Submerged water desalination system with replaceable dockable membrane modules

Abstract

A submersible water desalination apparatus includes an array of hot-swappable water separation membrane modules arrayed in an approximately polygonal configuration around a product water collection conduit that represents or is proximate to and generally aligned with a central axis of the array; a plurality of hot-swap product water valves connected to the conduit and detachably connected to generally radially-extending product water collection manifolds in fluid communication with a plurality of water separation membrane cartridges within the modules; the modules having in cross-section generally tapered module sides that converge towards the conduit and assist in underwater docking and attachment of a replacement module to a hot-swap product water valve.

1 . A submersible water desalination apparatus comprising an array of hot-swappable water separation membrane modules arrayed around and generally radially extending from a product water collection conduit; a plurality of hot-swap product water valves connected to the conduit and detachably connected to generally radially-extending product water collection manifolds in fluid communication with a plurality of water separation membrane cartridges within the modules; the modules having in cross-section generally tapered module sides that converge towards the conduit and assist in underwater docking and attachment of a replacement module to a hot-swap product water valve. 
     
     
         2 . An apparatus according to  claim 1 , wherein the water separation membranes are reverse osmosis membranes. 
     
     
         3 . An apparatus according to  claim 1 , wherein the array has an approximately polygonal perimeter in plan view. 
     
     
         4 . An apparatus according to  claim 1 , wherein the array has an approximately pentagonal to hexadecagonal perimeter in plan view. 
     
     
         5 . An apparatus according to  claim 1 , wherein the array has an approximately dodecagonal perimeter in plan view. 
     
     
         6 . An apparatus according to  claim 1 , wherein the modules have the same shapes and sizes and are interchangeable with one another. 
     
     
         7 . An apparatus according to  claim 1 , wherein the modules are generally wedge-shaped in plan view. 
     
     
         8 . An apparatus according to  claim 1 , wherein the modules have a generally trapezoidal perimeter in plan view. 
     
     
         9 . An apparatus according to  claim 1 , wherein each module comprises a supporting frame or housing made from corrosion resistant metal and surrounding the water separation membranes in such module. 
     
     
         10 . An apparatus according to  claim 1 , wherein each module comprises a supporting frame or housing made from fiber-reinforced polymer or other composite material and surrounding the water separation membranes in such module. 
     
     
         11 . An apparatus according to  claim 1 , wherein the water separation membrane cartridges have generally cylindrical shapes. 
     
     
         12 . An apparatus according to  claim 1 , wherein the product water collection conduit represents or is proximate to and generally aligned with a vertical central axis of the array, and the water separation membrane cartridges are generally parallel to the product water collection conduit. 
     
     
         13 . An apparatus according to  claim 1 , wherein the modules and array are not encased in a pressure-resistant outer vessel. 
     
     
         14 . An apparatus according to  claim 1 , wherein the apparatus further comprises a framework that is detachably connected to and receives, captures and supports the modules, and a hood that captures concentrate or brine from the water separation membrane modules. 
     
     
         15 . An apparatus according to  claim 1 , wherein the apparatus further comprises one or more guidance features or devices comprising hangers, hooks, snubbers, guiderails or magnets that attract, contact or repel a replacement module or an adjacent module during underwater docking and attachment of a replacement module to a hot-swap product water valve. 
     
     
         16 . An apparatus according to  claim 1 , wherein the modules have shapes and dimensions that enable a pair of modules or portions of modules to be placed alongside one another facing in opposite directions to provide one or more generally rectangular module pairs that will fit in and substantially fill the floor space of a standard ocean shipping container. 
     
     
         17 . An apparatus according to  claim 1 , wherein the water separation membrane cartridges produce a volume of desalinated product water and a volume of concentrate, and the product water volume is sufficiently less than the concentrate volume so that the concentrate does not contain sufficient salinity to qualify as brine in the jurisdiction where such concentrate is produced. 
     
     
         18 . An apparatus according to  claim 1 , further comprising one or more sensors that monitor the flow rate or salinity of desalinated water, concentrate or brine flowing through the apparatus. 
     
     
         19 . An apparatus according to  claim 1 , further comprising a Remotely Operated Vehicle (ROV) for module replacement. 
     
     
         20 . A method for maintaining a submerged water desalination apparatus, the method comprising the steps of:
 a. undocking from a submerged water desalination apparatus a first hot-swappable water separation membrane module that is a member of a plurality of such modules arrayed around and generally radially extending from a product water collection conduit and in fluid communication with the conduit via hot-swap product water valves connected to the conduit and detachably connected to generally radially-extending product water collection manifolds in fluid communication with a plurality of water separation membrane cartridges within the modules, the modules having in cross-section generally tapered module sides that converge towards the conduit and assist in underwater docking and reattachment of detached modules to a hot-swap product water valve; and   b. docking a similarly sized and shaped replacement module and attaching it to the array while underwater by guiding the converging tapered sides of the replacement module and a detached product water collection manifold on such module towards a detached hot-swap product water valve connection on the product water collection conduit.