Setting the standard in spiral heat exchangers
26 Nov 2007
Alfa Laval’s ALSHE LTL range of spiral heat exchangers is ideal for duties such as heating, cooling and heat recovery in liquid/liquid applications - where exchangers with narrower flow channels would be at risk of fouling - thanks to its single channel design.
The ALSHE LTL range consists of seven standard models, all available off the shelf in standard materials. Designed for maximum thermal efficiency, the spiral heat exchanger is compised of two concentric spiral flow channels. The hot medium, generally, flows from the centre to the periphery of the unit while the cold medium flows in the opposite direction. This counter-current flow ensures maximum heat transfer between the two media, providing very close temperature approach and temperature crosses.
The use of single channels also reduces the risk of fouling and clogging and bypassing. Whereas in multi-channel exchangers, if clogging occurs the fluid is redirected through other, clear channels, in the spiral unit the flow velocity increases, creating a scrubbing action which washes the obstruction away. This arrangement also increases the efficiency of chemical cleaning since cleaning solution is fully contained within the heat transfer channels.
The Spiral heat exchanger’s unique wrap-around design not only ensures high levels of heat transfer efficiency but results in a remarkably compact footprint. Generally speaking, a spiral unit will require less than 20% of the space needed by a shell and tube exchanger of equivalent thermal capacity. This attribute, combined with the spiral exchanger’s ability to be mounted either horizontally or vertically, gives process engineers a great deal more design freedom.
It also provides valuable savings in installation costs and the space required for operation and servicing the exchanger. When cleaning or maintenance are necessary, the complete heat transfer surface can be rapidly accessed with Downtime kept to a minimum.
The Spiral heat exchangers in the ALSHE LTL range operate at temperatures up to 250 0C and maximum design pressures of up to 6.5 bar g.
For further information please call 01276 413632