Method and device for raising temperature of backflushing gas used in coal gasification fly ash filter

Abstract

The invention relates to the field of blowback for gasification and particularly relates to a method and a device for increasing the blowback temperature of a gasifying fly ash filter. According to the method and the device, blowback air compressed by a compressor is divided into two air streams, and one air stream is warmed and pressurized to be blowback gas of a fly ash filter; a high pressure units and an ultrahigh pressure unit are arranged, a pressure valve group is arranged at the tail end of the ultrahigh pressure unit, and an emptying hole and a gas storage tank are respectively formed in and arranged at the tail end of the high pressure unit; a branch is arranged on a pipeline between the emptying hole and the gas storage tank and is formed by connecting stop valve with a pressure valve through the pipeline. Therefore, redundant blowback gas in a thermal high pressure unit is depressurized to replace thermal high pressure gas, the blowback air flow or the blowing frequency is increased, the requirements of the fly ash filter are met, the blowback quality of the fly ash filter is improved, the energy consumption is reduced, the starting time of the blowback treatment is shortened, the damage rate of the filter is reduced, and the service life of the filter is prolonged.

Description

technical field [0001] The invention relates to the technical field of back-blowing gas for coal gasification, in particular to a method and a device for raising the temperature of back-blowing gas used for a coal gasification fly ash filter. Background technique [0002] There are two methods of ash removal in modern large-scale coal gasification processes, one is wet ash removal represented by coal-water slurry technology, and the other is dry ash removal represented by pulverized coal pressurization technology. Dry ash removal can separate most of the fly ash from the syngas before wet washing, effectively reducing the pressure of wet washing ash removal and gray water treatment, which makes the dry ash removal technology more effective in dealing with high ash content Coal types have been widely used. [0003] The best pulverized coal pressurized gasification technology in the existing technology is to use a high temperature and high pressure fly ash filter for dry ash ...

AI Technical Summary

Problems solved by technology

[0007] One is that the backflush gas flow rate is low, and the buffer tank is far away from the filter, which leads to a longer retention time of the backflush gas in the system and a large change in gas quality, which leads to a lower temperature of the backflush gas and cannot meet the filtration requirements. The backflushing temperature requirements of the filter make it difficult to blow off the fly ash on the surface of the filter, which leads to a slow opening speed, and in severe cases, it may even cause corrosion of the filter rod or the filter rod bears too much weight, which leads to the start-up of the machine. When the filter is damaged, the service life of the filter is reduced

[0008] The second is to vent the back blowing gas, so that the flow rate of the back blowing gas in the system increases, and when the back blowing effect on the filter is achieved, the energy consumption of the entire system will be large, and the noise during the venting process will be large. Larger, causing noise pollution, difficult to meet environmental protection needs

[0009] The third is to speed up the blowback frequency of the blowback gas, thereby increasing the flow rate of the blowback gas and increasing the temperature of the blowback gas, which reduces the service life of the pulse valve and increases the cost, thereby reducing the service life of the filter rod , and it will also increase the content of inert gas in it, which will lead to greater difficulty in the separation process of synthesis gas and inert gas, and increase the separation cost of synthesis gas

[0010] Fourth, in the cold state of the equipment and pipelines, the starting condition of the blowback program needs to reach 200°C, and the on-site venting takes a long time, which affects the start-up progress of the device, reduces the working efficiency of the device, and increases the production cost

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