CN112304983A

CN112304983A - Multi-detector type online ash content meter

Info

Publication number: CN112304983A
Application number: CN202011113286.6A
Authority: CN
Inventors: 于海明; 张永君; 陈月红
Original assignee: Dongfang Measurement & Control Technology Co ltd
Current assignee: Dongfang Measurement & Control Technology Co ltd; Dandong Dongfang Measurement and Control Technology Co Ltd
Priority date: 2020-04-13
Filing date: 2020-10-17
Publication date: 2021-02-02
Also published as: CN112697816B; CN112697816A

Abstract

The multi-detector type online ash content instrument comprises a radioactive source, a detector array, a signal processing cabinet and a measuring device; a radioactive source is placed at the center above the belt, and the distance from the radioactive source to the belt is adjustable; and a detector array is arranged below the belt, the number of detectors in the detector array is more than or equal to 2, and the detectors are arranged on one substrate in parallel. The position of each detector on the substrate and the angle between the ray receiving window and the output port of the radioactive source can be adjusted, the set screw 1 is installed on the horizontal sliding block, the set screw 1 is loosened, and the detectors can integrally transversely translate. And a set screw 2 is arranged on the annular sliding block, a group of set screws 2 are loosened, and the detector round tube can rotate. The ash content on a plurality of position points of the material on the cross section of the belt can be measured, and the average ash content in any time period can be calculated.

Description

Multi-detector type online ash content meter

Technical Field

The invention relates to an online ash content meter.

Background

Coal is a main energy source and an important chemical raw material in China, and the size of ash content in the coal is directly related to the processing and utilization of the coal. The traditional coal ash content detection method is carried out according to the series of on-site sampling, crushing, division, drying, grinding, weighing and burning. Most of the procedures need to be carried out under laboratory conditions, and have a large dependence on personnel, environment and laboratory equipment. On the other hand, the ash values obtained with this process are not only the fastest but also two hours later, with the result that the production is severely delayed. Another disadvantage of conventional ash analysis methods is: the ash values obtained by this method are typically poor because field sampling typically results in the total coal on one cross-section of the belt, and the ash values obtained from the final assay are only the ash content of the coal on that cross-section of the belt and not the ash content of the entire belt. At present, on the basis of a patent technology, namely a method for detecting coal ash on a belt on line (patent number: 200810013224.0), an on-line ash analysis instrument well realizes real-time detection of the coal ash, gets rid of a complicated program of analysis after manual sampling, and greatly improves the production efficiency.

The device can be used for quickly and accurately measuring the ash content of coal on the whole conveying belt. However, in some application fields, the granularity of coal has large fluctuation, and meanwhile, the coal conveying belt runs for a long time and has a deviation phenomenon, and the conditions can influence the accuracy of ash value measured by an instrument.

Disclosure of Invention

The invention provides a multi-detector type online ash content instrument, and aims to solve the technical defects. The specific technical scheme for solving the problems is as follows: the analyzer comprises a radioactive source (1), a detector array (2), a measuring device (3) and a signal processing cabinet (4); a radioactive source (1) is placed in the center above the belt, and the distance from the radioactive source (1) to the belt is adjustable; the detector array (2) is arranged below the belt, ash content on a plurality of position points of the material on the cross section of the belt is measured, instantaneous flow information of coal is calculated, and average ash content in any time period is calculated by combining with the instantaneous ash content of the coal. The detector is a NaI detector, and comprises a crystal (6), a photomultiplier (7), an energy spectrum acquisition circuit (8) and a detector shell (5). The energy spectrum acquisition circuit comprises a high-voltage circuit (9), a pre-amplification circuit (10), a high-speed ADC (analog-to-digital converter) circuit and a controller circuit (11), all the circuits are fixed on a tube seat of a photomultiplier and used for converting analog signals output by the photomultiplier into digital signals, the whole detector is provided with a USB (universal serial bus) interface (12), and the USB interface (12) provides a direct-current power supply for the detector circuit and communicates with the outside simultaneously.

The detector array (2) comprises more than or equal to 2 detectors, the detectors are arranged on a substrate in parallel, the position of each detector on the substrate and the angle between a ray receiving window (16) and a radioactive source output port can be adjusted, a set screw 1 (17) is installed on a horizontal sliding block (15), the set screw 1 (17) is loosened, and the detectors can integrally and transversely translate. The annular sliding block (13) is provided with a set screw 2 (14), a group of set screws 2 (14) are loosened, and the detector round tube can rotate.

The signal processing cabinet provides power for each detector, and converts the USB communication into a network interface in a centralized manner for communicating with the industrial personal computer.

The method for calculating average ash content is characterized by that it adopts n detectors, n is greater than or equal to 2, and the ash content calculated by every detector is H₁,H₂，……，H_nAverage ash H = H₁*A₁/100+ H₂*A₂/100+ ……+H_n*A_n/100, wherein A₁,A₂, ……A_nIs the ratio coefficient of each detector gray value obtained by calibration experiment.

The invention has the beneficial effects that: the detector array is used, the angle between the position and the ray receiving window and the radioactive source of each detector can be adjusted, the ray intensity of each detector is maximized, the transmitted rays of the coal samples at different positions on the belt are received through the detectors, ash content of the coal samples at different positions is calculated, the average ash content on the belt is obtained through weighting calculation, random errors and the influence of the belt on ash content measurement are reduced, and ash content measurement is more accurate.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of the components of the detector of the present invention;

FIG. 3 is a schematic view of the detector mounting structure of the present invention.

In the figure: 1. the device comprises a radioactive source, 2, a detector array, 3, a measuring device, 4, a signal processing cabinet, 5, a detector shell, 6, a crystal, 7, a photomultiplier, 8, an energy spectrum acquisition circuit, 9, a high-voltage circuit, 10, a pre-amplification circuit, 11, a high-speed ADC (analog to digital converter) conversion circuit and controller circuit, 12, a USB (universal serial bus) interface, 13, an annular sliding block, 14, a

set screw

2, 15, a horizontal sliding block, 16, a ray receiving window, 17 and a set screw 1.

Detailed Description

The present invention will be further described with reference to the following detailed description and the accompanying drawings, which are only a part of the embodiments of the present invention, but not all of them. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of the present invention.

As shown in figure 1, the analyzer comprises a radioactive source (1), a detector array (2), a measuring device (3) and a signal processing cabinet (4); a radioactive source is placed at the center above the belt, and the distance from the radioactive source to the belt is adjustable; and arranging a detector array below the belt, and measuring ash content on a plurality of position points of the material on the cross section of the belt.

The detector is a NaI detector with the diameter of 2 inches, and comprises a crystal (6), a photomultiplier (7), an energy spectrum acquisition circuit (8) and a detector shell (5). The energy spectrum acquisition circuit comprises a high-voltage circuit (9), a pre-amplification circuit (10), a high-speed ADC (analog-to-digital converter) circuit and a controller circuit (11), all the circuits are fixed on a tube seat of a photomultiplier and used for converting analog signals output by the photomultiplier into digital signals, the whole detector is provided with a USB (universal serial bus) interface (12), and the USB interface (12) provides a 5V direct-current power supply for the detector circuit and communicates with the outside.

The detector array comprises 8 same NaI detectors, all the detectors are installed on a substrate, the shape of the substrate is equivalent to that of a belt, the position of each detector on the substrate and the angle between a ray receiving window (16) and a radioactive source output port can be adjusted, a set screw 1 (17) is installed on a horizontal sliding block (15), the set screw 1 (17) is loosened, and the detectors can integrally transversely translate. The annular sliding block (13) is provided with a set screw 2 (14), a group of set screws 2 (14) are loosened, and the detector round tube can rotate. And when the ray counting rate of the detector reaches the maximum, the position and the angle of the detector can be fixed.

The USB data cable of each detector is connected into the signal processing cabinet, the converter of the USB interface to the network interface is used for carrying out communication interface conversion in the signal processing cabinet, and meanwhile, the converter also provides a 5V direct current power supply for the detectors.

In this embodiment, 8 detectors are used, and 8 instantaneous ash values can be calculated simultaneously, assuming that the instantaneous ash value of each detector is H₁，H₂，H₃，H₄，H₅，H₆，H₇，H₈Average ash H = H₁*A₁/100+ H₂*A₂/100+ H₃*A₃/100+ H₄*A₄/100+ H₅*A₅/100+ H₆*A₆/100+ H₇*A₇/100+H₈*A₈/100, wherein A₁，A₂，A₃，A₄，A₅，A₆，A₇，A₈Is the ratio coefficient of the gray values of each detector obtained by calibration experiments, and the ratio of the instantaneous gray values of the detectors close to the central position of the belt is usually higher.

Claims

1. The utility model provides an online ash content appearance of many detectors formula which characterized in that: comprises a radioactive source (1), a detector array (2), a signal processing cabinet (3) and a measuring device (4); a radioactive source (1) is placed in the center above the belt, and the distance from the radioactive source (1) to the belt is adjustable; and arranging a detector array (2) below the belt, measuring the ash content on a plurality of position points of the material on the cross section of the belt, and calculating the average ash content in any time period.

2. The multi-detector online ash analyzer of claim 1, wherein: the method for calculating the instantaneous ash content assumes that n detectors are provided, n is more than or equal to 2, and the instantaneous ash content calculated by each detector is H₁,H₂，……，H_nAnalyzer instantaneous ash H = H₁*A₁/100+ H₂*A₂/100+ ……+H_n*A_n/100, wherein A₁,A₂, ……A_nThe ratio coefficient of the instantaneous ash content of each detector obtained by a calibration experiment is shown.

3. The multi-detector online ash analyzer of claim 1, wherein: the detector array (2) comprises more than or equal to 2 detectors, and the detectors are arranged on a substrate in parallel; each detector can be adjusted to the position on the substrate and the angle between the ray receiving window (16) and the output port of the radioactive source, a set screw 1 (17) is arranged on the horizontal sliding block (15), the set screw 1 (17) is loosened, and the detector can be wholly transversely translated; the annular sliding block (13) is provided with a set screw 2 (14), a group of set screws 2 (14) are loosened, and the detector round tube can rotate.

4. The multi-detector online ash analyzer of claim 1, wherein: the detector is a NaI detector, and comprises a crystal (6), a photomultiplier (7), an energy spectrum acquisition circuit (8) and a detector shell (5).

5. The multi-detector online ash analyzer of claim 4, wherein: the energy spectrum acquisition circuit comprises a high-voltage circuit (9), a pre-amplification circuit (10), a high-speed ADC (analog-to-digital converter) circuit and a controller circuit (11), all the circuits are fixed on a tube seat of the photomultiplier and used for converting analog signals output by the photomultiplier (7) into digital signals, the whole detector is provided with a USB (universal serial bus) interface (12), and the USB interface (12) provides a direct-current power supply for the detector circuit and communicates with the outside.

6. The multi-detector online ash analyzer of claim 1, wherein: the signal processing cabinet provides power for each detector and converts the USB communication into a network interface in a centralized manner.