Quality & Design

The type and quantity of the induction coil assemblies to be used is dependent upon the specific installation and the size and shape of the material to be heated. Billet or bar heater coils may be fitted with guide rails and be water cooled.

The basic coils are manufactured from highly conductive copper section, and the size and section of this copper will again be dependent upon the size and shape of the material to be heated. The coils are of helical construction, integral water cooling is provided, and the copper tube is insulated with a nylon coating.

Assembly

The coil assembly is cast in refractory cement and the cast coil is encased in an insulated box. The water and electrical connecting unions or flanges are left exposed. When the coils are in use, a protective cover encloses these connections.

The water connections to the coil are made through the main electrical connections and the drain outlets are hosed to drain manifolds on the insulated box. These are hosed directly to the turndish drain where the water flow is readily visible, if of an open water design. On a closed water system drain outlets are hosed to the return manifold -- quick connect fittings are often employed.

Location

The coils are located onto the heater either by two locating blocks or with two slide locking pins. To expose the electrical connections, the protective cover must be removed. This cover is locked using a special key which forms a part of the main equipment interlocking system. The key can only be removed when the heater is switched off.

This is an example of a Newelco induction heating coil. This particular coil has cast endboards (Newelco design), this effectively gives the coil a longer life due to the resilient nature of the material used. This coil has nitrogen injection fitted (top middle), this gives the customer the option of reducing billet size from size in size without an increase in scaling due to the larger air gap introduced. (<<--- Something missing here/makes no sense, helen --->>)

Technology

Newelco uses state of the art hardware and software to help achieve the most electrically efficient induction heating coils. Newelco designs every induction heater to achieve the shortest possible solution to the customers specifications and tolerances. Newelco uses Finite Element Analysis software to predict heating patterns and these graphs can be supplied to customers for their analysis.

When the temperature in the first coil increases, a transition begins to occur. This transition is the point where the metal in the coils is changing from sub-curie into super-curie metal. In Newelco terms this is known as "the forcing section." The second zone is where Newelco makes a uniform heating/power pattern to bring the metal up to forging temperature. This system is unique to Newelco induction heaters and allows for maximum power with minimum heater length.

In Newelco terms this is known as the "holding section." The last zone of heating is the point where the metal exits the induction coils so no more power is induced into billets by induction.

The graph to the right displays the surface and center temperatures of a round billet for ordinary milled steel to an average temperature of 1250degC. Obviously, other material types can be designed for and the optimum heating pattern will be guaranteed.