Abstract:
An insulated storage tank incorporating modular panels includes a structural rigidity to store large volumes of hot and cold liquids. The insulated storage tank includes a plurality of insulating panels disposed on an insulation substrate in a circumferential pattern, the insulating panels each in proximate contact with two other panels forming a cylindrical wall. The insulating panels are a rigid structure and provide structural support to an inner liner disposed within the cylindrical wall and operable to be filled with a hot or cold liquid. The cylindrical wall of insulating panels is further supported by a thin outer support jacket. The insulated storage tank has a lid disposed on the insulating panels thereby sealing the contents of the insulated storage tank.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/208,275 filed on Feb. 20, 2009. The entire disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to thermally insulated storage tanks. More particularly, the present technology relates to a modular, thermally insulated storage tank for storing hot or cold liquids. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Each day, the sun provides 10,000 times the amount of energy utilized by the human race. In a single day, it provides more energy than our current population would consume in 27 years. In North America alone, it is believed that close to two trillion dollars is spent annually on energy, much of which is designated towards non-renewable, carbon-based sources, such as oil, coal, and other fossil fuels. When energy consumption for the average U.S. household is approximately 65-80% thermal and approximately 20-35% electrical, it makes sense to derive a means of satisfying both of these requirements through renewable sources. 
     There have been many advances in the past few decades toward the capture of renewable energy resources, such as water turbines (which convert the kinetic energy of moving water into electricity), wind generators (which convert the energy of the wind into electrical energy), geothermal heating (which utilizes the stability of the subterraneous temperature to provide thermal energy), and solar cells (which allow the capture and conversion of solar energy into electrical energy). 
     An alternative type of renewable energy is a solar thermal heat exchanger, which utilizes the energy of sunlight to heat a liquid, thereby providing thermal energy for heating or cooling. In this type of energy harnessing, typically a flat plate is blackened on the front to improve absorption of solar radiation and is arranged with its blackened surface facing the sun and sloped at a suitable angle to optimize the energy collected. A series of tubes is secured to the panel, and water to be heated is circulated through these tubes to extract the heat received by the panel. The innovative thermal capture systems require that the circulated heated water be stored for further energy extraction. The warmed water from solar thermal heat exchangers is normally circulated through a separate tank so that the temperature may build up to a maximum value being a balance between the heat input and heat losses in the system. This water can then be used as feed water for heating non-heated water for domestic use through the use of in tank heat exchangers. 
     While the volumes of heated recirculation water varies with the size of the solar thermal heat exchangers mounted to a residential or commercial structure, a tank of sufficient size to store all of the systems liquid is required to be maintained on site. To maximize thermal energy capture, these liquid storage tanks are often located in basements of homes and businesses, particularly in the northern climates where placement of the storage tank in the exterior of the building structure may lead to tank failure and at best, loss of captured thermal energy, especially in the winter months. Similar but opposite considerations apply for the storage of cold liquids, refrigerants and the like in warmer climates, where the most suitable storage location for these tanks are also often in lower levels of the home or business, especially during the hotter months. 
     Often, large prefabricated storage tanks are difficult to maneuver and placement in lower levels and basements of homes and businesses are hampered by the fact that the average door widths range from 87 to 92 cm (34¼ to 36¼ inches), far smaller than the dimensions of the storage tanks. Moreover, given their bulk and weight, prefabricated storage tanks in capacities of hundreds of gallons to thousands of gallons are difficult to reposition once they have been previously established. 
     SUMMARY 
     It is therefore an object of the present technology to provide a thermally insulated storage tank, which may provide a temperature, regulated liquid for circulation to an outside tank or other thermal capture devices. 
     It is another object of the present technology to provide a thermally insulated storage tank that is thermally highly efficient in design, by being modular and easily assembled in difficult to reach areas. 
     A further object of the present technology is to provide a thermally regulated storage tank that can interface with a business or residential thermal capture panel system. A liquid stored in the thermally insulated tank is capable of heating or cooling a second source of circulating water for domestic or commercial use. When the stored liquid is hot, it can then be recirculated back to the thermal capture system to become reheated again. 
     Finally, it is an object of the present technology to provide an insulated storage tank, which is both economical and simple to manufacture, as well as easy to install. 
     These and other objects will become apparent from the present technology comprising an insulated storage tank designed to incorporate a means of storing both hot and cold liquids including water, antifreeze and compressed liquefied gasses. The insulated storage tank includes an inner liner supported by a plurality of vertical insulating panels. The insulating panels are arranged circumferentially to form a cylinder, each insulating panel in contact with a leading edge and a trailing edge of another insulating panel. The insulating panels are freestanding and are further supported by an outer support jacket. The liquid is placed within the inner liner and will assert a force against the insulating panels. Thermal energy in the liquids are further insulated by an insulating lid that is disposed within the upper circumference of the insulating panels and forms an insulating seal with the inner liner. Optionally, the insulating panel rests on an insulating floor that is sized and shaped to fit within the void provided by the lower circumference of the insulating panels 
     Other optional components can include a plumbing board having inlet and outlet liquid ports for introducing and removing liquid from the insulated storage tank chamber, microprocessors and pumps, temperature sensors, water level sensors and other monitoring systems to regulate the volume and temperature of a liquid in the thermally insulated tank. Also contemplated as an optional feature includes a heat exchanger operable to circulate a liquid, for example, domestic potable water capable of being heated by the stored liquid in the insulated storage tank. The potable water can be used for domestic purposes such as filling a home hot water tank, for use in laundry, for heating the home and other known heating or cooling applications. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1  is a perspective view of the thermally insulated tank comprising the preferred embodiment of the present technology; 
         FIG. 2  is a top plan view of the thermally insulated tank with the lid in place; 
         FIG. 3  is a perspective view of an insulating panel comprising the preferred embodiment of the present technology; 
         FIG. 4  is a side elevation view of the insulating panel of  FIG. 3  comprising the preferred embodiment insulated storage tank of the present technology; 
         FIG. 5  is a plan view as viewed from the top of the insulating panel of the present technology; 
         FIG. 6  is a plan view as viewed from the bottom of the insulating panel of the present technology; 
         FIG. 7  is a plan view of the bottom of the insulated storage tank comprising the preferred embodiment insulated storage tank of the present technology; 
         FIG. 8  is a cross-section view of the insulated storage tank comprising the preferred embodiment insulated storage tank of the present technology; 
         FIG. 9A  is a perspective view depicting a prepackaged insulated storage tank on a pallet; 
         FIG. 9B  is a perspective view of the insulating floor during a first construction step; 
         FIG. 9C  is a perspective view modified from  FIG. 9B  to include an insulating wall portion; 
         FIG. 9D  is a perspective view modified from  FIG. 9C  to include further insulating wall portions; 
         FIG. 9E  is a perspective view modified from  FIG. 9D  to include all of the insulating wall portions in assembled form; 
         FIG. 9F  is a perspective view modified from  FIG. 9E  to further show an inner liner in an installed position; 
         FIG. 9G  is a perspective view modified from  FIG. 9F  to further show the outer support jacket in an installed position; and 
         FIG. 10  is a top perspective view of the insulating panels arranged in a cylindrical fashion prior to circumferential application of the outer support jacket around the insulating panels. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     Referring now to the figures, particularly  FIGS. 1 and 2 , the preferred embodiment of the present technology comprising an insulated storage tank  10  is shown. The insulated storage tank  10  comprises an outer support jacket  30 , a plurality of insulating panels  100  in proximate contact with outer support jacket  30 , an inner liner  400  which conforms to the interior cavity of the thermally insulated tank  10  and an insulating lid  20  covering the circular opening to the insulated storage tank  10 . The insulated storage tank  10  comprises a generally cylindrical-shape. The thin outer support jacket  30  surrounds the exterior arcuate surface of insulating panels  100  shown in  FIG. 2 . The outer support jacket  10  provides structural rigidity and assists insulating panels  100  from collapsing or being forced apart. Outer support jacket  30  has a length that is generally slightly longer than the circumference of the insulated storage tank  10 . The outer support jacket  30  has a height that is typically the same height of insulated storage tank  10 . The outer support jacket  30  can be made from any structurally resilient polymer, plastic, metal or wood, including for example thermoplastic polyolefin (TPO) materials commercially available as SEQUEL E3000 sold by Solvay Engineered Polymers Inc. (Auburn Hills, Mich., USA), 
     In some embodiments the outer support jacket  30  can have a width ranging from about 0.1 mm about 10 mm wide, or from about 1 mm to about 10 mm, or from about 2 mm to about 10 mm, or from about 0.1 mm to about 9 mm, or from about 0.1 mm to about 7 mm, or from about 0.1 mm to about 5 mm. The ends  35  of the outer support jacket  30  can be overlaid and glued together around the insulating panels  100  as shown in  FIG. 1 . 
     In some embodiments, the insulated storage tank  10  includes an insulating lid  20 . Insulating lid  20  can be made from any generally known insulation material including expanded polypropylene, thermosetting plastic foams, thermoplastic polyolefins, fiberglass, expanded perlite, wood, metals and any material that is capable of retaining the heat or cold in the liquids within the insulated storage tank  10 . Foam is preferably used because of the superior heat transfer properties provided by foam materials, relative ease of manufacture and it&#39;s lightweight. As shown in  FIGS. 1 and 2 , the insulating lid  20  can be apportioned along a midline  80  in two sections to allow the opening and removal of one half of the lid while keeping the other half in place. 
     The insulating lid  20  can optionally house, support and integrate a variety of mechanical and electrical components that provide diagnostic and operational functionality to the insulated storage tank  10 . For example, insulating lid  20  can be mounted with a plumbing board to provide all of the hydraulic operational requirements of the tank, for example, liquid input and output and sampling. Control unit  60  can also include a variety of mechanical and electrical components such as logic boards, relays, microprocessors and the like to send and receive electrical signals to and from a variety of mechanical and electrical components, for example, pumps and sensors. A variety of sensors can be included and mounted onto insulating lid  20 , for example, water level sensor  75  mounted to the lid with the aid of a seal  70 . Water level sensor  75  can be free-standing or can be integrated with control unit  60  and a pump (not shown) to determine the level of liquid in the insulated storage tank  10 . Upon liquid volume loss in the insulated storage tank  10 , liquid level sensor  75  can detect the deficiency and send a signal to control unit  60  to activate a pump to fill the tank with more liquid. Temperature sensor  65  can also be integrated with control unit  60  and measure the temperature of the liquid in the insulated storage tank  10 . 
     If the liquid in the insulated storage tank  10  falls below a predetermined threshold, temperature sensor  65  can send a signal to a valve (not shown) to reduce the volume of liquid being recirculated on the roof of a residence from entering into the insulated storage tank  10 . Alternatively, the temperature sensor  65  can alert the system if the liquid in the insulated storage tank  10  rises above a predetermined threshold. In such a case, the temperature sensor  65  can send a signal to a pump (not shown) to increase the flow of a secondary liquid being circulated in a heat exchanger (not shown) which is placed in the insulated storage tank  10  to extract heat from the liquid in the insulated storage tank  10 . In addition, liquid inlet  50  and liquid outlet  55  can be used to add materials into the insulated storage tank  10 , or to remove materials, including liquids, within the insulated storage tank  10 . Generally, insulating lid  20  has a diameter that is slightly larger than the internal diameter  500  shown in  FIG. 8 . The thickness of insulating lid  20  can vary and is not critical. However, for aesthetic appeal, the exterior surface of the insulating lid  20  can be generally flush with the horizontal rim surface  110  of the insulating panels  100  shown in greater detail in  FIG. 3 . 
     Referring now to  FIGS. 3-6  and  8 - 10 , the insulated storage tank  10  also includes a plurality of vertical insulating panels  100 . In some embodiments, the insulating panels  100  are the cylindrical side walls of the insulated storage tank  10  that supports the insulating lid  20 . In use the insulating lid  20  is placed on the lid resting shelf  160 . With reference to  FIG. 3 , illustrating the insulating panel  100  in perspective view, the insulating panel  100  has a rim and a horizontal rim surface  110 , the rim also includes a rim side wall  170  and lid resting shelf  160 . Insulating panel  100  has a leading edge contact surface  140  and a trailing edge contact surface  150 . The insulating floor  25  is slotted into the recess formed by floor contact wall  180  and floor support shelf  185 . When the complete cylinder is formed by aligning all of the required insulating panels  100  as shown in  FIGS. 9 and 10  along with the insulating floor  25 , the inner liner  400  can be placed in the void created by the arrangement of the insulating panels  100  and insulating floor  25  as shown in  FIG. 9 . The inner liner  400  rests against and is supported by interior arcuate surface  130  of insulating panel  100 . 
     Insulating panel  100  has a leading edge contact surface  140  forms a leading edge apex  142  with a trailing edge offset  210 . The placement of the leading edge contact surface  140  of one insulating panel  100  in direct contact with the trailing edge contact surface  150  of the next insulating panel  100  in succession (in a clock wise fashion) has been surprisingly found to provide substantial resistance to radial movement of the insulating panels due to the hydrostatic force created by liquid. All of the insulating panels  100  can be connected with the use of a clasping mechanism placed on the exterior arcuate surface  120 . Alternatively, the leading edge contact surface  140  and the trailing edge contact surface  150  of insulating panels  100  can each have male and female interlocking structure that can approximate the two contact surfaces  140  and  150  and lock them into position. Preferably, the insulating panel  100  can all be clasped or structurally held in position by placing an outer support jacket  30  around the exterior arcuate surface  120  as shown in  FIGS. 1 and 9 . 
     It has been determined that for a 60 inch outer diameter/350 gallon insulated storage tank  10 , the pressure exerted on a 1 mm thick TPO outer support jacket  30  after the insulated storage tank  10  has been fully assembled having an insulating panel thickness of 4.4 inches, and an inner liner  400  storing 330 gal of water, 1 m high column of water, inner tank radius of 25.6 inches) is approximately 1084 psi which is well within its tensile yield of 3100 psi. For a 2000 gallon tank with a 2 mm thick TPO outer support jacket using the same column water height but an inner radius of 61.1 inches, the stress on the outer support jacket  30  is approximately 1184.5 psi and is also well within its tensile yield of 3100 psi. 
     The insulating panel  100  can also be made of any suitable modular material as described above for the insulating lid  20 . These can include expanded polypropylene, thermosetting plastic foams, thermoplastic polyolefins, fiberglass, expanded perlite, wood, metals and any material that is capable of retaining the heat or cold in the liquids within the insulated storage tank  10 . Foam is preferably used because of the superior heat transfer properties provided by foam materials, relative ease of manufacture and is lightweight. The dimensions of the insulating panel  100  can vary according to the size of the insulated storage tank  10  needed. For example, for a 330 gallon insulated storage tank, 5 insulating panels  100  can be used form a complete cylinder. For a 330 gallon insulated storage tank  10 , each insulating panel  100  can measure approximately 47 inches in height, an arcuate length of 34.5 inches and a width of approximately 4 inches. In some embodiments, the number of insulating panels  100  used to form the insulated storage tank  10  can vary, preferably there are 5 insulating panel  100  per insulated storage tank  10 . 
     In some embodiments of the present technology, the insulated storage tank  10  can also optionally have an insulating floor  25 . While not essential to the practice of the present technology, an insulating floor  25  can be used with the bottom cutout in the insulating panel  100  to provide a unified structure that is configured to resist the hydrostatic stresses imposed on the insulated storage tank  100  walls. As illustrated in  FIGS. 7 and 8 , the insulating floor  25  can be made from any insulation material as described above for the insulating panel  100 . Insulating floor  25  can be a single piece of insulation or it can be made from two halves divided by the line  82  as shown in  FIG. 7 . 
     Best shown in  FIG. 8 , the inner liner  400  can be constructed from any synthetic or natural material that is capable of withstanding liquids having temperatures ranging from about 0° C. to about 250° C., preferably from about 4° C. to about 190° C. In some embodiments, the inner liner  400  can be constructed of a synthetic plastic material, polymer material or thermoplastic materials capable of withstanding liquid temperatures ranging from about 0° C. to about 250° C. In some embodiments, the inner liner  400  can be made from a poly vinyl chloride material. 
     With general reference now to  FIGS. 9A-9G  and  10 , and with specific reference to  FIG. 9A , the insulated storage tank  10  can be prepacked on a pallet  182  saving transportation costs and freight charges. The small footprint of the delivery package containing the modular insulated storage tank also affords vastly improved maneuverability and locations for installation. As shown in  FIG. 9B , the modular parts of the insulated storage tank  10  can be easily assembled by first preparing the insulating floor  25 . As previously noted, the insulating floor  25  is not essential to the invention. However, it is preferred to other forms of insulation flooring. As sequentially shown in  FIGS. 9C-9E , the insulating panels  150  are fitted with floor contact walls  180  and floor support shelves  185 ; then, the insulating panel  100  can be slotted into position adjacent and on top of insulating floor  25 . Then, as shown in  FIGS. 9C-9E , all of the insulating panels  100  are placed around the floor  25 , ensuring that the leading edge contact surface  140  and a trailing edge contact surface  150  of insulating panels  100  are abutting one another. As shown in  FIG. 9F , once the insulating panels  100  have been positioned around the insulating floor  25  the next step is to place the inner liner  400  into the cavity of the insulated storage tank  10  and leave an overhang  402  of inner liner  400  extend over the horizontal rim surface  110  of the insulating panels  100 . As shown in  FIG. 9G , the last step can include placing an outer support jacket  30  around the exterior arcuate surface of all of the insulating panels  100  and joining the ends of the outer support jacket  30  leaving a joint  35  as shown in  FIG. 1 . 
     The present technology affords a simple manner in which to prepare on site an insulated storage tank having liquid capacities ranging from 50 gallons to 5,000 gallons. The insulated storage tank has many used for storing both hot and cold liquids. 
     In a preferred embodiment, the hot liquid stored in the insulated storage tank  10  can include liquids (e.g. water), that are recirculated through a solar thermal capture device, for example, the Power Panel Solar/Thermal capture device disclosed in International Application PCT/US2008/078822, filed Oct. 3, 2008, the disclosure of which is incorporated herein in its entirety. The stored hot liquids (e.g. water) recirculating through said Power Panel Solar/Thermal capture device can reach temperatures ranging from 75-120° C. The stored hot liquid in the insulated storage tank  10  of the present technology can be used to heat a secondary potable water source (for example a domestic home water source) with the use of heat exchangers placed in the insulated storage tank  10 . Similarly, heat exchangers placed in insulated storage tanks storing compressed liquids such as carbon dioxide can be used to cool a secondary liquid source for residential or commercial cooling. The rate of recirculation through the solar/thermal energy capture device and passage into the insulated storage tank  10  can be automated to maintain a set temperature within the insulated storage tank  10 . 
     The embodiments and the examples described herein are exemplary and not intended to be limiting in describing the full scope of compositions and methods of the present technology. Equivalent changes, modifications and variations of some embodiments, materials, compositions and methods can be made within the scope of the present technology, with substantially similar results.