Hydrocyclone Filter Enhancing Performance in Liquid Solid Separation
Hydrocyclones are highly effective at separating solid particles from liquid medium due to the centrifugal force generated within. However, it is crucial that both axial and tangential velocity be carefully managed so as not to obstruct or interrupt the separation process.
Optimizing the positioning dimensions of a slotted structure enables a balanced distribution between separation efficiency and pressure drop, enabling customized separation performance with either low or high axial velocity options.
Enhanced Separation Efficiency
Hydrocyclone separation efficiency is strongly determined by its internal flow conditions. An increase in inlet flow rate generally results in improved separation performance while decreasing diameter leads to smaller cut sizes and reduced energy usage [1].
Hydrocyclone structural parameters also play a significant role in its performance. A larger cylindrical section increases processing capacity and separation efficiency while larger conical sections provide improved collection efficiency [2].
In general, smaller particles tend to experience greater centrifugal force. This forces them to adhere more strongly to walls and enter overflow.
Design of a hydrocyclone is of vital importance in order to maximize its separation efficiency, especially in cases involving complex materials with wide particle size distribution. Achieve optimal results requires selecting an axial-tangential velocity combination of 50-60% as appropriate.
Reduced Pressure Drop
As slurry is fed into the hydrocyclone’s cylindrical section, centrifugal force spins it, producing a swirl that separates solid particles from liquid. Heavier particles move toward the wall of the cyclone for discharge through its underflow outlet while lighter finer particles travel upward through its overflow outlet to exit via its overflow outlet at its top.
A cyclone’s overall separation performance is determined by its geometry of design, including feed inlet configuration, diameter of cylindrical section and cone angle, vortex finder depth and overflow slit arrangement. Optimizing these parameters is essential to reaching desired separation efficiency with low pressure drop.
Results show that increasing the number of overflow slits in a cyclone was found to enhance its separation efficiency and pressure drop under identical operating conditions, due to decreased average tangential velocity in its overflow region (see Figure 7 for fluid velocity results across meshes used).
Reduced Maintenance Costs
Hydrocyclone filters provide a cost-cutting alternative to using multiple downstream equipment and can drastically cut maintenance costs. They’re particularly well suited for applications requiring high centrifugal force or separation efficiency such as desliming before classification tanks, screw fasteners and refute classifiers.
A cyclone comprises three sections, from its cylindrical section, where primary separation takes place, through to its conical section where centrifugal force increases even further, and finally to its overflow outlet at the top where cleaned water can be discharged. Adjustments to feed pressure, slurry concentration, size/density particle concentration and outlet size can enhance separation performance further.
An extensive experimental study demonstrates that overflow slit design factors, including number of layers, positioning dimensions and slot angle have significant effects on separation efficiency and pressure drop when operating under identical conditions. An optimal design may find the balance between separation efficiency and pressure drop by regulating its dimensions; customized separation can even be accomplished.
Customized Separation
Design of overflow slits for hydrocyclones is an integral factor that determines their separation performance. By optimizing positioning size and number of slits, we can find an optimum compromise between separation efficiency and pressure drop.
Orifice angle also greatly impacts the separation performance of hydrocyclones; therefore, our experiment included different models with differing orifice angles to test for pressure drop and separation efficiency under identical inlet flow rate conditions.
The relationship between axial velocity and tangential velocity and particle size efficiency of a hydrocyclone is directly proportional. By tailoring these two variables to meet the characteristics of materials being processed through, we can increase separation efficiency while expanding application range of our filter. Increasing tangential velocity may reduce energy loss while simultaneously increasing centrifugal force on light particles entering overflow outlet; while decreasing axial velocity will lengthen residence times for coarse particles for improved separation efficiency.