Avartin company have been involved in the design, construction and installation of flour mills since 1985. In the past few years, they have also been expanding their efforts in mechanization and manufacturing of machinery and equipment for silos and mechanized storage of wheat such as hammer mill. A hammer mill is an indispensable car in the pharmaceutical industry and food industry. You can use it for crushing, spraying, destroying, crushing and reducing materials to the right size.
Although there are several types of hammer mills, the principle of work is still the same. You will learn about it soon. First, let’s have a quick look at a hammer mill. Below is an hammer mill made by Avartin co:
From above, you can see that this hammer mill has five main parts. Typically, the number of pieces may vary depending on the complexity of the car’s design.
The principle of a hammer mill is based on a simple mechanism. However, before explaining how the whole process works, let’s look at some of the basic aspects of a hammer mill.
The following is an important aspect of a hammer mill:
· Nutrition mechanism
It refers to the process that the particles enter the crushing chamber. Depending on the design of the hammer mill machine, gravity or a measurement system can be used.
Metric feeding system is common in applications where product uniformity is a major concern. They eliminate all possible variables that may produce product incompatibility.
A good example is the pneumatic switch valve between the feeding hopper and the crushing chamber.
In gravity feeding systems, milling machines depend only on gravitational force. It is a force that helps feed particles in the crushing chamber.
· Control box
Users can change the device from the ON / OFF control box. The complexity of the control box to the unique design of the milling machine.
For example, you can control the power supply or engine speed. Some pharmaceutical milling machines have a screen that users can control all the steps.
· Crushing knife or hammer
These are the basic tools for crushing or crushing materials. They rotate at high speed, which varies from 2500 to 60,000 rpm.
In most cases, the hammer is mounted on a horizontal shaft, which can be rotated clockwise or counterclockwise. This may depend on the direction of rotation of the rotor.
A torque rotor is the electric motor axis. Hammers are in different styles and shapes.
Hammer mill crushing tool can be directly connected to a motor or by a belt. Compared to the direct connection, the belts can reduce the shock of the motor and allow for accurate speed adjustment.
· Hammer mill type machine
The output of a hammer mill is widely differentiated. Normally, particle size depends on page changes.
· Type of hammer mill screens
The output of a pharmaceutical hammer mill varies broadly. Normally, the size of the particles will depend on the screen variation.
These hammer mills may have over 12 different types of screen meshes. They are nicely arranged within the crushing chamber.
Depending on their arrangement, they can achieve a precision of 0 to 200.
How a Hammer Mill Works
i. Introducing material through the feed hopper
Choose materials with suitable and physical properties that have been cut to the right size. Place all your materials in the section labelled “1” above.
Depending on the design of the hammer mill. They will move into the crushing chamber either by gravity or controlled/metered process.
ii. In the crushing chamber
The ganged hammers or chopping knives hit the material severally. Theses knives or hammers rotate at a high speed reducing materials to a desired size.
Only particles whose diameter conform to that of the screen size will pass through. Otherwise, the hammer will continue to hit these materials until they are reduced to the required size.
Basically, within this chamber, the material is hit by a repeated combination of knives/hammer impact and collision with the wall of the milling chamber. Moreover, collision between particles to particles play an instrumental role in this size reduction process.
In short, this a mechanical process where particles are hit with high speed knives. Therefore, you need to wear all the necessary safety gears.
Again, don’t open the crushing chamber when the machine is operating. This is because you may be hit by particles flying at very high speed or crushing hammers/knives.
iii. Output of the milling chamber
The output of the milling chamber has perforated metal screens. They are also referred to as the bar gates.
Depending on the size and design of the metal screen, it allows the required size of particles to pass through while retaining coarse material.
The material that passes through is basically the finished product. It can either be packed using capsule filling machines or processed further depending on the specific requirements.
Now that you know the working principle of hammer mills, let’s explore the basic factors that determine the type of the final product.
Factors that Determine the Type of Hammer Mill Output
Basically, there are three aspects that determine the particle size of a hammer mill. These include:
Hammer or cutting knife configuration
Shaft speed (it depends on motor speed and coupling mechanism).
In most cases, the mechanical process of reducing large size particles into small particle may result in a fine or coarse finish. How is then is this possible when you use the same pharmaceutical hammer mill equipment?
First, to get a fine finish particle size, you should consider the following key aspects:
A fast rotating rotor speed
Small screen size
Large or/and more crushing knives/hammers
Second, in case you need a coarse finished output, it is important to consider the following key aspects:
Few or/and small crushing hammers/knives
Slow rotor speed
Another crucial aspect to consider when examining the working principle of hammer mills is the production capacity.
Factors Determining the Capacity of Hammer Mills
There are many factors that determine the overall capacity of hammer mills. These critical aspects include the following:
Characteristics of materials to be crushed
Nature or type of the crushing hammers or knives
Number of rows of crushing hammers or knives