Coal-tar powder combustion method and apparatus

Abstract

The invention provides a coke powder combusting method, comprising: combusting the coke powder in order through low-speed bed and high-speed bed at 0.3-3m/s and 3-25m/s, respectively; separating the combusted coke powder from gas through gas-solid separator and making the solid powder enter in heat-absorbing fluidized bed to reduce the temperature of the solid powder; making the solid powder enter in mixing segment and mix with fresh coke powder, and entering in circulating combustion again; thus, it can completely combust coke powders of different sizes and its combusting efficiency and sulfur-fixing rate are both largely improved.

Description

technical field [0001] The invention belongs to the field of coal chemical industry, and specifically relates to a combustion method capable of increasing the combustion rate and sulfur fixation rate of coal coke powder and the equipment used in the method. Background technique [0002] A large amount of coal coke powder with high sulfur content is produced in my country every year. This coal coke powder cannot be used efficiently due to its high sulfur content. The current gasification combustion method and the equipment used make the combustion not only inefficient, but also after gasification combustion The flue gas produced has high sulfur content and becomes the source of air pollution and acid rain. [0003] The combustion sulfur fixation experiment of coal coke powder shows that: (1) Coal coke powder gasification combustion has high sulfur content in flue gas, easy slagging, high ignition temperature, high ember temperature, slow combustion rate, and long effective com...

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Problems solved by technology

[0002] A large amount of coal coke powder with high sulfur content is produced in my country every year. This coal coke powder cannot be used efficiently due to its high sulfur content. The current gasification combustion method and the equipment used make the combustion not only inefficient, but also after gasification combustion Due to the high sulfur content in the flue gas, it becomes the source of air pollution and acid rain

[0003] The combustion sulfur fixation experiment of coal coke powder shows that: (1) Coal coke powder gasification combustion has high sulfur content in flue gas, easy slagging, high ignition temperature, high ember temperature, slow combustion rate, and long effective combustion time. Long, poor combustion performance and other characteristics

(2) The combustion of coal coke powder presents an obvious staged process. The first stage is easy to burn, the ignition temperature and ember temperature are lower, the burning rate is faster, and the combustion time is shorter; the second stage is difficult to burn, and the ignition temperature and The embering temperature is higher, the burning rate is slower, and the burning time is longer; and with the increase of particle diameter, the ignition temperature and embering temperature of coal coke powder increase, the burning time increases, and the burning rate decreases

The two combustion methods have their own advantages and disadvantages: (1) The low-velocity bed combustion method has factors such as larger particle concentration in the bed, more back-mixing, longer particle residence time, higher carbon conversion rate and gasification efficiency. Gasification combustion, but at the same time, the gasification combustion of coal coke powder is not conducive to the gasification and combustion of coal char powder due to factors such as low operating gas velocity and small circulation ratio in the bed; (2) Fast bed or conveying bed combustion method has high operating gas velocity and large circulation ratio Factors such as small amount of sulfur-fixing agent, high gas-solid ratio, and high gas yield are beneficial to the gasification and combustion of coal coke powder, but at the same time, due to less back-mixing, shorter particle residence time, and the heat generated per unit mass of coal Factors such as low value are not conducive to the gasification combustion of coal coke powder; (3) in low-velocity bed combustion, the particle concentration is large, the back-mixing is large, the gas-solid residence time is long, and the contact between sulfur-containing flue gas and sulfur-fixing agent As the time increases, the sulfur fixation rate increases, but at the same time, the single-pass charring amount of the particles is also larger, the sulfur content in the flue gas is larger, the sulfur fixation rate is lower, and the small particles that are easier to burn stay in the bed for too long, occupying The effective space of the burner is reduced, and the processing capacity is reduced; when burning in a fast bed or a conveying bed, the particle concentration is small, the back-mixing is small, the gas-solid residence time is short, the single-pass charring of the particles is small, and the sulfur content of the flue gas Smaller, the sulfur fixation rate increases, but at the same time the contact time between the sulfur-containing flue gas and the sulfur fixer is also reduced, the sulfur fixation rate is reduced, and the residence time of the large particles that are difficult to burn is too short in the bed, and they are not fully burned. less efficient combustion

Therefore, because the current combustion methods are all used independently, there are not only some characteristics that are beneficial to the clean combustion of coal coke powder, but also some characteristics that are not conducive to the clean combustion of coal coke powder.

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