EP0144945B1 - Process and apparatus for discontinuously operating coke ovens with vertical chambers - Google Patents

Description

The invention relates to a method for the discontinuous operation of vertical chamber coking ovens with indirect heating of the coking chambers to produce blast furnace coke from moist or preheated fine coal, and also devices for carrying out the method.

From DE-PS-2 657 213 battery-arranged vertical coking ovens are known with coal filling shafts, closures and extraction devices for the glowing coke, and heating walls arranged between the oven chambers with heating trains and adjacent regenerators for preheating the heating media and cooling the heating exhaust gases. In the vertical chamber coking ovens shown there, the hot coke is withdrawn from the bottom of the chambers at the end of the cooking time and filled into suitable devices for removing the glowing coke. Nothing is said in this document about utilizing the heat of the glowing coke.

The subject of DE-PS-2 756 330 is vertical chamber coking furnaces in battery-wise arrangement for the continuous coking of briquettes made of hard coal, brown coal or peat. In the process used, the briquettes are continuously moved downward through the coking shafts and, following the coking stage, reach a cooling stage in which they are cooled directly by cooling gases which are circulated. Such direct cooling is only possible with briquettes and not with coke from fine coal filled in the coking ovens.

Finally, from the English patent specification 670 301 discontinuously operated vertical chamber coking ovens are known, in which a gasification stage is located directly below the actual coking stage. At the lower end of this gasification stage, water vapor is introduced into the coke chamber to gasify part of the coke. At the transition from the gasification stage to the coking stage arranged above, the so-called degassing gas is then to be drawn off from the gasification chamber via openings and passed into a separate template. The water vapor required for gasification is generated in a cooling stage below the gasification stage by indirect cooling of the coke. However, all of the steam generated is reintroduced into the gasification stage, and no additional usable steam is available. In addition, the structural outlay due to the additionally provided gasification stage in the known vertical chamber furnaces is considerable.

The object of the invention is now to propose a method of the generic type, in which the coke can be cooled dry and used to produce economically usable steam without major additional structural outlay.

GB-A-485 244 describes a device for coking or carbonizing coal at coke end temperatures of 500 or 700 ° C., with metallic internals being arranged in the coking chamber to improve the heat transfer from the heating walls to the coal. With these devices, the production of blast furnace coke with a final temperature of more than 1000 ° C is not possible. For the rest, a device for the discontinuous operation of vertical chamber coking ovens with a cooling chamber arranged under the coking chamber for indirect cooling of the coke is known from this document. After the cooling chamber has been emptied, the closure device arranged between the cooling chamber and the coking chamber is opened and the coke is drained into the cooling chamber in one go.

In addition, an environmentally friendly process and devices for carrying out this process are to be found.

The achievement of this object is defined in the characterizing part of the main claim. Process claims 2 to 4 contain further, particularly advantageous measures according to the invention. A device for carrying out the method according to the invention and particularly favorable embodiments of the device are contained in claims 5 to 14.

The method according to the invention for the discontinuous operation of vertical chamber ovens provides that the fully cooked glowing coke cake from the coking chambers is lowered in the vertical direction at most by the amount of its height and the chamber is refilled with fine coal and the lowered coke cake does not move during the next cooking time and is only indirectly cooled and its heat completely on evaporator surfaces to generate z. B. emits a high-tension steam. The lowering of the fully cooked hot coke cake is brought about by the lower removal of the cold and cooled coke from the cooling chamber. The fully cooked coke cake should only be lowered by no more than the amount of its height, so that the new fine coal filling definitely gets into the hot, heated area of the coking chamber. In the method according to the invention, the furnace chamber doors with a thick insulating plug arranged directly below the coking stage are eliminated. Instead, in the method according to the invention, the column of the coke located in the cooling chamber forms the insulation and shield against the hot coking chamber and during the discharge the temperatures below the cooling chamber are low. Both the discharge of the cold coke and the sealing of the coking and cooling chamber from the atmosphere pose only minor problems in this temperature range. After the coke cake has been lowered by the amount of its height, the coking chamber is refilled and both the coal cake to be coked in the coking chamber and the coke cake to be cooled in the cooling chamber are not moved during the entire cooking time. The coke is only indirectly cooled in the cooling chamber and emits its heat completely to the evaporator surfaces to generate a high-tension steam.

Since a whole series of coking ovens and cooling chambers are always combined in one battery, steam production can be easily equalized during operation by combining as many cooling chambers with different temperature levels as possible and connecting one or more steam drums to the requirements. A steam superheater can also be connected downstream of the cooling walls.

The method according to the invention offers a number of important advantages over the previously known methods:

The direct connection of the cooling chamber to the coking chamber eliminates all additional facilities for transporting the hot coke, as is inevitably required in the conventional horizontal chamber coking ovens.

The coking chambers and cooling chambers each form a closed unit that can be easily sealed off from the atmosphere in regions with a relatively low temperature.

The combination of indirect heating of the coal cake and indirect cooling of the coke cake enables a clean separation of the heating stage and the steam generation stage from the coal, the raw gas and the hot coke. Sealing and pressure control problems do not arise.

Above all, it is possible to produce an economically viable, in particular highly strained, clean steam.

Finally, the dry cooling of the coke and the extremely low movement of the still hot coke produce an extremely coarse and abrasion-resistant, water-free coke.

It has proven to be advantageous according to the invention to lower the hot coke cake only until the crest of the hot coke cake is approximately one meter above the heating cable foot. In this way, the coke cake can be fully cooked.

It can also be provided according to the invention to form the entire coal cake in a coal storage chamber above the coking chamber and possibly even to pre-compress it and then to fill the coking chamber as a whole if possible. This filling system achieves a high bulk density in the coking chamber and, at the same time, there are no emission problems when filling the hot coking chambers because the coal storage chamber can be sealed gas-tight at the top while the prepared coal cake is being lowered.

To carry out the method of the generic type, a device according to the preamble of claim 5 is proposed, the coking chamber having a taper in the vertical direction of at least 0.3 to 0.5%, preferably about 1 m above the heating cable foot, a taper of 0.5 to 1% , owns. To achieve trouble-free operation, such a taper is particularly favorable.

Cooling walls from z. B. iron materials with high thermal conductivity have proven to be useful. It is advantageous to have the pipe axes run in the direction of movement of the coke and to connect the pipes to horizontal distributors and to let collectors that rise slightly in the flow direction open. With this construction of the evaporator surfaces, the evaporator circuit can easily be operated even in natural circulation.

Since in the method according to the invention and also the devices for performing this method, the z. B. in horizontal chamber coking ovens necessary operating machines such as coke squeezing machines, coke oven carriages, fire trucks, it is possible according to the invention in a relatively simple manner to arrange the entire coking oven battery with the cooling chambers and the regenerators in a gas-tight encapsulation. In this way, emissions can be almost completely avoided.

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

Figure 1 shows the device according to the invention with coal storage chambers, coking chambers, cooling chambers, intermediate bunkers and discharge lock in the schematic arrangement.

FIGS. 2 and 2a show, in comparison to FIG. 1, on a somewhat enlarged scale, partly in side view and partly in section, the device according to the invention.

FIG. 3 is a horizontal section along line AA of FIG. 2.

Figure 4 shows in detail the arrangement of the supply channels for the combustion media below the heating wall, as shown in Figure 6.

FIG. 5 shows, similar to FIG. 4, the arrangement of the feed channels below the heating wall, as shown in FIG. 7.

Figure 6 is a horizontal section through part of a heating wall for high gas operation according to the four-heating system.

Figure 7 is a horizontal section through part of the heating wall of a twin train system for high gas.

According to the representations in FIGS. 1, 2 and 2a, the coal storage chamber (21) with the upper coal filling funnel (24) and the upper closure flaps (22) and the lower closure flap (23) is located above the coking furnace chamber (1), which is expediently hydraulic in sections is operated. To remove the raw gases from the coking furnace chamber (1), the raw gas collecting space is located above the upper edge (19) of the coal filling and is limited at the top by the closure flap (23). The raw gases are withdrawn from the furnace chamber in the longitudinal direction of the furnace chamber via this raw gas collecting space and pass through the raw gas discharge line (26) into the receiver (27). Between the individual coking oven chambers (1) there is in each case a heating wall (18) which, according to FIGS. 4 and 5, the combustion media are supplied or the waste heat is removed. Directly adjacent to the individual coking oven chambers (1) are the cooling chambers (2) below, the evaporator walls (17) of which are equipped with lower distributor lines (15) and upper collectors (16). Between the evaporator walls (17) of the cooling chamber (2) there is the lattice support structure (52) on which the entire coking furnace chambers (1) are mounted. As can be seen in particular from FIG. 1, the transfer chutes (14) are located under the cooling chambers (2), from which the cooled coke is drawn off into the intermediate bunkers (3) by means of the cyclically operated rocking tables (4). An intermediate bunker can be assigned to two or three cooling chambers. From the intermediate bunkers (3), the coke is fed to a bunker lock system via rocker tables (5), cross conveyors (6), transfer chutes (7), scraper belts (8), as described, for example, in DE-PS-3 014 574 is described. The coke is alternately fed to the discharge locks (9), which are provided with the shut-off devices (11) and (12), via swivel tables (10). The coke can then be conveyed to conveyor belts for sieving, for example via vibratory conveyors (13). A gas-tight encapsulation (25) is also indicated in FIG. 1 by a dash-dotted line.

In the left half of FIG. 2, the heating wall (18) in the form of a four-pass system with the arrangement of the vertical heating trains (28) is indicated. This heating wall system could just as well consist of twin trains or a half-divided system. In contrast to the usual horizontal chamber coking ovens, the regenerators for preheating the combustion media are not located under the heating walls, but next to the entire vertical chamber coking ovens. If, for example, a four-pass system operated with high-power gas is assumed, the lower horizontal channel (43), (Fig.), Is shown, for example, via the regenerators (30) and (31) indicated on the left in FIG . 4), the supply channel (44), the vertical hollow channel (45) and the height-graded slot openings (46) to the heating cables (28) air. The heavy gas is then fed to the heavy gas nozzles (48) at the foot of the heating trains via the heavy gas channel (47) during the same changeover period. In the two adjacent heating trains (28a, Fig. 6) of the associated four-heating train group, the waste heat then flows through the slots (46a), the vertical hollow channel (45a), the supply channel (44a) into the lower horizontal channel (43a) and over the two connecting lines (32a) and (33a) to the regenerators (30a) and (31a). The direction of flow is then reversed in the next changeover period.

FIGS. 5 and 7 also show a twin heating train system with gradual supply of the combustion air for high-gas operation. During a changeover period, the combustion air flows through the lower horizontal channel (34), the supply channel (35), the hollow binder channel (36) and the height-graded outlet slots (37) into the heating cables (28). At the same time, the high-pressure gas is again supplied via the high-pressure gas duct (38) and the high-pressure gas nozzles (39). In the neighboring heating train (28a), the waste heat is drawn to the regenerators via the slots (37a), the hollow binder duct (36a), the feed duct (35a) and the lower horizontal duct (34a).

If you wanted to use the existing two lower horizontal channels in each heating wall to heat with lean gas, the semi-split system would be an option. For this purpose, the lower horizontal channels would be interrupted by a stable partition halfway through the furnace chamber. According to FIG. 2, the air would then be supplied via the regenerator (30) and the supply line (32) and a lower horizontal channel during a changeover period, and the lean gas would be supplied via the adjacent regenerator (31) and the supply line (33) and the other lower horizontal channel, while on the other half of the heating wall, the waste heat would be drawn off via the two lower horizontal channels lying next to one another and would be led via lines (32a), (33a) to the regenerators (30a) and (31a).

Finally, from FIG Heat recovery pots (51) and (53), which are assigned to the regenerators (31) and (31 a) as well as (32) and (32a).

Reference symbol list

• (1) coking chamber
• (2) cooling chamber
• (3) intermediate bunker
• (4) rocking tables
• (5) rocking tables
• (6) cross conveyor
• (7) delivery chutes
• (8) Scratching tape
• (9) discharge lock
• (10) swivel table
• (11) shut-off device
• (12) shut-off device
• (13) Vibratory conveyor
• (14) transfer chutes
• (15) distributor
• (16) collectors
• (17) Evaporator walls
• (18) heating walls
• (19) Top edge of coal filling
• (20) top edge of hot coke after emptying (1)
• (21) Coal Storage Chamber
• (22) upper closing flap to (21)
• (23) lower closing flap to (21)
• (24) Charcoal hopper
• (25) gastight encapsulation
• (26) Raw gas exhaust line
• (27) Submission
• (28 / 28a) heating cables
• (29) upper horizontal channel
• (30 / 30a) regenerators
• (31 / 31a) regenerators
• (32 / 32a) connecting lines
• (33 / 33a) connecting lines
• (34 / 34a) lower horizontal channel
• (35 / 35a) feed channels to (36 / 36a)
• (36 / 36a) vertical hollow tie channels
• (37 / 37a) vertical slot openings
• (38 / 38a) high-pressure gas ducts
• (39 / 39a) Power gas nozzles
• (42) Runner walls
• (43 / 43a) lower horizontal channels
• (44 / 44a) feed channels to (45 / 45a)
• (45 / 45a) vertical hollow tie channels
• (46 / 46a) tiered slot openings
• (47 / 47a) high-pressure gas ducts
• (48 / 48a) heavy gas nozzles
• (51) Heat sink to (31 / 31a)
• (52) Lattice structure under (18)
• (53) Heat sink to (32 / 32a)
• (54) Partition between the regenerators

Claims (13)

1. Process and apparatus for discontinuously operating coke ovens with vertical chambers with indirect heating of coking chambers to produce a blast furnace coke from wet or preheated fine coal, characterized in that the well carbonized hot red coke cake from the coking chambers is lowered in vertical direction by the amount of its height and in that the chamber is recharged and the lowered coke cake is not moved during the next carbonization time and cooled only indirectly and discharges its heat completely to evaporator surfaces to generate high-pressure steam.

2. A process pursuant to Claim 1, characterized in that the hot-red coke cake in the coking chamber is lowered only thus far until the crown of the hot-red coke cake is situated about 1 m above the heating flue foot.

3. A process pursuant to Claim 1 or 2, characterized in that the entire coal cake is formed and possibly pre-compressed in a coal reservoir chamber located above the coking chamber and subsequently charged in its entirety into the coking chamber.

4. A process pursuant to anyone of Claims 1 through 3, characterized in that the discharge of cooled coke is performed by means of tilting tables within a period of about 1 to 15 minutes.

5. An apparatus for discontinuously operating coke ovens with vertical chambers with indirect heating and indirect cooling of coke for performance and execution of the process pursuant to the preceding claims, with the cooling chamber being situated directly underneath the coking chamber and the cooling walls being designed as evaporator surfaces with plane membrane walls, e.g. in form of a tube- web-tube structure, characterized in that the coking chamber in vertical direction is tapered with at least 0.3 to o. 5 %.

6. An apparatus pursuant to Claim 5, characterized in that said coking chamber (1) at an elevation about 1 m above heating flue foot is tapered with 0.5 to 1 %.

7. An apparatus pursuant to claim 5 or 6, characterized in that the tube axes extend in the direction of coke movement and in that the tubes are connected to horizontally extending distributors (15) and mouth into slightly rising collectors (16) in the direction flow.

8. An apparatus pursuant to anyone or several of the preceding Claims, characterized in that the heating walls are comprised of heating flues with height-staged supply of combustion media fed in through hollow binders (36), (45) in the conventional way and manner, and in that two or four each or all of the heating flues of anyone heating wall above the heating flues mouth into a common upper horizontal flue (2) extending in the heating wall direction and are connected to the regenerators situated beside the vertical chamber coke oven battery through at least two horizontal flues arranged in parallel side by side and extending underneath the heating flues in heating wall direction.

9. Apparatus pursuant to Claim 8, characterized in that the vertical chamber coke ovens in terms of rich gas supply are designed and constructed as underjet or side gas gun burners.

10. Apparatus pursuant to anyone of the preceding Claims, characterized in that two each of the side-by-side arranged cooling chambers (2) are connected to a common intermediate bunker (3).

11. An apparatus pursuant to the preceding Claims, characterized in that a coal reservoir chamber (21) is arranged above each coking chamber (1), with said coal reservoir chamber accommodating exactly the quantity of one coal charge.

12. An apparatus pursuant to Claim 11, characterized in that said coal reservoir chamber (21) is equipped with facilities required for precompression of charging coal.

13. An apparatus pursuant to the preceding Claims, characterized in that the entire coke oven battery with laid cooling chambers (2) and the regenerators inclusive of a part of the upper coal reservoir bunkers and the lower discharge facilities for cooled coke is situated and located in a gastight encapsulation (25).

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