Coal gasification device for circulating fluidized bed and manufacturing method thereof

Abstract

A circulating fluidized bed coal gasification apparatus includes coal blending system, generator, cyclone dust collector, exhaust-heat boiler, water-cooling tower and Venturi scrubber, wherein the generator has up-and-down two rows of gasifying agent nozzles, helix dust collector and storage groove. The gas pipe which communicates to the cyclone dust collector is set on the top. A feed back pipe which communicates to the generator is set at the bottom of the cyclone dust collector. The cyclone dust collector communicates to the exhaust-heat boiler by gas pipe. The exhaust-heat boiler communicates to the water-cooling tower by gas pipe and communicates to the Venturi scrubber by gas pipe. The characteristics are: the feed back pipe facing to the generator hearth of the cyclone dust collector is a feed back machine with small-sized fluid bed; the cyclone dust collector is composed of at least two tandem dust collector; coal blending system has wind feeding and dust coal drier. The invention achieves the transition of the boiling bed to the circulating fluidized bed and increases the system gasification efficiency.

Description

technical field [0001] The present invention relates to a coal gas production equipment and its technological process, in particular to a circulating fluidized bed coal gasification device for coal gasification, especially low-quality coal gasification, and a method for generating coal gas using the device. The improvement of equipment and its technological process belongs to coal gasification production technology. Background technique [0002] Coal gasification technology is mainly divided into three categories depending on the gas-solid state and movement form in the furnace: fixed bed with lump coal (10-50mm) as raw material; fluidized bed with pulverized coal (less than 10mm) as raw material; Pulverized coal (less than 0.1mm) is an entrained flow bed as raw material. In order to improve the capacity of a single furnace and reduce energy consumption, modern gasifiers are operated under an appropriate pressure (1.5-4.5MPa), and pressurized fixed bed, pressurized fluidize...

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Problems solved by technology

[0008] The technical solution given by the present invention is: this circulating fluidized bed coal gasification device includes a coal feeding system composed of coal crushing, screening equipment, coal storage tank and feeding bin, generator, cyclone dust collector, waste heat boiler , a water cooling tower and a Venturi scrubber, wherein the bottom of the charging bin is provided with a spiral coal feeder for coal delivery to the generator, the generator is provided with upper and lower gasifying agent nozzles, and the generator bottom is provided with Spiral ash remover and ash storage tank, the upper part of the generator is provided with a gas pipe connected to the upper end of the cyclone dust collector, and the bottom of the cyclone dust collector is provided with a return pipe connected with the generator furnace, and the cyclone dust collector is connected with the waste heat boiler through the gas pipe. The waste heat boiler communicates with the water-cooling tower through the gas pipe, and the water-cooling tower communicates with the Venturi scrubber through the gas pipe. It is characterized in that the return pipe from the lower end of the cyclone dust collector to the generating furnace is a return device with a small fluidized bed , can dynamically adjust the amount of return material, and effectively realize two key functions: one is to make the recirculation bed material return to the furnace continuously and stably from the cyclone dust collector; the other is to provide the balance between the negative pressure of the cyclone dust collector and the positive pressure of the lower combustion chamber The seal between the feeder is composed of a standpipe, a wind cap or an air duct, a bottom air chamber, a side air chamber, a return pipe, a fluidization chamber, a horizontal air distribution plate and a longitudinal air distribution plate. There are horizontal air distribution boards and vertical air distribution boards, and the space in the feeder is divided into three parts: the fluidization chamber, the bottom air chamber and the side air chamber. One end of the standpipe is connected to the cyclone dust collector , the other end of which is connected to the fluidization chamber, one end of the return pipe is connected to the fluidization chamber, and the other end is connected to the generator, the high-pressure gas from the blower enters the bottom air chamber and the side air chamber through the inlet pipe, The backflow dust in the fluidization chamber is blown by the wind cap or air pipe on the air distribution board to form a small fluidized bed. A negative pressure zone is formed in the area below the joint, which not only facilitates the fly ash from the cyclone dust collector to enter the fluidization chamber smoothly through the standpipe, but also solves the problem of U-shaped, J-shaped, L-shaped return feeders in the prior art. The problem that the standpipe reverses and the amount of fly ash cannot be circulated back to the furnace through the return pipe when the amount of fly ash is small

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