Air flow and high frequency combined lignite drying device and process

Abstract

The invention discloses an air flow and high frequency combined lignite drying device and an air flow and high frequency combined lignite drying process. The air flow and high frequency combined lignite drying device comprises an air flow dryer, a high frequency dryer, an external heat exchanger, a feeding device, a compression device, a dust removal system and a hot flue gas generation device, wherein a feeding part of the air flow dryer is connected with the feeding device; a flue gas inlet part of the air flow dryer is connected with the hot flue gas generation device; a discharge part of the air flow dryer is connected with the dust removal system; the dust removal system is connected with the high frequency dryer and the compression device I; the compression device I is connected with the external heat exchanger and the hot flue gas generation device; the external heat exchanger is connected with the high frequency dryer through a ventilation system and is also connected with the compression device II; and the external heat exchanger and the high frequency dryer can be emptied. The air flow and high frequency combined lignite drying device and method have the advantages of safety, energy conservation, high efficiency, environmental friendliness and the like.

Description

technical field [0001] The invention relates to a lignite drying device and process, in particular to a device and a process for drying lignite in combination with air flow and high frequency. Background technique [0002] Hot flue gas direct contact drying uses high-temperature flue gas to directly contact lignite to remove moisture in lignite. It has the advantages of simple process, convenient operation, large processing capacity, and easy industrialization. It is a relatively mature lignite drying technology at present. [0003] There are constant-speed drying stage and falling-speed drying stage in lignite hot flue gas drying. In the constant-speed drying stage, the moisture in lignite drying is mainly external moisture, the drying rate is faster, and the energy utilization rate is high. In the stage of drying at reduced speed, the moisture in lignite drying is mainly internal moisture, and the variation law of the drying rate has been related to the properties and int...

AI Technical Summary

Problems solved by technology

In the stage of drying at reduced speed, the moisture in lignite drying is mainly internal moisture, and the variation law of the drying rate has been related to the properties and internal structure of the material. The general performance is that the transfer rate of moisture from the interior of the material to the surface is lower than that of the material surface to the drying gas. The evaporation rate has changed from surface vaporization control to internal diffusion control. At this stage, the drying rate drops sharply and the energy utilization rate decreases.

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