The Water Jet Eductor is a type of ejector which utilizes the kinetic energy of a pressurized liquid to entrain another liquid, mix the two, and discharge the mixture against a counter pressure. Ejectors of this type are used throughout industry for pumping and mixing operations.
Water jet eductors have numerous uses in the plant such as lifting, pumping, mixing and agitation of liquids, granular solids and slurries. Some specific applications are: draining flooded areas, emptying tanks and sumps, pumping and mixing operations in oil treating systems, dewatering sand and coal barges, introducing anti-knock agents and coloring additives into gasoline, continuous blending, acidifying, causticizing of oils, producing emulsions, pumping food products, pumping sand and filter clay, tank mixing, and various proportioning operations. As an example of eductor performance in a typical use, a jet eductor measuring 8 1⁄2” in length will empty a 500 gallon water tank in less than half an hour, using water at 60 psig, as the sole source of motive power.
Self Priming Eductors require no priming and can be used for either continuous or intermittent operation.
Simple and Reliable Since the basic eductor has no moving parts to wear or break, only periodic inspection is required.
Corrosion and Erosion Resistant Because they can be made from most materials, or coated with corrosion resistant materials, eductors can be made resistant to the corrosive effects of the liquids handled and the environment.
Automatic Control Units can be adapted for automatic operation by means of a regulating spindle or a snap valve and float arrangement.
Non-Electrical Eductors can be used in hazardous locations where electrically operated alternatives would require expensive explosion-proofing.
Easy to Install Either threaded or flanged connections are available. Units are compact, relatively light and can be adapted to a variety of piping configurations.
Low Cost Water eductors are inexpensive in relation to the work they do.
Water Jet Eductors consist of only three basic components: a converging nozzle, a diffuser (or venturi) and a body to hold these parts in their proper relative positions and provide a suction chamber.
Jet ejectors can be made from most workable materials, such as: cast iron, bronze, stainless steel, aluminum, polyvinyl chloride, polyester fiberglass, Phenolic Fiberglass Reinforced Plastic (FRP), Teflon 2 and Hastelloy 3.
A variety of types and sizes are available as noted on the following pages. Certain variables such as pressure, temperature, viscosity, density, operating conditions of suction and discharge fluids, and desired results must be considered in determining the type of eductor best suited to your needs. S&K engineers will work with you to select the proper eductor for your application.
Request Performance Data Supplement 2M for operating characteristics of water jet eductors.
S&K Fig. 264 and Fig. 266 Water Jet Eductors are designed for liquid pumping and mixing operations and for the handling of some solids where requirements do not necessitate capacities greater than those obtained with sizes up to and including 6”. They are considered the standard eductors within this size range. Typical applications begin on page 12.
In operation, pressure liquid enters the eductor through the pressure nozzle and produces a high velocity jet. This jet action creates a vacuum in the line which causes the suction liquid to flow up into the body of the eductor where it is entrained by the pressure liquid.
Both liquids are thoroughly mixed in the throat of the eductor and are discharged against back pressure. The streamlined body with no pockets permits the pressure liquid to move straight through the eductor and reduces the possibility of solids in the suction material collecting and clogging. In addition, pressure drop in the suction chamber is held to a minimum.
Accompanying Bulletin 2M Supplement Performance Data provides performance information.
Fig 1. FIG. 264 EDUCTOR
Eductors of this type have streamlined bodies with threaded pipe connections. They are made in sizes ranging from 1/2” to 3” and are stocked in these sizes in ductile iron and bronze and Fig. 316 stainless steel. They are stocked in sizes from 1/2”, 2”, and 3” in PVC. Other materials are available on order.
Fig. 2. FIG. 264 EDUCTOR
Fig. 3. FIG. 266 EDUCTOR
These eductors are similar to Fig. 264 Eductors except that they have flanged connections and removable throat bushings along with removable nozzles. They are supplied in cast iron, bronze-mounted in 4” and 6” sizes. Other materials can be supplied on special order.
Fig. 264 PVC and Kynar Eductors offer resistance to many corrosive media. PVC Eductors are not recommended, however, for acetone, ketones, ether, esters, aromatic hydrocarbons or chlorinated hydrocarbons. A table of recommended uses is available on request. Maximum temperature rating is 150°F. Kynar Eductors will handle PVC applications including those mentioned above. Kynar’s temperature limitation is 250°F. Pressure ratings are given in Table 2.
Fig. 264 PVC and Kynar Eductors operate on the same principle as do all other S&K Eductors. Performance characteristics with water are shown in Bulletin 2M Supplement Technical Data. For performance with other liquids, contact S&K.
Nozzles and diffusers are not removable on these eductors. Sizes 1” and smaller are of molded construction.
Fig. 4. FIG. 264 PVC EDUCTOR
Sizes from 1 1/2” up are designed as shown here and in Fig. 5. On these sizes, the pressure and suction connections are female and the discharge connection is male. All connections are threaded.
Fig. 5. FIG. 264 PVC EDUCTOR
Fig. 6. FIG. 264 KYNAR EDUCTOR
1/2” to 1” Design. Sizes 1/2”, 3/4”, and 1” look like this. All connections are female and are threaded.
Fig. 2645 Automatic Water Jet Eductors are used to pump out sumps (pits, tanks, etc.) where liquid accumulates slowly but must be evacuated when it reaches a predetermined level.
As the liquid in the sump (basin, tank, cellar, bilge, etc.) accumulates, it raises the ball float until the upward action of the float opens the snap-acting valve, admitting motive fluid into the pressure connection of the eductor.
The jet action of the motive fluid creates a vacuum in the eductor and entrains the suction fluid, discharging both fluids under pressure. As the suction fluid is thus pumped out, the sump level drops to a point where the snap-acting valve shuts off. No further pumping action takes place until the sump again fills to the operating level.
Operation of the Fig. 2645 Eductor is completely automatic. It is self-operated, requires no electrical connections or any external power other than the motive fluid. The snap-acting valve and ball float are the only moving parts. The full assembly is so compact it can be installed in tanks as small as 13 1/2” diameter.
For performance information, see accompanying Bulletin 2M Supplement Performance Data.
Fig. 265 Liquid Jet Eductor is similar in design to the Fig. 264 Water Jet Eductor and is made for liquid pumping and mixing operations and for handling some solids where requirements do not necessitate capacities greater than those obtained with sizes up to and including 3”. Typical applications begin on page 12.
The Fig. 265 Liquid Jet Eductor provides higher discharge pressures and higher suction flow capacities than other standard eductors.
In operation, pressure liquid enters the eductor through the pressure nozzle and produces a high velocity jet. This jet action creates a vacuum in the line which causes the suction liquid to flow up into the body of the eductor where it is entrained by the pressure liquid. Both liquids are thoroughly mixed in the throat of the eductor and are discharged against back pressure. The streamlined body with no pockets permits the pressure liquid to move straight through the eductor and reduces the possibility of solids in the suction material collecting and clogging. In addition, pressure drop in the suction chamber is held to a minimum.
Accompanying Bulletin 2M Supplement Performance Data provides performance information.
Fig 8. FIG. 265 LIQUID JET EDUCTOR
Eductors of this type have streamlined investment cast bodies with threaded NPT male pipe connections. They are made in sizes ranging from 3/4” to 3” and are stocked in these sizes in Fig. 316 stainless steel. Other materials are available on order.
Fig. 9. FIG. 265 EDUCTOR
Fig. 242 Water Jet Eductors are designed to mix two liquids intimately in various proportions in operations where the pressure liquid is the greater proportion of the mixture. Typical applications include: removal of condensate; mixing gasoline with acid; blending and proportioning chemical solutions; and diluting acids and alkali.
In operation, the pressure liquid issues from the nozzle at high velocity and entrains the suction liquid. The extreme turbulence in the throat of the eductor mixes the two liquids, blending and emulsifying thoroughly and completely. Colloidal suspensions can also be produced.
Entrainment ratio is dependent upon the eductor design. Close regulation within the design limits is usually obtained by a valve in the suction liquid line.
The pressure drop between the pressure liquid and the discharge should be at least 10 psi to give adequate mixing, and the difference between the discharge pressure and the suction pressure should not exceed 75% of the difference between the operating pressure and the suction pressure.
When used for removal of condensate, the eductor should be installed three feet below the condensate level at the drain of the condenser. For performance information, see Technical Data Supplement to Bulletin 2M.
Fig. 10. FIG. 242 EDUCTOR
Fig. 11. FIG. 242 EDUCTOR
The 242 is the flanged type Condensate and Mixing Eductor. This style, too, is made in bronze or cast iron, bronze mounted, but can be supplied in other materials. Nozzles and throat bushings are removable.
Fig. 258 and Fig. 268 Tank Mixing Eductors are used to agitate liquid, dissolve powdered solids in liquid, and to mix two or more liquids intimately within a tank or other vessel without the use of baffles or moving parts inside the tank. These units take the place of mechanical agitators.
The 268 is used in preference to the 258 in operations where it is desirable to start mixing from a shallow level or where uniform local agitation is required over large, shallow tank area. Typical applications of each are shown in the application section beginning on page 12.
Fig. 258 and 268 Eductors are operated by a flow of pressure liquid through the nozzle. As shown in the sectional drawings, the motive liquid entrains suction liquid, the two are mixed intimately in the venturi, and the mixture is discharged into the tank. Pressure liquid can be taken from the tank by means of a pump or it can be a new liquid. Standard, stock units are designed to entrain 3 gallons of suction fluid for each gallon of motive fluid. (Special designs of the 258 Eductor can be made to give 1 to 1 ratio.)
Normally, the tank is filled by means of the eductors. Mixing occurs as soon as the level of liquid in the tank covers the suction of the eductor. In addition to the mixing obtained between suction and motive fluids in the eductor, the jet action of the discharge from the eductor serves to agitate the tank and prevents stratification.
If a drawing or sketch of the mixing tank is furnished, S&K will recommend and quote on the proper type of distribution system.
Performance information is given in accompanying Performance Data, Bulletin 2M Supplement. Similar units using steam as motive fluid for heating, circulating and mixing are described in Bulletin 3A as “Fig. 314” units.
Fig. 12. FIG. 258 TANK MIXING EDUCTOR.
Fig. 14. FIG. 268 TANK MIXING EDUCTOR.
3/8” and 3/4” sizes.
Fig. 17. FIG. 268 TANK MIXING EDUCTOR.
1 1/2” size and over.
Fig. 13. FIG. 258 TANK MIXING EDUCTOR
Standard units are made in cast iron and bronze but can be made in many other materials on special order. Large sizes can be fabricated instead of cast.
Fig. 15. FIG. 268 TANK MIXING EDUCTOR
This design is used for 3/8” (3 3/4” overall length and 1 3/4” overall width), and 3/4” (5 1/4” overall length and 2 3/8” overall width) pressure connection sizes. It is threaded directly into threads tapped into the 1 1/2” diameter or larger pressure liquid pipeline. It is cast in one piece and is stocked in cast iron, bronze and 316 stainless steel. Other materials can be supplied on special order.
Fig. 16. FIG. 268 TANK MIXING EDUCTOR
This design is used for 1 1/2” (8 7/8” overall length x 4 1/8” overall width), 2” (12 1/4” overall length x 5 7/8” overall width) and 3” (17” overall length x 8 1/8” overall width) pressure connection sizes. All are cast in one piece and have female thread connections for installation on nipples welded into the pressure liquid piping. The 1 1/2” and 2” sizes are stocked in cast iron, bronze, and 316 stainless steel. The 3” size is stocked in cast iron and stainless steel only. Other materials can be supplied on special order.
Fig. 254 and Fig. 267 Hopper-Type Eductors are made for handling slurries or dry solids in granular form and are used extensively for ejecting sludges from tank bottoms, for pumping sand from filter beds and for washing and conveying granular materials. Typical materials handled include: borax, charcoal, diatomaceous earth, lime, mash, fly ash, rosin, rock and granulated salt, sand, dry sawdust, light soda ash, dry sodium nitrate, powdered sulphur, wheat and many others.
A typical application of Fig. 254 Eductor is shown in the application section of this bulletin, beginning on page 12. Wash-down nozzles keep the material from adhering to the sides of the hopper and keep it moving down into the eductor. Pressure water, passing through the eductor nozzle, entrains the sand, sludge or other materials and discharges into the piping system.
Fig. 18. FIG. 254 HOPPER-EQUIPPED EDUCTOR.
Standard units are made in cast iron and have hardened steel nozzles and throat bushings. Special materials are also available on special order. Both nozzles and throat pieces are removable and pressure and discharge connections can be fitted for hose where maximum portability is desired. Handles and supporting feet are optional.
Fig. 19. FIG. 267 HOPPER-EQUIPPED EDUCTOR.
This economical unit is available from stock with body and nozzle in cast iron, bronze, 316 stainless steel, Kynar and PVC. Hoppers are stocked in Type 304 stainless steel (1, 1 1/2 & 2” sizes) and are also available in galvanized steel, brass, aluminum and PVC.
Furnished with a stainless steel funnel, the eductor can be made of any machinable material. Bronze units up to and including 3″ and cast iron units up to and including 4″ sizes are available from stock. Prices, delivery or a sectional outline drawing 67-XS-081-J will be furnished on request. Stainless steel funnels are stocked in 1- 1/4″, 1- 1/2″ and 2″ sizes.
Fig. 224 Water Jet Sand and Mud Eductors are used in pumping out wells, pits, tanks, or sumps where there is an accumulation of sand, mud, or other material not easily handled by the standard eductor. They are ideal for handling the heavy sludge residue from refining operations. A typical application of a Fig. 224 Eductor is shown in the application section beginning on page 12.
These eductors have an open suction and are designed to be submerged in the material being handled. The pressure liquid, passing through the nozzle, produces a high velocity jet which entrains the sludge or mud. This mixture is then discharged through a vertical pipe or hose. For performance information, see Bulletin 2M Supplement.
Similar units which use steam as the motive power are described in Bulletin 2A under “Fig. 225 Syphons”.
Fig. 20. FIG. 224 WATER JET SAND AND MUD EDUCTOR.
Standard units are made of cast iron with bronze pressure nozzles. Other corrosion-resistant materials are available on special order.
Fig. 21. FIG. 224 EDUCTOR.
Fig. 235 Annular Multi-Nozzle Water Jet Eductors are designed to handle solids and semi-solids. They operate at highest efficiency in large sizes and at low discharge heads. Because these eductors have high air handling capacities, they are particularly well suited for priming large pumps such as dredging pumps which frequently encounter air pockets.
Nozzles on the periphery of the throat introduce the pressure water. The pressure water creates a vacuum which draws in and entrains the material being handled and all flow discharges through the discharge connection. All suction flow is in a straight line through the eductor. For performance information, see Bulletin 2M Supplement.
Fig. 22. FIG. 235 ANNULAR MULTI-NOZZLE WATER JET EDUCTOR.
These eductors are made to order from any workable material. Sizes from 1 1/2” to 6” are cast with flanged suction, discharge and pressure connections, except 2” size which has sil-brazed pressure connection. Sizes above 6” (to 28” and up) are generally fabricated.
Fig. 23. FIG. 235 EDUCTOR.
(2” size with sil-brazed connection).
The special-purpose eductors illustrated here are similar in operation to the basic Fig. 264 Eductor described on page 3.
Fig. 24. FIG. 222 PORTABLE EDUCTOR.
Is designed for use as an auxiliary with a pump where the suction lift is too great for the pump alone. Made of anodized aluminum, bronze or other materials as required.
Fig. 25. FIG. 212 CORROSION RESISTANT EDUCTOR.
Is made of Phenolic Fiberglass Reinforced Plastic (FRP). Body is of one-piece construction.
Fig. 26. FIG. 264 EDUCTOR USED TO EMPTY TANKS.
Water jet eductors are often used to empty tanks or to pump out sumps, penstocks, cellars, and the like. The pressure line should be fitted with a regulating stop valve and a pressure gauge while the suction line should be provided with an S&K Strainer. Discharge lines should be sealed for a positive pick-up of the liquid by turning the discharge line up or by submerging the end of the discharge line. It is recommended that the eductor be installed a short distance above the liquid to be handled and that short suction lines be used. Eductors will operate with long suction lines, as shown in the line drawing, however, with suction lifts greater than 15’, capacities are reduced considerably. When handling hot liquid the eductor must be arranged with a short suction line or must be submerged.
Fig. 27. FIG. 264 EDUCTOR USED IN MIXING LIQUIDS.
This illustration shows a typical arrangement used in mixing liquids such as chemicals or fertilizers in proportion for spraying. The solution to be applied is mixed in a container in approximately twice the strength at which it is to be used. The water jet proportioning apparatus is operated by a jet of high pressure water and is controlled by a 3/4” stop valve. A 3” pressure gauge indicates pressure. The jet action of the pressure water draws the solution from the container and the water and solution are mixed in the throat of the eductor and are discharged through a standard 3/4” hose to a spray nozzle. Solids can be handled and sprayed through a non-clogging type spray nozzle.
Fig. 28. FIG. 242 EDUCTOR USED IN TYPICAL PROPORTIONING SYSTEM.
This shows a typical proportioning system using a Fig. 242 Eductor. Rate of flow is measured by a Rotameter and is controlled by a valve in the line. A valve in the pressure line and orifice of the eductor nozzle control the flow of the pressure liquid. Fluids are thoroughly mixed in the desired proportions and are then discharged.
Fig. 30. FIG. 258 EDUCTOR IN BATCH MIXING APPLICATION.
This illustrates the batch mixing of two or more liquids with an S&K Fig. 258 Eductor. The pressure liquid, taken from the top of the tank is passed through a pump to the eductor. The jet action of this fluid entrains the liquid at the bottom of the tank and proper mixing results.
Fig. 29. FIG. 258 EDUCTORS FOR TANK BLENDING OF OILS.
For the tank blending of oils, the arrangement shown has proved highly satisfactory. In this particular installation five 8” Fig. 258 Eductors are used in a 100’ tank. Initially, the eductors are used to fill the tank during which time they provide continuous agitation. After the tank is filled, the oil is drawn off and recirculated by means of the same pumps. Oil from the top of the tank issues through the eductor nozzle and entrains oil from the bottom of the tank. The two are mixed in the throat of the eductor and are discharged with sufficient force to maintain constant agitation and further blending in the tank.
Fig. 31. FIG. 235 EDUCTOR USED IN MIXING DRY POWDER.
Mixing dry powder and a liquid prior to discharge into a tank is accomplished through the use of a Fig. 235 Eductor as shown here. Pressure liquid enters the eductor, entrains the powder, mixes the two in the venturi of the eductor and discharges the mixture into a receptacle. The streamline eductor design provides maximum efficiency in this operation.
Fig. 32. FIG. 264 OR FIG. 265 WATER JET EDUCTORS USED TO ENTRAIN ANOTHER LIQUID.
This illustration shows a Fig. 264 or Fig. 265 Eductor being used to introduce a water treating compound into boiler feed water. A portion of the water issuing from the pump is bypassed into the eductor where it acts as the pressure medium to draw in and entrain the water treating compound.
Fig. 32. FIG. 264 OR FIG. 265 WATER JET EDUCTORS USED TO ENTRAIN ANOTHER LIQUID.
This illustration shows a Fig. 264 or Fig. 265 Eductor being used to introduce a water treating compound into boiler feed water. A portion of the water issuing from the pump is bypassed into the eductor where it acts as the pressure medium to draw in and entrain the water treating compound.
Fig. 34. FIG. 264 OR FIG. 265 EDUCTOR USED TO ENTRAIN DETERGENT FROM A DRUM.
This is a system developed for the continuous application of detergent solution to paper mill felts. A Fig. 264 or Fig. 265 Eductor is used to entrain detergent from a drum. This detergent is mixed intimately with the pressure water and the solution is in turn, entrained by a Steam Jet Syphon where it is brought to the desired temperature by mixing with the syphon’s motive steam. The heated solution is discharged through spray jets into the felt.