Ejector design software ejector sizing calculation. 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. Ejectors 3 the ejector based heat pump system presents the same components of a typical vapour compression system except for the compressor which is replaced by an ejector, a pump and a generator. Basic components of a steam jet ejector a single stage steam ejector can produce only a limited vacuum cfr. 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. The steam ejector is a simple device consisting of three basic components, a motive steam nozzle, a suction chamber and a mixing diffuser. The steam required for the jet ejector is commonly drawn from boilers. Case studysteam jet ejector free download as powerpoint presentation.
Equivalent suction flows for steam jet vacuum pumps. Steam jet ejector is a device for producing vacuum which is achieved by using a high pressure motive steam. Steam jet ejector nozzle steam free 30day trial scribd. The main pump, often a centrifugal pump, is powered and installed at ground level. The basic criterion is diffuser velocity less than critical, that is mach numbers less than 1. A steam separator and trap should be installed immediately before the motivesteam inlet connection of each ejector. 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. Cop up to 30% in this case the twophase ejector is still driven by the condensate but prior to being sent to the ejector its pressure is raised through a booster pump so that the ejector is enabled to draw vapour refrigerant from the compressor. 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.
Steam ejectors provide vacuum in many process industries and utility companies. Ejector design software ejector sizing calculation ezejector. The system have a water ejector followed by three steam booster. Steam ejector, a railway locomotive component used to create vacuum. Power plants often have steam available for several operations. If moisture is present, a substantially lower exhaust temperature will exist. Graham corporation brings more than 70 years of proven experience to the application, design, and operation of ejector systems. Vacuum products steam jet ejectors by graham corporation. A schematic drawing of a vapourjet ejector that shows the characteristic dimensions used in this study is shown in fig. Ejector rack, an aircraft fitting for carrying bombs. Suction pressure ranges of single and multistage steam jet ejectors. Multiple units can be staged together in condensingor noncondensing configurations to 5 stages and dproduce vacuum levels to 500 microns.
Steam jet vacuum ejectors remove gases andor vapours from process operations thereby generating a vacuum in the reactor. Condensing of motive steam greatly improves ejector set efficiency. 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. Performance optimization of steam jet ejector using cfd.
Condensing ejector for heating applications expected performance improvement. The motive steam enters the ejector through the motive fluid nozzle and is expanded into the mixing diffuser converting pressure energy into velocity energy. These power systems have found wide acceptance in modern plants because of the small space requirements, simplicity, reliability, low maintenance and quick starting. 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. In operation, steam issuing through an expanding nozzle has its pressure energy converted to. 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. When first developed, its operation was intriguing because it seemed paradoxical, almost like perpetual motion, but it was later explained using thermodynamics. Ejector design software to do conceptual design and generate ejector sizes. Single and multistage steam jet ejectors scam technology.
This create a vacuum in a vessels or chamber to which ejector is connected. This is a comparatively cheap and readily available source of. Dear art montemayor hi i am currently working on existing vacuum system in my plant. Nash has been designing, manufacturing and troubleshooting steam jet air ejector systems since 1986. They operate by the con version of pressure energy into velocity in suitable nozzles. Liquid jet ejector motive medium contributing to designation. Constantarea jet ejector the different between both types is shown in figure 1.
Rotary airlocks can be replaced by venturi eductors to serve. The first class is non critical in operation and includes liquid jet liquid or gas pumps and certain types of gas jet gas pumps. Steamjet vacuum systems combine ejectors, condensers and interconnecting piping to provide relatively lowcost and lowmaintenance vacuum pumping. I want to know if first stage inlet temp is around 95 deg c then what should be first stage condenser outlet temp and similarly other stages outlet temps please help me. The steam nozzle discharges a highvelocity jet across the suction. In some applications another condenser aftercondenser can be used at the low vacuum ejector discharge.
Rotary airlocks can be replaced by venturi eductors to serve as conveying system for solids. Steamjet air ejector a steamjet ejector may be used to withdraw air and dissolved gases from the condenser. Silencing by encasing the ejector body in acoustic insulation and by means of a silencer on the discharge is essential. The most comprehensive source of design information for ejectors can be found in a series of engineering sciences data unit esdu data items, nos. The motive fluid passes succes sively through these two components.
Jet pumps are commonly used to extract water from water wells. Compression of a single stage ejector is limited due to its inherent performance characteristics, jet. The efficiency of the ejector cycle is very sensitive to the ejector efficiency. 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.
The terms of jet pumps ejectors are defined in din 24290. 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. 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, sophisticated process. This system have problem of droping vacuum and the tempearture of water circulation for ejector incraseaese rapidly desite the cooling. In this paper, the steam jet ejector was designed and then the cfd analysis was carried out for the geometry and the inlet condition data verified by the performance evaluation of the jet ejector. Steam jet ejectors for the process industries robert b. 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 definitions of overall ejector efficiency and ejector component efficiencies in literature are. I want to know if first stage inlet temp is around 95 deg c then what should be first stage condenser outlet temp and similarly other stages outlet temps. Product catalog gea engineering for a better world. These power systems have found wide acceptance in modern plants because of the small space requirements, simplicity, reliability, low maintenance and quick starting characteristics. In each stage of the steam jet ejector, high pressure steam is expanded in a convergentdivergent nozzle.
Because a steamjet ejector will operate with worn parts, operators sometimes delay the inconvenience and expense of replacing worn parts by increasing steam pressure to the ejector. These systems operate on the ejectorventuri principle, which relies on the momentum of a highvelocity jet of steam to move air and other gases from a connecting pipe or vessel. Steam jet ejectors are noisy, noise originated both from the body of the ejector and from the jet of vapours leaving the discharge nozzle. Using steam as the motive fluid steam jet syphons steam jet slurry heater singlestage vacuum pumps using air as the motive fluid using liquid as the motive fluid air jet exhausters water jet eductor,s 8. 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. Oct 22, 2016 ejector design very simply, an ejector is a pumping device. Steam jet ejector posted in refining, hydrocarbons, oil, and gas. Basic ejector components are the steam chest, nozzle, suction, throat, diffuser and they discharge fig. The primary advantages of steam jet ejector are simplicity of operation, no mechanical drive and has no moving parts. Scribd is the worlds largest social reading and publishing site. Steam jet ejector water jet ejector vacuum jet ejectors. It has been assumed that the ejector is axisymmetric along the zaxis, thus only a thin slice of an ejector is modelled. Other types of injector may use other pressurised motive fluids such as air. These ratios are computer calculated and are the key parameters in ejector design. To accomplish this, the steamjet ejector will only be dismantled and reassembled a single time. Note that the term jet pump is used to refer to a liquidliquid ejector.
Ejector design very simply, an ejector is a pumping device. The fume scrubber is a water jet air pump, designed for low drafts and large capacity. An animated overview of the operating principle of a nash steam jet ejector. Essentially, the ejector consists of two annular convergingdiverging nozzles. The suction flow is compressed to a higher pressure. Steam jet ejectors are based on the ejectorventuri principle. In practice, for suction pressure below 100 mbar absolute, more than one ejector will be used, usually with condensers between the ejector stages.
Steam jet ejectors steam jet ejectors are based on the ejector venturi principal and operate by passing motive steam through an expanding nozzle. In a steam jet ejector, the suction chamber is connected to the vessel or pipeline that is to be evacuated under vacuum. 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. Korting liquid jet vacuum ejectors christian berner. The drawback of a steam jet ejector is its large dimensions as well as its low efficiency. 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. Steam jet vacuum ejectors are like a compressor that utilizes high pressure steam as motive fluid to compress gas suction to atmospheric pressure from a sub atmospheric pressure vacuum at the suction of the system. Modelling and simulation of steam jet ejectors sciencedirect. The ejector sprays high speed steam, gas, or liquid through a nozzle and can produce vacuum stages. The steam entrains the suction gases and the mixture. Ejector transformers, a character from the transformers franchise. This basic principle applies to every jet ejector in different models and ranges of application.
In each stage of the steamjet ejector, high pressure steam is expanded in a convergentdivergent nozzle. Ejectors and steam jet ejectors document library graham. I have multi stage 3 stage steam jet ejector system for vacuum tower. A schematic drawing of a vapour jet ejector that shows the characteristic dimensions used in this study is shown in fig. The generator heat coming from a low temperature energy source such as waste heat supplies vapour at a high pressure p3 to the. Jet pumps, also referred to as ejectors, are devices for the conveyance, compression or mixing of gases, vapors, liquids or solids in which a gaseous or liquid medium serves as the motive force. The steam ejector utilizes high pressure steam to compress low pressure vapors or gases.
A complete guide to getting the best from steam jet ejectors. To conclude this outline of possible applications, it is important to mention two. Steam jet ejectors new field industrial equipment pvt ltd. Understanding ejector systems necessary to troubleshoot. The syphon is a stream jet liquid pump which requires condensation of the. A steam jet ejector is illustrated below as ex ample steam serves as motive fluid to create vacuum. 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. Steamjet ejector article about steamjet ejector by the. It may utilize a spray nozzle or multiple nozzles to improve contact with the suction gas. Steam jet ejectors for the process industries 2005.
Also tell me is there any ratio of steam to vapor to be maintained for efficient. Ejector or injector, a pumplike device without moving parts static mechanical equipment. Very often, the motive fluid is steam and the device is called a steam jet ejector. The steam leaves the nozzle at a very high velocity in the order of 1220 ms and a proportion of the kinetic energy in the steam.
Elmridge tgg series gasjet ejectors use steam, com pressed air, or other pressurized gas as the motive fluid and operate on the venturi principle to pump. To solve wetsteam problems, all lines up to an ejector should be well insulated. Ejectors can be divided into two categories based on the type of performance. Northvale korting fluid jet theory and applications of eductors by patrick belcher eductor basics. Jan 20, 2017 an animated overview of the operating principle of a nash steam jet ejector. 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. A jet ejector requires no mechanical drive and has no moving parts. Review on ejector efficiencies in various ejector systems. Twostage ejector twin element with inter surface condensers. Steam jet ejector refining, hydrocarbons, oil, and gas. The jet ejector is classified into two types depending on its convergence configuration. The jet ejector performance is mainly affected by mixing, turbulence, friction, separation, and energy.