New developments in deep shale extraction technologies have lead to an increase in the availability of natural gas in the USA with production up over 25% within the past 10 years. The abundance of inexpensive natural gas has created exciting alternatives for steel producers. Specifically direct reduced iron (DRI) fueled by natural gas is being produced on an increasingly larger. Now more than ever DRI is a cost competitive alternative to traditional coal fired blast furnaces. And perhaps even more important is that natural gas powered DRI plants potentially have a much smaller environmental footprint.
However, a DRI plant does present a few unique problems. One such problem occurs in the process gas heater, a key component of a DRI plant that feeds the reduction reactor with makeup gas. Within the process gas heater, radiant coils are situated on the outlet side of the manifold and they are exposed to temperatures up to 1900oF. These elevated temperatures have created some difficulty in the welded U-joints connections of the radiant coils. In some cased the welding has softened to the point where failures have occurred.
Worbo has worked closely with a DRI plant in the USA to develop an extremely high temperate resistant insulation cover to protect the radiant coil U-joints connections from weld failures. These covers have been specially designed to be removable for ease of installation and to minimize shut down time. And they can handle the heat. These covers are capable of withstanding continuous operating temperatures of 2100oF!
With nearly a full year in service and no weld failures we are proud that we have been able to contribute in a positive way to the development of this fiscally and environmentally responsible steel production technology.