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Renin Angiotensin Mechanism.

Ball Mill.

 Ball Mill.

Principle: 

  • Works on the principle of Impact and Attrition.

Diagram:

Construction:

  • The mill consists of a hollow cylinder fixed on a metallic frame in such a way that it can rotate around its horizontal axis.

  • The cylinder contains metallic balls occupying around 30 to 50% of total capacity.

  • The balls are usually made up of rubber, porcelain or metal.

  • The metallic balls are coated with chrome.

  • The weight of balls is kept constant and size of balls depends upon the size of feed and mill.

Working:

speed of ball mill

  • The material to be reduced in size is entered into the machine through a hopper.

  • The electrical supply to the machine is started after a careful closure of the machine feed.

  • The mill is rotated at optimum speed.

  • For effective size reduction, the speed of the machine plays a very important role.

  • If the machine is rotated at low speed the balls collide with each other and no or negligible size reduction takes place.

  • If the machine is rotated at very high speed the balls rotate along the cylinder wall due to centrifugal force and no size reduction takes place.

  • If the machine is moved at an optimum speed (two third speed)

  • Size reduction takes place as balls move at the top and fall down crushing the material by impact and attrition.

  • After sufficient time the mill is stopped and the product is collected.

Advantages:

  1. One of the most efficient mills can produce very fine powders.

  2. Suitable for both wet and dry grinding.

  3. As operation takes place in a closed environment, the mill is useful for potent materials.

  4. The mill, after some modifications, is useful for continuous operation.

Disadvantages:

  1. Not suitable for sticky products.

  2. Very noisy.

  3. Balls and casing material may wear off and can compromise the purity of the product.

Applications:

  • Useful for a variety of materials to produce fine powders.

Commonly Asked Questions.

  1. What is size reduction. Write Principle, Construction and working of Ball Mill.

  2. Write a note on Operation speed for Ball Mill.
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