Patent Publication Number: US-6714726-B1

Title: Shower warm water capacitor

Description:
DISCUSSION OF RELATED ART 
     The present invention relates to a shower heat exchanger. 
     Shower water is often susceptible to wide fluctuations in water temperature. The largest fluctuation is in the beginning when the shower water from the hot water pipe is cold. Another fluctuation occurs when the shower water from the hot water outlet begins warming up. A variety of solutions have been employed to address the problem of the initial cold water coming out of the hot water pipe, when a person is taking a shower. 
     Recirculating systems take a portion of the hot water and return it to the water heater. These systems require additional plumbing and can greatly increase the cost of building a bathroom. Other tank based systems are bulky and susceptible to leakage problems due to their size and complexity. Raya in U.S. Pat. No. 5,979,775 shows a large tank system that holds shower water in a large tank and adjusts the water shower temperature to a user defined temperature. When a user takes a shower, the water is used from the tank which becomes a closed system. The water is later replenished for later use. 
     Rivera U.S. Pat. No. 5,012,536 shows that the water diverter device that sends the initial cold water to storage. This is not preferable because the cold water is wasted, or a user must manually dispose of the cold water. Postmus U.S. Pat. No. 2,828,766 shows a similar device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of the invention having a type I lid. 
     FIG. 2 is a side view of the invention. 
     FIG. 3 is a side view of the lid member having a type II lid. 
     FIG. 4 is a perspective view of the device. 
     FIG. 5 a  is a side view of the lid having the heating coil configuration. 
     FIG. 5 b  is a side view of the lid having the heating coil configuration. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention stabilizes water flow temperature without using a large tank system or recirculation system. 
     The present invention comprises a main tank member  110 , a lower heating plate element  120 , an inlet pipe  130 , and an outlet pipe  140 . The terminology used here is based on the point of reference of the main tank member  110 . Therefore, any water entering the system is denoted as incoming water, and any water exiting the system is called outlet water. 
     The inlet pipe additionally contains a water flow valve  125  to prevent water from flowing backwards. 
     A user installs the present invention by removing the showerhead  180  in a shower. The user then connects the inlet pipe to the shower supply pipe. The inlet pipe leads to the main tank member. The user then installs the showerhead on the outlet pipe  140 . 
     There are two kinds of lids, here we will denote them as Type I and Type II. A Type I lid can be made from various individual parts and assembled. A Type I lid additionally features exposed L tube sections. A Type II lid may be injection molded, preferably as one piece of plastic. A Type II lid additionally features a circular top. The Type II lid is preferable for aesthetic purposes. 
     The inlet and outlet pipe are preferably formed as an integral single piece of plastic also formed with a circular lid having a circular top. This piece is the lid member that comprises the inlet pipe and outlet pipe. This allows the user to install the inlet pipe formed with the lid member to the shower supply pipe. The user then attaches the main tank member to the lid member  190 . The user also replaces the showerhead  180  to the outlet pipe  140  of the device. 
     The insulated main tank member has an opening; the top lid member is shaped to form a watertight seal with the periphery of the opening in the insulated main tank member. The main tank member may be insulated by a single wall construction or a double wall construction. In a double wall construction, the wall may be air evacuated for improved thermal resistance. The interior of the main tank member may also be covered with a silvered, or reflective coating for preventing radiation heat loss. 
     The top lid section comprises the inlet pipe and the outlet pipe. The inlet pipe may further include a lead pipe supply water member and the outlet pipe may further include a lead pipe feeding water member  116 . Thus, the inlet pipe may be defined as two sections: a first section being an L shaped inlet coupling  118  for connection with the shower supply water pipe; and a second section being the lead pipe supply water member  117 . Similarly, the outlet pipe may be defined as two sections: the first section being an L shaped outlet coupling  118  where water goes to the shower head, and a second section being the lead pipe feeding water member  116 . A lead pipe can be removable for cleaning of the lid and for ease of construction. 
     A free cap  145  secures the lid member to the main tank member. The free cap  145  rotates freely about threaded helical screw on the lid to close the lid on the main tank member. The free cap  145  is preferably retained on the lid so it is not lost. 
     The main tank member  110  additionally includes heat transfer fins  150  attached to a heating element preferably a lower heating plate. The heated plate warms the heating fins. The heat fin configuration  150  is preferably a series of planar metal protrusions that protrude from the lower heating plate  120 . 
     Lower voltage is preferable to high-voltage. The lower heating plate  120  may also include a coupling to a cord electrical outlet for plugging into 120V AC household current. Preferably the heating element operates on 12V DC power for safety considerations. Electrical resistance heats the lower heating plate. The heating of a heating plate by an electrical resistance is commonly known. 
     As an alternative to the electrical heating plate configuration, the invention may heat the water by a resistance heater encapsulated in a heating coil. Use of the resistance-heating coil in the main tank member allows a greater rate of heat transfer from the heating element to water. 
     Upon first use, the user turns on the hot and/ or cold water. The water enters the inlet pipe and fills the main tank member. The water mixes in the main tank member due to the heat fin configuration. The heat fins, are preferably mounted on the bottom part of the main tank member and extend axially from the periphery of the main tank member. The heat fins additionally transfer heat from the heating element to the inlet water. Water then flows out of the main tank member and exits the outlet pipe to the showerhead. When the user turns off the water supply the first time, a valve in the inlet pipe  125  prevents back flow of water. 
     After the first use, the main tank member  110  warms and stores heated water according to the preset thermostat temperature. A thermostat in the heating plate maintains a constant temperature of the main heating plate and the main tank member  110 . Subsequent uses mix the stored heated water with the initial inlet water. 
     Additionally, a silver like coating of the interior of the main tank member may insulate the device, or the interior supply pipes. A variety of material coatings may be used. These materials characterized by visually reflective surfaces are well known in the industry and have relatively low heat emittance. Loss of radiative heat saves electricity. 
     Thus, initial cold water mixes with stored hot water to allow a user to take a warm water shower. Subsequent lukewarm water mixes with warm water to allow a user to take a warm water shower. The thermal capacity of the tank  110  can be sized to the amount of cold water held in the hot water pipe. 
     The inlet pipe preferably leads into to the bottom portion of the main tank member for better mixing and convection heat transfer. The main tank member is insulated to prevent heat loss. 
     The foregoing describes the preferred embodiments of the invention and modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. 
     Call Out List of Elements 
       110  Main Tank Member 
       115  Main Tank Member Opening 
       116  Lead Pipe Feeding Water Member 
       117  Lead Pipe Supply Water Member 
       118  L Shaped Inlet Coupling 
       120  Lower Heating Plate Element 
       125  Water Flow Valve 
       130  Inlet Pipe 
       140  Outlet Pipe 
       145  The Free Cap 
       150  Heating Fins 
       160  Cord Electrical 
       170  Thermostat 
       180  Showerhead 
       190  Lid Member