JP2803901B2 - Structure of electromagnetic concentration meter detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a component meter for obtaining a concentration from the relationship between a concentration, a conductivity, and a temperature, and more particularly, to an improvement in an electromagnetic densitometer detection unit.

(Prior Art) A method of measuring the conductivity of a solution by an electromagnetic induction method to determine its concentration is disclosed in, for example, Japanese Utility Model Publication No. 54-34632, in which an exciting transformer, a detecting transformer, a liquid junction coil, and an insulating ring are used. When the test liquid is filled in the path and the excitation transformer and the detection transformer are electromagnetically coupled, and an alternating current is applied to the primary coil of the excitation transformer, the AC is generated by electromagnetic induction in the test liquid forming the liquid junction coil. Flows, a voltage corresponding to the AC current flowing in the test liquid is induced in the secondary coil of the detection transformer, and the magnitude of the AC current is proportional to the conductivity of the test liquid. A commonly known solution conductivity or concentration measuring device capable of determining the conductivity of a test solution by measuring a voltage induced in a secondary coil and showing the concentration of the test solution is shown. .

The insulating material used to seal each of the annular transformers is selected based on the properties of the test solution, but is made of a material with excellent chemical resistance such as hard vinyl chloride, heat-resistant polyethylene, and ethylene trifluoride. A tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter, referred to as PFA) is used as a material having a high heat resistance and excellent workability.

For the transformer as a component, a permalloy annular wound core (hereinafter, referred to as a core) of a high magnetic permeability alloy is generally often used for the purpose of reducing the shape and reducing the iron loss.

(Problems to be Solved by the Invention) Even if PFA having high heat resistance and high workability is used as an insulating material for sealing each of the transformers, hydrofluoric acid,
For example, when the detection unit is immersed in a 55% hydrofluoric acid aqueous solution, permeable and highly corrosive hydrofluoric acid gas penetrates the thin part of the PFA, and the copper wire for the coil of the transformer and the transformer There has been a problem that the core body, the lead wire, and the like are corroded, and characteristics are changed within one to three months after the start of use due to disconnection or poor contact, and the function as a detection function of the densitometer cannot be performed.

In addition, many conventional transformer fixing methods are designed so that they are inscribed in the body hole, and the present inventor has doubts about this fixing method, and has repeatedly conducted experimental research on the fixing method and the stability of the output value. The invention has been completed.

(Means for Solving the Problems) The present invention has been made in view of such conventional problems,
An object of the present invention is to provide a structure that can be used for a long period of time even in a hydrofluoric acid aqueous solution and a structure of a detection unit that can obtain a stable output value of an electromagnetic densitometer.

The inventor of the present invention has focused on the relationship between the direction of an external force when a constant external force is applied and the output value of an electromagnetic densitometer (hereinafter referred to as an output value) in a transformer using a permalloy core. While the output value largely fluctuates due to the external force toward the center or in the opposite direction, that is, the inner and outer radial directions (hereinafter referred to as the radial direction), the external force acting in the axial direction has very little effect. It is intended to stabilize the output and extend the life of the equipment against corrosion by considering the method of fixing the transformer based on the result and improving the environment around the fixation, based on the results of the experiment described below. To achieve this, two annular transformers are superimposed on the outer ring-shaped space of the double cylindrical body hole formed at the tip of the body made of an insulator immersed in the test solution,
In the part of the upper body where the double cylindrical body hole is not formed,
It is communicated with the inner cylindrical hole at the center of the inside of the double cylindrical body hole of the body that penetrates the two annular transformers, and penetrates the body horizontally to form a closed circuit by the test liquid. In the structure of the detection unit of the electromagnetic concentration meter having a through-hole formed therein, an introduction hole for injecting dry air or nitrogen gas through the body hole inserted into the transformer in a loose fit state, A plurality of exhaust holes to be discharged are provided, and preferably, a plurality of gear-shaped notches or holes penetrating near the periphery are provided in the annular inner and outer peripheral edges between the transformers. A reinforcing ring for contacting the peripheral edge, and a retainer provided with a concave groove on the inner and outer peripheral edges of the annular inner surface of the bottom of the body hole and a plurality of concave grooves formed or penetrated between the concave grooves. Provided is a structure of an electromagnetic densitometer detection unit comprising a plate.

Further, in the annular transformer having a permalloy core, the transformer is inserted into the body hole in a loose fitting manner, and the axial direction of the transformer is pressed and clamped via a packing made of an elastic body. Provided is a method for fixing a transformer used in a concentration meter detection unit.

(Operation) The structure of the electromagnetic densitometer detection unit of the present invention is such that two
The two annular transformers are mounted in a loose fit state, and an introduction hole through which dry air can be injected from the outside and an exhaust hole through which the air is discharged are provided in the body hole, and dry air or nitrogen gas is always injected. Eliminate corrosive gas to the outside and maintain a favorable environment to prevent corrosion and extend the life of equipment. On the other hand, the fixing of the transformer to be inserted into the body hole is intended to stabilize the output value by pressing and holding the core in the axial direction, thereby eliminating deformation distortion generated in the radial direction of the core having a large output value fluctuation. .

(Example) An example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an assembled vertical sectional view of a partially omitted and notched detector, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a perspective view of a reinforcing ring, and FIG. FIG. 5 shows a perspective view of a holding plate fixed to the bottom of the body hole, FIG. 5 shows a circuit diagram for explaining a measuring method, and FIG. 6 (A) shows a radial load applied to a core to be measured; FIG. 7B is a side view showing the load in the axial direction, and FIG. 7 is an assembled perspective view showing a partially omitted and notched conventional detector.

A detection unit 4 of an electromagnetic densitometer, which is seated by a flange 2 provided with a bolt hole 1 and a body 3 provided below the body 2 is immersed in a test solution of a hydrofluoric acid solution, has a lid 5 on an upper part of the flange. The terminal block 6 is attached inside, and the sockets 7, 8, which are inserted into the side walls,
Further, a connection box 10 for drilling the cable receiving port 9 is fixed, and a support tube 11 for continuously supporting the body 3 is fixed below. The support tube is welded with the same material as the flange 2 using, for example, stainless steel. Structure. The body portion 3 formed with a screw portion 12 on the outer periphery of the support cylinder 11 and screwed to the screw portion is an insulating material which is resistant to the corrosiveness of the test liquid and has excellent workability, for example, PFA.
Is provided, a double cylindrical body hole 13 that covers the top of the head is immersed in the test solution, and an annular excitation transformer 14 and a detection transformer whose core material is made of permalloy are provided in the body hole. Fifteen
Are loosely inserted and sealed.
Fixing inside the transformer 13 is a packing 1 made of an elastic body such as fluoro rubber and having a loose fit shape with respect to the body hole above and below the transformer.
Between the excitation transformer 14 and the detection transformer 15 via the packing, between the excitation transformer 14 and the detection transformer 15, a notch 17 cut out like a tooth tip of a gear at the inner and outer peripheral edges of the ring, or penetrates near the peripheral edge. A reinforcing ring 18 is provided, which is formed by drilling a plurality of holes (not shown) and inserting the holes into the body hole 13. Dimensions.

At the lower part of the body hole 13 below the detection transformer 15, a holding plate 19 that is welded to the body hole lower end via the packing 16 is provided.
The transformers 14 and 15 are fixed by the holding plate, and the fixing is performed by the concave grooves 20 and 20 on the inner and outer peripheral edges of the annular inner surface of the holding plate 19.
And a plurality of grooves 20 ′ extending therebetween are radially cut or pressed in the axial direction by a convex portion of a holding plate having a plurality of holes (not shown) penetrating between the grooves 20, 20. The transformers are supported in a sandwiched shape by applying a load, and are inserted into the annular inner and outer peripheries of the transformers 14 and 15 and the inner and outer cylindrical walls of the body hole 13 so as to have a gap of about 1 to 2 mm.

The trunk 3 between the lower part of the support cylinder 11 and the top of the trunk hole 13
Pierced in a cross shape parallel to the two faces of the flange
The fan-shaped section (see FIG. 2) divided into four sections by a one-pass through-hole 21 for forming a liquid junction circuit which is orthogonally connected to the inner cylinder hole 27 of the cylinder 13 communicates with the body hole 13 and the inside of the support cylinder 11. Inlet 22
And a plurality of exhaust holes 23, one end of a tube 24 provided inside the support cylinder 11 is inserted into the introduction hole, and the other end is connected to the hole of the socket 7 provided on the side surface of the connection box 10. Is inserted together with the tube 24 from the introduction hole 22, and is fastened and connected with a cap nut 25 using a packing (not shown) for fixing the tube, and the socket is connected to a dry air source (not shown) by a pipe or the like. On the other hand, the lead wire 26 from each of the transformers 14 and 15 mounted in the body hole 13 is soldered to the terminal of the terminal block 6 mounted in the connection box 10 via a part of the exhaust hole 23 and the support cylinder 11. And
A cable (not shown) screwed to the terminal block is wired from a cable port 9 to a transmitter and a measuring instrument (not shown),
A pipe or the like is connected to one of the sockets 8 provided on the side wall of the connection box 10 to an abatement facility (not shown).

 Hereinafter, the operation of the present invention will be described.

In the detector 4 of the electromagnetic densitometer in which the body 3 is immersed in the test solution, for example, a dry air having a dew point of about -50 ° C. is introduced into the introduction hole 22 through the socket 7 and the tube 24 from a dry air source (not shown) several liters per minute When constantly injected, the air is sealed into the body hole 13, the exciting transformer 14, the notch portion 17 of the reinforcing ring 18 through the gap between the annular shape of the detection transformer 15 and the body wall cylinder wall, and further, It passes through the concave groove 20, the concave groove portion 20 'of the holding plate 19, passes through the gap in the cylindrical wall of the body hole, passes through the outer cutout 17 of the reinforcing ring 18, and flows to the exhaust hole 23, but during the passage. The thin portion of the PFA body 3, ie, the thick body hole 13
Pressing plate on the cylindrical wall or bottom wall side of the hole 13 excluding the top side of
The highly corrosive gas slightly penetrating from 19 is diluted by dry air that passes through the cutouts 17 and the grooves 20 while contacting the outer surfaces of the transformers 14 and 15, and constantly purges the inside of the trunk hole 13. By spouting from the discharge holes 23, the corrosive environment is changed to a favorable environment without moisture to prevent corrosion of the equipment. On the other hand, the exhaust gas from the exhaust hole 23 is discharged from the socket 8 through the inside of the support cylinder 11 and is absorbed and neutralized by a detoxification facility (not shown).

Each of the transformers 14, 15 to be inserted into the body hole 13 in a loose fitting state sandwiches the packings 16, 16 vertically, and a holding ring 18 is provided between the transformers 16 and 16 so that the fitting with the body hole 13 is smooth. 19 is caused to seal supported by, but cylindrical wall portion of the reinforcing ring 18 Doana 13, namely a thinned portion external force, i.e., to prevent the deformation from external forces generated by the head pressure of the test liquid, practically the sensor 4 Another external force generated at the time is an external force generated by thermal expansion and contraction of the body 3 with a change in the temperature of the test liquid, that is, an external force generated in the axial direction with respect to each of the transformers 14 and 15 is an elastic body. Each of the packings 16, 16 ... absorbs. On the other hand, the external force generated in the radial direction of the transformer is not affected by the provision of a sufficient gap between the body portion 13 and each of the transformers 14 and 15, so that there is no deformation distortion of the core, and the The use of a core sealed with a protective damper material (silicone grease, etc.) in a case made of commercially available organic material such as Bakelite always stabilizes the output of the voltage induced in the secondary coil of the heater 15, and the external force It can be seen from the following experimental results that the stabilization of the above-mentioned characteristics generated from the above is further enhanced.

The measurement method is as shown in FIGS.
, A winding of an exciting coil D is connected thereto, which is connected to an AC power supply, and a detection coil K is wound around the core and connected to an AC voltmeter I, so that a constant AC current flows through the exciting coil D, The weight P is placed on the circular arc of the core C placed on the board via the insulating block B in the radial direction, with or without load. The core C is placed horizontally on the board and the weight is placed on the core via the insulating block B. The voltage from both ends of the detection coil K is read and compared with the load applied or no load in the axial direction where P is placed.

Measurement conditions Magnetomotive force ・ ・ 3mAT Core material ・ ・ Permalloy core size equivalent to JIS PC ・ ・ 35Φ × 25Φ × 5mm Plate thickness 25μm Load ・ ・ 700g Case material and dimensions ・ Phenol case Silicon damper with 38Φ × 22Φ × 8.2mm Evaluation method Output voltage value under no load = W Output voltage value under load = V (W-V) / W x 100 = fluctuation rate. ± (%) Result Output value fluctuation rate. ± (%) As described above, it is apparent that the output value of the load acting in the axial direction is smaller than that in the radial direction, and the core enclosed in the case is further reduced.

In addition, the reinforcing ring 18 provided in the middle of the body hole 13 prevents deformation of the body 3 due to the liquid pressure of the test liquid, stabilizes the shape and dimensions, the cell constant becomes constant, and the transformer 14,
It shows an output value that is always stable with the action of 15 fixed loads.

Furthermore, if the diameters of the coil and the lead wire 26 are increased, and a fluororesin or the like is used as the covering material, the detection unit 4 having higher reliability against corrosion can be obtained.

Needless to say, this configuration can be adopted in other insulating materials instead of PFA.

(Effects of the Invention) The present invention provides an inlet hole and an outlet hole for injecting dry air or nitrogen gas into a transformer sealing portion of a detection unit which is immersed in a highly corrosive test solution. Constant purging can extend the life of equipment with a highly corrosive environment as a favorable environment, and a stable output value can be obtained by a fixing method that has a load in the axial direction of the core, so high accuracy and high reliability It is most suitable as a detection unit of an electromagnetic densitometer.

[Brief description of the drawings]

FIG. 1 is an assembled vertical sectional view of a partially omitted and notched detector, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a perspective view of a reinforcing ring, and FIG. FIG. 5 shows a perspective view of a holding plate fixed to the bottom of the body hole, FIG. 5 shows a circuit diagram for explaining a measuring method, and FIG. 6 (A) shows a radial load applied to a core to be measured; B) is a side view showing the load in the axial direction, and FIG.
FIG. 1 is an assembled perspective view showing a conventional detection unit in which a part is omitted and notched. 3 ... body, 4 ... detection unit 10 ... connection box, 11 ... support cylinder 13 ... body hole, 14 ... excitation transformer 15 ... detection transformer, 16 ... packing 18 ... reinforcement ring , 19 ... Retainer plate 20 ... Concave groove, 20 '... Concave groove 22 ... Introduction hole, 23 ... Discharge hole

Claims (3)

(57) [Claims] An annular transformer is provided in an outer ring-shaped space portion of a double cylindrical body hole formed at a front end portion of a body portion made of an insulating material immersed in a test solution. A part of the upper trunk portion where the double cylindrical trunk hole is not formed has the 2
Penetrating through the torso in a horizontal direction to form a closed path by the test liquid, being communicated with the inner cylindrical hole at the center of the double cylindrical torso of the torso penetrating the two annular transformers. In the structure of the detecting part of the electromagnetic densitometer having the hole formed therein, an introduction hole for injecting dry air or nitrogen gas through the body hole inserted into the transformer in a loose fit shape, and discharging the air or gas. A detection unit structure for an electromagnetic densitometer, wherein a plurality of exhaust holes are formed in the body. 2. A plurality of gear-shaped notches or a plurality of holes penetrating near the periphery of the annular inner and outer peripheries are provided between two superimposed transformers. And a plurality of grooves provided in the outer ring-shaped space at the bottom of the body hole, provided with grooves at the inner and outer peripheral edges, and forming a plurality of grooves extending between them, or grooves at the inner and outer peripheral edges. 2. The structure of the detecting part of the electromagnetic densitometer according to claim 1, further comprising a holding plate having a plurality of holes penetrating therethrough. 3. The detecting part structure of an electromagnetic densitometer according to claim 1, wherein said two annular transformers are pressed and clamped in the axial direction thereof through an elastic packing.