A small particle size low-rank coal pyrolysis process and equipment coupled with multi-stage dust reduction

Abstract

The invention provides a pyrolysis furnace, small-particle-size low-rank coal pyrolysis equipment coupling multi-stage dust reducing and containing the pyrolysis furnace and a small-particle-size low-rank coal pyrolysis technology coupling multi-stage dust reducing and applying the equipment. The heat conducting efficiency of out heating pyrolysis can be improved; granular dust in the pyrolysis process is inhibited, and a raw coke oven gas dust carrying zone is minimized; high-temperature oil-dust separation is performed on dust in the raw coke oven gas carrying zone, and the tar quality is improved.

Description

technical field [0001] The invention relates to the technical field of small particle size low rank coal pyrolysis, in particular to a small particle size low rank coal pyrolysis process coupled with multi-stage dust reduction and corresponding equipment. Background technique [0002] Coal is one of the most important fossil energy sources in China, and my country's coal-based energy consumption structure will not change for a long period of time in the future. Low-rank coal includes lignite and bituminous coal with a low degree of metamorphism (long-flame coal, non-caking coal and weakly caking coal). Its proven reserves account for about 57% of the national coal resource reserves, and it has become an important component of energy production and supply. part. In recent years, with the continuous improvement of fully mechanized mining technology and the large-scale development of coal mining equipment, the coal crushing rate is high, and because the low-rank coal itself ha...

AI Technical Summary

Problems solved by technology

At present, the internal heating type vertical furnace pyrolysis technology is commonly used in the industry, using 30-80mm lump coal. The hot flue gas of combustion directly contacts the coal in the furnace to exchange heat, but the hot flue gas needs channels to circulate between the coal blocks. Therefore, only larger lump coal can be used, and small-sized crushed coal and pulverized coal cannot be used, otherwise the gas path will be blocked

[0004] In recent years, the development of pyrolysis technology for small particle size and low-rank coal has been rapid, but it is basically in the stage of laboratory research and development and pilot scale-up test, and has not yet achieved real industrial operation.

After laboratory research and development and pilot scale-up, it has been verified that there is no technical problem in realizing the pyrolysis of small particle size and low-rank coal. However, there is currently no pyrolysis technology that can be operated industrially. The key problem is that a large amount of fine dust is generated during the pyrolysis process. , and the raw coal gas produced by pyrolysis is entrained out of the reactor. At the same time, it is difficult to effectively separate the high-viscosity tar from the dust entrained by the pyrolysis oil gas, which not only greatly increases the subsequent gas purification load, but also easily causes tar condensation and deposition, resulting in The process pipeline of the follow-up purification system is blocked, which affects the overall continuous and stable operation

[0006] The essence of this invention can be regarded as a screw conveyor with a heating or cooling function in the outer jacket. The main disadvantages of this technical solution are: ①The hot flue gas runs between the inner and outer cylinders, which is prone to short circuit, and only flows from the inlet to the outlet. The shortest shortcut leads to uneven heating of various parts of the inner barrel wall; ②The auger can only push the material to move forward in parallel, the temperature of the material near the barrel wall is high, and the temperature of the material far away from the barrel wall is low, and the heat transfer between the materials The rate is low, resulting in different degrees of pyrolysis of materials during the pyrolysis process, and at the same time reducing the heat transfer efficiency; ③The drop between the incoming and outgoing materials is relatively large, which does not solve the problem of fine particle dust in the pyrolysis reactor, which can easily cause high dust content in the raw gas

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