SZB Series Liquid Ring Vacuum Pump Isothermal Compression & High Safety 2000

Product Specification

The SZB series liquid ring vacuum pump Isothermal Compression & High Safety

I. Introduction

The SZB series liquid ring vacuum pump is a type of rough vacuum pump capable of achieving an ultimate vacuum pressure of 2000~4000Pa. When coupled with an air ejector, this can be improved to 1~5kPa. Its operating principle involves an impeller eccentrically mounted inside a pump casing, which is pre-filled with a certain amount of water as the sealing liquid. As the impeller rotates, centrifugal force throws the water against the casing wall, forming a liquid ring concentric with the pump chamber. This liquid ring and the impeller vanes create crescent-shaped cavities of varying volume. The rotation of the impeller causes these cavities to expand, drawing gas in through the inlet port, and then compress, discharging the gas through the outlet port.

Using water as the operating fluid makes this pump exceptionally safe for handling flammable, explosive, and corrosive gases. It is renowned for its simple construction and ease of maintenance.

II. Advantages

1. Isothermal Compression & High Safety: The compression process is nearly isothermal with minimal temperature rise, making it ideal for pumping flammable and explosive gases without explosion risks.

2. Simple Construction & Easy Maintenance: The pump features a compact design with fewer components, making it easy to disassemble and maintain. It requires relatively lower technical skill for operation.

3. Corrosion Resistance: Key components in contact with the process gas can be manufactured from corrosion-resistant materials, suitable for handling certain corrosive gases.

4. Clean and Oil-Free Operation: Using water as the sealing liquid eliminates oil mist contamination, ensuring the discharged gas is clean. This is critical in industries like chemicals and pharmaceuticals.

5. Handles Wet Gases: Capable of pumping gas-liquid mixtures containing small amounts of liquid without the emulsification problems associated with oil-sealed pumps.

6. Smooth and Quiet Operation: The absence of internal metal-to-metal contact and the damping effect of the water ring contribute to low vibration and noise levels.

III. Key Technical Parameters (Typical for the Series)

• Model Example: SZB-4, SZB-8, SZB-15 (The number often indicates pump speed in L/s).

• Pumping Speed: Typically ranges from 1.5 to 30 liters per second (90 to 1800 L/min).

• Ultimate Vacuum:

  • Without air ejector: Up to -0.086 MPa (approx. 86% vacuum degree, or 14kPa abs. pressure).

  • With air ejector: Up to -0.093 MPa (approx. 93% vacuum degree, or 7kPa abs. pressure).

• Operating Water Flow: Approximately 10 ~ 40 L/min (a continuous supply of fresh water is required to maintain the ring and cooling).

• Motor Power: Typically ranges from 1.5 kW to 7.5 kW, depending on the model.

• Inlet Port Size: Typically DN25 ~ DN50.

• Material of Construction: Main components are usually cast iron, with stainless steel and other corrosion-resistant materials available.

IV. Application Fields
The SZB series liquid ring vacuum pumps are widely used in industrial applications requiring rough and medium vacuum:

• Priming Pumps: Used to evacuate air from water pumps and pipelines to prime them before startup.

• Vacuum Filtration: Providing vacuum source for drum filters, belt filters, etc., in chemical and mining industries.

• Gas Recovery: Evacuating and compressing various gases.

• Chemical Processes: Such as vacuum absorption, vacuum distillation, and vacuum crystallization.

• Pharmaceutical & Food Industries: Used in drying, distillation, and other processes valued for their oil-free operation.

• Paper Industry: Used for deaeration and suction in pulp handling.

• Others: Timber drying, soil irrigation, etc.