How to make use of intermediate frequency induction billet heater current frequency
Speaking of medium frequency induction billet heater, current frequency is one of the words we often mention. The basic parameters of induction billet heater are rated current frequency and heating power. It can be seen that the current frequency and heating power are very important for induction billet heater. But do you really know the frequency and power? Today, induction billet heater manufacturers will tell you one of them — current frequency.
The primary principle of current frequency selection: when the permeable heating workpiece is heated in the medium frequency induction billet heater, when the power frequency is fixed, the current penetration depth d is also determined, that is, the depth of the eddy current has been in a certain range. In fact, because the depth of the hardening layer of the workpiece has different requirements, two kinds of heating states will occur in the case of a certain current depth: one is that the depth of the current is d greater than the depth of the hardened layer Ds, called the permeable heating, and the other is that the depth of the current is less than the depth of the hardened layer, which is called heat conduction heating.
From the comparison of two heating methods, it is found that under a large number of production conditions, in terms of energy saving, labor productivity and surface overheat, the permeable heating method, also called deep heating, should be chosen. It is defined as the depth of the current under the thermal state of the workpiece, which is greater than the hardened layer required by the workpiece.
The second principle of current frequency selection of induction billet heater is that the current frequency can not be too low: when the current frequency is too low, that is, when the ratio of the current penetration depth and the depth of the hardened layer is too high, the high power density must be used. At this time, the carrier density on the inductor is very high (some companies specify that this value is not more than 1200A/mm2). The inductor is still easily damaged due to good current cooling. Therefore, it is generally stipulated that D8 is more than 0.25D.
The third principle of current frequency selection is that the electric efficiency of the inductor is based on the ratio of the diameter of the part (thickness) and the current penetration depth in the heating state, which is also called the electrical size.
The selection of current frequency of billet induction heating furnace is also related to noise, power factor of oscillating system and electromagnetic force. When the current frequency increases.and in the case of the same power, the electromagnetic force, vibration and noise level on the inductor decrease, and when the current frequency increases, the power factor of the system reduce.
Overseas manager: Tom Wang
Phone: 0086-13303078975(whatsapp, wechat,line)
Specialist of long bar heat treatment machine is glad to be your partner in the field of induction heating.
Post time: 07-13-2018