Top 10 Slurry Pump Feed Tank & Suction Pipe Design Recommendations
Often times problems with slurry pump performance are not with the pumps themselves, but rather occur on the pump's suction side.
Here are 10 recommendations when designing your pump feed tank and suction piping to give you the highest probability of trouble-free slurry pumping:
1. Pump feed tank bottom should have an angle of at least 45 degrees. Fast settling particles may need up to 60 degrees.
2. Pump feed tank slurry introduction should preferably be below the liquid surface (and away from the pump inlet) to avoid air entrainment. This is especially important with frothy slurries encountered in flotation.
3. Sump volume should be as small as possible. Sizing parameter is retention time for slurry; down to 15 seconds for coarse particles, and up to 2 minutes for fine particles.
4. Sump connection to the Slurry Pump should be as short as possible. As a basic rule it should be 5 x pipe diameter in length and have the same size as the pump inlet. Pipe lengths longer than 10 x pipe diameter should be avoided.
The following should be included on the sump connection:
5. Drain connection on the inlet pipe.
6. It’s recommended to have a floor channel under the drain to recover the slurry.
7. Flexible inlet connection (rubber compensator) that that is reinforced since vacuum can be created. This also helps with slight misalignment for installation and maintenance and helps reduce nozzle load and dampens vibrations.
8. Full bore shut off valve. Typically knife gate valves are utilized.
9. Separate sumps are preferred for standby pump installations. This will avoid settling out in the standby pump sump when not in use
10. Bonus: In certain applications a Vertical Tank (i.e. Metso Sala VT pump) with integral tank can be a convenient option (tank is already designed and supplied with pumps. Tank pumps take very little floor space and are easy to install and relocate and maintain.
These tips (minus a few comments from the undersigned) can be found in Metso's Slurry Pump Basic handbook
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Kind Regards,