Roots vacuum pump selection guide: manufacturer provides suggestions
Roots vacuum pump, as an important industrial equipment, plays a crucial role in various fields such as chemical engineering, metallurgy, electronics, and medicine. When selecting, the manufacturer of Roots vacuum pumps usually provides the following guidelines to ensure that the selected equipment can meet production needs and has good performance:
1、 Understand the basic characteristics of Roots vacuum pumps
The characteristic of Roots vacuum pump is that it has a higher pumping rate at lower inlet pressure (i.e. higher vacuum degree). But it cannot be used alone, and a front-end vacuum pump must be connected in series with its exhaust port for pre pumping. The Roots vacuum pump can only start working when the pressure in the pumped system is pumped to the starting inlet pressure allowed by the Roots vacuum pump by the front-end vacuum pump. In addition, Roots vacuum pumps can experience overload and overheating when operating under high pressure differentials, so it is necessary to select a reasonable front-end vacuum pump and install necessary protective equipment.
2、 Key factors for determining selection
1. The physical and chemical properties of the extracted gas, including its composition, corrosiveness, condensability, etc., will affect the selection of the front-end vacuum pump and whether additional devices such as filters and heat exchangers need to be installed.
2. Requirement for vacuum degree of the system under no-load conditions: Determine the type of main pump based on the vacuum required to be established in the vacuum chamber, and select the vacuum of the main pump to be higher than that of the vacuum chamber, usually by half to one order of magnitude.
3. The required working pressure in the process: It is required to be able to grasp the pressure range of the pumping speed of the main pump. The working pressure of various vacuum pumps can refer to the pump or unit performance curve of the manufacturer. The working pressure of the vacuum chamber should be ensured to be within the pumping speed pressure range of the main pump.
4. Working temperature: The working temperature range of Roots vacuum pumps is also one of the factors to consider when selecting.
5. The volume being pumped and the load of the process: This will affect the selection of the type and size of the main pump.
3、 Select the front-end vacuum pump
The front stage vacuum pump of Roots vacuum pump is generally an oil sealed mechanical pump or a liquid ring vacuum pump. If there is a large amount of water vapor and a large amount of condensable or corrosive gases in the extracted gas, the front stage pump should generally be an oil sealed mechanical pump, which is an economical configuration. However, in many industrial applications, when it is necessary to remove gases containing a large amount of water vapor and condensable or corrosive substances, it is ideal to use a liquid ring vacuum pump or a dry vacuum pump as the front-end pump, which can make the performance of the unit relatively stable. Due to the high price of dry pumps, the commonly used front-end vacuum pump in such situations is still a liquid ring vacuum pump.
4、 Consider other additional devices
According to the process conditions, additional devices such as filters and heat exchangers may need to be installed at the inlet or outlet of the Roots vacuum pump to meet the needs of the process.
5、 Refer to the manufacturer's recommendations
When choosing a Roots vacuum pump, in addition to considering the above factors, one should also refer to the manufacturer's recommendations. Manufacturers usually provide suitable selection plans and suggestions based on customers' actual needs and usage conditions.
In summary, the selection of Roots vacuum pumps is a process that comprehensively considers multiple factors. By understanding the basic characteristics of Roots vacuum pumps, determining the key factors for selection, choosing a suitable front-end vacuum pump, considering other additional devices, and referring to the manufacturer's recommendations, it can be ensured that the selected equipment can meet production needs and has good performance.
