Gravity-style furnace subunit inside a gas-induced draft furnace

Patent metadata

Field	Value
Publication number	US-10584897-B2
Application number	US-201715492873-A
Country	US
Kind code	B2
Filing date	Apr 20, 2017
Priority date	Dec 5, 2011
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A gravity-style furnace subunit for a gas-induced draft furnace. A heat conduction tube configured to be located inside of a gas-induced draft furnace cabinet, the heat conduction tube being separated from a row of draft-induced heat conduction tubes inside the cabinet. A burner assembly having a burner tube located within the heat conduction tube through an inlet opening of the heat conduction tube. The burner assembly permits air flow through the inlet opening into the heat conduction tube. A pilot assembly located within the heat conduction tube and adjacent to the burner tube. A thermopile module having located adjacent to a flame outlet of the pilot assembly within the heat conduction tube. A gas valve configured to control gas flow to the burner assembly, the gas valve electrically coupled to the thermopile module and to actuate gas flow there-through when the thermopile module generates a predefined voltage difference.

First claim

What is claimed is:

1. A gravity-style furnace subunit, comprising:
a heat conduction tube configured to be located inside a cabinet of a gas-induced draft furnace, the heat conduction tube being separated from:
a row of draft-induced heat conduction tubes coupled to a first burner assembly, and
an electrically-powered air blower located adjacent to the row of draft-induced heat conduction tubes, wherein the row of draft-induced heat conduction tubes and the electrically powered air blower are located inside the cabinet; wherein the gravity-style furnace subunit further comprises:

a second different burner assembly having a burner tube located within the heat conduction tube through an inlet opening of the heat conduction tube, wherein the second burner assembly permits air flow through the inlet opening into the heat conduction tube;
a pilot assembly located within the heat conduction tube and adjacent to the burner tube;
a thermopile module located adjacent to a flame outlet of the pilot assembly within the heat conduction tube; and
a gas valve configured to control gas flow to the second burner assembly, wherein:
the pilot assembly is configured to be automatically activated by a control module of the subunit that comprises a relay switch,
the control module is configured to activate the pilot assembly to produce a pilot flame when a temperature of a conditioned space is below a predetermined value, and
the gas valve is electrically coupled to the thermopile module and is configured to allow gas flow there-through when the thermopile module, upon exposure to the pilot flame, generates a predefined voltage difference that causes the gas valve to actuate to an open position;

wherein the gravity-style subunit and the draft-induced heat conduction tubes comprise separate air inlets and separate combustion outlets and wherein the heat conduction tube is operable to use gravity to facilitate the circulation of air heated by the gravity-style subunit when external electrical power is unavailable.

2. The subunit of claim 1 , wherein the gravity-style furnace subunit is operable to function independently of the gas-induced draft furnace.

3. The subunit of claim 1 , wherein the control module is configured to deactivate the pilot assembly to turn off the pilot flame, whereby the predefined voltage difference is no longer generated and the gas valve actuates to a closed position, when electrical power from the power grid to the electrically-powered air blower is resumed for a predefined period.

4. The subunit of claim 1 , further including a combustion inducer coupled to a combustion outlet connected to the heat conduction tube.

5. The subunit of claim 4 , wherein the combustion inducer is powered by the thermopile module.

6. The subunit of claim 1 , further including an air blower located below the heat conduction tube and configured to blow return air across an outer surface of the heat conduction tube.

7. The subunit of claim 6 , wherein the air blower is powered by the thermopile module.

8. The subunit of claim 6 , wherein the air blower is powered by a non-grid tied electrical power source of a building heated by the gas-induced draft furnace.

9. A furnace system, comprising
a gas-induced draft furnace housed inside of a cabinet; and
a gravity-style furnace subunit housed inside of the cabinet, the subunit including:
a heat conduction tube configured to be located inside of the cabinet, the heat conduction tube being separated from:
a row of draft-induced heat conduction tubes coupled to a first burner assembly, and
an electrically-powered air blower located adjacent to the row of draft-induced heat conduction tubes, wherein the row of draft-induced heat conduction tubes and the electrically powered air blower are located inside the cabinet; wherein the gravity-style furnace subunit further comprises:

a second different burner assembly having a burner tube located within the heat conduction tube of the gravity-style furnace subunit through an inlet opening of the heat conduction tube, wherein the second burner assembly permits air flow through the inlet opening into the heat conduction tube;
a pilot assembly located within the heat conduction tube and adjacent to the burner tube;
a thermopile module located adjacent to a flame outlet of the pilot assembly within the heat conduction tube; and
a gas valve configured to control gas flow to the second burner assembly, wherein:
the pilot assembly is configured to be automatically activated by a control module of the subunit that comprises a relay switch,
the control module is configured to activate the pilot assembly to produce a pilot flame when a temperature of a conditioned space is below a predetermined value, and
the gas valve is electrically coupled to the thermopile module and is configured to allow gas flow there-through when the thermopile module, upon exposure to the pilot flame, generates a predefined voltage difference that causes the gas valve to actuate to an open position;

wherein the gravity-style subunit and the draft-induced heat conduction tubes comprise separate air inlets and separate combustion outlets, and wherein the heat conduction tube is operable to use gravity to facilitate the circulation of air heated by the subunit when external electrical power is unavailable.

10. The system of claim 9 , wherein the gravity-style furnace subunit further includes:
a combustion inducer coupled to a combustion outlet connected to the heat conduction tube; and
an air blower located below the gravity-style heat conduction tube and configured to blow air across an outer surface of the heat conduction tube, wherein the combustion inducer, the combustion outlet and the air blower are separate from the gas-induced draft furnace.

11. The system of claim 10 , where one or both of the combustion inducer and the air blower are powered by the thermopile module.

12. The system of claim 9 , wherein the cabinet is located in a lowest level of a building that the gravity-style furnace subunit and the gas-induced draft furnace are configured to heat.

13. The system of claim 9 , wherein the control module is configured to deactivate the pilot assembly to turn off the pilot flame, whereby the predefined voltage difference is no longer generated and the gas valve actuates to a closed position, when electrical power from the power grid to the electrically-powered air blower is resumed for a predefined period.

14. A gravity-style furnace subunit, comprising:
a heat conduction tube configured to be located inside of a gas-induced draft furnace cabinet, the heat conduction tube being separated from:
a row of draft-induced heat conduction tubes coupled to a first burner assembly,
an electrically-powered air blower located adjacent to the row of draft-induced heat conduction tubes, and
an electrically-powered draft inducer coupled to the row of draft-induced heat conduction tubes, wherein the row of draft-induced heat conduction tubes and the electrically powered air blower are located inside the cabinet; wherein the gravity-style furnace subunit further comprises:

a second different burner assembly having a burner tube located within the heat conduction tube through an inlet opening of the heat conduction tube, wherein the second burner assembly permits air flow through the inlet opening into the heat conduction tube;
a pilot assembly located within the heat conduction tube and adjacent to the burner tube; a thermopile module located adjacent to a flame outlet of the pilot assembly within the heat conduction tube; and a gas valve configured to control gas flow to the

Assignees

• Lennox Ind Inc

Inventors

• Noman Shiblee S M
• Sanchez Jesse

Classifications

• F23D2900/00015

  Pilot burners specially adapted for low load or transient conditions, e.g. for increasing stability · CPC title

• F23N2231/04

  for electrical power failures · CPC title

• F23N5/242

  using electronic means · CPC title

• F23N2227/24

  the pilot burner not burning continuously · CPC title

• F24H3/105

  using fluid fuel · CPC title