Description of the Invention
This invention relates generally to heat devices, and is concerned in particular with a heat reclaimer adapted for installation in the flue connecting a heater, such as for example a gas or oil fired home heating unit, to an exhaust stack or chimney.
A general object of the present invention is to provide a heat reclaimer which is combined in a single integral unit with a motorized damper to thereby provide a compact economical unit which can be located conveniently between a heater and an exhaust stack.
Another object of the present invention is the provision of a heat reclaimer contained in an inner housing surrounded by an outer housing, the two housings being spaced to provide an intermediate chamber functioning as a draft diverter.
A further object of the present invention is to provide a heat reclaimer combined with a draft diverter and a motorized valve, the valve serving to significantly retard gas flow through both the heat reclaimer and gas diverter when the heater is inoperative.
These and other objects and advantages of the present invention will become more apparent as the description proceeds with the aid of the accompanying drawings wherein:
FIG. 1 is a schematic view of a heat reclaimer embodying the concepts of the present invention shown installed in a flue between a gas heater and an exhaust stack;
FIG. 2 is a perspective view with portions broken away of a heat reclaimer in accordance with the present invention;
FIG. 3 is a longitudinal sectional view on a reduced scale taken through the heat reclaimer shown in FIG. 2; and,
FIG. 4 is a sectional view taken along lines 4--4 of FIG. 3.
Referring initially to FIG. 1, a heat reclaiming apparatus in accordance with the present invention is generally indicated at 10 in an installed position between a heater 12 and an exhaust stack or chimney 14.
The heater 12 is illustrated as comprising a gas fired boiler or furnace of the type employed to heat a small building or dwelling. It will hereinafter be explained, however, that the invention is also applicable to or useful in conjunction with other types of heaters including those fired by oil.
Referring additionally to the other drawings, it will be seen that the apparatus 10 includes an inner housing 16 having first inlet and outlet openings 18 and 20. The first inlet opening 18 is adapted for connection to one section 22 of a flue leading from the heater 12. An outer housing 24 at least partially surrounds the inner housing 16. The inner and outer housings are spaced one from the other to define an intermediate chamber 26 therebetween. The first outlet opening 20 of the inner housing 16 is in communication with the intermediate chamber 26. The outer housing 24 is provided with second inlet and outlet openings 28, 30. The second inlet opening 28 is open to the ambient air and the second outlet opening 30 is located oppositely to the first outlet opening 20. The second outlet opening 30 leads to a damper housing 32 which preferably is fabricated as an integral unit with the outer housing 24. The damper housing 32 is in turn adapted for connection to another flue section 34 leading to the stack or chimney 14. The damper housing 32 contains a damper 36 which is adjustable rotatably between open and closed positions by means of a drive motor (not shown) contained in an associated motor and control box 38.
A plurality of heat transfer conduits indicated typically at 40 extend transversely across and are spaced one from the other within the inner housing 16. The conduits 40 are in communication at one end with an inlet plenum chamber 42 and at the opposite end with an outlet plenum chamber 43 adapted for connection to a conduit 44. A fan 46 is mounted in the inlet plenum chamber 42 for the purpose of drawing ambient air into and through the heat transfer conduits 40 in a direction transverse to the flow of combustion gases flowing through the inner housing 16 from the heater 12. It will thus be seen that the exterior surfaces of the heat transfer conduits 40 are heated by the combustion gases, and this heat is reclaimed by the ambient air flowing through the heat transfer conduits 40. The heated ambient air is then directed by conduit 44 to any suitable location. The damper 36 is adjustable between an open position allowing a mixture of combustion gases and entrained ambient air flowing respectively from the inner housing 16 and the intermediate chamber 26 to pass freely through the flue section 34 to the exhaust stack 14, and a closed position significantly retarding the flow of gases through both the inner housing and the intermediate chamber.
It will thus be seen that when the heater 12 is inoperative and the damper 36 is closed, heat will be retained in the heater 12 by virtue of the fact that gas flow therefrom is being significantly retarded. By the same token, little if any ambient air will be entrained into the intermediate chamber 26 and this will further conserve heat. Prior to allowing ignition to take place in the heater 12, the damper 36 is opened. Thereafter, as combustion takes place in the heater 12, the combustion gases will flow through the inner housing 16 where heat recovery will take place in the manner previously described. The exteriorily spaced outer housing 24 will provide a low temperature shield around the inner housing. The effects of any backdraft from the stack 14 experienced during operation of the heater 12 will be dissipated by the intermediate chamber 26 which acts as a draft diverter in addition to serving as a protective shield for the inner housing. The entire apparatus 10 provides a compact integral unit which can be installed conveniently between a heater 12 and a stack 14, even in relatively confined circumstances.
Where the draft diverter feature of the unit is not required, as is typically the case with oil fired heaters, then the second inlet opening 28 can be closed off. In this case, a conventional barometric damper would be installed at some point between the damper 36 and the heater, preferably in one side of the outer housing 24.
It is my intention to cover all changes and modifications of the embodiment herein chosen for purposes of disclosure which do not depart from the spirit and scope of the invention.