Cooling 500L of hot wort through a Thermaline T4 U-16, 2 stage plate heat exchanger. Design flow rate is 3gpm. Cooling is not a problem. The problem is that I need to run my brewhouse pump (centrifugal, open 4" impeller) at full speed (1.5 hp, 1750 rpm, 60Hz) in order to get anything resembling 3gpm at wort out port. Basically, 25gpm going in to HX and 4gpm coming out. I have a VFD on pump and have worked through frequencies but massive pressure loss exists throughout range. HX rated pressure loss at 3gpm is 4psi.
I have also tried other pumps (1 and 1.5hp, 1750 and 3500 rpm, 60Hz) and impellers (3-4"), even connected different suction tanks to increase NPSH but problem continues wether I'm pumping hot wort or cool water.
Pump curves are unavailable for pump/motor combination. Can pump simply be too powerful and create so much turbulence in HX that flow basically ceases? Why isn't VFD solving this? Do I need a much smaller pump only for this transfer which can flow at 3-5gpm but with a higher pressure?
I'm concerned about hot side aeration as impeller beats up wort and generally frustrated about unknown issue.
I'm in rural Guatemala, Central America so this forum is my best hope for an answer.
Thanks
I have also tried other pumps (1 and 1.5hp, 1750 and 3500 rpm, 60Hz) and impellers (3-4"), even connected different suction tanks to increase NPSH but problem continues wether I'm pumping hot wort or cool water.
Pump curves are unavailable for pump/motor combination. Can pump simply be too powerful and create so much turbulence in HX that flow basically ceases? Why isn't VFD solving this? Do I need a much smaller pump only for this transfer which can flow at 3-5gpm but with a higher pressure?
I'm concerned about hot side aeration as impeller beats up wort and generally frustrated about unknown issue.
I'm in rural Guatemala, Central America so this forum is my best hope for an answer.
Thanks
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