JP3596413B2 - High temperature, high pressure conductivity detection sensor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a boiler for measuring the conductivity of sample water using four electrodes, which is attached to a cross-shaped or T-shaped joint provided in the middle of a flow path of sample water from which a portion of boiler can water has been taken out. The present invention relates to a conductivity detection sensor used for a blow management device and a water quality management device for high-temperature cooling water.
[0002]
[Prior art]
The present applicant has proposed such a high-temperature, high-pressure type conductivity detection sensor in Japanese Patent Application Laid-Open No. H11-248658. This conductivity detection sensor is a two-electrode type, and has a large diameter between the outer periphery of the rod-shaped electrode portion of each electrode and the large-diameter hole of the stepped hole of the electrode holder, and the outer periphery of the rear portion of the electrode holder and the inner periphery of the nipple. A nipple that seals the space between the front half with an O-ring, between the rear end of the rod-shaped electrode portion of each electrode and the step of the stepped hole where the rear end faces, and between the rear end and the rear end of the electrode holder The space between the stepped hollow portion and the stepped portion is sealed with a sealing material.
[0003]
[Problems to be solved by the invention]
Since the two-electrode sensor directly measures the current flowing between the electrodes, when a film is formed on the electrode surface, cleaning and calibration are required to measure the electric conductivity. In this regard, the four-electrode sensor is said to be resistant to dirt, but it is larger than the two-electrode sensor, which requires a large amount of attachment to piping.
[0004]
Temperature measurement is required for conductivity measurement, so it is desirable to immerse the temperature sensor inside the conductivity detection sensor and make it an integral type, but doing so reduces the contact area with boiler water and other water samples. The temperature response becomes poor, and as a result, the wrong conductivity is measured.
[0005]
[Means for Solving the Problems]
The conductivity detection sensor according to claim 1 is a four-electrode type, but has a size similar to that of a two-electrode type, and is formed of a metal having a rod-shaped electrode portion and a screw shaft integrally projecting from a rear end thereof. Four electrodes and one of the four electrodes are supported by penetrating through four support holes parallel to each other in the axial direction, and the front end of the rod-shaped electrode portion of each electrode facing the front end is sampled. A resin-made electrode holder, a large-diameter front part holding the rear part of the electrode holder in the large-diameter hollow part, and a lead wire connected to the rear end of the screw shaft of each electrode are pulled out backward through the small-diameter hollow part. Ri Do and a metallic nipple having a stepped hollow portion having a small diameter rear half portion, the rod-shaped electrode portion of each electrode of the four and, the electrode portion of the support hole of the electrode holder accommodating the rod-shaped electrode portion Seal the space between the housing and the housing with a sealing material that solidifies by high-temperature drying. Between the screw shaft of the electrode holder and the screw shaft accommodating portion of the support hole of the electrode holder accommodating the screw shaft, and the outer periphery of the rear portion of the electrode holder and the inner periphery of the large-diameter hollow portion of the nipple holding the same. The gap was sealed with an O-ring, the rear end of the electrode holder and the rear end of the large-diameter hollow portion of the nipple were sealed with a sealing material, and a lead wire connected to the screw shaft rear end of each electrode was drawn out. filled with a sealing material to solidify inside the small-diameter hollow portion of the nipple by heat, in the above electrode holder to form a forward tubular portion surrounding around the test water portion of the front end together, silicone rubber front end of the forward tubular portion with closed with manufacturing of the protective cap, the side surface of the forward cylindrical portion, characterized in that opposed the water passing holes in the diameter direction for the flow of test water in the diameter direction of the front facing the tubular portion. According to a second aspect of the present invention, there is provided a conductivity detection sensor for high temperature and high pressure according to the first aspect , wherein the electrode holder is provided with a second support hole parallel to the electrode support hole. A single metal temperature sensor having a rod-shaped electrode portion and a screw shaft integrally projecting from the rear end of the hole is supported in the same direction as the electrode, and the front end of the temperature sensor is connected to the front end of the electrode holder. The present invention is characterized in that the four electrodes protrude longer than the front ends of the four electrodes . According to a third aspect of the present invention, there is provided the conductivity detection sensor for high temperature and high pressure according to the second aspect , wherein the four electrodes supported by the electrode holder through the support hole are diametrical at the front end of the electrode holder. One temperature sensor arranged in a line along the line and supported through the second support hole is provided near the center of the front end of the electrode holder.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Reference numeral 10 denotes four electrodes made of a conductive metal, for example, stainless steel, silver, copper, brass, gold, platinum, titanium, or the like. It has an integral screw shaft 13 of the same diameter, and the rod-shaped electrode part 11 has an annular groove 12 before the middle. Incidentally, in order to improve the accuracy of the electrode, the electrode may be subjected to a treatment such as silver brazing or plating.
[0007]
Reference numeral 20 denotes a cylindrical electrode holder formed of plastic, which is provided with four support holes 21 for penetrating and supporting the four electrodes 10 one by one in the axial direction. Each support hole 21 includes a rod-shaped electrode portion accommodating portion 22 and a screw shaft accommodating portion 23 of a screw hole accommodating the screw shaft 13.
[0008]
When each electrode 10 is supported by penetrating through the support hole 21 of the electrode holder, a sealing material, for example, a caulking agent, which is solidified by high-temperature drying is applied to the outer periphery of the rod-shaped electrode portion 11 and the annular groove 12 is also coated with the sealing material. Is filled and inserted into the rod-shaped electrode portion accommodating portion 22, and a Teflon sealing tape or the like is wound around the screw shaft 13 and screwed into the screw shaft accommodating portion 23 of the screw hole. It is sealed in the support hole 21 and fixed. Accordingly, it is possible to prevent the electrode from being displaced and moved in the support hole 21 by the axial force applied to the electrode. In this state, the rear end of the screw shaft 13 projects rearward from the rear end of the electrode holder 20, and the covered conductor 14 can be connected by high-temperature solder or the like. Further, the front end of the rod-shaped electrode portion 11 protrudes slightly, for example, 1 mm from the front end of the electrode holder 20.
[0009]
In front of the front end of the electrode holder 20 is a water detecting unit 24, and the electrode holder is provided with a concentric forward-facing cylinder 25 protruding forward from around the front end.
[0010]
In order to support the temperature sensor 30 together with the electrode 10, the electrode holder 20 is provided with the four support holes 21 in a line on the left and right in the left and right diametric directions D, and as described above, the four electrodes The second support hole 26 is provided in the axial direction at the lower central portion of the diameter direction D, and the temperature sensor 30 is supported through the second support hole 26 (see FIG. 1D).
[0011]
The temperature sensor 30 has a large-diameter portion 32 in front of a sensor main body 31 and an oval-shaped sensing portion 33 in front of the large-diameter portion 32. The oval circular arc surfaces 33 ′, 33 ′ of the sensing portion 33 are connected to the outer periphery of the large diameter portion 32.
[0012]
The second support hole 26 has a large-diameter portion 32 of the temperature sensor 30 and an enlarged-diameter portion for receiving an O-ring 34 fitted on the outer periphery of the sensor main body 31 immediately behind the large-diameter portion 32 at the front end. Therefore, the length of the oval sensing part 33 of the temperature sensor 30 supported by the second support hole 26 protruding forward from the front end of the electrode holder is, for example, 4 mm, and is longer than the front ends of the four electrodes 10. It is protruding. In addition, the sensing part 33 has the two flat surfaces of the oval shape turned to the left and right similarly to the arrangement of the four support holes. By making the sensing part 33 of the temperature sensor protrude from the water detection part 24 at the front end of the electrode holder in this way, the contact area of the temperature sensor with the water sample increases, and good sensitivity can be obtained.
[0013]
The length of the sensor main body 31 of the temperature sensor 30 is short, the rear end is located inside the first half of the second support hole, and the covered conducting wire 35 extends from the rear end and projects from the rear end of the second support hole. In addition to the above-described O-ring 34 for fixing the temperature sensor in the second support hole, a sealing material, such as a caulking agent, which is solidified by high-temperature drying as described above, is applied to the outer periphery of the front end of the conducting wire 35 connected to the rear end of the sensor body. It is applied and fixed with the solidified layer 36.
[0014]
On the side surface of the forward-facing cylinder portion 25 protruding from the front end of the electrode holder, water holes 27, 27 for diametrically facing the water are provided diametrically opposed to each other, so that water such as boiler water is supplied to the forward-facing cylinder portion 25. to be able to flow in the radial direction, arcuate surface 33 facing the upper and lower sensing portion of the oval of the temperature sensor ', 33' are exposed to test water such as boiler water flowing through the water-passing holes 27, 27. In addition, a protective cap 28 having a hole at the center is detachably fitted to the front end of the forward facing tubular portion 25 to close the water detecting portion 24. Preferably, the protective cap 28 is made of silicon rubber or the like and is easily detachable. A forward-facing cylindrical portion 25 having a water hole formed on the side surface facing the diametric direction and a cap 28 closing the front end prevent noise caused by leakage current at the time of four-electrode conductivity measurement, and perform stable measurement. It can be performed.
[0015]
Conductive members 37, 37 are attached to the rear end of the electrode holder 20 so as to partially fill the left and right sides of the second support hole 26, and the cores of the two conductive wires 35 of the temperature sensor 30 are addressed to one. 37, 37. In addition, coated conductive wires 38, 38 are connected to the respective conductive members 37, 37 backward by high-temperature solder. A concentric rearward-facing cylinder 29 is provided at the outer rear end of the electrode holder.
[0016]
Reference numeral 40 denotes a metal, for example, a stainless steel nipple, a large-diameter front half 42 for holding the rear portion of the electrode holder 20 on the inner periphery of the large-diameter hollow portion in front of the hexagonal tool engagement portion 41, and the screw shaft 13 of the electrode. And a small-diameter rear part 43 for drawing out the conductor 38 connected to the rear end of the conductive member 37 of the temperature sensor to the outside through the small-diameter hollow part.
[0017]
In order to hold the rear part of the electrode holder on the inner periphery of the large-diameter front half part 42, a packing 45 is applied to a step surface 44 ′ inside the stepped hollow part 44, and an O-ring 46 is placed in an annular groove on the rear outer periphery of the electrode holder. The packing 45 is compressed at the rear end of the rearward-facing cylinder 29 of the electrode holder by pushing it into the inner periphery of the large-diameter front half portion 42 from the front. Then, a set screw 47 is screwed into a plurality of radial screw holes provided around the large-diameter front half 42, and the outer periphery of the rear portion of the electrode holder 20 is tightened with the tip of the set screw. Although one O-ring 46 may be used, two O-rings are used in the figure to enhance the sealing performance. The conductors 14, 38 extending rearward from the rear end of the electrode holder are drawn out backward from the small-diameter hollow portion, and the inside of the stepped hollow portion includes the rearwardly facing cylinder of the electrode holder to maintain the sealing property at a high temperature. A sealing material, for example, a molding agent 48 such as an epoxy resin is filled and solidified.
[0018]
【The invention's effect】
According to the first aspect, it is possible to obtain a conductivity detection sensor which is a four-electrode type and has the same size as the two-electrode type and is strong against dirt. In addition, according to the second and third aspects, an integrated conductivity detection sensor with a temperature sensor in which a temperature sensor is embedded in an electrode holder together with four electrodes can be obtained.
[Brief description of the drawings]
1A and 1B show an embodiment of a conductivity detection sensor according to the present invention, wherein FIG. 1A is a side view of the whole, FIG. 1B is a plan view of the same, and FIG. (D) is a front view with the protective cap removed in (c), (e) is a cross-sectional view taken along line AA in (d), and (f) is BB in (d). Sectional view at the line.
[Explanation of symbols]
REFERENCE SIGNS LIST 10 electrode 11 electrode rod-shaped electrode part 13 electrode screw shaft 20 electrode holder 21 electrode support hole 22 support hole rod-shaped electrode part accommodation part 23 support hole screw shaft accommodation part 24 water detection unit 26 second support hole 30 Temperature sensor 31 Temperature sensor main body 32 Temperature sensor large diameter part 33 Temperature sensor oval sensing part 40 Nipple 41 Nipple tool engagement part 42 Nipple large diameter front half 43 Nipple small diameter rear half 45 After electrode holder Sealing material (packing) for sealing between the end and the rear end (step surface 44 ') of the large-diameter hollow portion of the nipple
48 Sealing material (molding agent) filled in the small-diameter hollow portion of the nipple (the inner periphery of the second half of the small diameter)

Claims (3)

Four metal electrodes having a rod-shaped electrode portion and a screw shaft integrally projecting from the rear end thereof, and each of the four electrodes is supported by penetrating through four support holes parallel to the axial direction. A resin electrode holder having a front end portion of the rod-shaped electrode portion of each electrode facing the front end as a water detecting portion, a large-diameter front half portion in which a rear portion of the electrode holder is held in a large-diameter hollow portion, and each electrode. Ri Do and a metallic nipple having a stepped hollow portion having a small diameter rear half portion to draw backward out through the small-diameter hollow portion of the conductive wire that is connected to the rear end of the screw shaft,
The gap between the rod-shaped electrode portions of the four electrodes and the electrode portion-accommodating portion of the support hole of the electrode holder accommodating the rod-shaped electrode portion is sealed with a sealing material that is solidified by high-temperature drying. Seal between the screw shaft and the screw shaft receiving portion of the support hole of the electrode holder accommodating this screw shaft, and between the outer periphery of the rear portion of the electrode holder and the inner periphery of the large-diameter hollow portion of the nipple holding this Is sealed with an O-ring, the rear end of the electrode holder and the rear end of the large-diameter hollow portion of the nipple are sealed with a sealing material, and a lead wire connected to the rear end of the screw shaft of each electrode is drawn out. Fill the inside of the small-diameter hollow part with a sealing material that solidifies due to heat,
The electrode holder is integrally formed with a forward-facing cylinder that surrounds the front-end water-sensing section, and the front end of the front-facing cylinder is closed with a protective cap made of silicone rubber. A high-temperature, high-pressure conductivity detection sensor, characterized in that a water passage hole for causing the water to flow in the diametric direction of the forward-facing cylindrical portion is provided opposite to the diametric direction . 2. The high-temperature and high-pressure conductivity detection sensor according to claim 1, wherein the electrode holder has a second support hole parallel to the electrode support hole, and the second support hole is integrally formed with the rod-shaped electrode portion and the rear end thereof. A single metal temperature sensor having a protruding screw shaft is supported by penetrating in the same direction as the electrodes, and the front end of the temperature sensor is moved from the water detecting section at the front end of the electrode holder to the front end of the four electrodes. A high-temperature, high-voltage conductivity detection sensor characterized by having a long protruding front. 3. The high-temperature and high-voltage conductivity detection sensor according to claim 2 , wherein the four electrodes supported by the electrode holder through the support hole are arranged in a line along a diametrical direction of a front end of the electrode holder. A high temperature and high pressure conductivity detection sensor, wherein one temperature sensor penetrating and supporting the support hole is provided near the center of the front end of the electrode holder.

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