Optimizing the separation characteristics of the waterinjection hydrocyclone using mathematical modelling

Purpose. Although the hydrocyclone separator has many advantages, it still has some limitations which decrease its separation efficiency in many mineral processing applications because of fine particles which are miss separated to the coarse product in the underflow. Water injection in the conical part of the cyclone was recently implemented to solve this problem. The water injection mechanism and the way in which the injected water affects the separation are still not clear and need to be more investigated. Methods. New design of water injection hydrocyclone was tried using a modified conical part with a water injection range consist of five equal distance injection openings open directly on the periphery of the cone part. Findings. This study presents a mechanical mathematical model that simulates the water injection to give a clear indication of the injection mechanism impact on the classification process. It could also predict the dependence of the basic characteristics of the classification on the amount of the injected water and the influence of different operating and design parameters of the hydrocyclone. Originality. The model accounts for the fluid flow, the particle motion, the turbulent particle diffusion, and particle settling. Particle interactions and fine particle entrainment by settling coarse particles are also included in the model. The model was found to predict well the injection effect and agrees with the experimental results. Practical implications. The results showed also that the increase in water injection velocity leads to an increase in both the cut size and the minimal value of the separation curve. It was found also that the hydrocyclone length has an important effect on the injection process, and the separation sharpness is directly proportional to it at higher values of water injection velocity.

Comparison of Suction/Injection Effect on Flow, Heat and Mass Transfer in Porous Media Using a Combined Similarity-Numerical Solution

This investigation deals with a comparison of suction/injection effect on flow, heat and mass transfer in porous media using a combined similarity-numerical solution. With this method of transformation, the governing transport PDEs are transformed into ODE and then solved numerically. The study reveals that suction/injection effect is more pronounce on the velocity distribution of a creeping flow (Darcy flow). The Darcy-Forchheimer flow has the steepest velocity curves due to non-linearity and has higher skin friction, heat and mass transfer rate when compared to the other porous media investigated.

Optimization Technique and Practice of Stratified Injection in Low and Medium Permeability Thin Interlayer Reservoirs

Reservoir S is a typical medium and low permeability thin interlayer reservoir. It is developed by co-production of directional Wells and separate injection of directional Wells. The comprehensive water content of the oilfield is 54%. Therefore, it is urgent to optimize the injection method of stratified injection distribution in this reservoir, so as to improve the degree of water driving and recovery. In this paper, the reservoir engineering and numerical simulation methods are adopted to introduce the impact factor of injection-production correspondence rate, modify the previously used fine injection matching model, and use the model to quantitatively analyze the sensitivity of key parameters such as longitudinal splitting coefficient, pressure recovery rate and injection-production correspondence rate. The results show that it is very important to select the influencing factors for the injection and production response ratio of medium and low permeability thin interlayer reservoirs, which directly affects the effect of stratified water injection. At present, this research technology has been widely applied in S oilfield, and the water injection effect is very significant, effectively improving the recovery rate of the implementation area by 2%, which provides experience for the water injection development of similar reservoirs.