Zhonghuan Furnace ZH-VDO Series Vacuum Drying Oven

Overview

The Zhonghuan Furnace ZH-VDO Series Vacuum Drying Oven is an engineered solution for moisture-sensitive, oxidation-prone, or thermally labile sample processing in research laboratories, quality control environments, and material science facilities. Unlike conventional forced-air ovens, this system operates under reduced atmospheric pressure—typically down to 10 Pa (0.1 mbar) when paired with a compatible two-stage rotary vane vacuum pump—to lower the boiling point of solvents and volatile compounds. This enables gentle, low-temperature drying without thermal degradation, decomposition, or surface oxidation. The oven employs resistive heating elements embedded within insulated chamber walls, delivering stable thermal energy directly to the stainless-steel interior. Its microprocessor-based PID control continuously monitors and adjusts power output to maintain setpoint accuracy within ±1 °C across the full 5–250 °C operating range—even under dynamic vacuum conditions—ensuring high reproducibility essential for method validation and regulatory compliance.

Key Features

• Robust 304 stainless-steel chamber with seamless welded corners and electropolished interior surface for corrosion resistance and easy decontamination
• Dual-display digital controller showing both chamber temperature and real-time vacuum level (when connected to optional vacuum gauge module)
• High-integrity door sealing system featuring dual silicone gaskets and clamping lever mechanism compliant with ISO 2859-1 sampling standards for leak integrity verification
• Tempered double-glass observation window with anti-fog coating, enabling continuous visual monitoring without compromising vacuum integrity
• Over-temperature protection circuit with independent mechanical cut-off switch (resettable) meeting IEC 61000-6-2 EMC immunity requirements
• Modular vacuum interface (ISO-KF 25) supporting integration with oil-lubricated or dry scroll vacuum pumps per ASTM E29-23 calibration guidelines

Sample Compatibility & Compliance

The ZH-VDO series accommodates a broad spectrum of sample types—including pharmaceutical powders, lithium-ion battery electrode coatings, polymer films, ceramic green bodies, and biological tissue specimens—without cross-contamination risk due to its non-porous, non-shedding chamber surface. It supports drying protocols aligned with USP , ISO 12100 (safety of machinery), and GB/T 29251–2012 (Chinese national standard for vacuum ovens). When operated with documented SOPs and calibrated instrumentation, the system meets GLP audit requirements for data traceability and environmental condition logging. Optional RS485 communication port enables connection to LIMS or SCADA systems for 21 CFR Part 11–compliant electronic record generation, including timestamped temperature/vacuum profiles and operator ID tagging.

Software & Data Management

While the base unit features standalone microcontroller operation, the optional ZH-Link software suite (Windows-compatible) provides extended functionality: real-time graphing of temperature and vacuum trajectories, automated protocol sequencing (e.g., ramp-hold-evacuate cycles), and export of .csv/.xlsx datasets with metadata (operator, batch ID, ambient conditions). All logged parameters include cryptographic hash signatures to prevent post-acquisition tampering—critical for FDA inspection readiness. Audit trails capture every parameter change, user login/logout event, and alarm activation with immutable timestamps, satisfying ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).

Applications

• Residual solvent removal from active pharmaceutical ingredients (APIs) prior to lyophilization or tablet compression
• Moisture conditioning and outgassing of optical components and vacuum-compatible sensors
• Thermal aging studies of encapsulants and conformal coatings per IPC-TM-650 2.6.25
• Drying of hygroscopic reference standards used in gravimetric calibration (e.g., NIST SRM 2890)
• Pre-treatment of metal oxide catalysts to eliminate physisorbed water before BET surface area analysis
• Stabilization of nanomaterial dispersions where oxidative aggregation must be avoided during solvent evaporation

FAQ

What vacuum level can the ZH-VDO achieve, and is a pump included?
The oven itself does not include a vacuum pump; it is supplied with an ISO-KF 25 vacuum port and sealing flange. When paired with a standard two-stage rotary vane pump (e.g., 2–4 m³/h capacity), typical ultimate pressure is 5–10 Pa. Dry scroll pumps may achieve lower base pressures (<1 Pa) but require evaluation for chemical compatibility.
Is the temperature uniformity specification valid under vacuum or at atmospheric pressure?
The stated uniformity (≤ ±1 °C) is verified under operational vacuum conditions at steady state, per ISO 14644-3 Annex B test methodology using nine calibrated PT100 probes distributed throughout the working volume.
Can the ZH-VDO be used for sterilization?
No. While capable of sustained temperatures up to 250 °C, this model lacks the steam generation, pressure containment, and cycle validation features required for sterilization per ISO 17665. It is intended for drying, degassing, and thermal conditioning—not microbiological kill validation.
Does the controller support programmable multi-step profiles?
Yes. The microprocessor allows up to 8 segments per program, including ramp rates (0.1–10 °C/min), dwell times (1 min to 99 h 59 min), and vacuum hold triggers synchronized with temperature events.
How often does the door seal require replacement?
Under normal use (≤5 cycles/day), the dual silicone gasket set maintains vacuum integrity for ≥24 months. A preventive maintenance checklist—including seal compression testing and visual crack inspection—is provided in the operation manual per ISO/IEC 17025 Clause 6.4.10.