Molasses pumps

Why molasses is hard to pump

Molasses is one of the thickest fluids found in food and feed processing. It is very viscous at room temperature, becomes almost solid in cold weather and clings to every surface it touches. A centrifugal pump loses most of its head with a fluid this dense and often fails to prime at all, because molasses does not flow into the impeller on its own.

An external gear pump behaves in the opposite way: the thicker the product, the better it seals the gaps between gears and body, so volumetric efficiency actually improves. The pump is self-priming, draws the product from a tank below the pump and delivers a constant flow regardless of back pressure. The same reasoning applies to the other viscous fluids we deal with every day.

Which molasses pump to choose: NAV, CR or FX

• NAV series — the workhorse for high-viscosity transfer: nine models from 54 to 2,770 l/min, flanged ports from DN 40 to DN 125, cast iron base, high volumetric efficiency and continuous duty. Available in a food version for molasses and chocolate.
• CR series — the jacketed pump for molasses that is stored warm to lower its viscosity, or that would set in the pump during winter stops. The jacket runs on hot water, steam or thermal oil; ten models from 30.7 to 2,812 l/min at 950 rpm.
• FX series — hygienic pump in AISI 316 stainless steel, machined from solid, fully dismantlable for cleaning, CIP configuration and optional heating jacket. Six models from 9.2 to 247.1 l/min for food-grade molasses, syrups and soya oil.

Applications in sugar mills, feed mills and distilleries

• Sugar mill: transfer of final molasses from the centrifuges to the storage tanks, tank recirculation and loading of road tankers and rail cars.
• Feed mill: feeding of molasses to the mixer and to the coating line, where a steady dose matters for the quality of the pellet; the flow is set with an inverter on the motor.
• Distilleries and yeast plants: dilution lines and fermenter feeding, with stainless steel execution where required.
• Blending of molasses with vegetable oils, including soya oil, for liquid feed supplements.
• Unloading of road tankers in cold climates with the CR series, where the jacket avoids a frozen pump at the first start of the day.

For other food products handled in the same plant, such as syrups, glucose and honey, see our food-grade gear pumps.

Heating and material choices for molasses

Molasses is often heated to make it easier to pump. If your tank is heated and the lines are traced, a standard NAV in cast iron is usually enough. If the pump stands outdoors, or the plant stops overnight, the CR with heating jacket keeps the product fluid inside the pump body, where a cold spot would otherwise block the gears. Where no hot water or steam is available, the same pump can be fitted with electric cartridges and a temperature controller.

On the material side, cast iron is the standard for industrial molasses and feed. Stainless steel AISI 316 is required for food-grade applications, for sanitary cleaning and for acidic or fermented products. The FX series is fully dismantlable and can be supplied in CIP configuration, so the line is cleaned in place without taking the pump apart.

How we size your molasses pump

To select the right model we need the type of molasses (cane or beet, Brix if known), the working temperature in the tank and at the pump, the flow required in l/min or m³/h, the suction conditions (tank height, length and diameter of the suction line) and the discharge back pressure. Tell us also whether a food-grade execution or a heating jacket is required and which drive you prefer.

Send the data on WhatsApp or through our quote form. Our Bologna factory, building self-priming external gear pumps since 1955, works under ISO 9001:2015 and replies with a precise technical proposal, not a generic catalogue page.