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

Overview

The Great Wall DLSB-ZC Low-Temperature Circulating Vacuum Pump is an integrated laboratory utility system engineered for simultaneous vacuum generation and precise low-temperature fluid circulation. Unlike conventional water aspirators or standalone diaphragm vacuum pumps, the DLSB-ZC employs a closed-loop refrigerated circulation architecture—combining a hermetically sealed compressor-based cooling system with a three-port oil-free vacuum manifold. Its operational principle relies on vapor compression refrigeration to maintain coolant temperature between –10 °C and 25 °C, while a corrosion-resistant stainless steel (AISI 304) evaporator ensures thermal stability and chemical compatibility during extended operation. Designed explicitly for rotary evaporation workflows, the unit delivers stable vacuum levels down to 20 mbar (0.098 MPa absolute) while concurrently supplying chilled coolant to condenser jackets—thereby enhancing solvent recovery efficiency, reducing bumping risk, and enabling controlled distillation of thermolabile compounds.

Key Features

• Integrated dual-function architecture: simultaneous vacuum generation and temperature-controlled coolant circulation in a single compact chassis
• Self-contained refrigeration system with adjustable setpoint (–10 to 25 °C); maintains coolant at ~4 °C under typical lab conditions for optimal vacuum pump performance
• Three independent vacuum ports with individual analog vacuum gauges (0–100 kPa scale), enabling real-time monitoring of pressure across multiple concurrent applications
• AISI 304 stainless steel evaporator core for resistance to organic solvents, acids, and alkaline media; supports long-term reliability in QC, synthetic chemistry, and natural product isolation labs
• High-capacity 20 L reservoir with 30 L/min rated flow rate and 600–2550 W variable refrigeration output—optimized for dynamic thermal load management during multi-stage evaporation protocols
• Oil-free, maintenance-minimized vacuum generation; no lubricant contamination risk to sensitive samples or downstream instrumentation

Sample Compatibility & Compliance

The DLSB-ZC is compatible with standard laboratory glassware interfaces—including 10/15/19/24 standard taper joints—and routinely deployed with rotary evaporators (e.g., Buchi R-300, IKA RV 10), cold traps, and short-path distillation systems. Its stainless steel wetted surfaces comply with general requirements for equipment used in ISO/IEC 17025-accredited testing laboratories. While not certified to UL/CSA or CE for medical device use, the unit meets IEC 61010-1:2010 safety standards for electrical equipment for measurement, control, and laboratory use. Its stable vacuum output supports method validation per USP <721> (Vacuum Drying) and ASTM E1510 (Standard Practice for Determining Volatile Content), and its temperature control fidelity aligns with GLP-compliant environmental monitoring expectations for sample preparation workflows.

Software & Data Management

The DLSB-ZC operates as a stand-alone benchtop instrument without embedded microprocessor control or digital connectivity. All operational parameters—including temperature setpoint, vacuum port activation, and pump status—are managed via front-panel mechanical dials and toggle switches. Analog vacuum gauges provide direct visual readouts without software dependency, ensuring uninterrupted functionality in environments where networked devices are restricted (e.g., explosion-proof zones, radio-frequency-sensitive NMR suites). For laboratories requiring audit-ready records, integration with external data loggers (e.g., Omega OM-DAQPRO-5300 series) via 4–20 mA or 0–5 V analog outputs is supported through optional signal interface modules—enabling traceable temperature and pressure trending compliant with FDA 21 CFR Part 11 when paired with validated electronic record systems.

Applications

• Rotary evaporation of heat-sensitive pharmaceutical intermediates and natural extracts under controlled sub-ambient condensation temperatures
• Multi-vessel parallel concentration in analytical chemistry labs—three independent vacuum ports allow simultaneous operation of up to three rotovaps or cold finger assemblies
• Vacuum-assisted crystallization and recrystallization workflows requiring stable sub-ambient jacket temperatures to modulate nucleation kinetics
• Distillation of high-boiling-point solvents (e.g., DMF, DMSO, ethylene glycol) where conventional water-cooled condensers exhibit insufficient thermal gradient
• Preparative chromatography fraction collection under reduced pressure with integrated cold trapping to minimize volatile loss
• Environmental sample preparation (e.g., EPA Method 502.2, 8081B) involving solvent exchange and concentration steps under inert, low-temperature vacuum conditions

FAQ

Can the DLSB-ZC be used with aggressive solvents such as chloroform or acetone?
Yes—the evaporator and internal coolant loop are constructed from AISI 304 stainless steel, which demonstrates broad compatibility with common organic solvents. However, prolonged exposure to halogenated solvents at elevated temperatures may accelerate surface passivation; routine inspection of seals and gaskets is recommended.

Does the unit require external chiller water or tap water connection?
No. The DLSB-ZC is fully self-contained: it circulates dielectric coolant internally and rejects heat via rear-mounted air-cooled condenser coils. No external water source or drainage is needed.

What is the expected service life under continuous 8-hour daily operation?
Based on manufacturer field data and component MTBF specifications, the compressor and vacuum manifold are rated for ≥15,000 hours of cumulative runtime when operated within ambient temperature (5–25 °C) and humidity (<80% RH non-condensing) specifications.

Is remote monitoring or Ethernet connectivity available?
Not natively. The base model features analog-only controls and displays. Digital telemetry requires third-party analog-to-digital conversion hardware and custom SCADA integration.

How does the DLSB-ZC compare to cryogenic vacuum pumps in terms of ultimate vacuum performance?
It is not a cryopump. The DLSB-ZC achieves 20 mbar ultimate vacuum using a robust diaphragm pump configuration—sufficient for most rotary evaporation and vacuum drying applications—but does not reach high-vacuum regimes (<10⁻³ mbar) associated with turbomolecular or diffusion pumping systems.