800°C Pit-Type Atmosphere Stirring Furnace

describe

The 800°C pit-type atmosphere stirring furnace combines controlled atmosphere heating and uniform stirring, ideal for thermal processing, material synthesis, alloy preparation, and laboratory research applications.

Product Features

Temperature Control System

The furnace is equipped with an advanced intelligent control system featuring a 10-inch industrial touchscreen for centralized operation and real-time process monitoring. The high-precision temperature controller supports up to 50-point temperature calibration, ensuring exceptional control accuracy throughout the thermal process. Operators can store and manage up to 15 sintering programs directly through the touchscreen interface, improving production efficiency and process repeatability. A Siemens PLC control platform combined with a high-performance IGBT power module enables multiple operating modes, including constant current, constant voltage, and constant power control, while providing real-time monitoring of voltage, current, and power parameters.
To ensure safe and reliable operation, the system adopts a dual-loop control and protection architecture. Comprehensive protection functions include overshoot prevention, over-adjustment protection, thermocouple failure detection, phase-loss protection, overvoltage protection, overcurrent protection, overtemperature protection, current feedback monitoring, and soft-start control. An integrated memory retention function preserves all operating parameters during unexpected power interruptions, preventing data loss and reducing downtime. In addition, operational records and alarm logs can be exported for process analysis and quality traceability, with historical data retained for up to three months without automatic overwriting.
For convenient transportation and installation, the equipment is fitted with four heavy-duty Fuma swivel casters for smooth movement and positioning. Four dedicated lifting lugs are also integrated into the furnace structure, allowing safe lifting and handling during installation, relocation, or maintenance procedures. This design enhances mobility while maintaining structural stability for industrial applications.

Stimmung

The furnace is designed to operate with a variety of protective and inert gases, including nitrogen (N₂), argon (Ar), and other non-reactive process gases. This flexible atmosphere control capability allows users to create highly stable processing environments tailored to specific material and thermal treatment requirements.
By introducing inert gases into the furnace chamber, oxidation, decarburization, and unwanted chemical reactions can be effectively minimized during high-temperature processing. This is particularly important for sensitive materials such as advanced ceramics, powder metallurgy components, battery materials, semiconductor materials, rare earth compounds, and specialty alloys, where product quality and material purity are critical.
The atmosphere control system supports precise gas introduction and continuous atmosphere maintenance throughout the heating cycle. The stable protective environment helps improve product consistency, enhance surface quality, reduce material loss, and optimize sintering or heat-treatment results. Different gas combinations can be selected according to process requirements, providing greater flexibility for research, development, and industrial production.
In addition, the sealed furnace structure works together with the gas control system to maintain atmosphere stability while reducing gas consumption. This design improves operational efficiency and ensures reliable performance during long-duration thermal processes. The ability to utilize nitrogen, argon, and various inert gases makes the furnace an ideal solution for laboratories, research institutes, universities, and industrial manufacturers requiring controlled-atmosphere high-temperature processing.

Aufheiz- und Abkühlgeschwindigkeit

The furnace features a highly flexible temperature control system with freely adjustable heating rates to accommodate a wide range of thermal processing requirements. Users can precisely configure heating ramps from as low as 1°C per hour for sensitive materials requiring gradual temperature changes, up to a maximum heating rate of 20°C per minute for rapid processing applications. This broad adjustment range allows the furnace to support diverse sintering, heat treatment, calcination, and material research processes while maintaining excellent temperature stability and process consistency.
The cooling process is also carefully controlled to ensure product quality and equipment reliability. Above 500°C, the system supports a controlled cooling rate of approximately 10°C per minute, helping to reduce thermal stress and improve process repeatability. Below 500°C, the furnace transitions to natural cooling, providing a safe and energy-efficient cooling method. In addition, programmable cooling functions are available, allowing users to create customized cooling profiles for materials that require precise thermal management.
To ensure safe and efficient operation, detailed temperature range specifications and recommended maximum heating rate settings are clearly documented within the equipment manual. This guidance helps operators select appropriate process parameters based on material characteristics and application requirements, reducing the risk of thermal shock and improving product quality. The combination of adjustable heating rates, programmable cooling capabilities, and comprehensive operational guidance makes the furnace suitable for advanced laboratory research, industrial production, and high-precision thermal processing applications.

Rührwerk

The system is equipped with an advanced frame-type stirring mechanism featuring a three-layer impeller structure designed for high-efficiency mixing and uniform material dispersion in high-temperature and reactive environments. The lowest impeller layer is positioned 10 ± 1 mm above the bottom of the reactor vessel, while the upper layer is set at 60% of the vessel height. The lateral clearance between the impeller frame and the inner wall of the reactor is precisely controlled at 10 ± 1 mm, ensuring stable operation and minimizing dead zones. The stirring assembly is centrally mounted inside the vessel and can be vertically adjusted, allowing flexible positioning to match different process requirements.
The impellers are manufactured from high-performance Nickel N6 material, providing excellent high-temperature resistance, corrosion resistance, and mechanical strength. The blade design is engineered with sufficient thickness according to structural drawings to prevent deformation or breakage during long-term operation. Final manufacturing drawings are confirmed with the customer to ensure precise customization and reliability.
Sealing performance is achieved through a combination of welded bellows between the stirring shaft and the reactor cover, along with a quick-lock flange structure. High-temperature resistant fluororubber O-rings ensure stable sealing, while a dedicated cooling water layer is integrated at the sealing zone to prevent thermal aging during continuous operation, significantly extending service life and ensuring safe operation under demanding conditions.
The stirring system is driven by a magnetic fluid coupling, providing non-contact power transmission for improved sealing integrity and reduced wear. The reactor cover and stirring assembly feature an integrated lifting and rotating mechanism, allowing automated opening, vertical adjustment of the stirrer, and lateral movement for maintenance and loading operations.
Operational flexibility is further enhanced through programmable control of stirring speed, direction, and bidirectional rotation (forward and reverse). These parameters can be synchronized with each segment of the sintering curve, enabling coordinated control of temperature, stirring speed, and rotational direction throughout the entire process. The system supports stepless speed adjustment within a range of 5–100 rpm, ensuring precise process control and excellent mixing uniformity for advanced material synthesis, chemical reactions, and high-temperature processing applications.

Druckfestigkeit

The furnace chamber is constructed using high-strength steel plates with a thickness ranging from 6 to 20 mm, ensuring excellent structural integrity and long-term durability under demanding operating conditions. All steel plates are double-sided welded to enhance mechanical strength and sealing performance. The chamber is engineered to withstand an overpressure of up to 20 kPa, providing a reliable safety margin for high-temperature and controlled-atmosphere processes.
The system supports a precisely controlled internal pressure range from 50 Pa to 250 Pa, which can be freely adjusted according to process requirements. Once set, the pressure can be maintained continuously for up to 24 hours, ensuring stable reaction conditions and consistent process quality. This stable pressure control is essential for applications requiring precise atmosphere regulation, such as material synthesis, heat treatment, and chemical reaction processes.
To achieve high-accuracy pressure regulation, the system is equipped with a high-sensitivity pressure transmitter with a measurement range of -1000 Pa to 1000 Pa. The transmitter continuously monitors real-time pressure changes inside the furnace chamber and feeds data back to the control system.
An intelligent PLC-based automation system coordinates the operation of multiple key components, including inlet and exhaust valves, nitrogen mass flow controllers, and exhaust gas discharge valves. Through real-time feedback control, the system automatically adjusts gas flow and ventilation to maintain stable pressure conditions, ensuring safe, reliable, and highly repeatable process performance.
In addition, the equipment is designed with ergonomic considerations, featuring a standard operating interface height of approximately 1.35 meters. This human-centered design improves operator accessibility, enhances usability, and reduces fatigue during long-term operation. Overall, the combination of robust structural design, precise pressure control, and intelligent automation ensures high performance and stability in advanced industrial and laboratory applications.

Messung des Sauerstoffgehalts

The system is equipped with a high-precision oxygen analysis and atmosphere control module, designed to ensure stable and accurately controlled furnace gas conditions during thermal processing. The oxygen sensor features a wide measurement range from 0 ppm to 10%, enabling reliable monitoring from ultra-low oxygen environments to standard atmospheric conditions. When connected to the exhaust pipeline, a pre-filtration unit is required to ensure measurement accuracy and protect the sensor from contamination or particulate interference.
Precise oxygen regulation is a key function of the system. Before the heating process begins, the oxygen concentration inside the furnace chamber is controlled to below 10 ppm, ensuring a low-oxygen starting environment for sensitive materials. During high-temperature operation, especially at around 700°C, the system further reduces oxygen levels to approximately 5 ppm to maintain strict atmosphere purity and ensure furnace gas tightness. This high level of control helps prevent oxidation, contamination, and unwanted chemical reactions during processing. Alternatively, the air damper opening can be automatically adjusted based on real-time pressure feedback, enabling dynamic atmosphere regulation.
To enhance operational flexibility, a manual control mode via PLC integration is optionally available before the oxygen analyzer stage. This allows operators to switch between automatic and manual control modes depending on process requirements, enabling independent adjustment of valve opening and closing operations when necessary. This dual-mode control strategy improves adaptability for complex process conditions.
Overall, the combination of high-accuracy oxygen measurement, intelligent automatic regulation, and optional manual override ensures stable atmosphere control, improved process safety, and reliable performance for advanced material processing, heat treatment, and research applications requiring strict oxygen control environments.

Application areas

Used for ceramic sintering, advanced material research, and powder metallurgy requiring precise temperature and atmosphere control.
Suitable for heat treatment processes including annealing, calcination, and oxidation/reduction experiments in laboratory and industry.
Applied in semiconductor materials, battery development, and rare earth processing with strict oxygen and gas atmosphere regulation.

Why Choose Us

Advanced furnace technology with precise temperature, pressure, and atmosphere control ensures stable and reliable high-performance operation.
Intelligent PLC system with multi-layer protection improves safety, reduces risk, and supports long-term continuous industrial use.
Flexible customization options and professional technical support provide tailored solutions for diverse laboratory and production needs.

FAQ

Q1: What is the oxygen measurement range of the system?
A: The oxygen analyzer measures from 0 ppm to 10%, ensuring accurate monitoring from ultra-low to high oxygen conditions.

Q2: What oxygen level is required during operation?
A: Before heating, oxygen should be below 10 ppm; at 700°C, it is controlled around 5 ppm for stable atmosphere control.

Q3: Does the system support automatic oxygen control?
A: Yes, the system automatically adjusts air dampers and gas flow based on real-time pressure and oxygen feedback.

Q4: Is manual control available for special conditions?
A: Yes, PLC-based manual mode allows independent control of valves and switching between automatic and manual operation.

Q5: Why is a pre-filter needed for the exhaust connection?
A: The pre-filter protects the oxygen sensor from dust and impurities, ensuring accurate measurement and long service life.