This present invention relates to a fluid separation module adapted to
separate a given fluid mixture into permeate and retentate portions using
bundles of hollow fiber membranes. The membranes may be composed of
different kinds of membranes depending on the application being used to
separate the fluid mixture. The fluid separation module may be used to
separate fluid mixtures by a number of different processes, including but
not limited to, pervaporation, vapour permeation, membrane distillation
(both vacuum membrane distillation and direct contact membrane
distillation), ultra filtration, microfiltration, nanofiltration, reverse
osmosis, membrane stripping and gas separation. The present invention
also provides an internal heat recovery process applied in association
with those fluid separation applications where separation takes place by
evaporation through the membrane of a large portion of the feed into
permeate. Desalination and contaminated water purification by means of
vacuum membrane distillation are just two examples where the internal
heat recovery process may be applied. In these two examples, large
portions of the feed are separated by membranes into a high purity water
permeate stream by evaporation through the membranes and into a retentate
stream containing a higher concentration of dissolved components than
present in the feed. In this process the permeate vapour that is
extracted from the fluid separation module is compressed by an external
compressor to increase the temperature of the vapour higher than the
temperature of the feed entering the separation module. Heat from the
permeate vapour at the elevated temperature is transferred back to the
incoming feed fluid mixture entering the fluid separation module in a
condenser/heat exchange.
