During decarburization procedures the vacuum system must operate very long time in a rough pressure range. An efficient gas-cooling is essential as the extracted hot gases would or else overheat the filter and vacuum system.
With the development of technology and the improvement of 
item quality in aerospace, energy, iron and steel processing, pharmaceutical and chemical industries, these industries have to obtain a specific vacuum environment. Simultaneously, the vacuum system used by these industries is continuously increasing, and the vacuum degree is continuously increasing. Moreover, the state’s environmental safety, energy saving and three wastes Gas-Cooling Roots Pump china discharge to the above-stated industries, etc. Certain requirements are more stringent. At the moment, the existing dry vacuum pumps in the marketplace, such as for example screw vacuum pumps and claw vacuum pumps, are unable to meet up with the requirements of oil-free large pumping acceleration clean vacuum environment proposed by these industries due to the restrictions of pumping velocity characteristics and structural system.
Because of the shortcomings of the prevailing technology, the technical problem to be solved by the utility model is to provide an all-gas-cooled vacuum system to satisfy the use in a clean vacuum environment with large oil-free pumping speed.
