You can solve problems at your own factory! Encyclopedia of coolant filtration equipment "Kuraroka" " Basic Knowledge of Centrifuges

centrifuge

What is a centrifuge?

Equipment that uses centrifugal force to separate liquids with different propertiesThe following is a list of the most common types of liquids that can be separated. It can separate liquids of different specific gravity that do not dissolve into each other, such as solid and liquid or water and oil.

The method of generating centrifugal force is high-speed rotation of the sample. A rotating object generates a force that acts outward. This is centrifugal force. An easy way for humans to experience centrifugal force is to fill a bucket with water and shake it vigorously. The water does not spill because of the centrifugal force generated.

This force is generated by a machine, the centrifuge.Centrifugal force, which is greater than gravity, can be used to bring out in a short time the property of liquids to be separated by the difference in specific gravity.

Centrifuge Mechanism

There are two types of separation. There are two types of separation: gravity sedimentation and centrifugal separation. The types of centrifugal separation are further divided into "centrifugal sedimentation" and "centrifugal filtration. A centrifuge is a machine that performs "centrifugal sedimentation" and "centrifugal filtration.

When a bucket of water is turned upside down, gravity causes the water inside to spill. However, if you hold the bucket, swing it around, and rotate it, the water will not spill. This is because centrifugal force exceeds gravity.Centrifugal force is a force many times greater than gravityIt is.

When mud is added to water in a bucket, "gravitational settling" causes the mud to slowly accumulate at the bottom of the bucket. Centrifugal force increases the speed of this separation. Centrifugal force, which is greater than gravity, causes the mud to accumulate at the bottom of the bucket more quickly. This is how "centrifugal settling" works.

Furthermore, if you make a small hole in the bottom of the bucket through which the sand cannot pass and swish it around, only the water can be let out and the sand can remain in the bucket. This is "centrifugal filtration.

Centrifuges generate forces hundreds to tens of thousands of times greater than gravity.The centrifugal sedimenter is a mechanism in which heavy liquid is formed on the wall of the rotor and light liquid is formed on top of it.The two are. Each is discharged to collect the separated liquid.A centrifugal filtration machine is a mechanism that separates the liquid from the individual pieces of processed material by attaching filtration material to a rotating body and passing it through it.It is the only one.

Types of centrifuges

Batch type, continuous type

Centrifuges can be classified into "batch type" and "continuous type. The batch type is a method in which a single cycle of "feeding, separation, de-liquidating, discharging, and washing" is completed each time. On the other hand, in the continuous type, the liquid is supplied again before the first feed is discharged, and the process is not completed one at a time, but rather continuously.

Vertical, horizontal, diagonal

The types by shape are "vertical type," "horizontal type," and "slanted type. Vertical centrifuges are those with the basket facing upward, horizontal centrifuges are those with the basket facing horizontally, and slanted centrifuges are those with the basket at an angle.

Top discharge type, bottom discharge type, suction type, ball type

Types by discharge method include "top discharge type," "bottom discharge type," "suction type," and "ball type. The top discharge type discharges solids from the top of the centrifuge, the bottom discharge type automatically discharges crystals from the bottom of the machine, the suction type discharges by pneumatic conveyance through a nozzle, and the ball type continuously discharges deoiled chips by continuously feeding cutting chips into a ball-type basket.

Advantages and disadvantages of centrifuges

Batch type, continuous type

The advantage of the batch system is that it can be cleaned,Capable of filtering a variety of liquidsThe advantage is that the batch-by-batch management makes it easy to identify when a product needs to be recovered, etc. Another advantage is that batch-by-batch management makes it easy to identify when a product needs to be collected. On the other hand, it takes a long time to process. It is not suitable for mass production and mass processing.

Continuous type is because it reduces processing time,Capable of mass production and mass processingThe disadvantage is that the machine cannot be stopped on a case-by-case basis. The disadvantage is that it is difficult to stop the machine at any time, making it difficult to respond flexibly, and when a defect occurs, it is difficult to trace the defect to the part of the machine where it occurred.

Vertical, horizontal, diagonal

Vertical type is,Space-saving and high-capacity processingIt is. However, containment of highly pharmacologically active and toxic substances is difficult, and there is a risk of contamination by foreign substances.

For horizontal type, only the front of the basket is installed inside the clean room, etc,Easy to prevent contamination by foreign objectsThe advantage is that the Since the drive unit can be outside the clean room, it saves space in the clean room. However, the overall machine size is larger than the vertical type. The maximum throughput is also small, so it is not suitable for mass processing.

The diagonal type is for working without bending at the waist,Reduced operator workloadThe product is then placed in a horizontal position. As with the horizontal type, the risk of foreign material contamination can be reduced. Similar to the horizontal type, the size and the fact that it is not suitable for mass production.

Top discharge type, bottom discharge type, suction type, ball type

What are the advantages of the top-discharge type?All of the crystals can be recovered.This means that It can handle small quantities, making it suitable for high-mix, low-volume production. It is not suitable for automation, and the high risk of foreign matter contamination is a disadvantage.

The bottom discharge type is,Automation is possible.It also reduces the risk of foreign material contamination. The disadvantage is that it is difficult to collect the entire amount.

The suction type is,Low risk of foreign material contaminationOn the flip side, the nature of the crystals may clog the pipes. Not suitable for high-mix production.

Summary of Centrifuges

The mechanism and types of centrifuges were explained.

Centrifuges are machines that utilize centrifugal force greater than gravity to separate
Centrifugal sedimentation and centrifugal filtration are available.
There are different types of centrifuges depending on "usage," "shape," and "discharge method.

The nature of the material to be separated determines whether it is separated by "centrifugal sedimentation" or "centrifugal filtration. In addition, each type of centrifuge differs in terms of processing efficiency, risk of foreign matter contamination, space saving, etc., and it is not possible to say which one is better than the other. It is important to select the centrifuge that best suits the processing content based on the merits and demerits.

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