A device for detecting the water content of concrete aggregates

Abstract

The present application belongs to the technical field of concrete preparation detection, and particularly relates to a concrete aggregate water content detection device, which comprises a base and a rack installed above the base. A controller is installed on the side wall of the rack. The device further comprises a through hole opened in the top of the base, a support seat slidably connected inside the through hole, and a weighing mechanism installed inside the through hole for supporting the support seat. A flat hopper is arranged above the base and located on the side of the feed end direction of the support seat. The rack is provided with an adjusting drive mechanism for driving the vertical movement of the flat hopper. A microwave detection unit is arranged on one side of the flat hopper. The present application can perform online detection of the water content of concrete aggregate, improve the detection accuracy by combining weight detection and thickness control, reduce single detection interference error by cross verification of multiple sensing data, and improve data reliability to support subsequent dynamic batching.

Description

Technical Field

[0001] This invention belongs to the field of concrete preparation and testing technology, and in particular relates to a device for detecting the moisture content of concrete aggregates. Background Technology

[0002] Concrete strength is determined by the water-cement ratio. Aggregates often contain free water, which can cause the actual water-cement ratio to be too high, leading to a decrease in strength and fluctuations in quality. Real-time online monitoring of moisture content and dynamic adjustment of water addition can ensure accurate proportioning and improve concrete performance and project quality.

[0003] Currently, in order to improve the quality of concrete preparation, concrete mixing plants need to test the moisture content of concrete aggregates. The traditional testing method is to take samples of the aggregates and then test the moisture content of the aggregates through methods such as drying. However, since the moisture content in concrete aggregates is not uniform, this sampling method is not representative enough. Now, online testing devices are usually used, such as the microwave transmission detection device for aggregate moisture content disclosed in patent publication number CN217385269U, which uses microwaves to detect the moisture content of concrete online.

[0004] However, during the transportation of concrete aggregates, the thickness is uneven. For example, the aggregates in the middle of the conveyor belt may be convex and thinner on both sides, or local depressions may be formed due to uneven material distribution. Insufficient thickness will result in a short microwave penetration path and abnormal energy attenuation, which will not accurately reflect the overall moisture content and thus affect the accuracy of the test results. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a device for detecting the moisture content of concrete aggregates.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a concrete aggregate moisture content testing device, comprising a base and a frame mounted on the base, wherein a controller is mounted on the side wall of the frame, and further comprising:

[0007] A through hole is provided at the top of the base, and a support seat is slidably connected inside the through hole. A weighing mechanism for supporting the support seat is installed inside the through hole.

[0008] A flat hopper is positioned above the base and on one side of the feed end of the support. The frame is equipped with an adjustment drive mechanism that drives the flat hopper to move vertically. A microwave detection unit is provided on one side of the flat hopper.

[0009] An auxiliary detection unit is installed on the side wall of the flat hopper, and the auxiliary detection unit is located on the side of the feed end of the support.

[0010] Preferably, the weighing mechanism includes several mounting blocks fixed inside the through holes, a pressure sensor is fixed to the top of the mounting block, and the pressure measuring end of the pressure sensor is fixedly connected to the bottom of the support base. The pressure sensor is electrically connected to the controller.

[0011] Preferably, the adjustment drive mechanism includes a synchronous electric push rod fixedly inserted into the end face of the frame, the movable end of the synchronous electric push rod is fixed with a lifting block, and the lifting block is fixed to the outer side wall of the flat hopper, and the synchronous electric push rod is electrically connected to the controller.

[0012] Preferably, the microwave detection unit includes a detection seat fixedly installed on the side wall of the flat hopper. The detection seat is located above the support base. A microwave receiving array is fixedly installed at the bottom of the detection seat. A microwave transmitting array corresponding to the position of the microwave receiving array is fixedly installed at the bottom of the support base. Both the microwave transmitting array and the microwave receiving array are electrically connected to the controller.

[0013] Preferably, the auxiliary detection unit includes a hollow plate fixedly installed on the side wall of the flat hopper. The bottom of the hollow plate is flush with the bottom of the flat hopper and is located on the feed end side of the support base. Multiple air jet holes are opened at the bottom of the hollow plate. An air pump is installed on the top of the hollow plate, and the air pump's delivery end is connected to the interior of the hollow plate. A hollow column is fixedly connected to the air pump's suction end. A gas turbidity detection probe and a humidity detection probe electrically connected to the controller are inserted at the top of the hollow column. An air suction hopper is fixedly inserted at the bottom of the hollow column away from the air pump. The bottom height of the air suction hopper is higher than the top height of the hollow plate, and the horizontal distance between the air suction hopper and the side wall of the hollow plate on the opposite side is no more than 5 cm.

[0014] Preferably, a sealing plate is fixedly installed inside the hollow plate, and an exhaust hole is opened on the end face of the sealing plate, and a pulse solenoid valve is installed inside the exhaust hole.

[0015] Preferably, two first mesh plates are installed inside the hollow column between the gas turbidity detection probe and the humidity detection probe, and filter filler is filled between the two first mesh plates. Two second mesh plates are fixedly installed inside the hollow column on the side of the humidity detection probe away from the first mesh plates, and moisture-absorbing filler is filled between the two second mesh plates.

[0016] Preferably, two symmetrical guide plates are fixedly installed on the inner side wall of the frame, and the two guide plates are located on both sides of the flat hopper. The guide plates are integrally provided with inclined outward expansions on the side of the feed end of the support seat, and the two outward expansions face opposite directions away from the guide plates.

[0017] Compared with existing technologies, the advantages of a concrete aggregate moisture content testing device are:

[0018] 1. Through the coordinated operation of the base, frame, controller, support, weighing mechanism, and microwave detection unit, the moisture content of concrete aggregate can be detected online. Combined with weight detection, the accuracy of moisture content detection is improved. Furthermore, through the set leveling hopper and adjustment drive mechanism, the thickness of the aggregate can be controlled before microwave detection of moisture content, so that the aggregate remains flat as it passes through the microwave detection position, thereby reducing the impact of uneven thickness on the accuracy of microwave detection.

[0019] 2. Through the set auxiliary detection unit, the dust concentration and humidity carried in the aggregate can be detected before the microwave detection of moisture content. The accuracy of the microwave detection of moisture content can be verified based on the dust concentration and humidity values. Through cross-verification of multi-sensor data, the error of single microwave detection caused by uneven thickness, agglomeration and other interferences can be reduced, the data reliability can be improved, and a more reliable sensing basis can be provided for subsequent dynamic batching.

[0020] 3. Through the cooperation of the sealing plate, exhaust port and pulse solenoid valve, the air pump output of the auxiliary detection unit can form a pulse airflow, which impacts the aggregate, breaks up clumps, blows away surface dust, and makes the aggregate distribution more uniform, providing a stable material environment for microwave detection, reducing interference and further improving detection accuracy. Attached Figure Description

[0021] Figure 1 This is a front three-dimensional structural diagram of a concrete aggregate moisture content detection device provided by the present invention;

[0022] Figure 2 This is a three-dimensional back structure diagram of a concrete aggregate moisture content detection device provided by the present invention;

[0023] Figure 3 This is a schematic diagram of the bottom three-dimensional structure of a concrete aggregate moisture content detection device provided by the present invention;

[0024] Figure 4 This invention provides a device for detecting the moisture content of concrete aggregates. Figure 3 Enlarged view of the structure of section A;

[0025] Figure 5 This is a three-dimensional structural schematic diagram of the auxiliary detection unit of a concrete aggregate moisture content detection device provided by the present invention;

[0026] Figure 6 This is a schematic diagram of the internal structure of the hollow plate of a concrete aggregate moisture content detection device provided by the present invention;

[0027] Figure 7This is a schematic diagram of the internal structure of the hollow column of a concrete aggregate moisture content detection device provided by the present invention;

[0028] Figure 8 This is a frontal plan view of a concrete aggregate moisture content detection device provided by the present invention.

[0029] In the diagram: 1. Base, 101. Through hole, 2. Frame, 3. Controller, 4. Support base, 5. Weighing mechanism, 51. Mounting block, 52. Pressure sensor, 6. Flat hopper, 7. Adjustment drive mechanism, 71. Synchronous electric push rod, 72. Lifting block, 8. Microwave detection unit, 81. Detection base, 82. Microwave receiving array, 83. Microwave transmitting array, 9. Auxiliary detection unit, 91. Hollow plate, 92. Air jet hole, 93. Air pump, 94. Hollow column, 95. Gas turbidity detection probe, 96. Humidity detection probe, 97. Suction hopper, 10. Sealing plate, 11. Exhaust hole, 12. Pulse solenoid valve, 13. First mesh plate, 14. Filter packing, 15. Second mesh plate, 16. Moisture-absorbing packing, 17. Guide plate. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] like Figures 1-8 As shown, a concrete aggregate moisture content detection device includes a base 1 and a frame 2 mounted on the base 1. A controller 3 is mounted on the side wall of the frame 2. The device also includes a through hole 101 opened at the top of the base 1. A support base 4 is slidably connected inside the through hole 101, and a weighing mechanism 5 for supporting the support base 4 is installed inside the through hole 101. The weighing mechanism 5 includes several mounting blocks 51 fixed inside the through hole 101. A pressure sensor 52 is fixed to the top of the mounting block 51, and the pressure measuring end of the pressure sensor 52 is fixedly connected to the bottom of the support base 4. The pressure sensor 52 is electrically connected to the controller 3, and the pressure sensor 52 can convert the passing aggregate into an electrical signal and feed it back to the controller 3.

[0032] The flat hopper 6 is positioned above the base 1 and on the side of the feed end of the support 4. The frame 2 is equipped with an adjustment drive mechanism 7 that drives the flat hopper 6 to move vertically. The adjustment drive mechanism 7 includes a synchronous electric push rod 71 that is fixedly inserted into the end face of the frame 2. The movable end of the synchronous electric push rod 71 is fixed with a lifting block 72, and the lifting block 72 is fixed to the outer side wall of the flat hopper 6. The synchronous electric push rod 71 is electrically connected to the controller 3. The synchronous electric push rod 71 can adjust the height of the flat hopper 6 to adapt to different aggregate feed amounts.

[0033] A microwave detection unit 8 is provided on one side of the flat hopper 6. The microwave detection unit 8 includes a detection seat 81 fixedly installed on the side wall of the flat hopper 6. The detection seat 81 is located above the support seat 4. A microwave receiving array 82 is fixedly installed at the bottom of the detection seat 81. A microwave transmitting array 83 corresponding to the position of the microwave receiving array 82 is fixedly installed at the bottom of the support seat 4. Both the microwave transmitting array 83 and the microwave receiving array 82 are electrically connected to the controller 3. The microwave emitted by the microwave transmitting array 83 passes through the support seat 4, the conveyor belt for conveying aggregates, and the aggregates before propagating to the microwave receiving array 82.

[0034] An auxiliary detection unit 9 is installed on the side wall of the flat hopper 6, and is located on the side of the support base 4 in the direction of the feed end. The auxiliary detection unit 9 includes a hollow plate 91 fixedly installed on the side wall of the flat hopper 6. The bottom of the hollow plate 91 is flush with the bottom of the flat hopper 6, and the hollow plate 91 is located on the side of the support base 4 in the direction of the feed end. Multiple air jet holes 92 are opened at the bottom of the hollow plate 91. An air pump 93 is installed on the top of the hollow plate 91, and the air delivery end of the air pump 93 is connected to the interior of the hollow plate 91. The air suction end of the air pump 93 is fixedly connected to... A hollow column 94 is provided. A gas turbidity detection probe 95 and a humidity detection probe 96, which are electrically connected to the controller 3, are installed on the top of the hollow column 94. An air intake hopper 97 is fixedly inserted at the bottom of the hollow column 94 away from the air pump 93. The bottom of the air intake hopper 97 is higher than the top of the hollow plate 91, and the horizontal distance between the air intake hopper 97 and the side wall of the hollow plate 91 facing each other is no more than 5cm. The gas turbidity detection probe 95 can detect the turbidity in the airflow, and the humidity detection probe 96 can detect the humidity of the airflow.

[0035] A sealing plate 10 is fixedly installed inside the hollow plate 91. An exhaust hole 11 is opened on the end face of the sealing plate 10, and a pulse solenoid valve 12 is installed inside the exhaust hole 11. The pulse solenoid valve 12 is energized and de-energized at a certain frequency. When energized, its valve plate opens, and when de-energized, its valve plate closes.

[0036] Inside the hollow column 94, between the gas turbidity detection probe 95 and the humidity detection probe 96, two first mesh plates 13 are installed, and filter media 14 is filled between the two first mesh plates 13. Inside the hollow column 94, on the side of the humidity detection probe 96 away from the first mesh plates 13, two second mesh plates 15 are fixedly installed, and moisture-absorbing media 16 is filled between the two second mesh plates 15. The hollow column 94 has a replacement port for replacing the filter media 14 and the moisture-absorbing media 16. A sealing cover (not shown in the figure) is installed at the replacement port. The controller 3 can remind the user to replace the filter media 14 and the moisture-absorbing media 16 based on the usage time or based on the dust concentration and humidity detected by the gas turbidity detection probe 95 and the humidity detection probe 96.

[0037] Two symmetrical guide plates 17 are fixedly installed on the inner side wall of the frame 2, and the two guide plates 17 are located on both sides of the flat hopper 6. The guide plates 17 are integrally provided with inclined outward expansions on the side of the feed end of the support base 4, and the two outward expansions are opposite in orientation away from the guide plates 17. Through the action of the guide plates 17 and the outward expansions of the guide plates 17, the aggregate on the aggregate conveyor belt can be concentrated between the two guide plates 17, ensuring that the aggregate passes through the microwave detection unit 8 intact.

[0038] The operating principle of this invention is explained as follows: The entire device is installed on the aggregate conveyor belt of a concrete mixing plant, so that the aggregate conveyor belt passes between the microwave transmitting array 83 and the microwave receiving array 82 (see reference). Figure 8 , Figure 8 The dotted line represents the aggregate conveyor belt. Before testing, an appropriate amount of spare aggregate is placed inside the flat hopper 6 (the top of the frame 2 has a square hole corresponding to the position of the flat hopper 6, which facilitates the placement of spare aggregate inside the flat hopper 6. A material level sensor can be placed inside the flat hopper 6 to facilitate the detection of the material level height inside the flat hopper 6). When preparing concrete, the controller 3 is started. The controller 3 controls the synchronous electric push rod 71 to work according to the preset program. The synchronous electric push rod 71 pushes the flat hopper 6 down to the specified height. At this time, a certain gap is maintained between the flat hopper 6 and the support seat 4. This gap is the detection thickness of the aggregate. When the aggregate conveyor belt moves the aggregate to the position of the flat hopper 6, it is blocked by the flat hopper 6. Aggregates that are too thick cannot pass through the gap between the flat hopper 6 and the support seat 4. When the thickness is too thin, the spare aggregate inside the flat hopper 6 will be supplemented to the position of the thinner part under the action of gravity when passing the bottom of the flat hopper 6, so that the thickness of the aggregate passing through the flat hopper 6 can be kept as uniform as possible.

[0039] After the controller 3 finishes controlling the synchronous electric push rod 71, the controller 3 will immediately control the air pump 93 to work and control the pulse solenoid valve 12 to work (the working frequency of the pulse solenoid valve 12 and the output power of the air pump 93 can be preset by the controller 3 according to the aggregate type and other parameters). The air pump 93 will deliver airflow into the hollow plate 91. When the valve plate of the pulse solenoid valve 12 is closed, the airflow above the sealing plate 10 cannot be discharged. At this time, the air pressure above the sealing plate 10 is getting higher and higher. When the valve plate of the pulse solenoid valve 12 is opened, the high-pressure air above the sealing plate 10 will be discharged through the exhaust hole 11 and finally sprayed out through each jet hole 92. By using the operation of the pulse solenoid valve 12, pulse airflow can be sprayed out from each jet hole 92. Under the action of the high-pressure pulse airflow, the airflow will impact the aggregate passing under the hollow plate 91. On the one hand, the airflow can loosen the agglomerated aggregate as much as possible, which is conducive to improving the accuracy of subsequent microwave detection. On the other hand, the airflow can carry away the dust and some moisture in the aggregate.

[0040] The suction end of the air pump 93 generates negative pressure suction on the feed end side of the support base 4 through the hollow column 94 and the suction bucket 97. Under the action of negative pressure suction, dust and moisture in the aggregate are sucked into the hollow column 94 (since the horizontal height of the suction bucket 97 is higher than that of the hollow plate 91, and the suction bucket 97 is located on the feed end side of the support base 4, the airflow discharged from the exhaust hole 11 will be quickly sucked away by the suction bucket 97; secondly, the output power of the air pump 93 is preset according to different concrete aggregates through the controller 3). When the airflow passes through the gas turbidity detection probe 95 and the humidity detection probe 96, the gas turbidity detection probe 95 can detect the turbidity of the airflow (the gas turbidity detection probe 95 emits a detection beam, and by utilizing the principle that dust and other impurities in the airflow will block the light, the intensity of the received light can be calculated to determine the dust concentration in the gas). The humidity detection probe 96 can detect the humidity of the airflow (when the humidity of the airflow increases, the dielectric constant of the hydrophilic membrane of the humidity detection probe 96 increases after absorbing water). The capacitance value increases as the aggregate moisture content increases, and decreases as the moisture content increases. By measuring the change in capacitance value in real time, the airflow humidity can be obtained. When the aggregate moisture content is low, the aggregate viscosity is weak, and the dust and other impurities carried by the aggregate are easily moved with the airflow. Therefore, the turbidity detected by the gas turbidity detection probe 95 will be higher, while the humidity detected by the humidity detection probe 96 will be lower. In addition, the moisture content detected by the microwave detection unit 8 will also be lower. Conversely, when the aggregate moisture content is high, the adhesion of dust and other impurities is increased, and dust and other impurities are not easily carried into the hollow column 94 with the airflow. Therefore, the turbidity detected by the gas turbidity detection probe 95 will be lower, the humidity detected by the humidity detection probe 96 will be higher, and the moisture content detected by the microwave detection unit 8 will be higher. Thus, the aggregate moisture content can be pre-determined by the gas turbidity detection probe 95 and the humidity detection probe 96, and used as reference data for the subsequent detection results of the microwave detection unit 8.

[0041] After the controller 3 is activated, it controls the microwave transmitting array 83 to emit microwaves. The microwaves pass through the support base 4, the aggregate conveyor belt, and the aggregate itself, and are then received by the microwave receiving array 82. Simultaneously, as the aggregate passes the support base 4 via the aggregate conveyor belt, gravity exerts pressure on the support base 4. This pressure acts on various pressure sensors 52, which convert the pressure into electrical signals and feed them back to the controller 3. This allows for real-time detection of the aggregate weight passing through the support base 4. Since moisture in the aggregate absorbs microwave energy and alters the microwave phase, the microwave receiving array 82 receives the microwaves after they have passed through the aggregate, detecting energy attenuation and phase shift, and transmits this data to the controller 3. The controller 3 then combines the aggregate thickness and weight data to calculate the aggregate moisture content. The controller 3 then compares the calculated aggregate moisture content with the gas turbidity data. The detection results of the turbidity detection probe 95 and the humidity detection probe 96 are compared. When the results are correct, the controller 3 feeds back the moisture content data to the control terminal system of the concrete mixing plant. If the result comparison deviation is large, for example, the amount of dust detected by the gas turbidity detection probe 95 is large, while the humidity detected by the humidity detection probe 96 is also large, and the moisture content detected by the microwave detection unit 8 is small, it indicates that the detection result has too large a deviation (this deviation can be preset by the controller 3 according to different concrete aggregates). At this time, the controller 3 will issue an alarm prompt to remind personnel to trace the cause in time (or a corresponding diversion conveyor belt can be installed on the aggregate conveyor belt. For example, when the detection result is deviated, the aggregate on the aggregate conveyor belt can be discharged by the diversion conveyor belt using an interception structure, thereby avoiding aggregates with uncertain moisture content from entering the mixing equipment).

[0042] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A concrete aggregate moisture content testing device, comprising a base (1) and a frame (2) mounted above the base (1), wherein a controller (3) is mounted on the side wall of the frame (2), characterized in that, Also includes: A through hole (101) is opened at the top of the base (1), and a support seat (4) is slidably connected inside the through hole (101), and a weighing mechanism (5) for supporting the support seat (4) is installed inside the through hole (101). A flat hopper (6) is set above the base (1) and located on the side of the feed end of the support (4). The frame (2) is equipped with an adjustment drive mechanism (7) for driving the flat hopper (6) to move vertically. A microwave detection unit (8) is set on one side of the flat hopper (6). An auxiliary detection unit (9) is installed on the side wall of the flat hopper (6), and the auxiliary detection unit (9) is located on the side of the feed end of the support base (4); The microwave detection unit (8) includes a detection seat (81) fixedly installed on the side wall of the flat hopper (6). The detection seat (81) is located above the support seat (4). A microwave receiving array (82) is fixedly installed at the bottom of the detection seat (81). A microwave transmitting array (83) corresponding to the position of the microwave receiving array (82) is fixedly installed at the bottom of the support seat (4). Both the microwave transmitting array (83) and the microwave receiving array (82) are electrically connected to the controller (3). The auxiliary detection unit (9) includes a hollow plate (91) fixedly installed on the side wall of the flat hopper (6). The bottom of the hollow plate (91) is flush with the bottom of the flat hopper (6), and the hollow plate (91) is located on the feed end side of the support base (4). The bottom of the hollow plate (91) is provided with multiple air jet holes (92). An air pump (93) is installed on the top of the hollow plate (91), and the air delivery end of the air pump (93) is connected to the interior of the hollow plate (91). The air pump (93) draws air... A hollow column (94) is fixedly connected to the end of the hollow column (94). A gas turbidity detection probe (95) and a humidity detection probe (96) electrically connected to the controller (3) are installed on the top of the hollow column (94). An air suction bucket (97) is fixedly inserted at the bottom of the hollow column (94) away from the air pump (93). The bottom height of the air suction bucket (97) is higher than the top height of the hollow plate (91), and the horizontal distance between the air suction bucket (97) and the side wall of the hollow plate (91) facing each other is no more than 5cm.

2. The concrete aggregate moisture content detection device according to claim 1, characterized in that, The weighing mechanism (5) includes several mounting blocks (51) fixed inside the through hole (101). A pressure sensor (52) is fixed on the top of the mounting block (51), and the pressure measuring end of the pressure sensor (52) is fixedly connected to the bottom of the support base (4). The pressure sensor (52) is electrically connected to the controller (3).

3. The concrete aggregate moisture content detection device according to claim 1, characterized in that, The adjustment drive mechanism (7) includes a synchronous electric push rod (71) fixedly inserted into the end face of the frame (2). The movable end of the synchronous electric push rod (71) is fixed with a lifting block (72), and the lifting block (72) is fixed on the outer side wall of the flat hopper (6). The synchronous electric push rod (71) is electrically connected to the controller (3).

4. The concrete aggregate moisture content detection device according to claim 1, characterized in that, A sealing plate (10) is fixedly installed inside the hollow plate (91). An exhaust hole (11) is opened on the end face of the sealing plate (10), and a pulse solenoid valve (12) is installed inside the exhaust hole (11).

5. The concrete aggregate moisture content detection device according to claim 1, characterized in that, Two first mesh plates (13) are installed inside the hollow column (94) between the gas turbidity detection probe (95) and the humidity detection probe (96), and filter filler (14) is filled between the two first mesh plates (13). Two second mesh plates (15) are fixedly installed inside the hollow column (94) on the side of the humidity detection probe (96) away from the first mesh plate (13), and moisture-absorbing filler (16) is filled between the two second mesh plates (15).

6. The concrete aggregate moisture content detection device according to claim 1, characterized in that, Two symmetrical guide plates (17) are fixedly installed on the inner side wall of the frame (2), and the two guide plates (17) are located on both sides of the flat hopper (6). The guide plates (17) are integrally provided with inclined outward expansions on the side of the feed end of the support base (4), and the two outward expansions are opposite in orientation to the guide plates (17).

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