Transfer pump struvite at the Robert W. Hite facility, Denver
Transfer pump struvite was taking a centrate transfer pump offline for acid cleaning twice a year at Denver’s Robert W. Hite facility. Hard grey scale about an eighth of an inch thick was also narrowing the eight inch centrate discharge pipe, and centrate ran 24 hours a day. Two HydroFLOW® i Range units were installed on the glass-lined ductile iron pipe, one at the pump suction and one on the discharge. Over a 60 day trial from 1 March 2017, independently verified by CH2M, cleaned pipe sections stayed free of new struvite and existing deposits became thinner and softer. The plant went on to install four more units.
The Challenge
- Transfer pump struvite forced the pump offline for acid cleaning twice a year
- Hard scale reduced the internal diameter of the centrate discharge pipe
- Scale was approximately an eighth of an inch thick, hard and greyish
- Centrate was transferred continuously, 24 hours a day
- Periodic shutdowns were needed for cleaning
The Solution
- Units installed: two HydroFLOW® i Range units
- Installation point: transfer pump suction and discharge, one unit on each
- Pipe size: eight inch glass-lined ductile iron centrate pipe
- Trial: 60 days from 1 March 2017, independently verified by CH2M
Transfer pump struvite was treated on both sides of the pump, so the suction and the discharge pipe were each covered. Weekly sampling and visual inspections followed the cleaned pipe sections and the existing deposits, and CH2M independently verified the data and observations. As the deposits softened, centrate flow gradually carried the scale off, exposing more of the glass-lined pipe surface.
