GB2144765A

GB2144765A - Method of using the sensible heat of hot coke in a coking plant

Info

Publication number: GB2144765A
Application number: GB08417294A
Authority: GB
Inventors: Dietrich Wagener; Claus Flockenhaus; Joachim Meckel
Original assignee: Didier Engineering GmbH
Current assignee: Didier Engineering GmbH
Priority date: 1983-08-12
Filing date: 1984-07-06
Publication date: 1985-03-13
Also published as: GB8417294D0; JPS6060184A; DE3329163A1; ES8504237A1; FR2550543A1; ES534852A0; BE900305A; DE3329163C2

Abstract

A combustible heat carrier gas (12) which is inert to the hot coke is passed through the hot coke (10) to dry cool it and take up the sensible heat of the hot coke and then through a steam generator (18) thereby giving up at least a part of the sensible heat for the production of steam. The heat carrier gas leaving the steam generator (18) is fed via (6) to the coke oven battery (4) as underfiring gas. <IMAGE>

Description

SPECIFICATION Method of using the sensible heat of hot coke in a coking plant The invention relates to a method of using the sensible heat of hot coke in a coking plant and is concerned with that type of such method in which a heat carrier gas which is inert to the hot coke is passed through the hot coke to dry cool it, thereby taking up the sensible heat of the hot coke and then through a steam generator thereby giving up at least a part of the sensible heat for the production of steam.

Such methods of reclaiming the heat of the hot coke increase the thermal efficiency of the cooking process In known methods of this type the inert heat carrier gas is fed in a closed circuit through the dry cooling zone and the steam generator.

After being recompressed the heat carrier gas reenters the dry cooling zone at a temperature between about 150"C and 200"C.

It is known from DE-AS 2738472 to use the exhaust gas leaving a coke oven battery and from DE-PS 2733365 to use blast furnace gas to dry cool the hot coke and then preheat the coal to be coked by passing the gas in an open circuit sequentially through these two process stages, thereby thermally coupling them. Either the exhaust gas leaving the coke oven battery or cold blast furnace gas is fed into the dry coke cooling stage and there take up the sensible heat of the hot coke in direct heat exchange in order subsequently to be able to give it up again to the coking coal in the coal preheating stage in direct heat exchange.The exhaust gas or blast furnace gas leaves the coal preheating at about lOOC to 150"C. It must subsequently be cleaned and cooled in order either to be discharged into the environment or to be introduced again under approximately the same conditions into the blast furnace gas network.

It is an object of the present invention to provide a method of the type referred to above which is even more efficient than the known methods.

According to the present invention there is provided a method of using the sensible heat of hot coke in a coking plant in which a combustible heat carrier gas which is substantially inert to the hot coke is passed through the hot coke to dry cool it, thereby taking up the sensible heat of the hot coke and then through a steam generator, thereby giving up at least a part of the sensible heat for the production of steam, the heat carrier gas then being used as underfiring gas in the coke oven battery.

In practice the combustible heat carrier gas leaves the steam generator at between about 1500C to 200"C and is then used in this state directly as under firing gas for the coke oven battery. In this manner the sensible heat remaining in the heat carrier gas after the steam generator is itself used in the coke ovens. In the previously known processes, which operate in an at least partially open circuit, the remaining heat is lost and thus represents a financial loss,is potentially injurious to the environment and is associated with additional operational costs.

It is preferred that blast furnace gas is used as the heat carrier gas. Blast furnace gas is a heat carrier gas which is inert with respect to hot dry coke and is available in a steel works at little or no extra cost. It is also extremely suitable as an underfiring gas. Blast furnace gas has never previously been used to couple the dry cooling and steam generation stages of a coking plant.

It is preferred that the heat carrier gas is passed through the dry coke cooling stage and the steam generator in a (completely) open circuit. It is thus ensured that the entire remaining sensible heat of the heat carrier gas leaving the steam generator is made use of in the coke ovens. The coupling of the dry coke cooling stage and the steam generator with a heat carrier gas has occurred previously exclusively in a completely closed circuit. By use of this feature a further increase of the efficiency of the process is achieved.

A coking plant operating in accordance with the present invention is illustrated schematically in the accompanying diagram. Coal to be coked is introduced at 2 into a coke oven battery 4, which is heated by the combustion of an underfiring gas in air which are fed in through conduits 6 and 8 respectively. The hot coke is then dry cooled in a dry cooling stage 10 by means of a heat carrier gas which in this case comprises blast furnace gas from an adjacent steel plant and is fed in through a conduit 12. The cooled coke is removed at 14 and the blast furnace gas which has taken up the sensible heat of the coke then passes through a conduit 16 into a steam generator 18 which is fed with water through a water line 20.The blast furnace gas gives up the majority of the sensible heat in the generation of steam which is removed through a steam line 22 and then itself flows into the conduit 6 and is used as the underfiring gas for the coke oven battery where the residual sensible heat is of necessity used.

1. A method of using the sensible heat of hot coke in a coking plant in which a combustible heat carrier gas which is substantially inert to the hot coke is passed through the hot coke to dry it thereby taking up the sensible heat of the hot coke and then through a steam generator thereby giving up at least a part of the sensible heat for the production of steam, the heat carrier gas then being used as underfiring gas in the coke oven battery.

2. A method as claimed in Claim I in which the heat carrier gas is blast furnace gas.

3. A method as claimed in Claim I or 2 in which the heat carrier gas is passed through the hot coke and the steam generator in an open circuit.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method of using the sensible heat of hot coke in a coking plant The invention relates to a method of using the sensible heat of hot coke in a coking plant and is concerned with that type of such method in which a heat carrier gas which is inert to the hot coke is passed through the hot coke to dry cool it, thereby taking up the sensible heat of the hot coke and then through a steam generator thereby giving up at least a part of the sensible heat for the production of steam. Such methods of reclaiming the heat of the hot coke increase the thermal efficiency of the cooking process In known methods of this type the inert heat carrier gas is fed in a closed circuit through the dry cooling zone and the steam generator. After being recompressed the heat carrier gas reenters the dry cooling zone at a temperature between about 150"C and 200"C. It is known from DE-AS 2738472 to use the exhaust gas leaving a coke oven battery and from DE-PS 2733365 to use blast furnace gas to dry cool the hot coke and then preheat the coal to be coked by passing the gas in an open circuit sequentially through these two process stages, thereby thermally coupling them. Either the exhaust gas leaving the coke oven battery or cold blast furnace gas is fed into the dry coke cooling stage and there take up the sensible heat of the hot coke in direct heat exchange in order subsequently to be able to give it up again to the coking coal in the coal preheating stage in direct heat exchange.The exhaust gas or blast furnace gas leaves the coal preheating at about lOOC to 150"C. It must subsequently be cleaned and cooled in order either to be discharged into the environment or to be introduced again under approximately the same conditions into the blast furnace gas network. It is an object of the present invention to provide a method of the type referred to above which is even more efficient than the known methods. According to the present invention there is provided a method of using the sensible heat of hot coke in a coking plant in which a combustible heat carrier gas which is substantially inert to the hot coke is passed through the hot coke to dry cool it, thereby taking up the sensible heat of the hot coke and then through a steam generator, thereby giving up at least a part of the sensible heat for the production of steam, the heat carrier gas then being used as underfiring gas in the coke oven battery. In practice the combustible heat carrier gas leaves the steam generator at between about 1500C to 200"C and is then used in this state directly as under firing gas for the coke oven battery. In this manner the sensible heat remaining in the heat carrier gas after the steam generator is itself used in the coke ovens. In the previously known processes, which operate in an at least partially open circuit, the remaining heat is lost and thus represents a financial loss,is potentially injurious to the environment and is associated with additional operational costs. It is preferred that blast furnace gas is used as the heat carrier gas. Blast furnace gas is a heat carrier gas which is inert with respect to hot dry coke and is available in a steel works at little or no extra cost. It is also extremely suitable as an underfiring gas. Blast furnace gas has never previously been used to couple the dry cooling and steam generation stages of a coking plant. It is preferred that the heat carrier gas is passed through the dry coke cooling stage and the steam generator in a (completely) open circuit. It is thus ensured that the entire remaining sensible heat of the heat carrier gas leaving the steam generator is made use of in the coke ovens. The coupling of the dry coke cooling stage and the steam generator with a heat carrier gas has occurred previously exclusively in a completely closed circuit. By use of this feature a further increase of the efficiency of the process is achieved. A coking plant operating in accordance with the present invention is illustrated schematically in the accompanying diagram. Coal to be coked is introduced at 2 into a coke oven battery 4, which is heated by the combustion of an underfiring gas in air which are fed in through conduits 6 and 8 respectively. The hot coke is then dry cooled in a dry cooling stage 10 by means of a heat carrier gas which in this case comprises blast furnace gas from an adjacent steel plant and is fed in through a conduit 12. The cooled coke is removed at 14 and the blast furnace gas which has taken up the sensible heat of the coke then passes through a conduit 16 into a steam generator 18 which is fed with water through a water line 20.The blast furnace gas gives up the majority of the sensible heat in the generation of steam which is removed through a steam line 22 and then itself flows into the conduit 6 and is used as the underfiring gas for the coke oven battery where the residual sensible heat is of necessity used. CLAIMS

4. A method of using the sensible heat of hot coke in a coking plant substantially as specifically herein described with reference to the accompanying diagram.