The Great Wall ZT-50-200-40H Closed-Loop Refrigerated & Heated Circulator

Overview

The Great Wall ZT-50-200-40H Closed-Loop Refrigerated & Heated Circulator is an engineered thermal management system designed for precise, dynamic temperature control of external process equipment—including jacketed reactors, stirred tanks, distillation columns, environmental test chambers, and semiconductor thermal platforms. Operating on a fully sealed dual-mode thermofluid circulation principle, it integrates independent refrigeration, heating, and pre-cooling subsystems within a single robust chassis. Unlike open-bath or single-function units, the ZT-50-200-40H enables continuous ramping across its full operational range (−40 °C to +200 °C) without manual intervention or fluid exchange—eliminating vapor loss, oxidation risk, and ambient moisture ingress. Its high-efficiency brazed plate heat exchanger, magnetically coupled circulation pump, and intelligent thermal load balancing architecture ensure stable setpoint maintenance (±0.5 °C) under variable process demands, making it suitable for GLP-compliant R&D labs and cGMP-managed pilot-scale production environments.

Key Features

• Fully sealed closed-loop design minimizes thermal fluid degradation, extends service life of synthetic heat transfer media (e.g., silicone oils, polyalkylene glycols), and eliminates evaporation-related top-ups or contamination risks.
• Triple-system architecture: independent refrigeration, electric heating, and pre-cooling circuits allow simultaneous or sequential operation—enabling rapid thermal transitions (e.g., from +180 °C to −30 °C in under 45 minutes under typical load conditions).
• Magnetically driven circulation pump ensures zero seal leakage across the entire temperature range, critical for handling flammable, toxic, or high-purity process fluids in pharmaceutical synthesis or fine chemical applications.
• 5.7-inch color TFT touchscreen with dual-language interface (English/Chinese), real-time graphical display of bath temperature, load temperature, and programmed thermal profiles.
• Advanced control logic combining fuzzy inference and adaptive PID algorithms delivers high repeatability and minimal overshoot—even during complex multi-segment ramp/soak cycles (up to 120 programs, 100 segments each).
• Comprehensive safety suite includes overtemperature cutoff, dry-run protection via level monitoring, phase-loss detection, earth-leakage circuit interruption, overload current limiting, and timed compressor restart delay.
• Air-cooled condensation and pre-cooling system reduces dependency on municipal water infrastructure—ideal for laboratories with limited cooling water access or sustainability mandates.

Sample Compatibility & Compliance

The ZT-50-200-40H circulates thermally stable, non-corrosive heat transfer fluids compatible with stainless steel (316L) wetted parts and fluoropolymer seals (e.g., FKM, PTFE). It supports common industrial media including Dowtherm J, Therminol VP-1, and Shell Heat Transfer Oil S2. While not certified to UL/CE as a standalone appliance, its electrical architecture conforms to IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emission) standards. When integrated into validated systems, it meets functional requirements for ASTM E2910 (thermal stability testing), ISO 17025 calibration traceability (via external PT100 reference), and FDA 21 CFR Part 11 data integrity protocols when paired with compliant SCADA or LIMS interfaces.

Software & Data Management

The embedded controller logs timestamped temperature data at user-selectable intervals (1–60 seconds) and stores up to 30 days of historical records internally. RS485 Modbus RTU communication enables integration with LabVIEW, MATLAB, or DeltaV DCS platforms for remote supervision and automated batch reporting. Optional Ethernet expansion supports OPC UA connectivity and secure TLS-encrypted data export. All programmable parameters—including setpoints, ramp rates, soak durations, and alarm thresholds—are subject to audit trail logging with operator ID tagging, satisfying ALCOA+ principles for regulated environments.

Applications

• Temperature control of double- and triple-jacketed glass or stainless-steel reactors in API synthesis, polymerization, and crystallization processes.
• Thermal conditioning of vacuum chambers during thin-film deposition or material aging studies.
• Dynamic thermal cycling for automotive component validation (e.g., battery thermal management system testing).
• Calibration of infrared sensors, thermocouples, and RTDs against NIST-traceable references.
• Stabilization of laser diodes, optical benches, and cryogenic sample stages requiring sub-ambient precision.
• Simulating process transient conditions—such as exothermic quenching or endothermic distillation reflux—in pilot-scale unit operations.

FAQ

What types of heat transfer fluids are compatible with the ZT-50-200-40H?

Synthetic silicone oils, polyalkylene glycols, and aromatic hydrocarbon-based fluids with flash points above 220 °C and pour points below −45 °C are recommended. Avoid water-glycol mixtures above 90 °C due to vapor pressure and corrosion concerns.

Can the unit operate unattended overnight or over weekends?

Yes—its programmable scheduler supports delayed start, automatic shutdown, and multi-day thermal profiles with built-in safety interlocks that remain active during standby mode.

Is remote monitoring supported out-of-the-box?

Standard RS485 Modbus RTU allows basic telemetry; Ethernet and OPC UA require optional hardware module installation and configuration by qualified personnel.

How is temperature uniformity maintained across large external loads?

By maintaining ≥30 L/min flow rate at 1.0 bar pressure and leveraging high thermal mass (13 L bath volume), the system compensates for thermal lag in jackets up to 100 L volume—provided external piping is insulated and minimized.

Does the unit meet GMP documentation requirements for pharmaceutical manufacturing?

While the device itself is not GMP-certified, its programmable logic, audit trail capability (with optional software), and deterministic control behavior support qualification under Annex 15 and IQ/OQ protocols when deployed within a validated system architecture.