Working Principle of Vibratory Sifter

A vibratory Sifter is used in the Sifting of materials in Pharmaceutical manufacturing with a different mesh of Sieves and it is widely used equipment in the pharmaceuticals and in food industries.

What is the principle of vibro sifter?

The vibro sifter machine works on the principle of gyratory vibrations. The material is separated on the basis of its particle size. Once the motor gets energized, vibration is caused in the screen/sieve making the material to travel across the sieves according to its particle size.

What is a Vibro sifter?

Pharmaceutical Vibro Sifter is used to separate the mass composition of solids, liquid from solid, and grade the material as per particle size. It is a type of pharmaceutical machine used for the separation of pharmaceutical solids or liquids. A vibro sifter machine consists of a screen/mesh placed on the base plate.

ALSO READ: Granulation Process in Pharmaceutical

Some essential components of this equipment:

High Quality Springs

From the images above (Parts of a Vibro Sifter Machines), you can see the sieves/screens are suspended on a spring. The main purpose of these springs include:

• Allow the entire upper section of the machine to vibrate freely
• It helps minimize power consumption
• Acts as damper; i.e. preventing any transmission of vibration to the floor.

 

A Vibratory Electric Motor

It is this motor that causes the multi-plane vibratory motion as you can see in the video above. Remember, this motion increases the rate at which the material passes through the various sieves. To achieve this, this equipment come with an out-of-balance weight assembly.

Screen Structures

• This is where the sieves are fitted. It is these sieves that separate materials depending on their size/shape.
• The screens are held in tension, making it easier for material to move in the direction of the vibration. This could be in horizontal or vertical direction.
• Depending on the type of material you wish to process, it is possible to adjust the screen motion precisely to the performance requirements. That is, a single machine can achieve both aggressive and gentle material separation.
• The screen structure uses the FDA-approved seals to prevent cross-contamination of the products in different sieves.

Outer Structure/Casing

The structure is made from stainless steel. It confines the product to be processed to a desired size and finesses. For easy mobility, the structure has nylon casters.

Hopper Lid

It confines the material, keeping both the machine and the surrounding environment from dust.

How a Vibrating Sifter Works

The image illustrates the movement of the various particles of the material being separated in a Vibrating Separator. 

Basically, the whole process in the image above can be summarized as:

• Feed the material you intend to separate through the hopper (the small hole at the top of the vibrating separator).
• Ensure the cover, screen structure and base frame is tightly secured with the clamping rings.
• Power the machine from the mains and switch it on
• The vibrating motor will be energized causing a vibratory motion due to the out-of-balance weight assembly.
• The screen/sieve will begin to vibrate. Material fed to the hopper will then travel across sieves depending on the particle size.
• Material travels in a controlled pathway and exits the system through the discharge system.
• Depending on the design of the vibrating sifter, you can use the machine for:
• Classifying particles for the case of multi-deck
• Scalping or sifting for the case of a single deck

ALSO READ: End Point Determination in a Wet Granulation Process

Uses of Vibratory Sifter

Sifting is done to remove lumps or growth that might have formed on the materials after being stored for a longer period and materials are passed through a mesh that opens, which leads to fine the materials. It also removes the unrequired foreign particles and separates the materials according to size.

Types of Vibratory Sifter

• One layer, Vibro sifter.
• Double layer Vibro sifter, which has two layers.
• Triple-layer Vibro sifter that has three layers.
• Industrial Vibro sifter which is commonly used in food processing industries.
• L-shaped sieve frame Vibro sifter.

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