Leakage sensor and leakage detection system

Abstract

PROBLEM TO BE SOLVED: To enable it to pinpoint easily a liquid leakage generation part, by using liquid leakage sensors arranged on the floor or at the lowest part of a system such as a liquid leakage accommodation part, when a liquid leakage abnormality occurs. SOLUTION: The liquid leakage sensor is provided with at least one liquid leakage sensing part which can contact the leaked liquid through a gas layer or a liquid permeating layer where the leaked liquid can permeate. In a liquid leakage sensing system provided with at least one liquid leakage sensor, an alarm means which includes a sounding means within a predetermined space region is established to the installed position of the liquid leakage sensor. When the liquid leakage sensor senses a sensor abnormality, the position of the liquid leakage sensor is pinpointed by using at least the sounding means so that it can be distinguished from the other liquid leakage sensors arranged outside the predetermined space region, and thus, the sensor abnormality of the liquid leakage sensor is alarmed. COPYRIGHT: (C)2005,JPO&NCIPI

Description

technical field [0001] The invention relates to an improvement of a liquid leakage sensor and a liquid leakage detection system. The liquid leakage sensor and the liquid leakage detection system detect conductive liquids such as water, acidic solution, and alkaline solution, as well as ultrapure water, alcohol, diluent, Leakage of insulating liquids such as gasoline and other organic solutions. Background technique [0002] [Patent Document 1] Japanese Patent Publication No. 4-70572 [0003] [Patent Document 2] JP-A-2002-350275 [0004] In current facilities such as factories, liquid is supplied through piping. However, since the pipes are provided with joints for connection in many places, there are many cases where liquid leakage occurs from the joints. Therefore, depending on the type of liquid, one must always monitor for liquid leakage. As such a current liquid leakage sensor, known are: a conductive type liquid leakage sensor that detects changes in impedance betwe...

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Problems solved by technology

[0006] However, (A) as a cleaning agent / solvent, for example, has 6×10 or less when detected at 20°C -2 In the case of leakage of liquids with low surface tension of N / m, especially when detecting low-molecular chlorofluorocarbons (CFCs) and halons that do not contain chlorine and bromine, the surface tension is less than or equal to 3× at 20°C 10 -2 In the case of leakage 2a of a liquid with a low surface tension of N / m, the leakage forms a very thin layer and spreads, for example, as Image 6 As shown in (B), it spreads uniformly and rapidly in the form of a thin film layer with a thickness d1 of 0.5 mm or less in the leaking layer, and can easily penetrate even into very narrow gaps of 0.1 mm or less. , Therefore, the leaked liquid first penetrates into the gap d2 (Image 6 (C)), it takes a long time for the leaked liquid to spread to the retainer, and as a result, there is a problem that detection of a small amount of liquid leakage cannot be performed at all or the detection of liquid leakage is delayed

[0007] (B) In addition, at present, the leakage sensor has the following problem: because it performs "OR" operation on the alarm digital output of multiple leakage sensors, for each specified group, the alarm output is uniformly performed through the sequence generator or the main machine, etc. , Therefore, when the alarm of abnormal liquid leakage detection is output, in fact, the maintainer of the system such as the factory can not immediately determine the location of the liquid leakage for the sensor where the sensor is installed to detect the liquid leakage; the liquid leakage sensor is generally installed on the base The lowest part of the system such as the surface or the leakage storage plate, on the other hand, under the use environment conditions such as various system structural components erected in the space above it, the LED and other light-emitting alarm display components installed on the leakage sensor itself In the case of abnormal liquid leakage, it is generally difficult to visually identify it, and it is difficult to determine the location of the leakage

[0008] (C) Furthermore, in liquid leakage detection systems such as Patent Document 2, in general, the person who installs the liquid leakage sensor has nothing to do with the person who maintains and manages the system at a factory or the like. For the person who installs the liquid leakage sensor, It is required to accurately set all the multiple liquid leakage sensors to the specified positions in a short time. Therefore, even if it is possible to register the sensor installation positions one by one in the monitoring device as a desktop theory, in practice, it requires one job. It is impossible for an operator to wire 40 or more sensors without errors, register them accurately, and confirm them. In the system construction work, multiple operators perform the installation work, which will cause the purchase cost of the device to skyrocket. From the point of view of the actual installation operator of the sensor, this is a completely impractical technology

[0009] In addition, in the technique of Patent Document 2, a system structure is adopted in which calculation processing is performed on the main machine side and then displayed or directly displayed on the display part on the main machine side. Therefore, there is the following problem: when the main machine fails, even if the liquid leakage sensor is normal Even when liquid leakage is detected, it is completely impossible to output an alarm for abnormality of liquid leakage detection.

[0010] Furthermore, the technology of Patent Document 2 is a system for announcing abnormality of liquid leakage through a sound message after performing calculation processing on the main machine side or directly through the alarm part of the main machine. Therefore, the location of the liquid leakage must be included in the content of the voice message. For those who maintain and manage systems in factories, etc., unless they are able to accurately listen to the sound position information and understand where the leakage location information actually corresponds to in space, it is impossible to determine the exact spatial position of the leakage location. Information, especially in the job / on-site environment where dispatched staff and personnel changes frequently, hardly spends time / expenses on education on the position where the leak sensor is installed. For new operators and operators with insufficient memory / learning ability, become a totally ineffective alarm system.

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