New design for pharma heat exchangers

The Pharma-X from Alfa Laval is a completely new type of compact heat exchanger, designed for duties in the pharmaceutical and other industries where high hygiene standards have to be met.

Designed specifically for cooling water-for-injection (WFI) at the point of use, the Pharma-X uses a combination of tubes and spirals to create a leak-proof construction that is said to achieve high levels of thermal efficiency, close temperature approaches and, under the right conditions, temperature cross.

Basically it consists of three concentric tubes inserted into each other, with the spirals fixed between each. The spirals not only maintain the correct tube spacing but also create turbulent flow, so improving heat transfer and reducing the risk of fouling by eliminating dead spots. The three tubes are bent through 180° to create a leak-free unit.

In operation, product flows through the central tube, with heating or cooling medium flowing through the inner and outer tubes. The design is said to be very resistant to thermal fatigue induced by frequent temperature fluctuations. It also has a very small hold-up volume compared with conventional exchangers, making it very responsive to process changes.

All surfaces likely to come into contact with product are electropolished and there are no internal welds to spoil the finish or provide a weak spot for potential leaks.

There are four sizes, with capacities ranging from 0.3m2 to 1m2, capable of handling a maximum product flow rate of 1800 l/h.