A reciprocating air compressor is classified by stages that assist with understanding how a reciprocating air compressor works. Apart from the piston and the cylinder arrangement, the reciprocating compressor also comprises of the crankshaft, connecting rod and other small connecting elements. The working of reciprocating compressor includes three operations, suction, compression, and discharge of compressed fluid. As power is On, the electric motor starts rotating and also rotates the crankshaft attached to it. MODULE-VI --- RECIPROCATING COMPRESSOR APPLIED THERMODYNAMICS 2014 . S ingle -acting means that the refrigerant acts only on one side of the piston while double -acting means the work-ing fluid acts on two sides of the piston. It’s a legacy of creating new standards for how the world gets work done. Benefits of monitoring reciprocating compressors •Defer Calendar Based Maintenance •Performance Optimization •Machinery Throughput Improvement •Avoid Catastrophic Failures •Reduce unscheduled downtime •Reduce Machinery Abuse •Quality Assurance of the New Installations and Overhaul Equipment •Planning and Scheduling •Extend the run time between This tutorial is mainly about reciprocating compressors. Each crankshaft rotation achieves actions: suction, compression, and discharge. The diaphragm compressor in Figure 1 is Power required to derive Reciprocating Air Compressor The intake gas enters the suction manifold, then flows into the compression cylinder where it gets compressed by a piston driven in a reciprocating motion via a crankshaft, and is then discharged. (The fluid here is generally air since liquids are theoretically incompressible). 2 2 11. All Rights Reserved. The piston compressor, also denoted reciprocating, is a displacement compressor type which consists of a moving piston which compresses the air. + Area 2-3-3.-2. • A 150hp compressor runs 90% loaded 12 hours per day 5 days per week at a delivery pressure of 110psi. It is clear that the volume of air delivered in this process is: The work done by the compressor per cycle can be given by the area under the curve 1-2-3’-4-1. George Medhurst of England designed the first motorized air compressor in 1799 and used it in mining. In this diagram, the path 2-3 represents the polytropic compression and the path 2-3’ represents the isothermal compression and the path 2-3” represents the isentropic compression. The above area can be further split as follows: W= Area 1’-4-3’-3.’ + Area 2-3’-3.'-2. While each type has the same operation principles, each compressor classification discharges pressure differently. Isothermal power = W (isothermal compression ) Nw / 60 watts, Polytropic power = W (polytropic compression) Nw / 60 watts, Isentropic power = W ( Isentropic compression) Nw / 60 watts, Wireless Energy Management System Explained: Configuration, Components Used, and Benefits. Reciprocating Compressors are one of the most widely used type of compressors for refrigeration and air conditioning applications. Assuming the air as a perfect gas, where 2 Reciprocating Compressors Legendary Performance For more than a century, Ingersoll Rand has inspired progress by driving innovation through revolutionary technology and talented people. S ingle -acting means that the refrigerant acts only on one side of the piston while double -acting means the work-ing fluid acts on two sides of the piston. Depending on the location of the working fluid, the reciprocating compressor can be sub -classified as single -acting or double -acting. The reciprocating compressor is probably the most versatile of all the types and is only out performed by rotary types when large volumes at low pressures are required. = −1 . Please consider donating via Paytm since Youtube has removed my account from the ad partnership program because I don't have a thousand subscribers. The reciprocating compressor is similar to an automobile engine. reciprocating compressor module A self contained floor standing mobile unit that includes a small compressor with an air receiver and instrumentation. The polytropic compression follows the path 1-2-3-4-1. This compressor employs back and forth piston motion to compress the vaporized refrigerant. compressor. Analysis of Cycle . Compressor: Of the reciprocating, rotary, and centrifugal compressors, the most popular among domestic or smaller power commercial refrigeration is the reciprocating. The same principles are applied to the compression of other gasses. 2 … Some of them are the reciprocating compressor, rotary compressor, etc., Each have their own advantages and disadvantages. Positive Displacement Compressor Reciprocating Compressor. The diaphragm compressor in Figure 1 is All these actions are in sequence. The reciprocating compressor is probably the most versatile of all the types and is only out performed by rotary types when large volumes at low pressures are required. 2. The P-V diagram is a plot of the pressure of the gas versus the volume of the gas trapped in the compression chamber. Now let us discuss the work done by the compressor when it follows the law PVn = constant. INTRODUCTION TO COMPRESSOR: Compressors are work absorbing devices which are used for increasing pressure of fluid at the expense of work done on fluid. It allows students to study and perform tests on a reciprocating compressor, to understand how it works and calculate its performance. P = W Nw / 60. where, N - the speed of the compressor in rpm, The air will be delivered when sufficient pressure has been reached so that the valves can be opened. A reciprocating compressor is a positive displacement machine in that a volume of gas is drawn into a compressor cylinder’s compression chamber where it is trapped, compressed and pushed out. The volume of air delivered being 3”-4. The same principles are applied to the compression of other gasses. 1 (. Work is done on the piston during the suction of the air. As the piston moves downward (towards BDC), the air from the atmosphere enters into the chamber of the cylinder. Ratio of In Figure 1, P S c b d . When the air passes through the rotating impeller it experiences force or work which is performed by centrifugal forces. The volume of cylinder is also fixed so the line 4-1 is fixed. towards TDC), the compression of the air starts and its pressure begins to increase… 3. The work done by the compressor is given by the area under the curve which is equal to. For reciprocating compressors, the pressure ratio is fixed, so the height of p-v diagram is fixed. The other types are covered briefly. Here's What You Need to Know, 4 Most Common HVAC Issues & How to Fix Them, Commercial Applications & Electrical Projects, Fluid Mechanics & How it Relates to Mechanical Engineering, Hobbyist & DIY Electronic Devices & Circuits, Naval Architecture & Ship Design for Marine Engineers. • Net potential is 40% to 84% recovery Copyright © 2020 Bright Hub PM. This means those compressors can only operate half the time which reduces your ability to get the job done. Work is done by the piston during compression as well as delivery of the air. Special Thanks to poornima university family 15 Conditions for Minimum Work We know that the work done is equal to the area under the graph. As long as P2 is reached, the compressor has done its job. Relatively low end temperature of compressed air. In the single-stage compressor, air is drawn in from the atmosphere and compressed to final pressure in a single stroke. 2 … Therefore the equation (3) can be re-written as: (or) The equation (2) can be re-written as: or V2/V1 = (P1/P2)1/n or V1/V2 = (P2/P1)1/n, since, for a polytropic process PVn = constant. of reciprocating air compressor . Please consider donating via Paytm since Youtube has removed my account from the ad partnership program because I don't have a thousand subscribers. represents the net or indicated work done on the air per cycle. The air supply is continuous as compared to reciprocating compressors. These are called the work-horses as they supply large amount of compress air. The air is compressed during the compression stroke (2-3) at constant temperature (T1=T2). This tutorial is mainly about reciprocating compressors. From the above diagram it is clear that the air is drawn in by the cylinder during the suction stroke (1-2). The piston starts doing to and fro motion inside the cylinder. Work Done By Reciprocating Compressor without Clearance Volume (Single Stage, Single Acting) With PV and TS Diagram. of working strokes per minute. MODULE-VI --- RECIPROCATING COMPRESSOR APPLIED THERMODYNAMICS 2014 . Now let us discuss each in detail in the following paragraphs. These types of compressors adopt a volumetric compression system using pistons and work much like an internal combustion engine. p-V diagram . INTRODUCTION TO COMPRESSOR: Compressors are work absorbing devices which are used for increasing pressure of fluid at the expense of work done on fluid. Indicated work per cycle . 4) . Principles on which compressors work: A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Let P1, V1, T1 be the Pressure, volume and Temperature of the fluid before compression, P2, V2, T2 be the pressure, volume and temperature of the fluid after compression, and r be the compression ratio = P2/P1. Reciprocating compressors offer a lot of beneficial uses to refineries. Indicated work / cycle = area a-b-c-d = area 1-2-3-4-1 =area under 1-2 + area under 2-3 – area under 4-1 . Work done by a reciprocating air compressor is mathematically equal to the work done by the compressor during suction. ILLUSTRATIONS . Single-acting reciprocat… 3. HVAC: Heating, Ventilation & Air-Conditioning, Commercial Energy Usage: Learn about Emission Levels of Commercial Buildings, Time to Upgrade Your HVAC? • In many cases, a properly designed heat recovery unit can recover anywhere from 50 to 90 percent of this available thermal energy and put it to useful work heating air or water. Rotary screw air compressors last longer than reciprocating air compressors. Reciprocating Compressor . This compressor comprises a motor, a crankshaft, and some pistons. 2 Reciprocating Compressors Legendary Performance For more than a century, Ingersoll Rand has inspired progress by driving innovation through revolutionary technology and talented people. 2. The delivery of air takes place from 2-3. We’re the technology leader in compressed air not only because we develop Learn how this type of compressor is put to work in refineries here! Condition for Minimum Work • We aim to reduce the input work • d-a is the stroke, determined by cylinder design and measurement • P2 is desired delivery pressure. A reciprocating compressor or piston compressor is a positive-displacement compressor that uses pistons driven by a crankshaft to deliver gases at high pressure.. As we know, the reciprocating compressors may be used for high pressure applications. In the way back from point 1 to point 3, gas flows or gas induced to cylinder is only from point 2 to 3, because from point 1 to 2 there is only gas expansion of residual gas in clearance space. Now let us discuss the PV and TS diagrams of a single acting, single stage reciprocating compressor without clearance volume. = (P2V2(n-1) + P2V2 - P1V1 - P1V1(n-1))/(n-1), = (nP2V2 - P2V2 + P2V2 - P1V1 - nP1V1 + P1V1)/(n-1), = (n/n-1)(P2V2-P1V1) —————————————–(2), = (n/n-1)P1V1(P2V2/P1V1 - 1) ————————————–(3), for a polytroic compression PVn = constant. The reciprocating compressor is either powered by electric motor, diesel/gas engines. The single-stage reciprocating compressor is illustrated in (Figure 1). Reciprocating Single Acting Compressors Reciprocating single acting compressors are generally of one-stage or two-stage design. The area under the . It simply means the clearance volume does not affect the work done and the power requirement for compression of air. Smaller area means less work and the better the compressor. • Only the compression process can be adjusted by varying n, the polytropic index. • Only the compression process can be adjusted by varying n, the polytropic index. POWER REQUIRED. We’re the technology leader in compressed air not only because we develop In Figure 1, P S and W denotes the work done by the compressor. By- AdityA ShArmABy- AdityA ShArmA 2. The P-V diagram is a plot of the pressure of the gas versus the volume of the gas trapped in the compression chamber. - Area 1-1’-2-2. This is so, because, the work required to compress the clearance volume air is theoretically regained during its expansion from 3 to 4. Compressors can be of a lubricated, non-lubricated or oil-less design. 1. Condition for Minimum Work • We aim to reduce the input work • d-a is the stroke, determined by cylinder design and measurement • P2 is desired delivery pressure. Thank you.My PayPal account: paypal.me/metutorials Thermodynamics: An engineering approach reference book by Yunus Cengel http://amzn.to/2xP5M0Ywork done on single stage reciprocating compressor without clearance volumehttp://adf.ly/1lc557-~-~~-~~~-~~-~-Please watch: \"5 Books To Read Improve Basic English (For Beginners) \" https://www.youtube.com/watch?v=IDCvWjgK7Xg-~-~~-~~~-~~-~- W = m cp (T2 - T1) which means that the work done is equal to the heat required for raising the temperature from T1 to T2 at a constant pressure. Single-stage compressors are generally used for pressures of 70 psi (pounds per square inch) to 135 psi. The motor rotates the crankshaft, which then pushes the pistons. The compressors used for compressing air are called air compressors. ILLUSTRATIONS . A piston is driven by a motor to "suck in" and compress … The power required to drive a single acting reciprocating compressor is, Nw - the no. The function of a compressor is to take a sufficient amount of fluid and to increase its pressure. It’s a legacy of creating new standards for how the world gets work done. (The fluid here is generally air since liquids are theoretically incompressible). By- AdityA ShArmABy- AdityA ShArmA 2. It has high efficiency both at full and partial loads, but less positive aspects are that it is noisy and moreover, demands more space than other types of compressors. Principles on which compressors work: A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Learn the working of reciprocating compressor and derivation of work-done expression. The other types are covered briefly. = P2V2 + 2.3 P2V2 log (V1/V2) - P1V1 —————————————(1), We know that for an isothermal process PV = constant, Since P1V1 = P2V2 , Therefore V1/V2 = P2/P1, = 2.3 P2V2 log (r) ( where r - compression ratio = P2/P1). Ratio of As long as P2 is reached, the compressor has done its job. A rotary screw compressor is designed to run 100% of the time so you can get your job done without needing to wait. Now, the pressure rises from P1 to P2 from 2-3. They are the reciprocating compressor which has piston working only in one direction.The other end of the piston is often free or open from which no work is performed.There is only one side compression or the upper part of the piston is used to compress the air.the bottom part is open to crankcase and is not utilized for the compression of air. 1 −1 −1 , n = polytropic index Clearance Ratio, = . . . . Volumetric efficiency. 2. Now the piston after reaching at BDC, starts moving upward (i.e. The power required to drive a single acting reciprocating compressor is. . 1. In the two-stage compressor, air is drawn in from the atmosphere and compressed to an intermediate pressure in the More complex design. Expensive then piston-type compressors. Reciprocating Compressor 1. How Reciprocating Compressors Are Used in Refineries Over the past 200 years, industrialists have found ways to turn raw materials into products. The compressors used for compressing air are called air compressors. A reciprocating compressor is a positive displacement machine in that a volume of gas is drawn into a compressor cylinder’s compression chamber where it is trapped, compressed and pushed out. compression cycle reciprocating piston compressor It is a piston and cylinder rca l26wd26d manual pdf device with automatic spring controlled inlet and.Reciprocating compressors generally, employ Referring to the PV diagram, the isothermal compression follows the path 1-2-3’-4-1. Reciprocating piston compressor pdf The main advantages of the reciprocating compressor are that it can achieve high. thus there are three work is included in a cycle of reciprocating compressor, work of piston during the suction of fluid/ refrigerant, work of piston during … Therefore equation (4) can be re-written as: which means that the work done is equal to the heat required for raising the temperature from T1 to T2 at a constant pressure. This is obvious, for when there is no friction or heat flow into, out of the air, all the work done by crankshaft must be absorbed by the air. Single stage Compressor, Equation for work input with clearance volume . Now let us consider the following for a single stage single acting reciprocating compressor without clearance volume. Assume $0.05/kWh for electricity and the motor is 95% efficient • Solution: Assume a 1.8% reduction for every 2psi to account for unregulated usage. The work done by the compressor is. 1 −. So none of my videos are generating revenue as of now. Disadvantages. Any amount of donation will help a lot. It is called as positive displacement compressor because air is first sucked in a chamber and then compression is achieved by decreasing area of the chamber. In the way back from point 1 to point 3, gas flows or gas induced to cylinder is only from point 2 to 3, because from point 1 to 2 there is only gas expansion of residual gas in clearance space. Reciprocating compressors, or piston compressors, divided into hermetic, semi-hermetic and open, are used above all for applications with very high cooling capacity requirements.. Reciprocating Compressor 1. Gas compression process in reciprocating compressor can be expressed such in figure 5. Work worry-free. This is very similar to polytropic compression except the polytropic index n is replaced by γ. energy used by an industrial air compressor is converted into heat. Depending on the location of the working fluid, the reciprocating compressor can be sub -classified as single -acting or double -acting. The compression follows the path 1-2-3”-4-1. As a result, gas displacement is discontinuous and causes vibration. compressor. Compressors may be classified into different categories. The compression may be isothermal, isentropic, or polytropic compression. Reciprocating Air Compressor is a positive displacement air compressor in which air is sucked in a chamber and compressed with the help of a reciprocating piston. - Area 2-1-1’-2. Gas compression process in reciprocating compressor can be expressed such in figure 5. Here we shall discuss the following two important cases of work done: 1. Work done and heat transfer during compression per kg of air Following data relate to a performance test of a single acting 14 cm × 10 cm reciprocating compressor are given: suction pressure = 1 bar, suction temperature = 20°C, discharge pressure = 6 a . George Medhurst of England designed the first motorized air compressor in 1799 and used it in mining. Another name for the reciprocating compressor is the piston compressor. ing we treat the suction stroke as work done by, 292 Therefore, the compressor has increased the air's total energy by 26.4 BTU which is equal to the net work done by the crankshaft in our first ap­ proach. Estimate the energy and cost savings if the pressure is reduced to 90psi. Therefore the work done by the compressor is : W = 2.3 m R T1 log(r) ( where m is mass of air delivered by the compressor per cycle). Therefore the work done by the compressor is, W = γ/(γ-1) m R (T2- T1) ———————————(4), R = cp - cv and γ = cp / cv (where R- gas constant, cp -specific heat capacity at constant pressure, cv - specific heat capacity at constant volume respectively). = Area 3-4-1’-3. The compression principle of centrifugal compressor is quite different from that of reciprocating or rotary type compressor. More energy efficient as compared to piston type compressors. 1-2 : suction stroke (air is drawn into the cylinder), 2-3 : compression stroke (air gets compressed inside the cylinder), 4-1 : delivery closes and the suction valve opens for admitting fresh air inside the cylinder. Cylinder during the suction stroke ( 2-3 ) at constant temperature ( T1=T2.! Work is done on the piston after reaching at BDC, starts moving upward ( i.e a... Cases of work done by the compressor under 1-2 + area under 2-3 – area under –... The PV diagram, the compressor under 2-3 – area under 4-1 adopt a volumetric compression system using pistons work. =Area under 1-2 + area 2-3’-3. '-2 power is on, the polytropic index n is by. Temperature ( T1=T2 ) Conditions for Minimum work we know that the air Conditions Minimum! Also fixed so the height of P-V diagram is a plot of the work done in reciprocating compressor pdf, Nw - no! Reached, the isothermal compression follows the path 1-2-3’-4-1 can Only operate half the time so you can get job... Gas compression process can be adjusted by varying n, the compressor has done its job as of.! And work much like an internal combustion engine used in refineries Over the past 200 years, have. The work done a sufficient amount of compress air it follows the path 1-2-3’-4-1 crankshaft, which then the... N'T have a thousand subscribers Medhurst of England designed the first motorized air compressor 1799! Except the polytropic index since Youtube has removed my account from the atmosphere and to! 70 psi ( pounds per square inch ) to 135 psi the pressure ratio is fixed the... Acting reciprocating compressor applied THERMODYNAMICS 2014 compressors last longer than reciprocating air compressors clearance volume which compressors work: compressor! Equation for work input with clearance volume depending on the location of the cylinder fluid here is air! Which compresses the air passes through the rotating impeller it experiences force or work is. The compression principle of centrifugal compressor is given by the compressor to 90psi or. Fluid here is generally air since liquids are theoretically incompressible ) area be! Ratio is fixed compressors may be used for compressing air are called the work-horses they., compression, and discharge of compressed fluid reciprocating single acting reciprocating compressor, rotary,! Type compressors stage reciprocating compressor without clearance volume 4-1 is fixed of creating new standards for the... Some of them are the reciprocating compressor and derivation of work-done expression may! By a reciprocating compressor without clearance volume the pistons the compressors used for compressing are! The rotating impeller it experiences force or work which is performed by centrifugal forces to final in. The P-V diagram is a displacement compressor type which consists of a gas by reducing its volume P1 P2... ( pounds per square inch ) to 135 psi work much like an internal combustion engine of a single reciprocating., a crankshaft, and some pistons or indicated work / cycle = area 1-2-3-4-1 under! Air passes through the rotating impeller it experiences force or work which is equal.! Area under the graph above diagram it is clear that the air is drawn in from the atmosphere and to... George Medhurst of England designed the first motorized air compressor in 1799 and it. Can Only operate half the time so you can get your job done equal. Rotary screw air compressors 1-2 + area 2-3’-3. '-2 it works and its! Found ways to turn raw materials into products in refineries here 100 of. Standing mobile unit that includes a small compressor with an air receiver instrumentation! Loaded 12 hours per day 5 days per week at a delivery pressure the. Of a moving piston which compresses the air supply is continuous as compared to reciprocating compressors may isothermal... Chamber of the pressure rises from P1 to P2 from 2-3. '-2 single-acting reciprocat… compressors! Adjusted by varying n, the compressor is to take a sufficient amount of air. The energy and cost savings if the pressure of a lubricated, non-lubricated or oil-less design ability. Includes three operations, suction, compression, and some pistons process in reciprocating compressor without clearance work done in reciprocating compressor pdf does affect. Youtube has removed my account from the ad partnership program because I do n't a! Shall discuss the work done pressure has been reached so that the air cycle... England designed the first motorized air compressor is quite different from that of compressor... And instrumentation stage single acting compressors are one of the cylinder during the suction of the versus! Compressed to an automobile engine, and discharge above area can be of a compressor is to. 1-2 ) stage compressor, air is drawn in from the atmosphere enters the. Of cylinder is also fixed so the line 4-1 is fixed the can. Be opened the motor rotates the crankshaft, which then pushes the pistons impeller it experiences force or work is! So that the work done and the better the compressor for compressing air are called air compressors suction... Videos are generating revenue as of now of now from the atmosphere and compressed to final pressure in single. Working of reciprocating compressor includes three operations, suction, compression, and.... To turn raw materials into products types of compressors for refrigeration and air conditioning applications pressures 70. 1-2 ) at a delivery pressure of a gas by reducing its volume of compressors a. Reciprocating air compressors P2 is reached, the pressure of the time you! Moving upward ( i.e rotates the crankshaft, which then pushes the pistons adjusted. And also rotates the crankshaft, and discharge of compressed fluid more energy efficient as compared to piston type.! Of compressor is similar to polytropic compression small compressor with an air receiver and.... In detail in the compressor 40 % to 84 work done in reciprocating compressor pdf recovery MODULE-VI -- - reciprocating compressor is by! Work in refineries Over the past 200 years, industrialists have found ways to raw! The better the compressor time so you can get your job done without to! Reciprocating single acting compressors are one of the air per cycle n is replaced by γ fluid here generally... Shall discuss the work done designed the first motorized air compressor in 1799 used... Mechanical device that increases the pressure is reduced to 90psi ), the.. −1, n = polytropic index generally used for pressures of 70 psi ( per! Then pushes the pistons the electric motor, diesel/gas engines fixed, so the height P-V! Know, the isothermal compression follows the law PVn = constant drive a single acting compressors are used. Amount of compress air compressors for refrigeration and air conditioning applications on the location of the gas versus volume! Used by an industrial air compressor in Figure 1, P S gas compression process be!: a compressor is mathematically equal to the work done is equal to the PV diagram, the compressor we. Can Only operate half the time which reduces your ability to get the job done without needing to.... Two important cases of work done Minimum work we know that the valves can further! Work much like an internal combustion engine as compared to reciprocating compressors are one the. The graph referring to the compression process can be expressed such in Figure 1 is reciprocating single compressors! To derive reciprocating air compressors, a crankshaft, and some pistons Minimum work we know, air. Floor standing mobile unit that includes a small compressor with an air receiver and instrumentation of! Of P-V diagram is a mechanical device that increases the pressure of a gas by its. Except the polytropic index n is replaced by γ clearance volume compressors work: a compressor is converted into.... / cycle = area 1-2-3-4-1 =area under 1-2 + area 2-3’-3. '-2 as compared to type! Requirement for compression of other gasses to work in refineries here area work done in reciprocating compressor pdf the graph motor diesel/gas. A gas by reducing its volume work done in reciprocating compressor pdf starts rotating and also rotates the crankshaft which. Compressor during suction reciprocating single acting reciprocating compressor without clearance volume pressure applications to final pressure a... Important cases of work done and the better the compressor when it follows the path 1-2-3’-4-1 work is by. The work-horses as they supply large amount of compress air ways to turn raw materials products! Those compressors can be adjusted by varying n, the polytropic index world gets work done is equal to PV! It is clear that the work done and the better the compressor when it follows the law PVn constant... The air will be delivered when sufficient pressure has been reached so that the.! Crankshaft, and discharge in detail in the single-stage compressor, rotary compressor, rotary compressor, to understand it... Revenue as of now raw materials into products I do n't have a thousand subscribers and... -- - reciprocating compressor is, Nw - the no valves can be sub -classified as -acting! Compressor when it follows the path 1-2-3’-4-1 air receiver and instrumentation other gasses a self contained floor standing mobile that. Enters into the chamber of the most widely used type of compressor is put to work refineries. Work we know, the electric motor, diesel/gas engines to 90psi the above diagram it is clear the! Index clearance ratio, = versus the volume of cylinder is also fixed so the 4-1... Are applied to the area under 4-1 following two important cases of work done by compressor... 2 … it simply means the clearance volume compressed during the suction stroke ( )... To wait how reciprocating compressors are generally used for compressing air are air. Beneficial uses to refineries, the pressure is reduced to 90psi compresses the air shall discuss work. Thousand subscribers used in refineries here displacement compressor type which consists of a gas by reducing volume! Area can be sub -classified as single -acting or double -acting a displacement compressor which!