Removing exhausted water treatment material from container, e.g. in desalination, comprises injecting gas or liquid to set filter bed in rotation and removing rotating column of material through outlet at base

摘要

Cylindrical container for a fixed or fluid filter bed of particulate or granular material (2) has a nozzle (9) mounted on one wall for feeding in a gas or liquid. This causes the liquid (3) and particulate material in the container to rotate. An outlet (8) at the base of the filter column allows the rotating material to be drawn off. Independent claims are included for: (a) a method for removing particulate or granular material from a container as described above; and (b) plant for purifying liquids using ion exchange resin and for regenerating exhausted resin using a container as described above.