ON-LINE MANUAL
Vibrator
Selection
In this section
you will find some suggestions on how to select vibrators, but selection
of the optimal vibrator cannot be done soely by using a calculator, some
graphs and tables. Every single application is to be treated in a different
way. Very often the free vibration is hindered by structural reinforcements,
stiffeners, or other impediments. The following tables may give you an
approximate idea to come close to the optimum, but in the end the final
adjustment has to be done by varying the air pressure and tuning in to
the object's natural frequency or a frequency that provides good working
conditions.
There are many
applications where three or more types of vibrators will do the job. In
these cases the decision on which vibrator to use needs to be made according
to noise and cost, both initial and long-term.
Generally speaking
there are 7 factors to be taken into consideration :
- air consumption
- noise
- space of the unit
/ mounting area
- frequency required
- amplitude / vibrating
energy
- cost / maintenance
cost
- air supply / lubrication
necessary
You will find different
types of vibrator listed in the following tables, listed according to their
force and amplitude. Other factors which are important are cost, noise
and air consumption. For example, it might sometimes be important to use
a Golden Turbine Vibrator, which is less noisy and consumes less than half
the air that a ball vibrator with similar characteristics. For other applications
there are no noise restrictions and a ball vibrator will be sufficient
and save money as well.
How to proceed
:
- Select all the
possible vibrator types and models according to the force needed in the
following tables.
- If silent operation
is required, then do not use noisy types.
- If oil-free running
is required, then do not use T-, DAR-, and FP-vibrators.
- If low air consumption
is required, do not use Ball- and Roller-Vibrators (K-, R- and DAR-vibrators).
For air consumption data please refer to Section 10--Technical Data.
- Check for the mounting
space needed.
- Compare the costs.
Take into consideration that one single GT-vibrator may do the job of two
ball vibrators and that it might be less expensive in the long run.
Bins And Hoppers
Formula
The most important
factor in selecting the optimal vibrator model is the weight of the good
that has to be vibrated. Where bins and hoppers are concerned, only the
material in the sloped part of the bin or hopper is of interest.
Weight of the
content :
W(cont) = Volume
x Volume Weight of the Material
(b1 x L1 + b2 x L2)
W(cont) = ------------------------
x h x VW for square bins
2
(r12 x p + r22 x p)
W(cont) = ------------------------
x h x VW for conical bins
2
Vibrator
table
Very often it is
better to run two smaller vibrators instead of a large one. The units should
be placed opposite each other on the bin or hopper so the structure is
not stressed toomuch at one single point.
. |
Materials
|
Weight
of
the
content
in
lbs |
dry/loose
grain, corn,
coffee
dry powders,
flours
|
humid/wet/bulky
cement, concrete,
sugar
salt, chemicals
|
. |
Ball
Vibrator
K-Type
|
Roller
Vibrator
R-Type |
Golden
Turbine
GT-Type |
(Ball)
Roller
Vibrator
R-Type |
DAR
Vibrator |
Golden
Turbine
GT-Type |
. |
noisy
|
noisy
|
silent
|
noisy
|
noisy
|
silent
|
100 |
K-8
|
. |
GT-8
|
K-10
|
. |
GT-8
|
200 |
K-8
|
. |
GT-8
|
K-13
|
. |
GT-8
|
400 |
K-10
|
. |
GT-8
|
K-16
|
. |
GT-8
|
600 |
K-13
|
. |
GT-10
|
K-20
|
. |
GT-8
|
1000 |
K-16
|
. |
GT-13
|
R-50
|
. |
GT-8
|
1600 |
K-20
|
R-50
|
GT-13
|
R-50
|
DAR-2
|
GT-10
|
2,000 |
K-25
|
R-50
|
GT-16
|
R-50
|
DAR-3
|
GT-16
|
3,000 |
K-30
|
R-50
|
GT-16
|
R-65
|
DAR-4
|
GT-20
|
4,000 |
K-36
|
R-65
|
GT-20
|
R-80
|
DAR-4
|
GT-25
|
6,000 |
K-36
|
R-65
|
GT-25
|
R-100
|
DAR-5
|
GT-36
|
10,000 |
. |
R-80
|
GT-30
|
R-120
|
DAR-6
|
GT-40
|
15,000 |
. |
R-100
|
GT-40
|
. |
DAR-7
|
GT-48
|
20,000 |
. |
R-100
|
GT-48
|
. |
DAR-7
|
GT-48-S
|
Selection
table for bins and hoppers
Chutes And
Screens
To select the correct
vibrator, first determine the weight of the material and the volume to
be moved. For smaller chutes and screens, up to a total of about 120 kg,
piston vibrators can be used but for larger chutes and screens, rotary
vibrators, especially turbines, are a better choice.
Where two vibrators
have to be used make sure both are fixed to the same stiffening iron so
they will immediately run in resonance and amplify their forces.
Formula
Total weight to
be vibrated :
W(vib) = Weight
of chute or screen (moving part) + weight of the material inside
Vibrator
table
Total
weight
in lbs |
Ball
vibrator
K-type
noisy
SA/HF
|
Roller
vibrator
R-type
noisy
MA/HF
|
Roller
vibrator
DAR-type
noisy
HA/LF
|
Turbine
vibrator
GT-type
silent
LA/MF
|
Piston
vibrator
FP-type
silent
1/LF
|
10
|
. |
. |
. |
. |
FP-12
|
20
|
. |
. |
. |
. |
FP-18
|
30
|
. |
. |
. |
. |
FP-18
|
40
|
K-8
|
. |
. |
. |
FP-25
|
60
|
K-8
|
. |
. |
. |
FP-25
|
80
|
K-10
|
. |
. |
. |
FP-25
|
100
|
K-13
|
. |
. |
. |
FP-35
|
150
|
K-16
|
. |
. |
. |
FP-35
|
200
|
K-20
|
. |
. |
. |
2xFP-35
|
300
|
K-25
|
R-50
|
DAR-2
|
GT-16
|
. |
400
|
K-30 |
R-50
|
DAR-3
|
GT-16
|
. |
600
|
K-36
|
R-65
|
DAR-4
|
GT-25
|
. |
800
|
2x K-36
|
R-80
|
DAR-5
|
GT-36
|
. |
1,000
|
. |
R-100
|
DAR-6
|
GT-36-S
|
. |
1,500
|
. |
R-120
|
DAR-7
|
GT-48
|
. |
2,000
|
. |
R-120
|
DAR-7
|
GT-48-S
|
. |
4,000
|
. |
2xR-120
|
2xDAR-7
|
2xGT-48-S
|
. |
Selection
table for chutes and screens
The FP-vibrators
are available as S(mall), M(edium) and L(arge)
amplitude types
SA = small
amplitude |
LF = low frequency |
MA = medium
amplitude |
MF = medium
frequency |
HA = high amplitude |
HF = high frequency |
Molding Forms
For Concrete and Iron Cast Applications
The important factors
in selecting a vibrator for concrete molds are the mold weight and the
condition of hte concrete, either dry, medium, or wet.
NOTE : Whatever
vibrator you choose from the table, you will always have to perform practical
tests to determine its best working conditions. Especially for concrete,
the time of vibration is of significant importance to insure that the concrete
is vibrated throughout. The table only provides a rough estimate.
|
Condition
|
Weight
of
filled mold
in lbs |
WET |
MEDIUM |
DRY |
40
|
R-50
DAR-2
GT-10-S
|
R-50
DAR-3
GT-10-S
|
R-65
DAR-4
GT-10-S
|
100
|
R-50
DAR-2
GT-10-S
|
R-65
DAR-3
GT-16-S
|
R-65
DAR-4
GT-16-S
|
200
|
R-65
DAR-5
GT-16-S
|
R-65
DAR-5
GT-16-S
|
R-80
DAR-6
GT-25-S
|
400
|
R-65
DAR-5
GT-25-S
|
R-80
DAR-6
GT-25-S
|
R-100
DAR-6
GT-36-S
|
1,000
|
R-80
DAR-6
GT-36-S
|
R-100
DAR-6
GT-48-S
|
R-120
DAR-7
2x GT-36-S
|
1,500
|
R-120
DAR-6
GT-48-S
|
R-120
DAR-7
2x GT-36-S
|
2x R-120
2x DAR-6
2x GT-48-S
|
2,000
|
2x R-120
DAR-7
|
2x R-120
2x DAR-6
|
2x DAR-7
|
Selection
table for concrete molds
Fixation
of the Vibrators depending on molding form
When more than
10 cm (4 inches) of concrete are to be compacted, DAR-vibrators (above,
on the right) are recommended. The DAR-vibrators produce very large amplitudes
which penetrate deeply into the concrete material.
For flat molding
forms (above, on the left), DAR-vibrators should be used if the total width
is more than 20 cm (8 inches) or 40 cm (16 inches) if two vibrators are
used. If the width is less than 20cm, roller R-series or turbine GT-vibrators
will produce good results.
To get a very
compact and bubblefree surface, a GT-vibrator should be run for about ten
seconds. Due to its higher frequency, it compacts sand material closely
around gravel stones.
4.5. Foundry Molding
Forms
To determine the
correct vibrator to separate the silica sand of molding forms use the DRY
column on the table. The use of GT-turbines is recommended since they can
be operated without lubrication and their ball bearings are shielded so
the silica sand dust can not harm the bearings. The vibrator should always
be supplied with about 0.5 bar in standby operation so that no silica sand
enters the exhaust port during the filling of the mold. Higher pressure
is necessary to start the vibrator.
NEXT TO MOUNTING PART 1