Patent GB-890594-A (GB)
Title: Improvements in and relating to burner units
IPC: F23D5/00
Filed: 1960-01-25
Abstract: 890,594. Vapour burners. CONTROLS CO. OF AMERICA. Jan. 25, 1960 [Aug. 28, 1959], No. 2571/60. Class 75(1) A pot burner 2 comprises a side wall having rows 5 . . . . 10 of air inlet apertures, a bottom wall providing a circumferential fuel trough 12 adjacent the side wall, circumferential baffles 17, 26, 29 located above the trough to shield the fuel from radiant heat and an axial projection 13 comprising an inner cylindrical wall 14 for the upward flow of air and an outer cylindrical wall 15 surrounding the inner wall 14 and defining therewith an annular path for the downward flow of air to apertures 24 leading to the interior of the pot. The air inlets 9 next below the uppermost row 10 are inwardly and upwardly directed and the lowermost inlet apertures 5 are directed downwardly and tangentially. The inner tube 14 of the axial projection 13 is supported in an aperture in the upwardly domed central part of the bottom wall and receives air from below the pot. The outer tube 15 has an annular partition 16 which rests on the upper edge of the inner tube 14 and which is provided with apertures 16a for the passage of air into the space between the two tubes. The lower end of the space between the tubes is closed by a partition 19 formed as an inward extension of the baffle 17. The partition 16 includes an upwardly extending portion 16b having openings 20 for the escape of air from the inner tube. A cap 21 is mounted on the portion 16b and has an inclined lip 22 forming with the inclined upper edge of the outer tube 15 an annular upwardly and outwardly directed air passage. The upper part of the outer tube has rows of apertures 25 which are more closely spaced than the apertures 24 below the partition 16. The total area of the apertures 24 exceeds the area of the apertures 16a in the partition 16. The air passing through the apertures 24 is at low pressure and supports local combustion of the rich mixture to form pin points of flame. The main combustion takes place at the mouth of the pot. The baffle 26 is supported on a flange or rivets 27 in the pot side wall and a further baffle may be supported on rivets 27a. In a modified construction Fig. 3, (not shown) the fuel trough has a local deepening in which the fuel supply pipe terminates. A pipe extends through the side wall of the pot to supply air to a point just above the local deepening and a starter assembly comprising an inclined tube extends through an outer casing and the side wall of the pot to terminate just above a lateral extension of the local deepening. The upper section of the pot is formed by a stainless steel ring which forms with. the upper end of the main pot section an annular pocket to which air passes through holes in the steel ring to impinge on the main section of the pot and then flow upwardly at low velocity. The steel ring has a row of air inlets above the annular pocket. Air is supplied to the burner by a fan mounted on the base of the outer casing below the burner base and baffles are arranged to direct the air into the inner tube of the axial projection and into the annular space between the pot and the outer casing and to prevent the air from impinging on the pot bottom. The baffles in the pot shielding the fuel trough from the flame are strengthened by concave ribs. In another embodiment, Fig. 10 (not shown), a duct delivers air from a fan to an inlet in the side wall of an outer casing and a cylindrical baffle between the outer casing and the pot directs the air downwardly to baffles at the bottom of the pot. In another embodiment, Fig. 14 (not shown), the outer tube of the axial projection is removably mounted on the inner tube.