Atmospheric water harvesting device and method

1 . A water harvesting apparatus, comprising:

a plurality of water harvesting units each including a cylindrical vessel having a central axis, the vessel including:

an at least partially fluid-permeable first cylindrical sidewall defining a vessel inlet;

an at least partially fluid-permeable second cylindrical sidewall defining a vessel outlet;

a fluid impermeable annular base, the annular base including a first locating formation disposed on an external surface of the annular base;

a fluid impermeable annular lip, the annular lip including a second locating formation disposed on an external surface of the annular lip; and

a charge of desiccant material configured to adsorb water;

an outer housing having a volute configuration, the outer housing including:

an air inlet channel in fluid communication with the vessel inlet of each water harvesting unit of the plurality of water harvesting units, the air inlet channel having a volute configuration; and

an air outlet in fluid communication with the vessel outlet of each water harvesting unit of the plurality of water harvesting units;

wherein the first cylindrical sidewall and the second cylindrical side wall extend between the annular base and the annular lip to define a plenum space;

wherein the second cylindrical side wall is disposed at least partially within the first cylindrical sidewall;

wherein the first cylindrical sidewall includes a mesh lining and/or covering;

wherein the first locating formation is configured to inter-engage with the second locating formation of an adjacent water harvesting unit;

wherein the plurality of water harvesting units are disposed in the outer housing, arranged for rotation within the outer housing, and orientated such that the central axis of each of the plurality of water harvesting units is vertical; and

wherein the plurality of water harvesting units are configured to be rotated with respect to the outer housing about a common central axis.

2 . The water harvesting apparatus of claim 1 , wherein the first cylindrical sidewall diverges away from the annular base such that the vessel is substantially frustoconical.

3 . The water harvesting apparatus of claim 1 , wherein the annular lip is angled with respect to the annular base.

4 . The water harvesting apparatus of claim 1 , wherein at least a subset of the plurality of water harvesting units are formed as an integral unit.

5 . The water harvesting apparatus of claim 1 , wherein the air inlet channel is configured such that a widest end of the air inlet channel receives airflow in use.

6 . A method of harvesting water from atmospheric air, comprising:

passing a flow of atmospheric air through at least one water harvesting apparatus according to claim 1 ;

stopping the flow of atmospheric air through at least one of the plurality of water harvesting units;

passing a flow of desorption air through at least one of the plurality of water harvesting units; and

cooling the flow of desorption air exiting at least one of the plurality of water harvesting units to recover liquid water from the flow of desorption air.

7 . The method of harvesting water from atmospheric air as claimed in claim 6 , wherein cooling the flow of desorption air includes a first cooling step followed by a second further cooling step.

8 . The method of harvesting water from atmospheric air as claimed in claim 7 , further comprising:

compressing the flow of desorption air before the second further cooling step; and

expanding the flow of desorption air after the second further cooling step.

9 . The method of harvesting water from atmospheric air as claimed in claim 8 , further comprising removing water from the flow of desorption air prior to compressing the flow of desorption air.

10 . The method of harvesting water from atmospheric air as claimed in claim 9 , wherein removing water from the flow of desorption air includes:

passing the flow of desorption air through a separator; and

collecting the water removed from the flow of desorption air.

11 . The method of harvesting water from atmospheric air as claimed in claim 7 , wherein the first cooling step includes passing the flow of desorption air through a first heat exchanger.

12 . The method of harvesting water from atmospheric air as claimed in claim 11 , wherein the second further cooling step includes passing the flow of desorption air through a second heat exchanger.