FACSITEDEV
Civil/Environmental
- Apr 14, 2004
- 8
We are cleaning aquaculture pond waste using a high-pressure eductor pump and a venturi. This creates a
nice suction to pull the sediment up from the ponds,
which are 5' deep, 100' long and 20' wide. The shear,
unfortunately, takes an easily-settleable sediment
and turns it into a chocolate milkshake consistency.
Our consultant recommended diaphram pumps, however,
the horsepower and volume of air requirement is not
feasible, there's no plant air on the project sites,
and generally only single-phase power. Progressive
cavity sounds potential, provided it can dry-pump up
from the ponds up through the hand-cleaning wands and
into the above-ground suction-piping, hanging from
pond access walkways. I suppose a small driving-water
pump could supply priming to the progressive cavity.
I think I've answered my own question, but if someone
has other insight or experience, pond cleaning occurs
about once a week, running net 50gpm for ~8 hours, or
maximum 25,000 gallons of a miscible slurry, running
1,000 mg/L to 10,000 mg/L TSS.
The ponds may accumulate sands and pea gravels, however,
which is where we chose to borrow eductor-venturi pump
concept from hydraulic mining technology. The current
eductor works great, low maintenance, low cost, but new
discharge regulations are killing us on the 'milkshake'.
It will cost >$500K for sediment floc and filtration, so
the hunt is on for a robust, low-shear pump alternative.
If sands and pea gravels present an impediment, we can
always build a passive hydrocyclone on the ponds inlet.
Recap: 50gpm, miscible sediment @ 1,000mg/l to 10,000mg/l.
Low-shear pump, self-priming to 10', outlet pressure 30psi.
nice suction to pull the sediment up from the ponds,
which are 5' deep, 100' long and 20' wide. The shear,
unfortunately, takes an easily-settleable sediment
and turns it into a chocolate milkshake consistency.
Our consultant recommended diaphram pumps, however,
the horsepower and volume of air requirement is not
feasible, there's no plant air on the project sites,
and generally only single-phase power. Progressive
cavity sounds potential, provided it can dry-pump up
from the ponds up through the hand-cleaning wands and
into the above-ground suction-piping, hanging from
pond access walkways. I suppose a small driving-water
pump could supply priming to the progressive cavity.
I think I've answered my own question, but if someone
has other insight or experience, pond cleaning occurs
about once a week, running net 50gpm for ~8 hours, or
maximum 25,000 gallons of a miscible slurry, running
1,000 mg/L to 10,000 mg/L TSS.
The ponds may accumulate sands and pea gravels, however,
which is where we chose to borrow eductor-venturi pump
concept from hydraulic mining technology. The current
eductor works great, low maintenance, low cost, but new
discharge regulations are killing us on the 'milkshake'.
It will cost >$500K for sediment floc and filtration, so
the hunt is on for a robust, low-shear pump alternative.
If sands and pea gravels present an impediment, we can
always build a passive hydrocyclone on the ponds inlet.
Recap: 50gpm, miscible sediment @ 1,000mg/l to 10,000mg/l.
Low-shear pump, self-priming to 10', outlet pressure 30psi.
-> I am thinking a 'swimming pool cleaner' system - like a baracuda cleaner ? - there is a model which looks like a lawn mower - the only thing you need to do is to have few of these units going linear next to each other from one end to the other when the cleaning is due....too simple to be true ?
