Dispensing Solutions

Whether you work in a laboratory, on a pilot plant or in full-scale production units, there is a strong possibility that at some time you will need to dispense materials accurately from one point to another. Applications as varied as dosing nutrients to fermentation vessels, adding flavourings to foodstuffs, or dosing municipal water supplies with chemicals, all demand levels of accuracy that can only best be met by positive displacement delivery methods. Unlike conventional centrifugal pumps, in which output volumes have to be controlled by flowmeters and valves, positive displacement systems deliver a fixed volume for each cycle of the device irrespective of input or output flow conditions.

This ability to dispense fixed volumes at controllable flow rates is the common feature behind positive displacement devices such as syringe mechanisms, piston pumps, diaphragm pumps, gear and lobe pumps, and peristaltic pumps. But when other factors are also taken into consideration – the need for contamination-free operation in hygienic applications, the accuracy and repeatability of the dose, the ease of operation and maintenance and, perhaps most importantly, the overall cost – then a very strong case can be made for choosing peristaltic pumps above all others.

EASE OF USE AND COST-EFFECTIVENESS

At first sight, a peristaltic pump is simplicity itself. Fluid flows through a flexible tube, which a number of rollers pass over, repeatedly squeezing and releasing the tube. The tube’s restitution or recovery to its normal diameter after its ‘squeeze’ creates a vacuum, which draws more fluid into the tube to be positively displaced by the rollers’ squeezing action. Behind the simplicity, however, lies a sophisticated metering and dosing technology that is proving its worth in a wide variety of applications.