Microporous cementing material infiltrating irrigation emitter and preparation method thereof

Abstract

The invention discloses a microporous cementing material infiltrating irrigation emitter and a preparation method thereof, and belongs to the technical field of infiltrating irrigation emitter design. The micropore cementing material infiltrating irrigation emitter comprises a micropore cementing material water seepage body, a water storage cavity is formed in the micropore cementing material water seepage body, a water inlet is formed in the wall of the micropore cementing material water seepage body, a water inlet pipe penetrates through the water inlet, one end of the water inlet pipe is communicated with the water storage cavity, and a plug is arranged at the other end of the water inlet pipe. The emitter takes dolomite, fly ash, magnesium chloride and water as raw materials, active MgO obtained by calcining the dolomite is subjected to a hydration reaction under the action of a blending liquid, and a microporous cementing material is obtained. According to the microporous cementing material plate-shaped infiltrating irrigation emitter and the preparation method thereof, the preparation method is simple, solidification and shaping can be achieved at the room temperature, the preparation cost of the emitter is greatly reduced, the emitter has excellent mechanical property and water permeability, and the raw materials are cheap and easy to obtain.

Description

Technical Field

[0001] The invention relates to the technical field of infiltration irrigation emitter design, in particular to a microporous gelling material infiltration irrigation emitter and a preparation method thereof. Background Art

[0002] Concrete, a widely used building material, poses environmental challenges, particularly the high carbon emissions associated with the production of Portland cement. To reduce carbon emissions, the search for alternative clinkers to Portland cement is underway. Magnesia-based cementitious materials are attracting attention due to their lower energy consumption and carbon emissions. Their production typically involves light burning of magnesite or extracting magnesium hydroxide from seawater. Their calcination temperature is much lower than that of conventional cement, thus reducing its adverse environmental impact.

[0003] my country's water resources are distributed with significant regional unevenness and seasonal variations, generally showing a pattern of "more in the east, less in the west, and more in the south, less in the north." The mismatch between the temporal and spatial distribution of water resources and the distribution of population, cultivated land, and the economy has led to significant imbalances between water supply and demand in some regions. Promoting water-saving irrigation technologies and improving water utilization efficiency are crucial for alleviating water shortages, ensuring food security, and promoting sustainable development. Water-saving irrigation can reduce agricultural water waste, increase crop yields and quality, alleviate pressure on the ecological environment, and achieve sustainable water resource utilization.

[0004] As an efficient and water-saving irrigation method, infiltration irrigation offers numerous advantages, including water and energy conservation, improved soil conditions, and increased crop yields. However, its practical application still faces challenges. Key issues include clogging of infiltration irrigation pipes, which can be caused by soil particles, organic matter, or chemical precipitates clogging the tiny pores within the pipes, resulting in reduced irrigation efficiency. Furthermore, ensuring uniform irrigation is difficult, especially over long infiltration irrigation lines, where uneven distribution of water pressure and flow can lead to insufficient irrigation in certain areas.

[0005] Chinese patent application number 202311431959.6 discloses a vortex cavity self-flushing seepage irrigation emitter and its preparation and flushing method. The emitter comprises a porous seepage body, the top of which is fixedly connected to an upper cover, a seepage cavity defined within the body, a water inlet provided in the upper cover, a bottom of which is fixedly connected to a bottom barrel, a cone disposed within the seepage cavity, a telescopic drain sleeve disposed within the bottom barrel, the bottom of the cone fixedly connected to the top of the telescopic drain sleeve, and a water outlet provided at the bottom of the bottom barrel. The emitter achieves automatic flushing, effectively flushing obstructions attached to the inner wall of the seepage cavity. However, the vortex cavity structure of the vortex cavity self-flushing seepage irrigation emitter is complex (e.g., the cone, warped edges, telescopic drain pipe, etc.), which increases production and assembly costs. Furthermore, the complexity of the assembly process makes it difficult to ensure the accuracy of the emitter.

[0006] Chinese patent application number 202210411398.2 discloses a self-cleaning, anti-clogging seepage irrigation device, as well as its preparation and anti-clogging methods. The device includes an upper cover with a water diversion chamber defined within it. The top of the diversion chamber communicates with the bottom of the water inlet, which in turn communicates with the top of a water conduit. The bottom of the water conduit extends into the seepage chamber of a porous water body, and a pressure-limiting tube is provided at the bottom of the seepage chamber. This device addresses the problems of poor anti-clogging performance, complex structure, and high cost of underground drip irrigation systems. However, the activated carbon, fly ash, and clay used in the self-cleaning, anti-clogging seepage irrigation device are inexpensive and readily available, but the sintering temperature is above 1000°C, consuming more fuel and electricity, increasing the economic cost and environmental burden of production.

[0007] Therefore, there is an urgent need to design a new type of emitter that is inexpensive, highly practical, has good energy dissipation, and effectively prevents physical clogging, as well as a method for its preparation. Based on the above problems, the present invention designs a microporous gelling material plate-shaped infiltration irrigation emitter and its preparation method. This will promote the future promotion of infiltration irrigation technology, promote the development of water-saving irrigation technology, and effectively utilize waste to alleviate environmental pollution caused by fly ash storage. Summary of the Invention

[0008] In view of the problems of high manufacturing cost, low irrigation uniformity, easy clogging and difficulty in promotion of the above-mentioned prior art infiltration irrigation emitters, the purpose of the present invention is to provide a microporous gelling material infiltration irrigation emitter and a preparation method thereof. The preparation method of the emitter is simple, low in cost, low in energy consumption, good irrigation uniformity, can prevent physical clogging and has excellent mechanical properties and hydraulic performance.

[0009] In order to achieve the above objectives, the technical solutions provided by this patent are as follows: A microporous gelling material infiltration irrigation device comprises a microporous gelling material infiltration body, a water storage cavity is provided inside the microporous gelling material infiltration body, a water inlet is provided on the wall of the microporous gelling material infiltration body, a water inlet pipe is passed through the water inlet, one end of the water inlet pipe is connected to the water storage cavity, and the other end is provided with a plug.

[0010] Preferably, the porosity of the microporous gelling material water seepage body is 30%-35%, and the pore size is 12-15 μm. Such microporous parameters provide excellent water permeability while maintaining sufficient mechanical strength, allowing the microporous gelling material water seepage emitter to have high water permeability while maintaining anti-clogging performance and structural stability.

[0011] Preferably, the microporous gelling material seepage irrigation device has two installation modes: under-pipe type and between-pipe type.

[0012] Preferably, the bottom of the water inlet pipe passes through the fixing piece, and the end is provided with a water inlet hole.

[0013] Preferably, the plug and the water inlet pipe are both made of polyethylene.

[0014] Preferably, the water inlet is fixedly connected to the water inlet pipe by hot melt adhesive, and the water inlet pipe is fixedly connected to the plug by hot melt adhesive.

[0015] Preferably, the microporous gelling material infiltration irrigation emitter is in the shape of a plate, a cylinder, a cone, a sphere or a multi-layer shape.

[0016] More preferably, when the microporous gelling material seepage irrigation device is in the shape of a plate, it has a length of 10 to 20 cm, a width of 7 to 10 cm, and a height of 2 to 4 cm.

[0017] The reason why the microporous gelling material seepage irrigation sprinkler has good anti-clogging performance is mainly due to its unique microporous structure and material properties. The microporous gelling material used in the microporous gelling material seepage irrigation sprinkler forms a porous structure through a blending liquid and high-temperature sintering reaction during the preparation process. The pore size and distribution are precisely designed to effectively prevent larger particles and impurities from entering the water flow channel. The micropores in the material are evenly distributed, and when water flows through, it can generate a certain flow disturbance in the pores, reducing the accumulation of sediment. The porosity of the microporous gelling material seepage irrigation sprinkler is relatively high, ensuring good water permeability. At the same time, during long-term use, the microporous structure formed on its surface is not easily clogged, avoiding the flow rate drop caused by particle accumulation. The pH of the microporous gelling material is close to neutral, and it itself has good water resistance and resistance to biological contamination, further reducing the risk of biological clogging caused by the growth of algae and microorganisms.

[0018] A method for preparing the microporous gelling material infiltration irrigation device comprises the following steps: S1. Calcination: Place an appropriate amount of dolomite in a dynamic calciner and calcine to obtain active MgO; S2, hydration: grinding the active MgO obtained in step S1, adding the blending liquid, modifier and water, and stirring to form a slurry; S3, shaping: placing the slurry obtained in step S2 in a mold and hardening and shaping it at room temperature to obtain a microporous gelling material permeable body; S4, assembling: assembling the microporous gelling material water seepage body obtained in step S3 with the water inlet pipe and the plug to obtain the microporous gelling material water seepage emitter.

[0019] Preferably, the calcination temperature in step S1 is 750-850° C., and the calcination time is 4-5 h.

[0020] Preferably, the blending liquid in step S2 is a magnesium chloride aqueous solution, and the modifier is fly ash.

[0021] Preferably, the molar ratio of the activated magnesium oxide, the blending solution, and water in step S2 is 4-6:1:8. When the molar ratio of the activated MgO to the MgCl2 is 4-6, the 5MgO·MgCl2·8H2O generated by the reaction is stable.

[0022] Preferably, the amount of the modifier added in step S2 is 20% to 40% of the total mass of the activated magnesium oxide, the blending solution and water.

[0023] Preferably, the hardening setting temperature in step S3 is not lower than 10°C.

[0024] The active MgO obtained by calcining dolomite has a porous structure because MgCO3 (the main component of dolomite) decomposes CO2 and H2O during the calcination process. The chemical reactions that occur during the calcination of dolomite are as follows: .

[0025] After the obtained active MgO is ground, MgCl2 aqueous solution, fly ash and a small amount of water are added and stirred into a slurry. The hydration reaction that occurs is as follows:

[0026] Wherein, MgO represents active magnesium oxide, x MgO· y MgCl2· z H2O represents magnesium cementitious material.

[0027] A hydration reaction occurs under the action of the blending liquid. When the generated Mg(OH)2 reaches saturation, the hydration product no longer dissolves but precipitates in the form of a colloid, forming a gel. This then gradually grows into a number of fine grains through crystallization, causing the slurry to solidify and harden, thereby generating strength. To shorten the hydration reaction time, a small amount of water is added to dilute the MgCl2 aqueous solution. To enhance the water resistance of the microporous gelling material plate-shaped infiltration irrigation emitter, fly ash is added. The pH of the microporous gelling material is close to neutral and has no corrosive effect.

[0028] The microporous cementitious material has good wear resistance, which is twice that of traditional silicate cement; the microporous cementitious material infiltration irrigation device is resistant to salt and alkali corrosion and is suitable for irrigation operations in saline-alkali lands in the Northeast Plain, Northwest arid and semi-arid areas, the Huanghuaihai Plain and the eastern coastal areas.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. High efficiency and water saving: The microporous gelling material infiltration irrigation emitter provided by the present invention has good water permeability due to the use of microporous gelling material. It can effectively control the water volume, avoid water waste, significantly improve the water resource utilization efficiency of irrigation, and has high irrigation uniformity, which can ensure that crops absorb water evenly and meet the water needs of plants.

[0030] 2. Excellent mechanical properties: The microporous gelling material infiltration irrigation emitter provided by the present invention adopts a special microporous gelling material with excellent mechanical properties. It can be used for a long time in various environments without being easily damaged. In particular, it performs outstandingly in terms of compression and bending resistance. It is suitable for use in various soil and climatic conditions, further ensuring its practicality and durability in agricultural irrigation.

[0031] 3. Low-cost and environmentally friendly: The microporous gelling material irrigation emitter provided by this invention is simple to prepare. Its main raw materials, dolomite and fly ash, are readily available, reducing production costs. Furthermore, the use of fly ash as a modifier effectively utilizes waste, mitigates environmental pollution, and contributes to the development of sustainable agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the three-dimensional structure of an under-tube microporous gelling material plate-shaped infiltration irrigation emitter; Figure 2 It is a schematic diagram of the three-dimensional structure of an inter-tube microporous gelling material plate-shaped infiltration irrigation emitter; Figure 3 It is the contour map of moisture content in wetted body at different irrigation durations; Among them: 1, microporous gel material water seepage body; 2, water storage cavity; 3, plug; 4, water inlet pipe. DETAILED DESCRIPTION

[0033] The technical scheme of the present invention is further described below through examples. The raw materials used in the examples can be purchased from the market or prepared by conventional methods.

[0034] Example 1 A microporous gelling material plate-shaped infiltration irrigation device such as Figure 1As shown, it includes a plate-shaped microporous gel material water seepage body 1, the length, width and height of the microporous gel material water seepage body 1 are 10 cm, 7 cm and 2 cm respectively; a water storage chamber 2 is provided inside the microporous gel material water seepage body 1, and a water inlet is provided on the wall of the microporous gel material water seepage body 1. The water inlet is penetrated by a water inlet pipe 4, one end of the water inlet pipe 4 is connected to the water storage chamber 2, and the other end is provided with a plug 3. The water inlet and the water inlet pipe 4 are fixedly connected by hot melt adhesive, and the water inlet pipe 4 and the plug 3 are fixedly connected by hot melt adhesive; the bottom of the water inlet pipe 4 passes through a fixing piece, and the end is provided with a water outlet hole; the plug 3 and the water inlet pipe 4 are both made of polyethylene.

[0035] The microporous gelling material infiltration irrigation device is installed in an under-pipe installation manner.

[0036] The preparation method of the microporous gel material plate-shaped infiltration irrigation emitter comprises the following steps: A method for preparing a microporous gelling material infiltration irrigation device comprises the following steps: S1. Calcination: Place an appropriate amount of dolomite in a dynamic calcining furnace and calcine it at a temperature of 800°C for 4 hours to obtain active MgO. S2. Hydration: After the active MgO obtained in step S1 is fully ground into a ball mill, an appropriate amount of active MgO is taken out, and an aqueous MgCl2 solution and water are added in a ratio of n(MgO):n(MgCl2):n(H2O)=5:1:8, and the mixture is stirred into a slurry. The slurry is weighed, and fly ash is added in an amount of 30% by weight of the slurry, and the mixture is stirred evenly to obtain a slurry. S3, shaping: placing the slurry obtained in step S2 in a mold and hardening and shaping it at room temperature to obtain a microporous gelling material permeable body; S4, assembling: assembling the microporous gelling material water seepage body obtained in step S3 with the water inlet pipe and the plug, and fixing them with hot melt adhesive to obtain the microporous gelling material water seepage emitter.

[0037] Example 2 A microporous gelling material plate-shaped infiltration irrigation device such as Figure 2As shown, it includes a plate-shaped microporous gel material water seepage body 1, the length, width and height of the microporous gel material water seepage body are 10 cm, 7 cm and 2 cm respectively; a water storage chamber 2 is provided inside the microporous gel material water seepage body 1, and a water inlet is provided on each of the opposite walls of the microporous gel material water seepage body 1. The water inlet is penetrated by a water inlet pipe 4, one end of the water inlet pipe 4 is connected to the water storage chamber 2, and the other end is provided with a plug 3. The water inlet and the water inlet pipe 4 are fixedly connected by hot melt adhesive, and the water inlet pipe 4 and the plug 3 are fixedly connected by hot melt adhesive; the bottom of the water inlet pipe 4 passes through a fixing member and the end is provided with a water outlet; the plug 3 and the water inlet pipe 4 are both made of polyethylene.

[0038] The microporous gelling material infiltration irrigation device is installed in an inter-pipe installation manner.

[0039] The preparation method of the microporous gel material plate-shaped infiltration irrigation emitter comprises the following steps: A method for preparing a microporous gelling material infiltration irrigation device comprises the following steps: S1. Calcination: Place an appropriate amount of dolomite in a dynamic calcining furnace and calcine it at a temperature of 800°C for 4 hours to obtain active MgO. S2. Hydration: After the active MgO obtained in step S1 is fully ground into a ball mill, an appropriate amount of active MgO is taken out, and an aqueous MgCl2 solution and water are added in a ratio of n(MgO):n(MgCl2):n(H2O)=5:1:8, and the mixture is stirred into a slurry. The slurry is weighed, and fly ash is added in an amount of 30% by weight of the slurry, and the mixture is stirred evenly to obtain a slurry. S3, shaping: placing the slurry obtained in step S2 in a mold and hardening and shaping it at room temperature to obtain a microporous gelling material permeable body; S4, assembling: assembling the microporous gelling material water seepage body obtained in step S3 with the water inlet pipe and the plug, and fixing them with hot melt adhesive to obtain the microporous gelling material water seepage emitter.

[0040] Example 3 The microporous gelling material plate-shaped infiltration irrigation device obtained in Example 1 can be used in a variety of ways: 1. Surface irrigation: In surface irrigation, the under-tube microporous cementitious material plate-shaped infiltration irrigation device is installed under the main water supply pipeline, laid flat on the surface, and arranged along the crop rows or root areas. Water penetrates evenly into the surface through the micropores for crop absorption.

[0041] 2. Underground irrigation: In underground irrigation, the under-tube emitter is buried in the soil, located in the middle and lower part of the main distribution layer of the crop root system. Water directly penetrates into the soil through micropores for root absorption.

[0042] Example 4 The microporous gelling material plate-shaped infiltration irrigation device obtained in Example 2 can be used in a variety of ways: 1. Surface irrigation: In surface irrigation, the inter-tube type is laid between two water pipes, spanning the pipes and covering the crop root area. Water enters the emitter from one pipe and penetrates to the surface through micropores. The unabsorbed water can flow into the other pipe, realizing water recycling.

[0043] 2. Underground irrigation: In underground irrigation, inter-tube emitters are also buried underground, with both ends connected to buried water pipes. They are laid out in parallel or in a grid pattern according to the crop layout. Water enters the emitter from one side of the pipe for infiltration and the remaining water flows into the other side of the pipe, forming a cycle and reducing water waste.

[0044] Testing and Analysis The inter-tube microporous gelling material plate-shaped infiltration irrigation device obtained in Example 2 was subjected to performance testing: 1. Density test Under room temperature, standardized operation, high-precision electronic balance was used to measure the sample mass, and the volume was calculated by measuring the size. The density value was obtained by dividing the mass by the volume. The measured density of the microporous cementitious material seepage body was 1.86g / cm 3 .

[0045] 2. Compressive strength test Compressive strength testing was performed using a compression testing machine. Samples were prepared as regular cubes according to ASTM C109 and then left for 6 and 12 hours before testing. The samples were placed in the fixture of the compression testing machine and gradually loaded at a constant loading rate (0.5 to 1 MPa / s). The maximum load at which the sample ruptured was recorded, and the compressive strength was calculated.

[0046] The compressive strength after 6 hours at room temperature is 9.2 MPa, and after 12 hours the compressive strength can reach 19.5 MPa, and the flexural strength is 58.29 MPa.

[0047] 3. Water permeability test Fix the inter-tube microporous cementitious material plate-shaped infiltration irrigation emitter on the horizontal test bench to ensure that it is sealed and leak-free. Connect the water head pressure device and adjust it to 3 m head pressure. After the water flow stabilizes, record the total flow rate per unit time (1 hour). The result is 7.92 L / h.

[0048] Tests show that the emitter has excellent mechanical properties and water permeability, and can meet the actual application needs of agricultural irrigation.

[0049] 4. Simulation test using Hydrus-2D software The inter-tube microporous gelling material plate-shaped infiltration irrigation emitter obtained in Example 2 was numerically simulated using Hydrus-2D software. Sandy loam, a characteristic soil suitable for citrus growth in Yichang, was selected as an example to measure its soil moisture content, bulk density, and other parameters required for the simulation, as shown in Table 1.

[0050] Table 1 Hydraulic characteristic parameters of the VG-M model of the test soil samples

[0051] The obtained parameters were input into Hydrus-2D software for numerical simulation. The results are as follows: Figure 3 As shown in the figure, after 6 hours of irrigation, the wetting front formed by the microporous cementitious plate-shaped infiltration emitter moved laterally at a faster rate, but there was no significant difference in the distance moved upward or downward. As the irrigation time increased to 12 hours, the wetting front's downward movement, influenced by gravity, intensified. When the irrigation time reached 18 hours, the downward movement of the wetting front, influenced by gravity, further intensified. After 24 hours of irrigation, the wetting front reached 50 cm below the simulated soil box. As 80% of citrus roots are located in the soil 10-50 cm below the surface, this microporous cementitious plate-shaped infiltration emitter can fully meet the irrigation water needs of citrus.

[0052] 5. Irrigation uniformity test Calculate irrigation uniformity using the Christiansen uniformity coefficient: .

[0053] Where, is the Christiansen coefficient; For the i Soil moisture content at each measuring point, cm 3 / cm 3 ; is the average soil moisture content, cm 3 / cm 3 ; n is the number of measuring points.

[0054] The irrigation uniformity corresponding to the four irrigation durations is shown in Table 2.

[0055] Table 2 Irrigation uniformity at different irrigation times

[0056] As shown in Table 2, the irrigation uniformity achieved using plate-shaped emitters is consistently above 0.9, meeting the requirements for a wetting uniformity Cu greater than 0.9 for micro-irrigation systems as specified in the "Technical Standards for Water-Saving Irrigation Engineering" and the "Technical Standards for Micro-Irrigation Engineering." Subsurface drip irrigation achieves this high-uniformity water-saving technology. Compared to traditional irrigation methods, it significantly improves water utilization efficiency while meeting plant water needs, thus conserving water resources.

[0057] It should be understood that the above embodiments are only intended to illustrate the present invention and are not intended to limit the scope of protection of the present invention. In addition, it should be understood that after reading the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A microporous gelling material infiltration irrigation device, characterized in that: It comprises a microporous gelling material water seepage body, wherein a water storage cavity is arranged inside the microporous gelling material water seepage body, a water inlet is arranged on the wall of the microporous gelling material water seepage body, a water inlet pipe is passed through the water inlet, one end of the water inlet pipe is connected with the water storage cavity, and the other end is provided with a plug.

2. The microporous gelling material infiltration irrigation device according to claim 1 is characterized in that: The porosity of the water seepage body of the microporous gelling material is 30%-35%, and the pore size is 12-15 μm.

3. The microporous gelling material infiltration irrigation device according to claim 1 is characterized in that: The microporous gelling material infiltration irrigation device has two installation modes: under-tube type and between-tube type.

4. The microporous gelling material infiltration irrigation device according to claim 1 is characterized in that: The bottom of the water inlet pipe passes through the fixing piece, and the end is provided with a water inlet hole.

5. The microporous gelling material infiltration irrigation device according to claim 1, characterized in that: The plug and the water inlet pipe are both made of polyethylene.

6. The microporous gelling material infiltration irrigation device according to claim 1, characterized in that: The shape of the microporous gelling material infiltration irrigation device is plate-like, cylindrical, conical, spherical or multi-layered.

7. A method for preparing a microporous gelling material infiltration irrigation device as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Calcination: calcining an appropriate amount of dolomite in a dynamic calcining furnace to obtain active MgO; S2, hydration: grinding the active MgO obtained in step S1, adding the blending liquid, the modifier and water, and stirring to form a slurry; S3, shaping: placing the slurry obtained in step S2 in a mold, and hardening and shaping it at room temperature, thereby obtaining a microporous gelling material water-permeable body; S4, assembling: assembling the microporous gelling material water seepage body obtained in step S3 with the water inlet pipe and the plug to obtain the microporous gelling material water seepage irrigation device.

8. The method for preparing the microporous gelling material infiltration irrigation device according to claim 7, characterized in that: The calcination temperature in step S1 is 750-850°C, and the calcination time is 4-5 h.

9. The method for preparing the microporous gelling material infiltration irrigation device according to claim 7, characterized in that: The blending liquid described in step S2 is a magnesium chloride aqueous solution, and the modifier is fly ash; the molar ratio of the active magnesium oxide, the blending liquid and the water described in step S2 is 4-6:1:8; the added amount of the modifier described in step S2 is 20%-40% of the total mass of the active magnesium oxide, the blending liquid and the water.

10. The method for preparing the microporous gelling material infiltration irrigation device according to claim 7, characterized in that: The hardening setting in step S3 is not less than 10°C.

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