A Separator functions differently from a Hydrocyclone even though it is a revised form of the latter. They work better in specific applications due to their different functionalities.
It could be helpful to consider their distinctions to choose between using a Hydrocyclone and a Separator inside a sand plant. Then, learn the fundamentals, including how they work and what you are used for, the benefits of employing hydrocyclones, how to choose and build a hydrocyclone, how to choose and install a hydrocyclone, and lastly, how to alter a hydrocyclone’s performance to get the better effect.
A rising gravity separation tool called a hydrocyclone is used to sort slurry particles according to particle weight. For instance, particles that are different in size but have the same particular gravity or particles that are different in size but have various individual gravity. Since cyclones have far higher throughput than alternatives like the conventional filter press, they are frequently employed for dewatering sludge. The hydrocyclone functions based on a conical chamber that creates vortices. Through a vortex finder, the liquid slurry is introduced at the summit of the hydrocyclone’s conical wall, producing tangential flow and a strong vortex. The slurry inside the cyclone swirls in a vortex with great speed.
In the mineral processing sector, hydrocyclones are commonly employed for slurry drying or elevated mean particle separation employing a vortex effect. They are not adversely affected by the alternatives’ percentage steps:
A mineral production plant frequently houses a complete battery of hydrocyclones since they can handle extremely high slurry throughput speeds. However, the high impact wear rate of the hydrocyclone inner surface lining caused by the rapidly moving gritty slurries somewhat offsets the benefit of producing high-quality hydrocyclone. For this reason, fatigue materials, often alumina ceramics, must be used to line the pipelines (inlet and overflowing), vortex detector, cyclones chamber, and outflow spigot (underflow). Additionally, the impingement degree varies inside the hydrocyclone for various regions. However, the wear loss should be equal for practical service reasons. Thus ceramics with better wear resistance may be utilized for high-impingement-angle locations like the top wall between the vortex finder and the flowmeter spigot.
One of aluminum’s most significant volume applications in the mineral processing industries is the refurbishment of hydrocyclones. Due to the high cost of loss of production in a minerals processing plant, which may reach the millions of dollars per day range in extensive facilities, it should ideally be performed as frequently as possible.
More people are aware of and use hydrocyclones, often known as cyclones.
A cyclone operates best under stable input conditions for flow rate and solids. For the Separation to occur predictably and repeatedly, the desired pressure must be maintained at a constant rate.
The input pressure and variations in flow rate are directly related. Smaller particles are sent into the integer overflow by high pressure, whereas larger particles are sent into the overflowing by low pressure.
A Separator can perform virtually as well as a cyclone in some applications, but particle recovery is such an application where a cyclone is recommended.
Over 15 psi is the maximum pressure at which a cyclone may function. When attempting to record as much information as possible, this is crucial. In addition, through increasing angular speeds, the higher pressure will boost the lateral force on all of the particles.
Finer particles will report towards the underflow as smaller particles are spun to the cyclone wall by more vital centrifugal forces.
Underflow changes are a result of variations in the slurry’s total solids. The amount of water that flows into the integer overflow and overflow is determined by the size of the apex.
Having the least quantity of water responding to the underflow is often a secondary objective.
When the right apex is chosen, a cyclone may still remove the bulk of the water even though its underflow won’t have as many solids as a Separator can.
One of these things will occur when the apex is not proportioned adequately to the ratio of particles reporting to the integer overflow and the number of solids is too much for the peak to handle:
When the volume of solids is larger than the apex can manage, roping in the integer overflow occurs. As a result, the air core collapses, and the cyclone division becomes ineffective.
Safeguards may be required, or Separators may be utilized in cases where roping has the potential to affect a downstream operation significantly. The large apex of a Separator dramatically reduces the possibility of roping.
Conversely, more water reports to the integer overflow as the number of solids in the slurry decreases. As water will always transport some fine particles, regardless of the cut, this circumstance will result in more fines entering the underflow.
There is a rise in fines due to the underflow because there is more water.
The input % solids, also known as density, should remain constant primarily to get the maximum performance from a cyclone.
The cyclone should be examined first if the size is a deciding factor. This is particularly true if the underflow can be diluted backward to less than 50% by weight or if it doesn’t need to be strictly regulated.
Desliming before a classification tank, screw fasteners, and refute classifiers (i.e., Hydrosizers) are a few applications that fit within this situation.
A cyclone placed in front of these kinds of applications might reduce the size of the following equipment that is needed. To do this, undesirable fines are eliminated while keeping the appropriate size fraction.
These uses are comparable to reducing the load on a sizing screen by using a scalping screen.
Water was drawn up through into the vortex finder to use a siphon in dividers to separate it from solids.
The upper-pressure limitation for this way of performing the Separation is between 14 and 15 psi.
The Separators are best suited for applications that require a consistent percentage of solids inside the underflow or experience significant changes in the percentage of solids in the feed.
The Separator’s efficiency can withstand variations in feed density from 1% to 25%.
Higher flow meter densities can be attained by doing away with the air core since the solids will accumulate in the area just above the flow path regulator.
To ensure a dry underflow, a Separator should be used. Due to this, a Separator is an excellent choice for material stockpiling without the need for extra machinery.
The word “stackable” is most frequently used to describe the stream from a Separator. The material will pile up even while there is still considerable water in the underflow. This is great when the stockpiling can be left unattended for one or two nights so that extra water can drain out.
A Separator and Dewatering Screen combo can create a “drip-free” product whenever the material can’t be left for a few days.
Drip-free means no water leaks when you compress a handful of sand.
Short of utilizing a filter and a dryer, this Separator and Dewatering Screen combination eliminates the most water from the end product, readying it for bulk storage or transport.
Although a cyclone can be employed in the combination since it is suitable for recovering fines, it will cause a greater wash-through of the material’s fine fraction.
Controlling the percentage of solids in the material is necessary for some technology, including attrition cells, to function at its best.
If the underflow is constantly in the area of 75% to 79% solids by weight, a Separator will remove more moisture than is required.
The optimal moisture range for an attrition cell is between 65% and 75%, but it is typically simpler to add water to assure appropriate operation.
A cyclone can produce an underflow concentration of up to 70% solids by weight, but any changes in the feed will result in inconsistencies in operation.
A hydrocyclone is the best option when the feed volume is constant, and sizing is the critical process criterion. A cyclone will always be preferred for high-pressure demands over 15 psi.
A separator is the best solution when the underflow must contain the least amount of moisture feasible or when the input density will fluctuate significantly.
