Heat Reclaimer for Stoves

Abstract

A heat reclaimer mounted on an exhaust-conveying flue, the flue having a flue inside surface in contact with the exhaust, the heat reclaimer including a heat-exchange assembly adjacent to and in contact with the flue. The heat-exchange assembly includes: (a) a fan for moving ambient air; (b) a chamber through which the fan drives the ambient air, the chamber defining a primary airflow direction; and (c) a plurality of heat transfer plates inside the chamber and transverse to the primary airflow direction, the plates defining airflow openings therethrough and having at least an edge in solid-to-solid thermal contact with a flue inside surface portion inside the chamber, thereby heating the ambient air with heat from the exhaust.

Claims

1. A heat reclaimer mounted on an exhaust-conveying flue, the flue having a flue inside surface in contact with the exhaust, the heat reclaimer including a heat-exchange assembly adjacent to and in contact with the flue, the heat-exchange assembly including: a fan for moving ambient air; a chamber through which the fan drives the ambient air, the chamber defining a primary airflow direction; and a plurality of heat transfer plates inside the chamber and transverse to the primary airflow direction, the plates defining airflow openings therethrough and having at least an edge in solid-to-solid thermal contact with a flue inside surface portion inside the chamber, thereby heating the ambient air with heat from the exhaust.

2. The heat reclaimer of claim 1 wherein the plates are configured as pairs of plates in U-shaped form having a base in thermal contact with the flue inside surface portion and the pair of plates extending from the base.

3. The heat reclaimer of claim 2 wherein the pairs of plates are parallel to one another.

4. The heat reclaimer of claim 3 wherein the airflow openings in one plate of each pair are aligned with the corresponding openings in the other plate of the pair.

5. The heat reclaimer of claim 1 wherein the plates are parallel to one another.

6. The heat reclaimer of claim 1 wherein the airflow openings on a plate define a pattern thereon and each plate has the same pattern of openings.

7. The heat reclaimer of claim 1 wherein the airflow openings in a plate are aligned with the corresponding openings in one of its immediately-adjacent plate.

8. The heat reclaimer of claim 1 wherein the plates are substantially perpendicular to the primary airflow direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a perspective-view drawing of the heat reclaimer of this invention, shown mounted in a section of a flue of a free-standing stove.

[0018] FIG. 2A is an exploded-view perspective drawing of the heat reclaimer of FIG. 1.

[0019] FIG. 2B is a second exploded-view perspective drawing of the heat reclaimer of FIG. 1 as viewed from a different angle from that of FIG. 2A.

[0020] FIG. 3 is a perspective-view drawing of the heat-exchange assembly of the heat reclaimer of FIG. 1 but shown without the fan.

[0021] FIG. 4A is a perspective-view drawing of a one embodiment of the internal components of the inventive heat reclaimer.

[0022] FIGS. 4B-4D are together a three-view set of top, front and side views of the embodiment of FIG. 4A.

[0023] FIG. 5A is a perspective-view drawing of a second embodiment of the internal components of the inventive heat reclaimer.

[0024] FIGS. 5B-5D are together a three-view set of top, front and side views of the embodiment of FIG. 5A.

[0025] FIG. 6A is a perspective-view drawing of a third embodiment of the internal components of the inventive heat reclaimer.

[0026] FIGS. 6B-6D are together a three-view set of top, front and side views of the embodiment of FIG. 6A.

[0027] FIG. 7A is a perspective view of one embodiment of a folded pair of heat transfer plates. FIG. 7B is a drawing of the unfolded pair of heat transfer plates of FIG. 7A.

[0028] FIG. 8A is a perspective view of a second embodiment of a folded pair of heat transfer plates. FIG. 8B is a drawing of the unfolded pair of heat transfer plates of FIG. 8A.

[0029] FIG. 9A is a perspective view of a third embodiment of a folded pair of heat transfer plates. FIG. 9B is a drawing of the unfolded pair of heat transfer plates of FIG. 9A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0030] Several embodiments or configurations of various components of the inventive heat reclaimer disclosed herein are shown, but like reference numbers are used for such different configurations without ambiguity. Note that not all components are numbered in each drawing. A table of reference numbers is included below for convenience.

TABLE-US-00001 COMPONENT REF # heat reclaimer 10 flue 12 flue cover section of heat reclaimer .sup. 12′ flue inside surface 14 flue inside surface portion  14p heat-exchange assembly 16 fan 18 chamber 20 primary airflow direction 22 heat transfer plate 24 airflow opening 26 plate edge 28 heat transfer plate pair 30 plate pair base  30b plate pair unfolded  30u plate opening pattern 32 ambient air outlet 34 heat outlet assembly  34a heat outlet opening  34o ambient air inlet 36 assembly internals (first embodiment) 40-1 assembly internals (second embodiment) 40-2 assembly internals (third embodiment) 40-3 stove 42 fan cover 44 chamber cover 46

[0031] FIG. 1 is a perspective-view drawing of one embodiment 10 of the inventive heat reclaimer (also 10) of this invention, shown mounted in a section of a flue 12 of a free-standing stove 42. FIGS. 2A and 2B are two exploded-view perspective drawings of heat reclaimer 10 which illustrate the various components of heat reclaimer 10. Heat reclaimer 10 is installed integrally with flue 12 such that portions of flue 12 may be considered to be both part of flue 12 and well as part of heat reclaimer 10. A flue cover section 12′ is such a component. Heat reclaimer 10 includes a flue inside surface 14 which receives heat transferred from exhaust from stove 42. On the opposite side of flue inside surface 14 is a flue inside surface portion 14p (see also FIGS. 4A, 4B, 5A, 5B, 6A and 6B) inside of a chamber 20. Heat is transferred to the inside components of chamber 20 and into the airflow flowing therethrough via flue inside surface portion 14p.

[0032] FIGS. 2A and 2B are two exploded-view perspective drawings of heat reclaimer 10 which illustrate the various components of heat reclaimer 10. Referring primarily to FIGS. 2A and 2B, heat reclaimer 10 includes a heat-exchange assembly 16 and a fan 18 for moving ambient air (e.g., room air) (i) through an ambient air inlet 36, (ii) through a chamber 20, and (iii) back into the room through an ambient air outlet 34. Heat-exchange assembly 16 also includes a plurality of heat transfer plates 24, each including at least one airflow opening 26.

[0033] FIG. 3 is a perspective-view drawing of heat-exchange assembly 16 of FIG. 1 without fan 18, illustrating the relative configuration of many of the components and features of heat reclaimer 10.′

[0034] The heat transfer plates of embodiment 10 are configured as pairs 30 of plates 24 in U-shaped form having a plate pair base 30b between plates 24 of pair 30. These details are more easily seen in FIGS. 7A through 9B. These figures include three pairs of drawings which illustrate three embodiments of heat transfer plate pairs 30. Each of the three embodiments is illustrated with a perspective drawing of pair 30 of plates 24 and a corresponding drawing of an unfolded pair 30u. Each of the three embodiments has a different plate opening pattern 32. The three embodiments of FIGS. 7A through 9B are not intended to be limiting. Note that each plate 24 of the embodiment of FIGS. 9A and 9B includes a single airflow opening 26 with a complex shape.

[0035] Note also that airflow openings 26 of plates 24 of each pair 30 are aligned with the corresponding openings 26 of the other plate 24 in pair 30. Such a configurational feature is not intended to be limiting.

[0036] Three sets of four figures, FIGS. 4A-4D, FIGS. 5A-5D and FIGS. 6A-6D, illustrate three different embodiments 40-1, 40-2 and 40-3, respectively, of internal assembly components of heat reclaimer 10. The three sets of figures include similar views with one exception—embodiment 40-1 of FIGS. 4A-4D include a flue cover section 12′ of heat-exchange assembly 16 while the other two sets of figures do not include such component.

[0037] Referring particularly now to the three embodiments 40-1, 40-2 and 40-3 of FIGS. 4A-4D, FIGS. 5A-5D and FIGS. 6A-6D, each heat transfer plate 24 has a plate edge 28 which is in solid-to-solid thermal contact with flue inside surface portion 14p, plate edges 28 each being part of a pair base 30b. The three different embodiments 40-1, 40-2 and 40-3 all include a plurality of plate pairs 30 but which are aligned differently. In embodiment 40-1, all of plates 24 are parallel to each other and perpendicular of the primary airflow direction 22 (see FIG. 2B) as defined above. As such, plates 24 are all transverse to primary airflow direction 22. In embodiment 40-2, some plate pairs 30 are oriented at an angle with respect to other pairs 30 which are perpendicular to primary airflow direction 22. As in embodiment 40-1, plates 24 are all transverse to primary airflow direction 22 in embodiment 40-2. In embodiment 40-3, some of the plate pairs 30 are oriented parallel to primary airflow direction 22 and are therefore not transverse to primary airflow direction 22. Since primary airflow direction 22 is defined above as a general direction and since local airflow turbulence may result in varying flow directions, such plate 24 orientation may still be beneficial for heat transfer.

[0038] Referring again to FIGS. 2A and 2B, heat reclaimer 10 includes a fan cover 44 and a chamber cover 46. Chamber cover 46 encloses chamber 20 along with flue inside surface portion 14p. In addition, heat reclaimer 10 includes a heat outlet assembly 34a which has a plurality of heat outlet openings 34o.

[0039] The overall concept of this invention is to transfer heat from the exhaust of a combustion source such as a wood-burning stove while maintaining relatively unobstructed flow within the flue such that periodic cleaning of the flue is relatively simple. To accomplish this, ambient airflow is provided through a chamber which contains a significant amount of heat transfer area in the configuration of the components within the chamber through which “clean” ambient air flows.

[0040] While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.