Energy conservation and emission reduction measures during the remanufacturing of used welded pipe machines must be implemented throughout the entire process, including disassembly, cleaning, inspection, repair, and assembly. Green transformation should be achieved through technological upgrades, process optimization, and resource recycling.
Traditional disassembly relies on mechanical crushing or flame cutting, which easily generates dust and harmful gases. Remanufacturing utilizes low-temperature plasma cutting technology, using a high-temperature plasma arc to precisely separate components, reducing metal deformation and exhaust emissions. The cleaning process abandons chemical solvents in favor of bio-enzymatic hydrolysis, leveraging the catalytic action of enzymes to decompose oil contaminants. Combined with high-pressure water jet flushing, this process avoids the generation of chemical wastewater and reduces cleaning energy consumption. One company's experience has shown that this process reduces wastewater COD by 90% and increases cleaning efficiency by 40%.
The core of remanufacturing lies in restoring the performance of old components, not simply replacing them. Non-destructive testing techniques (such as ultrasonic testing and magnetic particle testing) are used to locate defects such as cracks and wear. Digital twin technology is then used to develop component life prediction models to accurately assess remaining useful life. For high-value components such as rolls and bearings, nano-ceramic coating technology is used to repair surface damage. The coating hardness can reach over HV2000, increasing wear resistance by three times and extending service life to twice that of the original, reducing spare part replacement frequency and metal resource consumption.
In the remanufacturing of used welded pipe machines, welding is a key component in energy consumption and emissions. Traditional arc welding generates high heat input and produces a lot of spatter. High-frequency induction welding technology is being promoted in remanufacturing. This technology uses electromagnetic induction heating to achieve rapid fusion, reducing the heat-affected zone by 50%, increasing welding speed by 30%, and reducing nitrogen oxide emissions. A closed-loop cooling system increases the cooling water recycling rate in the welding area to 98%, and electromagnetic shielding reduces high-frequency radiation intensity, improving the working environment.
An energy management system (EMS) has been deployed in the remanufacturing production line. IoT sensors collect real-time electricity and gas consumption data, and AI algorithms are used to optimize equipment start-up and shutdown sequences and production scheduling. For example, high-energy-consuming processes are scheduled during electricity price peaks, and waste heat recovery equipment is used to convert annealing furnace exhaust into workshop heating energy, saving over 200,000 cubic meters of natural gas annually. Through intelligent control, a demonstration enterprise has reduced overall energy consumption per unit of product by 18%, meeting national clean production standards.
Scrap steel, swarf, and other metal materials generated during the remanufacturing process are magnetically separated and reused as steelmaking raw materials, increasing the comprehensive utilization rate of solid waste from 75% to 92%. Oily wastewater is treated using supercritical water oxidation technology, completely breaking down organic matter into carbon dioxide and water under high temperature and pressure. The treated water meets industrial water standards and is reused in the cooling system, achieving a closed-loop water resource utilization.
Environmentally friendly materials are prioritized when repairing old parts. For example, chromium-free passivation coating replaces traditional hexavalent chromium treatment, achieving a salt spray resistance of welded pipes exceeding 1,000 hours while eliminating heavy metal pollution. The production line's energy structure is shifting towards cleaner energy, with rooftop photovoltaic panels covering some of the electricity needs, and a supporting energy storage system balancing power supply and demand. Through this "photovoltaic + energy storage" model, one factory has reduced annual carbon dioxide emissions by 4,200 tons and achieved an energy self-sufficiency rate of 30%.
A remanufacturing digital twin platform was built to virtually mirror the physical production line and simulate energy consumption and emissions data for different process solutions. Through simulation testing, key variables such as rolling parameters and welding current were optimized, resulting in a 22% increase in RTO incinerator operating efficiency and a reduction of 12,000 tons of carbon emissions annually. The system also tracks the carbon footprint of each component, issuing carbon neutral certification for products and enhancing market competitiveness.
Energy conservation and emission reduction in the remanufacturing of used welded pipe machines must be driven by technological innovation, maximizing resource utilization through green transformation throughout the entire process. Uncovering energy-saving potential at every stage, from disassembly and cleaning to assembly and commissioning, not only reduces operating costs but also promotes the transition of manufacturing toward a circular economy model, providing a replicable solution for sustainable development in the industry.
