Feb. 27, 1962 R. K. ENGHOLDT I 3,022,743
NJECTOR PUMP Filed June 19, 1959 2 Sheets-Sheet 1 i lo F e A INVENTOR.
RHARD K. ENeHoLDT ATToRNf-:Y
Feb. 27, 1962 R.- K. ENGHOLDT INJECTOR PUMP 2 Sheets-Sheet 2 Filed June 19, 1959 RmHARD KENGHoLu-r ATTORNEY v' United States Patent() 3,622,743 INJECTOR PUMP Richard K. Enghoidt, Milwaukee, Wis., assigner to Erie Manufacturing Co., Milwaukee, Wis., a corporation of Wisconsin Filed .lune 19, 1959, Ser. No. 821,482 11 Claims. (Cl. 10S-258) This invention relates to injector pumps.
Injector pumps commonly have a number of cast and machined parts the relative size and positioning of which is critical. This results in inherently high manufacturing and inspection costs to maintain the desired performance and quality standards. Furthermore, the ehiciency of the prior art injectors is quite low.
The main object of this invention is to provide a low cost injector pump.
Another object is to provide an injector that can be mass produced While retaining constant performance characteristics.
Still another object is to provide an injector pump with increased efficiency.
The above objects are accomplished by molding a venturi with inlet and outlet ports and a secondary ow inlet port in an integral plate. This plate is secured to the exterior face of a'suitably ported body and an injector pump is thereby provided. The critical relationships and sizes of the venturi and its inlet and outlet ports are automatically established by the molding operation so that uniform injector ow characteristics are maintained without the need for the precise machining and assembly commonly required.
The capacity of the injector pump can be changed by merely varying the thickness of the plate. It is desirable to use an injector plate having the venturi opening extending clear through it so that the same dies can be used to mold injector plates of various thicknesses for use with the same ported body to provide injector pumps of vario-us capacities. A separate cover plate is used to close the openings in the injector plate. Of course, a single plate performing both as a cover plate and injector plate can be molded and has the advantage that leakage problems are reduced. The present injector pump can be easily repaired because the injector plate is mounted on the exterior or" a ported body. The exterior mounting of the plate is also convenient because the plate can be made of transparent material so that any obstructions affecting iiow conditions in the Venturi are readily observable.
The venturi molded in the plate has a throat of rectangular cross section which increases the efficiency of the injector. One explanation of this increase in efticiency is that in an injector pump part of the action derives from the contacting action between the primary and secondary flows and a rectangular venturi throat takes fuller advantage of this contacting action than a circular throat of equal capacity. This is because the center of a circular primary ow stream is relatively remote from the working surface of the stream and therefore does little work in pulling the secondary ow into the venturi throat whereas no portion of the thin rectangular low is very remote from the working surface of the uid. Another possible explanation for the increased etiiciency is that a rectangular throat permits more of the secondary flow surface to be exposed to the reduced pressure in the throat than does a circular throat of equal capacity. However, regardless of the explanation for it, the present rectangular throated injector is more eficient than common injectors of comparable capacity.
Other objects and advantages will be pointed out in, or be apparent from, the specication and claims as will 3,622,743 Patented Feb. 27, 1962 ice obvious modications of the three embodiments shown in the drawings in which:
FIG. l is a top View with the cover plate broken away to show the injector plate;
FIG. 2 is a side view showing primary ilow into, and mixed How out of, the injector plate;
FIG. 3 is a sectional View taken on line 3 3 of FIG. 2 showing secondary ow into the injector plate;
FIG. 4 is an enlarged fragmentary sectional view taken on line 4 4 of FIG. 2 at the junction of primary and secondary flows; l
FIG. 5 is a top view of an injector plate having sec ondary channels;
FIG. 6 is a fragmentary sectional view taken on line 6 6 of FIG. 5;
FIG. 7 is an enlarged perspective view of an injector plate having two venturis; and
FIG. 8 is a front View of the injector plate shown in FIG. 7.
Referring to the drawings, a body 10 has a one-piece injector plate 12 fastened to a face by screws 1i. Theinjecto-r plate has a venturi inlet 14 with which sec-l ondary ow openings 1S, 18 communicate. The primary flow is introduced into venturi inlet 14 through flow inlet 2? in the body and the secondary flow is introduced into openings l, i8 through tubes 2l branching from inlet 212. The primary and secondary ows are mixed in rectangular venturi throat 16 and ow through venturi outlet 26 into iiow` outlet 28 in the body. Venturi throat l5 is bounded by injector plate walls 17, cover plate 24 and body Iii. The injector plate has a cover plate 24 which contines the flow within the injector plate. Of course, the same injector characteristics may be secured by molding plates l2 and 24 integrally.
Another form of injector shown in FIGS. 5 and 6 has secondary channels eti which lead a portion of the flow yfrom, secondary ow openings 42, 42 past the main mixing area 44 in the venturi throat to a point downstream 4i where pressure, though not as low as in throat 44, is lower than secondary flow inlet pressure so that injection is accomplished. This multiple staging increases the capacity of the injector.
Two or more of the injectors can be used in parallel 4by use of the construction shown in FIGS. 7 and 8 in which the primary How enters at opening 32 and flows through venturi throats 34, 34 where it pulls secondary ilow from openings 35, 36, 36 and the resultant mixed ow exits at venturi outlet openings 38, 38. This double venturi unit is molded so that the openings do not extend clear through the plate in order that post 37 can be molded integrally with the plate.
The injector plate can be precision molded, or stamped or cast, etc. depending upon the exactitude of injector characteristics required. In any event the present device is much less expensive than a common multipart injector of comparable characteristics. j,
In many cases when other valving is needed in conjunction with an injector pump, an injector pump can be inexpensively provided by appropriately porting the parent valve body and mounting the injector plate of this invention thereon as shown in FIGS. 1-4. The external mounting of the injector plate permits easy replacement of a damaged or clogged unit. Furthermore, the ow conditions in the injector can be easily observed by constructing the cover and injector plates of transparent material. Because of the molding of all the injector parts into a single plate and the gain in eliiciency, the present device is considerably more compact than conventional -injectors of comparable performance.
Although but three embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.
1. An injector pump comprising, a body having a'ow inlet conduit, a flow outlet conduit, and a secondary flow conduit, `all of said conduits communicating with a face of the body, an integral injector member mounted on said face and including a venturi opening having an inlet communicating with said tiow inlet conduit, the venturi outlet communicating with said ow outlet conduit, and a secondary ow opening communicating with the venturi throat and said secondary ow conduit, and means cooperating with said openings to form closed flow passages.
2. The injector pump according to claim 1 in which the openings in said member extend through the member, said means including a cover member over the injector member and cooperating therewith to define the closed ow passages.
3. The injector pump according to claim 2 in which the injector member and cover member are plates with the walls of the venturi being normal to the face of the in# jector plate so that the plates and body face cooperate with the venturi in the injector member to define a closed flow passage of rectangular cross section.
4. In an injector, a plate, a Venturi recessed in` a face of the plate and having an inlet and an outlet, and a secondary fiow opening recessed in said face and communicating with the throat of the venturi.
5. The plate according to claim 4 in whichv theV walls of the Venturi are normal to the face of the plate.
6. The plate according to claim 4 having a plurality of ventnris.
7. An injector pump comprising, a body having a Vof the body, an injector plate secured to said face and comprising, a venturi shaped opening having an inlet communicating with the primary tiow inlet port, a secondary flow opening communicating with the secondary ow inlet port and opening into the venturi throat, the venturi outlet communicating with the mixed ow outlet port, and means cooperating with said openings to form closed How passages.
8. An injector pump according to claim 7 in which the injector plate has a channel which communicates between the secondary ow opening and a portion of the venturi downstream from the throat.
9. The injector pump according to claim 7 in which the injector plate has a plurality of venturis.
10. The injector pump according to claim 7 in which the venturi and the openings in said plate extend through the plate, said means including a cover plate over the injector plate and cooperating therewith to define closed Aflow passages.
11.V In an injector, a plate, a venturi in the plate having an inlet and an outlet, a secondary flow opening communicating with the throat of the venturi, and a channel in the plate communicating between the Vsecondary flow opening and a portion of the venturi downstream from where the secondary ow opening communicates with the throat.
References Cited in the file of this patent UNTTED STATES PATENTS 265,246 Conord Oct. 3, 1882 1,457,777 Kirgan June 5, 1923 1,502,203 Lucke July 22, 1924 1,986,489 Wahlbom Jan. 1, 1935