JPH01254829A - Slit nozzle blowout pressure measuring instrument - Google Patents

Abstract

PURPOSE:To take a measurement with high accuracy by providing a driving device which moves up and down a probe for receiving a blowout flow from a nozzle by a prescribed stroke and a device which receives the output signal of a transducer and outputs the blowout pressure from the nozzle. CONSTITUTION:The probe (Pitot tube) 2 is positioned opposite the opening part of the slit nozzle 1. This probe 2 is connected in an oscillatory state to a lead pipe tube 4 which transmits the pressure to a pressure sensor 3. Here, the probe 2 can moves up and down around a shaft 5-5 as a fulcrum in front of the opening part of the nozzle 1 by rotating of a step motor. Then those up-down driving mechanism 5 and sensor 3 are fixed on a running carriage 7-1. Then the pressure detected by the sensor 3 connected to the probe 2 through the tube 4 is transduced by the transducer into an electric signal, which is outputted by an output device as a pressure value. Thus, the high-accuracy measurement is performed speedily.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a device for measuring the ejection pressure of a fluid ejected from a nozzle having a slit-shaped opening, and particularly for measuring the ejection pressure of a fluid ejected from a nozzle having a slit-shaped opening.
The present invention relates to a slit nozzle ejection pressure measuring device that can be advantageously used for testing the performance of wiping nozzles in hot-dip galvanizing and continuous chemical conversion treatment equipment, or for testing the performance of nozzles for continuous cooling of steel plates.

<Conventional technology> Conventionally, the probe (pitot tube) was loaded onto a traveling cart mechanism, the vertical positional relationship between the probe and nozzle was manually set, and the cart was moved along the slit in that state. , the ejection pressure in the longitudinal direction of the nozzle was measured.

<Problem to be solved by the invention> The jet flow from the opening of the slit-shaped nozzle has a thickness of 0.65 mm.
Since it is extremely thin at ~3 mm, accurate measurements cannot be made unless the positional relationship between the nozzle opening and the probe of the measuring device is maintained with high accuracy.

However, in the conventional technology, because the position is set manually, it is complicated and difficult to completely adjust the vertical relative position of the opening and the probe over the entire length of the nozzle. In the case of a nozzle in which the gap between the jet ports is not constant, or in the case of a nozzle in which the maximum pressure point is not in a straight line, it is not easy to accurately measure the jet pressure.

<Means for Solving the Problems> The present invention provides a device for measuring the ejection pressure of fluid ejected from a nozzle having a slit-shaped opening, which includes a probe for receiving the pressure of the ejected flow from the nozzle, and the probe. a vertical drive mechanism for moving the probe up and down with a predetermined stroke, a traveling trolley mechanism for loading these and moving them at a predetermined speed along the nozzle, and converting the pressure value received by the probe into an electrical signal. This is a slit nozzle ejection pressure measuring device, which is composed of a transducer for measuring the ejection pressure, and an output 'li M for receiving the output signal of the transducer and outputting it as a measured value of the ejection pressure from the nozzle. Furthermore, by differentiating the output signal value of the transducer, the timing at which the pressure starts to decrease as the probe moves up and down is determined, and the up and down movement is performed so that the direction of the up and down movement of the probe is reversed at that timing. Slit nozzle ejection pressure equipped with a peak value hold circuit that holds and updates the maximum value of the output signal of the transducer detected during this period whenever the control device that controls the drive mechanism and/or the probe moves up and down. It is a measuring device.

<Operation> By automatically repeatedly moving the probe (pitot tube) directed to the jet stream from the slit nozzle up and down using the vertical drive mechanism, the pressure receiving port of the probe receives pressure that changes according to the vertical movement. .

This pressure is guided through a pressure tube to a transducer, where it is converted into an electrical signal.

The electrical signal corresponding to the pressure is output from the output device as a signal of the strength of the jet flow, that is, a measurement value.

Since this output value changes according to the vertical movement of the probe, it is difficult to apply it to an indicator or recorder as it is because of pulsation, which is practically inconvenient. Therefore, a peak value hold circuit is used to It is desirable to extract only the maximum value between them and then output it.

Further, the electric signal corresponding to the pressure is differentiated by a differentiation circuit within the controller, and it is also possible 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 stream from the nozzle, and if the differential value is negative, it is determined that it is moving away.

At the moment this differential value changes from positive to negative, the output of the flip-flop circuit in the controller is reversed and a command is issued to switch the direction of movement of the vertical drive mechanism, so the probe that was moving away from the maximum pressure point is pulled back again. .

In this way, the probe is always held close to the point of maximum pressure and repeatedly traversed over it with small amplitudes.

Therefore, no matter what height the jet stream is located within the vertical movement range of the probe during the initial setting stage, the probe can always capture the maximum pressure point of the jet stream.
It becomes possible to detect the pressure at that point.

The probe and the vertical drive mechanism are mounted on a traveling carriage mechanism and are moved along the nozzle, so that measurement values can be obtained over the entire length of the nozzle.

The measurement values obtained in this way are detected while automatically searching for the maximum pressure point in the vertical direction of the jet flow from the nozzle, and the setting error of the vertical position of the probe and nozzle is added. The accuracy is extremely high because there is no

<Example> Examples will be described based on the drawings.

FIG. 1 is an elevational view of the apparatus of the present invention, and FIG. 2 is a BB view of FIG. 1.

A pitot tube or probe 2 is set to be positioned substantially opposite the opening of the slit nozzle 1. The probe 2 is swingably connected to a pressure guiding tube 4 that transmits pressure to a pressure sensor 3. The rear end of the probe 2 is fixed to a bracket 5-4, which is rotatably attached to the support column 6 about a shaft 5-5. Further, a driving wheel 5-3 is rotatably provided at the other end of the bracket. 5-1 is a stepping motor for probe seeding, and the rotating shaft of this motor is equipped with an eccentric cam 5-2 at its end. Therefore, by rotation of the stepping motor 5-1, the probe 2 can be moved up and down in front of the opening of the slit nozzle l, using the shaft 5-5 as a fulcrum.

These vertical drive mechanism 5 and pressure sensor 3 are connected to the traveling trolley 7.
Fixed on -1. 7-2 is a running motor, which runs on a track 7-6 installed in the slit direction of the slit nozzle 1 by wheels 7-5 via gears 7-3. Note that 7-7 is a track support member, and the traveling bogie mechanism 7 is constructed from these members. The pressure detected by a pressure sensor 3 connected to the probe 2 via a pressure guiding tube 4 is converted into an electrical signal by a transducer and output as a pressure value by an output device as shown in FIG.

Incidentally, in this example, the transducer is provided on the traveling truck mechanism, but it can also be placed outside the truck by extending the pressure guiding tube.

Preferably, the pressure value can be output after being processed by a differential circuit shown in FIG. 4, a peak value hold circuit shown in FIG. 5, or a controller equipped with both shown in FIG.

The peak value hold circuit holds the maximum value of the pressure value during each period of vertical movement of the probe, and continues to output it as a pressure measurement value until the maximum value of the next period is held.

On the other hand, the differentiating circuit differentiates the signal to determine whether the pressure value is increasing or decreasing.

That is, for example, a positive signal is output if the value is increasing, and a negative signal is output if the value is decreasing.

Further, the output of the differentiating circuit is input to a flip-flop circuit, which outputs a signal that is inverted to positive or negative every moment the output of the differentiating circuit becomes negative.

The output of the flip-flop circuit is used to switch the switch that determines the rotation direction of the motor of the vertical drive mechanism. For example, when this output is positive, the switch is switched so that the motor rotates in the forward direction, and on the other hand, when it is negative, the switch is switched so that the motor rotates forward. Switch to the reverse side.

Note that the rotational speed of the motor 5-1, that is, the vertical speed of the probe is controlled by a motor drive circuit.

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

Moreover, the measuring device is compact and easy to carry.

Furthermore, even if the gap between the nozzle openings is not constant in the longitudinal direction, accurate measurement can be performed while automatically searching for the maximum pressure point.

Furthermore, even if the gap between the nozzle openings is not aligned in the longitudinal direction, accurate measurement can be performed while automatically searching for the maximum pressure point.

[Brief explanation of the drawing]

Figure 1 is an elevational view of the device of the present invention, and Figure 2 is the BB in Figure 1.
The cross-sectional views shown in FIGS. 3 to 6 are circuit diagrams showing embodiments of pressure value signal processing of the present invention. 1... Slit nozzle, 2... Probe (pitot tube), 3... Pressure sensor, 4... Pressure guiding tube,
5-1 to 5-5... Vertical drive mechanism, 7-1 to 7-7... Traveling trolley mechanism. Patent applicant Kawasaki Steel Corporation Figure 3 Figure 4 Figure 5 Figure m6

Claims (4)

[Claims] (1) A device for measuring the ejection pressure of fluid ejected from a nozzle having a slit-shaped opening, which includes a probe for receiving the pressure of the ejected flow from the nozzle, and a probe for moving the probe up and down with a predetermined stroke. A vertical drive mechanism, a traveling truck mechanism for loading these and moving them at a predetermined speed along the nozzle, a transducer for converting the pressure value received by the probe into an electrical signal, and an output signal of the transducer. 1. A slit nozzle ejection pressure measuring device comprising: an output device for receiving and outputting the measured value as a measured value of ejection pressure from the nozzle. (2) A device for measuring the ejection pressure of fluid ejected from a nozzle having a slit-shaped opening, which includes a probe for receiving the pressure of the ejected flow from the nozzle, and a probe for moving the probe up and down with a predetermined stroke. A vertical drive mechanism, a traveling truck mechanism for loading these and moving them at a predetermined speed along the nozzle, a transducer for converting the pressure value received by the probe into an electrical signal, and an output signal of the transducer. A control device that determines the timing at which the pressure starts to decrease as the probe moves up and down by differentiating the value, and controls the vertical drive mechanism so as to reverse the direction of the up and down movement of the probe at that timing;
A slit nozzle jet pressure measuring device comprising: an output device that receives an output signal from the transducer and outputs it as a measured value of the jet pressure from the nozzle. (3) A device for measuring the ejection pressure of fluid ejected from a nozzle having a slit-shaped opening, which includes a probe for receiving the pressure of the ejected flow from the nozzle, and a probe for moving the probe up and down with a predetermined stroke. A vertical drive mechanism, a traveling cart mechanism for loading these and moving them at a predetermined speed along the nozzle, a transducer for converting the pressure value received by the probe into an electrical signal, a peak value hold circuit that holds and updates the maximum value of the output signal of the transducer detected during this period, and an output that outputs the output from the peak value hold circuit as a measured value of the ejection pressure from the nozzle. A slit nozzle jet pressure measuring device comprising: (4) A device for measuring the ejection pressure of fluid ejected from a nozzle having a slit-shaped opening, which includes a probe for receiving the pressure of the ejected flow from the nozzle, and a probe for moving the probe up and down with a predetermined stroke. A vertical drive mechanism, a traveling truck mechanism for loading these and moving them at a predetermined speed along the nozzle, a transducer for converting the pressure value received by the probe into an electrical signal, and an output signal of the transducer. A control device that determines the timing at which the pressure starts to decrease as the probe moves up and down by differentiating the value, and controls the vertical drive mechanism so as to reverse the direction of the up and down movement of the probe at that timing;
A peak value hold circuit holds and updates the maximum value of the output signal of the transducer detected during this time every time the probe moves up and down, and the output from the peak value hold circuit is used to measure the ejection pressure from the nozzle. A slit nozzle jet pressure measuring device comprising: an output device that outputs a value.