DaWei Induction Heating Machine Co., Ltd specializes in Induction Heating equipments[induction heaters] manufacturing and marketing for more than 1 decade. The induction heating machines,induction heater cover Automatic Surface Induction Hardening & Induction Tempering Machines, Flexible Induction Brazing Systems, Compact Adhesive Curing Systems Efficient Tube Welders & Thermal Straightening Systems. Induction heating equipments[induction heaters] are wildly used in induction heat treatment,induction heating,induction bonding, induction brazing, induction welding, induction forging, induction melting and induction heat fitting solutions etc.Transistor converters from 500Hz to 2000KHz frequency & power sizes from 4.5 to 3000 KW.
Induction heating is a non-contact heating process. Induction heater uses high frequency electricity to heat materials that are electrically conductive. Since it is non-contact, the induction heating process does not contaminate the material being heated. Induction heating is also very efficient since the heat is actually generated inside the workpiece. This can be contrasted with other heating methods where heat is generated in a flame or heating element, which is then applied to the workpiece. For these reasons Induction Heating lends itself to some unique applications in industry.

How does Induction Heating work ?

A source of high frequency electricity is used to drive a large alternating current through a induction coil. This induction heating coil is known as the work coil. See the picture opposite.
The passage of current through this induction heating coil generates a very intense and rapidly changing magnetic field in the space within the work coil. The workpiece to be heated is placed within this intense alternating magnetic field.
Depending on the nature of the workpiece material, a number of things happen...
The alternating magnetic field induces a current flow in the conductive workpiece. The arrangement of the work coil and the workpiece can be thought of as an electrical transformer. The work coil is like the primary where electrical energy is fed in, and the workpiece is like a single turn secondary that is short-circuited. This causes tremendous currents to flow through the workpiece. These are known as eddy currents.
In addition to this, the high frequency used in Induction Heating applications gives rise to a phenomenon called skin effect. This skin effect forces the alternating current to flow in a thin layer towards the surface of the workpiece. The skin effect increases the effective resistance of the metal to the passage of the large current. Therefore it greatly increases the induction heating effect of the induction heater caused by the current induced in the workpiece.
(Although the induction heating due to eddy currents is desirable in this application, it is interesting to note that transformer manufacturers go to great lengths to avoid this phenomenon in their transformers. Laminated transformer cores, powdered iron cores and ferrites are all used to prevent eddy currents from flowing inside transformer cores. Inside a transformer the passage of eddy currents is highly undesirable because it causes induction heating of the magnetic core and represents power that is wasted.)