Patent GB-828478-A (GB)
Title: Improvements in liquid fuel firing means
Inventor: LAMPARD ARTHUR ERNEST
IPC: F23C5/02
Filed: 1957-06-11
Abstract: 828,478. Liquid fuel burners. BABCOCK & WILCOX Ltd. June 11, 1958 [June 11, 1957], No. 18442/57. Class 75(1) [Also in Group XXIX] Liquid fuel firing means includes a burner 5, a valve 1 for controlling the flow of fuel and of a purging fluid, such as steam, and means for ensuring a dwell of the valve in its purging position when the valve operator is moved from the fuel on to the fuel off position. A dwell in the purging position also occurs when the valve operator is moved from the fuel off to the fuel on position. The valve 1 comprises a cylindrical rotary plug 6 having a pair of radial passages 31, 32, Fig. 4, arranged normal to one another and it is connected to a fuel pipe 2, a steam pipe 3 and an outlet pipe 4 leading to the burner atomizer 5. The plug 6 is rotated by a dog clutch 8 one half 7 of which is formed on the outer end of the plug. The complementary part 13 of the clutch is mounted on the end of an operating shaft 15 and is urged by a spring 20 into engagement with the other clutch part 7. A stop plate 21 is secured to the part 13 of the clutch and is provided with a radial projection 24, Fig. 4, having radial stop faces 25, 26 adapted to engage with stops 27, 28 formed on a clutch mounting bracket 18. With the clutch engaged the operating shaft 15 is rotated clockwise through 90 degrees from the off position of the valve shown in Fig. 4 to the purge position in which the stop face 26 on the plate 21 engages the stop 28. Further rotation of the operating shaft is only possible if the shaft is pulled outwardly so that the stop plate 21 clears the fixed stops 27, 28. The clutch is thus disengaged and the valve remains stationary in the purge position until the shaft is released when the stop plate 21 has been rotated through a dwell angle to carry the projection 24 on the stop plate to the other side of the fixed stops 27, 28. To ensure that the clutch can only be disengaged during the dwell angle and to provide end stops for the rotation of the shaft through the dwell angle the stop plate 21 has an arcuate slot 29 displaced by 180 degrees from the projection 24 and ,pin 30 is mounted on a bearing plate 17. The pin 30 abuts the stop plate 21 to prevent disengagement of the clutch except when the operating shaft is in the dwell position, the end of the pin then passing into the arcuate slot 29 as the clutch is disengaged. Clockwise rotation of the valve through 90 degrees from the purge position connects the fuel pipe to the burner. An indicator plate 38 co-operating with a fixed pointer 44 is mounted on the operating shaft 15. The burner 5, Fig. 2, is mounted in a boss 67 in an adaptor 64 provided with a pair of downwardly extending arms 73, 74, Fig. 1, having cylindrical apertures engaging slidably with guide rods 75, 76 extending normally from the firing wall of a combustion chamber (not shown). Thumb screws 77, 78 lock the adaptor 64 in adjusted position on the guide rods. A locking ring 68, Fig. 2, on the burner co-operates with spring clips 69 on the adaptor 64. The fuel inlet pipe 65 and a steam inlet pipe 66 are removably connected to passages in a distributer head forming part of the adaptor 64. A bridle member 85 is pivoted by bolts 84 to the adaptor 64 and a threaded rod 92 screws into a threaded boss 87 on the bridle. The conical end 91 of the rod 92 engages in a recess in a lug on the steam inlet pipe 66 to clamp the burner in position. A member 83 for locking the rod 92 in position is pivoted at 82 to a bracket 79 secured by bolts 80, 81 to the burner 5. A recess in the locking member 83 embraces the rod 92 adjacent a collar 96 on the rod and so prevents outward movement of the rod. To ensure that the rotary fuel valve 1 can be rotated from its off position only when the burner 5 is properly clamped in position the lower end of the locking member 83 is adapted to co-operate with a fork 56, Figs. 1, 3, at the end of a yoke 49 pivoted on a rod 45 secured to the rotary valve 1. The yoke is formed with a convex projection 47 adapted to engage with a recess 46 in the valve indicator plate 38 to prevent rotation of the valve and with a recess 60 of curvature corresponding to that of the indicator plate and adapted to allow rotation of the valve. When the burner is properly positioned the yoke 49 can be rotated anti-clockwise from the position shown in Fig. 1 to the horizontal position since the lower end of the locking member 83 passes between the legs of the fork 56 on the yoke but if the locking member 83 is not upright the legs of the fork strike the locking member and the projection 47 cannot be moved completely out of the recess 46 in the valve plate 38. In order to remove the burner, the valve must be moved to the off position so that the yoke 49 can be rotated clockwise to bring the projection 47 into the recess 46 and thus withdraw the fork 56 from the locking member 83. In order to prevent opening of the valve 1 when the burner, and the locking member 83 attached thereto are removed from the combustion chamber auxiliary locking means are provided for locking the yoke 49 in its valve locking position. The auxiliary locking means comprises a twoarmed catch member 128, Fig. 1, having a recess 134 at its lower end adapted to engage a rod 61 rigidly attached to the yoke 49. The middle of the catch member 128 is pivoted by a pin 127 to arms 121, 124, Fig. 2, secured to the adaptor 64 on the wall of the combustion chamber and its upper end is pivoted to the lower end of a catch operating lever 113 rotatably mounted on a lock body 100 also secured to the adaptor 64. The free end of the catch operating lever 113 is adapted to engage with a cam plate 110 on the burner 5 in such manner that when the burner 5 is withdrawn the lever 113 is free to rotate under the influence of gravity or a spring thus causing the catch member 128 to engage the rod 61 on the yoke 49. The removal of the burner also allows a spring urged pawl 105 mounted in a bore in the lock body 100 to slide to the left to hold the catch operating member 113 in the locking position. In the modified locking means shown in Fig. 11 a lever 180 is pivoted about a pin 182 so that it is biased to rotate in a clockwise direction. An elongated flange 186 on one end of the lever 180 is adapted to engage in a recess 189 in the arcuate lower edge of the burner locking member 83 and a flange 187 on the other end of the lever is adapted to engage in a recess 170 in a flange on the valve indicator plate 38. The lever and flanges 186, 187 are so arranged that when one flange is in full engagement with its recess the other flange is just out of engagement with the other recess. When it is desired to remove the burner the valve is rotated to the off position and the lever is then tilted by hand so that the flange 187 enters the recess 170 and the other flange 186 withdraws from the recess 189. The locking member 83 is then rotated clockwise to the dotted line position in which a projection 172 on the end of the locking member 83 engages the flange 186. The burner clamp 86 can then be undone and the burner removed. The removal of the burner allows a spring urged pin 181 held retracted by the cam plate 110 on the burner to move outwardly to engage a shoulder 190 on the locking member 83 to prevent rotation of the locking member. In a further burner installation, Fig. 9 (not shown), the burner is supplied with fuel or purging steam through a rotary valve as described with reference to Figs. 1...4 and additionally an alternate fuel can be supplied to the burner by a pipe connected to the pipe extending from the rotary valve to the burner. Atomizing steam is supplied from a steam line through a valve to the burner. The steam line is also connected through a valve to the pipe supplying the alternate fuel so that purging of the alternate fuel pipe can be carried out.