Safety operation regulations for pit annealing furnace

Safety operation regulations for pit annealing furnace

Furnace operation

1. The spools wrapped with iron wire should be stacked neatly and stably when installed on the rack. There are 4 spools stacked on each shelf, and 4 wiping blocks are used between the two plates. Each furnace is equipped with 7 racks. Avoid bumping or scratching the wire during the loading process (loading with a forklift).

2. When the loaded rack is hoisted into the furnace with an electric hoist, it should be swayed and hoisted in the center to avoid collision.

3. After the hoisting is completed, cover the furnace cover, and tighten the fixing screws on the cover diagonally with even force.

 Vacuum

Connect the vacuum hose, turn on the vacuum pump, and open the vacuum isolation valve to vacuum. Vacuum negative pressure 0.05MP.

Heat up and keep warm

1. After vacuuming, turn on the control power supply, turn on the meter switch, turn on the cooling water pump, circulating fan, set the oven temperature (300 degrees), turn on the heating switch to dry the oven, the duration is 3-4 hours.

2 After the oven is over, the temperature is increased, and the temperature is set to 640 degrees (according to the actual situation). Under normal circumstances, it will rise from 300 degrees to 640 degrees in 3-3.5 hours. During the heating process, the pressure in the furnace rises continuously as the temperature rises. When the pressure reaches 0.025MPa, open the bleed valve to bleed and reduce the pressure. The control range is (0.005—0.025MPa).

3. After the furnace temperature reaches 640 degrees and keep it for 12 hours, the pressure in the furnace will increase during the process. When it reaches 0.025MPa, open the vent valve to vent and reduce the pressure. The control range is (0.005—0.025MPa).

Cool down

1. After the holding time is over, turn off the heating power, pull out the two blockages on the outer wall of the furnace, and turn on the cooling fan for cooling.

2. During the cooling process, the pressure in the furnace begins to drop, (to prevent oxidation of the iron wire, the positive pressure in the furnace must be ensured) to supplement the pressure with nitrogen to keep the pressure in the furnace always at positive pressure. About 0.01MPa.

3. When the temperature drops to about 250 degrees, the furnace cover can be opened and the discharge rack can be lifted.