The gases entering the first stages of the ejectors are entrained by the jets of steam from the first stage nozzles. These power systems have found wide acceptance in modern plants because of the small space requirements, simplicity, reliability, low maintenance and quick starting characteristics. Steam jet ejectors are based on the ejectorventuri principal and operate by. Have you experienced a breakdown of performance in your ejector or ejector system. Since steam was widely available at that time, the socalled steam jet refrigeration systems became popular in air conditioning of large buildings and. The unit is available in standard sizes up to 6 and custom fabricated for larger sizes. Exchange institute standards for steam jet ejectors describes the method to convert the mixture air, water vapor, and various hydrocarbons to a watervapor equivalent or an air equivalent load.
Therefore ejector curves at fixed ejector geometry are calculated at the design discharge pressure and an increased discharge pressure see 3. Steam jet vacuum ejectors for creating high levels of vacuum in. Ejector thermocompressor equirepsa vaccum production. These are more indicative of the response of a specific ejector to changes in inputs. If the air were not removed from the system it could cause corrosion problems in the boiler.
Understanding ejector systems necessary to troubleshoot. Combined vapour compressionejector refrigeration system. While i didnt know much about the theory the steam inlet pipes were hot and there were inches of ice on the ejectors just past the nozzle. According to program steam flow and sizing seems perfect. An ejector is essentially a fluidfluid pump that has no pistons, valves, rotors, or other moving parts and works by transfer of momentum from the primary fluid high pressure to the secondary fluid aspirated low pressure. Pdf geometrical optimization of a steam jetejector using the. Steam jet vacuum ejectors remove gases andor vapours from process operations thereby generating a vacuum in the reactor. Nash is globally recognized for assembling the most efficient steam jet and air ejectors and ejector vacuum systems. The motive steam of the upstream jet ejector is condensed in the downstream surface condenser. Steam jet ejectors bulletin 5eh singlestage ejectors fig. If an increase in suction pressure is not desired, then ejector nozzles must be replaced with ones having smaller throat diameters or the steam pressure corrected. Ejector design software ejector sizing calculation. A general simulation of an air ejector diffuser system. T he ejector computer model includes the following.
They are especially effective in the chemical industry where an onsite supply of the highpressure motive gas is available. Ser or steam ejector heat pump sehp systems are thermally driven heating and cooling technologies and. His setup allowed producing a refrigeration effect by utilizing lowgrade energy. Area 8 wrightpatterson air force base, ohlo 45a33 air force systems command j united states air forcel. Steam jet ejectors booster ejectors vacuum pumps evaporating distilling plants sea water desalting units boiler feed water heating and degassing units surface condensers direct contact condensers heat exchangers refrigerating machines air, water and oil coolers air air radiators natural, induced. It is one of the types of air ejector which is used in the steam like near the condenser to remove the non condensable gases and some vapour entering into main condenser by an air ejector and it is cooled by the main condensate and released in the ejector. In this article we discussed about the function of steam jet ejector in steam turbine operation and also know about its working principle. Ezejector is a computer model for gas ejector and steam ejector design that has been developed based on a unique approach using fundamental principles. Introduction the primary application of vacuum systems in the power generation industry is for the evacuation of air and.
The motive gas mach no is provided for information. The ejectors were quite large as i recall now around six feet long and maybe eight inches across at the inlet. Steam jet air ejector performance evaluation for nuclear plants. Multistage steam jet vacuum systems korting hannover ag. The suction flow is compressed to a higher pressure. Ejectors can be operated with many different motive fluids. Steam ejector design pdf schutte koerting has a century of experience in designing and building efficient jet vacuum ejectors. Twostage ejector twin element with inter surface condensers. The focus of this work is on an existing steam jetejector, whose primary flow. The attached figures illustrate the two types of steam jet air ejector sjae systems used in the industry to remove noncondensables and water vapor from main condensers. Feasibility study of replacing steam ejector with liquid. Steam quality is another important performance variable.
Steam at about 2000 kpag enters the nozzle where steam heat energy is converted to velocity. Steam jet ejectors are an essential part in refrigeration and air conditioning, desalination, petroleum re. Anyway, the ship had steam ejector air conditioning. Ejector performance ejector optimization fluid momentum exchange. Ejectors can be installed indoors or outdoors without restriction. Design and thermodynamic analysis of a steam ejector. Virtually maintenancefree with no moving parts, they can be fabricated from. Air jet vacuum pumps for connections to the suction side of liquid ring vacuum pumps. An additional use for the injector technology is in vacuum ejectors in continuous train braking systems, which were made compulsory in the uk by the regulation of railways act 1889. Basic design, operating information, and operation limitations of air ejectors. In this paper, the steam jet ejector was designed and then the cfd analysis was carried out for the geometry.
Direct contact or jet condenser these operate by condensing the steam. Reliable and efficient with proven performance with an innovative design that reduces steam consumption up to 15%, compared to previous nash ejector design, an ener jet steam and air ejectors can pay for itself in two years or less due to energy savings. Our company culture was formed by our origins in the 1960s as. Assure operation of installed mechanical equipment too much or too little steam. Transvac atmospheric air jet ejectors can be combined with liquid ring vacuum pumps to increase their ultimate vacuum levels. Product catalogue jet pumps mixers heaters vacuum systems. A vacuum ejector uses steam pressure to draw air out of the vacuum pipe and reservoirs of continuous train brake. The basic operating principle of an ejector is to convert the pressure into speed. Graham corporation ejector efficient operation youtube. A general simulation of an air ejector diffuser system derick thomas daniel university of tennessee knoxville, derick. Mostly jet ejectors use steam or compressed air as the motive fluid, which is. Air ejector theory learn how and air ejector works.
Air ejector unit description the ejectors are of the two stage condensing type and the assembly consists of two first stages and two second stages. The ejectors form an integral part of distillation columns, condensers and other heat exchange processes. Designations of jet pumps the terms of jet pumps ejectors are defined in din 24290. High vacuum performance ejectors can handle air or other gases at suction. Steam jet ejectors, the largest vacuum producing devices available are used in the most demanding of applications. The steam ejector is a simple device consisting of three basic components, a motive steam nozzle, a suction chamber and a mixing diffuser. The addition of an atmospheric air jet ejector enables the liquid ring vacuum pump to operate outside its cavitation range allowing operation down to nearly 4 mbar abs. Steam jet air ejectors have a low initial cost, so are an economical means and reliable equipment for producing a vacuum. How an air ejector works in a boiler feed system steam. A vacuum is created, air or gas is entrained and the mixture of gas and steam enters the venturi diffuser where its velocity energy is converted into pressure. How an air ejector works in a boiler feed system the air ejector draws out the air and vapours which are released from the condensing steam in the condenser.
Ejector design calculation, ejector dimensions, generate. These are mounted on surface tj e inter and after condensers. Ejector working principle mechanical engineering site. Fox venturi products integrates sixty years of venturi design experience with outstanding manufacturing capability. Air, gas, steam, and vacuum ejectors fox steam jet ejectors and vacuum systems. It is one of the types of air ejector which is used in the steam like near the condenser to remove the non condensable gases and some vapour entering into main condenser by an air ejector and it is cooled by the main condensate and released in the ejector condenser. Other important information noted on an ejector performance curve includes the minimum motive steam pressure, the maximum motive steam temperature. Steam jet ejectors offer a simple, reliable, lowcost way to produce vacuum. This experience is invaluable because correct design can. Steam ejector air conditioning trains magazine trains.
Graham corporation ejector troubleshooting youtube. Request pdf steam jet air ejector performance evaluation for nuclear plants improper design, operation and maintenance of the steam jet air ejector sjae. The high velocity primary stream is produced by expanding a high. Koerting multi stage vacuum systems with surface condensers offer maintenancefree and insensitive operation and be versatile applicable.
Hence low maintenance cost when to compare with other peer equipment. Hei steam jet vacuum systems troubleshooting guide. The ejector design has basic advantages such as absence of moving parts and simplicity of operation. Steam ejectors can also be combined with liquid ring vacuum pumps to create a hybrid capable of deep vacuum that ejectors can deliver but with lower energy use.
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