Raw coal storage and transportation system

1. The raw coal with particle size<35mm and moisture content <15% is transported by dump truck to the coal shed. The raw coal stored in the coal shed is loaded into the receiving coal hopper by a loader, and the raw coal in the receiving coal hopper is fed by speed regulation The belt conveyor is evenly fed to the bucket elevator. After the raw coal is lifted to the required height by the elevator, the raw coal is discharged and enters the pulverizing system through the double-layer lock valve.

2. There is a rod valve between the coal hopper and the vibrating feeder. The rod valve can be closed when the speed-regulating feeding belt conveyor is overhauled, which facilitates the overhaul operation. The speed-regulating feeding belt conveyor can realize the speed-regulating function, which is conducive to generation operation and management. The upper part of the speed-regulating feeding belt conveyor is equipped with an iron remover, which can remove the iron filings mixed in the raw coal and avoid the threat of iron filings to the system.

Milling System

1. The raw coal from the raw coal storage and transportation system enters the air-swept coal mill. After grinding, the pulverized coal conducts mass and heat transfer with hot air at 200°C to 350°C. Moisture enters the flue gas from the coal, and the pulverized coal is dried by the hot air. The pulverized coal enters the separator for separation with the air flow, and the selected coarse powder returns to the mill for grinding again, and the fine powder continues to enter the pulverized collection system through the coal air duct with the air flow.

2. Air-swept coal mill hot air inlet pipeline and coal air outlet pipeline are equipped with explosion relief valves and nitrogen protection interfaces to protect the safety of equipment and systems. The powder classifier adopts frequency conversion motor for speed regulation, and the adjustment of the frequency converter can remotely realize the control of the powder fineness of the powder classifier.

Powder collection system

The qualified fineness coal powder discharged from the classifier is under the negative pressure of the induced draft fan set behind the explosion-proof bag filter, enters the explosion-proof bag filter through the coal air duct, and passes through the dust collector. After filtering by the internal filter bag, the pulverized coal is captured and falls into the pulverized coal hopper at the lower part of the dust collector. The flue gas filtered and purified by the dust collector is discharged to the atmosphere through the chimney through the induced draft fan. The pulverized coal stored in the pulverized coal hopper is unloaded into the bucket elevator by the star unloader and screw conveyor, and is lifted to the top of the pulverized coal silo by the bucket elevator, and sent into the pulverized coal by the screw conveyor installed on the top of the silo warehouse.