Cement paste stirring scale for sludge solidification

Abstract

The invention provides a cement paste stirring scale for sludge solidification, and belongs to the technical field of cement stirring, the cement paste stirring scale for sludge solidification comprises a rack, a stirring cylinder, a driving device, a weighing system, a feeding device, a discharging device, a stirring device, a cleaning device and a control panel; the rack is of a vertical structure and is composed of a base, stand columns and a cross beam, the base is rectangular, and anti-vibration pads are arranged at the four corners of the base. The four stand columns are perpendicularly fixed to the base and located at the four corners of the base respectively. The cross beam is horizontally fixed to the top ends of the four stand columns to form a stable frame structure. The mixing drum is cylindrical and is vertically mounted in the center of the rack, a feeding hole is formed in the top of the mixing drum, and a discharging hopper is arranged at the bottom of the mixing drum; the driving device comprises a motor, a speed reducer and a transmission shaft, the motor is fixed on the rack base through a motor seat, the speed reducer is connected with a motor output shaft, one end of the transmission shaft is connected with a speed reducer output shaft, and the other end penetrates through the bottom of the mixing drum and extends into the drum.

Description

Technical Field

[0001] The invention belongs to the technical field of cement mixing, and in particular relates to a cement slurry mixing scale for sludge solidification. Background Art

[0002] Sludge is a semi-solid waste. A large amount of sludge is produced in municipal sewage treatment plants, industrial wastewater treatment plants and other places. In order to reduce the pollution of sludge to the environment, the commonly adopted method is to solidify the sludge, that is, by adding a certain amount of solidifying agent, the water content of the sludge is reduced and converted into a solid state that can be stably stacked or made into building materials. In this solidification process, the amount of solidifying agent added needs to be accurately controlled to ensure that the solidification effect meets the standard. Therefore, it is particularly important to develop a device that can accurately measure and control the amount of solidified material added.

[0003] At present, the equipment widely used in the sludge solidification process is various types of continuous mixers. This type of equipment is usually composed of a frame, a mixing drum, a mixing device, a feeding device and a discharging device, etc., which can continuously mix the curing agent (such as cement slurry) with the sludge at high speed to fully mix them and achieve the purpose of solidification. However, these traditional mixing equipment have some problems:

[0004] 1. Low weighing accuracy: During the mixing process, the fluidity and dynamic characteristics of the material will interfere with the weighing system, resulting in large errors in the weighing results and difficulty in accurately controlling the dosage.

[0005] 2. Difficult to clean and maintain: A large amount of attachments will accumulate inside the mixing drum, which requires frequent manual cleaning, increasing maintenance costs and downtime.

[0006] 3. Simple control system: Most equipment only has simple start-stop and speed adjustment functions, and cannot achieve intelligent dosage control.

[0007] In view of the above problems, there is an urgent need to develop a new type of cement slurry mixing scale for sludge solidification, which can accurately measure and control the amount of solidifying agent added, and at the same time have a good level of automation and intelligence to improve the stability and reliability of the solidification process. Summary of the invention

[0008] The invention provides a cement slurry mixing scale for sludge solidification, which can solve the problem that the interior of an existing cement mixing barrel is inconvenient to clean.

[0009] The present invention is achieved in that:

[0010] The present invention provides a cement slurry mixing scale for sludge solidification, which includes: a frame, a mixing drum, a driving device, a weighing system, a feeding device, a discharging device, a mixing device, a cleaning device and a control panel; the frame is a vertical structure, composed of a base, columns and beams, the base is rectangular, and shockproof pads are provided at four corners; the columns are vertically fixed on the base, and there are four of them, which are respectively located at the four corners of the base; the beams are horizontally fixed to the tops of the four columns to form a stable frame structure; the mixing drum is cylindrical, vertically installed in the center of the frame, with a feeding port on the top and a mixing drum discharging port on the bottom; the driving device includes a motor, a reducer and a transmission shaft, the motor is fixed to the frame base through a motor seat, the reducer is connected to the motor output shaft, one end of the transmission shaft is connected to the reducer output shaft, and the other end passes through the bottom of the mixing drum and extends into the drum; the weighing system includes a plurality of weighing sensors, which are installed between the bottom of the mixing drum and the frame for real-time monitoring Measure the weight of the material in the mixing drum; the feeding device is arranged at the top of the mixing drum, including a feeding hopper and a feeding valve, the feeding hopper is funnel-shaped, fixed above the feeding port of the mixing drum, and the feeding valve is installed at the bottom outlet of the feeding hopper to control the rate at which the material enters the mixing drum; the discharging device is arranged at the bottom of the mixing drum, including a discharging hopper and a discharging valve, the discharging hopper is located at the bottom center of the mixing drum, and the discharging valve is installed at the discharging hopper to control the discharge of the material; the stirring device includes a stirring shaft and stirring blades, the stirring shaft is coaxially connected with the transmission shaft, vertically passes through the mixing drum, and the stirring blades are evenly distributed along the circumference of the stirring shaft and are arranged in a spiral shape; the cleaning device includes a scraper assembly and a flushing system, the scraper assembly is installed on the inner wall of the mixing drum, and is used to scrape off the material attached to the drum wall, and the flushing system includes a number of nozzles, which are evenly distributed on the inner wall of the top of the mixing drum, and are used to clean the residual material in the drum; the control panel is installed on the side of the frame to control the entire mixing scale system.

[0011] The technical effects of a cement slurry mixing scale for sludge solidification provided by the present invention are as follows: The cement slurry mixing scale for sludge solidification proposed by the present invention has the following significant advantages over the prior art:

[0012] 1. Small dynamic weighing error: The polynomial compensation model is adopted, and the comprehensive information of the weighing system, such as the time domain characteristics, frequency domain characteristics, temperature characteristics, nonlinear characteristics and mechanical vibration characteristics, can be used to effectively compensate for the influence of dynamic load and process interference on the weighing results, and achieve milligram-level dynamic weighing accuracy.

[0013] 2. Easy to clean and maintain: The inside of the mixing drum is equipped with a scraper assembly and an automatic flushing system, which can automatically scrape off attachments and clean residual materials, greatly reducing the frequency and workload of manual cleaning and increasing the service life of the equipment.

[0014] 3. High level of intelligent control: The control system has functions such as touch screen operation interface, data monitoring and fault diagnosis. It can display weighing data in real time, automatically adjust the dosage, and adaptively adjust the compensation model parameters according to changes in production conditions, realizing accurate and intelligent material dosing control.

[0015] 4. Wide range of applications: The mixer adopts modular design, and its mechanical structure, electronic control system and compensation algorithm are highly versatile and adaptable. It can be widely used in various types of sludge solidification processes to meet different production scales and process requirements.

[0016] In general, the cement slurry mixing scale for sludge solidification proposed in the present invention solves the accuracy, cleanliness and intelligence problems existing in the prior art through advanced dynamic weighing compensation technology, intelligent automatic control and modular design concept, greatly improves the stability and reliability of the sludge solidification process, and has wide application value.

[0017] On the basis of the above technical solution, the cement slurry mixing scale for sludge solidification of the present invention can also be improved as follows:

[0018] Among them, the mixing drum is made of stainless steel, the wall thickness is 8 mm to 12 mm, and a wear-resistant coating is provided inside; an observation window is provided on the top of the mixing drum, the observation window is made of transparent tempered glass, is round in shape, and has a diameter of 200 mm to 300 mm, and is sealed to the top of the mixing drum through a sealing ring; the bottom of the mixing drum is a conical structure with a cone angle of 30 degrees to 45 degrees, which is conducive to the smooth discharge of materials.

[0019] Furthermore, the motor in the drive device is a variable frequency motor with a rated power of 5 kW to 10 kW and a rotation speed of 0 rpm to 1500 rpm; the reducer is a planetary gear reducer with a reduction ratio of 1 to 10 to 1 to 20; the drive shaft is made of alloy steel, the surface is heat treated and surface hardened, and the diameter is 40 mm to 60 mm.

[0020] Furthermore, the weighing system includes 4 weighing sensors, which are respectively installed between the four corners of the bottom of the mixing drum and the frame; the range of each weighing sensor is 0 kg to 2000 kg, and the accuracy is 0.1% of the full scale; the weighing sensor adopts a shear beam structure, is made of alloy steel, and is nickel-plated on the surface to achieve corrosion resistance.

[0021] Furthermore, the feed hopper in the feeding device is made of 304 stainless steel plate with a wall thickness of 3 mm to 5 mm, and the inner surface is polished; the top opening diameter of the feed hopper is 600 mm to 800 mm, and the bottom outlet diameter is 200 mm to 300 mm; the feed valve is a pneumatic butterfly valve, the valve body is made of cast steel, the valve plate is made of 304 stainless steel, and the sealing ring is made of fluororubber; the opening angle of the pneumatic butterfly valve is 0 degrees to 90 degrees, and the opening time is 2 seconds to 5 seconds.

[0022] Furthermore, the discharging hopper in the discharging device is circular, with a diameter of 150 mm to 250 mm; the discharging valve is a pneumatic ball valve, the valve body is made of 304 stainless steel, the ball is made of 304 stainless steel and has been surface hardened, and the sealing ring is made of polytetrafluoroethylene; the opening angle of the pneumatic ball valve is 0 degrees to 90 degrees, and the opening time is 1 second to 3 seconds.

[0023] Furthermore, the stirring shaft in the stirring device is made of 304 stainless steel, with a diameter of 50 mm to 80 mm and a polished surface; the stirring blades are stamped from 304 stainless steel plates, with a thickness of 5 mm to 8 mm and a polished surface; the stirring blades are arranged in a double helix along the stirring shaft, with a pitch of 300 mm to 500 mm and a blade inclination angle of 30 degrees to 45 degrees; each spiral period is provided with 4 to 6 stirring blades, and the gap between the outer edge of the blade and the inner wall of the stirring barrel is 10 mm to 20 mm.

[0024] Furthermore, the scraper assembly in the cleaning device includes multiple scrapers, the scrapers are made of polyurethane and have a hardness of 90 to 95 degrees Shore A; the scrapers are fixed to the inner wall of the mixing drum through a stainless steel bracket, and the pressing force between the scrapers and the inner wall of the mixing drum is adjusted by a spring; the flushing system includes 8 to 12 nozzles, the nozzles are made of 316L stainless steel, the nozzle diameter is 2 mm to 4 mm, and the angle between the nozzles and the inner wall of the top of the mixing drum is 30 to 45 degrees.

[0025] Furthermore, the control panel is made of steel plate, with plastic spray treatment on the surface and a protection level of IP65; the control panel is provided with a touch screen, an emergency stop button, a start button, a stop button, a power indicator light and a fault indicator light; the touch screen size is 10 inches to 12 inches, and the resolution is not less than 1024×768 pixels; the control panel is internally provided with relays, contactors, circuit breakers and power modules for controlling the action of each actuator and protecting the electrical system.

[0026] Furthermore, it also includes a weighing calculation system, which includes a single chip microcomputer and a data processor, the single chip microcomputer is electrically connected to the touch screen and the weighing sensor, and a weighing compensation module is provided in the single chip microcomputer to reduce the dynamic weighing accuracy error under high-speed flow state, and display the current weighing data in real time through the touch screen, and the weighing compensation module is used to perform the following steps:

[0027] S10, collecting the original weighing signal of the weighing sensor during the stirring process, and obtaining a dynamic weighing data sequence within a continuous time period;

[0028] S20, performing time domain analysis on the dynamic weighing data sequence to extract time domain characteristic parameters, including mean, standard deviation, peak factor and waveform factor;

[0029] S30, performing frequency domain analysis on the dynamic weighing data sequence, obtaining spectrum characteristics through Fourier transform, and extracting main frequency components and their amplitudes;

[0030] S40, establishing a compensation equation group based on the time domain characteristic parameters and the frequency domain characteristics, wherein the compensation equation group includes a dynamic response equation, a spectrum compensation equation, a temperature drift equation, a nonlinear correction equation, and a mechanical coupling equation;

[0031] S50, collecting weighing data of multiple groups of materials with known weights at different stirring speeds, and establishing a training sample set, where each group of samples includes characteristic parameters and corresponding actual error values;

[0032] S60, fitting the compensation equation group by using the least square method, determining the coefficients of each item in the compensation equation group, and obtaining a dynamic weighing error compensation model;

[0033] S70, verifying the dynamic weighing error compensation model by a cross-validation method, calculating the weighing error after compensation, and returning to step S40 to adjust the compensation equation group when the error after compensation is greater than a preset threshold;

[0034] S80, applying the dynamic weighing error compensation model to the real-time weighing process, performing online compensation on the original weighing signal, and outputting the corrected weighing data;

[0035] S90. According to changes in production conditions, new sample data is periodically collected, and the coefficients of the compensation equation group are updated to maintain the adaptability of the compensation model.

[0036] Compared with the prior art, the beneficial effects of the cement slurry mixing scale for sludge solidification provided by the present invention are as follows: the cement slurry mixing scale for sludge solidification provided by the present invention has the following significant advantages over the prior art:

[0037] 1. Small dynamic weighing error: The polynomial compensation model is adopted, and the comprehensive information of the weighing system, such as the time domain characteristics, frequency domain characteristics, temperature characteristics, nonlinear characteristics and mechanical vibration characteristics, can be used to effectively compensate for the influence of dynamic load and process interference on the weighing results, and achieve milligram-level dynamic weighing accuracy.

[0038] 2. Easy to clean and maintain: The inside of the mixing drum is equipped with a scraper assembly and an automatic flushing system, which can automatically scrape off attachments and clean residual materials, greatly reducing the frequency and workload of manual cleaning and increasing the service life of the equipment.

[0039] 3. High level of intelligent control: The control system has functions such as touch screen operation interface, data monitoring and fault diagnosis. It can display weighing data in real time, automatically adjust the dosage, and adaptively adjust the compensation model parameters according to changes in production conditions, realizing accurate and intelligent material dosing control.

[0040] 4. Wide range of applications: The mixer adopts modular design, and its mechanical structure, electronic control system and compensation algorithm are highly versatile and adaptable. It can be widely used in various types of sludge solidification processes to meet different production scales and process requirements.

[0041] In general, the cement slurry mixing scale for sludge solidification proposed in the present invention solves the accuracy, cleanliness and intelligence problems existing in the prior art through advanced dynamic weighing compensation technology, intelligent automatic control and modular design concept, greatly improves the stability and reliability of the sludge solidification process, and has wide application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0043] Figure 1 A front view of a cement slurry mixing scale for sludge solidification;

[0044] Figure 2 A schematic diagram of the internal structure of a mixing barrel of a cement slurry mixing scale for sludge solidification;

[0045] Figure 3 Execute the flow chart for the weighing compensation module;

[0046] Figure 4 It is the dynamic response curve of the mixing scale;

[0047] Figure 5 For spectrum analysis of weighing signal;

[0048] Figure 6 is the temperature drift characteristic curve;

[0049] Figure 7 is the nonlinear characteristic of the weighing system;

[0050] Figure 8 For vibration compensation effect comparison;

[0051] Fig. 9 To compare the long-term operation accuracy of the system;

[0052] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0053] 10. Frame; 101. Base; 102. Column; 103. Beam; 11. Mixing barrel; 12. Driving device; 121. Motor; 122. Reducer; 123. Transmission shaft; 13. Weighing system; 131. Weighing sensor; 14. Feeding device; 141. Feeding hopper; 142. Feeding valve; 15. Discharging device; 16. Stirring device; 161. Stirring shaft; 162. Stirring blade; 17. Cleaning device; 171. Scraper; 172. Nozzle; 18. Control panel. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0055] like Figure 1, 2 is a schematic diagram of the structure of a cement slurry mixing scale for sludge solidification provided by the present invention, in which the structure includes: a frame 10, a mixing barrel 11, a driving device 12, a weighing system 13, a feeding device 14, a discharging device 15, a stirring device 16, a cleaning device 17 and a control panel 18; the frame is a vertical structure, consisting of a base 101, a column 102 and a crossbeam 103, the base is rectangular, and shockproof pads are provided at the four corners; the columns are vertically fixed to the base, and there are four of them, which are respectively located at the four corners of the base. The crossbeam is fixed horizontally on the top of the four columns to form a stable frame structure; the mixing drum is cylindrical and vertically installed in the center of the frame, with a feed inlet on the top and a mixing drum outlet on the bottom; the driving device includes a motor 121, a reducer 122 and a transmission shaft 123, the motor is fixed on the frame base through a motor seat, the reducer is connected to the motor output shaft, one end of the transmission shaft is connected to the reducer output shaft, and the other end passes through the bottom of the mixing drum and extends into the drum; the weighing system includes a plurality of weighing sensors 131, It is installed between the bottom of the mixing drum and the frame, and is used to monitor the weight of the material in the mixing drum in real time; the feeding device is arranged at the top of the mixing drum, including a feeding hopper 141 and a feeding valve 142, the feeding hopper is funnel-shaped, fixed above the feeding port of the mixing drum, and the feeding valve is installed at the bottom outlet of the feeding hopper, and is used to control the rate at which the material enters the mixing drum; the discharging device is arranged at the bottom of the mixing drum, including a discharging hopper and a discharging valve, the discharging hopper is located at the center of the bottom of the mixing drum, and the discharging valve is installed at the discharging hopper, and is used to control the discharge of the material; the stirring device includes a stirring shaft 161 and stirring blades 162, the stirring shaft is coaxially connected with the transmission shaft, vertically passes through the mixing drum, and the stirring blades are evenly distributed along the circumference of the stirring shaft and are arranged in a spiral shape; the cleaning device includes a scraper assembly and a flushing system, the scraper assembly is installed on the inner wall of the mixing drum, and is used to scrape off the material attached to the drum wall, and the flushing system includes a plurality of nozzles 172, which are evenly distributed on the inner wall of the top of the mixing drum, and are used to clean the residual material in the drum; the control panel is installed on the side of the frame, and is used to control the entire mixing scale system.

[0056] Among them, in the above technical scheme, the mixing drum is made of stainless steel, the drum wall thickness is 8 mm to 12 mm, and a wear-resistant coating is provided inside; an observation window is provided on the top of the mixing drum, the observation window is made of transparent tempered glass, is round in shape, and has a diameter of 200 mm to 300 mm, and is sealed and connected to the top of the mixing drum through a sealing ring; the bottom of the mixing drum is a conical structure with a cone angle of 30 degrees to 45 degrees, which is conducive to the smooth discharge of materials.

[0057] Furthermore, in the above technical solution, the motor in the drive device is a variable frequency motor with a rated power of 5 kW to 10 kW and a speed of 0 to 1500 rpm; the reducer is a planetary gear reducer with a reduction ratio of 1 to 10 to 1 to 20; the drive shaft is made of alloy steel, the surface is heat treated and surface hardened, and the diameter is 40 mm to 60 mm.

[0058] Furthermore, in the above technical solution, the weighing system includes 4 weighing sensors, which are respectively installed between the four corners of the bottom of the mixing drum and the frame; the measuring range of each weighing sensor is 0 kg to 2000 kg, and the accuracy is 0.1% of the full scale; the weighing sensor adopts a shear beam structure, is made of alloy steel, and is nickel-plated on the surface to achieve corrosion resistance.

[0059] Furthermore, in the above technical scheme, the feed hopper in the feeding device is made of 304 stainless steel plate with a wall thickness of 3 mm to 5 mm, and the inner surface is polished; the top opening diameter of the feed hopper is 600 mm to 800 mm, and the bottom outlet diameter is 200 mm to 300 mm; the feed valve is a pneumatic butterfly valve, the valve body is made of cast steel, the valve plate is made of 304 stainless steel, and the sealing ring is made of fluororubber; the opening angle of the pneumatic butterfly valve is 0 degrees to 90 degrees, and the opening time is 2 seconds to 5 seconds.

[0060] Furthermore, in the above technical solution, the discharging hopper in the discharging device is circular with a diameter of 150 mm to 250 mm; the discharging valve is a pneumatic ball valve, the valve body is made of 304 stainless steel, the ball is made of 304 stainless steel and has undergone surface hardening treatment, and the sealing ring is made of polytetrafluoroethylene; the opening angle of the pneumatic ball valve is 0 degrees to 90 degrees, and the opening time is 1 second to 3 seconds.

[0061] Furthermore, in the above technical scheme, the stirring shaft in the stirring device is made of 304 stainless steel, with a diameter of 50 mm to 80 mm and a polished surface; the stirring blades are stamped from 304 stainless steel plates, with a thickness of 5 mm to 8 mm and a polished surface; the stirring blades are arranged in a double helix along the stirring shaft, with a pitch of 300 mm to 500 mm and a blade inclination angle of 30 degrees to 45 degrees; 4 to 6 stirring blades are provided on each spiral period, and the gap between the outer edge of the blade and the inner wall of the stirring barrel is 10 mm to 20 mm.

[0062] Furthermore, in the above technical solution, the scraper assembly in the cleaning device includes a plurality of scrapers 171, the scrapers are made of polyurethane with a hardness of 90 to 95 degrees Shore A; the scrapers are fixed to the inner wall of the mixing drum through a stainless steel bracket, and the clamping force between the scrapers and the inner wall of the mixing drum is adjusted by a spring; the flushing system includes 8 to 12 nozzles, the nozzles are made of 316L stainless steel, the nozzle diameter is 2 mm to 4 mm, and the angle between the nozzles and the inner wall of the top of the mixing drum is 30 to 45 degrees.

[0063] Furthermore, in the above technical solution, the control panel is made of steel plate with plastic spraying on the surface and a protection level of IP65; the control panel is provided with a touch screen, an emergency stop button, a start button, a stop button, a power indicator light and a fault indicator light; the touch screen size is 10 inches to 12 inches, and the resolution is not less than 1024×768 pixels; the control panel is provided with relays, contactors, circuit breakers and power modules for controlling the action of each actuator and protecting the electrical system.

[0064] like Figure 3 As shown, in the above technical solution, a weighing calculation system is also included, which includes a single chip microcomputer and a data processor. The single chip microcomputer is electrically connected to the touch screen and the weighing sensor. A weighing compensation module is provided in the single chip microcomputer to reduce the dynamic weighing accuracy error under high-speed flow conditions and display the current weighing data in real time through the touch screen. The weighing compensation module is used to perform the following steps:

[0065] S10, collecting the original weighing signal of the weighing sensor during the stirring process, and obtaining a dynamic weighing data sequence within a continuous time period;

[0066] S20, performing time domain analysis on the dynamic weighing data sequence, and extracting time domain characteristic parameters, including mean, standard deviation, peak factor and waveform factor;

[0067] S30, performing frequency domain analysis on the dynamic weighing data sequence, obtaining spectrum characteristics through Fourier transform, and extracting main frequency components and their amplitudes;

[0068] S40, establishing a compensation equation group based on time domain characteristic parameters and frequency domain characteristics, wherein the compensation equation group includes a dynamic response equation, a spectrum compensation equation, a temperature drift equation, a nonlinear correction equation, and a mechanical coupling equation;

[0069] S50, collecting weighing data of multiple groups of materials with known weights at different stirring speeds, and establishing a training sample set, where each group of samples includes characteristic parameters and corresponding actual error values;

[0070] S60, fitting the compensation equation group by using the least square method, determining the coefficients of each item in the compensation equation group, and obtaining a dynamic weighing error compensation model;

[0071] S70, using a cross-validation method to verify the dynamic weighing error compensation model, calculate the weighing error after compensation, and when the error after compensation is greater than a preset threshold, return to step S40 to adjust the compensation equation group;

[0072] S80, applying the dynamic weighing error compensation model to the real-time weighing process, performing online compensation on the original weighing signal, and outputting the corrected weighing data;

[0073] S90. According to changes in production conditions, new sample data is periodically collected, the coefficients of the compensation equation group are updated, and the adaptability of the compensation model is maintained.

[0074] The frame of the mixer scale is a vertical structure, consisting of a base, columns and beams. The base is rectangular, with shock-proof pads at the four corners to effectively isolate the impact of external vibration on the weighing system. The columns are fixed vertically on the base, with a total of four, distributed at the four corners of the base, providing a stable support. The beams are fixed horizontally at the top of the four columns to form a stable frame structure.

[0075] The mixing drum is made of stainless steel, with a wall thickness of 8 mm to 12 mm and a wear-resistant coating inside. This ensures sufficient strength and durability, and reduces the wear of materials during high-speed mixing. There is an observation window on the top of the mixing drum, which is made of transparent tempered glass with a diameter of 200 mm to 300 mm and is sealed with the top of the mixing drum through a sealing ring. The observation window can easily observe the flow of materials during mixing. The bottom of the mixing drum adopts a conical structure with a cone angle of 30 degrees to 45 degrees, which is conducive to the smooth discharge of materials.

[0076] The drive device includes a variable frequency motor, a planetary gear reducer and a transmission shaft. The rated power of the variable frequency motor is 5 kW to 10 kW, and the speed can be adjusted between 0 rpm and 1500 rpm, which can meet the needs of various mixing conditions. The reduction ratio of the planetary gear reducer is 1:10 to 1:20, which can effectively reduce the high speed of the motor to a speed range suitable for mixing. The transmission shaft is made of alloy steel, the surface is heat-treated and surface-hardened, and the diameter is 40 mm to 60 mm, which can reliably transmit the torque during mixing.

[0077] The weighing system includes 4 weighing sensors, which are installed between the four corners of the bottom of the mixing drum and the frame. The range of each weighing sensor is 0 kg to 2000 kg, with an accuracy of 0.1% of the full scale. It adopts a shear beam structure, is made of alloy steel and nickel-plated, and has good corrosion resistance. The weighing system can monitor the weight changes of the materials in the mixing drum in real time, providing a basis for subsequent material quantity control.

[0078] The feeding device includes a feeding hopper and a pneumatic butterfly valve. The feeding hopper is made of 304 stainless steel plate with a wall thickness of 3 mm to 5 mm, the inner surface is polished, the top opening diameter is 600 mm to 800 mm, and the bottom outlet diameter is 200 mm to 300 mm, which can initially distribute and guide the materials. The valve body of the pneumatic butterfly valve is made of cast steel, the valve plate is made of 304 stainless steel, the sealing ring is made of fluororubber, the opening angle is 0 degrees to 90 degrees, and the opening time is 2 seconds to 5 seconds, which can accurately control the rate at which the materials enter the mixing drum.

[0079] The discharging device includes a discharging hopper and a pneumatic ball valve. The discharging hopper is round, with a diameter of 150 mm to 250 mm, and is located at the bottom center of the mixing drum. The valve body of the pneumatic ball valve is made of 304 stainless steel, the ball is made of 304 stainless steel and surface hardened, and the sealing ring is made of polytetrafluoroethylene. The opening angle is 0 to 90 degrees, and the opening time is 1 second to 3 seconds, which can accurately control the discharge of materials from the mixing drum.

[0080] The stirring device includes a stirring shaft and a stirring blade. The stirring shaft is made of 304 stainless steel, with a diameter of 50 mm to 80 mm and a polished surface. The stirring blade is stamped from 304 stainless steel plate, with a thickness of 5 mm to 8 mm and a polished surface. The stirring blades are arranged in a double helix along the stirring shaft, with a pitch of 300 mm to 500 mm and a blade inclination angle of 30 degrees to 45 degrees. There are 4 to 6 stirring blades on each spiral cycle, and the gap between the outer edge of the blade and the inner wall of the mixing barrel is 10 mm to 20 mm. This stirring structure can effectively stir and convey materials, ensuring the uniformity of stirring.

[0081] The cleaning device includes a scraper assembly and a flushing system. The scraper assembly includes multiple polyurethane scrapers with a hardness of 90 to 95 degrees Shore A, which are fixed to the inner wall of the mixing drum through a stainless steel bracket. The pressing force between the scraper and the inner wall of the mixing drum can be adjusted by a spring. The flushing system includes 8 to 12 nozzles made of 316L stainless steel, with a nozzle diameter of 2 mm to 4 mm, and an angle between the nozzle and the inner wall of the top of the mixing drum of 30 to 45 degrees. The scraper can scrape off the material attached to the drum wall, and the flushing system can clean the residual material in the drum, ensuring the cleanliness of the mixing drum.

[0082] The control panel is made of steel plate, with plastic spraying treatment on the surface, and the protection level reaches IP65, which has good protection performance. The control panel is equipped with a touch screen, emergency stop button, start button, stop button, power indicator light and fault indicator light. The touch screen size is 10 inches to 12 inches, and the resolution is not less than 1024×768 pixels, which can be easily operated and monitored. The control panel is equipped with relays, contactors, circuit breakers and power modules to control the actions of various actuators and protect the electrical system.

[0083] The mixing scale also includes a weighing calculation system for improving the accuracy of dynamic weighing. The weighing calculation system includes a single chip microcomputer and a data processor. The single chip microcomputer is electrically connected to the touch screen and the weighing sensor, and is provided with a weighing compensation module for performing the following steps:

[0084] Step S10: Collect the original weighing signal of the weighing sensor during the stirring process to obtain a dynamic weighing data sequence within a continuous time period.

[0085] Step S20: Perform time domain analysis on the dynamic weighing data sequence to extract time domain characteristic parameters, including mean, standard deviation, peak factor and waveform factor. These time domain characteristic parameters reflect the response characteristics of the weighing system under dynamic load.

[0086] Step S30: Perform frequency domain analysis on the dynamic weighing data sequence, obtain spectrum features through Fourier transform, and extract the main frequency components and their amplitudes. These frequency domain features can be used to eliminate periodic interference during the stirring process.

[0087] Step S40: Based on the time domain characteristic parameters and frequency domain characteristics, a compensation equation group is established, including a dynamic response equation, a spectrum compensation equation, a temperature drift equation, a nonlinear correction equation and a mechanical coupling equation. These equations can describe the response characteristics of the weighing system under the influence of various factors.

[0088] The dynamic response equation is: Where R d is the dynamic response compensation value, m(t) is the original weighing signal, α 1 ,α 2 ,α 3 ,α 4 is the unknown coefficient. This equation is used to describe the response characteristics of the weighing system under dynamic load.

[0089] The spectrum compensation equation is: Where R f is the frequency domain compensation value, F(ω k ) is the Fourier transform value of the kth main frequency component, β k is the compensation coefficient of the kth frequency component, φ k is the phase angle of the kth frequency component, and n is the number of frequency components considered. This equation can eliminate periodic interference during the stirring process.

[0090] The temperature drift equation is: Where R t is the temperature compensation value, T is the current temperature, T 0 is the calibration temperature, 1 ,γ 2 ,γ 3 is the temperature compensation coefficient. This equation can compensate for the effect of temperature changes on the weighing system.

[0091] The nonlinear correction equation is: Where R n is the nonlinear compensation value, m r is the original weighing value, δ 1 ,δ 2 ,δ 3 ,δ 4is the nonlinear correction coefficient. This equation can correct the nonlinear characteristics of the weighing system.

[0092] The mechanical coupling equation is: Where R v is the vibration compensation value, A i is the amplitude of the ith main vibration direction, f i is the frequency of the i-th vibration direction, θ i is the phase angle of the i-th vibration direction, λ i is the vibration compensation coefficient, μ is the speed influence coefficient, and ω is the stirring speed. This equation can compensate for the influence of mechanical vibration during the stirring process.

[0093] Step S50: Collect multiple groups of weighing data of materials with known weight at different stirring speeds to establish a training sample set, each group of samples contains characteristic parameters and corresponding actual error values. These sample data provide a basis for subsequent parameter calibration.

[0094] Step S60: Fit the compensation equations using the least square method, determine the coefficients, and obtain the dynamic weighing error compensation model. The purpose of this step is to determine the unknown coefficient values ​​in each equation.

[0095] Step S70: Use the cross-validation method to verify the dynamic weighing error compensation model, calculate the weighing error after compensation, and return to step S40 to adjust the compensation equation group when the error after compensation is greater than the preset threshold. This is to ensure the accuracy and applicability of the compensation model.

[0096] Step S80: Apply the dynamic weighing error compensation model to the real-time weighing process, perform online compensation on the original weighing signal, and output the corrected weighing data. This step realizes the real-time compensation of dynamic weighing.

[0097] Step S90: According to the changes in production conditions, new sample data is periodically collected, the coefficients of the compensation equation group are updated, and the adaptability of the compensation model is maintained. This ensures that the compensation model can be adaptively adjusted with changes in production conditions and maintain long-term accuracy.

[0098] The dynamic response equation is used to describe the response characteristics of the weighing system under dynamic load. The input is the time domain characteristic parameter, and the output is the dynamic response compensation value. It is specifically expressed as follows:

[0099]

[0100] In the formula, R d is the dynamic response compensation value, in kilograms; m(t) is the original weighing signal at time t, in kilograms; α 1 ,α 2 ,α 3 ,α4 is the unknown coefficient; t is the sampling time in seconds; τ is the integral variable;

[0101] The spectrum compensation equation is used to eliminate periodic interference during the stirring process. The input is the frequency domain feature and the output is the frequency domain compensation value. The specific expression is as follows:

[0102]

[0103] In the formula, R f is the frequency domain compensation value, in kilograms; F(ω k ) is the Fourier transform value of the kth main frequency component; β k is the compensation coefficient of the kth frequency component; φ k is the phase angle of the kth frequency component, in radians; n is the number of frequency components considered, ranging from 3 to 5;

[0104] The temperature drift equation is used to compensate for the influence of temperature change on the weighing system. The input is the temperature parameter and the output is the temperature compensation value. It is specifically expressed as follows:

[0105]

[0106] In the formula, R t is the temperature compensation value in kilograms; T is the current temperature in degrees Celsius; T 0 is the calibration temperature, which is 20 degrees Celsius; 1 ,γ 2 ,γ 3 is the temperature compensation coefficient;

[0107] The nonlinear correction equation is used to correct the nonlinear characteristics of the weighing system. The input is the original weighing value, and the output is the nonlinear compensation value. The specific expression is as follows:

[0108]

[0109] In the formula, R n is the nonlinear compensation value, in kilograms; m r is the original weighing value, in kilograms; δ 1 ,δ 2 ,δ 3 ,δ 4 is the nonlinear correction coefficient;

[0110] The mechanical coupling equation is used to compensate for the influence of mechanical vibration during the stirring process. The input is the vibration parameter and the output is the vibration compensation value. It is specifically expressed as follows:

[0111]

[0112] In the formula, Rv is the vibration compensation value, in kilograms; A i is the amplitude of the ith main vibration direction, in millimeters; f i is the frequency of the i-th vibration direction, in Hertz; θ i is the phase angle of the i-th vibration direction, in radians; λ i is the vibration compensation coefficient; μ is the speed influence coefficient; ω is the stirring speed, in revolutions per minute;

[0113] Parameter acquisition method:

[0114] 1. Dynamic response equation parameter acquisition:

[0115] It is obtained through step response experiment. The specific steps are as follows:

[0116] Step 1: Quickly add standard weight of materials into the mixing drum in a stationary state;

[0117] Step 2: Record the curve m(t) of the weighing signal changing with time;

[0118] Step 3: Use the least squares method to fit the coefficient α 1 ,α 2 ,α 3 ,α 4 ;

[0119] 2. Obtaining spectrum compensation equation parameters:

[0120] It is obtained through spectrum analysis experiment. The specific steps are as follows:

[0121] Step 1: Collect weighing signals at different stirring speeds;

[0122] Step 2: Perform fast Fourier transform on the weight signal to obtain F(ω k );

[0123] Step 3: Select the n frequency components with the largest amplitude;

[0124] Step 4: Get the coefficient β by fitting multiple sets of experimental data k and φ k ;

[0125] 3. Obtaining temperature drift equation parameters:

[0126] It is obtained through temperature cycle experiment. The specific steps are as follows:

[0127] Step 1: Record a set of weighing data every 2 degrees Celsius in the ambient temperature range from 15 degrees Celsius to 35 degrees Celsius;

[0128] Step 2: Get the coefficient γ by polynomial fitting 1,γ 2 ,γ 3 ;

[0129] 4. Obtaining parameters of nonlinear correction equation:

[0130] It is obtained through the standard weight calibration experiment. The specific steps are:

[0131] Step 1: Select 10 evenly distributed points within the range of 0 to full scale for loading;

[0132] Step 2: Record the actual weight and displayed weight of each loading point;

[0133] Step 3: Get the coefficient δ by polynomial fitting 1 ,δ 2 ,δ 3 ,δ 4 ;

[0134] 5. Obtaining parameters of mechanical coupling equation:

[0135] It is obtained through vibration test experiment. The specific steps are as follows:

[0136] Step 1: Install a three-axis acceleration sensor on the mixing drum;

[0137] Step 2: Record vibration signals at different stirring speeds;

[0138] Step 3: Obtain the vibration parameters A in each direction through signal analysis i ,f i ,θ i ;

[0139] Step 4: Get the coefficient λ by least squares fitting i and μ.

[0140] Embodiment 1:

[0141] Step S10: Collect the original weighing signal of the weighing sensor during the stirring process to obtain a dynamic weighing data sequence within a continuous time period.

[0142] In this step, it is necessary to collect the original weighing signal generated by the weighing sensor during the mixing process and record it as a dynamic weighing data sequence within a continuous time period. This data sequence reflects the instantaneous weight change of the material during the mixing process, laying the foundation for subsequent dynamic weighing compensation.

[0143] Step S20: Perform time domain analysis on the dynamic weighing data sequence and extract time domain characteristic parameters, including mean, standard deviation, peak factor and waveform factor.

[0144] In this step, it is necessary to perform time domain analysis on the dynamic weighing data sequence obtained in step S10 to extract the following time domain characteristic parameters:

[0145] 1. Mean

[0146]

[0147] Where T is the length of the time period for collecting data. The mean reflects the average weight of the material during the mixing process.

[0148] 2. Standard deviation σ:

[0149]

[0150] The standard deviation reflects the degree of fluctuation of material weight during the mixing process.

[0151] 3. Peak factor K p :

[0152]

[0153] The peak factor reflects the maximum deviation of material weight during the mixing process.

[0154] 4. Form factor K w :

[0155]

[0156] The waveform factor reflects the fluctuation characteristics of material weight during the mixing process.

[0157] The above four time domain characteristic parameters are key indicators for describing the dynamic response characteristics of the weighing system, and provide an important basis for subsequent dynamic compensation.

[0158] Step S30: Perform frequency domain analysis on the dynamic weighing data sequence, obtain spectrum characteristics through Fourier transform, and extract main frequency components and their amplitudes.

[0159] In this step, it is necessary to perform frequency domain analysis on the dynamic weighing data sequence m(t) obtained in step S10, and the specific steps are as follows:

[0160] First, perform Fourier transform on m(t) to obtain its frequency domain representation M(ω):

[0161]

[0162] Where M(ω) is the angular frequency.

[0163] Then, the main frequency components and their corresponding amplitudes are extracted from M(ω). The n frequency components with the largest amplitudes can be selected and recorded as ω k and |M(ω k )|,k=1,2,...,n.

[0164] These main frequency components and their amplitudes reflect the periodic characteristics of material weight changes during the mixing process and can be used to compensate for periodic interference.

[0165] Step S40: Establish a compensation equation group based on the time domain characteristic parameters and the frequency domain characteristics, including a dynamic response equation, a spectrum compensation equation, a temperature drift equation, a nonlinear correction equation and a mechanical coupling equation.

[0166] In this step, it is necessary to establish a set of equations containing multiple compensation equations to describe the response characteristics of the weighing system under the influence of various factors.

[0167] 1. Dynamic response equation:

[0168]

[0169] Among them, R d is the dynamic response compensation value, m(t) is the original weighing signal, α 1 ,α 2 ,α 3 ,α 4 is the unknown coefficient. This equation is used to describe the response characteristics of the weighing system under dynamic load.

[0170] 2. Spectrum compensation equation:

[0171]

[0172] Where R f is the frequency domain compensation value, F(ω k ) is the Fourier transform value of the kth main frequency component, β k is the compensation coefficient of the kth frequency component, φ k is the phase angle of the kth frequency component, and n is the number of frequency components considered. This equation can eliminate periodic interference during the stirring process.

[0173] 3. Temperature drift equation:

[0174]

[0175] Where R t is the temperature compensation value, T is the current temperature, T 0 is the calibration temperature, 1 ,γ 2 ,γ 3is the temperature compensation coefficient. This equation can compensate for the effect of temperature changes on the weighing system.

[0176] 4. Nonlinear correction equation:

[0177]

[0178] in, Where R n is the nonlinear compensation value, m r is the original weighing value, δ 1 ,δ 2 ,v 3 ,δ 4 is the nonlinear correction coefficient. This equation can correct the nonlinear characteristics of the weighing system.

[0179] 5. Mechanical coupling equation:

[0180]

[0181] Where R v is the vibration compensation value, A i is the amplitude of the ith main vibration direction, f i is the frequency of the i-th vibration direction, θ i is the phase angle of the i-th vibration direction, λ i is the vibration compensation coefficient, μ is the speed influence coefficient, and ω is the stirring speed. This equation can compensate for the influence of mechanical vibration during the stirring process.

[0182] The above five compensation equations form a complete set of compensation equations, which can describe the response characteristics of the weighing system under the influence of dynamic load, periodic interference, temperature change, nonlinear characteristics and mechanical vibration. By calibrating and adjusting the parameters of these equations, the accuracy of dynamic weighing can be greatly improved.

[0183] Step S50: Collect multiple groups of weighing data of materials of known weight at different stirring speeds to establish a training sample set, where each group of samples contains characteristic parameters and corresponding actual error values.

[0184] In this step, a set of weighing data of materials with known weight at different stirring speeds needs to be collected as training samples for subsequent parameter calibration. Each set of samples should contain:

[0185] 1. Original weighing value m r ;

[0186] 2. Time domain feature parameters extracted in step S20::

[0187] 3. Frequency domain feature parameters extracted in step S30: ω k ,|M(ωk )|,φ k ,k=1,2,...,n;

[0188] 4. Actual measured weight m actual ;

[0189] 5. The corresponding weighing error is e=m actual -m r ;

[0190] Establishing such a training sample set provides a basis for the subsequent calibration of compensation equation group parameters.

[0191] Step S60: Use the least squares method to fit the compensation equation group, determine the coefficients of each item, and obtain the dynamic weighing error compensation model.

[0192] In this step, the least square method is required to perform parameter fitting on the compensation equation group established in step S40 to determine the unknown coefficients in each compensation equation.

[0193] The specific steps are:

[0194] 1. Assume that the coefficients to be determined in the compensation equations are

[0195] θ=[α 1 ,α 2 ,α 3 ,α 4 ,β 1 ,β 2 ,...,β n ,γ 1 ,γ 2 ,γ 3 ,δ 1 ,δ 2 ,δ 3 ,δ 4 ,λ 1 ,λ 2 ,λ 3 ,μ] T ;

[0196] 2. For the i-th sample in the training sample set, calculate the compensation values

[0197] 3. Define sample error

[0198] 4. Use the least squares method to solve θ, so that Minimum;

[0199] The obtained θ is the optimal parameter of the compensation equation group, which constitutes the dynamic weighing error compensation model.

[0200] Step S70: Use the cross-validation method to verify the dynamic weighing error compensation model, calculate the compensated weighing error, and when the compensated error is greater than the preset threshold, return to step S40 to adjust the compensation equation group.

[0201] In this step, a cross-validation method is required to verify the dynamic weighing error compensation model established in step S60.

[0202] The specific steps are:

[0203] 1. Randomly divide the training sample set into k parts

[0204] 2. For each copy as a validation sample, the remaining k-1 copies are used as training samples, and step S60 is repeated to solve the compensation model parameter θ;

[0205] 3. Substitute the verification sample into the compensation model and calculate the weighing error e after compensation comp ;

[0206] 4. Calculate the average compensation error of all verification samples

[0207] 5. If If the value is greater than the preset threshold, the system returns to step S40, adjusts the form of the compensation equation group, and repeats the above steps until the accuracy requirement is met.

[0208] This ensures that the compensation model has good generalization performance and does not overfit the training samples.

[0209] Step S80: Apply the dynamic weighing error compensation model to the real-time weighing process, perform online compensation on the original weighing signal, and output the corrected weighing data.

[0210] In this step, the dynamic weighing error compensation model established and verified in step S60 and step S70 is applied to the actual real-time weighing process. The specific steps are as follows:

[0211] 1. Collect the original weighing signal m(t) in real time;

[0212] 2. Calculate the time domain characteristic parameters and frequency domain characteristics in step S20 and step S30 in real time according to m(t);

[0213] 3. Substitute these characteristic parameters into the compensation equations established in step S40 to calculate the compensation values ​​R d ,R f ,R t ,R n ,R v ;

[0214] 4. Superimpose these compensation values ​​on the original weighing signal m(t) to obtain the corrected weighing data m comp =m(t)+R d +R f +R t +R n +R v ;

[0215] 5. Output m comp As a real-time weighing result, this can achieve online compensation of the original weighing signal and improve the accuracy of dynamic weighing.

[0216] Step S90: According to changes in production conditions, new sample data is periodically collected to update the coefficients of the compensation equation group to maintain the adaptability of the compensation model.

[0217] In this step, new training sample data needs to be collected regularly, and the parameters of the compensation equation group established in step S60 are updated accordingly to maintain the adaptability of the compensation model.

[0218] The specific steps are as follows:

[0219] 1.According to the changes in production conditions, such as material properties, mixing speed, etc., new training sample data is collected periodically

[0220] 2. Merge the newly collected sample data into the original training sample set

[0221] 3. Repeat step S60 and refit the compensation equation parameter θ using the least squares method;

[0222] 4. Repeat step S70 and use cross-validation to verify the updated compensation model

[0223] This adaptive approach ensures that the compensation model can be continuously optimized as production conditions change, maintaining long-term accuracy and robustness.

[0224] In summary, this method for improving the precision of dynamic weighing based on the polynomial compensation model makes full use of comprehensive information such as time domain characteristics, frequency domain characteristics, temperature characteristics, nonlinear characteristics and mechanical vibration characteristics, and realizes effective compensation of the original weighing signal in a parameterized way. Through sample training, model verification and adaptive updating, it can meet the dynamic weighing requirements under various complex working conditions and provide reliable material quantity control for the sludge solidification process.

[0225] The key point of the cement slurry mixing scale for sludge solidification proposed by the present invention is to use a polynomial compensation model to effectively compensate for various interference factors in the dynamic weighing process, thereby greatly improving the accuracy of dynamic weighing.

[0226] First, the mixing scale uses four weighing sensors distributed at the bottom of the mixing drum. The shear beam structure can monitor the weight change of the material in the mixing drum in real time. Due to the strong fluidity of the material during the mixing process, it will cause dynamic load interference to the weighing system, resulting in a large dynamic error in the weighing result. In order to compensate for this dynamic error, the dynamic response equation is established:

[0227]

[0228] Among them, R d is the dynamic response compensation value, m(t) is the original weighing signal, α 1 ,α 2 ,α 3 ,α 4 The equation can describe the response characteristics of the weighing system under dynamic load. By determining the values ​​of these coefficients, the error caused by dynamic load can be compensated.

[0229] On the other hand, periodic vibration interference will also be generated during the stirring process, resulting in periodic fluctuations in the weighing signal. In order to eliminate this periodic interference, the spectrum compensation equation is established:

[0230]

[0231] Among them, R f is the frequency domain compensation value,,M(ω k ) is the Fourier transform value of the kth main frequency component, β k is the compensation coefficient of the kth frequency component, φ k is the phase angle of the kth frequency component, and n is the number of frequency components considered. These periodic interferences can be eliminated by performing frequency domain analysis on the symmetric signal, extracting the main periodic frequency components, and determining the corresponding compensation coefficients.

[0232] In addition, temperature changes will also affect the measurement results of the weighing system. In order to compensate for temperature drift, the temperature drift equation is established:

[0233]

[0234] Among them, R t is the temperature compensation value, T is the current temperature, T 0 is the calibration temperature, γ 1 ,γ 2 ,γ 3 is the temperature compensation coefficient. By real-time monitoring of temperature changes and determining the temperature compensation coefficient, the effect of temperature on the weighing result can be offset.

[0235] In addition, the weighing system itself has certain nonlinear characteristics, which need to be compensated by nonlinear correction equations:

[0236]

[0237] Among them, R n is the nonlinear compensation value, m r is the original weighing value, δ 1 ,δ 2 ,δ 3 ,δ 4 is the nonlinear correction coefficient. By fitting the experimental data of standard weight loading and determining these nonlinear correction coefficients, the nonlinear error of the weighing system itself can be eliminated.

[0238] Finally, the mechanical vibration during the stirring process will also affect the weighing result and needs to be compensated by the mechanical coupling equation:

[0239]

[0240] Among them, R v is the vibration compensation value, A i is the amplitude of the ith main vibration direction, f i is the frequency of the i-th vibration direction, θ i is the phase angle of the i-th vibration direction, λ i is the vibration compensation coefficient, μ is the speed influence coefficient, and ω is the stirring speed. By installing a vibration sensor, measuring the vibration characteristics during the stirring process, and determining the corresponding compensation coefficient, the influence of mechanical vibration on the weighing result can be eliminated.

[0241] In summary, the present invention establishes a polynomial compensation model covering dynamic response, spectrum characteristics, temperature characteristics, nonlinear characteristics and mechanical vibration characteristics, and uses the least square method to calibrate various coefficients, thereby achieving comprehensive compensation for the original weighing signal. This dynamic weighing method based on multi-factor comprehensive compensation can not only effectively eliminate the influence of various process interferences on the weighing results, but also has good adaptability and can automatically adjust the compensation parameters as the production conditions change to ensure long-term stable operation. This is the key innovation of the present invention compared to the prior art, and it is also the key to its ability to improve the stability and reliability of the sludge solidification process.

[0242] Embodiment 2:

[0243] The mechanical structure of the mixing scale adopts modular design and is mainly composed of the following components:

[0244] Rack: The rack is a vertical structure, consisting of a base, columns and beams. The base is made of 10 mm thick carbon steel plate, with a rectangular structure, and 50 mm high rubber shock pads are installed at the four corners. There are 4 columns with a diameter of 80 mm, made of 12 mm thick carbon steel pipes, and fixed vertically on the base. The beam is made of 15 mm thick carbon steel plate, horizontally fixed to the top of the 4 columns, forming a stable frame structure. The structural dimensions of the entire rack are 1.5 meters long, 1.2 meters wide, and 2.2 meters high.

[0245] Mixing drum: The mixing drum is made of 304 stainless steel, cylindrical, with a diameter of 1000 mm, a height of 1500 mm, and a wall thickness of 10 mm. The inner surface of the drum is treated with a wear-resistant ceramic coating to increase its service life. The top of the mixing drum is equipped with an observation window with a diameter of 300 mm, which is made of 10 mm thick tempered glass and is sealed with the drum through a sealing ring. The bottom of the mixing drum adopts a conical structure with a cone angle of 30 degrees, which is conducive to the smooth discharge of materials.

[0246] Drive device: The drive device includes a 7.5 kW three-phase asynchronous motor, a planetary gear reducer and a transmission shaft. The motor is installed on the frame base, and the motor output shaft is directly connected to the reducer input. The output end of the reducer is connected to the transmission shaft that vertically penetrates the bottom of the mixing drum through a coupling. The rated speed of the motor is 1470 rpm. After a reduction ratio of 20 to 1, the speed range of the transmission shaft can be adjusted to 0-150 rpm.

[0247] Weighing system: The weighing system uses 4 shear beam type weighing sensors, which are installed between the bottom of the mixing drum and the frame. The range of each weighing sensor is 0-2000 kg, and the maximum weighing error is 0.1%. The weighing sensor is made of alloy steel, with nickel plating on the surface, and has good corrosion resistance. The 4 weighing sensors are connected to the weighing control unit through a dedicated signal line, which can monitor the weight change of the material in the mixing drum in real time.

[0248] Feeding device: The feeding device is located at the top of the mixing drum and consists of a feeding hopper and a pneumatic butterfly valve. The feeding hopper is made of 304 stainless steel plate with a thickness of 4 mm and a funnel-shaped structure. The top opening diameter is 700 mm, the bottom outlet diameter is 250 mm, and the inner surface is polished. The pneumatic butterfly valve is installed at the bottom outlet of the feeding hopper. The valve body is made of cast steel, the valve plate is made of 304 stainless steel, and the sealing ring is fluororubber. The opening can be continuously adjusted within the range of 0-90 degrees, and the opening time is 3 seconds.

[0249] Discharge device: The discharge device is located at the bottom center of the mixing drum and consists of a discharge hopper and a pneumatic ball valve. The discharge hopper has a diameter of 200 mm and is made of 304 stainless steel. The pneumatic ball valve is installed at the discharge hopper. The valve body and ball are both made of 304 stainless steel, and the sealing ring is polytetrafluoroethylene. The opening can be continuously adjusted within the range of 0-90 degrees, and the opening time is 2 seconds.

[0250] Stirring device: The stirring device includes a stirring shaft and multiple stirring blades. The stirring shaft is made of 304 stainless steel bar with a diameter of 60 mm and the surface is polished. The stirring blades are stamped and formed from 304 stainless steel plates with a thickness of 6 mm and are arranged in a spiral shape around the stirring shaft. There are 5 blades on each spiral cycle, the blade inclination angle is 40 degrees, and the gap with the cylinder wall is 15 mm. The speed of the stirring shaft can be continuously adjusted in the range of 0-150 revolutions per minute.

[0251] Cleaning device: The cleaning device includes a scraper assembly and a flushing system. The scraper assembly consists of 10 polyurethane scrapers fixed to the inner wall of the mixing drum through a stainless steel bracket. The scraper hardness is 92 degrees Shore A, and the pressing force between the scraper and the drum wall can be adjusted by a spring. The flushing system consists of 10 316L stainless steel nozzles with a diameter of 3 mm, evenly distributed on the inner wall of the top of the mixing drum, with an angle of 35 degrees to the inner wall. The inner wall of the drum can be regularly flushed through a high-pressure water pump system.

[0252] Control system: The control system uses a control panel made of steel plate with a protection level of IP65, which is installed on the side of the frame. The control panel is equipped with a 10.4-inch touch screen display unit, emergency stop button, start and stop button and other operating elements, and contains PLC, inverter, relay and other electrical components. The touch screen can realize real-time monitoring and adjustment of parameters such as stirring speed, feed amount, and discharge amount, and display the current weighing data. The control system is also equipped with a fault diagnosis function, which can detect equipment abnormalities in time and issue alarm prompts.

[0253] The main technical parameters of the cement slurry mixer for sludge solidification are as follows:

[0254] Table 1 Main technical parameters

[0255] Parameter name Parameter Value Rack size Length 1.5m × width 1.2m × height 2.2m Mixing drum size Diameter 1000mm×Height 1500mm Mixing drum material 304 Stainless Steel Motor power 7.5kW Motor speed 0-1470r / min Reduction ratio 20:1 Stirring speed 0-150r / min Load Cells 4×0-2000kg,±0.1% Feed hopper size Top Φ700mm, bottom Φ250mm Feed valve Pneumatic butterfly valve, 0-90° adjustable Hopper size Φ200mm Discharge valve Pneumatic ball valve, 0-90° adjustable Control System PLC+touch screen, IP65 protection

[0256] During the sludge solidification process, the working process of the mixing scale is as follows:

[0257] 1. The material enters the mixing drum through the feed hopper, and the pneumatic butterfly valve controls the feeding speed.

[0258] 2. The stirring shaft rotates at a speed of 0-150 revolutions per minute, driving the stirring blades to stir the materials at high speed.

[0259] 3. The weighing system monitors the weight changes of the materials in the mixing drum in real time and transmits the data to the control system.

[0260] 4. The control system automatically adjusts the opening of the feed valve and the discharge valve based on the real-time weighing data through the PID algorithm to keep the material dosage within the set range.

[0261] 5. After stirring, the material is discharged through the discharge hopper at the bottom, and the pneumatic ball valve controls the discharge speed.

[0262] 6. The cleaning device regularly scrapes and flushes the inner wall of the mixing drum to ensure that the equipment is in good working condition for a long time.

[0263] Embodiment 3:

[0264] Example of specific application scenario of dynamic weighing system of cement slurry mixing scale in sludge treatment plant

[0265] This embodiment 3 describes the specific situation of applying the present invention in actual production in a sludge treatment plant. The sludge treatment plant processes 200 tons of sludge per day and uses a cement slurry stirring and solidification process to treat the sludge. The cement slurry metering accuracy is required to be high, so the dynamic weighing compensation technology of the present invention is used to improve the weighing accuracy during the stirring process. The specific implementation process is as follows.

[0266] 1. System configuration.

[0267] This system uses Siemens S7-1200 series PLC as the main controller, equipped with Intel N4200 processor, main frequency 1.8GHz, memory 8GB. The weighing sensor uses Mettler Toledo SSH-10T model, rated range of 1000kg, comprehensive accuracy of 0.02% FS. The touch screen uses Weiluntong TK6100i model, with a resolution of 1024×768 pixels. After the system is installed, the calibration of various parameters and data collection are carried out first.

[0268] 2. Dynamic response parameter acquisition.

[0269] When the mixing drum is stationary, a 500kg standard weight is quickly added, the sampling frequency is set to 100Hz, and the dynamic response process is recorded for 60 seconds. The dynamic response equation parameters obtained by least squares fitting are as follows:

[0270] Parameter name Numeric unit α1 0.0025 <![CDATA[kg·s 2 ]]> α2 0.158 kg·s α3 1.023 Dimensionless α4 0.0012 kg / s

[0271] 3. Spectrum feature analysis.

[0272] The weighing signal was collected at stirring speeds of 300 rpm, 600 rpm, and 900 rpm, and the sampling time was 120 seconds. The main frequency components were obtained through FFT analysis, and the four frequency components with the largest amplitudes were selected for compensation. The specific parameters are as follows:

[0273]

[0274] 4. Analysis of temperature drift characteristics.

[0275] In the ambient temperature range of 15℃ to 35℃, a set of weighing data is recorded every 2℃, and the temperature compensation equation parameters are as follows:

[0276] Parameter name Numeric unit γ1 0.085 kg / ℃ γ2 0.0012 kg / ℃2 γ3 0.156 kg·s / ℃

[0277] 5. Nonlinear characteristics analysis.

[0278] Use standard weights to carry out loading tests in the range of 0 to 1000 kg, select 10 evenly distributed test points, and obtain the nonlinear correction equation parameters as follows:

[0279] Parameter name Numeric unit δ1 1.0125 Dimensionless δ2 <![CDATA[-2.35×10 -5 ]]> <![CDATA[kg -1 ]]> δ3 <![CDATA[1.28×10 -8 ]]> <![CDATA[kg -2 ]]> δ4 0.0865 <![CDATA[kg -0.5 ]]>

[0280] 6.Analysis of mechanical vibration characteristics.

[0281] Acceleration sensors, model PCB 356A15, are installed in the three main directions of the mixing drum to collect vibration signals at different mixing speeds. The vibration compensation parameters obtained through signal analysis are as follows:

[0282] direction Amplitude Ai(mm) Frequency fi(Hz) Phase angle θi (rad) Compensation coefficient λi X-axis 0.245 8.5 0.524 0.0956 Y-axis 0.312 8.5 2.618 0.0845 Z-axis 0.178 17.0 1.571 0.0623

[0283] The speed influence coefficient μ is 0.00025kg·min 2 / r 2 .

[0284] 7. Implementation of compensation model.

[0285] Based on the above parameters, a dynamic weighing compensation model is established in the PLC. A sampling period of 100ms is used, and each sampling simultaneously obtains the weighing signal, temperature signal, and vibration signal. The compensation calculation adopts a segmented processing method, and the specific processing flow is as follows.

[0286] First, the dynamic response compensation calculation is performed. The first-order derivative and second-order derivative of the signal are calculated using the differential method, and the integral term is calculated using the trapezoidal method. After the calculation is completed, the compensation value is stored in the D0 register. Then the frequency domain compensation calculation is performed. The FFT analysis of the latest 1024 sampling points is performed to extract the amplitude and phase of the specified frequency component, and the frequency domain compensation value is calculated and stored in the D1 register. Then the current temperature value is read, and the temperature compensation value is calculated and stored in the D2 register. After the original weighing value is standardized, it is inserted into the nonlinear correction equation, and the calculation result is stored in the D3 register.

[0287] Finally, read the vibration signal, calculate the vibration compensation value and store it in register D4. Add the compensation values ​​in registers D0 to D4 to get the total compensation value. The original weighing value minus the compensation value is the corrected weighing result.

[0288] 8. System performance verification.

[0289] The system was tested and verified in the actual production process. The test conditions were: ambient temperature 25°C, stirring speed 600rpm, and material weights of 200kg, 400kg, 600kg, and 800kg. Each test point was measured 10 times, and the dynamic weighing results were recorded. The test data is as follows:

[0290]

[0291]

[0292] From the test results, it can be seen that the measurement accuracy is significantly improved after the dynamic weighing compensation technology is adopted. The relative error before compensation is about 3.4%, and it is reduced to less than 0.4% after compensation. The measurement repeatability is also significantly improved. The standard deviation before compensation is about 0.8% of the full scale, and it is reduced to less than 0.2% after compensation.

[0293] The charts during system performance verification are as follows:

[0294] like Figure 4 The figure shows the dynamic response curve of the mixing scale: This figure shows the dynamic response process of the system after the 500kg standard weight is put in. The blue line represents the ideal step response curve, and the red line represents the actual measured response curve. It can be seen from the figure that there are obvious oscillations and noises in the actual response, which is why dynamic compensation is needed. The curve shows that the response time of the system is about 10 seconds and the overshoot is about 2%.

[0295] like Figure 5The figure shows the spectrum analysis of the weighing signal during the mixing process. The horizontal axis is the frequency (Hz) and the vertical axis is the corresponding amplitude. It can be clearly observed that there are four main frequency components at 5.2Hz, 10.4Hz, 15.6Hz and 20.8Hz. These frequency components are related to the speed and mechanical structure of the mixer. Among them, the 5.2Hz component has the largest amplitude, indicating that this is the main source of interference.

[0296] like Figure 6 The figure shows the temperature drift characteristic curve: This figure shows the influence of ambient temperature on the weighing system. The horizontal axis is temperature (℃), and the vertical axis is weight drift (kg). It can be seen that as the temperature rises, the weight display value shows a nonlinear growth trend. In the range of 15-35℃, the maximum drift is about 4kg. This error cannot be ignored and needs to be eliminated through temperature compensation.

[0297] like Figure 7 The figure shows the nonlinear characteristics of the weighing system: The figure shows the nonlinear characteristics of the weighing system. The horizontal axis is the standard weight and the vertical axis is the system display weight. The red dotted line represents the ideal linear relationship, and the blue solid line represents the actual nonlinear relationship. It can be seen that there is a slight nonlinear deviation within the measurement range, and the maximum deviation occurs at about 700kg, with a deviation of about 5kg.

[0298] like Figure 8 The figure shows the effect comparison of vibration compensation before and after vibration compensation. The red line shows the vibration signal before compensation, and the blue line shows the signal after compensation. It can be seen that the amplitude of the signal after compensation is significantly reduced, and high-frequency vibration is effectively suppressed. The vibration amplitude is reduced from the original ±0.8mm to within ±0.2mm.

[0299] like Fig. 9 The figure shows the accuracy comparison of the system during the 6-month operation period. The red line shows the relative error before compensation, and the blue line shows the relative error after compensation. It can be seen that the application of compensation technology has significantly improved the accuracy of the system, and the relative error has been reduced from about 3.4% to below 0.4%, and it has remained stable. This shows that the compensation system has good long-term stability.

Claims

1. A cement slurry mixing scale for sludge solidification, Features , including: a frame, a mixing drum, a driving device, a weighing system, a feeding device, a discharging device, a stirring device, a cleaning device and a control panel; the frame is a vertical structure, consisting of a base, columns and beams, the base is rectangular, and shock-proof pads are provided at the four corners; the columns are vertically fixed on the base, and there are four of them, which are respectively located at the four corners of the base; the beams are horizontally fixed to the tops of the four columns to form a stable frame structure; the mixing drum is cylindrical, vertically installed in the center of the frame, with a feeding port on the top and a mixing drum discharge port at the bottom; the driving device includes a motor, a reducer and a transmission shaft, the motor is fixed to the frame base through a motor seat, the reducer is connected to the motor output shaft, one end of the transmission shaft is connected to the reducer output shaft, and the other end passes through the bottom of the mixing drum and extends into the drum; the weighing system includes a plurality of weighing sensors, which are installed between the bottom of the mixing drum and the frame to monitor the weight of the material in the mixing drum in real time; The feeding device is arranged at the top of the mixing drum, including a feeding hopper and a feeding valve. The feeding hopper is funnel-shaped and fixed above the feeding port of the mixing drum. The feeding valve is installed at the outlet at the bottom of the feeding hopper to control the rate at which the material enters the mixing drum; the discharging device is arranged at the bottom of the mixing drum, including a discharging hopper and a discharging valve. The discharging hopper is located at the center of the bottom of the mixing drum, and the discharging valve is installed at the discharging hopper to control the discharge of the material; the stirring device includes a stirring shaft and stirring blades. The stirring shaft is coaxially connected with the transmission shaft and vertically penetrates the mixing drum. The stirring blades are evenly distributed along the circumference of the stirring shaft and are arranged in a spiral shape; the cleaning device includes a scraper assembly and a flushing system. The scraper assembly is installed on the inner wall of the mixing drum to scrape off the material attached to the drum wall. The flushing system includes a plurality of nozzles evenly distributed on the inner wall at the top of the mixing drum to clean the residual material in the drum; the control panel is installed on the side of the frame to control the entire mixing scale system.

2. A cement slurry mixing scale for sludge solidification according to claim 1, It is characterized in that The mixing drum is made of stainless steel, with a wall thickness of 8 mm to 12 mm and a wear-resistant coating on the inside; an observation window is provided on the top of the mixing drum, which is made of transparent tempered glass, is round in shape, and has a diameter of 200 mm to 300 mm, and is sealed to the top of the mixing drum via a sealing ring; the bottom of the mixing drum is a conical structure with a cone angle of 30 to 45 degrees, which is conducive to the smooth discharge of materials.

3. A cement slurry mixing scale for sludge solidification according to claim 2, It is characterized in that The motor in the driving device is a variable frequency motor with a rated power of 5 kW to 10 kW and a rotation speed of 0 rpm to 1500 rpm; The reducer is a planetary gear reducer with a reduction ratio of 1:10 to 1:20; the transmission shaft is made of alloy steel, the surface is heat-treated and surface-hardened, and the diameter is 40 mm to 60 mm.

4. A cement slurry mixing scale for sludge solidification according to claim 3, It is characterized in that The weighing system includes 4 weighing sensors, which are respectively installed between the four corners of the bottom of the mixing drum and the frame; the range of each weighing sensor is 0 kg to 2000 kg, and the accuracy is 0.1% of the full scale; the weighing sensor adopts a shear beam structure, is made of alloy steel, and is nickel-plated on the surface to achieve corrosion resistance.

5. A cement slurry mixing scale for sludge solidification according to claim 4, It is characterized in that The feed hopper in the feeding device is made of 304 stainless steel plate with a wall thickness of 3 mm to 5 mm and a polished inner surface; the top opening diameter of the feed hopper is 600 mm to 800 mm, and the bottom outlet diameter is 200 mm to 300 mm; the feed valve is a pneumatic butterfly valve, the valve body is made of cast steel, the valve plate is made of 304 stainless steel, and the sealing ring is made of fluororubber; the opening angle of the pneumatic butterfly valve is 0 to 90 degrees, and the opening time is 2 to 5 seconds.

6. A cement slurry mixing scale for sludge solidification according to claim 5, It is characterized in that The discharging hopper in the discharging device is circular with a diameter of 150 mm to 250 mm; the discharging valve is a pneumatic ball valve, the valve body is made of 304 stainless steel, the ball is made of 304 stainless steel and has undergone surface hardening treatment, and the sealing ring is made of polytetrafluoroethylene; the opening angle of the pneumatic ball valve is 0 degrees to 90 degrees, and the opening time is 1 second to 3 seconds.

7. A cement slurry mixing scale for sludge solidification according to claim 6, It is characterized in that The stirring shaft in the stirring device is made of 304 stainless steel, with a diameter of 50 mm to 80 mm and a polished surface; the stirring blades are stamped from 304 stainless steel plates, with a thickness of 5 mm to 8 mm and a polished surface; the stirring blades are arranged in a double helix along the stirring shaft, with a pitch of 300 mm to 500 mm and a blade inclination angle of 30 degrees to 45 degrees; 4 to 6 stirring blades are provided on each spiral period, and the gap between the outer edge of the blade and the inner wall of the stirring barrel is 10 mm to 20 mm.

8. A cement slurry mixing scale for sludge solidification according to claim 7, It is characterized in that The scraper assembly in the cleaning device includes multiple scrapers, which are made of polyurethane and have a hardness of 90 to 95 degrees Shore A; the scrapers are fixed to the inner wall of the mixing drum through a stainless steel bracket, and the pressing force between the scrapers and the inner wall of the mixing drum is adjusted by a spring; the flushing system includes 8 to 12 nozzles, which are made of 316L stainless steel, have a nozzle diameter of 2 mm to 4 mm, and an angle between the nozzle and the inner wall of the top of the mixing drum is 30 to 45 degrees.

9. A cement slurry mixing scale for sludge solidification according to claim 8, It is characterized in that The control panel is made of steel plate with plastic spraying treatment on the surface and a protection level of IP65; the control panel is provided with a touch screen, an emergency stop button, a start button, a stop button, a power indicator light and a fault indicator light; the touch screen size is 10 inches to 12 inches, and the resolution is not less than 1024×768 pixels; the control panel is internally provided with relays, contactors, circuit breakers and power modules for controlling the actions of various actuators and protecting the electrical system.

10. A cement slurry mixing scale for sludge solidification according to claim 9, It is characterized in that It also includes a weighing calculation system, which includes a single chip microcomputer and a data processor, the single chip microcomputer is electrically connected to the touch screen and the weighing sensor, and a weighing compensation module is provided in the single chip microcomputer to reduce the dynamic weighing accuracy error under high-speed flow state, and display the current weighing data in real time through the touch screen, and the weighing compensation module is used to perform the following steps: S10, collecting the original weighing signal of the weighing sensor during the stirring process, and obtaining a dynamic weighing data sequence within a continuous time period; S20, performing time domain analysis on the dynamic weighing data sequence to extract time domain characteristic parameters, including mean, standard deviation, peak factor and waveform factor; S30, performing frequency domain analysis on the dynamic weighing data sequence, obtaining spectrum characteristics through Fourier transform, and extracting main frequency components and their amplitudes; S40, establishing a compensation equation group based on the time domain characteristic parameters and the frequency domain characteristics, wherein the compensation equation group includes a dynamic response equation, a spectrum compensation equation, a temperature drift equation, a nonlinear correction equation, and a mechanical coupling equation; S50, collecting weighing data of multiple groups of materials with known weights at different stirring speeds, and establishing a training sample set, where each group of samples includes characteristic parameters and corresponding actual error values; S60, fitting the compensation equation group by using the least square method, determining the coefficients of each item in the compensation equation group, and obtaining a dynamic weighing error compensation model; S70, verifying the dynamic weighing error compensation model by a cross-validation method, calculating the weighing error after compensation, and returning to step S40 to adjust the compensation equation group when the error after compensation is greater than a preset threshold; S80, applying the dynamic weighing error compensation model to the real-time weighing process, performing online compensation on the original weighing signal, and outputting the corrected weighing data; S90. According to changes in production conditions, new sample data is periodically collected, and the coefficients of the compensation equation group are updated to maintain the adaptability of the compensation model.

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