During decarburization procedures the vacuum system needs to operate very long time in a tough pressure range. A competent gas-cooling is essential as the extracted incredibly hot gases would otherwise overheat the filter and vacuum program.
With the development of technology and the improvement of item quality in aerospace, energy, iron and steel digesting, pharmaceutical and chemical industries, these industries have to obtain a particular vacuum environment. Simultaneously, the vacuum system used by these industries is definitely continuously raising, and the vacuum level is continuously increasing. Furthermore, the state’s environmental protection, energy saving and three wastes discharge to the above-pointed out industries, etc. The requirements are more stringent. At present, the existing dry vacuum pumps available, such as screw vacuum pumps and claw vacuum pumps, cannot meet up with the requirements of oil-totally free large pumping velocity clean vacuum environment Gas-Cooling Roots Pump proposed by these industries due to the restrictions of pumping rate characteristics and structural mechanism.
Because of the shortcomings of 
the prevailing technology, the specialized problem to be solved by the utility model is to supply an all-gas-cooled vacuum system to satisfy the use in a clean vacuum environment with huge oil-free pumping speed.