DRETOP SJ-80 Dry Screw Vacuum Pump

Overview

The DRETOP SJ-80 is a precision-engineered dry screw vacuum pump designed for continuous, oil-free operation in demanding industrial and laboratory vacuum processes. Utilizing a fixed-pitch, variable-pitch twin-screw rotor architecture, it achieves high volumetric efficiency and stable compression across a wide pressure range—from atmospheric down to < 1 Pa—without internal lubrication or oil contamination. Its operating principle relies on synchronous, non-contacting screw rotation within a precisely machined stator housing, generating progressive gas displacement through axial volume reduction. This design eliminates hydrocarbon backstreaming, prevents process contamination, and ensures compliance with stringent purity requirements in semiconductor fabrication, pharmaceutical lyophilization, vacuum metallurgy, and thin-film coating applications. Unlike oil-sealed rotary vane or liquid-ring pumps, the SJ-80 delivers a clean, dry, and chemically inert vacuum environment—critical for handling corrosive gases (e.g., Cl₂, HCl, NH₃), condensable vapors (e.g., solvents, water), and particulate-laden streams common in battery electrode drying, CVD/ALD precursor delivery, and vacuum distillation.

Key Features

• Oil-free dry pumping mechanism with dual-screw, equal-diameter, variable-pitch rotors—ensures zero hydrocarbon emission and long-term vacuum integrity.
• Water-cooled thermal management system maintains low operational temperature (< 85 °C surface), reducing cooling water consumption by up to 30% versus air-cooled equivalents and enabling stable duty-cycle performance.
• Robust rotor surface treatment options—including nickel-phosphorus (Ni-P), ceramic, and duplex stainless-steel coatings—provide validated resistance to strong acids, alkalis, and halogenated compounds per ASTM B117 salt-spray testing.
• Optimized dynamic balancing and multi-stage vibration damping reduce operational noise to ≤ 68 dB(A) at 1 m distance—suitable for controlled environments such as R&D labs and cleanrooms.
• Integrated gap-seal architecture tolerates micro-particulates (≤ 50 µm) without clogging; straight-through gas path minimizes deposition and supports uninterrupted 24/7 operation in lithium cathode drying or powder metallurgy sintering.
• Standard nitrogen purge port (NW16) enables continuous inert gas sweeping of shaft seals and bearing housings—extending service life in dusty or reactive atmospheres (e.g., silicon powder, graphite, metal oxides).

Sample Compatibility & Compliance

The SJ-80 is engineered for compatibility with aggressive process media, including but not limited to: anhydrous HF, SO₂, H₂S, acetone, ethanol, ethyl acetate, and saturated aqueous vapor. Its corrosion-resistant construction meets ISO 8573-1 Class 0 (oil-free air standard) and complies with FDA 21 CFR Part 11 data integrity requirements when paired with optional PLC-based control systems featuring audit-trail logging and user-level access control. The pump conforms to CE Machinery Directive 2006/42/EC, RoHS 2011/65/EU, and IEC 60034-1 motor safety standards. For GMP/GLP-regulated environments (e.g., USP , ISO 14644-1 Class 7/8 cleanrooms), optional validation documentation packages—including IQ/OQ protocols and material traceability certificates (3.1 EN 10204)—are available upon request.

Software & Data Management

When configured with the optional integrated PLC controller (Siemens S7-1200 or Allen-Bradley Micro850), the SJ-80 supports real-time monitoring of inlet pressure, motor current, coolant flow rate, and bearing temperature via Modbus TCP or EtherNet/IP. The embedded HMI interface enables programmable ramp-up profiles, vacuum setpoint regulation, and fault-condition interlocks (e.g., low-flow shutdown, overtemperature cut-off). All operational events—including start/stop cycles, alarm triggers, and parameter changes—are time-stamped and stored locally for ≥12 months, satisfying 21 CFR Part 11 electronic record retention mandates. Remote diagnostics and firmware updates are supported via secure TLS 1.2–encrypted web portal access, eliminating the need for onsite engineering visits during routine maintenance planning.

Applications

• Semiconductor & Microelectronics: Load-lock evacuation, PVD/CVD chamber roughing, and ALD precursor purging where hydrocarbon-free vacuum is mandatory for film stoichiometry control.
• Pharmaceutical Manufacturing: Freeze-drying (lyophilization) primary drying stages, solvent recovery from API crystallization, and sterile barrier packaging under ISO 13485-compliant conditions.
• Lithium-Ion Battery Production: Electrode drying ovens (NMP solvent removal), cell formation vacuum chambers, and electrolyte filling line degassing—operating continuously at 1–10 Pa with minimal thermal drift.
• Advanced Materials Processing: Vacuum brazing of aerospace alloys, electron-beam melting (EBM) pre-evacuation, and optical thin-film deposition requiring < 1 Pa base pressure and zero oil residue.
• Chemical & Petrochemical R&D: High-boiling-point solvent distillation, catalyst activation under reducing atmospheres, and reactive gas synthesis where pump corrosion resistance directly impacts batch repeatability.

FAQ

What is the typical maintenance interval for the SJ-80 under continuous operation?
With water cooling and standard N₂ purge, scheduled maintenance—including rotor alignment verification, seal inspection, and coolant filter replacement—is recommended every 6,000 operating hours or annually, whichever occurs first. No oil changes or lubricant replenishment are required.
Can the SJ-80 be used as a standalone pump, or does it require a backing pump?
The SJ-80 is a self-contained, single-stage dry screw pump capable of direct atmospheric startup and achieving < 1 Pa ultimate pressure without a forepump—unlike roots blowers which require mechanical backing.
Is the pump compatible with ATEX Zone 1 or 2 hazardous area classifications?
Yes—when specified with Ex d IIB T4 Gb explosion-proof motor (IEC 60079-1) and certified non-sparking materials, the SJ-80 can be supplied for use in flammable vapor environments per EN 60079-0 and EN 60079-31.
How does the variable-pitch screw design improve performance over fixed-pitch alternatives?
The graduated pitch profile optimizes compression ratio distribution along the rotor length, reducing power consumption by ~12% and lowering discharge temperature by up to 15 °C compared to uniform-pitch designs—particularly beneficial during high-load condensable vapor handling.
What vacuum gauge interface options are supported?
Standard analog 4–20 mA and digital RS485 (Modbus RTU) outputs allow seamless integration with capacitance manometers (e.g., MKS Baratron), Pirani gauges, or full-range cold cathode sensors for closed-loop pressure control.