Sparger

A gas-to-liquid sparger comprising:

• a. an underlying element confining an inflow of gas to a gap between the underlying element and a flat underside of a superposed diffuser, the gap being a space created by a separation between the underlying layer and the diffuser, the gap having a height measured in a direction substantially perpendicular to the diffuser and the underlying layer, at least a portion of the gap being present at all times before, during, and after operation of the diffuser;
• b. the underlying element and the diffuser being bonded together around a periphery of the sparger surrounding the gap and periodically in a plurality of bonding regions spaced apart along a plane substantially parallel to the diffuser and the underlying layer within the gap, the gap including areas between bonding regions;
• and
• c. the gap bonding regions being configured and spaced to allow inflowing gas to spread around the gap bonding regions and throughout the gap not occupied by bonding regions.

A gas-to-liquid sparger comprising:

• a. a thin diffuser and a thin element underlying the diffuser being bonded together to leave a thin gap between the diffuser and the underlying element, the gap being a space created by a separation between the thin element and the diffuser, the gap having a height measured in a direction substantially perpendicular to the diffuser and the thin element, at least a portion of the gap being present at all times before, during, and after operation of the diffuser;
• b. the bonding of the diffuser and the underlying element being continuous around a periphery of the sparger and intermittent along a plane substantially parallel to the diffuser and the thin element throughout the gap within the periphery in a configuration that allows inflowing gas to spread throughout the unbonded parts of the gap within the periphery, the gap including areas between bonding regions;
• and
• c. the bonding regions being arranged for keeping the diffuser close enough to the underlying element during operation of the sparger to avoid applying peeling force at an angle of more than about 30.degree. to a line extending between adjacent bonding regions, thereby minimizing billowing of the diffuser during operation of the sparger and greatly reducing aggregation of bubbles emanating from the diffuser.

A gas-to-liquid sparger comprising:

• a. a diffuser formed of a thin upper layer of a gas-permeable, high surface energy material and a thin lower layer of a gas-permeable, low surface energy material bonded together in a multitude of tiny regions;
• b. the bonding of the diffuser layers together substantially restricting gas from flowing laterally between the layers while allowing gas to flow directly through both layers in more than half of the total diffuser area;
• c. the diffuser being bonded to an underlying element that confines an inflow of gas to the underside of the diffuser;
• and
• d. the bonding of the underlying element and the diffuser being arranged for holding the underlying element and the diffuser substantially together on opposite sides of a thin gap configured to allow inflowing gas to spread throughout the gap, the gap being a space created by a separation between the underlying element and the diffuser, the gap having a height measured in a direction substantially perpendicular to the diffuser and the underlying element, at least a portion of the gap being present at all times before, during, and after operation of the diffuser.

In a sparger having a double-layer diffuser arranged with a high surface energy layer at an interface with a liquid into which a gas is bubbled and a low surface energy layer at an interface with the gas that is bubbled into the liquid, the improvement comprising:

• a. the high surface energy layer and the low surface energy layer being bonded together in a multitude of tiny regions configured and spaced so that gas permeates a major area of both layers without flowing laterally between the layers;
• b. the diffuser being bonded to an underlying layer that confines inflowing gas within a thin gap bounded by the underlying layer and the low surface tension layer, the gap being a space created by a separation between the underlying layer and the diffuser, the gap having a height measured in a direction substantially perpendicular to the diffuser and the underlying layer, at least a portion of the gap being present at all times before, during, and after operation of the diffuser;
• and
• c. the bonding regions between the diffuser and the underlying layer being spaced apart along a plane substantially parallel to the underlying layer and the diffuser and being spaced close enough together to keep the diffuser flat enough during operation so that a height increase of the gap from pressure of the inflowing gas does not exceed the greater of about 6 mm or about 30% of the space between adjacent bonding regions, thereby minimizing billowing of the diffuser during operation of the sparger and greatly reducing aggregation of bubbles emanating from the diffuser.