During decarburization processes the vacuum system needs to operate very long time in a rough pressure range. An efficient gas-cooling is necessary as the extracted warm gases would otherwise 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. At the same time, the vacuum system used by these industries is usually continuously increasing, and the vacuum degree is continuously increasing. Furthermore, the state’s environmental protection, energy saving and three wastes discharge to the above-mentioned industries, etc. The requirements are more stringent. At the moment, the prevailing dry vacuum pumps available, such as screw vacuum pumps and claw vacuum pumps, cannot meet the requirements of oil-totally free large Gas-Cooling Roots Pump china pumping velocity clean vacuum environment proposed by these industries because of the restrictions of pumping velocity 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 supply an all-gas-cooled vacuum system to fulfill the utilization in a clean vacuum environment with huge oil-free pumping 
speed.