Abstract: Disclosed is a process for controlling injection of magnesium oxide (or precursor) for reducing the concentration of sulfur trioxide in combustion gases from a combustor burning vanadium and sulfur-containing fuel while operating the boiler with enhanced efficiency. In-fuel introduction is combined with mid-temperature introduction, where both can be operated effectively, are found to be of primary importance. When in-fuel introduction will not be effective due to selectivity problems, feed can be shifted to a high-temperature zone. Where the high- or mid-temperature zone cannot be fully utilized due to obstructions for injection or insufficient soot blowers to address fouling of that zone or boiler operational changes to integrate the magnesium oxide injection is insufficient, an entire or a portion of feed can be shifted to the low-temperature zones.

Abstract: Disclosed is a process for controlling injection of magnesium oxide (or precursor) for reducing the concentration of sulfur trioxide in combustion gases from a combustor burning vanadium and sulfur-containing fuel while operating the boiler with enhanced efficiency. In-fuel introduction is combined with mid-temperature introduction, where both can be operated effectively, are found to be of primary importance. When in-fuel introduction will not be effective due to selectivity problems, feed can be shifted to a high-temperature zone. Where the high- or mid-temperature zone cannot be fully utilized due to obstructions for injection or insufficient soot blowers to address fouling of that zone or boiler operational changes to integrate the magnesium oxide injection is insufficient, an entire or a portion of feed can be shifted to the low-temperature zones.

Abstract: A flow control device for a solder wave apparatus that includes an outlet or nozzle from which molten solder flows in an upward direction to contact the lower surface of a target, such as a circuit board. The flow control device provides a screen and baffle that control the flow pattern of molten solder to the nozzle so as to result in a near-parallel solder wave above the nozzle. The screen includes a pair of spaced-apart parallel panels that are disposed upstream of the nozzle. Each of the panels has apertures through which the molten solder flows before entering the nozzle. The apertures of the panels are offset from each other, such that none of the apertures are coaxial but instead overlap each other when superimposed. The baffle is disposed further upstream of the screen, and includes a number of fins disposed substantially perpendicular to the panels. The fins are arranged such that their lengths become progressively shorter in a direction away from the center of the baffle.