ZT-5-200-30H Closed-Loop Refrigerated & Heated Circulator by The Great Wall

Overview

The ZT-5-200-30H Closed-Loop Refrigerated & Heated Circulator is an engineered thermal management system designed for precise, stable, and bidirectional temperature control of external laboratory equipment—including jacketed reactors, rotary evaporators, calorimeters, and analytical instrumentation. Operating on a closed-loop circulation principle, it delivers conditioned heat transfer fluid (HTF) via an external circuit to maintain process temperatures within ±0.5 °C across its full operational range of −30 °C to +200 °C. Its air-cooled architecture eliminates dependency on chilled water infrastructure, making it suitable for standalone deployment in general-purpose and regulated lab environments. The unit integrates dual-mode thermal regulation—simultaneous heating and cooling capability enabled by independent compressor and electric heating circuits—ensuring rapid thermal response and minimal overshoot during dynamic setpoint transitions.

Key Features

• High-stability temperature control with real-time feedback loop and PID algorithm optimization, achieving ±0.5 °C uniformity at the outlet under steady-state conditions
• Air-cooled refrigeration system using environmentally compliant R404A refrigerant, eliminating need for facility-supplied cooling water or glycol loops
• Corrosion-resistant fluid path constructed entirely from AISI 304 stainless steel—including expansion tank, valves, and 1/2″ NPT external ports—ensuring compatibility with common HTFs (e.g., silicone oil, ethylene glycol/water mixtures)
• Touchscreen LCD interface with intuitive menu navigation, programmable ramp/soak profiles, and real-time display of outlet temperature, flow rate, system pressure, and alarm status
• Integrated safety architecture featuring delayed startup, overcurrent protection, dual-stage overtemperature cutoff (sensor + mechanical), and high-limit thermal fuse
• Robust circulation pump rated at 25 L/min maximum flow and 1.5 bar pressure head, supporting long-loop configurations up to 30 m total pipe length with minimal pressure drop

Sample Compatibility & Compliance

The ZT-5-200-30H supports a wide range of laboratory-scale thermal applications without requiring modifications to host equipment. It is routinely deployed with glass-jacketed reactors (1–50 L), rotary evaporators (up to 5 L capacity), and inline spectroscopic cells. All wetted materials comply with ISO 8502-3 for stainless steel surface cleanliness and meet RoHS Directive 2011/65/EU requirements. While not intrinsically rated for Class I Division 1 hazardous locations, optional ATEX-compliant variants (ZT-Ex series) are available upon request for flammable solvent environments. The unit’s design aligns with general Good Laboratory Practice (GLP) expectations for traceable temperature control, and its digital logging functionality supports audit readiness per FDA 21 CFR Part 11 when paired with validated software configurations.

Software & Data Management

The onboard controller stores up to 10 user-defined temperature programs, each supporting multi-segment ramps, holds, and cooldown sequences. Real-time operational data—including outlet temperature, setpoint deviation, pump current draw, and compressor runtime—is logged internally at 1-second intervals for up to 72 hours. Export is supported via USB flash drive in CSV format for post-processing in MATLAB, Excel, or LIMS platforms. Optional RS485 Modbus RTU communication enables integration into centralized building management systems (BMS) or SCADA networks. For GxP environments, third-party validation packages—including IQ/OQ documentation templates and electronic signature workflows—are available through certified partners.

Applications

• Controlled exothermic/endothermic synthesis in organic chemistry, including Grignard reactions, lithiation, and hydrogenation
• Temperature-dependent crystallization studies and polymorph screening in pharmaceutical development
• Stabilization of enzymatic assays and cell culture bioreactors requiring sub-ambient or elevated incubation
• Calibration and performance verification of DSC, TGA, and rheometry instruments requiring traceable thermal sourcing
• Process simulation for food science applications such as accelerated shelf-life testing and lipid phase behavior analysis

FAQ

What types of heat transfer fluids are compatible with the ZT-5-200-30H?

The system is compatible with silicone oils (e.g., DC200 series), aqueous glycol solutions (up to 60% v/v), and specialized low-temperature synthetic fluids—provided they exhibit viscosity 220 °C.
Can this circulator be used for vacuum jacketed applications?

Yes—its 1.5 bar pressure rating allows safe operation with vacuum-insulated reactors when configured with appropriate pressure-relief and venting protocols.
Is remote monitoring supported out of the box?

Standard configuration includes local touchscreen control only; remote access requires optional RS485-to-Ethernet gateway and custom SCADA integration.
How often does the refrigerant require servicing?

Under normal operating conditions and proper maintenance (e.g., annual condenser coil cleaning), the sealed R404A circuit typically requires no recharge for ≥8 years.
Does the unit support automatic shutdown upon reaching target temperature?

It maintains setpoint continuously unless manually paused or interrupted by safety interlock activation; programmable soak-and-hold logic is embedded in all temperature profiles.