Abstract:
The present invention relates a novel heat exchange system. More particularly, the invention concerns a heat exchange system for use in bathing apparatus, including showers, bathtubs and whirlpools. Advantageously, this system is simple to install, maintain and clean and can easily be integrated in a limitless variety of bathing apparatus.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 09/850,239 filed May 7, 2001, which claims priority on U.S. Provisional Patent Application No. 60/202,250 filed May 5, 2000, hereby incorporated in its entirety by reference into this application. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates a novel heat exchange system. More particularly, the invention relates to a heat exchange system for use with bathing apparatus, including showers, bathtubs and whirlpools, that is easy to install, maintain and clean. 
       BACKGROUND OF THE INVENTION 
       [0003]    Heat exchange systems for use with showers or other bathing apparatus are known in the art. They are used to recover heat from hot or warm waste water. In each of these systems, the spent water flows on one side of a heat exchanger before flowing out into the drainage system. Incoming cold water flows on the other side of the heat exchanger element and is thereby preheated before being mixed in a mixer with hot water or before entering a hot water heating device to be heated further. 
         [0004]    Sample patent applications and patents in the field include the following: Canadian Patent Application No. 2,566,351; Canadian Patent Application No. 2,559,296; United States Patent Application Publication No. 2004/0194916; International Patent Application No. PCT/SE00/01548; International Patent Application No. PCT/US2007/019689; International Patent Application No. PCT/GB2008/002129; UK Patent GB 2 052 698; German Patent No. DE 3319638; German Patent No. DE 3804534; German Patent No. DE 3919544; German Patent No. DE3932871; German Patent No. DE 4406971; German Patent No. DE 8600554; German Patent No. DE 19723148; German Patent No. DE 29709630; German Patent No. DE 29717073; German Patent No. DE 29806939; German Patent No. DE 29815304; German Patent Publication No. DE 202007007907; and Dutch Patent No. NL 1014215. 
         [0005]    In many instances, the heat exchanger is installed beyond the drain of the bathing apparatus and thus comes into with warm waste water after the water has flowed through the drain. There are a number of disadvantages with this kind of arrangement. First, heat that might otherwise have been captured is dissipated as it goes through the drain. Secondly, installing a heat exchanger beyond a drain unit requires the expertise of a professional plumber, as it is usually connected directly to the plumbing system in one manner or another. Finally, heat exchangers of this type can be inconvenient to clean, repair or replace, because they are not readily accessible. 
         [0006]    In addition, many heat exchange devices that are currently available are based on a coil system of some kind. Over time, the accumulation of dirt and minerals from the waste water can impede the efficiency of such devices. In some cases, their complexity can make maintenance and repair difficult. 
         [0007]    The present invention seeks to overcome some of the limitations of heat exchangers that are currently available. 
       SUMMARY OF THE INVENTION 
       [0008]    Advantageously, the system of present invention has a simple and clean design, allowing for ready access to the heat exchange element for maintenance, repair and replacement. It is also easy to install in a bathing apparatus and therefore does not necessarily require the intervention of a plumbing professional. 
         [0009]    The present invention provides a heat exchange device to recover hot water from bathing apparatus. The invention has particular, but not exclusive, application to showers. 
         [0010]    The basic features of the invention include: (a) a shower or bathtub base; and (b) a heat exchange plate made of a conductive material. The heat exchange device may further include (c) a cover positioned over the heat exchange plate that serves as a standing platform for the bather and that compliments the shower or bathtub base. The base further includes a draining element through which used water is evacuated from the shower or bathtub. 
         [0011]    The heat exchange plate is positioned at the bottom of the shower or bathtub base, usually flush with the bottom surface. In one embodiment, the bather is in direct contact with the heat exchanger, either partially or completely, when using the bathing apparatus. 
         [0012]    As stated above, the heat exchanger may optionally be concealed by a cover, which is manufactured in a shape and size that is suitable to cover the opening created by the base. The cover is made of a non-conductive material. In a specific embodiment, the base, heat exchange plate and cover all have a square or rectangular geometric shape. 
         [0013]    Most of the water originating from of the showerhead or faucet of the bathing apparatus flows on top of the heat exchanger before reaching the drainage system. The heat exchanger may be covered either fully or partially with a non-conductive material. 
         [0014]    The heat exchange system may include a dam that serves to control the flow of the waste water to the drain of the bathing apparatus. By slowing down the flow, the warm waste water is kept in contact with the heat exchange plate for a longer duration, enhancing heat transfer. Other elements may be substituted for or used with the dam to achieve this purpose, such as channels or dividing elements, as would be appreciated by a person of skill in the art. 
         [0015]    In any embodiment, the heat exchanger is part of the bathing apparatus and the entire assembly is water tight. 
         [0016]    Other objects, advantages and features of the present invention will become apparent upon reading of the following non-restrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  shows (A) an assembled view of a first embodiment of the heat exchange system of the present invention and (B) an exploded view of this system; 
           [0018]      FIG. 2  shows (A) an alternative assembled view of the heat exchanger system shown in  FIG. 1 , and (B) an exploded view of this system; 
           [0019]      FIG. 3  shows (A) a second alternative assembled view of the heat exchanger system shown in  FIG. 1 , and (B) an exploded view of this system; 
           [0020]      FIG. 4  shows (A) a third alternative assembled view of the heat exchanger system shown in  FIG. 1 , and (B) an exploded view of this system; 
           [0021]      FIG. 5  shows a second embodiment of the heat exchange system of the present invention, wherein: (A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 5(A) ; and (C) is an exploded view of the system; 
           [0022]      FIG. 6  shows an alternative to the embodiment shown in  FIG. 5 , wherein: (A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 6(A) ; and (C) is an exploded view of the system; 
           [0023]      FIG. 7  shows a second alternative to the embodiment shown in  FIG. 5 , wherein: (A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 7(A) ; and (C) is an exploded view of the system; 
           [0024]      FIG. 8  shows a third alternative to the embodiment shown in  FIG. 5 , wherein: A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 8(A) ; (C) is a side view of the system taken along line B-B; (D) is a side view of the system taken along line C-C of  FIG. 8(A) ; (E) is a perspective view of the system fully assembled; and (F) is a perspective view of the system without its cover; 
           [0025]      FIG. 9  shows a third embodiment of the heat exchange system of the present invention; wherein: (A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 9(A) ; and (C) is a perspective view of the system fully assembled; 
           [0026]      FIG. 10  shows an alternative to the embodiment shown in  FIG. 9 , wherein: (A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 10(A) ; and (C) is an exploded view of the system; and 
           [0027]      FIG. 11  shows a fourth embodiment of the heat exchange system of the present invention, wherein: (A) is a top plan view of the system, (B) is a side view of the system taken along line A-A of  FIG. 11(A) ; and (C) is a perspective, partially exploded view of the system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    As will be described more particularly below, the invention comprises four embodiments, and these embodiments can include additional features. 
         [0029]    Referring now to  FIG. 1 , there is shown a first embodiment of the invention wherein the heat exchange system is generally designated by the number  10 . The system comprises a bathing apparatus  2 , illustrated here as a tray-like element that is convenient for a shower. The system further comprises a heat exchange element  4 , which is in the general form of a plate, and a gasket  3  for sealing the heat exchanger within the bathing apparatus. In order to allow waste water to be eliminated from the bathing apparatus  2 , a drain  8  is provided. 
         [0030]    In operation, the heat exchange element  4  is connected to a cold water source (not shown). When warm from the showerhead or warm waste water from the bather falls onto the heat exchange element  4 , heat from the water is captured by the heat exchange element and used to warm the cold water that flows through the body of the heat exchanger element, in keeping with heat exchange principles known in the art. The cold water, which has now been partially heated by the captured energy from the waste water, exits from the heat exchanger (not shown), where it is directed to a mixer or to a hot water tank, once again in keeping with heat exchange principles known in the art. 
         [0031]    Use of a heat exchange system as described above results in energy conservation and is thus ecological sound. The simplicity of the heat exchange system exemplified here has several advantages. It facilitates cleaning and maintenance of the bathing system and, in distinction to what is currently available commercially, is very simple to install and/or replace. 
         [0032]    The heat exchange element  4  is conveniently shown as a plate or plate-like structure having a relative large surface area. The surface area and the thickness of the plate may be altered or otherwise designed with a view to increasing surface area exposure to warm shower or waste water to maximize the efficiency of the heat exchange. While illustrated as a rectangle in  FIG. 1 , the heat exchange element  4  can in practice assume any geometry that is required to fit within the shape of a desired bathing apparatus. 
         [0033]    The heat exchange element  4  may be made of any heat conductive material, including, without limitation, any metal, concrete or stones, composites comprising a polymer, or a conductive material, like graphite. 
         [0034]      FIG. 2  shows an alternative version of the heat exchange system illustrated in  FIG. 1 . In this version, a non-conductive material  9 , shown here as a series of circles, is applied on the surface of the heat exchange element  4  and serves as a barrier between the bather and the heat exchange element. It will be appreciated that the shape, size, configuration and/or pattern of the non-conductive material  9  is(are) limited only by creativity. The non-conductive material can be made of wood, rubber, plastic or any other synthetic material that is suitable for the desired purpose. It may in some instances serve the dual purpose of preventing the bather from slipping while in the bathing apparatus. 
         [0035]      FIG. 3  shows a slightly modified version of the heat exchange system illustrated in  FIGS. 1 and 2 . In this specific version, two small “dams” or dam-like elements  12  have been introduced in the bottom of the bathing apparatus in the vicinity of the drain  8  in order to control water flow through the controlled opening  14 . Warm shower or waste water remains in contact with the heat exchange element  4  for a longer duration than in the absence of the dams  12 , which enhances heat transfer from the water to the heat exchange element. 
         [0036]    A number of dams or dam-like elements  12  can be introduced into a bathing apparatus  2  so as to create one, or more than one, controlled opening(s)  14 . This allows the discharge of warm waste water to be controlled, and therefore allows modulation of the effective heat transfer. The dams or dam-like elements  12  may be integral to the bathing apparatus  2  or added to said bathing apparatus as separate elements thereto. 
         [0037]      FIG. 4  is yet another modified version of the heat exchange system illustrated in  FIGS. 1-3 . This version combines the dams or dam-like elements  12  of the heat exchange system of  FIG. 3  with the non-conductive material  9  of  FIG. 2 . 
         [0038]    Turning now to  FIGS. 5 to 8 , an alternative embodiment of the invention is presented. As illustrated in  FIG. 5 , this embodiment consists of a heat exchange system  20  comprising a bathing apparatus  22 , a heat exchange element  24  and a cover  29 . This cover is positioned over the heat exchange element and serves to enclose the bathing apparatus  22 . A drain  28  is included in the base of the bathing apparatus to allow the warm shower or waste water to leave the system. The heat exchange element optionally includes one or more spacers  25 , as illustrated in  FIGS. 5 to 8 . The spacers create a distance between the heat exchange element and the cover  29 . 
         [0039]    The cover  29  is made of any non-conductive material. Suitable non-conductive materials include, without limitation, plastic, composite materials, wood or wood-like materials or materials including wood (which may optionally be imbibed with a preservative, such as Accoya® or a resin-impregnated material), bamboo, organic materials, glass or ceramic. The cover  29  may optionally include openings  30  or the equivalent thereof to enhance water flow from the cover&#39;s surface to the heat exchange element  24 . These openings  30  are also used to assist in the lifting of the cover from the bathing apparatus for cleaning or maintenance purposes. 
         [0040]      FIG. 6  shows a slightly different embodiment from that appearing in  FIG. 5  wherein two “dams” or dam-like elements  32 , similar to those in  FIGS. 3 and 4 , have been included to control water flow to the drain. A controlled opening (not shown) analogous to that in  FIGS. 3 and 4  serves to delay flow of the shower and waste water towards the drain. 
         [0041]      FIG. 7  shows another variation of the heat exchange systems illustrated in  FIGS. 5 and 6 . In this version, a series of discontinuous dividers  34 , or the equivalent thereof, have been included within the bathing apparatus  22 . The purpose of these discontinuous dividers  34  is to keep warm shower and waste water within the confines of the bathing apparatus for a longer time in order to enhance heat transfer to the heat exchange element  24 . The buoys or equivalent thereof may be an integral part of the bathing apparatus  24  (i.e., cast at the same time as the bathing apparatus itself) or otherwise attached as a separate element to the bathing apparatus. 
         [0042]      FIG. 8  shows yet another variation of the heat exchange systems shown in  FIGS. 5 and 6 . This variation is very similar to that shown in  FIG. 7 , but includes a water channel  36  that surrounds the opening of the bathing apparatus  22  where the heat exchange element  24  is positioned. Warm shower or waste water accumulates in this channel  36  in proximity to the heat exchange element  24 . As a result, the warm shower or waste water remains in contact with the heat exchange element for a longer time, enhancing heat transfer and thereby increase the overall efficiency of the heat exchange system. 
         [0043]      FIGS. 9 and 10  show a third embodiment of the heat exchange system of the present invention. In this embodiment, the heat exchange system  50  comprises a bathing apparatus  54  that is made of a conductive material. The bathing apparatus is the heat exchange element in this particular embodiment. The bathing apparatus  54  may be comprised of one or more elements, wherein each element is made of a conductive material. As shown in  FIG. 9 , a surface  56  is made of the same conductive material as the bathing apparatus  54 , or of a different conductive material, but is fully attached to the bathing apparatus. This surface  56  is optionally covered, partially or totally, with a non-conductive material. A gasket or other sealing means may be optionally included in order to ensure that the bathing apparatus is water-tight. 
         [0044]    In the variation of this embodiment of the invention shown in  FIG. 10 , a surface  57  is made of a non-conductive material. This surface  57  is removable from the bathing apparatus  54  and is made of a non-conductive material, or of a conductive material that is partially or totally covered with a non-conductive material. 
         [0045]    As shown in  FIG. 9 , the heat exchange system  50  further includes a drain  58 . Alternatively, as shown in  FIG. 10 , water from the shower may flow in a channel  59  running between the surface  57  and the bathing apparatus  54 . The drain  58  is located beneath the surface in this version of the embodiment of the invention. 
         [0046]      FIG. 11  shows a fourth embodiment of the heat exchange system of the present invention. In this embodiment, the heat exchange system  70  comprises a bathing apparatus  72  and one or more heat exchange elements  74 . The top of the bathing apparatus  76  may be fully integrated with its base, or optionally, a separate cover. The heat exchange elements are not flat like those in the other embodiments of the invention but consist of rectangles whose width, height and length can be modified so as to increase effective surface area and hence promote heat exchange. This embodiment may offer a solution that is more suitable to the styles of certain baths and showers. 
         [0047]    As with the embodiment shown in  FIGS. 9 and 10 , the embodiment of the invention shown in  FIG. 11  comprises a cover  76  made of a non-conductive material. This cover can include an opening  78  that is positioned either in the cover  76  or in the bathing apparatus  72 . Once again, this opening facilitates access to the system for cleaning and maintenance purposes. 
         [0048]    In any embodiment, the heat exchanger is part of the bathing apparatus and the entire assembly is water tight. 
         [0049]    The embodiments of the invention all have the advantage of simplicity. Installing a heat exchange system as described above can be conveniently done in an existing bathing system or in a new one. Features of the invention, such as the limited number of components and their ability to be removed from each other in a relatively easy manner, allowing for ready cleaning, maintenance and replacement. 
         [0050]    In addition, the selection of embodiments allows for even greater flexibility. Depending on the style and function of the bathing apparatus, a heat exchange system can be selected to best accomplish heat exchange. 
         [0051]    The above-described embodiments of the invention are intended to be examples only. Variations, alterations and modifications can be made to the particular embodiments described herein by those of skill in the art without departing from the scope of the invention, as defined in the appended claims.