Oxygen furnaces pollutants

Air Pollution Emissions and Controls Basic Oxygen Furnace... 

The pollutants of concern are the same as in wet basic oxygen furnaces, but the concentration of metals (primarily lead and zinc, but also arsenic, cadmium, copper, chromium, and selenium) in wastewater is higher because of the higher percentage of scrap charged. Wastewater treatment operations are similar to those for the wet basic oxygen furnaces, including sedimentation in clarifiers or thickeners and recycle of the water.14... 

Carbonyl sulfide is an intermediate in this reaction. A mixture of sulfur dioxide and oxygen was blown into the bottom of coke-fired reduction furnace and sulfur vapor condensed from the off-gases. Trail is the location of a large mine and smelter in British Columbia. The process was originally used in the 1930s for abating air pollution from the smelter, but when the demand for sulfuric acid for fertilizer production increased in 1943 it became obsolete. See also Boliden (1), RESOX. 

Furnaces usually have to deal with on-demand load changes, i.e., a customer instantaneously needs more steam or more heat input to a unit. The control system on the furnace must be set up to respond quickly to these load changes. The process shown in Fig. 7.1 show s a furnace in which a stream is being heated in a furnace. The outlet temperature of the process stream is controlled by adjusting the fuel flowrate. The air flow is ratioed to the fuel flow. This ratio is adjusted by the output signal from an excess oxygen controller that looks at the composition of the stack gas. The use of too much air increases energy consumption, but too little air can lead to air pollution problems due to incomplete combustion. 

---