Reducing Product Loss in Food Processing with High-Priming Twin-Screw Pumps

In food processing, product loss does not always occur during filling, trimming, or packaging. A significant amount of valuable product can remain inside transfer pipelines, tanks, pump chambers, and low points of the process system. This becomes more noticeable when handling viscous sauces, syrups, concentrates, emulsions, dairy products, and food products containing soft or suspended particles.

For complete food processing systems, the pumping solution therefore needs to do more than move product from one vessel to another. It should support reliable priming, controlled transfer, product recovery, hygienic cleaning, and efficient integration with tanks, pipelines, valves, heating equipment, filling machines, and CIP circuits.

A sanitary twin-screw pump with strong self-priming capability can play an important role in this type of system. Its positive-displacement conveying principle, reversible operation, wide speed range, and ability to participate in both production and cleaning circuits provide a practical approach to reducing residual product and improving overall process utilization.

Why Product Loss Occurs in Food Processing Systems

Food products do not behave like simple low-viscosity liquids. A production line may handle materials that become thicker as temperature changes, contain suspended particles, or require gentle transfer to maintain their original characteristics.

When a conventional transfer arrangement cannot adequately empty a tank or recover product from a pipeline, material may remain in the system after the main transfer cycle has finished. Opening equipment for manual recovery is inefficient and can introduce additional cleaning requirements.

Pump priming can also become a challenge when the suction line contains air or when the pump is positioned away from the product source. If the pump cannot establish sufficient suction, the operator may need additional procedures or equipment to restart transfer.

For food processors, these losses can accumulate across repeated production batches. The solution is not simply to increase pump capacity. The complete transfer system needs to be designed around product recovery, suction conditions, flow direction, and cleaning requirements.

High-Priming Capability for More Reliable Product Recovery

The SLGP sanitary twin-screw pump uses two non-contact screws to create continuously moving conveying chambers. As the screws rotate, the product is drawn into the pump and transported toward the discharge side.

Its strong self-priming capability is particularly relevant when the pump must establish suction from a tank, pipeline, or other process vessel. Under the stated conditions, the pump chamber can achieve a vacuum level of approximately 0.8 bar when containing product.

This characteristic can help the pump handle suction conditions where air must first be displaced before stable product transfer is established.

For a complete food processing system, this is important because the pump is not operating in isolation. Its performance depends on the relationship between the product tank, suction piping, valves, heat exchangers, processing vessels, and downstream equipment. Strong priming capability gives engineers greater flexibility when arranging these components and planning product recovery routes.

Reversible Transfer Helps Recover Residual Product

Another feature that can contribute to reducing product loss is reversible operation.

The SLGP pump can change conveying direction simply by changing shaft rotation. This allows the same pump to move product in either direction without replacing or mechanically modifying the pump components.

In a food processing line, reverse operation can be incorporated into the system design for selected product recovery procedures. After the main transfer has finished, residual product in a connected section of pipeline can potentially be returned toward the designated collection vessel rather than remaining in the line.

The actual recovery effect depends on pipeline geometry, product properties, valve arrangement, temperature, and system configuration. However, the ability to reverse flow gives system designers an additional method for managing residual product without automatically installing another dedicated transfer pump.

Low-Pulse Conveying for Food Products

Product recovery should not come at the expense of product quality. The twin-screw pumping principle provides continuous axial conveying, producing relatively low pulsation compared with reciprocating positive-displacement pumping.

This can be useful when transferring food products whose appearance, texture, or suspended components need to be maintained during processing.

The screws operate without direct contact with each other or the pump housing. This non-contact design also makes the pump suitable for selected products with limited lubricity and for food materials containing soft or suspended solid particles, with the actual application depending on product characteristics and pump configuration.

The supplied design can accommodate particles up to 40 mm in diameter under appropriate conditions. This should be evaluated together with the product's hardness, concentration, viscosity, temperature, and required transfer speed during equipment selection.

Integrating the Pump into a Complete Food Processing Solution

Reducing product loss is most effective when the pump is considered as part of the entire processing system rather than as an independent component.

A sanitary twin-screw pump can be integrated with storage and mixing tanks, process vessels, hygienic piping, valves, heating or cooling equipment, filtration units, filling systems, and CIP circuits. The pump's reversible operation and variable speed range can provide additional flexibility when coordinating different stages of the process.

For example, a system handling a viscous sauce may use the pump to transfer product from a preparation tank through a heated pipeline toward a filling or holding stage. After the primary transfer is completed, the process sequence can use the pump's reverse capability to recover selected residual product from the transfer route.

The same pump can then participate in the cleaning circulation when the system is appropriately designed for CIP/SIP operation. This reduces the need to automatically provide a separate CIP pump and can help simplify the overall equipment arrangement.

Hygienic Design Also Supports Product Utilization

Product recovery cannot be separated from cleanability in food processing. A system that recovers product efficiently but leaves difficult-to-clean areas can create other production problems.

The SLGP pump uses a hygienic internal flow path designed without conventional dead zones. Product-contact areas can therefore be incorporated into a cleaning strategy in which the cleaning medium circulates through the pump and associated process piping.

The pump can handle media temperatures up to 130°C, while the stated cleaning temperature capability reaches 140°C, subject to the selected configuration and operating conditions.

Available sealing options include single mechanical seals, double mechanical seals, rubber shaft seals, and packing seals. Electropolishing is also available as an option for applications requiring an enhanced surface finish.

Designing Around the Whole Process, Not Just the Pump

A high-priming twin-screw pump can contribute to lower food product losses, but the final result depends on the complete system design.

Tank geometry, pump location, suction piping, pipeline length, product temperature, viscosity, valve configuration, transfer sequence, and recovery strategy all influence how much product can ultimately be recovered.

For this reason, food processing equipment should be selected around the complete process requirement rather than choosing a pump solely according to nominal flow. The SLGP modular design allows different pump body sizes and screw dimensions to be matched with different operating conditions, while its wide speed range provides additional flexibility for production transfer and cleaning duties.

By combining reliable priming, reversible conveying, low-pulse transfer, hygienic construction, and CIP/SIP compatibility, the sanitary twin-screw pump can become part of a broader food processing solution and complete equipment system focused not only on moving product, but also on recovering more of it, simplifying cleaning, and improving the efficiency of the overall process.