GB830209A - Improvements in high pressure apparatus - Google Patents

Abstract

<PICT:0830209/III/1> <PICT:0830209/III/2> High-pressure apparatus comprises a pair of opposed recessed pistons; means for exerting pressure against at least one of the pistons; a die positioned partly within the recess in each piston, each die being provided with an annular lip surrounding a central recess; a reaction vessel located within the recesses of opposing die faces; and an annular insulating and pressure-resisting gasket surrounding the reaction vessel, the gasket tapering laterally and being arranged to have its outer edge fit between and be engaged by the lips of the dies. Fig. 2 shows part of one arrangement wherein each die 18 is surrounded by a number of binding rings 19 (of which only one is shown) and is provided with a central recess surrounded by an annular lip 23. The recesses are filled with blocks of insulating material 24 and by a reaction vessel comprising a hollow conductive cylinder 27 arranged between conductive end discs 26 and surrounded by an insulating washer 29. The reaction vessel is surrounded by a thermal and electrical insulating washer 30 which is tapered so that its outer edge fits between and engages the lips 23. In operation pressure is applied to the dies by the pistons of an hydraulic press and at the same time an electric current is passed through the reaction chamber via the dies; thus a pressure of 35,000 atmospheres at a temperature higher than 2500 DEG C. may be maintained in the reaction vessel. Still higher pressures may be obtained if the washer 30 is surrounded by a compressible insulating gasket 31, Fig. 3, which may be of rubber or plastic and is held in place by soft steel retaining rings 32, 33. In a further arrangement, Fig. 4 (not shown), the apparatus is similar to that of Fig. 2 except that the washer 30 is divided into two halves with a metal washer arranged between the two halves.