What are the pros and cons of electromagnetic heating technology?
Electromagnetic heating works by generating an alternating magnetic field through electronic circuit board components. When a ferrous container is placed on it, the container surface cuts the alternating magnetic field lines, producing an alternating current (i.e., eddy current) in the metal part at the bottom of the container. The eddy current causes the iron atoms at the bottom to move rapidly and irregularly, colliding and rubbing against each other to generate heat energy, thus achieving the effect of heating objects. Since the iron container itself generates heat, the thermal conversion rate is particularly high, up to 95%. Current induction cookers and induction hobs all use electromagnetic heating technology.
Electromagnetic heating technology can be used in various applications
Industrial electromagnetic energy-saving retrofits are widely used in plastic injection machines, extruders, film blowing machines, wire drawing machines, plastic films, pipes, wires and other machinery, food processing, textiles, printing and dyeing, metallurgy, light industry, machinery, surface heat treatment and welding, boilers, water heaters and other industries, replacing traditional energy sources.
Textile printing and dyeing: Using electromagnetic heating for raw materials can improve energy efficiency, increase heating speed, and enhance temperature control accuracy.
Light industry: Sealing of cans and other plastic packaging, etc.
Boiler industry: Electromagnetic boilers utilize their fast heating speed to abandon the traditional overall heating method. They only heat at the water outlet end, completing heating as water flows, achieving fast heating and saving space.
Machinery industry: High-frequency electromagnetic heating can be applied to metal surface heat treatment, with significantly better results than traditional methods. Other applications include quenching of various mechanical parts, as well as tempering, annealing, and normalizing after quenching, and through heating before pressure processing.
The application of electromagnetic heating technology not only benefits product quality, production efficiency, energy saving, and cost reduction, but also enhances the technical level of equipment manufacturers. It is increasingly being accepted and used in traditional industries.
With the continuous development of science and technology, various power-saving technologies have emerged. Electromagnetic heating technology is one of many energy-saving technologies. Since electromagnetic heating energy-saving technology developed relatively late and is still in its infancy, many people are not familiar with it. Here, we briefly introduce the application of electromagnetic heating technology in plastic machinery, which has been studied in detail.
In our daily life and production activities, heating is often required. Electric heating is the most common method, and among electric heating methods, resistance wire heating is the most prevalent. However, resistance wire heating has low thermal efficiency and many other drawbacks. Currently, electric heating is widely used in the plastic industry, and over 90% of it uses resistance wire heating. This heating method relies mainly on contact conduction to transfer heat. Various heating plates and coils made of resistance wire only have one side in contact with the part to be heated, causing a large portion of heat energy to dissipate into the air.
Energy saving, first of all, we emphasize that it is about conservation; it cannot create new energy. From the above introduction, we can understand that the current energy-saving potential in the plastic industry is the part of energy dissipated into the air. Theoretically, a traditional heating ring transfers half of the heat to the inside and half to the outside. So the heat dissipated into the air is 50%. Therefore, the maximum theoretical energy-saving rate is 50%. However, we all know that nothing can be perfect, so it is impossible to achieve 50%. Thus, the normal energy-saving rate should be around 40%.
Currently, the heating method commonly used in plastic machinery on the market is electric heating ring heating, which transfers heat to the barrel through contact conduction. Only the heat on the inner side close to the barrel surface can be transferred to the barrel, while most of the heat on the outer side dissipates into the air, resulting in heat conduction loss and an increase in ambient temperature. In addition, resistance wire heating has another disadvantage: low power density.
