Coal quality on-line detection device and method based on array type near infrared spectrum acquisition

Abstract

The invention provides an array type near infrared spectrum acquisition coal quality online detection device and method, and relates to the technical field of mineral detection equipment. The multipoint array type near infrared spectrum acquisition on-line detection device comprises a laser range finder, a data processing system, a lifting control system, a liftable ribbon optical fiber, a spectrograph and a light source, the lifting control system can control the lifting and descending of the liftable ribbon-shaped optical fiber according to data acquired by the laser range finder, so that the optical path is kept consistent when the optical fiber acquires the coal flow cross section; and the data processing system performs coal quality information prediction on each detection point of the same coal flow section according to the collected data, and finally adds and sums to obtain a coal quality information prediction value for replacing the coal flow section. According to the coal quality online detection device and method based on array type near infrared spectrum collection, the accuracy of coal quality information prediction is improved, and the sampling and sample preparation process is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of coal quality detection devices, and in particular to the application of near-infrared spectroscopy technology in coal quality detection, and specifically to an array-type near-infrared spectroscopy collection online coal quality detection device and method. Background Art

[0002] Rapid analysis and detection of coal quality is of great significance for guiding coal production, transportation, storage and sales. Near-infrared spectroscopy technology has the advantages of rapid and non-destructive detection of coal quality. However, there is still much room for improvement in the related supporting equipment for near-infrared spectroscopy detection of coal quality. At present, the online detection technology of coal quality on the belt mainly includes two forms:

[0003] 1. Mainline belt detection: The detection equipment is directly installed on the mainline belt, and the light source forms a fixed light spot to sample the surface of the coal flow. The main problem with this method is that it is affected by the shape of the coal flow and the sampling height. The collected spectral data only reflects local coal quality information and it is difficult to accurately describe the entire coal flow;

[0004] 2. Branch line device detection: After sampling from the main line belt through a sampler, the sample is crushed and sampled before spectral analysis. Although this method improves the representativeness of spectral analysis, it increases the time cost due to multiple processing steps and destroys the original characteristics of the coal sample.

[0005] Therefore, how to achieve efficient, accurate and comprehensive near-infrared spectroscopy detection of coal quality on the main line belt has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to provide an innovative near-infrared spectrum acquisition device and method, which replaces the coal quality information of the coal flow section by array multi-point spectrum acquisition and predicted value addition and averaging, overcomes the limitations of the existing near-infrared spectrum acquisition of coal flow information on the main belt, and improves the accuracy and practicality of coal quality detection. The technical solution adopted by the present invention is:

[0007] The invention discloses an online detection device and method for coal quality by array-type near-infrared spectrum collection. The structure of the device comprises a laser rangefinder, a lifting control system, a data processing system, a spectrometer, a transfer interface, a light source, and a liftable optical fiber. The liftable optical fiber is composed of a plurality of optical fiber arrays, each of which is installed on an automatically controllable lifting device. The laser rangefinder is connected to the lifting control and data processing system, and the spectrometer is connected to the data processing system. The light source and the spectrometer are connected through a transfer interface. When a coal flow cross-section detection point on a conveyor belt passes directly below the laser rangefinder, the distance from the detector interface will be collected, and the data will be transmitted to the data processing system, and the height required to be adjusted for the corresponding optical fiber point will be analyzed, and finally the adjustment will be made through the lifting control system. When the coal flow cross-section detection point reaches the lower end of the optical fiber, the near-infrared spectrum data of the point can be collected in time, and the spectrometer will transmit the data to the data processing system. The data processing system combines the constructed prediction model to predict the coal quality information of each detection point of the coal flow in real time, and finally the prediction value of each detection point is averaged to obtain the prediction value that can represent the coal quality information of the coal flow cross section.

[0008] The beneficial effects of the present invention are:

[0009] (1) It can simultaneously collect spectral information from multiple points on the coal flow surface to improve the representativeness of the detection results;

[0010] (2) No need for crushing and sample preparation, retaining the original characteristics of the coal sample;

[0011] (3) Automatically adjust the sampling height to avoid spectral acquisition errors caused by irregular coal flow cross-sections;

[0012] (4) The sum-average algorithm is used to accurately predict the overall coal quality information of the coal flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall workflow of the present invention;

[0014] Figure 2 It is a schematic diagram of the connection between the liftable optical fiber and the spectrometer, light source and transfer interface;

[0015] Figure 3 It is a schematic diagram of the structure of the liftable optical fiber;

[0016] Figure 4 A schematic diagram of the transfer interface construction for merging the light source and spectrometer interfaces;

[0017] Explanation of serial numbers in the figure: 100 liftable optical fiber, 200 transfer interface, 300 spectrometer, 400 light source, 500 data processing system, 600 lifting control system, 700 laser rangefinder, 800 mineral conveyor belt, 110 lifting platform, 120 optical fiber detector, 130 optical fiber, 140 lifting platform connecting flange, 150 lifting rod, 160 motor gear, 170 rotating motor, 180 sawtooth on rod, 190 high-pressure jet gun, 191 air intake pipe, 210 optical signal buffer, 220 optical fiber entrance and exit, 230 light source interface, 240 spectrometer interface. DETAILED DESCRIPTION

[0018] according to Figures 1 to 4 The specific structure and working process of the present invention are described in detail. The device of the array-type near-infrared spectrum collection online detection equipment includes a laser rangefinder 700 for measuring the distance from the coal flow surface detection point to the laser detector end point, a liftable optical fiber 100, a lifting control system 600, a data processing system 500, a spectrometer 300, a light source 400, and a transfer interface 200; wherein the laser rangefinder 700 can measure the vertical distance from the coal flow surface detection point to the control point; the lifting control system 600 can control the rotation of the rotating motor 170 to drive the optical fiber 130 to lift and lower, and the transfer interface 200 can connect multiple optical fibers with the light source and the spectrometer; the data processing system 500 can predict the coal quality information of each detection point of the coal flow cross section according to the spectral data transmitted by the spectrometer.

[0019] The process of detecting the coal flow cross section of the invention is as follows:

[0020] When the coal flow detection point passes directly under the laser rangefinder 700, the laser rangefinder 700 will measure the distance x between the surface of the detection point and the laser port of the laser rangefinder 700, and send the data to the lifting control system 600. Assuming that the distance between the port of the optical fiber detector 120 and the surface of the detection point is to be kept at y, the lifting control system will move the distance xy; when xy is a positive value, the lifting control system 600 controls the rotating motor 170 to rotate in the corresponding direction, driving the saw teeth 180 on the driving rod to move downward, so that the lifting platform connecting flange 140 will drive the lifting platform 110 to move downward under the drive of the lifting rod 150; when xy is a negative value, the lifting control system 600 controls the rotating motor 170 to rotate in the corresponding direction, driving the saw teeth 180 on the driving rod to move upward, so that the lifting platform connecting flange 140 will drive the lifting platform 100 to move upward under the drive of the lifting rod 150.

[0021] When the coal flow section detection point reaches directly below the fiber optic detector 120, the fiber optic detector 120 has adjusted its height (the optical path from each fiber optic detector to the corresponding coal flow section control point is equal), and the optical signal is transmitted to the fiber optic port 180 through the fiber optic inlet and outlet 220. At this time, the optical signal in the fiber optic detector 120 irradiates the surface of the detection point, and the diffuse reflected light is returned to the signal buffer 210 through the fiber optic inlet and outlet 220. The optical signal in each optical fiber will be transferred from the optical signal buffer 210 to the spectrometer interface 240 in sequence. After the fiber optic detector 120 has collected the spectrum of the point, the lifting control system 600 will control the motor gear 160 to rotate and finally return the fiber optic detector 120 to the original position, waiting for the next data collection. At regular intervals, the high-pressure jet gun 190 sprays air to the fiber optic detector 120 through the air intake pipe 191 to prevent dust from covering the fiber optic port and affecting the spectrum collection.

[0022] After the spectrometer 300 receives the collected light signal, it converts the internal photoelectric signal and amplifies the information to obtain the near-infrared spectrum data of the detection point. The spectrometer 300 transmits the same set of collected data to the data processing system 500. The data processing system 500 contains a trained prediction model. After the spectral data is transmitted, the model will make corresponding predictions. Finally, the predicted values ​​of each detection point are added and averaged to replace the coal quality information of the coal flow section. The specific formula is as follows (Pn represents the model prediction value of the nth detection point):

[0023] P=(P1+P2+P3+P4+…+Pn) / n

[0024] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person skilled in the art can change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. The coal quality information mentioned in the above invention includes but is not limited to moisture, ash, and volatile matter.

Claims

1. An array-type near-infrared spectrum collection online detection device and method for coal quality, which includes a laser rangefinder, a data processing system, a lifting control system, a lifting optical fiber ribbon, a spectrometer, a light source, and a transfer interface, characterized in that: The laser rangefinder is composed of multiple rangefinders, which can simultaneously measure the distance of multiple detection points on the same coal flow section; The laser rangefinder can transmit the measured data to the lifting control system in a wired manner.

2. The device and method for online detection of coal quality by array-type near-infrared spectroscopy acquisition according to claim 1, characterized in that: The liftable ribbon optical fiber is composed of a rotating motor, motor gears, a lifting rod, a lifting platform, a lifting platform connecting flange, a high-pressure jet gun, an air intake pipe and an optical fiber probe; The motor can be controlled to rotate in a direction by a lifting control system; The lifting rod can move up and down driven by the rotating gear of the motor; The lifting platform is connected to the lifting rod via a lifting platform connecting flange and can move synchronously with the lifting rod.

3. The device and method for online detection of coal quality by array-type near-infrared spectroscopy acquisition according to claim 2, characterized in that: The high-pressure jet gun can periodically spray gas to the optical fiber detector through the air inlet pipe to prevent dust from covering the optical fiber.

4. The device and method for online detection of coal quality by array-type near-infrared spectroscopy acquisition according to claim 2, characterized in that: The lifting control system controls the rotation direction of the motor according to the data transmitted by the laser rangefinder.

5. The device and method for online detection of coal quality by array-type near-infrared spectroscopy acquisition according to claim 1, characterized in that: The spectrometer is connected to the light source via a transfer interface; The structure of the transfer interface includes: a light source interface, a spectrometer interface, an optical fiber inlet and outlet, and an optical signal buffer.

6. The device and method for online detection of coal quality by array-type near-infrared spectrum collection according to claim 5, characterized in that: The light source separately guides the optical signal into different optical fibers through the transfer interface; The optical fiber inlet can direct the optical signal in the optical fiber into the optical signal buffer in the transfer interface; The optical signal buffer can guide the introduced optical signal into the spectrometer through the spectrometer interface at time intervals.

7. The device and method for online detection of coal quality by array near infrared spectrum collection according to claim 1, characterized in that: The data processing system has a trained coal quality detection model module, which can detect coal quality information on the coal flow section according to the spectral data transmitted by the spectrometer.

8. The device and method for online detection of coal quality by array-type near-infrared spectrum collection according to claim 7, characterized in that: The detection model module detects the near-infrared spectrum data of the coal flow to obtain the coal sample information detection value of each detection point.

9. The device and method for online detection of coal quality by array-type near-infrared spectrum collection according to claim 7, characterized in that: The coal quality information detection of the coal flow section is obtained by summing and averaging the model detection values ​​of the coal quality information at each detection point. The specific formula is (Pn represents the model detection value of the nth detection point): P=(P1+P2+P3+P4+…+Pn) / n.

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