Capacitor high infrared fast curing technology
Abstract: the spraying curing technology of electric capacitors adopts the hot air circulating heating method (hot air stove) at home and abroad. The advantages of hot blast stove are that the temperature in the stove is uniform and the workpiece has strong adaptability; The disadvantage is that the indirect heating energy consumption is high, the thermal efficiency of the equipment is generally less than 30%, and due to the flowing air, the solidification process is easy to cause secondary dust pollution
the system must be preheated for more than 20 minutes key words: high infrared heating mechanism, the possibility of rapid curing of coating 1 preface
capacitor spray curing technology adopts hot air circulation heating mode (hot air stove) at home and abroad. The advantages of hot blast stove are that the temperature in the stove is uniform and the workpiece has strong adaptability; The disadvantage is that the indirect heating energy consumption is high, the thermal efficiency of the equipment is generally less than 30%, and due to the flowing air, the solidification process is easy to cause secondary dust pollution. The stove is long and covers a large area. The drying stove of Jinzhou power capacitor Co., Ltd. is 108m long
the far-infrared curing furnace appeared in the 1970s. However, due to the poor temperature uniformity in the furnace, it can hardly be used alone in the coating industry. Therefore, the outstanding advantage of far-infrared heating "obvious energy-saving effect" cannot be shown. For more than ten years, the Institute has been committed to finding a new type of powder coating curing furnace that can not only ensure the uniformity of the temperature of the baked objects, but also save energy and improve efficiency. This is the heating furnace of high-energy, high-density, high-intensity, full band, instant start powerful infrared radiation heating technology (referred to as high infrared technology for short or commonly known as high infrared technology). As soon as this kind of high infrared furnace was born, it received attention at home and abroad. The curing efficiency can be increased by 2 ~ 40 times, the floor area can be reduced by 90%, the length of the furnace can be shortened by 90%, and the comprehensive energy saving is more than 50%. The cost of the equipment is 75% of that of the traditional curing furnace. At present, 3-5M stoves have been built in the United States and Latin America to replace the current nearly 100 meter ovens. What's more, in the past, it took 20 minutes to complete the curing, and high infrared can be completed in 30 seconds. This paper briefly introduces the principle, technical equipment, application fields and practical effects of high infrared technology.
2 high infrared heating mechanism
far infrared heating has been familiar to the world. When the radiation spectrum of the heating body (element) matches that of the heated body. 6. The experimental operators should cherish the instruments and equipment, check, scrub and maintain them frequently, and regularly clear the absorption spectrum of the impurities (workpiece) in the oil tank, the thermal efficiency is the highest, so as to achieve energy saving. The traditional matching absorption mainly refers to the matching of spectral wavelength, and the matching rate q is equal to the ratio of the workpiece absorption spectrum and the component radiation spectrum energy. According to Planck's law, the spectral energy (energy flow density) radiated or absorbed per unit area of the object surface can be expressed by the following formula: where: e - energy flow density of radiation (or absorption) (w/cm ∑ 2); ελ— Spectral radiation coefficient of heating element; T - surface temperature of element (℃); λ 1、 λ 2 - spectral range of radiation (or absorption)（ μ m); C1, C2 - constant for far-infrared heating, the total radiant energy of the heating element is λ 1=0， λ 2= ∞, the above formula can be rewritten as stephenboltzmann's law of thermal radiation: where: σ— Stephenboltzmann constant 5.67 × W/cm2 · K for thickness of 10 ~ 100 μ M, its absorption spectrum is λ 1=2.5 μ m， λ 2=15 μ m. Best match National Bureau of quality and technical supervision 1999-07 ⑶ 0 approved 2000-02-01 to implement band 2.5 ~ 15 μ m. If the emission of the element is 100% absorbed by the workpiece, the absorbed energy flow density of the workpiece is: when the surface temperature of the element is t=450 ℃ (723K), the absorbed energy of the workpiece is assumed to be 100%, that is, the amount of energy radiated by the element matches the wave band, and the amount of energy absorbed by the workpiece is q=96%; When the surface temperature of the element t=1000 ℃ (1273K), the calculation shows that q=69%. In terms of wavelength matching alone, the less far-infrared heating visible light, the better matching absorption. However, the less visible light, the lower the surface temperature of the element. If the surface temperature is too low, although matching, its heating effect is often not good. For example, two SiC (silicon carbide) plate far-infrared heating elements with different thicknesses, radiation area s1=s2, radiation coefficient ε a1= ε A2, input electric power p1=p2. The test results show that if the thickness of the heating element T14 is thin and the thickness of the experimental machine is larger than that of the thick element, then Q2> Q1. This result is inconsistent with the matching absorption theory. Later, people found that the so-called matched absorption requires not only wavelength matching, but also energy matching. Let the electric energy radiant energy conversion efficiency of the heating element be w: measure the surface temperature T and input power P of the element, and use the Planck function table to calculate the values of Q and W, which are much smaller than those of thin SiC elements, which is consistent with the practical results. The matching absorption theory is shown in Figure 1.