Lignite drying system and lignite drying method

Abstract

The invention discloses a lignite drying system and a lignite drying method. The lignite drying system comprises a hot air system, a vibrating fluidized bed dryer, a nitrogen system and a dust removal system, wherein the hot air system is used for injecting work flue gas into the vibrating fluidized bed dryer through a gas inlet pipeline for drying lignite materials, the vibrating fluidized bed dryer is connected with the dust removal system through a gas outlet pipeline, and the nitrogen system is used for injecting nitrogen into the vibrating fluidized bed dryer. According to the lignite drying method, the lignite materials are evenly distributed on a bed surface of the vibrating fluidized bed dryer; the work flue gas at the temperature of 240-320 DEG C and with less than 14% of oxygen content is injected through the bottom of the vibrating fluidized bed dryer; under the combined action of exciting force and the buoyancy of the work flue gas, the lignite materials move towards the rear portion of the vibrating fluidized bed dryer in a fluidized state; and the lignite materials quickly exchange heat with the work flue gas for dehydration and then are discharged through a discharge end of the vibrating fluidized bed dryer. The lignite drying system and the lignite drying method can be used for drying the lignite materials quickly and effectively, and can guarantee safety in the drying process.

Description

technical field [0001] The invention relates to the field of material drying, in particular to a lignite drying system and drying method. Background technique [0002] Lignite is a low-rank coal with high moisture and volatile content and low calorific value. With the increasing demand for energy, lignite mining shows a rapid growth trend. However, due to its low calorific value, the application of lignite is severely restricted. The market urgently needs to develop advanced and practical technologies to improve the quality of lignite raw coal and increase the economic value of lignite. [0003] At present, it is recognized that there are mainly two types of lignite upgrading methods: physical upgrading and chemical upgrading. Physical upgrading is to use various drying equipment to reduce the moisture content of lignite; chemical upgrading is mainly to use dry distillation process to process lignite into semi-coke and tar. The two types of upgrading processes that have ...

AI Technical Summary

Problems solved by technology

Due to the high volatile content and low ignition point of lignite, when using traditional high-temperature drying methods to dry lignite, there are problems such as volatile precipitation, flammability and explosion.

Moreover, the above drying method also has low drying efficiency, and it is difficult to solve the problem of low processing capacity of a single machine

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