How Does A Vibrating Screen Work?

When smaller rocks have to be graded, a vibrating screen will be used. The simplest working principle of a vibrating screen can be explained by using a single deck screen and placing it on an inclined frame. The frame is mounted on a spring.

In the majority of cases, the types of screen decks that you will be operating will be either the horizontal screen or the inclined vibrating screen. The names of these screens do not reflect the angle that the screens are on, they reflect the direction of the motion that is creating the vibration.

Vibrating screen design

In vibrating screen design, it is common to install a screen prior to the secondary crusher to bypass any ore that has been crushed small enough to alleviate unnecessary work. Very tight screening is not required and some sort of moving bar or ring mesh screen can be well used.

 ZKg Series Linear Vibrating Screen

Depending on the length of the screen, one, two, or three vibrators are mounted on the frame and connected by their armatures to steel bars firmly fixed in the middle of the screen. The movement of the armature is directly controlled by the solenoid coil, which is connected via an external cable and provides 15 cycles of single-phase alternating current; this creates an alternating field in the coil, causing the armature to move up and down at a rate of 30 vibrations per second.

At the end of each return stroke, it hits an impact block and gives the sieve a shock that throws the larger ore blocks to the top of the bed and gives the fine particles a better chance of passing through the screen for the rest of the Circulation. The movement can be adjusted by means of a handwheel-controlled coil spring so that the intensity of the vibration can be adjusted within a close range. No lubrication is required for the vibrating mechanism or any other part of the screen, and 15 cycle AC power is usually supplied by a special electric generator set placed in a place where dust cannot reach.

Screen capacity

The determination of screen capacity is a very complex subject. Over many years of screen manufacture and extensive research into the results of their use, many theories on the subject have been developed. However, there is still a need to test the results of new installations to reasonably determine screen capacity.

 Large Linear Vibrating Screen     

A general rule of thumb for good screening is: "For material weighing 100 lbs. per cubic foot, the depth of the bed of material at the discharge end of the screen should not exceed four times the size of the screen surface opening and, for material 50 lbs per cubic foot. The depth of the feed end can be greater, especially if the feed contains a large amount of fines." Other interrelated factors are.

The speed or velocity at which the material moves over the screen.

Vibratory stroke characteristics - amplitude, the direction of rotation, type and frequency of motion; and surface moisture.

Vibration is generated by circular motion on an inclined screen in a plane perpendicular to the screen mesh from one-eighth to ½ inch. The amplitude of vibration is 700-1000 cycles per minute. The vibration lifts the material to produce stratification. And when the screen is tilted, the material will cascade down the slope, introducing the possibility of particles passing through the screen opening or over its surface.

The screen capacity depends on the type of screen, the available area, and cleanliness as well as the screening capacity of the aggregate.

If you want to get more information about the vibrating screen design, welcome to contact us today or request a quote.