Pulverized Coal Pipe Air Lock

Pulverized Coal Pipe Air Lock, also known as gravity counterweight airlock valve for pulverized coal pipeline, is a dedicated passive sealing device applied in coal pulverizing systems of thermal power plants and cement plants. It relies on material self-gravity and counterweight reset to realize pulverized coal conveying while isolating pressure differences between pipeline sections. It effectively prevents air backflow, pulverized coal channeling and negative pressure fluctuation, stabilizing the whole pulverized coal preparation system.

This equipment belongs to the gravity-type air lock series, perfectly matching the working conditions of dry pulverized coal pipelines. Single-flap and double-flap structures are optional according to air tightness requirements.

2. Main Structure

Welded carbon steel housing: Standard round flanges for seamless pipeline connection, smooth inner cavity to avoid coal accumulation and blockage

Wear-resistant sealing flap plate: Equipped with high-temperature resistant sealing gaskets to eliminate air leakage gaps

Adjustable counterweight lever mechanism: External weight block allows flexible adjustment of opening threshold without extra power

High-temperature resistant rotating shaft and bushing: Low friction, anti-deformation, long service life under continuous high-temperature pulverized coal environment

Optional wear-resistant lining plate: Extends service life for high-abrasion coal powder medium

3. Working Principle

Dry pulverized coal flows down from the upper pipeline and accumulates on the sealing flap plate.

When the weight of accumulated pulverized coal exceeds the torque generated by the counterweight, the flap plate automatically swings downward to discharge coal into the downstream pipeline.

After the pulverized coal is completely emptied, the counterweight pulls the lever to reset the flap plate tightly against the valve seat to form an airtight seal instantly.

For double-flap type: The upper and lower flaps open alternately, and at least one flap remains closed at all times, achieving near zero air leakage and thoroughly cutting off gas channeling between the front and rear pipelines.

4. Core Advantages

No external power supply: Operates automatically by gravity and counterweight, zero energy consumption and easy installation

Superior air locking performance: Stabilizes system negative pressure, stops cold air infiltration and pulverized coal reverse spraying

Anti-blockage design: Smooth inner cavity structure prevents dry pulverized coal from sticking and piling up

High temperature & wear resistance: Customizable high-temperature resistant parts to adapt to pulverized coal temperature up to 150℃

Simple maintenance: Few vulnerable components, convenient inspection and replacement of sealing gaskets on site

Adjustable throughput: Move the counterweight block to change opening sensitivity for different coal feeding volumes

5. Application Scenarios

Thermal power plant coal pulverizing system: Raw coal silo outlet, pulverized coal pipeline, ash hopper of coal mill and classifier

Cement plant coal powder preparation pipeline

Other industrial systems transporting dry powdery fuel under pressure difference

6. Operation & Selection Tips

Install vertically on pulverized coal pipelines to ensure smooth gravity feeding of coal powder

Choose double-flap airlock for strict air-sealing requirements; single-flap type for low-pressure auxiliary pipelines

Customize reinforced wear-resistant plates if dealing with hard, high-abrasive pulverized coal

Regularly check the tightness of flap plate seal and adjust counterweight position after long-term operation