JPH0820325B2 - Slit nozzle jet pressure measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an apparatus for measuring the ejection pressure of a fluid ejected from a nozzle having a slit-shaped opening, and particularly to continuous hot dip galvanization of strip steel sheets. Alternatively, the present invention relates to a jet pressure measuring device for a slit nozzle that can be advantageously used for performance verification of a wiping nozzle used in a continuous chemical conversion treatment facility or performance verification of a nozzle for continuous cooling of a steel sheet.
It is well known that the direction of the fluid ejected from the nozzle may be horizontal, vertical in the vertical direction, or in the middle thereof depending on the traveling direction of the steel strip to be processed. .

<Prior Art> Conventionally, in the case of measuring the ejection pressure of a fluid ejected from a nozzle having a slit-shaped opening, for example, a case of a hot dip galvanizing wiping nozzle in which a steel strip moves in a vertical direction will be described. A probe such as a pitot tube is loaded on the traveling carriage mechanism, the vertical positional relationship between the probe and the nozzle is initially set manually, and then the carriage is moved along the slit in that state to eject the nozzle in the longitudinal direction. I was measuring pressure.

<Problems to be Solved by the Invention> However, since the jet flow from the opening of the slit-shaped nozzle has an extremely thin thickness of 0.5 to 3 mm, the positional relationship between the nozzle opening and the probe of the measuring device is accurately maintained. If you don't, you can't measure correctly. Further, in the above-mentioned conventional technique, since the position is manually set, it is complicated and difficult to completely match the vertical relative positions of the opening and the probe over the entire length of the nozzle. It was not easy to accurately measure the ejection pressure in the case of a nozzle in which the gap between the outlets is not constant or in which the maximum pressure point is not on a straight line.

It is an object of the present invention to provide a slit nozzle jet pressure measuring device that solves the above-described problems of the prior art.

<Means for Solving the Problems> The present invention is a device for measuring the ejection pressure of a fluid ejected from a nozzle having a slit-shaped opening, and a probe for receiving the pressure of the ejection flow from the nozzle, A jet-orthogonal-direction swing mechanism for swinging the probe in a direction orthogonal to the jet flow with a predetermined stroke, and a probe and a jet-orthogonal-direction swing mechanism for loading and moving the probe and the jet-flow-direction swing mechanism at a predetermined speed along the nozzle A traveling carriage mechanism, a transducer for converting a pressure value received by the probe into an electric signal, and a timing at which the pressure starts to decrease due to the swing of the probe by differentiating an output signal value of the transducer is obtained. And a controller for controlling the jet orthogonal direction swing mechanism so as to reverse the swing direction of the probe at that timing; An output device that receives an output signal of a transducer and outputs the output signal as a measured value of the ejection pressure from the nozzle, and a slit nozzle ejection pressure measurement device.

Further, the present invention relates to a device for measuring a jet pressure of a fluid jetted from a nozzle having a slit-shaped opening, and a probe for receiving the pressure of the jet flow from the nozzle, and the probe with a predetermined stroke. A jet orthogonal swing mechanism for swinging in a direction orthogonal to the probe, a traveling carriage mechanism for loading the probe and the jet orthogonal swing mechanism and moving the probe along the nozzle at a predetermined speed, and the probe. A transducer for converting the pressure value received by the device into an electric signal, and the timing at which the pressure starts to decrease due to the oscillation of the probe by differentiating the output signal value of the transducer, and the probe is obtained at that timing. A controller for controlling the jet orthogonal direction rocking mechanism so as to reverse the rocking direction of, and each time the probe moves up and down, A peak value hold circuit that holds and updates the maximum value of the output signal of the transducer detected between, and an output device that outputs the output from the peak value hold circuit as a measured value of the ejection pressure from the nozzle, It is a slit nozzle ejection pressure measuring device characterized by comprising.

<Action> By automatically and repeatedly swinging the probe directed to the jet flow from the slit nozzle by the jet orthogonal swing mechanism, the pressure receiving port of the probe changes its pressure according to the swing motion. Receive This pressure is introduced into the transducer via the pressure guiding tube, where it is converted into an electrical signal. The electric signal corresponding to the pressure is output from the output device as a signal of the strength of the jet flow, that is, a measured value.

This output value may be used by directly outputting it to an indicator or recorder, but if it is practically inconvenient because it changes greatly due to the pulsation caused by the swing of the probe, a peak value hold circuit It is better to extract only the maximum value with.

It is also possible to differentiate the electric signal corresponding to the pressure by a differentiating circuit in the control device to determine whether the pressure is increasing or decreasing. That is, if the differential value is positive, it is determined that the pressure receiving port of the probe is approaching the maximum pressure point of the jet flow from the nozzle, and if the differential value is negative, it is moving away. At the moment when this differential value changed from positive to negative, the output of the flip-flop circuit in the control device was reversed, and a command to switch the moving direction of the jet orthogonal direction rocking mechanism was issued, so it tried to move away from the maximum pressure point. The probe can be pulled back again. In this way, the probe can always be held near the maximum pressure point, repeatedly crossing it with a slight amplitude.
Therefore, the probe can always capture the maximum pressure point of the jet flow regardless of the height of the jet flow within the swingable range of the probe in the initial setting stage.
It becomes possible to detect the pressure at that point.

The probe and the jet orthogonal swinging mechanism are mounted on the traveling carriage mechanism and moved along the nozzle, so that measured values can be obtained over the entire length of the nozzle. The measurement value obtained in this way was detected while automatically searching for the maximum pressure point in the swing direction of the jet flow from the nozzle, so that the setting error of the swing direction position between the probe and the nozzle is not added. Extremely accurate.

<Example> An example of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an outline of the device of the present invention, and FIG. 2 is a sectional view taken along the line BB of FIG.

The probe 2 such as a Pitot tube is set so as to be located at a position substantially opposite to the opening of the slit-shaped nozzle. The probe 2 is swingably connected to a lead-out tube 4 that transmits pressure to the pressure sensor 3. The rear end of the probe 2 is fixed to the bracket 5-4, and the bracket 5
-4 is mounted on the column 6 so as to be rotatable about an axis 5-5. A driving wheel 5-3 is rotatably provided at the other end of the bracket 5-4. Reference numeral 5-1 is a stepping motor for swinging the probe, and an eccentric cam 5-2 is attached to the end of the rotation shaft of the stepping motor 5-1. Therefore, the stepping motor 5-1
The rotation of the probe 2 allows the probe 2 to swing up and down in front of the opening of the nozzle 1 about the shaft 5-5 as a fulcrum.

The jet flow orthogonal direction swing mechanism 5 and the pressure sensor 3 are fixed on the traveling carriage 7-1. This traveling trolley-1
Is allowed to travel on the track 7-6 laid on the track support member 7-7 in the slit direction of the nozzle 1 by the traveling motor 7-2 and the wheel 7-5 via the gear 7-3. It In this way, the traveling carriage mechanism 7 is configured.

The pressure detected by the pressure sensor 3 connected to the probe 2 via the pressure guiding tube 4 is converted into an electric signal by the transducer incorporated in the pressure sensor 3, and the pressure value is output by the output device as shown in FIG. Is output as.

By the way, in this example, the transducer is provided on the traveling carriage mechanism 7, but it can be placed outside the carriage by extending the pressure guiding tube 4.

The pressure value is the differential circuit shown in FIG.
It is output after being processed by the peak value hold circuit shown in the figure or a controller provided with both shown in FIG.

The peak value hold circuit holds the maximum value of the pressure value for each cycle of the vertical swing of the probe 2, and outputs it as the pressure measurement value until the timing of holding the maximum value of the next cycle. to continue.

On the other hand, in the differentiating circuit, it is determined by differentiating the signal whether the pressure value is increasing or decreasing. That is, if there is an increasing tendency, for example, a positive signal is output, and conversely, if there is a decreasing tendency, a negative signal is output.

Further, the output of the differentiating circuit is input to the flip-flop circuit, where it outputs a signal that is inverted between positive and negative at each instant when the output of the differentiating circuit becomes negative. The output of the flip-flop circuit is the stepping motor 5-1 of the jet orthogonal swing mechanism 5.
When the output is positive, the switch is switched to the side in which the motor rotates in the forward direction, and when the output is negative, it is switched to the side in which the motor is rotated in the reverse direction. The rotation speed of the stepping motor 5-1, that is, the vertical swinging speed of the probe 2 is controlled by a motor drive circuit.

<Effects of the Invention> As described above, according to the present invention, setting of the measuring device is extremely easy, there is no setting error, and accurate measurement can be performed quickly over the entire nozzle length. The measuring device is compact and easy to carry.

Moreover, even if the gap between the nozzle openings is not constant in the longitudinal direction, the maximum pressure point can always be automatically searched for and measured accurately. In addition, even if the gap between the nozzle openings is not a straight line in the longitudinal direction, the maximum pressure point can always be searched automatically for accurate measurement.

[Brief description of drawings]

FIG. 1 is a side view showing the structure of the device of the present invention, and FIG.
3 to 6 are circuit diagrams showing an embodiment of the pressure value signal processing of the present invention. 1 ... Nozzle, 2 ... Probe, 3 ... Pressure sensor, 4
...... Pressure guiding tube, 5 ...... Jet oscillating direction swing mechanism, 5
-1 ... Stepping motor, 5-2 ... Eccentric cam, 5
-3: driving wheel, 5-4: bracket, 5-5: shaft,
6 ... Prop, 7 ... Traveling carriage mechanism, 7-1 ... Traveling carriage, 7-2 ... Traveling motor, 7-3 ... Gear, 7-5
...... Wheels, 7-6 ... Tracks, 7-7 ... Track support members.

Claims (2)

[Claims] 1. A device for measuring a jet pressure of a fluid jetted from a nozzle having a slit-shaped opening, and a probe for receiving the pressure of the jet stream from the nozzle, and the probe for jetting the jet stream at a predetermined stroke. A jet-orthogonal-direction swing mechanism for swinging in the orthogonal direction, a traveling carriage mechanism for loading the probe and the jet-orthogonal-direction swing mechanism and moving the probe and the jet-flow-direction swing mechanism at a predetermined speed, and the probe. A transducer for converting the received pressure value into an electric signal and a timing at which the pressure starts to decrease due to the oscillation of the probe by differentiating the output signal value of the transducer are obtained, and at that timing of the probe It receives an output signal of the transducer and a control device that controls the jet flow orthogonal direction swing mechanism so as to reverse the swing direction. A slit nozzle jet pressure measuring device, comprising: an output device that outputs this as a measured value of the jet pressure from the nozzle. 2. An apparatus for measuring the jet pressure of a fluid jetted from a nozzle having a slit-shaped opening, wherein a probe for receiving the pressure of the jet flow from the nozzle and the probe with a predetermined stroke A jet-orthogonal-direction swing mechanism for swinging in the orthogonal direction, a traveling carriage mechanism for loading the probe and the jet-orthogonal-direction swing mechanism and moving the probe and the jet-flow-direction swing mechanism at a predetermined speed, and the probe. A transducer for converting the received pressure value into an electric signal and a timing at which the pressure starts to decrease due to the oscillation of the probe by differentiating the output signal value of the transducer are obtained, and at that timing of the probe A control device for controlling the jet-orthogonal-direction swinging mechanism so as to reverse the swinging direction, and a controller for each time the probe moves up and down. A peak value hold circuit for holding and updating the maximum value of the output signal of the transducer detected between the output values, and an output device for outputting the output from the peak value hold circuit as a measurement value of the ejection pressure from the nozzle. A slit nozzle jet pressure measuring device characterized in that