Abstract:
A blower intensified gas flame kettle is disclosed. The kettle and gas burner jets of a gas burner are at least partially inserted into a first housing. Burning gases emanating from the gas burner jets are directed toward the kettle and contained by the first housing. The temperature and velocity of the burning gases are enhanced by action of a blower which blows air which mixes with flammable gas in the gas burner prior to burning. Higher temperatures and improved, radiant, conductive, and convection heating of the kettle are achieved. A mechanized stirrer is also disclosed which enhances heating of contents of the kettle by stirring the contents of the kettle.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates generally to gas flame kettles and more specifically to heating of a kettle with a blower intensified gas flame. 
       BACKGROUND 
       [0002]    Popcorn of the type commonly known as “kettle corn” is popped in a large metal kettle which is heated by an open flame. Tiresome stirring of the popping popcorn is required to provide even heat distribution to the popcorn and prevent burning. This method of popping popcorn dates back to colonial times and is considered to produce popcorn with enhanced flavor and texture. Kettle corn is made and sold primarily at outdoor locations such as fairs, festivals, and flea markets where the open flame is created by burners using liquid propane for fuel which are able to quickly flash heat the kettle to temperatures sufficient to pop the popcorn. The liquid propane is stored under pressure in tanks. Liquid propane, being under pressure, supplies sufficient fuel to the burner which enables the burner to heat the kettle to temperatures required to pop the popcorn. 
         [0003]    Making kettle corn at indoor locations, such as malls, presents particular problems. There are regulations for both building and fire codes that prohibit use of pressurized propane tanks at indoor locations. Use of natural gas, piped in through gas lines, is required. The natural gas is maintained at relatively low pressure as a safety precaution. This low pressure helps minimize the amount of natural gas that may escape through leaks in the gas lines and any devices or equipment that use the low pressure natural gas. Additives are used with odorless natural gas to give it a “rotten-egg” odor so that leaks may be more easily detected. This relatively low pressure, under which the natural gas is held, causes an insufficient supply of natural gas delivered to the burner to create high enough temperatures to flash heat the kettle to pop the popcorn. 
       SUMMARY 
       [0004]    The present invention has solutions to help overcome the described problems which may be advantageously applied to popping popcorn. The present invention not only helps to enhance heat transfer from a gas burner to a kettle but also helps to enhance heat transfer from the kettle to contents of the kettle. Heat transfer from the gas burner to the kettle is enhanced by, among other things, intensifying the gas flame with a blower and heat transfer from the kettle to the contents of the kettle is enhanced using a mechanized stirrer. 
         [0005]    The burner jets of the gas burner are at least partially extended into a first housing, which defines a combustion compartment, into which the kettle is also at least partially inserted. The burner is attached to a second housing. The temperature of the gas flame and its associated burning gases is intensified by a blower that blows air to the gas burner which burns relatively low pressure natural gas received from a gas pipeline. The blown air increases the temperature of the burning gases and also increases the velocity of the hot gases directed to the bottom of the kettle by the gas burner jets. 
         [0006]    The combustion compartment is enclosed except for an appropriately sized vent for the exhaust of built up hot gases. The kettle is heated by radiant, conductive, and convection heating by the high temperature and high velocity burning gases. The enhanced temperature of the burning gases yields better radiant and conductive heating of the kettle. Being enclosed, the combustion compartment helps improve convection heating the kettle. The high velocity high hot gases make constant and direct contact with the outer surface of the kettle ensuring more rapid heating of the kettle. Enclosing the combustion compartment also provides an insulating effect with helps to trap heat and contain the high velocity burning gases. In some embodiments, the first housing may be of multi-walled construction thereby providing improved insulating properties. Other embodiments may have insulating material incorporated into the multi-walled construction. 
         [0007]    Heat conduction from the kettle to contents of the kettle is enhanced with a mechanized stirrer. The arms of the mechanized stirrer are parallel to and in proximity with the inner surface of the kettle. The distance from the arms to the kettle is correlated with the size of the contents. Heat conduction is improved by the stirring action of the mechanized stirrer since the contents are stirred to contact a larger area of the kettle  110  thus being heated quickly and uniformly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a side view of an embodiment of a blower intensified gas flame kettle with a portion of a side broken away. 
           [0009]      FIG. 2  is a side view of an embodiment of a stirring apparatus for the gas flame kettle of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    With reference to  FIG. 1 , an embodiment of a blower intensified gas flame kettle with first housing  10  and second housing  12  is shown. First housing  10  forms combustion compartment  146  and second housing  12  forms burner compartment  158 . First housing  10  and second housing  12  are constructed of materials able to withstand temperatures generated by a burner apparatus  150 , and provide support for the various components described below. Such a material includes, although is not limited to, sheet metal. 
         [0011]    First housing  10  has first housing vertical side walls  140 A,  142 A,  144 A, and a fourth first housing vertical side wall (not shown) at the rear of first housing  10  opposite vertical side wall  140 A. Vertical side walls  142 A and  144 A are opposite each other. In this specific embodiment, the four first housing vertical side walls are flat planar surfaces. Each first housing vertical side wall is connected to adjacent side walls along their vertical edges forming an enclosed walled area of first housing  10 . The first housing vertical side walls may be fixedly connected or detachably connected. Other embodiments may have curved or angular first housing vertical side walls enabling two or three first housing vertical sidewalls to form the enclosed walled area of first housing  10 . Still other embodiments may have more than four first housing vertical side walls in various combinations of planar, curved, and angular first housing vertical side walls forming the enclosed walled area of first housing  10 . In addition, first housing vertical side walls may be of single or multi-layer construction with each layer spaced apart from any flanking layers. This spacing helps increase the insulating properties of the first housing vertical side walls thus aiding to reduce heat loss from the first housing  10  when burner apparatus  150  is in operation. The space between the layers may be filled with an insulting material to further reduce heat loss. 
         [0012]    First housing  10  also has a vent  138  and a diverter  139  positioned on vertical side wall  144 A. The vent  138  enables a buildup of hot gasses to escape from first housing  10  and the diverter  139  directs the flow of the escaping hot gasses. Vents and diverters are well known in the art ranging from vents of perforated sheet metal and diverters of a solid piece of sheet metal, as shown in  FIG. 1 , to complex chimneys and flues, and need not be discussed further. Vent  138  and diverter  139  may be positioned at any appropriate portion of first housing  10 . 
         [0013]    The bottoms of the first housing vertical side walls are connected to the perimeter of first housing bottom member  145 . First housing bottom member  145  is transverse to the first housing vertical side walls and is shaped to match the enclosed walled area of first housing  10 . First housing bottom member  145  may be of single or multi-wall construction as described above. In addition, the first housing vertical side walls may be fixedly or detachably connected to first housing bottom member  145 . 
         [0014]    The tops of the first housing vertical side walls are connected to the perimeter of top member  141 . First housing bottom member  145  is positioned transverse to the first housing vertical side walls and is shaped to match the enclosed walled area of first housing  10 . Top member  141  may be of single or multi-wall construction as described above. In addition, the first housing vertical side walls may be fixedly or detachably connected to top member  141 . In this specific embodiment, top member  141  has an opening in it enabling placement and removal of the kettle  110  into and out of the opening of the top member  141 . When the kettle  110  is placed into the opening of top member  141  the bottom of kettle  110  is in proximity to burner jets  153 . Top member  141  also has safety switch  116  bordering vertical side wall  140 A. Safety switch  116 , when released to its default position, extended above the surface of top member  141 , causes burner apparatus  150  to be shut off. When safety switch  116  is depressed into top member  141  operation of burner apparatus  150  is enabled. 
         [0015]    Also shown is kettle retaining member  111  which is attached by at least one hinge (not shown) to a first housing vertical side wall, which in this specific embodiment is the fourth first housing vertical side wall (not shown) at the rear of first housing  10 . Kettle retaining member  111  may be attached by the at least one hinge to top member  141  which in this specific embodiment is at the rear of top member  141  adjacent to the fourth first housing vertical side wall. Kettle retaining member  111  may be of single or multi-wall construction as described above. Kettle  110  is fixedly attached to kettle retaining member  111  so that the inner volume and inner surface of kettle  110  is open and easily accessible. Part of kettle  110  is kettle extension  113  which is a portion of kettle  110  protruding past kettle retaining member  111  and outside of combustion compartment  146 . Kettle extension  113  is basically a portion of kettle  110  resembling a circular collar or flange extending the upper edge of kettle  110  above kettle retaining member  111 . Kettle  110  is constructed of a metal with good heat conduction properties and of a thickness that can withstand heat and high temperatures produced by burner apparatus  150 . Metals used to construct kettle  110  include, but are not limited to, iron, copper, and food grade stainless steel. 
         [0016]    Kettle retaining member  111  has handles  112 ,  114  located near vertical side wall  140 A, opposite the at least one hinge. In this embodiment, handles  112 ,  114  are cylindrically shaped and extend outwardly from and in the same plane as kettle retaining member  111 . Lifting and lowering of handles  112 ,  114  enables rotation of kettle retaining member  111  about the axis of rotation of the at least one hinge thereby raising and lowering the kettle  110  from and into top member  141  and actuating safety switch  116 . 
         [0017]    When the kettle  110  is lowered into the opening of top member  141 , first housing  10  becomes enclosed and safety switch  116  is depressed enabling operation of burner apparatus  150 . When the kettle  110  is raised from the opening of top member  141 , first housing  10  becomes open and the safety switch  116  is released to its default position disabling operation of burner apparatus  150 . This reduces the possibility of an operator being burned when the kettle  110  is lifted and exposed to the opened first housing  10  since the burner apparatus  150  is shut off and stops burning when the safety switch  116  is released to its default position. 
         [0018]    In a specific alternate embodiment, top member  141  may not be present. Top member  141  is replaced by kettle retaining member  111 . In this specific embodiment, kettle retaining member  111  is attached by the at least one hinge (not shown) to a first housing vertical side wall as described above. Kettle retaining member also has kettle  110 , kettle extension  113 , and handles  112 ,  114  as described above. Kettle retaining member  111  may be raised and lowered by handles  112 ,  114  as described above thereby enclosing and opening the first housing  10  and actuating safety switch  116  as described above. In this specific alternate embodiment, safety switch  116  may be positioned at the top of vertical sidewall  140 A or at the top of vertical sidewalls  142 A  144 A adjacent to vertical sidewall  140 A thus enabling actuation of safety switch  116  as described above. 
         [0019]    Side housing  118  is shown attached to both first housing  10  and second housing  12 . In alternate embodiments, side housing  118  may be attached to either first housing  10  or second housing  12 . Side housing  118  is openable enabling access to the inside of side housing  118 . Electrical distribution system  124  is positioned inside side housing  118  and has electrical wire  126  which may be connected to a source of electricity thereby providing electrical power to electrical distribution system  124 . Electrical distribution system  124  enables distribution of electrical power to the various components and elements described in this document. Timer shutoff  128  is positioned inside side housing  118  and receives power from electrical distribution system  124 . Timer shutoff  128  imposes an adjustable upper limit for the amount of time during which the burner apparatus  150  may be in continuous operation. Burner apparatus  150  is shut off by the timer shutoff  128  when the upper limit for continuous operation is exceeded. 
         [0020]    Side housing  118  has master switch  120  and burner switch  122  positioned, in an accessible location, on the outside surface of side housing  118 . Master switch  120  and burner switch  122  receive electrical power from electrical distribution system  124 . Master switch  120 , which in this embodiment is an on/off switch, allows and disallows distribution of electrical power to all components. When master switch  120  is in the off position, electrical power is not distributed and components requiring electrical power are prevented from operating. When master switch  120  is in the on position, electrical power is distributed and electrical power may be received by components. Burner switch  122 , which in this embodiment is an on/off switch, allows and disallows distribution of electrical power to burner apparatus  150 . When master switch  120  is in the off position, no electrical power is being distributed and burner switch  122  has no effect on the operation of burner apparatus  150  which would not be in operation due to the absence of electrical power. When master switch  120  is in the on position, burner switch  122  may control the distribution of electrical power to burner apparatus  150  thereby turning burner apparatus on and off. 
         [0021]    Second housing  12  has second housing vertical side walls  140 B,  142 B,  144 B, and a fourth second housing vertical side wall (not shown) at the rear of second housing  12  opposite vertical side wall  140 B. In this embodiment, positioning of the second housing vertical side walls mirror the positioning of the first housing vertical side walls creating the same shape for first housing  10  and second housing  12 . Vertical side walls  142 B and  144 B are opposite each other. In this specific embodiment, the four second housing vertical side walls are flat planar surfaces. Each second housing vertical side wall is connected to adjacent side walls along their vertical edges forming an enclosed walled area of second housing  12 . The second housing vertical side walls may be fixedly connected or detachably connected. Other embodiments may have curved or angular second housing vertical side walls enabling two or three second housing vertical sidewalls to form the enclosed walled area of second housing  12 . Still other embodiments may have more than four second housing vertical side walls in various combinations of planar, curved, and angular second housing vertical side walls forming the enclosed walled area of second housing  12 . In addition, second housing vertical side walls may be of single or multi-layer construction as described above. In alternate embodiments, positioning of the vertical side walls of first housing  10  may differ from the position of the vertical side walls of second housing  12  yielding dissimilar shapes for first housing  10  and second housing  12 . 
         [0022]    The bottoms of the second housing vertical side walls are connected to the perimeter of second housing bottom member  143 . Second housing bottom member  143  is positioned transverse to the second housing vertical side walls and shaped to match the enclosed walled area of second housing  12 . Second housing bottom member  143  may be of single or multi-wall construction as described above. In addition, the second housing vertical side walls may be fixedly or detachably connected to second housing bottom member  143 . The second housing vertical side walls and the second housing bottom member  143  may be at least partially open thus enabling air flow to burner apparatus  150 . 
         [0023]    Second housing bottom member  143  has feet  132 ,  134  and electrical outlet  130 . Feet  132 ,  134  support second housing bottom member  143  from floor  133 . Feet  132 ,  134  may extend longitudinally across second housing bottom member  143 . In alternate embodiments, feet  132 ,  134  may be not extend across second housing bottom member  143  and at least one additional foot is used to support second housing bottom member  143  from floor  133 . Feet  132 ,  134  in this specific embodiment, impede movement relative to the floor  133 . In alternate embodiments, feet  132 ,  134  may facilitate movement relative to the floor  133 . Movement may be facilitated, for example, by use of wheels which may be lockable to reduce or impede movement when so desired. Electrical outlet  130  receives electrical power from electrical distribution system  124  and may be used to supply power to components not directly connected to electrical distribution system  124 . 
         [0024]    In alternate embodiments, a movement limiting device may be attached to either first housing  10  or second housing  12 , and to a stationary object which may be a wall or the floor  133 . The movement limiting device may include but is not limited to, a chain, a cable, and a steel bar. 
         [0025]    The tops of the second housing vertical side walls are connected to the perimeter of first housing bottom member  145 . First housing bottom member  145  is positioned transverse to the second housing vertical side walls and shaped to match the enclosed walled areas of first housing  10  and second housing  12 . First housing bottom member  145  may be of single or multi-wall construction as described above. In addition, the tops of second housing vertical side walls may be fixedly or detachably connected to first housing bottom member  145 . Since in this specific embodiment, positioning of the second housing vertical side walls mirror the positioning of the first housing vertical side walls, second housing vertical side walls are connected to first housing bottom member  145  at the same location as the first housing vertical side walls. Therefore, first housing vertical side walls are positioned directly on top of and supported by second housing vertical side walls. Correspondingly, first housing  10  is positioned directly on top of second housing  12 . Alternate embodiments may not have this mirroring and first housing vertical side walls and second housing vertical side walls may be attached to first housing bottom member  145  at different locations and are neither mirrored nor directly on top of one another. 
         [0026]    Burner apparatus  150  is attached to and is positioned inside of second housing  12  and is electrically connected to electrical distribution system  124 . Operation of burner apparatus  150  and its components may be controlled by safety switch  116 , master switch  120 , burner switch  122 , and timer shutoff  128  as described above. Burner apparatus  150  is a gas burning apparatus which includes gas burner  152  operatively connected to blower  156  and a gas inlet  154 . Gas burner  152  has gas burner jets  153 . Gas burner  152  extends partially through first housing bottom member  145  thereby protruding gas burner jets  153  into combustion compartment  146  so that gas burner jets  153  are positioned for heat transfer engagement with the kettle  110 . Gas inlet  154  is connected to gas line  137  which is connected to a source of flammable gas such as a natural gas pipeline (not shown) for enablement of the flow of flammable gas to gas burner  152  and gas burner jets  153 . Gas line  137  may have at least one gas flow control device for controlling the flow of flammable gas to gas inlet  154 . The at least one gas flow control device may include, but is not limited to, a valve, a gas flow regulator, and a pressure gauge. Blower  156  has at least one air inlet  157  enabling blower  156  to blow air to gas burner  152  where the air is mixable with the flammable gas entering from gas inlet  154  thereby intensifying the temperature and velocity of flames of burning gas emanating from the gas burner jets  153 . The intensified temperature and velocity of the burning gas not only produces enhanced radiant heating of the kettle  110  but also enhanced convection heating of the entire surface of kettle  110  extending into combustion compartment  146 . The intensified velocity of the gasses inside the enclosed combustion compartment  146  enables the hot gasses to be in constant contact with the kettle  110  providing intensified heat transfer to the kettle  110 . 
         [0027]    In an alternate embodiment, only one set of vertical side walls may be used which extends from the top of first housing  10 , top member  141 , to the bottom of second housing  12 , second housing bottom member  143 . In this alternate embodiment, first housing bottom member  145  is connected to the one set of vertical side walls thereby creating combustion compartment  146  of first housing  10  and burner compartment  158  of second housing  12 . 
         [0028]    With reference to  FIG. 2 , an embodiment of a stirring apparatus, for stirring contents of kettle  110  is shown. Motor  210 , having a rotor (not shown), is fixedly mounted on a surface of motor support  214  opposite the inner volume and inner surface of kettle  110  so that the rotor is at the midpoint of motor support  214 . In alternate embodiments, motor  210  may be detachably mounted to motor support  214 . Motor support  214  is a rectangular member extending diagonally across kettle  110  and approximately the width of motor  210  thus ensuring that the midpoint of motor support  214  and the rotor are centered relative to kettle  110 . Motor  210  and motor support  214  are dimensioned so that the inner volume and inner surface of kettle  110  remain open and easily accessible. Motor support  214  is of a strength and stiffness able to support motor  210 , stirrer shaft  220 , first stirrer arm  224 , and second stirrer arm  226  while in operation. Motor support  214 , stirrer shaft  220 , first stirrer arm  224 , and second stirrer arm  226  are preferably made of a food grade material including, but not limited to food grade stainless steel. Motor support  214  has motor support clamps  216 ,  218  which detachably connect motor support  214  to kettle extension  113 . 
         [0029]    Motor  210  has an electrical on/off switch  212 , and an electrical cord  228  terminating at electrical plug  230 . Electrical on/off switch  212  controls the flow of electricity to motor  210  thereby enabling motor  210  to be turned on and off. Electrical plug  230  may be detachable plugged into an electrical outlet such as the electrical outlet  130  of  FIG. 1 . When electrical plug  230  is detachably plugged into electrical outlet  130 , flow of electricity to motor  210  may also be controlled by safety switch  116 , master switch  120 , burner switch  122 , and timer shutoff  128  as described above for burner apparatus  150 . In alternate embodiments electric cord  228  may be wired to a source of electric power such as electrical distribution system  124 . Use of the electrical plug  230 , since it may be detachable plugged in an electrical outlet, facilitates removal of the stirring apparatus from the kettle  110 . 
         [0030]    The rotor is operatively connected to stirrer shaft  220  such that stirrer shaft  220  extends radially and centrally into kettle  110  toward the inner surface of kettle  110 . Stirrer shaft  220  has first stirrer arm  224  and second stirrer arm  226  which extend from stirrer shaft  220  at least partially towards kettle extension  113 . First stirrer arm  224  and second stirrer arm  226  are parallel to and in proximity to the inner surface of kettle  110 . The distance of stirrer shaft  220 , first stirrer arm  224 , and second stirrer arm  226  to the inner surface of kettle  110  is correlated with the size of the contents of the kettle  110 . This helps to enhance heat transfer to the contents by ensuring that the contents are stirred. This stirring enables the contents to contact a larger area of the kettle  110 , be heated quickly and uniformly, and to minimize burning. Small sized contents would require a smaller distance to the inner surface of kettle  110  than large sized contents. 
         [0031]    First stirrer arm  224  and second stirrer arm  226  may have various shapes, including but not limited to, solid round bar, solid flattened paddle, and perforated flattened paddle with holes of various sizes. Although two opposed stirrer arms are preferred, alternate embodiments may have only one stirrer arm or may have more than two stirrer arms.