The aim of the paper was to develop determination methods of sedimentation characteristics using PIV image anemometry and suspension image analysis. Two methods of the investigation of sed- imentation process based on visualization techniques were developed. In the first one, using PIV method, vector fields of the velocity of settling particles are determined and then average particle velocities are calculated to establish the so called sedimentation dynamics curve. In the second one, the methods of suspension image analysis are utilized to determine the positions of the upper dis- continuity and to establish the sedimentation curve. Laboratory research on the sedimentation of agalit particles suspended in glycerine was conducted (using PIV method). Additionally, industrial research on the sedimentation of water-absorbing granular material used after the first carbonation (carbonation I) was conducted in a sugar factory (using the second method). The research consisted of photographic registration of images of the settling suspension by means of the time-lapse photog- raphy technique. A laboratory study was conducted for four values of the volume concentration of agalit particles in glycerine (0.5; 1.0; 1.5 and 2.0 vol%). The research methodology, the scope of the conducted measurements and sample research results together with conclusions are presented in this paper.
This study is concerned with liquid flow induced by a disk which rotates steadily around its axis and touches the free surface of liquid contained in a cylindrical vessel. It is a simplified model of the flow in the inlet part of a vertical cooling crystallizer where a rotary distributor of inflowing solution is situated above the free surface of solution contained in the crystalliser. Numerical simulations of flow phenomena were conducted and the simulation results were interpreted assuming an analogy with Kármán’s theoretical equations. In a cylindrical coordinate system, the components of flow velocity were identified as functions of distance from the surface of the rotating disk. The experimental setup was developed to measure velocity fields, using digital particle velocimetry and optical flow. Conclusions concerning the influence of disc rotation on liquid velocity fields were presented and the experimental results were found to confirm the results of numerical simulation. On the basis of simulation data, an approximation function was determined to describe the relationship between the circumferential component of flow velocity and the distance from the disk.