How a Hydrocyclone Filter Works

Hydrocyclone filters are highly effective at filtering larger particles out of fluid, providing effective protection from heat exchanger clogging by sand, mud and clay particles.

Slurry feed enters a cyclone at an acute angle, creating a swirl flow. Heavier particles gravitate toward the wall of the cyclone while lighter ones pass out through its overflow outlet.

Centrifugal Force

Hydrocyclones provide an expedient method of separating solid contaminants from coolant by spinning them at greater rates than they would naturally settle out over time. Contaminated coolant enters through a feed connection tangential to its cylindrical section of the cyclone.

This generates a swirling motion and centrifugal force, pushing heavy components towards the wall of the cyclone. Heavier particles agglomerate together before discharging through an underflow outlet at the bottom, while cleaner coolant moves upward to an overflow outlet.

Separation Zone

Tangential injection of the slurry into the cylindrical chamber creates a cyclonic flow pattern, producing an area where lighter, finer particles exit as overflow while heavier coarser ones enter through a lower axial outlet as underflow.

Figure 9a-c illustrates axial, tangential, and radial fluid velocity fields inside of a filtering cylindrical hydrocyclone filtering device. Radial velocity increases from the inlet section until reaching a maximum near its bottom outlet axial outlet.

Cyclones can effectively separate solid contaminants from liquid medium. Their effectiveness depends on particle size and density differences between slurry and liquid media.

Inner Vortex

Hydrocyclones work by injecting liquid tangentially into cylindrical chambers which create large vortices, creating zones of low pressure where an air core forms.

Studies have investigated the influence of internal vortex-finder diameter and length on classification efficiency.

Outer Vortex

Hydrocyclones are closed vessels designed to convert liquid velocity into rotary motion by means of their conical shape and centrifugal force. Heavier components agglomerate at the bottom, funnelling towards an underflow outlet; lighter ones move towards an overflow outlet located higher up on its walls.

Size, feed inlet geometry, vortex finder and optional feedbox extension play an important part in shaping flow patterns and separation efficiency as well as pressure drop and reject port discharge capacity.

Cylindrical Section

Hydrocyclone filters use swirling motions to separate fluid contaminants, with heavy solid particles moving toward the walls and being discharged through an underflow outlet at the base. Clarified liquid moves towards the top and is discharged through an overflow outlet.

Particle size and density have an enormous effect on the separation efficiency of hydrocyclones, while feed pressure also plays a significant role by affecting centrifugal force distribution, centrifugal force generation, wear on inner surfaces of hydrocyclones as well as wear at their outer surfaces.

Conical Section

Made of durable reinforced engineering plastic for increased longevity – sand is collected in the collector chamber and easily cleaned out for low maintenance costs.

Entrained particles hit with the Cyclone body and move upwards into an inner vortex where they are separated from the gas stream. Entrained particles then move down spirally towards a reject port at the base of the separator where pressure can be changed by changing pump speed; this determines separation efficiency – coarser or finer cut cuts depending on its parameters.

Underflow Outlet

Slurry enters a hydrocyclone main body via tangential entry and spins within its conical shape, increasing centrifugal force while simultaneously concentrating heavier particles toward its wall.

Heavier particles tend to settle toward the apex opening and underflow outlet while lighter material rises through a vortex finder before exiting through an overflow outlet at the top.

Overflow Outlet

To increase separation efficiency and decrease pressure drop, the overflow outlet is modified. By increasing the number of slots, enlarging openings, lowering fluid resistance when flowing through overflow pipe and ultimately decreasing local pressure at bottom as well as dynamic pressure loss in internal swirling flow.

When applied to an otherwise identical hydrocyclone, this design produces a smaller pressure drop while still maintaining near constant separation efficiency – leading to significant energy reduction and cost savings.