JPS59176643A - Measuring device for fine leakage of valve - Google Patents

Abstract

PURPOSE:To measure fine leakage easily and quantitatively by allowing an acoustic sensor to detect an acoustic signal generated when fine liquid or gas leaks from a valve in a closed state, and converting its detection signal into a leak flow rate and outputting it. CONSTITUTION:When a leak occurs to the valve 1, an acoustic signal corresponding to the leak is generated at the leak part. This is detected by the acoustic sensor 2 and amplified by a signal amplifier 3, and an incorporated filter removes frequency components except in the frequency band of the acoustic signal generated by the leak. Further, a background noise in the signal from the acoustic sensor 2 is removed to improve the S/N ratio. The signal after the noise removal is inputted to an RM meter 4 and converted into an RMS value. The output of the RMS meter 4 is inputted to an RMS value/leak flow rate converter 5 and converted into leakage. A signal indicating the leakage is sent to an output part 6 to perform display and recording and generate an alarm when the leakage exceeds a set value. Consequently, fine leakage is measured easily, quantitatively, and automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve minute leak amount measuring device that quantitatively detects and outputs the minute leak amount of a valve in a closed state.

Conventionally, there has been no highly practical measuring device that can quantitatively detect and output minute leakage from a valve in a closed state in a flow path system for water or steam. However, it has not been possible to automatically monitor the amount of leakage in the air.

The present invention has been made in view of the above circumstances, and has a configuration in which an acoustic sensor detects an acoustic signal generated when a small amount of liquid or gas leaks from a valve in a closed state, and converts this detection signal into a flow rate and outputs it. It is an object of the present invention to provide a valve minute leak amount measuring device that can easily and quantitatively automatically measure the minute leak amount from a valve.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a valve that is interposed in a flow path for water, steam, etc. and is subject to measurement of a minute leakage amount. 2 is valve 1. or valve 1
This is an acoustic sensor that uses an acceleration detection element or a piezoelectric conversion element, etc., and is attached to a pipe connected to the 3 is an acoustic sensor signal amplifier that amplifies the output signal of the acoustic sensor 2 and includes a preamplifier, a main amplifier, a filter, and the like. 4 is the RMS (Ro
ot Mean Squdre) RMS meter that obtains 1 shift, 5 is an RMS value/leak flow rate converter that converts the RMS value of RMS meter 4 to a leak flow rate, 6 is an RMS value/leak flow rate converter that outputs the leak amount obtained from the leak flow rate converter 5. This is an output section that includes a display/recorder and an alarm for

FIG. 2 is a characteristic diagram showing the relationship between leakage amount and acoustic sensor output.

Here, the operation of one embodiment will be explained. Valve 1 in a closed state
Therefore, when a leak occurs, an acoustic signal corresponding to the leak flow rate is generated from the leak portion. This acoustic signal is detected by the acoustic sensor 2 and input to the acoustic sensor signal amplifier 3.

The acoustic sensor signal amplifier 3 amplifies the input detection signal, and uses a built-in filter to remove frequency components other than the frequency band of the acoustic signal due to leakage, and removes background noise contained in the signal from the acoustic sensor 2. to improve the S/N ratio. The signal amplified and noise removed by this acoustic sensor signal amplifier 3 is sent to an RMS meter 4.
is input. The RMS meter 4 calculates the RMS value from the input signal. This RMS meter 4 is for determining the strength of the sensor output signal, which is an AC signal.
The signal strength may be determined by other means instead of the above method.

The RMS IK determined by the RMS meter 4 is input to the RMS value/leak flow rate converter 5, and the relationship between the minute leak flow rate acoustic signal (RMS value) and the leak amount (%) shown in FIG.
The RM value is converted into a leakage amount using the

A signal indicating the amount of leak obtained from the RMS direct/leak flow rate converter 5 is sent to the output section 6, where it is displayed and recorded, and an alarm is issued when the amount of leak exceeds a set value.

As described above, minute leakage from the closed valve 1 is quantitatively measured, and when the leakage amount exceeds the allowable leakage amount, an alarm is issued and can be notified to workers, supervisors, etc.

As described in detail above, according to the valve minute leak amount measuring device of the present invention, the acoustic sensor detects the acoustic signal generated when a minute leak of liquid or gas from the valve in the closed state occurs, and this detection signal is used as the leakage signal. By converting it into a flow rate and outputting it, the minute leakage amount from the valve can be easily and automatically measured quantitatively.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a characteristic diagram showing the relationship between the acoustic sensor output signal and the amount of leakage in the above embodiment. DESCRIPTION OF SYMBOLS 1... Valve, 2... Acoustic sensor, 3... Acoustic sensor signal intensifier, 4... RMS meter, 5... RMS value/leak flow rate converter, 6... Output part. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 4 (Leak ¥: (So/min)

Claims (1)

[Claims] An acoustic sensor that is attached to a valve to be measured or a pipe connected to the valve and detects the intensity of an acoustic signal generated due to a minute leak from the valve, and a sensor that receives a detection signal from this acoustic sensor. 1. A valve minute leak amount measuring device, comprising means for converting the level of the detection signal and outputting it as a leak amount, and quantitatively measuring and outputting the minute leak amount of the valve.