An apparatus and method of controlling freezing in a liquid system is
disclosed. The apparatus includes a heat exchanger having a initial zone
characterized by a surface area to volume ratio. The apparatus also
includes means for initiating freezing of a fluid from the initial zone
to facilitate volume expansion during freezing in the direction of a
final zone characterized by a final zone surface area to volume ratio.
The apparatus can further include a plurality of zones located between
the initial zone and the final zone, wherein a zone surface area to
volume ratio is calculated for each zone. Preferably, the zone surface
area to volume ratio of each zone progressively decreases from the
initial zone in the direction of the final zone. Preferably, the final
freezing zone has the lowest surface area to volume ratio and has
sufficient elasticity to accommodate the volume expansion of all the
fluid that has frozen from the initial zone.