Measurements of the flow field in a gas cyclone with the aid of a two component laser Doppler Velocimeter

Abstract

Because of their elementary design and construction, added to a high operational reliability, the scope of application of gas cyclones has become very large. Indeed, in many instances where high temperatures and pressures are concerned, they are the only viable economic process. The knowledge of the flow field and of the particle motion constitutes a prerequisite for the understanding of the separation mechanisms under various operational conditions and thus also for constructive modifications aimed at improving the separation efficiency. This publication describes the simultaneous measurement of the tangential and radial velocity components of the fluid phase in a gas cyclone using a Laser-Doppler-Velocimeter system, developed at the above institute.In order to examine various types of appliances it is necessary to utilize equipment which offers a high flexibility regarding the optical accessibility. The 90° optical receiver presented in this report offers the advantage of being able to specifically define an almost cubic measuring volume by means of appropriate masking. Two-dimensional normalized frequency distributions of both radial and tangetial velocity components are to be presented, which offer a high degree of information concerning the flow at a particular location. Furthermore, profiles of the tangential and radial components’mean and r.m.s. values are also presented.Because of their elementary design and construction, added to a high operational reliability, the scope of application of gas cyclones has become very large. Indeed, in many instances where high temperatures and pressures are concerned, they are the only viable economic process. The knowledge of the flow field and of the particle motion constitutes a prerequisite for the understanding of the separation mechanisms under various operational conditions and thus also for constructive modifications aimed at improving the separation efficiency. This publication describes the simultaneous measurement of the tangential and radial velocity components of the fluid phase in a gas cyclone using a Laser-Doppler-Velocimeter system, developed at the above institute.In order to examine various types of appliances it is necessary to utilize equipment which offers a high flexibility regarding the optical accessibility. The 90° optical receiver presented in this report offers the advantage of being able to specifically defi...