Jihepu DFY-5/10 Cryogenic Circulating Thermostat

Overview

The Jihepu DFY-5/10 Cryogenic Circulating Thermostat is a precision-engineered laboratory temperature control system designed for stable, reproducible thermal management of external equipment and reaction vessels. It operates on a closed-loop refrigeration cycle utilizing a Danfoss hermetic scroll compressor and R22 refrigerant, enabling continuous heat exchange between the internal 5-liter stainless-steel bath and externally connected apparatus—such as rotary evaporators, spectrophotometer cells, jacketed reactors, or analytical detectors. Unlike simple immersion chillers, this unit integrates active magnetic stirring (50 W), high-flow circulation (20 L/min at up to 2 MPa pressure), and wide-range digital temperature control (–10 °C to +99 °C under standard ambient conditions), making it suitable for both exothermic reaction quenching and low-temperature kinetic studies. Its controller supports setpoint programming within an extended sensor range (–150 °C to +100 °C), though operational stability at extremes requires optional cryogenic fluid compatibility and environmental conditioning.

Key Features

• Hermetically sealed Danfoss compressor ensures long-term reliability and minimal maintenance in continuous-duty laboratory environments.
• PT100 platinum resistance temperature sensor delivers high linearity and repeatability across the full operating range, calibrated to ±0.5 °C accuracy at steady state.
• Dual-function bath design: combines direct immersion capability with high-pressure, high-flow external circulation via nickel-plated copper coil and 4# fittings (low-in/high-out orientation optimizes thermal homogeneity).
• Integrated 50 W internal magnetic stirrer eliminates need for external agitation in small-volume synthesis or calibration workflows.
• Digital microprocessor controller with real-time setpoint adjustment, 1 °C resolution display, and self-diagnostic fault logging—including compressor high-pressure lockout, pump thermal cutoff, and leakage detection.
• Corrosion-resistant epoxy-coated steel chassis (520 × 350 × 710 mm, 56 kg) provides mechanical stability and compatibility with fume hood or benchtop integration.

Sample Compatibility & Compliance

The DFY-5/10 is compatible with glass, stainless-steel, and PTFE-lined reaction vessels up to 5 L capacity when used in direct-bath mode. For external circulation, it interfaces with jacketed reactors (≥100 mL volume), HPLC column ovens, FTIR sample compartments, and calorimetric cells requiring precise thermal boundary conditions. The unit meets general electrical safety requirements per IEC 61010-1 (2010) for laboratory equipment and incorporates protections aligned with GLP-compliant operation: automatic shutdown on thermal runaway, pressure excursion, or power anomaly. While not intrinsically rated for Class I Division 1 hazardous locations, explosion-proof variants are available upon request—featuring ATEX-certified components, reinforced housing, and spark-free motor windings. All firmware and hardware configurations adhere to ISO/IEC 17025 traceability principles when paired with NIST-traceable calibration standards.

Software & Data Management

This model operates via embedded digital control without proprietary PC software; however, analog output (0–10 V or 4–20 mA) is available for integration into centralized lab monitoring systems (e.g., LabVIEW, DeltaV, or Siemens Desigo). Temperature logs can be manually recorded using the front-panel display and timestamped against lab notebook entries. For audit-ready environments, optional RS485 Modbus RTU interface enables connection to SCADA platforms supporting FDA 21 CFR Part 11-compliant electronic record generation—provided external data acquisition hardware implements appropriate user authentication, audit trail, and electronic signature protocols. Calibration certificates (including as-found/as-left data) are supplied with each unit and may be extended annually per ISO/IEC 17025-accredited service providers.

Applications

• Controlled-rate cooling of Grignard or organolithium reactions to suppress side-product formation.
• Stabilization of UV-Vis cuvettes and fluorescence detector flow cells during spectral acquisition.
• Thermal conditioning of viscosity standards prior to Brookfield or Anton Paar rheometer calibration.
• Low-temperature crystallization studies in pharmaceutical process development (e.g., polymorph screening between –5 °C and +10 °C).
• Pre-chilling of solvents and reagents in automated synthesis platforms interfaced via external circulation loops.
• Environmental stress testing of optical sensors and microfluidic chips under regulated thermal ramp profiles.

FAQ

What is the minimum achievable bath temperature under typical lab conditions?
Under ambient conditions of 20 °C and 65% RH, the DFY-5/10 achieves a stable no-load equilibrium temperature of –10 °C. Lower temperatures require pre-cooled heat transfer fluid (e.g., ethylene glycol/water mixtures) and reduced ambient humidity.
Can this unit maintain temperature stability during high-heat-load applications like reflux condensation?
Yes—the 1248 W peak refrigeration capacity at –10 °C and progressive derating to 319 W at +99 °C allow dynamic compensation for moderate exothermic loads (<500 W) when coupled with adequate external heat exchange surface area.
Is the circulation pump compatible with organic solvents?
The sealed circulation pump is rated for water, aqueous buffers, and glycol-based heat transfer fluids. For chlorinated or aromatic solvents, consult Jihepu’s chemical compatibility chart and consider optional fluoropolymer-sealed pump variants.
Does the unit support remote start/stop or setpoint modulation?
Standard configuration includes local keypad control only; RS485 Modbus RTU or 0–10 V analog input modules are available as factory-installed options for programmable logic controller (PLC) integration.
What calibration documentation is provided?
Each unit ships with a factory calibration report verifying PT100 sensor linearity, temperature uniformity across the bath (±0.3 °C radial gradient), and refrigeration performance at three setpoints (–5 °C, 25 °C, 70 °C). NIST-traceable calibration certificates are available upon request.