GB554113A - Method and means for treating ferrous objects - Google Patents

Abstract

554,113. Treating ferrous articles. HYDROBLAST CORPORATION. July 24, 1942, No. 10402. Convention date, July 25, 1941. [Class 60] In order to. prevent rusting of ferrous articles after being treated by a wet sand blasting process such as that described in Specification 498,478, a corrosion inhibiting chemical such as potassium dichromate is dissolved in water to form a saturated solution and is then pumped into the water supply line of the sand-blasting gun, the mixture of water and inhibiting fluid being heated to body temperature before passing to a high pressure pump and to the gun to which the abrasive particles are also supplied. As shown in Figs. 1 and 2, potassium dichromate crystals are placed in a metal perforated basket 16 immersed in a water tank 10 in which water is maintained at a constant level and at a uniform temperature by cold water circulating through a coil 20, The solution is maintained in an agitated condition by a pump 30 connected to the tank 10 by flow and return pipes 34, 42. The solution is supplied to the water supply pipe 52 of the sand-blasting gun 74 by a pipe 46 under the control of a needle valve 44. The solution mixed with water is passed through a heater 64 and to a high-pressure pump 62 and thence through a pipe 76 to the gun 74 supplied with sand from a tank 80. In an alternative arrangement (not shown) the water in the pipe line 52 is passed through the heater 64 before the corrosion inhibiting solution is mixed with it. In a more simplified form of plant (not shown) the cooling coil 20 is dispensed with and a by-pass pipe is arranged between the outlet and inlet of the pump 30 which does not recirculate the solution in the tank 10.