Because eductors are nonmechanical, they do not include moving parts or require lubrication. The basic principle of jet pumps consists in the liquid or gas jet being emitted by a nozzle at high speed entraining and accelerating the surrounding liquid, gas or solid matter. The first steam ejectors were developed in the early 1900s. Steam ejectors or steam jets, ejectors that use steam as motive gas, are by far the most popular type of ejectors.
Steam ejector design chemical process engineering engtips. Calculation of the constant pressure mixing process between sections 3 general assumptions and model equations, 4 ejector design. The system has also been erroneously called steam injector. Steam locomotives, with a ready source of steam, found ejector technology ideal with its rugged simplicity and lack of moving parts. Ejector modeling and examining of possibility of replacing. 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. Ejector design software ejector sizing calculation.
With cd ejector you can customize how you want to operate your drives, suit it to your laptop. In multistage ejectors, it is usually advantageous to condense the steam from each stage in a watercooled intercondenser so as to reduce the load to the succeeding stage. A free cpcv calculator for gas mixtures ideal gas can be downloaded here. With cdejector you can customize how you want to operate your drives, suit it to your laptop. An ejector is similar to an of vacuum pump or compressor. Evaluation of steam jet ejectors linkedin slideshare. They can operate with either incompressible or compressible fluids as the primary driving and secondary driven flows. Simplest procedure of spalding 15 in phoenics software, a general commercial cfd package. As an experienced provider of engineering answers since 1936, graham maintains the most comprehensive database of. A procedure for calculating gas ejectors springerlink. Working principle of steam ejector power plant tutorials. High pressure motive steam at pressure p 0a expands through a nozzle and exits at low pressure and at high velocity.
The main features of an ejector are shown in figure 1. Review on ejector efficiencies in various ejector systems. The methodology for ejector design and for the hp active gas is accelerated to sonic velocity in the throat of the ejector inlet nozzle prediction of performance, based on the. Ejector design calculation, ejector dimensions, generate. Other types of injector may use other pressurised motive. Hence it is relatively lowcost and easy to operate and maintenance free equipment. Convergence percent normally 99% is supplied to confirm. Steam jet ejectors steam jet ejectors are based on the ejector venturi principal and operate by passing motive steam through an expanding nozzle. A method for prediction of gasgas ejector performance. The reason for the lecture is that if you a trying to pump liquid you dont want to use and ejector velocities get pretty high. The steam ejector takes a high pressure motive steam flows in a supersonic nozzle while dragging a low pressure steam which comes from the. The stainless steel sump ejector uses a snapacting inconel x750 springassisted mechanism, which engages a steam motive valve, turning the pump on or off as the float rises and falls. I need to calculate how much vacuum pressure created if i used 15 barg steam pressure in steam ejector. They are especially effective in the chemical industry where an onsite supply of steam ejector calculation free download, steam ejector design software, steam.
Steam ejectors are virtually maintenancefree and can be constructed from a wide variety of steel, alloy and composite materials to include pp, ptfe and pvdf. Free demo programs for a short time are offered to let you see how the ejector program works they are not intended for your design work. 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 free demo programs for a short time are offered to let you see how the ejector program works they are not. Steam ejectors are frequently used in condensing steam turbine systems for creation of vacuum in vacuum condesers thus improving turbine and system performance. The major difference between the ejector and the vacuum pump or compressor is it had no moving parts. Ejector design calculation pdf download 08d661c4be this content was downloaded from ip address 66.
In ejector simulation computing, physical features in clude cross ejector throat and nozzle exit cross section and constant level of ejectors and operational levels, including the stimulus temperature and. The programs may be used for any liquid for which the physical properties are known. Previous 1d analytical models can be derived from this new. A new approach for determining the main parameters of an ejector is proposed, and a sequence for calculating it is given. The same ejector can be made to operate with essentially. A 4 see assumptions a11 and a12 the momentum equation for this control volume is considerably simplified and yields. Steam ejector calculation posted in industrial professionals. Steam ejector calculation industrial professionals.
Steam ejector software free download steam ejector. You are able to select up to a fourstage ejector system, with or without a precondenser, that includes either surface type or direct contact inter and after condensers. They were installed from the cddvd, and those installers didnt stay on your hard drive. It consists of an objectoriented server connected to a database, and web, java, and other ftp, smtp, irc, etc. Aug, 2009 results obtained from an analysis of the most widespread and commonly used procedure for calculating gas ejectors equipped with a cylindrical mixing chamber are presented. Best a generalized ejector model was successfully developed for gas ejector design and performance analysis. Aphornratanaan experimental investigation of a steam ejector refrigerator. Through the acquisition of hick hargreaves in 2001 edwards have been instrumental in the development of steam ejectors from the original crude single stage devices to the highly efficient multi stage. This system have problem of droping vacuum and the tempearture of water circulation for ejector incraseaese rapidly desite the cooling. Cpcv calculator ejector design software ejector sizing.
Calculation of the constant pressure mixing process between sections 3 general assumptions and model equations, 4. Eductors are used to lift, pump, mix, and agitate liquids, granular solids, and slurries. Applied vacuum designs and manufactures steam jet ejectors for the sugar industry. A jet ejector requires no mechanical drive and has no moving parts. 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. Because eductors are nonmechanical, they do not include moving parts or require.
They are sometimes called aspirators, venturi pumps, or jet pump ejectors. Mar 06, 2018 the programs may be used for any liquid for which the physical properties are known. Ejector calculations require cpcv values for each gas. The efficiency of the ejector cycle is very sensitive to the ejector efficiency. An ejector operation in the critical range is designed for a fixed compression ratio and requires a definite motive steam flow. Directx, games for windows live redist, vc redist, rapture3d, nvidia physx redist, etc. For example, a high vacuum exhauster operating at 150 psig steam pressure compressing from 1 hg. Steam flow from the discharge of the stronger ejector flowed backwards through the weaker ejector into the suction of the stronger ejector, which was then overloaded. When you installed a video game from a cd or a dvd, you installed some redistributable packages too.
Stainless steel sump ejector armstrong international. Steam jet ejectors, the largest vacuum producing device. 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. The motive gas mach no is provided for information. Armstrong offers a stainless steel sump ejector for use in draining unwanted water from steam pits, steam tunnels or enclosed spaces. If the steam pressure is being increased from a region of unstabile operation, the point at which the ejector first becomes stable is called the motive steam pickup pressure. Ejectors and eductors selection guide engineering360. As a result the roofs have some unique hatches often erroneously called ice hatches. A study was performed to establish a simpler primary flow active gas through nozzle. 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. A model for calculation of steam injector performance. Ejector design software to do conceptual design and generate ejector sizes. Hi, i need a help for expert in this process engineering side.
The equations of the constantpressure and constantarea models were verified. Steam ejector freeware free download steam ejector. Actually, i need the ejector to maintain the vacuum in the condenser of a steam turbine power plant and the turbine exhaust pressure is 9. The main goal of the simulation of ejector is calculation of driving steam consumption rate. You can also get wet steam into an ejector and this will cause back firing on the ejector also putting material back into process.
They were initially used to eject air from condensing plants on turbine systems. Ejector working principle mechanical engineering site. Ejectors, or jet pumps, utilize the pressure energy of a highpressure fluid stream to boost the pressure andor flow of a lowpressure source. This basic principle applies to every jet ejector in different models and ranges of application.
The steam ejector takes a high pressure motive steam flows in a supersonic nozzle while dragging a low pressure steam which comes from the crossover. Performance optimization of steam jet ejector using cfd. To create a deeper vacuum, ejectors can be staged or installed in series. The system have a water ejector followed by three steam booster. The low pressure induces a flow of load vapours at the suction pressure p 0b into the ejector. Northvale korting fluid jet theory and applications of eductors by patrick belcher eductor basics. Review of ejector design parameters and geometry for refrigeration and. The problem usually involved hardness deposits in the throat of the weaker ejector steam nozzle. A single ejector can be designed to create as much as 27 inches hg vacuum or about 76 mm hga. An ejector is a device used to suck the gas or vapour from the desired vessel or system. The best companion of steam users the good old time.
Case studysteam jet ejector free download as powerpoint presentation. Its main characteristic is that no moving parts are needed for its functioning, thermodynamic processes relying on direct transfers of mass, momentum and heat between the. Ejector design calculation pdf download unger i hedmark l. Ejector design software ejector sizing calculation ezejector. A steam injector is typically used to deliver cold water to a boiler against its own pressure, using its own live or exhaust steam, replacing any mechanical pump. Boundaries of the application field of this procedure are revealed. Basic ejector components are the steam chest, nozzle, suction, throat, diffuser and they discharge fig. Very often, the motive fluid is steam and the device is called a steam jet ejector. Featuring proven, unique internal geometries and tightly tolerancecontrolled steam nozzle configurations, graham ejectors produce very low steam consumption and highly efficient operation. In ejector simulation computing, physical features in clude cross ejector throat and nozzle exit cross section and constant level of ejectors and operational levels, including the. The definitions of overall ejector efficiency and ejector component efficiencies in literature are. In condesing system, steam ejector has function to extract air and other noncondensing gases from the sealed condenser, and in such way to maintain vacuum which corresponds to ratio of. At the higher discharge pressure, the ejector will regain its stability once the motive steam.
A temporary fix is to block in the process side of the weaker steam nozzle. Steam can be used as the motive fluid in either case. This reduces the size and steam consumption of the succeeding stages and results in a reprinted from petroleum refiner, december 1958 1 ejectors ejectors are simple pieces of. Results obtained from an analysis of the most widespread and commonly used procedure for calculating gas ejectors equipped with a cylindrical mixing chamber are presented. When a high pressure motive fluid steam liquid enters the steam nozzle, this result in a decreasing pressure and increasing velocity of the fluid again the fluid enters in the diffuser which result in a increasing pressure and decreasing velocity of the fluid so due to pressure difference vacuum is created in between the nozzle and diffuser we can say venture. Dear art montemayor hi i am currently working on existing vacuum system in my plant. The pickup pressure is a direct function of the discharge pressure. Relative suction flow of steam jet vacuum ejectors the result of calculation will be identical with the download fulltext pdf. Steam jet vacuum ejectors remove gases andor vapours from process operations thereby generating a vacuum in the reactor. An ejector is intended to move high gascut fluids and has a convergent section for an entry to the straight throat which is again followed by a divergent section. How to calculate the flowrate of motive fluid in an ejector free download as pdf file. Steam ejectors and deaerators custom engineered products the end product of the process and mechanical design expertise of hick hargreaves combined with project management skills is the perfect supply of individual items of plant, or the execution of complete fully systemized equipment packages. Ejector design and performance prediction sciencedirect.
The application determines the design of the flow section. Ejector systems ejectors gea engineering for a better world. A steam injector is a device whereby steam is used to pump cold water at low pressure and to produce an outlet water pressure which is higher than the steam inlet pressure. These are more indicative of the response of a specific ejector to changes in inputs. When first developed, its operation was intriguing because it seemed paradoxical, almost like perpetual motion, but it was later explained using thermodynamics. A variety of air conditioning systems were used by american railroads, and santa fe settled on steam ejector air conditioning for the majority of its cars. The steam ejector has four component parts, a nozzle holder, a steam nozzle, steam chest and a diffuser. Therefore ejector curves at fixed ejector geometry are calculated at the design discharge pressure and an increased discharge pressure see 3. How to calculate the mass flow rate of induced secondary.
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