A low-order pulverized coal rotary drying process with dust removal

A technology of rotary drying and pulverized coal, which is applied in the direction of non-progressive dryers, drying, drying machines, etc., can solve the problems of ineffective mechanical screening and a large amount of coal dust in the product, so as to improve the yield and increase the yield of coal tar Quality, reduce equipment and production costs, reduce the effect of coal dust content

CN104789246BActive Publication Date: 2017-07-18SHAANXI COAL & CHEM IND GRP SHENMU TIANYUAN CHEM IND +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-07-18

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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-order pulverized coal rotary drying process with dust removal, which is especially suitable for the field of pulverized coal dry distillation and quality improvement drying. Background technique

[0002] Low-rank coal refers to low-quality coal with a low degree of coalification and a short coal-forming age. According to coal types, it mainly includes lignite, long-flame coal, weakly caking coal, and non-caking coal. This kind of coal burns with a long flame and smoke, with a carbon content of 75-90%, no free humic acid, most of them are cohesive, and most of them can coke. Common low-rank coal treatment methods include low-rank coal direct combustion for power generation, low-rank coal pyrolysis (i.e. low-rank coal dry distillation), low-rank coal direct liquefaction, etc. Among them, the process route of producing coal tar by carbonization of low-rank coal and by-producting pyrolysis gas and upgraded coal has become a ...

Examples

Embodiment 1

[0044] 6000kg raw long-flame coal with a particle size of ≤30mm is continuously added to the rotary drying furnace from the furnace head, and at the same time, 2kpaG, 200°C flue gas (O 2 Content ≤ 5vol%) contact with coal countercurrent as dedusting gas; 600°C high-temperature flue gas is introduced into the jacket of the rotary drying furnace as the drying heat source, and the flue gas at the outlet enters the preheater to heat and circulate the drying gas and then empties. After the coal is heated and dried to 250°C and the water content is 0%, it is sent to the downstream pyrolysis furnace. The gas at 115°C 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, temperature reduction and recovery of dry water, pressurization and temperature rise, and then returns to the rotary drying furnace to form Closed circulation of drying gas. See the schematic dia...

Embodiment 2

[0055] 1000kg of raw material long-flame coal with a particle size of ≤30mm is added to the rotary drying furnace from the furnace head, and 2kpaG, 500°C flue gas (O 2 Content 2vol%) contacts with coal countercurrently, and the dry gas at 200°C at the outlet 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, and then returns to rotation after being pressurized by the fan and heated by the heater The tail of the drying furnace forms a closed loop of dedusting gas. At the same time, add a small amount of low-pressure N at the inlet of the heater 2 , vent the same amount of gas at the outlet of the fan to control the O of the dust removal gas in the rotary drying furnace 2 Content 3vol%. See the schematic diagram of the process flow figure 2 .