Verfahren und Vorrichtung zur Wasseraufbereitung nach dem Prinzip der umgekehrten Osmose

摘要

The invention concerns a reversed osmosis apparatus for treating water, in particular for supplying haemodialysis appliances. The apparatus is equipped with a preliminary filter (50) which is preferably in the form of a sterile filter or ultrafilter and is inserted in the untreated water delivery pipe. The preliminary filter can be cleaned by flow reversal without interrupting the operation of the apparatus. To this end, fluid flows through the filter in the opposite direction to the normal direction of flow, this fluid being taken from a part of the apparatus lying downstream of the reversed osmosis filter (14) and diverted in an appropriate manner via a valve circuit (54, 52). During flow reversal, the apparatus supplies itself from a buffer vessel (11) between the preliminary filter and the pump (13) feeding the reversed osmosis filter. In order to avoid the need of additional fluid, the concentrate which is generally drained out of the apparatus is preferably used to reverse the flow in the preliminary filter.