In recent years, EVP vacuum pump manufacturers provide reliable vacuum pumps and rotary vane vacuum pumps for pulp bleaching for the paper industry. Through product upgrading, we will continue to provide more innovative solutions, further improve reliability, and improve customers’ energy saving and profitability. The application of vacuum pump in pulp bleaching has proved that it can help the pulp and paper industry to produce high quality paper at lower cost. As for why rotary vane vacuum pump is selected, the following contents will be mentioned.
Principle of ozonation technology:
The main components of odor waste gas are ammonia, hydrogen sulfide, mercaptan, thioether, phenol, amine, amide, indole, alkane, alkene, alkyne, aromatic hydrocarbon, alcohol, aldehyde, ketone, organic acids (VOC) and inorganic substances, of which the amount of ammonia is the largest, followed by hydrogen sulfide (the largest contribution rate of hydrogen sulfide to odor), which are the key parts in the design. The absorption characteristics of acid absorption, alkali absorption and neutral absorption are studied comprehensively. According to the above characteristics of waste gas compounds, the chemical absorption method of ozone oxidation technology is used as the pretreatment process of waste gas treatment. Ozone is a strong neutral chemical absorption oxidant, and it has no secondary pollution, and after oxidation reduction to oxygen (O2) and water (H2O) decomposition gas, it has low volatility and cracking Odor gas makes the free pollutant molecules combine with ozone oxidation to form small harmless or low harmful compounds, such as CO2, H2O, etc.
The use of ozone as an oxidant to bleach paper pulp has developed into an environmentally friendly alternative to the traditional use of chlorine. Ozone is ideal for this process because it is an unstable gas that quickly changes to oxygen after bleaching, leaving a clean pulp free of harmful chemicals. It also reduces air and water pollution.
In this application, our rotary vane vacuum pump is used to compress ozone gas to mix it with pulp. The vacuum pump has the characteristics of isothermal compression, which will not lead to the thermal degradation of temperature sensitive ozone gas.
Rotary vane vacuum pump is one of the main pumps to obtain low and medium vacuum pumps. It can be divided into oil seal pump and dry pump. According to the required vacuum degree, single-stage pump and double-stage pump can be used, among which the application of double-stage pump is more common.
Rotary vane vacuum pump performance characteristics :
(1) the rotary vane vacuum pump can have a large pumping speed in a wide pressure range.
(2) the rotor geometry symmetry of the rotary vane vacuum pump is good, and the operation of the pump is relatively stable in the working process.
(3) in the structural design of the rotary vane vacuum pump, there is a gap between the rotors and between the rotors and the shell, so the wear is small; at the same time, the driving power is reduced to achieve high-speed operation.
(4) there is no need for oil sealing and lubrication in the cavity of the rotary vane vacuum pump, which can reduce the pollution of oil vapor to the vacuum system.
The specific application of rotary vane vacuum pump in pulp bleaching has the advantages of short technological process, stable operation and low cost, the compressed ozone gas can reach the required pressure and concentration, and the equipment is simple, stable operation and not easy to fail. The ozone gas with high concentration and pressure can be used in environmental engineering, circuit cleaning, fabric bleaching, medical and other industrial fields.