AnALytIcAL & LABorAtory EquIPMEnt 23
Peristaltic pumps deliver accurate
and contamination-free dosing
Fig. 1. Sophisticated
With factors such as
metering and dosing
contamination-free
technology is
operation, accuracy, important in many
dose repeatability, ease applications.
of operation and simple
maintenance on its
side, more and more
laboratories are opting to
use peristaltic pumping
technology. Ashley
Shepherd explains.
De plus en plus de
laboratoires optent
pour l’emploi de la
technologie du pompage
péristaltique, qui a pour
elle certains atouts
comme le fonctionnement
sans contamination,
l’exactitude, la
répétabilité des doses,
la facilité d’utilisation et
la simplicité d’entretien.
Les explications d’Ashley
Shepherd.
Immer mehr Labore
entscheiden sich aufgrund
von Vorteilen wie
kontaminierungsfreiem
Betrieb, Genauigkeit,
hether you work in a laboratory, syringe mechanisms, piston pumps, diaphragm
Dosiswiederholbarkeit,
on a pilot plant or in full-scale pumps, gear and lobe pumps, and peristaltic
Bedienungsfreundlichkeit
production units, there is a pumps. But it is only the lowest common
und einfacher Wartung
W
für den Einsatz von
strong possibility that at some denominator.
Peristaltikpumpen-
time you will need to dispense materials accurately At first sight, a peristaltic pump is simplicity
technologie. Mehr darüber
from one point to another. itself. Fluid flows through a flexible tube, which a
von Ashley Shepherd.
Applications as varied as dispensing nutrients number of rollers pass over, repeatedly squeezing
to fermentation vessels, adding flavourings and and releasing the tube. The tube’s restitution or
other additives to foodstuffs, or dosing municipal recovery to its normal diameter after its 'squeeze'
water supplies with chemicals, all demand creates a vacuum, which draws more fluid
levels of accuracy that can only best be met by into the tube to be positively displaced by the
positive displacement delivery methods. Unlike rollers’ squeezing action. This simple operation
conventional centrifugal pumps, where output owes much to the physiological phenomenon of
volumes have to be controlled by flow meters peristalsis, in which muscles alternately contract
and valves, positive displacement systems deliver and relax vessels, such as intestines, to move
a fixed volume for each cycle of the device, material through the body. Behind the simplicity,
irrespective of input or output flow conditions. however, lies a sophisticated metering and dosing
This ability to dispense fixed volumes at technology that is proving its worth in a wide
controllable flow rates is the common feature variety of applications (Fig. 1).
behind positive displacement devices such as According to Colin Paine, for example, his
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