External Vibratory Dischargers
The versatility of the External Vibratory Discharger is partly due to their ease of installation as retrofit. They may be classified based on the type of energy source (compressed air or electricity) and further on the basis of type of motion generated.
Linear vibrators produce vibration that are perpendicular to the wall of the hopper, act similar to beating the hopper wall with a hammer, whereas rotary vibrators produce components of force both perpendicular and parallael to the hopper wall. Rotary vibrators typically run at higher frequencies and have lower amplitudes than linear vibrators. Twin rotary vibrators mounted in a parallel axis arrangement will tend to run in synchrony and cancel the forces acting in one plane, to produce a linear type oscillating force.
The resulting forces produced by vibratory devices are function of their mass, amplitude and frequency. Frequencies ranging from 10Hz to 500Hz are used, depending on the energy source. Resulting force are normally limited to 10g for most application.