JPS59192966A - Speed measuring device for granule - Google Patents

Abstract

PURPOSE:To prevent the photodetection of reflected light from a transparent member and improve measurement precision by slanting the end surface of an optical fiber for illumination and photodetection which measure a granule speed optically to axial center. CONSTITUTION:Front end of the illumination optical fiber 1 and photodetection fibers 2 and 3 for photodetecting reflected light from granules in a solid-vapor mixed phase flow F are slanted to the axial center. Those optical fibers are provided to a protection cylinder 5 which measures the granule speed of the mixed phase flow F optically. Therefore, illumination light is incident to the surface of the transparent member of the cylinder 5 not at right angles, and the photodetection of the reflected light from the member 6 by the fibers 2 and 3 is prevented to improve the S/N, thereby improving the measurement precision of the granule speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for measuring the velocity of powder or granular material in a solid-gas multiphase flow in a tomato plant or the like.

FIG. 1 shows an outline of a conventionally used device. 01 is an optical fiber for illumination, and the illumination light A generated by the laser emitter 010 connected to the rear end is connected to the tip 01.
Irradiation is directed from A toward the solid-gas mixed phase flow F. 02 and 0
Reference numeral 3 denotes a light-receiving optical fiber arranged in parallel with the illumination optical fiber 01 in between, which receives the reflected light B from the solid-gas mixed phase flow F. These optical fibers 01, 02, 03
The tip portion of is supported in a line by the support portion 04,
It is housed in a protective tube 05. Protective tube 05 has tip 05
It is depicted as an open double cylinder A, and by introducing and flowing cooling water into the gap, the optical fiber 01 etc. can be protected from external heat. 06 is a flat transparent member,
This is to close the opening 05A at the tip of the protection tube 05. The tip of these optical fibers O1, the protective tube 05. The transparent member 06 constitutes the probe of the device. When measuring words, the axis of the illumination optical fiber 01 is made to intersect with the flow of the solid-gas multiphase flow F, and the light-receiving optical fiber 02 is
・Position the probes so that the probes 03 are offset in the flow direction.

07 and 08 are photoelectric converters, each with optical fiber 02 for light reception.
- It is attached to the rear end of the 03 and generates a voltage according to the intensity of the received reflected light B. A cross-correlator 09 calculates the cross-correlation coefficients of the output voltage signals of the photoelectric converters 07 and 08, and outputs and displays the time delay amount tlp at which the coefficient becomes the maximum.

Now, 1■ to the illumination light generated by the laser generator 010.
(+, Transmitted within Meimei optical fiber 01, its tip 01
Irradiate from Δ. The illumination light A is transmitted through the transparent member 06 and irradiated into the solid-gas multiphase flow F, and is scattered by hitting the group of ladle containing the ladle. Of the scattered illumination light, the so-called reflected light B that returns to the transparent member 06 passes through the transparent member 06 again and reaches the light receiving optical fibers 02 and 03. Optical fiber for light reception 02・
The light incident on 03 is transmitted to each photoelectric converter 0
At 7.08, it is converted into a voltage according to the light intensity. The cross-correlator 09 receives the outputs of the photoelectric converters 07 and 08 and outputs a time delay amount p, which is determined as follows.

X (L): Output voltage signal Y (L) of photoelectric converter 07
): When defined as the output voltage signal of photoelectric converter 08,
The cross-correlation coefficient Rχy(1') is Rxy(t') -
Calculated as Cxy(t')/f77. It is sufficient to find the value tlp of the time delay amount [□] at which this cross-correlation coefficient Rxy (L') is maximum. In other words, the receiving optical fiber 0
Since the light manually applied to 2.03 changes due to the movement of the particle group, this value L'p divided by the distance 1 between the two becomes the speed of the granular material.

Although it is possible to determine the velocity of the powder in the solid-gas mixed phase flow F in this way, the accuracy was not sufficient with the apparatus shown in FIG. After all, the optical fiber for light reception 07/08
The incident light includes not only reflected light B from the particle group but also reflected light B' reflected inside the transparent member o6. Comparing these reflected lights B and B', the reflected light Bl from the transparent member 06 is stronger. Therefore, the signal due to the reflected light 13 becomes a signal with a poor S/N ratio, and no outstanding peak appears in the phase IJ-correlation coefficient 17xy(t'), and the +? This is because the degree of l'6111i'i is reduced.

The present invention provides an illumination optical fiber that irradiates illumination light into a group of particles in a solid-gas multiphase flow in a direction that intersects the flow J;
The above illumination optical fiber is arranged parallel to the illumination optical fiber fj and separated from it in the force direction of the flow t1. a means for measuring the intensity of light received by the light-receiving optical fiber, a protective tube having an open end that surrounds the distal end portions of the illumination optical fiber and the light-receiving optical fiber, and protecting the illumination optical fiber and the light-receiving optical fiber; In a powder velocity measuring device comprising a transparent member that closes the tip opening of a cylinder, the tip surfaces of the illumination optical fiber and the light receiving optical fiber are oblique with respect to their axes, so the transparent member The light reflected by the powder will not enter the light-receiving optical fiber, and the accuracy of determining the powder velocity will be improved.

Hereinafter, the present invention will be described with reference to an apparatus according to an embodiment shown in FIG.
The structure and function are the same as those of the parts 04 to 010 in the figure, so the explanation will be omitted.

2 is an illumination optical fiber, and 2 and 3 are light receiving optical fibers.The light receiving optical fibers 2 and 3 are flattened into 11 pieces so as to sandwich the illuminating optical fiber, and can be fixed with a supporting part. Tip surfaces IA and 2A of these optical fibers 1, 2, and 3
-3A is formed along one plane oblique to its axis.

Note that the tip portions of these optical fibers 1 and the like are inserted into a protective tube 5 having a transparent layer 6 to form a probe, which is the same as O in FIG.

In the apparatus constructed in this manner, illumination light A generated by the laser generator 10 is irradiated toward the solid-gas multiphase flow F from the tip surface 1A of the illumination optical fiber 1. At this time, since the distal end surface IA of the irradiation optical fiber 1 is formed in a planar shape oblique to its axis, the illumination light A is irradiated with a deviation from the axis (downward in the figure). become. Therefore, the reflected light B" partially reflected by the transparent member 6 is transmitted to the light receiving optical fiber 2.
・It will be reflected in a direction that is not incident on 3. On the other hand, reflected light B generated when the illumination light that has passed through the transparent layer 6 hits the particle group passes through the transparent layer 6 again and enters the light-receiving optical fibers 2 and 3.

Note that the method of measuring the velocity of the powder from the intensity of the reflected light B incident on the light-receiving optical fibers 2 and 3 is performed in the same manner as in the apparatus shown in FIG. The reflected light used in this case is
Only the reflected light F from the particle group improves the S/N ratio of the signal.

As described above, in the device according to one embodiment of the present invention, the S/N ratio of the speech signal can be improved by forming the tip end face IA of the optical fiber 1 etc. obliquely with respect to its axis. did it. Therefore, the accuracy of the powder velocity measurements will also be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram of a conventional device, and FIG. 2 is a diagram of a device showing an embodiment of the present invention. 1: Optical fiber for illumination, 2.3゛ Optical fiber for light reception, I
A・2A・3A・Tip surface, 5: Protective part, 6: Transparent member,
7/8: Photoelectric converter, 9. Cross-correlator, 10 laser generator

Claims (1)

[Claims] An illumination optical fiber that irradiates illumination light into a group of particles in a solid-gas multiphase flow in a direction intersecting the flow; and an illumination optical fiber that is arranged parallel to the illumination optical fiber and separated from it in the flow direction. a light-receiving optical fiber that receives the reflected light from the particle group of the illuminated light at rt-+; a means for measuring the respective intensity of the light received by the light-receiving optical fiber; and the illumination optical fiber and the light-receiving optical fiber. In the speed measuring device for powder and granular material, which comprises a protective tube with an open tip that surrounds the tip of the fiber, and a transparent member that closes the opening at the tip of the protective tube, the illumination optical fiber and the light receiving optical fiber are connected to each other. A speed measuring device for powder and granular materials, characterized by having a tip end face diagonal to its axis.