Patent GB-539479-A (GB)
Title: Improvements in processes and apparatus for coating by dipping metal strands with metals
IPC: C23C2/02
Filed: 1939-10-04
Abstract: 539,479. Coating metals by dipping. SYNCRO MACHINE CO. Oct. 4, 1939. No. 27182. Convention date, Jan. 19. [Class 82 (ii)] In the coating by dipping of metal strands with metals, the strip is annealed by moving i continuously in the direction of its length in an elongated ribbonlike flame, then passing it through an atmosphere containing a vapour or gas, such as chlorine, which has a fluxing action thereor and then applying a molten metal coating to the strand. The metal strand W is passed from a drum over feeding rollers anc between cleaning brushes into a heating apparatus, Fig. 2, where it is annealed by passing through ribbon-like flames emanating from a slot in a pipe 4, Fig. 6, mounted in the top of a hollow post 39 which is connected by a pipe 40 to a fuel supply pipe 42 connected to a fuel and air mixer 45. The strip is fed through apertured guides 37 mounted on brackets 36 supported by the posts 39. The annealed strip then passes into a fluxing chamber 49 through an opening 51, Fig. 11, upon which plays the flame of a pilot burner so as to prevent the entry of oxidizing gases. The strand passes through a thermo-couple 53 and then into a glass chamber 61 mounted in the casing 50 of the chamber 47 and into which dry chlorine gas is passed by a pipe 62. To maintain a. slight sub-atmospheric pressure in the casing 50 and chamber 61, the exit pipes 63, 67 pass through chambers 64, 68 which are provided with electric heaters 65. 69. The fluxed strand then passes through adjustable jets 86, 87 mounted in the wall 85 of a coating apparatus 73 in the form of a pot containing molten tin, being coated with tin in the small space 88 between the ends of the jets 86, 87. The apparatus 73 comprises an upper pot 74, Fig. 13, and a lower pot 74' separated by a wall in which is mounted a valve 79, and the whole is contained in a heat insulated casing 75 in which are embedded electric coils. The wall containing the valve 79 is provided with a series of apertures by which when the valve is operated the molten metal in the compartment 74<SP>1</SP> is forced up by a pipe 101 into the compartment 74 by fluid pressure supplied by a pipe 110 from a supply line 107 which is also connected by a pipe 129 to an air jet for removing excess cooling water from the strand when it is cooled after leaving the apparatus 73 and through a valve 112 to the chamber 74. When the valve is in one position the metal is supplied to the upper chamber and when turned into another position the supply of metal is stopped. A trough 89 mounted below the well 85 catches molten metal dripping from the jet 87 and is provided with an opening 89<SP>1</SP> connected by a passage in the wall containing the valve so that when the latter is in a certain position it directs the metal into the compartment 74<SP>1</SP>. The metal in the trough is kept molten by an electric heater 90. Excess coating on the coated strand is removed by a wiper 95, Fig. 11, in the form of a coiled spring with another spring 96 mounted round it, both mounted on a plate 92 provided with a guide 92<SP>1</SP>. Lubricating oil may be applied to the coated wire before it enters the wiper 95 by a pipe 94. Another spring wiper 97, Fig. 2, may be mounted on the plate 92. The strand is then cooled by passing through two water troughs between which is mounted another spring wiper After leaving the second cooling chamber the strand passes through an air jet fed from the pipe 129 to remove excess water on the strand. The heated strand may be cooled before it enters the fluxing chamber by passing it through a chamber containing circulating water, and then the end of the annealing flame enters a small aperture in the side of the cooling chamber to prevent access of air thereto. In a modification the strip may be annealed by passing through the upper part of the heating flame and then returned through the lower part of the flame before it is fluxed and coated. Specification 525,936 is referred to.