GB1407099A - Method and apparatus for filtration and demineralization of water particularly condensate - Google Patents

Abstract

1407099 Ion-exchange; filtration CRANE CO 8 Dec 1972 56890/72 Headings B1D and B1J A process for demineralizing water in which, during onstream operation, water is caused to flow downwardly first through an upper bed including at least one ion exchange resin capable of filtering solids from the water and then through a lower bed including at least one ion exchange resin, the two beds being located in a single vessel, comprises the steps of removing the upper bed from the vessel and subjecting it to scrubbing to remove filteredout solids without chemical regeneration, then returning the scrubbed bed to the same vessel (or a similar vessel where a plurality of vessels is in use) for further onstream operation, repeating the removal and scrubbing and return of the upper bed one or more times, and chemically regenerating the bed after the last scrubbing and prior to returning it for further onstream operation. Each bed may be either anionic or cationic or mixed. A plurality of units each containing two beds in series, may be operated in parallel. A suitable apparatus comprises a vertical cylinder with one bed A in an upper region 4 and a second bed B in a region 6 separated by a grating 10 of parallel spaced bars 12, 14 provided with perforated pipes 20 connected to a header 18 and pipe 24. A similar header 34 and pipes are provided at. the foot of region 6. When necessary the bed A is removed via pipe 57 by means of water entering at 64, a slow upward flow through the grating preventing any of bed A from flowing downwards through the grating. The scrubbed material is replaced via pipe 68. The process and apparatus are suitable for treating condensate to be used as boiler feed.