Dongtai DTY-10A Low-Temperature Constant-Temperature Circulator

Overview

The Dongtai DTY-10A Low-Temperature Constant-Temperature Circulator is an engineered thermal management system designed for precise, stable temperature control in laboratory-scale applications requiring both active cooling and heating. It operates on a dual-mode thermoregulation principle—integrating a high-efficiency air-cooled hermetic compressor for refrigeration and a resistive heating element for upward temperature modulation—within a single integrated bath architecture. The unit maintains setpoint stability within ±0.1 °C across its full operational range of −10 °C to +99 °C, enabling reproducible thermal conditioning of samples, reactors, spectrometers, or external apparatus via external circulation. Its design follows fundamental heat transfer principles—including forced-convection fluid dynamics and optimized evaporator surface area—to ensure rapid thermal equilibration and minimal spatial gradient (<0.2 °C across bath volume), critical for kinetic studies, calibration traceability, and material property testing under controlled thermal environments.

Key Features

• Air-cooled, fully sealed rotary compressor delivering 700 W nominal cooling capacity at standard ambient (20 °C), eliminating dependency on external chilled water infrastructure.
• Independent 1000 W heating circuit with PID-regulated power output ensures seamless transition between cooling and heating modes without thermal overshoot.
• 10-liter stainless steel (304 grade) bath with seamless welds and polished interior—resistant to corrosion from aqueous, ethylene glycol, or ethanol-based heat-transfer fluids.
• Digitally controlled variable-speed circulation pump (1–10 L/min), supporting external loop configurations up to 15 m total tubing length and 3 m vertical lift.
• High-resolution LED display with intuitive touch-sensitive interface; real-time monitoring of bath temperature, setpoint, pump status, and alarm conditions.
• Dual-stage safety architecture: primary over-temperature cutoff and secondary differential-temperature alarm (ΔT > 5 °C between sensor and bath core) compliant with IEC 61010-1:2010 Class II requirements.
• Thermally optimized evaporator geometry based on extended surface-area heat exchange theory—reducing cooldown time from 20 °C to −10 °C by ≥35% versus conventional coil designs.

Sample Compatibility & Compliance

The DTY-10A supports direct immersion of glassware, metal reaction vessels, and probe-based sensors (e.g., Pt100, thermocouples) into the bath. Its open-top configuration (230 × 115 × 150 mm aperture) accommodates standard 1–5 L jacketed reactors and optical cells. When used in external circulation mode, it interfaces with jacketed columns, calorimeters, or UV-Vis cuvette holders via 1/4″–3/8″ compression fittings. The unit meets CE marking requirements per EMC Directive 2014/30/EU and LVD Directive 2014/35/EU. Its temperature control performance aligns with ASTM E2777-22 (Standard Practice for Calibration of Liquid-in-Glass Thermometers) and ISO/IEC 17025:2017 clause 6.4.7 for equipment suitability in accredited testing laboratories. No refrigerant containing CFCs, HCFCs, or HFC-404A is used; R134a refrigerant complies with EU F-Gas Regulation (EU) No 517/2014.

Software & Data Management

While the DTY-10A operates as a standalone instrument with local digital control, its RS-232 serial interface (standard) enables integration with LabVIEW™, MATLAB®, or custom SCADA systems for remote setpoint programming, real-time data logging, and alarm event capture. Optional USB-to-RS232 adapters support direct connection to Windows/Linux hosts. Logged parameters include timestamped bath temperature, setpoint, pump speed, and fault codes—exportable as CSV for audit trails. Though not FDA 21 CFR Part 11–compliant out-of-box, the device supports GLP/GMP workflows when deployed with validated third-party data acquisition software featuring electronic signatures, audit logs, and user access controls.

Applications

• Calibration of temperature-sensitive analytical instruments (e.g., HPLC column ovens, viscometer baths, densitometers).
• Stabilization of laser diodes, photomultiplier tubes, and CCD detectors requiring sub-0.2 °C thermal drift control.
• Controlled-rate cooling/heating cycles in polymer crystallization, protein folding, or phase-transition studies.
• External cooling of rotary evaporators, vacuum pumps, or grinding mills to prevent thermal degradation.
• Supporting ISO 17025-compliant environmental stress testing of electronic components under defined thermal profiles.

FAQ

What heat-transfer fluids are compatible with the DTY-10A bath?

Deionized water, 30–50% aqueous ethylene glycol solutions, and pure ethanol are routinely used. Avoid chlorinated solvents or mineral oils due to compatibility risks with seals and stainless steel.
Can the unit maintain −10 °C continuously under full load?

Yes—provided ambient temperature remains ≤25 °C and the bath is covered to minimize condensation and heat ingress. Continuous operation at minimum temperature requires adequate ventilation around the rear compressor grille.
Is the circulation pump flow rate adjustable during operation?

Yes—via dedicated soft key; flow changes take effect within 3 seconds without interrupting temperature control or triggering alarms.
Does the DTY-10A support external temperature feedback control?

No—the unit regulates only bath temperature. For process-critical external-loop control, a separate PID controller with external sensor input is recommended.
What is the mean time between failures (MTBF) for the compressor system?

Based on accelerated life testing per IEC 60068-2-64, MTBF exceeds 25,000 hours under typical lab usage (8 h/day, 5 days/week, ambient ≤28 °C).