Patent Publication Number: US-2002006592-A1

Title: Pot-type burner

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to liquid fuel burners and more particularly to improvements in pot-type oil burners.  
       [0003] 2. Description of the Prior Art  
       [0004] An important aim in the development of fuel burners is to reduce noxious emissions and to also reduce the creation of carbon deposits on the pot of the burner. As is well known such problems can be significantly resolved by producing a blue flame which indicates a very hot flame resulting in a more complete burn. Thus, several attempts have been made to attain a blue flame while operating this type of burner. An example of such a device includes Canadian patent 1,198,979 issued Jan. 7, 1986 to Toyotomi Kogyo Co. Ltd., for a Combustion Cylinder Construction For Oil Space Heater. This device is a double cylinder type of burner with recirculation of the products of combustion to arrive at complete combustion. A flame uniform-flow mechanism is provided that includes an annular plate having annular rows of different size holes. The heater in accordance with this patent may be effective but complex and expensive.  
       SUMMARY OF THE INVENTION  
       [0005] It is an aim of the present invention to provide a burner that is simple, with fewer parts, but will furnish a blue flame in order to reduce carbon deposits and air borne particles.  
       [0006] In order to obtain a blue flame condition, it is necessary to increase the temperature of the flame and the gases of combustion, namely air and the oil vapours. The prior art requires increased wall contact surfaces such as recirculation devices such as the double wall of Canadian patent 1,198,979. The purpose of the increased wall contact is to increase the heat exchange properties and thus the increased temperature of the gases.  
       [0007] A construction in accordance with the present invention comprises an open burner having a cylinder with a bottom wall and an open top defining a column, a means for supplying liquid fuel to the vicinity of the bottom wall within the cylinder, and a column barrier is spaced within the cylinder, spaced from the bottom wall, the column barrier comprising a catalyzer plate, extending in a plane normal to the axis of the cylinder, the plate having a central opening, and radially extending, spaced apart fins.  
       [0008] A more specific construction in accordance with the present invention comprises an open burner having a pot having a cylindrical wall defining a column with a bottom wall and an open top, a means for supplying liquid fuel to the vicinity of the bottom wall within the pot, and a first column barrier for restricting the flow of vapour derived from the liquid fuel. The first barrier is spaced from the bottom wall in order to form a first chamber with a restricted throat, and a second column barrier is spaced vertically within the cylinder, from the first barrier, and comprising a catalyzer plate, extending in a plane normal to the axis of the pot. The plate has a central opening, radially extending, spaced apart fins and an annular portion near the cylindrical wall but spaced therefrom to define an annular opening with the cylindrical wall. The fins each have a planar component extending axially relative to the column. The catalyzer plate defining a second chamber with the first column barrier and the first wall having perforations at the level of the second chamber in order to supply air to support combustion of the fuel vapours at the catalyzer plate whereby a blue flame will be sustained in the column at the plate.  
       [0009] The provision of the fins with the flat surfaces of the fins in the axial direction of the column permits a greater wall contact with the gases of combustion, thereby increasing the temperature through heat exchange from the metal pot wall including the fins to the vapours and the air mixture passing between the fins. The fins may be designed to increase or reduce the surface area and control the temperature of the gases can be attained. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010] Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings showing, by way of illustration, a preferred embodiment thereof, in which:  
     [0011]FIG. 1 is a fragmentary perspective view of an embodiment of a pot-type burner incorporating the present invention;  
     [0012]FIG. 2 is a top plan view of the burner in accordance with the embodiment of FIG. 1; and  
     [0013]FIG. 3 is a vertical cross-section taken along lines  3 - 3  of FIG. 2, 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0014] Referring to the drawings a pot-type burner  10  is shown which includes the pot  12 . The pot  12  includes a cylindrical wall  14  and a bottom wall  16 . As shown in FIGS. 2 and 3 an inlet  18  is provided for supplying a liquid fuel such as oil into the pot  12  on the bottom wall  16 . This provides a large evaporative surface for the fuel oil and the heat of the burner will cause rapid vaporization of the liquid fuel.  
     [0015] The pot  12  defines a column for the fuel vapours which can be said to be divided into two chambers. The first chamber  32  includes an annular series of holes  22  provided in the cylindrical wall  14 .  
     [0016] The first chamber  32  is delimited by a removable ring  22  having a peripheral flange  24  loosely fitted against the wall  14 , and an inner annular flange  26  defining the column throat between the first chamber  32  and the second chamber  34 . Pins  25  support the removable ring  22  in its position. Indentations  28  as shown in FIG. 1 are provided on the ring  22  to allow the ring  22  to be removed from the pot  12  pass the pins  35 . The second chamber  34  includes an annular series of holes  30  for allowing air to enter into the chamber  34 .  
     [0017] A catalyzer plate  36  is spaced axially from the ring  22  and delimits the second chamber  34 . The catalyzer plate  36  is made up of a first outer ring  38  and an inner ring  42 . The outer ring  38  includes tongues  40  which project radially from the periphery thereof and sit on support pins  35  on the inner surface of wall  14 .  
     [0018] The catalyzer plate  36  is made of two parts. The outer ring  38  may be a stamped metal member with the tongues  40  and includes an outwardly flared flange  52 . The tongues  40  ensure an annular space  54  between the outer flange  52  of ring  36  and the inner surface of wall  14 .  
     [0019] The inner ring  42  is also a stamped member and includes an annular row of openings  46  surrounding a central opening  44 . A series of fins  48  and  50  extend radially from the ring  42 . They are first stamped in a flat plane of the ring  42  and then twisted so that they define planes which are radial and in planes normal to the plane of ring  42 . When assembled to make up the catalyzer plate  36 , alternating fins  48  and  50  are staggered so that fins  48  will overlap the top of the ring  38  while fins  50  will overlap the bottom surface of the ring  38  as shown in the drawings, particularly in FIG. 3.  
     [0020] The fins  48 ,  50  present parallel planar surfaces which extend in the axis of the pot  12 , that is in the axis of the column form by the pot  12 . The area of the fins  48 ,  50  is designed to optimize the heat exchange with the vapours and air mixture passing upwardly between the fins  48 ,  50  from the second chamber.  
     [0021] In operation, oil is fed into the pot  12  through the inlet  18  to form a layer of oil at the bottom of the pot. The burner is ignited by known means and after the burner has been heated up, the heat of the pot will cause the oil to vaporize. The first ring  22  will act to retain the vapours in the first chamber  32  allowing the vapours to absorb more heat from the pot and from the ring  22 . The vapour will pass through the throat formed by the inner flange  26  of the ring  22  into the second chamber  34  where vapours and air coming into the pot will be temporarily held back because of the resistance of the catalyzer plate  36 . The vapours and air mixture must then pass between the fins  48  and  50  where it will pick up more heat from the fins. The annular space  54  is believed to be necessary to allow proper circulation.  
     [0022] A blue flame F has been witnessed which appears consistent with the structure and it is believed that the configuration of the fins and the temporary retention of the vapours and air within the first and second chambers of the temperature of the flame to be high enough to produce a blue flame, thereby providing a more complete burning of the gases of combustion and thus reducing pollution.  
     [0023] In a prototype of the pot of the type shown in the drawings, a flame extending about 3″ to 5″ above the catalyzer plate  36  was noted. The flame appeared to have about a 90% blue colour with a 10% orange colour. The flame formed a uniform curtain continuous from the level of the catalyzer plate  36 . The jets forming the blue flame extended from the perimeter of the plate  36  towards the center of the catalyzer plate and extended upwardly to the central opening  44 .