During decarburization procedures the vacuum system must operate very long time in a rough pressure range. A competent gas-cooling is necessary as the extracted popular gases would or else 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 need to obtain a specific vacuum environment. Simultaneously, the vacuum system utilized by these industries is continuously increasing, and the vacuum degree is continuously increasing. Furthermore, the state’s environmental safety, energy saving and three wastes discharge to the above-described industries, etc. Certain requirements are more stringent. At the moment, the prevailing dry vacuum pumps in the marketplace, such as screw vacuum pumps and claw vacuum pumps, cannot meet up with the requirements of oil-totally free large pumping Gas-Cooling Roots Pump china velocity clean vacuum environment proposed by these industries because of the restrictions of pumping quickness characteristics and structural mechanism.
Because of the shortcomings of the prevailing technology, the technical 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.