DK158109B

DK158109B - ADJUSTABLE EJECTOR

Info

Publication number: DK158109B
Application number: DK56388A
Authority: DK
Inventors: Dan Rosenbaek
Original assignee: Dems Eng
Priority date: 1988-02-04
Filing date: 1988-02-04
Publication date: 1990-03-26
Also published as: AU3064889A; DK56388A; WO1989007204A1; DK56388D0; DK158109C

Description

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Opfindelsen angår en ejektor af den i krav lfs indledning omhandlede art.The invention relates to an ejector of the kind referred to in the preamble of claim 1.

Der kendes ejektorer, jf. f.eks. GB-patentskrift nr.Ejectors are known, cf. GB patent no.

5 1.420.215 og det hertil svarende US-patentskrift nr.No. 5,420,215 and the corresponding US patent no.

3.891.353, FR-patentansøgning nr. 2.554.874 og EP-pa-tentansøgning nr. 0.142.424, hvori blandekammerets indvendige diameter kan ændres, ved at blandekammeret har en eftergivende væg af f.eks. gummi, som ved hjælp af 10 dertil indrettede organer kan underkastes et udvendigt tryk af varierende størrelse, således at væggen presses mere eller mindre langt ind i blandekammeret og derved ændrer dettes gennemstrømningstværsnitsareal.3,891,353, FR Patent Application 2,554,874 and EP Patent Application No. 0,142,424, wherein the internal diameter of the mixing chamber can be changed by the mixing chamber having a resilient wall of e.g. rubber which can be subjected to an external pressure of varying size by means of 10 means, such that the wall is pressed more or less far into the mixing chamber, thereby changing its cross-sectional area.

Til disse kendte ejektorer kræves der bl.a. tryktilfør-15 seis- og indstillingsorganer, der medfører, at sådanne ejektorer bliver forholdsvis kostbare og følsomme for driftsforstyrrelser. De er således ikke velegnede til anvendelse til f.eks. landbrugsformål.These known ejectors require, inter alia, pressure supply and adjustment means which cause such ejectors to be relatively costly and sensitive to interference. Thus, they are not suitable for use in e.g. agricultural purposes.

Desuden kendes, jf. f.eks. US-patentskrift nr. 2.623.474, 20 ejektorpumper, hvor blandekammerets udstrækning kan ændres, idet der rent mekanisk ved forskydning på tværs af strømningsretningen anbringes ansatser med forskellig diameter på blandekammerets plads. Denne udformning nødvendiggør imidlertid et forholdsvis stort rum, der står 25 i forbindelse med det egentlige blandekammer, for at give plads til de forskellige ansatser. Dette rum udgør i sig selv et "dødt rum", der kan medføre problemer ved skift fra én væske til en anden, og kræver desuden så meget plads, at ejektorpumpens ydre dimensioner bliver betyde-30 ligt større end hvad der er nødvendigt af hensyn til selve blandekammeret.Furthermore, cf. U.S. Patent No. 2,623,474, 20 ejector pumps, where the extent of the mixing chamber can be changed, by means of mechanically displacing transverse flows of different diameters in the space of the mixing chamber. However, this design necessitates a relatively large space, which is connected to the actual mixing chamber, to accommodate the various approaches. This space itself constitutes a "dead space" which can cause problems when switching from one liquid to another, and also requires so much space that the outer dimensions of the ejector pump become significantly larger than is necessary for the mixing chamber itself.

Det er opfindelsens formål at anvise udformningen af en ejektor af den indledningsvis nævnte art, hvormed de oven-It is an object of the invention to provide the design of an ejector of the kind mentioned above with which

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2 for omtalte ulemper kan undgås eller væsentligt formindskes, som på en enkel måde er opbygget af et lille antal komponenter, og som er meget ufølsom overfor drifts-5 forstyrrelser, og dette formål opnås ved en ejektor, der ifølge opfindelsen er udformet som angivet i krav l's kendetegnende del.2 for the aforementioned disadvantages can be avoided or substantially reduced, which is simply constructed of a small number of components and which is very insensitive to operational disturbances, and this object is achieved by an ejector designed according to the invention in accordance with the invention. The characteristic part of claim 1.

Den eller de bøsningformede indsatse, som ifølge opfindelsen anvendes til at ændre blandekammerets 10 indvendige diameter, kan på enkel og billig måde fremstilles som særdeles robuste maskinkomponenter, og kan ved hjælp af enkle mekaniske organer bevæges mellem de forskellige driftsstillinger.The bushing insert (s) used according to the invention to change the inside diameter of the mixing chamber 10 can be manufactured in a simple and inexpensive manner as extremely robust machine components, and can be moved between the various operating positions by simple mechanical means.

Hensigtsmæssige udførelsesformer for ejektoren ifølge 15 opfindelsen, hvis virkninger er nærmere forklaret i den efterfølgende specielle del af nærværende beskrivelse, er omhandlet i krav 2-7.Suitable embodiments of the ejector according to the invention, the effects of which are further explained in the following special part of the present disclosure, are set out in claims 2-7.

Opfindelsen skal i det følgende forklares nærmere under henvisning til det på tegningen viste udførelseseksempel 20 på en ejektor ifølge opfindelsen, idet fig. 1 viser ejektoren i en første driftstilstand eller ansugningstilstand, medens fig. 2 viser ejektoren i en anden driftstilstand eller pumpetilstand.BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be explained in more detail with reference to the embodiment example 20 of an ejector according to the invention, in which FIG. 1 shows the ejector in a first operating or suction mode, while FIG. 2 shows the ejector in another operating mode or pump mode.

25 For god ordens skyld bemærkes, at en ejektor ifølge opfindelsen ikke nødvendigvis er udformet med indbyrdes dimensioner svarende til dimensionsforholdene på tegningen.For the sake of good order, it should be noted that an ejector according to the invention is not necessarily designed with dimensions corresponding to the dimensions of the drawing.

Den på tegningen viste ejektor, hvis hus er betegnet med 30 1, omfatter på i princippet kendt måde - et indløb 2 for det fluidum, der skal transporteres, - en drivdyse 3, hvorigennem den væske, hvormed ejek- 3The ejector shown in the drawing, whose housing is designated 30 1, comprises in principle known manner - an inlet 2 for the fluid to be transported - a drive nozzle 3, through which the liquid by which ejector 3

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toren drives, i form af en ikke vist stråle kan rettes imod indgangsenden 4 i - et blandekammer 5, hvis nævnte indgangsende 4 er 5 forbundet med indløbet 2, og hvis udgangsende 6 udmunder i - en i strømningsretningen divergerende diffusor 7, hvorfra det transporterede fluidum forlader ejek-toren.the tower is driven, in the form of a beam not shown, directed towards the input end 4 of - a mixing chamber 5, the said input end 4 of which is connected to the inlet 2 and whose output end 6 opens into a flow direction divergent diffuser 7, from which the transported fluid leaving the eject tower.

10 Det nye ved ejektoren består først og fremmest i en aksialforskydelig, stort set bøsningformet indsats 8, som i den i fig. 1 viste driftstilstand udgør en del af blandekammerets væg, hvorved dettes indvendige diameter er betydeligt mindre end diameteren for en i huset 1 udformet 15 fast væg 9, som indsatsen 8 i den i fig. 1 viste stilling slutter sig tæt til.10 The new feature of the ejector consists primarily of an axially displaceable, largely bush-shaped insert 8, as in the embodiment shown in FIG. 1 forms part of the wall of the mixing chamber, the inside diameter of which is considerably smaller than the diameter of a fixed wall 9 formed in the housing 1, such as the insert 8 in the FIG. 1 position is close.

I den i fig. 1 viste tilstand, der passende kan betegnes som ansugningstiIstanden, er der mellem indervæggen i indsatsen 8 og den ikke viste drivstråle fra drivdysen 3 20 kun et snævert mellemrum, der er velegnet til udpumpning af luft fra indløbet 2, når dette gennem en slange eller et rør er forbundet med en lavereliggende væskemængde, der skal transporteres gennem ejektoren.In the embodiment shown in FIG. 1, which can conveniently be referred to as the suction state, between the inner wall of the insert 8 and the drive jet not shown from the drive nozzle 3 20, there is only a narrow gap suitable for pumping air from the inlet 2 when passing through a hose or a tubes are associated with a lower volume of fluid to be transported through the ejector.

Efterhånden som luften suges ud af det nævnte rør eller 25 den nævnte slange, vil væsken stige op til indløbet 2 og fylde dette hen til blandekammeret 5, hvor væsken på samme måde som den tidligere udsugede luft vil blive transporteret til diffusoren 7 af den ikke viste drivstråle fra drivdysen 3.As the air is sucked out of said tube or tubing, the liquid will rise to the inlet 2 and fill it to the mixing chamber 5 where the liquid will be transported to the diffuser 7 in the same way as the previously extracted air. drive jet from the drive nozzle 3.

30 Strømningsvejen gennem indsatsen 8 er imidlertid for snæver til at tillade ejektoren at transportere væsken med en volumenhastighed af den størrelsesorden, der kan opnås ved anvendelse af et blandekammer med større diameter endHowever, the flow path through the insert 8 is too narrow to allow the ejector to transport the fluid at a volume velocity of the magnitude achievable by using a larger diameter mixing chamber than

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4 den forholdsvis lille diameter i forhold til drivstrålen, der kræves ved transport af luft. Indsatsen 8 er derfor lejret forskydelig i ejektoren på en sådan måde, at den 5 fra den i fig. 1 viste stilling, hvor ejektoren befinder sig i ansugningstilstanden, kan bevæges bort fra blandekammerets faste væg 9, således at denne væg, hvis diameter er betydeligt større end indsatsens indvendige diameter, kommer til at udgøre blandekammerets radiale 10 begrænsning.4 shows the relatively small diameter relative to the propellant jet required for air transport. The insert 8 is therefore slidably mounted in the ejector in such a way that it 5 from the one shown in FIG. 1, in which the ejector is in the suction state, can be moved away from the fixed wall 9 of the mixing chamber, so that this wall, the diameter of which is considerably larger than the inside diameter of the insert, will constitute the radial 10 restriction of the mixing chamber.

Forskydningen af indsatsen 8 bort fra blandekammeret 5 sker i det viste udførelseseksempel ved hjælp af to skydestænger 10, der er fastgjort til indsatsen 8 og på ikke nærmere vist måde er ført tætnende ud gennem huset 15 1, så at de kan betjenes udefra. For at give plads til indsatsen 8 i den i fig. 2 viste driftstilstand, der passende kan betegnes som pumpetilstanden, er der dels i huset 1 udformet et rum 11 med et tilstrækkeligt stort tværsnit til at give plads til indsatsen 8, dels er 20 drivdysen 3 udformet på enden af et rør 12, som er så tyndt, at indsatsen 8 som vist i fig. 2 kan føres ind på eller omkring røret.The displacement of the insert 8 away from the mixing chamber 5 takes place in the illustrated embodiment by means of two sliding rods 10, which are attached to the insert 8 and which are not shown in a sealing way through the housing 15 1 so that they can be operated from the outside. In order to make room for the insert 8 in the embodiment of FIG. 2, which may conveniently be referred to as the pumping condition, a space 11 is formed in the housing 1 with a sufficiently large cross-section to accommodate the insert 8, and partly the drive nozzle 3 is formed on the end of a pipe 12 which is then thin, the insert 8 as shown in FIG. 2 can be inserted on or around the tube.

I den i fig. 2 viste pumpetilstand har ejektoren således et forhold mellem drivdysens og blandekammerets diameter, 25 der er velegnet til transport af en forholdsvis stor væskemængde pr. tidsenhed. Som det vil kunne ses af fig.In the embodiment shown in FIG. 2, the ejector thus has a ratio between the diameter of the drive nozzle and the mixing chamber, which is suitable for transporting a relatively large amount of liquid per unit of time. unit of time. As will be seen from FIG.

2, er indsatsen 8 ført så langt tilbage i forhold til drivdysen 3, at dennes funktion ikke forstyrres i nævneværdig grad.2, the insert 8 is retracted so far relative to the drive nozzle 3 that its function is not significantly disturbed.

30 Den viste ejektor kan på kendt, ikke vist måde være forbundet med føleorganer, hvormed det kan konstateres, hvorvidt det transporterede fluidum er en luftart eller en væske, samt styreorganer til i afhængighed af signaler fra føleorganerne at omstille ejektoren fra den ene driftstil- 5The ejector shown may be connected in a known, not shown way, to sensing means, whereby it can be ascertained whether the conveyed fluid is a gaseous or a liquid, and control means for switching the ejector from one mode of operation, depending on signals from the sensing means.

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stand til den anden og omvendt. I så fjald vil styreorganerne være indrettet til at bevæge indsatsen 8 mellem de to viste stillinger, f.eks. ved at være forbundet med 5 indsatsen gennem skydestængerne 10.capable of the other and vice versa. In that case, the control means will be arranged to move the insert 8 between the two positions shown, e.g. by being connected to the insert through the sliders 10.

Det på tegningen viste udførelseseksempel har kun de to i det foregående omtalte driftstilstande, men det ligger inden for opfindelsens ramme at udforme ejektoren på en sådan måde, at den kan have tre eller flere 10 driftstilstande. Dette kan opnås ved på ikke vist måde at anvende to eller flere bøsningformede indsatse, der kan anbringes inden i hinanden og enkeltvis bevæges mellem en stilling stort set svarende til den i fig. 1 viste og en stort set svarende til den i fig. 2 viste. Ved anvendelse 15 af f.eks. to koaksiale indsatse kan der opnås tre driftstilstande, nemlig - en ansugningstilstand stort set svarende til den i fig. 1 viste, hvori begge indsatse er anbragt inden i hinanden mellem indløbet og diffusoren, 20 - en første pumpetilstand, hvori den inderste af de to indsatse er ført ind i rummet 11 omkring røret 12, og - en anden pumpetilstand stort set svarende til den i fig. 2 viste, hvor begge bøsninger er anbragt inden i 25 hinanden i rummet 11 omkring røret 12.The embodiment shown in the drawing has only the two operating states mentioned above, but it is within the scope of the invention to design the ejector in such a way that it can have three or more operating states. This can be achieved by using two or more bush-shaped inserts not shown, which can be placed within each other and individually moved between a position substantially similar to that of FIG. 1 and substantially similar to that of FIG. 2. By using 15 of e.g. two coaxial inserts, three operating states can be obtained, namely - a suction state substantially similar to that of FIG. 1, wherein both inserts are disposed within each other between the inlet and the diffuser, 20 - a first pumping state in which the innermost of the two inserts is introduced into the space 11 around the tube 12, and - a second pumping condition substantially similar to that of the inlet. FIG. 2, where both bushings are disposed within one another in the space 11 around the tube 12.

Den nævnte første pumpetilstand, der driftsmæssigt set ligger mellem den i fig. 1 belyste ansugningstilstand og den i fig. 2 belyste pumpetilstand, kan f.eks. anvendes i tilfælde, hvor ejektoren skal arbejde mod et forholdsvis 30 højt tryk. Føle- og styreorganerne kan i så fald omfatte en i forbindelse med diffusoren anbragt trykføler, der giver signal til styreorganet om etablering af den nævnte første pumpetilstand, når trykket stiger over en forud fastlagt tærskelværdi.Said first pump condition, which is operationally located between the one shown in FIG. 1 illustrates the suction state and the embodiment shown in FIG. 2 illuminated pump condition, e.g. is used in cases where the ejector must operate at a relatively high pressure. In this case, the sensing and control means may comprise a pressure sensor arranged in connection with the diffuser which gives a signal to the control means for establishing said first pumping state when the pressure rises above a predetermined threshold value.

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66

Indsatsen 8 er med henblik på nedsættelse af strømningstab på kendt måde udformet med et i strømningsretningen konvergerende indløb 4 og et i strømningsretningen 5 divergerende udløb 6. I den ovenfor omtalte, ikke viste udførelsesform med to eller flere indsatse, er disse fortrinsvis også udformet med sådanne konvergerende og divergerende indløb henholdsvis udløb, idet udformningen i så fald kan være en sådan, at forskellige dele af de 10 konvergerende og divergerende flader befinder sig på hver sin indsats, således at strømningstabene også holdes nede i f.eks. den ovenfor omtalte første pumpetilstand.The insert 8 is designed to reduce flow losses in a known manner with a flow inlet 4 which converges in the flow direction and a flow diverge in the direction of flow 5. Convergent and divergent inlets and outlets, respectively, the design being such that different parts of the 10 converging and divergent surfaces are located on each insert, so that the flow losses are also kept down e.g. the first pump condition mentioned above.

Claims

7 DK 158109 B PATENT REQUIREMENT.

An ejector of the kind comprising a) an inlet (2) for the fluid to be transported by the ejector, b) a drive nozzle (3) to which pressurized drive fluid can be supplied, and from which it is in the form of a beam may flow toward the entrance end (4) (c) a mixing chamber (5) adapted for varying its internal diameter, said entrance end (4) being connected to the inlet (2) and whose exit end (6) opening out a diffuser (7), the downstream end of which is or is connected to the ejector outlet, characterized by, e) at least one substantially sleeve-shaped insert (8) which can be displaced axially between a first position (Fig. 1), in which its outside ends moving to a fixed wall (9) in the mixing chamber (5) and at least one other position (Fig. 2) in which it is axially spaced from the fixed wall (9) of the mixing chamber (5).

Ejector according to claim 1, characterized in that: (a) the drive nozzle (3) is formed on the end of a tube (12) whose axial length is at least as large as the insert (8) and whose outer diameter is at most with sliding fit corresponds to the inside diameter of the insert (8) and is arranged in a space (11) whose internal diameter is at least as large as the outside diameter of the insert (8), and at b) externally operable switching means (10), by which the insert (8) can be inserted so far into the tube (12) that it does not appreciably affect the operation of the drive nozzle (3) and return to said first position. 8 DK 158109 B

An ejector according to claim 1 or 2, characterized in that it comprises at least two mutually coaxial inserts arranged to lie within each other in at least one operating state.

Ejector according to one or more of claims 1 to 3, characterized in that: (a) the insert (8) or the largest outer diameter insert is connected to at least 10 a in the sliding rod (10) extending in the shear direction of the insert and and (b) any additional inserts of smaller outside diameter than the former are each connected to at least a in corresponding sliding rod and are slidably mounted on at least a in the sliding bars associated with the first insert.

Ejector according to one or more of claims 1-4 and having automatically acting sensing and control means for depending on whether the flowing fluid is an air or liquid to adjust the inside diameter of the mixing chamber * to that of the fluid in question. effective dimension, characterized in that the control means are arranged to move the insert (8) 25 or the inserts to the position necessary to achieve the internal diameter in question.

Ejector according to one or more of claims 1 to 5, characterized in that the insert and (8) or the inserts are designed such that the at least one in the operating position exhibits a flow converging in the direction of flow.

Ejector according to one or more of claims 1-6, 9, characterized in that the insert (8) or the inserts are designed such that the at least one operating position exhibits a diverging outlet (6) in the flow direction (6). ).