Paper mill shower nozzle scale in a bleach plant
Paper mill shower nozzle scale was a recurring problem in the bleach plant at Boise Paper’s mill in Wallula, Washington. Severe limescale built up in the pipework and nozzles of several shower units, and scaled nozzles had to be hydroblasted or replaced. To measure the effect, one HydroFLOW® Custom 8” was fitted to the metal inlet pipe of shower unit E1, about 30 ft before its nozzles, while unit D1 was left untreated for comparison. After 11 weeks the treated E1 opening and nozzles were substantially clearer than D1, including the nozzle 30 ft down the line, and the treated unit needed no hydroblasting.
The Challenge
- Paper mill shower nozzle scale built up in several bleach plant shower units
- Severe limescale restricted the nozzle openings
- Scaled nozzles needed periodic hydroblasting
- Nozzles that could not be cleared had to be replaced
The Solution
- Unit installed: one HydroFLOW® Custom 8”
- Installation point: metal inlet pipe of shower unit E1, about 30 ft before the nozzles
- Pipe: 8⅝ in outside diameter, metal
- Comparison: shower unit D1 left untreated
- Trial: 11 weeks, with the signal checked at 33 to 37 V peak to peak
The trial was set up as a direct comparison of paper mill shower nozzle scale on two shower units in the same bleach plant. E1 was treated from its inlet pipe, about 30 ft upstream of its nozzles, and D1 was left as it was. After 11 weeks both units were opened, and the openings and nozzles were photographed close up.
