LAC PKR & PKRC Series Gas-Circulating Box-Type Laboratory Furnaces

Overview

The LAC PKR and PKRC series are high-integrity, gas-circulating box-type laboratory furnaces engineered for precise thermal processing under controlled atmospheres. These furnaces operate on the principle of forced convection within a hermetically sealed chamber, enabling reproducible heat treatment—such as annealing, tempering, sintering, and brazing—under inert or reducing gases (e.g., nitrogen, argon, or synthetic forming gas). With maximum operating temperatures of 1100 °C (PKR models) or 900 °C (PKRC models), they meet stringent requirements for metallurgical research, powder metallurgy, ceramic development, and advanced materials synthesis. The furnace architecture integrates structural rigidity (medium-carbon steel frame), dual-zone heating (side-mounted ceramic-tube-wound elements and bottom-embedded SiC-protected resistive wires), and optimized airflow dynamics to achieve DIN 17052-1 Class A temperature uniformity across the working zone—typically ±3 °C at setpoint under steady-state conditions.

Key Features

• Hermetic chamber design with stainless steel water-cooled flange and high-temperature silicone rubber door gasket, minimizing gas leakage (<0.5 mbar·L/s under differential pressure testing)
• Dual-position heating system: side elements wound on ceramic tubes + bottom elements embedded in grooves and protected by robust silicon carbide (SiC) plates, ensuring mechanical durability and thermal stability
• Overpressure safety vent with manual reset, integrated into the chamber wall to prevent hazardous pressure buildup during gas purging or process ramping
• INDUSTRY-series PID temperature controller with real-time clock, supporting up to 30 independent multi-segment programs (15 steps each), including ramp rate control, soak dwell, and delayed start scheduling
• Type S noble-metal thermocouple for long-term stability and accuracy in oxidizing or inert environments up to 1100 °C
• Zero-crossing solid-state relay for contactless power switching—eliminating arcing, extending component life, and supporting GLP-compliant audit trails when paired with optional data logging
• Lightweight refractory brick insulation (density ~0.6 g/cm³) providing low thermal mass and rapid cool-down rates without compromising hot-face integrity

Sample Compatibility & Compliance

These furnaces accommodate a wide range of sample geometries and material classes—including metal powders (e.g., stainless steel, tool steels), ceramic green bodies, catalyst substrates, and composite preforms—within standardized crucibles or custom fixtures. The sealed atmosphere capability supports processes requiring oxygen partial pressures below 10⁻⁴ mbar, making them suitable for applications governed by ASTM B925 (sintering of metal powders), ISO 2738 (ceramic sintering characterization), and internal R&D protocols aligned with ISO/IEC 17025 calibration traceability. All electrical components comply with IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emission) standards; CE marking is affixed per Machinery Directive 2006/42/EC and Low Voltage Directive 2014/35/EU.

Software & Data Management

While the standard INDUSTRY controller operates as a standalone unit, optional RS232 or RS485 interfaces enable bidirectional communication with laboratory PC systems running third-party SCADA or LIMS platforms. When equipped with the optional graphic temperature recorder, time-stamped thermocouple data (±0.5 °C accuracy, 1 Hz sampling) is archived in CSV format for post-process analysis and regulatory submission. For GxP environments, the controller’s event log—including program start/stop timestamps, alarm triggers (overtemperature, door open, gas flow loss), and parameter modifications—is timestamped and non-erasable, satisfying FDA 21 CFR Part 11 requirements for electronic records when deployed with appropriate user access controls and audit trail validation.

Applications

• Sintering of ferrous and non-ferrous metal powders (e.g., Fe–Cu, Ni–Al, WC–Co) under nitrogen or dissociated ammonia
• Controlled-atmosphere annealing of cold-rolled strip samples to study recrystallization kinetics
• High-temperature brazing of aluminum alloys using argon-shielded cycles with precise dew point control
• Thermal stabilization of battery cathode precursors (e.g., NMC, LFP) prior to electrochemical testing
• Heat treatment of additive-manufactured Ti-6Al-4V components to relieve residual stress and homogenize microstructure
• Pre-oxidation of silicon carbide fibers for ceramic matrix composite fabrication

FAQ

What inert gases are compatible with the PKR/PKRC series?
Nitrogen, argon, hydrogen-nitrogen mixtures (e.g., 5% H₂/95% N₂), and synthetic forming gas (10% H₂/90% N₂) are routinely used. Hydrogen-only operation requires additional safety interlocks and is not supported in standard configuration.
Can the furnace be operated under vacuum?
No—these units are designed exclusively for positive-pressure gas circulation. Vacuum operation requires a separate vacuum-rated furnace (e.g., LAC VAC series) with reinforced chamber walls and diffusion-pump-compatible seals.
Is temperature uniformity validated per DIN 17052-1?
Yes—each unit undergoes factory verification using a 9-point sensor array per DIN 17052-1 Annex A. Uniformity reports (including worst-case deviation at max temperature) are supplied with delivery documentation.
What maintenance intervals are recommended for the water-cooled flange?
Coolant flow must be verified daily; deionized water should be replaced every 6 months or sooner if conductivity exceeds 5 µS/cm. Visual inspection of O-rings and flange surface integrity is required before each high-temperature cycle.
Are replacement heating elements field-serviceable?
Yes—side elements mounted on ceramic tubes and bottom SiC-encased wires are modular and replaceable using standard workshop tools. LAC provides OEM part numbers and torque specifications in the service manual.