Important Principle, Construction, and Working of Hammer Mill and Ball Mill (2023)

Principle, Construction, and Working of Hammer Mill and Ball Mill

Hammer Mill

A hammer mill is a machine that is commonly used in the pharmaceutical industry to reduce the particle size of active ingredients and excipients.

Diagram of Hammer Mill

Principle of Hammer Mill

The hammer mill operates on the principle of impact grinding, where the size reduction is achieved by repeatedly striking particles against a hard surface. The hammer mill has a rotor that is fitted with hammers, which strike the particles and cause them to be broken down into smaller pieces.

Construction of Hammer Mill

A hammer mill typically consists of a cylindrical drum containing a horizontal rotating shaft with hammers attached. The hammers are mounted on a series of pins that are located on the circumference of the rotor. The mill also includes a feed hopper, which is used to introduce the material to be ground, and a discharge chute, which is used to remove the ground material.

Working of Hammer Mill

The hammer mill works by introducing the material to be ground into the feed hopper. The material is then pulled into the mill by the rotation of the rotor. As the rotor spins, the hammers strike the particles, breaking them down into smaller pieces. The ground material is then discharged through the discharge chute.

Advantages of Hammer Mill

• High efficiency in size reduction
• Able to handle a wide range of particle sizes
• Versatile and can be used for a variety of materials
• Simple and easy to operate
• Low cost of maintenance

Disadvantages of Hammer Mill

• Not suitable for materials that are heat sensitive
• Can generate a lot of dust and noise
• Can cause wear and tear on the hammers and other parts of the mill
• Not suitable for materials that are sticky or have high moisture content

It is important to note that the hammer mill is not suitable for all types of material, and it should be used in conjunction with other size reduction techniques in order to achieve the desired particle size. Additionally, it is important to consider the application and specific requirements of the material being ground before selecting a hammer mill or any other type of size reduction equipment.

Ball Mill

A ball mill is a machine that is commonly used in the pharmaceutical industry to reduce the particle size of active ingredients and excipients.

Diagram of Ball Mill

Principle of Ball Mill

The ball mill operates on the principle of impact and attrition. The size reduction is achieved by the impact of the balls on the particles as well as by the attrition between the balls. The mill uses a combination of both impact and attrition forces to achieve the desired particle size.

Construction of Ball Mill

A ball mill typically consists of a cylindrical drum partially filled with balls, typically made of steel or ceramic. The drum is mounted on a horizontal axis and is rotated by a motor. The mill also includes a feed hopper, which is used to introduce the material to be ground, and a discharge chute, which is used to remove the ground material.

Working of Ball Mill

The ball mill works by introducing the material to be ground into the feed hopper. The material is then pulled into the mill by the rotation of the drum. As the drum rotates, the balls inside the drum strike the particles, breaking them down into smaller pieces. The ground material is then discharged through the discharge chute.

Advantages of Ball Mill

• High efficiency in size reduction
• Able to handle a wide range of particle sizes
• Versatile and can be used for a variety of materials
• Simple and easy to operate
• Low cost of maintenance

Disadvantages of Ball Mill

• Not suitable for materials that are heat sensitive
• Can be noisy
• Can cause wear and tear on the balls and other parts of the mill
• Not suitable for materials that are sticky or have high moisture content

It is important to note that ball mill is not suitable for all types of material, and it should be used in conjunction with other size reduction techniques in order to achieve the desired particle size. Additionally, it is important to consider the application and specific requirements of the material being ground before selecting a ball mill or any other type of size reduction equipment.

Also Read: Size Reduction MCQs with answers

FAQs on Hammer Mill & Ball Mill