Thomson Process Equipment and Engineering Ltd. How to Pump Molasses in the Winter

How To Pump Molasses in the Winter

Pumping Molasses in the Winter

What is the best way to pump molasses when the weather is cold, and the molasses gets harder and stickier?

Whether pumping molasses on a farm, for a tank pump, for a dairy, for animal feed, and for agriculture, there are a few factors to consider when choosing the correct pump for your application.

When pumping and handling molasses it is the viscosity of the liquid that is the most important factor.

What is the best type of pump for Molasses?

Viking Gear Pumps are ideal for Pumping Molasses, especially in the winter months. Here’s why.

  • Given the viscosity of molasses, a positive displacement pump must be used.
  • Many types of positive displacement pumps are used to transfer molasses.
  • These include rotary gear, lobe, worm and stator, sliding vane, and peristaltic.
  • There are two broad pump duty requirements, transfer pumps and variable speed metering pumps.

What information is needed to specify the pump unit needed for pumping molasses?

To know which pump unit you will need when pumping Molasses, the following information is needed:

  • The viscosity of molasses at the lowest pumping temperature
  • Delivery pressure of the molasses for pumping.

Pumps should be provided with a pressure relief valve either as an integral part or installed in a loop between delivery and suction.

The Viking Pump internal gear pump meets all the criteria for pumping molasses, especially when it gets thicker in the cold months as they have built-in relief valves and can be used for transferring and metering.

Viking Pump Molasses pumps are capable of relatively high pressures so long pipelines and high viscosity can be catered for.

How to ensure a Molasses Pump lasts a long time.

In general, molasses pumps should be oversized and run at a relatively slow speed.

If you do this, they will last for many years and pay back the extra investment in reduced power consumption, maintenance, and increased availability many times over.

We have supplied spares for pumps 30 years old.


How to find the right pump and measure the flow rate and viscosity of your pumping liquid.

To find the pump for your application, Viking Pumps pump selector is a useful tool.

By inputting different flow rates and viscosity the correct pump can be selected. 

How to use Viking Pump’s Pump Selector Tool

This takes a bit of patience


Pump Selection

Location – Europe

Construction – Cast Iron

Sealing Options – You can opt for Packed or for the O-Pro seal which is a cleaner option (it has a higher initial outlay, but saves time and money over lifetime of the pump)

Change the units.  You can use the example below or input the values of your own requirements. These are general Molasses application requirements.

Choose cP for Viscosity measurement (centipoise)
Choose 7000cp for viscosity
Choose 1.4 Specific Gravity
Choose 5Bar Pressure (change unit to Bar)
Choose Flow 200l/min,

These parameters will select the LS124A – This is a standard pump for Molasses often used on road tankers.

Playing around with this will give you a feel for what happens when you change the parameters.


How to deal with Pipelines and Pressure Loss when Pumping Molasses in the Winter

Viscosity has a very significant influence on pressure loss in pipelines.

Here’s how to deal with pressure loss problems

  • At a minimum, oversize the suction line one size larger than the pump and keep it short.
  • Use a strainer to protect the pump, straight through type valves, and calculate the pressure drop so the pipe is large enough.

How to calculate the Pressure Losses of my Pump?

The site Pressure Drop has a calculator we would recommend, this requires more patience but will calculate the pressure losses accurately.

The result for high viscosity can be eye-opening sometimes.


Flow and Pressure Power – how to convert flow and pressure units.

The flow comes from the moving gears in the pump.

The pressure comes from the resistance to flow in the system.

The Power required is the Flow x Pressure.

If the different units for the same thing get you to try this free app


Got more questions about your Molasses Application? Talk to Alan or William about it by calling us on 01 2750801 and we can help you or you can WhatsApp us on +353 87 130 1029

Our Viking Pumps come from Shannon in Ireland, so there are no customs forms to fill in.

Thomson Process Equipment and Engineering Ltd are the Viking Pump Agents of Ireland

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