Soil water content adjusting device and method without disturbing soil aggregate structure

Abstract

The invention discloses a soil water content adjusting device and method without disturbing a soil aggregate structure, the device mainly comprises a cylindrical box body and a soil sample storage platform, water mist is conveyed to a soil sample through a PWM speed regulation fan and an ultrasonic nebulizer arranged in the cylindrical box body, and the water content of the soil sample is adjusted. Under the condition that the consistency of the granular structure of the soil sample needs to be maintained in the test process, the device and the method provided by the invention overcome the inherent defects of the existing soil water content operation method. According to the device and the method, mist containing moisture is introduced into soil pores through air pressure difference, the soil moisture content is changed by capillary action, the influence on a soil aggregate structure in a disturbance process in the prior art can be avoided, the stability of a test sample is ensured, the influence on the soil aggregate structure in a moisture content adjusting process is reduced to the greatest extent, and the test accuracy is improved. The possibility is provided for performing finer sample condition control on a soil aggregate structure and designing a more perfect test.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil sample water content preparation and detection, and in particular relates to a test sample preparation device and method for adjusting soil water content without disturbing soil aggregate structure. Background Art

[0002] It is a common requirement of soil laboratories to adjust the moisture content of soil samples before conducting soil tests. Soil moisture content refers to the ratio of soil moisture mass to soil dry mass. Soil moisture refers to liquid water in the pores of soil, which exists in the form of bound water, film water and gravity water. Soil moisture content has a significant impact on the physical and chemical properties of soil, the survival status of soil animals and the activity of soil microorganisms, and can determine the accuracy of test results. In nature, the soil moisture content of healthy soil varies within a certain range. In soil with good infiltration, its moisture content generally does not exceed the field water holding capacity. Field water holding capacity is the ratio of soil moisture mass to soil dry mass after full infiltration and exclusion of gravity water after saturation. When designing soil tests in laboratories, the moisture content should not exceed the field water holding capacity unless there are special circumstances.

[0003] At present, soil laboratories will air-dry and sieve the soil after processing natural sampling to eliminate experimental interference factors such as plant residues and soil animals in the soil. Deionized water is then added to the air-dried and sieved soil, and after manual stirring and mixing, it is weighed to reach the soil moisture content required by the experiment. During the process of water flow impact and manual stirring, the aggregate structure of the soil will be greatly affected. Large aggregates will break into small aggregates, and small aggregates will stick to each other to form large aggregates. This will change the structural properties of the test soil. In experiments that have strict requirements on soil aggregate structure, there is currently a lack of a practical method for preparing test samples to adjust soil moisture content. Summary of the invention

[0004] In order to overcome the above problems existing in the soil test sample preparation process, the purpose of the present invention is to provide an experimental sample preparation method and a supporting device that can adjust the soil moisture content without disturbing the soil aggregate structure. The present invention can accurately and stably adjust the moisture content of the soil sample by combining an atomizing humidification device with a soil test sample preparation device without causing a large disturbance to the test soil.

[0005] The present invention adopts the following technical solution:

[0006] A soil moisture content regulating device that does not disturb the soil aggregate structure, comprising:

[0007] A cylindrical box body, in order from bottom to top, has a water tank for carrying deionized water at the bottom, an ultrasonic atomizer is arranged inside the water tank, and is used to atomize the deionized water into water mist; a PWM speed-regulating fan (pulse width modulation speed-regulating fan) is arranged above the water tank, and is used to transport the generated water mist upward; a mass sensor is arranged above the PWM speed-regulating fan, and is used to weigh the mass change of the soil sample.

[0008] The soil sample storage platform is cylindrical. From bottom to top, the bottom surface of the soil sample storage platform is a soil sample placement screen for placing soil samples to be processed; a water retaining plate is arranged above the soil sample placement screen to prevent condensed water on the inner wall of the box from dripping onto the soil sample, and the space inside the cylindrical box forms a sealed mist chamber; the top of the soil sample storage platform is a top cover with a handle to facilitate the overall taking of the soil sample storage platform.

[0009] Preferably, the material of the cylindrical box is selected from a waterproof and high-strength acrylic material, with a thickness of 5 mm and an inner diameter of 15-30 cm, more preferably 15-25 cm, and more preferably 20 cm.

[0010] Preferably, the water baffle is made of PC plastic material to prevent condensed water on the inner wall of the box from dripping onto the soil sample.

[0011] Preferably, the soil sample placement sieve is a nylon sieve with a pore size of 53 μm.

[0012] Preferably, the diameter of the soil sample storage platform is slightly smaller than the inner diameter of the cylindrical box, and a small gap is left between the side wall of the soil sample storage platform and the side wall of the cylindrical box.

[0013] Preferably, the mass sensor in the cylindrical box is configured as a circular ring structure, and when the soil sample storage platform is placed in the cylindrical box, the soil sample placement screen at the bottom of the soil sample storage platform is seated on the mass sensor to form a sealing structure to prevent water mist from leaking from the gap between the contact surfaces of the two.

[0014] Preferably, a water inlet is provided at the lower part of the cylindrical box body close to the side wall of the water tank for replenishing deionized water into the water tank.

[0015] A soil moisture content regulating method without disturbing the soil aggregate structure, the regulating method adopts the above-mentioned soil moisture content regulating device, and the method comprises:

[0016] 1) placing the soil sample on the soil sample placement screen of the soil sample storage platform and installing a water retaining plate;

[0017] 2) After the top cover is covered, the soil sample storage platform is placed in the cylindrical box;

[0018] 3) Turning on the ultrasonic atomizer and the PWM speed-adjustable fan to deliver water mist to the soil sample to be tested, and recording mass change data according to the mass sensor.

[0019] 4) When the mass sensor reading reaches the target water content, the ultrasonic atomizer and the PWM speed regulating fan are turned off, the experiment is ended, and the soil sample storage platform is taken out from the cylindrical box to obtain the required soil sample.

[0020] Among them, the power of the ultrasonic atomizer and the speed of the PWM speed-regulating fan can control the rising amount and rising speed of the water mist to control the changing speed of the soil moisture content. Both can be adjusted according to the looseness of the soil sample to be tested, experimental requirements, etc.

[0021] Preferably, the power of the ultrasonic atomizer is set to 0-20w, and the speed of the PWM fan is set to between 0-1600RPM, wherein the lower limit of the value 0 indicates that it can be turned off. The fine water droplets formed by the ultrasonic atomizer form a mist atmosphere, so that the mist covers the soil sample, and the soil humidity is adjusted based on the principle of soil water potential energy.

[0022] The mass of the soil sample is measured by the mass sensor. The mass changes when the soil moisture content changes. The change in the moisture content of the soil sample is determined based on the mass sensor reading. The specific formula is:

[0023]

[0024] Where Δw is the change in water content of the soil sample, m 1 is the current reading of the mass sensor, m 0 is the initial mass of soil sample. m s is the dry weight of soil samples.

[0025] Preferably, the soil samples should be placed flatly and evenly on the soil sample placement screen, and should not be piled up to too high a thickness to prevent uneven soil moisture content.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1) The soil moisture adjustment method without disturbing the soil aggregate structure and its supporting device according to the present invention can fill the inherent defects of the existing soil moisture operation method, minimize the impact of the moisture adjustment process on the soil aggregate structure, and provide the possibility of more precise sample condition control of the soil aggregate structure and designing a more complete experiment.

[0028] 2) According to the soil moisture content regulation method without disturbing the soil aggregate structure and its supporting device of the present invention, mist containing water is introduced into the soil pores through the air pressure difference, directly changing the soil moisture content. When the test process needs to maintain the same sample before and after (only the moisture content needs to change), the influence of the disturbance process of the prior art on other properties of the soil can be avoided, thereby ensuring the stability of the test sample.

[0029] 3) According to the soil moisture adjustment method and its supporting device without disturbing the soil aggregate structure of the present invention, the deionized water can be ultrasonically shattered to produce fine water droplets that surround the soil sample, and the soil sample moisture content can be adjusted continuously, smoothly and evenly, avoiding the situation in the prior art where local over-wetting occurs during the process of adding deionized water to the soil.

[0030] 4) According to the soil moisture content adjustment method and its supporting device without disturbing the soil aggregate structure of the present invention, the soil moisture content can be adjusted continuously and smoothly through the mass sensor, and the humidification can be stopped and the sample can be taken out when the target moisture content is reached. Compared with the prior art, the soil moisture content can be adjusted more finely and the test error can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a schematic diagram of the overall structure of the soil moisture content regulating device without disturbing the soil aggregate structure according to the present invention.

[0033] Figure 2 The soil sample storage platform of the soil moisture content regulating device according to the present invention, which does not disturb the soil aggregate structure, can be disassembled separately to place and take out the soil sample.

[0034] Reference numerals:

[0035] 1-top cover of soil sample storage platform with handle; 2-cylindrical box; 3-water baffle; 4-soil sample placement screen; 5-mass sensor; 6-PWM speed regulating fan; 7-fan speed controller and power supply device; 8-water inlet; 9-ultrasonic atomizer; 10-water tank. DETAILED DESCRIPTION

[0036] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general and dictionary meanings, but should be interpreted based on the principle of allowing the inventor to appropriately define the terms for the best interpretation, based on the meaning and concept corresponding to the technical level of the present invention. Therefore, the description herein is only a preferred example for illustrative purposes, and is not intended to limit the scope of the present invention, so it should be understood that other equivalent implementations and modifications can be made without departing from the spirit and scope of the present invention.

[0037] In this document, the terms "include", "including", "have", "contain" or any other similar terms are open conjunctions, which are intended to cover non-exclusive inclusions. For example, a composition or product containing multiple elements is not limited to the elements listed herein, but may also include other elements that are not explicitly listed but are generally inherent to the composition or product. In addition, unless otherwise explicitly stated, the term "or" refers to an inclusive "or" rather than an exclusive "or". For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and A and B are both true (or exist). In addition, in this document, the interpretation of the terms "include", "including", "have", and "contain" should be considered to have been specifically disclosed and simultaneously cover closed or semi-closed conjunctions such as "consisting of" and "consisting essentially of".

[0038] In order to clarify the present invention, parts irrelevant to the description are omitted in the drawings, and the same or similar components are denoted by the same reference numerals throughout the specification.

[0039] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

[0040] Furthermore, the terms used herein are only used to explain exemplary embodiments and are not intended to limit the present invention. Singular expressions also include plural expressions thereof, unless otherwise clearly indicated in the context. Terms such as "comprising", "equipped with" or "having" used herein are used to specify the existence of practical characteristics, numbers, steps, constituent elements or combinations thereof, and should be understood as not excluding the possibility of adding or existing one or more other characteristics, numbers, steps, constituent elements or combinations thereof.

[0041] Also, if a layer or an element is referred to as being formed “on” or “over” a “layer” or “element,” this means that each layer or element is formed directly on the layer or element, or other layers or elements may be formed between layers, bodies, or substrates.

[0042] refer to Figure 1 and Figure 2 The present invention is further described in detail: the soil moisture content regulating device without disturbing the soil aggregate structure according to the present invention comprises:

[0043] The cylindrical box body 2, in order from bottom to top, has a water tank 10 for carrying deionized water at the bottom, an ultrasonic atomizer 9 is arranged inside the water tank for atomizing the deionized water into water mist; a PWM speed-regulating fan 6 (pulse width modulation speed-regulating fan) is arranged above the water tank for conveying the generated water mist upward; a mass sensor 5 is arranged above the PWM speed-regulating fan 6 for weighing the mass change of the soil sample.

[0044] The soil sample storage platform is cylindrical. In order from bottom to top, the bottom surface of the soil sample storage platform is a soil sample placement screen 4 for placing the soil sample to be processed; a water baffle 3 is arranged on the soil sample placement screen 4 to prevent water mist condensation and prevent condensed water from dripping on the soil sample, and the space between the soil sample placement screen 4 and the water baffle 3 forms a sealed mist chamber; the top of the soil sample storage platform is a top cover 1 with a handle, which is convenient for the overall taking of the soil sample storage platform. The ultrasonic atomizer 9 and the PWM fan 6 will cause the temperature inside the box to be slightly higher than the outside. The condensation of water mist requires a temperature difference, so a small amount of lost water mist will condense into water droplets on the inner wall of the cylindrical box 2. Since the water baffle closes the mist chamber, there is no temperature difference between the inside and the outside, so water droplets will not condense, and the condensed water droplets on the inner wall of the cylindrical box 2 will be blocked from falling.

[0045] Preferably, the PWM speed-regulating fan 6 is connected to a fan speed controller and a power supply device 7 .

[0046] Preferably, the amount of soil sample placed at one time does not exceed 300g, the thickness does not exceed 1cm, and the placement thickness is as uniform as possible. Preferably, the amount of soil sample placed at one time is 100-300g, and the thickness is 0.1-1cm. If the amount of soil sample exceeds 300g or the thickness exceeds 1cm, the water mist may not fully enter the soil sample due to the excessive amount of soil sample or the excessive thickness, and the uniform moisture content of the soil cannot be adjusted.

[0047] In the soil moisture content regulating method for disturbing the soil aggregate structure according to the present invention, preferably, the power of the ultrasonic atomizer is set to 0-20w, and the PWM fan speed is set to between 0-1600RPM, wherein the lower limit of the value 0 indicates that it can be turned off. The higher the atomizer power, the higher the mist concentration, and the faster the soil moisture content increases. If the soil moisture content adjustment range is less than 5%, it is recommended to use a power of 0-10W to prevent over-humidification. The faster the PWM fan speed, the faster the air flows in the mist chamber. The speed needs to be controlled so that the soil sample is not dispersed by the airflow.

[0048] As soil moisture increases, the mass of the soil will also increase. When the mass reaches the amount calculated by the following formula, stop humidification. For example, a 100g dry soil sample is placed and it is planned to humidify until the soil moisture content is 20%. Turn on the instrument for humidification. When the mass sensor reads 120g, it means that the dry soil sample has absorbed 20g of water and its moisture content has reached 20%. Stop humidification.

[0049] The following examples are only listed as examples of embodiments of the present invention and do not constitute any limitation to the present invention. It can be understood by those skilled in the art that modifications within the scope of the essence and concept of the present invention fall within the scope of protection of the present invention. Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

[0050] Example 1

[0051] The obtained 200g dry soil sample is evenly spread on the soil sample placement screen 4 with a thickness of 0.6cm, and the soil sample storage platform is placed in the cylindrical box 2 and placed on the annular mass sensor 5. The inner diameter of the cylindrical box 2 is 20cm. Then the water baffle 3 and the top cover 1 are installed in sequence. Turn on the PWM speed-regulating fan 6 and the ultrasonic atomizer 9, the speed of the PWM speed-regulating fan 6 is set to 900RPM, and the power of the ultrasonic atomizer 9 is set to 15W. As the experiment proceeds, the data of the mass sensor 5 is read to 240g, that is, the moisture content of the soil sample is 20%. The experiment is terminated, and the soil sample storage platform is taken as a whole to obtain a soil sample that meets the requirements.

[0052] If the power of the ultrasonic atomizer 9 is lower than 10W and / or the speed of the PWM speed-adjusting fan 6 is set to 300RPM, the experimental time is too long. If the power of the ultrasonic atomizer 9 is higher than 20W, the water vapor is too dense, exceeding the soil capillary water conductivity, causing the apparent moisture content of the soil sample to quickly reach 20%, but the water is mainly enriched in the surface layer of the soil sample, and the internal moisture content of the soil sample is insufficient, and the moisture content is not fully improved. If the speed of the PWM speed-adjusting fan 6 is set to 1600RPM, the air flow rate is too fast, and when the placed soil sample is light, or the soil texture is tight and has poor air permeability, it is easy to cause the soil sample to be blown off the sample placement platform.

[0053] Example 2

[0054] The device of the present invention can also be used to reduce the moisture content of soil. A 300g wet soil sample collected naturally has a dry soil weight of 200g measured by a parallel sample, that is, the natural moisture content is 50%. The sample is evenly laid on the soil sample placement screen 4 with a thickness of 1cm. The soil sample storage platform is placed in the cylindrical box 2 and placed on the annular mass sensor 5. The inner diameter of the cylindrical box 2 is 20cm. Then the water baffle 3 and the top cover 1 are installed in sequence. The PWM speed regulating fan 6 is turned on, and the speed of the PWM speed regulating fan 6 is set to 600RPM. As the experiment proceeds, the data of the mass sensor 5 is read to 260g, that is, the moisture content of the soil sample is 30%. The experiment is terminated, and the soil sample storage platform is taken as a whole to obtain a soil sample that meets the requirements.

[0055] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A soil moisture regulating device that does not disturb the soil aggregate structure, comprising: A cylindrical box, in order from bottom to top, the bottom of the cylindrical box is a water tank for carrying deionized water, an ultrasonic atomizer is arranged inside the water tank, and is used to atomize the deionized water into water mist; a PWM speed-adjustable fan is arranged above the water tank, and is used to transport the generated water mist upward; a mass sensor is arranged above the PWM speed-adjustable fan, and is used to weigh the mass change of the soil sample; The soil sample storage platform is cylindrical. From bottom to top, the bottom surface of the soil sample storage platform is a soil sample placement screen for placing soil samples to be processed; a water retaining plate is arranged above the soil sample placement screen to prevent condensed water on the inner wall of the box from dripping onto the soil sample, and the space inside the cylindrical box forms a sealed mist chamber; the top of the soil sample storage platform is a top cover with a handle to facilitate the overall taking of the soil sample storage platform.

2. The soil moisture regulating device according to claim 1, characterized in that: The material of the cylindrical box is selected from a waterproof and high-strength acrylic material, with a thickness of 5 mm and an inner diameter of 15-30 cm, more preferably 15-25 cm, and more preferably 20 cm.

3. The soil moisture regulating device according to claim 1, characterized in that: The water baffle is made of PC plastic to prevent condensed water on the inner wall of the box from dripping onto the soil sample.

4. The soil moisture regulating device according to claim 1, characterized in that: The soil sample is placed on a nylon mesh with a pore size of 53 μm.

5. The soil moisture regulating device according to claim 1, characterized in that: The diameter of the soil sample storage platform is slightly smaller than the inner diameter of the cylindrical box, and a small gap is left between the side wall of the soil sample storage platform and the side wall of the cylindrical box.

6. The soil moisture regulating device according to claim 1, characterized in that: The mass sensor in the cylindrical box is set as a circular ring structure. When the soil sample storage platform is placed in the cylindrical box, the soil sample placement screen at the bottom of the soil sample storage platform is seated on the mass sensor to form a sealing structure to prevent water mist from leaking from the gap between the contact surfaces of the two.

7. The soil moisture regulating device according to claim 1, characterized in that: A water inlet is arranged at the lower part of the cylindrical box body and close to the side wall of the water tank, for replenishing deionized water into the water tank.

8. A method for regulating soil moisture content without disturbing the soil aggregate structure, the method using the soil moisture regulating device according to any one of claims 1 to 7, the method comprising: 1) placing the soil sample on the soil sample placement screen of the soil sample storage platform and installing a water retaining plate; 2) After the top cover is covered, the soil sample storage platform is placed in the cylindrical box; 3) turning on the ultrasonic atomizer and the PWM speed regulating fan to deliver water mist to the soil sample to be tested, and recording mass change data according to the mass sensor; 4) When the mass sensor reading reaches the target water content, the ultrasonic atomizer and the PWM speed regulating fan are turned off, the experiment is ended, and the soil sample storage platform is taken out from the cylindrical box to obtain the required soil sample.

9. The method according to claim 8, characterized in that The power of the ultrasonic atomizer is set to 0-20w, and the speed of the PWM fan is set to between 0-1600RPM, wherein the lower limit of 0 indicates that it may not be turned on.

10. The method according to claim 8, characterized in that The soil samples need to be placed flat and evenly on the soil sample placement screen and cannot be piled up to a too high thickness to prevent uneven soil moisture content.

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