The reason behind my question on the flow rate loss is, I just recalled a pump we worked on many years ago, its a 6 stage centrifugal pump with 350m head and 300 litres/sec at the pump discharge located near the river. The head and flow rate achieved at the mine about 150kms from the pumping...
many thanks JBA, the max we can pump into a 32mm hose is 338lpm which is 7m/sec velocity, from your graph the ΔP @ 350 lpm is 5 bar. You are pretty close to the values the hose manufacturer provided us - ΔP 4.21 bar at 338 lpm for 32mm hose.
Is there a way to convert the ΔP to flow loss or...
yes... some customers don't get any flow on a 60 meter hose reel (even all 60 meters is unwound), but the same pump and hose reel length for another customer is delivering 150lpm. the hose loss i mentioned earlier is laid out in a straight line (brand new from the factory), but after couple of...
to JBA - Truck's engine idle's at 700 rpm, there will be a PTO fitted to the truck's gearbox, its output is a constant 1000 rpm, the PTO drives a hydraulic pump which in turn runs the hydraulic motor at 1000 rpm. Once you mechanically engage the PTO, the pump will be running until you disengage...
Hi Chester, thanks for the calcs, I did get the same values while doing the calc verification on the hose reel pressure loss.
Hi JBA,
Its a positive displacement pump (one revolution is 900 cc and the pump rotates at 1000 rpm = 900lpm).
Once you go over 7 bar the in the pump - the bypass...
900 lpm 7 bar at pump discharge... yes
30 meter hose loss is 4.6 bar... (338lpm is the max allowed flow thru 32mm internal dia hose, anything over we have to restrict it with valves)
900 lpm at 7 bar.
hose loss 461kPa at 7m/sec velocity (diesel flow thru pipe/hoses velocity limiting factor to avoid static electricity generation) about 337.8 lpm.
pump and hose are at same elevation with a meter in between them.
not all pumping systems work in Q=A1V1=A2V2... in this case the pump keeps running unable to push diesel out the other end. you might remember that a pump does "x lpm @ "y" meters head at its discharge... but you get "zero" flow at "y" meters vertical elevation"
To keep it simple the practical...
thanks for the reply, when you are unloading from a truck thru a pump and hose reel system, the pump's discharge has 900lpm, but the hose end will not be 900 lpm, it will be less. I am trying to calculate the lpm lost in the hose.
I have a diesel pump doing 900 lpm with a hose reel 30 meters long, the inside diameter of the hose is 32mm. The frictional loss for 30 meters of hose is 461.04 kPa. The Viscosity of Diesel is 4.5 mPas. I would like to know the final flow rate.
thanks in advance