Once damaged insulation was replaced in the base of the furnace, the actual conversion process began. One of the first changes was to cut away sections of the steel furnace shell in the terminal compartment, without damaging structural integrity of the furnace, so passage holes for the new element system could be drilled through the sidewall insulation. The locations and cutout areas were part of the information package provided by Thermcraft to insure proper alignment and strength.
Once all the passage holes were drilled, it was possible to start installing the CoilCraft Element System (CCES). Basically a support structure was installed in the center of the furnace to both support and hold the elements in place to prevent electrical shorts and mechanical damage during assembly and for future element replacement operations. The elements were then slid in from both sidewalls into their respective niches. As the work progressed from one end of the furnace to the other, metal pans were installed to act as shields against product contamination.
Once all the internal work was completed, a new power distribution block was added to one terminal compartment for ease of connecting the incoming three phase power lines from the power supply. A series of jumpers then had to be installed between various heaters. Those heaters were then connected via additional “bank” wiring to the power block, all in accordance with Thermcraft’s supplied drawings and instructions.
Once the above wiring was complete, the power supply was reconnected, all wiring checked again, and the system buttoned up.
According to the Material Process Manager at Perryman Company, it was a rather easy conversion, without any problems. Drawings, supplied instructions, and other information accurately reflected the degree and scope of work required and all parts fit as shown. The supervisor of the area indicated the entire conversion only took three days and had they not been waiting on floor insulation, they would have finished sooner. It should be noted that the Perryman Employees did an outstanding job with respect to accuracy, workmanship, and speed in performing the conversion with the results looking very professional.
Temperature uniformity of the rebuilt unit is excellent and it also has a quicker heat-up cycle. One reason for the quicker heating is the lower thermal mass of the CoilCraft Element System (CCES). In comparison, the existing Thermcraft Cast Plate Heaters are rather massive, very dense, and once at temperature, will hold heat for quite some time. The material costs of the CoilCraft Element System (CCES) elements are on par with the Cast Plate Heaters. Perryman did some test change outs before the conversion was complete and found the elements were as easy to replace as originally indicated, whether replacing one or several. This ease of replacement will greatly reduce maintenance costs and lost production when it becomes necessary to replace a burned-out heater. Based on the outcome of this conversion, Perryman plans to retrofit the other units as production requirements allow.
We certainly hope this information is helpful and we realize that it does not answer all questions that arise. Thus for additional assistance, contact your nearest Thermcraft representative or contact us directly.