DESC:Technical Field
[0001] The present disclosure relates to a stationary storage type electric water heater. More particularly, the disclosure relates to a tank to be used in a stationary storage type electric water heater.

Background
[0002] Conventional commercial and residential water heater construction typically includes a metal inner storage tank and an outer appearance/protective shell or enclosure. The shell is larger than the tank and the shell and the inner storage tank are arranged in such a manner that the shell surrounds the tank. As the shell is larger than the outside diameter of the tank a space is created between the tank and the shell. An insulation material is generally placed in said space for thermal insulation around the tank. Insulating material may be either fiberglass or urethane foam or a combination of an insulation blanket and foam-in-place insulation. Thus, this outside foam helps to keep water hot for long hours. Further the outer shell generally made of plastic/metal body covers the insulating material and provides an aesthetic appeal to the electric water heater. Figure 1 illustrates a conventional system of stationary storage type electric water heater. Said convention system comprise of an enclosure (1), a tank (2), a heating element (3), a thermostat (4), a thermal cut off (5) and an insulation (6).
[0003] In such water heaters, water should be heated in an efficient matter. Moreover, over once heated the heated water should remain hot for a substantial period of time.

Summary of the Invention
[0004] In one aspect, the disclosure relates to a water heating and storage system. The water heating and storage system includes an inner tank having a first top wall, a first side and a first bottom wall including a first flange, the first top wall, and the first side wall defining a volume configured for holding water, and an outer tank having a second top wall, a second side and a second bottom wall including a second flange, the first top wall and the second side wall defining a volume configured for receiving the inner tank. The inner tank is disposed inside the outer tank. The inner tank is connected to the outer tank via the first flange engaged with second flange to define a sealed space between the inner tank and the outer tank, wherein said sealed space is evacuated of air.
[0005] In another aspect, the disclosure is directed to a constructing a water heating and storage system. The method includes providing an inner tank having a first top wall, a first side and a first bottom wall including a first flange, providing an outer tank having a second top wall, a second side and a second bottom wall including a second flange, placing the inner tank within the outer tank and engaging the first flange with the second flange to define a sealed space between the inner tank and the outer tank, and evacuating air from the sealed space thereby creating a vacuum in the sealed space.

Brief Description of the Drawings
[0006] FIG. 1 illustrates a conventional system of stationary storage type electric water heater;
[0007] FIG. 2 illustrates a cross-sectional view of a water heating and storage system in accordance with an embodiment of the present disclosure;
[0008] FIG. 3 illustrates a blown-up view of the cross-sectional view of FIG. 1.

Detailed Description
[0009] Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Generally, corresponding reference numbers may be used throughout the drawings to refer to the same or corresponding parts, e.g., 1, 1`, 1``, 101 and 201 could refer to one or more comparable components used in the same and/or different depicted embodiments.
[0010] Referring to FIG. 2, a water heating and storage system 100 is illustrated. The water heating and storage system may be installed in various location where there is a requirement of hot water. Such locations include a bathroom or a kitchen in a home or a commercial establishment such as a hotel, a hospital or a restaurant. The water heating and storage system may also be attached to equipment such as a washing machine or dishwasher that require hot water.
[0011] As illustrated in FIG. 2 The water heating and storage system 100 includes an inner tank 101 configured for receiving and storing water and an outer tank 102 disposed outside the inner tank 101 in a generally concentric manner to define a space 103 between the inner tank 101 and the outer tank 102. The inner tank 101 and the outer tank 102 are engaged with each other in a manner that the space 103 is sealed. Air from the space 103 is evaluated such that a vacuum is created and maintained in the space 103. By maintaining a vacuum, the loss of heat from the inner tank 101 is greatly reduced resulting a greater efficiency of the water heating and storage system.
[0012] Referring to FIG. 2 the inner tank 101 includes a first top wall 104, a first side wall 105, and a first bottom wall 106 having a first flange 107. The first top wall 104, and the first side wall 105, define a space that is configured for receiving and storing water. The first flange 107 extends (e.g., circumferentially) from the first bottom wall 105 of the inner tank 101 to define a first opening. The inner tank 101 may be of any shape that will allow the inner tank 101 to receive and store water. By way of example, the inner tank 101 may have a cylindrical, or a cuboidal shape. In an exemplary embodiment, as shown in FIG. 2 the inner tank 101 may be a cylindrical structure with a closed end. In the FIG. 2 the first top wall 104 is closed. The inner tank 101 may be formed of a unitary, single piece or alternatively, as multiple discrete pieces joined together. The inner tank 101 may be constructed of any suitable rigid and heat-resistant material having a suitable thickness capable of holding heated water. By way of example, the inner tank 101 may be constructed of steel or stainless steel. In an embodiment, the inner tank 101 is constructed of stainless steel having a thickness in a range of 0.5 to 1.2 mm.
[0013] Referring to FIG. 2 again the outer tank 102 is disposed outside the inner tank 101 in a generally concentric manner. The outer tank 102 includes a second top wall 108, a second side wall 109, and a second bottom wall 110 having a second flange 111. The second top wall 108 and the second side wall 109 define a space configured for receiving the inner tank 101. The second flange 111 extends (e.g., circumferentially) from the second bottom wall 110 of the outer tank 102 to define a second opening. The outer tank 102 may be of any shape that will allow it to surround the inner tank 101. By way of example, the outer tank 102 may have a cylindrical, or a cuboidal shape. In an exemplary embodiment, as shown in FIG. 2 the outer tank 102 may be a cylindrical structure with a closed end. In the FIG. 2 the second top wall 104 is closed. While the shape of the inner tank 101 and the outer tank 102 may be different, it is preferable that both the inner tank 101 and the outer tank 102 have the same or similar shape. The outer tank 102 may be formed of a unitary, single piece or alternatively, as multiple discrete pieces joined together. The outer tank 102 may be constructed of any suitable rigid and heat-resistant material. By way of example, the outer tank 102 may be constructed of steel or stainless steel. In an embodiment, the outer tank 102 is constructed of stainless steel having a thickness in a range of 0.5 to 1.2 mm.
[0014] The first flange 107 and the second flange 111 are configured for engaging with each other such that the space 103 is sealed. The first flange 107 and the second flange 111 may be engaged in any suitable manner such that the space 103 is sealed. The first flange 107 and the second flange 111 are engaged in such a manner that the first opening with the second opening align. By way of an exemplary embodiment, the first flange 107 and the second flange 111 are welded together. The sealed space103 between the inner tank 101 and the outer tank 102 is completely evacuated of air. Evacuation is affected by pumping out though an aperture (not shown) in the outer tank 102 which is subsequently sealed. In an exemplary embodiment the aperture is in the second top wall 108 or the second side wall 109.
[0015] In an embodiment, the inner tank and outer tank are integrally formed.
[0016] In accordance with an embodiment, the space 103 is of substantially uniform thickness throughout its entirety. In accordance with an embodiment, the space 103 has a thickness in the range of 6 to 29 mm. In accordance with an alternate embodiment, the space 103 varies. For example, in one embodiment the space between the first top wall of the inner tank and the second top wall of the outer tank is larger than the space between the first side wall of the inner tank and the second side wall of the outer tank. In another embodiment, the space between the first top wall of the inner tank and the second top wall of the outer tank is smaller than the space between the first side wall of the inner tank and the second side wall of the outer tank.
[0017] In accordance with an embodiment the inner tank 101 includes a cover 112 configured for covering the opening in the first bottom wall 106. The cover 112 engages with the first bottom wall 106 in a manner such that water stored within the inner tank 101 does not leak. The cover 112 includes at least one water inlet 113 in fluid communication with the inner tank 101 for receiving water from a water source (not shown) for heating and at least one water outlet 114 in fluid communication with the inner tank 101 for conveying water from the inner tank 110 to a hot water outlet. The cover may be formed from the same material as the inner tank 101. By way of example, the cover 112 may be constructed of steel or stainless steel. In an embodiment, the cover 112 is constructed of stainless steel having a thickness in a range of 0.5 to 1.2 mm.
[0018] The water heating and storage system 100 is provided with a controlled electrical heating unit 115 for heating the water within the inner tank 101. The controlled electrical heating unit 115 includes a heating element 116 connected to a controller 117. The heating element 116 extends through the cover 112 of the inner tank 101 such that it can heat the water present within the inner tank 101. The controller 117 is positions such that it is outside the cover 112 of the inner tank 101.

Industrial Applicability
[0019] A method of constructing a water heating and storage system 100 is now discussed. The method includes providing an inner tank having a first top wall 104, a first side 105 and a first bottom wall 106 having a first flange 107, providing an outer tank 102 having a second top wall 108, a second side wall 109 and a second bottom wall 110 having a second flange 111, placing the inner tank 101 within the outer tank 102 and connecting the first flange 107 with the second flange 111 to define a sealed space 103 between the inner tank 101 and the outer tank 102, and evacuating air from the sealed space. The first flange 107 and the second flange 111 may be connected with each other by welding.
[0020] The water heating and storage system 100 that has sealed space 103 between the inner tank 101 and the outer tank 102 with the sealed space 103 is evacuated of air has improved efficiency. As the inner tank is vacuum insulated the heat loss from the inner tank is minimal. As a result of this water can be heated much faster than convention systems. Moreover, once heated the water will remain heated for a longer period of time, allowing the consumer to have heater water for a longer period even after the water heating and storage system 100 is switched off.
[0021] Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not exclude the use of plural such components, structures, or operations or their equivalents. The use of the terms “a” and “an” and “the” and “at least one” or the term “one or more,” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B” or one or more of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B; A, A and B; A, B and B), unless otherwise indicated herein or clearly contradicted by context. Similarly, as used herein, the word "or" refers to any possible permutation of a set of items. For example, the phrase "A, B, or C" refers to at least one of A, B, C, or any combination thereof, such as any of: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple of any item such as A and A; B, B, and C; A, A, B, C, and C; etc.
[0022] It will be apparent to those skilled in the art that various modifications and variations can be made to the water heating and storage system of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the water heating and storage system disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalent.

LIST OF ELEMENTS

A WATER HEATING AND STORAGE SYSTEM

100 water heating and storage system
101 inner tank
102 outer tank
103 space
104 first top wall
105 first side wall
106 first bottom wall
107 first flange
108 second top wall
109 second side wall
110 second bottom wall
111 second flange
112 cover
113 water inlet
114 water outlet
115 electrical heating unit
116 heating element
117 controller
,CLAIMS:1. A water heating and storage system, comprising:
an inner tank having a first top wall, a first side and a first bottom wall including a first flange, the first top wall, and the first side wall defining a volume configured for holding water; and
an outer tank having a second top wall, a second side and a second bottom wall including a second flange, the first top wall and the second side wall defining a volume configured for receiving the inner tank;
the inner tank disposed inside the outer tank, the inner tank connected to the outer tank via the first flange engaged with second flange defining a sealed space between the inner tank and the outer tank, wherein said sealed space is evacuated of air.
2. A water heating and storage system, as claimed in claim 1, wherein the first flange and the second flange are welded.
3. The water heating and storage system as claimed in claim 1, wherein the space between the inner tank and the outer tank is in a range of 6 to 29 mm.
4. The water heating and storage system as claimed in claim 1, wherein the space between the inner tank and the outer tank is constant.
5. The water heating and storage system as claimed in claim 1, wherein the inner tank and outer tank is constructed from 304 stainless steel having a thickness in a range of 0.5 to 1.2 mm.
6. The water heating and storage system as claimed in claim 1, wherein the inner tank and outer tank have the same shape.
7. The water heating and storage system as claimed in claim 1, wherein the first flange extends from the first bottom wall 105 of the inner tank 101 to define a first opening in the inner tank.
8. The water heating and storage system as claimed in claim 7, wherein the inner tank 101 includes a cover configured for engaged with the first bottom wall 106 to close the opening in the first bottom wall.
9. The water heating and storage system as claimed in claim 1, comprising:
at least one water inlet in fluid communication with the inner tank for receiving water from a water source;
at least one water outlet in fluid communication with the inner tank for conveying water from the inner tank to a hot water outlet; and
a controlled electrical heating unit configured for heating water.
10. A method of constructing a water heating and storage system comprising the following steps:
providing an inner tank having a first top wall, a first side and a first bottom wall including a first flange;
providing an outer tank having a second top wall, a second side and a second bottom wall including a second flange;
placing the inner tank within the outer tank and engaging the first flange with the second flange to define a sealed space between the inner tank and the outer tank; and
evacuating air from the sealed space thereby creating a vacuum in the sealed space.