Injection nozzle for a spray device and spray device

Abstract

An injection nozzle for a spray device for drawing in a fluid suction medium by a fluid propellant which is under excess pressure and for spraying an admixture of the suction medium and the propellant. The injection nozzle has a nozzle housing, an injection chamber arranged in the nozzle housing, a jet nozzle which opens in the injection chamber for producing a propellant jet which is introduced into the injection chamber, and a fluid suction opening for the fluid suction medium. The fluid suction opening opens in an annular channel which has a flow connection to the injection chamber.

Claims

1. An injection nozzle for a spray device for drawing in a fluid suction medium by a fluid propellant which is under excess pressure and for spraying an admixture of the fluid suction medium and the fluid propellant, the injection nozzle comprising a nozzle housing having an injection chamber which is arranged in the nozzle housing, a jet nozzle which opens in the injection chamber for producing a propellant jet which is introduced into the injection chamber, and a fluid suction opening for the fluid suction medium, wherein the fluid suction opening opens in an annular channel which has a flow connection to the injection chamber, and wherein at least one pin diaphragm is provided in a suction channel upstream of the fluid suction opening.

2. The injection nozzle according to claim 1, wherein the annular channel is open at one side towards the injection chamber so that the flow connection to the injection chamber is formed by means of an annular gap.

3. The injection nozzle according to claim 1, wherein the fluid suction opening opens in the annular channel upstream of an outlet opening of the jet nozzle.

4. The injection nozzle according to claim 1, wherein the flow connection from the annular channel to the injection chamber opens in the injection chamber at the height of an outlet opening of the jet nozzle.

5. The injection nozzle according to claim 1, wherein the annular channel is delimited at least at one side by a jet nozzle housing of the jet nozzle.

6. The injection nozzle according to claim 1, wherein the nozzle housing is provided with a pin diaphragm insert which has a portion of the suction channel for drawing in the fluid suction medium and the pin diaphragm and which is releasably arranged on the nozzle housing.

7. The injection nozzle according to claim 6, wherein the pin diaphragm insert is connected to the nozzle housing by a sliding guide.

8. The injection nozzle according to claim 6, wherein the pin diaphragm insert is releasably arranged on an injector component which has at least the jet nozzle and the injection chamber.

9. The injection nozzle according to claim 1, wherein the injection chamber downstream of an outlet opening of the jet nozzle has a first conical portion which expands in the flow direction and has a second conical portion which adjoins the first conical portion and which expands in the flow direction, wherein the second conical portion has a larger cone angle than the first conical portion.

10. The injection nozzle according to claim 9, wherein a cone angle of the first conical portion is in the range from 5° to 15°.

11. The injection nozzle according to claim 9, wherein a cone angle of the second conical portion is in the range from 30° to 40°.

12. The injection nozzle according to claim 9, wherein the first conical portion has when viewed in the flow direction a length which is in the range from two to four times the length of the second conical portion.

13. The injection nozzle according to claim 1, wherein an outlet opening of the jet nozzle opens in a portion of the injection chamber which tapers in a conical manner in the flow direction.

14. The injection nozzle according to claim 13, wherein a ratio between a diameter of a cylindrical portion of the injection chamber and a length of the portion of the injection chamber which tapers in a conical manner in a flow direction between the outlet opening of the jet nozzle and the beginning of the cylindrical portion is in the range from 0.5 to 5.

15. The injection nozzle according to claim 1, wherein a cylindrical portion of the injection chamber is arranged upstream of a first conical portion, wherein the first conical portion adjoins the cylindrical portion.

16. The injection nozzle according to claim 15, wherein a ratio between a surface-area of the cylindrical portion of the injection chamber and a surface-area of the flow connection from the annular channel to the injection chamber is in the range from 0.25 to 2.5.

17. The injection nozzle according to claim 1, wherein the flow connection between the annular channel and the injection chamber is arranged in a portion directly upstream of an opening in the injection chamber between two walls which taper in a conical manner in the flow direction.

18. A spray device for spraying an admixture of a fluid suction medium and a fluid propellant, including at least one injection nozzle according to claim 1.

19. An injection nozzle for a spray device for drawing in a fluid suction medium by a fluid propellant which is under excess pressure and for spraying an admixture of the fluid suction medium and the fluid propellant, the injection nozzle comprising a nozzle housing having an injection chamber which is arranged in the nozzle housing, a jet nozzle which opens in the injection chamber for producing a propellant jet which is introduced into the injection chamber, and a fluid suction opening for the fluid suction medium, wherein the fluid suction opening opens in an annular channel which has a flow connection to the injection chamber, wherein a cylindrical portion of the injection chamber is arranged upstream of a first conical portion, wherein the first conical portion adjoins the cylindrical portion, wherein a pin diaphragm is provided in a suction channel upstream of the fluid suction opening, and wherein a ratio between a diameter of the cylindrical portion of the injection chamber and a diameter of a through-opening of the pin diaphragm is in the range from 1.5 to 15.

20. The injection nozzle according to claim 19, wherein the ratio between the diameter of the cylindrical portion of the injection chamber and a diameter of an outlet opening of the jet nozzle is in the range from 1 to 3.

21. An injection nozzle for a spray device for drawing in a fluid suction medium by a fluid propellant and for spraying an admixture of the fluid suction medium and the fluid propellant, the injection nozzle comprising: a nozzle housing having an injection chamber within the nozzle housing; a jet nozzle that opens into the injection chamber for producing a propellant jet introduced into the injection chamber; and a fluid suction opening configured to receive the fluid suction medium; wherein the fluid suction opening opens into an annular channel fluidly connected to the injection chamber; and wherein at least one pin diaphragm is provided in a suction channel upstream of the fluid suction opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an exploded illustration of an injection nozzle according to an embodiment of the invention,

(2) FIG. 2 is a sectioned view of the injection nozzle according to an embodiment of the invention,

(3) FIG. 3 is an enlarged sectioned view of an injector component of the injection nozzle according to an embodiment of the invention,

(4) FIG. 4 is a view of an injector component according to another embodiment of the invention,

(5) FIG. 5 is a pin diaphragm insert for the injector component of FIG. 4,

(6) FIG. 6 is a sectioned view of the pin diaphragm insert of FIG. 5, and

(7) FIG. 7 shows the injector component of FIG. 4 without the pin diaphragm insert.

DETAILED DESCRIPTION

(8) FIG. 1 shows an injection nozzle 10 according to an embodiment of the invention in the exploded state. The injection nozzle 10 has an injector component 12 and an outlet nozzle component 14. The injector component 12 is partially inserted into the outlet nozzle component 14 (for example, as shown in FIG. 2) in order to achieve an operational state of the injector nozzle 12. The injection nozzle 12 is then inserted in known manner into a nozzle holder (not illustrated) of a spray device, in particular an agricultural spray device.

(9) A pin diaphragm 16 marks the beginning of a suction channel in the injector component 12. Via the pin diaphragm 16, fluid suction medium is drawn from a storage tank, mixed with a fluid propellant, and an admixture of fluid suction medium and fluid propellant is discharged at an end 18 of an injection chamber 24 located downstream. The admixture then enters the outlet nozzle component 14 (shown in FIG. 2) and is discharged as a flat jet via an outlet opening 20 of a flat jet nozzle 22. In place of the flat jet nozzle 22, of course substantially any outlet nozzle may be provided on the outlet nozzle component 14, for example, a hollow cone nozzle or full cone nozzle.

(10) FIG. 2 is a sectioned view of the injection nozzle 10 of FIG. 1 in the assembled state. The injector component 12 is shown as being partially inserted into the outlet nozzle component 14. At the end 18 of the injection chamber 24, the admixture of fluid suction medium and fluid propellant is introduced into an outlet chamber 26, at the downstream end of which the outlet nozzle 22 is then arranged.

(11) In the injector component 12 there is arranged a jet nozzle housing 28 via which the fluid propellant, which can be pressurized water, is introduced into the injection chamber 24 in the form of a propellant jet. In the embodiment illustrated, the propellant jet is constructed as a full jet and enters the injection chamber 24 via an outlet opening 30 of the jet nozzle housing 28. The outlet opening 30 has a diameter d.sub.TR.

(12) The jet nozzle housing 28 is surrounded by an annular channel 32. A suction channel 34 opens at a fluid suction opening 36 in the annular channel 32. A left end of the suction channel 34 as illustrated in FIG. 2 is delimited in the illustration of FIG. 2 by the pin diaphragm 16. The pin diaphragm 16 has a through-opening 38 having a diameter d.sub.R.

(13) The annular channel 32 is delimited at one side by the jet nozzle housing 28 and is in flow connection with the injection chamber 24. In the embodiment illustrated, the flow connection between the annular channel 32 and the injection chamber 24 is constructed in the form of an annular gap 40. The annular gap 40 is produced by the annular channel 32 being open at one side towards the injection chamber 24. A surface-area of the annular gap 40 at the height of the downstream end of the outlet opening 30 is designated A.sub.S. In the context of the illustrated embodiment of the invention, the flow connection between the annular channel 32 and injection chamber 24 may also be constructed differently, for example, by a plurality of channels.

(14) The injection chamber 24 has four portions when viewed in the flow direction.

(15) The outlet opening 30 of the jet nozzle housing 28 and the annular gap 40 open in a portion 42 of the injection chamber 24 which tapers in a conical manner and which is constructed in a generally frustoconical manner. The portion 42 which tapers in a conical manner is adjoined by a cylindrical portion 44. The cylindrical portion 44 is adjoined by a first conically expanding portion 46, which has a first cone angle. The first portion 46 which expands in a conical manner is adjoined by a second conically expanding portion 48 which has a second cone angle. The second cone angle is greater than the first cone angle. The first conically expanding portion 46 is constructed to be longer than the second conically expanding portion 48. A cone angle of the first conical portion is in the range between 5° and 15° and in particular between 5° and 10°. A cone angle of the second conical portion 48 is in the range from 30° to 40°. The first conical portion 46 has, when viewed in the flow direction, a length which is in the range from two times to four times, in particular three times, the length of the second conical portion 48. The two successive conically expanding portions 46, 48 contribute to a constant mixture ratio between the fluid propellant and the fluid suction medium, even in the event of pressure fluctuations of the propellant.

(16) A propellant jet which is produced by the jet nozzle and which is discharged from the outlet opening 30 of the jet nozzle housing 28 is then introduced into the conically tapering portion 42 of the injection chamber 24 and produces by the so-called Venturi effect a reduced pressure in the injection chamber 24. Consequently, the fluid suction medium is drawn via the through-opening 38 of the pin diaphragm 16 into the suction channel 34 and is introduced via the fluid suction opening 36 into the annular channel 32. The suction medium is distributed in the annular channel 32 and then enters, distributed in a uniform manner when viewed over the periphery of the jet nozzle housing 28, the injection chamber 24 through the annular gap 40. In place of the annular gap 40, for example, a plurality of through-channels may also be provided between the annular channel 32 and the injection chamber 24.

(17) The propellant jet enters the cylindrical portion 44 together with the drawn-in suction medium and then the two conically expanding portions 46, 48 of the injection chamber 24. Already in the conically tapering portion 42 of the injection chamber 24, the propellant jet begins to break up and there is produced a mixing between the propellant jet and the drawn-in suction medium. At the end 18 of the injection chamber 24 located downstream, the admixture of the fluid suction medium and the fluid propellant is thereby introduced into the outlet chamber 26. In the outlet chamber, there is brought about further homogenization of the admixture between the fluid propellant and the fluid suction medium. In the embodiment illustrated, a flat jet comprising the admixture of the fluid propellant and the fluid suction medium is then discharged from the outlet nozzle 22. As has been set out, as a result of the special construction of the injection nozzle 10, a constant mixture ratio between the fluid propellant and the fluid suction medium can be ensured, even in the event of pressure fluctuations of the fluid propellant. The injection nozzle 10 according to an embodiment of the invention is thereby particularly suitable for use in agricultural engineering. In the context of an embodiment of the invention, the outlet nozzle 22 may also be constructed as a full cone nozzle or hollow cone nozzle.

(18) FIG. 3 is an enlarged illustration of the injector component 12 of the injection nozzle 10 of FIGS. 1 and 2.

(19) A diameter of the through-opening of the pin diaphragm 16 is designated d.sub.R. A diameter of the outlet opening 30 of the jet nozzle housing 28 is designated d.sub.TR. A length of the portion 42 of the injection chamber 24 which tapers in a conical manner is designated h when viewed in the flow direction. A diameter of the cylindrical portion 44 of the injection chamber 24 is designated d.sub.DH and a cross-sectional surface-area of the cylindrical portion 44 is designated A.sub.DH.

(20) A surface-area of the annular gap 40 at the downstream end of the flow connection between the annular channel 32 and the injection chamber 24 is designated A.sub.S. A cone angle of the first conically expanding portion 46 of the injection chamber 24 is designated α1 and a cone angle of the second conically expanding portion 48 of the injection chamber 24 is designated α2. A length of the cylindrical portion 44 of the injection chamber 24 is designated L.sub.0. A length of the first conically expanding portion 46 is designated L.sub.1 and a length of the second conically expanding portion 48 is designated L.sub.2.

(21) L.sub.0 is significantly smaller than h and is in the embodiment illustrated only approximately a third of h. L.sub.1 and L.sub.2 are significantly larger than L.sub.0. L.sub.1 is larger than L.sub.2 and L.sub.1 is approximately from twice as large up to four times as large as L.sub.2. α1 is in the range from 5° to 15°, in particular between 5° and 10°. α2 is in the range from 30° to 40°.

(22) A ratio d.sub.DH/h between the diameter d.sub.DH of the cylindrical portion 44 of the injection chamber 24 and the length h of the portion 42 of the injection chamber 24 which tapers in a conical manner in the flow direction between the outlet opening 30 and the beginning of the cylindrical portion 44 is in the range from 0.5 to 5, in particular between 1 and 2, in particular 1.4.

(23) A ratio d.sub.DH/d.sub.TR between the diameter d.sub.DH of the cylindrical portion 44 of the injection chamber and a diameter d.sub.TR of the outlet opening 30 of the jet nozzle is in the range from 1 to 3, in particular between 1.5 and 1.7, in particular 1.6.

(24) A ratio d.sub.DH/d.sub.R between the diameter d.sub.DH of the cylindrical portion 44 of the injection chamber 24 and a diameter d.sub.R of a through-opening of the pin diaphragm 16 is in the range from 1.5 to 15, in particular between 4 and 6, in particular 4.7.

(25) A ratio A.sub.DH/A.sub.S between a surface-area A.sub.DH of the cylindrical portion 44 of the injection chamber 24 and a surface-area A.sub.S of the flow connection from the annular channel 32 to the injection chamber 24, in particular a surface-area A.sub.S of the annular gap 40, is in the range from 0.25 to 2.5, in particular between 0.5 and 1, in particular 0.76.

(26) The above-explained relationships and also the above-explained lengths and diameters and angles contribute to a constant mixture ratio between the fluid suction medium and the fluid propellant, even in the event of pressure fluctuations of the fluid propellant. The injection nozzle according to an embodiment of the invention is thereby particularly suitable for use in agricultural engineering.

(27) FIG. 4 shows an injector component 112 according to another embodiment of the invention. The injector component 112 is constructed in a very similar manner to the injector component 12 of FIGS. 1 to 3 so that identical elements are either not explained or indicated with the same reference numerals. The injector component 112 may be inserted into the outlet nozzle component 14 illustrated in FIGS. 1 to 3 in place of the injector component 12 of FIGS. 1 to 3.

(28) The injector component 112 has a modular pin diaphragm insert 114. The modular pin diaphragm insert 114 has the pin diaphragm or aperture plate 16 and a portion of the suction channel. The suction channel is then continued into the injector component 112.

(29) FIG. 5 shows the pin diaphragm insert 114 obliquely from below and FIG. 6 shows the pin diaphragm insert 114 as a sectioned view. FIG. 6 shows that the pin diaphragm insert 114 defines a portion 34A of the suction channel. However, the remaining portion 34B of the suction channel which then leads to the annular channel around the jet nozzle (see FIG. 2), is formed in the injector component 112.

(30) The pin diaphragm insert 114 has at the upstream end of the suction channel 34A thereof the pin diaphragm 16 which defines the restrictor hole 38. Depending on the flow resistance of the restrictor hole 38, that is to say, depending on the diameter of the restrictor hole 38 and depending on the length of the restrictor hole 38, the flow resistance of the restrictor hole 38 changes and consequently a ratio between the quantity of suction medium drawn in and the quantity of the fluid propellant can be adjusted.

(31) FIG. 5 shows that the portion 34A of the suction channel is formed at the downstream end thereof by a connecting piece 116 which protrudes over a stop face 118 of the pin diaphragm insert 114. The connecting piece 116 is provided (see FIG. 7) to be inserted into an appropriate recess 120 in the injector component 112. By simply inserting the pin diaphragm insert 114 into the sliding guide of the injector component 112, wherein at the end of the sliding movement the pin 116 is introduced into the recess 120, on the one hand, the portion 34A is tightly connected to the portion 34B of the suction channel. This is achieved by the connecting piece 116 being provided with a peripheral projection 122 which can engage in an appropriate peripheral groove 124 in the recess 120. For example, the peripheral projection 122 is formed by a sealing ring so that, after the engagement of the projection 122 in the groove 124, the two portions 34A, 34B of the suction channel are connected tightly to each other. Only small demands are placed on the fluid-tightness of this connection since the suction channel 34 and consequently also the connection of the portions 34A, 34B is under reduced pressure during operation of the injection nozzle.

(32) The projection 122, which in the assembled state of the pin diaphragm insert 114 is engaged in the groove 124, also ensures mechanical securing of the pin diaphragm insert 114 on the injector component 112.

(33) The sliding guide is formed on the injector component 112 by two strip-like projections 126 which protrude into a recess on the injector component 112 which extends as far as the edge of the injector component. An undercut is thereby formed at both sides between the strip-like projections 126 and a base 128 of the recess.

(34) The pin diaphragm insert 114 also has at both sides strip-like projections 130 which are adapted to the length, height and width of the undercut in the recess. By simply pushing the strip-like projections 130 into the undercuts on the injector component 112, the pin diaphragm insert is thereby guided on the injector component 112. The pin diaphragm insert 114 can be inserted along the sliding guide into the injector component 112 until the end face 118 of the pin diaphragm insert 114 strikes the end-side delimitation 132 of the recess in the injector component 112. This state is illustrated in FIG. 4. As soon as the pin diaphragm insert 114 has reached the end position thereof illustrated in FIG. 4, the projection 122 on the connecting piece 116 of the pin diaphragm insert 114 is also engaged in the groove 124 in the recess 120 of the injector component 112.

(35) In order to be able to change the pin diaphragm insert 114, that is to say, to be able to remove it from the position illustrated in FIG. 4, the edge of a coin or the blade of a screwdriver is introduced into a rectangular recess 134 at the upper side of the injector component 112. A delimitation of this recess 134 forms the end face 118 of the pin diaphragm insert 114. By turning the coin or the blade of the screwdriver, the pin diaphragm insert 114 can thereby be moved a small distance along the sliding guide in a radial direction away from the injector component 112. This movement has to be carried out only until the peripheral projection 122 on the connecting piece 116 of the pin diaphragm insert 114 has been moved out of the groove 124 of the recess 120 in the injector component 112. The locking connection between the pin diaphragm insert 114 and the injector component 112 is thereby released. The pin diaphragm insert 114 can then be readily removed from the injector component 112 by hand along the sliding guide. The pin diaphragm insert 114 can then, for example, be replaced with another pin diaphragm insert which differs from the pin diaphragm insert 114 only in terms of another dimension of the restrictor hole 38 of the pin diaphragm 16. In this manner, the injection nozzle according to an embodiment of the invention can be adapted in a simple manner so that different relationships of the quantity of suction medium and the quantity of propellant can be adjusted.