High efficiency cyclone gasifying combustion burner and method

Abstract

A cyclone gasifying combustion burner and its operation is described. An exemplary burner has an inner cylindrical wall with a contour chamber feeding combustion air into the inner cylindrical wall, with an open end and a solid fuel support end where a combustible material forms a fuel bed. The inner cylindrical wall has a series of inclined air jet holes of substantially predetermined diameter and disposed at substantially predetermined locations therein to create a unidirectional cyclone within a combustion zone defined within the inner cylindrical wall. The air jet holes are disposed at a tangential and vertical angle whereby the combustion air is drawn into the inner cylindrical wall and creates a cyclone flow to mix with the combustion gases released from the flaming pyrolysis fuel bed and causes the combustion gases to flow in a cyclone path within a reaction zone to increase the residency, mixing and turbulence time of the combustion gases and simultaneously precipitate suspended particles against an inner surface of the inner cylindrical wall whereby the particles are caused to gravitate to the fuel bed where they are removed in a controlled manner during the operation of the burner.

1 . A cyclone gasifying combustion burner comprising a combustion housing defined by an inner cylindrical wall surrounded by a manifold chamber configured with an combustion air inlet, said inner cylindrical wall having air jet holes therein of substantially predetermined diameter and disposed at a substantially predetermined angle to create an air cyclone flow in a reaction zone in said inner cylindrical wall spaced above a lower air starved flaming pyrolysis gasifying fuel bed thereof whereby to increase at least one of the residency time, turbulence, mixing of oxygen, and volatile gases for substantially complete combustion of gases within said reaction zone.  
   
   
       2 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said gasifying fuel bed is supported on a platform having a controllable discharge device for the automatic removal of ash accumulating in a lower section of said fuel bed.  
   
   
       3 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said air jet holes are disposed by spacing apart at substantially predetermined distances and in series on at least one substantially predetermined inclined axis to create a unidirectional combustion air cyclone flow in said reaction zone.  
   
   
       4 . A cyclone gasifying combustion burner as claimed in  claim 3  wherein said predetermined angle of said air jet holes is defined by a first tangential angle with respect to the curvature of said inner cylindrical wall.  
   
   
       5 . A cyclone gasifying combustion burner as claimed in  claim 4  wherein said predetermined angle of said air jet hole is further defined by a second transverse angle with respect to a transverse axis of said inner cylindrical wall and angulated in the direction of an open end of said inner cylindrical wall.  
   
   
       6 . A cyclone gasifying combustion burner as claimed in  claim 3  wherein said suspended particles are projected by said air cyclone flow against an inner surface of said inner cylindrical wall wherein at least some of said particles will agglomerate with other particles and thereby increase the molecular weight thereof and gravitate to said fuel bed and thereby substantially reducing the emission of pollutants into the atmosphere.  
   
   
       7 . A cyclone gasifying combustion burner as claimed in  claim 4  wherein said tangential angle is in the range of between approximately 15° to 89° with respect to the curvature of said cylindrical wall.  
   
   
       8 . A cyclone gasifying combustion burner as claimed in  claim 7  wherein said tangential angle is at approximately 60 degrees.  
   
   
       9 . A cyclone gasifying combustion burner as claimed in  claim 5  wherein said transverse angle is in the range of approximately 1° to 15° from said transverse axis.  
   
   
       10 . A cyclone gasifying combustion burner as claimed in  claim 9  wherein said transverse angle is approximately 13 degrees.  
   
   
       11 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said combustion burner is a low pressure burner having an air/fuel ratio of from about 6:1 to 10:1.  
   
   
       12 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said predetermined diameter is within the range of from about 1 to about 48 inches with respect to the height of said inner circumferential wall which height is from about 4 to about 48 inches and in which said reaction zone is established.  
   
   
       13 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said predetermined diameter of said air jet holes is from about 1/16 to about 2 inches.  
   
   
       14 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said solid fuel is a biomass solid fuel in a particle, granular, pellet form or whole grain or seed or coal form  
   
   
       15 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said series of inclined air jet holes extend in said inner cylindrical wall from above said fuel bed whereby said fuel bed is substantially starved from combustion air to lower the temperature of combustion of said flaming pyrolysis fuel bed below the fusion point of inorganic elements that may be present within said fuel bed to prevent agglomeration within said bed.  
   
   
       16 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said reaction zone has a length sufficient to provide said substantially complete combustion of said combustion gases and the containment of said particles to substantially eliminate the emission of pollutants.  
   
   
       17 . A cyclone gasifying combustion burner as claimed in  claim 15  wherein there is further provided additional air jet holes in said inner cylindrical wall and spaced from said series of inclined air jet holes to activate said flaming pyrolyisis gasification combustion zone.  
   
   
       18 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said air jet holes in each said series are spaced at a substantially predetermined distance from one another.  
   
   
       19 . A cyclone gasifying combustion burner as claimed in  claim 18  wherein there is provided a substantially predetermined number of series of said inclined air jet holes dependent upon the diameter and height of said inner cylindrical wall, said series of inclined air jet holes being equidistantly spaced about the circumference and height of said inner cylindrical wall.  
   
   
       20 . A cyclone gasifying combustion burner as claimed in  claim 19  wherein there are at least two series of inclined air jet holes for a 4 inch diameter inner cylindrical wall, said air jet holes having a diameter of about 1/16 inch.  
   
   
       21 . A cyclone gasifying combustion burner as claimed in  claim 2  wherein said platform is a support tray having a solid fuel support section and an ash discharge section, at least two auger screws rotatably supported in said tray and extending from said solid fuel support section to said discharge section, and a drive device to rotate said auger screws to percolate smaller particles of ash to the bottom of said fuel bed, said ash material at the bottom of said fuel bed support section being transported by said auger screws to said discharge section.  
   
   
       22 . A cyclone gasifying combustion burner as claimed in  claim 21  wherein said drive device to rotate is an electric motor drive coupled to said auger screws, said electric motor drive being controlled by a controller to discharge said ash material at a controlled rate dependent on the percentage of ash in the fuel and the operating parameters of said cyclone combustion burner, whereby to inhibit the release of fly ash during the combustion process of solid fuel and reduce slag deposition and fused minerals and to control the level of said fuel bed in tandem with each other for optimal performance.  
   
   
       23 . A cyclone gasifying combustion burner as claimed in  claim 2  in combination with a heating device having a combustion chamber in which said burner is incorporated, a heat exchanger in said combustion chamber, an air displacement device to create a negative pressure in said combustion chamber to displace hot air against said heat exchanger and to draw air through said air jet holes in said inner cylindrical wall of said combustion burner, and a controller to control said air displacement means.  
   
   
       24 . A cyclone gasifying combustion burner as claimed in  claim 23  wherein said heating device is a hot air furnace.  
   
   
       25 . A cyclone gasifying combustion burner as claimed in  claim 23  wherein said solid fuel is coal.  
   
   
       26 . A cyclone gasifying combustion burner as claimed in  claim 23  wherein said heating device is a biomass pellet stove and said heat exchanger is comprised of isolated air circulating flow paths in contact with surfaces heated by said hot air in said combustion chamber, and an air circulating device to circulate ambient air through said flow path.  
   
   
       27 . A cyclone gasifying combustion burner as claimed in  claim 26  wherein said platform is a support tray having a solid fuel support section and an ash discharge section, at least two auger screws rotatably supported in said tray and extending from said solid fuel support section to said discharge section, and a drive device to rotate said auger screws to cause ash material at the bottom of said fuel bed support section to be transported to said discharge section, and a solid fuel pellet storage hopper having discharge means to feed solid biomass fuels to said flaming pyrolyisis combustion bed, and an exhaust device to exhaust gases from said combustion chamber to atmosphere.  
   
   
       28 . A cyclone gasifying combustion burner as claimed in  claim 27  wherein there is further provided a deflector element extending into said combustion zone to deflect said combustible biomass fuels released in said inner cylindrical wall of said burner from said discharge device to distribute same over said fuel bed to substantially promote an even distribution of said biomass fuels onto said fuel bed.  
   
   
       29 . A cyclone gasifying combustion burner as claimed in  claim 27  wherein there is further provided an ash removal tray positioned under said ash discharge section of said support tray, said ash removal tray being accessible through a door secured in a housing of said biomass stove, said drive device to rotate said auger screws being an electric motor coupled thereto by a gear linkage.  
   
   
       30 . A cyclone gasifying combustion burner as claimed in  claim 27  wherein there is further provided a controller for automatically controlling the operation of said pellet stove, and a user interface pad having a memory and switches to set parameters into said controller relating to a desired mode of operation, and a visual display device.  
   
   
       31 . A cyclone gasifying combustion burner as claimed in  claim 30  wherein said switches comprise combustion fan switches to set the speed of said exhaust means and consequently the quantity of air admitted in said combustion zone to increase or decrease the temperature in said combustion chamber, ash control switches to fine tune the evacuation rate of ashes according to the fuel type selected and percentage of ash present in said fuel type during combustion by adjusting the speed of said drive device to rotate said auger screws, and output temperature control switches to set the BTU output of said pellet stove.  
   
   
       32 . A cyclone gasifying combustion burner as claimed in  claim 31  wherein said controller is provided input signals from a low temperature sensor to sense the temperature of said stove, input signals from an operational thermo sensor to indicate the absence of a fire in said combustion burner, and signals from a high temperature sensor to shut-down the controller when the stove reaches a pre-set temperature.  
   
   
       33 . A cyclone gasifying combustion burner as claimed in  claim 32  wherein said display device is a digital numerical display window which displays a number indicative of the speed of said exhaust device, the speed of said drive device to rotate said auger screws, the speed of said hopper discharge device, and the speed of said air circulating device.  
   
   
       34 . A cyclone gasifying combustion burner as claimed in  claim 33  wherein said controller controls the said devices set by the user interface pad for optimum efficiency and further controls said discharge device of said hopper to set the feed rate of solid particle biomass fuel to said combustion bed based on the set parameters and said input signals from at least some of said sensors.  
   
   
       35 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said manifold chamber is defined by a concentrically spaced outer cylindrical wall having annular opposed end walls connected to said inner cylindrical wall to form a cylindrical contour chamber.  
   
   
       36 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said combustion housing is secured in a vertical or horizontal plane, or at a desired angle, and coupled to a combustion chamber of a solid fuel, oil or gas device for residential, commercial or industrial use.  
   
   
       37 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said combustion housing is a vertical combustion housing having an open top end, a feed device to feed a solid biomass fuel particle, pellet, granular material, grain or seed form to said fuel bed, and a further combustion housing having an inner cylindrical wall surrounded by a manifold chamber, said inner cylindrical wall of said further combustion housing having said air jet holes therein to create a reaction zone therein for the combustion of gases, said further combustion housing having a closed end wall and an opposed open end and being secured adjacent to said closed end wall to an open top end of said combustion housing and extending substantially transversely thereto, said inner cylindrical wall of both said vertical combustion housing and said further combustion housing communicating with one another to form a continuous internal combustion chamber.  
   
   
       38 . A cyclone gasifying combustion burner as claimed in  claim 37  wherein there is further provided an igniter in said inner cylindrical wall of said further combustion housing.  
   
   
       39 . A cyclone gasifying combustion burner as claimed in  claim 37  wherein said feed device to feed said solid biomass fuel is a supply conduit having an open end in said inner cylindrical wall of said vertical combustion housing disposed above said fuel bed, and an auger to transport said biomass fuel in said supply conduit.  
   
   
       40 . A cyclone gasifying combustion burner as claimed in  claim 37  wherein each said manifold chamber is connected to a combustion air pressure generating device.  
   
   
       41 . A cyclone gasifying combustion burner as claimed in  claim 40  wherein said air pressure generating device is a fan.  
   
   
       42 . A cyclone gasifying combustion burner as claimed in  claim 40  wherein each said manifold chamber is interconnected together.  
   
   
       43 . A cyclone gasifying combustion burner as claimed in  claim 1  wherein said combustion housing is a vertical combustion housing having an open top end, a feed device to feed a solid biomass fuel in a particle, granular, pellet or whole or partial grain or seed form to said fuel bed, a further combustion housing having an inner cylindrical wall surrounded by a manifold chamber, said inner cylindrical wall of said further combustion housing having said air jet holes therein to create a reaction zone therein for the combustion of gases and further having an open rear end and an open front end, said open rear end being connected to said open top end of said vertical combustion housing by a conduit for the supply of hot combustible gases released from said open top end and for mixing with an air cyclone of said further combustion housing.  
   
   
       44 . A cyclone gasifying combustion burner as claimed in  claim 43  wherein there is further provided an igniter in said inner cylindrical wall of said further combustion housing.  
   
   
       45 . A cyclone gasifying combustion burner as claimed in  claim 43  wherein said feed device to feed said solid biomass fuel is a supply conduit having an open end in said inner cylindrical wall of said vertical combustion housing disposed above said fuel bed, and an auger to transport said biomass fuel in said supply conduit.  
   
   
       46 . A cyclone gasifying combustion burner as claimed in  claim 43  wherein each said manifold chamber is connected to a combustion air pressure generating device.  
   
   
       47 . A cyclone gasifying combustion burner as claimed in  claim 46  wherein said air pressure generating device is a fan.  
   
   
       48 . A method of substantially reducing at least one of the emission levels of volatile organic compounds (VOC), particulate and entrained fly ash, and the level of nitrogen oxides (NO x ) during combustion of a solid or gas fuel within a heating device, said method comprising the steps of: 
 i) feeding said solid fuel in an open end of a cyclone gasifying combustion burner and onto a flaming pyrolysis fuel bed thereof, disposed below a reaction zone of said burner, said burner having a burner chamber defined by an inner cylindrical wall having a predetermined number of inclined air jet holes of predetermined diameter and height disposed at substantially predetermined locations to create a cyclone air flow within said reaction zone; and    ii) providing air into said burner chamber through said inclined air jet holes whereby to direct combustion gases from said fuel bed into said reaction zone to mix with said cyclone air flow thereby increasing at least one of the residency time of said combustion gases, turbulence, and mixing of oxygen and volatile gases for substantially complete combustion of gases in said reaction zone.    
   
   
       49 . A method as claimed in  claim 48  wherein there is further provided the step of (iii) removing said agglomerated particles and ash from said fuel bed in a controlled manner, according to the type of said solid fuel and percentage of ash present in said solid fuel so as to maintain a fuel bed of specific height, to maintain the reaction of flaming pyrolysis and to protect said ash removal augers from excessive temperatures and oxidation.  
   
   
       50 . A method as claimed in  claim 48  wherein providing air into said burner chamber through said inclined air jet holes is configured to simultaneously precipitate suspended particles against an inner surface of said inner cylindrical wall to cause at least some of said particles to agglomerate with other particles to increase their molecular weight and gravitate to said fuel bed.  
   
   
       51 . A method as claimed in  claim 49  wherein prior to step (i) there is provided the step of igniting a starter fuel bed below said combustion zone and thereafter enabling a controller for automatic operation of said burner.  
   
   
       52 . A method as claimed in  claim 51  wherein said cyclone combustion burner is mounted in a heating device having a combustion chamber, said controller effecting the steps of: 
 (a) actuating an air displacement device communicating with said combustion chamber to effect said step (i) of drawing combustion air and simultaneously displacing heated air in said combustion chamber against a heat exchanger disposed in said combustion chamber, and    (b) displacing a medium to be heated through said heat exchange means.    
   
   
       53 . A method as claimed in  claim 52  wherein said controller further effects the steps of (c) sensing the temperature of said heating device, (d) sensing the temperature of said burner chamber, and (e) sensing a high limit temperature of said heating device to deactivate said heating device if necessary by effecting an orderly shut down of said heating device.  
   
   
       54 . A method as claimed in  claim 52  wherein said controller further effects the steps of controlling the discharge of said solid fuel particles from a hopper and into said fuel bed.  
   
   
       55 . A method as claimed in  claim 52  wherein said controller further comprises the step of automatically adjusting the operational parameters of said heating device in accordance with selected programmed input signals received from a user interface pad according to a fuel type being selected for combustion.  
   
   
       56 . A method as claimed in  claim 48  wherein said heating device is one of a domestic/commercial and industrial hot air furnace, a boiler or a liquid (fluid) heater.  
   
   
       57 . A method as claimed in  claim 48  wherein there is further provided the step of agitating a fluidized bed to improve combustion and to percolate particles of ash to the bottom of said fuel bed.  
   
   
       58 . A method as claimed in  claim 48  wherein there is further provided the step of transporting said ash from said bottom of said fuel bed to a discharge area at a rate according to a selected fuel type and the percentage of ash typically present in said fuel type.  
   
   
       59 . A gasifying combustion burner having a housing defined by an inner cylindrical wall surrounded by a manifold chamber configured with an combustion air inlet, said inner cylindrical wall having air jet holes therein disposed at predetermined angles to create an air cyclone flow in a reaction zone in said inner cylindrical wall spaced above a lower combustion gas supply, said cyclone flow in said reaction zone configured for increasing at least one of residency time, turbulence, and mixing of oxygen with volatile gases for substantially complete combustion of gases within said reaction zone thereby substantially reducing the emission of pollutants into the atmosphere.  
   
   
       60 . A cyclone gasifying combustion burner as claimed in  claim 59  wherein said combustion gas supply is delivered by a gas conduit injector secured to said inner cylindrical wall, and an igniter adjacent to an injection nozzle of said injector.  
   
   
       61 . A cyclone gasifying combustion burner as claimed in  claim 60  wherein said gas injector has a gas supply line conduit connected thereto and a gas control regulator connected to said gas supply line.  
   
   
       62 . A method of substantially reducing the emission levels of any one of volatile organic compounds (VOC), particulate, entrained fly ash and the level of nitrogen oxides (NO x ) during combustion of a gas, said method comprising the steps of: 
 i) supplying a combustion gas below a reaction zone of a cyclone gasifying combustion burner, said burner having a burner chamber defined by an inner cylindrical wall having a substantially predetermined number of inclined air jet holes disposed to create a cyclone air flow within said reaction zone when combustion air is drawn therethrough,    ii) drawing air into said burner chamber through said inclined air jet holes whereby to draw said combustion gases into said reaction zone to mix with said cyclone air flow thereby increasing at least one of the residency time of said combustion gases, turbulence, and mixing of oxygen with volatile gases for substantially complete combustion of gases in said reaction zone to substantially reduce the emission of pollutants into the atmosphere.    
   
   
       63 . A cyclone gasifying combustion burner as claimed in  claim 62  wherein said step ii) comprises injecting said combustion gas in said inner cylindrical wall through a gas injector connected to a gas supply line, and regulating the flow of gas in said supply line.