Industrial Air Compressors Introduction and Working

Summary

This video script explains the two main types of compressors: positive displacement compressors and dynamic (centrifugal) compressors. It covers how each type operates, their components, and how they are used in compressed air systems. The script also delves into the various safety devices and auxiliary components, such as filters, lubricators, oil separators, desiccant dryers, and coolers, which ensure optimal operation and prevent system failures. Additionally, it addresses the hazards associated with compressed gas systems, emphasizing the importance of safety protocols to prevent injuries or damage to equipment.

Takeaways

• 😀 Positive displacement compressors trap and compress gas into a smaller volume, with reciprocating compressors being a common example.
• 😀 Centrifugal compressors use an impeller to accelerate the gas, converting its energy into pressure as it slows down.
• 😀 Compressors are rated by discharge pressure (PSI) and flow rate (CFM), with electric motors being a common drive mechanism.
• 😀 A typical compressed air system includes a multi-stage reciprocating compressor, intercooler, aftercooler, demister, safety valve, and receiver.
• 😀 Multi-stage compressors compress air in stages, with intercoolers and aftercoolers used to remove heat and moisture from the gas.
• 😀 The safety valve protects the system from excessive pressure by releasing gas if the pressure becomes too high.
• 😀 Compressed air used in pneumatic systems must be clean, dry, and at lower pressures, often requiring additional filtration and moisture removal devices.
• 😀 Pneumatic tools and hoses must be inspected regularly to prevent accidents, and proper hearing and eye protection is necessary when working around compressors.
• 😀 Certain gases like hydrogen can be hazardous, with risks including flammability, toxicity, or displacement of air, requiring appropriate safety precautions.
• 😀 The lubrication system in compressors helps reduce friction, prevent wear, and keep gas from leaking, often involving oil pumps, filters, and heat exchangers.
• 😀 Oil separators and desiccant dryers are essential for removing contaminants such as oil and moisture from compressed air to protect downstream equipment.

Q & A

What is the primary difference between positive displacement compressors and centrifugal compressors?

Positive displacement compressors work by trapping a specific amount of gas and forcing it into a smaller volume, which increases its pressure. Centrifugal compressors, on the other hand, use an impeller to spin the gas, accelerating it and converting its energy into pressure as it slows down.

What are the key components of a typical compressed air system?

A typical compressed air system includes a compressor, intercooler, aftercooler, demister, safety valve, and a receiver. The compressor can be multi-stage, and the system also includes components to cool, filter, and regulate the pressure of the air.

How does a multi-stage reciprocating compressor work?

In a multi-stage reciprocating compressor, air is compressed in two or more cylinders. After the first stage, the air is cooled in an intercooler before entering the second stage, where its pressure is further increased. The compressed air is then cooled again in an aftercooler.

Why is moisture removal important in compressed air systems?

Moisture removal is critical because water vapor in compressed air can cause damage to equipment. Moisture separators, such as demisters, remove moisture to prevent potential damage and ensure the efficiency and longevity of the system.

What is the function of an oil separator in a compressor system?

An oil separator removes oil from the compressed gas. Oil is used to lubricate components within the compressor, but it must be removed from the compressed air to prevent damage to downstream equipment and ensure air quality.

What are the hazards associated with working around compressors?

Hazards include moving parts that can catch clothing or jewelry, high temperatures that may cause burns, excessive noise that can lead to hearing loss, and risks from compressed gas systems like leaks that can cause dirt or dust to blow at high speeds. Additionally, some gases are toxic or flammable.

What are intercoolers and aftercoolers used for in a compressor system?

Intercoolers are used in multi-stage compressors to cool the air between stages, while aftercoolers cool the air after the compression process is complete. Both devices help remove excess heat generated during compression.

How does a desiccant dryer work to remove moisture from compressed air?

A desiccant dryer uses a material like silica gel or activated alumina to absorb moisture from the compressed air. It typically has two tanks, with one tank active and the other undergoing regeneration to dry the desiccant, ensuring continuous moisture removal.

Why is lubrication necessary for compressors?

Lubrication reduces friction between moving parts within the compressor, preventing excessive wear and damage. It also helps cool components and seals the gas inside the compressor by lubricating the piston rings, which helps maintain efficiency.

What role does the safety valve play in a compressor system?

The safety valve protects the system from excessive pressure. If the pressure exceeds a set limit, the valve opens to release the excess pressure and prevent damage to the compressor or the rest of the system.