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Selection
and Usage of Motor Vibrators :
Importance of vibrator selection need not be over
emphasized. However good a range of vibrators available
may be, unless a right model is chosen and applied
correctly, no good and efficient results can be
obtained. Therefore we, Sinex Primemovers present
below at your, our valued customers' disposal, all the
data, information and experience gathered during our
over a decade long working on this subject.
Industrial uses of motor vibrators could be categorized
into two types based on amplitudes involved ; (1)
Tremors - micron level vibrations and (2) Large
oscillations, in several millimeters. The former are
encountered in silo and bin discharge applications and
promoting material flow down chutes, ducts etc. while
the later are found in equipment such as feeders,
conveyors, spiral elevators, screens, vibratory tables
etc.
Vibrator
Selection for Bin, Hopper & Silo Discharge Application :
Years of experience and data collection have shown that
force applied to bin walls should be 10 to 20% of
material weight in the lower convergent part for
satisfactory activation, dechoking and discharge.
Figure-1: Positioning Vibrators for Material Discharging
Taking into
consideration the above in conjunction with bin sizes
and wall thickness recommendations are tabulated at
Table-2 to facility easy selection. Since tremors
are at high frequencies it is appropriate to use 3000
rpm vibrators hence recommended force values correspond
to this speed.
Table-2 :
Vibrator Force values for Bin, Hopper & Silo Discharge
|
Bin
Wall Thicknessup to |
Bin
dia./ diagonalup to |
Material
Weightto be activated Kg.s |
Recommmended
Vibrator Force in Newtons
|
Remarks |
|
Single |
Two |
Three |
|
2 |
450
560
700 |
25
40
70 |
400
560
900 |
500 |
|
Use Pneumatic Turbine
Vibrators |
|
3.2 |
630
800
1000 |
50
100
200 |
1000
1600
2500 |
1250 |
|
Pneumatic
Piston Vibrators may also be considered |
|
5 |
900
1100
1400 |
150
270
550 |
2800
3600
4500 |
1800
2250 |
1600 |
|
6.3 |
1250
1600
2000 |
400
825
1600 |
4500
5600
7100 |
3200
4000 |
2750 |
For
diffult to flow materials & to gate uniform discharge other
flow aids like Bin activator etc. may be considered |
|
8 |
1800
2250
2800 |
1200
2300
4500 |
7100
9600
|
5600
7100 |
5000 |
|
10 |
2500
3200
4000 |
3200
6400
12500 |
12500
16000
|
8000
10000
12500 |
7100
9000 |
The above assumes material
bulk density of 800 Kg s / cu.mt., bin walls not heavily stiffened
and discharge openings not too small, which as a rule should be largest
practically feasible. Forces may be varied in direct proportion to
densities and in cubic to wall thickness.
Location of vibrators on storage vessel is very important from the
view point of obtaining reliable discharge with minimum detrimental
effect of brute force on the bin structure. Recommendations in this
regards based on experience are shown in Figure-1 |
