As we all know, liquid ring vacuum pump and water ring compressor are widely used in all walks of life because of their simple structure and convenient maintenance. Especially with the characteristics of isothermal compression, it is easy to suck and compress flammable and explosive gases. In a more harsh environment, the liquid ring vacuum pump is uniquely designed to save space and easy to install.
Vacuum distillation, concentration, dehydration, drying in many chemical and pharmaceutical industries and tail gas extraction in power plants require large suction capacity between 3-8 kPa of suction pressure. The suction capacity of single-stage liquid-ring vacuum pump in this section is quite weak, while that of two-stage liquid-ring vacuum pump and two-stage liquid-ring with one-stage atmospheric ejector is true. The characteristic of the air pump is that it has a large suction capacity in this area.
Before 2000, the demand for two-stage liquid ring vacuum pump was mostly less than 1553/min, but now it is up to 40-50m3/min. In addition, it should be pointed out that when a single stage liquid ring vacuum pump is equipped with a first stage atmospheric ejector, if the design of the liquid ring vacuum pump is reasonable, there is still a large amount of air pumping when the suction pressure is 4-5 kPa, which greatly enlarges the application scope of the single stage liquid ring vacuum pump.
The liquid ring vacuum pump and water ring compressor are widely used in various industries as the basic equipment for obtaining rough and low vacuum. It can also be said that the rapid development of various industries in the national economy has promoted the development and production of liquid ring vacuum pump and water ring compressor. Therefore, in order to make it better adapt to the development of various industries.
2BE1 Series Liquid Ring Vacuum Pump
1. Feasibility design and high performance seals for liquid ring vacuum pumps can improve the average trouble-free operation period of the whole machine.
The working reliability of liquid-ring vacuum pump and water-ring compressor, i.e. the average fault-free operation period, should be said to be higher than other equipment for obtaining rough and low vacuum. The average fault-free operation period can reach more than 10,000 hours. However, with the enhancement of technological progress in various industries and the improvement of reliability requirements for the whole vacuum system, the reliability requirements for the vacuum system are correspondingly higher. Especially in the chemical industry and coal mine gas extraction under such strict safety requirements, the pump should continue to operate for a long time, the international advanced level can reach tens of thousands of hours or more. Therefore, the design and development of liquid ring vacuum pump and water ring compressor, the limitation of manufacturing conditions and the quality status of seals (especially mechanical seals), in order to truly improve the reliability of the whole machine, we need to further strengthen the above aspects of work.
2. Optimum design method is adopted to improve pump efficiency and reduce energy consumption.
Liquid-ring vacuum pump and water-ring compressor are products with high energy consumption and low efficiency, which is a recognized fact. Small-scale liquid-ring vacuum pump is generally 30-35%, and large-scale liquid-ring vacuum pump is 40% or slightly higher. Such low efficiency is very incompatible with the national requirements for mechanical and electrical products and the current situation of energy shortage in China. Therefore, the optimal design method should be adopted as soon as possible to establish mathematical models for the geometric parameters of impellers and the starting position and area of suction and exhaust holes, which are key factors affecting the efficiency of pumps. Optimal design should be carried out to select the best combination scheme of parameters, and the relevant theories and calculation formulas of vapor-liquid two-phase flow should be adopted to design the impellers so as to minimize the number of The eddy current loss of water ring can improve the efficiency. So it is an important task for the design and development of liquid ring vacuum pump and compressor with high efficiency and energy saving to eliminate the backward products with high energy consumption and low efficiency.
3. Increase the gas volume at the operating point with an air ejector
In foreign countries, whether single-stage liquid-ring vacuum pump or two-stage liquid-ring vacuum pump equipped with air ejector to improve the pumping capacity at lower suction pressure is still more. From the technical data of foreign advanced enterprises, it can be seen that when a single-stage liquid-ring vacuum pump is equipped with a primary air ejector, the suction pressure is 5 kPa, and the suction rate can reach 65-70% of the suction pressure of 400 hPa (common point of the single-stage liquid-ring vacuum pump commonly used by users), when the suction pressure is 5 kPa. When a liquid ring vacuum pump is equipped with a primary air ejector, the suction rate at the suction pressure of 1.5 kPa point can reach 70-75% of the suction pressure at 8 kPa point when the pump is not equipped with an atmospheric ejector, which greatly enlarges the application scope of the liquid ring vacuum pump, i.e. meets the requirements of chemical industry and pharmaceuticals. In light industry, instrument, metallurgy, power generation and other industries, the process conditions of high extraction rate at the point of 1.5-5 kPa of suction pressure are required.
At present, the application of liquid ring vacuum pump with air ejector is not wide enough in China, and the pumping rate at 1.5-5kPa is relatively low, which has a certain gap with the technology level of foreign advanced manufacturers. For further popularization and application, it is necessary to study and improve the design of atmospheric ejector and the optimum ratio of liquid-ring vacuum pump. Because the flow of air in the nozzle and diffuser of atmospheric ejector is supersonic flow, and the momentum exchange in the mixing process of atmospheric and pumped gas is complex, it can not be completely depended on. In order to design the theoretical calculation method, many experiments must be carried out, but from the point of view of enlarging the application of liquid ring vacuum pump and improving its efficiency, the experimental study should be strengthened to improve its pumping efficiency.