A method for utilizing waste heat of fluidized bed coal coke powder

Abstract

The invention relates to a fluidized bed coke powder waste heat utilization method, and belongs to the field of powdered coal fluidized bed pyrolysis dry distillation. High-temperature coke powder obtained after dry distillation is cooled to the safe packaging temperature, the coke powder waste heat is used for generating steam, according to the fluidized bed coke powder waste heat utilization method, according to the coke powder temperature grade, the multi-stage series manner is adopted, a high-temperature steam generation part and a medium preheating part are obtained through dividing, andthe coke powder waste heat is subjected to graded utilization. The high-temperature coke powder sequentially flows through the steam generation area and the cooling medium preheating area, and the high-temperature coke powder flows out of the cooling medium preheating area.

Description

technical field [0001] The invention belongs to the field of pulverized coal fluidized bed pyrolysis and dry distillation, and in particular relates to a method for utilizing waste heat of fluidized bed coal coke powder. Background technique [0002] Coal dry distillation is to convert coal into semi-coke, coal tar and gas three-state products by heating under an inert atmosphere. According to different heating temperatures, coal carbonization can be divided into low-temperature carbonization, medium-temperature carbonization and high-temperature carbonization. The heating temperature is 500-600°C for low-temperature dry distillation, 700-900°C for medium-temperature dry distillation, and 900-1100°C for high-temperature dry distillation. At present, there are many coal dry distillation technologies, and there are great differences in heating temperature and heating method. Coal dry distillation products mainly consist of coal tar and semi-coke. Semi-coke is a product with...

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Problems solved by technology

There are also different methods for coke cooling due to different coke powders. The influence of particle size on pulverized coal cooling is mainly realized through heat transfer and mass transfer. The size of coal particles directly affects the specific surface area, density, and pore structure of coal. Heat transfer can have a big impact, so fluidized bed retorting is only suitable for fine coal particles with small particle sizes

However, pulverized coal is far from most catalyst particles for gas-solid reactions. This is because the material specific gravity (density), particle shape, and particle distribution are completely different from ordinary catalysts, and pulverized coal cannot be cooled according to the conventional flow state. carry out

[0003] The temperature of coal coke powder (also called powder coke) after pulverized coal pyrolysis is relatively high, and the low-temperature carbonization temperature is 500-600°C, but the required temperature for coal coke powder to be directly bagged is less than 60°C, and the economical use of coke powder is good. The waste heat realizes the deep cooling of the coke powder at the same time, which poses a great challenge to the design of the cooling system

In addition, the coal coke powder after dry distillation usually contains tar, and the coal coke powder is easy to agglomerate after low temperature, which affects the transportation and heat transfer

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