DL20 Series Low-Temperature Circulating Chiller

Overview

The DL20 Series Low-Temperature Circulating Chiller is an integrated, air-cooled refrigeration system engineered for precise thermal management in laboratory-scale analytical and process-critical applications. Based on vapor-compression refrigeration cycle architecture, it delivers stable sub-ambient temperature control by circulating a heat-transfer fluid (typically water/ethanol or water/glycol mixtures) through external equipment—such as rotary evaporators, spectrophotometers, NMR pre-cooling jackets, or reaction calorimeters. Its operational envelope spans −30 °C to +5 °C with continuous-duty capability, making it suitable for extended-duration experiments requiring reproducible thermal conditions. Designed for benchtop integration in compact laboratory spaces, the unit features a fully sealed circulation loop, eliminating volatile losses and minimizing contamination risk to connected instrumentation.

Key Features

• Hermetic scroll compressor from Copeland (Emerson), incorporating dual-flex mounting and unload-start technology to reduce mechanical stress during startup and ensure long-term reliability under cyclic load conditions.
• Air-cooled fin-and-tube condenser with oxygen-free copper spiral tubing and proprietary expansion joint bonding—optimized for high heat-transfer coefficient and simplified field maintenance.
• Coil-type evaporator immersed directly within the 30 L stainless-steel reservoir, enabling freeze-tolerant operation: even if the coolant solidifies, structural integrity of the heat exchanger remains uncompromised.
• Danfoss DML-series desiccant filter with 3A molecular sieve core, delivering deep moisture removal to prevent acid formation and corrosion within the refrigerant circuit—critical for sustaining system longevity and oil stability.
• High-efficiency canned motor circulation pump rated for 20 L/min at 0.4 bar pressure head, featuring low-vibration operation and chemical resistance to common coolant formulations.
• Integrated digital microprocessor controller with backlit Chinese-language LCD interface, supporting real-time monitoring of setpoint, actual bath temperature, system pressure, and reservoir level.
• Comprehensive safety architecture including delayed compressor restart, earth-leakage protection, overcurrent cutoff, and dual-stage thermal overload safeguards—aligned with IEC 61010-1 requirements for laboratory electrical equipment.

Sample Compatibility & Compliance

The DL20 chiller circulates non-corrosive, low-viscosity heat-transfer fluids compatible with standard laboratory plumbing materials (e.g., EPDM, Viton, and stainless-steel tubing). It supports ASTM E2913-21 protocols for thermal stability testing and meets ISO 17025-relevant environmental conditioning requirements when used as part of accredited test setups. While not certified to FDA 21 CFR Part 11 out-of-the-box, its controller logs timestamped temperature and fault events—enabling manual audit trail reconstruction for GLP/GMP-aligned workflows. The R134a refrigerant complies with Montreal Protocol phase-out schedules and EU F-Gas Regulation (EU) No 517/2014 Annex III.

Software & Data Management

The embedded controller provides local data logging of temperature setpoint, actual reservoir temperature, and runtime hours. Optional RS485 Modbus RTU interface (available via accessory module) enables integration into centralized LabVantage or LabWare LIMS environments for automated parameter capture. All alarm states—including low-level detection, overtemperature, and pump failure—are latched with persistent memory retention across power cycles. No cloud connectivity or proprietary software installation is required; configuration remains accessible via front-panel navigation only—reducing cybersecurity exposure in regulated lab networks.

Applications

• Condenser cooling for rotary evaporation systems operating below ambient temperature, especially during low-boiling-point solvent recovery (e.g., diethyl ether, pentane).
• Thermal stabilization of UV-Vis and FTIR spectrophotometer detectors to minimize dark-current drift and improve signal-to-noise ratio.
• Temperature control of electrophoresis apparatuses and PCR thermal cyclers requiring consistent cold-stage performance.
• Pre-cooling of gas chromatography inlet liners and detector zones to enhance compound resolution and reduce column bleed.
• Supporting cryo-microscopy sample stages and laser cavity cooling where moderate sub-zero capacity suffices without liquid nitrogen dependency.

FAQ

What coolant solutions are recommended for use with the DL20 chiller?

Deionized water mixed with 30–40% ethanol or propylene glycol is preferred for −30 °C operation. Pure water is acceptable above 0 °C but requires periodic biocide treatment to inhibit microbial growth.

Can the unit operate unattended overnight?

Yes—the continuous-duty design, combined with multi-layer safety interlocks and thermal cutouts, permits unmonitored operation for up to 72 hours when installed in ventilated, non-hazardous laboratory environments.

Is remote monitoring supported natively?

No native Ethernet or Wi-Fi interface is included; however, the optional RS485 port allows connection to programmable logic controllers (PLCs) or SCADA systems using standard Modbus register mapping.

How often should the desiccant filter be replaced?

Under typical usage (8 hrs/day, ambient RH 15% over baseline.

Does the chiller meet CE marking requirements?

The DL20 series conforms to EN 61000-6-3 (EMC emission) and EN 61000-6-2 (immunity) standards; full CE documentation is available upon request for EU-based procurement.