Design and performance of a high velocity air-sand jet impingement erosionfacility

This paper describes the design, construction and capabilities of a high ve locity air-sand erosion rig. It has been designed with the aid of computati onal fluid dynamics to approximately simulate the erosion conditions often experienced by subsea choke valves used in the offshore oil industry. It ha s also been designed to evaluate the erosion performance of CVD diamond coa tings at sonic velocity. The rig is of the gas-blast design in which solid particles, typically sand 60-660 mu m in size, are injected into a high vel ocity air stream and accelerated down a 16-mm-diameter tube, 1 m in length, before striking the sample under test. Tests can be carried out with parti cle velocities of up to 340 m/s under a wide range of sand fluxes, impact a ngles and standoff distances. The results of pressure, velocity and sand fl ux calibration work are described. In addition, preliminary experimental da ta on tests carried out on mild steel, bulk and sprayed tungsten carbide ar e also presented. The flexibility of the air-sand rig allows the erosion be haviour of materials to be studied under a wide range of conditions. (C) 19 98 Elsevier Science S.A. All rights reserved.