Unesco eolss sample chapters mechanical engineering types and performance of pumps and compressors essam e. Rotary compressors and typesworking principleengineering. They received their names from the actions of their mechanical parts. Fet, opto, vca, varimuyouve probably heard these names to describe types of compressors, you sort of know which type is right for what, but what do they really mean.
Another type of air compressor is the rotary screw compressor which are positive displacement compressors. In order to do this efficiently, centrifugal compressors rotate at higher speeds than the other types of compressors. Compressor types, classifications, and applications david. Each name represents a different type of circuit design that the compressor uses to react to the signal you put through it. There are two lobes attached to the driving shaft by the prime mover. As the name implies, it uses centrifugal force to pull in the refrigerant gas and then spins it rapidly with an impeller to compress it. Refrigerators compressors types of compressor used in hvac introduction to refrigerator compressors. Main types of compressors used in industrial refrigeration are screw, piston, centrifugal and rotary vane.
An air compressor is a specific type of gas compressor compressors are similar to pumps. Vapor compression chillers are the most common and include 1 air chillers and 2 waterfluid chillers. The features like a rise in pressure, working pressure, mechanical design and specific speed become the basis for the classification and differentiation. The type label that can be found on every hermetic compressor contains critical information for the customer or user, as well as for the dispatch process. There is much confusion in the marketplace about different compressor types and their characteristics. How the air compressor works types of air compressors. In positive displacement type compressors, compression is achieved by trapping a refrigerant vapour into an enclosed space and then reducing its volume.
A comparison of the two basic types of compressors with respect to flow. Refrigerators compressors types of compressor used in hvac. Axial and centrifugal compressors application guide. Report broken links to contact us compressors introduction download a practical guide to compressor technology second edition download atlas. Read here to know about various types of air compressors used and get a clear inside view of each type of compressor with the attached pictures. The most fundamental configuration of a centrifugal compressor is the straightthrough design.
Chillers are further categorized by the type of compressor technology used. Another type, which is produced in large quantities, a scroll compressor, but still these compressors are not available in the amount normally encountered in industrial refrigeration. These types of compressors are also designed for higher capacity because flow through the compressor is continuous. Types of air compressor compressors may be characterized in several different ways, but are commonly divided into types based on the functional method used to generate the compressed air or gas. We will look at the machine itself, as well as the overall compression system and the components required in a screw compressor package. Companies are discovering the void in talent that right sizing has created and most organizations retain a core group of experienced. Pumps are used to move liquids and slurries, while compressors are used in gas or vapor service. Reciprocating compressors play a major role in the chemical, petrochemical, gas, and general industry processes.
The final type of ac compressor is the centrifugal compressor. Multiple compression trains are normally supplied in parallel to achieve total flow and head requirements of a specific application. Compressors, fans, and blowers are devices which are designed in such a way that they deliver gas at a pressure which is more than the genuinely existing pressure. Centrifugal compressors are used where larger quantity and lower pressure is required. Cylinders of the reciprocating compressor are used in the process. Piston compressor has the piston travels back and forth in the cylinder. Advantages and disadvantages of each compressor type. What is different between centrifugal compressor and. The rocking piston type compressors are generally of a smaller. The following types of compressors are used depending the required flow rate of air and maximum delivery pressure piston type or reciprocating compressors rotary type compressors vane type or screw type. Scribd is the worlds largest social reading and publishing site. Different compressor types are used to meet specific requirements based on their working principle. Different applications call for different types of air compressors and while there are many types of compressors in size and power supply, you will find two main designs for the majority of air compressors. 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.
There are a variety of compressor types and designs. In the sections below, we outline and present the common compressor types. Compressors compressors are machines designed to deliver gas at a pressure higher than that originally existing. These type of compressors are generally operated by oversized steam engines and gas turbines. Centrifugal air conditioning compressors are usually reserved for extra large hvac systems. The knowledge on classification of the air compressor will help you to choose the best compressor to fulfil your need. In this paper, each of these compressors is defined, benefits and limitations are listed, and practical applications of each are discussed. In this section of mechanical books you will find compressor handbook pdf for direct downlod. Rotary screw compressors generally have a higher initial cost when compared to the other compressor types, but last longer as they have fewer wearing parts. Rotary vane compressors are still used as a low stage compressors, but very little installed. Rotary compressor center rotor, which rotates inside the cylinder. Function of nozzle application types, flow of steam through nozzles. Centrifugal compressors support a wide variety of refrigerants and thermodynamics and are also able to supply compression in water chiller cycles due to which it has a high demand for usage in refrigerators and air.
This layout is composed of one or more impellers, aligned in the same direction, contained within a single casing fitted with a single. As shown in figure 1, the wrst broad division between compres sor types is continuous flow type vs. In this article, we will learn about the reciprocating compressor basic parts. A typical refrigeration system consists of several basic components such as compressors, condensers, expansion devices, evaporators, in addition to several accessories such as controls, filters, driers, oil separators etc. For different kind of requirements, different types of the compressor have to be used. Positive displacement compressors use screws, sliding vanes, lobes, gears. As gases are compressible, the compressor also reduces the volume of a gas. A rotaryscrew compressor is a type of gas compressor, such as an air compressor, that uses a rotary type positivedisplacement mechanism. The two most common types of compressors are positive displacement and dynamic.
These compressors utilize nonmetallic, low friction rings and do not require lubrication. Rotary vane compressors are still used as a low stage compressors, but very little. Compressors are used to compress gas or air for various process requirements. It is best known and most widely used compressors of the positive displacement type. Here is an introductory description of three types of compressor valves. Reciprocating compressors and typesworking principle. Each compact module is preassembled and ready for use. Piston compressors, or reciprocating compressors, rely on the reciprocating action of one or more pistons to compress gas. They have simple design and commonly driven by electric motors. The impart of the kinetic energy is done with the help of the centrifugal force. Here are the five types of compressors is most commonly used for mechanical cooling. Compressor types classification yes yen graphitech. Number of stages singlestage, 2stage and multistage, cooling method and medium air cooled, water cooled and oilcooled, drive types engine driven, motor driven, turbine driven, belt, chain, gear or direct coupling drives, lubrication method splash lubricated or.
They are commonly used to replace piston compressors where large volumes of highpressure air are needed, either for large industrial applications or to operate highpower air tools such as jackhammers and impact wrenches. These are most commonly used compressors in the area where there is a need of varying pressure. Reciprocating compressors the compressing and displacing. Read here to know about various types of air compressors used and get a clear inside view of each type of compressor with the attached. Positive displacement compressors cab be further divided into reciprocating and rotary compressors. They have a highefficiency rate but are much more expensive than other types of air compressors, and can get up to many thousands of horsepower, which is why they are mainly reserved for aerospace research. In this paper, each of these compressors is defined, benefits. Compressor forces more and more air into a storage tank, increasing the pressure. In air compressors, surge control can be accomplished by opening a discharge end bypass valve and venting air to the atmosphere.
Dynamic displacement air compressor in dynamic displacement compressor, it has a rotating part which imparts its kinetic energy to the air and converts it into pressure energy. Details include the type of compressor, the refrigerant which it is designed for, the frequency, and the mains voltage. Different types of process chillers fall under two main categories. Compressor types, classifications, and applications by.
Major types of reciprocating compressors include reciprocating single acting, reciprocating diaphragm and reciprocating rocking piston type. Advantages and disadvantages of each compressor type by taking the estimated full. The primary difference is the service in which they are used. While there are compressors that use rotating impellers to generate air pressure, positivedisplacement compressors are more common and include the models used by homeowners. Khalil encyclopedia of life support systems eolss 1. The different types of cooling compressors executive summary there is much confusion in the marketplace about different compressor types and their characteristics. Depiction above shows compressor types based on their classification as dynamic and positive. The compressor has the function of circulating refrigerant inside the circuit, specifically drawing it in as a gas from the evaporator and then compressing it and delivering it at higher pressure to the condenser. The plate valve, the radiused disc valve, and the highflow valve. An air compressor is a specific type of gas compressor. The engineering unit may be small or big, everyone uses an air compressor to perform various tasks as per the requirement. Major types of rotary air compressors include rotary sliding vane, rotary helical screw and rotary scroll air compressors. Compressors are a major category of equipment used in industries. Compared to the other compressor types, rotary screw air compressors have fewer wearing parts and maintenance usually consists of changing filters and oil.
The cylinders of various stages are found in a straight line when seen from the top thats why they are called in line compressors. The screw compressors we will focus on are the oil flooded, heavy duty process gas machines rather than the air derivative types. Thus if one of the lobe is in horizontal direction the other lobes will be exactly. Compressor valves control the pressure flow of a reciprocating compressor cylinder. This type of compressor develops pressure through a reciprocating action of a onepiece connecting rod and piston. Adjusting the inlet guide vanes is the most common method to control capacity of a centrifugal compressor. Axial air compressors are not typically used in construction projects but are instead found in highspeed engines on ships or planes. These lobes are displaced with 90 degrees to one another. A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Compressor surge is typically controlled by detecting when the compressor is nearing the surge line on the compressor characteristic curve and modifying the compressor operation to avoid entering into a surge cycle. Development of high specific speed mixed flow compressors pdf.
975 470 1063 72 724 1105 826 701 788 1041 806 1422 125 476 311 1434 266 1403 565 189 584 599 679 822 278 136 812 727 1205 709