CA1170134A - Electric/secondary fuel furnace - Google Patents
Electric/secondary fuel furnaceInfo
- Publication number
- CA1170134A CA1170134A CA000419264A CA419264A CA1170134A CA 1170134 A CA1170134 A CA 1170134A CA 000419264 A CA000419264 A CA 000419264A CA 419264 A CA419264 A CA 419264A CA 1170134 A CA1170134 A CA 1170134A
- Authority
- CA
- Canada
- Prior art keywords
- combustion chamber
- air
- furnace
- fan
- enclosure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
Abstract of the Disclosure The invention relates to an electric/secondary fuel furnace which includes a combustion chamber. The combustion chamber is tubular in shape and has an oval shaped cross-section and receives and burns wood fuel in one embodiment and gas or oil in the embodiment shown in the Supplementary Disclosure hereto. The combustion chamber is made of a heat exchange material. Heating elements are disposed externally of the combustion chamber on either side thereof. The combustion chamber is enclosed in a combustion chamber enclosure means which houses both the combustion chamber and the electrical elements and which also defines airflow paths on either side of the combustion chamber between the combustion chamber side walls and res-pective ones of the enclosure side walls. The combustion chamber enclosure includes a warmed air escape opening disposed over the combustion chamber. A fan enclosure means, which houses a fan, is disposed beneath the combus-tion chamber enclosure means, and there are provided means for providing air communications between the fan enclosure means and the combustion chamber enclosure means. Thus, air is forced from the fan enclosure along the air paths and out the air escape opening, the air being heated during its travel along the air paths.
Description
The invention relates to a wood/electric furnace, More specifically, -the invention relates to such a furnace which includes a forced air system"
In these times o-f increasing cost and scarcity of fossel and electric fuels, and greater availability of wood fuel, wood furnaces are a desirable source of home heating, However, wood furnaces have the disadvantage of not being able to provide enought heat during severe winter weather, It is therefore desirable to provide a supplementary source of heat along with a wood furnace.
Such s~stems are taught in U, S, Patent 3l175,552, Sutton, March 30, 1965, U, S. Patent 4,076,011, Proulx, February 28, 1978, and U, S, Patent 4,253,444, Johnson, March 3, 1981, The Sutton patent teaches a fireplace and space heater arrangement, As seen in the drawings of ths patent, the space heater 3 is disposed above the fireplace and in-cludes a plurality of burner elements, There is no inte-gration between the woodburning fireplace and the space heater, The Proulx patent teaches a side-by-side wood-burning fireplace and electrical heating arrangement, The electrical elements are disposed behind the door 14 in Figure 1 of the patent. A thermostat 36 is connected to actuator 18 to turn down the electrical heaters when the heat of the fireplace exceeds a certain value, The JGhnson patent teaches a firebox 2 with a plurality of electrical elements 18 disposed on either side of the firebox. The elements are disposed in air plenums extending along the side of the firebox, and air is provided to the plenums from a rear plenum 15 best seen -1- ~
3~L
in Figure 2 of the patent. The air which is provided from the plenum 15 and then distributed to the plenums 3 on either side of the firebox is heated by the heat produced by the burning of wood, or other fuel, as well as the heat produced by the electrical elements 18, The Johnson patent teaches an integrated system, and the present invention constitutes an improvement of the system as taught in the Johnson patent.
In accordance with the invention there is provided an electric/secondary fuel furnace which includes a combus-tion chamber. The combustion chamber is tubular in shape and has an oval shaped cross-section and receives and burns a secondary fuel. The combustion chamber is made of a heat exchange material. Heating elements are disposed externally of the combustion chamber on either side thexeof.
The combustion chamber is enclosed in a combustion chamber enclosure means which houses both the combustion chamber and the electrical elements and which also defines airflow paths on either side of the combustion chamber between the com-bustion chamber side walls and respective ones of the enclo-sure side walls. me combustion chamber enclosure includes a warmed air escape opening disposed over the combustion chamber. A fan enclosure means, which houses a fan, is disposed beneath the combustion chamber enclosure means, and there are provided means for providing air communi-cations between the fan enclosuxe means and the combustion chamber enclosure means. Thus, air is forced fxom the fan enclosure along the air paths and out the air escape opening, the air being heated during its travel along the air paths.
The invention will be better understood by an examination of the following ~escription together with the accompanying drawings in which:
FIGURE 1 is a perspective view of the wood/
electric furnace, partially in section, in accordance with the invention, and FIGURE 2 is a perspective phantom view of the combustion chamber to illustrate the internal structure thereof.
ReEerring now to Figure 1, the furnace in accord-ance with the invention, illustrated generally at 1, in-cludes a cornbustion chamber enclosure means 3 and a fan enclosure means 5. As can be seen, the combustion chamber enclosure means is disposed directly above the fan enclosure means.
Disposed within the combustion chamber enclosure means, and completely enclosed thereby, is a cor~bustion char~ber 7 which is made of a heat exchange material such as a metallic material. As better seen in Figure 2, the cor~bustion char~er is tube-like in shape and has an oval cross-section, Returning now to Figure 1, a plurality of heating elements 9 are disposed ajdacent to the side walls in the Iower half of the cor~bustion chamber. Although only one set of elements :is shown in the drawings, it will be appreciated that a similar set of elements is included on the other side oE the combustion chamber.
The fan enclosure means 5 includes an inlet sur-face 11 which comprises a filter material to filter the incoming cold air. Disposed within the fan enclosure means, and completely enclosed thereby, is a variable speed fan 13.
As also seen, an airflow path is formed between side wall 15 of the enclosure 3 and side wall 17 of the com-bustion chamber. A similar airflow path is formed on the other si.de o-E the enclosure.
The combustion chamber a].so includes a variable opening combustion air inlet 19 and a fuel loading door ~1.
Thermostat 23 is located in a posllion to be influenced by the temperature of the air in the airflow path between the side wall of the enclosure 3 and the side wall of the combustion chamber, and the thermostat is operatively connected to a control means 25 which is, in turn, operatively connected to the inlet 19. The control means is adapted to vary the opening of the inlet 19 in accordance with temperature requirements, Thus, if the temperature of the air:flowing through is too low, the inlet will be opened wider. In the same way, if the air flowing through is too warm, the opening of the inlet 19 will be reduced, The thermo-stat and control comprise means well known for this purpose in the art and require no further description here, A fan control means 27 can be operated manually or automatically to adjust the feed of the variable speed fan 13, Means 29, such as, for example, duct means, provide air communication between the fan enclosure 5 and the com-bustion chamber enclosure 3. Disposed at the top of the combustion chamber enclosure means 3 is a warmed air escape opening 31.
A thermostat in the living area measures the temperature of the air therein, and controls the electricity input to the heating elements 9 (as well known), so that the operation of the elements can be made completely automatic.
Turning now to Figure 2, the combustion chamber includes a grate 32 for carrying the wood. A removable ash pan 33 is provided for removing ashes which ~all under the grate.
Also included is a baf-fle means 34 for directing flue gases out of the combustion chamber and into a flue removal system. The baffle means includes a horizontal plate 35 and vertical plates 37. Disposed at the rear of the combustion chamber is a flue gas exhaust opening, and the baffle means are arranged to direct flue gases out through the opening 39 to a flue gas disposal system.
It will of course be appreciated that the opening 31 could be exposed directly to the air, or it could be connected to a system of heating pipes as well ~nown in the art.
In operation, the furnace works as follows:
Incoming cold air, illustrated by arrow A in Figure 1, is drawn into the fan 13 through the filter means 11, and the fan then blows air up through the means 29 into the airflow paths between the side walls of the enclosure and the side walls of the combustion chamber as shown by the arrows s in Figure 1. Air travelling through the airflow paths is warmed up by the heat of the combustion chamber. If the tem-perature of the air flowing through the paths is not high enough, ! then the heat can be increased both by opening the combustion air inlet and/or increasing the speed of the variable speed fan, When the limits of the combustion chamber heating capacity ha~e been reached, and the air is still not warmed to a high enough temperature, electricity will be supplied to the heating elements 9 to further warm the air until a correct temperature is reachedO
The warmed air will escape through the opening 31 either directly into the surroundings to be heated, or it will be distributed through a piping system as is well known in the art, As can be seen, with the inventive wood/electric furnace in accordance with the invention, the use of forced air permits greater control so as to avoid using electric heating power unless absolutely necessary, In addition, the use of the side walls of the enclosure for the com-bustion chamber and the side wall of the combustion chamber to provide airflow paths ensures a maximum heat transfer to the air flowing through the air path without requiring extra structure accommodations, Because the air is filtered before being drawn in by the fan, the air of the surroundings will also be cleansed by the inventive furnace.
SUPPLEMENTARY DISCLOS~JRE
Applicant has also learned that the novel arrange-ment can be used with either gas or oil as a secondary fuel.
It is therefore a further object of the invention to provide an electric~gas or oil Eurnace, The further embodiment will be better understood by an examination of the following description together with the accompanying drawings in which:
FIGURE 3 is a perspective view of the electric/
gas or oil furnace partially in section, in accordance with the invention, and FIGURE 4 is a perspective phantom view of the combustion chamber to illustrate the internal structure thereof.
Referring now to Figure '3, as can be seen, the ~
structure of the electric/gas or oil furnace is substantially the same as the structure of the wood/electric furnace illustrated in Figures 1 and 2. However, the furnace in accordance with the Supplementary Disclosure includes an oil or gas burner 26 as well as a flame viewing port 27.
Of course, the wood loading door 21 illustrated in Figure 1, is eliminated as is the combustion air inlet 19.
As shown in Figure 4, the internal combustion chamber is once again made of a heat exchange material 28, The oil or gas burner also has a housing 30 for including a control mechanism as well known in the art, In accordance with the invention, the control mechanism can either be manually or automatically actuated as is also well known in the art and as will be discussed below.
~1 - 7 -~ 7~
In operation, the furnace can be fueled either by electricity or by oil or gas to follow the best price advantages of the different fuels. At the same time, the system can be switched from one fuel to another depending on the time of day. Thus, around supper time, when the electricity load is typically at ils highest and the cost of electricity is, consequently, at its highest, the gas or oil burning system could be turned on and the electric system turned off. It is also contemplated that the control mechanism be controlled remotely by an electric utility company which would turn off electric power and turn on the gas or oil heating system when its load is at a peak, and it would turn off the gas or oil system and turn on the electric system when its load is at a minimum. Thus, the electric utility company could flatten its load over the day to provide better service to all its customers and to keep the costs down for the individual home owner.
Although particular embodiments have been illustrated, this was for the purpose of describing, but not limiting, the invention~ Various modifications, which will come readily to the mind of one skilled in the art, are within the scope of the invention as defined in the appended claims.
_ B -
In these times o-f increasing cost and scarcity of fossel and electric fuels, and greater availability of wood fuel, wood furnaces are a desirable source of home heating, However, wood furnaces have the disadvantage of not being able to provide enought heat during severe winter weather, It is therefore desirable to provide a supplementary source of heat along with a wood furnace.
Such s~stems are taught in U, S, Patent 3l175,552, Sutton, March 30, 1965, U, S. Patent 4,076,011, Proulx, February 28, 1978, and U, S, Patent 4,253,444, Johnson, March 3, 1981, The Sutton patent teaches a fireplace and space heater arrangement, As seen in the drawings of ths patent, the space heater 3 is disposed above the fireplace and in-cludes a plurality of burner elements, There is no inte-gration between the woodburning fireplace and the space heater, The Proulx patent teaches a side-by-side wood-burning fireplace and electrical heating arrangement, The electrical elements are disposed behind the door 14 in Figure 1 of the patent. A thermostat 36 is connected to actuator 18 to turn down the electrical heaters when the heat of the fireplace exceeds a certain value, The JGhnson patent teaches a firebox 2 with a plurality of electrical elements 18 disposed on either side of the firebox. The elements are disposed in air plenums extending along the side of the firebox, and air is provided to the plenums from a rear plenum 15 best seen -1- ~
3~L
in Figure 2 of the patent. The air which is provided from the plenum 15 and then distributed to the plenums 3 on either side of the firebox is heated by the heat produced by the burning of wood, or other fuel, as well as the heat produced by the electrical elements 18, The Johnson patent teaches an integrated system, and the present invention constitutes an improvement of the system as taught in the Johnson patent.
In accordance with the invention there is provided an electric/secondary fuel furnace which includes a combus-tion chamber. The combustion chamber is tubular in shape and has an oval shaped cross-section and receives and burns a secondary fuel. The combustion chamber is made of a heat exchange material. Heating elements are disposed externally of the combustion chamber on either side thexeof.
The combustion chamber is enclosed in a combustion chamber enclosure means which houses both the combustion chamber and the electrical elements and which also defines airflow paths on either side of the combustion chamber between the com-bustion chamber side walls and respective ones of the enclo-sure side walls. me combustion chamber enclosure includes a warmed air escape opening disposed over the combustion chamber. A fan enclosure means, which houses a fan, is disposed beneath the combustion chamber enclosure means, and there are provided means for providing air communi-cations between the fan enclosuxe means and the combustion chamber enclosure means. Thus, air is forced fxom the fan enclosure along the air paths and out the air escape opening, the air being heated during its travel along the air paths.
The invention will be better understood by an examination of the following ~escription together with the accompanying drawings in which:
FIGURE 1 is a perspective view of the wood/
electric furnace, partially in section, in accordance with the invention, and FIGURE 2 is a perspective phantom view of the combustion chamber to illustrate the internal structure thereof.
ReEerring now to Figure 1, the furnace in accord-ance with the invention, illustrated generally at 1, in-cludes a cornbustion chamber enclosure means 3 and a fan enclosure means 5. As can be seen, the combustion chamber enclosure means is disposed directly above the fan enclosure means.
Disposed within the combustion chamber enclosure means, and completely enclosed thereby, is a cor~bustion char~ber 7 which is made of a heat exchange material such as a metallic material. As better seen in Figure 2, the cor~bustion char~er is tube-like in shape and has an oval cross-section, Returning now to Figure 1, a plurality of heating elements 9 are disposed ajdacent to the side walls in the Iower half of the cor~bustion chamber. Although only one set of elements :is shown in the drawings, it will be appreciated that a similar set of elements is included on the other side oE the combustion chamber.
The fan enclosure means 5 includes an inlet sur-face 11 which comprises a filter material to filter the incoming cold air. Disposed within the fan enclosure means, and completely enclosed thereby, is a variable speed fan 13.
As also seen, an airflow path is formed between side wall 15 of the enclosure 3 and side wall 17 of the com-bustion chamber. A similar airflow path is formed on the other si.de o-E the enclosure.
The combustion chamber a].so includes a variable opening combustion air inlet 19 and a fuel loading door ~1.
Thermostat 23 is located in a posllion to be influenced by the temperature of the air in the airflow path between the side wall of the enclosure 3 and the side wall of the combustion chamber, and the thermostat is operatively connected to a control means 25 which is, in turn, operatively connected to the inlet 19. The control means is adapted to vary the opening of the inlet 19 in accordance with temperature requirements, Thus, if the temperature of the air:flowing through is too low, the inlet will be opened wider. In the same way, if the air flowing through is too warm, the opening of the inlet 19 will be reduced, The thermo-stat and control comprise means well known for this purpose in the art and require no further description here, A fan control means 27 can be operated manually or automatically to adjust the feed of the variable speed fan 13, Means 29, such as, for example, duct means, provide air communication between the fan enclosure 5 and the com-bustion chamber enclosure 3. Disposed at the top of the combustion chamber enclosure means 3 is a warmed air escape opening 31.
A thermostat in the living area measures the temperature of the air therein, and controls the electricity input to the heating elements 9 (as well known), so that the operation of the elements can be made completely automatic.
Turning now to Figure 2, the combustion chamber includes a grate 32 for carrying the wood. A removable ash pan 33 is provided for removing ashes which ~all under the grate.
Also included is a baf-fle means 34 for directing flue gases out of the combustion chamber and into a flue removal system. The baffle means includes a horizontal plate 35 and vertical plates 37. Disposed at the rear of the combustion chamber is a flue gas exhaust opening, and the baffle means are arranged to direct flue gases out through the opening 39 to a flue gas disposal system.
It will of course be appreciated that the opening 31 could be exposed directly to the air, or it could be connected to a system of heating pipes as well ~nown in the art.
In operation, the furnace works as follows:
Incoming cold air, illustrated by arrow A in Figure 1, is drawn into the fan 13 through the filter means 11, and the fan then blows air up through the means 29 into the airflow paths between the side walls of the enclosure and the side walls of the combustion chamber as shown by the arrows s in Figure 1. Air travelling through the airflow paths is warmed up by the heat of the combustion chamber. If the tem-perature of the air flowing through the paths is not high enough, ! then the heat can be increased both by opening the combustion air inlet and/or increasing the speed of the variable speed fan, When the limits of the combustion chamber heating capacity ha~e been reached, and the air is still not warmed to a high enough temperature, electricity will be supplied to the heating elements 9 to further warm the air until a correct temperature is reachedO
The warmed air will escape through the opening 31 either directly into the surroundings to be heated, or it will be distributed through a piping system as is well known in the art, As can be seen, with the inventive wood/electric furnace in accordance with the invention, the use of forced air permits greater control so as to avoid using electric heating power unless absolutely necessary, In addition, the use of the side walls of the enclosure for the com-bustion chamber and the side wall of the combustion chamber to provide airflow paths ensures a maximum heat transfer to the air flowing through the air path without requiring extra structure accommodations, Because the air is filtered before being drawn in by the fan, the air of the surroundings will also be cleansed by the inventive furnace.
SUPPLEMENTARY DISCLOS~JRE
Applicant has also learned that the novel arrange-ment can be used with either gas or oil as a secondary fuel.
It is therefore a further object of the invention to provide an electric~gas or oil Eurnace, The further embodiment will be better understood by an examination of the following description together with the accompanying drawings in which:
FIGURE 3 is a perspective view of the electric/
gas or oil furnace partially in section, in accordance with the invention, and FIGURE 4 is a perspective phantom view of the combustion chamber to illustrate the internal structure thereof.
Referring now to Figure '3, as can be seen, the ~
structure of the electric/gas or oil furnace is substantially the same as the structure of the wood/electric furnace illustrated in Figures 1 and 2. However, the furnace in accordance with the Supplementary Disclosure includes an oil or gas burner 26 as well as a flame viewing port 27.
Of course, the wood loading door 21 illustrated in Figure 1, is eliminated as is the combustion air inlet 19.
As shown in Figure 4, the internal combustion chamber is once again made of a heat exchange material 28, The oil or gas burner also has a housing 30 for including a control mechanism as well known in the art, In accordance with the invention, the control mechanism can either be manually or automatically actuated as is also well known in the art and as will be discussed below.
~1 - 7 -~ 7~
In operation, the furnace can be fueled either by electricity or by oil or gas to follow the best price advantages of the different fuels. At the same time, the system can be switched from one fuel to another depending on the time of day. Thus, around supper time, when the electricity load is typically at ils highest and the cost of electricity is, consequently, at its highest, the gas or oil burning system could be turned on and the electric system turned off. It is also contemplated that the control mechanism be controlled remotely by an electric utility company which would turn off electric power and turn on the gas or oil heating system when its load is at a peak, and it would turn off the gas or oil system and turn on the electric system when its load is at a minimum. Thus, the electric utility company could flatten its load over the day to provide better service to all its customers and to keep the costs down for the individual home owner.
Although particular embodiments have been illustrated, this was for the purpose of describing, but not limiting, the invention~ Various modifications, which will come readily to the mind of one skilled in the art, are within the scope of the invention as defined in the appended claims.
_ B -
Claims (13)
1. An electric secondary/fuel furnace comprising:
a combustion chamber, being tubular in shape and having an oval shaped cross-section, for receiving and burn-ing a secondary fuel, the combustion chamber being made of a heat exchange material, electric heating elements disposed externally of said combustion chamber on the sides thereof, combustion chamber enclosure means for housing said combustion chamber and said elements and for defining airflow paths on either side of the chamber between the side walls of the combustion chamber enclosure means and adjacent side walls of the combustion chamber, said com-bustion chamber enclosure means including a warmed air escape opening disposed over said combustion chamber fan means;
fan enclosure means, disposed beneath said com-bustion chamber enclosure means, for housing said fan means, means providing air communications between said fan enclosure means and said combustion chamber enclosure means;
whereby air is forced from said fan enclosure along said air paths and out said air escape opening, said air being heated during its travel along said air paths,
a combustion chamber, being tubular in shape and having an oval shaped cross-section, for receiving and burn-ing a secondary fuel, the combustion chamber being made of a heat exchange material, electric heating elements disposed externally of said combustion chamber on the sides thereof, combustion chamber enclosure means for housing said combustion chamber and said elements and for defining airflow paths on either side of the chamber between the side walls of the combustion chamber enclosure means and adjacent side walls of the combustion chamber, said com-bustion chamber enclosure means including a warmed air escape opening disposed over said combustion chamber fan means;
fan enclosure means, disposed beneath said com-bustion chamber enclosure means, for housing said fan means, means providing air communications between said fan enclosure means and said combustion chamber enclosure means;
whereby air is forced from said fan enclosure along said air paths and out said air escape opening, said air being heated during its travel along said air paths,
2, A furnace as defined in claim 1 wherein said fan comprises a variable speed fan to control air volume in said air paths.
3, A furnace as defined in claim 2 wherein said combustion chamber has a variable opening combustion air inlet.
4. A furnace as defined in claim 3 and including a first thermostat operatively coupled to a first control means said first control means being operatively coupled to said combustion air inlet to vary the opening of said combustion air inlet in accordance with the temperature of said air in said airflow paths.
5, A furnace as defined in claim 4 and including means for controlling the speed of said variable speed fan,
6, A furnace as defined in claim 5 wherein said means for controlling the speed of said variable speed fan com-prises manual means.
7, A furnace as defined in claim 5 wherein said means for controlling the speed of said variable speed fan com-prises thermostatically controlled means.
8. A furnace as defined in claim 7 and comprising a second thermostat operatively connected to a second control means for controlling the amount of electricity delivered to said electric heating elements.
9. A furnace as defined in claim 8 wherein said com-bustion chamber has a baffle arrangement for directing flue gases out of said combustion chamber.
10, A furnace as defined in claim 9 wherein said baffle arrangement comprises:
a horizontal plate two vertical plates, a flue outlet, at the rear of said combustion chamber, said vertical plates being disposed on either side of said flue outlet,
a horizontal plate two vertical plates, a flue outlet, at the rear of said combustion chamber, said vertical plates being disposed on either side of said flue outlet,
11. A furnace as defined in claim 10 wherein said secondary fuel comprises wood fuel.
CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE
CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE
12. A furnace as defined in claim 10 wherein said secondary fuel comprises oil fuel.
13. A furnace as defined in claim 10 wherein said secondary fuel comprises gas fuel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US43632682A | 1982-10-25 | 1982-10-25 | |
| US436,326 | 1982-10-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1170134A true CA1170134A (en) | 1984-07-03 |
Family
ID=23731998
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000419264A Expired CA1170134A (en) | 1982-10-25 | 1983-01-11 | Electric/secondary fuel furnace |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1170134A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5377297A (en) * | 1990-12-31 | 1994-12-27 | Suomen Vuolukivi Oy | Method of modifying masonry furnace by inserting electric heating elements through furnace top cover |
-
1983
- 1983-01-11 CA CA000419264A patent/CA1170134A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5377297A (en) * | 1990-12-31 | 1994-12-27 | Suomen Vuolukivi Oy | Method of modifying masonry furnace by inserting electric heating elements through furnace top cover |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |