coal screw weighing feeder

A coal screw weighing feeder is a specialized device used to measure and control the flow rate of coal or other bulk materials in industrial processes. It combines a screw conveyor with a weighing mechanism to ensure accurate and consistent material feeding. Here’s a breakdown of its key aspects:

Key Components
1. Screw Conveyor – Transports coal via a rotating helical screw.
2. Weighing System – Typically includes load cells to measure the weight of material being conveyed.
3. Speed Sensor – Monitors the rotational speed of the screw.
4. Control System – Adjusts screw speed based on weight data to maintain a set feed rate (e.g., PLC or PID controller).
5. Hopper/Inlet – Stores coal before it enters the feeder.

Working Principle
– Coal is fed from the hopper into the screw conveyor.
– As the screw rotates, the material moves forward while the load cells measure its weight per unit length.
– The system calculates the flow rate (e.g., kg/h or t/h) by combining weight and speed data.
– The controller adjusts the screw speed to maintain the desired feed rate.

Applications
– Coal-fired power plants (fuel feeding).
– Cement industry (raw material dosing).
– Chemical processing (bulk solid handling).
– Steel plants (coke or pulverized coal injection).

Advantages
– High precision in continuous feeding.
– Enclosed design reduces dust and spillage.
– Suitable for both fine and granr coal.
– Can handle high temperatures if designed properly.

Challenges
– Wear and tear on screws due to abrasive coal.
– Requires regular calibration for accuracy.
– Potential for material buildup or blockages.

Selection Considerations
1. Material Properties – Coal size, moisture, abrasiveness.
2. Capacity Range – Required feed rate (e.g., 0.5–100 t/h).
3. Accuracy Needs – Typically ±0.5–1% of full scale.
4. Environmental Conditions – Temperature, dust, corrosion resistance.

Manufacturers & Models
Popular brands include:
– Schenck Process (MULTIDOS®)
– Merrick Industries (Loss-in-Weight Feeders)
– FLSmidth (Pfister® feeders)
– K-Tron (Coperion)

Would you like details on installation, calibration, or troubleshooting?