Smelt spout enclosure for chemical recovery boilers

Abstract

An enclosure (10) for a smelt spout (16) of a chemical recovery boiler comprises a skirt (20) having a central region through which smelt (26) flowing from the smelt spout (16) falls in route to a dissolving tank (24). The central region is defined by a wall (38) and has a trough (32) disposed around its perimeter. The trough (32) is supplied with a fluid (34) that overflows the trough (32) and flows downward across the wall (38) toward the dissolving tank (24) to clean and cool the central region of the skirt (20). A hood cover (18) has a pair of shields (39) disposed on opposite sides of rodding doors (37) and a chain curtain (41) extending between the pair of shields (39) to deflect smelt particles ejected through the rodding doors (37). A primary nozzle system (44) is configured to direct at least one shatter jet (29) onto the smelt (26) flowing from the smelt spout (16). In addition, a secondary nozzle system (46) is configured to direct a plurality of interlaced shatter jets (29) onto the smelt (26).

Description

Background technique [0001] [0001] Chemical recovery boilers perform two basic functions: burning organic matter to make steam for the various milling processes and recovering inorganic chemical materials for the pulping process. Processed inorganic chemical material or "melt" from the recovery boiler collects at the bottom of the furnace and is discharged into the main dissolution tank through a dedicated opening in the lower part of the furnace. The main dissolution tank is filled with waste water from the stucco washing process, also known as thin wash liquor. The molten smelt, with temperatures as high as 1500°F, must be broken up into small droplets using steam or jets of dilute scrubbing liquid before the molten smelt enters the main dissolution tank. If the melt is not comminuted properly, there will be an explosive reaction with the water in the dilute wash solution in the dissolution tank. In the dissolution tank, during start-up, the melt is dissolved into either w...

AI Technical Summary

Problems solved by technology

This curvature disrupts the baffle action of the initial wash system and if allowed to continue, the area will not be able to be properly washed again until the side panel walls straighten

Another effect of this situation is that locally higher temperatures can accelerate the corrosion of the side wall

Fluid air ensues and, either distorts the smelt flow from the chute, which tends to re-oxidize the smelt (reducing reduction efficiency), or can overload the capacity of the scrubber exhaust that would allow gases to escape from the dissolution tank into the working environment

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