JPS6047530B2 - flow measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the flow rate of dripping metal or glass melt fluid.

This type of fluid appears continuous to the human eye, but when photographed using a high-speed camera, it is known that it separates into individual pieces and falls, or drops. ing.

FIG. 1 is a state diagram showing this state, in which the fluid becomes approximately spherical particles ae and drips in the direction of the arrow in the figure.
By the way, since the metal or glass molten fluid that drips in this way is generally at a high temperature, it is extremely difficult to measure the flow rate, and it is difficult to measure the flow rate, and it is necessary to collect the fluid for a certain period of time using a ladle or the like, for example, by manual labor. In particular, they relied on primitive techniques to measure the flow rate.

However, this method has disadvantages in that it is extremely dangerous because it requires close contact with a high-temperature fluid and the measurement accuracy is not sufficient. The present invention has been made in view of these points, and an object of the present invention is to measure this type of fluid flow rate with high precision without requiring manual labor. The features of this invention are:
The trick is to measure the flow rate by regarding the dropping fluid particles as spheres and finding the volume from their cross-sectional area.

That is, the flow rate is measured by observing a dripping fluid particle from the side, determining its cross-sectional area S, converting the cross-sectional area S into a volume V, and multiplying the converted value by a predetermined constant. In this case, when calculating the cross-sectional area of a fluid particle, an industrial television camera with a shutter (hereinafter referred to as
An image of the dropping fluid particles is captured as a still image using an ITV camera or a video sensor, and the area S is calculated by appropriately processing the image signal. In other words, if the area S of the fluid particle is known, the volume V of the fluid particle, which is considered to be a sphere, can be calculated by simple conversion, that is, V■-5/5=
3,/π can be easily obtained by converting -5/S.

Then, the value obtained by integrating the volumes of each fluid particle in one screen is
The flow rate per unit time is determined by multiplying by a conversion coefficient determined separately. Note that this conversion factor can be determined as appropriate through experiments and the like. Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the invention.

The same figure shows an ITV camera unit IT that images dripping fluid particles, and an image signal obtained from the unit IT that is converted into a binary signal by comparing it with a predetermined level signal, and the particles in one screen are an image processing/judgment unit VI that calculates the number n and the area S of each particle; and the image processing/judgment unit VI
an arithmetic processing unit P that converts each area calculated in step 1 into a volume, performs an operation of integrating the volume of each particle per screen on multiple screens, and calculates the arithmetic mean; and the arithmetic processing unit. A data recording unit RE and the like are shown for recording the processing results of the DP. The ITV camera unit IT is equipped with a video sensor 1 with a built-in mechanical shutter for capturing still images of dripping fluid particles. For example, the video sensor 1 can capture images four times per second at a shutter speed of about 11,100 to 2. Let's do it.

The shutter speed is appropriately determined depending on the speed required to convert the fluid particle image into a still image, and the number of times of photographing is appropriately determined depending on the processing speed of the calculation processing MDP. Image processing/determination section V
The area calculation unit 2 of I converts the image signal converted into a still image by the ITV camera 1 into a binary pixel signal of black and white, for example, and counts the number of pixels represented by black to calculate the area of the fluid. Calculate the area S of the particle. The calculated area data is
Operate switch SWl as appropriate. It is stored in a storage device 3 such as a hard disk. The image processing/determination section VI also has a function of counting the number of fluid particles in one screen of a still image, the width of each particle, the interval between each particle, and the like. Therefore, as shown in FIG. 1, for example, particles a1 hanging at the edge of the screen, particles C smaller than a certain size, or particles d'' falling out of the dropping line are excluded from measurement, and two It is possible to easily make a selection such as assuming that the particle b in which the particles overlap is normal and adopting it.The volume conversion unit 4 of the arithmetic processing unit DP performs the calculation using the image processing/judgment unit VI. In order to convert the area value S of each fluid particle into a volume value, calculate the value of S!
The screen summation unit 5 sums up the SJ'S values of each fluid particle and calculates 1.
The total value ΣSiJ drunkenness for the screen is calculated. Furthermore, the number of screens N (N is a positive integer) preset in the N screen totaling section 6
The average value ΣSJ100 is calculated and temporarily stored in a memory (not shown). Stored average value ΣSJ′S
When a plurality of pieces of data are collectively reprinted by the printer 7 at regular time intervals), they are both converted into analog signals by the digital/analog converter 6' and recorded by the ink recording unit 8. The area S data stored on the floppy disk 3 is converted into a volume value by the volume conversion unit 4, and printed out from the printer 7 by operating switch SW2 during a period when no measurement operation is being performed. You can let it go out. In this way, the average volume integrated value per screen obtained in the N screen totaling section 6 is
For example, the fluid flow rate per predetermined time can be determined by multiplying by a predetermined constant found through experiments.Although not shown in FIG. It is assumed that the computer has an appropriate storage device for storing data to be processed or data resulting from processing.

Here, if a still image as shown in FIG. 1 is obtained by, for example, the ITV camera 1, the area calculation unit 2 performs a predetermined process to calculate the fluid particles B,
Calculate each area of d and e.

As mentioned above, particle a hangs over the edge of the screen, particle c is too small, and particle d'' is out of line, so they are excluded from the measurement target.Each fluid Letting the areas of the particles be Sll, Sl2, and Sl3, respectively, the volume conversion unit 4 converts these into volumes Zheng,,V[,S,2!?, and Sl3V?, respectively, and the one-screen summation unit 5 calculates The total value of these, ie, S1, J faction+S, 2!?;+Sl3JS;- is calculated.

The N screen totaling unit 6 performs this operation for N (N is a positive integer and is arbitrarily set) screens, and calculates the total value,
That is, calculate SNll110;).

Since this value is proportional to the average volume integrated value in one screen, the flow rate per unit time can be determined by multiplying this value by a predetermined proportionality constant. Note that the flow rate that should be measured generally changes over time, but depending on the relationship such as the dropping speed of fluid particles, the imaging time, and the imaging time interval, it may be possible to measure only the peaks where the flow rate is always high or the flow rate is low. There is a possibility that there is no point in extracting only the valley portion where , and taking the average, so in such a case, it is desirable to take a moving average instead of the arithmetic average described above.

Further, it is also possible to control the flow rate by feeding back a signal layer obtained by converting the output from the arithmetic processing section into an analog signal by the digital/analog conversion section 6''.

As described above, according to the present invention, the dripping fluid particles are photographed with a video sensor to form a still image, and the flow rate of the fluid is measured by appropriately digitally processing the still image signal. Therefore, measurements can be carried out in a non-contact manner and with high precision without requiring any manual labor.

[Brief explanation of the drawing]

FIG. 1 is a state diagram for explaining the state of dripping fluid, and FIG. 2 is a block diagram showing an embodiment of the present invention. Code explanation, IT...ITV camera unit, ■
I... Image processing/judgment section, DP... Calculation processing section, RE... Data recording section, SWl, S
W2...Switch, 1...ITV camera, 2...Area calculation section, 3...Storage device/device, 4...Volume conversion section , 5...1 screen total section, 61...N screen total section, 6''...digital/analog conversion section, 7...printer, 8...
...Recorder.

Claims (1)

[Claims] 1. A television camera that captures images of continuously dripping fluid particles at a predetermined speed to capture them as still images, and means for calculating the area of each fluid particle as an image from the image signal obtained by the camera; means for calculating the volume of each particle from the calculated area, and calculating the average by performing an operation of integrating the volume of each particle per screen for a plurality of screens, and calculating the average value. A flow rate measuring device, characterized in that the flow rate of the fluid is measured by multiplying by a predetermined conversion coefficient.