Working principle The vacuum in dry screw pumps is created through two parallel-arranged screw rotors that rotate in opposite directions. These rotors trap the gas coming in through the inlet and deliver it to the gas discharge or pressure side. As the gas is getting compressed, there is no contact between the rotors. This does away with any need for the compression chamber to have any operating fluids or lubrication. The lubricant used to lubricate the gears and shaft seal is sealed in the gearbox by the shaft seal. The pump can be cooled either directly by circulating cooling water or by a cooling unit with fan and radiator. The dry screw vacuum pump adopts a special rotor pitch design, compared with the ordinary rotor pitch design, reduce the energy consumption by about 30%, the temperature rise of the exhaust end is reduced by about 100 ºC, the reliability and stability of the operation of the product is greatly improved, can be suitable for any working conditions of vacuum. The dry screw pumps can be widely used in solvent recovery, vacuum drying, concentration, crystallization, distillation and other processes in the chemical and pharmaceutical industries, vacuum extrusion and molding in the plastic and rubber industries, vacuum degassing in the metallurgical industry; vacuum degassing and drying in the solar energy, microelectronics, lithium battery and other industries. Pump body and end caps: high-strength cast iron. Pump body and end caps: high strength cast iron. Screw rotor: ductile cast iron. Anti-corrosion coating: corrosion-resistant Hastelloy. Synchronous gears: alloy steel. Radial lip seal: imported PTFE mixture or high-temperature resistant fluorine rubber; Seal bushings: stainless steel surface covered with ceramic. Flow chart Main features 1. The screw rotor is designed with variable pitch structure, the ultimate vacuum can reach below 1Pa, which can meet all kinds of vacuum processing from atmosphere to high vacuum. 2. Oil free - Adapt to various special working conditions for reliable use. 3. It can operate reliably in the pressure range from atmosphere to several Pa. 4. No friction between moving parts, simple structure, lower operation and maintenance cost. 5. Nitrogen seal and composite seal design is optional, which has the benefit of good reliability, low cost of use, simple maintenance. 6. The rotor is dynamically balanced at high speed and the motor is connected by flange, with high concentricity, low vibration and low noise. 7. Hastelloy anti-corrosion coating is optional for rotor surface, condensable material is not easy to condense in the pump cavity, better corrosion resistance. 8. Compared with oil seal pump, liquid ring pump, there is no waste gas, no waste liquid, no waste oil emission, energy saving and environmental friendly. It can be used alone or with Roots vacuum pump, air-cooled Roots vacuum pump, molecular vacuum pump, etc. to obtain an oil-free high vacuum system. The benefit of dry screw vacuum pump compared to liquid ring vacuum pump: -Shorten the process cycle and improve production efficiency -Reduce water consumption -Save energy -Improve product quality -Can recover solvent by reducing the drying time of products -Reduce the cost of wastewater and waste gas treatment A CASE in a pharmaceutical factory Process introduction:The penicillin sodium salt solution is fed into the crystallization tank through vacuum. By steam heating, agitator stirring, and adding butanol, the water and butanol in the penicillin solution are pumped into the condenser and condensed into the liquid collecting tank,