What Is Air Swept Coal Mill
The air-swept coal mill is also called a coal grinder. It is the main equipment of the cement plant, used for drying and pulverizing coal powder. It mainly consists of the feeding device, main bearing, rotary part, transmission device, discharging device, the high-pressure starting device, and lubrication system.
Feeding device: the feeding device consists of the feeding pipe, air inlet pipe, and support. The air intake pipe is welded with a steel plate, the inner wall is covered with heat-resistant concrete, and a sealing device is installed at the connection with the hollow shaft to prevent the cold air from entering.
Main bearing: the air-swept coal mill is supported by the main bearing. The main bearing adopts a large hollow shaft diameter structure, and the bearing bush is mounted on the bearing base, which can be automatically aligned while the grinding machine is in operation.
Rotary part: the rotary part is the main body of the mill, where drying and grinding are completed. It is composed of a coarse grinding chamber and a fine grinding chamber and welded by the steel plate with flat end covers at both ends. The weight of the rotating part is mainly supported by the feed hollow shaft and the discharge hollow shaft.
Air Swept Coal Mill Diagram
Air Swept Coal Mill Working Principle
First, the raw coal is fed into the feed chute by the feeding device. Then, the hot air with a temperature of about 300 ℃ enters through the air intake pipe and begins to dry the raw coal while they are falling. After that, the raw coal will be sent into the mill chamber. Because of the rotation of the cylinder, the raw coal in the chamber is brought to a certain height and thrown down. They will be crushed and ground by the impact and friction force when landing. During this process, the special induced draft fan extracts the grinding fine powder together with the used hot air and sends them to the air classifier. The qualified powder will enter the fine powder chamber through the dust collector, and the unqualified powder will be returned to the grinder for re-grinding.
Air Swept Coal Mill Specifications
| Model | Specification | Weight (t) | Capacity (t/h) | Feeding Size (mm) | Screen Residue Rate (%) | Feeding Moisture (%) | Discharge Moisture (%) |
| MFB2230 | 2.2×3 | 31.5 | 5-6 | ≤25 | 10-12 | ≤12 | 1.5 |
| MFB2244 | 2.2×4.4 | 35.3 | 8-9 | ≤25 | 10-12 | ≤10 | |
| MFB2447 | 2.4×4.75 | 49.1 | 14 | ≤25 | ＜10 | ＜8 | |
| MFB2675 | 2.6×5.25+2.25 | 87.4 | 9-10 | ≤25 | 1-3 | ≤10 | |
| MFB2853A | 2.8×5+3 | 108 | 18 | ≤25 | 10-12 | ≤10 | |
| MFB2853B | 2.8×5+3 | 108 | 16-17 | ≤30 | 10-12 | ≤9 | |
| MFB3090 | 3×6.5+2.5 | 115 | 20 | ≤25 | 10-12 | ≤10 |
| Model | Electromotor | Reducer | Rotation Speed（r/min） | |
| Model | Power(kw) | Model | ||
| MFB2230 | JR136-8(380V) | 180 | ZD50-9-I | 22 |
| MFB2244 | JR136-8(380V) | 240 | ZD60-11-I | 22.4 |
| MFB2447 | JR500-8(10KV) | 280 | JD450N0120 | 22 |
| MFB2675 | JRKK500-8(10KV) | 400 | ZDY400-4.5-II | 21 |
| MFB2853A | JRKK500-8(10KV) | 500 | JDX630N0104 | 19 |
| MFB2853B | JKR5003-8(6KV) | 500 | MBY630N0104 | 19 |
| MFB3090 | YR5602-8(10kv) | 630 | MBY630N0104 | 18.2 |
Air Swept Coal Mill Features
- The main bearing of the air swept coal mill adopts the sliding bearing and its sealing device adopts the composite seal.
- The gears of the air swept coal mill are lubricated by oil mist, which ensures the reliable lubrication, prolongs their service life and saves the lubricating oil.
- The air swept coal mill adopts chute feeding and air sweeping discharging.
