Microwave drying equipment and traffic roadbed dehumidification method

Abstract

The invention provides microwave drying equipment and a traffic roadbed dehumidification method, and belongs to the technical field of roadbed water damage renovation, the microwave drying equipment comprises a buried drainage pipe, a microwave unit, a fan unit and a control unit, the buried drainage pipe is provided with a wave feed port and a drainage port and is buried in rock-soil filler, and the microwave unit is connected with the fan unit; the microwave unit is communicated with the wave feeding port or the water discharging port and heats the rock-soil filler around the buried water discharging pipe, the fan unit sucks water from the interior of the buried water discharging pipe to the exterior, and the control unit monitors the temperature and humidity in the rock-soil filler and controls the microwave unit and the fan unit to operate. The traffic roadbed dehumidification method sequentially comprises the following steps: delimiting a roadbed dehumidification range, determining parameters of the buried drainage pipe and arranging the buried drainage pipe, installing the microwave unit, the fan unit and the control unit and operating the microwave unit, the fan unit and the control unit, and dehumidifying the roadbed. The device has the advantages that gravity water in rock and soil filler can be drained, thin film water and capillary water can also be drained, and the technical effect of dehumidifying the traffic roadbed is achieved.

Description

Technical Field

[0001] This invention belongs to the field of roadbed water damage control technology, and more specifically, it relates to a microwave drying device and a method for dehumidifying traffic roadbeds. Background Technology

[0002] The roadbed is a major foundational structure for railways and highways, constructed from granular soil and rock materials. This porous medium possesses permeability, water-holding capacity, and capillary action, making it susceptible to infiltration and erosion by atmospheric precipitation and groundwater. This can easily lead to water-rich deformation problems such as fill material deterioration and settlement. Furthermore, due to the water-holding capacity of soil and rock, roadbed drainage and desiccation are difficult and time-consuming, easily causing unevenness in the superrail and pavement damage, threatening traffic safety. High-speed railways and highways operate at high speeds and carry large volumes, resulting in significant post-operation maintenance challenges and risks. Therefore, once roadbed water damage occurs during operation, efficient and convenient drainage and desiccation measures must be implemented.

[0003] Currently, roadbeds mainly employ gravity drainage structures such as seepage blind ditches, drainage pipes, and side ditches. The challenge is that these structures can only remove gravity water from the pores of the roadbed filler, and are only effective for early desiccation when the roadbed has a large amount of seepage and is saturated. However, current high-speed railway and highway roadbed fillers use artificially graded fillers with low porosity and low gravity water content. The main factors contributing to water damage are film water and capillary water. Film water is weakly bound water on the surface of soil particles, while capillary water consists of groundwater rising from the ground and surface suspended water in the tiny interconnected pores of the filler; both can reach levels exceeding 5%. However, conventional gravity drainage structures can only remove free water that migrates by gravity, and cannot remove film water and capillary water. Furthermore, natural hot air drying has limited penetration into the roadbed, only desiccifying the surface and having a limited impact, making it difficult to eradicate roadbed water damage.

[0004] It is evident that in the design and construction of high-grade roadbeds in rainy areas, the technical requirements for drainage structures include the ability to drain early-stage gravity water in both water-rich and saturated states, as well as to eliminate film water and capillary water. Therefore, it is necessary to design a roadbed drainage structure capable of efficiently draining different types of water. Summary of the Invention

[0005] The purpose of this invention is to provide a microwave drying device and a method for dehumidifying roadbeds, which aims to solve the technical problem that existing roadbed drainage structures can only remove gravity water inside the filler, but cannot remove film water and capillary water.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a microwave drying device, comprising: The buried drainage pipe is installed inside the soil and rock fill of the roadbed. One end of the buried drainage pipe is sealed and the other end is open. A positioning column is installed coaxially inside the buried drainage pipe. The side wall of the buried drainage pipe is alternately provided with wave feed ports and drainage ports at equal intervals along its axial direction. A microwave unit has a microwave output terminal, which is connected to the feed port or the drain outlet. The microwave unit is adapted to transmit microwaves to the soil and rock filler around the buried drainage pipe through the feed port or the drain outlet and heat it to remove film water and capillary water. A fan unit is located at one open end of the buried drainage pipe. The exhaust end of the fan unit is connected to the buried drainage pipe and is used to draw water from the inside of the buried drainage pipe to the outside. The control unit is suitable for monitoring the internal temperature and humidity of the soil and rock filler in the roadbed. The control unit is electrically connected to the microwave unit and the fan unit respectively and controls their operation.

[0007] In one possible implementation, the microwave drying apparatus further includes: The power supply has an energy output terminal, which is electrically connected to the microwave unit, the control unit and the fan unit through multiple wire harnesses and is used to supply power. The control unit is adapted to control the power supply to start and stop.

[0008] In one possible implementation, a positioning flange is connected to one end of the open end of the buried drainage pipe, and the positioning post is connected to the positioning flange at one end near the open end of the buried drainage pipe. The positioning flange is used to fix the fan unit.

[0009] In one possible implementation, a cavity suitable for accommodating the microwave unit is formed between the inner wall of the buried drainage pipe and the positioning post, and the microwave unit is coaxially arranged with the positioning post or the buried drainage pipe.

[0010] In one possible implementation, the microwave unit includes: The base column is hollow and is fitted onto the outer circumference of the positioning column and is coaxial with the positioning column. Multiple magnetrons are connected to the outer wall of the base column. The magnetrons are used to generate microwaves, and the microwave output terminal is the microwave output terminal of the magnetron. Waveguides are provided in multiple ways, each corresponding to one of the magnetrons. One end of each waveguide is connected to the microwave output end, and the other end is connected to the feed port or the drainage port. The waveguides are used to convert the microwave oscillations generated by the magnetrons into electromagnetic waves with appropriate propagation modes in the waveguides, and to deliver microwaves into the soil and rock fill material around the buried drainage pipe to heat the soil and rock fill material.

[0011] In one possible implementation, the buried drainage pipe is alternately arranged with one ring of wave feed ports and one ring of drainage ports at equal intervals along its axial direction, with four wave feed ports or drainage ports in each ring, and they are evenly distributed along the circumference of the buried drainage pipe.

[0012] In one possible implementation, the base column is provided with multiple turns of the magnetron at equal intervals along its axial direction. Each turn of the magnetron consists of four magnetrons, which are connected one-to-one with multiple waveguides. The multiple waveguides are connected one-to-one with multiple feed ports.

[0013] In one possible implementation, the wind turbine unit includes: The base is connected to one open end of the buried drainage pipe; A centrifugal motor is connected to the base; An impeller is powered by the centrifugal motor, which is adapted to drive the impeller to rotate and create a negative pressure inside the buried drainage pipe to draw water from the inside of the buried drainage pipe to the outside.

[0014] In one possible implementation, the control unit includes: A PLC controller is electrically connected to the microwave unit and the fan unit, and the PLC controller is adapted to control the operation of the microwave unit and the fan unit respectively; The temperature and humidity sensors are multiple and are all embedded inside the soil and rock fill material of the roadbed, and are suitable for monitoring the temperature and humidity at different locations inside the soil and rock fill material. The data acquisition instrument has its signal input terminal electrically connected to multiple temperature and humidity sensors, and is adapted to acquire temperature and humidity information monitored by the multiple temperature and humidity sensors; the signal output terminal of the data acquisition instrument is electrically connected to the PLC controller, and is adapted to send temperature and humidity information to the PLC controller. The PLC controller has an adjustment module for adjusting the power, frequency, and center wavelength of the microwave unit, thereby controlling the temperature rise, dehumidification efficiency, and effective range of the roadbed.

[0015] The beneficial effects of the microwave drying equipment provided by this invention are as follows: Compared with the prior art, the microwave drying equipment of this invention includes a buried drainage pipe, a microwave unit, a fan unit, and a control unit. The buried drainage pipe is buried inside the rock and soil filler and is equipped with a feed port and a drainage outlet. The microwave unit is used to connect the feed port or the drainage outlet and heat the rock and soil filler around the buried drainage pipe to remove film water and capillary water. The fan unit can draw water from inside the buried drainage pipe to the outside. The control unit can monitor the internal temperature and humidity of the rock and soil filler in real time and control the operation of the microwave unit and the fan unit. This invention has the technical effect of removing both gravity water inside the rock and soil filler and film water and capillary water, thus achieving the dehumidification effect of roadbed.

[0016] The present invention also provides a method for dehumidifying a roadbed, comprising the following steps: S1. Delineate the desiccation range of the roadbed, including the longitudinal length, vertical depth and transverse width along the route; collect soil and rock filler samples within the desiccation range to determine the geometric dimensions and performance parameters of the buried drainage pipe, microwave unit and fan unit. S2. Determine the length, vertical burial depth, and longitudinal spacing of the buried drainage pipes. First, calculate the length of the buried drainage pipes based on the transverse width of the roadbed desiccation range and the design inclination angle of the buried drainage pipes. Second, select half of the vertical depth of the roadbed desiccation range as the vertical burial depth of the buried drainage pipes. S3. According to the underground drainage pipe layout plan determined in S1 and S2, the underground drainage pipe is installed after drilling holes on site, and temperature and humidity sensors are buried at the dehumidification control position. S4. If the roadbed is in a water-rich or saturated state and there is gravity water flowing in the pores of the soil and rock filler, the buried drainage pipe is used as a gravity drainage pipe. Gravity water flows into the buried drainage pipe through the wave feed port and the drainage port, and is discharged at an angle under the action of gravity until the gravity water is basically discharged, leaving mainly particulate film water and capillary water. S5. Install the microwave unit, fan unit, and control unit. First, insert the microwave unit into the first buried drainage pipe and position it by connecting the positioning post of the buried drainage pipe to the base post of the microwave unit, so that the waveguide outlet is connected to the feed port. Second, install the fan unit at the open end of the buried drainage pipe. Then, connect the control unit to the microwave unit, fan unit, and power supply. S6, Subgrade dehumidification; According to the set heating limit, the control unit controls the microwave unit and fan unit to operate until the humidity monitoring value at the subgrade dehumidification control position reaches below the preset target value; S7. Positioning is achieved by connecting the buried drainage pipe positioning column with the microwave unit base column, so that the waveguide outlet is connected to the drainage outlet. At this time, the feed port plays a drainage function, so that there are no dead corners in the microwave dehumidification range. S8. Disassemble the microwave unit, fan unit, and control unit, and assemble them into the next buried drainage pipe. Repeat steps S5, S6, and S7 until the roadbed filler around all buried drainage pipes has been dehydrated.

[0017] The beneficial effects of the dehumidification method for roadbed provided by the present invention are as follows: Compared with the prior art, the dehumidification method for roadbed provided by the present invention can achieve dehumidification of the interior of the roadbed filler by using microwave heating, which can remove gravity water and residual film water and capillary water, so that there are no dead corners in the dehumidification range, improve the drainage effect and achieve the effect of dehumidification of the roadbed. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the underground drainage pipe structure of a microwave drying equipment provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the microwave unit structure of a microwave drying device provided in an embodiment of the present invention; Figure 3 A schematic diagram of the magnetron and waveguide structure of a microwave unit in a microwave drying device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a microwave drying device after the underground drainage pipe and microwave unit are assembled, as provided in an embodiment of the present invention. Figure 5 A schematic cross-sectional view of the buried drainage pipe and microwave unit assembled according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the fan unit structure of a microwave drying device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of a microwave drying equipment with its control unit and power supply integrated and installed in a cabinet, as provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of the electrical connections of a microwave drying device provided in an embodiment of the present invention; Figure 9 A schematic diagram illustrating a solution for applying a microwave drying device to roadbed dehumidification, as provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of a microwave drying device applied to roadbed dehumidification, provided as an embodiment of the present invention. Figure 11 This is a cross-sectional schematic diagram of a microwave drying device used for dehumidifying roadbeds, as provided in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Buried drainage pipe; 101. Positioning post; 102. Wave feed port; 103. Drain outlet; 104. Positioning flange; 2. Microwave unit; 201. Base column; 202. Magnetron; 203. Waveguide; 3. Fan unit; 301. Centrifugal motor; 302. Impeller; 303. Base; 4. Control unit; 401. Temperature and humidity sensor; 402. PLC controller; 403. Data acquisition unit; 404. Cabinet; 5. Power supply. Detailed Implementation

[0021] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0022] Please refer to the following: Figures 1 to 4 The present invention provides a microwave drying device. The microwave drying device includes a buried drainage pipe 1, a microwave unit 2, a fan unit 3, and a control unit 4. The buried drainage pipe 1 is embedded inside the roadbed soil and rock filler. One end of the buried drainage pipe 1 is sealed, and the other end is open. A positioning column 101 is coaxially arranged inside the buried drainage pipe 1. Feed ports 102 and drain ports 103 are alternately arranged at equal intervals along the axial direction of the sidewall of the buried drainage pipe 1. The microwave unit 2 has a microwave output terminal, which is connected to either the feed port 102 or the drain port 103. Microwave unit 2 is adapted to transmit microwaves to the surrounding soil and rock filler material of buried drainage pipe 1 through feed port 102 or drain port 103 and heat it to remove film water and capillary water; fan unit 3 is located at the open end of buried drainage pipe 1, and the exhaust end of fan unit 3 is connected to buried drainage pipe 1 and used to draw water from inside buried drainage pipe 1 to the outside; control unit 4 is adapted to monitor the internal temperature and humidity of the soil and rock filler material of traffic roadbed, and control unit 4 is electrically connected to microwave unit 2 and fan unit 3 respectively and controls their operation respectively.

[0023] The present invention provides a microwave drying device, which, compared with the prior art, alternately arranges wave feed ports 102 and drainage ports 103 at equal intervals along the axial direction of the buried drainage pipe 1 and buries it inside the rock and soil filler. The microwave unit 2 connects the wave feed ports 102 or the drainage ports 103 to heat the rock and soil filler around the buried drainage pipe 1 and remove film water and capillary water. The fan unit 3 can draw water from the inside of the buried drainage pipe 1 to the outside. The control unit 4 can monitor the temperature and humidity inside the rock and soil filler in real time and control the operation of the microwave unit 2 and the fan unit 3 to heat the rock and soil filler around the buried drainage pipe 1 and remove film water and capillary water. The present invention has the technical effect of removing both gravity water inside the rock and soil filler and film water and capillary water.

[0024] In this embodiment, the buried drainage pipe 1 is installed at an angle, meaning its axis forms an angle with the horizontal plane. The buried drainage pipe 1 is inclined at an angle of 2–5°. The microwave output terminal of the microwave unit 2 can be connected to the feed port 102 or the drainage port 103, or they can be switched alternately. After the fan unit 3 draws in air, it can create a negative pressure environment with a certain degree of vacuum inside the buried drainage pipe 1, thereby promoting the discharge of liquid and gaseous moisture from the roadbed to the outside.

[0025] In some embodiments, please refer to Figures 7 to 8 The microwave drying equipment also includes a power supply 5, which has a power output terminal. The power output terminal is electrically connected to the microwave unit 2, the control unit 4, and the fan unit 3 via multiple wire harnesses and is used to supply power. The control unit 4 is suitable for controlling the start and stop of the power supply 5. The control unit 4 is equipped with a control module (such as control buttons) for controlling the operation of the microwave unit 2, the control unit 4, and the fan unit 3. Thus, the operation of the microwave unit 2, the control unit 4, and the fan unit 3 can be controlled by manually operating the control module. This can remove gravity water inside the soil and rock filler, as well as film water and capillary water, thereby achieving dehumidification of the roadbed.

[0026] The present invention also includes a cabinet 404, in which the PLC controller 402 and the data acquisition instrument 403 are both located. There are four sets of power supplies 5. The cabinet 404 has a multi-layer structure, and the PLC controller 402, the data acquisition instrument 403 and the power supplies 5 are all located on the multi-layer structure.

[0027] To achieve the connection between the fan unit 3 and the buried drainage pipe 1, in some embodiments, please refer to... Figure 1 , Figure 4 and Figure 6A positioning flange 104 is connected to one open end of the buried drainage pipe 1. A positioning column 101 is connected to the positioning flange 104 near the open end of the buried drainage pipe 1. The positioning flange 104 is used to fix and connect the fan unit 3. The fan unit 3 is connected and installed on the positioning flange 104. The exhaust end of the fan unit 3 faces the open end of the buried drainage pipe 1 and can draw water out of the buried drainage pipe 1. That is, by suction, a negative pressure environment can be formed inside the buried drainage pipe 1, which is conducive to the discharge of water.

[0028] In this embodiment, the specifications of the positioning flange 104 are matched with the specifications of the fan unit 3 and the buried drainage pipe 1. The buried drainage pipe 1 is a hollow cylindrical metal pipe.

[0029] For ease of installation of microwave unit 2, please refer to the following embodiments: Figures 4 to 5 A cavity suitable for accommodating the microwave unit 2 is formed between the inner wall of the buried drainage pipe 1 and the positioning post 101. The microwave unit 2 is coaxially arranged with the positioning post 101 or the buried drainage pipe 1. By fitting the microwave unit 2 onto the positioning post 101, the microwave unit 2 can be positioned inside the buried drainage pipe 1, and the microwave output end can be connected to the feed port 102 or the drain outlet 103, which facilitates the establishment of a microwave passage, thereby enabling the delivery and heating of microwaves to the surrounding rock and soil filler.

[0030] In some embodiments, please refer to Figures 2 to 3 The microwave unit 2 includes a base column 201, a magnetron 202, and a waveguide 203. The base column 201 is hollow and is fitted onto the outer circumference of the positioning column 101 and is coaxial with the positioning column 101. There are multiple magnetrons 202, all connected to the outer wall of the base column 201. The magnetrons 202 are used to generate microwaves. The microwave output end is the microwave output end of the magnetron 202. The microwave output end of the magnetron 202 is provided with a wave-transparent and waterproof structure, which is preferably made of polytetrafluoroethylene. There are multiple waveguides 203, each corresponding to one of the magnetrons 202. One end of each waveguide 203 is connected to the microwave output end, and the other end is connected to the feed port 102 or the drain port 103. The waveguide 203 is used to convert the microwave oscillation generated by the magnetron 202 into electromagnetic waves with an appropriate propagation mode in the waveguide and to deliver microwaves to the soil and rock filler around the buried drainage pipe 1 to heat the soil and rock filler. The base post 201 is hollow, cylindrical in shape, with an inner diameter equal to or slightly larger than the outer diameter of the positioning post 101. This allows the base post 201 to fit over the positioning post 101, thus positioning the magnetron 202 and waveguide 203, enabling the waveguide 203 to connect and communicate with the feed port 102 or drain port 103. The transmitting end of the magnetron 202 is connected to the waveguide 203. The magnetron 202 is an electrovacuum device used to generate microwaves and serves as the output element of the magnetron 202 within the waveguide 203.

[0031] In some embodiments, please refer to Figure 1 The buried drainage pipe 1 has a ring of feed ports 102 and a ring of drain ports 103 arranged alternately at equal intervals along its axial direction. Each ring of feed ports 102 or drain ports 103 consists of four ports, evenly distributed along the circumference of the buried drainage pipe 1. The feed ports 102 and drain ports 103 are arranged alternately, and the spacing of the waveguide 203 is the same as the spacing of the adjacent two rings of feed ports 102 and drain ports 103, enabling a one-to-one correspondence. The outlet of the waveguide 203 can be completely sealed to the feed ports 102 or drain ports 103 to improve the thermal efficiency of the microwave unit 2 and prevent microwave leakage to avoid accidents that could cause injury.

[0032] In some embodiments, please refer to Figures 2 to 4 The base column 201 has multiple coils of magnetrons 202 evenly spaced along its axial direction. Each coil of magnetrons 202 consists of four coils, each connected to a corresponding waveguide 203. Each waveguide 203 is connected to a corresponding feed port 102. The spacing of the magnetrons 202 is determined by their frequency and center wavelength, aiming to uniformly feed energy to the filler, ensuring uniform drying and effectively preventing localized overheating. The conical shape of the cones ensures that the microwaves emitted by the waveguides 203 are not aligned or intersecting, avoiding microwave interference and ensuring efficient microwave thermal utilization.

[0033] Specifically, the feed port 102 is adapted to uniformly disperse the microwave power irradiated from the waveguide 203 to the roadbed soil and rock fill material around the buried drainage pipe 1.

[0034] In some embodiments, please refer to Figure 6 The fan unit 3 includes a base 303, a centrifugal motor 301, and an impeller 302. The base 303 is connected to the open end of the buried drainage pipe 1; the centrifugal motor 301 is connected to the base 303; the impeller 302 is poweredly connected to the centrifugal motor 301, and the centrifugal motor 301 is adapted to drive the impeller 302 to rotate and create a negative pressure inside the buried drainage pipe 1 to draw water from inside the buried drainage pipe 1 to the outside. The diameter of the impeller 302 is the same as the inner diameter of the open end of the buried drainage pipe 1. The centrifugal motor 301 and the impeller 302 are fixed inside the base 303, which is mounted on the positioning flange 104 at the open end of the buried drainage pipe 1. The centrifugal motor 301 is used to draw water from inside the buried drainage pipe 1 to the outside. A dielectric film is laid on the impeller 302 to shield microwaves and prevent microwave leakage, ensuring that the microwave leakage is <2mW / cm².

[0035] In some embodiments, please refer to Figures 7 to 8The control unit 4 includes a PLC controller 402, temperature and humidity sensors 401, and a data acquisition unit 403. The PLC controller 402 is electrically connected to the microwave unit 2 and the fan unit 3, and is adapted to control the operation of the microwave unit 2 and the fan unit 3 respectively. There are multiple temperature and humidity sensors 401, all of which are buried inside the soil and rock filler of the roadbed, and are adapted to monitor the temperature and humidity at different locations inside the soil and rock filler. The signal input terminal of the data acquisition unit 403 is electrically connected to multiple temperature and humidity sensors 401, and is adapted to collect the temperature and humidity information monitored by multiple temperature and humidity sensors 401. The signal output terminal of the data acquisition unit 403 is electrically connected to the PLC controller 402, and is adapted to send temperature and humidity information to the PLC controller 402. The PLC controller 402 has an adjustment module for adjusting the power, frequency, and center wavelength of the microwave unit 2, thereby controlling the temperature rise, dehumidification efficiency, and effective range of the roadbed. Power supply 5 uses energy storage battery. When the electrical load of microwave unit 2 is large, it can also be connected to the power grid or off-grid photovoltaic and wind power generation system for power supply via PLC controller 402. PLC controller 402 has both automatic and manual operation functions. It controls the operation of microwave unit 2 by monitoring the temperature and humidity of the roadbed through temperature and humidity sensor 401.

[0036] The working principle of the microwave drying equipment in this application is as follows: Microwaves are high-frequency electromagnetic waves with a frequency of 300MHz to 300GHz and a center wavelength of 1mm to 1m. They possess unique characteristics such as short oscillation period and strong penetration ability. Water has a large dielectric constant and dielectric loss coefficient, making it a material capable of absorbing microwaves and converting them into heat energy; it is called a microwave absorbing medium. Simultaneously, water molecules are polar, possessing positive and negative ends, and tend to align with the electric field. When microwaves irradiate the roadbed, the filler material is placed within the high-frequency electric field of the microwaves. The water molecules in its internal pores become polarized and align neatly along the direction of the microwave electric field. Then, they rapidly rotate with the alternating changes in the direction of the high-frequency alternating electric field, generating intense collisions and friction. This converts microwave energy into molecular kinetic energy, manifested as heat, raising the water temperature. Once the temperature reaches the vaporization temperature, the water turns into water vapor, which migrates away from the filler material, thus drying it. Therefore, unlike traditional heat conduction drying methods, the heat conduction direction in the microwave drying process is the same as the moisture diffusion direction, resulting in "heating from the inside out," thus achieving rapid moisture diffusion and high dehumidification efficiency.

[0037] In some embodiments, please refer to Figures 9 to 11The dehumidification scheme for the roadbed using microwave drying equipment is a modular installation method. First, within the area requiring dehumidification, holes are drilled laterally at certain longitudinal intervals on the side slopes of the roadbed, and buried drainage pipes 1 are inserted vertically. The buried drainage pipes 1 are inclined at an angle of 2–5°. Then, microwave unit 2 emits microwaves through feed port 102, causing the moisture inside the roadbed soil and rock filler surrounding the buried drainage pipes 1 to heat up and vaporize into water vapor. When the roadbed boundary is open, the water vapor can be discharged from the top surface or both side slopes of the roadbed. Even when the roadbed boundary is waterproofed, the water vapor can enter the buried drainage pipes 1 through drain outlet 103 and then be drawn out of the roadbed by the fan unit 3 at the open end of the buried drainage pipes 1.

[0038] In addition to dehumidification, microwave drying equipment can also be used to heat and raise the temperature of roadbeds, thus it can also be used to treat frost heave diseases of roadbeds in permafrost areas.

[0039] Preferably, the underground drainage pipe 1 is made of stainless steel and has a diameter of 90-130mm.

[0040] Preferably, the distance between the wave feed port 102 and the drain port 103 of the buried drainage pipe 1 is 0.4 to 1.0 m.

[0041] Preferably, the microwave power of the magnetron 202 is set to 2-5kW, and the frequency setting range is 915-2450MHz.

[0042] Preferably, the feed port 102 is rectangular with dimensions of 40mm × 40mm.

[0043] Preferably, the upper limit of the temperature control of the control unit 4 is 120°C, in order to prevent the filler from thermally solidifying at high temperatures, forming an uneven modulus distribution that would affect the uniformity of the roadbed.

[0044] Preferably, the longitudinal length of the buried drainage pipe 1 is selected to be in the range of 1.5 to 2.5m.

[0045] Preferably, the dielectric film on the impeller 302 is made of silicon oxide.

[0046] For dehumidification zones with specific requirements, there is theoretically a suitable frequency that balances heating effect and heating range. Therefore, this invention also provides a design method for a hot air drying device, specifically including the following steps: S1. Determine the heat required for moisture vaporization of the soil and rock fill material within the dehumidification zone of the roadbed; use the heat calculation formula: Q = c * V * γ *( T s -T 0)+ V * γ * w * L In the formula, c It is the specific heat capacity of the packing, J / (kg·℃); V It is the designated desiccation volume of the roadbed, in meters. 3 ; γ It is the density of the packing material, kg / m³ 3 ; T s This is the vaporization temperature of water, taken as 100℃; T 0 is the natural temperature of the packing material, in °C; w It represents the moisture content of the packing material, %; L It is the latent heat of phase change of water, J / kg. The test method is existing technology and will not be described in detail here.

[0047] S2. Determine the tangent of the medium loss angle of the roadbed fill material at the construction site (tan... δ This parameter refers to the energy consumed by a dielectric to convert electrical energy into heat energy per unit volume per unit time. It is the ratio of the active to reactive components in the dielectric under AC voltage, a dimensionless number that reflects the magnitude of energy loss per unit volume within the dielectric. The Schering bridge method is used for testing; this method is existing technology and will not be elaborated upon here.

[0048] S3. Determine the frequency of the microwave output from magnetron 202 ( ν ) and center wavelength ( λ According to the aforementioned recommendations, the microwave frequency range generated by magnetron 202 is 915–2450 MHz, and the speed of light ( c ) is 3×10 8 m / s, the conversion relationship is: c = λ * ν The wavelengths corresponding to 915MHz and 2450MHz can be calculated to be 0.328m and 0.122m respectively, which are the center wavelengths ( λ The proposed value range is 0.122 to 0.328 m.

[0049] S4. Calculate the microwave penetration length ( L The calculation method is as follows: L = λ 0 / tan δ In the formula, λ 0 represents the intended center wavelength, in meters (m).

[0050] S5. Determine the spacing between adjacent wave feed ports 102 on the wall of the buried drainage pipe 1 and the longitudinal spacing of the buried drainage pipe 1 along the roadbed. The spacing between adjacent wave feed ports 102 on the wall of the buried drainage pipe 1 is taken as follows: L Therefore, by dividing the length of the underground drainage pipe 1 by L The number of magnetrons 202 on microwave unit 2 is four times the calculated result. N The longitudinal spacing of the underground drainage pipes 1 along the roadbed is taken as 2. L .

[0051] S6. Calculate the minimum heat generation power of each magnetron 202 in microwave unit 2. P The calculation method is as follows: P = Q *2 L / ( l * N * t ) In the formula, l The length of the desiccation zone for the roadbed is defined in meters; t The microwave dehumidification time (s) for a single buried drainage pipe 1 is the proposed time.

[0052] S7. Calculate the minimum input power of magnetron 202. V This serves as the basis for selecting the magnetron 202. The calculation method is as follows: V=P / cos φ In the formula, cos φ The power factor is determined by testing the power consumption of the microwave components and the heat storage inside the roadbed. This testing method is existing technology and will not be described in detail here. S8, Calculate the required power supply capacity for power source 5 ( T This serves as the basis for power supply compatibility. The calculation method is as follows: T = V * N The present invention also provides a method for dehumidifying a roadbed, comprising the following steps: S1. Delineate the dehumidification range of the roadbed, including the longitudinal length, vertical depth and transverse width along the route; collect soil and rock filler samples within the dehumidification range to determine the geometric dimensions and performance parameters of the buried drainage pipe 1, microwave unit 2 and fan unit 3. S2. Determine the length, vertical burial depth, and longitudinal spacing of the underground drainage pipe 1. First, calculate the length of the underground drainage pipe 1 based on the transverse width of the roadbed desiccation range and the design inclination angle of the underground drainage pipe 1. Second, select 1 / 2 of the depth as the vertical burial depth of the underground drainage pipe 1 based on the vertical depth of the roadbed desiccation range. S3. According to the layout scheme of the underground drainage pipe 1 determined by S1 and S2, the underground drainage pipe 1 is drilled on site and then implanted, and the temperature and humidity sensor 401 is buried at the dehumidification control position. S4. If the roadbed is in a water-rich or saturated state and there is gravity water flowing in the pores of the soil and rock filler, then the buried drainage pipe 1 is used as a gravity drainage pipe, so that the gravity water flows into the buried drainage pipe 1 through the wave feed port 102 and the drainage port 103, and is discharged at an angle under the action of gravity until the gravity water is basically discharged, leaving mainly particulate film water and capillary water. S5. Install microwave unit 2, fan unit 3, and control unit 4; First, insert microwave unit 2 into the first buried drainage pipe 1, and position it by connecting the positioning post 101 of the buried drainage pipe 1 with the base post 201 of the microwave unit 2, so that the outlet of the waveguide 203 is connected to the feed port 102; Second, install fan unit 3 on the positioning flange 104 at the open end of the buried drainage pipe 1; Then, connect control unit 4 to microwave unit 2, fan unit 3, and power supply 5. S6. Subgrade dehumidification: According to the set heating limit, the control unit 4 controls the microwave unit 2 and the fan unit 3 to operate until the humidity monitoring value at the subgrade dehumidification control position reaches below the preset target value. S7. Positioning is achieved by connecting the positioning column 101 of the underground drainage pipe 1 with the base column 201 of the microwave unit 2, so that the outlet of the waveguide 203 is connected with the drain port 103. At this time, the feed port 102 plays a drainage function so that there are no dead corners in the microwave dehumidification range. S8. Disassemble microwave unit 2, fan unit 3, and control unit 4, and assemble them into the next buried drainage pipe 1. Repeat steps S5, S6, and S7 until the roadbed filler around all buried drainage pipes 1 has been dehydrated.

[0053] The beneficial effects of the dehumidification method for roadbed provided by the present invention are as follows: Compared with the prior art, the dehumidification method for roadbed provided by the present invention can achieve dehumidification of the interior of the roadbed filler by using microwave heating, which can remove gravity water and residual film water and capillary water, so that there are no dead corners in the dehumidification range, improve the drainage effect and achieve the effect of dehumidification of the roadbed.

[0054] The specific analysis is as follows: 1) From the perspective of implementation effectiveness, microwaves have strong penetrating power into porous media fillers and are a non-contact heating method that uses the filler itself as the heat source. In traditional drying processes, to increase the drying speed, the external temperature needs to be raised, increasing the temperature gradient, which can easily lead to uneven temperature distribution and differential material changes. In contrast, microwaves can quickly penetrate the interior of the material, making the drying rate of the filler more uniform. At the same time, it can significantly reduce the drying temperature, and regardless of the state of the filler, heat can penetrate evenly, achieving uniform drying of the roadbed.

[0055] 2) From the perspective of functional principle, the heat of microwaves is generated directly inside the roadbed filler, with little heat loss, high thermal efficiency, and fast heating speed. It can quickly heat the filler in a short time, with low energy consumption and high energy utilization rate.

[0056] 3) From the perspective of implementation process. The microwave drying equipment adopts an assembly and modular installation method, which is convenient to operate. After dehumidification is completed, all components except the buried drainage pipe 1 can be disassembled and removed from the site, resulting in a small footprint and no interference with the normal passage of the line. The equipment is programmed and controlled by a PLC controller 402, with adjustable temperature, continuous operation, and convenient automated management. A temperature and humidity sensor 401 is used to measure the temperature and humidity inside the roadbed and achieve precise control throughout the process.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microwave drying apparatus, characterized in that, include: The buried drainage pipe is installed inside the soil and rock fill of the roadbed. One end of the buried drainage pipe is sealed and the other end is open. A positioning column is installed coaxially inside the buried drainage pipe. The side wall of the buried drainage pipe is alternately provided with wave feed ports and drainage ports at equal intervals along its axial direction. A microwave unit has a microwave output terminal, which is connected to the feed port or the drain outlet. The microwave unit is adapted to transmit microwaves to the soil and rock filler around the buried drainage pipe through the feed port or the drain outlet and heat it to remove film water and capillary water. A fan unit is located at one open end of the buried drainage pipe. The exhaust end of the fan unit is connected to the buried drainage pipe and is used to draw water from the inside of the buried drainage pipe to the outside. The control unit is suitable for monitoring the internal temperature and humidity of the soil and rock filler in the roadbed. The control unit is electrically connected to the microwave unit and the fan unit respectively and controls their operation.

2. The microwave drying equipment as described in claim 1, characterized in that, Also includes: The power supply has an energy output terminal, which is electrically connected to the microwave unit, the control unit and the fan unit through multiple wire harnesses and is used to supply power. The control unit is adapted to control the power supply to start and stop.

3. The microwave drying equipment as described in claim 1, characterized in that, One end of the underground drainage pipe is connected to a positioning flange, and the end of the positioning post near the opening of the underground drainage pipe is connected to the positioning flange. The positioning flange is used to fix the fan unit.

4. The microwave drying equipment as described in claim 1, characterized in that, A cavity suitable for accommodating the microwave unit is formed between the inner wall of the buried drainage pipe and the positioning column, and the microwave unit is coaxially arranged with the positioning column or the buried drainage pipe.

5. The microwave drying equipment as described in claim 4, characterized in that, The microwave unit includes: The base column is hollow and is fitted onto the outer circumference of the positioning column and is coaxial with the positioning column. Multiple magnetrons are connected to the outer wall of the base column. The magnetrons are used to generate microwaves, and the microwave output terminal is the microwave output terminal of the magnetron. Waveguides are provided in multiple ways, each corresponding to one of the magnetrons. One end of each waveguide is connected to the microwave output end, and the other end is connected to the feed port or the drainage port. The waveguides are used to convert the microwave oscillations generated by the magnetrons into electromagnetic waves with appropriate propagation modes in the waveguides, and to deliver microwaves into the soil and rock fill material around the buried drainage pipe to heat the soil and rock fill material.

6. The microwave drying equipment as described in claim 5, characterized in that, The buried drainage pipe is alternately arranged with one ring of wave feed ports and one ring of drainage ports at equal intervals along its axial direction. Each ring of wave feed ports or drainage ports consists of four ports and is evenly distributed along the circumference of the buried drainage pipe.

7. The microwave drying equipment as described in claim 6, characterized in that, The base column is provided with multiple turns of the magnetron at equal intervals along its axial direction. Each turn of the magnetron consists of four magnetrons, which are connected one-to-one with multiple waveguides. The multiple waveguides are connected one-to-one with multiple feed ports.

8. The microwave drying equipment as described in claim 1, characterized in that, The fan unit includes: The base is connected to one open end of the buried drainage pipe; A centrifugal motor is connected to the base; An impeller is powered by the centrifugal motor, which is adapted to drive the impeller to rotate and create a negative pressure inside the buried drainage pipe to draw water from the inside of the buried drainage pipe to the outside.

9. The microwave drying equipment as described in claim 1, characterized in that, The control unit includes: A PLC controller is electrically connected to the microwave unit and the fan unit, and the PLC controller is adapted to control the operation of the microwave unit and the fan unit respectively; The temperature and humidity sensors are multiple and are all embedded inside the soil and rock fill material of the roadbed, and are suitable for monitoring the temperature and humidity at different locations inside the soil and rock fill material. The data acquisition instrument has its signal input terminal electrically connected to multiple temperature and humidity sensors, and is adapted to acquire temperature and humidity information monitored by the multiple temperature and humidity sensors; the signal output terminal of the data acquisition instrument is electrically connected to the PLC controller, and is adapted to send temperature and humidity information to the PLC controller. The PLC controller has an adjustment module for adjusting the power, frequency, and center wavelength of the microwave unit, thereby controlling the temperature rise, dehumidification efficiency, and effective range of the roadbed.

10. A method for dehumidifying roadbed, characterized in that, Includes the following steps: S1. Delineate the desiccation range of the roadbed, including the longitudinal length, vertical depth and transverse width along the route; collect soil and rock filler samples within the desiccation range to determine the geometric dimensions and performance parameters of the buried drainage pipe, microwave unit and fan unit. S2. Determine the length, vertical burial depth, and longitudinal spacing of the buried drainage pipes. First, calculate the length of the buried drainage pipes based on the transverse width of the roadbed desiccation range and the design inclination angle of the buried drainage pipes. Second, select half of the vertical depth of the roadbed desiccation range as the vertical burial depth of the buried drainage pipes. S3. According to the underground drainage pipe layout plan determined in S1 and S2, the underground drainage pipe is installed after drilling holes on site, and temperature and humidity sensors are buried at the dehumidification control position. S4. If the roadbed is in a water-rich or saturated state and there is gravity water flowing in the pores of the soil and rock filler, the buried drainage pipe is used as a gravity drainage pipe. Gravity water flows into the buried drainage pipe through the wave feed port and the drainage port, and is discharged at an angle under the action of gravity until the gravity water is basically discharged, leaving mainly particulate film water and capillary water. S5. Install the microwave unit, fan unit, and control unit. First, insert the microwave unit into the first buried drainage pipe and position it by connecting the positioning post of the buried drainage pipe to the base post of the microwave unit, so that the waveguide outlet is connected to the feed port. Second, install the fan unit at the open end of the buried drainage pipe. Then, connect the control unit to the microwave unit, fan unit, and power supply. S6. Subgrade dehydration; According to the set heating limit, the control unit controls the microwave unit and the fan unit to operate until the humidity monitoring value at the roadbed dehumidification control position reaches below the preset target value; S7. Positioning is achieved by connecting the buried drainage pipe positioning column with the microwave unit base column, so that the waveguide outlet is connected to the drainage outlet. At this time, the feed port plays a drainage function, so that there are no dead corners in the microwave dehumidification range. S8. Disassemble the microwave unit, fan unit, and control unit, and assemble them into the next buried drainage pipe. Repeat steps S5, S6, and S7 until the roadbed filler around all buried drainage pipes has been dehydrated.

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