VIBCO AUSTRALIA PTY LTD
For details contact Ken Gower
Phone 02 9983 9397 or mobile 0409 842 262
EMail :- firstname.lastname@example.org
Application of VIBCO Pneumatic Turbine Bin Vibrators
Vibrator selection and installation is based upon individual application requirements.
VIBCO is always available to assist with the selection of the best vibrator to suit your needs.
For distribution of the vibration, each pneumatic turbine vibrator should be securely mounted midway, on a length of channel, welded with its legs against the side of the bin. Hopper should not "Drum" as this flexing will cause cracking of the hopper walls.
All vibrator models can be mounted with the shaft in any position, from horizontal to near vertical however VIBCO recommends, if possible, to mount the vibrator with it's shaft horizontal.
For maximum effectiveness, chutes requiring vibrators should be independently isolated. In addition, the vibrator should be mounted midway on a channel located underneath the length of the chute.
For free flowing materials applications, vibrators on hoppers should operate only when the hopper is open to flow otherwise, packing of the material can result.
Normally - Do not use a VIBCO vibrator on an empty bin other than for a short period to clean out residue from the bin.
CONICAL BINS OR HOPPERS The VIBCO vibrator should be placed approximately 1/3 for coarse materials (1/4 for fine grain materials) of the distance from the discharge opening to the top.
Should a second vibrator be necessary, it should be mounted diametrically opposite; for coarse material, mount one vibrator 1/3 up the side, the other 1/2 up. For fine materials mount the first vibrator 1/4 up and the second one 1/3 up. Welding a channel Iron with toes to bin wall is recommended. Where possible the mounting plate on the channel iron should be ' placed 1/3 to 1/4 of the distance L on the bin. Tack weld channel iron in place, then weld intermittent welds (75-150mm) 3-6" long with (750mm) 3' between them. Note: Stop welds at least (25mm) 1' from the ends of the channel iron -- do not weld the ends. The heat concentration when welding the ends could cause crystallization of the metal and the start of fatigue cracks.
Also see below detail on interference vibration.
RECTANGULAR BINS AND HOPPERS. One VIBCO vibrator generally clears the walls; if the material still sticks in the corners, increase the vibration by first changing the impact of the vibrator, or change to a larger size or use a second unit mounted opposite the first.
Check out the actual valley angle, this where the product hangs up. To give an idea a rectangular hopper with 45° sides has 35° valleys, even with 60° sides valley is 51°, check if product flows at the valley angle.
PARABOLIC BINS OR HOPPERS. Normally only one VIBCO vibrator is needed for each discharge point.
BINS WITH SLOPING DISCHARGE. The VIBCO vibrator is best mounted close to the transition between chute and bin to give the chute sufficient vibration for a steady flow.
BIN OR HOPPER WITH VERTICAL SIDES reacts the same as paragraph 2
BELT CONVEYOR Vibrators should be placed 1/3 from front.
STANDARD BIN If 2 vibrators are used place 2nd one directly opposite 1/3 from back. Do not run back one until bin is empty in front. Stop front unit.
LONG BIN Belt conveyor feeds from the front. Vibrator
VIBRATORY FEEDERS As the product is feed from the front of the bin, place the vibrator 1/3 the way up the back face.
SHORT SCREW FEEDER - Standard Screw Feeders (with fixed pitch) feed from the back. Vibrator should be mounted as close as possible to feeder on the back face. If 2 vibrators are used place 2nd vibrator directly opposite 1/3L on front face. Do not run front one until bin is empty in back.
LONG SCREW FEEDERS-As fixed pitch screws feed from the rear product in front does not move and therefore will be compacted if vibrated. fit vibrator as for short screw or on the side onto a channel 1/3 the way along the bin. If screw is variable pitch vibrator can be moved forward, but recommend running intermittely to avoid compacting.
For real tough materials, large bins, bins containing different particle sizes or on a bin used to store different materials, "Interference Vibration" will obtain a better result in moving the material.
This is achieved by using two VIBCO vibrators on the bin with different frequencies (speed). The most common electric vibrator speeds are 3000 and 1400 rpm. For example., A bin containing 15,000 lbs. of material needs 1500 lbs. of vibration force. We elect to use two vibrators, one 1400 rpm 4P-700 with 700 lbs. of force max, and one 2P-450 3000 rpm with 900 lbs. half force. The 3000 rpm unit is mounted closest to the discharge, 1/3 up the bin side, the 4P-700, directly opposite and 1/2 way up the bin side. The two frequencies of the vibrators will "interfere" with each other and create a simulated vibration of 3000 + 1400 = 4400 vpm to 3000 - 1400 = 1600 vpm. The cycling between 4400 vpm and 1600 vpm will, in 90% of all materials, go through the materials "resonance" frequency. At "resonance" frequency, any material will flow easily and freely. This is the reason why at interference vibration you will move the most stubborn materials. Consult VIBCO for further details.
Air vibrators can also be used in the same way and they give a wider range of possible speeds.
FOLLOWING EXAMPLES OF OTHER SPECIAL APPLICATIONS
A small VIBCO turbine vibrator mounted to the inlet chute of a elevating conveyor.
Vibrating table with a VIBCO turbine vibrator.
Foundry match plate
By fitting the special Vibco foundry Turbine vibrator to a match plate, the operator can strip the pattern easily, and not have to be exposed to the loud hammer of the conventional piston vibrators.
If you must have a piston Vibrators, we recommend the Vibco units as the most economical, but still noisy!
Small VIBCO turbine vibrators on a filling head.
By mounting a VIBCO turbine vibrator on to a movable clamping system the operator can control the vibration of these complex concrete molds by moving the vibrator up the mold as it is filled with the mix.
To keep parts moving along a gravity feed track a VIBCO turbine vibrator is mounted onto the side of the track.
For Tip Trucks
For small hoppers
For Sludge Waste Truck
To successfully move material in a chute, the "angle of repose" of the material has to be known. It can be found in most handbooks or can easily be measured by dumping a cup of the material on a table. The angle between the table and the cone the material makes is the angle of repose. To move the material in the chute, it should be inclined no less than 1/2 of the angle of repose. If this cannot be obtained, a feeder is necessary to move the material.
A. Chutes up to 2m are generally handled by one vibrator mounted approximately 1/3 the length form the discharge.
B. On chutes 2 to 3m long, two vibrators are needed, one should be placed 450-600mm from the discharge. The other approximately in the middle. Since chutes are very sensitive to vibration, provision should be made to move the lower vibrator 150mm in either direction. This could mean the difference between moving the material or not moving it.
C. The direction of rotation of the vibrator shaft should be in the direction of material flow.
D. Force (impact) needed on vibrator is equal to weight of chute + vibrator + max material in chute.
Chutes must have an inclination of at least 10° for vibrators to be able to move the material. If inclination is less the chute has to be made into a feeder. Contact VIBCO for selecting the proper size vibrator or ask for bulletin covering chutes.
HEAT MOUNTS FOR (INSULATED) BINS CONTAINING HIGH TEMP MATERIALS
When materials in bin have a temperature over 65°C (150ºF) it is advisable to use a "heat" mount to prevent excessive heat reaching the vibrator causing vibrator overload or bearing failures. Also ask for "high" temp. grease in the electric vibrator bearing and special high heat resistant winding. Consult with a VIBCO engineer.
CONTINUOUS VERSUS INTERMITTENT OPERATION
Experience has taught us that it is always preferable to use a vibrator intermittently instead of continuously.
When vibrating a bin 1/2 or more full continuously, a densification effect due to the vibration will occur in the straight part as well as the sloping part of the bin. This is especially so during low discharge rates. This densification will, in some cases, set up dead storage of dormant material in the corners of the bin. This material will not be moved out of the bin until all other material has been removed and in some cases additional vibration force is necessary to move this material.
The intermittent operation or cycling of the vibrators will prevent this dead storage build-up due to the vibrator exciting it's speed from 0 to maximum and then from maximum to 0 when stopping. Most materials have a resonance frequency in the range. When the vibrator frequency reaches the material resonance the vibrator force will move and vibrate the material more violently than at any other speed. This will reduce the chance of build-up and dead storage.
To obtain cycling automatically a timer can easily be connected into the circuit. For a manual operation a simple push for "on" and release for "off", switch can be installed. A micro-switch, actuated by a paddle in the material flow direction is useful to automatically control intermittent flow application, or for continuous flow installations where bridging occurs infrequently.
The "on" and "off" time is easily determined by observing the discharge rate, when the discharge is just above the minimum rate required, a new vibration shock is necessary to keep it moving. The vibration shock should be between 5 to 30 seconds. Very short periods have the best effect. Always be sure, on electric units, to use an "on-off' ratio of at least 1:7 for short spurts of vibration of up to 10 seconds. For example, 5 seconds on, 35 seconds off. By observing this, you will stay within the limits for the motor and it will not overheat. For shorter off time, the motor duty is called "severe duty" and the life of the motor will be severely reduced due to overheating.
Capacitor start motors have a maximum of 30 stops and starts per hour. If more frequent, the capacitor may short out. For more stops and starts, either use 3 phase units for larger applications or the VIBCO SCR line.