Device for measuring water content of plastic bottle brick

Abstract

The invention relates to the technical field of plastic bottle recycling, in particular to a device for measuring the water content of a plastic bottle brick, which comprises an automatic conveying line, a microwave transmitting probe and a microwave receiving probe, vertical plates are mounted on a door frame moving along with the line, and when the plastic bottle brick moves to a position between the two vertical plates, the vertical plates are clamped on the side wall of the plastic bottle brick; the line-following moving door frame and the plastic bottle bricks move synchronously; the probe vertical driving assembly is fixedly mounted on the side wall of the vertical plate and is used for driving the microwave transmitting probe and the microwave receiving probe to move up and down; after the line-following moving portal frame moves by a measured width along with the plastic bottle bricks, the reset assembly drives the line-following moving portal frame to move in the direction opposite to the conveying direction of the automatic conveying line. The vertical plate is clamped on the side wall of the plastic bottle brick, so that the microwave transmitting probe and the microwave receiving probe can be close to the side wall of the plastic bottle brick to perform up-and-down reciprocating scanning, and the measurement error of the whole water content is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of plastic bottle recycling, in particular to a device for measuring the water content of a plastic bottle brick. Background Art

[0002] Plastic bottle bricks are rectangular blocks formed from recycled plastic bottles through a pressing process. This pressing process is common at waste recycling stations, where large quantities of collected plastic bottles are placed in a pressing device, which causes them to deform and reduce their volume. Due to the varying tonnage of the pressing devices used by different recycling stations, the specifications of the resulting plastic bottle bricks vary. After pressing, the plastic bottle bricks are bundled to prevent them from loosening or re-expanding. Bundling may involve nylon rope, wire, or polyethylene strapping. The reduced size of the plastic bottle bricks greatly facilitates transportation and effectively reduces transportation costs. These plastic bottle bricks are then shipped to plastic recycling companies for processing and conversion into reusable plastic pellets. To ensure fairness in the plastic bottle brick trade, accurate measurement of the water content within the plastic bottle bricks is crucial, as pressure differences during the pressing process can lead to variations in the water content within the bricks. This can then be deducted during weighing. Furthermore, high moisture content in plastic bottle bricks can negatively impact subsequent recycling processes, such as drying. Specifically, high moisture content significantly increases energy consumption. Therefore, moisture content testing can be used to assess the pressing quality of plastic bottle bricks, enabling precise control of moisture content.

[0003] The Chinese patent with the authorization announcement number CN211318249U discloses a device for real-time detection of moisture changes in a whole package of raw materials, including a microwave transmitting probe, a microwave transmitting and receiving probe, a control host, and a bracket. The microwave transmitting probe and the microwave receiving probe are arranged relative to each other, and the microwave transmitting probe and the microwave receiving probe are respectively connected to the control host through test wires; the microwave transmitting probe includes a microwave transmitting module, a transmitting antenna, and a transmitting centralized control circuit board. The microwave transmitting module is integrated on the transmitting centralized control circuit board, and the transmitting centralized control circuit board is connected to the transmitting antenna. The microwave transmitting module adopts a single-band microwave transmitting module. The microwave receiving probe includes a microwave receiving module. , receiving antenna, receiving centralized control circuit board, the microwave receiving module is integrated on the transmitting centralized control circuit board, the receiving centralized control circuit board is connected to the temperature and humidity acquisition module and the receiving antenna, and the microwave receiving module adopts a single-band microwave receiving module; the bracket is installed between belt conveyor 1 and belt conveyor 2, the bracket includes two columns, an upper cross bar, and a lower cross bar, the upper cross bar and the lower cross bar are respectively installed between the two columns, the microwave transmitting probe is installed on the lower cross bar, and the microwave receiving probe is installed on the upper cross bar. The microwave transmitting probe is located on the conveying plane of belt conveyor 1 and belt conveyor 2, and the microwave transmitting probe is higher than the conveying plane of belt conveyor 1 and belt conveyor 2. Single-band microwaves are emitted through the microwave transmitting module. After passing through the whole bag of raw materials, the microwaves will be absorbed by water molecules and then received by the microwave receiving module. The amount of different water molecules is positively correlated with the change in the microwave amount, so the water content in the whole bag of raw materials can be determined by measuring the change in the microwave amount.

[0004] However, during the pressing process of plastic bottle bricks, residual moisture in some plastic bottles affects the pressing effect. It is worth noting that plastic materials themselves are not water-absorbent, which leads to highly uneven moisture distribution within the plastic bottle bricks. When the entire package is tested at once through the microwave transmitting and receiving modules, the limited radiation coverage area of the microwave transmitting and receiving modules means that only the moisture content of a certain area can be measured. Determining the moisture content of the entire package of plastic bottle bricks based on the measurement results of a local area may result in large errors in the moisture content of the entire package. Summary of the Invention

[0005] The present invention provides a device for measuring the water content of a plastic bottle brick, aiming to solve the problem in the related art that when testing the water content of a plastic bottle brick, a large error in the water content of the entire bag is caused.

[0006] The present invention provides a device for measuring the moisture content of plastic bottle bricks, comprising an automatic conveyor line and a microwave transmitting probe and a microwave receiving probe for measuring the moisture content of plastic bottle bricks, and further comprising: an on-line movable gantry, which is slidably connected to the frame of the automatic conveyor line along the conveying direction of the automatic conveyor line; two vertical plates, which are mounted on the on-line movable gantry and are parallel to the side walls of the plastic bottle bricks placed on the automatic conveyor line. When the plastic bottle bricks move between the two vertical plates, the vertical plates are clamped on the side walls of the plastic bottle bricks, and the on-line movable gantry and the plastic bottle bricks are moved synchronously; a probe vertical driving assembly, which is fixedly mounted on the side walls of the vertical plates and is used to drive the microwave transmitting probe and the microwave receiving probe to move up and down; a reset assembly, which is arranged on the frame of the automatic conveyor line. When the on-line movable gantry moves a measuring width along with the plastic bottle bricks, the on-line movable gantry is driven to move in the opposite direction of the conveying direction of the automatic conveyor line to adjust the measuring positions of the microwave transmitting probe and the microwave receiving probe for the plastic bottle bricks.

[0007] The effect is that: the plastic bottle bricks are directly placed on the automatic conveyor line, and the automatic conveyor line can drive the plastic bottle bricks to move along the conveying direction of the automatic conveyor line. When the plastic bottle bricks pass through the on-line moving door frame, the two vertical plates on the on-line moving door frame are clamped on the side walls of the plastic bottle bricks. Since the on-line moving door frame is slidably connected to the frame of the automatic conveyor line, the on-line moving door frame will also move synchronously with the plastic bottle bricks. At this time, the vertical drive assembly of the probe located on the vertical plate can drive the microwave transmitting probe and the microwave receiving probe to move up and down synchronously, so that the microwave transmitting probe and the microwave receiving probe can measure the plastic bottle bricks. All the width is measured up and down, then the two vertical plates are released to clamp the plastic bottle brick, and then the line-moving door frame is moved in the opposite direction of the conveying direction of the automatic conveyor line through the reset component, so that the microwave transmitting probe and the microwave receiving probe are moved to the plastic bottle brick corresponding to the next measured width, and then the up and down measurements are carried out. In this way, the plastic bottle brick can be continuously moved on the automatic conveyor line, and the microwave transmitting probe and the microwave receiving probe can be fully measured on the plastic bottle brick, so that when the moisture content of the plastic bottle brick is measured, the measurement error caused by uneven moisture distribution in the plastic bottle brick can be reduced.

[0008] Preferably, the microwave transmitting probe and the microwave receiving probe are both arranged on opposite surfaces of two vertical plates, and the two vertical plates are connected with a horizontal driving assembly for driving the vertical plates to clamp on the side walls of the plastic bottle brick.

[0009] The effect is that the two vertical plates, driven by the horizontal drive assembly, can be moved horizontally toward the plastic bottle brick, squeezing the abnormally protruding areas on the plastic bottle brick's outer wall. The microwave transmitting and receiving probes are positioned on opposing surfaces of the two vertical plates, allowing them to be closer to the plastic bottle brick, reducing the impact of distance on measurement accuracy. This arrangement also protects the microwave transmitting and receiving probes. Using the vertical plates as a physical barrier between the microwave transmitting and receiving probes reduces damage, signal interference, and positional shifts caused by direct contact or collision with the rough, easily deformable plastic bottle brick's sidewalls.

[0010] Preferably, the horizontal drive assembly includes two drive screws and a motor for driving the two drive screws to rotate. The threads of the two drive screws have opposite rotation directions and are respectively threadedly connected to the two vertical plates. The two drive screws rotate synchronously to drive the two vertical plates towards or away from each other.

[0011] Preferably, the upper part of the line-moving gantry is provided with a slide that slides horizontally perpendicular to the conveying direction of the automatic conveyor line, and a horizontal rotation component is installed on the slide. The horizontal rotation component is connected to a slide rail for installing two vertical plates, and the horizontal rotation component is used to drive the slide rail to rotate horizontally to adjust the angle between the vertical plate and the conveying direction of the automatic conveyor line, so that the vertical plate is parallel to the side wall of the plastic bottle brick.

[0012] The effect is that the two drive screws rotate synchronously under the action of the motor, driving the two vertical plates toward or away from each other. When the plastic bottle brick is not in the center of the automatic conveyor line, only one vertical plate contacts the side wall of the plastic bottle brick. At this time, the slide can slide horizontally, so that both vertical plates contact the side wall of the plastic bottle brick. At the same time, the plastic bottle brick may be at an angle to the conveyor line's conveying direction. In this case, the horizontal rotation assembly will activate and rotate the two vertical plates to ensure that the vertical plates are parallel and closely attached to the side wall of the plastic bottle, thereby improving the accuracy of moisture content measurement.

[0013] Preferably, the line-moving gantry is provided with a power assembly for driving the slide to move horizontally, the power assembly includes a synchronous belt and a synchronous wheel, the synchronous wheel is used to support the synchronous belt so that the synchronous belt is arranged along the sliding direction of the slide, the slide is fixed at a position where the synchronous belt is parallel to the sliding direction of the slide, and the synchronous wheel is connected to a motor for driving the synchronous wheel to rotate.

[0014] The effect is that when the plastic bottle brick begins to enter between the two vertical plates, in order to ensure that the plastic bottle brick enters the vertical plates unobstructed, the slide can drive the synchronous belt to move through the synchronous wheel, so that the slide is in the middle position, and the distance between the two vertical plates reaches the maximum, ensuring that the plastic bottle brick can smoothly enter between the two vertical plates.

[0015] Preferably, the microwave transmitting probe and the microwave receiving probe use microwaves of three different frequencies to measure the moisture content, and establish a moisture content model W based on the microwaves of three different frequencies, W=α×A1+β×A2+γ×A3+δ×H+ε, where A1, A2 and A3 are the microwave attenuations at three different frequencies, α, β, γ, δ and ε are coefficients, and H is the distance between the microwave transmitting probe and the microwave receiving probe.

[0016] The result: using three different microwave frequencies, the moisture content at different depths can be accurately measured, overcoming the limitations of single-frequency measurement in terms of penetration and accuracy. By taking into account the distance between the microwave transmitter and receiver, this technology can compensate for the attenuation effect of fixed microwave transmitters and receivers when measuring plastic bottle bricks of varying widths, thereby improving measurement accuracy.

[0017] Preferably, the probe vertical drive assembly is a linear drive module, which is fixed on the vertical plate, and an L-shaped connecting plate is fixedly provided on the output component of the linear drive module; wherein, one linear drive module is fixedly installed with a microwave transmitting probe through one end of the connecting plate, and the other linear drive module is fixedly installed with a microwave receiving probe through one end of the connecting plate, and the two probe vertical drive assemblies synchronously drive the microwave transmitting probe and the microwave receiving probe.

[0018] Preferably, the reset assembly includes a rack, a gear and a drive motor. The drive motor is fixed on the frame of the automatic conveyor line. The gear is driven by the drive motor. The rack is fixedly mounted on the moving door frame. The length direction of the rack is parallel to the conveying direction of the automatic conveyor line. The gear is engaged with the rack.

[0019] The effect is: by driving the motor to drive the gear to rotate, the gear then drives the rack, so that the line-moving gantry can move parallel to the conveying direction of the automatic conveyor line under the action of the rack, so that the microwave transmitting probe and the microwave receiving probe can return in time after measuring within a detection width, ensuring the continuity of the measurement.

[0020] Preferably, the horizontal rotation assembly includes an intermediate shaft and a motor that drives the intermediate shaft to rotate. The intermediate shaft is vertically arranged and the upper end of the intermediate shaft is rotatably connected to the slide. The lower end of the intermediate shaft is fixed in the middle position of the upper surface of the slide rail. The vertical plate is slidably connected to the slide rail through a slider.

[0021] The effect is that the lower end of the intermediate shaft is used to fix the slide rail, making the middle of the slide rail the adjustment base for the two vertical plates. When the two vertical plates rotate with the slide rail, they can ensure that the relative position of the two vertical plates is always maintained, and the microwave transmitting and receiving probes can accurately realize the transmission of microwaves.

[0022] Preferably, the vertical plate is made of plastic.

[0023] By adopting the above technical solution, the beneficial effects of the present invention are: The present invention utilizes vertical plates to instantly clamp and follow moving plastic bottle bricks, ensuring that the microwave probe always maintains a precise relative position with the bricks. The vertical drive assembly of the probe, combined with the horizontal tracking of the on-line moving gantry, enables the microwave beam to continuously and evenly scan and detect the height of the bricks, thereby achieving a comprehensive measurement of the moisture distribution within the bricks. The reset assembly drives the gantry to automatically reset after completing a detection width, forming a reciprocating detection path, ensuring that all moisture information from the entire package of plastic bottle bricks, from top to bottom and from front to back, is collected without omission during the conveying process. This reduces measurement errors caused by uneven moisture distribution within the plastic bottle bricks when measuring the moisture content of the plastic bottle bricks. The self-sliding slide and horizontal rotation assembly work together to enable the two vertical plates to adapt to the placement of the plastic bottle bricks, ensuring the universality and reliability of moisture content detection even if the plastic bottle bricks are randomly deflected during conveyance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of a device for measuring the water content of a plastic bottle brick according to the present invention; Figure 2 This is a front view of a device for measuring the moisture content of a plastic bottle brick according to the present invention; Figure 3 Schematic diagram of the installation structure of the vertical plate in an embodiment of the present invention; Figure 4 Schematic diagram of the position of the vertical drive assembly of the probe in an embodiment of the present invention; Figure 5 2 is a schematic diagram of the connection structure of the slide in an embodiment of the present invention; Figure 6 is a schematic structural diagram of a horizontal rotation assembly in an embodiment of the present invention; Figure 7 yes Figure 2 A partial enlarged view of part A.

[0025] Reference numerals: 1. Automatic conveyor line; 21. Microwave transmitting probe; 22. Microwave receiving probe; 3. Line-moving gantry; 31. Vertical plate; 4. Probe vertical drive assembly; 5. Reset assembly; 51. Rack; 52. Gear; 53. Drive motor; 6. Slide; 7. Horizontal rotation assembly; 71. Intermediate shaft; 8. Horizontal drive assembly; 81. Drive screw; 9. Power assembly; 91. Synchronous belt; 92. Synchronous wheel; 10. Slide rail; 11. Connecting plate; 12. Slider. DETAILED DESCRIPTION

[0026] The following combination Figures 1 to 7 The embodiments of the present invention are described in detail, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0027] This embodiment discloses a device for measuring the water content of a plastic bottle brick. Figure 1 and Figure 2 As shown, the device includes an automatic conveyor line 1, a microwave transmitting probe 21, a microwave receiving probe 22, an on-line movable gantry 3, a probe vertical drive assembly 4, and a reset assembly 5 for driving the on-line movable gantry 3 back. The automatic conveyor line 1 is used to horizontally convey plastic bottle bricks packaged into rectangular shapes. In this embodiment, the plastic bottle bricks move horizontally from left to right along the length of the automatic conveyor line 1. The on-line movable gantry 3 is mounted on the automatic conveyor line 1. The on-line movable gantry 3 slides along the length of the automatic conveyor line 1 and can be driven along the length of the automatic conveyor line 1 by the reset assembly 5. In this embodiment, the reset assembly 5 drives the on-line movable gantry 3 from right to left. In other embodiments, the reset assembly 5 can also drive the on-line movable gantry 3 from left to right, so that the movement direction and speed of the on-line movable gantry 3 are the same as the conveying direction and speed of the automatic conveyor line 1. The probe vertical drive assembly 4 is mounted on the on-line movable gantry 3, causing the on-line movable gantry 3 to move horizontally with the probe vertical drive assembly 4. Two probe vertical drive assemblies 4 are provided and a microwave transmitting probe 21 or a microwave receiving probe 22 is installed on one probe vertical drive assembly 4. The microwave transmitting probe 21 and the microwave receiving probe 22 are arranged relative to each other in the horizontal direction. The microwave transmitting probe 21 and the microwave receiving probe 22 are respectively located on both sides of the automatic conveyor line 1 and are both located above the automatic conveyor line 1.

[0028] During use, a rectangular plastic bottle brick is first placed at the left end of the automatic conveyor line 1. As the automatic conveyor line 1 operates, the plastic bottle brick is moved from left to right. When the plastic bottle brick reaches the position between the microwave transmitting probe 21 and the microwave receiving probe 22, the line-moving gantry 3 will move at the same speed as the automatic conveyor line 1, causing the probe vertical drive assembly 4 to drive the microwave transmitting probe 21 and the microwave receiving probe 22 to move vertically simultaneously. After the microwave transmitting probe 21 and the microwave receiving probe 22 complete a vertical movement, the microwave transmitting probe 21 and the microwave receiving probe 22 have a certain detection width when performing moisture content detection on the plastic bottle brick, and the size of the detection width depends on the microwave transmitting probe 21 and the microwave receiving probe 22. The time taken by the microwave transmitting probe 21 and the microwave receiving probe 22 to move in the vertical direction for one detection is less than the time taken by the plastic bottle brick to move one detection width along the automatic conveyor line 1. Therefore, the reset component 5 can move the on-line movable door frame 3 from right to left, so that the microwave transmitting probe 21 and the microwave receiving probe 22 can detect the next detection width of the plastic bottle brick. After multiple vertical movements of the microwave transmitting probe 21 and the microwave receiving probe 22, the entire plastic bottle brick can be tested at least once, thereby solving the problem of large errors in detection data caused by uneven moisture distribution of the plastic bottle brick.

[0029] The microwave transmitting probe 21 and microwave receiving probe 22 use multi-spectrum microwaves, each spectrum targeting a different depth of the measurement object. In this embodiment, three sets of multi-frequency microwaves ranging from 1 GHz to 5 GHz are deployed. These microwaves scan the measured medium 10 times per second from low to high frequency, generating microwave signals at different spectra. This allows for more accurate measurement of moisture content within the plastic bottle brick. This embodiment uses three frequencies (1.2 GHz, 1.8 GHz, and 2.4 GHz) to establish the moisture content model W: W = α × A1 + β × A2 + γ × A3 + δ × H + ε, where A1 is the microwave attenuation at 1.2 GHz, A2 is the microwave attenuation at 1.8 GHz, and A3 is the microwave attenuation at 2.4 GHz. Other frequencies may be used in other embodiments. H is the distance between the microwave transmitting probe 21 and the microwave receiving probe 22. The microwave transmitting probe 21 and the microwave receiving probe 22 should be placed close to the sidewalls of the plastic bottle brick, which has different widths. α, β, γ, δ, and ε are coefficients. 500-1000 plastic bottle bricks with standard moisture content were tested. The size and moisture content of the plastic bottle bricks with standard moisture content were measured. The coefficients α, β, γ, δ, and ε were optimized through linear regression. The optimized coefficient values were affected by the different microwave transmitting probes 21 and microwave receiving probes 22 and the accuracy of the H measurement value.

[0030] refer to Figure 3In order to adjust the distance between the microwave transmitting probe 21 and the microwave receiving probe 22 according to the width of the rectangular plastic bottle brick, two vertical plates 31 that can approach each other are installed on the line-moving gantry 3. The two vertical plates 31 are arranged on both sides of the automatic conveyor line 1 and are opposite to each other, so that the plastic bottle brick can pass between the two vertical plates 31. The height of the vertical plates 31 is greater than the height of the plastic bottle brick. The surfaces facing away from each other of the two vertical plates 31 are used to arrange the microwave transmitting probe 21 or the microwave receiving probe 22. When the two vertical plates 31 approach the plastic bottle brick, the microwave transmitting probe 21 and the microwave receiving probe 22 also approach the side wall of the plastic bottle brick along with the vertical plates 31. As for the outside of the plastic bottle brick, there are some abnormally protruding parts that will affect the distance between the microwave transmitting probe 21 and the microwave receiving probe 22, so the vertical plates 31 are used to squeeze them to ensure that the microwave transmitting probe 21 and the microwave receiving probe 22 are closer to the plastic bottle brick. Abnormally protruding portions of the plastic bottle brick's sidewalls are typically caused by rebound after compression or by the location of wire joints during bundling. These protrusions can be squeezed into the plastic bottle brick's sidewalls using two vertical plates 31. This allows the microwave transmitting and receiving probes 21 and 22 to be closer to the brick's surface, enhancing measurement accuracy. Furthermore, squeezing by the vertical plates 31 reduces the chances of collision between the microwave transmitting and receiving probes 21 and 22 and the protruding portions, ensuring safe operation of the device.

[0031] refer to Figure 2 and Figure 3 A slide 6 is provided on the line-moving gantry 3, which slides horizontally perpendicular to the conveying direction of the automatic conveyor line 1. The slide 6 is located on the upper part of the line-moving gantry 3 and above the automatic conveyor line 1. A horizontal rotation component 7 is installed on the slide 6, and a slide rail 10 for mounting two vertical plates 31 is provided on the horizontal rotation component 7. The slide rail 10 is arranged horizontally, and the horizontal rotation component 7 is connected to the middle of the slide rail 10. The horizontal rotation component 7 can drive the slide rail 10 to rotate horizontally, and the two vertical plates 31 are located at both ends of the slide rail 10. When the horizontal rotating component 7 rotates the slide rail 10 horizontally, the angle between the two vertical plates 31 and the conveying direction of the automatic conveyor line 1 can be adjusted. Since the plastic bottle bricks placed on the automatic conveyor line 1 are directly placed by a forklift, they have random deflection and the plastic bottle bricks may not be parallel to the automatic conveyor line 1. Therefore, the vertical plates 31 can be parallel to the surface of the plastic bottle bricks after adjustment through the horizontal rotating component 7, and then the vertical plates 31 are flattened on the surface of the plastic bottle bricks, and then slid perpendicular to the conveying direction of the automatic conveyor line 1 through the slide 6. The positions of the two vertical plates 31 can be adjusted to adapt to the moisture content measurement of plastic bottle bricks of various widths.

[0032] refer to Figure 3 、 Figure 4 and Figure 5The probe vertical drive assembly 4 uses a linear drive module. The probe vertical drive assembly 4 is fixed to one side of the vertical plate 31 and arranged vertically. The output component of the probe vertical drive assembly 4 is fixedly provided with an L-shaped connecting plate 11. One end of the connecting plate 11 is used to fix the microwave transmitting probe 21 or the microwave receiving probe 22, so that the microwave transmitting probe 21 and the microwave receiving probe 22 can be vertically driven by the linear drive module. The two probe vertical drive assemblies 4 move synchronously to ensure the relative positions of the microwave transmitting probe 21 and the microwave receiving probe 22. A horizontal drive assembly 8 is also provided on the slide rail 10 for driving the vertical plate 31 to move along the slide rail 10. The horizontal drive assembly 8 includes two drive screws 81 and a motor for driving the two drive screws 81 to rotate. The two drive screws 81 are coaxially fixed by a coupling. The drive screws 81 pass through the vertical plate 31. The drive screws 81 can be threadedly connected to the vertical plate 31 or connected to the vertical plate 31 by a threaded sleeve. The threads of the drive screws 81 have opposite rotation directions. Two drive screws 81 are used to drive the two vertical plates 31. When the two vertical plates 31 approach each other, they cooperate with the slide 6 to clamp both vertical plates 31 against the side walls of the plastic bottle bricks. As the plastic bottle bricks are transported through the automatic conveyor line 1, the vertical plates 31 drive the entire on-line mobile gantry 3, thereby synchronizing the on-line mobile gantry 3 with the automatic conveyor line 1, allowing the microwave transmitting probe 21 and microwave receiving probe 22 to scan and measure the plastic bottle bricks vertically. A slider 12 is fixedly mounted on the upper end of the vertical plates 31, and the slider 12 is slidably connected to the slide rail 10.

[0033] refer to Figure 5 and Figure 6The horizontal rotation assembly 7 includes an intermediate shaft 71 and a motor for driving the intermediate shaft 71. The intermediate shaft 71 is vertically arranged and its upper end is rotatably mounted on the slide 6. The lower end of the intermediate shaft 71 is fixed to the middle position of the upper surface of the slide rail 10. A power assembly 9 for driving the slide 6 horizontally is provided on the line-moving gantry 3. The power assembly 9 includes a synchronous belt 91 and synchronous pulleys 92. At least two synchronous pulleys 92 are provided. In this embodiment, four synchronous pulleys 92 are provided. The synchronous belt 91 is connected to the four synchronous pulleys 92. The four synchronous pulleys 92 support the synchronous belt 91, forming a rectangular shape. The four synchronous pulleys 92 are respectively arranged at the four corners of the rectangle formed by the synchronous belt 91. The synchronous belt 91 is fixedly connected to the slide 6 at a position parallel to the sliding direction of the slide 6. A motor is connected to one of the synchronous pulleys 92. The motor can be a servo motor or a stepper motor. When the synchronous pulley 92 rotates, it drives the synchronous belt 91, thereby driving the slide 6 to move on the line-moving gantry 3. Since the length direction of the plastic bottle brick is at an angle to the conveying direction of the automatic conveyor line 1, when the water content in the plastic bottle brick is measured along the length direction of the plastic bottle brick, the vertical plate 31 can drive the horizontal rotating component 7 to adjust its position relative to the automatic conveyor line 1 through the slide 6 to ensure that the vertical plate 31 can be close to the side wall of the plastic bottle brick.

[0034] refer to Figure 7 The reset assembly 5 includes a rack 51, a gear 52 and a drive motor 53. The drive motor 53 is fixedly mounted on the frame of the automatic conveyor line 1 and will not be transported by the automatic conveyor line 1. The gear 52 is connected to the output shaft of the drive motor 53, and the drive motor 53 drives the gear 52 to rotate. The gear 52 is located on one side of the automatic conveyor line 1, and the rack 51 is fixed on the on-line movable gantry 3. The length direction of the rack 51 is parallel to the conveying direction of the automatic conveyor line 1. When the on-line movable gantry 3 needs to move from right to left along the automatic conveyor line 1, the drive motor 53 works and drives the gear 52 to rotate. The gear 52 drives the rack 51, so that the microwave transmitting probe 21 and the microwave receiving probe 22 installed on the on-line movable gantry 3 move to the next area that needs to be measured.

[0035] The working process of this embodiment is as follows: First, a rectangular plastic bottle brick is placed on the automatic conveyor line 1 by a forklift. The length direction of the rectangular plastic bottle brick should be basically parallel to the left and right direction of the automatic conveyor line 1. If the angle is too large, it needs to be readjusted to prevent the plastic bottle brick from exceeding the edge of the automatic conveyor line 1 or colliding with the vertical plate 31. Then, one end of the plastic bottle brick first reaches between the two vertical plates 31, and the distance between the two vertical plates 31 is greater than the width of the plastic bottle brick. Then, the two vertical plates 31 are driven toward each other by the two driving screws 81. When the vertical plates 31 abut the plastic bottle brick, if only one vertical plate 31 abuts the side wall of the plastic bottle brick, the driving screws 81 continue to move the two vertical plates 31 toward each other. The forces on both sides of the slide 6 are different. At this time, the motor connected to the synchronous wheel 92 is not energized, and the synchronous wheel 92 can rotate freely. The slide 6 will drive the synchronous belt 91 to move, so that both vertical plates 31 abut the outer wall of the plastic bottle brick. At this point, the vertical plates 31 may not be parallel to the sidewalls of the plastic bottle bricks. The horizontal rotating assembly 7 can be used to rotate forward or reverse, gradually reducing the distance between the vertical plates 31 to the minimum distance, clamping them against the sidewalls of the plastic bottle bricks. The friction between the vertical plates 31 and the plastic bottle bricks causes them to move synchronously, which in turn drives the linear moving gantry 3 and the microwave transmitting and receiving probes 21 and 22 mounted on the vertical plates 31. The microwave transmitting and receiving probes 21 and 22 then move synchronously up and down within the two probe vertical drive assemblies 4, completing the measurement of the plastic bottle bricks within a detection width. Under the action of the horizontal driving component 8, the two vertical plates 31 move outward at the same time, loosening the plastic bottle brick. At this time, the two vertical plates 31 still remain parallel to the side walls of the plastic bottle brick. The reset component 5 drives the online moving door frame 3 to move to the right, so that when the vertical plates 31 reach the next detection width position, the two vertical plates 31 approach each other again. At this time, the two vertical plates 31 can be directly clamped on the surface of the plastic bottle brick one after another without adjusting the angle of the vertical plates 31. The entire plastic bottle brick is inspected in sequence, thereby reducing the detection error caused by uneven moisture distribution of the plastic bottle brick.

[0036] In other embodiments, the two risers 31 can move independently along the slide rail 10, without requiring the two risers 31 to simultaneously move toward or away from each other. The two risers 31 can be made of plastic to minimize the impact on microwave measurement. The distance H between the microwave transmitting probe 21 and the microwave receiving probe 22 can be measured based on the distance the two risers 31 are moved by the horizontal drive assembly 8.

[0037] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A device for measuring the moisture content of plastic bottle bricks, comprising an automatic conveying line (1) and a microwave transmitting probe (21) and a microwave receiving probe (22) for measuring the moisture content of plastic bottle bricks, characterized in that: Also includes: The line-moving door frame (3) is slidably connected to the frame of the automatic conveying line (1) along the conveying direction of the automatic conveying line (1); Two vertical plates (31), the vertical plates (31) are mounted on the line-moving door frame (3) and are parallel to the side walls of the plastic bottle bricks placed on the automatic conveyor line (1); when the plastic bottle bricks move between the two vertical plates (31), the vertical plates (31) are clamped on the side walls of the plastic bottle bricks, and the line-moving door frame (3) and the plastic bottle bricks move synchronously; A probe vertical drive assembly (4) is fixedly mounted on the side wall of the vertical plate (31) and is used to drive the microwave transmitting probe (21) and the microwave receiving probe (22) to move up and down; The reset assembly (5) is arranged on the frame of the automatic conveyor line (1). When the line-moving gantry (3) moves along with the plastic bottle bricks for a measured width, the line-moving gantry (3) is driven to move in the opposite direction of the conveying direction of the automatic conveyor line (1) to adjust the measuring positions of the microwave transmitting probe (21) and the microwave receiving probe (22) on the plastic bottle bricks.

2. A device for measuring the moisture content of a plastic bottle brick according to claim 1, characterized in that: The microwave transmitting probe (21) and the microwave receiving probe (22) are both arranged on opposite surfaces of the two vertical plates (31), and the two vertical plates (31) are connected to a horizontal driving assembly (8) for driving the vertical plates (31) to clamp onto the side walls of the plastic bottle brick.

3. The device for measuring the water content of a plastic bottle brick according to claim 2, characterized in that: The horizontal drive assembly (8) includes two drive screws (81) and a motor for driving the two drive screws (81) to rotate. The threads of the two drive screws (81) rotate in opposite directions and are respectively threadedly connected to the two vertical plates (31). The two drive screws (81) rotate synchronously to drive the two vertical plates (31) to move closer to or farther away from each other.

4. A device for measuring the moisture content of a plastic bottle brick according to claim 3, characterized in that: The upper portion of the line-moving gantry (3) is provided with a slide (6) that slides horizontally perpendicular to the conveying direction of the automatic conveying line (1); a horizontal rotation component (7) is installed on the slide (6); the horizontal rotation component (7) is connected to a slide rail (10) for installing two vertical plates (31); the horizontal rotation component (7) is used to drive the slide rail (10) to rotate horizontally to adjust the angle between the vertical plates (31) and the conveying direction of the automatic conveying line (1), so that the vertical plates (31) are parallel to the side walls of the plastic bottle bricks.

5. The device for measuring the water content of a plastic bottle brick according to claim 4, characterized in that: The linear movable gantry (3) is provided with a power assembly (9) for driving the slide (6) to move horizontally. The power assembly (9) includes a synchronous belt (91) and a synchronous wheel (92). The synchronous wheel (92) is used to support the synchronous belt (91) so that the synchronous belt (91) is arranged along the sliding direction of the slide (6). The slide (6) is fixed at a position where the synchronous belt (91) is parallel to the sliding direction of the slide (6). The synchronous wheel (92) is connected to a motor for driving the synchronous wheel (92) to rotate.

6. The device for measuring the moisture content of a plastic bottle brick according to claim 1, characterized in that: The microwave transmitting probe (21) and the microwave receiving probe (22) use microwaves of three different frequencies to measure the moisture content, and establish a moisture content model W based on the microwaves of the three different frequencies, W=α×A1+β×A2+γ×A3+δ×H+ε, wherein A1, A2 and A3 are the microwave attenuations at the three different frequencies, α, β, γ, δ and ε are coefficients, and H is the distance between the microwave transmitting probe (21) and the microwave receiving probe (22).

7. The device for measuring the moisture content of a plastic bottle brick according to claim 1, characterized in that: The probe vertical drive assembly (4) is a linear drive module, which is fixed on the vertical plate (31). An L-shaped connecting plate (11) is fixedly provided on the output component of the linear drive module. One linear drive module is fixedly mounted with a microwave transmitting probe (21) via one end of the connecting plate (11), and the other linear drive module is fixedly mounted with a microwave receiving probe (22) via one end of the connecting plate (11). The two probe vertical drive assemblies (4) synchronously drive the microwave transmitting probe (21) and the microwave receiving probe (22).

8. The device for measuring the moisture content of a plastic bottle brick according to claim 1, characterized in that: The reset assembly (5) includes a rack (51), a gear (52) and a drive motor (53). The drive motor (53) is fixed on the frame of the automatic conveyor line (1). The gear (52) is driven by the drive motor (53). The rack (51) is fixed on the line-moving door frame (3). The length direction of the rack (51) is parallel to the conveying direction of the automatic conveyor line (1). The gear (52) is meshed with the rack (51).

9. The device for measuring the moisture content of a plastic bottle brick according to claim 4, characterized in that: The horizontal rotation assembly (7) includes an intermediate shaft (71) and a motor for driving the intermediate shaft (71) to rotate. The intermediate shaft (71) is vertically arranged and the upper end of the intermediate shaft (71) is rotatably connected to the slide (6). The lower end of the intermediate shaft (71) is fixed to the middle position of the upper surface of the slide rail (10). The vertical plate (31) is slidably connected to the slide rail (10) through a slider (12).

10. The device for measuring the moisture content of a plastic bottle brick according to claim 1, characterized in that: The vertical plate (31) is made of plastic material.

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