The Great Wall ZT-100-200-30H Closed-Loop Refrigerated & Heated Circulator

Overview

The Great Wall ZT-100-200-30H is a high-performance closed-loop refrigerated and heated circulator engineered for precise, stable thermal control of external process equipment—including jacketed reactors, calorimeters, distillation columns, and analytical instrumentation. Operating across a wide temperature span from −30 °C to +200 °C with ±0.5 °C stability under load, the system employs dual-mode thermodynamic architecture: a dedicated refrigeration circuit based on Emerson hermetic scroll compressors and Danfoss thermostatic expansion valves, coupled with a high-efficiency flanged immersion heater compliant with JB/T 2379 for thermal oil service. Its fully sealed circulation loop eliminates vapor loss and oxidation of heat transfer fluids, ensuring long-term fluid integrity and consistent thermal performance in continuous laboratory and pilot-scale applications.

Key Features

• Hermetic Emerson scroll compressor with dual-flex design, IP44-rated terminal housing, and DU bearing assembly for >30,000-hour service life and low acoustic emission (<62 dB(A))
• AISI 316 stainless steel plate evaporator rated for −160 °C to +200 °C, offering 3–5× higher heat transfer coefficient than shell-and-tube alternatives and reduced fouling susceptibility
• Dual-stage thermal management: pre-cooling air-to-fluid heat exchanger enables rapid transition from high-temperature setpoints to ambient, reducing compressor cycling and energy consumption by up to 35% during ramp-down sequences
• SUS304 reservoir and fluid pathways with integrated expansion tank featuring level-indicating float switch and pressure-relief safety valve (set at 2.5 bar)
• Magnetically coupled circulation pump rated for continuous operation at −30 °C to +200 °C, eliminating seal leakage risk and enabling compatibility with synthetic heat transfer fluids (e.g., silicone oils, polyalkylene glycols)
• 5.7″ full-color TFT touchscreen interface supporting 120 programmable profiles (100 segments each), real-time temperature curve logging, and dual control modes (constant setpoint or time-temperature ramping)

Sample Compatibility & Compliance

The ZT-100-200-30H is designed for use with non-corrosive, low-viscosity heat transfer media—including water-glycol blends, silicone oils, and specialized synthetic fluids—within their specified thermal and chemical stability limits. It complies with IEC 61000-6-2 (EMC immunity) and IEC 61000-6-4 (EMC emissions) standards. All electrical components meet CE marking requirements. The control architecture supports audit-ready operation per GLP and GMP environments: event logs (including parameter changes, alarms, and power interruptions) are timestamped and stored internally for ≥12 months; MODBUS RTU protocol enables integration into centralized SCADA or LIMS platforms with full traceability. While not intrinsically rated for hazardous areas, optional ATEX-compliant variants are available upon request.

Software & Data Management

The embedded controller records all operational parameters—including bath temperature, outlet/inlet delta-T, compressor suction/discharge pressures, heater duty cycle, and pump status—at user-configurable intervals (1 s to 10 min). Data export is supported via USB flash drive in CSV format. Remote monitoring and control are enabled through optional Ethernet gateway modules supporting HTTP API and OPC UA protocols. Firmware updates are performed via secure signed packages to ensure integrity. All alarm conditions trigger automatic data snapshot capture and persistent storage, satisfying FDA 21 CFR Part 11 requirements for electronic record retention when paired with validated network infrastructure.

Applications

• Temperature-controlled synthesis in glass or stainless-steel jacketed reactors (1–50 L scale)
• Calibration of thermocouples, RTDs, and infrared sensors across extended thermal ranges
• Stability testing of pharmaceutical formulations per ICH Q1A(R3) guidelines
• Thermal cycling of composite materials during mechanical property evaluation (ASTM D696, ISO 11359)
• Preconditioning of optical components prior to interferometric measurement
• Support for HPLC column ovens, GC injectors, and rheometer temperature blocks requiring tight gradient control

FAQ

What heat transfer fluids are compatible with the ZT-100-200-30H?

Synthetic silicone oils (e.g., Dow Corning DC-200 series), polyalkylene glycols (e.g., Marlotherm SH), and inhibited ethylene glycol/water mixtures (up to 60% glycol) are validated for use. Avoid chlorinated solvents, mineral oils above 150 °C, and fluids with flash points below 60 °C.

Can the unit operate unattended for extended periods?

Yes—integrated safety interlocks (high/low pressure cutoffs, dry-run detection, overtemperature shutdown) and scheduled auto-start/stop functionality enable 72+ hour unattended operation under validated protocols.

Is remote diagnostics supported?

Standard RS-485 MODBUS RTU allows integration with third-party monitoring systems. Optional Ethernet module adds web-based status dashboard and email/SMS alerting via SMTP/HTTP POST.

What maintenance intervals are recommended?

Compressor oil analysis every 5,000 operating hours; refrigerant charge verification annually; heat exchanger cleaning every 12 months (or per fluid analysis report); touchscreen calibration biannually.

Does the system meet ISO/IEC 17025 requirements for calibration labs?

When operated with NIST-traceable reference thermometers and documented SOPs, the ZT-100-200-30H satisfies temperature uniformity and stability criteria for accredited calibration of secondary standards per ISO/IEC 17025:2017 Clause 6.4.6.