During decarburization processes the vacuum system 
needs to operate long time in a rough pressure range. A competent gas-cooling is essential as the extracted incredibly hot gases would or else overheat the filter and vacuum program.
With the development of technology and the improvement of product quality in aerospace, energy, iron and steel digesting, pharmaceutical and chemical industries, these industries have to obtain a certain vacuum environment. At the same time, the vacuum system Gas-Cooling Roots Pump utilized by these industries is continuously increasing, and the vacuum degree is continuously increasing. Moreover, the state’s environmental safety, energy conservation and three wastes discharge to the above-mentioned industries, etc. Certain requirements are more stringent. At present, the existing dry vacuum pumps available, such as for example screw vacuum pumps and claw vacuum pumps, are unable to meet the requirements of oil-free large pumping rate clean vacuum environment proposed by these industries because of the restrictions of pumping swiftness characteristics and structural mechanism.
In view of the shortcomings of the existing technology, the technical problem to be solved by the utility model is to provide an all-gas-cooled vacuum system to satisfy the utilization in a clean vacuum environment with huge oil-free pumping speed.