Manual Nitrogen Generation Plant with Integrated Air Compressor and Hydraulic Booster, boosted to 200 bar.

Introduction

The Manual Nitrogen Generation Plant is a self-contained system designed to produce high-purity nitrogen gas for cylinder filling, industrial processes, and laboratory applications. Combining a diesel-driven air compressor, air-drying unit, Pressure Swing Adsorption (PSA) module, and a hydraulically driven booster, this plant offers on-site, reliable nitrogen generation up to 200 bar. Its modular design ensures portability and ease of operation in environments lacking stable electrical infrastructure.

Key features

• Integrated diesel engine & air compressor: Graeves Cotton G-1510 diesel engine (9 HP @ 3000 RPM) directly powers an 8.8 CFM, 2-stage air compressor delivering clean compressed air at 12 kg/cm² (approximately 7 bar); air-cooled, single-cylinder design ensures efficient operation in ambient temperatures up to 50°C.
• High-efficiency air drying & filtration: activated carbon filter (15 kg) and ceramic candle pre-filter (1 µm) remove oil, moisture and particulates before entering the PSA module; heatless regenerative air dryer (IS 2825 compliance) maintains dew point below –60°C, safeguarding molecular sieve beds.
• PSA nitrogen generation module: twin-tower PSA unit (150 × 1000 mm, 16 L each) equipped with Carbon Molecular Sieves (CMS) produces nitrogen at up to 99.9% purity, at an adjustable flow rate of 0.5–5 Nm³/hr; a 60 L surge tank buffers nitrogen output to maintain steady pressure.
• Hydraulic booster assembly: single-stage, single-acting hydraulic booster delivers nitrogen from PSA-module pressure (approx. 5.8 kg/cm²) up to 200 bar, enabling direct filling of high-pressure cylinders; bronze piston (Ø 70 mm) within an Italian-honed barrel ensures minimal leakage and consistent performance.
• Robust hydraulic power pack: Dowty gear pump (40 L/min, 132 bar max) driven by a 3 HP electric motor (220 VAC); EPE 10 µm filter and 100 µm strainer protect hydraulic components from contamination; mild steel tank (250 L) with integrated Rexroth DC solenoid valve (4/2 way) controls hydraulic flow.
• Comprehensive instrumentation & controls: six SS 304 pressure gauges (0–10 kg/cm², 4″ dia) and two Bourdon-type pressure switches monitor air and nitrogen stages; nine solenoid valves (12 V DC) automate air-dryer regeneration, PSA switching and venting cycles; Siemens PLC (12 DI / 8 DO) provides sequence control for start-up, shutdown and changeover.
• Portable & field-ready design: self-contained skid with forklift pockets and lifting points for easy transport; modular arrangement of engine, compressor, cooler, PSA towers, surge tank and booster allows straightforward maintenance.

Working principle

1. Air compression & pre-treatment

The diesel engine (G-1510) is started via rope pull (or optional 12 V electric start). It drives the two-stage air compressor, which compresses ambient air to approximately 7 bar. Compressed air enters the pre-filter (ceramic candle) to remove particulates above 1 µm, then passes through the activated carbon filter (12 L volume) to eliminate oil vapor and hydrocarbon contaminants.

2. Air drying & storage

The filtered air is directed into a regenerative heatless dryer. Two alternately switching towers filled with Zeolite Molecular Sieves (ZMS) adsorb moisture, ensuring the dew point is maintained at or below –60°C. Dried air is collected in the Dry Air Receiver (250 mm × 1200 mm, 60 L), where it is held at 7 bar until the PSA module is activated.

3. Pressure Swing Adsorption (PSA) nitrogen generation

Upon reaching the required air pressure (7 ± 0.5 kg/cm²), the PLC energizes solenoid valves to route air to one of the two CMS-filled absorber towers. Under pressure, oxygen and trace gases are adsorbed onto the CMS bed, allowing high-purity nitrogen to exit at the bottom of the active tower, while the opposite tower undergoes regeneration (depressurization and ambient venting). Nitrogen flows through a rotameter (0.5–5 Nm³/hr, typically set to 2 Nm³/hr); after 10 minutes of vent-purge, pure nitrogen is ready at approximately 5.8 bar.

4. Hydraulic boosting & cylinder filling

Once surge-tank pressure stabilizes at ~5.8 kg/cm², manual valve operation opens the inlet to the hydraulic booster. The hydraulically driven piston, powered by the hydraulic power pack, compresses nitrogen from PSA pressure up to 200 bar. Integrated check valves at the booster inlet and outlet prevent backflow into the PSA module and ensure one-directional high-pressure discharge; high-pressure nitrogen is routed through safety valves to fill storage cylinders directly via the bottom outlet needle valve.

Component details

4.1 Diesel engine (Graeves Cotton G-1510)

• Type: vertical, single-cylinder, air-cooled, cold start, compression ignition, four-stroke
• Rated power: 9 HP @ 3000 RPM (centrifugal governor; reflection-type silencer)
• Displacement: 510 cm³ (bore 85 mm × stroke 90 mm)
• Fuel tank capacity: 5.5 L; lubrication via 15W-40 API CH-4 oil
• Start method: rope start (standard); optional 12 V electric start available
• Dry weight: 62 kg (involute crankcase design)

4.2 Air compressor

• Output: 8.8 CFM @ 12 kg/cm² (7 bar)
• Tank: integral 160 L ASME-rated air receiver with safety relief valve
• Construction: deep-finned cast iron cylinders, aluminum cooler tubes, forged steel crankshaft, belt-driven by the diesel engine
• Safety: pressure relief after each compression stage; fully enclosed belt guard conforming to Euro norms

4.3 Air drying & filtration

4.4 PSA nitrogen generator

4.5 Hydraulic boosting system

4.6 Instrumentation & controls

• Pressure gauges: six SS 304, 4″ dial, 0–10 kg/cm² (3/8″ NPT)
• Pressure switches: two Bourdon type, 0–10 kg/cm², ¼″ connection
• Solenoid valves: nine total (2-way, 3-port), five NC and four NO, ¼″ ports, 12 V DC
• Rotameter: ½″ connection, 0.5–5 Nm³/hr range, calibrated at 5.5 kg/cm²
• PLC: Siemens unit with 12 digital inputs and 8 digital outputs, 12 V DC supply

Maintenance & safety guidelines

Daily checks

• Verify diesel engine oil level and hydraulic oil in power pack.
• Ensure adequate air supply to compressor and confirm correct dryer & PSA sequence.
• Observe operation of DC solenoid valves and manual valves for smooth opening/closing.

Weekly checks

• Drain condensate from the ceramic candle filter (PSA pre-filter) and check activated carbon filter for moisture.
• Inspect and align compressor and engine pulley belts; tighten all connection fittings.

Monthly & annual checks

• Replace or top-up ZMS and CMS desiccants every 12–15 months for optimal nitrogen purity.
• Examine hydraulic booster seals (piston and O-rings) and replace if wear is detected.
• Grease radial bearings in compressor and booster assemblies.

Safety precautions

• Always read and follow the maintenance manual and schedule before performing any service.
• Allow equipment to cool before touching hot surfaces such as the exhaust, engine block, or hydraulic lines.
• Never attempt to adjust or tighten any pressured-system components while under pressure; use proper tools and wear protective equipment.
• Avoid inhalation of vented gases, especially during air-dryer and PSA regeneration cycles.

Advantages & benefits

• Off-grid operation: diesel engine drive enables nitrogen generation in remote locations without stable electricity.
• High purity & pressure: PSA technology ensures up to 99.9% nitrogen purity; hydraulic booster delivers up to 200 bar for direct cylinder filling.
• Cost-effective: eliminates recurring costs of cylinder-based nitrogen supply; simple maintenance schedule minimizes downtime.
• Modular & portable: skid-mounted design allows relocation within industrial facilities or job sites; forklift pockets and lifting points enable easy repositioning.
• Robust construction: IS 2825-compliant pressure vessels, high-quality molecular sieves from CECA, and a proven Graeves Cotton diesel engine guarantee long-term reliability.
• Automated sequencing: PLC-controlled solenoid valves and pressure switches handle air-dryer regeneration, PSA switching and safety interlocks, reducing operator workload.

Ordering & support

Model reference: MN2MS — Manual Nitrogen Plant with Diesel Compressor & Hydraulic Booster

Standard scope of supply

• Diesel engine & air compressor (complete skid assembly)
• Heatless air dryer & pre-filters (ceramic candle, activated carbon)
• PSA module (twin towers with CMS, piping, valves, PLC control)
• Hydraulic booster & power pack (pump, tank, filter, piping)
• Instrumentation (pressure gauges, switches, solenoid valves, rotameter)
• Electrical panel (Siemens PLC, control wiring, indicators)
• Installation manual, maintenance manual, and spare parts list

Optional accessories

• Electric start kit for diesel engine (12 V)
• Additional nitrogen storage cylinders and manifold
• Customized skid platform or acoustic enclosure
• Remote monitoring package (online purity/flow data logging)

Technical support & after-sales service

• Comprehensive commissioning assistance by factory-trained technicians.
• Annual maintenance contracts covering preventive inspections, sieve replacement, and filter servicing.
• 24/7 helpline for troubleshooting and part replacement.

Conclusion

The Manual Nitrogen Generation Plant offers a turnkey solution for industries and laboratories requiring a reliable, on-site nitrogen source. By leveraging robust diesel engine drive, high-efficiency PSA technology, and a powerful hydraulic booster, this system delivers consistent, high-purity nitrogen up to 200 bar. Compact, portable, and engineered for ease of operation, it minimizes dependency on external gas suppliers, reduces operational costs, and ensures uninterrupted production and testing processes — even in remote or off-grid locations.