Applied Vibration Expertise (Continued)
A Rotary Ball Vibrator
Rotary vibration develops force vectors tangential to the rotation; these shear vectors must be accounted for in the mounting. To do so, long channels with intermittent welds are normally used for mounting. This type of mounting also stiffens the bin wall, raising the natural frequency of the bin in that area. Caution must be taken not to operate the vibrators at the resonance frequencies of the bin wall. If operated at resonance, mounting failure can occur–- regardless of vibrator size.
The image at left is an actual measurement of sinusoidal vibration using a vibration measuring device. The inset shows a constantly even amount of energy emitted.
Pneumatic piston vibrators that are silent or air cushioned can also create sinusoidal output. In this case there are no shearing forces because force vectors are normal to the bin wall. Generally, these vibrators are characterized as low frequency/high amplitude, so resonance is not often a problem. However, the bin response is still proportional to the forcing function f(x), with much of the vibrating energy used as it passes through the bin wall.
For more information, pease visit:
href="https://edir.bulk-online.com/profile/1566-navco.htm" target="blank">https://edir.bulk-online.com/profile/1566-navco.htm
href="http://www.google.com/search?client=safari&rls=de-de&q=NAVCO+site:bulk-online.com&ie=UTF-8&oe=UTF-8" target="blank">http://www.google.com/search?client=...UTF-8&oe=UTF-8
Attachments
■
Applied Vibration Expertise (Continued)
Short Time Duration Impulse
The second type of vibration is short time duration impulse or ‘impacting’. This type of vibration is commonly delivered by pneumatic piston vibrators (
href="http://www.navco.org/industrial-bin-vibrators/hopper-vibrator.html" target="blank">http://www.navco.org/industrial-bin-...-vibrator.html). The impulse is a form of elastic collision between the piston and the base of the bore. The ideal result is conservation of energy and momentum, with the energy being efficiently transferred through the hopper wall; the bin responds with its own natural frequencies (like ringing a bell) and the energy is transmitted efficiently into the material in order to facilitate flow. This is the most effective way to promote flow in bins, hoppers, chutes, railcars and any other bulk material containers.
For more information, pease visit:
href="https://edir.bulk-online.com/profile/1566-navco.htm" target="blank">https://edir.bulk-online.com/profile/1566-navco.htm
href="http://www.google.com/search?client=safari&rls=de-de&q=NAVCO+site:bulk-online.com&ie=UTF-8&oe=UTF-8" target="blank">http://www.google.com/search?client=...UTF-8&oe=UTF-8
Attachments
■
Applied Vibration Expertise (Continued)
A Pneumatic Piston Vibrator
Pneumatic piston vibrators generally operate with a forcing frequency well below the bin wall natural frequencies, so resonance is not a concern.
This image illustrates the vibrational energy emitted by a pneumatic piston vibrator.
For more information, pease visit:
href="https://edir.bulk-online.com/profile/1566-navco.htm" target="blank">https://edir.bulk-online.com/profile/1566-navco.htm
href="http://www.google.com/search?client=safari&rls=de-de&q=NAVCO+site:bulk-online.com&ie=UTF-8&oe=UTF-8" target="blank">http://www.google.com/search?client=...UTF-8&oe=UTF-8
Attachments
■
Applied Vibration Expertise (Continued)
Analogy: The desk toy known as Newton's Cradle which has five metal balls in a line, suspended by thin strings. When you lift and drop a ball at one end, the energy is transmitted to the opposite end ball, through the three middle balls, with no loss of energy.
This device demonstrates the conservation of momentum and energy that is the principal of operation utilized by NAVCO pneumatic impacting piston vibrators.
NAVCO supplies applied vibration solutions and vibratory equipment products for both types of vibration methods. In some specific applications rotary vibration is more effective than impacting vibrators. Contact NAVCO for assistance with determining the best solution for your particular flow application. NAVCO can also recommend a complete applied vibration solution that virtually guarantees material flow from any storage vessel of any shape or size. It is only available with NAVCO’s proprietary Bin Map Solution; Visit this page (<
href="http://www.navco.org/industrial-bin-vibrators/bhbinmap.htm" target="blank">http://www.navco.org/industrial-bin-...s/bhbinmap.htm>
href="http://www.navco.org/industrial-bin-vibrators/bhbinmap.htm" target="blank">http://www.navco.org/industrial-bin-...s/bhbinmap.htm ) to learn more about the scientifically engineered NAVCO Bin Map.
For more information, pease visit:
href="https://edir.bulk-online.com/profile/1566-navco.htm" target="blank">https://edir.bulk-online.com/profile/1566-navco.htm
href="http://www.google.com/search?client=safari&rls=de-de&q=NAVCO+site:bulk-online.com&ie=UTF-8&oe=UTF-8" target="blank">http://www.google.com/search?client=...UTF-8&oe=UTF-8
Attachments
■
Applied Vibration Expertise
APPLIED VIBRATION EXPERTISE
Summary:
There are two basic types of vibration that can be applied to storage vessels such as bins, hoppers and railcars to effect material flow. In this article the differences and advantages or disadvantages of each are described.
Comparing Sinusoidal and Short Timed Duration Impulses
Sinusoidal
One vibration type is sinusoidal. Sinusoidal vibration is commonly delivered by rotary, or “silent “ piston vibrators. Rotary vibrators (http://www.navco.org/other-vibrators/ball.html) are characterized as high frequency/low amplitude. Common types of rotary vibrators are Ball, Turbine and Electromechanical vibrators (http://www.navco.org/vibratory-drives/index.html). With rotary vibrators, bin displacement response is proportional to the frequency and amplitude of the forcing function of the vibrator. This means the bin wall deflects according to the forcing function of the vibrator in order to transmit the vibrating energy into the bulk material. With this method, much of the vibration energy is spent on creating the wall deflection and is lost to the purpose of facilitating material flow.
For more information, pease visit:
https://edir.bulk-online.com/profile/1566-navco.htm
http://www.google.com/search?client=...UTF-8&oe=UTF-8
Attachments
1_navco_3 (JPG)
■