Patent GB-586293-A (GB)
Title: Improved process of and apparatus for the flame machinery of metal bodies
IPC: B23K7/06
Filed: 1944-09-06
Abstract: 586,293. Removing surface metal by blowpipes. LINDE AIR PRODUCTS CO. Sept. 6, 1944, No. 16986. Convention date, Nov. 13, 1943. [Class 83 (iv)] In de-surfacing a succession of metal bodies such as blooms, billets, sheetbars, &c. on one or more sides by means of a gas blow-pipe head which extends completely across the side of the billet, whilst the latter is fed axially, the gas stream produced by the head is adjusted in width automatically according to the width of the side of the work being treated. A machine for effecting this purpose and which is similar in general construction to that described in Specification 488,612, comprises standards 10 arranged at each side of an ingot conveyer line in a steel mill. The standards are tied together by a pivoted linkage 11, as in the above Specification, which supports two frames 14 guiding horizontally slidable carriers 15 movable by pneumatic cylinders acting between the frames and carriers. The weight of the frames and parts thereon is counterbalanced by levers 17 pivoted on the standards 10 and connected by links 18 to the carriers and bv links 19 to pneumatic cylinders 20. A plate 21 on each carrier supports at its inner edge a burner head 22 consisting of one or more sections of nozzles N similar to those described in Specification 546,733, and the frames 14 are connected by a jointed member 24 which carries a roller 26 contacting the lower surface of the billets W at the same level as the lower edges of the heads 22. Mixed oxygen and fuel gas for the pre-heating jets is supplied to the nozzles from mixers 29 by pipes 28, the mixers being supplied with oxygen and fuel by manifolds 31, 32 respectively, and cutting oxygen is fed to the nozzles by pipes 28<1> from a selector valve 35. Ports 33 in the valve are connected singly or in groups to the nozzles and a vertically slidable piston 37 is adapted to expose the required number of ports to the oxygen supply 36 to feed a number of nozzles corresponding to the vertical width of the billet being treated. Each piston is adjusted by a rack 38 thereon and a pinion 39 rotated by a gear 44 engaging a toothed segment 45 on a lever 46 freely pivoted at 47 and urged upwardly by a spring 52 acting on a rod 48 attached to the lever. A bracket 49 on the plate 21 acts as an abutment for the spring and an adjustable stop collar 53 limits the upward movement of the piston &c. A roller 43 maintains the rack 38 in engagement with its pinion. The pivot 47 is carried by a bracket lift on the plate 21 and the pivot also supports a boom 57 carrying a billet contacting shoe 58 and actuated by the piston-rod 62 of a double-acting pneumatic cylinder 60. In operation, the shoes 58 are raised, the frames 14 are lowered and the heads 22 are retracted laterally by the cylinders 60, 20, &c. to allow a billet W to be advanced to a position opposite the heads. The frames 14 are then raised until the roller 26 contacts the billet, the heads 22 are advanced -to engage the sides of the billet and the shoes 58 are lowered into contact with the top lateral edges of the billet. Oxygen and acetylene are next supplied to the manifolds 31, 32 to feed the small orifices of the nozzles with mixed pre-heat gasses which are ignited by the hot billet and fluid such as compressed air is supplied to nozzles 66, 68 mounted respectively on the plate 21 and the shoe 58 to direct air jets on the bottom and top edges of the billet and confine the molten slag to the vertical surfaces being treated. When the billet reaches ignition temperature, its feed through the machine is started and the oxygen supply is connected to the nozzles N and also directly from the supply 36 by a pipe 77 to a single nozzle N' mounted on each shoe 58, the latter producing molten slag on the upper corners of the billet to assist the action of the uppermost nozzles N. As the boom 57 is lowered an adjustable screw 65 thereon engages the lever 46 and depresses the piston 37 and so adjusts the number of nozzles N which are supplied with cutting oxygen to the number required by the vertical width of the billet. When the billet has been de-surfaced, the supply of gases is shut off and the heads &c. retracted in preparation for the next billet which is contacted by the shoe 58 to again adjust the number of nozzles N in operation to suit the size thereof. Shields 78 are attached to the plates 21 to protect the gas mixers &c. from heat and cooling water is supplied to sprays within the shields and also to the burner heads. Hard metal wearing surfaces 23, 59 for engagement with the billets are provided on the heads 22 and shoes 58. The pre-heat gases to the nozzles N may be controlled in the same manner as the cutting oxygen supply and the billets may be at rolling temperature or cold.