The selection of vacuum pump is mainly based on the pumping rate and the limit vacuum degree. It is not difficult to know that the limit vacuum degree is determined by the production process conditions. However, when selecting the vacuum pump, there is often a lack of data on its pumping capacity, which makes it helpless. Next, EVP vacuum pump manufacturers will introduce some calculation methods of vacuum pump size for reference.
The pumping capacity of the vacuum pump shall include: the non condensable gas discharged from the production process, the dissolved air released from the cooling water, the equivalent level of the saturated vapor pressure of the fluid in the process, and the air leaked from the place where the equipment and pipeline are not tightly connected. However, due to the small amount of non condensable gas released in the process, it can be ignored, so the key components are the last two.
The amount of air leaking from the vacuum system can be determined by any of the following four methods:
1. According to the total volume of vacuum system equipment and pipeline;
2. Equipment and pipe accessories assembled according to vacuum system;
Although this method is conservative, the results obtained can be adapted to the situation of large fluctuation of air leakage and is suitable for operation.
3. It can also be calculated according to the joint length of vacuum equipment, pipeline and other accessories gasket, and the air leakage per meter is 0.05 ~ 0.07 [kg / h], and then it can be doubled.
If the system is equipped with dynamic sealing parts, appropriate value shall be added.
water ring vacuum pump application and scope:
The water ring vacuum pump is a single-stage pump with integral structure and pump coaxial. The shaft seal adopts mechanical seal, which has the characteristics of simple structure, simple installation, oil-free, safe and reliable.
The water ring vacuum pump is suitable for pumping out gas and wet steam. The suction pressure can reach 33mbar absolute pressure (97% vacuum degree). When the vacuum pump works for a long time when the suction pressure is lower than 80mbar, the cavitation protection pipe should be connected to protect the pump. If the suction pressure of the air ejector can reach 10mbar, the ejector can be directly installed on the suction port of the vacuum pump. When it is used as a compressor, it The maximum pressure is 0.26mpa (absolute pressure).
Water ring vacuum pump is widely used in petroleum, chemical, pharmaceutical, food, sugar industry and other fields. Because the gas compression process is isothermal in the working process, it is not easy to explode when compressing and pumping flammable and explosive gas, so it is more widely used.
water ring vacuum pump equipment installation :
1. Pump installation
During the installation of vacuum pump and compressor, the installation surface must be horizontal and firmly installed with bolts through the holes at the bottom corner. In order to prevent welding slag from entering the vacuum pump during installation, a filter screen shall be installed on the suction pipe during installation.
2. Installation of gas water separator
The gas water separator can be directly installed on the exhaust port of the vacuum pump and fixed firmly with bolts. The gas-water separator has a pipeline connected with the pump to supply the working water demand of the pump, and the rest of the working water is supplied by the water supply pipe, and the size of the water supply is regulated by the valve on the pipeline.
Check valve shall be installed on the intake pipe of the vacuum pump or compressor to prevent the water in the vacuum pump or compressor from returning to the system under the pressure of the exhaust pipe when stopping.