SPB Series Water Jet Vacuum Ejector Pump No Post Processing Needed

The SPB series water jet ejector vacuum pump Can Exhaust to Atmosphere, No Post-Processing Needed:

I. Introduction

The SPB series water jet ejector vacuum pump is a rough vacuum acquisition device that operates on the Bernoulli's principle. It generates a vacuum by creating a high-velocity water jet through a specially shaped nozzle. Its core components are the nozzle, suction chamber, and diffuser within the pump body. When high-pressure water (typically supplied by a centrifugal pump) passes through the nozzle, its pressure energy is converted into kinetic energy, forming a high-speed jet into the mixing chamber/diffuser. This creates a low-pressure zone (i.e., a vacuum) in the suction chamber area. The process gas is entrained by the pressure difference, mixes with the high-speed water stream in the throat for momentum exchange, and the mixture then passes through the diffuser where kinetic energy is reconverted into pressure energy before being discharged from the outlet.

It features an extremely simple structure with no moving mechanical parts or the complex lubrication systems of mechanical vacuum pumps. It is essentially a momentum transfer device.

II. Advantages

1. Extremely Simple Structure, No Moving Parts: The pump body itself has no rotating or reciprocating mechanical components, resulting in extremely low failure rates and high reliability.

2. Highly Reliable Operation, Very Low Maintenance: Requires no mechanical seals, bearings, or lubricating oil. It is almost immune to mechanical failure, resulting in minimal daily maintenance.

3. Corrosion Resistant, Wide Applicability: The pump body can be constructed from materials like cast iron, stainless steel, plastic (PP), or graphite, easily handling various corrosive media and conditions.

4. Can Exhaust to Atmosphere, No Post-Processing Needed: The mixed gas-water fluid can often be discharged directly into a drain or settling tank, requiring no additional exhaust piping or vacuum breakers.

5. Combines Vacuum Pumping and Condensation: When pumping condensable vapors (e.g., steam, solvent vapors), the high-speed water jet directly condenses and carries them away, improving pumping efficiency and protecting downstream equipment.

6. Intrinsically Safe and Explosion-Proof: As it uses water as the working medium and generates no sparks from mechanical friction, it is ideal for use in hazardous and explosive environments.

7. Low Capital Investment: The initial investment for the equipment itself and its supporting system is usually lower than that of mechanical vacuum pumps.

III. Key Technical Parameters

• Model Example: SPB-30, SPB-50, SPB-100, SPB-200 (The number often indicates the head of the matched centrifugal pump or serves as an identifier for pumping capacity).

• Pumping Speed: Highly dependent on working water pressure, temperature, and vacuum level. Ranges from a few cubic meters per hour to several hundred cubic meters per hour.

• Ultimate Vacuum: Primarily limited by the saturated vapor pressure of the working water at its temperature. Theoretically, it cannot achieve a vacuum better than this pressure. For example:

  • At 20°C water temperature, the ultimate vacuum is about -0.098 MPa (approx. 733 mmHg, 2.3 kPa abs.).

  • Higher water temperature results in worse (higher) ultimate vacuum.

• Operating Water Pressure: Typically requires 0.2 ~ 0.6 MPa inlet pressure, provided by a matched centrifugal pump.

• Operating Water Flow: Requires several to tens of tons per hour of circulating water flow, depending on the model.

• Material: Pump bodies are commonly made of cast iron, stainless steel (304/316), polypropylene (PP), etc. Nozzles and throats often use more wear-resistant and corrosion-resistant materials like stainless steel or ceramic.

• Essential Auxiliaries: Must be paired with a centrifugal water pump, a liquid-gas separator tank (or water sump), and piping/valves to form a complete system.

IV. Application Fields
Water jet ejectors are particularly suitable for applications involving large amounts of condensable vapor, corrosive gases, or gases containing small particles:

• Vacuum Evaporation, Concentration, Crystallization: Used in chemical, pharmaceutical, food, and dye industries to remove and simultaneously condense large volumes of secondary vapor.

• Vacuum Deaeration, Degassing: Used to remove dissolved oxygen or bubbles from liquids, e.g., in water treatment and food processing.

• Pumping Corrosive Gases: Handling acidic gases like HCl, SO₂ in pesticide and chemical production.

• Paper Industry: Processes like black liquor concentration.

• Plastics Extrusion: Providing vacuum deaeration for plastic extruders.

• Laboratories: Used for obtaining simple, economical rough vacuum environments.