The efficiency of the ejector cycle is very sensitive to the ejector efficiency. The lowest possible suction pressure in the reactor is only limited by the vapour pressure of the motive liquid. Steam jet ejectors for the process industries robert b. Rotary airlocks can be replaced by venturi eductors to serve as conveying system for solids. A steam jet air ejector is a kind of pump that pulls a fluid in the form of steam via a vacuum effect. An animated overview of the operating principle of a nash steam jet ejector. 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. They are especiallyeffectivein the chemicalindustry where an onsite supply of the highpressure motivegas is available. Ejector modeling and examining of possibility of replacing. Performance optimization of steam jet ejector using cfd.
Vacuum pumps or steam jet air ejectors proceedings of the asme 2016 power conference collocated with the asme 2016 10th international conference on energy sustainability and the asme 2016 14th international conference on fuel cell science, engineering and technology. How can i calculate the motive steam pressure of a steam jet air ejector. Steam jetejectors offer a simple,reliable,low cost way to produce vacuum. Conversely, problems associated with the condenser and circulating water system may. The steam required for the jet ejector is commonly drawn from boilers. In multistage ejectors, it is usually advantageous to condense the. Ejector design software to do conceptual design and generate ejector sizes. They are commonly used with jet pump systems in residential well applications. Review on ejector efficiencies in various ejector systems.
Case studysteam jet ejector free download as powerpoint presentation. Of the multiple components that make up the entire ejector refrigeration system ers, the ejector is the heart of the system and the ers efficiency is tightly coupled with the efficiency of the ejector itself. This basic principle applies to every jet ejector in different models and ranges of application. Nash has been designing, manufacturing and troubleshooting steam jet air ejector systems since 1986. Steam jet vacuum systems combine ejectors, condensers and interconnecting piping to provide relatively lowcost and lowmaintenance vacuum pumping. Efficiencies of each step within the ejector based on. Relatively light in weight, jet ejectors are easy to install, require no foundations. Steamjet air ejector for motor ships general cargo ship.
Specialize in design, manufacturing, testing and supply of portable ejectors, bilge ballast cargo ejectors, liquid jet ejectors, air ejectors, acidalkali dilution ejectors, liquid jet exhausters, venturi scrubbers, tank mixer eductors, steam jet heaters, solid conveying eductors. Transvac steam ejectors also atmospheric air ejectors are often run in combination with mechanical vacuum pumps liquid ring. Virtually maintenancefree with no moving parts, they can be fabricated from. Transvac design and manufacture steam jet ejector systems in both standard and exotic materials.
The steam ejector utilizes high pressure steam to compress low pressure vapors or gases. Jul, 2016 steam jet ejectors, the largest vacuum producing devices available are used in the most demanding of applications. Onedimensional model of an optimal ejector and parametric study of ejector efficiency ronan k. Furthermore, most jet ejectors use steam or compressed air as the motive fluid, which is easily found in chemical plants. A general simulation of an air ejector diffuser system derick thomas daniel university of tennessee knoxville, derick. Venturi air jet, steam ejector, liquid eductor ejector. Depending on the application, an injector can also take the form of an eductor jet pump, a water eductor or an aspirator. Steam jet ejectors are based on the ejector venturi principal and operate by passing motive steam through an expanding nozzle. Retubeco will inspect and repair every component of your steam jet air ejector, detecting erosion, steam impingement, and tube failures. Onedimensional model of an optimal ejector and parametric.
From single stage ejectors to fully packaged multistage ejector systems all transvac products are custom designed to meet the clients. Process technology can a steam jet ejector fit your vacuum process. S a k jeelani,k v kasipathi rao, g r balasubramanian designing steam jet ejectors chemical engineering april 9 1979 7. High pressure steam enters the steam chest and expands to the suction pressure through a properly designed steam nozzle. Jet pump ejectors are a nozzle and a venturi attached to a compatible jet pump to create a vacuum to draw water up the well. The definitions of overall ejector efficiency and ejector component efficiencies in literature are summarized. Based upon the use of auxiliary equipment, two and threestage ejectors can either be condensing or noncondensing types. Transvac steam ejectors also atmospheric air ejectors are often run in combination with. Nash steam jet ejectors are available in a wide variety of materials. These shallowwell jet pump ejectors connect to compatible shallowwell jet. The most comprehensive source of design information for ejectors can be found in a series of engineering sciences data unit esdu data items, nos. Both of these facilities are capable of testing scramjetsramjets at high mach numbers. The nozzle provides controlled expansion of the motive steam to convert pressure in to velocity which creates a vacuum with in the body chamber to draw in and entrain gases or vapours.
Steam jet ejectors can handle air or other gases at suction pressures as low as three microns hg. An ejectorperformance curve gives the expected suction pressure as a function of watervapor equivalent loading fig. The air or gases to be evacuated enter the ejector suction, are entrained by the jet. Pdf steam jet air ejector performance evaluation for.
Exhaustive survey has been conducted on the influence of geometrical parameters on the efficiency of the ejector as well as critical flow parameters to improve the overall performance. The thermocompressor is a steam jet steam compressor, shown with a diaphragmoperated spindle for control purposes. Steam jet ejectors for the process industries by robert b. Sunder raj and others published steam jet air ejector performance evaluation for nuclear plants find, read and cite all the research you need on researchgate. Due to their simplicity and high reliability, they are widely used in chemical. This system have problem of droping vacuum and the tempearture of water circulation for ejector incraseaese rapidly desite the cooling.
The system have a water ejector followed by three steam booster. In each stage of the steam jet ejector, high pressure steam is expanded in a convergentdivergent nozzle. Even multistage units are readily adaptable to existing conditions. The steam jet blower normally utilizes highpressure steam as the motive force, but compressed air or gas at 15 venturi jet type media. In this paper, the steam jet ejector was designed and then the cfd analysis was carried out for the geometry. The low pressure induces a flow of load vapours at a pressure p1 into the ejector. The operator verifies that condense r cooling water system parameters have not changed. Steam jet air ejectors air ejectors retubeco ooltewah, tn.
This disambiguation page lists articles associated with the title ejector. Optimization of a highefficiency jet ejector by computational fluid dynamics software a thesis by somsak watanawanavet. These systems operate on the ejector venturi principle, which relies on the momentum of a highvelocity jet of steam to move air and other gases from a connecting pipe or vessel. A jet ejector requires no mechanical drive and has no moving parts. Calculation of releases of radioactive materials in. The ejector design principles used in the ejector calculations for the program are explained including the ejector energy balance and effects of the ejector flow cones. Modelling and simulation of steam jet ejectors sciencedirect. Air and noncondensible vapors from the main condenser, enter the first stage ejector suction connection. Ejector design software ejector sizing calculation ezejector. Primetech ejector is the leading manufacturer and supplier of steam jet ejectors in india, chennai. Ejector crosssectional drawing h ydrocarbon engineering has previously reported on ejector system fundamentals, operating characteristics, and guides for.
Steam jet blowers utilize the ejector venturi principle to move large volumes of air and other gases against low back pressures. Power plants often have steam available for several operations. Pumps of the ejector type are small in relation to the work they do and their cost is low in comparison with other types of equipment. Steam jet air ejector performance evaluation for nuclear. The fundamental operation of an ejector is shown in the illustration. Liquid jet ejectors are most suitable for low non condensable and high condensable loads in applications like distillation and evaporation. Liquid jet ejectors are specially designed to operate using water, solvent or any others clear liquid and generate vacuum corresponding to the vapor pressure of the liquid. Designing air jet ejectors chemical engineering september 25 1976 p5 6. The definitions of overall ejector efficiency and ejector component efficiencies in literature are. The ejector sprays high speed steam, gas, or liquid through a nozzle and can produce vacuum stages.
The thermocompressor is a steam jet steam compressor, shown with a diaphragmoperated. Note that the term jet pump is used to refer to a liquidliquid ejector. Venturi effect the vacuum used in steam jet air ejector pumps. Chemical engineering and processing 41 2002 551561 evaluation of steam jet ejectors hisham eldessouky, hisham ettouney, imad alatiqi, ghada alnuwaibit department of chemical engineering, college of engineering and petroleum, kuwait uni6ersity, p. Ejector or injector, a pumplike device without moving parts static mechanical equipment steam ejector, a railway locomotive component. The ejector was first developed in 1901 1 for removing air from a steam engine. This creates a vacuum in a vessel or chamber to which the ejectors is connected. It is has a wide range of application in steam ejector in boiler condenser, fresh water generator and in priming the centrifugal pump.
Controlling ejector performance pumps operating on the ejector principle are in use on many processes. Lines, graham corporation, usa, presents the problems associated with ejector system performance and subsequent solutions. This is a comparatively cheap and readily available source of energy used in steam jet ejectors. A nuclear power plant is operating at 100 percent power when the only in service steam jet air ejector is inadvertently isolated from the main condenser.
An ejector operates on similar principles to create a vacuum feed connection for braking systems etc. The steam leaves the nozzle at a very high velocity in the order of 1220 ms and a. The dae is typically represented in terms of the flow capacity on the performance curve for an ejector showing suction pressure versus flow capacity. Combining low capital cost, simple operation, high reliability and the ability to handle large volumes at very high vacuum levels, they can be optimized to. Ejectors are used in many areas of water treatment. By staging ejectors it is possible to obtain a very large range of suction pressures from atmospheric down to as low as one micron of mercury absolute. Nureg0017, revision 2 calculation of releases of radioactive materials in gaseous and liquid effluents from pressurizedwater reactors galepwr 3. Steam jet ejectors for the process industries 2005. Steam jet air ejectors sjae turbine bypass desuperheating systems general. The steam jet blower is a steam jet or air jet air pump designed for large capacities at low drafts. Understanding ejector systems necessary to troubleshoot. This create a vacuum in a vessels or chamber to which ejector is connected. In this study, with attention to work done by previous researchers to evaluate and recognize ejectors, different parts of ejector has been modeled and simulated with the computer analysis of production system of tehran refinery vacuum in which ejector.
Steam jet air ejector for motor ships steam jet air ejector a steam jet ejector may be used to withdraw air and dissolved gases from the condenser. How can i calculate the motive steam pressure of a steam jet. Ejector disambiguation jump to navigation jump to search. The dae is an absolute unit that defines the performance capacity of any ejector stage. Steam ejector calculation industrial professionals. Steam at pressure pi expands through a nozzle and exits at very low pressure px and at very high velocity.
Heat 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 airequivalent load. The purpose of this project is to optimize the geometry of steam jet ejector used for refrigeration application in chemical plant. Steam ejector design chemical process engineering engtips. Steam ejectors provide vacuum in many process industries and utility companies. If an internal link led you here, you may wish to change the link to point directly to the intended article. Steam jet air ejector sjae manufacturer exporter in mumbai. Comprehensive study indicates that placement of a vacuum pump with ejector of third stage is more possible than the first and second stages of development. Modeling an air ejector diffuser system for a hypersonic propulsion test facility includes modeling three coupled systems. An attempt at numerical modelling 451 during numerical modelling, a twolayer structural grid nearwall region the inside of an area has been used, with the total number of. Steam jet ejectors manufacturers and suppliers in india. Graham corporation ejector efficient operation youtube.
Steam jet vacuum systems multistage steam jet ejectors. Rating is available when the video has been rented. A general simulation of an air ejector diffuser system. An air ejector or steam ejector is a device which uses the motion of moving fluid motive fluid to transport another fluid suction fluid. Hi i am currently working on existing vacuum system in my plant. Steam jet air ejector sjae exporter in india jet flow technologies private limited is manufacturer of steam jet air ejector sjae in mumbai, steam jet air ejector sjae exporter, steam jet air ejector sjae export company from mumbai maharashtra india. Ejector design software ejector sizing calculation. Mostly jet ejectors use steam or compressed air as the motive fluid, which is. Staging of ejectors becomes necessary for economical operation as the absolute suction pressure decreases.
Ejectors and steam jet ejectors document library graham. Exhaustive survey has been conducted on the influence of geometrical parameters on the efficiency of the ejector as well as critical flow parameters to. 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. Lienhard vd a massachusetts institute of technology, cambridge, ma, u. The steam jet exhauster or vacuum pump is gas jet gas pump and is the basic stage for all high vacuum equipment. Liquid jet vacuum ejector mounted on base frame liquid jet vacuum ejectors suck off gases andor vapours from a process. Steam jet ejectors are based on the ejectorventuri principle. Steam jet air ejectors are some of the most reliable vacuum creators, but they require proper tube maintenance and replacement of corroded or eroded tubes in order to function efficiently. Steam ejector calculation posted in industrial professionals.
Pumps are devices used to move liquids or gases by displacing the materials volume. These are ejector system, the primary freethejet nozzle that entrains secondary airflow from the test cell, and the test article. Ejectors, or jet pumps, utilize the pressure energy of a highpressure fluid stream to boost the pressure andor flow of a lowpressure source. They can operate with either incompressible or compressible fluids as the primary driving and secondary driven flows. In the bothy, 7 chains down the line from dodmans lane level crossing, in the nation formerly known as great britain, and now disconnecting brexit ugh as little england and wales not too sure about wales bit, either. The principal advantages of steam jet ejectors over other types of vacuum producing units are. The drawback of a steam jet ejector is its large dimensions as well as its low efficiency. Ezejector is a computer model for gas ejector and steam ejector design that has been developed based on a unique approach using fundamental principles. Air ejector theory learn how and air ejector works. The motive fluid passes succes sively through these two components. Todays blog entry discusses what dry air equivalent dae is all about in ejector terminology. Hi, i need a help for expert in this process engineering side. A steam jet ejector is illustrated below as ex ample steam serves as motive fluid to create vacuum. Actually, i need the ejector to maintain the vacuum in the condenser of a steam turbine power plant and the turbine.