How to choose a good Roots vacuum pump? What should we pay attention to? But the choice of Roots vacuum pump to choose pressure, otherwise it will not work for the enterprise, the following for you to share knowledge about Roots vacuum pump.
The selection of pumping speed ratio between Roots vacuum pump and front pump is very important. Because the compression ratio of the pineapple pump is very limited. This compression ratio determines the capacity of the front pump, because the compression ratio is the inverse ratio of the pumping speed. Generally, the compression ratio is chosen in the range of 2 to 10. In addition, consideration should be given to the requirement of pre-sampling time. Vacuum equipment is used as auxiliary equipment in various mechanical equipment. If the normal working time is much longer than pre-pumping time, a smaller front pump can be selected (compression ratio can be larger), and if the vacuum suffocation is larger, and the requirement of rapid pre-pumping, a larger front pump will be used. Sometimes in order to better play the efficiency of the equipment, the unit is equipped with a larger pre-pumping pump in front, which is stopped after normal operation, and maintained with a smaller pre-pumping, so as to save power.
The limit pressure requirement of Roots vacuum pump unit must also be considered when choosing the front stage pump. For the high limit vacuum (1 *10-3 Pa~1 *10-2 Pa pressure), two-stage rotary vane oil seal mechanical pump or two-stage sliding mechanical pump are generally used as the front stage pump. The limit vacuum degree requires that a single-stage oil seal mechanical pump be selected as the front-stage pump between (1*10-2Pa~1*10-1Pa) and a reciprocating vacuum pump or a liquid ring vacuum pump be selected as the front-stage pump between 133 and 1333 PA.
When the reciprocating or liquid ring rough vacuum pump is selected as the front pump of Roots vacuum pump, the speed of the front pump is generally 1/2-1/4 of that of Roots vacuum pump, which can not be too large, otherwise the compression ratio will be too large, resulting in high exhaust temperature of Roots vacuum pump and can not work normally. When choosing the front-stage pump, it is also necessary to consider whether there is corrosive medium in the pumped gas and whether it contains condensable gas, whether it is large or small. If there are corrosive gases, oil-seal mechanical pumps can not be selected. Oil-seal mechanical pumps are not suitable for extracting gases containing a large amount of condensable steam. Otherwise, the sealing fluid will be quickly emulsified. When extracting gases containing a small amount of condensable steam, oil-seal mechanical pumps with gas-ballast devices must also be used as the front-stage pumps.
In order to obtain high pumping rate at low inlet pressure (1-100pa), a Roots vacuum pump can be used as the first stage pump of another Roots vacuum pump to form a three-stage or four-stage unit. At this time, the pumping speed ratio of Roots vacuum pump is generally between 2 and 5.
Matters needing attention in selecting roots vacuum pump：
Roots vacuum pump is a common industrial equipment in industrial production, and the types, models and specifications are various, the difficulty of the work can be different, in order to select the right products, the company also has to prepare courses in advance, grasp the necessary selection methods.
1. Willing to select suitable Roots Vacuum Pump for their company’s application, the first thing you have to know is the office environment of Roots Vacuum Pump of your company. To understand that this commodity is necessary for the office environment.
2. Provide as much as possible in high-efficiency residential areas, that is to say, operating in areas with critical vacuum or working pressure of exhaust pipes.
3. It should be prevented from operating around large vacuum value or working pressure of large exhaust pipe. The operation in this area is not only very efficient, but also very unstable and easy to cause vibration and noise.
4. If it is only used as Roots vacuum pump, it is better to use single-effect Roots vacuum pump. Because of the simple structure of single-effect pump, it is very easy to manufacture and maintain, and has strong cavitation resistance under the condition of high vacuum pump.
5. If it is used only for refrigeration compressors with large air supply, it is more suitable to use dual-effect pumps. Because of its large air supply, light weight and light weight, the dual-effect Roots vacuum pump can achieve full-automatic balance of axial force, the shaft is not easy to cause fatigue rupture, and the service life of the pump is longer.
Before purchasing Roots vacuum pump, we should first establish its own application natural environment, its specific requirements, cost, and then select the appropriate model specifications for all aspects of the comprehensive elements, and effectively apply machinery and equipment in accordance with the provisions, so as to maintain a large interest.