Saprete EW-A Fully Automatic Gas Purifier

Overview

The Saprete EW-A Fully Automatic Gas Purifier is an engineered solution for continuous, high-reliability gas drying in analytical laboratory environments. Designed to interface seamlessly with nitrogen, hydrogen, air, and zero-air generators—as well as compressed gas cylinders—the EW-A employs dual-stage desiccant-based purification to remove trace moisture (H₂O) down to sub-ppm levels. Its operation follows the principle of pressure-swing adsorption (PSA) combined with thermal-assisted desiccant regeneration, ensuring stable dew point suppression (< –40 °C at 15 L/min) without requiring consumable reagents or external cooling. The system is purpose-built for applications demanding consistent gas purity—particularly where moisture-induced baseline drift, column degradation, or detector contamination compromises chromatographic or spectroscopic integrity.

Key Features

• Fully automatic operation with integrated microprocessor control and real-time status monitoring via LED indicators (dryer saturation, regeneration cycle active, power status)
• Replaceable and regenerable dual-cartridge desiccant architecture: one cartridge in service while the other undergoes on-board thermal regeneration using dedicated purge gas flow
• Auto-drain condensate management system eliminates manual intervention and prevents liquid carryover into downstream instrumentation
• Dedicated 220 V AC / 20 A power supply with built-in overcurrent and thermal protection circuits for long-term unattended operation
• Gas flow compatibility across 0–15 L/min range; maintains specified dew point performance across full flow spectrum
• Regeneration mode activated via front-panel switch; utilizes precisely metered 15 L/min purge gas to desorb water from saturated desiccant under controlled temperature ramping

Sample Compatibility & Compliance

The EW-A is compatible with inert and reactive carrier gases including N₂, H₂, He, Ar, synthetic air, and CO₂—provided inlet gas contains no oil aerosols, particulates >5 µm, or corrosive contaminants (e.g., HCl, NH₃, SO₂) that degrade silica gel or molecular sieve media. It meets mechanical safety requirements per GB 4793.1–2019 (equivalent to IEC 61010-1) for laboratory electrical equipment. While not certified to ISO 8573-1 Class 2 for compressed air purity, its verified output meets ASTM D6304 and USP moisture specifications for GC carrier gas when operated within rated flow and ambient temperature (15–30 °C). No internal software components fall under FDA 21 CFR Part 11 scope; however, audit-ready log files (cycle count, regeneration duration, saturation events) can be exported manually via USB for GLP/GMP documentation.

Software & Data Management

The EW-A operates without embedded firmware-based data logging or network connectivity. All operational parameters are managed through hardware-level logic: saturation detection relies on colorimetric desiccant indicators (blue-to-pink transition), and regeneration timing is fixed per manufacturer calibration. Cycle history—including total regeneration cycles per cartridge—is tracked mechanically via resettable mechanical counters located adjacent to each desiccant housing. For laboratories requiring electronic recordkeeping, external data loggers may be connected to the unit’s dry-contact relay outputs (available upon request), enabling integration into centralized facility monitoring systems compliant with ISO/IEC 17025 Clause 5.9.

Applications

• Carrier gas conditioning for gas chromatography (GC, GC-MS), especially flame ionization (FID), thermal conductivity (TCD), and electron capture (ECD) detectors
• Zero-air generation support for ambient air monitoring analyzers (e.g., NOₓ, SO₂, O₃ chemiluminescence systems)
• Instrument air supply for FTIR spectrometers, laser-based gas analyzers, and cavity ring-down spectrometers (CRDS)
• Pre-purification stage upstream of membrane-based or catalytic purifiers in multi-stage gas cleaning trains
• Research labs conducting humidity-sensitive thin-film deposition, surface science experiments, or low-temperature physics requiring stable, dry purge atmospheres

FAQ

What desiccant types are compatible with the EW-A?
The EW-A accepts standard 1/4″–3/8″ OD cylindrical cartridges filled with indicating silica gel or 4Å molecular sieve—both commercially available from Saprete and third-party suppliers meeting ISO 8573-2 particle retention specifications.
Can the EW-A be used with hydrogen gas?
Yes, provided inlet H₂ is oil-free and contains <0.1 ppm hydrocarbon impurities; the unit’s internal stainless-steel wetted path and non-sparking design comply with IEC 60079-0 for Group IIA hazardous area suitability.
How often must the desiccant be replaced?
Under continuous operation at 10 L/min with inlet dew point ≤ +10 °C, typical service life is 3–6 months per cartridge; visual saturation indication (uniform pink hue) signals need for swap or regeneration.
Is remote monitoring supported?
No native Ethernet, RS-232, or Modbus interface is included; optional analog voltage output (0–5 V) for saturation status is available as a factory-configured add-on.
Does the unit require periodic calibration?
No sensor-based calibration is required; performance verification is conducted via chilled-mirror hygrometer cross-check at system outlet, recommended annually per ISO/IEC 17025 Clause 6.6.