Low-rank coal powder rotary drying technology with dust removing function

A rotary drying and pulverized coal technology, which is used in the petroleum industry, special forms of dry distillation, coke ovens, etc., can solve the problems of a large amount of coal dust and ineffective mechanical screening, so as to reduce equipment and production costs, improve yield and The quality of coal tar and the effect of reducing equipment investment

CN104789246AActive Publication Date: 2015-07-22SHAANXI COAL & CHEM IND GRP SHENMU TIANYUAN CHEM IND +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2015-07-22

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Abstract

The invention provides a low-rank coal powder rotary drying technology with a dust removing function. The low-rank coal powder rotary drying technology comprises the following steps: feeding coal powder of which the particle size is smaller than or equal to 30 mm into a rotary drying furnace; heating the coal powder to 80 to 280 DEG C for drying, so as to reduce the water content of coal powder to 0 to 5 percent; moreover, removing more than 85 percent of coal dust of which the particle size is smaller than 0.5 mm from the dried coal in the rotary drying furnace. Gas discharged from the rotary drying furnace contains coal dust; the coal dust is removed after the gas enters a gas dust remover; the coal dust-free gas enters a drying gas cooling system for temperature reduction; the cooled gas enters a blower for pressurization; the pressurized gas returns to the rotary drying furnace. After dust removing and drying, coal powder of which the particle size is 0.5 to 30 mm enters a downstream pyrolyzing furnace for pyrolyzing. Through the adoption of the technology, the dust content of coal powder entering into the downstream pyrolyzing furnace can be reduced; the yield of a coal tar product can be improved.
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Description

Technical field

[0001] The invention relates to a low-rank pulverized coal rotary drying process with dust removal, and is particularly suitable for the field of dry distillation and quality upgrading and drying of pulverized coal. Background technique

[0002] Low-rank coal refers to low-quality coal with a low degree of coalification and a short coal age. According to coal types, it mainly includes lignite, long flame coal, weakly caking coal and non-caking coal. When this kind of coal burns, the flame is longer and smokey, the carbon content is 75-90%, and it does not contain free humic acid. Most of it has cohesiveness and most of it can coke. Common low-rank coal processing methods include direct combustion of low-rank coal for power generation, low-rank coal pyrolysis (ie, dry distillation of low-rank coal), and direct liquefaction of low-rank coal. Among them, the process of producing coal tar by dry distillation of low-rank coal and by-product pyrolysis gas and upgraded ...

Examples

Embodiment 1

[0044] 6000kg of raw material long flame coal with particle size ≤30mm is continuously fed into the rotary drying furnace from the furnace head, and at the same time, 2kpaG, 200℃ flue gas (O 2 Content ≤5vol%) countercurrent contact with coal is used as dust removal gas; 600℃ high temperature flue gas is passed into the jacket of the rotary drying furnace as the drying heat source, and the outlet flue gas enters the preheater to heat the circulating drying gas and then empties. After the coal is heated and dried to 250°C with a water content of 0%, it is sent to the downstream pyrolysis furnace. The 115°C gas at the furnace head outlet of the rotary drying furnace enters the bag filter, washing tower, fan, and preheater in sequence, and performs unit operations such as dust removal, cooling and recovery of drying water, boosting and heating, and then returning to the rotary drying furnace to form Closed circuit of dry gas. See the detailed process diagram figure 1 . After the ...

Embodiment 2

[0055] Add 1000kg of raw material long flame coal with a particle size of ≤30mm from the furnace head into the rotary drying furnace, and at the same time pass 2kpaG, 500℃ flue gas (O 2 Content 2vol%) is in countercurrent contact with coal, and the dry gas at the outlet of 200℃ enters the metal filter to remove coal dust, then enters the water cooler and gas-liquid separation tank to recover most of the dry water, pressurized by the fan and heated by the heater, then return The tail of the drying furnace forms a closed loop of dust removal gas. At the same time, add a small amount of low pressure N to the heater inlet 2 , The outlet of the fan vents the same amount of gas to control the O of the dust removal gas in the rotary drying furnace 2 The content is 3vol%. See the detailed process diagram figure 2 .