Abstract: An assembly of immersed filtering membrane modules on the order of a cassette or larger are aerated in a series of air-on or high flow rate periods, each in the range of 0.5 to 20 seconds long, separated by longer air-off or low flow rate periods, each in the range of 5 to 40 seconds long. A manifold is in fluid communication with one or more aerators. The manifold and aerators are located in association with the modules. The assembly of immersed filtering membrane modules are provided with a burst of air from the plurality of aerators. The aerators may be fed with a continuous supply of air. The modules may be connected together in a cassette or rack. Bubbles from the aerators may be redirected or dissipated with a deflector before they contact the modules.

Abstract: A gas sparger for a filtering membrane system produces an intermittent flow of bubbles even if provided with a relatively continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for can comprise a plurality of smaller units or areas. The supply of gas to the sparger may vary in flow rate over larger periods of time in response to changes in conditions in the membrane system to change the time between consecutive bursts of bubbles. A gas supply pipe may have two or more outlets at different elevations in communication with each of two or more units or areas.

Abstract: An assembly of immersed filtering membrane modules on the order of a cassette or larger are aerated in a series of air-on or high flow rate periods, each in the range of 0.5 to 20 seconds long, separated by longer air-off or low flow rate periods, each in the range of 5 to 40 seconds long. A manifold is in fluid communication with one or more aerators. The manifold and aerators are located in association with the modules. The assembly of immersed filtering membrane modules are provided with a burst of air from the plurality of aerators. The aerators may be fed with a continuous supply of air. The modules may be connected together in a cassette or rack. Bubbles from the aerators may be redirected or dissipated with a deflector before they contact the modules.

Abstract: An assembly of modules on the order of a cassette or larger are aerated simultaneously in a series of air-on or high flow rate periods, each in the range of 0.5 to 20 seconds long, separated by longer air-off or low flow rate periods, each in the range of 5 to 40 seconds long. A plurality of aerators located in association with a plurality of modules are provided with a burst of air simultaneously from a shared air accumulator or pulsator connected to all of the aerators. The air accumulator or pulsator may be fed with a continuous supply of air. The plurality of modules may be connected together in a cassette or rack. The accumulator or pulsator may be located outside of a tank of water containing the membranes.

Abstract: A gas sparger for a filtering membrane system produces an intermittent flow of bubbles even if provided with a relatively continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for can comprise a plurality of smaller units or areas. The supply of gas to the sparger may vary in flow rate over larger periods of time in response to changes in conditions in the membrane system to change the time between consecutive bursts of bubbles. A gas supply pipe may have two or more outlets at different elevations in communication with each of two or more units or areas. The discharge of gas between two or more units or areas may be synchronized. One or more of a set of units or area may receive a supplied gas at a higher flow rate.

Abstract: A membrane module may have, or may be fitted with, a transparent or translucent cover over a block of potting material holding hollow fiber membranes. To locate a defective fiber, a liquid may be placed over the ends of the membranes while the separating surfaces of the membranes are exposed to a gas and a pressure differential is applied to produce bubbles of the gas in the liquid through a defect requiring repair. The location of the defective fiber is revealed by the bubbles. The module may be repaired by closing the potted end of the defective fiber. The pressure differential may be applied by suction on the cover. The separating surfaces of the membranes may not need to be installed in a pressure vessel. The end of the defective membrane may be sealed by manipulating devices from outside of the cover such that the cover does not need to be removed. The cover may also be used to create a permeate cavity, or other part of a header assembly, used in normal operation of the module.

Abstract: A method for spraying a liquid on plants by means of a spraying assembly adapted for mounting on a pair of upper and lower wires parallel to each other. The spraying assembly comprises a sprayer having at least one nozzle adapted for fluid communication with a source of the liquid, and a sprayer holder. The sprayer holder comprises a rigid rod and upper and lower holder members mounted on the rod and having clamping means for being clamped to the respective upper and lower wires. One of the holder members has a sprayer seat for fixedly supporting the sprayer in a predetermined orientation relative to the rod.

Abstract: A method for spraying a liquid on plants by means of a spraying assembly adapted for mounting on a pair of upper and lower wires parallel to each other. The spraying assembly comprises a sprayer having at least one nozzle adapted for fluid communication with a source of the liquid, and a sprayer holder. The sprayer holder comprises a rigid rod and upper and lower holder members mounted on the rod and having clamping means for being clamped to the respective upper and lower wires. One of the holder members has a sprayer seat for fixedly supporting the sprayer in a predetermined orientation relative to the rod.