Flow-reducing Device Particularly Useful For Trickle Irrigation

Abstract

A flow-reducing device is described particularly useful for trickle irrigation. The device includes a flow-retarding member formed with a plurality of holes extending therethrough from one face to the opposite face. The member is further formed on both faces with a plurality of recesses, each recess bridging a pair of holes. The recesses on one face overlap those on the opposite face, such that the pair of holes bridged by a recess on one face lead to separate recesses on the opposite face. The water is thus caused to flow through the holes and recesses in succession, passing back and forth from one to the other face of the member and finally exiting in a slow trickle.

Description

BACKGROUND OF THE INVENTION

The present invention relates to flow-reducing devices, and particularly to such devices useful for trickle irrigation.

Trickle irrigation is increasingly gaining wide-spread use as a means for supplying water, and sometimes fertilizer and other soil additives, to field crops and orchards.. In some known devices, the trickle flow of the water is effected by small openings, but these devices have the disadvantage that they easily clog. In other devices, a long-circuitous path, sometimes called a labyrinth or maze, is provided for the water so that it eventually discharges in the form of a slow trickle. The known devices of this type, however, are generally large, expensive, and/or difficult to clean and maintain because of the long circuitous path that must be provided.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide a novel flow-reducing device, particularly for trickle irrigation, the type including a long circuitous path for the water, which device can be built of small size and low cost when compared to the known trickle devices.

Briefly, the novel device includes a flow-retarding member disposed within a housing and formed with a large number of holes extending completely through the member from one face to the opposite face, and hole-bridging means providing flow paths between the holes at both faces to direct the fluid entering through the inlet hole to flow through the holes in succession, passing back and forth from one to the opposite face of the member, before exiting from the housing.

Conceivably, the hole-bridging means would be recesses formed in the housing walls (or other members disposed within the housing) which contact the two faces of the flow-retarding member. Preferably, however, and in accordance with another feature of the invention, the hole bridging means comprises a plurality of recesses formed on both faces of the flow-retarding member, each recess bridging a pair of holes, the pair of holes bridged on one face by one recess leading to separate recesses on the opposite face. The walls in contact with both faces of the member thus direct the fluid to flow through these recesses when passing from one hole to the next.

Such a construction produces a very large flow path in a very small space. Moreover, the flow path produced has many sharp turns, wall discontinuities, and alternations of narrow cross-sections (the holes) with large cross-sections (the recesses). The velocity of the fluid thus changes frequently and abruptly, the fluid moving faster through the holes and slower through the recesses. The fluid is thus subjected, in a relatively small space, to considerable friction, eddying swirling, and turbulence, which thus reduces its pressure until it exits at a very slow rate.

Another advantage of such a construction is that it can be produced in volume at low cost.

The flow-retarding member may take many different forms, some of which are described below. In general, it is relatively thin, having a thickness which is a small fraction of its length.

According to a further feature of the invention, the flow retarding member may be in the form of an insert which is removably applied through one end of the housing. Such an arrangement simplifies the manufacutre of the device, and particularly simplifies its maintenance and repair, since the insert may be conveniently removed, inspected, cleaned and replaced in the field.

Further features and advantages of the invention will be apparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described herein, by way of example only, with reference to the accompanying drawings, wherein:

FIG. 1 is a longitudinal sectional view of one form of trickle irrigation device constructed in accordance with the invention, FIGS. 1a and 1b illustrating the two faces of the flow-retarding member used in the device;

FIG. 2 is a longitudinal sectional view of another trickle device constructed in accordance with the invention, FIG. 2a illustrating a modification thereof;

FIG. 3 is a view, partly in transverse section, illustrating a further trickle device constructed in accordance with the invention, FIG. 3a being an enlarged fragmentary view thereof, and FIG. 3b illustrating one face of the flow-retarding member used therein;

FIG. 4 is a transverse sectional view of a further trickle device constructed in accordance with the invention, FIG. 4a illustrating the flow-retarding member used therein, and FIG. 4b being a partial sectional view along lines B--B of FIG. 4a;

FIG. 5 is a view, partly in transverse section, illustrating a still further trickle device constructed in accordance with the invention, FIG. 5a being a sectional view along lines A--A of FIG. 5, and FIG. 5b illustrating the flow-retarding member used in the device of FIG. 5;

FIG. 6 is a longitudinal sectional view of a further trickle device constructed in accordance with the invention, FIG. 6a being a sectional view along lines A--A of FIG. 6, and 6b illustrating the flow-retarding member used in the device of FIG. 6; and

FIG. 7 is an end elevational view illustrating a still further trickle irrigation device constructed in accordance with the invention, FIG. 7a being a sectional view along lines A--A of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The trickle irrigation device or nozzle illustrated in FIG. 1, 1a, 1b of the drawings is embodied in an in-line coupling, for coupling two water supply pipes (not shown). The device comprises a housing, generally designated 2, including two sections 4,6 each formed with ribbed sleeve 8,10, for receiving the respective ends of the water supply pipes. The two sections 4,6 are joined together by threads as shown at 10, and each includes an annular wall 12,14 of disc-shape. A radial opening 16 is formed in section 6, this opening leading into the space between the two walls 12,14, and serving as an inlet thereto for the water passing through the water supply pipes.

A disc-shaped flow-retarding member 20 is disposed in the space between the two walls 12,14 of the housing. Member 20 is formed with a large number of holes 22 extending therethrough from one face 24 (FIG. 1b) to the opposite face 26 (FIG. 1a) thereof. Each face is also formed with a plurality of channels or recesses 28 each bridging a pair of holes 22. The recesses on one face (e.g., 24) overlap those on the other face (e.g., 26) such that the pair of holes bridged by a recess on one face lead to separate recesses on the opposite face.

One hole 22' in member 20 communicates with inlet opening 16 of the housing via a recess 28', this hole being called the inlet hole; and another hole 22" serves as the outlet hole of the device, this hole leading to the outside via recess 28 ".

In the assembled device, both faces 24, 26 of the flow-retarding member 20 are firmly pressed against the flat faces of housing walls 12,14 whereupon the recesses 20 provide flow-paths between the holes 22 at both faces of the member. The water entering the inlet hole 22' is thus directed by the recesses to flow through the holes 22 successively to pass back and forth from one to the opposite face of the member, and then to exit through outlet hole 22" and its recess 28".

Many arrangements may be used for the holes 22 and recesses 28. In FIGS. 1a and 1b, the holes 22 are formed on concentric circles 30, as also are the recesses 28, but the latter further include radially extending recesses 29 to bridge the holes of adjacent concentric circles.

It will thus be seen that the flow-retarding member 20, and the faces of the walls 12,14 in contact therewith, force the water to flow through a very long circuitous path back and forth from one face of the member to the other until it exits through outlet opening 22". It will also be seen that this flow path has many sharp turns. Further, the cross-sectional area of this path frequently and abruptly changes, relatively small cross-sectional areas (the holes 22) alternating with relatively large cross-sectional areas (the recesses 28). This produces frequent and abrupt changes in the velocity of the flowing water, and also discontinuities in the wall bounding the flow path. All these factors increase the friction, eddying, swirling and turbulence of the water as it moves through this path such that a very reduced flow or trickle is produced at the outlet end.

Moreover, this slow trickle is produced by the use of a relatively small device which can be inexpensively manufactured, and by the use of relatively large holes which have less tendency to clog. As one example, trickle irrigation nozzles can be produced according to the designs of FIGS. 1, 1a and 1b having a flow-rate as low as 2 liters per hour using opening (22) as large as 1.5 mm, and even larger.

The flow-rate can be even further reduced or even larger openings can be used, by providing a plurality of flow-retarding members producing a series path for the water from one member to the next.

Such a trickle device is illustrated in FIG. 2, wherein two flow-retarding members, 120a, 120b are interposed between the flat walls 112,114 of the nozzle housing 102. Each member 120a, 120b is of the same construction as the flow-retarding member 20 of FIG. 1, except the outlet hole (22", FIG. 1) of the member communicates, via an opening 130 in a separator member 132, with the inlet hole of the second flow-retarding member 120b. Thus the water flowing through inlet 116 of the trickle device passes successively through the holes (22, in FIG. 1) in flow-retarding member 120a, back and forth from one to the opposite face of the member, then through opening 130 of separator 132, and then successively through the holes of the second flow-retarding member 120b, finally exiting through outlet 134.

The trickle device illustrated in FIG. 2a is the same as that of FIG. 2, except that one of the walls, 114, of the housing is provided with a shroud 136, which together with the other wall 112 of the housing, completely encloses the flow-retarding members 120a, 120b and the separator member 130.

FIGS. 3, 3a and 3b illustrate a trickle device having a large number of flow-retarding members, each being in the form of a flat ring 220a, 220b, etc. (FIG. 3a), each pair of rings being separated by a separator ring 230. Thus, each flow-retarding ring 220 (see FIG. 3b) includes the plurality of holes 222 and bridging recesses 228, but in this case there is only one (or a few) circular arrays of such openings and recesses. In addition, as in the case of separator member 130 in FIG. 2, each separator ring 230 in the embodiment of FIG. 3 includes an opening 232 (FIG. 3a) providing communication between the outlet hole of one ring 220 and the inlet hole of the next ring 220.

The water thus flows back and forth from one face to the opposite face of each ring 220, and then through opening 232 of the separator 230, to the next flow-retarding ring, until it traverses all the rings, and exits in the form of a slow trickle.

The flow-retarding member is illustrated in the above-described trickle devices as being in the shape of a relatively thin flat plate or disc having a thickness which is a small fraction of both the length and width (i.e., the diameter, in the case of the illustrated annular discs or rings) of the member. The member however, may take other shapes.

FIGS. 4, 4a and 4b illustrate a trickle device wherein the flow-retarding member is in the form of a strip 320 (i.e., its thickness is a small fraction of its length) which is helically wound within the housing. In this case the housing includes two sleeves, namely an outer sleeve 312 and an inner sleeve 314, the latter being formed with a helically-winding, upstanding wall 330. The flow-retarding strip 320, e.g., of flexible plastic material, is formed with the through-going holes 322, and with the bridging recesses 328 on its opposite faces. The strip is wound onto the inner sleever 314 between and against the helical wall 330, and then the outer sleeve 312 is placed thereover.

It will be seen that the water entering the device through inlet 316 will flow back and forth from one to the opposite face of strip 320 while it progresses helically along the length of the device until it exits from outlet 334.

FIGS. 5, 5a and 5b illustrate a still further variation. Here, the flow-retarding member (shown as 420 in FIG. 5b) is of flat flexible material, such as plastic. It is formed with the through-going holes 422 and the bridging recesses 428 on both faces, as described earlier. In addition, it is formed with a central aperture 424 which communicates with the inlet hole 422'. The holes and recesses are arranged spirally around the central aperture 424, the outlet hole 422" being formed in a corner (the upper right corner in FIG. 5b) of the member.

FIG. 5 illustrates the trickle device applied as a tap to a water supply pipe, rather than as an in-line coupling between a pair of water supply pipes as in the previously described embodiments. In this case, a hole is formed in the wall of the water supply pipe 430, and an inlet stem 432 is inserted through the hole and through the center aperture 424 of the flow-retarding member 420. The latter is wrapped around the pipe 430 and is retained in place by a sleeve 412, constituting a portion of the housing. A further sleeve 413 is inserted through the open end of sleeve 412, between the latter and the flow-retarding member 420, and the open end is closed by a collar 414 threaded onto sleeve 412. Sleeve 413 is conical, and collar 414 abuts against the end of it, forcing same to press tightly against the flow-retarding member 420.

It will be seen that the inlet to the trickle device of FIG. 5 is through stem 432, the water flowing through inlet hole 422' of the member, and then successively through the other holes 422, back and forth from one to the other side of the member, and finally exits through outlet hole 422" and the housing outlet 434.

FIGS. 6, 6a, and 6b illustrate a trickle device in which the flow-retarding member is in the form of an insert which can be readily inserted and removed from the housing. The insert, identified as 520 and shown per se in FIG. 6b, is in the form of a strip of flat material, preferably plastic of rectangular section. The holes 522 and the recesses 528 are formed in zig-zag fashion beginning with the lower end and proceeding to the upper end. Thus, the inlet hole 522' is at a lower (right) corner of the strip, and the outlet hole 522" is at an upper (left) corner.

FIGS. 6 and 6a illustrate the flow-retarding member 520 of FIG. 6b used in an in-line coupling between a pair of water supply pipes. The coupling includes a sleeve 512 adapted to receive a water supply pipe at each end, and an outer sleeve 514 of rectangular section joined to sleeve 512 along one side thereof. Outer sleeve 514, and the portion of sleeve 512 to which it is joined, together form an axially-extending compartment 518 closed at one end 519 and opened at its opposite end. The compartment is of similar rectangular section as the flow retarding member 520, and the latter is disposed within the compartment with the inlet hole 522' of the member communicating with inlet opening 516 in sleeve 512.

It will be seen that the water entering inlet opening 516 will travel through the holes and recesses of the flow-retarding member 520, back and forth from one face to the other, until it exits through outlet hole 522" and housing outlet 534, as described earlier with respect to the other embodiments.

The embodiment of FIGS. 6, 6a and 6b has the further advantage that the flow-retarding member 520 can be easily inserted and removed through the open end (left) of the compartment 518, for purposes of inspection, cleaning, and replacement in the field. Also, if a different flow-rate is desired, this can easily be accomplished by merely substituting the insert designed for the desired flow rate.

FIGS. 7 and 7a illustrate another embodiment of the invention, wherein the trickle device is in the form of a tap which may be clamped onto a water supply pipe to tap the water from an opening formed in a wall of the pipe.

In this case, the housing of the trickle device also includes spaced inner and outer axially-extending walls 612, 614 defining an axially-extending compartment 618 therebetween for receiving the flow-retarding member 620. Here, however, the walls are curved to form a curved compartment and terminates in extensions 615 enabling the housing to be clamped onto the water supply pipe 630. Further, the housing contains a stem 632 formed with a bore 634 to provide communication with the flow-retarding member 620 within compartement 618. The flow-retarding member 620 is preferably also of flat flexible plastic material of rectangular section, for example as members 420 and 520 in the embodiments of FIGS. 5 and 6. This member also includes the through-going holes and recesses on both faces to cause the water to flow through the holes successively and to pass from one face to the other, beginning with the inlet hole communicating with stem 632.

To facilitate clamping the housing, constituting by sleeves 612 and sleeve 614, onto the water supply pipe 630, the housing is made of flexible material preferably plastic. The flow-retarding member 620 inserted within compartment 618 is tightly press-fitted into the compartment. To remove this member, it is only necessary a to flex the two ends 615 of the housing which releases the insert and permits its removal. Thus, the compartment may be open at both ends since the insert is firmly retained therein.

Many other variations, modifications and applications of the illustrated embodiments will be apparent.

Claims

What is claimed is:

1. A flow-reducing device particularly for trickle irrigation, comprising, a housing, a flow-retarding member disposed therein, said member being formed with a large number of holes extending therethrough from one face to the opposite face thereof, said housing including an inlet communicating with one of said holes, constituting the inlet hole of the member, and hole-bridging means providing flow paths between the holes at both faces of said member to direct the fluid entering through the inlet hole to flow through said holes in succession, passing back and forth from the one to the opposite face of the member, and then to exit through an outlet hole in the member.

2. A device according to claim 1, wherein said hole-bridging means comprises a plurality of recesses formed on both faces of the flow-retarding member, each recess bridging a pair of the holes, the pair of holes bridged on one face by one recess leading to separate recesses on the opposite face, and walls in contact with both said faces of the flow-retarding member to direct the fluid to flow through said recesses.

3. A device according to claim 2, wherein said flow-retarding member is relatively thin having a thickness which is a small fraction of its length.

4. A device according to claim 2, wherein there are a plurality of said flow-retarding members, and a separator member between each pair, said separator member being formed with a hole providing communication between the outlet hole of one of the respective pair of flow-retarding members and the inlet hole of the other flow-retarding member of the pair.

5. A device according to claim 4, wherein each of said flow-retarding and separator members is in the form of an annular disc.

6. A device according to claim 1, wherein said housing includes an inner sleeve, and an outer sleeve, and said flow-retarding member is in the form of a strip helically wound around the inner sleeve and enclosed by the outer sleeve.

7. A device according to claim 1, wherein said flow-retarding member is in the form of a removable insert, and said housing defines a compartment for said insert, said compartment being open at least at one end to permit removal and insertion of the flow-retarding member insert.

8. A device according to claim 7, wherein said compartment is curved, and said flow-retarding member insert is of flat flexible material flexed to assume the curvature of the compartment.

9. A device according to claim 7, for applying to a fluid supply pipe having an opening in a wall thereof, wherein said housing includes curved flexible inner and outer walls defining said compartment and clampable onto the supply pipe, and an inlet stem carried by said inner wall for passing through the pipe wall opening, the flow-retarding member insert being disposed in the compartment between the outer and inner housing walls and being removable from the open end thereof, said inlet stem including a passageway communicating with the inlet opening of the flow-retarding member insert.

10. A trickle device including an inlet and an outlet for application to a water supply pipe to provide a slow water trickle therefrom, said device comprising: a housing having an outer wall and a spaced inner wall; mean carried by said inner wall for attaching the housing to a water supply pipe to extend laterally of and parallel to the axis of the water supply pipe when applied thereto; said outer and inner walls defining an axially extending compartment of rectangular section and open at at least one end; the inner wall of the compartment including said inlet, the latter communicating with the water flowing through the water supply pipe; and a flow-retarding insert in said compartment and removable from said open end thereof, said insert being of rectangular section and formed with a circuitous path for the water to travel from said inlet to the outlet thereof.

11. A device according to claim 10, wherein said inner and outer walls are of flexible material enabling same to be clamped onto the water supply pipe and firmly holding the insert in the compartment; and wherein said inlet is in the form a stem adapted to pass through an opening in the water supply pipe when the device is clamped thereto.

12. A device according to claim 10, wherein said flow-retarding insert includes a member formed with a plurality of holes extending therethrough from one face to the opposite face thereof, said insert being further formed with a plurality of recesses on both faces thereof, each recess bridging a pair of the holes, the pair of holes bridged on one face by one recess leading to separate recesses on the opposite face.