Hanuo DL-1005 Cryogenic Constant Temperature Circulator

Overview

The Hanuo DL-1005 Cryogenic Constant Temperature Circulator is an air-cooled, microprocessor-controlled recirculating chiller engineered for precise thermal management in life science, pharmaceutical, and analytical laboratories. It operates on the principle of vapor-compression refrigeration, utilizing a hermetically sealed compressor and environmentally compatible refrigerant to deliver stable low-temperature coolant flow to external instruments or internal bath applications. Unlike immersion chillers or dry-block systems, the DL-1005 maintains continuous, closed-loop circulation of heat-transfer fluid—typically water/ethylene glycol mixtures—enabling both active cooling and accurate temperature hold across a range of −15 °C to +5 °C. Its design prioritizes long-term operational reliability, thermal uniformity, and seamless integration with spectrophotometers, rotary evaporators, calorimeters, NMR precooling units, and other temperature-sensitive equipment requiring secondary cooling or auxiliary thermal regulation.

Key Features

• Stainless steel bath and housing construction ensures corrosion resistance, low particulate shedding, and compatibility with aqueous and mild organic coolants—critical for GMP and GLP lab environments.
• Integrated open-bath reservoir (5 L capacity) supports direct sample immersion while simultaneously enabling external circulation via dual-port fittings (inlet/outlet), facilitating dual-zone thermal control or remote instrument cooling.
• Microprocessor-based touch interface provides intuitive setpoint adjustment, real-time temperature display, and programmable auto-shutdown (0–100 h timer), reducing energy consumption and mitigating unattended operational risk.
• Air-cooled hermetic compressor system incorporates multi-stage protection: compressor start-delay logic prevents short-cycling; thermal overload cutoff safeguards against coil overheating; and current-sensing circuitry interrupts power during electrical anomalies.
• High-flow peristaltic-style circulation pump delivers up to 15 L/min at low backpressure, ensuring sufficient thermal exchange rate for jacketed reactors, condensers, and flow-cell systems without cavitation or flow instability.
• Factory-calibrated temperature control achieves ±0.5 °C stability under steady-state conditions, verified using traceable NIST-traceable reference sensors—meeting requirements for ISO/IEC 17025-compliant calibration workflows.

Sample Compatibility & Compliance

The DL-1005 circulator is compatible with standard laboratory heat-transfer fluids, including deionized water, 30% ethylene glycol/water blends (down to −15 °C), and select silicone oils (with viscosity ≤50 cSt). It is not rated for flammable solvents, strong acids/bases, or chlorinated hydrocarbons. All wetted components—including bath liner, pump head, and tubing connectors—are electropolished 304 stainless steel, minimizing leachables and supporting USP endotoxin testing protocols. The unit complies with IEC 61010-1:2010 for laboratory electrical safety and meets CE marking requirements for EMC (EN 61326-1) and low-voltage directives. While not FDA 21 CFR Part 11 validated out-of-the-box, its audit-ready event log (time-stamped temperature deviations, power cycles, alarm triggers) supports retrospective validation under GxP frameworks when deployed with documented SOPs.

Software & Data Management

The DL-1005 operates via embedded firmware with no external PC dependency. All operational parameters—including setpoint, actual bath temperature, runtime, and alarm history—are stored in non-volatile memory and accessible through the front-panel interface. Event logs retain the last 100 entries (e.g., “Overtemp Alert – 2024-06-12 14:22:07”, “Auto-Shutdown Executed”) with timestamp resolution of ±1 second. Optional RS-485 serial output (Modbus RTU protocol) enables integration into centralized lab monitoring systems (e.g., LabArchives, DeltaV, or custom SCADA) for remote setpoint adjustment, real-time telemetry, and automated report generation aligned with ISO 15197 or ASTM E2500-13 data integrity guidelines.

Applications

• Temperature stabilization of UV-Vis and fluorescence spectrophotometer Peltier cells during extended kinetic assays.
• Cooling of rotary evaporator condensers to improve solvent recovery efficiency at sub-ambient pressures.
• Maintaining constant bath temperature for differential scanning calorimetry (DSC) reference cells and thermal conductivity probes.
• Supplying chilled fluid to jacketed bioreactors during high-yield fermentation to manage exothermic metabolic heat.
• Precooling mobile phase reservoirs in HPLC systems to reduce baseline drift and improve retention time reproducibility.
• Supporting cryo-microtome operation by circulating −10 °C coolant through specimen stage jackets.

FAQ

What is the minimum operating temperature achievable with the DL-1005 using standard coolant?
The unit reaches −15 °C with a 30% ethylene glycol/water mixture under ambient conditions ≤25 °C and relative humidity ≤60%. Lower temperatures require specialized fluids and are not supported.
Can the DL-1005 be used for heating applications?
No. This model is refrigeration-only; it lacks integrated resistive heating elements and is not designed for above-ambient temperature control.
Is external calibration of the internal temperature sensor possible?
Yes. The unit features a dedicated PT100 sensor port for connection to external calibrated references; firmware allows offset correction within ±2.0 °C range per ISO/IEC 17025 calibration procedures.
Does the circulation pump support variable speed control?
No. Pump speed is fixed at optimal flow rate (15 L/min) to ensure consistent pressure head across typical lab tubing configurations (ID ≥6 mm). Flow modulation is achieved externally via bypass valves.
What maintenance intervals are recommended for long-term reliability?
Compressor oil and refrigerant charge require inspection every 24 months; air filter cleaning is advised quarterly; stainless steel bath should be rinsed with deionized water after glycol use to prevent residue buildup.