Air Compressor Types and What Are They Used For – Comprehensive Guide Posted on September 18, 2023 by Nurul Afsar Air compressors are versatile devices used to convert power into potential energy stored in pressurized air. By forcing air into a storage tank, the pressure increases, and this compressed air can then be utilized for a variety of applications, ranging from industrial processes to simple power tools. The design, mechanism, and capability of air compressors differ depending on their type. This article delves into the primary types of air compressors, elucidating the characteristics of each. Air Compressor Types 1. Positive Displacement Compressors: Reciprocating Air Compressors: These are the most common type in smaller operations like workshops and garages. A reciprocating compressor works by drawing in air and compressing it within a piston-cylinder arrangement. This type can be further classified into: Single-Stage: Ideal for jobs requiring pressures up to 150 psi. They compress air in a single piston stroke. Two-Stage: Utilized for jobs demanding pressures up to 200 psi. Air is compressed in two piston strokes. Rotary Screw Compressors: These are popular in larger industrial applications. Two helical screws, or rotors, are used to compress air. When the rotors turn, the volume of the air decreases, leading to compression. Rotary screw compressors are efficient and can operate continuously, making them apt for tasks that require a consistent air supply. Rotary Vane Compressors: These use a rotor with varied blade placement that compresses the air against the casing. They’re less common than screw compressors but serve a similar market. 2. Dynamic Displacement Compressors: Centrifugal Compressors: These leverage a spinning impeller’s kinetic energy to compress air. As the impeller rotates, air is drawn in and is flung outward by centrifugal force, thus compressing it. Due to their design, centrifugal compressors can produce large volumes of compressed air and are most suitable for factories and big industrial settings. 3. Special Compressors: Scroll Compressors: A scroll compressor comprises two interleaved spiral vanes. One vane is stationary, while the other moves in small orbits, compressing the air. They are notably quiet and efficient, commonly found in HVAC systems. Diaphragm Compressors: Here, a flexible diaphragm separates the air from the driving mechanism, reducing the risk of contamination. This makes them suitable for applications where purity is crucial, like in the pharmaceutical or food industries. Axial Compressors: These are employed in very specific applications like aircraft engines. Air flows parallel to the axis of rotation and gets compressed through aerodynamic action by a series of rotors and stators. 4. Oil-Free and Oil-Flooded Compressors: Apart from design-based classification, air compressors can also be categorized based on their lubrication: Oil-Free: These compressors don’t use oil for cooling or sealing, ensuring that the output air remains uncontaminated. They are ideal for food, medical, or electronics manufacturing. Oil-Flooded: Oil is used for sealing and cooling but can mix with the compressed air. Though filters can remove most of the oil, a trace amount remains. These are typically more efficient and longer-lasting than oil-free models. What are Air Compressors Used For? 1. Positive Displacement Compressors: Reciprocating Air Compressors: Single-Stage: These are commonly used in homes, garages, and workshops for tasks like inflating tires, powering pneumatic tools, and other tasks requiring lower pressure. Two-Stage: Employed in auto repair shops, production facilities, and tasks necessitating higher pressures. They might be used in certain HVAC applications or for running large tools. Rotary Screw Compressors: Given their continuous operation capability, these are commonly used in large-scale manufacturing, construction sites, and big industrial applications where a consistent air supply is vital. Rotary Vane Compressors: Often found in automotive applications, they also serve printing presses, vacuum pump applications, and airtight transport of bulk goods. 2. Dynamic Displacement Compressors: Centrifugal Compressors: Due to their capability to produce large volumes of compressed air, they are widely used in chemical plants, refineries, natural gas processing plants, and other large facilities. 3. Special Compressors: Scroll Compressors: These are predominantly used in HVAC systems, providing a quiet and efficient solution for air conditioning and refrigeration. Diaphragm Compressors: Their ability to prevent contamination makes them a prime choice for pharmaceuticals, food and beverage, nuclear power, and other sensitive industries where purity is essential. Axial Compressors: Primarily used in high-speed, high-flow applications such as in jet engines. 4. Oil-Free and Oil-Flooded Compressors: Oil-Free: Given the zero-oil contamination, these compressors are vital in food and beverage production, pharmaceutical manufacturing, electronics assembly (where even trace amounts of oil can harm products), and medical applications like supplying hospital air systems. Oil-Flooded: Suitable for general industrial applications where a trace amount of oil in the compressed air isn’t a concern. This includes manufacturing, construction, and automotive industries. Because of their efficiency, oil-flooded compressors can be found in heavy-duty industrial settings where air purity isn’t the topmost priority. Other Noteworthy Applications: Energy Storage and Power Generation: Compressed air can act as a form of energy storage, often referred to as Compressed Air Energy Storage (CAES). Breathing Air: High-quality air compressors are used in scuba diving to fill dive tanks and in firefighting to provide breathable air. Cleaning and Painting: Air compressors are invaluable tools in sandblasting operations, spray painting, and for cleaning purposes in various industries. Transportation: Compressed air is crucial in brake systems of large vehicles and trains. Medical Equipment: Devices like nebulizers utilize compressed air. Air compressors, with their versatility and various designs, cater to a broad spectrum of industrial, commercial, and personal needs, making them indispensable in our modern world. We also have some articles on How to use an air compressor Why Air Compressor is needed Frequently asked questions about Air Compressors
