Abstract:
A multi-layer membrane includes a fluorine containing layer and a substrate which are joined through spray coating and heat treatment in a multi-step technique.
Abstract:
The invention relates to an arrangement for introducing gas bubbles into a liquid, a device (1) for fastening a perforated aeration membrane (2) to an aerator base plate (3) as well as to an aerator base plate (3) therefor. The aerator base plate (3) has an undercut groove (4) in at least one rim region thereof, into which a locking body (7) clamping the membrane (2) in said groove (4) fits clampingly. The locking body (7) has a generally circular cross-section. The groove (4) has an at least substantially oval cross-section. The locking body (7) is designed to be generally cylindrical.
Abstract:
An aeration system for a submerged membrane module has a set of aerators connected to an air blower, valves and a controller adapted to alternately provide a higher rate or air flow and a lower rate of air flow in repeated cycles. In an embodiment, the air blower, valves and controller, simultaneously provide the alternating air flow to two or more sets of aerators such that the total air flow is constant, allowing the blower to be operated at a constant speed. In another embodiment, the repeated cycles are of short duration. Transient flow conditions result in the tank water which helps avoid dead spaces and assists in agitating the membranes.
Abstract:
A wastewater treatment method. The method includes establishing a setpoint value of oxidation-reduction potential of a mixed liquor, measuring a measured value of oxidation-reduction potential of the mixed liquor, comparing the measured value of oxidation-reduction potential and the setpoint value of oxidation-reduction potential, generating a control signal based at least in part on the step of comparing, controlling operation of an aeration device using the control signal, acquiring at least one value corresponding to the control signal and adjusting the setpoint value of oxidation-reduction potential using the at least one value. The value includes a frequency of operation of the aeration device.
Abstract:
A flexible diffuser membrane for diffusing gas into a liquid includes a substrate covered wholly or partially by a thin fluorocarbon elastomer coating. The coating is applied after the substrate has been fully constructed and cured. The coating is then mixed with an adhesive catalyst and applied by spraying or in another suitable manner to the substrate. The substrate and coating are then heated to a temperature such as 350° F.-800° F. adequate to form a strong chemical, molecular and adhesive bond between the coating and substrate. Perforations are formed in the membrane, the substrate may be treated with a biocide allowing the uncoated edges of the perforations to be coated with the biocide and resist biological growth.
Abstract:
Membrane strip diffusers are disclosed, useful for example in aerating wastewater in activated sludge plants. These diffusers have membranes, diffuser bodies and gas conduits elongated in the same general direction. Such conduits may be attached to or formed integrally with the diffuser bodies. Gas chambers form beneath the membranes when they inflate, and these are separate from but communicate with the gas conduits, e.g., through passageways distributed along the lengths of the membrane supports. Preferably, the passageway flow cross-sections are small, thus tending toward uniform distribution of gas along the membrane's length. Ways to edge- and end-seal the membranes to the diffuser bodies are also disclosed.
Abstract:
A multi-layer membrane includes a fluorine containing layer and a substrate which are joined through spray coating and heat treatment in a multi-step technique.
Abstract:
A flexible aeration panel is described, which does not include a rigid support plate. The flexible aeration panel can comprise a first perforated, flexible sheet sealed to a second non-perforated flexible sheet at their peripheral edges, thereby defining one or more cavities that are in fluid communication with at least one gas inlet. The flexible aeration panel can be configured to produce preferably evenly spaced bubbles of gas when positioned in a liquid body. Applications include, but are not limited to, aeration of wastewater, lakes, streams, water basins and the like.
Abstract:
The present invention provides an aeration device comprising a rectangular elastic porous body, a support base supporting the elastic porous body from below and having an orifice for pressurized air, and a securing component which secures the elastic porous body to the support base integrally, wherein the support base comprises a supporting portion supporting the elastic porous body from below and an attaching portion connected to the supporting portion and attaching the supporting portion to a pressurized air distribution pipe, the rectangular elastic porous body having a box shape having an opening portion, and the supporting portion being disposed in an elastic porous body. In addition, the present invention provides an aeration system comprising two or more above described aeration devices installed on a pressurized air distribution pipe, wherein each aeration device is disposed contacting mutually with no space between.
Abstract:
A process for supplying bubbles to a membrane module and cleaning an aerator producing the bubbles includes, in repeated cycles, steps of producing bubbles from an aerator and reducing pressure in the aerator such that water in the tank enters the aerator.