What Is a Blower?
A blower is a mechanical device used to force air to move.
It is typically driven by a motor or engine and has rotating blades or fans. This equipment is widely used for the purpose of blowering and exhausting air.
Blowers can be broadly classified into three types: fans, blowers and compressors. Fans are machines that produce a differential pressure of less than 10 kPa, while blowers produce a differential pressure of between 10 and 100 kPa. Compressors produce higher differential pressures.
Blowers produce powerful wind power to move large volumes of air in industrial applications. They contribute to material transport and process efficiency in factories and production lines. They are also often used to blow harmful gases.
Uses of Blowers
Blowers are widely used in a variety of applications. The following are examples of common uses.
1. Heating and Cooling Systems
Blowers assist in air circulation and temperature control in the heating and cooling systems of buildings and houses. They are used in combination with air-conditioning units and heaters to ensure efficient air distribution and temperature uniformity.
They are also often used in ventilation systems in buildings and facilities. Air quality can be improved by forcing out indoor air and bringing in fresh outdoor air.
2. Metallurgical Processes
Blowers provide cool air as a cooling device and may also control the temperature of a machine or process. In casting and welding processes, blowers deliver cooling material to provide cooling.
3. Mining
In mining, blowers are important devices in the ventilation system within the mine. Blowers supply fresh air into the mine and ensure a safe working environment for the miners.
Toxic gases and dust are also generated when ore is fed into the furnace. Blowers are needed to detoxify these without letting them out of the system. Blowers suction the exhaust gases and introduce them into flue-gas desulphurisation plants, for example.
4. Automotive Industry
Blowers are often used to accelerate drying in the automotive paint process. Blowers are responsible for rapidly removing volatile components of the paint and drying the painted surface.
Blower Principle
Blowers are driven by a motor or engine and operate on the principle of moving air through a rotating impeller. The basic principle of blower airflow is Bernoulli’s law.
This law states that as the velocity of a fluid increases, the pressure decreases, and as the velocity decreases, the pressure increases. The rotation of the blower increases or decreases the velocity of the surrounding air, which in turn creates a pressure differential that blows or exhausts the air.
The change in air velocity is often created by centrifugal force. The air is rotated by a rotating impeller and the centrifugal force pushes the air outwards. The force of the pushing outwards causes the air to be blown or exhausted.
Types of Blowers
Different types of blowers exist. The following are examples of blower types
1. Roots Blower
This type of blower blows air by rotating a pair of vane-shaped parts called rotors inside the housing. It consists of two to four blades; the higher the number of blades, the more air is blown per rotation and the higher the efficiency.
It is so called because the Roots brothers came up with the current configuration in 1866. There are three main rotor configurations: involute, cycloidal and envelope.
2. Centrifugal Blowers
Centrifugal blowers are blowers that use centrifugal force to blow air by rotating the air by means of rotating blades. There are various types with different blower characteristics depending on the shape and arrangement of the blades. Common examples of use are in cooling and exhaust systems.
3. Multi-Stage Blowers
These are blowers with multiple stages. Each stage has an impeller and a mechanism for increasing pressure in stages. Generally, air is compressed at each stage and sent to the next stage for further pressure increases.
They are therefore capable of generating high pressures and are therefore ideal for applications where pressure is required. Typical applications are industrial processes requiring high-pressure blasts or air supply, exhaust systems, etc.