GAS AND ELECTRIC HEATING SYSTEM

TECHNICAL FIELD

The present invention generally relates to heating systems. More specifically, the present invention is drawn to a gas and electric heating system having a boiler that utilizes both gaseous fuel and electric energy to generate steam.

BACKGROUND ART

Potential shortages of gas and oil and pollution generated during hydrocarbon combustion have caused builders to consider electric energy as a cleaner alternative for heating steam-producing boilers. However, the high costs of producing electricity and the relative inefficiency of using only electric power to generate steam render this alternative economically imprudent. The heating industry and the consumer would certainly welcome a heating system that could incorporate the best features of both an electric and a hydrocarbon- fueled, steam-generated heating system. Thus, a gas and electric heating system solving the aforementioned problems is desired.

DISCLOSURE OF THE INVENTION

The gas and electric heating system is a high-efficiency heating system that employs combination gas and electric heat generators to provide energy to a boiler that tfβrϊerates steam. In one embodiment, the system comprises a blue-flame, gaseous-fuel burner disposed externally of the boiler to provide heat to a steam-generating boiler. A second embodiment employs a jet flame burner having a heating tube disposed in the boiler. Both embodiments employ electrical heating elements positioned inside the boiler. Steam generated in the boiler flows to a heating core. The core is positioned in an air duct so that heat is transferred from the core to air flowing through the duct. The heated air flows from the duct into an area to be heated. Controls are provided to correlate the functions of the various components in the system. The duct can be oriented in any direction (horizontal, down-flow, up-flow, etc.).

Accordingly, the instant invention presents a heating system that employs a combination of energy sources to produce steam. The heating system is effective and efficient and may reduce the user's annual heating bill up to 80%. The system provides for an arrangement of improved elements for the purposes described that are inexpensive, dependable and fully effective in accomplishing their intended purposes.

These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a diagrammatic view of a first embodiment of a gas and electric heating system according to the present invention.

Fig. 2 is a schematic drawing of the electrical control circuitry for a first embodiment of a gas and electric heating system according to the present invention.

Fig. 3 is a partial, perspective view of the boiler tank for a first embodiment of a gas and electric heating system according to the present invention. Fig. 4 is diagrammatic view of a second embodiment of a gas and electric heating system according to the present invention.

Fig 5 is a diagrammatic section view of the boiler and heat tube of the gas and electric heating system of Fig. 4.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

BEST MODES FOR CARRYING OUT THE INVENTION

Attention is first directed to Fig. 1, wherein a first embodiment of the gas and electric heating system is diagrammatically illustrated and is generally indicated at 10. System 10 comprises a blue-flame, gaseous-fuel, burner manifold assembly 12. Gaseous fuel is provided via conduit 14 to the manifold assembly 12. Primary and secondary combustion air is provided in a conventional manner in quantities to allow blue-flame combustion. A pilot burner 12a is positioned adjacent manifold assembly 12 and functions to ignite the mixture of fuel and air to produce a flame indicated at 15. Valves 16 and 18 control the flow of gas to manifold assembly 12 and pilot burner 12a. Flame 15 is directed to heat boiler tank 20 to generate steam therein. A flame shield 22 surrounds the space between manifold assembly 12 and boiler tank 20. Flame shield 22 functions to concentrate the heat to an area beneath the boiler tank 20 and to prevent extraneous air from entering the flame area, thereby allowing the flame to burn steadily.

Water is fed to boiler tank 20 via water conduit 24. Shutoff valve 26, low-water cutout valve and switch 28, and water-feeder sensor 30 control the flow of water through conduit 24. A drain valve 32 and pressure-relief valve 34 are disposed on boiler tank 20 for

obvious safety reasons. Electric heating elements 36, 38 (shown in phantom lines) are positioned within the interior of boiler tank 20. Two elements are preferred. It should be noted however, that one element or more than two elements may be used, if suitable.

Energy applied to boiler tank 20 by flame 15 and electrical elements 36, 38 combine to generate steam. The generated steam flows from boiler tank 20 through conduit 40 and into heating core 42. Gauge 44 is positioned on conduit 40 to monitor the temperature and pressure of steam flow. Control 46 functions to regulate and monitor the pressure of the steam. Heating core 42 is positioned in the exit duct 50a of blower 50. Blower-driven air is heated as it flows over core 42 and into space S (the space that is to be warmed by the heated air). A control sensor 52 is disposed at the exit of duct 50a to monitor blower output and air temperature. A relatively small bleeder line 54 allows an amount of steam to pass from the core directly into space S for humidification purposes. A conventional thermostat 64 is disposed in space S to control system operation in the usual manner.

Circuitry for controlling operation of the system is illustrated in Fig. 2. The circuit includes a fuse 60 in series with an on/off switch 62. Parallel sub-circuit 63 comprises thermostat 64, pressure control 46, low water cutout switch 28a, gas valve control 16, contactor 66 and transformer 66a. Heating elements 36, 38, water feeder sensor 30 and blower motor 68 are in parallel. Switches 46a and 52a are responsive to pressure control 46 and control sensor 52 respectively. As best seen in Fig. 3, boiler tank 20 is positioned adjacent burner manifold 12. The burner generates flames at approximately 300° Fahrenheit. The flame shield has been omitted for clarity. Tank 20 can be fabricated from any suitable metallic material (steel, alloys of steel, etc.). The tank 20 houses heating elements 36, 38 therein. The heating elements are each rated at 1,500 watts. Steam generated in tank 20 exits to the heat core via line 40. Steam condensed in the core is returned to the tank through conventional return lines.

Figs. 4 and 5 are illustrative of a second embodiment of the instant invention. The second embodiment includes a flame jet burner 70 to provide heat to boiler tank 20 in lieu of a blue flame burner. As best seen in Fig. 5, flame jet burner 70 ejects gaseous fuel to be burned in heating duct 72. The duct traverses boiler tank 20. Heating duct 72 is immersed in water in tank 20. Jet flame burner 70 includes conventional igniter and flame sensor controls. Electric heating elements 36, 38 are disposed in the tank 20, as described in the first embodiment. Burning gases G flow through duct 72 to provide heat to the water surrounding the duct 72, thereby changing the water to steam. An inducer 74 is provided in duct 72 to

enhance the flow of burning gases G through the duct 72. Steam generated in tank 20 exits via lines 76 and 78 to flow to heating core 42. Condensed steam is returned to boiler 20 via a return line. The embodiment of Figs. 4 and 5 incorporates all appropriate control elements described above in the first embodiment.

It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims.