Pumping machines are an integral part of food and drink processing machinery. They are used to move finished and unfinished food products at all stages of processing, from unloading drums and tanks to filling mixing vessels and cooking equipment. They are also used in dosing operations and to fill food packaging. Food grade pumps have a significant bearing on the quality of the product.
What types of pump are used in food processing?
The choice of pump for food processing plants is primarily dictated by the viscosity of the material it will handle:
- Centrifugal pumps are suitable for low viscosity products including juices, beer, batters and oils.
- Rotary lobe pumps have larger cavities and gentle handling characteristics. They are used for fruits and fruit pieces, fruit and meat pie fillings, beans, potato salad and many other foodstuffs.
- Progressive cavity pumps use an auger-shaped rotor to transfer very viscous materials such as dough.
- Positive displacement pumps propel viscous fluids through food processing equipment and are suitable for many products including purees, baby food, pastes, sauces, cream, cheese, salad dressings and mayonnaise.
Viscosity, however, is not the only consideration. Vacuum pumps are used in food processing techniques such as cooking ‘sous-vide’ which allows for long, gentle heating while maintaining product integrity. They are also used in other processes such as the evisceration of meat, bottling carbonated drinks, and vacuum packaging.
Pumping machine features for food processing
Hygiene is paramount in food processing, and stainless steel is the core material used throughout the industry, including in food grade pumps. Pumps feature barriers to avoid contact between food materials and working parts of the equipment, such as lubricated pistons.
Food grade pumps need to be cleaned and sterilised and meet the requirements of national and international food standards. The ease with which hygiene requirements can be met, and the ease of servicing are important from the point of view of downtime. The longevity of pumping equipment also has a major influence on the efficiency of any food processing operation.
Pumping machines come with various controls and displays. Many food processing operations require variable speed controls, monitoring systems and temperature controls, as well as repeatable, accurate dosing and metering.
A gentle, low speed pumping action is needed for many products. Low shear pumps such as rotary lobe pumps are best suited to maintaining product integrity. Temperature controls are also important because heat can also affect product quality such as runny or separated sauces, and damage to solid food elements.
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