Preheater system for water heater input water

Abstract

Double cylinder walls are adjustably sealed to an exhaust gas conduit of any of a variety of hot water heating systems. An inner cylinder wall houses a water preheater pipe coil with an inner turbulator coil to circulate source water to be preheated by the exhaust gasses prior to feeding into the water heating system. An outer cylinder wall sealed to the inner cylinder wall prevents exhaust gas leakage from the inner cylinder wall from escaping. Insulation between the cylinder walls retains the heat within the inner cylinder for maximum preheating and an outer cylinder wall that is safe to the touch. A series of valves and pressure and flow gauges control the flow of water and diverts the flow or shuts down the preheater system or the entire hot water heating system as needed for failsafe operation.

What is claimed is: 
     
         1 . A universal failsafe water preheater system for preheating input water for any of a variety of hot water heating systems utilized hot exhaust gases, the water preheater system comprising:
 a double-walled insulated sealed water preheater housing adapted for replacing a section of an exhaust gas pipe for any of a variety of water heating systems; the housing comprising an elongated inner wall housing an inner chamber having a hollow interior and two end openings communicating with an interior passageway of the exhaust gas pipe to admit the exhaust gasses to pass from a first section of the exhaust gas pipe through the inner chamber to a second section of the exhaust gas pipe and two end connectors having exhaust gas sealing connectors adapted for sealing with the two sections of the exhaust gas pipe to prevent exhaust gasses from escaping; an elongated outer wall sealed to and spaced apart from the inner wall adjacent to each of the two end openings of the inner wall, the outer wall spaced apart from the inner wall along the length of the inner chamber, the outer wall adapted to seal in any exhaust gasses which might escape from the inner wall; at least one layer of heat insulation between the inner wall and the outer wall to retain heat within the inner chamber and maintain the outer wall at a temperature which is safe for human contact;   a water preheater element adapted to be attached between a water supply source and a water inlet to a heating source for any of the variety of water heating systems to receive water passing through the water preheater element between the water supply source and the water inlet to the heating source, the water preheater element installed inside the inner chamber with at least one sealed connector through the inner and outer walls, the water preheater element extending along a substantial portion of the inner chamber, the water preheater element adapted to preheat the water prior to entering the heater source, the water preheater element further comprising an internal means to add more friction to water flowing within the water preheater element to further increase the heat transfer from the exhaust gasses flowing through the inner chamber to the water flowing within the water preheater element;   at least one water flow bypass valve for opening water flow from the water supply through the water preheater element as desired and alternately for closing water flow from the water supply through the water preheater element to allow the water from the water supply to flow directly into the heating source in case of a malfunction in the water preheater system;   a plurality of safety valves and pressure gages for sensing water pressure entering and leaving the water preheater element, the safety valves adapted for shutting off the flow of water through the water preheater element as needed in the event of water pressure increase at an inlet to the water preheater element due to blockage of water flow through the water preheater element and in the event of water pressure decrease at an outlet from the water preheater element due to leakage of water flow through the water preheater element.   
     
     
         2 . The water preheater system of  claim 1  wherein the water preheater element comprises a water pipe shaped into a configuration adapted to occupy a substantial portion of the inner chamber while allowing maximum flow of exhaust gasses around the water pipe to preheat the water therein while still allowing natural exhausting of the exhaust gasses through the exhaust gas pipe. 
     
     
         3 . The water preheater system of  claim 1  wherein the water preheater element comprises a water pipe structured in an elongated cylindrical coil pipe configuration aligned with and separated from the inner wall along the length of the inner chamber. 
     
     
         4 . The water preheater system of  claim 3  wherein the internal means to add more friction to water flowing within the water preheater element comprises a turbulator inside at least a portion of the elongated cylindrical coil pipe to create turbulence in the water flowing through the elongated cylindrical coil pipe to add more friction and further increase the heat transfer from the exhaust gasses flowing through the inner chamber to the preheater water flowing through the elongated cylindrical coil pipe water preheater element. 
     
     
         5 . The water preheater system of  claim 4  wherein the turbulator comprises at least one coiled spring fit into at least a portion of the elongated cylindrical coil pipe. 
     
     
         6 . The water preheater system of  claim 5  wherein the at least one coiled spring is fabricated of coiled copper nickel in a spiral coil configuration having a diameter less than the inner diameter of the water heating element coil pipe to allow full contact of the preheater water with the wall of the water heating element coil pipe for maximizing heat transfer to the preheater water. 
     
     
         7 . The water preheater system of  claim 1  wherein the water preheater element has at least one inlet pipe from the water supply pipe into the water heating element and at least one preheated water outlet pipe from the water heating element passing through the inner and outer walls with at least one air-tight seal therebetween. 
     
     
         8 . The water preheater system of  claim 1  wherein the water preheater element has at least one water supply inlet pipe and at least one preheated water supply outlet pipe both passing through a single opening through the housing walls with an air-tight seal therebetween. 
     
     
         9 . The water preheater system of  claim 1  the plurality of safety valves and pressure gauges comprises at least one relief valve adapted to measure water pressure of water entering the water preheater element and adapted to shut off the water preheater system upon a loss of water pressure signaling a blockage in the water preheater element. 
     
     
         10 . The water preheater system of  claim 1  one of the plurality of valves comprises a low flow pressure valve in a preheated water outlet from the water preheater element, the low flow pressure valve adapted to measure water pressure of the preheated water leaving the water preheater element so that in the event of water pressure decrease indicating a water leak in the water preheater element the low flow pressure valve will shut down the water preheater system. 
     
     
         11 . The water preheater system of  claim 1  wherein the inner wall and outer wall of the double walled sealed insulated housing are separated by at least one inch all around and further comprising at least a one inch layer of heat insulation between the inner wall and the outer wall to retain heat within the inner chamber. 
     
     
         12 . The water preheater system of  claim 1  wherein the heating source comprises a gas heater in a gas water heater tank having an exhaust gas pipe, a portion of the exhaust gas pipe being replaced by the double-walled insulated sealed housing having the inner chamber conducting the exhaust gasses through the inner chamber to contact the water preheater element housed therein transferring heat the preheater water flowing through the water preheater element. 
     
     
         13 . The water preheater system of  claim 1  wherein the heating source comprises a boiler furnace separate from a water heater holding tank, the boiler furnace comprising a heat exchanging means for heating water from a water heating input pipe from the water heater holding tank and a heated water output pipe from the boiler into the water heater holding tank and further comprising a boiler exhaust gas pipe, a portion of the boiler exhaust gas pipe being replaced by the double-walled insulated sealed housing having the inner chamber conducting the exhaust gasses through the inner chamber to contact the water preheater element housed therein transferring heat the preheater water flowing through the water preheater element and further comprising a preheated water pipe feeding from the preheater element into the water heating input pipe into the boiler. 
     
     
         14 . The water preheater system of  claim 1  wherein the heater source comprises a boiler furnace and a separate indirect water heater tank heated by the boiler furnace, the indirect water heater tank comprising a water heating element inside the indirect water tank communicating with the boiler by a water heating input pipe feeding from the boiler furnace into the water heating element to heat the water in the indirect water heater tank and further communicating with the boiler by a water return pipe from the water heating element back into the boiler for reheating; and further comprising a boiler exhaust gas pipe, a portion of the boiler exhaust gas pipe being replaced by the double-walled insulated sealed housing having the inner chamber conducting the exhaust gasses through the inner chamber to contact the water preheater element housed therein transferring heat to the preheater water flowing through the water preheater element and further comprising a preheated water pipe feeding from the preheater element into the water return pipe leading into the boiler. 
     
     
         15 . The water preheater system of  claim 1  wherein the heating source comprises a boiler furnace heating a tank-less hot water system, the tank-less hot water system comprising a heat exchanging means in the boiler furnace for heating water from a water supply source fed into the boiler furnace through a water heating input pipe to the heat exchanging means and further comprising a heated water output pipe from the boiler furnace heat exchanging means feeding the hot water supply pipes, the boiler furnace further comprising a boiler exhaust gas pipe, a portion of the boiler exhaust gas pipe being replaced by the double-walled insulated sealed housing having the inner chamber conducting the exhaust gasses through the inner chamber to contact the water preheater element housed therein transferring heat the preheater water flowing through the water preheater element and further comprising a preheated water pipe feeding from the preheater element into the water heating input pipe into the boiler. 
     
     
         16 . The water preheater system of  claim 1  wherein the heating source comprises a heater in a stand-alone tank-less water heater, the stand-alone tank-less water heater comprising a heat exchanging means communicating with the heater in the stand-alone tank-less water heater for heating water from a water supply source fed into the stand-alone tank-less water heater through a water heating input pipe to the heat exchanging means and further comprising a heated water output pipe from the stand-alone tank-less water heater heat exchanging means feeding the hot water supply pipes, the stand-alone tank-less water heater further comprising a stand-alone tank-less water heater exhaust gas pipe, a portion of the stand-alone tank-less water heater exhaust gas pipe being replaced by the double-walled insulated sealed housing having the inner chamber conducting the exhaust gasses through the inner chamber to contact the water preheater element housed therein transferring heat the preheater water flowing through the water preheater element and further comprising a preheated water pipe feeding from the preheater element into the water heating input pipe into the stand-alone tank-less water heater.