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How Is Vibrating Screen Capacity Calculated?

Jun. 20, 2022

You want your vibrating screen to last a long time, but what factors can affect its lifespan? One of the most important things to look at and check regularly is the shape of the screen's vibrating motion. Among the conditions to be checked regularly on the screen, the shape of the motion is one of the most important conditions. The shape of the vibration movement is circular (A), oval (B), or even linear (C).


Let us examine some concepts related to amplitude.

Vibration amplitude is not dependent on the rotation of the vibrating mechanism.

The combination of amplitude and rotation will give a certain acceleration to the equipment, and that acceleration is responsible for the material conveyed.

The larger the material conveyed, the greater the amplitude of vibration of the equipment should be.


Depending on the mesh aperture mounted on the vibrating screen, there is an ideal relationship between the operating rotation, amplitude, and inclination of the equipment. The nominal rotation is determined based on ideal operating conditions and further ensures that the equipment operates safely below the critical frequency of the vibrating structure.

LZSF Series Asphalt Linear Vibrating Screen

 LZSF Series Asphalt Linear Vibrating Screen

The vibration amplitude can be changed by changing the position of the moveable counterweight. This adjustment is performed based on the application. Screening of coarse material requires a higher amplitude than that required for fine-grain classification.


For other models of vibrating equipment (e.g. feeders, chutes, etc.), please consult the respective manuals.


The higher the operating amplitude of the vibrating equipment, the shorter the service life of the equipment bearings. The bearing life will be satisfactory even if all available eccentric masses initially supplied with the equipment are used.


Warning: Never use eccentric masses larger than those provided by the original equipment. This will result in a significant reduction in bearing life, as well as possible unbalance of the vibrating equipment.


Vibrating screen efficiency calculation

In order to use vibrating screens efficiently, many conditions need to be met, starting with the selection of the right screen. When selecting a suitable screen, many factors related to the screen material should be considered, such as type, moisture content, and particle size distribution.

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Another important factor affecting the screening efficiency is the choice of screen baffle, which can be made of silk, polyurethane, and other materials. The screen baffle should be resistant to vibration, should have sufficient open space, and should be wear-resistant.

The efficient operation of the screen is closely related to the way the screen is fed. The belt feeding the screen should be parallel to the flow direction of the material and provide the feed in such a way that it brings the material to the center of the loading container.


Another important factor for effective screening is the layer height (or bed). The layer height is the height of the wire surface layer formed at the point where the material is loaded. The ideal height is four times the screen aperture diameter.


Screen capacity and efficiency are usually inversely proportional. A typical target is a screening efficiency of 95%. 99% efficiency would equate to a significant loss of capacity.


Screening efficiency is the ratio of the screened material in the feed that actually passes through the screen media to the screened material that should pass through the screen media. This ratio is desired to be 100%, but due to factors affecting the screening process, this is not possible.

Y(A/K)Q Series Double Shaft Forced Synchronization Elliptical Vibrating Screen

 Y(A/K)Q Series Double Shaft Forced Synchronization Elliptical Vibrating Screen

However, an acceptable efficiency range has been determined by the screening producer and quarry manager to ensure an optimal screening process. Depending on the range determined, the screening efficiency should be in the range of 90-95% relative to the above equation.


The feed rate is the main parameter that determines the efficiency. If the flow rate is lower than the screening capacity of the media, the screen idles and therefore no screening takes place. On the other hand, if the flow rate is higher than the screening capacity of the media, the screen operates at an overflow rate, in which case no screening will take place due to the high depth of material on the media. Therefore, screening selection must be made with proper attention to flow rate to obtain maximum screening efficiency.


Screening efficiency is influenced by the following factors.

Screen baffle wears, abrasion, and tearing.

Feeding too much or too little material through the screen.

High-grade variation.

The moisture level of the screened material.

The efficiency of the machine used prior to screening.

 Screening Equipment

 Screening Equipment

Find A Reliable Vibrating Screen Supplier

Anshan Heavy Duty Mining Machinery Co., Ltd. is the vibrating screen base in China and a leading company in the vibrating screen industry. It was listed on A share market in China in 2012. It is the only listed company in the vibrating screen industry in China. Having a large product range including vibrating screen, crusher, feeder, ball mill, asphalt mixing plant, PC production line, trash separation complete plant, etc. 

ANSHAN has been dedicated to the design, manufacture, and installation of vibratory equipment for the efficient processing of bulk materials. Our vibratory conveyors, feeders, screeners, and separators can be found in sawmills, foundries, quarries, power plants, downstream metal processing, and recycling facilities in 32 countries. We have earned a reputation as vibratory specialists with common-sense engineering solutions, technological ingenuity, unwavering equipment reliability, and responsive customer service. We invite you to discover ANSHAN’s uncompromised commitment to excellence.

Let us help you find the best vibrating screen for your project. When you contact us, please provide your detailed requirements. That will help us give you a valid quotation. 

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Anshan Heavy Duty Mining Machinery Co., Ltd.