Working principle of dry screw vacuum pump

The dry screw vacuum pump utilizes a pair of screw rotors with opposite rotational directions to rotate synchronously and at high speed within the pump housing, generating suction and exhaust functions. This series of screw vacuum pumps can be applied to various vacuum processing techniques in various industrial fields, such as drying and concentration processes in the chemical and pharmaceutical sectors. The maintenance-free design technology adopted solves the problems of troublesome maintenance and high costs for vacuum pumps. There is no need for lubricating oil and sealing fluid in the working chamber of the vacuum pump, and various condensable gases can be recovered, eliminating the potential pollution problems caused by steam jet pumps, slide valve pumps, rotary vane pumps, and liquid ring pumps to the vacuum system and the environment. At the same time, the recovered substances can also create additional economic benefits.

　　

① Intake port ② Exhaust port ③ Cooling water chamber ④ Screw ⑤ Fuel tank ⑥ Gas passage ⑦ Synchronous gear

⑧ Bearing ⑨ Mechanical Seal ⑩ Frame Oil Seal

Features of the constant pitch screw vacuum pump

1. Special rotor profile, capable of continuous operation from atmospheric pressure to the maximum pressure.

2. Low rotational speed, long service life, low noise, stable performance;

3. Special nano-coating effectively resists corrosion from gases and liquids;

4. Compared with variable pitch, the extracted medium does not tend to condense and can be easily discharged of impurities.

The dry screw vacuum pump operates at low speed (3600 min-1/60Hz, 3000 min-1/50Hz). It has the following advantages: ① prolongs the service life of bearings, shaft seals and synchronous gears; ② reduces noise; ③ reduces vibration and achieves stable performance.

The dry screw main unit can smoothly discharge all reaction by-products such as condensate, powder, and dust, without any remaining in the pump body. Compared with variable pitch, the constant pitch oil-free screw vacuum pump is less prone to condensation when extracting the medium, and can easily discharge particulate impurities.

There are few components and the structure is very simple, making disassembly and assembly very convenient.

The contact parts with the gas to be pumped in the dry screw vacuum pump are coated with a special nano-layer, which has excellent corrosion resistance, including various strong acid media such as hydrochloric acid.

According to different corrosion resistance requirements, for special industries, Kohleri can customize special material shells to adapt to the production environment to the greatest extent.

The dry screw vacuum pump adopts a multi-stage lip-type sealing design, which reduces the probability of failure of the sealing components and effectively prevents leakage. At the same time, it is protected by nitrogen pressure to prevent the erosion of the sealing components by the gas being pumped, thereby extending the service life of the seals.

The rotor and shaft of the dry screw vacuum pump main unit are manufactured as a single piece through molding, and then undergo grinding processing. The manufacturing process is complex, but the rotor has a long service life and high strength.

The precise control of the gap between teeth ensures minimal leakage of the vacuum pump and high pumping efficiency.

Characteristics of Variable Pitch Screw Vacuum Pump

1.Compared with the constant pitch screw pump, it has higher pumping efficiency and lower energy consumption.

2. The suction speed range is wide. It can be directly discharged into the atmosphere. With a single pump, it can achieve the effect of multiple stages in series. A single-stage design can achieve a vacuum of 5 Pa.

3. Nitrogen purging can be adopted. The cleaning and maintenance procedures are simple and the maintenance is convenient.

4. The screw is made of integral ductile iron, which has high strength and stable performance.

5. The screws do not come into contact with each other, there is no friction, no lubricating oil is required, no oil contamination flows back, no waste gas or waste fluid is discharged, it is clean, environmentally friendly, and has low energy consumption.

6. The interior of the pump chamber and its components can be treated for surface anti-corrosion as needed, meeting the special requirements of the chemical and pharmaceutical industries.

7. The screw has undergone precise dynamic balance adjustment, ensuring smooth operation with low noise and minimal vibration, and a long service life.