During decarburization processes the vacuum system must operate very long time in a tough pressure range. A competent gas-cooling is necessary as the extracted sizzling gases would or else overheat the filter and vacuum system.

With the development of technology and the improvement of item quality in aerospace, electric power, iron and steel digesting, pharmaceutical and chemical industries, these industries have to obtain a certain vacuum environment. Simultaneously, the vacuum system utilized by these industries is certainly continuously increasing, and the vacuum degree is continuously increasing. Furthermore, the state’s environmental protection, energy Gas-Cooling Roots Pump saving and three wastes discharge to the above-described industries, etc. The requirements are more stringent. At the moment, the existing dry vacuum pumps on the market, such as screw vacuum pumps and claw vacuum pumps, cannot meet up with the requirements of oil-free large pumping swiftness clean vacuum environment proposed by these industries due to the restrictions of pumping acceleration characteristics and structural mechanism.

In view 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 large oil-free pumping speed.