JPS623729Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a particle velocity measuring device for measuring particle velocity in a solid-gas mixed phase flow in, for example, a coal gasifier, a coal mill, a cement plant, etc.

This type of conventional particle velocity measuring device has a first
It is constructed as shown in Figures a and b. In Figures 1a and b, 01 is the particle group to be measured, 0
Reference numeral 2 denotes an optical fiber probe to which an illumination optical fiber and a light receiving optical fiber, which will be described later, are fixed. 0
3,04,05,06,07,08,09,01
0 are first, second, third, fourth, fifth, sixth, seventh, and eighth illumination optical fibers that receive laser light from a laser device to be described later to illuminate the granular material. .
011,012,013,014,015,01
6,017,018 are first, second, third, fourth, fifth, sixth, seventh and eighth optical fibers for receiving light, which receive reflected light from powder and granular material, and The light is transmitted to the light receiving element. A laser device 019 generates laser light. Reference numerals 020 and 021 denote first and second light receiving elements, which generate voltages proportional to the intensity of reflected light, and input the output voltages to a differential amplifier to be described later. 022 is a differential amplifier that generates a voltage proportional to the difference between two input voltage signals. The output voltage is then input to a frequency analyzer, which will be described later. 02
3 analyzes the frequency spectrum of the input voltage signal using a frequency analyzer and outputs the result.

In the above FIG.
4, 05, 06, 07, 08, 09, and 010 to irradiate the granular material 01 to be measured. A portion of the reflected light from the granular material is transmitted to the first, second, third, fourth, fifth, sixth, seventh, and eighth light-receiving optical fibers 011, 012, 013, 01.
4,015,016,017, and 018. The first, third, fifth, and seventh light receiving optical fibers 011, 013, 015, 017
The reflected light that has been transmitted is incident on the first light receiving element 020. In addition, second, fourth, sixth and eighth light receiving optical fibers 012, 014, 016 and 018
The reflected light that has been transmitted is incident on the second light receiving element 021.

The reflected light incident on the first and second light receiving elements 020 and 021 becomes a voltage signal proportional to the intensity of the light, and is input to the differential amplifier 022. The differential amplifier 022 receives two input voltage signals, that is, the output voltage x ₁ (t) of the first light receiving element 020.
A voltage x(t) proportional to the difference [x ₁ (t) - _{x 2} (t)] between the output voltage x ₂ (t) of the second light receiving element 021 and the output voltage x 2 (t) of the second light receiving element 021 is generated and input to the frequency analyzer 023 . The frequency analyzer 023 analyzes the frequency spectrum of its input signal x(t) and outputs the result.
From the output results, the outstanding peak frequency _p
I understand.

By the way, when the frequency _p is determined, the light receiving optical fiber group 011, 012, 013, 0
Interval d of 14,015,016,017,018
From the relationship _between

Although the conventional particle velocity measuring device described above can measure particle velocity relatively easily, it has the following drawbacks.

FIG. 2 shows the basic structure of the optical fiber probe used in the conventional device shown in FIG. In the figure, the laser light emitted from the illumination optical fiber 03 irradiates the area indicated by the solid arrow. The area where the light-receiving optical fiber 011 receives the reflected light is the area indicated by the dotted arrow. Therefore, the shaded area 02 in the same figure
4, but under the condition that the powder or granule is not present in other parts, the powder or granule to be measured is illuminated by the illumination optical fiber 03, and the reflected light is transmitted to the light receiving optical fiber 011. There is no problem because the light is received by the

However, if there is a high concentration of powder other than the shaded area 024, the laser light from the illumination optical fiber 03 will be suppressed, and the reflected light that should be incident on the light receiving optical fiber 011 will be suppressed. The required powder velocity signal cannot be obtained because of the powder and granule material being washed away.

Therefore, the conventional device has the disadvantage that it cannot be applied to speed measurement of highly concentrated powder and granular materials in performance improvement and development research experiments of coal gasifiers, coal mills, cement plants, etc.

The present invention has been made in view of the above points, and includes at least three large-diameter optical fibers whose tips are inserted at equal intervals into a group of particles in a solid-gas multiphase flow, and the same large-diameter optical fibers. 2 connected to the rear end of the fiber respectively
A set of small-diameter optical fibers, a means for emitting light from one side of the small-diameter optical fibers, and a light-receiving element for receiving the light entering the other side of the small-diameter optical fibers and detecting its intensity, arranged at equal intervals as described above. A differential amplifier that alternately converts the polarity of the large-diameter optical fibers and calculates the difference, a frequency analyzer that analyzes and processes the frequency spectrum obtained by the differential amplifier, and a frequency analyzer that analyzes the frequency spectrum obtained by the differential amplifier. The object of the present invention is to provide a particle velocity measuring device that can reliably measure the velocity of particles even in highly concentrated powder and granular materials, by determining the velocity of particles from the peak value of and the distance between the large-diameter optical fibers. With the goal.

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 3a and 3b, 1 is the granular material to be measured, 2 is an optical fiber probe, and the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, and 8th A single optical fiber is fixed. 3, 4, 5, 6,
7, 8, 9, 10 are the first, second, third, fourth,
With the fifth, sixth, seventh and eighth single optical fibers,
One of its both end faces is inserted into the powder 1, and the other end face is inserted into the 9th and 10th, and 11th and 11th, which will be described later.
12th, 13th and 14th, 15th and 16th, 17th and 18th, 19th
and 20th, 21st and 22nd, and 23rd and 24th single optical fibers. The part inserted into the powder is fixed to the optical fiber probe at a certain interval d'. 11, 13, 15,
17, 19, 21, 23, 25 are the 9th, 11th,
13th, 15th, 17th, 19th, 21st, and 23rd single optical fibers, one of the end surfaces of which are connected to the first, second, third, fourth, fifth, and sixth single fibers, respectively. , seventh and eighth single optical fibers. Further, the other end face is connected to a first light-receiving element described later for the 9th, 13th, 17th, and 21st single optical fibers, and the 11th, 15th, 19th, and 23rd single optical fibers are connected to a first light receiving element described later. is connected to a second light-receiving element, which will be described later. 12, 14, 16, 18, 20,
22, 24, 26 are the 10th, 12th, 14th, 16th,
18th, 20th, 22nd and 24th single optical fiber,
One of the end faces is connected to the first, second, third, fourth, fifth, sixth, seventh and eighth single optical fibers, respectively, and the other end face is connected to the laser device described below. connected. A laser device 27 generates a laser beam. Reference numerals 28 and 29 denote first and second light-receiving elements, each of which generates a voltage proportional to the intensity of incident light, and transmits the output signal to a differential amplifier to be described later. 30 is a differential amplifier that generates a voltage proportional to the difference between two input voltage signals. The output voltage signal is then input to a frequency analyzer, which will be described later. A frequency analyzer 31 analyzes the frequency spectrum of the input voltage signal and outputs the result.

Next, the operation of the above embodiment will be explained.

In FIGS. 3a and 3b, the laser beams generated by the laser device 27 are
18, 20th, 22nd and 24th single optical fiber 12,
14, 16, 18, 20, 22, 24, 26, respectively, the first, second, third, fourth, fifth, sixth,
seventh and eighth single optical fibers 3, 4, 5, 6,
Transmit to 7, 8, 9, 10. Above 1st, 2nd,
The third, fourth, fifth, sixth, seventh, and eighth single optical fibers each irradiate the above-mentioned laser light onto the powder 1 to be measured. The light reflected by the granular material 1 is again transmitted to the first, second, third, fourth, fifth, sixth, seventh and eighth single optical fibers, respectively.
9th, 11th, 13th, 15th, 17th, 19th,
21 and 23rd single optical fiber 11, 13, 15,
It is transmitted to 17, 19, 21, 23, and 25.

The reflected light transmitted through the 9th, 13th, 17th, and 21st optical fiber single wires 11, 15, 19, and 23 enters the first light receiving element 28, and is proportional to the intensity of the incident light. The voltage signal x ₁ (t) is then input to one of the two input sections of the differential amplifier 30 . The reflected light transmitted through the 11th, 15th, 19th, and 23rd optical fiber single wires 13, 17, 21, and 25 enters the second light receiving element 29, and is proportional to the intensity of the incident light. It is converted into a voltage signal x ₂ (t) and input to the other input section of the differential amplifier 30.

_The differential amplifier 30 calculates _the difference [x ₁
(t)−x ₂ (t)] and inputs the signal to the frequency analyzer 31. The frequency analyzer 31 receives its input signal x
The frequency spectrum of (t) is analyzed and the result is output. From the output result, the prominent peak frequency ′ _p can be found. Once this ′ _p is determined, the velocity ν′ of the powder is determined as ν′=2d′′ _p in the same manner as in the conventional method. However, d' is the distance between the first, second, third, fourth, fifth, sixth, seventh, and eighth optical fibers.

By the way, according to the present invention described above, the first, second, third, fourth, fifth, sixth, seventh and eighth single optical fibers inserted into the powder material are as shown in FIG. As shown in Figure 2, since the emission of illumination light A and the reception of reflected light B are performed on the end face of a single optical fiber, there is no possibility that the illumination light or reflected light is suppressed by powder or granules. . Therefore, it can be applied to high concentrations regardless of the concentration of powder and granules, and it is now possible to measure particle velocity in fluidized beds in coal gasifiers, differential coal transport pipes in coal mills, etc., which were previously impossible to measure. , the industrial value of the device of the present invention is extremely large.

[Brief explanation of the drawing]

Figure 1a is a diagram showing the configuration of a conventional particle velocity measuring device, Figure 1b is a view taken along the line X-X in Figure 1a, and Figure 2 shows the basic structure of the optical fiber probe in Figure 1. Figure 3a is a configuration diagram showing an embodiment of the present invention, Figure 3b is a view taken along the line X--X in Figure 3a, and Figure 4 shows the single optical fiber portion in Figure 3. FIG. 1... Powder, 2... Optical fiber probe, 3
~10...first to eighth single optical fibers, 11~
26... 9th to 24th single optical fiber, 27...
Laser device, 28, 29...first and second light receiving elements, 30...differential amplifier, 31...frequency analyzer.

Claims (1)

[Scope of utility model registration request] At least three or more large-diameter optical fibers whose tips are inserted at equal intervals into the particle group of the solid-gas multiphase flow, and a set of two large-diameter optical fibers whose tips are respectively connected to the rear ends of the same large-diameter optical fibers. a small-diameter optical fiber, a means for irradiating light from one side of the small-diameter optical fiber, a light-receiving element that receives the light entering the other side of the small-diameter optical fiber and detects its intensity, and a large-diameter arranged at equal intervals. A differential amplifier that takes the difference by alternately converting the polarity of the optical fiber, a frequency analyzer that analyzes the frequency spectrum obtained by the differential amplifier, and a frequency peak value obtained by the analyzer. A particle velocity measuring device characterized in that the particle velocity is determined from the interval between the large-diameter optical fibers.