A kind of subgrade moisture content detector and detection method

Abstract

This invention relates to a roadbed moisture content detector and detection method. The invention effectively solves the problems of low detection accuracy and potential safety hazards in roadbed moisture content detection. The technical solution includes two methods: contact and non-contact water absorption detection. First, the acetylene generated by the contact water absorption method is ignited to generate heat, causing water trapped in the soil sample and difficult to contact with calcium carbide to evaporate. This allows the water to come into contact with the calcium carbide that is not in contact with the soil sample, achieving complete absorption of water from the soil sample. The moisture content is calculated by collecting the carbon dioxide gas generated during combustion, ensuring the accuracy of the detection results while also utilizing the generated acetylene gas.

Description

Technical Field

[0001] This invention relates to the field of roadbed construction testing technology, and in particular to a roadbed moisture content analyzer and testing method. Background Technology

[0002] During roadbed construction, it is essential to ensure the compaction degree of the roadbed. Factors affecting the compaction effect of the roadbed include internal and external factors. Internal factors refer to soil quality and moisture content, while external factors refer to compaction function and other external natural and human factors during compaction. Among these, the moisture content of the roadbed soil is one of the important factors affecting the quality of roadbed construction and is also one of the issues that road engineers are most concerned about in the quality control of roadbed construction.

[0003] Existing methods for determining the moisture content of roadbeds include the drying method, alcohol combustion method, capacitance method, and calcium carbide weight loss method. When using the drying method, the results are relatively accurate and less affected by factors. However, the drying time is too long (ranging from 6-8 hours to 8-10 hours), which can affect the construction progress of highway projects.

[0004] The alcohol combustion method is suitable for quickly and easily determining the moisture content of fine-grained soil, but its measurement results differ significantly from the actual situation because alcohol is difficult to burn dry clay soil, and moist soil is difficult to crush, which also reduces the accuracy of the alcohol combustion method.

[0005] The advantages of the capacitance method are its simplicity, speed, and convenience, and it can be used for on-site measurements. The disadvantage is that the measurement range is limited. For example, the error is large when measuring soil samples with a moisture content of more than 20% (different soils have large differences in conductivity, and the organic matter content is different, resulting in a large error at high moisture content).

[0006] The calcium carbide loss-of-gravity method, which involves absorbing water from a soil sample with calcium carbide and calculating the moisture content of the subgrade by detecting the amount of acetylene gas generated in the reaction, is widely used in road construction for detecting subgrade moisture content due to its relatively low susceptibility to environmental and human factors, fast detection speed, and lack of limitations between indoor and outdoor settings. However, it is difficult to ensure that all the water in the soil sample comes into contact with the calcium carbide and reacts to generate acetylene gas when the sample is mixed, leading to discrepancies between the test results and the actual moisture content. Furthermore, the generated acetylene gas is flammable, posing a safety hazard if released into the air. Additionally, if gas leakage occurs during indoor testing, it can lead to poisoning of the testing personnel (acetylene has an anesthetic effect, and at high concentrations, it can cause symptoms of hypoxia, such as headache, dizziness, nausea, and vomiting).

[0007] In view of this, we provide a roadbed moisture content detector and detection method to solve the above problems. Summary of the Invention

[0008] This invention provides a roadbed moisture content detector and detection method. The solution includes two water absorption detection methods: contact water absorption and non-contact water absorption. First, the acetylene generated by the contact water absorption method is ignited to generate heat, thereby causing the water mixed in the soil sample and difficult to contact with calcium carbide to evaporate. This allows the water to come into contact with the calcium carbide that has not been in contact with the soil sample, achieving complete absorption of water in the soil sample. The moisture content is calculated by collecting the carbon dioxide gas generated by combustion, ensuring the accuracy of the detection results while also utilizing the generated acetylene gas.

[0009] A roadbed moisture content detector includes a detection cylinder, characterized in that a stirring unit is provided inside the detection cylinder and a plurality of storage air bladders are arranged around the upper end of the stirring unit at intervals, the plurality of storage air bladders are connected to an external air supply unit, and a plurality of adjusting air bladders arranged vertically at intervals around the stirring unit located above the plurality of storage air bladders are arranged around the stirring unit, and the storage air bladders and adjusting air bladders store calcium carbide powder.

[0010] An annular high-pressure chamber is coaxially arranged inside the detection cylinder above the stirring unit and fixed to the inner wall of the detection cylinder. The annular high-pressure chamber stores inert gas. Several of the regulating air bags are connected to one axial side of the annular high-pressure chamber, and the other axial side of the annular high-pressure chamber is connected to several regulating air bags via an air pump.

[0011] The bottom wall of the detection cylinder is coaxially provided with a conical hopper, and the conical hopper is connected to the detection cylinder space located above the stirring unit via a gas supply pipe. The conical hopper is provided with a ignition mechanism and is connected to an external oxygen supply device. The bottom of the conical hopper is connected to an exhaust pipe, and the other end of the exhaust pipe is inserted into a collection bottle, which stores lime water.

[0012] The beneficial effects of the above technical solution are as follows:

[0013] (1) This scheme includes two water absorption detection methods: contact water absorption and non-contact water absorption. First, the acetylene generated by the contact water absorption method is ignited to generate heat, thereby causing the water mixed in the soil sample and difficult to contact with calcium carbide to evaporate. Then, the water in the soil sample is brought into contact with the calcium carbide that has not been in contact with the soil sample, thus achieving complete absorption of water in the soil sample. The water content is calculated by collecting the carbon dioxide gas generated by combustion, which ensures the accuracy of the detection results and also utilizes the generated acetylene gas (avoiding its emission into the air and causing harm, and saving the cumbersome process of special treatment afterward).

[0014] (2) In this scheme, the combination of the annular high-pressure chamber and several regulating air bags enables the acetylene gas generated to be delivered into the conical bucket (combustion) under controllable conditions to ensure the supply of heat. In addition, the annular high-pressure chamber releases gas (reduces the temperature of the annular high-pressure chamber wall, which helps to condense water vapor in the air into droplets and react with calcium carbide) and fills gas (raises the temperature of the annular high-pressure chamber wall, which is more conducive to the evaporation of water in the soil sample). Moreover, as the gas in the regulating air bags is recovered, the pressure in the space above the detection tube is reduced, which is more conducive to the evaporation of water in the soil sample, so as to collect water in the soil sample that is difficult to contact with calcium carbide. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the internal structure of the detection cylinder after cross-section.

[0017] Figure 3 This is a schematic diagram of the internal structure of the annular high-pressure cavity of the present invention after cross-section.

[0018] Figure 4 This is a schematic diagram showing the relationship between the stirring unit and the annular high-pressure chamber of the present invention;

[0019] Figure 5 This is a schematic diagram showing the installation relationship of the annular high-pressure cavity and several receiving rings of the present invention;

[0020] Figure 6 This is a schematic diagram of the internal structure of the stirring shaft of the present invention;

[0021] Figure 7 This is a schematic diagram of the storage airbag and regulating airbag of the present invention when they are filled with calcium carbide.

[0022] Figure 8 This is a schematic diagram showing the positional distribution of the ignition mechanism of the present invention within the conical hopper;

[0023] Figure 9 This is a schematic diagram showing the installation relationship between the movable column and the conduit in this invention. Detailed Implementation

[0024] The foregoing and other technical contents, features and effects of the present invention are described in conjunction with the appendix below. Figures 1 to 9 As will be clearly shown in the detailed description of the embodiments, the structural contents mentioned in the following embodiments are all based on the accompanying drawings.

[0025] Example 1: This example provides a roadbed moisture content detector, as shown in the attached document. Figure 1 As shown, including the detection cylinder 1, the improvement of this solution lies in:

[0026] As attached Figure 3 As shown, a stirring unit is provided inside the detection cylinder 1, and several storage air bladders 2 are arranged around the upper end of the stirring unit at intervals. The storage air bladders 2 are connected to an external air supply unit (the external air supply unit can supply inert gas into the storage air bladders 2). Several sets of regulating air bladders 3 are provided on the stirring unit located above the storage air bladders 2, as shown in the attached diagram. Figure 4 As shown in the diagram, this scheme is described using an example of four regulating airbags 3 per group. Two groups of regulating airbags 3 are set at a certain vertical distance. This scheme is further described using an example of two storage airbags 2 (the number of storage airbags 2 and regulating airbags 3 can be adjusted according to actual conditions). Each storage airbag 2 and regulating airbag 3 stores a certain amount of calcium carbide powder particles, ensuring that the regulating airbags 3 and storage airbags 2 are positioned as shown in the diagram under the gravity of the calcium carbide powder particles. Figure 7 The state shown;

[0027] An annular high-pressure chamber 5, fixed to the inner wall of the detection cylinder 1 and located coaxially above the stirring unit, is provided inside the detection cylinder 1. The annular high-pressure chamber 5 stores an inert gas (argon, which is highly inert, neither flammable nor combustion-supporting) with a certain gas pressure (greater than standard atmospheric pressure). One axial side of the annular high-pressure chamber 5 is connected to several regulating gas bags 3, and the other axial side of the annular high-pressure chamber 5 is connected to several regulating gas bags 3 via an air pump 7, as shown in the attached diagram. Figure 2 As shown, a conical hopper 8 is installed on the bottom wall of the detection cylinder 1, and the conical hopper 8 and the bottom wall of the detection cylinder 1 form a sealed space. Gas supply pipes 4 are respectively provided on both axial sides of the detection cylinder 1 above the annular high-pressure chamber 5, and are connected to it (the gas supply pipes 4 are normally non-conductive; they only become conductive when the gas pressure inside the detection cylinder 1 reaches the required parameters). The other end of the gas supply pipes 4 is connected to the conical hopper 8. An ignition mechanism 35 is provided inside the conical hopper 8, and the conical hopper 8 is connected to an external oxygen supply device (which can supply oxygen into the conical hopper 8). An exhaust pipe 9 is connected to the bottom of the conical hopper 8, and the other end of the exhaust pipe 9 is inserted into the collection bottle 10 (the other end of the exhaust pipe 9 opens near the bottom of the collection bottle 10). The collection bottle 10 stores a lime water solution (used to collect carbon dioxide gas). In specific operation, this embodiment works as follows:

[0028] The staff first placed the soil sample to be tested into testing tube 1, as shown in the attached... Figure 1 As shown, a feeding port can be provided on the top wall of the testing cylinder 1 to allow the soil sample to be tested to be fed into the testing cylinder 1 through the feeding port, as shown in the attached diagram. Figure 2As shown, it is important to note that the amount of soil sample in the testing cylinder 1 should meet the following requirements: the upper surface of the soil sample should be located below the lower surface of the annular high-pressure chamber 5 (not exceeding the lower surface of the annular high-pressure chamber 5). After a certain amount of soil sample is fed into the testing cylinder 1, the staff will seal the feeding port (to prevent internal gas leakage during the testing process). Then, the staff will start the stirring unit to rotate at a certain speed and first inflate the storage air bladder 2 through the external air supply unit to make it expand, so that it is filled with excessive inert gas and bursts (when several storage air bladders 2 burst, the external air supply unit will stop supplying gas), thereby realizing the storage of the soil sample. The calcium carbide powder particles inside the air bladder 2 are scattered outwards (under the action of the explosion shock wave, the calcium carbide powder particles stored inside it spread outwards in the detection cylinder 1 and fall onto the surface of the soil sample). Since the stirring unit is always rotating, when the air bladder 2 explodes and the calcium carbide powder particles stored inside it diffuse outwards, it will cover as much area as possible inside the detection cylinder 1 as the stirring unit rotates, so that every part of the surface of the soil sample is covered by calcium carbide powder particles as much as possible (which helps to better mix with the soil sample under the action of the stirring unit, making the mixture more uniform).

[0029] Under the action of the stirring unit, the calcium carbide powder particles falling on the surface of the soil sample mix with the soil sample, thereby allowing the calcium carbide powder particles to absorb water from the soil sample and undergo a chemical reaction: CaC2 + 2H2O ═ Ca(OH)2 + C2H2 (gas). During the above reaction, acetylene gas is generated and overflows from the soil sample into the space above the detection cylinder 1. (Note: In this scheme, the inert gas supplied by the external gas supply unit to the storage gas bladder 2 is argon, with a density of 1.784 g / L.) The argon concentration is higher than 1.2416 g / L for acetylene gas. Therefore, when the storage gasbag 2 bursts, the argon gas exists in the space located on the upper surface of the soil sample, while the generated acetylene gas, due to its lower density, moves upward and resides in the space above the detection cylinder 1. Additionally, the reaction process releases heat (causing the temperature inside the soil sample to rise). After the reaction continues for a certain period, the operator controls the annular high-pressure chamber 5 to inflate several regulating gasbags 3 (causing the regulating gasbags 3 to expand to a certain extent), thus increasing the gas pressure inside the detection cylinder 1. When the gas pressure inside the detection cylinder 1 rises to the required parameters, the gas supply pipe 4 opens (note: the gas supply pipe 4 is set to automatically close after a certain period of time), thereby actively transporting the acetylene gas located at the top of the detection cylinder 1 into the conical hopper 8 through the opened gas supply pipe 4. At this time, the external oxygen supply equipment connected to the conical hopper 8 supplies oxygen into the conical hopper 8 at a certain flow rate, and the ignition mechanism 35 located in the conical hopper 8 is activated, thereby achieving that when the acetylene gas enters the conical hopper 8, it mixes with oxygen and burns in the conical hopper 8 under the action of the ignition mechanism 35 (2C). (2H₂ + 5O₂ → 4CO₂ + 2H₂O) This generates heat and produces carbon dioxide gas and water (Note: Except for the bottom wall, the entire part of the detection cylinder 1 is covered with heat-insulating material, and the outer wall of the conical hopper 8 is also covered with heat-insulating material. The bottom wall of the detection cylinder 1 is made of a material with high thermal conductivity). The heat generated by the mixing and combustion of acetylene and oxygen is transferred to the soil sample through the bottom wall of the detection cylinder 1, further increasing the internal temperature of the soil sample. This helps to evaporate the water in the soil sample that has not yet come into contact with the calcium carbide powder particles under the action of heat. The water is released and diffused into the space above the detection cylinder 1 (the stirring unit cannot ensure that the calcium carbide powder particles fully contact and mix with all the water in the soil sample). Note: When the initial storage airbag 2 bursts, some calcium carbide powder particles will adhere to the wall of the annular high-pressure chamber 5. When the water evaporates from the soil sample and moves upward, it will come into contact with the calcium carbide powder adhering to the wall of the annular high-pressure chamber 5, and a chemical reaction will occur to generate acetylene gas (achieving that the water in the soil sample that is difficult to contact with calcium carbide powder can also come into contact with calcium carbide powder and be absorbed).

[0030] Note: After the regulating air bladders 3 have expanded for a certain period of time, the operator controls the air pump 7 to start and draws the gas originally filled into the regulating air bladders 3 back into the annular high-pressure chamber 5. During this process, the regulating air bladders 3 gradually deflate until they return to their initial state. During the above process, the air pressure in the space above the detection cylinder 1 gradually decreases. When the regulating air bladders 3 return to their initial state, the air pressure in the space above the detection cylinder 1 is lower than the standard atmospheric pressure (in a certain degree of negative pressure). That is, the air pressure in the space above the detection cylinder 1 is reduced, which is more conducive to the evaporation of water mixed in the soil sample that has not yet come into contact with the calcium carbide powder in the soil sample (the air pressure decreases and the evaporation is accelerated). Thus, under the dual effects of temperature and air pressure, the water in the soil sample that has not come into contact with the calcium carbide powder evaporates better. (In this embodiment, the operator can control the annular high-pressure chamber 5 to repeatedly perform inflation and deflation operations on the regulating air bladders 3 to actively and controllably deliver acetylene gas into the conical hopper 8).

[0031] As the testing process continues (the space above the soil sample in test cylinder 1 will contain high humidity due to the evaporation of some water from the soil sample), and the water in the soil sample reacts with the calcium carbide powder to continue generating acetylene gas, the air pressure inside test cylinder 1 gradually increases (i.e., the acetylene content inside test cylinder 1 gradually increases). A humidity sensor can be installed in the upper space of test cylinder 1 to monitor the air humidity inside test cylinder 1 (indicating that there is a significant amount of moisture in the space above test cylinder 1 at this time). When the humidity exceeds a certain range, the operator controls the annular high-pressure chamber 5 to inflate several regulating air bladders 3 in one group (the lower group) and fills them with excessive gas (to the point that the regulating air bladders 3 rupture), thereby achieving... The calcium carbide powder particles stored in the regulating air bladder 3 are scattered into the space of the detection cylinder 1 located above the soil sample. Under the rotation of the stirring unit, the scattered calcium carbide powder particles are evenly scattered into as many detection cylinder 1 spaces as possible above the soil sample. During the fall, the scattered calcium carbide powder particles come into contact with and react with the moisture in the humid air (generating acetylene gas), thus achieving the effect of collecting the moisture diffused in the air. In addition, during the fall, some of the calcium carbide powder particles will adhere to the wall of the annular high-pressure chamber 5 (replenishing the calcium carbide powder on the wall of the annular high-pressure chamber 5), and the other part will fall onto the upper surface of the soil sample (mixing with the soil sample under the action of the stirring unit).

[0032] Because the above process is rapid, the above effect can be achieved in a short time. Then, the staff controls the annular high-pressure chamber 5 to inflate the remaining set of regulating air bladders 3 (located at the upper end) to the set level, thereby raising the air pressure inside the detection cylinder 1 to the required parameter value. At this time, the gas supply pipe 4 opens and continues to supply gas (containing acetylene and inert gas: argon) into the conical hopper 8. Finally, the gas burns and generates heat inside the conical hopper 8, which is used to heat the soil sample inside the detection cylinder 1 (so that the water in the soil sample that has not yet come into contact with the calcium carbide powder can better evaporate and adhere to the annular high-pressure chamber 5). (The calcium carbide powder on the wall of the pressure chamber 5 is absorbed). After several regulating air bags 3 are inflated and remain inflated for a certain period of time, the air pump 7 is started and the gas is drawn back into the annular high-pressure chamber 5 (the following process is the same as above and will not be described in detail here). As the detection process continues, when the gas humidity in the detection cylinder 1 reaches the required range again, excess gas is injected into the remaining set of regulating air bags 3 through the annular high-pressure chamber 5 and the bags are ruptured. This allows the absorption of moisture in the air with high humidity in the space above the detection cylinder 1, thereby absorbing as much moisture as possible from the soil sample and reacting it with the calcium carbide powder to produce acetylene gas.

[0033] As attached Figure 2 As shown, acetylene gas is burned in conical hopper 8 to produce carbon dioxide gas. The produced carbon dioxide gas is transported to limewater in collection bottle 10 through exhaust pipe 9 and absorbed by limewater. Although argon gas is soluble in water, its solubility is extremely small (the impact on the detection results is negligible). Finally, the amount of carbon dioxide gas produced can be calculated by weighing the increase in weight of collection bottle 10. The amount of acetylene gas produced can be calculated by the amount of carbon dioxide gas produced using the chemical formula: 2C2H2+5O2→4CO2+2H2O. Then, the water content in the soil sample can be calculated using the chemical formula: CaC2+2H2O═Ca(OH)2+C2H2.

[0034] In this embodiment, the generated acetylene gas is burned in a sealed environment, and the heat generated by the combustion is used to better evaporate the moisture mixed in the soil sample that is difficult to contact with the calcium carbide powder. Then, the calcium carbide powder particles thrown out by the bursting of several regulating airbags 3 come into contact with and are absorbed by the evaporated moisture located in the space above the detection cylinder 1. This solves both the problem of subsequent treatment of acetylene gas and the problem that the calcium carbide powder and the moisture in the soil sample cannot be thoroughly mixed under traditional physical stirring.

[0035] Example 2, based on Example 1, as shown in the appendix. Figure 3As shown, the inner wall of the annular high-pressure chamber 5 is triangular and includes an upper end 12 and a lower end 13 connected at a certain angle (the lower end 13 is inclined upward at a certain angle, which will not hinder the upward movement of acetylene gas generated in the soil sample, thus serving as a guide). The upper end 12 is longer than the lower end 13 (in order to allow more calcium carbide powder to adhere to the upper end 12 position, increasing the storage capacity of calcium carbide powder, so as to absorb the moisture evaporated into the air). The surface of the upper end 12 is vertically spaced with several horizontally arranged receiving rings 14 (as shown in the attached diagram). Figure 4 As shown), in this embodiment, the outer wall of the lower end 13 is covered with a layer of thermal insulation material, and the area outside the receiving ring 14 on the upper end 12 is also covered with a layer of thermal insulation material (the area of ​​the upper end 12 covered by several receiving rings 14 is not covered with thermal insulation material). In specific implementation of this embodiment, it is as follows:

[0036] As attached Figure 5 As shown, several receiving rings 14 are vertically spaced at the upper end 12 of the annular high-pressure chamber 5. This design allows for the retention of more calcium carbide powder particles at the horizontal position of the receiving rings 14 when the storage airbag 2 and regulating airbag 3 burst and scatter calcium carbide powder particles outwards. (Because the upper end 12 of the annular high-pressure chamber 5 is inclined, the amount of calcium carbide powder retained in this area is relatively small, resulting in a reduced amount of moisture absorbed and evaporated into the air.) By setting several receiving rings 14, a larger amount of calcium carbide powder particles can be stored on the receiving rings 14 (as shown in the attached diagram). Figure 5 As shown in the enlarged view in the middle, this allows for better absorption of moisture evaporated into the air (ensuring that as much moisture as possible is absorbed from the soil sample).

[0037] In addition, except for the area covered by several receiving rings 14, the rest of the wall of the annular high-pressure chamber 5 is covered with thermal insulation material. When the operator controls the annular high-pressure chamber 5 to inflate the regulating air bladders 3, the high-pressure inert gas inside the annular high-pressure chamber 5 does work on the outside, causing its internal temperature to decrease (except for the area covered by the receiving rings 14, the rest of the wall is covered with thermal insulation material, and the process of inflating the gas inside the annular high-pressure chamber 5 into the regulating air bladders 3 can be approximated as the adiabatic expansion of the high-pressure gas inside the annular high-pressure chamber 5). When the annular high-pressure chamber 5 inflates the regulating air bladders 3, the area covered by the receiving rings 14 is located (as shown in the attached figure). Figure 5The temperature of the upper end 12 in region F drops rapidly (creating a low-temperature zone), which causes the moisture in the air in or near this region to condense into small droplets and eventually fall onto the upper end 12 (to gather the moisture evaporated into the air as much as possible). This allows the calcium carbide powder particles attached to the surface of the upper end 12 to be absorbed. If there is too much moisture, the gathered droplets will flow down the slope of the upper end 12 and eventually flow to the horizontal surface of the corresponding receiving ring 14 (i.e., the location where a large amount of calcium carbide powder particles are stored). The calcium carbide powder particles attached to the surface of the upper end 12 and the calcium carbide powder particles on the upper surface of the receiving ring 14 can continuously absorb the moisture evaporated into the space above the detection cylinder 1. The bursting of the two sets of regulating airbags 3 and the throwing of calcium carbide powder into the outside can only absorb the moisture floating in the air within a specific time. Therefore, by combining the above two methods, a better absorption effect on the moisture diffused in the air can be achieved.

[0038] Similarly, when the air pump 7 starts and draws the gas from the regulating airbag 3 back into the annular high-pressure chamber 5, the air pressure inside the annular high-pressure chamber 5 will further increase (doing work on the compression of the gas inside), causing its internal temperature to rise. This, in turn, causes the temperature at the upper end 12 wall position within the F region to rise, and radiates heat to the F region and the space near the F region through heat transfer (i.e., causing the attached...). Figure 3 The temperature within the G region increases, thereby increasing the temperature in the space above the detection cylinder 1, which is more conducive to the evaporation of water mixed in the soil sample. The heat generated by the reaction of calcium carbide powder with water and the heat generated by the combustion of acetylene work together to promote the evaporation of water in the soil sample that has not come into contact with calcium carbide powder into the space above the detection cylinder 1 (thereby utilizing the calcium carbide powder thrown outward by the bursting of the regulating airbag 3, the calcium carbide powder adhering to the surface of the upper end 12, and the calcium carbide powder on the horizontal surface of the receiving ring 14 to achieve the absorption of as much water in the soil sample as possible).

[0039] Example 3, based on Example 2, as shown in the appendix. Figure 4 As shown, the stirring unit includes a stirring shaft 15 rotatably mounted on the detection cylinder 1 (the stirring shaft 15 is driven by a motor located on the top wall of the detection cylinder 1). The bottom of the stirring shaft 15 is provided with stirring blades 16, and several sets of connecting pipes 17 are vertically spaced on the stirring shaft 15 above the stirring blades 16. The regulating airbag 3 is connected to the corresponding connecting pipe 17 (the connecting pipe 17 can be inserted into the regulating airbag 3 through the port of the regulating airbag 3, and then the regulating airbag 3 can be secured to the connecting pipe 17 by a rope. A sealing rubber ring can be provided on the outer wall of the connecting pipe 17 to ensure the airtightness between the regulating airbag 3 and the connecting pipe 17). The connecting pipe 17 is provided with an electric control valve 18 (several electric control valves 18 are electrically connected to a microcontroller).

[0040] As attached Figure 6 As shown, an upward-through air passage 19 is coaxially arranged inside the stirring shaft 15 (the air passage 19 is connected to several connecting pipes 17). A conversion chamber 20 is fitted to one end of the stirring shaft 15 extending upwards from the detection cylinder 1 (the conversion chamber 20 is fixed to the detection cylinder 1 and rotatably mounted with the stirring shaft 15 to accommodate the rotation of the stirring shaft 15). See attached... Figure 3 As shown, control pipes 21 are respectively provided on both sides of the conversion chamber 20 and connected to it (the other end of the control pipe 21 is connected to the annular high-pressure chamber 5). One control pipe 21 is equipped with a throttle valve 22 (the throttle valve 22 is electrically connected to the microcontroller), and the air pump 7 is installed on the other control pipe 21. In this embodiment, the specific implementation is as follows:

[0041] When it is necessary to inflate the regulating air bladder 3, the operator controls the throttle valve 22 to open via the microcontroller and simultaneously controls the electrically controlled valve 18 installed on the connecting pipe 17 to open. Subsequently, the high-pressure inert gas in the annular high-pressure chamber 5 is inflated into several regulating air bladders 3 at a certain flow rate under the action of the throttle valve 22, so that the several regulating air bladders 3 expand to a certain extent (thus increasing the gas pressure in the detection cylinder 1, until the gas pressure increases to the required parameters, the gas supply pipe 4 opens and transmits acetylene gas into the conical hopper 8). Then the microcontroller... The controller closes the throttle valve 22 and starts the air pump 7, so that the inert gas filled into several regulating air bags 3 is drawn back into the annular high-pressure chamber 5. Note: A filter screen (not shown in the figure) can be provided at the connection position between the connecting pipe 17 and the regulating air bag 3 to prevent the calcium carbide powder particles stored in the regulating air bag 3 from being drawn out with the airflow when the air pump 7 starts and draws the inert gas back into the annular high-pressure chamber 5. The filter screen is set to filter the calcium carbide powder particles and keep them in the regulating air bag 3.

[0042] When the air humidity in the space above the detection cylinder 1 reaches the required parameter, the microcontroller controls the opening of the set of electrically controlled valves 18 located below and on the connecting pipe 17, and the annular high-pressure chamber 5 fills the regulating airbag 3 with an excessive amount of inert gas (causing it to burst), thereby absorbing the moisture floating in the air. When the air humidity reaches the required parameter again, the microcontroller controls the opening of the set of electrically controlled valves 18 located above and on the connecting pipe 17, with the same effect as above, which will not be described in detail here.

[0043] Example 4, based on Example 1, as shown in the appendix. Figure 6As shown, an air chamber 23 is provided in the stirring shaft 15 located below the air passage 19, and several storage air bags 2 are connected to the air chamber 23 via conduit 24. A gas pipe connected to the air chamber 23 is coaxially provided in the stirring shaft 15, and the gas pipe extends upward out of the stirring shaft 15 and is connected to a transition chamber 6 (the transition chamber 6 is fixed on the detection cylinder 1 and is rotatably installed with the gas pipe). The upper end of the transition chamber 6 is connected to an external gas supply unit via a pipe. Initially, the external gas supply unit fills the several storage air bags 2 with inert gas (argon) through the transition chamber 6, the gas pipe, and the conduit 24, causing them to burst, thereby scattering the calcium carbide powder particles in the detection cylinder 1 (a small portion falls on the wall of the annular high-pressure chamber 5, and a large portion falls on the upper surface of the soil sample).

[0044] Example 5, based on Example 4, as shown in the appendix. Figure 6 As shown, a channel 26 is provided through the storage airbag 2 and is connected to the conduit 24 (the material used to form the channel 26 is the same as the material used to form the storage airbag 2). The channel 26 and the conduit 24 in the storage airbag 2 are installed in the same way as the connection between the adjusting airbag 3 and the connecting pipe 17 (i.e., the conduit 24 is inserted into the channel 26 and the storage airbag 2 is secured to the conduit 24 by a rope). Branch pipes 27 are provided on both sides of the conduit 24 and are connected to the storage airbag 2. A movable column 28 is slidably installed in the conduit 24 (with a spring connected to the conduit 24). A through hole 29 is coaxially provided in the movable column 28 and branch holes 30 connected to the through hole 29 are provided on both sides of the movable column 28 away from the storage airbag 2. Figure 9 As shown, a circular plate 31 is coaxially fixed inside the end of the conduit 24 near the storage airbag 2, and the diameter of the circular plate 31 is slightly larger than the inner diameter of the through hole 29. In this embodiment, the specific implementation is as follows:

[0045] First, the staff introduces sufficient inert gas (argon) into the detection cylinder 1 through the external gas supply unit via transition chamber 6, gas pipe, gas chamber 23, conduit 24, and channel 26. This allows the air originally located in the detection cylinder 1 to be discharged outward through gas supply pipe 4, conical hopper 8, and exhaust pipe 9. The carbon dioxide gas originally located in the detection cylinder 1, gas supply pipe 4, conical hopper 8, and exhaust pipe 9 is then drawn into the lime water by the inert gas (achieving carbon dioxide gas collection). Once the weight of the collection bottle 10 (set as g1) no longer increases, the external gas supply unit stops supplying gas (at this point, the detection cylinder 1...). The carbon dioxide gas in the inner gas inlet pipe 4, conical hopper 8, and exhaust pipe 9 has been completely discharged and absorbed by lime water. Note: Although argon is slightly soluble in water, it will not dissolve in water when its solubility reaches its limit. Therefore, the detection experiment can be started as long as the weight of the collection bottle 10 no longer increases (the above operation is used to eliminate the influence of carbon dioxide gas in the detection cylinder 1 on the detection results). When the detection is finished, weigh the collection bottle 10 (set as g2). g2 minus g1 is the weight of the carbon dioxide to be measured. The water content in the soil sample can then be calculated according to the above chemical formula.

[0046] Note: When the weight of the collection bottle 10 hardly increases (indicating that the moisture in the soil sample has been completely absorbed), it is necessary to fill the detection cylinder 1 with sufficient inert gas (argon) through the external gas supply unit to thoroughly clean the carbon dioxide gas remaining in the detection cylinder 1, gas supply pipe 4, conical hopper 8, and exhaust pipe 9 and pass it into the lime water.

[0047] In its natural state, the movable column 28 is positioned as shown by the spring connected to it. Figure 6 At the indicated position (where branch pipe 27 and branch hole 30 are not corresponding and not connected), the operator controls the external gas supply unit to fill the detection cylinder 1 with inert gas and ensures that the above process is carried out at a relatively slow flow rate. During this process, the inert gas is directly delivered through the through hole 29 to the channel 26 and finally enters the detection cylinder 1 (the moving column 28 experiences minimal impact from the gas and will not come into contact with the circular plate 31). After the carbon dioxide gas is completely removed, the external gas supply unit is controlled to continue supplying inert gas into the conduit 24 at a higher flow rate. When the gas flow rate is relatively high, the moving column 28 is subjected to a large gas impact force and stretches the spring connected to it (so that the moving column 28 abuts against the circular plate 31, and the circular plate 31 blocks the through hole 29). At this time, the branch hole 30 in the moving column 28 moves to the position corresponding to the branch pipe 27 and achieves communication. Then, the high-velocity inert gas flows rapidly into the storage air bag 2 through the branch hole 30 and the branch pipe 27, so that an excessive amount of inert gas is filled into it and it bursts (so that the calcium carbide powder particles stored inside are thrown and released to the outside).

[0048] Example 6, based on Example 1, as shown in the appendix. Figure 2 As shown, a pressure valve 32 (electrically connected to the microcontroller) is provided on the gas supply pipe 4, and a waterproof and breathable membrane 33 is provided at the connection between the gas supply pipe 4 and the detection cylinder 1. As the regulating airbag 3 expands, the air pressure inside the detection cylinder 1 gradually increases. When the internal air pressure reaches the required parameters, the microcontroller controls the pressure valve 32 to open for a certain period of time and then close (severing the connection with the conical hopper 8). During the opening phase, the acetylene gas generated inside the detection cylinder 1 is transported to the conical hopper 8 through the gas supply pipe 4.

[0049] After the pressure valve 32 is closed, the gas in several regulating air bladders 3 is drawn back into the annular high-pressure chamber 5, which reduces the air pressure in the detection cylinder 1 (helping the water in the soil sample that has not come into contact with the calcium carbide powder particles to evaporate more easily to the outside). A waterproof and breathable membrane 33 is provided at the connection between the gas supply pipe 4 and the detection cylinder 1 to prevent the water in the detection cylinder 1 from flowing into the gas supply pipe 4 with the flow of gas (causing water loss and affecting the test results), while not hindering the passage of gas, thus achieving the effect of water blocking and air passage.

[0050] Example 7, based on Example 1, as shown in the appendix Figure 2 As shown, the two ends of the exhaust pipe 9 are at different heights, and the end of the exhaust pipe 9 that connects to the conical hopper 8 is lower than the end of the exhaust pipe 9 that is fitted with the collection bottle 10. The reason for this setting is that water is produced during the combustion of acetylene, and the different heights of the two ends of the exhaust pipe 9 can prevent the generated water from flowing into the collection bottle 10, which would increase the weight of the collection bottle 10 (affecting the test results).

[0051] Example 8, based on Example 1, as shown in the appendix. Figure 2 As shown, a baffle plate 34 is coaxially mounted inside the conical hopper 8 and is driven by the stirring shaft 15, as shown in the attached diagram. Figure 4 As shown, the baffle 34 rotates synchronously with the stirring shaft 15, causing it to rotate within the conical hopper 8. When acetylene gas enters the conical hopper 8 through the gas delivery pipe 4, the rotation of the baffle 34 helps to evenly disperse the acetylene gas accumulated at the connection between the gas delivery pipe 4 and the conical hopper 8 into other areas within the conical hopper 8, as illustrated in the attached diagram. Figure 1 As shown, multiple sets of oxygen delivery pipes 11 are arranged around the outer wall of the conical bucket 8 at intervals, and the oxygen delivery pipes 11 are connected to the external oxygen supply equipment via valves. When the microcontroller controls the pressure valve 32 to open, the microcontroller synchronously controls the valve to open and the external oxygen supply equipment delivers oxygen into the conical bucket 8.

[0052] As attached Figure 8As shown, the ignition mechanism 35 includes several ignition heads spaced around the wall of the conical bucket 8 (the principle is similar to that of a lighter, which will not be described in detail here). Under the action of the baffle 34, the acetylene gas and oxygen are diffused in the conical bucket 8 and ignited by the ignition mechanism 35, causing them to burn and generate heat (to heat the soil samples in different parts of the detection cylinder 1).

[0053] Note: An external oxygen supply device can introduce sufficient oxygen into the conical hopper 8. Once the acetylene is completely burned, there will be no more combustion in the conical hopper 8. Although oxygen is also soluble in water, its solubility is extremely small. When the carbon dioxide gas in the initial cleaning of the detection cylinder 1 was removed, the oxygen content in the lime water was already saturated. Therefore, even if more oxygen is introduced into the lime water later, it will not dissolve in it (and will not affect the detection results).

[0054] Example 9, a method for detecting the moisture content of roadbed, using a roadbed moisture content detector as described in any one of claims 1-8, characterized by comprising the following steps:

[0055] S1: First, put an appropriate amount of soil sample into the test tube;

[0056] S2: Inert gas is introduced into the detection cylinder through the external air supply unit until all the air in the detection cylinder, air supply pipe, conical hopper, and exhaust pipe is discharged;

[0057] S3: When the weight inside the collection bottle no longer increases, the external air supply unit introduces inert gas into the storage air bladder, causing the storage air bladder to expand until it bursts, thus sprinkling calcium carbide powder particles onto the surface of the soil sample.

[0058] S4: The stirring unit starts to mix the calcium carbide powder with the soil sample evenly. The generated acetylene gas enters the conical hopper through the gas delivery pipe and burns inside. The heat generated by the combustion of acetylene causes the water in the soil sample that has not come into contact with the calcium carbide powder particles to evaporate. At the same time, the combustion of acetylene also prevents it from being emitted into the outside world (polluting the environment).

[0059] S5: Control the annular high-pressure chamber to fill a certain amount of inert gas into several regulating airbags, regulate the expansion of the airbags and force the acetylene gas in the detection cylinder into the conical bucket;

[0060] S6: When the regulating airbag inflates to the set level, the annular high-pressure chamber retracts the inert gas that was originally filled into the regulating airbag;

[0061] S7: Repeat steps S5-S6 at regular intervals. When the humidity inside the detection cylinder reaches the set level, control the annular high-pressure chamber to introduce excess gas into a group of regulating air bladders below and cause them to expand and burst. During the fall, the calcium carbide powder particles come into contact with the moisture in the air and absorb the moisture (generating acetylene gas), thereby reducing the humidity of the air in the space above the detection cylinder.

[0062] S8: When the humidity of the air inside the detection cylinder is set to a certain level again, the control ring high-pressure chamber will introduce excessive gas into a group of regulating air bladders above and cause them to expand and burst, thereby achieving the absorption of moisture floating in the air once again.

[0063] The above is merely for illustrating the present invention. It should be understood that the present invention is not limited to the above embodiments, and various modifications that conform to the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A roadbed moisture content detector, comprising a detection cylinder (1), characterized in that, The detection cylinder (1) is equipped with a stirring unit and a number of storage air bags (2) are arranged around the upper end of the stirring unit at intervals. The storage air bags (2) are connected to an external air supply unit. A number of adjustment air bags (3) are arranged vertically around the stirring unit on the upper end of the storage air bags (2). The storage air bags (2) and adjustment air bags (3) store calcium carbide powder particles. An annular high-pressure chamber (5) is coaxially provided in the detection cylinder (1) above the stirring unit and fixed on the inner wall of the detection cylinder (1). The annular high-pressure chamber (5) stores inert gas. Several of the regulating air bags (3) are connected to one side of the annular high-pressure chamber (5) in the axial direction, and the other side of the annular high-pressure chamber (5) is connected to several regulating air bags (3) via an air pump (7). The bottom wall of the detection cylinder (1) is coaxially provided with a conical hopper (8), and the conical hopper (8) is connected to the space of the detection cylinder (1) located above the stirring unit through the gas supply pipe (4). The conical hopper (8) is provided with a ignition mechanism (35) and is connected to an external oxygen supply device. The bottom of the conical hopper (8) is connected to an exhaust pipe (9), and the other end of the exhaust pipe (9) is inserted into the collection bottle (10). The collection bottle (10) stores lime water.

2. The roadbed moisture content detector according to claim 1, characterized in that, The inner wall of the annular high-pressure chamber (5) is triangular and includes an upper end (12) and a lower end (13) connected at a certain angle. The upper end (12) is longer than the lower end (13) and the surface of the upper end (12) is vertically spaced with several horizontally arranged receiving rings (14).

3. A roadbed moisture content detector according to claim 2, characterized in that, The stirring unit includes a stirring shaft (15) and stirring blades (16), and several sets of connecting pipes (17) are vertically spaced on the stirring shaft (15) above the stirring blades (16). The regulating airbag (3) and the corresponding connecting pipe (17) are connected, and an electric control valve (18) is provided on the connecting pipe (17). The stirring shaft (15) is provided with an upward-through air passage (19) and the air passage (19) is connected to a conversion chamber (20) that is rotatably installed coaxially with the stirring shaft (15). The conversion chamber (20) is provided with control pipes (21) on both sides of the transverse direction, which are connected to the annular high-pressure chamber (5). The air pump (7) is installed on one of the control pipes (21) and a throttle valve (22) is provided on the other control pipe (21).

4. A roadbed moisture content detector according to claim 3, characterized in that, An air chamber (23) is provided in the stirring shaft (15) located below the air passage (19), and several storage air bags (2) are connected to the air chamber (23) via a conduit (24). An extension tube (25) connected to the air chamber (23) is coaxially provided in the stirring shaft (15), and the extension tube (25) extends upward through the stirring shaft (15) and is connected to an external air supply unit.

5. A roadbed moisture content detector according to claim 4, characterized in that, The storage airbag (2) has a channel (26) that is connected to the conduit (24). The storage airbag (2) is connected to the conduit (24) via a branch pipe (27). A movable column (28) is slidably installed coaxially and elastically connected to the conduit (24). A through hole (29) is provided on the movable column (28). Branch holes (30) connected to the through hole (29) are provided on both sides of the movable column (28) along its radial direction. A circular plate (31) is provided coaxially in the conduit (24) at the end of the movable column (28) away from the stirring shaft (15). The diameter of the circular plate (31) is slightly larger than the inner diameter of the through hole (29).

6. A roadbed moisture content detector according to claim 1, characterized in that, The gas supply pipe (4) is equipped with a pressure valve (32) and a waterproof and breathable membrane (33) is provided at the connection between the gas supply pipe (4) and the detection cylinder (1).

7. A roadbed moisture content detector according to claim 1, characterized in that, The two ends of the exhaust pipe (9) are at different heights, and the end of the exhaust pipe (9) that connects to the conical bucket (8) is lower than the end of the exhaust pipe (9) that is connected to the collection bottle (10).

8. A roadbed moisture content detector according to claim 1, characterized in that, A baffle plate (34) is coaxially mounted inside the conical bucket (8) and is driven by the stirring shaft (15).

9. A method for detecting the moisture content of roadbed, using a roadbed moisture content detector as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: First, put an appropriate amount of soil sample into the test tube; S2: Inert gas is introduced into the detection cylinder through the external air supply unit until all the air in the detection cylinder, air supply pipe, conical hopper, and exhaust pipe is discharged; S3: When the weight inside the collection bottle no longer increases, the external gas supply unit introduces inert gas into the storage air bladder, causing the storage air bladder to expand until it bursts. S4: The stirring unit starts to mix the calcium carbide powder particles with the soil sample evenly. The generated acetylene gas enters the conical hopper through the gas delivery pipe and burns inside it. S5: Control the annular high-pressure chamber to fill a certain amount of inert gas into several regulating airbags, regulate the expansion of the airbags and force the acetylene gas in the detection cylinder into the conical bucket; S6: When the regulating airbag inflates to the set level, the annular high-pressure chamber retracts the inert gas that was originally filled into the regulating airbag; S7: Repeat steps S5-S6 at regular intervals. When the humidity inside the detection cylinder reaches a certain level, control the annular high-pressure chamber to introduce excessive gas into a group of regulating air bladders located below, causing them to expand and burst. S8: When the detection process reaches the final stage, control the annular high-pressure chamber to introduce excessive gas into a group of regulating airbags above and cause them to expand and burst.

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