Read about a thermal oxidizing system that has been developed to significantly reduce the emission of waxy hydrocarbons generated from lubricants used in the powder metallurgy (pm) industry.
During its first three years of operation, Environmental Engineering Corporation (EEC), Cranston, RI, spent considerable time working on a thermal oxidizer for diesel engines. The purpose was to create a commercial product that would perform as a muffler replacement, but be capable of lowering particulate emissions in accordance with the U.S. Urban Bus Retrofit and Rebuild Program, sponsored by the U.S. EPA. The goal of the program is to clean up the exhaust of dirty, pre-1989 city buses. The effort to develop a competitive product for this program created a wealth of information about the dynamics of heat, the thermal properties of various pollutants, and residence time necessary for complete combustion.
During one of the frequent tours of the company's facility where a thermal oxidizer prototype had been constructed, a visiting colleague observed that the PM industry could use such a device for combusting waxy emissions. EEC began investigating the powder metallurgy/heat treatment industry and learned that zinc stearate and other blended lubricants are used for binding and die wall friction reduction in powder metal parts production. In heat treating furnaces, especially those designed to sinter powdered metal products at very high temperature, waxy emissions flow up through the furnace hood and result in air pollution and noxious odors being vented to the outside atmosphere. These pollutants also condense on the inside walls of the flue, creating a serious fire hazard.