Hydrocyclones centrifugal separation

Hydrocyclones. Particle separation in hydrocyclones uses the centrifugal force as the means of separation. The slurry, consisting of clean soil and contaminated particles, is separated... 

A hydrocyclone is a device employing centrifugal separation without the need for mechanically moving parts, other than a punq). They are cheap, conq)act and versatile as a means of solid-liquid separation. It is similar in operation to a centrifuge, but with much larger values of g -force (ranging from 800 g in a 300 mm diameter cyclone to 50 000 g in a 10 mm diameter cyclone). This force is, however, applied over a much... 

Separation criteria are fundamentally different depending on whether the flnid flow is of sohd-body rotation type or vortex type. By way of example, the qnality of separation is affected when the flow rate through a centrifugal separator is increased, while the inverse property is obtained in a hydrocyclone. 

Hydrocyclones are centrifugal separators which enable the separation of solid partieles that are denser than the fluid, or of less dense partieles (those are often non-tniscible droplets in another liquid). Such apparatus present the advantage of not including any moving parts. The rotation results from the winding of the flow in a circular cyhndrical cavity. 

Time is a critical variable because the magnetite settles if the mixture is held too long in a static condition. Use of hydrocyclones makes possible the separation in a fraction of a minute (21). These devices impart centrifugal force to the system, thereby permitting a separation to be made at a specific gravity less than that required in static, heavy-Hquid separations. 

In 1981, a novel flotation device known as the air-sparged hydrocyclone, shown in Figure 3, was developed (16). In this equipment, a thin film and swid flotation is accompHshed in a centrifugal field, where air sparges through a porous wall. Because of the enhanced hydrodynamic condition, separation of fine hydrophobic particles can be readily accompHshed. Also, retention times can be reduced to a matter of seconds. Thus, this device provides up to 200 times the throughput of conventional flotation cells at similar yields and product quaHties. 

Cyclones, hydrocyclones and centrifuges utilize centrifugal force to separate material of differing... 

The capacity of filtration centrifuges is very dependent on the solids concentration in the feed. For example, at 10 per cent feed slurry concentration 9 kg of liquid will be centrifuged for every 1 kg of solids separated whereas with a 50 per cent solids concentration the quantity will be less than 1 kg. For dilute slurries it is well worth considering using some form of pre-concentration such as gravity sedimentation or a hydrocyclone. 

Hydrocyclones are used for solid-liquid separations as well as for solids classification, and liquid-liquid separation. It is a centrifugal device with a stationary wall, the centrifugal force being generated by the liquid motion. The operating principle is basically the same as that... 

Centrifugal force can also be used to separate solid particles from fluids by inducing the fluid to undergo a rotating or spiraling flow pattern in a stationary vessel (e.g., a cyclone) that has no moving parts. Cyclones are widely used to remove small particles from gas streams ( aerocyclones ) and suspended solids from liquid streams ( hydrocyclones ). 

In the hydrocyclone, or hydraulic cyclone, which is discussed extensively in the literature(29 35), separation is effected in the centrifugal field generated as a result of introducing the feed at a high tangential velocity into the separator. The hydrocyclone may be used for ... 

The degree of cell separation is an important parameter to be evaluated in perfusion systems. This can be done through the use of some concepts as cell separation efficiency, grade efficiency, and cut size. These concepts are applicable to any equipment whose performance remains constant if the operational conditions do not change. They are valid, therefore, for equipment such as sedimenting centrifuges, hydrocyclones, gravitational settlers, etc. 

---