Molasses Pump

[SimonUK]

We have been making Gin in the UK for a few years now and will be starting to make Rum later this  year. We aim to ferment molasses and i am sourcing the extra equipment i need. Does anybody have any insight into what pumps would be good to pump the molasses from our storage tanks to the fermenters? We are looking at pumping around 500 litres at a time. Thanks in advance!

[Jedd Haas]

Air powered diaphragm pump, 3/4" or larger.

[Silk City Distillers]

Gear pumps.  Desmi Rotan, Roper, etc etc.  These are not typically pretty looking sanitary style pumps, they are workhorses that can deal with the high pressure/suction requirements.  Guys down in the islands like them, as they can easily grind up and pass a mouse or other occasional rodent.

Regardless of pump, it's very difficult to pull suction/prime on cold molasses.  Even my big Viking lobe pumps struggle to pull enough suction to lift/prime.  If you have a pump that has flooded suction (no need to pull suction to lift up, out of a container), and warmer molasses, it's far, far easier.

We use use a forklift and gravity.

 

[MichaelAtTCW]

This has been discussed a few times:

I would recommend something like a Ragazzini Peristaltic Pump or Ampco ZP1. Molasses is around 5-10k centipoise, which is not anywhere near the highest viscosity either pump is capable of pumping. In any case, you can't run the pumps at full speed when pumping viscous materials. You must run them at lower RPMs so that material can be pulled into the inlet. Running more slowly means that the flow rates will be lower, so you typically have to oversize the pump. E.g. if you need 10 GPM of flow rate, you would need a pump with a max flow rate of 20-30 GPM for products with water-like viscosity. The higher the better, as a lot of efficiency is lost with pumping viscous materials.

The advice to warm the molasses up and have it flood the inlet is sound. Self-priming with viscous materials is very difficult, even pumps that can pull nearly perfect vacuum like the above.

[SimonUK]

Thank you everyone for your comments, really helpful.

[SimonUK]

Just an update - we have been making our rum for a few months now, we ended up buying an eccentric screw pump to pump the molasses. It takes around 45 mins to 60 mins to pump across when cold, which is fine for us, I assume this will speed up as we head into summer and things get warmer.