Measures to prevent dust explosion during crushing and classification

Many metal powders are prone to explode when they are classified due to their strong activity. So how can we effectively prevent dust explosions and improve equipment safety?

1: Nitrogen replacement device

Start the system, and replace the oxygen-containing air in the system to the set value through the nitrogen supplement valve, and continue By routinely supplementing nitrogen, the oxygen content of the entire system reaches an equilibrium value. The nitrogen discharge valve automatically discharges nitrogen when the pressure is higher than the set pressure value, and the nitrogen compensation valve automatically replenishes the nitrogen when the pressure is lower than the set pressure value, so that the pressure of the entire system reaches a balance value. Even if the entire system is operated under reasonable oxygen content conditions, the system is also operated under the set pressure conditions. The nitrogen discharged from the nitrogen discharge port is connected with the inlet of the nitrogen generator, reducing the start-up time of the nitrogen generator and reducing energy consumption.

2: Feeding part

Place the raw material container with the material on the transition raw material bin, which has a nitrogen inlet and a nitrogen outlet respectively, which are controlled by a solenoid valve. When feeding, first turn on the cleaning button of the feeding system, and add nitrogen to it to replace the oxygen-containing air. After the oxygen content test reaches the standard, the feeding double-layer pneumatic butterfly valve is automatically opened, and the material to be crushed enters safely from the raw material container and the transition raw material bin The feeding device is added into the system at a uniform speed to prevent the raw materials from bringing air into the system and reduce the risk of nitrogen consumption and dust explosion.

3: Finished product collection

Place the prepared finished product collection container under the finished product transition silo. The finished product transition silo has a nitrogen inlet and a nitrogen outlet respectively. The same as the feeding method, first replace the oxygen-containing air in the collection container and pipeline. When the oxygen content reaches the standard, the system automatically closes the two nitrogen ports and opens the double-layer pneumatic discharge valve to prevent qualified materials from falling into the finished product collection container. The discharge brings air into the system, reducing nitrogen consumption and the risk of dust explosion.

4: Fan sealing

In order to prevent the system oxygen content from exceeding the standard due to the fan leakage, the fan is installed in a closed tank, and the fan motor is an explosion-proof motor to ensure that the fan is both No leakage, nor will the fan explode due to explosions in other parts.

5: Cooler

Due to the high-speed operation of the fan in the classification system, the temperature of the air in the system will gradually increase. In order to prevent dust explosion due to temperature rise, a water cooler is installed in the system to reduce the temperature of the system in time to keep the system at a constant temperature.

6: Dust collector

The dust collector adopts a waterproof and anti-static filter belt to take away static charges in time and reduce the explosion of dust due to excessive discharge of charges in the dust collector. risk.

7: Control system

The motors (classifier motor, fan motor, screw feeder motor) installed on the production site are all explosion-proof motors, and the control cabinet requires zinc oxide classification Isolate the production site (set up a special room and set up explosion-proof walls) to prevent the explosion of the control part due to the dust explosion on the site.