Tough pumps for a tough job

Johnson’s Wellfield Quarries Ltd decided to change their holding sump pumps to heavy-duty slurry pumps due to a change in the slurry-handling process.

Quarried York stone is cut on site and the resultant stone slurry from the cutting processes had traditionally been pumped into old quarry workings where the slurry settled out and the water was returned to the plant. The process changed, however, with the stone slurry entering gravity channels and flowing into holding sumps prior to being pumped by vertical long-shaft slurry pumps to a final holding sump. The slurry is then pumped to a silo where the settled slurry goes to a filter press and fresh water decants from the top of the silo.

Due to the abrasion from the sandstone slurry, Johnson’s needed a heavy-duty slurry pump that offered reliability and minimum downtime to meet the 24h, six-days-a-week stone-cutting operation.

After an evaluation of the application, Flygt engineers suggested using a 5150 slurry pump. An HS 5150 432 30kW pump was chosen and has operated trouble-free since its installation, running via an inverter drive.

Johnson’s had found that their vertical long-shaft slurry pumps suffered periodically from shaft and keyway problems and decided that Flygt’s submersible slurry pump technology would give them a cost-effective and reliable alternative.

Since the initial installation Flygt have supplied two additional slurry pumps. Johnson’s have standardized on the model and impeller to give themselves a high degree of interchangeability around the plant.