The amplitude and frequency of the trommel screen determine the speed and acceleration of drum movement. It also determines the speed and acceleration of the relative motion of the material on the screen. If the speed and acceleration of the machine screen movement is too large, the sand is not easy to pass through. And the strength of the equipment is affected; on the contrary, if the speed and acceleration of the machine screen movement is too small, the material can not reach a certain degree of looseness, which is not conductive to screening. Therefore, the screening of the coarse material should use a large amplitude and a small frequency, and the fine material can be screened with a small amplitude and a large frequency. At the screening time of the trommel screen, it can be assumed that the sand is an oblate spheroid and its long axis is parallel to the plane of movement of the sieve. The direction in which the oblate spheroids are arranged on the screen surface is related to the vibration frequency and amplitude.
When the vibration frequency of the trommel screen is greater than the vibration frequency of the sand, the long axis of the sand particles will be parallel to the screen; when less than the vibration frequency, the long axis of the sand particles will be perpendicular to the screen, and the sand particles will be the same as the machine surface. When the vibration frequency of the sand particles is less than the vibration frequency of the sand particles, the direction of the friction causes the sand to rotate toward a position perpendicular to the movement of the sieve. When the sand particles rotate, the frictional force component causes the sand to vibrate and the arm is reduced.
Therefore, when using the trommel screen to sieve coarse-grained materials, larger amplitudes and small frequencies can be used , while fine-grained materials can be used with small amplitudes to increase the frequency of screening, because the vibration frequency is different, and the amount of sand passing through the screen is different.
Through the adjustment of the frequency and amplitude of the trommel screen, it has a direct screening effect. In actual use, we can debug several times to a satisfactory sand-screening effect, which also requires us to explore and accumulate experience when using the trommel screen.