Open bottom multiple channel gas delivery device for immersed membranes
A gas delivery device includes a manifold and a plurality of channels. The manifold is adapted to be connected to a source of a pressurized gas. Each of the plurality of channels is in fluid communication with the manifold through a distinct associated port. Each of the plurality of channels has a generally open bottom.
1. A gas delivery device comprising:
a manifold adapted to be connected to a source of a pressurized gas; and
a plurality of channels, each of the plurality of channels having a first end, a second end and a single outlet formed by the second end of the channel being open, the first end being in fluid communication with the manifold through a distinct associated port, each of the plurality of channels having an open bottom between the first end and the second end,
wherein the plurality of channels have different lengths relative to each other,
wherein the plurality of channels are parallel to each other, and wherein each of the plurality of channels extends in the same direction from the first end of the channel to the second end of the channel.
2. The gas delivery device of claim 1 wherein the outlets of the plurality of channels are spaced apart from each other horizontally.
3. The gas delivery device of claim 1 , wherein each of the channels has a cross sectional area and each of the ports has an area less than the cross sectional area of the channel that the port is associated with.
4. The gas delivery device of claim 1 , wherein the ports are configured as open-bottomed slots.
5. The gas delivery device of claim 1 , wherein the manifold is open-bottomed.
6. The gas delivery device of claim 1 , in combination with an immersed membrane module.
7. The gas delivery device of claim 1 , in combination with a transducer adapted to convert continuous streams of bubbles released from the outlets into intermittent flows of bubbles.
8. The gas delivery device of claim 1 wherein each outlet is as large as a cross sectional area of the outlet's associated channel at the end of the channel.
9. The gas delivery device of claim 1 wherein the plurality of channels are formed by a top and a plurality of side walls extending downwards from the top.
10. The gas delivery device of claim 9 wherein adjacent channels share a common side wall.
11. A gas delivery device comprising:
a distribution manifold adapted to be connected to a source of a pressurized gas; and
a plurality of channels, each of the plurality of channels being in fluid communication with the distribution manifold through a distinct associated port, each of the plurality of channels having an outlet at the end of the channel adapted to discharge gas,
wherein the ports have a smaller area than the channels and the ports are located close together relative to a spacing between the outlets
wherein the device has four or more channels, each of the channels has a different length, the channels are parallel to each other, and a largest horizontal distance between two of the ports is less than 10% of a largest distance from one of the ports to one of the outlets, and wherein each of the plurality of channels extends in the same direction from the port associated with the channel to the outlet of the channel.
12. The gas delivery device of claim 11 , associated with a transducer having multiple compartments, wherein each compartment is associated with one of the channels.
13. The gas delivery device of claim 12 , wherein each of the compartments has an inverted siphon.
14. The gas sparger of claim 11 , wherein each of the plurality of channels is open bottomed.
15. The gas sparger of claim 14 , wherein the manifold and the ports are open-bottomed.
16. An aeration process comprising:
providing a gas delivery device according to claim 1 ; and
providing a flow of pressurized gas to the gas delivery device.
17. The process of claim 16 wherein the flow of pressurized gas is varied within a range of input gas flows.