DK169611B1 - Convertible spray nozzle, especially for application of liquids such as agricultural chemicals - Google Patents

Description

The present invention relates generally to spray nozzles and, more particularly, to spray nozzles which are adapted to apply liquids such as agricultural chemicals.

Agricultural chemicals are generally applied through a number of spray nozzles mounted on and spaced apart along a common mounting boom. In particular, in recent years, it has been found that such chemicals can be effectively applied through air-assisted nozzles such as those disclosed in the description of the licensee's GB patent specification No. 2 157 591, entitled "Air-assisted Spray Nozzle". Such a spray nozzle comprises an elongated, hollow nozzle housing with a first and a second end, a chamber defined in the housing, means in the housing forming an air inlet connection through which a compressed air stream 15 can be blown into the chamber, means in the housing forming a liquid access connection. for introducing liquid into the housing, means in the housing for causing the liquid to flow through the chamber in a stream which mixes with the compressed air stream blown through the air supply connection in such a way that the liquid is temporarily atomized in the chamber, and a nozzle element removably inserted in the housing away from the fluid inlet connection. In such a nozzle, a compressed air stream is injected into the nozzle housing to atomize the liquid before it exits from the nozzle's nozzle tip.

25 In some cases, however, it is preferred to apply chemicals through non-assisted nozzles (i.e., usual hydraulic nozzles) in which the spray pattern is formed when the pressurized liquid flows out of the nozzle tip. Due to the relatively large number of single spray nozzles mounted on a typical agricultural spray boom, it may be time-consuming to replace air-assisted nozzles with hydraulic nozzles or vice versa. In addition, if one wishes to choose between both air assisted application and conventional hydraulic application, one must usually purchase a stock of both types of nozzles.

2

The invention according to claim 1 relates to a spray nozzle which can be converted from an air-assisted nozzle to a non-air-assisted nozzle, which comprises an elongated, hollow nozzle housing with a first and second ends, a chamber delimited in the housing, means in the housing forming an air inlet connection. , through which a compressed air stream can be blown into the chamber, means in the housing forming a liquid supply connection for introducing liquid into the housing, means in the housing for causing the liquid to flow through the chamber in a stream which mixes with the compressed air stream which is blown into the chamber through the air inlet connection in such a way that the liquid is temporarily atomized in the chamber and a nozzle element removably inserted into the chamber away from the liquid access connection, the spray nozzle 15 being characterized in that the nozzle element defines a nozzle flow to limit flow. , after this stream come enters the fluid inlet connection, and before this flow is temporarily atomized into the chamber by the air flow, means defining an outflow nozzle located adjacent the first end of the housing and in connection with the chamber, which outflow nozzle receives provisional atomized liquid from the chamber and causes ejection of this liquid from the nozzle, and means on the housing and selectively removable therefrom to allow the nozzle member to be withdrawn from the housing so that the fluid flow is allowed to flow through the chamber without limiting the flow rate of the fluid flow before this flow reaches the outlet nozzle.

The invention also relates, according to claim 8, to a liquid spray nozzle comprising a hollow nozzle housing defining a chamber, members of the housing forming an air inlet connection through which a compressed air flow can be conducted into the chamber, selectively activating means for passing compressed air through the air inlet. means in the housing 35 forming a liquid access connection for introducing a liquid flow into the housing, means for passing a pressurized 3 liquid through the liquid access connection and an insert element removably mountable in the housing, said liquid spray nozzle being characterized in that the insert element is formed with an interior a liquid flow channel through which liquid introduced into the housing passes and a stop surface aligned with the passage of the liquid through the liquid channel and against which the liquid strikes to deflect and mix it with a compressed air stream introduced into the housing chamber from the air supply connection e after activation of the compressed air guide means in such a way that the liquid is provisionally atomized in the chamber, and a spray tip defining a discharge nozzle in connection with the chamber to receive provisional atomized liquid from the chamber and cause the liquid to be ejected from the mouthpiece determined 15 patterns of liquid drops.

Thus, the present invention provides a new and improved syringe nozzle which can be used either as an air assisted nozzle or as a hydraulic nozzle by making a relatively simple and easy conversion of the nozzle.

This can be achieved by providing a unique nozzle with internal components which makes the nozzle useful as an air assisted nozzle according to the first aspect of the invention, but which can be easily removed from the nozzle housing to enable the nozzle to be used as a hydraulic nozzle. according to the second aspect of the invention.

A set of equipment may be provided comprising a relatively simple and inexpensive nozzle housing and interior components adapted to be interchangeable with the housing to enable the same housing to be used either as part of an air assisted nozzle according to the first aspect of the invention or as part of a hydraulic nozzle according to the second aspect 35 of the invention.

The design of the insert, when used 4 in the nozzle housing, causes turbulent mixing of compressed air and liquid to produce good atomization of the liquid before the liquid is discharged from the nozzle.

The invention will now be described in more detail with reference to the drawing, in which: FIG. 1 shows a fractional view from the end and partly in cross section of a new and improved spray nozzle, including the unique features of the present invention, the reproduction being taken substantially along line 1-1-1 of FIG. 2, FIG. 2 is a fragmentary view taken substantially along line 2-2 of FIG. 1, FIG. 3 is a fragmentary view taken substantially along line 3-3 of FIG. 2 and showing certain parts of the nozzle in moving positions; FIG. 4 is a fragmentary view taken substantially along line 4-4 of FIG. 2, FIG. 5 is a perspective view of certain parts of the nozzle in separate condition; FIG. 6 is a perspective view and separated with the parts of a modified version of one of the nozzle parts; and FIG. 7 is a view similar to FIG. 2 but showing the nozzle converted from an air-assisted nozzle to a hydraulic nozzle.

In order to illustrate the invention, it is shown in the drawing as a spray nozzle 10 which is adapted for use in spraying liquid and in particular for spraying liquid fertilizer or insecticide on an agricultural field. Used for agricultural purposes, several 30 nozzles are attached to and spaced apart along an elongated hollow boom not shown, which also serves as a pipe branch for delivering high pressure liquid to the nozzles. Reference is made to U.S. Pat.

No. 4,527,745 for an explanation of how a 35 nozzle of the same general type as the present nozzle can be attached to a boom or tube and receive 5 pressurized fluid therefrom.

The nozzle 10 includes an elongated hollow housing 11 molded of plastic and with opposed end beads 12 and 13 which are provided with an external thread. An internal threaded branch 14 is integrally formed with and protrudes from one side of the housing and receives a threaded tube 15 which communicates with the boom to receive pressure fluid therefrom. The lower end of the branch 14 defines a circular inlet connection 16 (Fig. 2) through which 10 liquid is introduced into the nozzle housing 11.

As is most clearly shown in FIG. 2, an outflow nozzle tip 20 is located adjacent the end of the bead 12 on the housing 11. To mount the tip, the latter is formed with a radially extending circumferential flange 15 21 which is clamped to the end of the bead 12 by a fixed tension nut or cap 22 which is designed to be screwed onto the bead. An annular gasket 23 is inserted between the tip 21, the cap 22 and the end of the bead 12 to seal the circumference of the tip.

20 An axially extending outflow nozzle 25 is formed through the nozzle tip 20. One integrally formed with the nozzle tip is a deflection flange 26 (Fig. 2) disposed across the line of movement of the fluid flowing through the outflow nozzle 25. This fluid strikes the flange of the nozzle 25. 26 and is broken down and atomized into particles of relatively small size. In addition, the deflection flange aligns the particles in a well-defined flat fan spray pattern across the axis of the nozzle housing 11. The construction, function and benefits of the nozzle tip 20 and deflection flange 26 are described in more detail in the aforementioned GB patent specification No. 2 157 591.

Liquid supplied to the nozzle housing 11 via the inlet connection 16 is formed into a longitudinal flow of a cylindrical tube 30 (Fig. 2). The tube is coaxial with and spaced inwardly from the wall of the housing, and its downstream end is threadedly connected to the housing at 31. As mentioned in U.S. Patent No. 4,660,598, the tube interacts with an elastically flexible membrane 32 to form a anti-drip valve which prevents liquid from dripping from the nozzle tip 20 after the supply of pressure fluid to the supply tube 15 has been interrupted. For this purpose, the diaphragm is positioned adjacent the upstream end of the tube 30 and its circumferential edge is clamped between the end of the bead 13 and a cap 33 screwed onto the bead. A valve follower 34 is supported slidably within the cap and is functionally connected to the diaphragm. Telescopically disposed in the cap is a wound compression spring 35 which pushes the diaphragm towards a closed position against the upstream end of tube 30 as shown in FIG. 2. When pressurized liquid is delivered to the nozzle housing 11 via the inlet pipe 15, the pressurized liquid 15 presses the membrane 32 away from the upstream end of the pipe as shown in FIG. 3, to allow the liquid to flow through the tube and be ejected from the nozzle tip 20. After interrupting the liquid at the pressure source, the spring 35 forces the sealing system diaphragm 32 to the upstream end 20 of the tube 30 to substantially prevent fluid in dripping out from the tip of the mouthpiece.

As described, the nozzle 10 is in principle suitable for use as a hydraulic or non-assisted nozzle in the same general manner as the nozzle disclosed in the above-mentioned patent. In a clean hydraulic nozzle (i.e., a non-assisted nozzle), the pressurized liquid is dispensed through the nozzle at a relatively high flow rate and is broken up into relatively large particles after being ejected from the nozzle 20. Hydraulic nozzles are generally preferred for use under conditions. where one wishes to spray a field with relatively large amounts of a liquid chemical solution with a large percentage of water.

For other agricultural applications, air assisted nozzles are preferred over purely hydraulic nozzles. In general, an air-assisted nozzle is a nozzle in which the liquid flows through the nozzle at a relatively low flow rate and in which a stream of compressed air is blown into the nozzle for the purpose of temporarily breaking or spraying the liquid before the liquid is sprayed. from the nozzle tip. Air-assisted nozzles are generally used in situations where a relatively small amount of a more highly concentrated chemical solution must be sprayed on a field of a given area.

According to the present invention, the nozzle 10 10 is provided with a unique insert member 40 (Figures 2 and 5) which can be placed in the nozzle to enable the nozzle to operate in an air assisted manner and which can be easily removed from the nozzle to converting the nozzle to use in a hydraulic manner. As will become clear, insert 40 allows the nozzle 10 to be easily changed from the air assisted to hydraulic or vice versa, without the need to maintain a supply of each type of nozzle and without the need to remove one of the nozzles. type of nozzle from the boom and install the other type of nozzle on the boom 20 each time a conversion is made.

More specifically, the insert 40 includes a tubular nozzle member 41 (Figs. 2 and 5) made of brass or similar material. The nozzle element is cylindrical and is telescopically disposed at the downstream end of tube 30 with a tight but sliding fit. An O-ring 42 (Fig. 2) fits into a groove 43 (Fig. 5) around the outer circumference of the nozzle member 41 and is compressed against the inner wall of the tube 30 to establish a seal between the nozzle member and the tube.

Formed through the downstream end portion of the nozzle element 41, there is a flow limiting nozzle 45 which serves to reduce the flow cross-section of fluid flowing from the tube 30 toward the nozzle tip 20. In this particular case, the nozzle includes a cone-shaped upper stream portion. , whose small diameter end joins a cylindrical downstream portion.

Dirt and other foreign particles are filtered from the liquid before the liquid flows through the nozzle 45. For this purpose, a tubular screen-like filter screen 46 extends from the upper end of the nozzle member 41 and is spaced radially inward from the wall of the tube 30 so that fluid entering the tube must pass radially through the filter screen before flowing to the nozzle 45. One end of the filter screen 46 abuts the upstream end of the nozzle member 41 while the other end of the filter screen abuts and is closed. of a head 47 (Fig. 5) on a pin 48. The latter is telescopically displaceable both in the filter screen and the upstream end of the nozzle element. In the embodiment shown in FIG. 1-5, the pin is of cruciform cross-section and is formed with four angularly spaced fins 49 (Fig. 5) defining flow passages which allow liquid to flow through the filter screen and into the nozzle element. When the insert 40 is removed from the nozzle housing 11, the pin 48 can be pulled out of the nozzle member 41, and then the filter screen 46 can be pulled off the pin to allow cleaning or replacement of the filter screen.

A modified pin 48 for supporting filter 46 is shown in FIG. 6. In this case, the pin is hollow and generally cylindrical and is formed with four angularly spaced and longitudinally extending slots 49 'which allow fluid to flow into the pin and then to the nozzle member 41. Two axially spaced rings 50 extend 25 in the circumferential direction. around the pin 48 and keeps the filter screen in radially outwardly spaced relation to the body of the pin.

In carrying out the invention, the insert 40 includes an elongate impact member 55 (Fig. 5) for breaking the flow of fluid flowing through the nozzle 45 and for causing the fluid to mix with a compressed air stream which is also broken by the impact element. Herein, the abutment member 55 is in the form of an elongated and flat bar formed integrally with the downstream end of the nozzle element 41, the bar being of rectangular cross section. The rod 55 extends longitudinally into an axially elongate mixing chamber 56 of circular cross-section bounded within the nozzle housing 9 11. As shown in FIG. 2 and 3, the rectangular bar 55 is spaced inward from the circular wall of the chamber along the entire perimeter of the bar.

A transverse circular hole 60 is formed 5 through the rod 55 immediately downstream of the nozzle 45. The hole 60 communicates with the nozzle 45 and, when pressurized fluid exits from the nozzle, it strikes the downstream wall of the hole. The downstream wall thus forms an abutment surface which, by bending, is the liquid in the transverse direction to break the liquid and cause the liquid to flow through the chamber 56 along the sides of the rod 55.

As the liquid flows through the chamber 56, it is temporarily interrupted by a compressed air stream which is fed to the chamber 56 through a circular air inlet connection 62 (Fig. 3) 15 formed in the nozzle housing 11 and extending across the chamber and the flow of liquid flowing through the chamber. . The supply connection 62 is located at the inner end of a nipple 63 (Figs. 1 and 3) connected to the nozzle housing 11 and connected to a flexible hose 64 which 20 communicates with a supply of compressed air by means of a shut-off valve 65 When the valve is opened, a stream of compressed air is injected transversely into the chamber 56.

As shown in FIG. 2 and 3, the axis of the air inlet connection 62 extends parallel to the axis of the hole 60 in the rod 55, but the connection 62 is smaller in diameter than the hole 60 and its axis is offset in a downstream direction of the axis of the hole. As a result, only approx. half of the area of the air inlet connection 62 outside of the hole 60, while the downstream half of the air inlet connection 30 is located opposite a side surface area 66 (Fig. 4) of the rod 55. Because of this arrangement, the surface 66 forms an abutment surface which deflects and breaking the airflow. Substantial turbulence is created to atomize the fluid flow by breaking the airflow by the impact surface 66, by breaking the fluid flow by the wall in the hole 60 and, as a result, the air flow being blown transversely into it. longitudinal flowing fluid flow. Thus, the liquid flows against the nozzle tip 20 in the form of finely divided particles.

The insert 40 is completed by two radially spaced legs 70 5 (Fig. 5) formed integrally with and extending axially from the rod 55 and with the downstream ends connected to a cylindrical bushing 71. An outwardly radially extending outlet is provided. flange 72 which is adapted to be secured with the cap 22 between the sealing gasket 23 and an inner shoulder at the downstream end portion of the nozzle housing 11. An axially extending locking pin 73 (Fig. 5) fits on the upstream side of the flange 72 locking note in the nozzle housing 11 for orienting the insert 40 angularly in the housing such that the axis of the hole 60 extends parallel to the axis of the air inlet connection 62.

When the insert 40 is in place in the nozzle housing 11, the flow cross-section is reduced by the fluid flow of the nozzle 45, and in addition, the flow is temporarily atomized by the co-operation 20 of the wall in the hole 60, the impact surface 66 of the rod 55, and the transverse flow relationship between the fluid flow and the air flow. The insert 40 can be removed from the housing 11 by simply unscrewing the cap 22 and removing the cap, the nozzle tip 20 and the sealing gasket 23 from the housing as a unit. Thereafter, the insert with the fastened pin 48 and the filter screen 46 can be pulled axially out of the downstream end of the housing 11.

When the insert 40 is out of the housing 11, the nozzle 10 can be converted for use in a hydraulic manner by simply inserting a tubular filter screen 80 into the chamber 56 as shown in FIG. 7. The filter screen 80 is telescopically disposed over a pin 81 which may be similar to the pins 48 or 48 'and formed with a radially extending flange 83 at the downstream end of the screen. The flange 83 is arranged to be able to clamp 35 against the inner shoulder of the housing 11 with the seal 23 as the cap 22 and the nozzle tip 20 are screwed 11 back on the housing. To facilitate faster application and removal. The cap 22 may also be of a similar size to the filter screen disclosed in this patent. The cap 22 may also be of the rapidly separable bayonet type as disclosed in U.S. Patent No. 4,527,745.

When the nozzle is constructed as shown in FIG. 7 for use in the hydraulic manner, the air nipple 63 is closed to prevent fluid from escaping through the nipple. This can be accomplished either by closing the valve 65, by clamping the hose 64 closed with a hose clamp, or by removing the hose from the nipple 63 and inserting a plug into the nipple.

It will be clear from the foregoing that the present invention contributes to the state of the art with a new and improved nozzle 10 which can be quickly and easily transformed from an air-assisted, relatively low flow mode, to a non-assisted operation with a relatively large flow rate. When built into the air assisted mode of operation, the nozzle causes a very good preliminary atomization of the liquid 20 as a result of the mutual action of the insert 40 with the air and liquid flows.

Claims (11)

12 Patent claims. A spray nozzle which can be converted from an air-assisted nozzle to a non-air assisted nozzle, comprising an elongated, hollow 5 nozzle housing (11) with a first and second ends (12,13), a chamber (56) bounded in the housing (11), means (63) in the housing forming an air inlet connection (62) through which a compressed air stream can be blown into the chamber (56), means (14) in the housing forming a liquid inlet connection (16) for introducing liquid into the housing, means in the housing for causing the liquid to flow through the chamber in a stream which mixes with the compressed air stream which is blown into the chamber through the air inlet connection (62) in such a way that the liquid is temporarily atomized in the chamber (56) and a nozzle element (40) removably inserted into the housing (11) at a distance from the fluid access connection (16), characterized in that the nozzle element (40) defines a nozzle (45) for limiting the flow cross-section of the flow of liquid after a stream enters the liquid inlet connection (16) and before this stream is temporarily atomized in the chamber (56) of the air stream, means defining an outlet nozzle (25) adjacent the first end (12) of the housing (11) and in communicating with the chamber (56), which outflow nozzle (25) receives provisional atomized liquid from the chamber (56) and 25 causes injection of said liquid from the nozzle, and means (22) on the housing (11) and selectively removable therefrom to allow the nozzle element (40) is withdrawn from the housing (11) so that the fluid flow is allowed to flow through the chamber (56) without limiting the flow cross-section of the fluid flow 30 before this flow reaches the flow nozzle (25). Spray nozzle according to claim 1, characterized in that the chamber (56) is elongated and the air flow is blown transversely into the chamber (56), the liquid flow flowing longitudinally in the chamber, and means (55) in the chamber 35 for deflecting air. and the fluid flow to promote mixing thereof and to promote preliminary atomization of the liquid, 13 which deflection means (55) are connected to the nozzle element (40) and are removable from the housing (11) as a unit with the nozzle element (40). Spray nozzle according to claim 2, characterized in that the deflection means comprise a rod (55) extending longitudinally of the chamber (56) and separated in the transverse direction inwardly from the walls of said rod (55). one piece with the nozzle element (40) and a hole (60) formed through and extending transversely to the rod (55) 10 and disposed immediately downstream of and in contact with the nozzle (45) in the nozzle element (40) in such a manner; fluid flowing through this nozzle (45) hits it downstream wall of the hole (60) and deflects in the transverse direction to flow along the sides of the rod (55). Spray nozzle according to claim 3, characterized in that the axis of the hole (60) extends parallel to and spaced upstream of the axis of the air inlet connection (62), the air inlet connection (62) only partially extending over the hole (60) on such in that a portion of the air flow blown through the air inlet connection (62) strikes against the rod (55) while another portion of the air flow passes through the hole (60). Spray nozzle according to claim 2, characterized in that the nozzle element (40) is tubular, that a pin 25 (48) is telescopically arranged in the upstream end portion of the nozzle element (40) and a tubular filter screen (46) is telescopically disposed over the pin (48), said pin (48) including means (49) which allow liquid to flow through the filter screen (46) and into the nozzle element (40). Spray nozzle according to claim 2, characterized in that it further includes a sleeve (71) on the downstream end of the deflection means (55) and in connection with the chamber (56) and a radially extending flange (72) on the downstream end of the said sleeve (71), and said selectively removable means comprises a cap (22) on said first end (12) of said housing (11) which may act to clamp said flange (72) against said first end (12) ) by the House. Spray nozzle according to claim 6, characterized in that the outlet nozzle (25) is supported by this cap (22). A liquid spray nozzle comprising a hollow nozzle housing (11) defining a chamber (56), means (63) in the housing (11) forming an air inlet connection (62) through which a compressed air stream can be conducted into the chamber ( 56), selectively activatable means for passing compressed air 10 through the air inlet connection (62), means in the housing forming a liquid inlet connection (16) for introducing a liquid flow into the housing (11), means for passing pressurized liquid through the liquid inlet connection ( 16) and an insert element (40) removably mountable in the housing (11), characterized in that the insert element (40) is formed with an internal fluid flow passage through which liquid introduced into the housing (11) passes and an abutment surface. (55) in line with the direction of passage of the liquid through the liquid duct and against which the liquid strikes with a view to deflecting the liquid and mixing it with a compressed air stream introduced into the housing chamber (56) from the air inlet connection. one (62) after activating the compressed air guide means in such a way that the liquid is temporarily atomized in the chamber (56) and a spray tip (20) defining a discharge nozzle (25) in connection with the chamber (56) to receive provisionally atomized liquid from the chamber (56) and caused to spray this liquid from the mouthpiece in a predetermined pattern of liquid droplets. Liquid spray nozzle according to claim 8, characterized in that the flow channel of the insert element defines a nozzle (45) for limiting the flow of the liquid stream before it strikes the abutment surface (55). Liquid spray nozzle according to claim 8, characterized in that the air inlet connection (62) conducts a compressed air flow into the chamber in a direction transverse to the direction of liquid passing through the channel of the insert element 15, that the air inlet connection (62) conducts compressed air into the chamber ( 56) such that at least a portion thereof passes across the impact surface (55) and the impact surface (55) of the insert member is oriented such that it is substantially perpendicular to the fluid flow direction through the flow channel of the insert element. Liquid spray nozzle according to claim 1, characterized in that it includes means on the housing and selectively removable therefrom to permit removal 10 of the insert element (40) from the housing (11), so that after deactivation of the compressed air guide means a liquid flow which is introduced into the housing (11) from the fluid inlet connection (16), through the chamber (11) without engaging with an abutment surface (55) and without substantial preliminary atomization and delivered 15 directly by the spray tip (20) into a predetermined spray pattern of liquid droplets.