Device for gassing a liquid
A device for gassing a liquid, particularly for membrane facilities used in immersion operation, has a gas supply channel and at least one gas lance from which a gas flow exits in gassing operation. The gas lance is connected to the gas supply channel via at least one connection channel including a first mouth area on the side of the gas lance and a second mouth area on the side of the gas supply channel and generating as a throttle a flow pressure loss of the gas flow entering the gas lance. Below the first mouth area an extension section is provided, which adjoins the gas lance and has an opening below the first mouth area.
1. A device for gassing a liquid for membrane facilities used in immersion operation, having a gas supply channel and at least one gas lance from which a gas flow exits in gassing operation, wherein the gas lance is connected to the gas supply channel by means of at least one connection channel comprising a first mouth area on the side of the gas lance and a second mouth area on the side of the gas supply channel and generating as a throttle a flow pressure loss of the gas flow entering the gas lance, and wherein below the first mouth area an extension section is provided, which adjoins the gas lance and has an opening below the first mouth area.
2. The device according to claim 1 , wherein the connection channel has a throttle point or has a cross-section over its entire length which is smaller than the cross-section of the gas lance.
3. The device according to claim 1 , wherein the second mouth area is arranged in the bottom of the gas supply channel.
4. The device according to claim 1 , wherein the connection channel is provided by means of a connecting piece attached to the gas supply channel, wherein the gas lance extends up into a receiving chamber of the connecting piece, and wherein a cover is located on the connecting piece, which is open on the bottom and forms the extension section.
5. The device according to claim 4 , wherein the connection channel has a throttle point at the end of the gas lance plunging into the receiving chamber.
6. The device according to claim 5 , wherein the cover has an inner face , which encloses the end of the gas lance with an annular gap, which forms the throttle point.
7. The device according to claim 4 , wherein the cover has a depression, which is opposite to the end of the gas lance and forms a flow calming chamber of the extension section, and wherein the cover-side opening discharges into the flow calming chamber.
8. The device according to claim 4 , wherein a throttle valve comprising two valve bodies is situated in an annular chamber delimited by the connecting piece and the gas lance, the first valve body being situated on the end of the gas lance and bridging the annular chamber between the gas lance and the connecting piece as well as having gas passage openings, and the second valve body having a valve seat working together with the gas passage openings, and being situated in a chamber between the cover and the first valve body.
9. The device according to claim 8 , wherein the second valve body has a passage, which forms a flow calming chamber of the extension section behind the throttle point and is aligned with the opening in the cover.
10. The device according to claim 1 , wherein the gas lance ends without a constriction and without a cap freely in the liquid to be gassed at its end projecting from the gas supply channel.
11. The device according to claim 10 , wherein the gas lance has a diffuser expansion at its upper end projecting from the gas supply channel.
12. The device according to claim 1 , wherein the gas lance is enclosed by a bundle of hollow fiber membranes, which is embedded at one end in a head piece and discharges into a permeate collecting chamber separated from the gas supply channel.
13. The device according to claim 1 , wherein the extension section passes continuously into the gas lance, the extension section and the gas lance having the same cross-section.
14. The device according to claim 1 , wherein the gas lance and/or the extension section has a conical course in at least some sections.
15. The device according to claim 1 , wherein multiple gas lances are connected to the gas supply channel, from which gas flows exit simultaneously in gassing operation, the gas lances are each connected via at least one separate said connection channel to the gas supply channel, the connection channels generating a flow pressure loss of the gas flows entering the gas lances as throttles, and said extension section is provided below each of the connection channels, which has said opening below the assigned connection channel and adjoins the assigned gas lance.