Vacuum eductor design pdf

If the pump is undersized, it wont be able to push enough liquid through the eductors to maintain that minimum velocity. Design of eductor posted in industrial professionals. P100 liquid jet eductor sizing eductor sizing simple example sizing an eductor for a water flow. Basicprinciplesofvacuumtechnology,briefoverview festo. The major difference between the ejector and the vacuum pump or compressor is it had no moving parts. Fox liquid eductors are venturi jet pumps that use liquid to create vacuum to mix, blend, or dilute other liquids, dry solids, or gasses into a liquid stream. Best a generalized ejector model was successfully developed for gas ejector design and performance analysis. In general, the term ejector is used when the motive fluid is a gas and the produced vacuum is used to.

Eductors are a kind of jettype pump that do not require any moving parts to be able to pump out a liquid or gas from a certain area. A transvac ejector venturi, eductor, jet pump operation is based upon bernoullis principle which states. In most installations manual selectors are set up to allow manual control of any. Deep wells vacuum wellpoints eductor wells dewatering. Graham corporation ejector efficient operation youtube. Motive pressures in excess of the design pressure may also be detrimental to the operation. The jet pump system works by pumping pressurized fluid through nozzles in the eductors, creating a partial vacuum on the suction side of the eductors. A steam jet ejector is illustrated below as ex ample steam serves as motive fluid to create vacuum. The design operating pressure is stamped on the ejector nameplate. Theyre all in the same family, but theyre each a different beast. In the practical scenario the flow field developed is really important from the view of designing the ejector system. The two fluids mix and repressurise within the eductor to an intermediate pressure as the velocity is converted back into pressure, before discharging through the outlet nozzle.

The calculations are a bit complex, requiring one to determine the draw rate of the device that will match your needs based on an unknown feed pressure and an unknown back pressure. When the driving fluid is passed through the eductor at the required capacity which depends on the design of the eductor, a low pressure is created inside it. An ejector is a device used to suck the gas or vapour from the desired vessel. The eductors jetvac technologies provides operate by converting highpressure liquid, usually water, into a highvelocity steam or can also use process liquid as the motivating fluid. Their design simplicity, absence of moving parts, and because they can be made from any machineable material, make them ideal for a multitude of applications. Allows the use of all types of liquids or solutiosn, provided that there is no impediment to mix them. An eductor is required to pump 20 gpm of water from a tank 15 feet below and discharge the water 10 feet vertically equivalent to a back pressure of 4. The purpose of this penberthy jet pump application guide is to identify.

The application below will give the required inlet pressure and water flow needed with each size eductor at various discharge pressures. Preface fundamentals of vacuum technology revised and compiled by dr. In general the following are the advantages of using venturi vacuum generators. Eductors operate according to the bernoulli theorem kinetic energy of one liquid can be used to produce flow of. Vacuum ejector high vacuum, relatively low flow rate. There is a lot of an emperical component to vacuum jet design and manufacturing. Depending on the application, an injector can also take the form of an eductor jet pump, a water eductor or an aspirator. Eductor require only a motive fluid or driving fluid for its operation, which allows it to use at any part of the ship including hazardous areas. How does an eductor work northeast controls eductors. Eductors use the venturi principle to entrain a low pressure fluid with a high pressure fluid and discharge the mixture against an intermediate pressure.

Use our eductor calculator to determine the inlet pressure and water flow you require. Water and gas jet eductors jet pumps are designed for liquid pumping, mixing operations and to handle some solids in the liquid process stream. Ejector design software ejector sizing calculation. In orderto determine the necessaryholding forces the above masscalculation isneeded. A complete understanding of ejector system performance characteristics can reduce the time and expense associated with troubleshooting poor crude vacuum distillation unit cvdu performance. Special venturi designs are particularly effective for ozonation and oxygenation of wastewater ventingexhausting gasses with liquid eductors. Please select from the options below to see more details about each one. Eductor systems are most advantageous when dewatering deep excavations where the volume of water to be pumped is relatively small because of the low permeability of the aquifer.

Ejector design calculation, ejector dimensions, generate. The photo shows an eductor, which is a device which can pull a moderate vacuum on the suction. These range from offtheshelf solidsconveying, liquid, and gas jet eductors to highly qualified flow controls for spacecraft, energy research, and advanced product development projects. A parametric study on the starting transients of a vacuum ejector. They are especially effective in the chemical industry where an onsite supply of the highpressure motive gas is available. The structure of the pump is such that it has an injector chamber with a narrow shaped nozzle or tapered jet that is located inside the. This experience is invaluable because correct design can only be achieved using both empirical and theoretical considerations. The eductor is a liquidliquid ejector, which used pressurized water for pumping other liquid from a lower to another higher level. Design features and operation of jet ejectors korting hannover ag. 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 motive gas mach no is provided for information. Other types of injector may use other pressurised motive fluids such as air. The ejectors which are distinguished from other types of compressors as. Using jergusonjacobytarbox eductors for pumping gases. Speaking for my experience with at least one of them, they calculate a design and then make one and test it.

The following discussion is designed to introduce the designer and user to some of the criteria which should be considered for the various types of vacuum pumping systems. An eductor converts the pressure energy of a fluid the motive into velocity. We also lead the industry in the duplication of parts and assemblies for rotating equipment such as steam turbines, compressors and more. Steam ejector design chemical process engineering engtips. Miller plastic products offers stateoftheart machining services.

Liquid jet mixers for food applicationsorbitally welded design 63 fm2 liquid jet ventilators 65 fv1 oquestionnaire for liquid jet ventilators, fv1 67 steam jet pumps 69. Table of contents page index basics and worksheets 5 general information on jet pumps 7 abl1. An ejector operates on similar principles to create a vacuum feed connection for braking systems etc. If it works as designed, then they produce curves and that becomes the performance standard for that particular design. 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. Fox liquid eductors can create vacuum that can be used to pump, vent, or exhaust gasses, such as the headspace of tanks and vessels with hydrocarbons. Steam jet ejectors, the largest vacuum producing devices available are used in the most demanding of applications.

Other agitators are not used along with an eductor because in order to work properly, an eductor requires a minimum liquid velocity at the orifice of the nozzle section. These are more indicative of the response of a specific ejector to changes in inputs. Remote vacuum chlorinators uses a venturi style injector eductor to generate a vacuum. Understanding ejector systems necessary to troubleshoot. Chubb michaud cwsvi eductors, also called injectors, work on the venturi principle. The primary or high vacuum ejector is designed to operate at a fixed motive. These pumps make use of their structure to transfer energy from one fluid to another via the venturi effect. Ejector designs can be classified either as critical or noncritical. In this case, the eductor serves both as the final pumping stage as well as a fairly good direct contact condenser, condensing the motive steam from the high vacuum steam ejectors. Fox valve manufactures a broad range of engineered products based on one core technology. Liquid jet eductors the pumps with no moving parts. Eductors are a kind of jettype pump that do not require any moving parts to be able to pump out a liquid or gas. Aquavactors can also be staged with higher vacuum steam ejectors. Previous 1d analytical models can be derived from this new.

Eductors, ejectors, jet pumps, hoseend sprayers, and sand blasters are all in the family of equipment called thermocompresors. Steam ejector design pdf schutte koerting has a century of experience in designing and building efficient jet vacuum ejectors. Design of eductor industrial professionals cheresources. And technically, the photo does not show a vacuum pump. How do i design an eductorjet or venturi system to rapidly. For priming of centrifugal pumps or other vacuum purposes. Eductors work in just about any place where there is a need for a more efficient way to pump liquids and solids. The function depends, above all, on the design of the motive. A kinetic pump which use the pressure decrease due to a venturi effect and in which the gas is entrained in a highspeed stream towards the outlet. Steam jet air ejectors have a low initial cost, so are an economical means and reliable equipment for producing a vacuum. Normally the excessive motive pressure will waste motive fluid. The nozzle design utilizes the same orifice size as a typical 38 npt tank mixing eductor, with a. High pressure water in, low pressure water out vacuum created. Therefore ejector curves at fixed ejector geometry are calculated at the design discharge pressure and an increased discharge pressure see 3.

Penguin penductors, are efficient space saving eductor s designed specifically for the process metal finishing industry for fluid sparging applications. Virtually maintenancefree with no moving parts, they can be fabricated from. An eductor is a device intended to move high liquidcut fluids. Ejectors offer intelligent functions for energy and process. Eductor principle, operation and maintenance on ships. Using eductors for nonpowered tank mixing mead obrien. The photo shows an eductor, which is a device which can pull a moderate vacuum on the suction stream. The eductor venturi must be strong enough to suck a sandwater mixture all the way up that pipe against gravity. Eductors and ejectors have the same functionality, in that they both use a motive fluid, to produce some level of vacuum. Use ezejector software as your one stop service for ejector design. The jet action of the motive fluid creates a vacuum in the.

Like vacuum wellpoints, eductor wells are spaced 2 to 10 feet on center. This kind of eductor finds a wide use in priming centrifugal pump casings prior to startup. Water jet eductors are products made for liquid pumping. Get quick and accurate results to close in on your best alternative. Ejector design software ejector sizing calculation ezejector. Ejector design software to do conceptual design and generate ejector sizes. Alternative vacuum generation by a motorized induction unit. In the case of a system having twin 100% ejector elements, all four ejectors can be. Understanding ejector systems necessary to troubleshoot vacuum distillation james r. The ejector design has basic advantages such as absence of moving parts and simplicity of operation. Ejectors with no induced flow may also be used to produce a vacuum.

Jet pump application guide northeast controls eductors. It is probably more correct to say that conservation of momentum leads to entrainment of the suction stream. Product catalog gea engineering for a better world. An alternative to vacuum pumps video steam jet ejectors offer a simple, reliable, lowcost way to produce vacuum. May, 2015 discover the basic principles behind ejector technology. Ejectors are designed depending on the rheological properties of the activated sludge temperature, dry solids contents for a suitable airwater ratio. Mathematical model of ejector and experimental verification. 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. How do i design an eductorjet or venturi system to.

This then entrains and accelerates the gasesvapors, on the process suction side of the device, to create a vacuum. Steam jet ejectors offer a simple, reliable, lowcost way to produce vacuum. Pneumatic vacuum generators implement short cycle times and can be integrated directly into the system due to their compact and lightweight design. Jet eductor systems pumps distributor pumping solutions. If this pressure exceeds 120% of the design, a pressure reducing station should be utilized. The new line of jrgjt eductors offers advanced design features and superior technical capabilities to create the eductor for virtually any application. Because they are efficient and inherently dusttight, pneumatic conveying systems provide the most practical method for moving large quantities of dry materials, whether powdered, granulated, or pelletized. A steam ejector is of critical design when the suction pressure is lower than approximately 55% of the discharge pressure.

In fact, you will be surprised at what a jet pump can do to solve your problem. Vacuum pumping systems the performance of a vacuum pumping system depends not only on the pumps employed but also on the piping design, the valving, the gauging and the controls. Jul 15, 2018 eductor require only a motive fluid or driving fluid for its operation, which allows it to use at any part of the ship including hazardous areas. We can size and specify ejectors for a wide range of applications. The motive expands through the eductor nozzle to create a vacuum and this entrains the second fluid the suction. The ejectors which are distinguished from other types of compressors as having no moving parts, work on the ejector venturi principle of converting the pressure energy of a motivating fluid to velocity energy in order to entrain the suction fluid. Vacuum generators vn features at a glance vacuum generators for high vacuum levels of up to 93% laval nozzles in six nominal sizes.

By definition, an ejector is a jet device which uses an operating fluid at a high. Fox liquid eductors made in usa fox venturi products. The fluid in the nozzle jet and the entrained liquid are forced through a diffuser where the high throughput velocity creates a turbulent flow. Both should be sized to find the proper unit for the appli cation. Ejector working principle mechanical engineering site. In noncritical units the fluid velocity is subsonic. To ensure maximum efficiency with minimum capital costs all vacuum systems are custom designed to meet. An ejector is similar to an of vacuum pump or compressor. Both the water jet eductor and the steam jet syphon can be used for the handling of corrosive or abrasive liquids and solids. Vacuum induction requires an adequate water supply and water pressure, an eductor, a foam concentrate container normally a plastic. Critical design means that the fluid velocity in the diffuse throat is sonic. As the liquid in the sump basin, tank, cellar, bilge, etc. The vacuum is generated either pneumatically ejectors or electrically pumps, blowers.

Vacuum is created, air or gas is entrained and mixture of gas and steam entersread more. In addition, the suction padsmust be capable of handling the acceleration forceswhich, in a fullyautomaticsystem are byno meansnegligible. Eductor operating principles basic theory an eductor uses a nozzle to produce a high velocity fluid jet to entrain the liquid surrounding the eductor fluid can be either a gas or a liquid. The result is a nearly constant high oxygen yield over the whole control range of the oxygen transfer system with its maximum value in partial load operation near the design point. Basic principles of vacuum technology, brief overview festo. An eductor is a pump that uses a fluid to perform the work of pumping another fluid or solid. Liquid or vapor is then pulled up from recovery wells into suction tubes that are attached to the suction side of each eductor.