ZiQi DLSB-10/20 Cryogenic Constant Temperature Circulator (-20°C to Ambient)

Overview

The ZiQi DLSB-10/20 Cryogenic Constant Temperature Circulator is a mechanically refrigerated, closed-loop liquid circulation system engineered for precise thermal management in laboratory and analytical instrumentation environments. Operating on vapor-compression refrigeration principles with a hermetically sealed compressor, it delivers stable sub-ambient cooling capacity across a controlled range of –20°C to ambient temperature. Unlike open-bath chillers or tap-water-based cooling solutions, the DLSB-10/20 maintains consistent coolant temperature, flow rate, and pressure—critical parameters for sustaining thermal equilibrium in sensitive downstream equipment such as rotary evaporators (e.g., 5 L scale), vacuum freeze dryers, electron microscopes, X-ray diffractometers, laser systems, and high-vacuum deposition tools. Its design prioritizes operational continuity under variable ambient conditions, including high-temperature or low-humidity lab environments where conventional water-cooling infrastructure may fail due to scaling, evaporation, or microbial growth.

Key Features

• Hermetically sealed, imported high-efficiency compressor delivering reliable long-term operation at sustained low-temperature setpoints
• Microprocessor-based digital temperature controller with LED display—enabling intuitive setpoint entry, real-time monitoring, and ±0.2°C thermal stability
• Corrosion-resistant fluid path constructed from stainless steel, fluoropolymer-lined tubing, and chemically inert pump housings—compatible with aqueous and mild organic coolants (e.g., 30% ethylene glycol/water)
• Constant-flow, constant-pressure circulation architecture supporting simultaneous multi-instrument cooling without flow redistribution or pressure drop-induced instability
• Integrated over-temperature, low-level, and phase-loss protection circuits compliant with IEC 61000-6-2 (EMC immunity) and IEC 61000-6-3 (EMC emission) standards
• Energy-efficient thermal design minimizing power draw during extended unattended operation—suitable for 24/7 deployment in GLP- and GMP-aligned laboratories

Sample Compatibility & Compliance

The DLSB-10/20 circulates non-hazardous heat-transfer fluids only; it is not intended for direct sample immersion or biological containment. Coolant compatibility includes deionized water, water–glycol mixtures (up to 40% v/v), and other low-viscosity, non-flammable, non-corrosive fluids meeting ASTM D1384 (corrosion inhibition) specifications. The unit complies with CE marking requirements under the EU Machinery Directive 2006/42/EC and Low Voltage Directive 2014/35/EU. While not certified to ISO 13485 or FDA 21 CFR Part 11, its deterministic control logic, non-volatile parameter storage, and absence of user-modifiable firmware make it suitable for use in IQ/OQ/PQ-validated workflows where traceable temperature stability is required per ISO/IEC 17025 clause 5.10.3.

Software & Data Management

The DLSB-10/20 operates via embedded firmware without external software dependency. All operational parameters—including setpoint, actual bath temperature, runtime hours, and fault logs—are retained in non-volatile memory and accessible through the front-panel interface. No USB, RS-232, or Ethernet connectivity is provided; however, analog 0–10 V or 4–20 mA output options (optional accessory) enable integration into centralized building management or SCADA systems for remote status monitoring. For audit-trail compliance in regulated labs, users are advised to pair the unit with external calibrated data loggers meeting NIST-traceable accuracy requirements (e.g., ±0.1°C over –20°C to 30°C).

Applications

• Condenser cooling for rotary evaporation of thermolabile compounds (e.g., natural product isolates, pharmaceutical intermediates)
• Thermal stabilization of vacuum manifold systems and cold traps in lyophilization pre-chilling stages
• Heat rejection for high-power optical components—including Ti:sapphire lasers, Raman spectrometers, and confocal microscope laser sources
• Process cooling in thin-film deposition systems (e.g., sputtering, e-beam evaporation) requiring ≤±0.5°C coolant temperature deviation over 8-hour cycles
• Environmental simulation support for material stress testing under controlled sub-zero thermal gradients
• Backup cooling redundancy for critical analytical instruments in core facility settings where chilled-water plant downtime poses operational risk

FAQ

What is the minimum achievable temperature with a full 10 L coolant load?
The DLSB-10/20 achieves –20°C under no-load conditions; with a full bath and typical 30% glycol–water mixture, the practical lower limit remains –18.5°C to –19.2°C depending on ambient temperature and heat load.
Can this unit be used with flammable solvents like acetone or ethanol as coolant?
No. The DLSB-10/20 is rated for non-flammable, non-toxic heat-transfer fluids only. Flammable liquids pose explosion hazards within the sealed refrigeration loop and violate IEC 60335-1 safety provisions.
Is the pump flow rate adjustable?
Flow is fixed at design specification (≥20 L/min at 4 m head); no manual or electronic flow modulation is supported. For variable-flow applications, an external bypass valve or secondary pump station is required.
Does the unit include a filtration system for coolant maintenance?
No integrated particulate or chemical filtration is included. Users must implement inline 5–10 µm mesh filters and periodic coolant replacement per ASTM D1121 guidelines to prevent pump wear and heat exchanger fouling.
What electrical supply is required for continuous operation?
220 V ±10%, 50 Hz single-phase supply with dedicated 16 A circuit breaker and proper grounding—essential to prevent compressor stall during voltage sag events common in shared lab power distribution networks.