GB792107A - Improvements in or relating to cutting or piercing refractory materials with powder-laden oxydising gas - Google Patents

Abstract

792,107. Flame drills. UNION CARBIDE CORPORATION, [formerly UNION CARBIDE & CARBON CORPORATION]. July 16, 1956 [Aug. 3, 1955], No. 21985/56. Class 68(1). [Also in Groups XXII and XXIII] In the cutting or piercing of a body of refractory material, such as stainless steel, slag, concrete, brick, by an oxygen lance comprising a ferrous metal pipe P which is supplied with oxidizing gas and a combustible adjuvant powder, the adjuvant powder is introduced into the pipe after the flow of oxidizing gas has been initiated, and is stopped before the oxidizing gas is shut off so as to purge the pipe P of powder and avoid pre-ignition. The pipe P of iron or stainless steel is secured by a coupling K and an adaptor 20 to a handle H carrying a valve body 16 and a single valve operating lever L. Oxygen is supplied through an inlet 18 and a valve C, Fig. 4 not shown) to a pipe 14; the adjuvant powder, comprising a mixture of iron and aluminium, is supplied through an inlet 26 and valve V, Fig. 3 (not shown) to a pipe 24 extending co-axially into the pipe P Depression of the lever L first opens the oxygen valve and then the powder valve and upon release of the lever the powder valve closes before the oxygen valve. The oxygen-powder mixture issuing from the end of the pipe P is ignited by directing it against a piece of smouldering cloth or wood. The lance may be used for flame desurfacing without the ferrous pipe being consumed. Examples are given of the preferred composition of the powder, the oxygen and powder pressures used and the dimensions of the pipe P