Water heater

Abstract

A water heater apparatus includes an inner tank, an outer tank, heat bands disposed on the outside of the outer tank, an interior coil supplying water to the inner tank, and a heating element for heating water in the inner tank. The inner tank and outer tank are concentrically arranged with a labyrinthine passage in between, so that water spends an additional amount of time flowing in the passage while it is being heated by the heat supplied from the band heaters. The water heater apparatus can thereby provide heated water ready for delivery, as well as maintaining a start up heat.

1 . An apparatus for heating water, comprising:
 an outer tank having a circumferential wall, a top plate, and a bottom plate;   an inner tank having a circumferential wall, a top plate, and a bottom plate; and said inner tank being disposed within said outer tank,   a coil having a main body portion, an inlet, and an outlet; wherein said main body portion of the coil is disposed inside said inner tank, said inlet of the coil extends through the bottom wall of the inner tank and the bottom wall of the outer tank;   a heating element extending into an interior of said inner tank; and   an outlet conduit connected to said outer tank, and communicating with an interior of said outer tank.   
   
   
       2 . An apparatus for heating water as claimed in  claim 1 , further comprising a plurality of band heaters connected to an exterior of said outer tank. 
   
   
       3 . An apparatus for heating water as claimed in  claim 2 , further comprising a plurality of spacers disposed between said inner tank and said outer tank, forming a labyrinthine passage for fluid flow, so that all of the fluid flowing into said outlet conduit first passes through said labyrinthine passage. 
   
   
       4 . An apparatus for heating as claimed in  claim 3 , wherein said labyrinthine passage provides additional time for heat transfer to occur between said band heaters and said fluid. 
   
   
       5 . An apparatus for heating water as claimed in  claim 3 , wherein said plurality of band heaters are selectively actuatable, to selectively vary the amount of heat supplied to said outer tank. 
   
   
       6 . An apparatus for heating water as claimed in  claim 1 , further comprising a pop off valve disposed through an upper plate of said outer tank. 
   
   
       7 . An apparatus for heating water as claimed in  claim 1 , wherein said inner tank has a cylindrical wall, an upper plate and a lower plate; and said outer tank has a cylindrical wall, an upper plate and a lower plate. 
   
   
       8 . An apparatus for heating water, comprising:
 an outer tank having a circumferential wall, a top plate, and a bottom plate;   an inner tank having a circumferential wall, a top plate, and a bottom plate; and said inner tank being disposed within said outer tank,   a coil having a main body portion, an inlet, and an outlet; wherein said main body portion of the coil is disposed inside said inner tank, said inlet of the coil extends through the bottom wall of the inner tank and the bottom wall of the outer tank;   a heating element extending into an interior of said inner tank;   an outlet conduit connected to said outer tank, and communicating with an interior of said outer tank;   a plurality of band heaters connected to an exterior of said outer tank; and   an elongated spacer member helically arranged along the outside surface of said inner tank, forming a helical passage for fluid flow, so that all of the fluid flowing into said outlet conduit first passes through said helical passage.