Article Title

The operators of industrial plants throughout the world have to cope with a wide variety of fluid transfer and waste treatment processes, of which the most common, and troublesome, component is often the pumps. The simple fact is that there are a very large number of pump manufacturers, each offering a bewildering array of types and sizes, which almost always ensures that the best pump for the job will not make it to the site. The replacement of an unsuitable pump is also likely to be less than ideal for the same reasons.

As the range of liquids is vast, the materials from which the parts in contact

with the pumped liquid must be equally varied. Experienced pump suppliers must

be able to supply casings, impellers, bearings and other parts in materials

suitable for dealing with the most abrasive and aggressive liquids.

From a core business viewpoint, the most ignored feature of pump selection

is the

damage to the pumped liquid. The high turbulence within pumps, and in the downstream

tail effect within the pipe, can impart significant damage to molecular structures. Fluids as diverse as

paints, yoghurts and bio-cultures such as activated sludge, all require the

gentlest handling.

Absolve the supplier

Physical damage is equally important. The undamaged transfer of fruit and vegetables

is a frequent duty, as is the transfer of live fish. High speed, centrifugal

pumps are not well suited for such damage-free situations, even when using the

famous non-clog variants which pass a 75mm sphere.

So how much do you need to pump, now and next year? With damage issues sorted,

the actual sizing of the pump usually occupies little time as the end user is

expected to supply the figure. No matter whether it is litres/second, gallons/

minute, or even tons (or tonnes) per day, all absolve the pump supplier, and

that is that.

Not too sure of the flow, now or in the future? Then what is needed is an expensive

variable speed unit. Or – a pump output which matches inflow, whilst using a

fixed-speed motor. Hidrostal’s Prerostal technology provides a variable output

without the need for a variable speed drive. The flow to each pump enters a

compact sump and the basin geometry produces a rotational speed which is proportional

to inflow. The output of the fixed speed pump is directly related to rotational

speed and, consequently, output matches inflow. No pump downtime means uninterrupted

production. The breakdown of a manufacturing process pump, or pumps within the

plant treating production waste, is not just a pain for the maintenance department;

production can cease. This is every manager’s nightmare, particularly where

continuous processes are involved. Real costs pile up and the situation is often

compounded when it is found that no spares are available for that immobile pump.

Pleasure it most definitely is not. Production pleasure is influencing the initial

selection and never experiencing problems thereafter. This is possible, as major

multi-national companies are well aware.