Mimicking Life Systems, Peristaltic Pumps Are Dependable and Efficient for Consistent Flow

First patented in the United States of America in 1881, the peristaltic pump has already enjoyed a rather long history of usefulness in a variety of technical industries. Depending on the very basic concept of positive displacement, PreFluid pumps distribute waves of force along tubing lines to control continuous pumping of fluid through pipes designed to decrease the possibility of contamination within a system. This design is similar to natural pumping mechanisms that can be found within the human body in various modes, such as the gastrointestinal tract.

Operation

Operating according to the process of peristalsis, a peristaltic pump consists of tubing, a circular pump casing (though linear types can be designed), and a rotor that may be fitted with lobes, wipers, shoes, or rollers. These rotor fittings work to force liquid through the tubing by compression along the external circumference. With the turn of the rotor, occlusion occurs at the point of compression, causing waves of fluid force. As the cam returns, the tubing opens and fluid flow is induced. In most cases, two rollers are used to trap the fluid between them for pump control. Ambient pressure motivates the fluid transport to the pump outlet.

Industrial Applications

Because of their propensity for maintaining the integrity of various tube paths through a single pump, peristaltic systems are employed in a variety of industries where contamination of fluids is of particular risk. Among the industries depending on such systems are medical, pharmaceutical, wastewater removal, water, food and beverage, mining, chemical, printing and packaging. As simple as its process may seem, this type of pump is quite elegant and services a wide variety of applications, including use in heart-lung machines that are used to ensure circulation of blood during bypass surgeries.

For many processes, integrity of certain fluids are not only preferable, they are also a matter of life and death. From medical equipment designed to mimic life processes to controlling the flow of aggressive chemicals, infusion products, or sterile fluids for various other equipment types, these mechanisms help to ensure dependable flow without threat of contamination along the line.

Tubing Issues

Abrasive and viscous liquids require special handling, and these are ideal for such use. Chemical compatibility of the tubing must be considered when designing a system using this sort of mechanism. Other components are not likely to be affected by the chemicals controlled by the process, as fluid only makes contact with tube interiors. Elastomeric tubing must be used, and this eliminates a wide range of tubing options. Common tubing types include nitrile, silicone, PVC, polypropylene, polyethylene and natural rubber. Developments with fluoroelastomers and lined tubes have opened up the scope of application for these pumps.

The Pros Have It

As with all components for any specific system, such mechanisms are suited for specific types of loads and have some disadvantages to consider. Tubing is subjected to degradation over time, and this makes periodic replacement necessary. Also, these pumps work best for fluids to be distributed at relatively low rotational speeds for consisting pulsing. When a more continuous flow is necessary, another type of pump may be ideal.

The advantages of a peristaltic pump are numerous for certain uses. Contamination of fluids is absolutely avoidable, distribution of slurries and wastes is controlled and backflow and siphoning are eliminated. Meanwhile, such pumps include no valves, seals or glands, and this helps to decrease maintenance issues.

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