説明
ZW-2/4 Nitrogen Compressor – Compact Oil-Free N2 Booster for Small-Scale Air Separation
Delivering 2 m³/min at 0.40 MPa discharge pressure, the ZW-2/4 is a two-stage, two-row oil-free piston nitrogen compressor engineered for compact cryogenic air separation units, laboratory nitrogen supply, and small-scale VPSA nitrogen generation. Zero lubricant contamination, space-efficient design, and built for reliable continuous operation.
製品概要
The ZW-2/4 nitrogen compressor represents a compact yet powerful solution in our oil-free piston compressor range, purpose-built for nitrogen boosting duties in small-scale cryogenic air separation, laboratory gas supply chains, and compact VPSA nitrogen generation systems. With a capacity of 2 m³/min and a discharge pressure of 0.40 MPa, this unit delivers professional-grade performance in a footprint that fits confined industrial spaces.
Unlike conventional lubricated compressors that compromise nitrogen purity with oil vapor carryover, the ZW-2/4 operates on a completely oil-free lubrication architecture. This design philosophy eliminates downstream oil filtration requirements, slashes maintenance schedules, and guarantees nitrogen purity compliance for sensitive applications including pharmaceutical R&D, electronics testing, and food preservation laboratories.
The compressor employs a two-stage, two-row (二列二级) piston configuration that optimizes compression efficiency across the pressure ratio. Each compression stage features independent cooling circuits, ensuring discharge temperatures remain within safe thermal envelopes even during extended duty cycles. The compact cast-iron frame and precision-balanced crankshaft assembly are engineered for 60,000+ hours of operational longevity under standard service intervals.
Technical Specifications – ZW-2/4
| Parameter | Value | Unit |
|---|---|---|
| モデル | ZW-2/4 | – |
| パターン | Two-stage, Two-row (二列二级) | – |
| 容量 | 2 | m³/分 |
| 吐出圧力 | 0.40 | MPa |
| Compressor Size (L × W × H) | 720 × 763 × 1475 | mm |
| 重さ | 0.60 | t |
| 力 | 18.5 | kW |
| 電圧 | 380 | V |
| ガス媒体 | Nitrogen (N₂) | – |
| Lubrication | オイルフリー | – |
* All specifications are rated at standard reference conditions (ISO 1217, Annex C). Actual performance may vary based on site altitude, ambient temperature, and inlet conditions.
Key Features & Engineering Advantages
1. Ultra-Compact Footprint
At just 720 × 763 × 1475 mm and 600 kg, the ZW-2/4 occupies less than 0.55 m² of floor space. This compact form factor makes it ideal for retrofit installations in existing facilities where space is at a premium, such as university research labs, hospital gas supply rooms, and small manufacturing plants. The vertical orientation of the two-row cylinder arrangement minimizes horizontal footprint while maintaining full two-stage thermodynamic efficiency.
2. Oil-Free PTFE Piston Technology
The ZW-2/3 utilizes a self-lubricating PTFE composite piston ring and rider band system that operates without any hydrocarbon lubricants. This achieves ISO 8573-1 Class 0 oil content certification, making it suitable for the most demanding nitrogen purity applications. The elimination of oil from the compression chamber removes the risk of oil-induced polymerization in nitrogen streams containing trace oxygen, a critical safety consideration for high-purity gas handling.
3. Two-Stage Efficiency at Small Scale
Most small-capacity compressors sacrifice efficiency by using single-stage designs. The ZW-2/4 maintains a two-stage compression architecture with inter-stage cooling, achieving a specific power consumption of approximately 9.25 kW per m³/min—exceptional for this capacity class. The inter-stage shell-and-tube cooler reduces second-stage inlet temperature, improving volumetric efficiency and extending valve service life.
4. Low Inertia Crankshaft Design
The forged alloy steel crankshaft is dynamically balanced to ISO 1940 G2.5 and features a low-inertia design that enables rapid start-stop cycling. This is particularly valuable for laboratory applications where the compressor may cycle on demand rather than running continuously. The two-row opposed-cylinder layout provides natural force cancellation, reducing foundation requirements and allowing installation on standard industrial flooring without special inertia blocks.
Application Scenarios
Small-Scale Cryogenic Air Separation
In compact cryogenic ASU installations producing 50–200 Nm³/h of gaseous nitrogen, the ZW-2/4 serves as the primary booster between the cold box and the process distribution network. Its 2 m³/min capacity aligns precisely with the output of small-scale liquid nitrogen plants and mini-ASU systems. The 0.40 MPa discharge pressure provides adequate head for pipeline distribution to nearby process equipment, glove boxes, and instrument gas panels.
Laboratory & Research Gas Supply
Research laboratories, university chemistry departments, and pharmaceutical R&D facilities require a reliable supply of high-purity nitrogen for inert atmosphere work, solvent evaporation, and chromatography carrier gas. The ZW-2/4’s oil-free certification ensures that no hydrocarbon contaminants interfere with sensitive analytical instruments such as GC-MS, HPLC, and ICP-MS. The compact size allows installation directly adjacent to laboratory gas distribution panels, eliminating long pipeline runs that can introduce atmospheric contamination.
Compact VPSA Nitrogen Generators
のために small-scale VPSA nitrogen generator packages, the ZW-2/4 compresses the low-pressure nitrogen product (typically 0.05–0.10 MPa from the adsorption bed) to usable distribution pressure. The oil-free design is critical because VPSA systems rely on molecular sieve adsorbents that would be permanently poisoned by oil vapor. The compact footprint allows the compressor to be integrated directly into the VPSA skid, creating a complete turnkey nitrogen generation package.
Electronics Manufacturing & Soldering
In electronics assembly facilities, nitrogen is used for wave soldering inerting, reflow oven atmosphere control, and component storage. The ZW-2/4’s 0.40 MPa discharge pressure is sufficient for typical soldering machine nitrogen requirements (0.20–0.35 MPa), with pressure regulation at the point of use. The oil-free certification prevents hydrocarbon contamination of solder joints and flux residues, which could cause electrical conductivity issues in high-reliability electronics.
Material & Construction
The ZW-2/4 is constructed from materials selected for nitrogen compatibility, compact durability, and maintenance accessibility:
| Component | Material | 仕様 |
|---|---|---|
| Cylinder Block | Gray Cast Iron | GG25 / HT250, compact casting |
| Crankshaft | Forged Alloy Steel | 42CrMo4, Q&T, low inertia |
| Piston Rings | PTFE Composite | Self-lubricating, oil-free |
| Valve Plates | ステンレス鋼 | SS316, corrosion resistant |
| Intercooler | Aluminum Fin-Tube | Compact, high heat transfer |
| Frame | Welded Steel Plate | Powder coated, vibration damped |
All pressure-bearing components are designed to GB 150 pressure vessel standards. The compact intercooler uses aluminum fin-tube construction for maximum heat transfer in a minimal envelope, reducing overall unit height while maintaining inter-stage cooling effectiveness. Weld joints undergo hydrostatic testing at 1.5× design pressure before shipment.
Installation & Maintenance Guidelines
Foundation & Mounting
At only 600 kg, the ZW-2/4 can be installed on standard reinforced industrial flooring without a dedicated inertia block. The unit ships with four vibration isolation mounts that reduce transmitted vibration to less than 2 mm/s RMS. Minimum installation clearances: 800 mm front (valve access), 500 mm sides, and 600 mm rear (cooler access). The compact footprint (720 × 763 mm) allows installation in standard laboratory equipment bays and small mechanical rooms.
Cooling Requirements
Cooling water flow requirement is approximately 3.5 m³/h at 32°C inlet temperature. For facilities without cooling water infrastructure, an optional air-cooled aftercooler package is available, using ambient air with a dedicated fan and fin-tube heat exchanger. This configuration increases the overall height by 200 mm but eliminates the need for cooling water piping.
Electrical Connection
The 18.5 kW motor operates on standard 380V/3-phase/50Hz industrial power. A 32A circuit breaker with motor protection (thermal overload + short circuit) is recommended. The motor is IE3 efficiency class, complying with EU ecodesign directives. For North American installations, a 460V/60Hz motor variant is available with 2–3 weeks additional lead time.
Maintenance Schedule
| Interval | Service Item | Action |
|---|---|---|
| Daily | Visual Inspection | Check for leaks, abnormal noise, vibration |
| 500 hours | Valve Inspection | Inspect suction/discharge valve plates |
| 2,000 hours | Piston Ring Check | Measure wear, replace if groove clearance > 0.25mm |
| 6,000 hours | Major Service | Replace rings, bands, valves; inspect bearings |
| 12,000 hours | Crankshaft & Bearing | Full inspection, measure runout, replace bearings |
The oil-free architecture dramatically simplifies maintenance. There are no lubricant filters, no oil sampling programs, and no separator element changes. The primary consumables are the PTFE piston rings and rider bands, with typical service life of 4,000–6,000 hours in clean nitrogen service. All wear components are accessible from the front and top of the unit, allowing service without moving the compressor from its installed position.
Compliance & Safety Certifications
The ZW-2/4 nitrogen compressor meets or exceeds the following international standards and regulatory requirements:
GB 150 Pressure Vessel Standard, PED 2014/68/EU (Module A)
IEC 60034-1 (Rotating Machines), IEC 60204-1 (Machine Safety), CE Marked
ISO 8573-1 Class 0 (Oil Content), TÜV Rheinland Tested
ISO 9001:2015, ISO 14001:2015
Nitrogen is an odorless, colorless asphyxiant gas. All ZW-2/4 installations must include oxygen deficiency monitoring in enclosed spaces. Maintain ventilation rates that keep ambient oxygen above 19.5% per OSHA 29 CFR 1910.146. Install oxygen sensors with alarm at 19.5% and automatic shutdown at 18.0%. Never enter compressor enclosures without portable oxygen monitoring equipment.
Performance & Efficiency Analysis
The ZW-2/4 achieves a specific power consumption of approximately 9.25 kW per m³/min of nitrogen at 0.40 MPa discharge pressure. While this specific power is higher than large-capacity units due to the physics of small-scale compression, it represents excellent efficiency within the compact oil-free piston compressor category. For context, typical oil-lubricated screw compressors in this capacity range consume 10–12 kW/m³/min, while diaphragm compressors (often used for high-purity applications) may exceed 15 kW/m³/min.
Over a 4,000-hour annual operating cycle, the ZW-2/4’s oil-free advantage eliminates approximately $800–$1,200 in annual lubricant and filter costs compared to lubricated alternatives. The compact design also reduces installation costs—no dedicated compressor house, no cooling tower, and minimal electrical infrastructure. The total cost of ownership for small nitrogen compressors is dominated by energy and maintenance, and the ZW-2/4 optimizes both.
The 18.5 kW motor is IE3 premium efficiency class, reducing electrical losses by 3–5% compared to IE2 motors. For facilities operating on time-of-use electricity tariffs, the ZW-2/4’s ability to start and stop rapidly (low inertia crankshaft) allows demand-response strategies that shift compression to off-peak rate periods, further reducing operating costs.
Customization & OEM Capabilities
Beyond the standard ZW-2/4 configuration, we offer tailored solutions for specific installation environments:
- Air-Cooled Package: Eliminates cooling water requirement with integrated air-cooled intercooler and aftercooler. Ideal for remote installations and mobile nitrogen generation trailers. Adds 200 mm to overall height.
- Sound-Attenuated Enclosure: Reduces noise emission from 82 dB(A) to 68 dB(A) at 1m, suitable for indoor laboratory installations. Enclosure includes integrated ventilation fans and oxygen monitoring ports.
- Variable Frequency Drive (VFD): Matches compressor output to fluctuating nitrogen demand, improving part-load efficiency by 15–25%. Includes pressure transducer and PID control for automatic speed modulation.
- Skid-Mounted Turnkey System: Pre-assembled with nitrogen receiver tank (500L), pressure regulator panel, and moisture analyzer. Reduces field installation to electrical and inlet gas connections only.
- Explosion-Proof Variant: ATEX Zone 2 certified motor and electrical components for installation in hazardous area classifications. Available for 380V/50Hz and 460V/60Hz power systems.
Minimum order quantity for customized configurations is 1 unit. Standard delivery is 6–8 weeks; customized packages deliver in 8–10 weeks. OEM private labeling and co-branded documentation are available for system integrators and gas equipment distributors.
Case Study: University Research Lab Nitrogen Supply Upgrade
Client: A leading research university in East Asia, Department of Materials Science
Challenge: The department’s existing high-pressure nitrogen cylinder bank (200 bar, 50L cylinders) was proving inadequate for multiple simultaneous glove box operations, inert atmosphere furnaces, and thermal analysis instruments. Cylinder changeouts were disrupting experiments, and the logistics of cylinder handling in a multi-story laboratory building were becoming a safety concern.
Solution: We supplied a ZW-2/4 oil-free nitrogen compressor integrated with a small VPSA nitrogen generator (producing 99.9% N₂ at 0.08 MPa) and a 500L receiver tank. The compact compressor fit within the existing mechanical room (1.2m × 1.5m floor space), and the oil-free certification met the department’s analytical purity requirements.
Results:
- Nitrogen supply continuity: 100% on-demand availability, eliminating cylinder changeout delays
- Annual operating cost: Reduced by 58% versus cylinder rental and delivery (from $12,400 to $5,200)
- Laboratory safety: Eliminated manual cylinder handling in confined elevator and corridor spaces
- Nitrogen purity: Consistently >99.95% with oil content <0.01 mg/m³, meeting all analytical instrument requirements
“The ZW-2/4 transformed our laboratory operations. We no longer worry about running out of nitrogen mid-experiment, and the compact size meant we didn’t need to sacrifice valuable lab space. The oil-free certification gives us confidence that our analytical results aren’t compromised by hydrocarbon contamination.” — Laboratory Manager, Materials Science Department
FAQ & Selection Guide
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Explore our complete range of industrial nitrogen compressors, including oil-free oxygen compressors, hydrogen boosters, and specialty gas handling solutions. Contact our engineering team for application-specific recommendations and custom package design.
Ready to Upgrade Your Nitrogen Supply System?
Our application engineers specialize in matching compressor specifications to your exact nitrogen flow, pressure, and purity requirements. We provide complimentary technical proposals, layout drawings, and lifecycle cost analysis within 48 hours of your inquiry.
