Steam jet ejector manufacturers are always available to advise on troubleshooting as well as system operation. The heart of all hijet systems is the hijector a liquid jet ejector of proprietary design. We also lead the industry in the duplication of parts and assemblies for rotating equipment such as steam turbines, compressors and more. The lowest possible suction pressure in the reactor is only limited by the vapour pressure of the motive liquid. The ejector will handle less fluid asthe temperature of that fluid increases. Steam ejector fundamentals steam jet ejectors offer a simple, reliable, lowcost way to produce vacuum. How it works working principle hvac industrial engineering phx heat transfer duration. The ejector design has basic advantages such as absence of moving parts and simplicity of operation. Basic principles of vacuum technology, brief overview festo. The first two stages of these units arefourstage ejectors usually steam jacketed. Four, five and sixstage steam jet ejector principle of operation. The main pump, often a centrifugal pump, is powered and installed at ground level. The major difference between the ejector and the vacuum pump or compressor is it had no moving parts. Steam ejectors operate in rough or medium vacuum range 7600.
An ejector is similar to an of vacuum pump or compressor. Evaluation of steam jet ejectors linkedin slideshare. Ejector rack, an aircraft fitting for carrying bombs. Pdf download for some problems in the design and operation of jet. Ejector design calculation pdf download anpsortigas. Some problems in the design and operation of jet ejectors, m. Since at least 5000 pounds per hour is reduced in the amount of steam consumed of ejectors total of all three stages, the maximum ratio of return on investment roi and the mini mum initial investment will be needed. The figure 1 illustrates basic operation principle of the steam jet ejector. Its discharge is split, with the greater part of the flow leaving the system, while a portion of the flow is returned to the jet pump installed below ground in the well. Performance optimization of steam jet ejector using cfd. The fourstage unit consists of 1 a primary booster while four, five, and sixstage ejectors are usuallyejector.
The choice of most suitable type of ejector for a given application depends upon the following factors. Condensing of motive steam greatly improves ejector set efficiency. An ejector is a device used to suck the gas or vapour from the desired vessel or system. If you can then use the typical steam jet ejector, the second.
How it works working principle hvac industrial engineering phx heat transfer. A complete guide to getting the best from steam jet ejectors. Oct 22, 2016 ejector design very simply, an ejector is a pumping device. Steam jet ejectors are based on the ejector venturi principle. Basic components of a steam jet ejector a single stage steam ejector can produce only a limited vacuum cfr. Ejectors will handle highly corrosive vapours and fluids.
The steam jet blower normally utilizes highpressure steam as the motive force, but compressed air or gas at 15 venturi jet type media. Steam jet ejector applications home products steam jet ejector applications. In a steam jet ejector, the suction chamber is connected to the vessel or pipeline that is to be evacuated under vacuum. In contrast to other processes, ejectors are formed of a single unit connected to tubing of motive, entrained and mixture streams. Notwithstanding the large losses of work energy in the nozzle, combining cone, and diffuser, the diffuser was found to obey the same laws of discharge as in convergent nozzles. Ejector design software ejector sizing calculation. The reverse of thisis true where suction fluid temperatures are concerned. Understand realworld problems of vacuum ejector performance. This first case has momentum addition from the sidepipe into the main.
The attached article has a equation english units as given in the standards for steam jet vacuum systems published by heat exchange institute hei. In this article we discussed about the function of steam jet ejector in steam turbine operation and also know about its working principle. Ejector modeling and examining of possibility of replacing. 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. Download our steam jet ejector calculation manual ebooks for free and learn more about steam jet ejector calculation manual venturi wet scrubber design calculation. Threestage condensing steam jet ejectors consist of a booster ejector, a booster condenser, and a twostage ejector consisting of a highvacuum ejector, intercondenser, and low vacuum ejector. Essentially, the ejector consists of two annular convergingdiverging nozzles. The main purpose of this paper has been to express experimental results in a form which reveals the fundamental principles for application to the design of ejectors.
The compression process takes place in absorption, adsorption, chemical or jet ejector vapor compression cycles. The vacuum created by the ejector is strongly affected by the distance between the steam nozzle outlet and the diffuser throat section. Ejector or injector, a pumplike device without moving parts static mechanical equipment. 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. The concept will be realized in a first demonstration plant. Venturi air jet, steam ejector, liquid eductor ejector. If you can then use the typical steam jet ejector, the second article tells points. Designing air jet ejectors chemical engineering september 25 1976 p5 6. Virtually maintenance free with no moving parts, they can be fabricated from almost any material, and can be used in every industry that requires vacuum. Singlestage steam jet ejectors are based on the ejector venturi principle. The ohnesorge number is used to describe free jet flows. It has been assumed that the ejector is axisymmetric along the zaxis, thus only a thin slice of an ejector is modelled. How to calculate the flowrate of motive fluid in an ejector free download as pdf file.
Wet steam install a separator and trap at ejector system. A steam jet ejector is a simple device that uses pressurized steam to create a partial vacuum inside an enclosed system by pumping gases and vapors out of the system. This basic principle applies to every jet ejector in different models and ranges of application. Onedimensional model of an optimal ejector and parametric. They are especially effective in the chemical industry where an onsite supply of the highpressure motive gas is available. Nash has been designing, manufacturing and troubleshooting steam jet air ejector systems since 1986. The energy required to increase the pressure head of a fluid is provided by another fluid motive fluid moving at high velocity.
Other types of injector may use other pressurised motive fluids such as air. Pdf on apr 10, 2012, kavous ariafar and others published effect of nozzle geometry on a model thermocompressor. 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. Pumps of the ejector types are small in relation to work they do and their cost is low in comparison with other type of equipment.
A vacuum is created and the high velocity of steam entrains air. 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. Ejector transformers, a character from the transformers franchise. Ejector efficiency, entrainment ratio, onedimensional model, perfect expansion. Vacuum pumps timmer gmbh vacuum pump timmerpneumatic. Steam jet ejectors can handle air or other gases atsuction pressure as low as three micron hg. Basic ejector components are the steam chest, nozzle, suction, throat, diffuser and they discharge fig. Can operate safely under the most hazardous conditions. Steam jet ejectors for the process industries robert b. Insulate lines, trap low spots, set line sizes for 150ftsec. Haltmeler steam jet ejector filed march so, 1940 patented jan. Thermocompressors are based on proven jet pump technology and often used to reduce venting of lowpressure steam. For example, a steam ejector willhandle approximately 23% more free dry air than it will saturated vapor.
Ejector working principle mechanical engineering site. The gas that is to be induced into the suction chamber can be any fluid that is compatible with the steam and the components materials of construction. In practice, for suction pressure below 100 mbar absolute, more than one ejector will be used, usually with condensers between the ejector stages. 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. Ejector or injector, a pumplike device without moving parts static mechanical equipment steam ejector, a railway locomotive component used to create vacuum ejection seat, an escape device for aircraft. Typical threestage steam jet ejector used in processing vegetable oils. As a first estimate, a five stage ejector is assumed. Steam ejector calculation started by khair, mar 26 2012 08. Relative suction flow of steam jet vacuum ejectors the result of calculation will be identical with the download fulltext pdf.
Steam ejectors handle high volumes of gasses, including wet, corrosive, or particulateladen vapors. The detailed operation of the steam ejector is further represented in the form of a literature study. An animated overview of the operating principle of a nash steam jet ejector. The basic principle of jet pumps consists in the liquid or gas jet being emitted by a nozzle at high. 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. The suction flow is compressed to a higher pressure. A steam jet ejector is illustrated below as example steam serves as motive fluid to create vacuum.
Ejectors also known as jet ejectors fit the definition of pumps and compressors section 2. Steam jet ejectors educt process gases into the steam chest and then through a specially understand realworld problems of vacuum ejector performance use these guidelines and case histories to evaluate and troubleshoot. Gea designs, manufactures and delivers gas jet compressor. Steam air ejector performance and its dimensional parameters. Hence it is relatively lowcost and easy to operate and maintenance free equipment. Equivalent suction flows for steam jet vacuum pumps. Review on ejector efficiencies in various ejector systems fang liu shanghai university of electric power. Ejectors operate optimally under a single set of conditions. The most important components are the jet nozzle venturi nozzle. Steam jet ejector nozzle steam free 30day trial scribd.
They are simple in operation and rugged in construction, can use a wide range of steam. The efficiency of the ejector cycle is very sensitive to the ejector efficiency. A schematic drawing of a vapour jet ejector that shows the characteristic dimensions used in this study is shown in fig. The physique of our ejector vacuum pumps can be characterized by the terms.
Unique systems designs and manufactures process vacuum systems including condensers, steam jet ejectors, liquid ring vacuum pumps and hybrids along with instrumentation, complete automation and auxiliary equipment. The function and fluid dynamics of a steam jet ejector is explained by means of a theoretical model found in literature. Primary working liquid is its source of driving energy. Steam jet ejectors the largest vacuum producing devices available are used in the most demanding of applications. Liquid jet mixers for food applicationsorbitally welded design. Jet pumps are commonly used to extract water from water wells. This paper presents a plant concept of a solardriven steam jet ejector chiller with latent heat and cold storage. Liquid jet vacuum ejector mounted on base frame liquid jet vacuum ejectors suck off gases andor vapours from a process. Jet ejectors have the simplest configuration among various vapor compression cycles.
Apr 26, 2017 i worked on a project before where a medical waste facility cooked the medical waste in a pressure vessel called an autoclave. Four, five and sixstage steam jet ejector units are used for applications where required suction pressures are beyond the range of the ejectors previously described. 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 relation between this distance, which is called in. Steam jet ejector free download as powerpoint presentation.
A jet ejector requires no mechanical drive and has no moving parts. Steam jet vacuum ejectors remove gases andor vapours from process operations thereby generating a vacuum in the reactor. Ejector efficiency is found to be highest at low compression ratios and at low driving pressure ratios. This thesis reports a two part investigation of single and twostage ejector systems in which the primary fluid is steam and the secondary fluid is air. It is important to realize that the steam jet ejector is the most forgiving device in the process industry. I worked on a project before where a medical waste facility cooked the medical waste in a pressure vessel called an autoclave. Steam jet ejectors for the process industries mcgrawhill. Steamjet ejector article about steamjet ejector by the. The definitions of overall ejector efficiency and ejector component efficiencies in literature are. Very often, the motive fluid is steam and the device is called a steam jet ejector.
After the cooking process the pressure inside the autoclave was around 3 bar. However, at lower compression ratios, the optimal area of the mixing chamber becomes large relative to the motive nozzle throat area. The application determines the design of the flow section. 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. Download zip, 499 kb jet pumps and gas ejectors demo. In operation, steam issuing through an expanding nozzle has its pressure energy converted to velocity energy.
Downloand our brochures nash liquid ring solutions. In this network five different approaches are described in order to model jet pumps and steam or gas ejectors in flownex. Basic operating principle of the hijector is a momentum transfer from highvelocity and highdispersed liquid flow to gas or vapours, formation of supersonic two phase flow, subsequent braking of the flow and thus converting kinetic energy of. Steam ejectors provide vacuum in many process industries and utility companies. The single stage ejector, in its simplest form, consists of an actuating nozzle, suction. The model consists in solving mass, energy, and momentum onedimensional equations for compressible flow. It is similar to a pipe fitting and it has the same function as a pump. Steam jet air ejectors have a low initial cost, so are an economical means and reliable equipment for producing a vacuum.
General purpose industrial, analytical scientific, chemical corrosive gas, food processing, manufacturing. The iigure attached to this specication shows 1 a steam jet ejector of the ordinary type. Ejector is a device whose task is to transport liquids through the pipeline. Steam flow to an ejector must be maintained at the design rates, otherwise vacuum column operating pressure may increase. Steam jet blowers utilize the ejector venturi principle to move large volumes of air and other gases against low back pressures. Printed on chlorinefree bleached paper printed in country subject to modification. Steam ejector calculation industrial professionals. The primary advantages of steam jet ejector are simplicity of operation, no mechanical drive and has no moving parts. The principal application of ejectors in the food industry is their use for drawing a vacuum and for thermal vapor recompression in. Ezejector now offers a program for design of multi stage steam ejectors. Pdf effect of nozzle geometry on a model thermocompressor. Ejector design software to do conceptual design and generate ejector sizes. S a k jeelani,k v kasipathi rao, g r balasubramanian designing steam jet ejectors chemical engineering april 9 1979 7.
Steam jet ejectors steam jet ejectors are based on the ejector venturi principal and operate by passing motive steam through an expanding nozzle. The steam jet refrigeration system also known as ejector system refrigeration system is one of the oldest methods of producing refrigeration effect. In some applications another condenser aftercondenser can be used at the low vacuum ejector discharge. Review on ejector efficiencies in various ejector systems. When first developed, its operation was intriguing because it seemed paradoxical, almost like perpetual motion, but it was later explained using thermodynamics. These ratios are computer calculated and are the key parameters in ejector design. Download our bee certificate download our iso certificate. Steam ejector design chemical process engineering engtips.
The author presents some of the more recent ejector design theories and compares. A jet ejector is a device which uses the kinetic energy of a driving fluid. Vacuum products steam jet ejectors by graham corporation. Steam jet ejectors are based on the ejectorventuri principle. First, equal steam flow rate is assumed to each stage. The proper functioning of a steam jet ejector is depen.
Solar driven steam jet ejector chiller request pdf. The new standard now integrates the previous three separate standards on steam jet ejectors. Steam ejector, a railway locomotive component used to create vacuum. Ejector design software ejector sizing calculation ezejector.
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