Cement screw feeder (also called gravimetric screw feeder / screw metering feeder) is a sealed continuous feeding and metering equipment, specially designed for powder and fine granular materials such as cement, fly ash, mineral powder and limestone powder. It integrates conveying, feeding, weighing and flow control, widely adopted in automatic batching and powder feeding systems.

 Working Principle

The unit is composed of drive motor, reducer, screw shaft with helical flights, tubular housing, weighing sensor, speed encoder and control system.

The motor drives the screw shaft to rotate at a regulated speed. Raw powder falls into the feeding section from the silo or hopper. The rotating helical blades push the material axially along the sealed tube to the discharge outlet.

For gravimetric metering type: the weighing frame detects the real-time material weight inside the screw tube, while the speed sensor collects screw rotation speed. The controller calculates instantaneous flow and cumulative weight automatically. It adjusts the motor speed via PID closed-loop control to stabilize the feeding rate at the set value, realizing accurate quantitative feeding and continuous metering.

The fully enclosed tubular structure prevents powder leakage and dust escape, meeting environmental protection requirements. It can be installed horizontally or at a certain inclination angle.

 Main Applications

1. Automatic batching & proportioning

Used in concrete batching plants, dry mortar lines, cement plants, ceramic and glass production lines for accurate proportioning of cement, fly ash, slag powder, raw meal and silica powder, to guarantee stable product quality.

2. Powder feeding for environmental protection systems

Continuous quantitative feeding of lime powder and limestone powder for flue gas desulfurization and denitrification in power plants, waste incineration projects.

3. Flow measurement and material statistics

Real-time monitoring of instantaneous flow and total consumption of powder materials, supporting production data recording, cost accounting and inventory management.

4. Metallic & chemical industry

Quantitative feeding of iron powder, mineral powder, chemical additives and other dry fine powders.

5. **Building materials & solid waste treatment**

Stable feeding of various powdery additives for stabilized soil mixing, sludge solidification and solid waste resource disposal.

 Key Advantages

- Sealed structure, low dust emission, friendly to dust control

- Stable feeding performance, high metering accuracy

- Compact layout, easy installation in limited space

- Variable speed adjustable, compatible with automatic DCS control system

- Suitable for dry, free-flowing powder and small granular materials