Belt conveyors are widely used in various industries such as home appliances, machinery, tobacco, printing, and food for the assembly, testing, debugging, packaging, and transportation of diverse objects. The main body of the conveyor belt line can be selected according to process requirements, such as rhythmic operation, variable-speed operation, and continuous operation. Belt conveyors can also be configured as straight, curved, or inclined lines based on local conditions.
The protection system of belt conveyors primarily consists of speed sensors. Speed Sensor: Hall effect sensors are employed to detect the conveyor belt's speed. When the driven pulley's operating speed reaches 50-70% Va (Va being the rated belt speed), or when the conveyor belt speed is less than or equal to 50% Va or greater than or equal to 110% Va, the controller automatically cuts off power to the belt conveyor after a delay of (5-10) seconds to halt operation and implement speed protection. Deviation Sensor: Normally open in standby state and closed during movement. It automatically cuts power to the belt conveyor and stops operation.
Coal Pile Sensor: Utilizes two electrodes to conduct signals. Coal level is monitored via wiring connected to the protection device, tracking coal levels in hoppers or bins. When the bin is full or coal accumulates at the discharge head, it automatically cuts power to the belt conveyor, achieving full coal protection. Emergency Stop Protection: Each controller's control panel and belt line is equipped with a pull-cord emergency stop switch for fault emergency shutdown protection. Overheat Protection: Temperature sensors monitor the temperature of the belt conveyor's bearings, other components, or the ambient environment. When the temperature at the monitoring point exceeds the set value, the controller automatically cuts off the belt conveyor's power supply to achieve overheat protection and activates the sprinkler system for cooling. Smoke Sensor: When smoke is detected on the belt or coal by the smoke sensor, the controller initiates shutdown protection and activates the sprinkler system and dust suppression system. Tear Sensor: In the event of a longitudinal tear in the belt, coal falling onto the sensor triggers its activation. The controller then cuts off power to the belt conveyor to halt operation.
Safety protection devices for belt conveyors are systems that monitor and alarm during material conveyor malfunctions. They ensure safe and normal operation of the conveyor system, prevent damage to mechanical components, and protect operator safety. Additionally, they facilitate centralized control and enhance automation levels. Common protection and monitoring equipment includes:
Belt Conveyor Longitudinal Tear Prevention Device: This device monitors the conveyor belt itself. When sharp objects are present on the belt and it begins to tear from the center, it automatically triggers an alarm and initiates an emergency stop.
Belt Conveyor Deviation Switch: A deviation switch is a protective device that detects belt misalignment and twisting. It prevents edge damage and material spillage caused by belt deviation, triggering automatic alarms and shutdowns. Minor deviations produce warning signals, while severe deviations activate delayed action with automatic shutdown. Deviation switches are typically installed at the head, tail, midpoint, and required detection points of the belt conveyor.
Belt Conveyor Pull Cord Switch: The pull cord switch is a protective device for emergency on-site shutdown of the conveyor. During emergencies, pulling the cord at any location triggers an alarm signal, followed by self-locking and shutdown. Cord switches are typically installed every 60 meters on both sides of the conveyor frame.
Belt Conveyor Chute Blockage Switch: The chute blockage switch monitors for obstructions within the belt conveyor system's chutes. When a blockage forms in the chute, it automatically triggers an alarm and initiates an emergency shutdown.
Belt Conveyor Slip Detection Device: This slip detection device monitors the linear speed difference between the drive rollers and the conveyor belt. It can trigger an alarm signal, enabling automatic belt tensioning and normal shutdown.
