Design requirements for the nozzle, mixing tube and diffuser are similar to those for jet pumps. Current advances in ejector modeling, experimentation and. Eductors require no power, which means no moving parts. The ones ones i used were a venturi often with a nozzle to boost velocity with a port at the low pressure point near the middle of the throat im no engineer, but your design looks like it would work, but would be very inefficient as for dimensions, thats over my.
Fortunately, we dont have to design this eductor but merely do the calculations and select the proper one. Cone shaped plume to circulate liquid in tanks with no moving parts. If pressure is in outlet head, specific gravity of the outlet fluid will be required. Plastic tank eductors nci tank eductors are designed for intank applications. Also, any good sites that thoroughly explain steam usage in refineries. The movement of this stream through a tapered tube and venturi nozzle increases the pressure of the flow. These range from offtheshelf solidsconveying, liquid, and gas jet eductors to highly qualified flow controls for spacecraft, energy research, and advanced product development projects. Both portable and truck eductors have metering capability at 14%, 12%, 1%, 3%, and 6% settings. Conveying eductors enable the use of low pressure air to be used to move powders, pellets, and bulk solids with no moving parts. The eductor used for gases is basically a convergingdiverging nozzle from what i understand. The demo programs are simplified and intended to give a feel for results you can get. How to size liquid motive eductors for pumping liquids.
There are literally hundreds of uses for eductors and jet pumps, particularly in the petrochemical, process, and power industries. Their advanced design provides superior flow paths for optimum performance, while the rugged construction is your assurance of reliability in demanding applications. Let us consider the above hypothetical scenario of a stagnant suction stream. Clean coal program research activities it employs a ktron lossinweight twinscrew coal feeder with modified eductor design is installed to provide steady and consistent coal feeing, which is the key to study the coal jet flame stability. How does an eductor work northeast controls eductors. Solids handling eductors employ motive air or liquid under pressure through a nozzle in the eductor that produces a high velocity jet to entrain and transport dry solids or slurries. The eductor design application below will give the required inlet pressure and water flow needed with each size eductor at various discharge pressures. Ejectors online course and simulator for engineering.
Fox liquid eductors made in usa fox venturi products. See energy balance data is entered into the highlighed fields and the program is run. A customer is pumping water from a river into a pond and wants to keep the area under and around the pump clear of sediment. The nci eductor nozzle in this section takes advantage of the physical properties of the motive fluid. They are sometimes called aspirators, venturi pumps, or jet pump ejectors.
Asymmetric nozzles this type nozzle was developed in an effort to capitalize on the generally superior entrainment characteristics of the symmetric crossslot nozzle configuration while maintaining packaging imit ipo,, d b. 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. Nci solids conveying eductors are used to economically transport free flowing solids, powders and slurries with an available liquid or gas pressure source. Modeling of eductor nozzles layout in a treatment bath. Solids can be transported for distances up to 400 feet pneumatically and farther using water or other liquid as a transport medium. 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. Whether or not the primary nozzle s exit is before the mixing chamber, or somewhat inside. Gas ejector modeling for design and analysis a dissertation by chaqing liao. Specific gravity is the measure of the weight per volume of a liquid. Make sure that flow and pressure are available under flowing conditions. The fluid in the nozzle jet and the entrained liquid are forced through a diffuser where the high throughput velocity creates a turbulent flow. Significant amounts of steam condense in ejectors, typically much less or none in gas ejectors.
Eductors with liquid motives use a converging nozzle as liquids are not generally compressible. The two then exit the eductor at an intermediate pressure. An ejector or injector figure below receives as input two fluids normally. Ejector design calculation, ejector dimensions, generate. Venturi nozzle is designed as a combination of isa 1932 nozzle and the venturi tube. A description of the energy balance is also availabe. Eductors are a kind of jettype pump that do not require any moving parts to be able to pump out a liquid or gas. Fox designs its eductors to convey product at about 3500 to 4500 ftmin. Liquid jet eductors the pumps with no moving parts. Akron eductors are designed for use with all class a and b foam concentrates.
The design of the eductor creates pressure differential allowing fluid to flow naturally. Eductors and jet pumps are the most efficient way to pump or move many types of liquids and gases. These pumps make use of their structure to transfer energy from one fluid to another via the venturi effect. Ejectors and eductors selection guide engineering360 globalspec. Ejector design software ejector sizing calculation. Determine the size and number of eductors required based on your tank configuration, volume and the number of turnovers required. How do i design an eductorjet or venturi system to.
Our flow simulation software allows us to reach an optimized agitation in your tank. Design of eductor posted in industrial professionals. Plastic tank eductors for tank mixing and tank blending. All the eductors ive seen had a different design than what you show. Spray nozzle, eductor, and application specialistsbex. An eductor is a pump that uses a fluid to perform the work of pumping another fluid or solid. Use ezejector software as your one stop service for ejector design. 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. Modelling of eductor nozzles layout in a treatment bath. Spray nozzle, eductor and application specialists bex has manufactured and sold spray nozzles and tank mixing eductors for over 50 years. No blowback, dry bulk is actually sucked into the line.
Jet pump to determine the correct eductor for a specific application, follow the steps. Eductors, jet pumps, injectors, ejectors, tank mixing, and. Turbomix eductor nozzles are arranged to keep water flowing across these surfaces and hence keep silt from settling. The pressure of the motive stream is dropped, to increase its velocity. Entrance of the venturi nozzle is equal to the rounded inlet of isa 1932 nozzle and this entrance opens into cylindrical neck ended by conical diffuser similar to the venturi tube. This is high enough to convey most bulk materials with plenty of margin fluidization velocity is not a direct function of bulk density and minimizes line losses and degradation. The siebec agitation system with eductor nozzle uses the venturi principle in order to amplify the. The eductor nozzle in this section takes advantage of the physical properties of the motive fluid. Eductors work in just about any place where there is a need for a more efficient way to pump liquids and solids. Recognized as the chameleon of the nozzle underworld, the same basic eductor design can be. Conveying eductors have a major advantage over rotary airlocks. The pressure of the secondary fluid at the entry of the ejector, pa p5. Using eductors for nonpowered tank mixing mead obrien. By application of the bernoulli principle, the pressure in the output nozzle must be lower than in atmosphere outside of the eductor, since the two regions are connected via the nozzle, and the flow is much faster in the nozzle.
Slightly superheated steam is often used to prevent condensation in the motive steam nozzle. To validate the cfd simulation, the numerical predictions. Mixing effectively to create a multiplying effect of 3 to 5 times fluid flow. A similar application in enclosed sump pits is frequent. Agitating eductor nozzles for clogresistant mixing bete. The siebec agitation system with eductor nozzle uses the venturi principle in order to. Get quick and accurate results to close in on your best alternative. Liquidgas ejectors these ejectors utilize liquid as the primary fluid. The primary fluid is accelerated in a convergingdiverging nozzle, creating a. These nozzles are often underappreciated because theyre hidden from view in mixing or holding tanks.
Eductors with gas motives utilize convergingdiverging nozzles to achieve maximum benefit from the compressibility of the gas. 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. The calculations are a bit complex, requiring one to determine the draw rate of the device that will match your needs based on an. Special venturi designs are particularly effective for ozonation and oxygenation of wastewater ventingexhausting gasses with liquid eductors.
By continuing to browse or by clicking accept you agree to the storing of first and third party cookies on your device to enhance site navigation, analyze site usage and assist in our marketing efforts. Design the elements of an eductor design are shown in figure 1. Design features effective, economical way to circulate liquids in closed or open tanks no moving parts inherently clog resistant requires minimal maintenance nozzle operation creates multiplying effect on fluid flow the volume of discharge liquid will be 35 times greater than the motive liquid pumped spray characteristics. We can size and specify ejectors for a wide range of applications. Turbomix eductor nozzles are arranged to keep water flowing across these surfaces and. The pressure of the primary fluid entering its nozzle, pa p2. Fox valve manufactures a broad range of engineered products based on one core technology.
Solids handling eductors solids handling eductors overview. The streamline eductor design provides maximum efficiency in this operation. Customers around the world rely on bex for knowledgeable people, responsive delivery, consistent quality and flexible solutions. The new line of jrgjt eductors offers advanced design features and superior technical capabilities to create the eductor for virtually any application. In the case steam ejector below the motive gas pressure is varied, while entrained gas pressure and entrainment ratio are kept constant. For your convenience, our online ejector sizing software remains fully functional here.
The effects of viscosity on the pressure drops in the line leading to the eductor must be calculated separately. As an example, this program will be introduced and used to design and evaluate a gas ejector performance. Siebec can help you in the calculation of the number and size of the eductor nozzles and design the installation of your agitation system. Eductor nozzles allow better fluid circulation in the tank which enables an enhanced. The nci tlm operates on the principle of flow dynamics pressurized fluid is accelerated through the nozzle to become a high velocity stream that entrains tank contents and intimately mixes with them.
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