Reverse osmosis filtration system storage tanks

1. A reverse osmosis product water storage tank comprising:

first and second molded shells coupled together to form an enclosure;

a bladder within the enclosure and coupled to separate product water from squeeze water within the enclosure;

a first port through a wall of the enclosure to provide water access to the product water side of the bladder;

a second port through a wall of the enclosure to provide squeeze water access to the squeeze water side of the bladder;

inner surfaces of the enclosure having a plurality of protrusions integrally molded to the inner surfaces of the first and second molded shells to protrude from the inner surfaces toward the bladder and emanating from the second port to hold said bladder only locally away from said inner surfaces when the bladder is full of product water for accommodating squeeze water flow into the enclosure between the enclosure and the bladder.

2. The tank of claim 1 wherein the first and second molded shells define a substantially spherical enclosure.

3. The tank of claim 2 wherein the first and second molded shells are welded together.

4. The tank of claim 1 wherein the first and second ports are concentric ports.

5. The tank of claim 1 wherein the first molded shell has an opening with an insert therein defining a central first port for product water and at least one second port adjacent the central first port for squeeze water, the bladder being coupled to the central first port.

6. The tank of claim 1 wherein the plurality of protrusions emanate from the vicinity of the second port.

7. A reverse osmosis product water storage tank comprising:

first and second molded shells coupled together in a plane to form an enclosure, the shells having a common axis perpendicular to the plane;

a bladder within the enclosure and coupled to separate product water from squeeze water;

an opening in the first molded shell substantially on its axis with an insert therein defining a central conduit for product water and at least one passage adjacent the central conduit for squeeze water, the bladder being coupled to the central conduit;

inner surfaces of the enclosure having a plurality of protrusions integrally molded to the inner surfaces of the first and second molded shells to protrude from the inner surfaces toward the bladder and emanating from the second port to hold said bladder only locally away from said inner surfaces when the bladder is full of product water for accommodating squeeze water flow into the enclosure between the enclosure and the bladder.

8. The tank of claim 7 wherein the first and second molded shells define a substantially spherical enclosure.

9. The tank of claim 7 wherein the first and second molded shells are spin welded together.

10. The tank of claim 7 wherein the plurality of protrusions emanate from the vicinity of the opening in the first molded shell.

11. A reverse osmosis product water storage tank comprising:

first and second molded shells welded together in a plane to form a spherical enclosure, the shells having a common axis perpendicular to the plane;

a bladder within the enclosure and coupled to separate product water from squeeze water;

an opening in the first molded shell substantially on its axis with an insert therein defining a central conduit for product water and at least one passage adjacent the central conduit for squeeze water, the bladder being coupled to the central conduit;

inner surfaces of the enclosure having a plurality of protrusions integrally molded to the inner surfaces of the first and second molded shells to protrude from the inner surfaces toward the bladder and emanating from the second port to hold said bladder only locally away from said inner surfaces when the bladder is full of product water for accommodating squeeze water flow into the enclosure between the enclosure and the bladder.

12. The tank of claim 11 wherein the plurality of protrusions emanate from the vicinity of the opening in the first molded shell.

13. A reverse osmosis product water storage tank comprising:

first and second molded shells spin welded together in a plane to form a spherical enclosure, the shells having a common axis perpendicular to the plane;

a bladder within the enclosure and coupled to separate product water from squeeze water;

an opening in the first molded shell substantially on its axis with an insert therein defining a central conduit for product water and at least one passage adjacent the central conduit for squeeze water, the bladder being coupled to the central conduit;

inner surfaces of the enclosure having a plurality of protrusions to protrude from the inner surfaces toward the bladder and emanating from the second port to hold said bladder only locally away from said inner surfaces when the bladder is full of product water for accommodating squeeze water flow into the enclosure between the enclosure and the bladder.