Because of the rapid development of vacuum application, the liquid ring vacuum pump has always been paid attention to in rough vacuum acquisition. Because the gas in the liquid ring vacuum pump is isothermal, it can extract flammable and explosive gas, in addition, it can also extract dust. Therefore, the use of liquid ring vacuum pump is increasing. Liquid ring vacuum pump is widely used in canning machinery. How is liquid ring vacuum pump used in canning machinery? There may be many people who have this question. Let’s have a look at it today.
Vacuum pumping system is composed of vacuum pump, pressure regulator, dust collector and valve connecting pipeline. The selection of vacuum degree and pumping volume of liquid ring vacuum pump is the key to the success of V-shaped model. In production, the highest vacuum is about – 66500Pa (- 500mmHg). Pressurized tank is a sealed container. Its main function is to stabilize the pressure of vacuum system, cushion the effect of system pressure on the shape, and also play the role of filtering dust. Dust removal tank; long-term reuse of sand box and pouring of hot metal can easily cause damage to the filter screen of sand box. Sand is sucked into the vacuum pump and causes wear and tear. It is better to increase the dust collector when entering the vacuum pump, link the dust removal tank and finally enter the vacuum pump to ensure the service life of the vacuum pump.
When choosing the vacuum pumping system, the capacity of the vacuum pump should be determined firstly. The following factors should be considered mainly:
1. The size and number of sand boxes that need to work in vacuum at the same time;
2. Number of concurrent casting moulds;
3. Size and shape of pouring;
4. The permeability of the mold surface close to the film controls the amount of air entering the mold through the cracks in the plastic film. Therefore, the casting coating helps to provide an “auxiliary sealing layer” during casting.
V-process casting and EPC process:
V-casting and EPC, also known as negative pressure casting, are named after the word “V” in English. It is different from the traditional sand casting without adhesives. V-method casting uses plastic film to seal sand box, draws out air in the mould by vacuum pumping system, makes dry sand dense inside and outside the mould, forms a required cavity, solidifies the castings through core, box and pouring vacuum, relieves negative pressure, and then the sand collapses to obtain the castings.
Compared with traditional sand casting, V method casting and lost foam casting have the following advantages: firstly, negative pressure casting has fewer sand holes, high product density, smooth surface, clear outline and accurate size. Second, energy-saving, efficient and clean production. The use of V method and EPC technology can make dry sand reusable without drying, reduce coal consumption and electricity consumption, save labor force more effectively and reduce labor intensity greatly, reduce harmful gases in the pouring process, and truly realize environmental protection production.
V-process casting process:
1. Manufacture profiles with suction chambers and suction holes.
2. The plastic film baked in plastic state is covered in the mold plate, and the heating temperature is generally between 80 ~120 ~C. The vacuum pump pumps air to make the film close to the mold plate to form.
3. Place the sand box with the filter suction pipe on the template covered with plastic film.
4. Fill the sand box with dry quartz sand of 100-200 mesh in size without binder and additives. Make the sand compact by micro-shock, scrape it flat, put the sealing film on, open the valve and take out the air in the sand to make the casting.
2SK Liquid Ring Vacuum Pump
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