WHAT IS VIBRO SIFTER OR SIEVE SIFTER:
Vibro Sifter Or Sieve Sifter is one of the most commonly used industrial sieving equipments. It is extremely easy to use, simple in construction and requires minimum maintenance with rare cases of breakdown.
GYRATORY MOTION AND PRINCIPLE OF WORKING OF VIBRO SIFTER:
Vibrosifter makes use of the principle of Gyratory Motion. As per Physics, Angular Momentum (L) for a rotating object is a product of its Moment Of Inertia (I) and its Angular Velocity (w). It can be explained with the help of the Right Hand Principle. However, as per the law of conservation of Angular Momentum (L), if there is no change in the Torque (tou), Or no external torque acts on the object, there is NO change in the Angular Momentum.
Now imagine a situation, where you fix one end of the axis of the spinning object and leave the second end free. Because of the rotary motion, the object has already attained a gyratory state. Now, with the imbalance we created, the plane of rotation of the object starts changing. The object in gyratory motion tries to balance the situation by changing the direction of the angular momentum (Note: Angular momentum is a vector quantity and can be shown by the right hand thumb as per the fig above), such that, the object starts rotating around the point where the axis is fixed.
Vibrosifter uses gyro motor Or vibratory motor, which creates this kind of imbalance, hence, the plate above the motor shaft tries to attain the gyratory motion. However the number of springs attached to a fixed support ensures the plate and all the decks above do not rotate of go far from the original position, resulting into continuous vibrations.
MAJOR COMPONENTS OF VIBROSIFTER:
1. Top Charging Lid: The topmost nozzle is provided for feeding the material to be sieved.
2. Mesh or Screen: Depending on the number of deck, the screens Or meshes of different aperture are fixed to the bottom of each deck. Due to continuous vibrations, the material particles of lower size passes through the mesh and oversize material either stays above the mesh or can flow out from the side discharge nozzle.
3. Discharge Nozzles: Each deck has a discharge nozzle which facilitates the discharge of the material which has already passed through the mesh from the previous Or top deck.
4. TC Clamps: Tri-Clover Or quick release clamps are provided to hold the two adjacent decks together. In order to avoid the leakage of the powder through the clamps, PP Or Food Grade Silicon gaskets are used on the edges of the deck
5. Bottom housing plate and Springs: The plate is attached to the fixed supports with the help of the metal springs.
6. Vibro Motor - A special purpose eccentric shaft AC powered motor is used to generate gyratory motion in the plate above it.
7. Metal Structure: The structure supports the sifter body with the help of the metal springs and does not pass the vibrations to the floor below.
MATERIAL OF CONSTRUCTION:
Incase of Pharmaceutical and Food applications, the Contact Parts are SS316 Or superior, whereas, the Non Contact are SS304. Incase of non corrosive chemicals, the Contact Parts can be SS304 and Non COntact parts can be MS + Epoxy painted also.
SURFACE FINISH:
As per the GMP (Good Manufacturing Practice) guidelines, the product contact surface needs to be extremely smooth. This also helps in preventing the surface corrosion due to electrolytic cell formation. Hence the Product Contact Surface usually is minimum 240 grit Mirror Finish and Non Contact Surface is 180 grit matt finish. Incase of a Non-GMP set up, if Mild Steel is used (for Product Non Contact in some cases), the surface is either epoxy painted Or coated with protective layer.
ADVANTAGES OF VIBROSIFTER:
1. Various Sizes available: Vibrosifter can be available in sizes ranging from lab scale model to large diameters viz 72 inches Or 6 feet.
2. Economical: Sifter only consumes the electrical power for running the motor. No other ancillary equipments Or resources are needed. Hence, it is economical in nature.
3. Minimum Downtime Or Maintenance needed: Apart from the gaskets of TC clamps, no other part of sifter gets damaged usually. Infact, this is one of those rare equipments that can run 24 X 7 without breakdowns.
4. Screens and Meshes can be replaced based on requirement: Various sizes of meshes Or screens can be kept in spares and can be used as per the need.
5. Can be integrated with other equipments in the granulation line: Usually Vibrosifters are used in line with Multimill or Comill or sometimes with RMG or FBD also.
Please feel free to contact me regarding any questions, queries Or additional assistance needed on Design, Sales, Qualification or other aspects at shg.techo@gmail.com
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