Start With The Basics For Designing
You need a vibrating screen questionaire sheet, this will identify all aspects of what is being screened, tph needed imput, tph needed of actual sized product and all aspects of the material characteristics.
Once you know that.......and most importantly wgt per cu ft of the material being screened you can then proceed to properly size the machine to handle the tonnage or start with a 14' long screen and backup to see if it is big enough.
I will forward you a questionnaire sheet for you review.
keep smiling.........George Baker Moderator ■
Vibratory Conveyours
Dear Friend
Basically vibrators are two types. High amplitudes , Low frquency
Other one is High frquency , Low amplitude. Basically High amplitude , Low frequency Vibratory conveyours are called Screeners, Shaker conveyours
High frequency , Low Amplitude vibratory conveyours are called vibratory conveyours.
If you design Vibratory conveyours you have to choose vibration method. It can Ecentric Shaft (crank shaft) , Electrical magnet , Vibratory Motors or pneumatic piston type (musle)
Both system have advantages and disadvantages.
basically base , upper frame should have mass rate. Because designer try to get fundemental component of vibration wave form.
Any way try to design screener. I can give you maximum support. In sri lanka i have more experience in design vibratory conveyours (more then 60 feet long) for rolling tea leaf , plastic pellets , fetilizers , rice mills etc..
Regards
Uditha Kohowala
COlombo
Sri Lanka
0094 0777 55 16 50
Udithausk@yahoo.com.sg ■
Re: Eccentric Vibrating Screener
Guys, thanks for the advise.
Have a look at the specification given to us by our university lecturers
Scope of Project
Nwe screener must be 4230mm (14’).
The aim of this project is to design a vibrating grid 610mm longer than the current 12’ vibrating grid.
The project write up should also provide a report on all calculations and analysis carried out in designing the longer vibrating grid.
Vibrating Grid Operation
The purpose of a vibrating grid is to separate aggregate by size. Aggregate is loaded directly unto the top of the grid using wheeled loader or excavator. The aggregate over the size of the mesh aperture is passed over the top of grid. Aggregate under mesh size falls through the grid and is collected in hopper below
Vibration in the grid is produced by an eccentric mass rotating in the grid frame. The grid frame is mounted on springs to damp vibration from the rest of the machine structure. For most efficient operation the eccentric mass is run at 1100 RPM, this produces a stroke of 6mm. The grid frame is constructed using ‘huck’ bolts these are cold formed rivets.
The operating angle of the grid can be changed from 5 to 15degrees when operating the grid should always be mounted on support arms. The grid can also be operated for short periods of time at 45degrees this is done to clear any aggregate that may be jammed in structure of vibrating grid.
The grid must also be capable of folding to 0degrees for transport of complete machine. The wing plates at either end of grid also fold down for transport.
600 TPH depending on the material
Approx 10 tonnes being applied per load directly on top by excavator or wheeled loader
Maximum grid bars must allow 600 x 600mm through and then secondary mesh will filter the rest.
I was thinking of trying to use electro magnets as a new concept rather than the eccentric rotating mass, what do you think??
Also I was going to try other methods of fixing, it seems that huck bolts are currently used.
Can anyone think of other fixings?
Any help would be great
■
Re: Eccentric Vibrating Screener
I think the electromagnet idea has been around for quite a while. Do a search for FMC Syntron electromagnetic feeders & screens. ■
Vibratory Conveyours
I think best way is ecentric crank shaft drive mechanism with balance fly wheel. you can fixed ROSAT oscillating drive head and Rosta Roker arms
Uditha Kohowala
Originally posted by shakka
Guys, thanks for the advise.
Have a look at the specification given to us by our university lecturers
Scope of Project
Nwe screener must be 4230mm (14’).
The aim of this project is to design a vibrating grid 610mm longer than the current 12’ vibrating grid.
The project write up should also provide a report on all calculations and analysis carried out in designing the longer vibrating grid.
Vibrating Grid Operation
The purpose of a vibrating grid is to separate aggregate by size. Aggregate is loaded directly unto the top of the grid using wheeled loader or excavator. The aggregate over the size of the mesh aperture is passed over the top of grid. Aggregate under mesh size falls through the grid and is collected in hopper below
Vibration in the grid is produced by an eccentric mass rotating in the grid frame. The grid frame is mounted on springs to damp vibration from the rest of the machine structure. For most efficient operation the eccentric mass is run at 1100 RPM, this produces a stroke of 6mm. The grid frame is constructed using ‘huck’ bolts these are cold formed rivets.
The operating angle of the grid can be changed from 5 to 15degrees when operating the grid should always be mounted on support arms. The grid can also be operated for short periods of time at 45degrees this is done to clear any aggregate that may be jammed in structure of vibrating grid.
The grid must also be capable of folding to 0degrees for transport of complete machine. The wing plates at either end of grid also fold down for transport.
600 TPH depending on the material
Approx 10 tonnes being applied per load directly on top by excavator or wheeled loader
Maximum grid bars must allow 600 x 600mm through and then secondary mesh will filter the rest.
I was thinking of trying to use electro magnets as a new concept rather than the eccentric rotating mass, what do you think??
Also I was going to try other methods of fixing, it seems that huck bolts are currently used.
Can anyone think of other fixings?
Any help would be great
■
Re: Eccentric Vibrating Screener
600mm x 600mm (Nominal 24" x 24")
1. I do not think electromagnetic drive is the way to go here...not really designed for this type of operation. Meant more as the live bottom of feed hopper arrangement. No typically used in separation application vs straight feeding.
2. Mechanical crank offset drive would be much more typical if you will and more likely to take the abuse of dropping material on it. Here you have vibration and a tad LIFT to help elevate the coarse fractions in the feed from the fine fractions in the feed to allow the fines to PASS whatever opening it is on.
3. Springs: people typically utilize little coil spring arrangements to isolate or dampen vibration from structure below. ROSTA mounts are a nice clean different user friendly alternate and are well proven to replace coil springs. Rubber in shear is another possible alternate solution or rubber in compression....QUIETER.
4. ANGLE: at 2" x 2" separation........you are basically scalping vs screening as we know it. Do not really need huge angle here normally. Gravity of course helps FPM foot travel per minute rate.
Tippable GRID to clear is a good idea....costly though and not generally needed for this type of deal. Proper designed grids ...with a self relieving aspect will help keep screen deck area clear but, probably will still encounter a certain percentage of plugging due to nearsize feed mtl.
HUCK BOLTS: super hardware for constant TIGHTNESS or torque values. Yes...you can use other.......GRADE 8 or grade 5 Ntl coarse or ntl fine hardware.......with lock washers etc.....but, do have a tendency to loosen off over period of time especially when we are VIBRATING the frame to which those little babies are trying so hard to HOLD TOGETHER.
Hucks come from aircraft industry and work great in my experience.
George Baker MODERATOR.........good luck. ■
Eccentric vibrating Screener
Hi guys,
I am a student who is currently designing a new 14 foot vibrating screener, i am trying to get information regarding other products on the market. it seems to be most manufacturers aren't willing to send me technical information,i need is product sizes,through put etc...
at the moment i am trying to carry out market reseach and will hopefully design it later.
if you could help me or point me in the right direction it would be great. ■