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. After the cooking process the pressure inside the autoclave was around 3 bar. Vacuum products steam jet ejectors by graham corporation. The heart of all hijet systems is the hijector a liquid jet ejector of proprietary design.
Ejector design software to do conceptual design and generate ejector sizes. Pardee engineering is backed by over 50 years of specialized jet ejector technology and knowhow. 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. Steam ejectors are frequently used in condensing steam turbine systems for creation of vacuum in vacuum condesers thus improving turbine and system performance. When a high pressure motive fluid steamliquid 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. 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. I worked on a project before where a medical waste facility cooked the medical waste in a pressure vessel called an autoclave.
It is has a wide range of application in steam ejector in boiler condenser, fresh water generator and in priming the centrifugal pump. As for the ejector performance, it is defined in terms of entrainment, expansion and compression ratios. Dec 11, 20 nash enerjet steam ejector how it works duration. Ejector efficiency is found to be highest at low compression ratios and at low driving pressure ratios. Onedimensional model of an optimal ejector and parametric study of ejector efficiency ronan k. However, at lower compression ratios, the optimal area of the mixing chamber becomes large relative to the motive nozzle throat area. The ejector was first developed in 1901 1 for removing air from a steam engine. Graham corporation brings more than 70 years of proven experience to the application, design, and operation of ejector systems. 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. In a liquid jet ejector, the motive fluid is a noncompressible liquid generally water with no heat energy hence with a single stage centrifugal pump we can not increase its pressure much. Steam jet ejectors are based on the ejectorventuri principle. Northvale korting fluid jet theory and applications of eductors by patrick belcher eductor basics. 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.
Ejector rack, an aircraft fitting for carrying bombs. Steam jet ejectors steam jet ejectors are based on the ejector venturi principal and operate by passing motive steam through an expanding nozzle. Basic components of a steam jet ejector a single stage steam ejector can produce only a limited vacuum cfr. 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. A general simulation of an air ejector diffuser system. The main pump, often a centrifugal pump, is powered and installed at ground level. A jet ejector requires no mechanical drive and has no moving parts. The fourstage unit consists of 1 a primary booster while four, five, and sixstage ejectors are usuallyejector. Operating principles thermocompressors and ejectors operate on the same thermodynamic and physical principle.
Steam jet ejectors are noisy, noise originated both from the body of the ejector and from the jet of vapours leaving the discharge nozzle. Performance optimization of steam jet ejector using cfd. Steam jet ejector water jet ejector vacuum jet ejectors. Nash has been designing, manufacturing and troubleshooting steam jet air ejector systems since 1986. 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. Very often, the motive fluid is steam and the device is called a steam jet ejector. 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. 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. The definitions of overall ejector efficiency and ejector component efficiencies in literature are. As a result motive fluid velocity at the nozzle tip is very less and it affects its noncondensable load handling capacity drastically. Four, five and sixstage steam jet ejector principle of operation. Steam jet ejectors for the process industries robert b.
These power systems have found wide acceptance in modern plants because of the small space requirements, simplicity, reliability, low maintenance and quick. When first developed, its operation was intriguing because it seemed paradoxical, almost like perpetual motion, but it was later explained using thermodynamics. The steam ejector utilizes high pressure steam to compress low pressure vapors or gases. The sum of the motive and entrained vapor mass flow rates gives the mass flow rate of the compressed vapor.
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 design software ejector sizing calculation ezejector. The aim of this study is to investigate the use of computational fluid dynamics in predicting the performance and geometry of the optimal design of a steam ejector used in a steam turbine. The suction flow is compressed to a higher pressure. Steam jet ejectors for the process industries by robert b. In addition, the sizes in the major sections of the novel ejector lie in the best range. The first two stages of these units arefourstage ejectors usually steam jacketed. Other types of injector may use other pressurised motive. Onedimensional model of an optimal ejector and parametric. This basic principle applies to every jet ejector in different models and ranges of application. Used extensively throughout the process industries, steam ejector vacuum systems offer a reliable and economical means of handling high volumes of gas and vapor streams at low pressures.
Oct 22, 2016 ejector design very simply, an ejector is a pumping device. How an air ejector works in a boiler feed system steam. 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. An air ejector or steam ejector is a device which uses the motion of moving fluid motive fluid to transport another fluid suction fluid. Jet ejectors the term jet ejector describes a device in which a pumping effect is achieved using a motive fluid. Jan 14, 2005 in general, when the motive fluid is a gas and the produced vacuum is used to evacuate or to vent a vessel or system, i would use the word ejector. Basic ejector components are the steam chest, nozzle, suction, throat, diffuser and they discharge fig. In some applications another condenser aftercondenser can be used at the low vacuum ejector discharge. If the steam pressure is too low for the intended application, a steam jet thermocompressor can boost the pressure and temperature to the required level. Review on ejector efficiencies in various ejector systems.
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. Ejector or injector, a pumplike device without moving parts static mechanical equipment. The ejector capacity is defined in terms of the flow rates of the motive steam and the entrained vapor. Reliable vacuum service for the process industries. A complete guide to getting the best from steam jet ejectors. Our experience spans a wide range of applications and markets, including systems for space simulation, high vacuum applications in metals vacuum degassing, applications involving vaporliquid and chemical equilibrium for fertilizer plants. 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. Hello,could anyone please educate me the differences between eductor and ejector. Primetech ejector is the leading manufacturer and supplier of steam jet ejectors in india, chennai. Typical threestage steam jet ejector used in processing vegetable oils.
Silencing by encasing the ejector body in acoustic insulation and by means of a silencer on the discharge is essential. From design through manufacture and installation, pardee engineers have the jet apparatus capability to meet the processing industrys special requirements for pumping, transferring and mixing of liquids, solids, vapors and gases. Steam jet ejectors and associated equipment applied vacuum. When the motive fluid is a liquid and the produced vacuum is use to draw in another fluid or a powder and mix it with the motive fluid, then i would use the word eductor.
Steam jet ejector nozzle steam free 30day trial scribd. Jet pumps are commonly used to extract water from water wells. 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. How it works working principle hvac industrial engineering phx heat transfer duration. Ejector transformers, a character from the transformers franchise. Ejector design software ejector sizing calculation.
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. 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. A general simulation of an air ejector diffuser system derick thomas daniel university of tennessee knoxville, derick. The application determines the design of the flow section. Steam ejectors provide vacuum in many process industries and utility companies. Aug 08, 2012 an air ejector or steam ejector is a device which uses the motion of moving fluid motive fluid to transport another fluid suction fluid. Suction pressure 20 mbar load air 30 kghr load orthochlorophenol 76. How an air ejector works in a boiler feed system steam turbines. Steam jet vacuum ejectors remove gases andor vapours from process operations thereby generating a vacuum in the reactor. Ejector efficiency, entrainment ratio, onedimensional model, perfect expansion.
Steam jet air ejectors sjae turbine bypass desuperheating systems general. 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. 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. The efficiency of the ejector cycle is very sensitive to the ejector efficiency. If the air were not removed from the system it could cause corrosion problems in the boiler. In a steam jet ejector, the motive fluid is a jet of high pressure and. 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. Steam ejector, a railway locomotive component used to create vacuum. The first two stages of these units arefourstage ejectors usually steamjacketed. Producing a vacuum with steam jet ejectors in a vacuum jet ejector, the lowpressure vent steam is the motive energy source.