Air Compressor System provides high force per unit area compressed air with subsequent decrease in volume for a scope of industrial and domestic applications. They have become imperative equipment in about every industry. Due to its high efficiency, executable operational parametric quantities and diverse scope of applications, they have gained widespread popularity and no industry is complete without a compact compressor system.
The primary aim of this study is to understand the importance of air compressor systems. In add-on, the study covers a broad spectrum of compressor applications and procedures. The different types of compressors, along with their virtues and demerits have been delineated. The of import operational parametric quantities have been defined along with their importance in the compaction procedure.
“ Air is free, whereas compressed high force per unit area air is non ” . True to the phrase, bring forthing high force per unit area compressed air is non an economical and energy efficient procedure. High initial and care costs can increase the overall compressor cost to a great extent. Proper and good maintained compressor systems can cut down energy ingestion from 30-50 % . Assorted stairss to cut down energy ingestion and increase overall efficiency have been detailed in the study.
For a practical application of compressor acumen, a instance survey has been conducted on an ELGI Compressor which is under operation in Arabian Cement Industry. With the informations collected from the survey, certain operational parametric quantities were calculated and matching illations were drawn. At the terminal of the survey, we are able to reason the current province of the compressor and item certain stairss to better efficiency and compressor public presentation.
The hereafter of air compressor systems has been a changeless research subject among industrialists. The modern techniques of Heat Recovery Systems in air compressors and usage of Variable Speed Drives have been briefly detailed to supply a position into a bright hereafter of air compressor systems.
Introduction to Air Compressor Systems
In most industrial applications, compressed air is considered as the “ 4th public-service corporation ” , preceded by the three indispensable public-service corporations ; H2O, electricity and natural gas. Typically, a simple air compressor is an industrial device that intakes ambient air and increases the pressurewith decrease in volume by making work on the working fluid, viz. air or gas.
The primary aim of using a compressor is to supply high force per unit area air utilizing least possible power ingestion. The compaction can happen in any one of the three ways ; adiabatic, isothermal or polytropic. For an Adiabatic compaction procedure, there is assumed to be no heat loss or addition from the system. When the temperature of air at recess peers temperature of tight air at mercantile establishment, the compaction procedure is Isothermal. Normally, a typical compaction procedure involves Polytropic Compression. The force per unit area, temperature and volume of air it recess and mercantile establishment vary with the several conditions. The least possible work of compaction is achieved in an adiabatic compaction procedure as the net work done by the system is zero. [ 1 ] The adiabatic efficiency is the maximal possible compressor efficiency and compressors are designed with compressor efficiencies such that, there is small or no fluctuation among the two.
As mentioned earlier, tight air is considered a public-service corporation because of their diverse applications in assorted industrial and metallurgical operations. The tight air supply is clean, convenient, safe and flexible for usage. Industrial uses can be attributed to when they are in connexion with tight air motors for operation of pneumatic tools, natural stuff conveying through canals, in connexion with a reservoir for storage of tight air for future applications.
1.2 Historical Background
The earliest documented usage of the compressor dates back to around fourth century B.C. In those times, the compressor was termed as a “ H2O organ ” . The H2O organ was invented by Ctesibius of Alexandria. The design comprised of a chamber filled with air and H2O, a H2O pump, aggregation of pipes of assorted dimensions and linking tubings and valves. The mechanism of operation was comparatively simple ; by pumping H2O into the chamber, the air gets compressed. [ 2 ] With promotion of clip and engineering, assorted betterments and inventions were made to the H2O organ.
In 1808, the Multi Stage Axial Compressor, designed by John Dumball, came into industrial application. However, this design did non accomplish wide-spread popularity because the compressor comprised of traveling blades without stationary blades to reassign the air flow into the consecutive compaction phase.
During the nineteenth century, the innovation of the Roots Blower was a immense measure taking to innovation of modern air compressor systems. Philander and Francis Roots designed the Roots blower, while inventing a suited replacing for the H2O wheel at their woollen factory. The roots blower consisted of legion impeller braces revolving in opposite waies. [ 3 ]
Dr. Franze Stolze designed the modern compressor in 1900 ; which comprised of a multi phase axial flow compressor with a burning chamber, multi-stage axial turbine along with a regenerator to heat the dismissed air using exhaust waste gases.
1.3 Applications of Compressed Air
High force per unit area compressed air is widely used for industrial and domestic applications due to their high efficiency and facile operational nature.
The powering of pneumatic equipment is one of the major applications of tight air. Pneumatic tools are lighter, deliver more power and non prone to overloading, unlike electric motor tally equipment. Compressed air goaded tools can accomplish high overall torsion and optimal velocity in a short span of clip. They are safer as compared to electric driven tools because of no flicker conditions and less overheating. [ 4 ]
Compressed air is besides used for natural stuff conveyance, burning procedures ; such as oxidization, thermodynamic operations ; such as infrigidation and cryogenies. Filtration, aeration and desiccation procedures are besides driven by tight air.
Non-industrial applications of tight air include transit, excavation and agribusiness. [ 5 ]
1.4 Components of Air Compressor System
Due to the diverse applications of tight air, air compressor systems merit an intricate and complex design. Air compressor systems consist of a figure of sub-systems and constituents, which include the air compressor, motor and thrust unit, control systems, air recess filters, air driers, after-coolers and assorted other retrofitted constituents.
During the operation of an air compressor system, the ambient air is taken into the system by air recess filters. The motor and gear unit powers the compressor system to increase the force per unit area of air. The primary map of an integrated control system is to modulate the sum of air consumption and air discharge from the system.
Treatment equipment, such as an Air Dryer and Air Separator are used to take contaminations and supply wet and oil free pressurized air. The Outlet and Distribution systems play the polar function of transporting the tight air to the assorted needed beginnings. In typical industrial applications, the pressurized air is stored in an Air Reservoir or Storage Tank for future usage.
The major constituents of an air compressor are detailed below:
Intake Air Filter: Ambient air enters the compressor via recess air filters. Filtration elements in consumption filters facilitate filtration of particulate affair nowadays in air. This allows the entry of clean and dry air into the compressor.
Compressor Cooling: A significant sum of heat is generated during compressor procedure. As a consequence, chilling and lubrication of the system is compulsory for cut downing wear and harm to the compressor spares ; thereby increasing compressor efficiency. Compressors are usually cooled utilizing air, H2O or oil ( lubricator ) . [ 6 ]
Inter-Stage Coolers: Inter ice chests act as heat money changers to take down the temperature of air before it enters into consecutive phases of compaction. [ 7 ] This decrease of temperature is overriding to cut down the overall compaction work and increase compressor efficiency.
After-Coolers: After ice chests are employed at the terminal of compaction procedure to take down the discharge temperature of air. During this concluding phase of operation, as the temperature is lowered, wet nowadays in air condenses and separated from the discharge air.
Air Centrifuges: Centrifuges act as an enhanced after-cooler. Theyare installed either after an inter-cooler or after-cooler to dehydrate discharge air.
Air-Dryers: Normally, after the tight air has passed through all the above mentioned equipment, discharge air is passed into the air-dryer before storage in the reservoir. The air that reaches the drier is saturated. If this saturated air enters the piping, it can take to corrosion and harm to the conveyance equipment. The Relative Humidity ( wet content ) in atmospheric air is comparatively high. When this air is compressed at high force per unit area, it occupies a little volume and high temperature. At a specific temperature, all the wet nowadays in air condenses. This temperature is known as Dew Point. This procedure is cycled in an air-dryer to guarantee that moisture-free air reaches the storage country. [ 8 ]
Pressure Regulators/Flow Controller: Perfluorocarbon ‘s are subsidiary equipmentthat minimizes force per unit area beads in the system by stabilising system force per unit area.
Lubrication: Lubrication is a paramount demand for effectual tight air operation. A lubricant is employed to lubricate and chill the moving parts and prevent overheating. In some systems, the lubricant is retrofitted with a tight filter and force per unit area flow regulator to manner a system known as Filter Regulator Lubricant ( FRL ) . [ 10 ]
Air Receivers: The high force per unit area compressed air from the system is discharged to a storage armored combat vehicle or an air-receiver harmonizing to the demand. The capacity and type of air receiving system varies depending on the demand of tight air within the system. For convulsive demand of tight air, a big capacity reservoir is employed for a comparatively little capacity compressor. Furthermore, a receiving system maps depending on demand, thereby cut downing overwork and burden on the compressor.
Air Transport and Distribution System: The concluding phase in a compaction procedure is the proper distribution of tight air to the demand points. A common distribution system includes piping, valves and hosieries. To minimise the force per unit area bead during distribution, it is imperative that the pipe length is kept minimal and diameter to maximum.
Figure 1 depicts a typical air compressor system and corresponding constituents.
Degree centigrades: Users
Fig 1: Components of Air Compressor System