11 is a sectioned front view of the coal discharging device of the coal-charging-machine hopper; Figure 12 is a side view corresponding to Figure 11; Figure 13 is a front view of an extensible gas withdrawing device in the operating position, i.e.

introduced into a charging hole of a coking chamber; and Figure 14 is a side view corresponding to Figure 13.

In the following description, normal operating conditions are assumed to exist.

For charging a coke-oven battery 1 (Figures 1 and 2) with a coal charge a coal-charging machine 2 is positioned thereon so that the centres of the discharging holes of the discharging devices 3,4,5 of its hoppers 6, 7, 8, respectively, coincide with the centres of the extreme charging holes 9 and 10 of a coking chamber 1' in which charging is to be commenced and the centre of the middle charging hole 11 of a preceding coking chamber 1" in which charging is to be completed, the coking chamber doors 12 and 13 and the covers (not shown) of the charging holes 9, 10, 11 being closed. Charging the coking chamber 1' with coal is commenced from the extreme end hopper 6 of the coal-charging machine through the extreme end charging hole 9 located on the pusher side shown by arrow M.To start charging, the cover of the charging hole 9 is removed, the coal discharging device of the coal-charging machine is lowered onto the said hole, and the gate of the hopper 6 is opened. The coal pours by gravity from the hopper into the coking chamber 1' and forms therein a heap in the form of a cone A.

Simultaneously, gases evolving from the coal being charged are withdrawn through the middle charging hole 14 of the chamber 1' and pass through a pipe 15 to ventilation gas-purifying apparatus incorporated in the gas withdrawing means intended for removing gases from the coking chamber through the middle charging holes (disclosed below). After the coal is completely discharged from the hopper 6, the gate thereof is closed, the coal discharging device is raised, and the charging hole 9 is closed with the cover. During the above operation the ascension pipes 16 and 17 of the coke oven, located on the coke pusher side and the coke discharge side (shown by arrow K) respectively, are closed.

After this, the coal is charged to the same chamber 1' through its extreme charging hole 10 from the hopper 8 on the coke discharge side of the battery (Figure 3). Removing the cover from the charging hole 10, lowering the coal charging device onto it, and opening the gate of the hopper 8 are done in the above sequence. The coal pouring from the hopper 8 into the coking chamber 1' forms a heap in the form of a cone B. The gases evolving from the coal being charged are withdrawn through the middle charging hole 14 ofthe same coking chamber 1 ' in the manner described above.

Simultaneously with charging the chamber 1' with coal from the hoppers 6 and 8 through the extreme charging holes 9 and 10 of the chamber 1', a preceding (relative to the sequence of the charging operation) coking chamber 1" is charged through its middle charging hole 11 from the middle hopper 7 (Figures 2 and 4), with the cover of the charging hole removed, the coal charging device of the hopper lowered, and the gate of the hopper opened. The coal pouring from the hopper 7 into this coking chamber 1" forms a heap in the form of a cone C between cones A and B previously formed as a result of first-stage charging as described above. The gases evolving from the coal being charged are withdrawn through the discharging device 4 and a pipe 18.At the same time into a gas jacket of the said discharging device through a pipe 19 is introduced a gas inert to the coke-oven gas, for instance, such as q fume gas, nitrogen, or preferably combustion gases of the coke-oven gas, with the amount of said inert gas being introduced constituting from 15 to 20% of the total amount of the coke-oven gas being discharged. In the case of using combustion gases as an inert gas, the latter is fed from the gas purifying apparatus (disclosed below) with the aid of a blowing means. After the charging of the coking chamber 1" has been completed, the coal therein is levelled with the aid of a levelling bar 21 introduced into the chamber 1" through a hole 20 in the door 12.

As a result of such levelling, between the coal charge and the chamber roof is formed a passage for gases to flow through. The charging operation finished, the middle charging holes 11 and 14 of the coking chambers 1' and 1" are closed and the valves of the ascension pipes 16 and 17 are opened so that gases resulting from the coking process are withdrawn through the ascension pipes to collection mains 22 and 23.

As has been indicated above, the gases evolving from the coal during the charging of the coking chambers 1' and 1" are passed to the ventilation gas purifying apparatus of the coal-charging machine,.

wherein the said gases are purified, burned, and discharged into the atmosphere (Figure 5). Withdrawing gases from the coking chamber is effected with the aid of a telescopic pipe including a stationary part 24 and movable part 25 which is introduced into the middle charging hole 14 of the coking chamber. The movable part 25 of the telescopic pipe is connected with a lifting winch 26 having a drive 27. The stationary part 24 of the telescopic pipe is communicated with the pipe 15.

From the charging device 4 of the hopper 7 the charging gases are withdrawn through the pipe 18 of the ventilation gas purifying apparatus. Both pipes 15 and 18 are connected with a gas washer 28 wherefrom the washed gases are passed to a gas separator (scrubber) 29 provided with a slime collector 30 having a tap 31 for discharging slime. The slime is periodically discharged into a collector (not shown) located under the coal bin. The gas flow in the purifying system is produced by fans 32 and 33 connected in series. An exhaust pipe 34 of the fan 33 is led up to a gas burner 35 having an igniter 36. To maintain a flame in the gas burner 35 the burner is connected to an additional fuel source such as, for example, a gas cylinder disposed for safety in a container 38 filled with water. The air for burning is fed by a fan 39.

To cause the dust and coal particles contained in the charging gases to more intensely settle down the ventilation gas purifying apparatus is provided with a pumping device 40 for taking water from a water tank 41 located on the coal-charging machine. Filling the tank 41 with water is effected during the filling the hoppers of the coal charging machine with coal under the coal bin. During the charging of the coking chamber, with the ventilation gas purifying apparatus being operated, water is delivered under pressure by the pumping device 40 to sprayers 42,43,44 located in the separator 29 and the washer 28 respectively. Excess water from the container 38 overflows into the tank 41 through a pipe 45, and the slime from these tanks is removed through pipes 46 and 47.

The charging gases after being purified, are burned in the gas burner 35 and discharged through a pipe 48 into the atmosphere. A part of the combustion gases, constituting from 15 to 20% of the total amount of the gases being discharged is passed by a blowing device which is an additional fan 49 through a pipe 19 to a gas chamber of the charging device 4. In the gas chamber the charging gases are mixed with the combustion gases fed through the pipe 19 so that they are rarefied to a safe concentration.

At the same time, to prevent ingress of the ambient air into the charging device 4 and into its gas chamber, a positive pressure is provided therein.

All the above measures make it possible to provide for full fire and explosion safety of the process, to improve the efficiency of charging operation, and to prevent ingress of nitrogen oxides, dust, and coal particles into the gas collection mains wherethrough the coke-oven gas is withdrawn.

Since the charging gas from the coking chamber 1' in which charging is being completed is withdrawn through its middle charging hole 11 and the charging device 4 of the hopper 7 (Figures 1,4, and 5), and from the coking chamber 1' through its middle charging hole 14 and a special device (disclosed below), the gas chambers of the discharging devices 3 and 5 of the extreme end hoppers 6 and 8 are closed, i.e. the openings through which the said gas chambers communicate with the pipes 18 and 19 are choked.

As has been mentioned above, the method has been described as carried out under the normal operating conditions, which implies the charging of all the coking chambers except for the first two and the last two chambers of the coke oven battery.

Since the discharging devices of the extreme hoppers and the middle hopper of the coal-charging machine are displaced for a distance equal to the distance equal to the distance between the longitudinal axis of the coking chamber being charged and the coking chamber in which charging is being completed, the coal-charging machine has to be additionally shifted. Charging the outer coke ovens is scheduled for the beginning and the end of the whole charging cycle of the coke-oven battery.

The above example also applies to the case of charging coke ovens having four or five charging holes, in which case completion of the charging of the coking chamber is preferably effected through the middle charging holes analogously to the case of the coking chamber having three charging holes, considering the middle two or three holes as a single one. Whatever the number of the charging holes, the followina aeneral rule should preferably be observed: the total capacity of the extreme hoppers of the coal-charging machine should constitute 75-80% of the total capacity of all the hoppers. This is accounted for by the fact that the cone-shaped heaps of coal formed as a result of pouring the coal through the exteme end charging holes constitute 75-80% of the total amount of the coal charge of the coking chamber.

As can be seen from the above the method can be carried out with the aid of the coal-charging machine 2 (Figures 1,6,7,8), comprising hoppers 6,7,8 for the coal charge. The number of the hoppers mounted on the coal-charging machine is equal to the number of the charging holes 9, 10, 11 of one coking chamber. The number of the charging hoppers depends on the type of coal-charging machine (three, four, five and more).

The coal-charging machine has a frame 50 (Figures 6,7) in the form of a gantry carriage installed on undercarriages 51,52, and travelling along the rails 53 laid on the top of the coke oven battery 1.

Each hopper has a coal feed device (Figures 1 and 10) located in the upper portion thereof.

The coal feed device comprises a doser 54 made in the form of a ring fixed coaxially with the centre of the charging hole of the hopper. The circular edge of the doser 54 is adapted to form a cone of the coal charge in the hopper and to control the amount of the coal charge. Each hopper of the coal charging machine is provided with a means for opening a gate 55 of the coal bin 56 (Figures 7 and 9), which means is mounted on the platform 57 and has a lever 58 which operates the gate 55 through a rocker 58 and a rod 59. The rocker 58 on its turn is actuated by a rod 60 and a crank 61 of the drive including a reduction gear 62 and an electric motor 63.

The drive is switched on by the operator of the coal-charging machine, and is switched off automatically when the amount of coal in the hopper reaches its predetermined value. At the moment when the height of the coal in the hopper reaches a predetermined level the coal acts upon the lever 64 of a limit switch 65, in response to which the latter switches off the electric motor 63. The coal flowing from the coal bin 56 continuously acts on a coal flow sensor made in the form of a balance 66 with a ring 67, and therethrough on the limit switch 68. In the case of interruption of the coal flow as a result of hanging of the coal in the coal bin 56, the coal flow sensor produces a signal to actuate a means for stirring the hanging coal.

Each hopper 6 (or 7 or 8) is provided with a discharging device (Figures 11 and 12) located in the lower portion thereof, each of which discharging devices has a housing 69 connected by means of a flange 70 to the lower part of the hopper 6 (or 7 or 8).

Located within the housing is a discharging chute 71 having a round in cross section outlet opening and adapted for being closed by a gate 72. The gate 72 is hinged by means of a pivot 73 for rotation under action of levers 74,75,76, 77, interacting with a driving rod 78. On the side walls of the housing 69 there are flanges 79 for connection to the pipe 18 and 19 (Figures 5,6). The flanges installed on the extreme end hoppers 6 and 8 of the coal-charging machines (Figure 6) are choked. The flanges on the middle hopper 7 are open. To the lower portion of the housing 69 is connected extensible guiding device communicating the hopper with the coking chamber during the charging operation and containing a stationary sleeve 80, with conical and cylindrical portions, and two movable sleeves 81 and 82.The sleeve 82 is connected with the aid of suspensions 83 to the sleeve 81 which in its turn is connected with levers 84,85,86. The lever 86 is set on an axle 87 movably connected through a rod 88 and a lever 89 with the driving rod 78. Circular gaps between the said sleeves are closed with sealing means in the form of movable rings 90 and 91. The gas chamber of the coal discharging device is a cavity defined by the housing 69, walls of the chute 71, and the gate 72.

For withdrawing coke-oven gases from the coking chamber through the middle charging hole 14 located on the same axis as the extreme hoppers 6 and 8, the coal-charging machine is provided with a special means including a telescopic (extensible) pipe, a pipe 15 and a ventilation gas-purifying apparatus. The telescopic pipe comprises a stationary part 24 and a movable part 25 (Figures 5, 13, and 14). The stationary part 24 of the telescopic pipe is communicated with the pipe 15 for passing gases to be purified to the gas purifying apparatus (Figure 5) and rigidly connected on a platform 92 of the coai-charging machine. The movable part 25 of the telescopic pipe is suspended on chains 93 fastened with their one end to the flange of the telescopic pipe and with the other end to the winch 26.The flange 94 has guiding rollers 95 for guiding the movable part 25 of the telescopic pipe, the rollers 95 moving along guiding elements 96 secured on the platform 92. A circular gap between the walls of the movable part 25 and the charging hole 14 of the coking chamber is closed by a circular plate 97 connected by means of chains 98 to the movable part 25 of the telescopic pipe.

The coal-charging machine operates in the following manner. The charging cycle begins with positioning of the coal-charging machine 2 under the bottom gates of the coal bin (Figure 7). The coalcharging machine is so positioned that the centres of the coal feed devices 54 of its hoppers coincide with the centres of the bottom gates 55 of the coal bin 56, whereafterthe drive 63 is switched on to actuate the lever 58 and to thereby open the respective bottom gate 55 of the coal bin 56. The coal pours by gravity into the hoppers 6,7, 8 of the coal-charging machine.

The quantity of the coal being loaded in each hopper is controlled by the doser 54. In the case of hanging of coal in the coal bin 56 the coal flow sensor automatically switches on the means for stirring the coal in the coal bin (not shown).

After each hopper (6,7,8) is filled with coal, the gate 55 of the coal bin 56 is closed by rotating the lever 58 in the opposite direction. Controlling the charging of the hoppers with coal and operating the drive may be carried out either by an operator or by any means known in the art.

Then the coal-charging machine is moved to a coking chamber from which the coke has been discharged, and positioned thereover so that the centres of the discharge holes of the coal discharging devices 3 and 5 (Figure 1) of the extreme hoppers 6 and 8 coincide with the centres of the extreme charging holes 9 and 10 of the coking chamber 1' to be charged and the centre of the coal discharging device 4 of the middle hopper 7 with the charging hole 11 of the coking chamber 1" in which charging is.

to be completed. The movable part 25 of the telescopic pipe (Figure 13) will be positioned over the centre of the charging hole 14. Before charging is begun, the covers of the charging holes 9, 10, 11, 14 are removed.

After that, the extensible sleeves 82,81 of the coal discharging devices of the hoppers 6,7,8 (Figures 1 and 12) are lowered onto the charging holes 9,10, 11, whereas the movable part 25 of the telescopic pipe of the gas withdrawing means is introduced into the charging hole 14. Charging the coking chamber with coal from the hoppers 6,7,8 and handling the gases are effected in the sequence disclosed in the above description of the method.

Before starting the charging operation, the drives of the fans 32,33,39,49 (Figure 5) of the ventilation gas-purifying apparatus are switched on.

After charging is over, the gates 72 of the coal discharging devices of the hoppers 6,7, 8 are closed (Figure 12), the extensible sleeves 82,81 of the coal discharging devices and the movable part 25 of the telescopic pipe (Figure 13) are raised, the charging holes 9, 10, 11, 14 are closed with covers and the coal-charging machine is moved to under the coal bin to receive a next batch of the coal charge and positioned thereunder as described above.

Claims (7)

1. A method of charging a coke oven battery whose coking chambers each have at least three charging holes, the method comprising charging coal into a coking chamber through its extreme charging holes and simultaneously withdrawing gases through at least one middle charging hole of the said chamber, and subsequently completing the charging of the said chamber by charging coal into the said chamber through at least one middle charging hole of the said chamber and simultaneously withdrawing gases through at least one middle charging hole of the said chamber, the gases withdrawn from the said chamber being diiuted with a substantially inert gaseous diluent constituting 15 to 20% of the total amount of the gases withdrawn.

2. A method as claimed in claim 1, in which, simultaneously with the completion of the charging of the said chamber, charging coal into a second coking chamber through its extreme charging holes and simultaneously withdrawing gases through at least one middle charging hole of the second chamber, the gases withdrawn being diluted with a substantially inert gaseous diluent constituting 15 to 20% of the total amount of the gases withdrawn.

3. A method as claimed in claim 1 or 2, in which the gaseous diluent comprises products of combustion of the gases withdrawn.

4. A coal-charging machine for charging a coke oven battery, comprising a frame with undercarriages, at least three hoppers for the coal charge, spaced transversely with respect to the direction of movement of the machine on the undercarriages, coal feed devices located in the upper part of the hoppers and coal discharging devices located in the lower part thereof, the centres of the discharging holes of the coal discharging devices of the extreme hoppers being displaced in the direction of movement of the coal-charging machine relative to the centre(s) of the discharging hole(s) of the coal discharging device(s) of the middle hopper(s), means for withdrawing gases from a coking chamber through at least one middle charging hole, a blowing device located in the same row with the extreme hoppers and communicating through the middle hopper(s) with the coking chamber, each middle hopper being connected to the means for withdrawing gases from the coking chamber.

5. A coal-charging machine as claimed in claim 4, in which means for withdrawing gases from the coking chamber includes a ventilation gas-purifying apparatus and communicates through a gas burner with the said blowing device.

6. A method of charging a coke oven battery, substantially as described with reference to the accompanying drawings.

7. A coal-charging machine substantially as described with reference to, and as illustrated in, the accompanying drawings.