That comment about pump cavitation finally clicked for me

I was reading a forum post last week where a guy mentioned his 8-inch Ellicott started shaking bad after 3 hours of running in sandy mix near Baton Rouge. He said it was all cavitation from running the pump too lean. I always thought I had to push the cutter hard to get production, but backing off the swing speed by about 20% dropped my downtime from twice a shift to maybe once. Anyone else found that running a lighter cut actually keeps the pump happier?

2 comments

2 Comments

cooper.taylor17d ago

Last summer I was running a 10-inch dredge in a gravel pit near Tulsa and the pump started making this noise like someone was shaking a bag of rocks inside it. I figured it was the impeller eating stones but it was just me running the throttle wide open with a thin slurry. Switched to a slower swing and a heavier cut and the noise stopped dead. Now I tell the new guys that a happy pump sounds like it's barely working and if you hear anything interesting you're about to buy parts.

drew_thomas916d ago

Jumped on the same thing about a year ago on a 12-inch job down near Mobile Bay. We were chewing through wear parts like crazy until an old-timer showed me how to feel the pump vibration through the ladder instead of listening for it. Once I started running the cutter at about 70% of max swing speed and letting the pump actually fill up with material, the whole operation got way smoother. The slurry density readout jumped from like 11% to 18% solid and I think the pump started lasting twice as long between overhauls. Were you seeing your discharge pressure flatten out too when you leaned it back?