A drip irrigation system for watermelon cultivation

Abstract

This application relates to a drip irrigation device for watermelon cultivation, comprising a backbone pipeline for conveying liquid and gas respectively. Drip irrigation units are installed underground on the backbone pipeline, directly facing the watermelon root system. Each drip irrigation unit includes a circular circulation pipe. The backbone pipeline is connected to the circular circulation pipe via an inlet pipe, an outlet pipe, and at least one air inlet pipe, conveying liquid and gas to the circular circulation pipe. At least one first-type liquid-gas conveying structure is connected to the upper surface of the circular circulation pipe. The first-type liquid-gas conveying structure has an inner cavity extending upwards from underground to a depth close to the ground surface, and its inner cavity is filled with liquid or bubble-like gas under the action of fluid pressure in the circular circulation pipe. A conveying head is provided on the first-type liquid-gas conveying structure, which releases gas and liquid into the soil under the action of pressure in the inner cavity. This application achieves water conservation and random water dispensing, preventing water accumulation.

Description

Technical Field

[0001] This application relates to the field of agricultural irrigation technology and equipment, specifically to a drip irrigation device for watermelon cultivation. Background Technology

[0002] Watermelon is a common crop, and drip irrigation is widely used in its cultivation. Drip irrigation involves burying pipes in the soil or near the plant roots to deliver water in small drips, offering advantages such as significant water conservation and precise control. Watermelons require a large amount of water during their fruiting period, but their roots are susceptible to waterlogging, have high oxygen consumption, and require well-aerated soil. While existing drip irrigation systems incorporate moisture sensors to control soil moisture, the relatively fixed water outlets often lead to water accumulation, stimulating root tropism and causing young roots to rot. Furthermore, high humidity levels make it difficult for the soil to meet the root oxygen needs. Summary of the Invention

[0003] (I) Technical Issues

[0004] 1. Traditional drip irrigation systems supply water downwards, causing a large amount of water to seep into the ground and not be effectively utilized;

[0005] 2. Traditional drip irrigation devices have a fixed water outlet position and a basically fixed water output, which easily leads to excessive water accumulation around the outlet and causes the roots to grow towards the water, resulting in root rot.

[0006] 3. Watermelon cultivation requires measures to reduce waterlogging and increase soil oxygen supply, but there is currently a lack of targeted drip irrigation devices.

[0007] (II) Technical Solution

[0008] A drip irrigation device for watermelon cultivation includes a backbone pipeline for conveying liquid and gas respectively. Drip irrigation units are installed on the backbone pipeline, located underground and facing the watermelon root system. Each drip irrigation unit includes a circular circulation pipe. The backbone pipeline is connected to the circular circulation pipe through an inlet pipe, an outlet pipe, and at least one air inlet pipe, and conveys liquid and gas to the circular circulation pipe.

[0009] At least one type of first-class liquid-gas transport structure is connected to the upper surface of the annular circulation pipe. The first-class liquid-gas transport structure has an inner cavity that extends upward from underground to a depth close to the ground surface. Under the action of fluid pressure in the annular circulation pipe, the inner cavity is filled with liquid or bubble-like gas. The first-class liquid-gas transport structure is provided with a transport head, which releases gas and liquid into the soil under the action of inner cavity pressure.

[0010] The inner ring of the circular circulation tube is also provided with a second type of liquid-gas conveying structure, which extends towards the center of the circular circulation tube and conveys liquid or gas outward through the extrusion nozzle provided thereon.

[0011] Furthermore, the number of the first type of liquid-gas conveying structure is three or six, and they are evenly distributed on the annular circulation pipe; the number of the second type of liquid-gas conveying structure is three or six, and they are evenly distributed on the annular circulation pipe; the diameter of the inlet pipe is smaller than the inner diameter of the annular circulation pipe and larger than the diameter of the outlet pipe.

[0012] Furthermore, the first type of liquid-gas conveying structure includes two generally vertical risers that are inclined toward the center of the annular circulation pipe. One end of each riser is connected to the annular circulation pipe, and the other end is connected through a "∏"-shaped connecting pipe that is further inclined toward the center of the annular circulation pipe. Multiple conveying heads are randomly arranged on the risers and the "∏"-shaped connecting pipe. Each conveying head includes an upwardly inclined conveying branch with a gradually decreasing inner diameter. The conveying branch is provided with an upward-opening air nozzle and a downward-opening liquid nozzle. Under a certain pressure, gas is discharged from the air nozzle and liquid is discharged from the liquid nozzle.

[0013] Furthermore, the inlet pipe and outlet pipe are arranged in parallel and located on one side of the annular circulation pipe; there are three air inlets and the airflow direction is consistent with or at an acute angle to the liquid flow direction in the annular circulation pipe. The three air inlets are evenly distributed on the outer periphery of the annular circulation pipe, and gas at a certain pressure is injected into the air inlets at intervals.

[0014] Furthermore, the gas is air or a mixture of gases with an oxygen content greater than that of air.

[0015] Furthermore, the air nozzle and liquid nozzle are pressure-activated one-way valves.

[0016] Furthermore, the second type of liquid-gas conveying structure is an upwardly inclined cylindrical tube with an extrusion nozzle at its end that can discharge gas or liquid. The extrusion nozzle discharges liquid when the pressure inside the annular circulation tube is greater than a threshold and discharges gas when the pressure inside the tube is normal. There are 6 of the second type of liquid-gas conveying structures, which are evenly distributed in the inner diameter of the annular circulation tube.

[0017] Furthermore, the first type of conveying device is provided with a circulating plug that floats in its inner cavity with the water flow. During the floating process, it closely adheres to the inner wall holes of the conveying branches at different positions to temporarily block them.

[0018] The circulating plug is a ring-shaped connecting line with multiple unevenly distributed counterweights and float plugs fixed on it. The float plug is a cylinder with a diameter smaller than the inner diameter of the column and a height slightly larger than the inner wall hole diameter of the conveying branch. The counterweights make the density of the floating plug close to the density of the liquid in the backbone pipeline. The connecting line passes sequentially through the first riser, the "∏"-shaped connecting pipe, the second riser, and the pipe section connecting the two risers to the ring, which constitute the first type of liquid-gas conveying structure, and makes the float plug float and drift with the water flow in the above path.

[0019] (III) Beneficial Effects

[0020] This device firstly achieves "three-dimensional" water supply, with water dripping directly onto roots at various depths instead of seeping downwards, thus improving water utilization. Secondly, by injecting gas, it increases soil oxygen content, and combined with the setting of the circulation plug, it makes it uncertain whether the water delivery branch will produce water and the timing of water production, achieving a random water production effect and completely solving the problem of water accumulation in traditional drip irrigation. Attached Figure Description

[0021] Figure 1 A schematic diagram showing the use of the drip irrigation device before and after the application was applied;

[0022] Figure 2 This is an overall schematic diagram of the drip irrigation device of this application;

[0023] Figure 3 A schematic diagram of the entire application from another angle;

[0024] Figure 4 This is a top view and a schematic diagram of the material supply of this application, wherein the arrows marked "gas" and "liquid" indicate the direction of material supply, and the slanted arrows indicate the direction of liquid circulation in the circular tube at the bottom of the device.

[0025] Figure 5 This is a side view of the device;

[0026] Figure 6 This is a schematic diagram showing the internal structure of a pipe after a section has been cut open.

[0027] Figure 7 for Figure 6 Enlarged view of a portion of point A in the middle;

[0028] Figure 8 for Figure 7 Schematic diagram of the split assembly structure;

[0029] Figure 9 This is a schematic diagram illustrating the working principle of the float plug in this device.

[0030] Figure labels: I. Watermelon plant leaves; II. Watermelon root system; 1. Drip irrigation unit; 2. Circular circulation pipe; 3. Liquid inlet pipe; 4. Liquid outlet pipe; 5. Air inlet pipe; 51. First air inlet pipe; 52. Second air inlet pipe; 53. Third air inlet pipe; 6. Type I liquid-gas transport structure; 61. Riser pipe; 62. "∏" shaped connecting pipe; 63. Transport branch; 64. Liquid nozzle; 65. Air nozzle; 66. Branch end; 7. Transport head; 8. Type II liquid-gas transport structure; 81. Extrusion nozzle; 9. Circulation plug; 91. Connecting line; 92. Counterweight bead; 93. Float plug. Detailed Implementation

[0031] The present invention will be further described below with reference to the embodiments.

[0032] like Figure 1 As shown, the left side is a schematic diagram of watermelon cultivation in ordinary irrigated land, where I represents the watermelon plant and leaves, and II represents its root system. Literature indicates that watermelon roots can reach a depth of 1.2-1.4 meters depending on the variety, and generally spread outwards from this depth. The right side is a schematic diagram of the root system effect after the drip irrigation device of this application is installed. The relative positions in the attached diagrams are for illustrative purposes only.

[0033] like Figure 2-5 As shown, a watermelon cultivation drip irrigation device according to this application includes a backbone pipeline for conveying liquid and gas respectively. A drip irrigation unit 1 located underground and facing the watermelon root system is provided on the backbone pipeline. Each drip irrigation unit includes a circular circulation pipe 2. The backbone pipeline is connected to the circular circulation pipe through an inlet pipe 3, an outlet pipe 4 and at least one air inlet pipe 5, and conveys liquid and gas to it.

[0034] At least one first-type liquid-gas transport structure 6 is connected to the upper surface of the annular circulation pipe. The first-type liquid-gas transport structure has an inner cavity that extends upward from underground to a depth close to the ground surface. Under the action of fluid pressure in the annular circulation pipe, the inner cavity is filled with liquid or bubble-like gas. The first-type liquid-gas transport structure is provided with a transport head 7, which releases gas and liquid into the soil under the action of inner cavity pressure.

[0035] The inner ring of the circular circulation pipe is also provided with a second type of liquid-gas conveying structure 8, which extends towards the center of the circular circulation pipe and conveys liquid or gas outward through the extrusion nozzle provided thereon.

[0036] Furthermore, the number of the first type of liquid-gas conveying structure is three or six, and they are evenly distributed on the annular circulation pipe; the number of the second type of liquid-gas conveying structure is three or six, and they are evenly distributed on the annular circulation pipe; the diameter of the inlet pipe is smaller than the inner diameter of the annular circulation pipe and larger than the diameter of the outlet pipe.

[0037] The initial working principle of this scheme is to inject liquid and gas into the circular circulation pipe through pressurized backbone pipelines, and then transport them to the crop roots through the first and second types of liquid-gas transport structures.

[0038] To make it easier to understand, we can first consider the case where there is only an inlet pipe and an outlet pipe. It is easy to control or make the pressure of the inlet pipe greater than that of the outlet pipe by adjusting the pipe diameter, so that there is a certain pressure in the annular circulation pipe filled with water, and the water pressure fills the first type of liquid-gas conveying structure upward. The conveying head of the first type of liquid-gas conveying structure has the following characteristic: under sufficient pressure, water droplets can be squeezed out from the conveying head.

[0039] Modern irrigation systems often incorporate fertilization systems, where a fertigation unit can be added to the water tank to add prepared soluble fertilizer to the water and pump it in.

[0040] Considering gas delivery, the advantage of underground irrigation systems is that they can use the same set of pipelines (of course, the pipelines for delivering liquids and those for delivering gas are separate, but together they form the backbone pipeline) to deliver gas (air or oxygen) while supplying water. Depending on the specific watermelon variety's habits and oxygen requirements at different growth stages, gas can be pumped into the drip irrigation unit intermittently. This operation primarily maintains the pressure within the system, because this device supplies liquid upwards (and then the liquid permeates downwards to the roots at different locations). Therefore, the pressure within the circular circulation pipe is very important. However, it is difficult to accurately maintain the pressure when using water pressure to connect many drip irrigation devices to the backbone pipeline. But maintaining the pressure within the device by inflation is very easy, and even if a leak occurs, there are no negative effects.

[0041] Another reason for aeration is, as mentioned above, the oxygen demand of the roots. Because the circular circulation pipe has an inlet pipe and an outlet pipe, the fluid inside is in a state of rapid flow, while aeration is intermittent. Therefore, apart from a small amount dissolving into the liquid, most of it exists in the form of bubbles in the inner cavity of the drip irrigation unit, and after floating into the first type of delivery structure, it is discharged from the delivery head, thus playing the role of soil aeration and oxygenation.

[0042] Because the first type of transport structure extends upwards to the location where the watermelon plant begins to root, and is circumferentially symmetrical, it is actually like... Figure 1 The cage defines the space for root development, and in a further embodiment below, multiple conveying heads are randomly distributed at various heights of the first type of conveying structure, so that they can supply water to the roots at different locations when they discharge water.

[0043] In traditional drip irrigation systems, water flows from top to bottom (because if the nozzles don't point downwards, they can easily get blocked by soil, etc.). The irrigation water flows downwards, with only a small portion being absorbed by the plants, while the majority flows into groundwater, resulting in significant waste.

[0044] To achieve better practical results from the above process, in a specific embodiment: (see appendix) Figure 7-8 )

[0045] Furthermore, the first type of liquid-gas conveying structure includes two generally vertical risers 61 that are inclined toward the center of the annular circulation pipe. One end of each riser 61 is connected to the annular circulation pipe, and the other end is connected through a "∏"-shaped connecting pipe 62 that is further inclined toward the center of the annular circulation pipe. Multiple conveying heads 7 are randomly arranged on the risers and the "∏"-shaped connecting pipe. Each conveying head 7 includes an upwardly inclined conveying branch 63 with a gradually decreasing inner diameter. The conveying branch 63 is provided with an upwardly opening air nozzle 65 and a downwardly opening liquid nozzle 64. Under a certain pressure, gas is discharged from the air nozzle and liquid is discharged from the liquid nozzle.

[0046] It can be seen that three to six sets of liquid-gas transport structures actually limit the... Figure 1 The enclosure space on the right coincides with the root growth range. Depending on the watermelon variety, it is easy to determine the root growth range and customize the length and inclination of the corresponding conveying structure. In this way, the air nozzles, randomly located on the first type of conveying structure, exhaust air upwards, ideally from the bottom up; the liquid nozzles drain water downwards, ideally dripping downwards at each stage to supply water to the roots at the corresponding location.

[0047] from Figure 1 As can be seen, because this application is a "three-dimensional" water outlet system, it avoids the continuous seepage into the ground like traditional devices, thus greatly saving water resources.

[0048] The water nozzles are randomly distributed, reducing the possibility of accumulation. More importantly, because of the intermittent gas filling, air bubbles of random size and position are distributed in the inner cavity. These air bubbles will occupy the inner cavity of some delivery branches, causing the liquid nozzles of these delivery branches to temporarily not dispense liquid. In other words, the effect of liquid dispensing from different delivery branches at any time is achieved.

[0049] The gas is released only under certain pressure, which also ensures that the bubbles do not disappear quickly. Instead, the liquid outlet is "blocked" for an indefinite period of time before being refilled with liquid. This ensures the effect of "random liquid outlet", which increases the oxygen supply to the roots and avoids the duplication of water supply positions. This is one of the technical means of this application to address its technical problems.

[0050] Meanwhile, to ensure sufficient pressure and air bubbles within the annular circulation pipe, and to allow the fluid to circulate within the annulus (excluding the portion from the discharge device):

[0051] Furthermore, the inlet pipe and outlet pipe are arranged in parallel and located on one side of the annular circulation pipe; there are three air inlets and the airflow direction is consistent with or at an acute angle to the liquid flow direction in the annular circulation pipe. The three air inlets are evenly distributed on the outer periphery of the annular circulation pipe, and gas at a certain pressure is injected into the air inlets at intervals.

[0052] refer to Figure 4Firstly, the inlet and outlet pipes of the circulation pipe are parallel to each other, allowing the liquid in the pipe to circulate and maintain a certain water pressure. The reason for circulation is that air bubbles in the liquid need to be continuously transported to the delivery structure during circulation, rather than being discharged through the outlet pipe. That is, the entire inner cavity of the drip irrigation unit, whether it is the annular circulation pipe or each delivery structure, is in a mixed state of liquid-air bubble-liquid-air bubble, and is constantly divided, replenished, and merged as the fluid in the annular circulation pipe circulates. The three evenly distributed air inlets are set because the delivery structure can have up to six, preventing the air-liquid ratio of each delivery structure from being too different when there is only one air inlet point.

[0053] With liquid injection through the inlet pipe and intermittent air filling through the air inlet pipe, the water pressure and the gas flowing with the water cause the fluid inside the pipe to be in a mixed state of liquid and bubbles, and continuously circulate in the annular circulation pipe. The bubbles and pressurized water rise into the conveying structure and are discharged.

[0054] Furthermore, the air nozzle and liquid nozzle are pressure-activated one-way valves.

[0055] In another specific embodiment, the liquid nozzle is a fine orifice with a diameter that allows the liquid transported by the backbone pipeline to flow out; the air nozzle is a fine orifice with a diameter smaller than that of the liquid nozzle, and under system pressure, the liquid transported by the backbone pipeline cannot flow out from the air nozzle due to surface tension.

[0056] Under moderate pressure, a sufficiently large orifice is required to discharge the liquid because the surface tension of the liquid prevents it from easily passing through a small orifice. Of course, cost is not a concern, using a pressure check valve would be a more accurate solution.

[0057] Furthermore, the second type of liquid-gas conveying structure is an upwardly inclined cylindrical tube with an extrusion nozzle at its end that can discharge gas or liquid. The extrusion nozzle discharges liquid when the pressure inside the annular circulation tube is greater than a threshold and discharges gas when the pressure inside the tube is normal. There are 6 of the second type of liquid-gas conveying structures, which are evenly distributed in the inner diameter of the annular circulation tube.

[0058] It is easy to understand that the second type of liquid-gas conveying structure is more commonly used for exhaust because it can discharge both gas and liquid fluids. Since it is located at the lowest position of the entire device, the gas it discharges can facilitate the respiration of the entire root system during its ascent. Furthermore, since it can discharge liquid according to pressure, it actually functions as a pressure relief valve to prevent excessive pressure inside the device.

[0059] Furthermore, the first type of conveying device is provided with a circulating plug that floats in its inner cavity with the water flow. During the floating process, the plug closely adheres to the inner wall holes of the conveying branches at different positions to block them.

[0060] In one specific embodiment, the circulating plug is an annular connecting line with multiple unevenly distributed counterweights and float plugs fixed on it. The float plug is a cylinder with a diameter smaller than the inner diameter of the column and a height slightly larger than the inner wall hole diameter of the conveying branch. The counterweights make the density of the floating plug close to the density of the liquid in the backbone pipeline. The connecting line passes sequentially through the first riser, the "∏"-shaped connecting pipe, the second riser, and the pipe section connecting the two risers to the annular structure that constitute the first type of liquid-gas conveying structure, and makes the float plug circulate and drift with the water flow in the above path.

[0061] For the specific structure described above, please refer to the appendix. Figure 7-8 .

[0062] The primary purpose of the circulating plug is to prevent situations where injected gas rapidly merges into a large cavitation bubble within the first conveying structure, or where the structure is filled with water but, due to insufficient pressure, fails to drain completely. Therefore, a preferred embodiment allows the circulating plug to float back and forth within the first type of conveying structure. This prevents bubble merging and, because the draining conveying branch is connected to the outside, its internal pressure is lower than that within the annular circulation pipe, causing the floating plug to be pressed against the orifice wall by water pressure (this principle is explained in the appendix). Figure 9 This essentially blocked the water supply branch, preventing it from flowing out any more water.

[0063] But see appendix Figure 7 Because the floating plug also has a portion in the annular circulation pipe, it is also pushed by the liquid flow in the annular circulation pipe, making the entire circulation plug (shaped like a necklace) in a circulating "flowing" state. During the flow, the fluid in the first type of gas-liquid transport structure also circulates, preventing the bubbles from merging. When the floating plug passes through the inner wall hole of the transport branch, it is temporarily sucked in. After blocking the hole for a short period of time, it detaches and continues to float. This makes the actual water discharge situation more random, preventing excessive waterlogging at the roots.

[0064] The counterweight beads make the overall density of the circulation plug close to that of the liquid, so that its drifting is not affected by buoyancy.

[0065] This application, through the above-mentioned working principle, achieves randomness in whether or not water is discharged from the delivery branch and the timing of water discharge, thus completely solving the problem of water accumulation in drip irrigation devices.

[0066] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A drip irrigation device for watermelon cultivation, comprising a backbone pipeline for conveying liquid and gas respectively, wherein drip irrigation units are installed on the backbone pipeline, which are located underground and directly opposite the watermelon root system, and each drip irrigation unit includes a circular circulation pipe, wherein the backbone pipeline is connected to the circular circulation pipe through an inlet pipe, an outlet pipe and at least one air inlet pipe, and conveys liquid and gas to the circular circulation pipe. At least one type of first-class liquid-gas transport structure is connected to the upper surface of the annular circulation pipe. The first type of liquid-gas transport structure has an inner cavity that extends upward from underground to a depth close to the ground surface. Under the action of fluid pressure in the annular circulation pipe, the inner cavity is filled with liquid or bubble-like gas. The first type of liquid-gas transport structure is provided with a transport head, which releases gas and liquid into the soil under the action of inner cavity pressure. The inner ring of the circular circulation tube is also provided with a second type of liquid-gas conveying structure, which extends toward the center of the annular ring of the circular circulation tube and conveys liquid or gas outward through the extrusion nozzle provided thereon. The first type of liquid-gas conveying structure has three or six components, which are evenly distributed on the annular circulation pipe; the second type of liquid-gas conveying structure has three or six components, which are evenly distributed on the annular circulation pipe; the diameter of the inlet pipe is smaller than the inner diameter of the annular circulation pipe and larger than the diameter of the outlet pipe. The first type of liquid-gas conveying structure includes two generally vertical risers that are inclined toward the center of a circular circulation pipe. One end of each riser is connected to the circular circulation pipe, and the other end is connected through a "∏"-shaped connecting pipe that is further inclined toward the center of the circular circulation pipe. Multiple conveying heads are randomly arranged on the risers and the "∏"-shaped connecting pipe. Each conveying head includes an upwardly inclined conveying branch with a gradually decreasing inner diameter. The conveying branch is provided with an upwardly opening air nozzle and a downwardly opening liquid nozzle. Under a certain pressure, gas is discharged from the air nozzle and liquid is discharged from the liquid nozzle. The inlet pipe and outlet pipe are arranged in parallel and located on one side of the annular circulation pipe; there are three air inlets and the airflow direction is consistent with or at an acute angle to the liquid flow direction in the annular circulation pipe. The three air inlets are evenly distributed on the outer periphery of the annular circulation pipe, and gas at a certain pressure is injected into the air inlets at intervals. The second type of liquid-gas conveying structure is an upwardly inclined cylindrical tube with an extrusion nozzle at its end that can discharge gas or liquid. The extrusion nozzle discharges liquid when the pressure inside the annular circulation tube is greater than a threshold and discharges gas when the pressure inside the tube is normal. The first type of liquid-gas conveying structure is provided with a circulating plug that floats in its inner cavity with the water flow. During the floating process, it closely adheres to the inner wall holes of the conveying branch at different positions to temporarily block them. The circulating plug includes an annular connecting line, on which multiple unevenly distributed counterweights and float plugs are fixed.

2. The drip irrigation equipment for watermelon cultivation according to claim 1, characterized in that: The floating plug is a cylinder with a diameter smaller than the inner diameter of the column and a height slightly larger than the inner wall hole diameter of the conveying branch. The counterweight bead makes the density of the floating plug close to the density of the liquid in the backbone pipeline. The connecting line passes through the first riser, the "∏"-shaped connecting pipe, the second riser, and the pipe section connecting the two risers to the ring in sequence, which constitute the first type of liquid-gas conveying structure, and makes the floating plug float in the above pipe sections with the liquid flow.

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