Everything You Need to Know About Crushers, Tumblers, and Vibratory Screens

Tumbling drums, cement crushers, vibratory screeners, and other similar machines are essential to the food processing industry, but also to other industries as well. Here’s what you need to know about tumbling drums.

Popular Sizes

Tumbling drums come in a variety of sizes. The most popular have barrels between 18 inches and 36 inches in diameter. Barrel length is typically 18 inches to 42 inches. In most tumbling drums, the diameter will be smaller than the length.

Barrel Loading

Barrel loading can fall anywhere between 45% and 60% of the barrel’s capacity. Considering both parts and media, the load should never be lower than 45% in order to ensure effective operation. The load should never be more than 60% in order to guarantee safe operation. The optimum load height is 50%.

The ideal barrel loading should be three parts media to one parts. this load make-up keeps the parts from impinging, and the number of parts that can safely be put into a barrel varies. Some of the considerations when determining how many parts will fit include:

  • Barrel size
  • The fragility of the parts in question
  • The shape and weight of the end desired product
  • The size of the individual parts

Tumbling Speeds

Tumbling drums can take anywhere from six hours to 24 hours to remove all the material from the included parts. The amount of time it takes will depend upon the material’s fragility, which in turn determines the speeds at which tumbling drums can operate. Horizontal barrel speed can vary from 20 rpm to 38 RPM, depending on size and items to be tumbled.

Some media will require even longer tumbling times. Plastic parts, for example, can be tumbled until they reach a finish almost identical to that which is achieved by hand buffing. Because plastic is so light, this type of result takes between 10 hours and 15 hours to accomplish.

Rotary Crushers

Rotary crushers are ideal for recycling and for the processing of food. They crusher themselves are capable of being calibrated, and their size reduction ratio can be adjusted between 10:1 and 25:1. Most rotary crushers include shaft impactors to create extra force.

Rotary speeds will vary from anything as slow as 85 RPM to as fast as 1200 RPM. The newest rotary models are customizable and include interchangeable hammer sets so that the machine is capable of working with a variety of materials.

Double Compartment Mills

Some tumbling drums have a two-compartment barrel mill. This type is typically used in the construction industry, often in cement crushers or a similar machine. The double barrel allows construction materials of two different hardness levels to be simultaneously dry milled; usually low hardness and medium hardness materials.


There are two categories of screening. Some screening is done dry and other screening is done wet. In general, both methods involve separating a flow of material into different grades. The various grades of material are then processed by other methods until the finished product or an intermediate product is produced.

A high-frequency vibratory screen is a shaker affixed to a frame. The shaking drive vibrates only the cloth screen. The high vibrations achieved by this method are suitable for separating out particles from 3 mm down to +150 mesh.

Dry Tumbling

dry tumbling uses horizontal octagon all tumbling drum barrel. At times this barrel will be fitted with the metal skin. Most have a lining made of a hardwood can be replaced on a regular basis as necessary. The standard barrel size for dry tumbling is 30 inches diameter with a length of either 36 inches or 42 inches.

Tumbling drums, crumblers, and crushers are of enormous value in construction, food processing, and other essential industries. As we continue to develop better machines and more efficient methods of screening, crushing, and tumbling, look to see even better quality and speed out of these machines.

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