Application and Precautions of Water Ring Vacuum Pumps in Graphite and Carbon Production

1. Applications

Water ring vacuum pumps are widely used in graphite and carbon production for vacuum extraction, gas transfer, and impregnation processes, including:

1)Impregnation Process

During pitch or resin impregnation of graphite products (e.g., electrodes, crucibles), the pump removes air from pores before pressure injection, ensuring thorough saturation.

2)Calcination & Graphitization

In high-temperature treatments (e.g., calcination, graphitization), the pump extracts oxygen, moisture, and volatiles to prevent oxidation or cracking, often combined with nitrogen purging.

3)Exhaust Gas Recovery

Handles pitch fumes, tar vapors, and other hazardous gases, often paired with condensers for recovery or purification.

4)Vacuum Conveying

Transfers powders (e.g., graphite, carbon black) via pneumatic systems, minimizing dust pollution.

2. Selection Criteria

1)Corrosion Resistance

For acidic gases (e.g., SO₂, HF) or tar-laden media, choose stainless steel or PTFE-lined pumps.

2)Pumping Speed

Calculate required flow rate (m³/h) based on chamber volume and evacuation time to avoid undersizing.

3)Ultimate Vacuum Level

Impregnation typically requires ≥ -0.095 MPa; select high-vacuum models (e.g., 2BV series).

4)Clogging Prevention

For tar or particle-laden media, opt for filters or two-stage pumps to reduce impeller blockage risks.

3. Operational Precautions

1)Water Quality Control

Use clean, debris-free working fluid (usually water); replace regularly to prevent scaling/corrosion.

For condensable media (e.g., pitch vapor), switch to antifreeze or specialized sealing fluids.

2)Liquid-Gas Separation

Install separators at the inlet to avoid liquid ingress damaging the impeller.

3)Temperature Management

Monitor working fluid temperature (≤40°C); add coolers if overheating occurs to maintain vacuum.

4)Explosion Protection

For flammable gases (e.g., H₂, CH₄), use explosion-proof motors and ensure ventilation.

5)Maintenance

Regularly inspect bearings, mechanical seals, and clear internal deposits (e.g., tar, carbon).

Drain fluid after shutdown to prevent scaling/freezing (winter).

4. Common Issues and Solutions for Water Ring Vacuum Pumps

1. Insufficient Vacuum Level

Possible Causes:Working fluid temperature too high;System leakage.

Recommended Solutions:Cool down the working fluid.Inspect and replace damaged seals.

2. Excessive Vibration or Noise

Possible Causes:Impeller clogging;Bearing failure

Recommended Solutions:Clean the impeller thoroughly.Replace worn-out bearings.

3. Motor Overload

Possible Causes:Excessive media viscosity;Inlet filter blockage

Recommended Solutions:Dilute the process media.Clean or replace inlet filters.