JHOLLAND1
Titanium
- Joined
- Oct 8, 2005
- Location
- western washington state
so i reviewed builder records of salvage pumps--aka trash pumps--and found an interesting factoid
pertaining to ability to handle solids
so a one inch discharge trash pump handles solids up to 0.5 inch
two inch discharge solids up to 1 inch
4 inch discharge ---2 inch solids
6 inch discharge==== 3 inch solids---and there is no advancement in solid diameter capability
in pump sizes larger than 6 inches
therefore--12 inch discharge pump has 3 inch solid handling capacity
i found no explanation in literature as to the three inch limit---but today--in process of
parting out a 10 inch barnes us navy pump--discovered the limiting geometry-- impeller
dimensions
the 10 inch pump was powered by 80 hp detroit 3-53 heat engine
flow volume an excepitional 3000 gpm--typical for 80 hp would be 1800 gpm
likely explanation is dedicated to naval ship pump out with low discharge pressure head requirement
therefore--increased discharge volume at tradeoff of lower discharge pressure
the critical measurement is height of impeller blisk--3 inches
blisk clearance from stationary pump frame is 0.010 in
therefore--no object larger than 3 inches in any dimension should be introduced into pump
cavity
my conjecture is probability of cavitation with suction feed limits pumps of this category
to 3 inch or less impeller blade height--comments welcome
pertaining to ability to handle solids
so a one inch discharge trash pump handles solids up to 0.5 inch
two inch discharge solids up to 1 inch
4 inch discharge ---2 inch solids
6 inch discharge==== 3 inch solids---and there is no advancement in solid diameter capability
in pump sizes larger than 6 inches
therefore--12 inch discharge pump has 3 inch solid handling capacity
i found no explanation in literature as to the three inch limit---but today--in process of
parting out a 10 inch barnes us navy pump--discovered the limiting geometry-- impeller
dimensions
the 10 inch pump was powered by 80 hp detroit 3-53 heat engine
flow volume an excepitional 3000 gpm--typical for 80 hp would be 1800 gpm
likely explanation is dedicated to naval ship pump out with low discharge pressure head requirement
therefore--increased discharge volume at tradeoff of lower discharge pressure
the critical measurement is height of impeller blisk--3 inches
blisk clearance from stationary pump frame is 0.010 in
therefore--no object larger than 3 inches in any dimension should be introduced into pump
cavity
my conjecture is probability of cavitation with suction feed limits pumps of this category
to 3 inch or less impeller blade height--comments welcome