Internal and external heating type medium and low temperature powdered coal temperature division dry distillation system and method

Abstract

The invention discloses an internal and external heating type medium and low temperature powdered coal temperature division dry distillation system and method. The system comprises a spiral pushing medium and low temperature external heating dry distillation device and a low temperature internal heating rotary kiln dry distillation device, wherein a spiral pushing dry distillation chamber in the spiral pushing medium and low temperature external heating dry distillation device is arranged in a combustion chamber of the spiral pushing medium and low temperature external heating dry distillation device, combustion smoke in the combustion chamber is directly supplied to the interior of a rotary kiln cylinder, and solid materials in the rotary kiln cylinder are supplied to the interior of the spiral pushing dry distillation chamber. Dry distillation of coal is divided into two or more phases according to temperature and is achieved through organic combination of the internal heating rotary kiln dry distillation device and the spiral pushing external heating dry distillation device, winnowing and dust removal, preheating and drying and dehydration are conducted on raw coal by means of a rotary kiln, high-efficiency medium and low temperature dry distillation and high-calorific-value raw gas and tar product precipitation are achieved by means of the spiral pushing external heating dry distillation device, the advantages of the internal heating dry distillation device and the external heating dry distillation are fully combined, dry distillation efficiency, heat utilization efficiency and the quality of dry distillation products are improved greatly, and marketing prospects are broad.

Description

technical field [0001] The invention belongs to the technical field of coal pyrolysis and dry distillation, and in particular relates to an internal and external heat type medium and low temperature pulverized coal temperature fractional dry distillation system and a dry distillation method. Background technique [0002] Pulverized coal dry distillation technology, also known as coal dry distillation or coal pyrolysis, refers to the process of heating coal under air-isolated conditions to evaporate the tar and gas in the coal to obtain tar, gas, and semi-coke. This technology was first produced in the 19th century and originated in Germany. At the beginning of its invention, it was mainly used to produce coal tar, and also used to produce coke and fuel gas for ironmaking. Due to the high energy conversion rate of this technology, it has always been recognized at home and abroad. It is the third coal conversion technology alongside coal gasification and coal liquefaction, and...

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Problems solved by technology

[0005] However, as far as the current situation is concerned, the industrialization of coal dry distillation in China is still in its infancy, and most of them use vertical block coal pyrolysis furnaces. There are serious problems in the dry distillation process, such as the low calorific value of raw coal gas produced during dry distillation, low calorific value, Atmospheric pressure or slightly positive pressure is a common problem

The common problem in the current coal carbonization industry technology is that it does not fully consider and utilize the temperature-specific weight loss characteristics in the coal pyrolysis process, that is, it does not organically combine the pyrolysis characteristics of coal at different temperature stages. pyrolysis devices, but they basically work independently of each other, and the organic combination of heat, raw materials and products has not been realized. At the same time, the pyrolysis products of each stage cannot be collected separately, and tar and raw gas with high calorific value cannot be obtained. Therefore, designing a high-efficiency carbonization system that can realize the heating process of raw coal from room temperature to medium temperature is of great significance for promoting the industrialization of raw coal carbonization

At the same time, the current domestic coal carbonization has industrial advantages based on the external heating coal carbonization technology, and the main problems affecting the efficiency of the external heating coal carbonization are the coal propulsion method and heating efficiency. Most of the methods used are gravity propulsion based on vertical furnace, crawler conveying propulsion, furnace body rolling propulsion, etc. These raw coal propulsion methods have relatively large industrialization defects in actual use, and at the same time, it has been difficult to improve the heating efficiency of external heat. To a certain extent, it limits the industrial application of dry distillation of raw coal

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