TECHNICAL FIELD
Present disclosure generally relates to the field of water treatment. Particularly, but not exclusively,
the present disclosure discloses a system for desalinating saline water. Further, embodiments of
the present disclosure disclose configuration of a heat exchanging element for the desalination
system.
BACKGROUND OF THE INVENTION
Freshwater crisis is one of the major concerns for world population, as great number of being
suffer from acute shortage of drinking water. Generally, sea water or saline water is processed in
desalination systems for removal of dissolved mineral salts and for obtaining fresh water. The
fresh water may be further used for human consumption or may be used for agricultural purposes.
Further, commercial large-scale desalination systems implementing multistage desalination and
reverse osmosis, have helped in desalination of water and have reduced water stress to some extent
in the recent decades.
Currently, reverse osmosis is one of commercially employed process for desalination, while
thermal processes such as multi-effect desalination and multi-stage flash, are also used for
desalination. Such approaches of reverse osmosis, multi-effect desalination and multi-stage flash
require well-developed infrastructure and centralized installations, which are difficult to establish
in remote locations. Further, the above-mentioned technologies also consume a significant amount
of power for desalination, which inherently increases cost of desalinated water/fresh water. Also,
such systems may often be difficult to set-up and operate in remote or rural areas where access to
saline water infrastructure is limited. Furthermore, the above systems are also dependent on
centralized water supply sources for receiving and processing the saline water into fresh water.
Any disruptions in the water supply from centralized water supply sources may also render the
above-mentioned systems to be non-operational.
Generally, conventional desalination systems include evaporators and condensers, where the
evaporators are configured to evaporate saline water to generate water vapours, and the condenser
is configured to condense the generated water vapours to fresh water. The water productivity for
such conventional desalination system is dependent on the gained output ratio, which is the amount
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of desalinated water produced per kilogram of vapor generated. Conventionally, the abovementioned systems include multiple stages, and each stage includes individual assemblies of
evaporators and condensers. The number of stages in conventional assemblies is low due to the
provision of individual assemblies of evaporators and condensers in each stage. A lower number
of stages results in lower processing of saline water and a lower output of fresh water.
Conventional systems, often have a low operational efficiency. Furthermore, conventional
desalination systems are prone to excessive salt accumulation. The salt accumulation leads to
fouling and degradation of the evaporator, thereby reducing the durability and sustainable
performance of the desalination systems. The salt precipitation on the evaporator also reduces the
evaporation rate during longer duration of operation and also hinders the operational efficiency of
the desalination systems.
The drawbacks/difficulties/disadvantages/limitations of the conventional techniques explained in
the background section are just for exemplary purpose and the disclosure would never limit its
scope only such limitations. A person skilled in the art would understand that this disclosure and
below mentioned description may also solve other problems or overcome the other
drawbacks/disadvantages of the conventional arts which are not explicitly captured above.
SUMMARY OF THE DISCLOSURE
One or more shortcomings of the conventional system or device are overcome, and additional
advantages are provided through the provision of the method as claimed in the present disclosure.
Additional features and advantages are realized through the techniques of the present disclosure.
Other embodiments and aspects of the disclosure are described in detail herein and are considered
a part of the claimed disclosure.
In a non-limiting embodiment of the disclosure, a heat exchanging element for a desalination
system is disclosed. The heat exchanging element includes a body defined by a first major surface
and a second major surface. The first major surface is defined with a plurality of first grooves that
extend along the first major surface, where the plurality of first grooves are adapted to merge and
form at least one channel in the first major surface. The first major surface is configured to receive
4
and channelize water vapor along the plurality of first grooves to condense water vapor to water
about the at least one channel. Further, the second major surface is defined with a plurality of
second grooves, where each of the plurality of second grooves are oriented to terminate at a bottom
region of the second major surface. The second major surface is configured to channelize saline
water along the plurality of second grooves to heat the saline water and produce water vapor.
In an embodiment of the disclosure, the first major surface is defined with a plurality of third
grooves adapted to merge with the plurality of first grooves, and the plurality of third grooves are
defined at an inclination relative to the plurality of first grooves, to fluidly connect the plurality of
first grooves with the at least one channels at the bottom region of the first major surface.
In an embodiment of the disclosure, each of the plurality of second grooves are oriented to end at
a substantially central region of the second major surface.
In an embodiment of the disclosure, the body of the heat exchanging is defined with a thickness
ranging from 1 mm to 2 mm and the heat exchanging element is made of a thermally conducting
material.
In an embodiment of the disclosure, the second major surface is defined with a slot extending in a
width-wise direction of the heat exchanging element at a top region of the heat exchanging
element.
In an embodiment of the disclosure, one or more of the plurality of first grooves and the plurality
of second grooves are defined with a width ranging from 350 μm to 450 μm, a depth ranging from
450 μm to 550 μm, and a pitch ranging from 350 μm to 440 μm.
In a non-limiting embodiment of the disclosure, a system for desalination of saline water is
disclosed. The system includes an enclosure, a wick defined by a first end and a second end, where
the first end is immersed in saline water and the second end is disposable in the enclosure. The
system includes a heater positioned in the enclosure. A plate is positioned adjacent to the heater
and is coupled with the second end of the wick. The plate is configured to receive saline water
5
from the wick, where the saline water on the plate is heated and evaporated to produce water vapor
by the heater. Further, at least one heat exchanging element disposed in the enclosure, and the heat
exchanging element includes a body defined by a first major surface and a second major surface.
The first major surface is defined with a plurality of first grooves that extend along the first major
surface, where the plurality of first grooves are adapted to merge and form at least one channel in
the first major surface. The first major surface is configured to receive and channelize water vapor
along the plurality of first grooves to condense water vapor to water about the at least one channel.
Further, the second major surface is coupled with the second end of the wick. The second major
surface is defined with a plurality of second grooves, where each of the plurality of second grooves
are oriented to terminate at an bottom region of the second major surface. The second major surface
is configured to channelize saline water along the plurality of second grooves to heat the saline
water and produce water vapor.
In an embodiment of the disclosure, the second major surface is defined with a slot extending along
a width of the at least one heat exchanging element at a top region of the at least one heat
exchanging element.
In an embodiment of the disclosure, the second end of the wick is coupled with the slot defined on
the second major surface of the at least one heat exchanging element. In an embodiment of the
disclosure, the heater is oriented to define a first side of the enclosure.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In
addition to the illustrative aspects, embodiments, and features described above, further aspects,
embodiments, and features will become apparent by reference to the drawings and the following
detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
The foregoing summary is illustrative only and is not intended to be in any way limiting. In
addition to the illustrative aspects, embodiments, and features described above, further aspects,
embodiments, and features will become apparent by reference to the drawings and the following
detailed description.
6
Figure. 1 illustrates a schematic view of desalination system, in accordance with an embodiment
of the present disclosure.
Figure. 2 illustrates a schematic view of a portion of a heat exchanging element in the desalination
system and depicts a first major surface of the heat exchanging element, in accordance with an
embodiment of the present disclosure.
Figure. 3 illustrates a front view of the first major surface in the heat exchanging element, in
accordance with an embodiment of the present disclosure.
Figure. 4 illustrates a magnified front view of a portion of the first major surface in the heat
exchanging element from the Figure 3, in accordance with an embodiment of the present
disclosure.
Figure. 5 illustrates a schematic view of a portion of the heat exchanging element and depicts a
second major surface of the heat exchanging element, in accordance with an embodiment of the
present disclosure.
Figure. 6 illustrates a front view of the second major surface in the heat exchanging element form
the Figure 5, in accordance with an embodiment of the present disclosure.
Figure. 7 illustrates a magnified front view of a section of the second major surface in the heat
exchanging element, in accordance with an embodiment of the present disclosure.
Figure. 8 illustrates a magnified perspective view of a section of the second major surface in the
heat exchanging element, in accordance with an embodiment of the present disclosure.
Figure. 9 illustrates a graphical representation of water collection data, in accordance with an
embodiment of the present disclosure.
The figure depicts embodiments of the disclosure for purposes of illustration only. One skilled in
the art will readily recognize from the following description that alternative embodiments of the
desalination system without departing from the principles of the disclosure described herein.
7
DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure
in order that the description of the disclosure that follows may be better understood. Additional
features and advantages of the disclosure will be described hereinafter which form the subject of
the disclosure. It should be appreciated by those skilled in the art that the conception and specific
embodiment disclosed may be readily utilized as a basis for modifying or designing other system
for carrying out the same purposes of the present disclosure. It should also be realized by those
skilled in the art that such equivalent constructions do not depart from the spirit and scope of the
disclosure. The novel features which are believed to be characteristic of the disclosure, as to its
organization, together with further objects and advantages will be better understood from the
following description when considered in connection with the accompanying figures. It is to be
expressly understood, however, that each of the figures is provided for the purpose of illustration
and description only and is not intended as a definition of the limits of the present disclosure.
In the present document, the word "exemplary" is used herein to mean "serving as an example,
instance, or illustration." Any embodiment or implementation of the present subject matter
described herein as "exemplary" is not necessarily to be construed as preferred or advantageous
over other embodiments.
While the disclosure is susceptible to various modifications and alternative forms, specific
embodiment thereof has been shown by way of example in the drawings and will be described
below. It should be understood, however, that it is not intended to limit the disclosure to the
particular forms disclosed, but on the contrary, the disclosure is to cover all modifications,
equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a nonexclusive inclusion, such that a system that comprises a list of components does not include only
those components but may include other components not expressly listed or inherent to such
mechanism. In other words, one or more elements in the device or mechanism proceeded by
“comprises… a” does not, without more constraints, preclude the existence of other elements or
additional elements in the mechanism.
8
In an embodiment, the first surface 110a and the second surface 110b of the plate 110 described
below may be opposite surfaces of the plate 110. In an embodiment, the first surface 110a and the
second surface 110b of the plate 110 may be surfaces that exclude the thickness of the plate 110.
In an embodiment, the first surface 110a and the second surface 110b may be surfaces that are
defined along the length and the width of the plate 110. In an embodiment, the first surface 110a
and the second surface 110b may be defined as the sides of the plate 110 with major surface area.
The following paragraphs describe the present disclosure with reference to Figures 1 to 9. The
following detailed description is merely exemplary in nature and is not intended to limit
application and uses. Furthermore, there is no intention to be bound by any theory presented in the
preceding background or summary or the following detailed description. It is to be understood that
the invention may assume various alternative orientations and step sequences, except where
expressly specified to the contrary. It is also to be understood that the specific devices or
components illustrated in the attached drawings and described in the following specification are
simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence,
specific dimensions, directions or other physical characteristics relating to the embodiments that
may be disclosed are not to be considered as limiting, unless the claims expressly state otherwise.
Figure 1 illustrates a schematic view of desalination system 100. The desalination system 100 may
include a reservoir 104. The reservoir 104 may be configured to store saline water. The reservoir
104 may be an artificially constructed reservoir or may be derivable from a natural source of the
saline water, which should not be considered as a limitation for working of the present disclosure.
The desalination system 100 may include at least one wick 108 [hereinafter also referred to as the
wick]. The at least one wick 108 may be defined by a first end 108a and a second end 108b. The
wick 108 may be made of materials including but not limited to a bundle of fabrics or fibres. The
first end 108a of the wick 108 may be disposed within the reservoir 104 and the first end 108a of
the wick 108 may be configured to lie in contact with the saline water within the reservoir 104. In
an embodiment, the first end 108a of the wick 108 may be directly disposed in sea water or other
sources of the saline water including but not limited to reservoirs 104. Further, the wick 108 may
be a hydrophilic capillary wick 108 configured to supply the saline water from the reservoir 104
to one of the components in the desalination system 100. In an embodiment, the provision of
9
hydrophilic capillary wick 108 ensures that the saline water is transferred to the components within
the desalination system 100 without any additional power source.
The desalination system 100 may include an enclosure 102. The enclosure 102 may be configured
to accommodate various components of the desalination system 100. The enclosure 102 may be
made of materials including but not limited to metals and/or polymer composites. The enclosure
102 may be defined by a first side 102a. The first side 102a may be one of the major sides/surfaces
of the enclosure 102. The major side of the enclosure 102 may herein be defined as the side that
receives the components of the desalination system 100.The major side or the first side 102a may
also be defined as the side of the enclosure 102 to which the components of the desalination system
100 abut. The enclosure 102 may be configured to receive the second end 108b of the wick 108.
The second end 108b of the wick 108 may be coupled with a top end/top region of the enclosure
102. In an embodiment, the second end 108b of the wick 108 may be merely disposed at the top
end/top region of the enclosure 102. The wick 108 may be configured to supply water from the
reservoir 104 to the enclosure 102. The saline water in the reservoir 104 may be drawn at the first
end 108a of the wick 108, where the saline water may travel along the wick 108 towards its second
end 108b by the hydrophilic capillary action. The saline water at the second end 108b of the wick
108 may be further communicated or supplied into the enclosure 102 through the top end/top
region of the enclosure 102. In an embodiment, dimensions and number of wicks 108 in the
desalination system 100 may not be a limitation and the number of wicks 108 may be provided
proportionally with respect to the quantity of saline water that is to be distilled within the
desalination system 100.
The desalination system 100 may further include a heater 106. The heater 106 may be positioned
within the enclosure 102 and the heater 106 may be configured to abut the first side 102a of the
enclosure 102. In an embodiment, the heater 106 may be a source that generates and transmits
heat, where such heater 106 may be including an electric heater, a solar heater, an induction coil,
and among others. The heater 106 may be configured to transmit heat in a direction that lies
opposite to the first side 102a of the enclosure 102. In an embodiment, the heater 106 may be a
solar heater that is configured to receive solar radiation and convert the solar radiation to heat. The
heat may be further transmitted into the enclosure 102 and away from the first side 102a of the
enclosure 102. In an embodiment, the heater 106 may be oriented to define the first side 102a of
10
the enclosure 102. As seen from the Figure 1, one of the side surfaces of the heater 106 may itself
be the first side 102a of the enclosure 102. In an embodiment, the heater 106 may also be an
assembly where firewood may be burnt to generate heat and transmit heat into the enclosure 102.
The desalination system 100 may include a plate 110. The plate 110 may be defined by a first
surface 110a and a second surface 110b. The plate 110 may be made of a thermally conductive
metal including but not limited to aluminium, copper, silver, steel, and among others. Further, the
first surface 110a of the plate 110 may be oriented to abut the heater 106. Furthermore, a top end
or a top region of the plate 110 may be coupled with the second end 108b of the wick 108. The
second surface 110b of the plate 110 may be configured to receive the second end 108b of the
wick 108. The plate 110 may also be configured to conductively receive the heat from the heater
106. Further, the saline water received from the wick 108 may be supplied to the second surface
110b of the plate 110. The saline water may be configured to gradually flow over the second
surface 110b of the plate 110. Further, the heat from the heater 106 that is absorbed by the plate
110 may heat and evaporate the saline water on the second surface 110b of the plate 110. The
water vapor 116a generated by the evaporation of the saline water may further be directed to travel
away from the first side 102a of the enclosure 102. Further, as the water evaporates from the
second surface 110b, the remining water with the mineral salts, hereinafter also collectively
referred to as “brine 114”, may flow downwardly and may exit the plate 110 into a tank.
The desalination system 100 may further include at least one heat exchanging element 112
[hereinafter referred to as the heat exchanging element]. The heat exchanging element 112 may be
a thermally conductive structure that is made of metals including but not limited to aluminium, or
copper, or silver, or any suitable alloy having high thermal conductivity for operation of the
desalination system 100. The heat exchanging elements 112 may be defined by a first major surface
112a and a second major surface 112b. The first major surface 112a and the second major surface
112b may be diametrically opposite to each other. As seen from the Figure 1, the desalination
system 100 may include multiple heat exchanging elements 112. The first heat exchanging element
112 of the multiple heat exchanging elements 112 may be positioned adjacent to the plate 110.
Further, each of the heat exchanging element 112 may be oriented and positioned parallel to the
plate 110. Further, each of the heat exchanging element 112 may be positioned equidistantly from
the successive or adjacent heat exchanging element 112. The distance between each of heat
11
exchanging elements 112 may range from 1 mm to 3 mm. In an embodiment, the distance or air
gap between each of the heat exchanging elements 112 may be 2 mm. In an embodiment, the total
number of heat exchanging elements 112 in the desalination system 100 may range from 1 to 20.
Further, the second major surface 112b of the heat exchanging elements 112 may be coupled with
the second end 108b of the wick 108. In an embodiment, a top region at the second major surface
112b of the heat exchanging element 112 may be coupled with the second end 108b of the wick
108. The second major surface 112b of the heat exchanging elements 112 may be configured to
receive the saline water from the reservoir 104 through the wick 108 and the first major surface
112a of the heat exchanging element 112 may be configured to receive the water vapor 116a from
the plate 110. The constructional configuration of the heat exchanging element 112 is described
below in detail.
Reference is made from Figure 2 to Figure 4 that depict the first major surface 112a of the heat
exchanging element 112. The heat exchanging element 112 may be defined with the top region
112x and the bottom region 112y [seen from the Figure 2 and 3]. Further, the first major surface
112a of the heat exchanging element 112 may be defined with a plurality of first grooves 118. The
plurality of first grooves 118 may be configured to extend along a length of the first major surface
112a and the plurality of first grooves 118 may extend in a vertical direction. The first major
surface 112a may also be defined with a plurality of third grooves 118a. The plurality of third
grooves 118a may be defined at an inclination with respect to the plurality of first grooves 118.
Each of the plurality of first grooves 118 may be configured to merge with the plurality of third
grooves 118a for receiving and circulating the liquid. The first major surface 112a may also be
defined with at least one channel 124. The at least one channel 124 may be oriented to lie along
either ends of the first major surface 112a. The at least one channel 124 may be defined at or
proximal to the corners of the first major surface 112a, while the at least one channel 124 may end
or terminate at the bottom region 112y of the first major surface 112a. The plurality of third
grooves 118a may be configured to merge into the at least one channel 124. The inclination of the
plurality of third channel 124 causes the liquid from the plurality of first channel 124 to be redirected towards the corners of the first major surface 112a and the liquid may flow out of the first
major surface 112a through the at least one channel 124 at the corners of the first major surface
112a. Further, the first major surface 112a of the heat exchanging elements 112 that are positioned
12
away from the plate 110 may be configured to receive water vapor 116a from the adjacent heat
exchanging element 112. The water vapor 116a may condense into desalinated water 116 along
the plurality of first grooves 118 and then into the plurality of third grooves 118a. Further, the
inclination of the plurality of third grooves 118a may re-direct the desalinated water 116 from the
plurality first grooves 118 to the at least one channel 124 at the corners of the first major surface
112a. The condensed desalinated water 116 may flow out of the at least one channel 124 at the
bottom region 112y of the first major surface 112a.
Reference is made from Figure 5 to Figure 8 that depict the second major surface 112b of the heat
exchanging element 112. The second major surface 112b may be defined opposite to the first major
surface 112a in the same heat exchanging element 112. The second major surface 112b of the heat
exchanging element 112 may be defined with a plurality of second grooves 120. The plurality of
second grooves 120 may extend along the length of the second major surface 112b and the plurality
of second grooves 120 may be configured to terminate at the bottom region 112y of the second
major surface 112b. The plurality of second grooves 120 may be oriented to lie along a
substantially central region 112z of the second major surface 112b. The plurality of second grooves
120 may be defined between the corners or sides of the second major surface 112b. In an
embodiment, the above configuration of the at least one channel 124 being configured at the
corners of the first major surface 112a and the plurality of second channel 124 being configured at
the central region 112z of the second major surface 112b, enables the liquid from the first major
surface 112a and the second major surface 112b to be collected separately. Referring to Figures 6
to 8, the second major surface 112b may also be defined with a slot 122 extending in a width-wise
direction of the heat exchanging element 112 at the top region 112x of the heat exchanging element
112. In an embodiment, the slot 122 may extend for a width that is equivalent to the width of the
central region 112z. Further, each of the plurality of second grooves 120 may be defined to fluidly
engage with the slot 122 at the top region 112x of the second major surface 112b. The plurality of
second grooves 120 may extend from a bottom end of the slot 122 and the plurality of second
grooves 120 may terminate at the bottom region 112y of the second major surface 112b. The slot
122 may be configured to receive the second end 108b of the wick 108. Further, the saline water
from the reservoir 104 may be directed or supplied into the slot 122 of the second major surface
112b through the second end 108b of the wick 108 that is positioned in the slot 122 of the second
13
major surface 112b. The saline water is further circulated through the plurality of second grooves
120. The second major surface 112b surface is configured to heat and evaporate the saline water.
In an embodiment, the plurality of first grooves 118 and the plurality of second grooves 120 may
be defined on the heat exchanging element 112 by the process of laser engraving. In an
embodiment, the first major surface 112a of the heat exchanging element 112 may be defined as a
condenser side of the heat exchanging element 112, while the second major surface 112b of the
heat exchanging element 112 may be defined as an evaporator side of the heat exchanging element
112.
In an embodiment, the second surface 110b of the plate 110 may be defined with the orientation
that is similar to the second major surface 112b of the heat exchanging element 112 as described
above. The first surface 110a of the plate 110 may be configured to abut the heater 106 and the
second surface 110b of the plate 110 may be defined with a plurality of second grooves 120 with
a slot 122 that extends along the width of the second surface 110b of the plate 110. Further, the
second end 108b of the wick 108 may be disposed in the slot 122 at the second surface 110b of the
plate 110. The wick 108 may be configured to supply saline water at the second surface 110b of
the plate 110. The saline water may further flow in the plurality of second grooves 120 of the plate
110. Furthermore, the heat from the heater 106 may be conductively transferred to the plate 110.
The second surface 110b of the plate 110 may be heated by the heat from the heater 106. The heat
on the second surface 110b of the plate 110 may further heat the saline water flowing in the
plurality of second grooves 120 and the saline water may be evaporated to generate water vapor.
The generated water vapor 116a may further be directed onto the first major surface 112a of the
adjacent heat exchanging heat exchanging element 112. In an embodiment, the thickness of the
plate 110 may range from 1 mm to 2 mm. In an embodiment, each of the heat exchanging elements
112 may be defined with a thickness ranging from 1 mm to 2 mm. In an embodiment, the plurality
of first grooves 118 and the plurality of second grooves 120 are defined with a width ranging from
350 μm to 450 μm, a depth ranging from 450 μm to 550 μm, and a pitch ranging from 350 μm to
440 μm. In an embodiment, the above dimensions of the plurality of first grooves 118 and the
plurality of second grooves 120 may reduce the water droplet size on the first major surface 112a
and the second major surface 112b. In an embodiment, reduction in size of water droplets also
ensures that the water droplets on one heat exchanging element 112 does not mix with the water
14
droplets on the adjacent heat exchanging element 112. Therefore, the distance of air gap between
each heat exchanging element 112 may be reduced. Further, the working of the desalination system
100 is further described below.
The saline water from the reservoir 104 is initially supplied to the second surface 110b of the plate
110 and the second major surface 112b of the heat exchanging element 112. The water initially
flows from the slots 122 and into the plurality of second grooves 120 in the second surface 110b
of the plate 110. Further, the heat from the heater 106 may heat the plate 110 and the second surface
110b of the plate 110. The heat may further cause the saline water in the plurality of second grooves
120 of the plate 110 to be heated and vaporized to water vapor. As the saline water is vaporized to
water vapor 116a, the brine 114 with mineral salts may flow downwardly along the plurality of
second grooves 120 of the plate 110. The water vapor 116a may further travel from the second
surface 110b of the plate 110 to the first major surface 112a of the adjacent heat exchanging
element 112. Furthermore, the saline water may also be simultaneously circulated in the plurality
of second grooves 120 on the second major surface 112b of the heat exchanging element 112. The
saline water which may be at lower temperatures may initially cool the second major surface 112b
and the heat exchanging element 112. Further, the first major surface 112a may also be cooled and
the water vapor 116a that comes in contact with the first major surface 112a may be condensed
due to lower temperatures of the heat exchanging element 112. As seen from the Figures 2 to 4,
the water vapor 116a may initially come in contact with the first major surface 112a and as the
water vapor condenses to water, the water may flow through the plurality of first grooves 118. The
water from the plurality of first grooves 118 may further travel into the plurality of third grooves
118a. The inclination of the plurality of third grooves 118a may cause the water to be re-directed
towards the corners or the sides of the first major surface 112a of the heat exchanging element
112. The water may further travel into the at least one channel 124 and the water may exit the first
major surface 112a through the at least one channel 124 and the bottom region 112y of the heat
exchanging element 112. The water that exits the heat exchanging element 112 through the at least
one channel 124 may further be collected and may be used for human consumption of other
agricultural purposes.
Further, during the condensation process where the water vapor 116a is condensed to water, the
heat lost by the water vapor 116a may be transferred or absorbed by the first major surface 112a
15
of the heat exchanging element 112. This heat lost during the process of condensation of the water
vapor 116a may further heat the first major surface 112a and the second major surface 112b of the
heat exchanging element 112. Consequently, the saline water flowing through the plurality of
second grooves 120 of the second major surface 112b may be heated and evaporated to water vapor
116a. The water vapor 116a generated at the second major surface 112b may further travel to the
first major surface 112a of the adjacent heat exchanging element 112 and the brine 114 with the
mineral salts may flow downwardly along the plurality of second grooves 120. Further, as
described above, the water vapor 116a may condense at the first major surface 112a of the adjacent
heat exchanging element 112 and the saline water at the second major surface 112b of the adjacent
heat exchanging element 112 may be converted to water vapor 116a. In an embodiment, the abovedescribed configuration of the heat exchanging element 112 enables one of the surfaces to
condense water vapor 116a to water and the other surface evaporates the saline water to water
vapor 116a. In an embodiment, different surfaces of the single/same heat exchanging element 112
may be configured to condense water vapor 116a and evaporate saline water. In an embodiment,
configuring the evaporator and the condenser on different sides of the same heat exchanging
element 112, prevents the usage of different/individual components for evaporation and
condensation. Therefore, the overall size restrictions of the desalination system 100 is reduced.
Further, the number of heat exchanging element 112 used in the desalination system 100 may be
increased due to reduction in the number of components used and the reduction in size of the heat
exchanging element 112.
In an embodiment, defining the plurality of first grooves 118 on the first major surface 112a and
defining the plurality of second grooves 120 on the second major surface 112b, ensures that the
mixing of the desalinated water 116 and the brine 114 is prevented. Consequently, lower air gaps
of around 2 mm between each heat exchanging element 112 may be configured and the number of
heat exchanging element 112 used in the desalination system 100 may be increased to around 15
to 20 in number. Increase in the number of heat exchanging element 112 also increases the quantity
of desalinated water 116. In an embodiment, the grooved evaporator on the second first major
surface 112a and the grooved condenser on the second major surface 112b prevents the mixing of
the water vapor 116a and the brine 114 at lower air gaps between the heat exchanging element
112. In an embodiment, the second major surface 112b being defined with the slot 122 and the
16
plurality of second grooves 120 helps to uniformly spread the saline water evenly throughout the
area of the second major surface 112b. A thin film of saline water is created over the second major
surface 112b instead of rivulets which forms in the absence of non-textured plain surface. The
plurality of second grooves 120 and the texture of the grooves help to eliminate the usage of fabric
over the entire area of the second major surface 112b, and also prevents the need of laminating the
fabric on the heat exchanging element 112.
Reference is made to Figure 9 depicting the water collection data of the desalination system 100.
The Figure 9 is indicative of a bar graph depicting the quantity of desalinated water generated in a
given time frame. The Figure 9 indicates various test results of the desalinated water generated
with varying number of heat exchanging elements 112. The number of heat exchanging elements
112 is indicated by “n” and the test results for desalination system 100 with heat exchanging
elements 112 up to 15 in number (n) are conducted and the corresponding results are depicted in
the Figure 9. In an embodiment, the above-described desalination system 100 with 10 heat
exchanging elements 112 and an air gap (a) of 2 mm between each heat exchanging element 112,
produced a water productivity flux of ~5.73 Lm-2
hr-1
from 3.5 wt.% saline water for a supplied
heat flux of 1000 W/m2
. Further, water productivity flux was increased to ~6.23 Lm-2
hr-1 with 15
heat exchanging elements 112 and an air gap of 2 mm between each heat exchanging element 112.
In an embodiment, a preliminary filtration step may be incorporated into the desalination system
100 to prevent impurities such as sand, silt, clay, and other small debris from reaching the heat
exchanging element 112. In an embodiment, a separate pre-filter may be provided in the reservoir
104 and the pre-filter may prevent the need for replacing the entire wick 108 material due to
coagulation.
In an embodiment, the above disclosed configuration of the desalination system 100 provides
improved thermal to water efficiency. The thermal to water efficiency may be herein defined as
the efficiency with which the applied heat for a given area is effectively utilized for the conversion
of the saline water into water vapour. In an embodiment, the provision of multiple heat exchanging
elements 112 with the above disclosed configuration ensures that the latent of vaporization is being
reused, which further leads to a cumulative increase of thermal to water efficiency. Consequently,
the thermal to water efficiency is greater than 100% in the desalination system 100. Referring to
the Figure 9, the maximum thermal to water efficiency obtained for the generation of water vapor
17
from the saline water is around 420% for a pre-determined amount of heat applied at a predetermined area of heat exchange elements 112
Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill
in the art can translate from the plural to the singular and/or from the singular to the plural as is
appropriate to the context and/or application. The various singular/plural permutations may be
expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, are generally
intended as "open" terms (e.g., the term "including" should be interpreted as "including but not
limited to," the term "having" should be interpreted as "having at least," the term "includes" should
be interpreted as "includes but is not limited to," etc.). It will be further understood by those within
the art that if a specific number of an introduced claim recitation is intended, such an intent will
be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For
example, as an aid to understanding the description may contain usage of the introductory phrases
"at least one" and "one or more" to introduce claim recitations. However, the use of such phrases
should not be construed to imply that the introduction of a claim recitation by the indefinite articles
"a" or "an" limits any particular claim containing such introduced claim recitation to inventions
containing only one such recitation, even when the same claim includes the introductory phrases
"one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an"
should typically be interpreted to mean "at least one" or "one or more"); the same holds true for
the use of definite articles used to introduce claim recitations. In addition, even if a specific number
of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that
such recitation should typically be interpreted to mean at least the recited number (e.g., the bare
recitation of "two recitations," without other modifiers, typically means at least two recitations, or
two or more recitations). Furthermore, in those instances where a convention analogous to "at
least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one
having skill in the art would understand the convention (e.g., "a system having at least one of A,
B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and
B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those
18
instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such
a construction is intended in the sense one having skill in the art would understand the convention
(e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that
have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A,
B, and C together, etc.). It will be further understood by those within the art that virtually any
disjunctive word and/or phrase presenting two or more alternative terms, whether in the
description, or drawings, should be understood to contemplate the possibilities of including one of
the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood
to include the possibilities of "A" or "B" or "A and B."
While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and embodiments
disclosed herein are for purposes of illustration and are not intended to be limiting, with the true
scope and spirit being indicated in the description.
Referral numerals:
Description Referral numeral
System 100
Enclosure 102
First side 102a
Reservoir 104
Heater 106
Wick 108
First end of the wick 108a
Second end of the wick 108b
Plate 110
First surface of the plate 110a
Second surface of the plate 110b
Heat exchanging element 112
First major surface 112a
Second major surface 112b
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Top region 112x
Bottom region 112y
Central region 112z
Brine 114
Desalinated water 116
Water vapor 116a
First grooves 118
Third grooves 118a
Second grooves 120
Slot 122
Channel 124
20
We claim:
1. A heat exchanging element 112 for a desalination system 100, the heat exchanging element
112 comprising:
a body defined by a first major surface 112a and a second major surface
112b, the first major surface 112a being defined with a plurality of first grooves
118 that extend along the first major surface 112a, wherein the plurality of first
grooves 118 adapted to merge and form at least one channel 124 in the first major
surface 112a, wherein the first major surface 112a is configured to receive and
channelize water vapor 116a along the plurality of first grooves 118 to condense
water vapor 116a to water about the at least one channel 124; and
the second major surface 112b being defined with a plurality of second
grooves 120, wherein each of the plurality of second grooves 120 oriented to
terminate at a bottom region 112y of the second major surface 112b, wherein the
second major surface 112b is configured to channelize saline water along the
plurality of second grooves 120 to heat the saline water and produce water vapor.
2. The heat exchanging element 112 as claimed in claim 1, wherein the first major surface
112a being defined with a plurality of third grooves 118a adapted to merge with the
plurality of first grooves 118, and the plurality of third grooves 118a are defined at an
inclination relative to the plurality of first grooves 118, to fluidly connect the plurality of
first grooves 118 with the at least one channels 124 at the bottom region 112y of the first
major surface 112a.
3. The heat exchanging element 112 as claimed in claim 1, wherein each of the plurality of
second grooves 120 are oriented to end at a substantially central region 112z of the second
major surface 112b.
4. The heat exchanging element 112 as claimed in claim 1, wherein the body of the heat
exchanging element 112 is defined with a thickness ranging from 1 mm to 2 mm and the
heat exchanging element 112 is made of a thermally conducting material.
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5. The heat exchanging element 112 as claimed in claim 1, wherein the second major surface
112b is defined with a slot 122 extending in a width-wise direction of the heat exchanging
element 112 at a top region 112x of the heat exchanging element 112.
6. The heat exchanging element 112 as claimed in claim 1, wherein one or more of the
plurality of first grooves 118 and the plurality of second grooves 120 are defined with a
width ranging from 350 μm to 450 μm, a depth ranging from 450 μm to 550 μm, and a
pitch ranging from 350 μm to 440 μm.
7. A system 100 for desalination of saline water, the system 100 comprising:
an enclosure 102;
a wick 108 defined by a first end 108a and a second end 108b, wherein the first end
108a is immersed in saline water and the second end 108b is disposable in the enclosure
102;
a heater 106 positioned in the enclosure 102;
a plate 110 positioned adjacent to the heater 106 and coupled with the second end
108b of the wick 108, the plate 110 is configured to receive saline water from the wick
108, wherein the saline water on the plate 110 is heated and evaporated to produce water
vapor 116a by the heater 106;
at least one heat exchanging element 112 disposed in the enclosure 102, the heat
exchanging element 112 comprises:
a body defined by a first major surface 112a and a second major surface
112b, the first major surface 112a being defined with a plurality of first grooves
118 that extend along the first major surface 112a, wherein the plurality of first
grooves 118 adapted to merge and form at least one channel 124 in the first major
surface 112a, wherein the first major surface 112a is configured to receive and
channelize water vapor 116a along the plurality of first grooves 118 to condense
water vapor 116a to water about the at least one channel 124; and
the second major surface 112b coupled with the second end 108b of the
wick 108, the second major surface 112b being defined with a plurality of second
grooves 120, wherein each of the plurality of second grooves 120 oriented to
terminate at an bottom region 112y of the second major surface 112b, wherein the
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second major surface 112b is configured to channelize saline water along the
plurality of second grooves 120 to heat the saline water and produce water vapor.
8. The system 100 as claimed in claim 7, wherein the second major surface 112b is defined
with a slot 122 extending along a width of the at least one heat exchanging element 112 at
a top region 112x of the at least one heat exchanging element 112.
9. The system 100 as claimed in claim 7, wherein the second end 108b of the wick 108 is
coupled with the slot 122 defined on the second major surface 112b of the at least one heat
exchanging element 112.
10. The system 100 as claimed in claim 7, wherein the heater 106 is oriented to define a first
side 102a of the enclosure 10