On 2018-08-08 14:48:54
How to pressurize and inflate a hot pressing furnace
Hot pressing furnace is widely used because of its structural advantages. The hot pressing furnace is a vertical structure with double-layer water interlayer structure. The inner and outer walls and flanges are made of 304 stainless steel. The furnace body is divided into two parts, one third of which is the furnace cover, which can be opened manually and completely, and two thirds of which is the fixed furnace body, which is unique in design and easy to operate.
The vacuum system of hot press furnace is composed of oil diffusion pump, roots pump, mechanical pump distribution magnetic differential pressure valve (to prevent sudden power failure and mechanical pump oil backflow), inflation valve, vent valve, vacuum butterfly valve, vacuum pressure gauge (± PA) bellows, vacuum pipeline and bracket, etc.
Pressure operation steps of hot pressing furnace:
① Put two graphite pillars at the bottom, then put the mold, and put one graphite pillar on the top;
② The pressure rises to the level of the graphite pillar and the insulation barrel;
③ Close the furnace cover;
④ First, vacuum and lock the three screws on the furnace cover;
⑤ Turn on the "hydraulic pump", select the oil cylinder to "rise" to the pressure block on the furnace cover to move up 3 ~ 4mm, and then the oil cylinder to "descend" to 0mm;
⑥ Manually turn the upper pressure head on the furnace cover down, counter the furnace cover, lock it, and turn the round one up to protect it;
⑦ For cold pressure, select the cylinder to "rise" until the displacement and pressure are constant;
⑧ Select "stop" of oil cylinder, select "potentiometer" to switch to "instrument", and "heating" is allowed only when the pressure gauge is consistent up and down;
⑨ Set up the temperature rise curve and raise the temperature. When the temperature reaches 200 ℃, the oil cylinder can be selected to "rise" and pressurize;
⑩ After heating, when the furnace temperature drops below 1000 ℃, the oil cylinder "stops" and "instrument" switches to "potentiometer".
Charging operation steps of hot pressing furnace:
1) Whether the furnace is heated or not, it can be inflated;
2) For the first time, the boiler needs to be washed three times. When washing the boiler, first close the "upper butterfly valve", close the "main baffle valve", close the "diffusion pump", and open the "inflation";
3) When the inflation pressure is -0.06mpa, close "inflation" and open "upper butterfly valve" to exhaust to the pressure
4) Open "inflation" again, so 3 times, the fourth time "inflation" to + 0.01Mpa, close "inflation", argon (nitrogen) bottle can be closed;
5) 1 hour later, close the "lower butterfly valve" and "mechanical pump";
6) When the temperature drops below 1000 ℃, open "mechanical pump", open "upper butterfly valve", open "lower butterfly valve", and vacuum to less than 20Pa.