HEAT RECOVERY DEVICE FOR Fume Hoods on Wood Stoves

Abstract

Flue Gas Heat Recovery Device for a Wood Stove. The invention comprises a device for recovering some of the heat from the combustion gases that are expelled through the flue and chimney. It consists of a sealed assembly (1) called the flue gas circuit. The smoke is drawn in through three rectangular tubes (8), then through a flue gas receiving compartment (3), and then ejected by a flue gas extractor fan (5) to a flue gas discharge compartment (6) and finally to the chimney. It also consists of another assembly called the heat exchanger circuit (2). Air is drawn in from the top of the stove (11), recovers heat from the tubes (8), then from the heat sink (9) and the rear of the stove, and is then ejected from under the stove by the heat extractor fan (7).The smoke extractor fan (5) regulates the draft and therefore the heat of the stove; the heat extractor fan (7) regulates the heat distribution and therefore the temperature of the dwelling. Add [fig.1].

Description

Title of the invention: RECOVERY DEVICE THE HEAT FROM THE SMOKE ON A WOOD STOVE Scope of the invention.

[0001] The present invention relates to a device which makes it possible to recover from a wood stove some of the calories contained in the combustion gases which escape into the smoke evacuation ducts and thus to improve the efficiency of the stove.

[0002] This heat is returned under the stove or directed into ducts which distribute the heat.

[0003] It allows the stove's draft to be regulated by modifying the speed of a smoke-drafting fan, thus modulating the temperature of the dwelling. When the stove door is opened for loading, it allows the smoke to be eliminated and accelerates the start of combustion of the newly loaded log.

[0004] It facilitates the ignition of the stove by modulating the draft using the smoke extraction fan. Previous technique

[0005] Pellet stoves which operate by the combustion of wood pellets supplied by an automatic loader regulated by a draft whose power will depend on the temperature required.

[0006] Advantage: it has automatic loading and automatic draft regulation according to heating demand

[0007] Disadvantage compared to a wood-burning stove: it has a lower calorific value and does not work in the event of a power outage.

[0008] Wood-burning stoves that operate by burning manually loaded wood logs and regulated by a manually adjustable draft located at the ash pan.

[0009] Advantage, it uses cheap fuel, it works even in case of power outages, it has good calorific value.

[0010] Disadvantages, it does not have automatic drawing regulation and automatic loading. Description of the invention

[0011] The device according to the invention allows, by modifying a wood stove [Fig. 1], to recover and manage the heat from the fumes evacuated from the stove by adding an air-to-air exchanger (subject of the invention) positioned between the fume receiver and the rear of the stove.

[0012] The device according to the invention consists (see [Fig.1], [Fig.2], [Fig.3]) of a smoke outlet made up of three rectangular tubes (8)

[0013] From a sealed compartment (1) called the flue circuit partitioned into two parts, one part called the flue receiver (3) with an extractor fan (5) which sucks up the smoke and expels it towards the second part called the flue evacuation (6) which opens onto the outlet connected to the piping and the chimney.

[0014] Of a heat sink (9) attached to the first part

[0015] Of a box (2) which covers the face of the first part and which guides the air which is at contact of the top of the stove (11), the flue outlet tubes (8), the back of the stove, the heat sink (9) and which is drawn in by the hot air fan (7) and returned under the stove [Fig.3], or in the other direction to a hot air distribution circuit [Fig.3],

[0016] A control panel (4) located on the top of the stove towards the air inlet equipped with a power switch, an on button, a potentiometer for adjusting the speed of the smoke extraction fan (5), a three-position switch (pv-0-gv) adjusting the speed of the hot air fan, and a display indicating the temperature of the stove.

[0017] Of a temperature probe (12) located on the back of the stove.

[0018] Of a manual pull handle (13). Description of the process

[0019] The control panel is switched on and kindling is started. The manual damper (13) is opened and the speed of the smoke extractor fan is adjusted with the potentiometer as needed. The combustion gases are collected at the top of the stove, pass through the rectangular tubes (8), are drawn in by the smoke extractor fan (5) into the smoke receiving compartment (3) and are expelled into the smoke exhaust duct (6). Once combustion has started, the manual damper (11) and the speed of the extractor fan (5) are adjusted according to the heat requirement, and the hot air fan (7) is activated. The hot air is collected on top of the stove under the control panel (4), enters the heat exchanger (2), passes between the smoke exhaust tubes (8), recovers heat at the back of the stove and heat in the heat sink (9) and is directed under the stove [Fig.3] or behind the stove to supply a heating circuit [Fig.3] The temperature of the stove is measured by the probe (12) and indicated on the control panel by a display.

[0020] When reloading the stove with logs, the manual draft control is opened and the smoke extractor fan is set to full power, thus opening the stove door while preventing the dispersion of smoke into the room.

[0021] Similarly, if the fuel burns poorly and begins to go out, the

[0022] smoke extractor fan to reactivate combustion.

Claims

Demands

1. A flue gas heat recovery device for a wood-burning stove, characterized in that it comprises three rectangular tubes (8) through which the flue gases from the wood-burning stove (11) pass to a sealed compartment (1) partitioned into two parts: a first part (3) called the flue gas receiver, equipped with a flue gas extractor fan (5), and a second part (6) called the flue gas outlet. An air-to-air heat exchanger located between the rear of the stove and the compartment (1) guides the hot air through a heat sink (9) to a hot air fan (7) and below the stove. The air drawn in from the top of the stove (11) recovers heat from the walls of the tubes (8), then from the heat sink (9) attached to the flue gas receiver compartment (3), then from the rear of the wood-burning stove, drawn in by the hot air fan (7), and expelled below the stove, thus distributing the captured heat over the various elements of the exchanger,The speed of the hot air extractor fan (7) is changed by a 3-position switch (pv-O-gv).

2. The device according to claim 1, characterized in that the fumes are drawn through the tubes (8) and then through the fume collection compartment (3) by the fume extraction fan (5) and expelled through the fume discharge compartment (6) towards the stove chimney. The heat sink (9) exchanges the heat contained in the combustion gases. Modulating the speed of the fume extraction fan allows the stove draft to be adjusted.

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