Development direction of mesh belt furnaces:

　　The mesh belt furnace production line adopts DX gas tempering blackening technology and uses tempering waste heat blackening technology to replace the traditional polluting blackening process. The mesh belt furnace has zero thermal pollution.

　　Detailed introduction of mesh belt furnaces:

　　After more than half a century of development, mesh belt furnaces have gradually developed from heating under oxidizing atmosphere to protective atmosphere, less or no oxidation heating, and then to the third generation of controllable atmosphere heating, and the fourth generation of computer management. In the 21st century, how have mesh belt furnaces developed? What are the characteristics of mesh belt furnaces?

　　The driving force for the development of heat treatment mesh belt furnaces, like other products, comes from market demand, and the results of development come from technological progress. China's reform and opening-up policy is greatly promoting and accelerating the development process of the heat treatment industry.

　　Mesh belt furnace technology in the 21st century will have distinct characteristics of the times, with four main features: intelligent heat treatment, high-quality heat treatment, low-cost heat treatment, and clean heat treatment.

　　1.1 Intelligent heat treatment

　　Research and development personnel use new CAD programs and heat treatment databases, computer simulation and control technology, and adopt a highly flexible and intelligent integrated control and management system for mesh belt furnaces and their production lines.

　　Future mesh belt furnace operators only need to input the number of workpieces to be processed and drawings into the computer, and the entire set of equipment will automatically process high-quality products.

　　At present, real-time multi-project operation control of the entire system has been realized. For example, controlling the loading thickness, mesh belt speed, temperature, carbon potential, etc. The movement of batch feeding can be fully monitored and controlled on the screen. Process program control can store 9999 processes. It can record the process parameters (part number, material, temperature, carbon potential, etc.) detected during the operation of the equipment and send them to the computer for processing and storage. It can be accessed and printed at any time. Records for ten years can be stored. Password hierarchical control, hierarchical. Contains new furnace heating-up program, furnace shutdown heating-up program can execute the heating-up process, etc.

　　1.2 High-quality heat treatment

　　Zero quality dispersion rate, zero heat treatment distortion. Quality control measures:

　　Loading control system: Weight, quantity, and uniformity are controllable. The tipping, suction cup, magnetic tape, stepped, and vibration feeding systems are widely adopted. Automatic control of loading rhythm, frequency conversion speed regulation. Automatic arrangement of parts direction. Real-time monitoring of feeding thickness. Providing a guarantee for the accurate execution of heat treatment processes from the source.

　　Equipment temperature control: Furnace temperature stability ±1℃, furnace temperature uniformity ±10℃, cold treatment temperature uniformity ±5℃, switch-type temperature control will be eliminated.

　　Furnace atmosphere control: Furnace atmosphere uniformity 0.05% oxygen probe, decarbonization air pump, carbon potential controller, and furnace gas regulator are reliably used on mesh belt furnaces. Suitable for nitrogen methanol atmosphere, methanol acetone (toluene) atmosphere, endothermic atmosphere, exothermic atmosphere, etc. The development of multi-element carbon potential control technology combining oxygen probes and infrared instruments, and the emergence of other new carbon potential control technologies, can not only improve the accuracy and stability of carbon potential control, but also adapt to various gas source atmospheres. The two-oxygen probe two-zone carbon potential control technology further optimizes the control of the carburizing and carbonitriding layer quality. The emergence of continuous mesh belt furnace water quenching water vapor device stabilizes the furnace atmosphere and ensures the accuracy of carbon potential control. The new development of methanol gasification and cracking technology and the widespread use of internal stirring fans have further improved the uniformity of the furnace atmosphere. The furnace shell sealing welding method not only saves energy but also is conducive to the long-term stability of the furnace atmosphere.

　　Quenching tank control: In terms of ensuring the uniformity of workpiece hardness and reducing part deformation, it has developed from simply reducing the cooling rate to focusing on improving the cooling uniformity. The quenching tank adds an adjustable high-speed stirrer, pays attention to the quenching tank flow field, and emphasizes the uniformity of the quenching tank temperature. The quenching tank temperature is controllable. The computer cooling medium performance tester is also accepted by many users.

　　Heat treatment distortion control; using a longer stress relief hot zone in the quenching furnace. Using a fully enclosed belt with insulation and controllable graded quenching oil tank. Quenching medium temperature uniformity 5℃. Anti-collision and damage design of the quenching tank and elevator dropping system. In order to reduce the amount of residual austenite in bearing parts and control the slight deformation after bearing processing, a cold treatment device will be popularized after quenching in the mesh belt furnace production line.

　　1.3 Low-cost heat treatment

　　In the 21st century, with China's accession to the WTO, Chinese enterprises will be in a competitive environment in the large market, and the market will be more urgently in need of inexpensive and high-quality heat treatment equipment. Inexpensive and high-quality heat treatment equipment will be low-cost heat treatment equipment, not low-priced heat treatment equipment. The cost of heat treatment equipment consists of five parts: equipment purchase cost, equipment operation cost, equipment maintenance cost, equipment 4T labor cost, and heat treatment failure processing cost.

　　Usually, the equipment purchase cost only accounts for 5-10% of the total equipment cost. Therefore, equipment manufacturers will not strive to provide low-priced heat treatment equipment, but strive to provide low-cost heat treatment equipment.

　　Therefore, mesh belt furnaces designed and manufactured according to the RMs (reliability, maintainability, supportability) engineering theory are widely welcomed.

　　Furnace type selection: The design starts with the selection of the correct type of furnace with or without a muffle.

　　Heat-resistant steel selection: High-quality Fe-Cr-Ni, Fe-Ni-Cr, Ni-based alloy materials are used, and reasonable material selection is carried out according to the operating temperature range of the furnace, heat treatment process, etc. This makes the actual service life longer and the performance-price ratio more reasonable. The muffle life can reach 2-5 years, the mesh belt 2-4 years, the roller 5-10 years, the radiation tube 2-4 years, and the fan 5-10 years.

　　Instrument and electrical selection: Widely used high-reliability PLC programmable controllers, SRC heating modules, adaptive digital display temperature controllers, carbon controllers, can achieve trouble-free operation during the entire equipment life cycle.

　　Sensing element selection: The service life of the atmosphere control oxygen probe is 1 year, the carbon potential control accuracy is ±0.05%, the thermocouple service life is more than 5 years, and the control accuracy is ±0.05%.

　　Refractory material selection: Using 0.48 quality anti-carbonization bricks, quality insulation boards, and refractory cotton, with a service life of 5 years.

　　Common defect devices: Part knocking and bumping buffer pads; part bouncing and falling baffle plates; part bouncing and jamming transmission

　　Torque limiter for the actuator; parts adhesion spray washing device: parts adhesion grooved lifting; parts dent washing

　　Mountain-shaped and drum-type drying devices where liquid is difficult to drain. Increase the size and length of the tempering furnace to ensure high hardness and uniformity.

　　(2) Maintainability: Automatic display of fault points; automatic shutdown of the preceding process of the fault point after a fault occurs; automatic audio-visual alarm; equipped with repair tools, etc.

　　(3) Security: Sincere service to users and consideration for users are no longer empty words. More and more manufacturers are publicly committing to assisting buyers in solving problems quickly after receiving a call for help; problems that cannot be solved by phone are immediately addressed by dispatching personnel. The seller establishes a spare parts warehouse for the buyer. The seller establishes a forecasting system for spare parts required by the buyer. With the development of emerging network technologies, remote control has become a reality, and the cooperation between suppliers and users will be more tacit, and the application of new technologies and processes will further reduce costs.

　　(4) Energy saving: According to the "15th Five-Year Plan" requirements for heat treatment, the average electricity consumption of heat treatment specialized factories in major industrial cities should be reduced to below 500 KWh/t. The energy utilization rate of mesh belt furnaces will be increased to 360-420 KWh/t (including quenching, cleaning, and tempering).

　　Heat exchanger technology, waste heat utilization technology, airtight welding technology for furnace shells, and energy-saving technologies that reduce the surface area of the furnace body (such as cylindrical type) are widely used. The use of 0.48-quality anti-carbonization bricks, quality insulation bricks, quality insulation boards, and refractory cotton furnace construction technology increases the furnace wall temperature by 6℃. Rapid cooling technology for tempering furnaces is used. High-pressure fan oil blowing technology is used to save oil. The use of direct-type atmosphere using air plus propane can save 80% of atmosphere costs. With the implementation of the West-to-East Gas Transmission Project in China, mesh belt furnaces that directly use primary energy gas will be more widely used, bringing significant overall energy savings. The promotion and application of equipment process energy-saving technologies will shorten the heat treatment process cycle, such as carbon steel zero-heat preservation heat treatment: thin-layer carburizing (carbonitriding) direct quenching omitting tempering: dual oxygen probe two-zone carbon potential control shortens carburizing and carbonitriding time, etc., will be widely used.

　　1.4 Clean Heat Treatment

　　The 1992 United Nations Conference on Environment and Development adopted the "Agenda 21", advocating the development of clean production. In 1995, China officially listed clean production as a key technology for development and promotion in the "Decision to Accelerate Scientific Progress". Further promote and develop various clean heat treatment technologies and cleaning technologies. During the "15th Five-Year Plan", the discharge of various wastewater, waste gas, and waste residue will meet national standards, and by 2015, we strive to make the heat treatment production's environmental pollution close to zero. The mesh belt furnace of "Agenda 21" will reduce its environmental impact to zero during production. More water-based quenching media will be used to gradually replace quenching oil. Online closed-loop control of quenching oil is realized, using advanced oil-water separation technology and oil purification technology (oil-water separator separation effect can be less than 10 PPM. Centrifugal separation type oil purifier, 1 liter of impurities in the oil). The electrostatic recovery technology for oil fume pollution can achieve a recovery rate of 0.999. The use of an extended quenching mesh belt furnace heating zone length implements clean combustion degreasing.

　　The mesh belt furnace production line adopts DX gas tempering blackening technology and uses tempering waste heat blackening technology to replace the traditional polluting blackening process. The mesh belt furnace has zero thermal pollution.