Device for drying lignite by microwave fluidization

Abstract

The invention discloses a device for drying lignite by microwave fluidization. The device comprises a microwave heating chamber and a fluidized bed, wherein the fluidized bed is arranged at the bottom of the microwave heating chamber and communicated with the microwave heating chamber; the microwave heating chamber comprises a metal furnace shell capable of shielding microwaves, a material inlet and a smoke gas exhaust port are arranged at the top of the furnace shell, at least one microwave generation device is arranged on the side surface of the furnace shell, a cylindrical ceramic furnace tube through which microwaves can penetrate is further arranged in the furnace shell, a plurality of layers of annular metal baffle plates are arranged along the inner wall of the ceramic furnace tubefrom top to bottom, a rotating shaft is arranged at the center of the ceramic furnace tube, a plurality of rake-shaped structural members which correspond to the metal baffle plates respectively are fixedly arranged on the rotating shaft along the axial direction, and a tapered material guide disc is fixedly arranged on each rake-shaped structural member; and the fluidized bed is in vertical structure, an air chamber of the fluidized bed is connected with a hot air furnace through a first hot air inlet pipe and an overflow pipe connected with a finished product warehouse is arranged at the upper part of the fluidized bed. By adopting the device, the large-scale, fast, low-energy-consumption and deep-drying production of the lignite can be realized.

Description

technical field [0001] The invention belongs to the field of lignite drying, in particular to a device for drying lignite by microwave fluidization. Background technique [0002] International geologists predict that the geological reserves of hard coal in the world are about 6 trillion tons, and the geological reserves of lignite are about 4 trillion tons. my country's lignite reserves account for about 16% of the world's total lignite reserves, and it is one of my country's main coal resources. [0003] Lignite is a kind of brown-black low-grade coal whose coalification degree is between peat and bituminous coal. The total moisture content can generally reach 20-50%. At present, lignite is generally dried by flue gas pre-drying or steam drying process abroad, and then directly sent to pit-mouth power plants for combustion and power generation. The number of pit-mouth power plants in my country is small, and most power plants are far away from coal mines, and the transport...

AI Technical Summary

Problems solved by technology

If it is not dried, it is not conducive to transportation and storage, and it is difficult to meet the quality requirements of various users.

[0004] Wan Yongzhou et al. introduced drying lignite technologies such as rotary tube heat method, steam fluidized bed, thermal dehydration process / method in "Coal Engineering" 2008 No. 8, page 91-92; patent CN10132626 discloses "coal Microwave Drying": After the coal is graded, it is loaded into a two-stage or multi-stage microwave chamber through a conveyor to dry to obtain coal with a moisture content within the target moisture content. This method has the disadvantage that the evaporated moisture during the drying process is difficult to be taken out quickly. And because the depth of microwave penetration of water-containing lignite is limited, it is impossible to increase the thickness of the coal seam to achieve large-scale drying, and it is difficult to ensure the uniformity of drying and deep drying, which is easy to cause combustion and reduce the coking quality of coal. If the capillary pores are opened and deep drying is not carried out, the effect of quality improvement will not be achieved, but the hydrophilicity of coal will be enhanced, and it will easily absorb water, which is not conducive to storage

[0005] The above known technical solutions all have such or such problems as complex equipment and process, low drying efficiency, high energy consumption, and inability to deep dry, which makes it difficult to realize large-scale lignite drying.

Images