Industrial electric furnace pump of application
In order to ensure the high vacuum in the vacuum furnace, in addition to the reliable gas tightness and vacuum pipeline of the vacuum furnace, it is also necessary to have appropriate vacuum equipment for use, so the selection of vacuum pump in the vacuum furnace becomes very important.
The requirement of vacuum pump is put forward according to the condition of reducing period. After the furnace is opened and closed, the air in the furnace must be extracted. Then, as the charge is cooked, the inhaled and combined oxygen (steam and carbon dioxide) is precipitated from the mass. When these oxygen bodies are precipitated at higher temperatures, even in small amounts, they can greatly increase the furnace pressure and destroy the vacuum process. In addition, carbon dioxide and water vapor can interact with silicon and precipitated magnesium vapor when they move into hotter areas. Therefore, rapid and adequate extraction of the precipitated gas must be ensured.
Therefore, the vacuum pump should complete the following tasks: first, it should ensure that the period starts to extract a large number of oxygen bodies under normal pressure, and second, it should maintain a considerable oxygen body extraction speed under low pressure during the whole operation period.
In order to realize the above tasks, the industrial electric furnace pump adopts the following types of pumps:
1. Mechanical rotary oil pump (oil vacuum pump);
2. Multi-pole oxygen pump;
3. Combined device of diffusion pump and mechanical pump.
Although the efficiency of rotary vane oil pump decreases with the decrease of pressure, it is still suitable for the extraction of gas in various pressure ranges.
Multistage air pump is best used in large furnace.
Mechanical pumps are not very suitable for sealing these furnaces, as large capacity pumps are required.
The disadvantage of the pumping system is that if the pump is interrupted due to nozzle blockage or steam supply interruption, the pressure may increase, and even steam may enter the pumping system.
The diffusion condensing pump guarantees a high vacuum. At the same time, they are suitable for low pressure operation. So the pump is connected to the distillation unit in conjunction with the rotary pump used as the front vacuum pump.
The operation practice of silicon thermal plant has proved that it is possible to adopt all kinds of vacuum pumps mentioned above. The choice of vacuum pump type depends on the construction of vacuum furnace.
Small volume distillation tank most of the more convenient and economic rotary oil vacuum pump.