WO1990010683A1

WO1990010683A1 - Process and device for extracting dry-cooled coke from a coke-quenching tower

Info

Publication number: WO1990010683A1
Application number: PCT/EP1990/000348
Authority: WO
Inventors: Gerd Nashan; Wilhelm Stewen; Horst Dungs; Willi Brinkmann; Robert Hoffmann; Willi Kissmann; Manfred Rudel
Original assignee: Still Otto Gmbh
Priority date: 1989-03-16
Filing date: 1990-03-02
Publication date: 1990-09-20
Also published as: EP0462992A1; DE3908534C1; KR920701395A

Abstract

Process and device for extracting dry-cooled coke from a coke-quenching tower (1). The coke is extracted from the coke-quenching tower (1) discontinuously or in batches over non gas-tight extraction devices, preferably by actuating extraction rockers (3) distributed uniformly over the cooling tower cross-section. It is then sluiced out of the gas-tight system. The coke extracted discontinuously from the coke-quenching tower (1) is extracted over a cellular wheel sluice (18) which ensures the gas-tight seal, preferably over a drum sluice (4) fitted with two sluice chambers (13)/(14).

Description

Process for discharging dry-cooled coke from a coke cooling shaft and device for carrying out this process,

description

The invention relates to a method for discharging dry-cooled coke from a coke cooling shaft, the coke being withdrawn from the coke cooling shaft and then from the coke disc continuously or in batches via non-gas-tight extraction devices, preferably by actuating discharge rockers arranged uniformly over the cooling shaft cross section gastight system is removed and a device for performing this method.

Such a method is e.g. B. from DE-PS 34 29 292 known, the cooled coke at the lower end of the cooling shaft on curved coke chutes with discharge rockers is discontinuously withdrawn and then reaches a slide with a swiveling coke table in each of the two alternately operated lock bunkers. Since there is usually a gas overpressure of 10 to 20 mbar in the area of the coke discharge system and the circulating cooling gas with high proportions of CO and H_ should not be allowed to escape to the outside as far as possible, the two adjacent lock bunkers are provided in the known system. Each lock bunker has a gas-tight flap at the inlet and outlet. This coke discharge system has a relative one

_[ REPLACEMENT LEAF large height and is therefore expensive.

Also known is a system with a continuous discharge of the cooled coke from a round cooling shaft, the full coke bed resting on the retracted shaft outlet nozzle resting on a vibrating trough which continuously draws off the amount of coke and feeds it to a rotary valve in a multi-chamber construction. The cooled coke is drawn off over an opening cross section which is greatly reduced compared to the cooling shaft diameter. Despite special installations, this leads to the coke sinking unevenly in the shaft or being discharged at different speeds and being cooled inadequately.

The invention is therefore based on the object of proposing a method and a device for discharging dry-cooled coke of the type defined at the outset, which are improved with regard to the problems described. In particular, a gas-tight, wear-resistant discharge system with a low overall height and low investment costs should also be obtained.

To solve this problem, the measures listed in the characterizing part of the main claim are proposed. The subclaims 2 to 7 contain particularly favorable process proposals for this. Claim 9 contains a device for performing the method. Preferred embodiments are given in claims 10 and 11.

According to the invention, the cooled coke is then extracted from a preferably square or rectangular coke cooling shaft z. B. by actuating discharge rockers discontinuously and discharged via a cellular lock which ensures the gas-tight closure, preferably via a drum lock equipped with two lock chambers. According to claim 2, each of the two lock chambers of the drum lock can be at least the one thrown off a discharge rocker

REPLACEMENT LEAF Take up the amount of coke.

It has surprisingly been found that the amount of coke thrown from a discharge rocker can be accommodated in one of the two lock chambers of a two-chamber drum lock, the drum lock not being moved during the coke discharge over the discharge rockers arranged above the drum lock and this being emptied first, so¬ as soon as the last coke has reached the receiving lock chamber from the discharge rocker actuated. When the drum lock is actuated, it is pivoted through 180 °, so that the entire coke, which had previously reached the lock chamber which is ready to receive via the discharge rocker, falls out downwards and z. B. is discharged in a metered manner via a subsequently arranged vibration channel.

According to the invention, the movement and thus the emptying of the two-chamber drum lock is locked with the actuation of the discharge rockers in such a way that the lock chamber is only emptied after the coke flow has come to a complete standstill via the respective discharge rocker. Depending on the cycle time for actuating the discharge rockers, it has proven to be advantageous to start moving the lock chambers and discharging the coke 5 to 10 seconds after the discharge rocker has been actuated. As a result, coke-side overshoot and thus overfilling of the two lock chambers with wear of the housing wall and any sealing strips due to clamped coke pieces is prevented at all times.

In the method according to the invention, it has proven to be advantageous to continuously add inert gas as the barrier medium at the inlet port of the drum sluice, one already

"*> a small amount of 2 to 4 Nm / t cooled coke is sufficient. This inert gas consumption is very low in comparison to other discharge systems, since the gap between the housing wall of the drum lock and the rotating one is due to the non-existent wear Circular segments of the lock

REPLACEMENT LEAF chambers can be kept.

In addition to the use of the two-chamber drum sluice with a subsequent vibrating trough, the invention alternatively provides that the discontinuously withdrawn coke is fed with the aid of a vibrating trough to a continuously operating cellular wheel sluice with a large number of sluice chambers. On the one hand, the vibrating trough can be arranged above the cell wheel lock for the transition to the continuous further transport of the coke and, on the other hand, below the drum lock. When arranged above the rotary valve, a residual cushion of coke can form on the vibrating channel in the discharge funnel, which can also contain the quantity of several coke batches thrown off with the discharge rockers. This residual coke is expediently monitored by level probes and regulated by changing the discharge quantity in the vibratory trough and the rotary valve. In any case, it should be ensured that between the discharge rockers and the upper edge of the residual coke pad in the discharge funnel there is a free space for the even addition of the cooling gas below the discharge rockers.

To implement the two-chamber drum sluice, the invention provides that the sheet metal dividing the sluice in two chambers is connected on the outside to circular segments or other side plates adapted to the circular part of the housing shell, which are also rotated by 180 ° when the sluice chambers are emptied. These circular segments form a largely gastight seal with respect to the housing jacket. They are at least as large as the inlet and outlet openings of the drum lock. This ensures that the cooling gas, which is under pressure above the lock, cannot flow directly to the outside during the emptying or rotation of the lock chambers.

The invention is explained in more detail, for example, with the aid of the attached FIGS. 1 to 4.

ER _S ATZBLATT In these figures, the discharge device is shown in longitudinal and cross-section below a coke cooling shaft (1). FIGS. 1 and 2 show the two-chamber drum lock (4) according to the invention with the vibration channel (5) arranged underneath and in FIGS. 3 and 4 the arrangement of the vibration channel (17) above a rotary valve (18). The coke is usually cooled in the cooling shaft by a circulating cooling gas. The cooled coke is withdrawn in a metered manner at the end of the square or rectangular cooling shaft via the curved coke chutes (2) and by alternately actuating the discharge rockers (3), a large number of discharge rockers being evenly distributed over the shaft cross section. The entire coke bed rests on a sort of sieve tray, with the cooling gas below the discharge rockers (3) being distributed evenly over the cross-section of the cooling shaft. The actuation of the discharge rockers (3) is controlled via the final coke temperature.

According to FIGS. 1 and 2, the coke falls directly and completely from the discharge rockers (3) via the outlet funnel (9) into the upper chamber (13) of the drum lock (4) which holds the coke.

After this process has been completed, the inner movable part of the drum sluice with the sheet metal (12) and the circular segments (15) attached to it are rotated by 180 ° around the central horizontal axis of rotation, the coke being released from the chamber which now releases coke ( 14) onto the vibration channel (5) underneath and from there evenly to a conveyor belt (6) for further transport.

It has been shown that with a usual cycle time of the discharge rockers of approx. 20 seconds there is sufficient time to empty the filled lock chamber of the drum lock before the second lock chamber has to be available again in the ready position for rest. In a Kokskühl¬ shaft with a higher throughput of z. B. 250 t / h, it has proven to be expedient to operate two discharge rockers at the same time, the amount of coke discharge completely from

REPLACEMENT LEAF a lock chamber can be accommodated. Here too, the cycle time of the coke discharge rockers is approx. 20 seconds.

The two-chamber drum lock shown in FIGS. 1 and 2 is characterized in that the essentially circular drum space of the drum lock (4) is divided into two lock chambers by a flat plate (12) which can be rotated about a central horizontal axis. So that the coke does not come into contact with the inner wall of the circular part of the casing (16) and grinds along it when the drum lock is actuated, circular segments (16) which are adapted to the circular part of the casing (16) are attached to the ends of the sheet (12). 15) or similar side panels attached.

The space between the circular segments (15) and the housing jacket (16) can be sealed off by additional sealing elements (not shown here) in order to seal the cooling shaft as completely as possible from the outside. In addition, cooling gas can be prevented from escaping through the introduction of inert gas (N ^ application (11)) at the inlet port of the drum lock.

When using the so-called cellular wheel sluices (18) with a large number of individual cell chambers (19), the vibrating trough, as shown in FIGS. 3 and 4, is arranged directly under the discharge funnel (9) in order to ensure an even application to the To ensure cellular wheel sluice (18). In the case of particularly large cooling shafts or in order to have a reserve discharge, two vibrating troughs (17) and the associated cell wheels (18) and the conveyor belts (6) can also be arranged next to one another. The discharge funnel (9) is constructed in such a way that all of the coke thrown off the coke discharge rockers (3) can be removed either from one or the other vibrating channel. In addition to interrupting the flow of coke, a needle slide (21) can be arranged in the outlet funnel (9).

From the figures it can also be seen that the supporting structure

_E REPLACEMENT LEAF (8) for the coke cooling shaft (1) is supported on the supporting walls (7). The drum sluice (4) with the further transport organs for the coke is expediently supported separately, a compensator (10) being attached to compensate for expansion between the discharge funnel and the drum sluice (4).

ER ^SA TZBLATT Reference list

(1) Coke cooling shaft

(2) Coke chutes

(3) discharge rockers

(4) drum sluice

(5) vibrating trough

(6) Conveyor belt

(7) retaining wall

(8) Support frame for (1)

(9) discharge funnel

(10) compensator

(11) N ₂ task

(12) sheet metal

(13) Upper, coke-absorbing chamber

(14) lower, coke-dispensing chamber

(15) Circular segments or other side panels

(16) circular part of the casing shell

(17) Vibration trough

(18) Cell wheel lock

(19) Cell chamber

(20) Residual coke pad

(21) Needle pusher

REPLACEMENT LEAF

Claims

Process for discharging dry-cooled coke from a coke cooling shaft and device for carrying out this process

1. A method for discharging dry-cooled coke from a coke cooling shaft, the coke being withdrawn from the coke cooling shaft discontinuously or in batches via non-gas-tight extraction devices, preferably by actuating discharge rockers arranged uniformly over the cooling shaft cross section, and then discharged from the gas-tight system that the coke withdrawn discontinuously from the coke cooling shaft is discharged via a cellular wheel sluice which ensures the gas-tight closure, preferably via a drum sluice equipped with two sluice chambers.

2. The method of claim 1, d a d u r c h g e k e n n ¬ z e i c h n e t that each of the two lock chambers of the drum lock receives at least one batch of coke withdrawn discontinuously from the Kokskühl¬ shaft.

3. The method according to claim 1 or 2, so that the receiving lock chamber of the drum lock is not moved and the bed is not moved during the withdrawal of a batch from the coke cooling shaft.

E ^R SET BLADE Cleaning devices of the non-gas-tight discharge device and the drum lock are locked together.

4. The method according to at least one of the preceding claims, that the emptying of the drum lock only begins when the removed batch of coke has completely entered the lock chamber which is ready to take up, preferably 5 to 10 seconds after the actuation of the discharge rocker has been completed.

5. The method as claimed in at least one of the preceding claims, that the drum lock equipped with two lock chambers is rotated by 180 when the lock lock is emptied.

6. The method according to at least one of the preceding claims, that the inert gas is continuously fed in at the inlet port of the drum lock as a barrier medium, preferably

3 in an amount of 2 to 4 Nm / t coke.

7. The method according to at least one of the preceding claims, d a d u r c h g e k e n e z e i c h n e t that the coke after leaving the drum lock, preferably via a vibrating trough, is fed to a conveyor belt evenly metered.

8. The method of claim 1, d a d u r c h g e k e n n ¬ z e i c h n e t that the discontinuously withdrawn coke with the help of a vibrating trough is placed on a continuously working cellular wheel lock with a plurality of lock chambers.

9. Apparatus for carrying out the method according to at least one of the preceding claims, that as a non-gas-tight, discontinuously operating extraction device below

REPLACEMENT LEAF the discharge cushions (3) arranged evenly over the cooling shaft cross section and for the gas-tight closure underneath at the coke cooling shaft outlet a drum lock (4), preferably equipped with two lock chambers (13), (14), is provided.

10. The device according to claim 8, dadurchge ¬ indicates that in one with two lock chambers (13), (14) equipped drum lock (4) on which the lock in two lock chambers (13), (14) parting sheet ( 12) externally adapted to the circular part (16) of the housing shell and sealing against it circular segments (15) or other side plates are attached, which leave at least the upper filling opening in the horizontal filling position of the plate (12).

11. The device according to claim 9, so that the circle segments (15) have at least the size of the inlet and outlet openings of the drum sluice.

REPLACEMENT LEAF