Common knowledge on selecting water ring vacuum pumps

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Basic knowledge for selecting water ring vacuum pumps I. Determination of the vacuum pump type The type of vacuum pump is primarily determined by the volume of air required for operation, the level of vacuum needed, or the exhaust pressure. When a vacuum pump is in operation, the following two aspects need to be taken into account: 1. It is advisable to operate it within the high-efficiency range, that is, in the area corresponding to the critical vacuum level or critical exhaust pressure. 2. Operation near the maximum vacuum level or maximum exhaust pressure should be avoided. Operating in this area not only results in extremely low efficiency, but also leads to unstable operation, with frequent vibrations and noise. For vacuum pumps with a high degree of vacuum that operate in this range, cavitation often occurs as well; obvious signs of this phenomenon are noise and vibration inside the pump. Cavitation can cause damage to components such as the pump body and impeller, resulting in the pump failing to operate. Based on the above principles, when the vacuum level or gas pressure required by the vacuum pump is not high, a single-stage pump should be preferred. If the vacuum level or exhaust pressure is high, a single-stage pump often fails to meet the requirements. Alternatively, if it is necessary for the pump to handle a large volume of gas even at high vacuum levels, that is, if a relatively flat performance curve at high vacuum levels is required, a two-stage pump can be used. If a vacuum level of above –710 mmHg is required, a water ring-atmospheric pump or a water ring-Rotary vane vacuum unit can be used as the vacuum pumping device. If it is to be used only as a vacuum pump, a single-acting pump is a better choice. This is because single-acting pumps have a simple structure, are easy to manufacture and maintain, and exhibit good cavitation resistance in high-vacuum conditions. If it is to be used only as a compressor with a large capacity, a double-acting pump is more suitable. Because double-acting pumps have a large air volume, small size, and light weight, the radial forces can be automatically balanced, the shaft is less prone to fatigue fracture, and thus the pump has a longer service life. II. Selecting the vacuum pump based on the air volume required by the system: After initially determining the type of pump, it is also necessary to choose the specific model of the vacuum pump according to the amount of air required by the system. For the selection of the pumping speed and the calculation of the pumping time for vacuum pumps, refer to: Vacuum calculation formulas. Facing various types of water ring vacuum pumps and compressors, we have compiled their respective features below to assist users in making selection choices.

Vacuum Pump Catalogue
Name | Model | Pumping Speed (L/s) | Ultimate Vacuum (Pa) | Power Consumption (kW)
Rotary vane vacuum pump | 2X(Z) type rotary vane vacuum pump | 0.5–70 | 6×10⁻² | 0.55–5.5
XD, X single-stage rotary vane vacuum pump | 2.8–150 | 2×10⁻² | 0.37–15
X type single-stage rotary vane vacuum pump | 30–150 | 6 | 4–11

Reciprocating vacuum pump | W type reciprocating vacuum pump | 32–300 | 2000 | 4–30 | 55–600 | 5.5–45

Roots vacuum pump | ZJ type roots vacuum pump | 30–5000 | 5×10⁻² | 0.75–55 | 70–3000 | 1.1–30

Sliding vane vacuum pump | H type sliding vane vacuum pump | 8–600 | 1 | 1.1–55 | 70–600 | 7.5–55
2H type sliding vane vacuum pump | 8–150 | 0.1 | 4–15

Water ring vacuum pump | 2BE1, CBF water ring vacuum pump | 2–450 m³/min | 3.3×10³ | 7.5–710
2BE1 type two-stage water ring vacuum pump | 5–320 m³/min | 11–380
2BV type water ring vacuum pump | 0.3–8.3 m³/min | 0.81–15
2SK type two-stage water ring vacuum pump | 0.4–30 m³/min | 3.5×10³ | 2.2–55
S, SK type water ring vacuum pump | 0.67–25 m³/min | (3.5–4)×10³ | 1.5–55
SK type water ring vacuum pump | 0.4–120 m³/min | (8–15)×10³ | 1.1–185
SZ, SK type water ring vacuum pump | 1.5–27 m³/min | (5–14)×10³ | 5.5–75
SK, 2YK type water ring vacuum pump | 5–280 m³/min | 10⁴ | 22–380
FSK type water ring vacuum pump | 3–9 m³/min | (5–14)×10³ | 7.5–22
YL type water ring vacuum pump | 5–25 m³/min | 9×10⁴ | 30–132

Vacuum pump units | JZJ type roots and rotary vane vacuum pump unit | 30–1200 | (1–5)×10⁻² | 1.3–26
JZJ1 type roots and rotary vane vacuum pump unit | 70–1200 | (5–10)×10⁻² | 4.3–22.5
JZJS type roots and water ring vacuum pump unit | 70–600 | 25–650 | 7–39.5
JZJ1S type roots and water ring vacuum pump unit | 150–600 | 9.7–24.7
JZJH type roots and sliding vane vacuum pump unit | 300–1200 | 10⁻¹ | 11.5–26
2BW4 type water ring vacuum pump complete set | 10–95 m³/min | 10³ | 45–185