The Great Wall ZT-20-200-30H Closed-Loop Refrigerated & Heated Circulator
| Brand | The Great Wall |
|---|---|
| Origin | Henan, China |
| Manufacturer Type | Direct Manufacturer |
| Instrument Type | Integrated Unit |
| Cooling Method | Air-Cooled |
| Temperature Range | −30 °C to +200 °C |
| Refrigeration Capacity | 0.3 kW (at −30 °C) to 1.7 kW (at +200 °C) |
| Temperature Stability | ±0.5 °C |
| Circulation Pump Pressure | 1 bar |
| Circulation Flow Rate | 30 L/min |
| Reservoir Volume | 20 L |
| Operating Mode | Continuous Duty |
Overview
The Great Wall ZT-20-200-30H is an integrated, air-cooled closed-loop refrigerated and heated circulator engineered for precise, dynamic temperature control across demanding laboratory and pilot-scale process applications. Unlike open-bath or single-function chillers, this system employs three independent yet interoperable thermal subsystems—refrigeration, heating, and pre-cooling—to enable seamless bidirectional temperature modulation without manual intervention. Its operational range spans −30 °C to +200 °C, making it suitable for high-temperature synthesis requiring thermal stability at elevated setpoints and low-temperature crystallization or cryogenic reaction quenching. The unit utilizes a fully sealed circulation architecture with magnetic-drive pumping, eliminating vapor loss, oxidation of heat-transfer fluid (e.g., silicone oil or specialized synthetic fluids), and environmental contamination—critical for GLP-compliant process validation and long-term fluid integrity. Heat exchange is accomplished via a compact, high-efficiency fully brazed plate heat exchanger, optimized for rapid thermal response and minimal footprint.
Key Features
- Triple-subsystem architecture: Independent refrigeration, heating, and pre-cooling circuits support continuous ramping, plateauing, and stepwise temperature transitions.
- Air-cooled condensation and pre-cooling design eliminates dependency on external water sources, reducing infrastructure requirements and enabling deployment in water-restricted environments.
- Magnetic-coupled circulation pump ensures zero leakage across the full operating temperature range, maintaining system integrity during extended operation with aggressive or viscous heat-transfer media.
- 5.7-inch color TFT touchscreen interface with dual-language support (English/Chinese), programmable logic control, and real-time graphical display of load temperature profiles.
- Advanced temperature regulation combining fuzzy logic and adaptive PID algorithms delivers ±0.5 °C stability under variable thermal loads, validated per ASTM E2877-21 for thermal performance testing.
- Comprehensive safety suite including overtemperature cutoff, delayed startup, ground-fault detection, overcurrent protection, overload monitoring, and real-time reservoir level sensing with audible/visual alerts.
- Programmable controller supports up to 120 multi-segment temperature programs (100 steps per program), scheduled operation, standby mode for experimental time-gating, and both constant-setpoint and dynamic ramp/soak control modes.
Sample Compatibility & Compliance
The ZT-20-200-30H is compatible with standard laboratory heat-transfer fluids rated for −40 °C to +220 °C service, including polyalkylene glycols, silicone oils, and specialized low-volatility synthetic formulations. Its sealed loop design meets ISO 17025:2017 requirements for calibration traceability in temperature-controlled test systems and supports audit-ready documentation when paired with optional data logging modules. The unit complies with IEC 61000-6-3 (EMC emissions) and IEC 61000-6-2 (immunity), and its electrical safety conforms to IEC 61010-1 for laboratory equipment. While not certified for Class I Div 1 hazardous locations, it is routinely deployed in non-explosive zones of pharmaceutical cleanrooms (ISO 5–8), chemical pilot plants, and materials R&D labs operating under cGMP-aligned quality systems.
Software & Data Management
The embedded controller provides native RS485/RS232 serial communication (Modbus RTU protocol) for integration into centralized lab automation platforms (e.g., LabVantage, Thermo Fisher SampleManager). Optional USB data export enables CSV-formatted temperature logs with timestamps, setpoint history, alarm events, and pump status. Audit trail functionality records operator actions, parameter changes, and fault resets—supporting FDA 21 CFR Part 11 compliance when used with validated third-party electronic lab notebook (ELN) systems. Firmware updates are performed via secure USB stick, with version rollback capability and checksum verification.
Applications
- Temperature control of double- and triple-jacketed glass reactors in API synthesis and fine chemical development.
- Thermal conditioning of stirred-tank bioreactors during fermentation and cell culture processes.
- Calibration and performance verification of DSC, TGA, and rheometry instrumentation requiring stable thermal boundary conditions.
- Process simulation for distillation column reboilers and condensers under dynamic reflux conditions.
- Material testing per ASTM D3418 (DSC), ISO 3146 (melting point), and ISO 11357 (thermal transitions) protocols.
- Thermal cycling of semiconductor packaging substrates and power electronics modules under controlled ramp rates.
- Environmental stress screening of automotive components in thermal shock test rigs.
- Temperature stabilization of vacuum chambers during thin-film deposition or plasma etching.
FAQ
What heat-transfer fluids are recommended for operation at +200 °C?
Silicone-based oils (e.g., Dow Corning 200 Fluid Series) or polyphenyl ether blends (e.g., Santowax RP) with flash points >300 °C and thermal stability ratings exceeding 220 °C are recommended. Always consult fluid manufacturer specifications for compatibility with stainless-steel wetted parts.
Does the unit support external temperature feedback from the process load?
Yes—the controller accepts analog input (0–10 V or 4–20 mA) from an external Pt100 or thermocouple sensor mounted on the reactor jacket, enabling cascade control for improved load-side accuracy.
Can the ZT-20-200-30H be operated in a ventilated fume hood?
Air-cooled operation makes it suitable for fume hood placement; however, minimum clearance of 300 mm around rear and top vents must be maintained to ensure adequate airflow and prevent compressor overheating.
Is remote monitoring possible via Ethernet or Wi-Fi?
The base model includes only RS485/RS232; Ethernet or Wi-Fi connectivity requires an optional industrial gateway module configured for OPC UA or MQTT protocol translation.
How is calibration traceability maintained for regulatory submissions?
The unit supports NIST-traceable PT100 sensor calibration using external reference standards. Full calibration records—including as-found/as-left data, uncertainty budgets, and technician signatures—can be generated manually or via integrated ELN interfaces.
