The Great Wall DLSB-ZC Vacuum-Capable Low-Temperature Circulating Pump

Overview

The Great Wall DLSB-ZC Vacuum-Capable Low-Temperature Circulating Pump is an integrated laboratory utility system engineered for simultaneous vacuum generation and precise low-temperature fluid circulation. Unlike conventional standalone chillers or water aspirators, this device employs a hermetically sealed vapor-compression refrigeration cycle coupled with a three-port diaphragm-based vacuum manifold to deliver stable sub-ambient coolant temperatures and reliable negative pressure—both critical for efficient rotary evaporation, solvent recovery, and cold-trap applications. Its dual-function architecture eliminates the need for separate chiller and vacuum pump units, reducing footprint, interconnection complexity, and thermal drift during extended distillation protocols. The system maintains coolant temperature at approximately 4 °C under operational load—a condition optimized to suppress vapor pressure of common organic solvents while sustaining vacuum integrity across all three ports. Designed for continuous duty in analytical and preparative chemistry labs, the DLSB-ZC complies with IEC 61010-1 safety standards for laboratory equipment and incorporates overheat, overcurrent, and low-level liquid protection circuits.

Key Features

• Integrated dual-mode operation: simultaneous refrigerated circulation (–10 °C to 25 °C range) and vacuum generation (down to 2 kPa absolute) within a single chassis
• Triple independent vacuum ports with individual analog vacuum gauges (0–0.1 MPa scale), enabling real-time monitoring and parallel operation with multiple evaporators or reaction vessels
• Stainless steel evaporator coil and reservoir construction ensures long-term resistance to corrosion from aqueous, acidic, and mildly organic coolants
• High-capacity 20 L insulated reservoir with level sensor and overflow protection; supports extended unattended operation during multi-hour distillations
• Refrigeration system rated for 600–2550 W cooling output, dynamically adjusted via PID-controlled compressor modulation to maintain ±2 °C setpoint stability under variable thermal load
• Low-noise diaphragm vacuum pump assembly with chemically resistant PTFE/NBR membranes, rated for 10 L/min per port at 2 kPa ultimate vacuum

Sample Compatibility & Compliance

The DLSB-ZC is compatible with standard ground-glass jointed glassware—including 24/40 and 29/32 rotary evaporator assemblies—and interfaces seamlessly with condensers, cold traps, and vacuum manifolds requiring ≤2 kPa operating pressure. It accepts ethylene glycol/water mixtures, ethanol/water blends, and other non-flammable, low-viscosity heat transfer fluids. All wetted materials meet ISO 8502-3 requirements for metallic surface cleanliness and are certified free of leachable heavy metals per EN 71-3. The unit conforms to CE marking directives (2014/30/EU EMC and 2014/35/EU LVD), carries RoHS 2011/65/EU compliance documentation, and supports GLP-aligned operation through traceable setpoint logging (when paired with optional RS485 interface module).

Software & Data Management

While the base DLSB-ZC operates via front-panel digital controls with LED setpoint display and manual parameter adjustment, an optional RS485 communication module enables integration into centralized lab automation platforms. When connected, users may log temperature setpoints, actual reservoir temperature, vacuum readings per port, and runtime hours via Modbus RTU protocol. Data export supports CSV format for post-processing in MATLAB, LabVIEW, or LIMS environments. Audit trail functionality—including operator ID tagging and timestamped parameter changes—is available when deployed with compliant third-party SCADA software satisfying FDA 21 CFR Part 11 electronic record requirements.

Applications

• Rotary evaporation of thermolabile compounds under controlled low-temperature vacuum conditions
• Coolant supply for jacketed reactors requiring simultaneous vacuum sealing and external temperature control
• Condenser cooling in fractional distillation setups where vapor-phase backpressure must remain below 2 kPa
• Low-temperature trapping of volatile solvents during vacuum filtration or lyophilization pre-chilling cycles
• Multi-station vacuum drying of hygroscopic samples using distributed port allocation

FAQ

Can the DLSB-ZC operate continuously for 24 hours?
Yes—the system is rated for continuous duty with built-in thermal cutouts and automatic restart after cooldown.

What is the recommended coolant mixture for optimal performance?
A 30% v/v ethylene glycol–water solution is advised for freeze protection down to –15 °C and minimal viscosity increase at 4 °C operating point.

Is the vacuum performance affected by ambient temperature fluctuations?
The refrigeration subsystem compensates for ambient variations between 5–25 °C; however, sustained operation above 25 °C ambient may reduce ultimate vacuum by up to 0.5 kPa due to condenser inefficiency.

Does the unit support external temperature probe feedback for process control?
Not natively—but the RS485 option allows connection to external Pt100 sensors via programmable logic controllers for closed-loop bath-to-jacket temperature regulation.

Are replacement diaphragms and refrigerant service kits available through authorized channels?
Yes—genuine OEM diaphragm kits (P/N: DLSB-ZC-DIA-KIT) and R134a recharge kits (P/N: DLSB-ZC-REF-KIT) are supplied with full technical bulletins and leak-test certification.