Automatic fine aggregate screening equipment and screening method

Abstract

The automatic fine aggregate screening equipment comprises a screening assembly, a driving assembly, a weighing assembly and a controller, the screening assembly comprises a screen containing groove, a screen cover is arranged above the screen containing groove, a collecting funnel is connected to the lower portion of the screen containing groove, a collecting disc is arranged at the position, below the collecting funnel, of the screen containing groove, and a test screen can be placed in the screen containing groove; the driving assembly comprises a motor, an eccentric wheel is installed on an output shaft of the motor, an eccentric roller is arranged at the bottom of the screen containing groove, the side face of the screen containing groove is hinged to one end of a push rod, a spring is arranged on a rod body of the push rod and connected to a fixing piece, and the other end of the push rod penetrates and extends to the outer side of the fixing piece and is provided with a driven roller in rolling contact with the eccentric wheel; the weighing assembly comprises an electronic balance, a supporting frame is arranged on the electronic balance, and a collecting disc is placed on the supporting frame; the controller is connected with the motor to control start-stop and rotation speed of the motor. The fine aggregate screening device can replace a manual hand screen, and meanwhile dust diffusion during fine aggregate screening is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical screening tests, and in particular to an automatic screening device and a screening method for fine aggregates. Background Art

[0002] With the continuous growth of infrastructure construction demand in my country in recent years, the requirements for concrete are getting higher and higher. The key to ensuring the quality of concrete is to strictly control the composition and properties of various aggregates. Among them, fine aggregate is one of the main materials for concrete, and its technical properties affect the performance of concrete. Grading is a very important technical parameter of fine aggregate, which is generally determined by screening test. Screening of fine aggregate is one of the common test operations of testing units and project engineering site laboratories. At present, for the screening of fine aggregate, the sieve is placed on the shaking sieve machine, and the sieve is removed after shaking for 10 minutes. Then, the sieve is hand-screened one by one according to the order of sieve hole size until the amount passing through per minute is less than 0.1% of the total sample. This operation process requires the test personnel to weigh and screen repeatedly, which is not only time-consuming and labor-intensive but also inefficient. In addition, dust diffusion is easily generated during the screening of fine aggregate, which is not conducive to the physical and mental health of the test personnel. Summary of the invention

[0003] In order to solve the technical problems that the existing fine aggregate screening is time-consuming, labor-intensive and inefficient, and dust diffusion occurs during the fine aggregate screening process, the present invention provides an automatic fine aggregate screening device and screening method, which can replace manual hand screening and avoid dust diffusion during fine aggregate screening.

[0004] The present invention solves the technical problem by adopting the following technical solution: An automatic screening device for fine aggregates comprises: a screening component, a driving component, a weighing component and a controller, wherein the screening component comprises a screening slot, a screening cover is arranged above the screening slot, a collecting funnel is connected below the screening slot, a collecting tray is arranged below the collecting funnel, a test sieve can be placed in the screening slot, and aggregates with smaller particles pass through the screen of the test sieve and then fall into the collecting tray through the collecting funnel; The driving assembly includes a motor, an eccentric wheel is installed on the output shaft of the motor, an eccentric roller is arranged at the bottom of the screen slot, the side of the screen slot is hingedly connected to one end of a push rod, a spring is arranged on the rod body of the push rod and connected to a fixing piece, the other end of the push rod penetrates and extends to the outside of the fixing piece, and a passive roller is arranged to roll and contact the eccentric wheel, the passive roller is driven by the combination of the eccentric wheel and the spring, slides forward repeatedly, and the eccentric roller at the bottom of the screen slot rolls, driving the screen slot to bump up and down; The weighing assembly includes an electronic balance, a support frame is arranged on the electronic balance, and a collecting plate is placed on the support frame; The controller is connected to the motor to control the start, stop and speed of the motor.

[0005] Furthermore, the inner side wall of the sieve slot is provided with a groove for convenient placement and removal of the test sieve.

[0006] Furthermore, it includes a supporting frame, on which a screening component, a driving component, a weighing component and a controller are all mounted, the weighing component is arranged below the screening component, and the controller is arranged below the driving component and on one side of the weighing component.

[0007] Furthermore, the fixing member is fixed on the supporting frame, the supporting frame is provided with a slide rail, and the eccentric roller rolls in the slide rail.

[0008] Furthermore, an outer shell is provided on the outside of the supporting frame, a conformal opening is reserved above the outer shell at the position of the screen cover, a first opening for taking and placing the collecting tray is provided on the side of the outer shell at the collecting tray, a transparent protective cover is installed at the first opening, and a second opening for leaking out the control panel is provided on the side of the outer shell at the electronic balance and controller.

[0009] Furthermore, the electronic balance is adjusted to weigh the weight of the aggregate particles in the collection tray after taring every one minute to determine whether the weight of the aggregate particles falling into the collection tray per minute is less than 0.1% of the total sample weight, thereby controlling the operation of the motor.

[0010] Furthermore, the controller is connected to an electronic balance, and the controller can read data from the electronic balance, and control the motor to stop when the weight of the aggregate particles dropped into the collection tray is less than a set threshold value within a certain period of time.

[0011] Furthermore, the controller collects and records the data of the weight of the aggregate particles in the collection tray from the electronic balance every 10 seconds, and after calculation and processing, determines whether the weight of the aggregate particles falling in the collection tray for 60 consecutive seconds is less than 0.1% of the total sample volume, thereby controlling the operation of the motor.

[0012] The present invention also provides a screening method of the fine aggregate automatic screening device, the screening method adopts the above-mentioned screening device, and comprises the following steps: 1. Sampling according to the requirements of the specification standard, screening out particles larger than 9.50 mm, and calculating the percentage of the sieve residue, and reducing the sample to about 1100g, placing it in an oven and drying it at 105±5°C to constant weight, and after cooling to room temperature, dividing it into two equal parts for standby; 2. Weigh 500g of the sample, accurate to 1g, and pour the sample onto a set of sieves with sieve bottoms arranged from top to bottom according to the aperture size, and then sieve; 3. Place the sieve set on the shaking sieve machine, shake the sieve for 10 minutes, remove the sieve set, and put them into the sieve slot of the fine aggregate automatic screening equipment one by one in the order of sieve hole size; 4. Turn on the switch of the equipment, and the automatic screening begins. When the screening volume per minute is less than 0.1% of the total sample volume, the equipment stops screening, takes out the test sieve in the sieve slot, and weighs the weight of the residual aggregate in the sieve (m).i , accurate to 1g. Then take out the sample from the collection plate and put it into the next sieve, and put it into this equipment together with the sample from the next sieve for sieving, and do it in sequence until all the sieves have been sieved, and finally weigh the mass of the sieve bottom m 底 ; 5. Calculate the results.

[0013] The sieve residue rate of each sieve size of the sample is calculated according to formula 1-1, accurate to 0.01%.

[0014] (1-1) Where: P i The residual rate (%) of each sieve fraction of the sample.

[0015] The sample's sieve residue rate A i , which is the sum of the residual rates of this sieve and all the sieves above it, accurate to 0.01%.

[0016] The fineness modulus of the sample is calculated according to formula 1-2, accurate to 0.01.

[0017] (1-2) Where: M x is the fineness modulus of fine aggregate; A 0.15 , A 0.3 , …A 4.75 The residue rates (%) of sieves of 0.15mm, 0.3mm, .., and 4.75mm respectively.

[0018] Furthermore, when the equipment stops screening, an alarm is sounded.

[0019] The present invention has the following beneficial effects: 1. Improve screening efficiency: The equipment adopts automatic screening and intelligent weighing system, which greatly improves the screening efficiency and avoids the repetitive operations and cumbersome processes in the traditional manual screening process.

[0020] Traditional manual screening is time-consuming and labor-intensive, but this equipment, through motor drive and automatic detection, can complete the screening work continuously and efficiently, effectively reducing the test time.

[0021] 2. Improved screening accuracy: The controller accurately collects and processes the data from the balance to ensure that the screening results meet the specifications. The system can automatically monitor the screening completion conditions (i.e. the throughput per minute is less than 0.1% of the total sample volume), thereby ensuring the accuracy and consistency of the screening process.

[0022] The automatic screening method reduces the interference of human factors on the results and improves the repeatability and accuracy of screening.

[0023] 3. Reduce dust pollution: The shell and cover design of the equipment effectively close the screening process, prevent the spread of dust generated during the screening of fine aggregates, protect the health of test personnel, and improve the operating environment.

[0024] This technology reduces the harm caused by dust inhalation to operators, meets environmental protection requirements, and improves the safety of on-site work.

[0025] 4. Intelligent and automated operation: The equipment automatically detects the screening progress and automatically stops screening according to the change of aggregate weight, avoiding frequent manual inspection of the screening process and reducing labor intensity.

[0026] The automated screening process combined with intelligent control enables the equipment to work stably for a long time, which not only improves work efficiency but also increases the service life of the equipment.

[0027] 5. Adapt to different aggregate screening requirements: By setting screens with different apertures, the equipment can be adapted to the screening needs of aggregates of different finenesses, especially for screening of fine concrete aggregates. It can accurately and quickly obtain aggregate grading data, thereby ensuring the quality of concrete.

[0028] The equipment supports flexible adjustment and precise control, can meet different standards and engineering requirements, and has strong adaptability.

[0029] 6. The present invention solves the problems of time-consuming, labor-intensive, and dust diffusion in the traditional fine aggregate screening process through intelligent automatic screening technology, which not only improves the screening efficiency and accuracy, but also significantly improves the working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the fine aggregate automatic screening device of the present invention; Figure 2 It is a schematic diagram of the internal structure of the automatic screening device for fine aggregates of the present invention; Figure 3 It is a schematic diagram of the internal structure of the automatic screening device for fine aggregates of the present invention; Figure 4 It is a structural schematic diagram of the screen slot in the automatic screening equipment for fine aggregates of the present invention; Figure 5 It is a flow chart of automatic screening control of the automatic screening equipment for fine aggregates of the present invention.

[0031] In the figure: 1. screening assembly; 11. sieve slot; 111. groove; 12. sieve cover; 13. collecting funnel; 14. collecting plate; 15. test sieve; 16. eccentric roller; 2. driving assembly; 21. motor; 22. eccentric wheel; 23. push rod; 24. spring; 25. passive roller; 3. weighing assembly; 31. electronic balance; 32. support frame; 4. controller; 5. support frame; 51. fixing part; 52. slide rail; 6. housing; 7. transparent shield; 8. control panel. DETAILED DESCRIPTION

[0032] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of an automatic fine aggregate screening device and screening method of the present invention in conjunction with the accompanying drawings.

[0033] like Figure 1~Figure 4 As shown, an automatic screening device for fine aggregates of the present embodiment comprises a screening component 1, a driving component 2, a weighing component 3 and a controller 4. The screening component 1 comprises a screening slot 11, a screen cover 12, a collecting funnel 13 and a collecting tray 14. A test sieve 15 can be placed in the screening slot 11. Aggregates with smaller particles pass through the screen of the test sieve 15 and then fall into the collecting tray 14 through the collecting funnel 13. A groove 111 is provided on the inner side wall of the screening slot 11 for convenient placement and removal of the test sieve 15, and an eccentric roller 16 is provided at the bottom.

[0034] The driving assembly 2 includes a motor 21, an eccentric wheel 22, a push rod 23, a spring 24 and a passive roller 25. The output shaft of the motor 21 is connected to the eccentric wheel 22. The spring 24 is sleeved on the push rod 23. A passive roller 25 is provided at one end of the push rod 23. The other end of the push rod 23 is hingedly connected to the screen slot 11. One end of the spring 24 is connected to the hinged connection end of the push rod 23, and the other end is connected to a fixing member 51. Driven by the combination of the eccentric wheel 22 and the spring 24, the passive roller 25 slides forward repeatedly, thereby causing the screen slot 11 and the test sieve 15 to shake back and forth. At the same time, the eccentric roller 16 at the bottom of the screen slot 11 rolls, driving the screen slot 11 to bump up and down, making the screening effect more obvious.

[0035] The weighing assembly 3 includes an electronic balance 31 and a support frame 32 . The support frame 32 is placed on the electronic balance 31 , and the collecting tray 14 is placed on the support frame 32 .

[0036] The controller 4 is connected to the motor 21 to control the start and stop and the speed of the motor 21. The electronic balance 31 is adjusted to weigh the aggregate particles in the collection tray 14 once every one minute after peeling, and it is determined whether the weight of the aggregate particles falling in the collection tray 14 per minute is less than 0.1% of the total sample, so as to manually control the motor 21 to continue screening or stop screening.

[0037] In this embodiment, a support frame 5 is further included, and the screening component 1, the driving component 2, the weighing component 3 and the controller 4 are all installed on the support frame 5, wherein the weighing component 3 is arranged below the screening component 1, and the controller 4 is arranged below the driving component 2 and on one side of the weighing component 3. The fixing member 51 is fixed on the support frame 5, and a slide rail 52 is arranged on the support frame 5, and the eccentric roller 16 rolls in the slide rail 52.

[0038] A shell 6 is provided on the outside of the supporting frame 5, a conformal opening is reserved above the shell 6 at the position of the sieve cover 12, a first opening for taking and placing the collecting tray 14 is provided on the side of the shell 6 at the collecting tray 14, a transparent protective cover 7 is installed at the first opening, and a second opening for leaking out the control panel 8 is provided on the side of the shell 6 at the electronic balance 31 and the controller 4.

[0039] In an optional embodiment, the controller 4 is connected to the electronic balance 31, and the controller 4 can read the data of the electronic balance 31, and control the motor 21 to stop when the weight of the aggregate particles dropped into the collection tray is less than a set threshold value for a certain period of time. Figure 5 As shown, the controller collects and records the data of the weight of the aggregate particles in the collection tray 14 by the electronic balance 31 every 10 seconds, and determines through calculation and processing whether the weight of the aggregate particles falling in the collection tray 14 for 60 consecutive seconds is less than 0.1% of the total sample volume, thereby automatically controlling the motor 21 to continue screening or stop screening.

[0040] The device of the present invention has the advantage of replacing the manual hand screening function and avoiding the diffusion of dust during fine aggregate screening, thereby solving the problem that the existing fine aggregate screening is time-consuming, labor-intensive and inefficient, and dust is diffused during the fine aggregate screening process.

[0041] This embodiment provides a screening method of an automatic screening device for fine aggregates, the screening method using the above-mentioned screening device, comprising the following steps: 1. Take samples according to the requirements of the standard, screen out particles larger than 9.50 mm, calculate the percentage of the residue on the screen, and reduce the sample to about 1100g. Dry it in an oven at 105±5℃ to constant weight. After cooling to room temperature, divide it into two equal parts for later use.

[0042] 2. Weigh 500g of the sample, accurate to 1g, pour the sample onto a set of sieves with sieve bottoms arranged from top to bottom according to the aperture size, and then sieve.

[0043] 3. Place the set sieve on the shaking sieve machine and shake the sieve for 10 minutes; remove the set sieve and place them one by one in the sieve slot 11 of the fine aggregate automatic screening device of the present invention in the order of sieve hole size, cover them with the sieve cover 12, then install the collecting tray 14, and cover them with the transparent protective cover 7.

[0044] 4. Turn on the switch of this equipment, and automatic screening begins. When the amount of screening per minute is less than 0.1% of the total sample, this equipment automatically stops screening and alarms. Take out the test sieve 15 in the sieve slot 11 and weigh the weight of the residual aggregate in the sieve to an accuracy of 1g. Then take out the sample in the collection tray 14 and put it into the next sieve, and put it into this equipment together with the sample in the next sieve for screening. This sequence is carried out until all sieves are screened.

[0045] 5. Calculate the results.

[0046] The sieve residue rate of each sieve size of the sample is calculated according to formula 1-1, accurate to 0.01%.

[0047] (1-1) Where: Pi is the sieve residue rate (%) of each sieve size of the sample.

[0048] The sieve residue rate Ai of each sieve number of the sample is the sum of the sieve residue rates of that sieve number and above, accurate to 0.01%.

[0049] The fineness modulus of the sample is calculated according to formula 1-2, accurate to 0.01.

[0050] (1-2) Where: Mx is the fineness modulus of fine aggregate; A0.15, A0.3, …A4.75 are the residue rates (%) of sieves of 0.15mm, 0.3mm, .., 4.75mm respectively.

[0051] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. An automatic screening device for fine aggregates, characterized in that: include: A screening component (1), a driving component (2), a weighing component (3) and a controller (4), wherein the screening component (1) comprises a screening slot (11), a screening cover (12) is arranged above the screening slot (11), a collecting funnel (13) is connected below the screening slot (11), a collecting tray (14) is arranged below the collecting funnel (13), and a test sieve (15) can be placed in the screening slot (11), and aggregate with smaller particles passes through the screen of the test sieve (15) and then falls into the collecting tray (14) through the collecting funnel (13); The driving assembly (2) comprises a motor (21), an eccentric wheel (22) is mounted on the output shaft of the motor (21), an eccentric roller (16) is arranged at the bottom of the sieve slot (11), a side surface of the sieve slot (11) is hingedly connected to one end of a push rod (23), a spring (24) is arranged on the rod body of the push rod (23) and is connected to a fixing member (51), the other end of the push rod (23) penetrates and extends to the outside of the fixing member (51), and is provided with a passive roller (25) that rolls and contacts the eccentric wheel (22), the passive roller (25) is driven by the combination of the eccentric wheel (22) and the spring (24) to slide forward repeatedly, and the eccentric roller (16) at the bottom of the sieve slot (11) rolls, driving the sieve slot (11) to bump up and down; The weighing assembly (3) comprises an electronic balance (31), a support frame (32) is arranged on the electronic balance (31), and a collecting plate (14) is placed on the support frame (32); The controller (4) is connected to the motor (21) to control the start and stop and the rotation speed of the motor (21).

2. The automatic screening equipment for fine aggregate according to claim 1, characterized in that: The inner side wall of the sieve placement slot (11) is provided with a groove (111) for convenient placement and removal of the test sieve (15).

3. The automatic screening equipment for fine aggregate according to claim 1, characterized in that: The invention comprises a supporting frame (5), wherein a screening component (1), a driving component (2), a weighing component (3) and a controller (4) are all mounted on the supporting frame (5), the weighing component (3) is arranged below the screening component (1), and the controller (4) is arranged below the driving component (2) and on one side of the weighing component (3).

4. The automatic screening equipment for fine aggregate according to claim 3, characterized in that: The fixing member (51) is fixed on the supporting frame (5), and a slide rail (52) is provided on the supporting frame (5), and the eccentric roller (16) rolls in the slide rail (52).

5. The automatic fine aggregate screening device according to claim 3 or 4, characterized in that: A shell (6) is provided on the outside of the support frame (5), a shaped opening is reserved above the shell (6) at the position of the screen cover (12), a first opening for taking and placing the collecting tray is provided on the side of the shell (6) at the collecting tray (14), a transparent protective cover (7) is installed at the first opening, and a second opening for leaking out the control panel (8) is provided on the side of the shell (6) at the electronic balance (31) and the controller (4).

6. The automatic screening equipment for fine aggregate according to claim 1, characterized in that: The electronic balance is regulated to weigh the weight of the aggregate particles in the collection tray (14) after peeling at regular intervals, and it is determined whether the weight of the aggregate particles dropped in the collection tray (14) during this period is less than a specified percentage, thereby controlling the operation of the motor (21).

7. The automatic screening equipment for fine aggregate according to claim 1, characterized in that: The controller (4) is connected to the electronic balance (31). The controller (4) can read the data of the electronic balance (31) and control the motor (21) to stop when the weight of the aggregate particles dropped into the collection tray (14) is less than a set threshold value within a certain period of time.

8. The automatic screening equipment for fine aggregate according to claim 7, characterized in that: The controller (4) regularly collects and records data on the weight of aggregate particles in the collection tray (14) from the electronic balance (31), and determines through calculation and processing whether the weight of aggregate particles dropped in the collection tray (14) within a predetermined time period is less than a set threshold value, thereby controlling the operation of the motor (21).

9. A screening method for fine aggregate automatic screening equipment, the screening method using the screening equipment according to any one of claims 1 to 8, characterized in that: The following steps are involved:

1. Take samples according to the requirements of the specifications and standards, screen out particles larger than the specified size, calculate the percentage of the residue on the screen, and reduce the sample to a suitable mass range. Dry it in an oven at an appropriate temperature to a constant weight. After cooling to room temperature, divide it into two equal parts for standby use; 2. Weigh an appropriate amount of sample, pour it onto the sieves with sieve bottoms arranged from top to bottom according to the aperture size, and then sieve; 3. Place the sieve set on the shaking sieve machine, shake the sieve for a preset time, remove the sieve set, and place them one by one in the sieve slot of the fine aggregate automatic screening equipment in the order of sieve hole size; 4. Turn on the switch of the equipment, and automatic screening begins. When the amount of material passing through the equipment per unit time is less than the specified percentage, the equipment stops screening, takes out the test sieve (15) in the sieve slot (11), weighs the weight of the residual aggregate in the sieve, then takes out the sample in the collection tray (14), puts it into the next sieve, and puts it into the equipment together with the sample in the next sieve for screening, and continues in sequence until all the sieves have been screened; 5. Calculate the results.

10. The screening method of the fine aggregate automatic screening equipment according to claim 9, characterized in that: When the equipment stops screening, an alarm will sound.

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