The Basics of Hydrocyclones

 The use of fluid dynamics holds a key role in a wide variety of industries. You will observe the application of fluid dynamics in a number of processes from wastewater treatment to processes applied to obtain purity in various materials. Hydrocyclones are a prime example of fluid dynamics. A hydrocyclone can be referred to as a piece of equipment that generates centrifugal force using fluid pressure. We have put together some useful details about the structure and working of hydrocyclones, that will help you understand the basics of this useful equipment. Further details are given below:

Working of a Hydrocyclone:

The centrifugal force generated by a hydrocyclone results in a flow pattern that forces the separation of particles or droplets from the liquid medium. To achieve separation, these particles or droplets must have a sufficiently different density relative to the medium. The centrifugal force makes the flow pattern cyclonic, which is why this piece of equipment is called a hydrocyclone. This flow pattern occurs because the liquid is induced into the cylindrical chamber using the tangential injection method. This tangential injection of liquid into the cylindrical chamber results in the development of a vortex. The cylindrical chamber of a hydrocyclone is equipped with a restricted axial bottom outlet. Not all of the liquid can leave the cylindrical chamber at once via this outlet. This is why some quantity of liquid reverses its path and flows concurrently towards the axial top outlet of the cylindrical chamber. This whole reverse flow process continues to go on, and ultimately an air core is generated because of the low pressure at the axis of rotation.

 

Separation of Particulates:

As both the upward and downward flow streams exist in the cylindrical chamber, the locus of vertical velocity becomes zero as a result. On the other hand, both these flow streams are also equipped with tangential velocity. This tangential velocity decreases in the outer vortex, if the radius increases. In general, the outer fluid approaches a free vortex and experiences shear, while the inner fluid acts like a solid. The centrifugal force produced in the cylindrical chamber of a hydrocyclone is substantial to separate particulate solids down to around 5 to 10 microns in size. There will be a higher amount of force and efficiency of separation of small particles because of a cyclone with a smaller diameter. Hydrocyclones with longer cones designs is said to be efficient enough to deal with particles of less than 5 microns. However, the small diameter of a hydrocyclone means low fluid capacity. Such hydrocyclones are manifold and linked in parallel for industrial applications. 

 

Applications of Hydrocyclones:

Here are some applications of hydrocyclones:

• These hydrocyclones were at first used in the mining industry for efficient separation of solids and liquids, such as the dewatering of particulate solids that are suspended in the water stream. 
• Hydrocyclones are also used in the food industry to ensure the quality and purity of food products.
• These useful pieces of equipment also find their use in the chemical industry, where chemicals need to be in their purest form to deliver the desired results.