Industrial Pyrolysis Furnaces - Technical Structure, Operating Principle, and Detailed Product Description
Pyrolysis furnaces are industrial cleaning systems used in the plastics industry to remove polymers, additives, and organic residues that accumulate on metal parts by converting them into carbon through a controlled thermal process. These systems are specifically designed to recover components such as nozzles, mould parts, filters, caps, tips, and metal carriers used in injection moulding, extrusion, and blow moulding processes, restoring them as close as possible to their original condition without causing damage.
The process applied in pyrolysis furnaces takes place in a controlled or oxygen-limited environment. Plastic residues do not burn directly; instead, under high temperature, their molecular bonds are broken down and converted into carbon-based ash. This allows effective cleaning without causing mechanical wear, chemical deformation, or dimensional loss on metal surfaces.
General Structure and Mechanical Design
Industrial pyrolysis furnaces are built with high-temperature-resistant steel housings, internal insulation layers, and heating elements designed to ensure uniform heat distribution. The furnace chamber is equipped with removable stainless steel baskets in which the parts to be cleaned are placed.
Key structural features include:
• High-temperature-resistant steel construction
• Multi-layer thermal insulation ensuring low external surface temperature
• Stainless steel (inox) loading and transport baskets
• Front door with safety locking system
• Automatic locking mechanism and temperature safety switches
The furnace doors are protected by safety switches that prevent opening until the internal temperature drops below a defined threshold, typically around 80°C. This design ensures maximum operator safety.
Operating Principle - Thermal Carbonization (Pyrolysis)
The operating principle of pyrolysis furnaces is based on a combination of natural convection and infrared heating. Electric heating elements raise the internal chamber temperature in a controlled manner, causing plastic residues to carbonize within a predefined temperature range.
The process steps can be summarized as follows:
• Plastic-coated metal parts are placed in baskets inside the furnace
• The door is closed and the automatic locking system is engaged
• The target temperature is set via a PID-controlled system
• Plastic residues carbonize under the effect of heat
• At the end of the cycle, only dry carbon residue remains
• These residues are removed using simple mechanical methods or compressed air
Throughout the process, the geometry, surface tolerances, and mechanical properties of the metal parts are preserved.
Temperature Ranges and Heating Power
Pyrolysis furnaces are typically designed to operate within the following temperature ranges:
• Operating temperature: approximately 350°C
• Maximum structural temperature: 400°C
This temperature range is ideal for safely carbonizing the majority of plastics used in injection and extrusion processes, such as PE, PP, PS, ABS, and PA.
Depending on the model and capacity, the furnaces are available with:
• Electric heating power between 4 kW and 9 kW
• Power supply options of 230 V single-phase or 400 V single-phase
The required heating power is determined by the internal chamber volume and basket dimensions.
Technical Dimensions and Capacity Options
Pyrolysis furnaces are offered in different internal volumes to accommodate various part sizes and production intensities.
Typical technical specifications for compact models include:
• Usable internal volume: 350 x 350 x 350 mm
• External dimensions: approximately 624 x 490 x 942 mm
• Weight: approximately 80-90 kg
• Heating power: 4 kW
For medium and large-capacity models:
• Usable internal volume: 650 x 650 x 650 mm
• External dimensions: approximately 925 x 850 x 1245 mm
• Weight: approximately 140 kg
• Heating power: 9 kW
This range allows effective cleaning of components from small nozzles and filters to large mould parts.
Control System and Electrical Equipment
Pyrolysis furnaces are equipped with PID or proportional temperature controllers designed for industrial use. These systems provide:
• Precise temperature control
• Protection against overheating
• Optimized energy consumption
In addition, a timer allows the processing time to be programmed. In standard applications, the pyrolysis cycle is typically set between 2 and 4 hours, although this duration may vary depending on the type of material being treated.
The electrical control panel includes fuses, contactors, relays, thermocouples, and indicator lamps. All systems are designed in compliance with CE standards.
Gas Exhaust and Emission Management
During the pyrolysis process, gaseous by-products are discharged through the exhaust outlet located on the furnace. The composition and quantity of these gases depend on the type of plastic being treated. Therefore:
• The exhaust line must be properly connected to the outside environment
• External filtration or chimney systems should be used when required
These provisions are the responsibility of the user. In industrial facilities, pyrolysis furnaces are typically integrated into centralized ventilation or exhaust systems.
Maintenance and Operational Advantages
Pyrolysis furnaces require minimal maintenance. Under normal operating conditions, the following procedures are sufficient:
• Annual inspection of electrical connections
• Periodic cleaning around the heating elements
• Routine inspection of the baskets
Since there are no moving mechanical parts that cause wear, service and maintenance costs remain very low.
Areas of Application
Pyrolysis furnaces are critical equipment across many sectors of the plastics and rubber processing industries:
• Plastic injection - cleaning of nozzles, tips, and filters
• Extrusion - cleaning of dies and screen packs
• Blow moulding and film lines - metal carrier components
• Recycling facilities - plastic-coated metal parts
• Maintenance workshops - moulds and process equipment
Key Advantages
• Cleaning without the use of chemicals
• Removal of plastics without damaging metal surfaces
• Long service life with low maintenance requirements
• Operator safety-focused design
• Energy-controlled and repeatable process
• Environmentally responsible cleaning method
Industrial pyrolysis furnaces are an indispensable solution for maintenance, quality, and operational continuity in plastics processing facilities. By enabling the safe, controlled, and cost-effective removal of plastic residues, they extend equipment life and improve production quality. Compared to chemical and mechanical cleaning methods, pyrolysis offers a safer, more precise, and more sustainable cleaning technology.
