Working Reset Process of Mine Pneumatic Pressure-Free Air Doors

The reset process of mine pneumatic pressure-free air doors is an automatic cycle where the system transitions from the "passage state" back to the "standby state," accomplished through the coordinated action of sensor detection, controller commands, and pneumatic drive. The specific steps are as follows:

1. Passage Completion Detection

After personnel or vehicles completely pass through the air door, infrared sensors (or other sensing devices) on both sides of the door monitor the detection range in real time. Once it is confirmed that there are no remaining targets in the area, an electrical signal indicating "passage completed" is sent to the core controller.

• If there is continuous obstruction, such as by a long vehicle, the sensors will continue to send signals to ensure the door remains open until the target completely leaves the detection area.

2. Delay Program Initiation

Upon receiving the "passage completed" signal, the controller automatically initiates a preset delay program (the delay time can be adjusted according to passage needs, typically 5-30 seconds), providing a buffer period to prevent secondary passage within a short time.

• During the delay period, the door remains open, and the audible and visual warning devices continue to operate (e.g., green light on, warning sound active), indicating that the passage phase is still ongoing.

3. Door Closing Command Triggered

After the delay period ends, the controller determines that there is no need for secondary passage and immediately sends a door closing command to the pneumatic drive system. The pneumatic valve actuates and switches, stopping the input of compressed air into the cylinder, which then begins to exhaust and depressurize.

4. Door Closing Action

The cylinder piston rod retracts under the release of air pressure, driving the door to slowly rotate and close via a linkage mechanism. During the closing process, the speed control device regulates the action speed (typically taking 5-8 seconds to complete closing), ensuring smooth movement of the door and avoiding impact.

• When the door closes, the sealing strip between the door frame and the door leaf tightly adheres, achieving effective sealing and maintaining air pressure balance in the ventilation area.

5. System Status Reset

After the door is fully closed, the controller activates the locking device to ensure that air doors on the same side or opposite sides cannot open simultaneously, preventing abnormal airflow. At the same time, the pneumatic system resets to its initial pressure state, and the sensors resume real-time monitoring mode.

• The audible and visual warning devices turn off, and the entire system enters standby mode, awaiting the next sensing signal to trigger and complete the entire work cycle.

Through the above process, mine pneumatic pressure-free air doors can automatically complete the reset from post-passage closing to standby state without manual intervention, ensuring continuous adaptation to the ventilation control needs of complex underground environments.