US3537431A

US3537431A - Outdoor gas-burning appliance

Info

Publication number: US3537431A
Application number: US792463*A
Authority: US
Inventors: Robert M Ramey
Original assignee: Teledyne Inc
Current assignee: TDY Industries LLC
Priority date: 1969-01-21
Filing date: 1969-01-21
Publication date: 1970-11-03
Anticipated expiration: 1987-11-03
Also published as: CH515460A; DE1965812A1; GB1257540A; NL146281B; NL7000798A; FR2028807A1

Description

United States Patent Inventor Robert M. Ramey North Hollywood, California 792,463

Jan. 21, 1969 Nov. 3, 1970 Teledyne Inc.

Los Angeles, California a corporation of Delaware Appl. No. Filed Patented Assignee OUTDOOR GAS-BURNING APPLIANCE 14 Claims, 3 Drawing Figs.

US. Cl 122/494, 126/85 Int. Cl F22b 37/36 Field of Search 126/ Primary Examiner-Kenneth W. Sprague AttorneyJackson and Jones ABSTRACT: The invention disclosed herein describes a gas burning appliance that provides a means for aspirating air into the appliance for use in the combusting and exhausting of the flue products of combustion, without utilizing any stack means, or the like.

OUTDOOR GAS-BURNING APPLIANCE BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to heating devices and more particularly to outdoor gas burning appliances.

2. Description of the Prior Art All gas burning appliances are usually provided with a combustion chamber having a gas burner located therein which is supplied with a quantity of gas and air under pressure. In such devices, the air-gas mixture is ignited by a pilot burner as it leaves the gas burners; after which the mixture combusts within the chamber. A source of secondary air also enters into the combustion chamber from an intake opening to mix with the original air-gas mixture to aid in the combustion process. Upon combustion, the flue products rise and exhaust through an outlet located above the combustion chamber. ,A heat transfer device is located below the outlet directly in the path of the combustion products. The heat transfer device usually includes a plurality of conduits extending across the outlet whereby the generated heat energy is transferred through the device to heat the fluid traveling through the conduits. The

flue products are then vented through the outlet to the atmosphere.

Normally, all gas burning appliances are provided with means for equalizing static air pressure at the outlet with the static air pressure existing at the secondary air intake opening. These means are necessary because any imbalance would adversely affect the combustion. Such an imbalance is usually created by adverse wind conditions which result from a wind blowing against a nearby wall or roof and pressurizing an isolated pocket. For example, if the static air pressure were greater at the outlet. a downdraft would be created which would enter the combustion chamber through the outlet and cause the burner flame to deflect or mushroom. sometimes passing outside the firebox protection to damage the thermostatic controls. Conversely. if the static air pressure were greater at the intake, an updraft would be created and the excessive amount of combustion air passing through the chamber would cause the burner to lift and carry a significant amount of the generated heat out of the chamber without performing any useful work. Such a condition often occurs because prior gas burning appliances locate their secondary air intakes near the bottoms of the appliances. adjacent the gas burners and remote from the outlet. Such a distance between the intake and the outlet makes possible the differences of the static air conditions between the two. Furthermore, any gust of wind which enters the inlet is usually unbaffled, thereby enabling it to enter under a high velocity as it approaches the gas burners. This also causes an updraft condition which, as mentioned above, is detrimental to the efficient operation of the appliance. Furthermore, an updraft condition causes a significant amount of uncombusted products to exhaust into the atmosphere which, of course, is unsafe and hazardous. Besides distributing the flames of the burner and creating a poor combustion, both conditions also create nuisance shutdowns of the appliance by extinguishing the pilot burner.

Heretofore, prior gas burning appliances included a stack connected to the outlet to permit the outlet to function independently of wind velocities and static air pressure around or near the stack. However, with just a simple stack, downdrafts still occur. As a result, various means such as draft diverters. barometric dampers and vent hoods have been designed to correct this deficiency. A draft diverter provides a relief opening through which any downdrafts from the atmosphere are spilled or deflected into the room rather than entering the flueways of the appliance. The barometric damper is an ad Although these stack means have been necessary to overcome the abovementioned problems, various shortcomings are encountered which make these stacks undesirable. The most notable shortcomings is that such stack means are quite unsightly. By law, stacks are usually required to extend over the surrounding structures, such as fences or eaves. If the appliance is used as a swimming pool heater the unsightly stack is usually clearly visible. Another disadvantage resulting from the use of this device is if the heating appliance were located at the top of the building a larger frontal wallabove the main structure of the building must be erected to hide the stack from view.

These stacks are also inconvenient to erect'since they must be stabilized by guy wires to properly support these stacks and protect them from collapsing from high winds or the like.

SUMMARY OF THE INVENTION This invention obviates the above-mentioned difficulties by providing a gas-burning appliance that is capable of equalizing the static air condition at both the air intake and exhaust points without utilizing any stacks or draft diverter means. The gas burner appliance includes secondary air inlet means which is located adjacent the outlet means to enable both means to be exposed to the same static air conditions Thedevice is also provided with a baffle construction located within the inlet to impede the high velocity winds and create a larger static air pressure. Blades are also longitudinally spaced at the mouth of the inlets to further create a turbulence to impede the flow of air, and further to dampen any cross winds approaching the appliance from any direction.

Thus, the invention fulfills a primary object by providing a gas-burning appliance that is capable of operating under any adverse wind conditions without the use ofany stack means or the like.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention. both as to its organization and manner of operation, together with further objects and advantages thereof. may best be understood by reference to the following description. taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the gas-burning appliance in accordance with the invention:

FIG. 2 is a front cross-sectional view of the gas-burning appliance taken along lines 2-2 of FIG. I; and

FIG. 3 is a side cross-sectional view of the gas-burning appliance taken along lines 33 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIG. I shows a gas burning appliance, indicated generally by arrow 10, that is adapted to be used as an outdoor water heater. However, it is in the realm of the invention that such a device could easily be adapted to heat any gas or liquid.

The gas burning appliance 10 includes four external walls 11 being joined at their ends to form a rectangular housing which completely encloses the interior of the appliance. The front wall 11 is removable to permit access to the interior of the appliance 10. To facilitate the removal of the front wall 11, the front wall ll includes a horizontal groove I2 formed therein to provide a gripping surface for the operator's hands.

The top section of each of the walls 11 extend inwardly to justable device of the same type and function. A vent hood is a form the bottom surface of secondary air inlet ports 13 which extends around the periphery of the appliance 10. The upper portion of the inlet ports 13 is formed by a wind baffle assembly which is made of four lateral sections 14 that are joined at their ends to extend around the periphery of the appliance 10.-The advantage of having the inlet ports 13 extend around the periphery of the appliance 10 is that the air supply will not be dependent on the wind blowing from any one direction. The interior of the air inlet means will be described in greater detail hereinafter with reference to FIGS. 2 and 3. A plurality of blades are longitudinally spaced within the inlet ports 13, about the periphery of the appliance 10. Each blade 15 is triangularly shaped with the apex being formed at the mouth of the inlet and the sides thereof extending into the interior of the inlet 13. The blades 15 function to impede the travel of the air entering the inlet ports 13 thereby creating a turbulence about the inlet to slow down the air velocity and increase the static air pressure within the appliance 10. The blades 15 further function to dampen any cross winds that approach the appliance 10 from any direction, thereby negating the possibility of a reverse flow condition being created at the air inlet 13. A protective screen 16 is mounted on the top side of the appliance 10 within the interior of the baffle assembly 14. The screen 16 functions to protect the interior of the appliance 10 from any leaves, debris or the like, while still per mitting the passage of air therethrough.

Located on one side of the appliance 10 is a temperature control box 17 which also houses the water inlet and outlet conduits 18 for connection to external water pipes in the conventional manner. The conduits 18 also extend to the interior of the appliance 10 for connection to a heat transfer device that will be described in greater detail with reference to FIGS. 2 and 3. The water temperature controls are electrically connected to the thermostatic controls located within the appliance 10 in the conventional manner.

Referring now to F168. 2 and 3, it is seen that each section 14 of the baffle assembly, of which only one is shown in each figure, is comprised of a single sheet of metal formed into a O shaped configuration. Each of the C-shaped sections 14 is connected by brackets, not shown, to the upper sections of the side walls 11. The protective screen 16 is also mounted at its corners to the upper sections of the walls 11 by means of brackets 20.

The interior of the appliance 10 adjacent the inlet ports 13 forms a plenum chamber 21 for collecting the air entering therein. As shown in FIG. 3, the front portion of the interior of the appliance 10 includes a passageway or conduit 22 which communicates with the plenum chamber 21. The passageway 22 extends downwardly to the bottom of the appliance l0 and then around a base 23 which is mounted on a floor panel 24. The base 23 is positioned inwardly from the walls 11 and cooperates with the walls 11 to form the bottom portion of the passageways 22. The base 23 is also utilized to support a plurality of firewalls 25 by means of brackets 25' that is integrally connected thereto. The firewalls 25 are of a castable refractory material and are positioned to form a rectangular com bustion chamber 26. Located adjacent the exterior sides ofthe firewalls 25 are four sections of fiberglass insulation 27. A heat shield 28 (FIG. 3) of aluminum foil is mounted adjacent the forward section of fiberglass insulation 27 The upper ends of firewall assembly are capped with channels 30 to seal the construction thereof and to protect the assembly from any exterior elements.

A plurality of louvers 31 are formed on each side of the base 23 to permit communication of the passageway 22 with the interior of the combustion chamber 26. A plurality of gas burners 32 are longitudinally spaced across the front section of the base 23 with each burner 33 extending completely across the combustion chamber 26 to the back end thereof. The forward end of each burner 32 extends into the passageway 22 and is connected to a gas supply means (not shown) which is of a conventional construction.

The top ends of the firewalls 25 form the outlet or exhaust means 33 to exhaust the products of combustion from within the combustion chamber 26. Located at the outlet 33 and mounted on the top ends of the firewalls 25 is a bank of conduits 34 which form the water tube assembly or heat exchange device. The bank of conduits 34 is a continuous pipe that provides a single path of flow for the water to be heated, with the initial and final ends thereof being connected to the conduits 18.

Located directly above the heat exchanger is a flue collector assembly which is of a dome-shape construction with the base section adapted to be mounted on the firewalls 25. It should be noted that the plenum chamber 21 extends around the flue collector 35 and is further defined at its upper end by a plate 36. The plate 36 has an aperture 37 for receiving the flue collector 35 with the outer extremities of the plate 36 extending nearly to the interior of the baffle sections 14. Since the appliance 10 has been designed for outdoor use, any rain that enters the combustion chamber 26 through the openings of the flue collector 35 will drop to the floor panel 24 and exit the appliance 10 through a plurality of drainholes (not shown) located thereon. Any rain that collects on the plate 36 will run off onto the baffle sections 14 and then onto the top sections of the external walls 11 to be directed to the outside of the appliance.

In operation, gas under air pressure is supplied to the gas burners 32 and is ignited by pilot burner, not shown, as the airgas mixture exits through the gas burners 32.

The air-gas mixture then combusts within the combustion chamber 26. The secondary air enters through the inlet ports 13 into the plenum chamber 21. The air then travels downwardly through the conduit 22 to the base 23, and finally through the louvers 31 to enter the combustion chamber 26 to mix with the original air-gas mixture to aid in the combustion thereof.

The hot gases generated within the combustion chamber 26 are transferred upward by convection through the bank of conduits 34 for heating the water flowing therethrough. The flue products of combustion are then collected through the flue collector 35 and are exhausted therethrough to the atmosphere.

lt should be noted that no stack means whatever are required to be connected to the outlet of the flue collector 35. This is possible because the inlet ports 13 are located adjacent or on the same plane as the exhaust 33. Therefore, the static air pressure that exists over the appliance 10 is substantially the same for both the inlet 13 and the exhaust 33. Furthermore. the air that enters the inlet 13 is impeded by the blades 15 to create a turbulence and slow down the air velocity as it enters the plenum chamber 21. Furthermore. upon entering the plenum chamber 21 the air is funneled down through the conduit 22. around the base 23 and through the louvers 31. This circuitous route further tends to slow down the wind velocity of the air to raise the static air pressure as it enters the combustion chamber 26. This lowering of the wind velocity eliminates the possibility of the air lifting the flame off the gas burners 32, or extinguishing the pilot burner flame. As a result, since the conditions are the same at both the intake and the exhaust means, the static air pressures at both ends of the combustion chamber 26 are equalized. which, of course, is necessary for clean and efficient combustion to occur therewithin.

Although this appliance has been described as a gas burning device, this structure could easily be modified to operate as an oil burning appliance. Furthermore, this appliance could also be easily modified for indoor use by simply removing the screen 16, fitting a stack to the top of the flue collector 35 and leading the stack through the roof to the outside atmosphere.

lclaim:

1. A stackless heating appliance adapted for outdoor instal lation, comprising:

a plurality of vertically oriented wall portions housing a combustion chamber;

burner means extending into the combustion chamber for combusting an air-gas mixture;

a plenum chamber located within the external wall means communicating with burner means;

heat transfer means located above and communicating with the combustion chamber for receiving the heat energy generated thereby;

inlet means provided on an upper extremity of at least one of said wall portions for channeling air into said plenum chamber, said inlet means being positioned in a horizontal plane; exhaust means including an exhaust port communicating with the combustion chamber for discharging the flue.

products of combustion, said exhaust port terminating in horizontal plane immediately adjacent the horizontal plane of said inlet means for positioning the inlet means and the exhaust port termination in the same pressure zone; and

air velocity spoiling means forming a portion of the inlet means and extending above the horizontal plane of the exhaust port termination for increasing the static air pressure at both the inlet means and the exhaust port termination to stabilize combustion conditions at said burner means.

2. The invention of claim 1 wherein the inlet means and air velocity spoiling means are located about the upper extremity of each of the external wall portions.

3. The invention of claim 2 wherein the exhaust means includes a flue collector assembly comprising a dome positioned over the combustion chamber with the top of the said dome being apertured to form the exhaust port.

4. The invention of claim 3 including a plate extending transversely across the top of the appliance to form the top wall portion of the plenum chamber, said plate further including an aperture formed thereon for receiving the flue collector dome. said plate functioning to prevent recirculation of exhaust gases into said plenum chamber.

5. The invention of claim 4 wherein the outer periphery of said plate terminates adjacent said air velocity spoiling means to provide communication between the exhaust and the inlet to balance the effect of any downdraft occurring at the apparatus.

6. The invention in accordance with claim 1 wherein the air velocity spoiling means further comprises additional air velocity spoiling means positioned in the mouth of said inlet means and between the inlet means and said plenum chamber.

7. The invention in accordance with claim 6 wherein the additional air velocity spoiling means includes a plurality of blades longitudinally spaced within the inlet means, each of the blades being positioned adjacent the mouth of the inlet means and extending inwardly therefrom.

8. A stackless heating appliance adapted for outdoor installation comprising:

a plurality of vertically oriented wall portions housing a combustion chamber;

a plenum chamber located within the external wall means communicating with burner means; inlet means provided on an upper extremity of one said wall portions for channeling air into said plenum chamber;

exhaust means including an exhaust port communicating at one end with the combustion chamber for discharging the flue products of combustion, and terminating at the other end adjacent the inlet means in the same pressure zone; and

air velocity spoiling means forming a portion of the inlet means and extending above the exhaust port for increasing the static air pressure at both the inlet means and the exhaust port to stabilize combustion conditions at said burner means.

9. The invention of claim 8 wherein the inlet means and air velocity spoiling means are located about the upper extremity of each of the external wall portions.

10. The invention of claim 9 wherein the exhaust means includes a flue collector assembly comprising a dome positioned over the combustion chamber with the top of the said dome beinlg a ertured to form an exhaust port.

1 he invention of claim 10 including a plate extending transversely across the top of the appliance to form the top wall portion of the plenum chamber, said plate further including an aperture formed thereon for receiving the flue collector dome. said plate functioning to prevent a recirculation of exhaust gases into said plenum chamber.

12. The invention of claim 11 wherein the outer periphery of said plate terminates adjacent said air velocity spoiling means to provide communication between the exhaust and the inlet to balance the effect of any downdraft occurring at the apparatus.

13. The invention in accordance with claim 8 wherein the air velocity spoiling means further comprises additional air velocity spoiling means positioned in the mouth of said inlet means and between the inlet means and saidplenum chamber.

14. The invention in accordance with claim 13 wherein the additional air velocity spoiling means includes a plurality of blades longitudinally spaced within the inlet means, each of the blades being positioned adjacent the mouth of the inlet means and extending inwardly therefrom.