by David Kirk, Dover Corporation

Leak-free operation optimizes waste-reduced food production capabilities.

Mankind reached its latest population milestone on October 31, 2011, when the United Nations Population Fund estimated that a baby boy born in the Russian city of Kaliningrad became Earth's seven billionth resident. That meant that only 11 years were needed to add another billion people to the world's population since the six-billion threshold was reached in 2000, while the population has doubled from 3.5 billion in the early 1970s. Even with fertility rates declining, the U.N. predicts that the world's population will continue to grow and reach eight billion in 2025 and 9.2 billion by 2050.

Any way you look at it, that is a lot of mouths to feed. The challenge, then, for food producers around the globe is to put into place systems that not only grow, raise or fabricate enough food to meet the needs of the worldwide population but to do so in the most efficient, cost-effective manner and with the smallest amount of spoilage or waste possible. Because of this, a 2008 report commissioned by the Stockholm (Sweden) International Water Institute should have been an eye-opener for food producers everywhere. In the report, titled “Saving Water: From Field to Fork—Curbing Losses and Wastage in the Food Chain,” the authors noted that the most often quoted estimate on global food waste is that “as much as half of all food grown is lost or wasted before and after it reaches the consumer.”

This article will show how an innovative pump technology can help food producers, processors and packagers optimize op-erations on the front end. This will result in waste reduction that will benefit the growing world population and the production company's bottom line.


The Challenge


When it comes to sanitary food-processing applications, lobe/circumferential-piston pump technologies—the designs of which force the pumped material to flow around the interior of the pump's casing—has often been a top choice of plant operators. The popularity of lobe/circumferential-piston pumps in these types of operations stems from their continuous-flow and dry-run capa-bilities, which affords them the ability to handle the wide range of solids, slurries, pastes and liquids that are found in sanitary food production and packaging operations.

The plant operators who rely on these pumps are, however, forced to live with a series of operational inefficiencies that are inherent to the pump. These inefficiencies come not only in the form of decreased reliability over time, but an increase in energy consumption and cost, which is becoming a more crucial consideration for production-plant operations worldwide as “green” energy initiatives take hold.

Because of their method of operation, from day one, lobe/circumferential-piston pumps will wear constantly. This wear means that the internal clearances in the pump's housing will become greater, resulting in reduced flow capacity and volumetric consistency over time, along with the increased possibility that product “slip” will occur. These conditions will combine to produce an overall reduction in the pump's efficiency and a corresponding increase in the cost of operating it due to the increased speeds required to maintain the desired volumetric consistency.

Other shortcomings of lobe/circumferential-pump operation that food processors must be aware of include:

  • The need to seal two shafts, which doubles both seal expenses and the potential for leakage
  • Chronic seal failures that can cause products to solidify inside the pump
  • Self-draining that requires vertical porting, which can decrease volumetric efficiency by 20 percent or more
  • Greatly reduced speeds required to handle 
  • high-viscosity liquids
  • Diminished performance when handling low-viscosity liquids


The Solution


This new type of eccentric disc pump is sealless and uses a unique stainless steel bellows that results in increased performance.

Eccentric disc pump technology is becoming a growing option for food production. When looking for  an acceptable alternative to lobe/circumferential-piston-style pumps regarding optimized performance, highest volumetric consistency, lowest life-cycle costs and the best energy efficiency, eccentric pumps are the solution. 

The versatility, reliability and sanitary operation of this technology make it ideal for an array of food-production applica-tions—including the handling of yogurts; ice cream; custards and chocolate; beverages such as fruit juices and milk; confectionary items like glucose and aromas; sauce-type liquids such as tomato sauce, mayonnaise, mustard and baby food; and many semi-abrasives.

The eccentric disc (or movement) principle was invented by French engineer André Petit more than a century ago. Basically, the eccentric disc pumping principle has produced a family of pumps that does not need mechanical or dynamic seals to operate. This makes eccentric disc pumps perfectly suitable for the sanitary/hygienic operating conditions that are the hallmark of food production, processing and packaging.