DD289775A5 - METHOD FOR PURIFYING A CARBON LOAD - Google Patents

Abstract

The invention relates to a method for Bespülung a coal sluice. The invention relates to the field of fixed bed pressure gasification of lignite, in particular, the invention relates to the time required for the loading of a fixed bed pressure carburetor coal lock. The essence of the invention is that the inert gas used for the spewing of the coal sluice is then fed, when a defined minimum level is reached when emptying the coal sluice. The amount of inert gas supplied is controlled as a function of the reactor power and the flow direction, for which temperature measurements are arranged in the discharge zone of the coal sluice or in the upper part of the fixed bed pressure gasifier {fixed-bed gasification; Fixed bed pressure gasifier; Coal lock; purging; flushing medium; inert gas; Temperature measurement; Ausfluszbereich; Throttle body}

Description

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Field of application of the invention

The invention relates to the field of fixed bed pressure gasification of lignite and non-baking coal, and more particularly to the feed operation of a fixed bed pressure carburetor.

Characteristics of the known prior art

The feeding of a fixed bed pressure gasifier, in particular a gasification reactor for high outputs, is carried out discontinuously via a so-called coal sluice.

From the filled or partially filled coal sluice slips down during the gasification process, the coal in the reactor down and fuel gas rises in countercurrent to the coal sluice. After sluice emptied of coal, the lower sluice closure is closed and the fuel gas is released into a low-pressure sliding-gas system. The residual gases are released into the atmosphere via a vent system.

Di3 so relaxed coal sluice is again filled with coal, covered with fuel gas or inert gas to reactor pressure and switched dero reactor.

The low-pressure expanded lock gas is compressed or reused without being compressed. Known technical solutions for the reuse of the relaxed sluice gas are the return to other under medium pressure process gases with prior compression or use as Unterfeuerungsgas in the power plant.

Both methods have economic disadvantages, since the compression of the sluice gases require a high level of technical and energy expenditure and combustion in the power plant is detrimental to efficiency. Another decisive disadvantage of this solution is that the residual expansion gases are discharged into the atmosphere and thereby significantly increase the emission of pollutants.

Another known technical solution that the combustion gas located after the emptying of the coal lock in the coal lock is flushed with flushing steam in the reactor or in the Rohgasnetz and the remaining vapor is then expanded with a residual amount of B ^r enngas in the vapors gas system and thereafter the Residual relaxation in the coal bunker or in a Spülsystom done.

Another known solution is that the coal lock after filling with coal and the covering with fuel gas is constantly purged with steam, that after emptying the coal lock the steam is released with a share of fuel gas in the Dämpfegassystem and connect ^ the rest relaxation in a Rinse system must be done.

The last two methods have the disadvantage that in the first case, the scavenging takes place after emptying the coal sluice and thus the lock and reactor power is limited, that in the second case during the ted emptying time the coal sluice is purged with steam and thus unnecessarily increases the operating costs become. Another disadvantage is that the relaxation and Restentspannungsgasn are still mixed with a proportion of fuel gas and can not be passed without damage to the atmosphere without further processing.

Another known technical solution for charging a reactor is deposited under DE 2607754. For the covering and rinsing during emptying of the coal sluice, carbon dioxide and nitrogen are fully extinguished here. The disadvantage of this solution is that although the inert gases carbon dioxide and nitrogen are present, but not in the necessary pressure stage and in sufficient quantity and quality and their preparation for the above purpose is costly and requires a lot of equipment.

Object of the invention

The aim of the invention is to develop a method for inerting the coal sluice of a reactor, which substantially improves environmental protection, occupational and production safety as well as the economy of the process.

Explanation of the essence of the invention

The object of the invention is to provide a method for low-delay and inexpensive flushing the Kohleschleuje of fuel gases.

The object is achieved, i'aß from a defined minimum level of the coal sluice, which corresponds to the Freispülzeit the lock content wr.lirend the emptying into the reactor for purging the coal sluice of fuel gases above the bed in selbige purging or other inert gas, for example Nitrogen, is abandoned, whereby the fuel gas in the coal lock is also pressed in the last phase of the loading of the reactor with coals in the reactor. The inert gas then remaining in the coal sluice is released into an inert gas system with the lower coal cone closed. The residual relaxation takes place via a torch system into the open air.

The amount of inert gas necessary for the rinsing cycle is controlled as a function of the instantaneous reactor power. Ensuring the rinsing cycle is achieved so that the inert gas for rinsing the coal sluice is introduced below the upper coal cone and according to the invention the monitoring of the flow direction in the lower part of the coal sluice or in the upper part of the reactor, or at both locations by temperature measurements is realized. The temperature in said region has according to the invention during the reactor feed tax character of the inert gas.

embodiment

The solution according to the invention will be explained below using an exemplary embodiment.

After the filling of the coal sluice 2, it is covered with fuel gas via the stringing line 8 up to the reactor pressure

and technologically connected by opening the lower coal cone β with the reactor 1 and the emptying of the coal into the reactor 1 introduced. During the last phase of charging the reactor 1 with coal from the coal sluice 2 10 so much purging steam is supplied depending on the minimum level 11 on the Flüldampfleitung that at the end of the emptying of the coal sluice 2 of coals and the fuel gas was completely returned to the reactor 1 , The SpUldampfmenge is set in dependence of the reactor power, which is known to be indicated by the oxygen load, by the scavenging control valve 12. It is a measure of the determination of the flow direction of the media between coal sluice 2 and reactor 1 and sets the end of the scavenging cycle fixed.

If steam is used for the rinsing cycle, the steam rinse is terminated when the temperature measurement 7 has increased to the known word of the steam temperature. When the temperature 7 drops, fuel gas flows from the reactor 1 into the coal lock 2.

When using an inert gas other than flushing medium, for example nitrogen, the flushing is terminated when the Tsmperaturmessung 7 has fallen to the value of the known nitrogen temperature. In this case, when the temperature measurement 7 increases, fuel gas flows from the reactor 1 into the coal lock 2.

After completion of the scavenging cycle, the lower carbon cone 6 and the scavenging control valve 12 are closed. The inert gas remaining in the coal sluice 2 is released via the expansion line 5 into an inert gas system. The residual relaxation of the coal sluice then takes place via the residual discharge line 9 or the open upper coal cone 4 and the filling 3 via a flare system, free of toxic gases in the atmosphere.

Claims (2)

Claim: 1. A method for purging a coal sluice for loading a Festbettdruckvergasers with lignite, soft lignite briquettes or non-baking coal using inert gas, in particular steam, characterized in that the flushing medium is added upon reaching a defined minimum level (11), wherein the minimum level (11 ) is defined so that the time of the coal flow between this minimum level (11) and complete emptying of the coal lock (2) corresponds to the required flushing time of the lock contents and that the amount of the flushing medium is controlled in dependence on the reactor power and the flow direction of the flushing medium. 2. The method according to claim 1, characterized in that the monitoring and control of the flow direction of the purge medium and the fuel gas via one or more arranged in the outflow of the coal sluice or in the upper part of the fixed bed pressure carburetor temperature measurements.