N-Impeller Clog 1

[SMIAH]

thread378-310492

I am reviewing a N-Impeller Clog proposed pump where it was clearly stated that solids this pump is capable of passing has to be 4 inches.
Wondering why Xylem can't claim that their Neva Clog impeller are capable of passing x inches debris.
Can someone provide more information about it?

 

[bimr]

The NevaClog is a self-balancing, split-vane impeller The throughlets are not as large on this type of pump. The smallest section in a pump is the passage through the impeller.

http://www.xylemwatersolutions.com/...Documents/WhitePaperThroughletSizeMay2012.pdf

http://www.flygt.com/en-us/Pumping/...ownloads/White papers/SustainedEfficiency.pdf

Flygt claims their pump has less clogging even though the throughlet size is smaller.

 

[SMIAH]

Thanks!

I'll read this.

 

[SMIAH]

I understand that specifying minimum debris diameter might be an "old concept" but if not, I don't know how to measure the "non clogging" of a pump.
We specify 5 different brands that we're used to work with + a criteria of 4 inches minimum.

 

[bimr]

A good, non-clog impeller has vanes with a hydraulic foil cross-section and blunt, well-rounded leading edges to prevent catching stringy material. Small pumps have only one or two vanes. Larger pump are built with two or three vanes. A reduced number of vanes increases the size of flow passages and allow larger solids to pass.

The solids-handling capability of the pump is customarily defined as the solid-sphere size that will pass through the pump. It is accepted in the industry that passing a sphere 75 mm (3 in.) in diameter is require for smaller pumps and that a 100-mm (4-in.) sphere is acceptable for virtually all capacities. It should b noted that a restricting area may exist in the pump casing as well as in the impeller, and the pump specification should clearly indicate the minimum sphere diameter for the pump, not just for the impeller.

However, there is no globally accepted clog test standard.

The answer to your query would be for Flygt to provide a list of references of similar size pump installations and you can call and verify whether the pumps have clogged.