Automatic unloading device of plate and frame filter press and control method thereof

Abstract

The present invention relates to an automatic unloading device of a plate and frame filter press and a control method thereof, wherein the automatic unloading device comprises a filter press frame, a clamping plate is arranged at one end of the filter press frame, a thrust plate is arranged at the other end, the clamping plate is connected to the clamping device, a plurality of filter plates are arranged between the clamping plate and the thrust plate, guide rails are arranged at the tops of both sides of the filter press frame along the length direction thereof, two groups of unloading mechanisms are arranged between the two guide rails, the unloading mechanism comprises a crossbeam arranged perpendicularly to the guide rail, a movable frame is arranged at both ends of the crossbeam, and the movable frame can move along the guide rail under the drive of a first servo motor; two vertical slide rails are symmetrically arranged on both sides of the crossbeam, the two slide rails can slide up and down under the drive of a second servo motor, and a scraper assembly is arranged between the lower ends of the two slide rails. Based on the control method of the above-mentioned unloading device, the problems of incomplete unloading of the plate and frame filter press, uncontrollable unloading process, and low efficiency of unloading and filter cloth cleaning are solved.

Description

Technical Field

[0001] The invention relates to the technical field of plate and frame filter presses, and in particular to an automatic unloading device of a plate and frame filter press and a control method thereof. Background Art

[0002] The plate and frame filter press has great advantages in bulk material processing and viscous and fine material separation. It completes the solid-liquid separation through three main steps: suspension feeding-plate and frame pressing-discharging. The plate and frame filter press needs to be centrally unloaded after filtration. The unloading method directly affects the processing efficiency and processing capacity of the plate and frame filter press.

[0003] At present, the existing unloading methods of plate and frame filter presses include manual unloading and automatic unloading by unloading devices. Automatic unloading mainly uses motors, hydraulic motors, oil cylinders, etc. to pull the filter plates apart for unloading. Later, in order to enhance the unloading effect, some products added vibration devices or vibration mechanisms on the original basis to unload by impacting or vibrating the filter frame.

[0004] With the development of industrial intelligence, manual unloading has been gradually replaced. The existing automatic unloading method still has the following problems: incomplete unloading of filter cakes with high humidity, vibration or vibration schemes can easily cause deformation of the plate frame and reduce the service life of the equipment, and the unloading process is uncontrollable.

[0005] The purpose of the patent of this invention is to solve the problems of incomplete unloading of plate and frame filter press, uncontrollable unloading process, and low efficiency of unloading and filter cloth cleaning. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an automatic unloading device for a plate and frame filter press and a control method thereof, so as to solve the problems of incomplete unloading of the plate and frame filter press, uncontrollable unloading process, and low unloading and filter cloth cleaning efficiency.

[0007] To solve the above problems, the technical solution adopted by the present invention is:

[0008] An automatic unloading device for a plate-frame filter press, comprising a filter press frame, a pressing plate is arranged at one end of the filter press frame, a thrust plate is arranged at the other end, the pressing plate is connected to a pressing device, a plurality of filter plates are arranged between the pressing plate and the thrust plate, a plate pulling trolley is arranged on the side of the filter plate, guide rails are arranged at the top of both sides of the filter press frame along the length direction thereof, two groups of unloading mechanisms are arranged between the two guide rails, the unloading mechanism comprises a crossbeam arranged perpendicularly to the guide rail, a movable frame is arranged at both ends of the crossbeam, and the movable frame can move along the guide rail under the drive of a first servo motor;

[0009] Two vertical slide rails are symmetrically arranged on both sides of the crossbeam, and the two slide rails can slide up and down under the drive of the second servo motor. A scraper assembly is arranged between the lower ends of the two slide rails, and the scraper assembly is swingably installed on the lower end of the slide rail through a connecting rod. A first cylinder is connected between the connecting rod and the slide rail; the scraper assembly includes a mounting plate and a scraper component, a gas-liquid nozzle and a brush arranged in sequence along the upper and lower directions of the mounting plate.

[0010] As an embodiment of the present invention, one end of the connecting rod is fixedly connected to the mounting plate, and the other end is provided with a rotating groove, and the rotating groove is rotatably hinged to the side of the slide rail through a rotating shaft, and a long sliding groove is provided in the middle of the connecting rod; the first cylinder is fixedly provided on the side of the slide rail, and a guide rod is fixedly provided at the free end of the first cylinder rod of the first cylinder rod, and the guide rod is located in the sliding groove.

[0011] As an embodiment of the present invention, one end of the connecting rod is fixedly connected to the mounting plate, and the other end is provided with a rotation groove, and the rotation groove is rotatably hinged to the side of the slide rail through a rotating shaft; the first cylinder is rotatably hinged to the side of the slide rail, and the free end of the first cylinder rod of the first cylinder is hinged to the middle part of the connecting rod.

[0012] As an embodiment of the present invention, the scraper assembly, the gas-liquid nozzle and the brush are arranged in sequence from top to bottom, and a plurality of the gas-liquid nozzles are evenly arranged along the horizontal direction. A dovetail groove is opened at the lower part of the mounting plate along the horizontal direction, and a dovetail-shaped block is clamped in the dovetail groove, and the brush is evenly fixed on the block.

[0013] As an embodiment of the present invention, the scraper assembly includes a plurality of second cylinders horizontally and evenly fixed on the mounting plate, a reinforcing shaft is threadedly connected to the second cylinder rod of the second cylinder, and a rubber scraper is inserted into the reinforcing shaft; a connecting groove is provided on the side of the reinforcing shaft, and a connecting protrusion matching the connecting groove is provided in the socket on the rubber scraper; the second cylinder rod is connected to the piston located in the second cylinder, and a spring is provided on the part of the second cylinder rod in the second cylinder.

[0014] As an embodiment of the present invention, a laser displacement sensor and an industrial camera are arranged on the side of the beam opposite to the two groups of unloading mechanisms; the laser displacement sensor is located in the middle of the beam and is used to detect the distance from the filter plate; the industrial camera is arranged on each side of the beam for taking pictures and analyzing the filter plate.

[0015] As an embodiment of the present invention, each group of unloading mechanisms is provided with two parallel beams between two movable frames, the slide rail is located between the two beams, gear teeth are evenly arranged on the slide rail along the length direction, the second servo motor is a double-output shaft motor, and the two output shafts of the second servo motor respectively drive the slide rail to move up and down through a transmission module.

[0016] As an embodiment of the present invention, gear teeth are evenly arranged on the side of the guide rail, a gear meshing with the guide rail is arranged on the movable frame, and the gear is fixed on the output shaft of the first servo motor; a roller is arranged between the movable frame or the end of the beam and the filter press frame.

[0017] A control method for the automatic unloading device based on the plate and frame filter press comprises the following steps:

[0018] Step 1: Pull the filter plate apart with the plate-pulling trolley, and the two sets of unloading mechanisms move to both sides of the filter plate respectively, and are positioned relative to the filter plate with the help of laser displacement sensors;

[0019] Step 2: Control the slide rail to drive the scraper assembly, gas-liquid nozzle and brush to move downward, and discharge the material downward from the side of the filter plate. During the unloading process, the scraper assembly is controlled to tilt downward by the first cylinder, and the gas-liquid nozzles are all opened to realize the unloading process of blowing first and then hanging. After the unloading is completed, the filter plate is photographed by an industrial camera for image acquisition, and the position of the residual sludge on the filter plate is analyzed;

[0020] Step 3: After the analysis is completed, the control rail drives the scraper assembly to move upward to clean the side of the filter plate. During the cleaning process, the scraper assembly is tilted upward by the first cylinder, and the corresponding gas-liquid nozzle below the residual sludge position is opened when it runs to the residual sludge position. The gas-liquid nozzle is always kept closed when passing through the non-residual sludge position of the filter plate to increase the flow rate of the ejected gas to strongly blow the sludge. At the same time, the brush is used to comprehensively clean all positions of the filter plate to realize the cleaning process of blowing first and then sweeping. After the cleaning is completed, the filter plate is photographed again by the industrial camera for image acquisition and analysis to determine whether the filter press needs to be washed with water;

[0021] Step 4: Finally, pull the next filter plate by the plate pulling trolley to start the next unloading cycle until all filter plates are cleaned.

[0022] As an embodiment of the present invention, in step 2, the residual sludge on the filter plate is located by visual recognition technology, and the visual recognition technology includes the following steps: 1) image acquisition; 2) image preprocessing; 3) image enhancement; 4) image segmentation; 5) image contour fitting algorithm to determine the minimum bounding rectangle; 6) determine the center point of the sludge; 7) output the center point coordinates and the minimum bounding rectangle parameters;

[0023] In step 4), the image segmentation adopts color gamut region segmentation, deep learning image segmentation or binarization processing;

[0024] When judging whether the filter press needs to be washed in step three, logical threshold control is used to make a judgment, and the filter plate color depth threshold values ​​A and B are set. After completing a discharge cleaning, the system analyzes the images taken after each cleaning and calculates the average color depth, and compares the result with the threshold value. If it is lower than the threshold value A, it means that the filter cloth is in good condition and does not need to be cleaned; if it is between the threshold values ​​A and B, it means that the filter cloth is in general condition, and the gas-liquid nozzle will spray high-pressure water for unloading during the next discharge; if it is higher than the threshold value B, it means that the filter cloth is in poor condition and the filter press needs to be washed before use.

[0025] The beneficial effects of adopting the above technical solution are:

[0026] The automatic unloading device of the plate-frame filter press provided by the present invention directly uses the original air pressure station and hydraulic station of the plate-frame filter press, and completes the double-sided unloading of the filter plate by setting two sets of unloading mechanisms to cooperate simultaneously. During unloading, the scraper assembly, the gas-liquid nozzle and the brush cooperate to move downward and upward to perform secondary unloading and cleaning, and realize automatic unloading and automatic cleaning based on visual recognition technology. The unloading is complete and thorough, and the detection of the filter cloth state is completed in combination with the logic threshold control, which greatly extends the water washing cycle of the filter press and improves the working efficiency. A control method for the automatic unloading device of the plate-frame filter press is also provided. The control method is used for unloading, which solves the problems of incomplete unloading of the plate-frame filter press, uncontrollable unloading process, and low unloading and filter cloth cleaning efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention.

[0028] Figure 2 yes Figure 1 A partial enlarged schematic diagram in the middle.

[0029] Figure 3 It is a structural schematic diagram from another angle of the present invention.

[0030] Figure 4 It is a structural schematic diagram of the slide rail and scraper assembly in the present invention.

[0031] Figure 5 It is a schematic structural diagram of the slide rail and scraper assembly from another angle in the present invention.

[0032] Figure 6 yes Figure 5 A partial enlarged schematic diagram of point B in the middle.

[0033] Figure 7It is a structural schematic diagram of the scraper assembly in the present invention.

[0034] Figure 8 It is a main structural schematic diagram of the present invention.

[0035] Fig. 9 yes Figure 8 A partial enlarged schematic diagram of point C in the middle.

[0036] Fig.10 This is the air pressure control schematic diagram of the scraper assembly.

[0037] Among them: 1 machine base, 2 clamping device, 3 clamping plate, 4 thrust plate, 5 filter plate, 6 pull plate trolley, 601 walking frame, 7 gantry truss, 8 guide rail, 9 beam, 10 mobile frame, 1001 roller, 11 first servo motor, 1101 gear, 12 slide rail, 13 transmission module, 14 second servo motor, 15 first cylinder, 16 first cylinder rod, 17 guide rod, 18 rotating shaft, 19 connecting rod, 20 rotating groove, 21 sliding groove, 22 mounting plate, 23 dovetail groove, 24 block, 25 brush, 26 gas-liquid nozzle, 27 scraper assembly, 28 second cylinder, 29 piston, 30 second cylinder rod, 31 reinforcement shaft, 3101 connecting groove, 32 rubber scraper, 33 connecting protrusion, 34 bearing, 35 laser displacement sensor, 36 industrial camera, 37 spring. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is clearly and completely described below in conjunction with specific embodiments.

[0039] like Figure 1-Figure 3 An automatic unloading device of a plate and frame filter press shown in the figure comprises a filter press frame, the filter press frame comprises a machine base 1 and a gantry truss 7 arranged on the machine base 1, the guide rail 8 is arranged on the gantry truss 7, a pressing plate 3 is arranged at one end of the filter press frame, and a thrust plate 4 is arranged at the other end, the pressing plate 3 is connected to the pressing device 2, a plurality of filter plates 5 are arranged between the pressing plate 3 and the thrust plate 4, a plate pulling trolley 6 is arranged on the side of the filter plate 5, guide rails 8 are arranged on the top of both sides of the filter press frame along the length direction thereof, two groups of unloading mechanisms are arranged between the two guide rails 8, the unloading mechanism comprises a crossbeam 9 arranged perpendicularly to the guide rail 8, and movable frames 10 are arranged at both ends of the crossbeam 9, and the movable frame 10 can be moved along the guide rail 8 under the drive of a first servo motor 11;

[0040] Two vertical slide rails 12 are symmetrically arranged on both sides of the crossbeam 9. The two slide rails 12 can slide up and down when driven by a second servo motor 14. A scraper assembly is arranged between the lower ends of the two slide rails 12. The scraper assembly is swingably mounted on the lower end of the slide rail 12 through a connecting rod 19. A first cylinder 15 is connected between the connecting rod 19 and the slide rail 12. The scraper assembly includes a mounting plate 22 and a scraper assembly 27, a gas-liquid nozzle 26 and a brush 25 arranged in sequence along the upper and lower directions of the mounting plate 22.

[0041] The automatic unloading device of the plate-frame filter press provided by the present invention directly uses the original air pressure station and hydraulic station of the plate-frame filter press, and completes the double-sided unloading of the filter plate 5 by setting two sets of unloading mechanisms to cooperate at the same time. During unloading, the scraper assembly 27, the gas-liquid nozzle 26 and the brush 25 cooperate to move downward and upward to perform secondary unloading and cleaning, and realize automatic unloading and automatic cleaning based on visual recognition technology. The unloading is complete and thorough, and the detection of the filter cloth state is completed in combination with the logic threshold control, which greatly extends the water washing cycle of the filter press and improves the working efficiency. A control method for the automatic unloading device of the plate-frame filter press is also provided. The control method is used for unloading, which solves the problems of incomplete unloading of the plate-frame filter press, uncontrollable unloading process, and low unloading and filter cloth cleaning efficiency.

[0042] In order to enable the scraper assembly to swing, there are two implementation methods. As an implementation method, Figure 2 As shown, one end of the connecting rod 19 is fixedly connected to the mounting plate 22, and the other end is provided with a rotation groove 20. The rotation groove 20 is rotatably hinged to the side of the slide rail 12 through the rotating shaft 18, and a long sliding groove 21 is provided in the middle of the connecting rod 19; the first cylinder 15 is fixedly arranged on the side of the slide rail 12, and the free end of the first cylinder rod 16 of the first cylinder rod 15 is fixedly provided with a guide rod 17, and the guide rod 17 is located in the sliding groove 21. The first cylinder rod 16 is extended and retracted to drive the connecting rod 19 to drive the scraper assembly to swing.

[0043] As another embodiment, one end of the connecting rod 19 is fixedly connected to the mounting plate 22, and the other end is provided with a rotation groove 20, and the rotation groove 20 is rotatably hinged to the side of the slide rail 12 through the rotating shaft 18; the first cylinder 15 is rotatably hinged to the side of the slide rail 13, and the free end of the first cylinder rod 16 of the first cylinder 15 is hinged to the middle part of the connecting rod 19, and the connecting rod 19 is driven to drive the scraper assembly to swing through the extension and contraction of the first cylinder rod 16 and the rotation of the first cylinder 15.

[0044] like Figure 4-Figure 6As shown, in this embodiment, the scraper assembly 27, the gas-liquid nozzle 26 and the brush 25 are arranged in sequence from top to bottom, and a plurality of the gas-liquid nozzles 26 are evenly arranged along the horizontal direction. A dovetail groove 23 is opened at the lower part of the mounting plate 22 along the horizontal direction, and a dovetail-shaped block 24 is clamped in the dovetail groove 23, and the brush 25 is evenly fixed on the block 24.

[0045] As an implementation method, Figure 2 As shown, the scraper assembly 27 is a long horizontal scraper with a rubber sleeve on the outside. As another embodiment, Figure 4-Figure 7 As shown, the scraper assembly 27 includes a plurality of second cylinders 28 evenly fixed on the mounting plate 22 horizontally, a reinforcing shaft 31 is threadedly connected to the second cylinder rod 30 of the second cylinder 28, and a rubber scraper 32 is inserted into the reinforcing shaft 31; a connecting groove 3101 is provided on the side of the reinforcing shaft 31, and a connecting protrusion 33 matching the connecting groove 3101 is provided in the plug hole on the rubber scraper 32; the second cylinder rod 30 is connected to the piston 29 located in the second cylinder 28, and a spring 37 is sleeved on the part of the second cylinder rod 30 in the second cylinder 28. During operation, high-pressure gas enters from the air inlet of the second cylinder 28, pushes the piston 29 to drive the second cylinder rod 30 to extend, and the air at the rear end of the second cylinder 28 is discharged through the exhaust port. At this time, the spring 37 is compressed, which can reduce the force applied by the rubber scraper 32 to the filter cloth, and play a certain protective role. When a convex or concave shape is required, the rubber scraper 32 can be retracted to adapt to the external shape of the filter plate 5. After the work is completed, the second cylinder 28 is deflated, and the rubber scraper 32 returns to the initial position driven by the spring 37. The scraper assembly 27 is composed of a plurality of closely arranged rubber scrapers 32. Since the surface of the filter plate 5 is not flat, and some of the filter plates 5 have convexities and concave shapes on the surface, if the scraper assembly 27 cannot be well matched with the external shape of the filter plate 5, the filter cloth will be damaged during the work process. By setting a plurality of small-area rubber scrapers 32 to adapt to the outer surface of the filter plate 5, the filter cloth can be protected from damage while the unloading can be better completed. In addition, the head of the second cylinder 28 is also provided with an inverted bearing 34, which plays a supporting role during the work process and greatly weakens the radial force on the second cylinder rod 30. The reinforcing shaft 31 is made of a material with high strength and toughness, and its connecting groove 3101 is closely matched with the connecting protrusion 33 on the rubber scraper 32 to prevent the rubber scraper 32 from falling off during unloading.

[0046] In order to achieve the above-mentioned air pressure control, Fig.10As shown, the air pressure control mechanism includes a bus part and a branch part. The bus part includes a normally closed solenoid valve, a two-position five-way solenoid valve and two silencers. The branch part is connected in parallel with multiple groups of small cylinders (the second cylinder 28) and their control systems. The branch part includes a cylinder actuator, a relief solenoid valve, a one-way valve and a one-way throttle valve group. When the unloading mechanism is unloading downward, the normally closed valve opens, the two-position five-way valve cuts into the left side, the compressed gas flows into the left chamber of the second cylinder 28, and the gas in the right chamber flows into the atmosphere through the silencer. At this time, the piston pushes out the rubber scraper 32, and the rubber scraper 32 is unloaded. When there is a bulge on the filter plate 5, it is necessary to retract some of the branch cylinder pistons to a certain stroke. The excess gas flows out from the relief valve due to the increase in pressure. The outflowing gas enters the silencer of the bus and is discharged to the atmosphere, so that the piston can be retracted smoothly.

[0047] like Figure 1 and Figure 3 As shown, a laser displacement sensor 35 and an industrial camera 36 are provided on the beam 9 on the side opposite to the two groups of unloading mechanisms; the laser displacement sensor 35 is located in the middle of the beam 9 and is used to detect the distance from the filter plate 5; the industrial camera 36 is provided on each side of the beam 9 and is used to take pictures and analyze the filter plate 5.

[0048] Each set of unloading mechanisms is provided with two parallel beams 9 between the two moving frames 10. The slide rail 12 is located between the two beams 19. The slide rail 12 is evenly provided with gear teeth along the length direction. The second servo motor 14 is a double-output shaft motor. The two output shafts of the second servo motor 14 drive the slide rail 12 to move up and down through a transmission module 13 respectively. The transmission module 13 is a gear transmission module, and a gear assembly is arranged inside to cooperate with the gear teeth on the slide rail 12.

[0049] like Figure 8 and Fig. 9 As shown, the side of the guide rail 8 is evenly provided with gear teeth, the movable frame 10 is provided with a gear 1101 meshing with the guide rail 8, and the gear 1101 is fixed on the output shaft of the first servo motor 11; a roller 1001 is provided between the movable frame 10 or the end of the beam 9 and the filter press frame.

[0050] The present invention also provides a control method for the automatic unloading device based on the plate and frame filter press, comprising the following steps:

[0051] Step 1: Pull the filter plate 5 apart by the plate pulling trolley 6, and the two sets of unloading mechanisms are respectively moved to the two sides of the filter plate 5 by the drive of the first servo motor 11, and the distance between the unloading mechanism and the filter plate 5 is positioned by the laser displacement sensor 35;

[0052] Step 2: The second servo motor 14 controls the slide rail 12 to drive the scraper assembly 27, the gas-liquid nozzle 26 and the brush 25 to move downward, and discharge the filter plate 5 downward from the side. During the unloading process, the first cylinder 15 controls the scraper assembly 27 to tilt downward, the brush 25 does not contact the filter plate 5, and the gas-liquid nozzle 26 is fully opened to realize the unloading process of blowing first and then hanging. After the unloading is completed, the filter plate 5 is photographed by the industrial camera 36 for image acquisition, and the position of the residual sludge on the filter plate 5 is analyzed, and then the residual sludge coordinate information is transmitted to the controller;

[0053] Step 3: After the analysis is completed, the control rail 12 drives the scraper assembly 27 to move upwards, and the side of the filter plate 5 is cleaned upwards. During the cleaning process, the scraper assembly 27 is controlled to tilt upwards by the first cylinder 15, and the gas-liquid nozzle 26 corresponding to the residual sludge position below is opened when it runs to the residual sludge position. The gas-liquid nozzle 26 always remains closed when passing through the non-residual sludge position of the filter plate 5, so as to increase the flow rate of the ejected gas to strongly blow the sludge. At the same time, the brush 25 comprehensively cleans all positions of the filter plate 5, realizing the cleaning process of blowing first and then sweeping; after the cleaning is completed, the filter plate 5 is photographed again by the industrial camera 36 for image acquisition and analysis, so as to determine whether the filter press needs to be washed with water;

[0054] Step 4: Finally, the next filter plate 5 is pulled by the plate pulling trolley 6 to start the next unloading cycle until all the filter plates 5 are completely cleaned.

[0055] In step 2, the residual sludge on the filter plate 5 is located by visual recognition technology, and the visual recognition technology includes the following steps: 1) image acquisition; 2) image preprocessing; 3) image enhancement; 4) image segmentation; 5) image contour fitting algorithm to determine the minimum circumscribed rectangle; 6) determine the sludge center point; 7) output the center point coordinates and the minimum circumscribed rectangle parameters;

[0056] Wherein, in step 4), the image segmentation adopts color gamut region segmentation, deep learning image segmentation or binarization processing;

[0057] When judging whether the filter press needs to be washed in step three, logical threshold control is used to make a judgment, and the color depth threshold values ​​A and B of the filter plate 5 are set. After completing one unloading and cleaning, the system analyzes the images taken after each cleaning and calculates the average color depth, and compares the result with the threshold value. If it is lower than the threshold value A, it means that the filter cloth is in good condition and does not need to be cleaned; if it is between the threshold values ​​A and B, it means that the filter cloth is in general condition, and the gas-liquid nozzle will spray high-pressure water for unloading during the next unloading; if it is higher than the threshold value B, it means that the filter cloth is in poor condition and the filter press needs to be washed before use.

[0058] Since the frame is relatively wide, the present invention adopts two industrial cameras 36 to shoot simultaneously in hardware. Therefore, the image preprocessing stage mainly completes the stitching of the captured images, image graying and the like. The image graying adopts the weighted average algorithm, see the following formula.

[0059]

[0060] in represents the grayscale image, , , Represents the R, G, and B components of the original filter cloth image; , , Represents the weighting coefficients of R, G, and B respectively.

[0061] The grayscale filter cloth image often has a weak contrast and is prone to missing residual sludge, so the image needs to be enhanced. The enhanced image can clearly reflect the state of the sludge residue on the filter cloth. At this time, the image segmentation result is more accurate. The present invention provides three solutions for image segmentation.

[0062] Solution 1: HSV color gamut area segmentation image. This method does not require grayscale but image enhancement. The threshold is selected according to the state of the filter cloth. The threshold in the present invention is variable. After image enhancement, the RGB color value of the area accounting for 80% is visually identified, and the control system selects the threshold according to the HSV threshold calibration table. After multiple filter pressings, the surface color of the filter cloth becomes darker, and the difference with the sludge residue becomes smaller and smaller. The advantage of this method is that the visual system changes the appropriate threshold in real time according to the state of the filter cloth, making the sludge residue identification more accurate.

[0063] Solution 2 is binarization processing, which requires grayscale, adaptive binarization of the enhanced image, and setting of thresholds for image segmentation. The threshold selection here is similar to the above HSV.

[0064] Solution three, deep learning image segmentation method, is based on yoloV8. This method specifically segments the edges of each instance, thereby more accurately segmenting the image to filter out sludge residues.

[0065] After image segmentation, the image contour fitting algorithm is used to determine the minimum circumscribed rectangle of each sludge residue. Then, the center point of each rectangle is determined based on the determined minimum circumscribed rectangle of the sludge residue. Finally, the center point coordinates and the parameters of the circumscribed rectangle are output to the control system. The control system controls the unloading mechanism to move upward for unloading and cleaning based on the output information.

[0066] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic unloading device for a plate-frame filter press, comprising a filter press frame, a pressing plate at one end of the filter press frame, a thrust plate at the other end, the pressing plate being connected to a pressing device, a plurality of filter plates being arranged between the pressing plate and the thrust plate, a plate pulling trolley being arranged on the side of the filter plate, characterized in that: Guide rails are arranged on the top of both sides of the filter press frame along the length direction thereof, and two sets of unloading mechanisms are arranged between the two guide rails, and the unloading mechanism comprises a crossbeam arranged perpendicularly to the guide rails, and movable frames are arranged at both ends of the crossbeam, and the movable frames can move along the guide rails under the drive of the first servo motor; Two vertical slide rails are symmetrically arranged on both sides of the crossbeam, and the two slide rails can slide up and down under the drive of the second servo motor, and a scraper assembly is arranged between the lower ends of the two slide rails, and the scraper assembly is swingably installed at the lower ends of the slide rails through a connecting rod, and a first cylinder is connected between the connecting rod and the slide rail; the scraper assembly includes a mounting plate and a scraper assembly, a gas-liquid nozzle and a brush arranged in sequence along the upper and lower directions of the mounting plate; the scraper assembly includes a plurality of second cylinders fixed horizontally and evenly on the mounting plate, a reinforcing shaft is threadedly connected to the second cylinder rod of the second cylinder, and a rubber scraper is inserted into the reinforcing shaft; a connecting groove is provided on the side of the reinforcing shaft, and a connecting protrusion matching the connecting groove is provided in the socket on the rubber scraper; the second cylinder rod is connected to a piston located in the second cylinder, and a spring is partially sleeved on the second cylinder rod in the second cylinder.

2. The automatic unloading device of a plate and frame filter press according to claim 1, characterized in that: One end of the connecting rod is fixedly connected to the mounting plate, and the other end is provided with a rotation groove, and the rotation groove is rotatably hinged to the side of the slide rail through a rotating shaft, and a long sliding groove is provided in the middle of the connecting rod; the first cylinder is fixedly arranged on the side of the slide rail, and a guide rod is fixedly arranged at the free end of the first cylinder rod of the first cylinder rod, and the guide rod is located in the sliding groove.

3. The automatic unloading device of a plate and frame filter press according to claim 1, characterized in that: One end of the connecting rod is fixedly connected to the mounting plate, and the other end is provided with a rotation groove, and the rotation groove is rotatably hinged to the side of the slide rail through a rotating shaft; the first cylinder is rotatably hinged to the side of the slide rail, and the free end of the first cylinder rod of the first cylinder is hinged to the middle part of the connecting rod.

4. The automatic unloading device of a plate and frame filter press according to claim 2 or 3, characterized in that: The scraper assembly, gas-liquid nozzle and brush are arranged in sequence from top to bottom. A plurality of gas-liquid nozzles are evenly arranged in the horizontal direction. A dovetail groove is opened in the lower part of the mounting plate in the horizontal direction. A dovetail-shaped block is clamped in the dovetail groove. The brush is evenly fixed on the block.

5. The automatic unloading device of a plate and frame filter press according to claim 1, characterized in that: A laser displacement sensor and an industrial camera are arranged on the side of the beam opposite to the two groups of unloading mechanisms; the laser displacement sensor is located in the middle of the beam and is used to detect the distance from the filter plate; the industrial camera is arranged on each side of the beam and is used to take pictures and analyze the filter plate.

6. The automatic unloading device of a plate and frame filter press according to claim 1, characterized in that: Each set of unloading mechanisms is provided with two parallel beams between the two moving frames, the slide rail is located between the two beams, gear teeth are evenly arranged on the slide rail along the length direction, the second servo motor is a double-output shaft motor, and the two output shafts of the second servo motor drive the slide rail to move up and down through a transmission module respectively.

7. The automatic unloading device of a plate and frame filter press according to claim 6, characterized in that: The guide rail side surface is evenly provided with gear teeth, the movable frame is provided with a gear meshing with the guide rail, and the gear is fixed on the output shaft of the first servo motor; a roller is provided between the movable frame or the end of the crossbeam and the filter press frame.

8. A control method for the automatic unloading device of the plate and frame filter press according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Pull the filter plate apart with the plate-pulling trolley, and the two sets of unloading mechanisms move to both sides of the filter plate respectively, and are positioned relative to the filter plate with the help of laser displacement sensors; Step 2: Control the slide rail to drive the scraper assembly, gas-liquid nozzle and brush to move downward, and discharge the material downward from the side of the filter plate. During the unloading process, the scraper assembly is controlled by the first cylinder to tilt downward, and the gas-liquid nozzle is fully opened to realize the unloading process of blowing first and hanging later; After unloading is completed, the filter plate is photographed by an industrial camera for image acquisition, and the position of the residual sludge on the filter plate is analyzed; Step 3: After the analysis is completed, the control rail drives the scraper assembly to move upward to clean the side of the filter plate. During the cleaning process, the scraper assembly is tilted upward by the first cylinder, and the corresponding gas-liquid nozzle below the residual sludge position is opened when it runs to the residual sludge position. The gas-liquid nozzle is always kept closed when passing through the non-residual sludge position of the filter plate to increase the ejected gas flow rate to strongly blow the sludge. At the same time, the brush comprehensively cleans all positions of the filter plate to realize the cleaning process of blowing first and then sweeping; After cleaning, the filter plate is photographed again by an industrial camera for image acquisition and analysis to determine whether the filter press needs to be washed; Step 4: Finally, pull the next filter plate by the plate pulling trolley to start the next unloading cycle until all filter plates are cleaned.

9. The control method of the automatic unloading device of the plate and frame filter press according to claim 8, characterized in that: In step 2, the residual sludge on the filter plate is located by visual recognition technology, and the visual recognition technology includes the following steps: 1) image acquisition; 2) image preprocessing; 3) image enhancement; 4) image segmentation; 5) image contour fitting algorithm to determine the minimum enclosing rectangle; 6) determine the sludge center point; 7) output the center point coordinates and the minimum enclosing rectangle parameters; In step 4), the image segmentation adopts color gamut region segmentation, deep learning image segmentation or binarization processing; When judging whether the filter press needs to be washed in step three, logical threshold control is used to make a judgment, and the filter plate color depth threshold values ​​A and B are set. After completing a discharge cleaning, the system analyzes the images taken after each cleaning and calculates the average color depth, and compares the result with the threshold value. If it is lower than the threshold value A, it means that the filter cloth is in good condition and does not need to be cleaned; if it is between the threshold values ​​A and B, it means that the filter cloth is in general condition, and the gas-liquid nozzle will spray high-pressure water for unloading during the next discharge; if it is higher than the threshold value B, it means that the filter cloth is in poor condition and the filter press needs to be washed before use.

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