Velocity measurements in a shotblasting machine

Abstract

Abrasive shotblasting particles and a high concentration of dust within the closed testing chamber make particle velocity measurement in a shotblasting machine very difficult. The application of non-obstructive optical methods is usually impossible. Robust shields protecting the sensors from abrasion have to be used for contacting velocity measurements and make direct application of capacitive or electrodynamic sensors usually applied in the correlation-based velocity measurements methods not possible. An alternative electronic measurement system has been developed. It has a simple construction and uses low cost elements which can be replaced very quickly and, therefore, no robust shields are necessary. This enables very good mobility and positioning of the sensor along both axis in a cross-section plane of a particle stream. The system has been tested along with a robust mechanical measuring device. The development, operation and application of mechanical and electronic particle velocity measurement system are described in this paper. Experimental results are presented, discussed and both methods are compared.