Optimal clean combustion process and system of coal washing slime compound circulating fluidized bed

Abstract

The invention relates to a technology and a system for optimizing the clean combustion of a coal washing slurry composite circulating fluidized bed, wherein a double helical feeder and a double-cylinder coal washing slurry piston pump are taken as continuous and stable supply sources of coal washing slurry for combustion, and coal materials and coal washing slurry particle clusters taken out by hot exhaust gas after combustion are separated and captured and then returned to a combustion chamber through a reinfusion channel as circulating fuel for secondary combustion. Through the adoption of composite circulating fluidized bed combustion technology, clean resource utilization is carried out on waste material coal washing slurry generated during the coal washing process, so that the environmental pollution and energy loss are reduced, the recovery utilization problem of coal washing slurry is effectively solved, and a new way for efficiently treating washing coal slurry in large scale is developed.

Description

technical field [0001] The invention relates to a method and device in the technical field of energy saving and emission reduction, in particular to an optimized clean combustion process and system of a combined circulating fluidized bed for washing coal and slime. Background technique [0002] Coal washing slime is a waste of the coal washing process and a by-product of the coal washing industry, and its quantity accounts for 5% to 8% of the total washing coal. The characteristics of washing slime are: 1) High water content. Generally 30%, even after pressure filtration, the water content is about 20%; 2) The ash content is large. The received base ash content is generally 20% to 30% (dry basis ash content 30% to 70%)); 3) The calorific value is low. The low calorific value of the received base is generally 14653.8kJ / kg~16726.4kJ / kg; 4) The volatile content is low, usually about 25%; 5) The particle size is very fine. The maximum particle size generally does not exceed 0...

AI Technical Summary

Problems solved by technology

The conventional circulating fluidized bed boiler adopts the external circulation recycling method, which has complicated process, difficult operation, large space occupation and high cost

Secondly, conventional circulating fluidized bed boilers do not have enhanced internal circulation components and cannot increase fuel combustion efficiency

Third, conventional circulating fluidized bed boilers cannot meet the combustion needs of low calorific value and high moisture fuel washing slime, which may cause problems such as low combustion efficiency and unsatisfactory boiler load

First of all, this technology is aimed at the combustion of high-quality fuel coal-water slurry, which has poor fuel adaptability and cannot meet the combustion needs of low calorific value, high moisture and high ash fuel washing coal slime

Secondly, adopting the method of external recycling, the process is complicated, the operation is difficult, the space is large, and the cost is increased

Third, the furnace structure of this technology is simple, there is no component to enhance the internal circulation, and it is impossible to increase the combustion efficiency of fuel

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