Five reasons for using electric heating in continuous heat treatment furnaces
By installing Tubothal® heating elements combined with APM® tubes in their continuous heat treatment furnaces, steel producers can achieve a number of benefits. Here are the top five:
By electrifying the heating, all the exhaust and flue gases associated with gas burners are eliminated. This means CO2 emissions are reduced substantially, and if the electricity used is from a renewable source, emissions will be virtually zero.
Over 90 percent thermal efficiency
Despite measures such as gas preheating, the overall thermal efficiency of gas burners is poor at just 50 to 60 percent. However, with electric heaters, since virtually all of the heat is released into the furnace chamber, thermal efficiency is well over 90 percent, reducing energy consumption and costs.
Longer service life
Over time, the middle sections of the W and U tubes typically used in continuous heat treatment furnaces will tend to drop and sag, especially in the preheating section. This means they generally have to be replaced every two years. However, this issue can be eliminated by using straight Kanthal® APM or APMT tubes instead of one W tube. The extra supports, combined with the superior strength of the Kanthal® APM material, will allow the tubes to be used for years to come.
Tubothal® offers a far higher level of precision in temperature control compared with gas burners. It also distributes a uniform heat across the entire length of the tube, which ensures higher quality and yields in the end product.
Unlike NiCr (nickel-chromium) tubes, Kanthal® APM offers very good oxidation in addition to high corrosion resistance. If combined with a Tubothal® electric heating element, because of its Kanthal® APM wire, there will be no oxide spoilation inside. This means they will not require the same high levels of maintenance needed for NiCr.