A sludge moisture content measurement system based on multiple infrared detection reflection bands

Abstract

The present invention relates to the technical field of sludge moisture content measurement, and discloses a sludge moisture content measurement system based on multiple infrared detection reflection bands. The system includes a supporting plate for supporting sludge, an infrared light source for emitting infrared light to illuminate the sludge, an infrared detection array composed of a plurality of infrared detectors, each of which is equipped with a filter. The filter is used to limit the wavelength range of the infrared light received by the infrared detector, allowing only infrared light within the wavelength range to pass through, thereby causing the infrared detector to output a corresponding voltage signal; and a signal processing module for receiving and processing the voltage signal output by the infrared detector. The sludge moisture content measurement system based on multiple infrared detection reflection bands uses infrared spectroscopy technology to achieve rapid, non-contact measurement of sludge moisture content without the need for sampling or destroying sludge samples, and is also conducive to achieving online real-time monitoring.

Description

Technical Field

[0001] The invention relates to the technical field of sludge moisture content measurement, in particular to a sludge moisture content measurement system based on multiple infrared detection reflection bands. Background Art

[0002] In the wastewater treatment process, accurately measuring the moisture content of sludge is crucial for optimizing treatment processes and improving efficiency. Traditional methods for measuring sludge moisture content, such as gravimetric and drying methods, are reliable. However, these methods often require removing sludge samples from the site for processing, making them complex and time-consuming. Furthermore, online, real-time monitoring is difficult to achieve.

[0003] Infrared spectroscopy, a non-contact measurement technology, has been widely used in recent years to measure moisture content due to its rapid and non-contact nature. However, existing infrared spectroscopy systems still have some limitations, particularly in measuring sludge with complex composition. Single-band infrared detectors, faced with interference from multiple components, struggle to effectively distinguish the moisture signal from the absorption signals of other components in the sludge, resulting in reduced measurement accuracy and stability. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the shortcomings of the existing technology, the present invention provides a sludge moisture content measurement system based on multiple infrared detection reflection bands, which has the advantages of being able to collect signals from characteristic bands and reference bands respectively through multiple infrared detectors, and combining model construction and data processing to accurately measure the sludge moisture content.

[0006] (2) Technical solution

[0007] To achieve the above-mentioned purpose of being able to collect signals from characteristic bands and reference bands respectively through multiple infrared detectors, and combining model construction and data processing to accurately measure the sludge moisture content, the present invention provides the following technical solution: a sludge moisture content measurement system based on multiple infrared detection reflection bands, including a supporting plate for supporting sludge, and also including:

[0008] An infrared light source, used for emitting infrared light to irradiate the sludge;

[0009] The infrared detection array is composed of a number of infrared detectors, each of which is equipped with a filter. The filter is used to limit the wavelength range of infrared light received by the infrared detector, allowing only infrared light within this wavelength range to pass through, thereby causing the infrared detector to output a corresponding voltage signal;

[0010] A signal processing module is used to receive and process the voltage signal output by the infrared detector;

[0011] A model building module, used to build a correlation model between reflected light power and moisture content;

[0012] Moisture content calculation module calculates sludge moisture content based on the correlation model.

[0013] As a preferred technical solution of the present invention, the signal processing module includes:

[0014] Signal amplification and filtering unit: used to receive and process the voltage signal output by the infrared detector, amplify the signal and remove noise interference;

[0015] Analog-to-digital conversion unit: used to convert analog signals into high-precision digital signals;

[0016] The data storage unit is used to store the processed voltage signal.

[0017] As a preferred technical solution of the present invention, the infrared detector includes:

[0018] Characteristic band detector, whose filter is used to receive infrared light affected by sludge moisture absorption and scattering, and output characteristic voltage signal;

[0019] Reference band detector, whose filter is used to receive infrared light that is not affected by sludge moisture absorption and scattering, and output a reference voltage signal;

[0020] The model building module builds a correlation model between the reflected light power and the water content according to the characteristic voltage signal of the characteristic band detector and the reference voltage signal of the reference band detector.

[0021] As a preferred technical solution of the present invention, it also includes:

[0022] Water vapor measurement channel, including a temperature sensor and a humidity sensor, used to measure the temperature and relative humidity in the air and calculate the absolute humidity;

[0023] The absorption interference of water vapor in the air on the infrared light reflection signal is corrected by the absolute humidity value.

[0024] As a preferred technical solution of the present invention, the calibration process includes:

[0025] According to the absolute humidity value of water vapor, the absorption coefficient of water vapor in a specific infrared band is determined. Combined with the reference voltage signal of the reference band detector, the voltage attenuation caused by water vapor absorption is compensated to obtain a corrected voltage signal after eliminating water vapor interference.

[0026] As a preferred technical solution of the present invention, it also includes a focusing lens, which is arranged below the filter.

[0027] As a preferred technical solution of the present invention, it also includes a fixing plate, in which an inner cavity is formed, a top tube connected to the inner cavity is fixedly installed on the side of the top, and a bottom tube connected to the inner cavity is fixedly installed on the side of the bottom, the infrared detector is loaded in the top tube, and the focusing lens is fixed in the bottom tube;

[0028] A switching disk is rotatably installed in the inner cavity, and a plurality of mounting slots for mounting optical filters are evenly opened on the switching disk.

[0029] As a preferred technical solution of the present invention, a sensor fixing housing is fixedly installed on the outer wall of the bottom cylinder, and a measuring sensor is fixed in the sensor fixing housing.

[0030] As a preferred technical solution of the present invention, it also includes an exhaust pipe with an air jet head at the end;

[0031] The nozzle at the end of the exhaust pipe is inserted into the bottom tube and faces the focusing lens.

[0032] (3) Beneficial effects

[0033] Compared with the existing technology, the present invention provides a sludge moisture content measurement system based on multiple infrared detection reflection bands, which has the following beneficial effects:

[0034] 1. This sludge moisture content measurement system based on multiple infrared detection reflection bands can simultaneously obtain infrared light information of multiple wavelengths by using multiple infrared detectors equipped with filters, thereby improving the accuracy and stability of moisture content measurement.

[0035] 2. The sludge moisture content measurement system based on multiple infrared detection reflection bands adds a water vapor measurement channel to obtain the absolute humidity of water vapor, and uses the absolute humidity to correct the infrared light signal, eliminating the interference caused by water vapor absorption and obtaining more accurate moisture content measurement results.

[0036] 3. The sludge moisture content measurement system based on multiple infrared detection reflection bands can realize rapid and non-contact measurement of sludge moisture content through infrared spectroscopy technology, without the need for sampling or destruction of sludge samples, and is also conducive to online real-time monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the measurement system of the present invention;

[0038] Figure 2 is an enlarged schematic diagram of the fixed plate portion of the present invention;

[0039] Figure 3 is a cross-sectional view of the fixing plate portion of the present invention;

[0040] Figure 4 It is an enlarged schematic diagram of the switching disk portion of the present invention;

[0041] Figure 5 is a cross-sectional view of a fixed plate portion in another embodiment of the present invention;

[0042] Figure 6 It is an enlarged schematic diagram of the plug barrel portion of the present invention.

[0043] In the figure: 1. Carrying plate; 2. Infrared light source; 3. Light source bracket; 4. Infrared detector; 5. Filter; 6. Focusing lens; 7. Fixing plate; 8. Inner cavity; 9. Switching disk; 10. Mounting groove; 11. Top cylinder; 12. Bottom cylinder; 13. Sensor fixing housing; 14. Measuring sensor; 15. Vertical axis; 16. Fixed bearing; 17. Drive disk; 18. Arc groove; 19. Column groove; 20. Drive shaft; 21. Positioning disk; 22. Eccentric disk; 23. Sliding column; 24. Pressure plate; 25. Connecting rod; 26. Piston; 27. Plug cylinder; 28. Support spring; 29. ​​Intake pipe; 30. Exhaust pipe. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] Example 1:

[0046] See also Figure 1 , a sludge moisture content measurement system based on multiple infrared detection reflection bands, including a carrying plate 1 for carrying sludge, such as Figure 1 As shown, an infrared light source 2 is also provided for emitting infrared light to irradiate the sludge;

[0047] An infrared detection array is provided above the sludge. The infrared detection array is composed of a number of infrared detectors 4. The infrared detectors 4 are equipped with filters 5. The filters 5 are used to limit the infrared light band range received by the infrared detectors 4, allowing only infrared light within the band to pass through, thereby causing the infrared detectors 4 to output a corresponding voltage signal. The signal processing module then receives and processes the voltage signal output by the infrared detectors 4.

[0048] In this embodiment, the signal processing module includes a signal amplification and filtering unit, an analog-to-digital conversion unit and a data storage unit, wherein the signal amplification and filtering unit is used to receive and process the voltage signal output by the infrared detector 4, amplify the signal and remove noise interference, the analog-to-digital conversion unit is used to convert the analog signal into a high-precision digital signal, and the data storage unit is used to store the processed voltage signal.

[0049] In the present invention, the infrared detector 4 is specifically divided into a characteristic band detector and a reference band detector. The filter 5 of the characteristic band detector is used to receive infrared light affected by sludge moisture absorption and scattering, and output a characteristic voltage signal (such as selecting a filter 5 with a central wavelength of 1400nm and a bandwidth of 24nm). The filter 5 of the reference band detector is used to receive infrared light that is not affected by sludge moisture absorption and scattering, and output a reference voltage signal (such as selecting a filter 5 with a central wavelength of 1100nm and a bandwidth of 20nm). The specific selection of the filter 5 can be made by those skilled in the art according to the measurement requirements.

[0050] The model building module builds a correlation model between the reflected light power and the moisture content according to the characteristic voltage signal of the characteristic band detector and the reference voltage signal of the reference band detector.

[0051] To construct the correlation model, first, the voltage signal of the reflected light is collected by the infrared detector 4, and the voltage signals V of the characteristic band and the reference band are recorded respectively. f and V r Among them, the voltage signal of the characteristic band is affected by the moisture content of the sludge, while the signal of the reference band is used to correct the error.

[0052] In order to eliminate the influence of environmental noise and other external interference, the voltage signals of the characteristic band and the reference band are differentially processed to obtain the relative change ΔV:

[0053] ΔV=V r -V f

[0054] In the present invention, a quadratic polynomial model is used to fit the relationship between the reflected light power and the moisture content. The sludge moisture content W and the voltage change ΔV can be expressed as:

[0055] W=a﹒ (ΔV) 2 +b﹒ (ΔV)+c

[0056] Among them, a, b, c are the model parameters to be fitted, and W is the actual moisture content of the sludge.

[0057] By collecting a large amount of data and using regression analysis, we can fit a, b, and c. We use the actual moisture content W of each sample and the corresponding voltage change ΔV as input data and use the least squares method to fit the model parameters:

[0058]

[0059] Through the above optimization, the values ​​of a, b, and c can be obtained, and the fitting error of the model is small.

[0060] After the model is constructed, the model can be used to calculate the sludge moisture content. During the calculation, ΔV is substituted into the fitted model to obtain the sludge moisture content (i.e., the moisture content calculation module).

[0061] In the present invention, a water vapor measurement channel is also provided, specifically including a temperature sensor and a humidity sensor, for measuring the temperature and relative humidity in the air and calculating the absolute humidity. The absolute humidity value can be used to correct the absorption interference of water vapor in the air on the infrared light reflection signal.

[0062] The specific correction method is to determine the absorption coefficient of water vapor in a specific infrared band based on the absolute humidity value of water vapor, and combine it with the reference voltage signal of the reference band detector to compensate for the voltage attenuation caused by water vapor absorption, so as to obtain the corrected voltage signal after eliminating water vapor interference. The corrected voltage signal is used to construct the correlation model, so as to ensure that the final reflected signal only contains the light intensity attenuation caused by water absorption on the sludge surface, thereby improving the measurement accuracy of the sludge moisture content.

[0063] Example 2:

[0064] See also Figure 1-Figure 4 Based on the first embodiment, in this embodiment, the infrared light source 2 can be a continuous spectrum infrared lamp or a laser with a specific wavelength. The infrared light source 2 is installed on an adjustable light source bracket 3, which can adjust relevant parameters such as height and angle.

[0065] like Figure 1 As shown, a focusing lens 6 is further provided below the filter 5 , which acts like a magnifying glass to increase the intensity of light entering the effective detection area of ​​the infrared detector 4 .

[0066] In the present invention, Figure 3 As shown, a fixing plate 7 is further provided, with an inner cavity 8 formed therein, a top cylinder 11 connected to the inner cavity 8 is fixedly mounted on the side of the top, and a bottom cylinder 12 connected to the inner cavity 8 is fixedly mounted on the side of the bottom, the infrared detector 4 is loaded in the top cylinder 11, and the focusing lens 6 is fixed in the bottom cylinder 12. A switching disk 9 is rotatably mounted in the inner cavity 8, and a plurality of mounting grooves 10 for mounting filters 5 are evenly opened on the switching disk 9, and the filters 5 are mounted in the mounting grooves 10;

[0067] By rotating the switching disk 9 , the optical filters 5 at different positions on the switching disk 9 can correspond to the infrared detector 4 and the focusing lens 6 , thereby realizing convenient switching of the optical filters 5 .

[0068] like Figure 3 As shown, a sensor fixing shell 13 is fixedly installed on the outer wall of the bottom tube 12, and a measuring sensor 14 is fixed in the sensor fixing shell 13. The measuring sensor 14 is a temperature sensor and a humidity sensor, which is used to measure the temperature and relative humidity in the air and calculate the absolute humidity. Furthermore, the absolute humidity value can be used to correct the absorption interference of water vapor in the air on the infrared light reflection signal.

[0069] like Figure 5 As shown, an exhaust pipe 30 with a nozzle connected to the end is also provided. The nozzle at the end of the exhaust pipe 30 is inserted into the bottom tube 12 and faces the focusing lens 6. The gas ejected is sprayed on the bottom of the focusing lens 6, thereby effectively cleaning the focusing lens 6. Since the filter 5 is always located in the inner cavity 8 and the infrared detector 4 is fixed in the top tube 11 and is not in contact with the external environment, it does not need to be cleaned.

[0070] Example 3:

[0071] See also Figure 5 and Figure 6 On the basis of the first and second embodiments, this embodiment specifically provides a mechanism for driving the switching disk 9 to rotate, such as Figure 5 As shown:

[0072] A vertical shaft 15 is fixedly installed at the center of the bottom of the switching disk 9. The vertical shaft 15 is fixed by a fixed bearing 16. The bottom end of the vertical shaft 15 is fixedly connected to a driving disk 17. The driving disk 17 is evenly provided with column grooves 19, and arc-shaped grooves 18 are formed between adjacent column grooves 19.

[0073] In addition, a drive shaft 20 driven by a motor (not shown) is provided. A positioning disc 21 and an eccentric disc 22 are fixedly mounted on the drive shaft 20. The positioning disc 21 corresponds to the arc-shaped groove 18. A sliding post 23 is fixedly mounted on the eccentric disc 22. The sliding post 23 can slide into or out of the column groove 19.

[0074] When the motor drives the drive shaft 20 to rotate, the drive shaft 20 will also synchronously drive the positioning disk 21 and the eccentric disk 22 to rotate. When the eccentric disk 22 rotates, it can slide into a column slot 19 through the sliding column 23 thereon, and then drive the drive disk 17 to rotate a certain angle, and then slide out of the column slot 19, thereby realizing the rotation control of the directional angle of the drive disk 17, and then realizing the switching of different filters 5.

[0075] The positioning disc 21 serves to position the driving disc 17 . Meanwhile, a groove is provided on the positioning disc 21 to allow the “sharp corner” of the driving disc 17 to pass through.

[0076] In the present invention, Figure 6 As shown, a plug cylinder 27 is fixedly installed at the bottom of the fixed plate 7, and a piston 26 is movably arranged in the plug cylinder 27. One side of the piston 26 is supported by a support spring 28, and the other side is fixedly connected to a pressure plate 24 through a connecting rod 25. The pressure plate 24 is arranged close to the eccentric disk 22. When the eccentric disk 22 rotates, it can cyclically push the pressure plate 24.

[0077] In this embodiment, an air inlet pipe 29 is connected to the plug tube 27, and a one-way air inlet valve is provided on the air inlet pipe 29. An exhaust pipe 30 is also connected to the plug tube 27, and a one-way exhaust valve is provided on the exhaust pipe 30.

[0078] When the eccentric disk 22 rotates and pushes the pressure plate 24, the movement of the piston 26 can be used to pump the air sucked into the intake pipe 29 out from the nozzle at the end of the exhaust pipe 30, thereby effectively cleaning the focusing lens 6 without the need for an additional gas generating device or an additional electronic control system.

[0079] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A sludge moisture content measurement system based on multiple infrared detection reflection bands, comprising a supporting plate (1) for supporting sludge, characterized in that: Also includes: an infrared light source (2), for emitting infrared light to irradiate the sludge; An infrared detection array is composed of a plurality of infrared detectors (4), each of which is provided with a filter (5). The filter (5) is used to limit the wavelength range of infrared light received by the infrared detector (4), allowing only infrared light within the wavelength range to pass through, thereby causing the infrared detector (4) to output a corresponding voltage signal. A signal processing module, used for receiving and processing the voltage signal output by the infrared detector (4); A model building module, used to build a correlation model between reflected light power and moisture content; Moisture content calculation module, which calculates the sludge moisture content based on the correlation model; A quadratic polynomial model is used to fit the relationship between reflected light power and moisture content. The sludge moisture content W and voltage change ΔV can be expressed as: W = a·(ΔV) 2 +b·(ΔV)+c, where a, b, and c are the model parameters to be fitted, and W is the actual moisture content of the sludge; The sludge moisture content measurement system based on multiple infrared detection reflection bands also includes: Water vapor measurement channel, including a temperature sensor and a humidity sensor, used to measure the temperature and relative humidity in the air and calculate the absolute humidity; The absorption interference of water vapor in the air on the infrared light reflection signal is corrected by the absolute humidity value; The calibration process includes: determining the absorption coefficient of water vapor in a specific infrared band based on the absolute humidity value of water vapor, combining it with the reference voltage signal of the reference band detector, compensating for the voltage attenuation caused by water vapor absorption, and obtaining a calibrated voltage signal after eliminating water vapor interference; It also includes a focusing lens (6) disposed below the filter (5); It also includes a fixing plate (7) with an inner cavity (8) formed therein, a top tube (11) connected to the inner cavity (8) fixedly mounted on the side of the top, and a bottom tube (12) connected to the inner cavity (8) fixedly mounted on the side of the bottom, the infrared detector (4) is loaded in the top tube (11), and the focusing lens (6) is fixed in the bottom tube (12); A switching disk (9) is rotatably mounted in the inner cavity (8), and a plurality of mounting slots (10) for mounting optical filters (5) are evenly arranged on the switching disk (9); A sensor fixing housing (13) is fixedly mounted on the outer wall of the bottom cylinder (12), and a measuring sensor (14) is fixed inside the sensor fixing housing (13); It also includes an exhaust pipe (30) with an air jet nozzle at the end; The nozzle at the end of the exhaust pipe (30) is inserted into the bottom barrel (12) and faces the focusing lens (6).

2. The sludge moisture content measurement system based on multiple infrared detection reflection bands according to claim 1 is characterized in that: The signal processing module includes: Signal amplification and filtering unit: used for receiving and processing the voltage signal output by the infrared detector (4), amplifying the signal and removing noise interference; Analog-to-digital conversion unit: used to convert analog signals into high-precision digital signals; The data storage unit is used to store the processed voltage signal.

3. The sludge moisture content measurement system based on multiple infrared detection reflection bands according to claim 1 or 2, characterized in that: The infrared detector (4) comprises: A characteristic band detector, whose filter (5) is used to receive infrared light affected by sludge moisture absorption and scattering, and output a characteristic voltage signal; A reference band detector, whose filter (5) is used to receive infrared light that is not affected by sludge moisture absorption and scattering, and output a reference voltage signal; The model building module builds a correlation model between the reflected light power and the water content according to the characteristic voltage signal of the characteristic band detector and the reference voltage signal of the reference band detector.

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