CA2239153C - Drip irrigation hose and method of its manufacture - Google Patents
Drip irrigation hose and method of its manufacture Download PDFInfo
- Publication number
- CA2239153C CA2239153C CA002239153A CA2239153A CA2239153C CA 2239153 C CA2239153 C CA 2239153C CA 002239153 A CA002239153 A CA 002239153A CA 2239153 A CA2239153 A CA 2239153A CA 2239153 C CA2239153 C CA 2239153C
- Authority
- CA
- Canada
- Prior art keywords
- hose
- flow regulating
- outlets
- inlets
- passage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 230000002262 irrigation Effects 0.000 title claims abstract description 20
- 238000003973 irrigation Methods 0.000 title claims abstract description 20
- 238000000034 method Methods 0.000 title description 7
- 238000004519 manufacturing process Methods 0.000 title description 4
- 230000001105 regulatory effect Effects 0.000 claims abstract description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 3
- 239000002985 plastic film Substances 0.000 claims description 2
- 229920006255 plastic film Polymers 0.000 claims description 2
- 230000003252 repetitive effect Effects 0.000 claims 1
- WYTGDNHDOZPMIW-RCBQFDQVSA-N alstonine Natural products C1=CC2=C3C=CC=CC3=NC2=C2N1C[C@H]1[C@H](C)OC=C(C(=O)OC)[C@H]1C2 WYTGDNHDOZPMIW-RCBQFDQVSA-N 0.000 abstract description 2
- 230000001939 inductive effect Effects 0.000 abstract description 2
- 239000011324 bead Substances 0.000 description 5
- 238000000465 moulding Methods 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G25/00—Watering gardens, fields, sports grounds or the like
- A01G25/02—Watering arrangements located above the soil which make use of perforated pipe-lines or pipe-lines with dispensing fittings, e.g. for drip irrigation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
- Y02A40/22—Improving land use; Improving water use or availability; Controlling erosion
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Water Supply & Treatment (AREA)
- Environmental Sciences (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
Abstract
The serpentine, turbulence inducing path lengths (30) from the inlets (26) to the outlets (28) of the flow regulating passage (22) of a continuous emitter drip irrigation hose are arranged in back to back fashion relative to the outlets in the sense that the chevrons angle away from each of outlets, so there is parallel turbulent flow from two inlets to each outlet. The inlets are sufficiently large that they do not limit the flow rate through the outlets. This doubles the flow rate from each outlet without changing the dimensions of the flow regulating passage.
Description
DRIP IRRIGATION HOSE AND METHOD OF ITS MANUFACTURE
Field of the Invention This invention relates to the field of drip irrigation and, more particularly, to a turbulent, high flow drip irrigation hose and method for its manufacture.
Back4round of the Invention Drip irrigation hose can be classified as having either discrete emitters or continuous integral emitters.
An example of discrete emitters is shown in U.S. Patent No. 4,850,531. An example of continuous integral emitters is shown in U.S. Patent No. 4,247,051.
A design objective of drip irrigation hose is uniformity of the drip rate from each emitter. Since the water pressure in a drip irrigation system varies as a function of elevation of the field, it is customary to incorporate a pressure regulating mechanism into the emitters. Turbulent flow is less sensitive to pressure variation than laminar flow. Accordingly, it has become common practice for drip irrigation hose to employ a serpentine flow regulating passage as continuous integral emitters to promote turbulent flow. An example of such drip irrigation hose is disclosed in U.S. Patent No.
4,984,739, where a series of staggered, upstream angled chevrons or weirs form the serpentine passage.
In a typical drip irrigation hose with continuous integral turbulent flow emitters, the emitters comprise a flow regulating passage formed by ribs that also seal the overlapping margins of an elongated bent sheet of plastic film. The passage is divided by cross ribs to form flow regulating segments. The bent film forms an elongated water supply passage having a large diameter. An inlet is formed from the water supply passage to one end of each segment of the flow regulating passage. An outlet is formed from the other end of each segment of the flow regulating passage to the exterior of the hose. Between the inlet and outlet., each segment has staggered, upstream angled chevrons.
Complications can occur when the dimensions of this type of drip irrigation hose are changed to increase the flow rate. General.7_y, the flow rate can be increased by decreasing the length of the segments, increasing the height of the ribs, or increasing the separation between the ribs of the flow regulating passage. However, these measures tend to decrease the reliability and uniformity of the product and t:o cause the water to squirt out of the outlets because the line pressure is not fully dissipated by the flow regulating passage.
Summary of the Invention The present inventlOrl provides a drip irrigation hose made from a water impervious material comprising:
an elongated water supply passage having a cross section;
a longitudinal flow regulating passage having a cross section smaller than the cross section of the water supply passage, the flow regulating passage being disposed along the water supply passage;
a plurality of longitudinally spaced non flow limiting inlets from the water supply passage to the flow regulating passage; and a plurality of longitudinally spaced outlets from the flow regulating passage to the exterior of the hose, the outlets being offset from the inlets to provide two path lengths from each inlet to a respective outlet.
Brief Description of the Drawings The features of specific embodiments of the best mode contemplated of carrying out the invention are illustrated i.n the drawings, in which:
Fig. 1 is a top plan view of a drip irrigation hose incorporating the principles of the invention with the outer margin partially cut away;
Field of the Invention This invention relates to the field of drip irrigation and, more particularly, to a turbulent, high flow drip irrigation hose and method for its manufacture.
Back4round of the Invention Drip irrigation hose can be classified as having either discrete emitters or continuous integral emitters.
An example of discrete emitters is shown in U.S. Patent No. 4,850,531. An example of continuous integral emitters is shown in U.S. Patent No. 4,247,051.
A design objective of drip irrigation hose is uniformity of the drip rate from each emitter. Since the water pressure in a drip irrigation system varies as a function of elevation of the field, it is customary to incorporate a pressure regulating mechanism into the emitters. Turbulent flow is less sensitive to pressure variation than laminar flow. Accordingly, it has become common practice for drip irrigation hose to employ a serpentine flow regulating passage as continuous integral emitters to promote turbulent flow. An example of such drip irrigation hose is disclosed in U.S. Patent No.
4,984,739, where a series of staggered, upstream angled chevrons or weirs form the serpentine passage.
In a typical drip irrigation hose with continuous integral turbulent flow emitters, the emitters comprise a flow regulating passage formed by ribs that also seal the overlapping margins of an elongated bent sheet of plastic film. The passage is divided by cross ribs to form flow regulating segments. The bent film forms an elongated water supply passage having a large diameter. An inlet is formed from the water supply passage to one end of each segment of the flow regulating passage. An outlet is formed from the other end of each segment of the flow regulating passage to the exterior of the hose. Between the inlet and outlet., each segment has staggered, upstream angled chevrons.
Complications can occur when the dimensions of this type of drip irrigation hose are changed to increase the flow rate. General.7_y, the flow rate can be increased by decreasing the length of the segments, increasing the height of the ribs, or increasing the separation between the ribs of the flow regulating passage. However, these measures tend to decrease the reliability and uniformity of the product and t:o cause the water to squirt out of the outlets because the line pressure is not fully dissipated by the flow regulating passage.
Summary of the Invention The present inventlOrl provides a drip irrigation hose made from a water impervious material comprising:
an elongated water supply passage having a cross section;
a longitudinal flow regulating passage having a cross section smaller than the cross section of the water supply passage, the flow regulating passage being disposed along the water supply passage;
a plurality of longitudinally spaced non flow limiting inlets from the water supply passage to the flow regulating passage; and a plurality of longitudinally spaced outlets from the flow regulating passage to the exterior of the hose, the outlets being offset from the inlets to provide two path lengths from each inlet to a respective outlet.
Brief Description of the Drawings The features of specific embodiments of the best mode contemplated of carrying out the invention are illustrated i.n the drawings, in which:
Fig. 1 is a top plan view of a drip irrigation hose incorporating the principles of the invention with the outer margin partially cut away;
Fig. 2 is a sectional view taken through plane 2-2 in Fig. 1 illustrat;:ing two inlets to the flow regulating passage;
Fig. 3 is a sectional view taken through plane 3-3 in Fig. 1 illustrat::ing an outlet from the flow regulating passage;
Fig. 4 is a schematic block diagram of the method for manufacturing t:he drip irrigation hose shown in Fig.
l; and Fig. 5 is a perspective view of apparatus for performing the bead laying, rib forming, film folding, and regulating pas~~age forming steps of Fig. 4.
Detailed Description of the Specific Embodiment As illustrated in Figs. l, 2 and 3, a drip irrigation hose 10 is formed from a thin (e.g., 4 to 15 mil) film 12 of flexible water impervious plastic material bent alone its length - 2a -1 to form an overlapping longitudinal seam between opposing longitudinal margins, namely an inner margin 14 and an outer margin I6. Margins 14 and 16 are sealed together by a continuous repeating pattern of longitudinally eztending spaced apart ribs 18 and 20 made of the same or compatible plastic material as film 12. Ribs 18 and 20 and margins 14 and 16 define a flow regulating passage 22 as described in more detail in the referenced '05I and '739 patents. A water supply passage 24 is defined by the remainder of film I2. At spaced intervals, rib 18 has a series of interruptions and pillars that form inlets 26 to flow regulating passage 22. Midway between each pair of inlets 26, an outlet 28 is formed by one or more holes in outer margin 16. A series of staggered chevrons 30 are formed along the inner sides of ribs 18 and 20 between each of inlets 26 and outlets 28. In each case, the chevrons are angled toward inlets 26 to promote turbulent flow along the path length from each inlet 26 to outlet 28 of flow regulating passage 22. As illustrated in Fig. 1, inlets 26 have a substantially larger cross sectional area than outlets 28 and the flow regulating passages. As a result, inlets 26 are not flow limiting. Thus, the serpentine turbulence inducing path lengths are arranged in back to back fashion relative to the outlets in the sense that the chevrons angle away from each of outlets 28, so there is parallel flow throughout the length of hose 10 from two of inlets 26 to one of outlets 28. The pattern of ribs illustrated in FIG.
I is repeated continuously along the entire length of hose 10 between overlapping margins 14 and I6. As a result, outlets 28 are spaced from each other and offset from inlets 26, which are also spaced from each other. Since inlets 26 are not flow limiting, each of inlets 26 feeds two of outlets 28 and each of outlets 28 is fed by two of inlets 26.
As a result, the flow rate through each outlet 28 is doubled because it is fed by two inlets and two flow regulating passages.
In operation when hose 10 is pressurized irt the field, water flows through supply passage 24 to inlets 26, passes from inlets 26 through flow regulating passage 22 to outlets 28, and ezits from outlets 28 to the ezterior of hose I0. Two back to back path lengths are formed from adjacent pairs of inlets 26 to each outlet 28, thereby doubling the flow rate for the dimensions of the flow regulating passage, i.e., path length, rib height and rib spacing, vis-a-vis the drip irrigation hose disclosed in the '739 patent. It should be noted that cross ribs dividing the flow regulating passage into segments as disclosed in the '739 patent are not required in the practice of the invention. Such cross ribs could be provided, however, if desired at insets 26 (or outlets 28), effectively dividing each inlet 26 (or outlet 28) into two inlets (or outlets) , one for each adjacent segment of the flow regulating passage.
The method for making the described drip irrigation hose is illustrated in FIGS. 4 and 5. As represented in FIG. 4 by a block 40, outlets 28 are first formed in film 12, preferably in the manner disclosed in the '984 patent. Then, as represented by a block 42 inner margin 14 is folded. As represented by a block 44, one or more beads are laid on the outside surface of inner margin 14 by one or more extrusion nozzles. As represented by a block 46, a pattern W~ 97/19759 PCT/US95/15481 1 of ribs, i.e., ribs 18 and 20, is formed by a molding wheel. As represented by a block 48, outer margin 16 is next folded onto inner margin 14 with the formed ribs therebetween.
Finally, as represented by a block 50, flow regulating passage 22 is finished by passing inner margin 14, outer margin 16, and the ribs 18 and 20 through the nip of a form wheel and a backing wheel to set precisely the height of ribs 18 and 20. This method is described in more detail in the '984 patent.
FIG. 5 illustrates apparatus for performing the steps represented by blocks 44 to 50.
One or more extrusion nozzles 52 deposit one or more continuous longitudinal beads 54 on the outside surface of inner margin 14. Film 12 then passes through the nip of a rotating molding wheel 56 and a rotating backing wheel 58. Molding wheel 56 has a pattern of depressions 60 corresponding to the desired rib pattern on drip irrigation hose 10, i.e., the pattern shown in FIG. 1. In the nip of wheels 56 and S8, beads 54 are shaped by molding wheel 56 to form the desired brad pattern repeatedly and continuously on film i2 for the entire length of hose l 0. Thereafter, external margin 16 of film I2 is folded by a guide 62 to overlap inner margin 14. As a final step, the overlapped margins of film 12 pass through the nip of a form wheel 64 and a backing wheel 66. Form wheel 64 has a groove 68 that depresses the ribs formed by beads 54 to set the rib height at a specified value that determines the flow rate of the hose. During the described process, film 12 is continuously transported by conventional means not shown. For example, the disclosed wheels could be driven or other drive wheels could be provided to transport the film.
The described embodiment of the invention is only considered to be preferred and illustrative of the inventive concept; the scope of the invention is not to be restricted to such embodiments. Various and numerous other arrangements may be devised by one skilled in the art without departing from the spirit and scope of this invention.
..4_
Fig. 3 is a sectional view taken through plane 3-3 in Fig. 1 illustrat::ing an outlet from the flow regulating passage;
Fig. 4 is a schematic block diagram of the method for manufacturing t:he drip irrigation hose shown in Fig.
l; and Fig. 5 is a perspective view of apparatus for performing the bead laying, rib forming, film folding, and regulating pas~~age forming steps of Fig. 4.
Detailed Description of the Specific Embodiment As illustrated in Figs. l, 2 and 3, a drip irrigation hose 10 is formed from a thin (e.g., 4 to 15 mil) film 12 of flexible water impervious plastic material bent alone its length - 2a -1 to form an overlapping longitudinal seam between opposing longitudinal margins, namely an inner margin 14 and an outer margin I6. Margins 14 and 16 are sealed together by a continuous repeating pattern of longitudinally eztending spaced apart ribs 18 and 20 made of the same or compatible plastic material as film 12. Ribs 18 and 20 and margins 14 and 16 define a flow regulating passage 22 as described in more detail in the referenced '05I and '739 patents. A water supply passage 24 is defined by the remainder of film I2. At spaced intervals, rib 18 has a series of interruptions and pillars that form inlets 26 to flow regulating passage 22. Midway between each pair of inlets 26, an outlet 28 is formed by one or more holes in outer margin 16. A series of staggered chevrons 30 are formed along the inner sides of ribs 18 and 20 between each of inlets 26 and outlets 28. In each case, the chevrons are angled toward inlets 26 to promote turbulent flow along the path length from each inlet 26 to outlet 28 of flow regulating passage 22. As illustrated in Fig. 1, inlets 26 have a substantially larger cross sectional area than outlets 28 and the flow regulating passages. As a result, inlets 26 are not flow limiting. Thus, the serpentine turbulence inducing path lengths are arranged in back to back fashion relative to the outlets in the sense that the chevrons angle away from each of outlets 28, so there is parallel flow throughout the length of hose 10 from two of inlets 26 to one of outlets 28. The pattern of ribs illustrated in FIG.
I is repeated continuously along the entire length of hose 10 between overlapping margins 14 and I6. As a result, outlets 28 are spaced from each other and offset from inlets 26, which are also spaced from each other. Since inlets 26 are not flow limiting, each of inlets 26 feeds two of outlets 28 and each of outlets 28 is fed by two of inlets 26.
As a result, the flow rate through each outlet 28 is doubled because it is fed by two inlets and two flow regulating passages.
In operation when hose 10 is pressurized irt the field, water flows through supply passage 24 to inlets 26, passes from inlets 26 through flow regulating passage 22 to outlets 28, and ezits from outlets 28 to the ezterior of hose I0. Two back to back path lengths are formed from adjacent pairs of inlets 26 to each outlet 28, thereby doubling the flow rate for the dimensions of the flow regulating passage, i.e., path length, rib height and rib spacing, vis-a-vis the drip irrigation hose disclosed in the '739 patent. It should be noted that cross ribs dividing the flow regulating passage into segments as disclosed in the '739 patent are not required in the practice of the invention. Such cross ribs could be provided, however, if desired at insets 26 (or outlets 28), effectively dividing each inlet 26 (or outlet 28) into two inlets (or outlets) , one for each adjacent segment of the flow regulating passage.
The method for making the described drip irrigation hose is illustrated in FIGS. 4 and 5. As represented in FIG. 4 by a block 40, outlets 28 are first formed in film 12, preferably in the manner disclosed in the '984 patent. Then, as represented by a block 42 inner margin 14 is folded. As represented by a block 44, one or more beads are laid on the outside surface of inner margin 14 by one or more extrusion nozzles. As represented by a block 46, a pattern W~ 97/19759 PCT/US95/15481 1 of ribs, i.e., ribs 18 and 20, is formed by a molding wheel. As represented by a block 48, outer margin 16 is next folded onto inner margin 14 with the formed ribs therebetween.
Finally, as represented by a block 50, flow regulating passage 22 is finished by passing inner margin 14, outer margin 16, and the ribs 18 and 20 through the nip of a form wheel and a backing wheel to set precisely the height of ribs 18 and 20. This method is described in more detail in the '984 patent.
FIG. 5 illustrates apparatus for performing the steps represented by blocks 44 to 50.
One or more extrusion nozzles 52 deposit one or more continuous longitudinal beads 54 on the outside surface of inner margin 14. Film 12 then passes through the nip of a rotating molding wheel 56 and a rotating backing wheel 58. Molding wheel 56 has a pattern of depressions 60 corresponding to the desired rib pattern on drip irrigation hose 10, i.e., the pattern shown in FIG. 1. In the nip of wheels 56 and S8, beads 54 are shaped by molding wheel 56 to form the desired brad pattern repeatedly and continuously on film i2 for the entire length of hose l 0. Thereafter, external margin 16 of film I2 is folded by a guide 62 to overlap inner margin 14. As a final step, the overlapped margins of film 12 pass through the nip of a form wheel 64 and a backing wheel 66. Form wheel 64 has a groove 68 that depresses the ribs formed by beads 54 to set the rib height at a specified value that determines the flow rate of the hose. During the described process, film 12 is continuously transported by conventional means not shown. For example, the disclosed wheels could be driven or other drive wheels could be provided to transport the film.
The described embodiment of the invention is only considered to be preferred and illustrative of the inventive concept; the scope of the invention is not to be restricted to such embodiments. Various and numerous other arrangements may be devised by one skilled in the art without departing from the spirit and scope of this invention.
..4_
Claims (8)
1. A drip irrigation hose made from a water impervious material comprising:
an elongated water supply passage having a cross section;
a longitudinal flow regulating passage having a cross section smaller than the cross section of the water supply passage, the flow regulating passage being disposed along the water supply passage;
a plurality of longitudinally spaced non flow limiting inlets from the water supply passage to the flow regulating passage; and a plurality of longitudinally spaced outlets from the flow regulating passage to the exterior of the hose, the outlets being offset from the inlets to provide two path lengths from each inlet to a respective outlet.
an elongated water supply passage having a cross section;
a longitudinal flow regulating passage having a cross section smaller than the cross section of the water supply passage, the flow regulating passage being disposed along the water supply passage;
a plurality of longitudinally spaced non flow limiting inlets from the water supply passage to the flow regulating passage; and a plurality of longitudinally spaced outlets from the flow regulating passage to the exterior of the hose, the outlets being offset from the inlets to provide two path lengths from each inlet to a respective outlet.
2. The hose of claim 1, in which the water supply passage comprises an elongated strip of plastic film folded lengthwise to form an overlapping seam from opposing outer and inner margins of the film and a seal between the margins in the overlapping seam.
3. The hose of claim 2, in which the flow regulating passage comprises a continuous repetitive pattern of plastic ribs extending between the margins in the overlapping seam to form the seal.
4. The hose of claim 3, in which the pattern of ribs includes a longitudinal rib facing the water supply passage and the inlets each comprise one or more interruptions in the rib.
5. The hose of claim 2, 3 or 4, in which the outlets each comprise one or more holes in the outer margin.
6. The hose of claim 3 or 4, in which the pattern of ribs includes first and second parallel longitudinal ribs having inner sides that face each other, a series of staggered chevrons being formed along the ribs.
7. The hose of claim 1, 2, 3, 4, 5 or 6, in which each outlet is fed by two inlets and two flow regulating passages and the inlets comprise a larger cross sectional area than the outlets and the flow regulating passages.
8. The hose of claim 1, 2, 3, 4, 5, 6 or 7, in which each inlet feeds two outlets.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002239153A CA2239153C (en) | 1995-11-29 | 1995-11-29 | Drip irrigation hose and method of its manufacture |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US1995/015481 WO1997019759A1 (en) | 1995-11-29 | 1995-11-29 | Drip irrigation hose and method of its manufacture |
| CA002239153A CA2239153C (en) | 1995-11-29 | 1995-11-29 | Drip irrigation hose and method of its manufacture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2239153A1 CA2239153A1 (en) | 1997-06-05 |
| CA2239153C true CA2239153C (en) | 2002-10-29 |
Family
ID=4162495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002239153A Expired - Fee Related CA2239153C (en) | 1995-11-29 | 1995-11-29 | Drip irrigation hose and method of its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2239153C (en) |
-
1995
- 1995-11-29 CA CA002239153A patent/CA2239153C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2239153A1 (en) | 1997-06-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |