Factors to Consider When Picking an Air Classifier

An air classifier is a machine that is used to separate materials according to their size, shape or density. It is used in industrial processes where we are dealing with large volumes of mixed materials where the constituents are of differing physical properties. An air classifier can separate the constituent particles quickly and efficiently. For air classifier manufacturers, the construction industry is one of the most important where a classifier is used to separate aggregate materials.

It is equally important in the cement, pigments, food processing, pharmaceuticals, chemical and cosmetics industry. Another interesting application of the air classifier is in air pollution control where the pollutants are separated using the classifier and then processed as required. As a machine the air classifier’s performance will depend on the manufacturer. So, if you are alloying for a classifier, these are the following factors you should look for:

They have what you need

All air classifiers are not the same. The basic property of the classifier is to use air, centrifugal force and gravity to classify the different materials. This simple definition has a wide scope. Consequently, there are many different types of classifiers that one can choose from. While an air classifier will use a combination of gravitation and centrifugal forces in its functioning, there are classifiers that lay more emphasis on one function than another.

For instance, there are centrifugal classifiers that use the drag force generated by internal baffles to create a very effective centrifugal force. With a rounded belly that ensures a spiral path for the particles and an almost cyclonic force built up inside its chamber, the centrifugal classifier uses the force of air and the centrifugal force an even more efficient solution.

The gravitational air classifier, on the other hand relies mainly on gravity. This classifier has a vertical body where the particle mix is dropped from the top and the air force separates the particles into vents at the sides of the classifier. This is a more efficient method for coarse particles. Similarly, there are other constructions that are equally useful. The selection depends on the material you are working with. A good air classifier manufacturers will advise you on the right design.


Air classifiers can be huge or quite small. The requirement depends on the volume of processing you are looking at. If you want a huge classifier, ensure that your manufacturer can arrange the appropriate transfer, since it will be difficult to do so on your own. If you do decide to ship it by yourself, be sure to take all instruction on secure transportation.

Particle size

The classifier should have an adjustable particle size even if your mixed material is usually the same. Remember mixed media is seldom made of uniform sizes when it comes to individual particles. So, one sample may have particles of certain size that are totally different from another sample. To ensure that the classifier works in both the cases, it must have an adjustable setting. This will also allow you to switch to other products if you want to.

You should also have few options when it comes to particle size distribution. This will be decided as per the design. The number of vents or racks will decide the number of classifications you can get. This effects the overall accuracy of the classification as well because a wider segregation means that the classifier will separate the material more thoroughly.


Look for an air classifier manufacturer who offers the best energy efficiency within the model. The information is usually available on the manufacturer website or brochure. Do a comparison between different models to see the options available. An energy efficient model will be worth a slightly extra cost.

There are other efficiencies that you must consider. For instance, look for continuous air classifiers if you want a steady stream of production. You should also look models that can be easily dissembled and cleaned. This shortens the downtime between two cycles, especially if you are dealing with two different type of materials. Easy access also makes maintenance easy and economic.

Grinding model

Most air classifiers are used as grinding mills. If that is your purpose, look for an air classifier manufacturer who specialize in this. You need to check the fine grinding ability and the particle size you can achieve. Pick a machine that grinds particles in sizes smaller than you are actually looking for. You may want a machine that combines the classification and grinding functions for convenience and saving time.

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