How crushing machine crushes gravel?

A gravel crushing machine, often referred to as a crusher, is a piece of heavy machinery used in the mining and construction industries to break down large rocks into smaller, more manageable pieces. The process of crushing gravel involves several stages and different types of equipment, each designed to handle specific tasks. Here’s a detailed explanation of how a crushing machine crushes gravel:

1. Feeding the Crusher

The process begins with the raw material being fed into the crusher. This is typically done using a vibrating feeder, which ensures a steady and controlled flow of material into the machine. The feeder helps to prevent overloading and ensures that the crusher operates efficiently.

2. Primary Crushing

The first stage of crushing is known as primary crushing. This is where the largest rocks are broken down into smaller pieces. The primary crusher is usually a jaw crusher or a gyratory crusher.

• Jaw Crusher: This type of crusher uses compressive force to break down the material. The material is fed into a V-shaped chamber, where a movable jaw compresses it against a fixed jaw, breaking it into smaller pieces.
• Gyratory Crusher: This crusher has a conical head that gyrates inside a larger cone-shaped chamber. The material is crushed between the outer wall and the gyrating head.

3. Secondary Crushing

After primary crushing, the material is typically conveyed to a secondary crusher for further reduction. Secondary crushers can be cone crushers, impact crushers, or hammer crushers.

• Cone Crusher: This crusher uses a rotating cone inside a fixed outer shell to crush the material. The material is squeezed and broken down as it moves through the narrowing gap between the cone and the shell.
• Impact Crusher: This type of crusher uses high-speed impact to break down the material. The material is fed into a chamber where it is struck by rotating hammers or blow bars, causing it to shatter.
• Hammer Crusher: Similar to an impact crusher, but it uses a series of hammers to crush the material.

4. Screening

Once the material has been through the primary and secondary crushers, it is typically screened to separate it into different size fractions. This is done using vibrating screens, which have different sized openings to allow smaller particles to pass through while larger particles are retained for further crushing.

5. Tertiary Crushing

For finer material, a tertiary crusher may be used. This stage further reduces the size of the material to meet specific requirements. Tertiary crushers can be similar to secondary crushers, such as cone crushers or impact crushers, but they are often designed to produce finer output.

6. Final Screening and Washing

After the tertiary crushing stage, the material is often screened again to ensure it meets the desired specifications. In some cases, the material may also be washed to remove any remaining dust or impurities. This is typically done using a washing plant, which sprays water over the material as it moves along a conveyor belt.

7. Stockpiling

The final step in the process is stockpiling the crushed gravel. The material is transported to a storage area where it is piled up and ready for use in construction projects or further processing.

Summary

In summary, a gravel crushing machine works by feeding raw material into the crusher, where it undergoes primary, secondary, and sometimes tertiary crushing stages. The material is screened and possibly washed to ensure it meets the desired specifications before being stockpiled for use. Each stage of the process involves different types of equipment, each designed to handle specific tasks and produce the desired output.