Great Wall ZT-50-200-30H Closed-Loop High-Low Temperature Circulator
| Brand | The Great Wall |
|---|---|
| Origin | Henan, China |
| Manufacturer Type | Direct Manufacturer |
| Country of Origin | China |
| Model | ZT-50-200-30H |
| Instrument Type | Vertical |
| Temperature Stability | ±0.5 °C |
| Temperature Uniformity | ±0.8 °C (typical in 13 L bath at mid-depth) |
| Setpoint Accuracy | ±0.5 °C |
| Operating Temperature Range | −30 °C to +200 °C |
| Bath Volume | 13 L |
| Heating Power | 6 kW |
| Cooling Capacity | 7.5 kW @ 10 °C, 4.6 kW @ −10 °C, 2.5 kW @ −20 °C, 1.0 kW @ −30 °C |
| Pump Flow Rate | 30 L/min |
| Maximum Pump Pressure | 2.5 bar |
| Power Supply | 3-phase, 380 V, 50 Hz |
| Overall Dimensions (W×D×H) | 813 mm × 1092 mm × 1445 mm |
| Net Weight | 251 kg |
| Heat Exchanger | Fully Brazed Plate Type |
| Circulation Medium | Synthetic Heat Transfer Fluid (e.g., silicone oil or polyalkylene glycol-based) |
| Control Interface | 5.7″ TFT Color Touchscreen |
| Safety Protections | Overtemperature, overcurrent, overload, phase loss, low-level, leakage current, delayed startup, and dry-run prevention |
Overview
The Great Wall ZT-50-200-30H is a vertically oriented, fully closed-loop high-low temperature circulator engineered for precise, stable, and continuous thermal control of external process equipment. It integrates three thermally independent subsystems—refrigeration, heating, and pre-cooling—within a single robust chassis, enabling uninterrupted operation across its full −30 °C to +200 °C working range. Unlike open-bath chillers or standalone heaters, this unit maintains a hermetically sealed circulation path, eliminating vapor loss, oxidation of heat transfer fluid at elevated temperatures, and moisture ingress during cryogenic operation. Its core architecture employs a high-efficiency brazed plate heat exchanger and a magnetically coupled centrifugal pump, ensuring zero fluid leakage across the entire temperature span—a critical requirement for GMP-compliant pharmaceutical synthesis, catalyst testing, and high-purity material processing.
Key Features
- Triple-system architecture: Independent refrigeration, heating, and pre-cooling circuits allow seamless transition between extreme temperature setpoints without system downtime or manual intervention.
- Magnetically driven circulation pump: Eliminates mechanical seals, guaranteeing zero leakage and extended service intervals—even under thermal cycling from −30 °C to +200 °C.
- Brazed plate heat exchanger: Compact footprint with >92% thermal efficiency; optimized for rapid heat exchange between refrigerant and synthetic heat transfer fluid.
- Intelligent PID+ algorithm with adaptive tuning: Delivers ±0.5 °C temperature stability and <±0.8 °C uniformity in standard 13 L bath configuration, validated per ASTM E742 and ISO 17025 traceable protocols.
- 5.7-inch color TFT touchscreen interface: Graphical real-time display of bath temperature, outlet/inlet differential, pump status, alarm history, and system pressure—supporting multilingual UI (English, German, French, Spanish).
- Comprehensive safety suite: Dual-stage overtemperature cutoff, level-sensing float switch with audible/visual alert, earth leakage protection (30 mA), motor overload relay, and phase-failure detection compliant with IEC 61000-6-2 EMC standards.
- Air-cooled condensation: No external water supply required; suitable for laboratories with limited utility infrastructure or strict water conservation policies.
Sample Compatibility & Compliance
The ZT-50-200-30H is designed for integration with jacketed reactors (single-, double-, or triple-walled), stirred tanks, distillation columns, environmental test chambers, and vacuum-compatible thermal platforms. It supports common industrial heat transfer media—including methyl silicone oils (e.g., DC-200 series), polyalkylene glycols (PAGs), and specialized low-volatility ester blends—compatible with USP Class VI and FDA 21 CFR 178.3570 requirements. All electrical components meet CE marking directives (2014/30/EU EMC, 2014/35/EU LVD), and the control firmware implements audit-trail-capable event logging aligned with GLP/GMP Annex 11 expectations. While not intrinsically rated for hazardous areas, optional ATEX-compliant variants are available upon request for Zone 2 installations.
Software & Data Management
The unit includes embedded Ethernet (RJ45) and RS485 Modbus RTU interfaces for bidirectional communication with laboratory information management systems (LIMS) or SCADA platforms. Optional Great Wall LabLink™ software enables remote monitoring, scheduled temperature ramps, data export in CSV/Excel format, and synchronized timestamping traceable to NTP servers. Alarm logs retain 10,000 entries with ISO 8601 timestamps, supporting root-cause analysis during regulatory audits. Firmware updates are performed via USB or network push, with SHA-256 signature verification to ensure integrity—fully compatible with IT security policies enforcing secure boot and firmware signing.
Applications
- Temperature control of glass-lined or stainless-steel jacketed reactors in API synthesis and polymerization processes.
- Thermal conditioning of calorimetric cells and rheometers requiring sub-zero stability and rapid ramp rates (≥2.5 °C/min from −30 °C to +100 °C).
- Simulating transient thermal profiles in automotive component testing (e.g., battery thermal management validation per ISO 12405-4).
- Stabilizing optical benches and interferometer stages where vibration-induced drift must remain <50 nm RMS.
- Supporting freeze-drying cycle development by coupling with shelf-cooling manifolds in pilot-scale lyophilizers.
- Calibration of platinum resistance thermometers (PRTs) and thermocouples across ITS-90 reference points.
FAQ
What types of heat transfer fluids are compatible with the ZT-50-200-30H?
Synthetic silicone oils, polyalkylene glycols (PAGs), and select low-volatility ester-based fluids meeting flash point >200 °C and pour point <−40 °C are recommended. Mineral oils are not advised due to oxidation risk above 120 °C.
Can this unit operate continuously at −30 °C ambient temperature?
Yes—the air-cooled condenser is rated for ambient operation up to +40 °C; however, sustained sub-zero bath operation requires adequate ventilation (>0.5 m³/s airflow) and clearance ≥300 mm on all sides.
Is the touchscreen interface programmable for multi-step temperature profiles?
Yes—up to 16 segments with ramp/hold parameters, trigger conditions (e.g., time, external digital input), and user-defined alarm thresholds.
Does the system support 21 CFR Part 11 compliance?
The base unit provides electronic audit trails and user-access controls; full Part 11 compliance requires LabLink™ software with role-based authentication, digital signatures, and encrypted database storage—available as a validated installation package.
What maintenance intervals are recommended for long-term reliability?
Compressor oil and refrigerant charge verification every 24 months; heat transfer fluid analysis annually; pump bearing inspection every 5 years or 10,000 operating hours—per manufacturer’s Maintenance Logbook (Ref. GW-ZT-MAN-REV4).
