WATER HEATER WITH IMPROVED ENERGY EFFICIENCY AND METHOD FOR PRODUCING SAME
Publication Date: 2002-Aug-28
The IP.com Prior Art Database
This invention relates to a water heater with improved energy efficiency and methods of manufacturing such a water heater. A water heater comprising: an inner water tank, comprising; a cylindrical main body, and attached thereto, a convex, inward top; and a bottom; an outer enclosure means disposed over and around said inner water tank and defining there between a clearance space; and a foam insulation material between the inner water tank and the outer enclosure means in said clearance space. A water heater construction wherein the foam insulation material consists of a combination of foam types selected from epoxy, isocyanurate, phenolic, silicone, urea formaldehyde, polyolefin, polypropylene, polystyrene, polyethylene, poly(vinyl chloride), ethylene/vinyl acetate, ethylene/styrene, phenol/formaldehyde, and mixtures thereof. A water heater construction, wherein the foam insulation material is blown with a volatile blowing agent selected from the group consisting of hydrochlorofluorocarbons of one or two carbon atoms, hydrofluorocarbons of two to four carbon atoms, carbon dioxide, a hydrocarbon of I to 8 carbons atoms, pentane, cyclopentane, isopentane, isobutane, propane and 2-chloropropane, or a mixture thereof, or a mixture of the volatile blowing agent with water.
Field of the Invention:
This invention relates to a water heater with improved energy efficiency and methods of manufacturing such a water heater. Typically, the top cap of a steel water heater storage tank is convex, pointing upward and outward relative to the main body of the tank, while the bottom cap of the tank is convex upward and points inward relative to the main body of the tank tank. The invention is additionally directed towards a method of improving the energy efficiency of a water heater. The invention further encompasses a method for foaming the inventive water heater via the use of multiple foam injections.
Description of the Related Art:
Typically, the top cap of a steel water heater storage tank is convex, pointing upward and outward relative to the main body of the tank, while the bottom cap of the tank is convex upward and points inward relative to the main body of the tank. Simplistically, steel water heater internal tanks are usually manufactured using three components: a) a sheet of steel which is wrapped into a cylinder shape and then welded along the seam to prepare the main body of the tank; b) a circular bottom cap prepared from drawn or stamped steel; and c) a circular top cap prepared from drawn or stamped steel. Both the top and the bottom caps are welded to the cylinder according using well known methods so that they are convex upwards, with the bottom cap protruding into the interior of the body of the tank and the top cap protruding upwards and outwards from the body of the tank. Figure 1, provides a pictorial representation of a conventional electric water heater. Water heater tanks have also been designed in which both end caps are convex outwards, providing the maximum water capacity.
Conventional construction of a complete water heater includes a generally cylindrical outer shell concentrically placed around the inner water tank leaving an annular space therebetween. Construction further comprises fillingthe annular space with some type of thermal insulation material, typically a liquid, foam-in-place insulation material. The construction is completed by putting some type of top cover or enclosure over the top of the inner water tank and over the upper top edge of the outer shell so as to enclose the annular space. Likewise, some type of lower or base cover or enclosure is provided beneath the water tank in a similar fashion. Ideally, the foam used will provide the highest insulation value, i.e., the highest energy efficiency, for a given configuration.
The specific arrangement of foam insulation within the annular space may include any of the variations disclosed by the, following U.S. Pat. Nos.:
U.S. Pat. No. Patentee Issue Date
4,477,399 Tilton 10/16/1984