Fully Automatic Pressure-Balanced Air Door

The mining fully automatic pressure-balanced air door is a key equipment in the underground mine ventilation system, primarily used to regulate and control airflow within the mine, ensuring the normal operation of the mine ventilation system. It integrates automated sensing, drive technology, and a pressure-balanced structure, enabling automatic opening and closing of the door without human intervention. Through its special structural design, it balances environmental wind pressure, adapting to the complex working conditions underground.

Structural Composition

1. Door Structure

Typically designed with a double-leaf structure, it consists of a door frame, door leaf, balancing mechanism, counterweight, and other components. The door frame is usually welded from steel profiles, while the door leaf is constructed with a steel profile frame and an outer shell formed by folding steel plates and welding them together. The balancing mechanism, through an ingenious linkage design, converts wind pressure acting on the door into internal forces, making the door opening force independent of wind pressure and direction, thus allowing for easier opening.

2. Control System

Includes sensors, controllers, and actuators. Sensors are used to detect the approach of personnel or vehicles, commonly including infrared sensors and photoelectric sensors. The controller is typically a PLC (Programmable Logic Controller), which receives signals from the sensors and controls the actuators based on preset programs. Actuators are usually pneumatic cylinders or electric push rods, responsible for driving the door's opening and closing.

3. Locking Device

To prevent both air doors from opening simultaneously and causing airflow short-circuiting, the mining fully automatic pressure-balanced air door is equipped with a locking device, including electrical and mechanical locking methods, ensuring that only one door can be open at any time.

4. Audible and Visual Warning Device

When the air door opens or closes, it emits sound and light signals to alert personnel for safety and to inform underground workers of the door's status.

Working Principle

1. Sensing Trigger: When personnel or vehicles enter the detection range of the sensor, the sensor detects the signal and transmits it to the controller.
2. Command Execution: After receiving the signal, the controller processes and judges it, then sends a control signal to the actuator, such as a pneumatic cylinder or electric push rod, to drive the door open.
3. Passage Process: The door opens to a suitable angle and remains open, waiting for personnel or vehicles to pass through.
4. Automatic Closing: After personnel or vehicles pass through the air door, the sensor detects no objects in the passage. The controller then sends a closing signal after a set delay, causing the door to close automatically and return to its initial state.

Performance Features

1. Low Opening Force: Due to the pressure-balanced structure, the door opening force is independent of wind pressure and direction, significantly reducing the force required to open the door. It can be easily opened even in roadways with high wind pressure.
2. Bidirectional Air Isolation and Sealing: Capable of bidirectional air isolation with minimal air leakage, eliminating the need for additional reverse air doors. This effectively ensures the stability of the ventilation system and the normal direction of airflow, reducing energy waste and ventilation failures caused by air leakage.
3. High Automation: Enables fully automatic control without manual operation, not only improving passage efficiency but also reducing labor intensity and the possibility of human error. It also facilitates centralized management and remote control of the air door from the ground monitoring center.
4. Safe and Reliable: Equipped with multiple safety protection features, such as anti-pinch functionality to prevent injuries to personnel or vehicles during passage, and interlocking between two air doors to avoid airflow short-circuiting, ensuring mine ventilation safety.
5. Robust and Durable: The door structure is made of steel, with a simple design and high strength. It offers excellent corrosion resistance, moisture resistance, and flame retardancy, adapting well to the harsh working environment of underground coal mines and providing a long service life.

Application Scenarios

Primarily used in connecting roadways between intake and return air passages in underground mines, as well as in other underground roadways where airflow control and ventilation safety are required, such as mining district stone gates, transport roadways, and return air passages.