JP2854256B2 - Apparatus for discontinuously detecting the thickness of a layer above a metal melt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for discontinuously detecting the thickness of a layer above a metal melt using a sensor device movable in the direction of the layer.

[0002]

2. Description of the Related Art Generally known devices as described above are used in the production of metals. Due to the manufacturing process, i.e. in the various cleaning processes of the metal melt, the non-metallic components contained in the metal melt are collected on the melt surface, where the melt is subjected to atmospheric influences and excessive heat. Forms a viscous solid slag layer that protects against loss.

Various devices are known for detecting the slag layer thickness on which the further processing steps of metal production depend.

[0004] From DE-A-364 1987, a device is known for measuring the slag height of a metal melt, in which case a support is used which is designed as a lancet. The support comprises a hum detector connected to an antenna, said antenna detecting a power hum near the antenna. When the lancet is immersed in the metal melt, a hum detector detects the air / slag transition and an inductive sensor indicates that the boundary layer between the slag and the metal melt has been reached. In order to determine the slag thickness from this, the signal obtained as described above must additionally be linked to a continuous distance measurement. The coupling of this device to an external distance measuring device impairs the mobility of the device and makes it particularly difficult to implement as a manual lancet.

[0005] DE-A 38 32 763 discloses a device for detecting the level of a slag boundary layer of a metal melt, which is based on the principle of detecting an impedance change via an impedance circuit.
Such an impedance circuit is connected to the oscillator and the measuring rod or the measuring rod feed cable.

The oscillator operates at a frequency different from the power supply frequency. The change in impedance is detected using a synchronous detector. When the output signal of the synchronization detector passes through the circuit corresponding to the predetermined corresponding interface, the corresponding threshold circuit forms one signal. This signal indicates that the measuring rod is at a certain distance from the corresponding interface. Again, only the thickness of the slag can be determined by additionally associating the signal of the threshold circuit with a continuous distance measurement. In addition to the drawbacks mentioned above with regard to the impediment of mobility of the device, the device also requires a particularly precise and constant speed. This is because distance and speed significantly affect the quality of impedance change.

[0007] Japanese Patent Application Laid-Open No. 61-212702 discloses a device for detecting the thickness of a slag, which is configured as a lancet. In this device, the electrode at the tip of the lancet is immersed in a metal melt. At that time, the impedance changes between the electrode and the melt container in the air / slag transition region and the slag / metal melt transition region. Such impedance changes are detected by the threshold circuit, but the impedance changes must additionally be associated with a continuous distance measurement in order to detect the slug thickness.

[0008] EP-A-0421828 discloses a method for continuously measuring the thickness of a liquid slag layer on the surface of a metal melt. Here, the distance to the melt surface is continuously measured by a fixedly installed level sensor. In doing so, the isothermal block is held at the powder / liquid slag transition using the adjusted follow-up control. In this case, in order to obtain the slag density from the difference between the results of the two measuring devices, the following control device needs a distance measuring device for detecting the position of the isothermal block. A continuous individual measurement with a configuration based on such a method takes longer than a non-continuous measurement and hastens wear of the isothermal block. Further, the isothermal block requires a costly moving device (displacement device) using a distance measuring device and a control device.

[0009] The known devices and methods described above have common drawbacks. In other words, mobile devices that are expensive to measure,
Further, a device that reliably detects the moving distance is required. As a result, such devices must be additionally equipped with a travel distance detection device, as long as corresponding mobile devices already exist.

[0010] Further, from Japanese Patent Laid-Open No.
Devices for detecting slag thickness are already known, but do not necessarily require a distance measuring device.
This apparatus is provided with a gas injection port at the tip of one gas injection pipe, from which an inert gas flows. When the dynamic pressure is detected each time using a pressure sensor, the dynamic pressure initially rises slowly at the air / slag transition,
It rises sharply at the liquid metal transition. From the pressure difference between the entry into the slag and the entry into the metal melt, the thickness of the slag is detected taking into account the respective density of the slag. However, such a measurement principle can only be used for viscous slag. Even in the case of viscous slag, the dynamic pressure is not only affected by the density, but also by the immersion depth and the fluctuating viscosity which can reach from a liquid state to a solid state in a slag layer. Another disadvantage of this device is as follows. That is, the transition cannot be accurately detected, and it is actually impossible to measure a thin slag layer. If a distance measuring device is not used, the immersion rate must be kept low and constant. Otherwise, in some cases,
The transition between the slag and the metal melt cannot be identified.

[0011]

SUMMARY OF THE INVENTION The object of the invention is to provide a device of the type mentioned at the outset in such a way that, with little equipment cost, reliable detection of the layer thickness is ensured. That is. In particular, the accuracy of the layer measurement should be independent of the moving device and the moving distance detecting device.

[0012]

According to the present invention, there is provided an image forming apparatus comprising:
The sensor device is connected to two evaluation devices and is arranged to detect the thickness of the layer above the metal melt discontinuously using a sensor device movable in the direction of the layer, the sensor device comprising:
At least two sensors and a round bar holding the sensors, wherein the first sensor is an electromagnetic sensor;
With this electromagnetic sensor, a measurement signal is generated which represents the respective distance from the metal melt to the sensor, and with a second sensor a signal is generated at a predetermined distance from the layer above the metal melt. When the second sensor generates a signal indicating a predetermined distance from the layer, the problem is solved by evaluating the signal of the first sensor using the evaluation device. Using the sensor device of the present invention, one signal is generated at one of the layer boundaries.
Is generated as a distance signal of the electromagnetic sensor for one surface,
There is a clear relationship between signal and distance in the measurement area. In addition, at least one further signal is generated for each layer to be detected, wherein at least one distance from the sensor device to the layer to be detected in each case, the distance between the signal and the distance An obvious relationship holds.

With the sensor device according to the invention, it is possible to measure the thickness of the slag layer on the metal melt without taking into account generally unknown travel distances or travel speeds. This is particularly advantageously possible with the following arrangement. That is, at least one sensor is configured as an electromagnetic sensor, said sensor generating a distance signal to one of the layer boundaries. The distance signal is evaluated by the evaluation device when the switch signal signals that another layer has been reached, together with another sensor that sends a simple signal, for example a switch signal, when one of the layers is reached. By doing so, it is possible to directly measure the thickness.

The sensor arrangement includes similar or different sensors having the same or different operating principles.

When the sensor device approaches the layer, it can penetrate the layer.

[0016] If the sensor device, which is preferably moved perpendicular to the metal melt, moves at an angle deviated from perpendicular to the metal melt, the angular deviation is detected and the correction of the signal can be easily performed. Can be done.

In another embodiment of the invention, the second sensor is configured as an acceleration sensor, by which a signal is sent when the sensor device reaches the upper layer.

According to such an embodiment, it is possible to detect whether a layer has reached a layer in a layer having a wide viscosity range.

In order to detect relatively thin liquid media on the basis of their electrical properties, it is advantageous if all sensors are configured as electromagnetic sensors.

In order to make the device according to the invention independent of external distance measurements, the sensor-mounted round bar is configured as a hand-held round bar so that the sensor device can be moved manually in the layer direction. It is possible. Such an embodiment is particularly suitable in tight space situations or in measurement situations where the cost of mobile equipment is high, for example test measurements.

Further, the embodiment of the present invention has a configuration in which the sensor is exchangeably attached to the round bar.

According to such an embodiment, the sensor device provided for measuring the layer thickness can be replaced by another sensor, for example to detect another measured value or to easily replace a defective sensor device. It can be easily replaced with a device.

A device for detecting at least one of the further measured values may be provided in a round bar and connected to the device according to the invention or as part of a protective sleeve. It does not depart from the scope.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a schematic diagram of a sensor device according to the present invention. In this sensor device, α = 9
It is movable at an angle of 0 °, that is, vertically. The metal melt 1 is covered with a slag layer 2 and the thickness of the slag layer 2 must be detected. The device comprises a round bar 3 holding a sensor, shown cut out, which is placed in a protective tube 4, also shown notched. At the far end of the round bar 3, the first sensor 5 and the second sensor 6 are arranged side by side so as to be flush with the end of the round bar 3.

The first sensor 5 is configured as an electromagnetic sensor, and is connected to the first pre-processing device 8 via the conductor 7. The preprocessing device 8 is connected via a conductor 9 to an evaluation device, not shown. The first sensor 5 generates a first signal. With this signal,
The respective distance from the metal melt 1 to the first sensor 5 can be determined.

The second sensor 6 is connected to a second
Are connected to a pre-processing device 11 and to an evaluation device (not shown) via a conducting wire 12. Second
The second signal is generated only at a certain defined distance from the slag layer 2 using the sensor 6 of FIG.

FIG. 2 shows a waveform diagram for explaining the signal evaluation of the sensor device according to FIG. As shown in FIG. 2, when the second sensor 6 generates a second signal indicative of a defined distance from the slag layer 2, the first signal of the first sensor 5 is evaluated. Therefore, the slag layer thickness can be derived from the characteristic signal for the slag layer 2 to be evaluated.

Other detection methods are known to those skilled in the art when the signal is recorded and stored during the measurement and is not evaluated until the measurement is completed. In other words, it is also advantageously possible to measure a layer thickness which is greater than the measurement area of the first sensor.

[Brief description of the drawings]

FIG. 1 shows a schematic view of a sensor device according to the invention.

FIG. 2 shows a waveform diagram for explaining the signal evaluation of the sensor device according to FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal melt 2 Slag layer 3 Round bar 4 Protection tube 5 1st sensor 6 2nd sensor 7 Conductor 8 Pre-processing device 9 Pre-processing device 10 Conductor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-212702 (JP, A) JP-A-62-248547 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01B 21/00-21/32 G01B 7/00-7/34 G01F 23/00-23/76

Claims (5)

(57) [Claims] 1. A device for discontinuously detecting the thickness of a layer above a metal melt using a sensor device connected to one evaluation device and movable in the direction of the layer, The sensor device comprises at least two sensors (5, 6)
And a round bar body (3) holding the sensor. The first sensor is an electromagnetic sensor (5), and the electromagnetic sensor (5) is used to separate the metal melt (1) from the molten metal (1). Sensor (5)
A measurement signal is generated which represents the respective distance to the second sensor (6) and a signal is generated at a predetermined distance from the layer (2) above the metal melt using the second sensor (6). 6) When the signal indicating the predetermined distance from the layer (2) is generated, the signal of the first sensor (5) is evaluated by using the evaluation device. For discontinuously detecting the thickness of a layer. 2. The second sensor (6) is configured as an acceleration sensor, and the second sensor (6)
2. The method according to claim 1, wherein a signal is transmitted when the sensor device contacts the layer above the metal melt, wherein the thickness of the layer above the metal melt is discontinuously detected. Equipment for. 3. The method according to claim 1, wherein the two sensors (5, 6) are configured as electromagnetic sensors. Equipment. 4. The method as claimed in claim 1, wherein the sensor device is manually movable in the direction of the layer above the metal melt. A device for discontinuously detecting thickness. 5. The sensor (5, 6) is replaceable.Round bar
2. The device according to claim 1, wherein the device is attached to (3).
5. The layer above the metal melt according to any one of
A device for discontinuously detecting thickness.