Low energy consumption, low emission, coal quality guaranteed and safe drying method and device for chemical feed coal

Abstract

The invention discloses a low energy consumption, low emission, coal quality guaranteed and safe drying method and a device for chemical feed coal. The method includes the steps that saturated steam is used for indirect heating, superheated steam is used for drying through direct contact, secondary steam generated by evaporation is recycled, and condensation water serves as industrial water. The device comprises a coal preheating device, a drying device, a steam boiler and a superheated steam generator, wherein the coal preheating device and the drying device are in a processing connection, the drying device is composed of an indirect heating layer and a drying area, the steam boiler is connected with the indirect heating layer and the superheated steam generator through a saturated steam distributor respectively, a steam outlet of the superheated steam generator is communicated with the drying area, a condensate water outlet of the indirect heating layer is connected with a water inlet pipe of the steam boiler, a steam outlet of the drying area is connected with a secondary steam distributor through a dust collector, the secondary steam distributor is connected with the superheated steam generator through a compressor pump, and a feed coal outlet of the drying area is in a processing connection with a coal storage bunker. According to the drying method and the device, double heating and wet process drying are adopted, drying efficiency of the coal is high, pyrolysis efficiency is low, and quality is good.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry, and in particular relates to a safe drying method and device for chemical raw material coal with high drying efficiency, energy saving, environmental protection, good safety performance, low energy consumption, low emission and coal quality preservation, which has little influence on coal quality. Background technique [0002] Coal drying, the common practice at home and abroad is to use the drying method of direct contact between hot smoke and coal, such as drum drying, mixed vibrating baffled bed, fluidized bed, entrained bed drying, etc. However, most of these methods have the disadvantages of high energy consumption, large pollution, poor safety and low thermal efficiency. During the drying process, the moisture in the coal is discharged together with the flue gas, the latent heat of steam vaporization is not utilized, and the vaporized water cannot be recycled. The high-tempe...

AI Technical Summary

Problems solved by technology

However, most of these methods have the disadvantages of high energy consumption, large pollution, poor safety and low thermal efficiency.

During the drying process, the moisture in the coal is discharged together with the flue gas, the latent heat of steam vaporization is not utilized, and the vaporized water cannot be recycled

The high-temperature flue gas is in direct contact with the coal, and the moisture in the coal is vaporized rapidly, which may easily cause the thermal collapse of the coal

Secondly, the coal itself collides and rubs in the dryer, and there is a large free fall, which increases the probability of secondary crushing

It is easy to produce more fine coal powder, which not only causes a waste of resources, but also easily generates dust, which has a great impact on the environment

[0003] Drying of high-temperature flue gas will lead to different degrees of physical and chemical changes in coal (such as decarboxylation, pyrolysis, etc.). Hidden dangers; and have adverse effects on subsequent processing and utilization

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