Dual Fuel Vent Free Gas Heater
A dual fuel vent free gas heater having at least one gas burner with a plurality of gas outlet ports in an upper surface thereof. The gas outlet ports are in flow communication with at least one pilot flame burner. An adjustable fuel injector or at least two fuel injectors feed fuel to the burner providing for introduction of more than one fuel to the burner. Optionally, an oxygen detection system, manual fuel selection control valve, and/or temperature shut off control system may be incorporated into the dual fuel vent free heater.
Not applicable
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates generally to gas heaters and, more particularly, to unvented gas heaters.
2. Description of the Related Art
Unvented gas heaters are designed to be used indoors without pipes, ducts, or other conduit to vent the heater's exhaust to the exterior atmosphere. Vent free gas heaters typically include one or more gas burners and optionally one or more ceramic containing heating elements in a housing. The gas and air mix in the heater where combustion takes place. These heaters may have a blower to force air flow through the heater providing the release of heated gases or convective heat.
Unvented gas heaters have been designed to be free standing, mounted on a wall, or in a decorative housing such as a vent free fireplace. The housing providing a vent free fireplace is typically substantially the size of a fireplace and has artificial logs above the burners. Some have even been designed with a glass front to provide the appearance of an enclosed fireplace.
The unvented heaters of the prior art are typically designed to use either natural gas or liquid propane gas as a fuel source. It is not permitted for a manufacturer to supply a conversion kit for an unvented gas heater to convert from one fuel source to another. Even if such a conversion kit were permitted, as is the case with vented gas heaters, to change fuel source gas type on a heater in the field, requires the installer to change the regulator, pilot orifice and burner orifice for the alternate gas type.
SUMMARY OF THE INVENTIONA dual fuel gas burner is provided for use in a vent free heater. Embodiments of the dual fuel vent free gas burner can be used in free standing heaters, wall mount heaters, gas fireplaces, or other vent free heaters as is known in the art. A dual fuel vent free gas heater provides convective and/or radiant heat preferably to an indoor environment. The heater may be designed to use natural convective air currents and may optionally have a fan enhancing the natural convective currents within the heater. Alternatively, a fan may be used to force the gases and/or air within the heater at desired flow patterns which may be counter to natural convective forces.
This gas heater can be operated with multiple fuels such as liquid propane or natural gas. In some embodiments, an installer turns a selector valve plumbed in the product gas train. This selection sends the correct gas type to the correct fuel injector and pilot burner. Preferably, all plumbing connections are performed at the factory rather than onsite by the user or installer.
Embodiments of the gas heater can be operated on liquid propane or natural gas by connecting the fuel supply to the correct regulator on the heater. The installer or user then turns a selector valve, in selected embodiments, plumbed in the product gas train. This selection sends the correct gas type to the correct injector and pilot burner for the supply gas. Optionally, an oxygen detection system is incorporated within the heater. Advantageously, the heater is thermostatically controlled.
The following description describes embodiments of a dual fuel vent free heater. In the following description, numerous specific details and options are set forth in order to provide a more thorough understanding of the present invention. It will be appreciated, however, by one skilled in the art that the invention may be practiced without such specific details or optional components and that such descriptions are merely for convenience and that such are selected solely for the purpose of illustrating the invention. As such, reference to the figures showing embodiments of the present invention is made to describe the invention and not to limit the scope of the disclosure and claims herein.
Dual fuel vent free gas heater 100 comprises two regulators 112 and 114 in flow communication with “T” connector 110 via fuel lines 148 and 150 respectively. Fuel line 146 extends from “T” connector 110 to thermostatic control valve 130. Pilot line 144 leads from thermostatic control valve 130 to pilot control valve 118. Injector line 142 leads from thermostatic control valve 130 to injector control valve 116. Fuel lines 138 and 140 lead from pilot control valve 118 to pilot flame burners 122 and 120 respectively. Fuel lines 136 and 134 lead from injector control valve 116 to injectors 126 and 128 respectively. Control valves 118 and 116 are manually adjusted for the fuel type being connected to regulator 112 or 114. Typically control valves 118 and 116 each have a setting for natural gas and a setting for liquid propane gas and are adjusted according to the fuel connected to regulator 112 or 114.
Claims
1-30. (canceled)
31. A dual fuel vent free gas heater comprising:
- A main gas burner adapted to receive one of a first type of fuel or a second type of fuel,
- a thermal switch in close proximity to the main gas burner; and
- a control valve positioned in the fuel flow path proximal to the main gas burner and electrically coupled to the thermal switch, the thermal switch adapted to reoccurringly cause the control valve to shut off the flow of fuel to the main gas burner when the thermal switch detects a temperature indicative that an inappropriate fuel type is being fed to the main gas burner.
32. A dual fuel vent free gas heater according to claim 31, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner when the first type of fuel is delivered to the second nozzle.
33. A dual fuel vent free gas heater according to claim 31, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner when the first type of fuel is delivered to the second nozzle or the second type of fuel is delivered to the first nozzle.
34. A dual fuel vent free gas heater according to claim 32, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
35. A dual fuel vent free gas heater according to claim 33, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
36. A dual fuel vent free gas heater according to claim 31, further comprising a pilot burner adjacent the main gas burner, the control valve positioned in the fuel flow path proximal to the pilot burner, the control valve electrically coupled to the thermal switch, the thermal switch causing the control valve to shut off the flow of fuel to the main gas burner and pilot burner when the thermal switch detects a temperature indicative that an inappropriate fuel type is being fed to the main gas burner.
37. A dual fuel vent free gas heater according to claim 36, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner and pilot burner when the first type of fuel is delivered to the second nozzle.
38. A dual fuel vent free gas heater according to claim 36, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner and pilot burner when the first type of fuel is delivered to the second nozzle or the second type of fuel is delivered to the first nozzle.
39. A dual fuel vent free gas heater according to claim 37, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
40. A dual fuel vent free gas heater according to claim 38, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
41. A dual fuel vent free gas heater comprising:
- a main gas burner adapted to receive one of a first type of fuel or a second type of fuel,
- a thermal switch having a temperature sensor in proximity to the main gas burner; and
- a control valve positioned in the fuel flow path proximal to the main gas burner and electrically coupled to the thermal switch, the thermal switch adapted to reocurringly cause the control valve to shut off the flow of fuel to the main gas burner when the temperature sensor of the thermal switch detects a temperature indicative that an inappropriate fuel type is being fed to the main gas burner.
42. A dual fuel vent free gas heater according to claim 41, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner when the first type of fuel is delivered to the second nozzle.
43. A dual fuel vent free gas heater according to claim 41, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner when the first type of fuel is delivered to the second nozzle or the second type of fuel is delivered to the first nozzle.
44. A dual fuel vent free gas heater according to claim 42, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
45. A dual fuel vent free gas heater according to claim 43, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
46. A dual fuel vent free gas heater according to claim 41, further comprising a pilot burner adjacent the main gas burner, the control valve positioned in the fuel flow path proximal to the pilot burner, the control valve electrically coupled to the thermal switch, the thermal switch causing the control valve to shut off the flow of fuel to the main gas burner and pilot burner when the temperature sensor detects a temperature indicative that an inappropriate fuel type is being fed to the main gas burner.
47. A dual fuel vent free gas heater according to claim 46, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner and pilot burner when the first type of fuel is delivered to the second nozzle.
48. A dual fuel vent free gas heater according to claim 46, comprising a first nozzle positioned at an inlet of the main gas burner to deliver the first type of fuel to the main gas burner and a second nozzle positioned at the inlet of the main gas burner to deliver the second type of fuel to the main gas burner, the thermal switch adapted to cause the control valve to shut off the flow of fuel to the main gas burner and pilot burner when the first type of fuel is delivered to the second nozzle or the second type of fuel is delivered to the first nozzle.
49. A dual fuel vent free gas heater according to claim 47, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
50. A dual fuel vent free gas heater according to claim 48, wherein the first type of gas is liquid propane gas and the second type of fuel is natural gas.
Type: Application
Filed: Aug 8, 2011
Publication Date: Dec 1, 2011
Inventor: Steve Manning (Bowling Green, KY)
Application Number: 13/205,279
International Classification: F24H 9/20 (20060101); F24H 3/00 (20060101); F23Q 9/08 (20060101);