Abstract:
An incinerator has a combustion vessel, a base trap and an afterburner. The combustion vessel has a combustion chamber, an exhaust leading from the chamber, an air intake leading to the chamber, and a gas intake leading to the chamber. Fresh air is mixed with burning propane gas to elevate the temperature to incinerate waste with little ash. Household waste burns in the chamber generating flue gas that is moved from the chamber to the base trap where it is cooled. The cooled flue gas is moved from the base trap through a filter to the afterburner where it is oxygenated and burned prior to release to the atmosphere.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to an incinerator, and, more particularly, to a refuse incinerator for home use for burning most household wastes. 
     BACKGROUND OF THE INVENTION 
     Incinerators for home use were once very popular with thousands of units manufactured each year. In 1993 during an energy conservation movement, the use of gas for incineration was effectively banned thereby halting the manufacture of home incinerators. When the ban was lifted, manufacturing did not resume. A gas incinerator for home use required a masonry chimney which meant that in addition to the purchase of an incinerator unit, skilled tradesmen had to be employed for the installation. A problem with conventional incinerators was that the metal stove pipe connecting the incinerator to the masonry chimney became very hot during use often glowing red thereby posing a hazard. These incinerators would not burn magazines or similar articles and created considerable ash which had to be shoveled out by hand. It is desirable to have an outdoor home incinerator to burn combustible home waste materials that would otherwise find their way to a landfill. 
     SUMMARY OF THE INVENTION 
     Briefly summarized, according to one aspect of the present invention, an incinerator, comprises a combustion vessel having a chamber, an exhaust leading from the chamber, an air intake leading to the chamber, and a gas intake leading to the chamber. The incinerator has a base trap, means for moving flue gas from the chamber to the base trap, and means for cooling flue gas in the base trap. The incinerator has an afterburner, means for moving cooled flue gas to the afterburner, and a filter interposed between the base trap and the afterburner for removing any particulate from the cooled flue gas. 
     The incinerator mixes fresh air with burning propane gas to amplify the heat generated by the flames for high temperature burning in short periods of time. At the same time, a flue gas transport system cools down the flue gas and moves it into an afterburner for mixing with fresh air and final burning to produce harmless carbon dioxide and water vapor. The incinerator does not require a chimney, emits no smoke and stores the small amount of solid residue in a small ash tray. Once started, operation is automatic requiring no attention from an operator. 
     These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is diagrammatic perspective view of a preferred embodiment of an incinerator for home use according to the present invention. 
     FIG. 2 is a perspective view similar to FIG. 1 but showing some internal components in broken lines. 
     FIG. 3 is an exploded diagrammatic view of the incinerator of FIG.  1 . 
     FIG. 4 illustrates the combustion chamber for the incinerator. 
     FIG. 5 is a diagrammatic side view with a longitudinal section of the combustion vessel removed. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, an incinerator  10  for outdoor home use has a housing  12  constructed of metal resistant to deterioration from exposure to the elements, such as porcelain on steel or rust resistant steel, for example. Waste material to be burned is inserted in the unit through a lid  14  at the top of the unit. Also positioned at the top of the unit is a control panel  16  with controls for regulating gas and air flow. At the front of the unit are air inlets  18 , a fresh air port  20  and access to an ashtray  22 . The incinerator receives refuse through lid  14  which is locked in position with clamps  24  during combustion. The unit is compact in size approximating the dimensions of an automatic washing machine. 
     Referring to FIGS. 1-5, the incinerator  10  has a combustion vessel  26  that is preferably cylindrical in configuration defining a combustion chamber within its sidewalls. Combustion vessel  26  is open at its top end which is closed during combustion by the lid  14 . The vessel is also constructed of a heat and corrosion resistant material such as cast iron, tungsten steel or other material suitable for furnace use. 
     Air flows from air inlets  18  through air inlet ducts  28  to air regulator  30  and through air flow guides  32  which enter the combustion vessel  26  through its sidewall. Several air flow guide  32  spaced about the inside of the combustion vessel cause the input air to swirl or whirlwind in the combustion vessel. Swirling effectively mixes the input air and fuel gas in the combustion chamber so that there is complete combustion. The swirling also helps push ash to the ash tray  22 . 
     Air regulator  30  preferably includes an electric fan that draws air into the air inlets  18  and exhausts it into the air flow guides  32  at a higher speed. The speed is sufficient to create an air swirl in the combustion chamber. Preferably, the fan is a variable speed fan whose speed varies automatically with temperature inside the combustion chamber. The forced air in a whirlwind pattern mixes air and burning gases to achieve higher burning temperatures in shorter periods of time than merely introducing extra combustion air. 
     Exhaust pipes  34  enter near the bottom of the vessel and bend 90 degrees to extend toward the top of the vessel. The two exhaust pipes  34  are connected by an arcuate perforated pipe  36  which is nearly circular in configuration. The perforations exist on the bottom side of pipe  36  and serve to suction out ash and products of combustion. Pipes  34  enter a dual exhaust engine  38  which includes a fan  48 . The fan  48  creates suction in exhaust pipes  34  and perforated pipe  36  to draw in combustion gases and ash. As the fan operates, fresh air is drawn in through fresh air port  20  to cool internal wiring and components. 
     Control panel  16  has attached to it an igniter  40  and fuel lines  42  which enter the combustion chamber through the sidewall. A gas regulator  44  regulates the flow of fuel gas, which is preferably propane, while a timer on the control panel determines the length of time the fuel flows. Switches on the control panel turn the power on, start the igniter and start fuel gas flowing to begin the incineration process. Gas shut off is automatic when the timer is set. 
     A base plate  46  in the combustion chamber receives the refuse to be burned. As the refuse burns, ash is forced into ash tray  22 . Ash, along with gaseous products of combustion, exits through perforated pipe  36  and enters a mixing chamber where it mixes with fresh air from air regulator  30 . The mixing cools the exhausted air to prevent damage to wiring or other components. Exhaust air flow is regulated by a damper  50  in the bottom of the mixing chamber. The heavier ash is deposited in ash tray  22  while the lighter combustion gas and fresh air mixture is drawn into base trap  52  and exhausted through exhaust pipe  54 . 
     A cool down unit  56  reduces the temperature of the exhaust gas in pipe  54 . The cool down unit  56  incorporates a fan  58  to blow air over radiator type pipes that divide the flow from exhaust pipe  54  into several pipes or coils to receive air from fan  58  and then recombine the flow into a single, cooled exhaust  60 . 
     A filter  62  receives the exhaust from pipe  60  and separates tar, debris and other solids from the exhaust gas. Filtered exhaust gas is routed via pipe  64  to an afterburner  66 . Afterburner  66  has a gas inlet  68  which inputs fuel gas to mix with he exhaust gas to form a combustible mixture to completely burn the exhaust gas. Afterburner  66  also has inlets for air so the propane fuel gas and exhaust gas mixture will burn completely. Because filter  62  removes all solids, the exhaust gas contains only hydrocarbons which burn completely when mixed with propane and air. 
     A primary exhaust engine  70  creates suction in exhaust pipe  54  to draw in the combustion gas and fresh air mixture when the darner  50  is open. 
     Operation of the present invention is beleived to be apparent from the foregoing description and drawings, but a few words will be added for emphasis. Loosening the clamps  24  holding lid  14  reveals the combustion chamber where household debris is placed to be incinerated. When the combustion chamber is full or burning is desired, the lid is secured in position with the clamps. The controls on control panel  16  are set including the timer which determines the length of the burning cycle. Fuel gas flows into the combustion chamber through gas lines  42  and is ejected through the vessel sidewall into the combustion chamber. Fresh air from air inlets  18  enter the air flow regulator  30  and flows to the combustion chamber through air flow guides  32 . The fuel gas and air mixture is lighted by ignitor  40 . As the temperature in the vessel rises, a variable speed fan in regulator  30  increases air flow through the guides  32  creating a whirlwind further increasing the temperature and burning the debris. Ash that would normally collect on base plate  44  in the bottom of the vessel is blown off the base plate by the whirlwind. 
     Combustion gases and scattered ash are suctioned into exhaust pipe  36  by fan  48  in dual exhaust engine  38 . The exhaust gas is mixed with fresh air drawn in through air vent  20  by fan  48  which cools the exhaust to protect wiring and other components. Damper  50  regulates the flow of the exhaust. Ash precipitates out of the exhaust and is collected in bottom ash tray  22  while gases are drawn into the bottom base trap  52 . Suction to move gases from base trap  52  is provided by exhaust engine  70  through exhaust pipe  54 . 
     Exhaust gases are cooled in cooler  56  with the aid of fan  58  before entering filter  62  where solids are filtered out of the exhaust. Afterburner  66  mixes fuel gas and fresh air with the filtered exhaust and completely burns the mixture. 
     While the invention has been described with particular reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the preferred embodiments without departing from invention. Also, certain aspects of the invention are not limited to the particular details of the examples illustrated, and it is therefore contemplated that other modifications and applications will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications as do not depart from the true spirit and scope of the invention.