摘要 |
<p>A module of vertical membranes has a lower header with integral air holes. Modules are mounted in line on upper and lower beams. A skirt is formed under the cassette. Adjustable side members between the beams allow for membrane slack adjustment and bottom beam levelling. A flat aerator assembly can be inserted into spaces between the cassettes and provide bubbles into the skirts, the spaces between cassettes, or both. An aeration method involves producing bubbles primarily or only to one side of the module, alternating from one side of the module to the other, while also producing bubbles within the module or between the membranes, optionally continuously. A cleaning method involves flowing a chemical cleaning solution by force of gravity through a membrane module, optionally by injected a concentrated solution into a vented potion of a permeate withdrawal system located above the water level in a tank holding the module.</p> |