Method of designing and forming a channel of flow-type thin-wall drip irrigation belt

Patent metadata

Field	Value
Publication number	US-11449648-B2
Application number	US-201816960898-A
Country	US
Kind code	B2
Filing date	Jan 29, 2018
Priority date	Jan 29, 2018
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

The present disclosure discloses design and forming method of a channel of flow-type thin wall drip irrigation belt. The method includes the steps of construction of a double-layer asymmetric channel structure, determination of a structure parameter control threshold and optimal value, design of water inlets and water outlets of the double-layer asymmetric channel structure, proposal of a machining method of a molding wheel matching the double-layer asymmetric structure and an optimization method of a flow-type drip irrigation belt molding process, material modification of a flow-type drip irrigation belt and design of a reasonable formulation, realization the stereotype production of the flow-type drip irrigation belt, etc.

First claim

The invention claimed is:

1. A method of designing and forming a channel of flow-type thin wall drip irrigation belt, the method comprising:
step 1: forming a double-layer asymmetric channel structure and determining control thresholds and optimal values of structure parameters of the channel structure;
step 2: designing water inlets and water outlets of the double-layer asymmetric channel structure;
step 3: determining a method of machining a molding wheel matching the double-layer asymmetric channel and optimization of a flow-type drip irrigation belt molding process;
step 4: designing and modifying formulation materials of the flow-type drip irrigation belt including addition of a toughening master batch POE to the materials to enhance the toughness, addition of an anti-UV agent to the materials to improve the aging resistance, and addition of a compatibilizer to improve the uniformity and workability of the materials; and
step 5: forming the flow-type drip irrigation belt;
wherein the step 1 comprises model simulation and solution, forming an optimal channel structure;
wherein the step 2 comprises designing self-cleaning water inlets and anti-negative suction water outlets; and
wherein the step 3 comprises of improving the structure of the molding wheel and calculating groove channel structure parameters thereof, and determining positions of vacuum adsorption points of the groove channel; wherein improving the structure of the molding wheel comprises: addition of the same channel molding groove as the main channel to the side portion corresponding to the main channel of the molding wheel and adjustment of the degree of vacuum, thereby ensuring that the same channel is synchronously formed on one side wall corresponding to the main channel during molding.

2. The method according to claim 1 , wherein the forming of the optimal channel structure in the step 1 comprises optimizing the arc on tooth tips of the channel structure and abrupt structural change portions at water outlets; the forming the optimal channel structure further comprises forming a double-layer asymmetric channel structure, that is, the arc-optimized channel structure is simulated by a numerical simulation method, the turbulence distribution is compared and the average turbulent kinetic energy is calculated, the channel structure with maximum turbulent region and average turbulent kinetic energy is selected, and two identical optimal channel structures are constructed as upper and lower structures, aligned on left and right and offset by ¼-½ of the channel width in front and back direction.

3. The method according to claim 2 , wherein the determining control thresholds and optimal values of channel structure parameters in the step 1 comprises: comparison using a numerical simulation method to select the parameters of a unit segment of the inner wall of the sheared channel where the shear force is in the most unsuitable shear force interval (0-0.2 Pa∪0.4 Pa−∞) for growth of blocking matters and where the turbulence intensity is the highest based on optimized channel structure parameters, where the range of tooth height H is 1.3-1.6 mm, the range of tooth angle θ is 50°-60°, the range of adjacent tooth pitch S is 1.8-2.1 mm, the range of channel width d is 0.8-1.2 mm, the range of channel length L is 27.5-42.5 mm, the range of channel depth w is 0-1 mm, and the left arc radius R 0 of the tooth tip, the right arc radius R 1 of the tooth tip, the arc radius R 2 of the tooth root are all not less than 0.2 mm.

4. The method according to claim 3 , wherein the tooth height H is 1.3 mm, the tooth angle θ is 60°, the adjacent tooth pitch S is 1.8 mm, the channel width d is 0.8 mm, the channel length L is 34.5 mm, the channel depth w is less than 0.8 mm, the left arc radius R 0 of the tooth tip is 0.4 mm, the right arc radius R 1 of the tooth tip is 0.2 mm, and the arc radius R 2 of the tooth root is 0.4 mm.

5. The method according to claim 2 , wherein the determining positions of vacuum adsorption points of the groove channel in the step 3 comprises:
arrangement of the vacuum adsorption points at the positions where the turbulence intensity is the highest, that is, based on different radii of the arcs on the left and right sides of the tooth tip, the vacuum adsorption holes are arranged at centers of arcs on left and right sides, and the molding precision of the tooth tip is ensured by asymmetric adsorption; and in order to ensure the molding precision of the arc of the tooth root, the center of the adsorption hole is substantially at a center of the arc of the tooth root.

6. The method according to claim 1 , wherein the designing self-cleaning water inlets in the step 2 comprises designing of double layers of asymmetric water inlets, the offset direction and distance of the water inlets are consistent with the channel part, each water inlet is ensured to be narrower than but as high as the channel, and the edges of the water inlets are connected with outside.

7. The method according to claim 1 , wherein the designing anti-negative suction water outlets in the step 2 comprises designing of abrupt size change structures at the water outlets, such that the cross-sectional area of the water outlets increases to reduce the occurrence of blockage caused by negative pressure.

8. The method according to claim 1 , wherein the calculation of groove channel structure parameters of the molding wheel in the step 3 comprises forming the structural size of a groove channel on the molding wheel, wherein
the formula for calculating the structural size of a straight segment of the molding wheel channel is:
L 1 =L 2 ±2 B

in the formula, L 1 is the length size of the straight segment of the molding wheel, L 2 is the length size of the straight segment of the channel, and B is the wall thickness of the drip tape;
the formula for calculating the structural size of an arc segment of the molding wheel channel is:

R
3

=

{

R
4

+
B

R
4

>

0.2
⁢

⁢
mm

)

0.2
+
B

R
4

<

0.2
⁢

⁢
mm

Assignees

• Univ China Agricultural

Inventors

• Li Yunkai
• Hou Peng
• Feng Ji
• Wang Zhifu

Classifications

• G06F2113/08

  Fluids · CPC title

• G06F30/28

  using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD] · CPC title

• A01G25/02 Primary

  Watering arrangements located above the soil which make use of perforated pipe-lines or pipe-lines with dispensing fittings, e.g. for drip irrigation · CPC title

• G06F2111/10

  Numerical modelling · CPC title

• G06F30/17 Primary

  Mechanical parametric or variational design · CPC title