JPS6032599Y2 - plugging meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for measuring the concentration of impurities contained in a liquid.

For example, in a fast breeder reactor, liquid is used as a medium to extract the heat generated in the reactor core to the outside).
It uses a liquid metal coolant represented by Um.

When the concentration of impurities in the liquid metal used for such purposes increases, it can corrode or block cooling piping or impede detection of water leaks in steam generators.

Therefore, when using liquid metals for the above purposes, it is necessary to constantly or periodically measure the concentration of impurities by some means, and to promptly take countermeasures based on the results.

By the way, there are various devices known in the past for measuring the concentration of impurities in liquid metal, and among them, there is a device called a plugging meter.

This device makes use of the phenomenon that the solubility of impurities depends on temperature, and is generally constructed as shown in FIG.

That is, numeral 12 in the figure is a conduit, and a sample liquid metal is passed through the conduit 12 via the pump 2.

A throttling mechanism 9 is provided in the conduit 12 to locally reduce the flow cross-sectional area of the conduit 12.
A heating and cooling device 6 for selectively heating and cooling the liquid metal flowing through the pipe 12 is provided on the upstream side of the pipe 12 .

Additionally, a temperature detector 8 for detecting the temperature of the flowing liquid metal is provided between the throttle mechanism 9 and the heating/cooling device, and a flow rate sensor typified by an electromagnetic flowmeter is installed upstream of the heating/cooling device. A container 4 is provided.

Therefore, this device measures the impurity concentration in the following manner.

To explain this with reference to FIG. 2, first, the blower 7 is operated while the liquid metal is flowing through the pipe line 12.

When the blower 7 operates, the liquid metal passing through the throttle mechanism 9 is gradually cooled.

Now, assuming that the liquid metal contains impurities,
When the liquid metal is cooled to a temperature slightly lower than the saturation dissolution temperature of the impurities, the supersaturated portion is deposited on the inner surface of the throttling mechanism 9.

Therefore, the flow rate decreases. In this way, a value close to the impurity concentration can be obtained by setting the temperature of the throttle mechanism (orifice temperature) at point A, where the flow rate is lower than before, as the plug temperature.

Next, with impurities precipitated on the inner surface of the aperture mechanism 9,
When the heating/cooling device 6 heats the liquid metal flowing through this portion, the unsaturated liquid metal containing impurities can be made to flow through the throttle mechanism 9.
The impurities that precipitate are dissolved and the flow rate increases.

By setting the temperature of the throttle mechanism at point B as the plug temperature, a value close to the impurity concentration can be obtained.

By determining the relationship between this plug temperature and the saturated dissolution temperature, the concentration of impurities can be determined from the plug temperature.

However, the detection of these liquid metal flow rate change points A and B is
This is extremely difficult due to the poor ratio of the noise signal to the flow rate signal and the influence of changes in the flow rate of the main pipe 1.

Therefore, the plug temperature is obtained from the temperature of the throttling mechanism 9 at the point where the temperature has changed by an appropriate amount (for example, 5%), although there is a time delay, so the difference from the saturated melting temperature is large.

The present invention was devised in view of these circumstances, and its purpose is to provide a plugging meter that can improve measurement accuracy and is resistant to external influences.

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

Figure 3 shows the configuration of the device according to the present invention.
The same parts as in the figure are indicated by the same symbols, and instead of detecting the starting point of precipitation of impurities and the starting point of dissolution of impurities in the throttling mechanism 9 due to flow rate changes, ultrasonic waves are transmitted from the ultrasonic wave transmitting transducer 10. , the ultrasonic wave is passed through the aperture mechanism 9, the amount of the ultrasonic wave passing through is measured by the ultrasonic receiving transducer 11, the point at which impurity dissolution starts is detected from the change in the amount of passing, and the plug temperature is measured.

In this way, the inventive measuring device is less affected by noise and changes in the main piping flow rate than the flow rate signal.

Generally, in order to increase the sensitivity of flow rate changes, a bypass throttle mechanism 3 is provided in parallel with the throttle mechanism 9 to keep the pressure loss of the throttle mechanism 9 constant.

However, the amount of change in the flow cross section due to precipitated impurities and the amount of flow rate change are not the same, and the sensitivity to flow rate changes is poor. The diaphragm mechanism 3 becomes unnecessary.

As described in detail above, according to the present invention, ultrasonic waves are passed through the orifice section, the amount of attenuation of the ultrasonic waves due to impurities is measured, and impurities precipitated at the orifice section are detected with high sensitivity, increasing the measurement sensitivity and accuracy. It is possible to provide a plugging meter that can perform high-level measurements, and has the advantage of being less affected by flow rate changes and noise than conventional flowmeters.

[Brief explanation of the drawing]

FIG. 1 is a sectional view illustrating the configuration of a conventional device, FIG. 2 is a graph illustrating an example of use of the same device, and FIG. 3 is a sectional view illustrating the configuration of an embodiment of the present invention. 1...Main piping, 2...Electromagnetic pump, 3...Bypass throttle mechanism, 4...Flowmeter, 5...Heat exchange device, 6... Heating/cooling device, 7... Air blower, 8... Temperature detector, 9... Throttle mechanism, 10...・Transmission transducer, 11... Receiving transducer, 12...
...Pipeline.

Claims (1)

[Scope of utility model registration request] a conduit through which a sample liquid flows; a throttle mechanism provided within the conduit to locally reduce a flow cross-sectional area of the conduit;
a heating/cooling device provided upstream of the aperture mechanism to selectively heat and cool the sample liquid; a temperature detector for detecting the temperature of the sample liquid passing through the aperture mechanism; A plugging meter comprising a pair of transmitting and receiving ultrasonic transducers for measuring impurities.