Great Wall DL30-700 Integrated Circulating Chiller (-30°C to +5°C)

Overview

The Great Wall DL30-700 is an integrated, water-cooled circulating chiller engineered for precise and stable low-temperature thermal management in analytical and synthetic laboratory applications. Operating within a controlled range of –30°C to +5°C, it delivers consistent cooling performance via a closed-loop circulation system that maintains thermal equilibrium across connected instrumentation. Its core thermodynamic architecture employs a hermetically sealed, high-efficiency compressor paired with an environmentally compliant refrigerant (R-404A or equivalent), eliminating ozone-depleting chlorofluorocarbons while meeting international refrigerant phase-out directives (e.g., EU F-Gas Regulation No. 517/2014). Unlike open-bath chillers, the DL30-700 utilizes a fully sealed fluid circuit—minimizing evaporation loss, reducing operator exposure to coolant, and preventing contamination of heat-transfer media. This design supports long-term operational integrity in regulated environments where reproducibility, safety, and resource efficiency are critical.

Key Features

• Integrated, space-efficient chassis with side-panel access for rapid maintenance and component inspection
• Stainless steel (SUS 304 standard) wetted parts and chemically inert polymer fittings—resistant to corrosion from common organic solvents, aqueous buffers, and mild acids/bases
• 20 L/min flow rate at 0.4 bar delivery pressure—sufficient to support simultaneous cooling of multiple high-heat-load instruments (e.g., rotary evaporators, jacketed reactors, or laser sources)
• Real-time liquid level monitoring via calibrated sight tube; integrated low-level cutoff prevents dry-run damage to pump and heat exchanger
• Multi-layer protection logic: automatic freeze inhibition, flow obstruction detection, compressor overload prevention, and pressure anomaly alerting
• Dual-point temperature control with ±0.3°C stability over full operating range—calibrated per internal reference sensor traceable to NIST-traceable standards
• Onboard pressure gauge at outlet port enables verification of system hydraulic integrity and filter status
• High-efficiency particulate filtration installed inline to protect downstream equipment from debris and precipitate accumulation

Sample Compatibility & Compliance

The DL30-700 is designed for compatibility with a broad spectrum of laboratory instrumentation requiring active thermal regulation—including but not limited to rotary evaporators, jacketed glass reactors, vacuum freeze dryers, electrophoresis power supplies, TEM/SEM cold stages, and continuous-wave laser diodes. Its closed-loop architecture ensures compatibility with both water-based and water-glycol coolant mixtures (up to 30% v/v ethylene glycol), enabling extended low-temperature operation without freezing risk. All materials contacting coolant comply with USP Class VI biocompatibility requirements and EU REACH Annex XIV restrictions. The unit meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU). While not certified for FDA 21 CFR Part 11 out-of-the-box, its analog control interface and non-networked architecture allow straightforward integration into validated systems under GxP frameworks when deployed with documented calibration and change-control procedures.

Software & Data Management

The DL30-700 operates via a dedicated microprocessor-based controller with LED display and tactile keypad interface—designed for reliability in electromagnetically noisy lab environments. It does not feature network connectivity, remote software, or cloud data logging, thereby eliminating cybersecurity vulnerabilities and simplifying qualification under ISO/IEC 17025 or GLP audit conditions. Temperature setpoints, real-time bath temperature, flow status, and fault codes are displayed locally. Calibration records—including sensor offset adjustments and verification against external platinum resistance thermometers (PRTs)—can be maintained manually in lab notebooks or electronic quality management systems (QMS). Optional RS-485 Modbus RTU output is available upon request for integration with building management systems (BMS) or centralized HVAC monitoring platforms.

Applications

This chiller serves as a foundational thermal utility in pharmaceutical development labs (e.g., crystallization studies, lyophilization cycle support, and stability chamber auxiliary cooling), chemical synthesis workflows (low-temperature Grignard reactions, nitration, or lithiation), bioprocessing (fermentor jacket cooling, chromatography column temperature control), and materials science (cryo-SEM sample preparation, polymer rheology testing). Its –30°C capability enables solvent condensation in large-scale rotary evaporation setups, while its +5°C upper limit supports controlled thawing protocols and enzymatic assay stabilization. Universities and contract research organizations leverage its robustness for multi-user shared instrumentation cores where uptime, chemical compatibility, and minimal consumables dependency are operational priorities.

FAQ

What coolant fluids are compatible with the DL30-700?
Deionized water is recommended for operation above 0°C. For sub-zero use, a mixture of deionized water and USP-grade propylene glycol (≤30% v/v) is validated to prevent freezing and maintain thermal conductivity.
Can the unit operate continuously under full load?
Yes—the compressor and pump are rated for 24/7 duty cycles at ambient temperatures ≤32°C and relative humidity ≤80% non-condensing, provided adequate ventilation and coolant replenishment intervals are observed.
Is external water supply required for water-cooled operation?
No—the DL30-700 is self-contained; “water-cooled” refers to its internal condenser cooling loop, which uses recirculated process coolant—not municipal water—in contrast to air-cooled models.
How often should the filter cartridge be replaced?
Under typical lab use with clean coolant, replacement is recommended every 6 months or after 1,000 operating hours—whichever occurs first—as part of routine preventive maintenance.
Does the unit include factory calibration documentation?
Each unit ships with a Certificate of Conformance and a temperature verification report at three points (–30°C, 0°C, +5°C) generated using NIST-traceable reference standards.