JPS63212842A - Apparatus for automatically measuring viscosity of high temperature molten material - Google Patents

Abstract

PURPOSE:To automatically obtain the data of viscosity and a temp. characteristic without requiring manual work, by calculating the viscosity of a molten material being an object to be measured by the vibration piece and displacement meter immersed in the molten material and judging the coagulation point of the molten material when an amplitude value reaches a predetermined value or less to stop the measurement of viscosity. CONSTITUTION:An operational control part 31 takes in the temp. in a heating furnace 1 and the temp. of an object whose viscosity must be measured held to a molten state in a crucible 11 from probes 15a, 15b. The temp. of the object to be measured is lowered to viscosity measuring temp. through a furnace controller 14 and a vibration source 21 is vibrated at predetermined vibration frequency through an oscillator 35 and a power amplifier 36. The amplitudes of a vibration piece 24 in air, the object to be measured and a standard viscous liquid at that time are taken in as the detection value of a displacement meter 25 to calculate the viscosity. The calculation of viscosity eta is performed on the basis of the vibration amplitude E of the vibration piece 24 in the object to be measured according to formula I (wherein rho is the density of the object to be measured, RM is the impedance resistance value of a viscometer, fa is the resonance frequency in air, f is the resonance frequency in the object to be measured and S is the area of both surfaces of the vibration piece) in the control part 31.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention mainly relates to the melting characteristics of powder used in continuous casting,
In particular, it relates to a device for automatically measuring viscosity.

[Prior art]

In general, methods other than the rotating cylinder method, sphere pull-up method, and vibrating single-sided method are known as methods for measuring the viscosity of powders, etc. However, with the exception of the vibrating single-sided method, the time required for one measurement is long, and the viscosity is When determining temperature characteristics, it is necessary to perform measurements many times, so there is a problem in that the measurement time is extremely long.

[Problem that the invention seeks to solve]

By the way, in the case of a vibrating single-sided type viscometer, the time required for one viscosity measurement is shorter than that of other methods, but when determining the viscosity-temperature characteristics over a wide temperature range, the internal temperature of the object to be measured is necessary. Due to the time constraints caused by the need to make the distribution uniform, the measurement time becomes long, and the measurement workers are forced to wait for a long time, and the measurement work itself is a lot of manual work, making it difficult to work. It requires skill, and because the cycle time in the upper chamber is long, measurement values tend to vary due to differences in measurement timing. This method is very inconvenient in estimating temperature characteristics, solidification temperature, and crystal precipitation temperature, and also has problems such as poor reproducibility.

The present invention was developed in view of the above circumstances, and its purpose is to automatically perform viscosity measurement using a vibrating one-sided method with almost no human intervention, and to measure a large number of viscosity-concentration characteristics in a short cycle time. An object of the present invention is to provide an automatic viscosity measuring device for high-temperature melts that allows data to be obtained.

Means for Solving Problem C] In the present invention, a crucible that accommodates an object to be measured for viscosity;
a heating furnace that heats and melts the object to be measured for viscosity; a temperature control means that adjusts the temperature of the melt after heating the object to be measured for viscosity to at least the highest temperature at which the viscosity measurement should be performed;
A vibrating piece immersed in the melt and a displacement meter that detects its amplitude; and a displacement meter that detects the vibration piece immersed in the melt and the amplitude value of the vibrating piece obtained by the displacement meter during the cooling process of the melt and the temperature of the melt at that time, and measuring the amplitude value. and means for determining that the molten material has reached its freezing point when the amplitude value becomes less than a predetermined value, and emitting a signal to stop the viscosity measurement operation.

[Effect]

According to the present invention, the temperature of the object to be measured for viscosity can be automatically and accurately set for each temperature at which each viscosity measurement is to be performed, the uniformity of the internal temperature distribution can be improved, and the object can be kept in a molten state. It is also possible to automatically determine the point in time when a certain object to be measured for viscosity solidifies due to temperature drop and the viscosity measurement operation is finished.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof.

FIG. 1 is a schematic diagram of an automatic viscosity measuring device for high-temperature melts according to the present invention (hereinafter referred to as the device of the present invention), in which 1 indicates a heating furnace, 2 indicates a viscosity measuring device, and 3 indicates the main body of the measuring device. There is.

The heating furnace 1 is composed of an electric furnace or the like, and has an opening 1a at the center of the upper wall, and has a crucible 11 for storing the object to be measured and a heater 1 for heating and melting the object to be measured for viscosity.
2 is disposed, and a feeder 13 for supplying the material to be measured for viscosity to the crucible 11 is installed at the upper outside of the furnace. The material is put into the crucible 11 through the guide hole 1b, and heated and melted to a predetermined temperature by the heater 12.

The heater 12 is controlled by a furnace controller 14 that operates based on a control signal from the arithmetic control section 31 of the measuring device main body 3, and the results are transmitted to the furnace temperature detection probe 15a and the temperature detection probe 15b of the object to be measured for viscosity. Detected temperature using multi-thermometer 32. Furnace controller 1 through arithmetic control section 31
This will be fed back to 4th. Further, the amount of the material to be measured for viscosity taken out from the supply device 13 is also adjusted by the arithmetic control section 31 through the sequencer 33 of the measuring device main body 3.

The viscosity measuring device 2 has a shaft 22 whose upper end is connected to an excitation source 21 constituted by a cone-shaped speaker, etc., which passes through a heat shielding plate 23 equipped with a water cooling jacket and hangs down, and vibrates at its lower end. A displacement meter 25 for detecting the amplitude of the vibrating piece 24 is provided near the upper end of the shaft 22, and a displacement meter 25 for detecting the amplitude of the vibrating piece 24 is provided. The vibrating piece 24 can be moved up and down between a position where it is pulled up to the outside and a position where the vibrating piece 24 is immersed in the object to be measured for viscosity inside the crucible 11 through the opening 1a.

The vibration source 21 is configured to vibrate the diaphragm using an electric means such as an electromagnet or a drive coil, and transmit the vibration to the vibrating piece 24 through the shaft 22.
The amplitude is transmitted from the arithmetic control section 31 of the measuring device main body 3 to the oscillator 35.
, is set to the excitation source 21 through the power amplifier 36. The resonance frequency of the vibration system is mainly used as the frequency, and the amplitude at that time is also used as the amplitude.

The displacement meter 25 is configured to detect the amplitude of the vibrating piece 24 through the shaft 22, and the detection signal is taken into the calculation control section 31 through the controller 26 and the multimeter 34 of the measuring device main body 3.

Reference numeral 16 indicates a standard viscosity liquid, and the temperature at which the vibrating piece 24 was immersed in the liquid before starting viscosity measurement.

It is used to detect the amplitude and define the characteristics of the viscosity measuring device 2 itself.

As described above, the arithmetic control unit 31 of the measuring device main body 3 outputs a signal for adjusting the cutout amount of the material to be measured for viscosity to the feeder 13 via the sequencer 33, and also outputs a signal for adjusting the cutout amount of the material to be measured for viscosity, and also outputs a signal to the feeder 13 via the sequencer 33.
The temperature inside the heating furnace 1 and the temperature of the object to be measured for viscosity in a molten state in the crucible 11 are taken in through a and 15b, and a control signal is outputted through the furnace controller 14 to set the temperature of the object to be measured for viscosity to the viscosity measurement temperature. Also, the oscillator 35
, the vibration source 21 is vibrated at a predetermined frequency via the power amplifier 36, and the displacement meter 25 detects the amplitude of the vibrating piece 24 in the air, the object to be measured for viscosity, or a standard viscosity liquid. The viscosity is calculated by importing it as a value.

The calculation of the viscosity η by the arithmetic control unit 31 is performed according to the following formula (1) based on the vibration amplitude E of the vibrating piece 24 at the source of the resonance frequency within the object to be measured for viscosity detected by the displacement meter 25. be exposed.

However, ρ: Density of the object to be measured for viscosity R14: Resistance outline of mechanical impedance specific to the viscometer a: Resonance frequency in air f: Resonance frequency S in the object to be measured for viscosity; Area of both sides of the vibrating piece (RM!/πfaS'' in Equation 11 is a device constant, and since this is K, it is 8.) If we set this as 8, Equation (11) can be rewritten as Equation (2).

ρη” K A o ... (2) The resonance frequency fa in the air and the vibration amplitude Ha in the air are determined by applying vibrations of different frequencies to the vibrating piece in the air before starting the measurement,
The frequency at which the amplitude is maximum is defined as the resonance frequency fa, and the amplitude at that time is defined as Ha.

In addition, for n, before starting the measurement, the vibrating piece is immersed in two or more types of standard viscosity liquids, and the vibrating piece is vibrated at different frequencies, and the frequency at which the amplitude is maximum is f.

The amplitude at that time is defined as E, and the density of the standard viscosity liquid is ρ.
, is determined in advance based on viscosity, etc.

The temperature and viscosity of the object to be measured for viscosity determined by the arithmetic control section 31 are displayed and recorded on a CRT or printer each time.

Next, an example of the viscosity measurement procedure will be explained according to the temperature patterns shown in FIGS. 2 and 3. Figure 2 shows the temperature pattern of the object to be measured for viscosity, and Figure 3 shows the temperature pattern inside the heating furnace.
In both cases, time is plotted on the horizontal axis and temperature is plotted on the vertical axis.

The setting control of the temperature pattern as shown in FIG. 2 for the object to be measured for viscosity is carried out by directly detecting the temperature through the probe 15b inserted into the object to be measured for viscosity in the crucible 11, and adjusting the temperature to follow a predetermined temperature pattern. Settings may be controlled from the calculation control unit 31 through the furnace controller 14, but
Since the temperature response of the object to be measured for viscosity is slow and it takes a long time for the internal temperature to become uniform, it is inconvenient to control the temperature while directly detecting the temperature of the object to be measured for viscosity.

For this reason, usually the relationship between the object to be measured for viscosity and the furnace temperature and set time required to set and maintain the object at a predetermined temperature is determined in advance, and the temperature is controlled so that the object to be measured for viscosity follows a predetermined temperature pattern. It is desirable to determine the necessary furnace temperature control pattern as shown in FIG. 3 and control the furnace temperature in accordance with this pattern so that the viscosity measurement temperature follows the temperature pattern shown in FIG.

Of course, the actual viscosity value needs to be specified in relation to the temperature of the object to be measured for viscosity, so the temperature of the object to be measured for viscosity at the time of viscosity measurement must be input into the calculation control section 31 through the probe 15b each time. shall be.

If there is an error exceeding the allowable range between the actual temperature of the object to be measured for viscosity detected at this time and the target temperature of the object to be measured for viscosity, the viscosity measurement object detected by operating the furnace controller 14 will be changed each time. The temperature may be set so that the object temperature matches the target temperature.

Although the furnace temperature control pattern as shown in Fig. 3 varies depending on the characteristics of the furnace, it is usually approximately similar to the temperature pattern of the object to be measured for viscosity shown in Fig. 2, so the following explanation will be based on Fig. 2. This will be performed on the temperature pattern of the object to be measured for viscosity.

First, after performing pre-measurement setups such as adjusting each device and supplying the material to be measured for viscosity into the feeder 13 and the crucible 11, a control signal is output from the arithmetic control unit 31 to the furnace controller 14,
The object to be measured for viscosity is heated and melted, and the temperature of this melt is adjusted to the highest temperature T, 4 (
or a higher temperature) and maintain the heating at that temperature T8 to make the internal temperature uniform. After a certain period of time has elapsed, the viscosity measuring device 2 is lowered while vibrating the vibrating piece 24 at its resonance frequency to measure the level of the molten material, and then the amplitude of the vibrating piece 24 in the air is measured. is immersed in the melt to a predetermined depth, and the first viscosity measurement is performed as it is. O0 The temperature of the object to be measured for viscosity is T. A second viscosity measurement is carried out at a certain time interval while maintaining the temperature at 02. After that, the viscosity is measured a predetermined number of times while gradually lowering the temperature to the temperature at which the viscosity measurement should be carried out (,G)-C)).

Once the temperature is lowered to a temperature TN that is slightly higher than the predicted solidification temperature of the object to be measured, the temperature is lowered continuously at a constant gradient, and the viscosity is measured in small increments in shorter cycles than the previous viscosity measurement cycle. Do (■～■).

Then, when the amplitude of the vibrating element attenuates below a predetermined setting value, it is determined that the object to be measured for viscosity has solidified, and each device is stopped to complete the measurement operation [F].

Thereafter, the object to be measured for viscosity is heated and melted again via the furnace controller 14, the vibrating piece 24 incorporated in the object for viscosity measurement is extracted [F], and the probe 15b for temperature measurement is extracted. The process is completed and the object to be measured for viscosity is left to cool.

Each task will be explained in detail below.

A. Pre-measurement setup work, mainly inspection of various equipment, supply device 13, crucible 11
This is a manual process, such as supplying the material to be measured for viscosity into the chamber.

The amount of the material to be measured for viscosity supplied into the crucible 11 is determined so as to ensure a level that does not interfere with viscosity measurement within the crucible 11 when the material is melted.

B1. Measuring the melt level When the vibrating piece 24 is vibrated at the resonant frequency and lowered by operating the elevating means, the amplitude changes rapidly when the lower end of the vibrating piece 24 comes into contact with the surface of the melt. The output signal of the displacement meter 25 is read, and the position of the vibrating piece 24 is determined to be the level position based on the position of the elevating means.

Note that this level measurement may be calculated based on the amount of the object whose viscosity is to be measured into the crucible 11, the content of the crucible 11, and the density of the object whose viscosity is to be measured.

Bt, measuring the amplitude of the vibrating piece in the air Drive the lifting means of the viscosity measuring device 2 to lift the vibrating piece 24 from the estimated position on the surface of the molten material to a certain height, make it vibrate in the air, and change the amplitude at that time. The detection signal is input to the multimeter 34 via the controller 26, converts the eddy current into distance, that is, amplitude, and sends it to the arithmetic control section 3.
1, and its amplitude is stored and displayed and recorded through the CRT and printer 37.

C1, immersion of the vibrating piece 24 and determining the descending dimension of the vibrating piece 24 from the level of the object to be measured for viscosity in the crucible 11 detected by the first viscosity measuring device, and moving the vibrating piece 24 into the melt to a predetermined depth. Soak. Immediately after immersing the vibrating piece 24 into the melt to a predetermined position, the first measurement is performed.

That is, the melt temperature is read into the arithmetic control section 31 through the multi-thermometer 32 using the temperature measurement probe 15b, and at the same time the output of the displacement meter 25 is read into the controller 26 and the multimeter 3.
4 as an amplitude to the arithmetic control section 31, and calculates the viscosity according to equation (1) above.

After that, change the frequency, read the amplitude each time, calculate the average amplitude, and measure the viscosity.

C2, Second viscosity measurement After the first viscosity measurement is completed, the melt temperature is maintained constant and after a certain period of time, the temperature and amplitude are read again and the above-mentioned process to determine the viscosity is repeated for the second time. Measure the viscosity of

C8 to C7, 3rd to nth viscosity measurements After that, the furnace controller 14 is controlled to lower the furnace temperature at a predetermined gradient, and after a certain period of time, the furnace controller 14 is controlled again to maintain the current temperature for a certain period of time. to make the melt temperature uniform, and perform the third viscosity measurement.

Thereafter, each time the melt temperature is lowered at a predetermined gradient, the temperature is maintained for a certain period of time repeatedly, and one viscosity measurement is performed.

D,~D,1. Small-step Measurement Once the required number of viscosity measurements have been completed, the viscosity measurements are repeated in small steps in short cycles while lowering the furnace temperature at a predetermined gradient.

The viscosity measurement operation itself is substantially the same as in the case described above.

Then, when the absolute value of the amplitude value at the resonant frequency of the vibrating piece 24, which is the output of the displacement meter 25, becomes less than a predetermined setting value, the amplitude of the vibrating piece 24 is determined first. When the ratio to the amplitude value at the resonance frequency of the vibrating piece 24 in air becomes lower than the set value, in other words, when the following equation (2) holds true, it is determined that the molten body has solidified.

Amplitude measurement value in air However, K: Approximately 1/3 to 1710 Piece 24. The probe 15b is taken out, the viscosity measuring device 2 is pulled up by the elevating means, and the vibrating piece 24 is pulled out to the outside of the furnace.

〔effect〕

As described above, in the apparatus of the present invention, after raising the temperature of the object to be measured for viscosity to at least the highest temperature at which viscosity measurement should be performed, the temperature of the object to be measured for viscosity is sequentially lowered to the temperature at which each viscosity measurement is to be performed. Since the temperature distribution is set symmetrically, there is little variation in the temperature distribution within the object to be measured, and the temperature pattern for the object to be measured for viscosity measurement can be automatically set. The present invention has excellent effects, such as being able to accurately determine the freezing point of , and most of the viscosity measurement work can be done without requiring manual labor, resulting in significant labor savings.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the apparatus of the present invention, FIG. 2 is a temperature pattern to be set for the object to be measured for viscosity, and FIG. 3 is a temperature pattern in the furnace. 1... Heating furnace 2... Viscosity measuring device 3... Measuring device body 11... Crucible ■2... Heater 13.
...Supplier 14... type controllers 15a, 15b
... Temperature detection probe 16 ... Standard viscosity liquid 2
1... Vibration source 22... Shaft 24... Vibration piece 25... Displacement meter 31... Arithmetic control unit time Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Kawa
No Nobo Time Figure 3

Claims (1)

[Claims] 1. A crucible that accommodates the object to be measured for viscosity, a heating furnace that heats and melts the object to be measured for viscosity, and after heating the melt temperature of the object to be measured for viscosity to at least the highest temperature at which the viscosity measurement should be performed. A temperature control means for adjusting the temperature drop, a vibrating piece immersed in the molten material and a displacement meter for detecting its amplitude, and an amplitude value of the vibrating piece obtained by the displacement meter during the cooling process of the molten material and the fusion value at that time. It is equipped with means for reading the body temperature and calculating the viscosity based on the amplitude value, and means for determining the freezing point of the molten material when the amplitude value becomes less than a predetermined value and emitting a signal to stop the viscosity measurement operation. An automatic viscosity measuring device for high-temperature melts.