Volm Two-Stage Vacuum Compressors Revolutionize SINOPEC Waste Gas Processing

The plant handled waste gas containing acrylonitrile (Class 1 carcinogen), acetonitrile (highly flammable), hydrogen cyanide, and steam, requiring: suction vacuum: ≤ -90 kPa; discharge pressure: ≈ 0.1 MPa (G).

Legacy System Failures:

1.Safety Hazards

• Vibration-induced pipeline leaks caused 3 annual acrylonitrile leakage alarms, endangering personnel;

2.Inefficiency

• Inter-stage pressure loss (15%) and poor equipment matching resulted in 35% energy waste;

3.Operational Burden

• Dual systems required separate lubrication/cooling, costing ¥2 million/year in maintenance and 12 m² footprint.

1. Corrosion-Proof Materials and Sealing

• Duplex S31603 stainless steel impellers/casings (hydrogen cyanide-resistant);

• Solution heat-treated components (HB200 hardness);

• Double mechanical seals + independent flushing system (white oil, +0.2MPa vs. pumped media), coupled with nitrogen buffer tank (0.5MPa), resulting in “zero” leakage (<5 ppm).

2. Two-Stage Compression Breakthrough

• Stage 1: Achieves -95 kPa vacuum;

• Stage 2: Compresses to 0.1 MPa;

• Two-stage compression prevents capacity drop from one-stage high compression ratio.

3. Intelligent Control System

• Adaptive Flow: PID controller + online waste gas analyzer (±2% accuracy) adjusts bypass valves for 300-1000 m³/h stepless flow (<10s response);

• Energy Savings: IE4 VFD motors (96% efficiency) cut energy use by 22% (500,000 kWh/year saved);

• Safety Protection: At discharge, burst discs (0.35MPa) + O₂ monitors (>5% shutdown) prevent acetonitrile explosions.

Reliability Validation:

• Material corrosion: <0.05mm/year (vs. <0.1mm spec);

• Seal stability: no wear for continuous 5,000+ hours (3× longer than single seals);

• Adaptability: Handled 30% acrylonitrile spikes (1,500 ppm) with<±0.01 MPa pressure fluctuation.