Tianfeng TF-HX-20A Digital Precision Circulating Chiller/Heater

Overview

The Tianfeng TF-HX-20A Digital Precision Circulating Chiller/Heater is a self-contained, dual-mode temperature control system engineered for laboratory environments requiring high-stability thermal management across a broad operational range (−10 °C to 99 °C). Unlike passive water baths, this unit integrates an air-cooled hermetic compressor and precision resistive heating elements within a single compact chassis, enabling active thermoregulation via closed-loop PID feedback. Its core function is to maintain a spatially uniform, time-invariant temperature field—either inside its 20-liter stainless-steel bath or externally via pumped circulation—making it suitable as both a primary test environment and a secondary temperature source for peripheral instrumentation. The device operates on the principle of forced convection heat exchange: chilled or heated fluid is circulated through an optimized evaporator and heat exchanger assembly, then delivered at controlled flow rates to external apparatuses such as rotary evaporators, viscometers, electrophoresis systems, cryogenic medical devices, or vacuum pumps. Its design adheres to fundamental thermodynamic constraints for lab-scale thermal stability, prioritizing minimal thermal gradient (<0.05 °C/mm vertically in bath), rapid thermal response (<15 min to stabilize from ambient to −10 °C), and long-term drift resistance (<±0.05 °C over 8 h at setpoint).

Key Features

• Microprocessor-controlled PID algorithm with adaptive tuning for ±0.1 °C temperature stability across full operating range
• Stainless-steel bath chamber (20 L capacity) with corrosion-resistant finish and integrated fluid-level sensor
• Dual-circulation architecture: independent internal recirculation for bath homogeneity + external port for auxiliary equipment integration
• Air-cooled, sealed refrigeration system using imported high-efficiency compressor; no external chiller water required
• Touch-sensitive soft-key interface with dual digital LED display showing real-time temperature and programmable timer
• Programmable functions including scheduled startup, delayed shutdown, and user-defined temperature ramp profiles
• Comprehensive safety monitoring: over-temperature cutoff, differential-temperature alarm (indicating pump failure or blockage), and dry-run protection
• Compact footprint (550 × 368 × 898 mm) optimized for benchtop or under-bench installation in regulated laboratory spaces

Sample Compatibility & Compliance

The TF-HX-20A accommodates aqueous, ethylene glycol–water mixtures, silicone oils, and other non-corrosive heat-transfer fluids compatible with stainless-steel wetted parts. It supports sample containers up to 200 mm in diameter and 300 mm in height within the bath. For external applications, the unit delivers flow rates of 12–18 L/min at ≤0.3 bar backpressure, sufficient for coupling with standard rotary evaporators (e.g., Buchi R-300), electrophoresis tanks, laser cooling manifolds, and analytical instrument chillers. Manufactured under ISO 9001:2000–certified quality management systems, the device meets structural and electrical safety requirements per IEC 61010-1 for laboratory equipment. While not intrinsically rated for hazardous locations, its construction complies with general-purpose lab environmental standards (EN 61326-1 for EMC, EN 60335-1 for household/industrial safety). Documentation includes factory calibration reports traceable to NIM (National Institute of Metrology, China), supporting GLP-compliant recordkeeping when paired with validated external sensors.

Software & Data Management

The TF-HX-20A operates via embedded firmware without proprietary PC software; all configuration and monitoring occur through the front-panel interface. However, it supports RS-232 serial output (optional adapter) for integration into centralized lab automation platforms. Logged parameters—including setpoint, actual bath temperature, compressor status, alarm events, and runtime hours—are stored in non-volatile memory for retrieval during maintenance audits. When deployed in regulated environments (e.g., pharmaceutical QC labs), users may implement manual logbooks or third-party SCADA systems to satisfy FDA 21 CFR Part 11 requirements for electronic records. The unit does not feature built-in audit trails or user-role authentication, but its deterministic behavior and stable thermal output enable reproducible experimental conditions essential for ISO/IEC 17025 method validation.

Applications

• Chemical synthesis: precise temperature control for exothermic/endothermic reactions in jacketed reactors and calorimetry setups
• Pharmaceutical R&D: cold-chain simulation for drug stability testing (ICH Q1A–Q5C), dissolution apparatus temperature regulation
• Materials science: thermal conditioning of polymer melts prior to rheological analysis or DSC sample loading
• Biochemistry: maintaining constant electrophoresis buffer temperature to prevent band distortion or gel denaturation
• Instrument cooling: sustained thermal management for electron microscopes, mass spectrometer ion sources, and laser diodes
• Quality control: standardized viscosity measurement using capillary or rotational viscometers requiring ISO 8502-compliant bath temperatures

FAQ

What types of heat-transfer fluids are compatible with the TF-HX-20A?
Deionized water, 30–50% ethylene glycol/water mixtures, and low-viscosity silicone oils (≤100 cSt at 25 °C) are recommended. Avoid halogenated solvents, strong acids/bases, or fluids with flash points below 60 °C.
Can the unit operate continuously at −10 °C ambient temperature?
Yes—the air-cooled condenser is rated for continuous operation in ambient environments from 10 °C to 35 °C. Below 10 °C, condenser efficiency declines; supplemental insulation of external tubing is advised.
Is external temperature monitoring supported?
The unit includes a PT100 sensor input port (optional accessory) for connecting an external probe; temperature readings from this probe can be displayed and used for cascade control in advanced configurations.
How is calibration verification performed?
Users should verify accuracy annually using a NIST-traceable reference thermometer immersed at the bath’s geometric center. Factory calibration covers three points: 0 °C, 25 °C, and 60 °C; deviation must remain within ±0.1 °C at each point.
What maintenance is required for long-term reliability?
Biannual inspection of condenser coil cleanliness, annual replacement of circulating fluid (if glycol-based), and verification of pump seal integrity. Compressor oil is sealed for life; no user-serviceable parts exist within the refrigeration circuit.