JP5224828B2 - Oxygen gas detector for liquid fuel storage tank - Google Patents

Description

  The present invention relates to an oxygen gas detector for a liquid fuel storage tank, and more particularly to a stationary oxygen gas detector used for measuring the oxygen gas concentration in a hydrocarbon-based liquid fuel storage tank.

  Conventionally, in storage tanks for hydrocarbon-based liquid fuels such as oil storage bases and oil tankers, there is a risk of explosion if the internal oxygen gas concentration becomes high, so the oxygen gas concentration in the storage tank is measured. An oxygen gas detector is used, and the oxygen gas detector is set to issue a warning when, for example, the oxygen gas concentration exceeds 5% by volume.

  In such an oxygen gas detector, for example, in a supply line for supplying hydrocarbon-based liquid fuel to a storage tank, a gas introduction port faces the supply line in the vicinity of the supply opening of the storage tank. Thus, the gas inlet is provided in a state where the portion where the gas inlet is provided is inserted (see FIG. 5).

  As a certain type of oxygen gas detector, as shown in FIG. 7, for example, an oxygen gas sensor (not shown) such as a diaphragm galvanic cell type sensor is held, and a gas to be inspected with respect to the oxygen gas sensor. A substantially cylindrical housing 70 in which a columnar gas introduction space 72 in which a path for supplying gas is to be formed is partitioned, and a plurality of gas introduction holes are provided in the gas introduction space 72 of the housing 70. A plurality (three in the illustrated example) of the air permeable porous plate-like bodies 75 in which the holes 75A are formed are provided in a state of being separated from each other so as to block the opening 71. The inspection gas introduced into the housing 70 from the gas introduction through hole 75A of the cylindrical body 75 passes through the gas introduction space 72 and covers a gas inlet of the oxygen gas sensor (illustrated). There is a structure to be supplied to the oxygen gas sensor through a gas acting portion made of not).

  However, the oxygen gas detector having such a configuration is supplied because the hydrocarbon-based liquid fuel stored in the storage tank 60 expands in an environment where the temperature is high, such as in summer. The droplets of the hydrocarbon-based liquid fuel ejected from the opening into the supply line adhere to the portion inserted in the supply line of the oxygen gas detector. In particular, when the droplets are attached and held in the gas introduction through-hole 75A of the breathable porous plate 75 in the oxygen gas detector and the vicinity thereof, the gas introduction through-hole 75A is clogged. By being blocked, the air permeability of the air permeable porous plate-like body 75 is hindered, and the supply amount of the gas to be inspected to the oxygen gas sensor is reduced, so that the measurement reliability of the oxygen gas detector cannot be obtained. There's a problem.

In the oxygen gas detector, the inspection target gas is introduced into the housing 70 through a bent path by sequentially passing through the gas introduction through holes 75A of each of the plurality of air-permeable porous plates 75. Since the plurality of breathable porous plate-like bodies 75 are arranged so as to be, the droplets of hydrocarbon-based liquid fuel that enters linearly by the action of the plurality of breathable porous plate-like bodies 75 are It is possible to prevent adhesion to the filter. However, on the other hand, a large area is required in the length direction for disposing a plurality of air-permeable porous plate-like bodies 75 in the gas introduction space 72 of the housing 70 in a state of being separated from each other. Since the path until the inspection target gas introduced into the oxygen gas sensor becomes longer, the time required to supply the inspection target gas to the oxygen gas sensor becomes longer, and as a result, sufficient responsiveness is ensured. There is also a problem that there is a risk that it may become impossible.
In addition, as a prior art of this invention, what is disclosed by the following patent document 1 is mentioned.

JP 2005-321346 A

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide an oxygen gas detector for a liquid fuel storage tank having high measurement reliability and excellent responsiveness. There is.

The oxygen gas detector for a liquid fuel storage tank of the present invention comprises a housing, an oxygen gas sensor held in the housing, and a guard member.
The housing has a gas introduction space that communicates with the gas working part of the oxygen gas sensor,
The guard member has a diameter larger than the diameter of the opening of the gas introduction space, is fixed in the skirt portion of the housing, and is disposed to face the opening of the gas introduction space.
The gas inlet formed by the gap between the guard member and the housing and the gas action part of the oxygen gas sensor are communicated by a bent gas flow path and are not opposed to each other along a straight line. .

In the oxygen gas detector for a liquid fuel storage tank according to the present invention, the housing has a guard member holding portion formed so as to protrude inward in the radial direction, and is held so as to penetrate the guard member holding portion. It is preferable that the guard member is fixed by the use screw, and the head of the holding screw is disposed on the inner surface side of the guard member holding portion.

  According to the oxygen gas detector for a liquid fuel storage tank of the present invention, the gas inlet is formed by the gap between the housing and the guard member, and communicates with the gas action portion of the oxygen gas sensor by the bent gas flow path. Since the gas to be inspected introduced into the gas introduction space from the gas inlet is supplied to the oxygen gas sensor through the curved path, the liquid fuel splashes are generated. Even when the gas enters from the gas inlet, since the splash does not bend and advance, it does not adhere to the gas action part of the oxygen gas sensor arranged to face the gas introduction space, Even when splashes adhere to the guard member, the gas inlet is not clogged and clogged, so the liquid fuel splashes adhere to the oxygen gas sensor. It is necessary to provide a member for forming a curved path in the gas introduction space from the gas inlet to the oxygen gas sensor. Therefore, it is possible to prevent an increase in the time required for supplying the gas to be inspected to the oxygen gas sensor due to the length of the gas introduction space being increased. Excellent responsiveness can be obtained.

  Hereinafter, the oxygen gas detector for a liquid fuel storage tank of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing an example of the configuration of an oxygen gas detector for a liquid fuel storage tank according to the present invention, and FIG. 2 is an enlarged view of the main part of the oxygen gas detector for a liquid fuel storage tank of FIG. FIG. 3 is an enlarged view for explanation, and FIG. 3 is an enlarged view for explanation showing a main part of the oxygen gas detector for the liquid fuel storage tank of FIG. 1 in a cross section different from FIG. 2, and FIG. It is explanatory drawing which shows the shape of the gas inlet of the oxygen gas detector for liquid fuel storage tanks.
This oxygen gas detector for liquid fuel storage tank (hereinafter also referred to as “fuel tank oxygen gas detector”) 10 is an oxygen in a hydrocarbon-based liquid fuel storage tank such as an oil storage base or an oil tanker. It is a stationary detector used to measure the gas concentration.

  The fuel tank oxygen gas detector 10 includes, for example, a detection unit 12 including an oxygen gas sensor 31 such as a diaphragm galvanic cell sensor, and a data processing unit for processing oxygen gas concentration data measured by the detection unit 12 13.

The detection unit 12 of the fuel tank oxygen gas detector 10 includes a housing 20 whose overall shape is a cylindrical shape, and a filter 33 made of, for example, Teflon (registered trademark) is provided in the sensor housing space 25 of the housing 20. An oxygen gas sensor 31 having a structure in which a gas action part is formed by being provided so as to cover the gas inlet is accommodated.
In the example of this figure, the housing 20 includes a housing portion 20A for disposing a sensor cable 35 for transmitting oxygen gas concentration data measured by the detection portion 12 to the data processing portion 13, and the housing. The cap portion 20B is fitted to the tip of the portion 20A (the lower end in FIG. 1). A sensor housing space 25 is formed in the cap portion 20B, and the oxygen gas sensor 31 is held.
In the figure, 21 is an O-ring disposed in the fitting portion between the housing portion 20A and the cap portion 20B, 26 is a C-ring that divides the sensor housing space 25, and 34 is a sensor housing space. 25 is an O-ring disposed together with the filter 33 on the filter mounting portion 25A, 25 is a connector portion for electrically connecting the oxygen gas sensor 31 and the sensor cable 35, and 18 is for a fuel tank. A fixing member used for installing the oxygen gas detector 10, 15 is an external ground, 16 is an external cable, and 17 is a waterproof connector.

The cap 20 </ b> B of the housing 20 communicates with the sensor housing space 25, and is a substantially cylindrical gas that flows so that the gas to be inspected flowing from the opening 22 reaches the filter 33 that constitutes the gas action part of the oxygen gas sensor 31. An introduction space 23 is formed, and a skirt portion 24 formed of a cylindrical protruding edge is suspended from an end portion (lower end portion in FIGS. 2 and 3) where the opening 22 is formed. .
A disc-shaped guard member 40 having a diameter larger than the diameter of the opening 22 of the gas introduction space 23 is provided in the skirt portion 24.
In the example of this figure, the gas introduction space 23 is constituted by a truncated cone portion 23A having an opening 22 and a columnar portion 23B.

The guard member 40 is disposed in the skirt portion 24 of the housing 20 in front of the opening 22 (downward in FIGS. 2 and 3) so as to face the gas inflow opening 22, and the separation distance B is, for example, 1 to 2 mm.
In the example of this figure, the guard member 40 is provided so as to face the filter 33 constituting the gas action part of the oxygen gas sensor 31 through the gas introduction space 23.

The guard member 40 has four screw holes 41 formed at equal intervals on the outer edge portion thereof, and is formed in the housing 20 by a holding screw 45 inward in the radial direction (FIGS. 2 and 3). Are fixed to a guard member holding portion 28 protruding in the left-right direction).
The holding screw 45 is mounted in the through hole 29 of the guard member holding portion 28, and the head 45 </ b> A is fitted into the head fitting insertion portion 29 </ b> A in the through hole 29, whereby the guard member holding portion 28 is arranged on the inner surface side (the upper surface side in FIGS. 2 and 3).

A gas inlet 42 is formed by a gap between the peripheral edge of the guard member 40 and the inner peripheral surface of the skirt portion 24 of the housing 20.
In the example of this figure, the gas inlet 42 is formed in an annular shape so as to go around the periphery of the guard member 40.

The gas inlet 42 preferably has an area of 200 to 300 mm ² in order to obtain a sufficient supply amount of the inspection target gas to the oxygen gas sensor 31.
Further, a separation distance A between the peripheral edge of the guard member 40 and the inner peripheral surface of the skirt portion 24 that forms the gas inlet 42 is, for example, 3 to 4 mm.

Further, the gas inlet 42 is required to be in a state where it is communicated with the filter 33 constituting the gas action portion of the oxygen gas sensor 31 by a bent gas flow path and is not opposed along a straight line.
That is, the inspection target gas introduced into the housing 20 from the gas inlet 42 is an area above the guard member 40 (upward in FIGS. 2 and 3) in the skirt portion 24 (hereinafter referred to as “guard member upper area space”). And the oxygen gas sensor 31 is passed through the gas path forming space consisting of the gas introducing space 23, and the gas to be inspected, which is formed in this gas path forming space, is introduced from the gas inlet 42 and is filtered. The gas path up to 33 is required to be a curved path, not a straight path.
In the example of this figure, the fuel tank oxygen gas detector 10 has a guard member 40 having a diameter larger than the diameter of the opening 22 of the gas introduction space 23. The gas inlet 42 formed so as to make a round of the periphery has a structure in which the filter 33 cannot be directly viewed through the gas path forming space.
In FIG. 3, an example of a route from the gas inlet 42 into the housing 20 through the gas inlet 42 to the filter 33 is indicated by a broken line.

  Here, in the oxygen gas detector 10 for the fuel tank, in order to make the gas inlet 42 and the filter 33 communicate with each other through a bent gas flow path and do not oppose each other along a straight line, for example, gas introduction is performed. The shape of the space 23, the shape of the opening 22 of the gas introduction space 23, the shape of the guard member 40, the separation distance between the guard member 40 and the opening 22, and the like are adjusted.

  The fuel tank oxygen gas detector 10 having such a configuration is configured to supply a hydrocarbon-based liquid fuel 61 to the storage tank 60, for example, as shown in FIG. In the vicinity of the supply opening 60A of the storage tank 60 in the supply line 62 for supply, the fixing member 18 causes the gas inlet 42 to face the supply line 62 so that the tip end portion of the detection unit 12 (in FIGS. 2 and 3). The lower end portion is placed in the inserted state.

  In the fuel tank oxygen gas detector 10, the atmosphere present above the liquid fuel 61 in the storage tank 60 is used as the inspection target gas, and this inspection target gas is introduced into the housing 20 from the gas inlet 42. When supplied to the oxygen gas sensor 31 via the filter 33 constituting the action unit, the oxygen gas concentration in the inspection target gas is measured by the oxygen gas sensor 31, and the measurement data is sent to the data processing unit via the sensor cable 35. 13 is transmitted. The measurement data processing unit 13 issues a warning based on the oxygen gas concentration measurement data transmitted from the detection unit 12, for example, when the oxygen gas concentration exceeds 5% by volume.

  As described above, the fuel tank oxygen gas detector 10 is used by being arranged in a state where the tip portion of the detection unit 12 is inserted into the supply line 62 of the storage tank 60. When the stored liquid fuel 61 expands in an environment where the temperature is high, such as in summer, and is ejected from the supply opening 60 </ b> A into the supply line 62 due to this, it is generated along with this ejection. The sprayed liquid fuel 61 may adhere.

However, in the fuel tank oxygen gas detector 10, the gas inlet 42 is formed around the guard member 40 by a gap between the peripheral edge of the guard member 40 and the inner peripheral surface of the skirt portion 24 in the housing 20. Therefore, even when liquid fuel droplets adhere to the guard member 40, the gas inlet 42 is not clogged and blocked.
Further, since a straight path is not formed in the housing 20 and the gas to be inspected introduced from the gas inlet 42 reaches the filter 33 through a bent gas path, the droplets of the liquid fuel are gas. Even when entering the housing 20 through the inlet 42, the droplets do not bend and travel, and the traveling path is substantially straight, so that the droplets pass through the gas path forming space in the housing 20. Even if it adheres to the partitioning inner peripheral surface, it does not adhere to the filter 33.
Furthermore, since a bent gas path can be formed in the gas introduction space without arranging a member for forming a bent path in the gas introduction space 23, a region for arranging such a member is provided. Accordingly, the gas introduction space is lengthened, and it is possible to prevent the gas path from being lengthened due to this.
Therefore, in the oxygen gas detector 10 for the fuel tank, the gas inlet 42 is blocked by the droplets of the liquid fuel, and the droplets adhere to the filter 33 constituting the gas action part of the oxygen gas sensor 31. Since the supply amount of the inspection target gas to the oxygen gas sensor 31 can be prevented from being reduced, high measurement reliability can be obtained, the gas path is shortened, and the inspection target gas is compared to the oxygen gas sensor 31. Since the time required to supply the pressure can be reduced to, for example, 30 seconds, excellent responsiveness can be obtained.

  Further, in the fuel tank oxygen gas detector 10, the holding screw 45 for fixing the guard member 40 is guarded with the head 45 </ b> A disposed on the inner surface side of the guard member holding portion 28 in the housing 20. Since the member 40 is fixed, the holding screw 45 can be loosened and the holding screw 45 can be prevented from dropping into the supply line 62 or the storage tank 60 together with the guard member 40.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above examples, and various modifications can be made.
For example, as shown in FIG. 6, the guard member 50 is a ring-shaped guard member body 51 having a fixed part 52 formed with, for example, a screw hole 53 connected to a disc-like guard member main body 51, and the periphery of the guard member 50 intermittently. The shape of the gas inlet 55 may be formed.
Here, the oxygen gas detector for a fuel tank in FIG. 6 has the same configuration as the oxygen gas detector for a fuel tank in FIG. 1 except that a guard member 50 is provided instead of the guard member 10. is there.

It is explanatory drawing which shows an example of a structure of the oxygen gas detector for liquid fuel storage tanks of this invention. FIG. 2 is an enlarged explanatory view showing a main part of the oxygen gas detector for the liquid fuel storage tank of FIG. 1 in an enlarged manner. FIG. 3 is an explanatory enlarged view showing a main part of the oxygen gas detector for the liquid fuel storage tank of FIG. 1 in a cross section different from FIG. 2. It is explanatory drawing which shows the shape of the gas inlet_port | entrance of the oxygen gas detector for liquid fuel storage tanks of FIG. It is explanatory drawing which shows the state with which the oxygen gas detector for liquid fuel storage tanks of FIG. 1 is provided in the supply line for supplying hydrocarbon liquid fuel with respect to a storage tank. It is explanatory drawing which shows the other example of a structure of the oxygen gas detector for liquid fuel storage tanks of this invention. It is the elements on larger scale for explanation which show an example of the composition of the conventional oxygen gas detector for liquid fuel storage tanks.

Explanation of symbols

10 Oxygen gas detector for liquid fuel storage tank (oxygen gas detector for fuel tank)
DESCRIPTION OF SYMBOLS 12 Detection part 13 Data processing part 15 External ground 16 External cable 17 Waterproof connector 18 Fixing member 20 Housing 20A Housing part 20B Cap part 21 O-ring 22 Opening 23 Gas introduction space 23A Frustum-shaped part 23B Cylindrical part 24 Skirt part 25 Sensor Accommodating space 25A Filter mounting portion 26 C ring 28 Guard member holding portion 29 Through hole 29A Head fitting insertion portion 31 Oxygen gas sensor 33 Filter 34 O ring 35 Sensor cable 36 Connector portion 40 Guard member 41 Screw hole 42 Gas inlet 45 Retaining screw 45A Head 50 Guard member 51 Guard member main body 52 Fixed portion 53 Screw hole 55 Gas inlet 60 Storage tank 60A Supply opening 61 Liquid fuel 62 Supply line 70 Housing 71 Opening 72 Gas introduction space 75 Breathable porous plate 75A Gas guide Use the through-hole

Claims (2)

A housing, an oxygen gas sensor held in the housing, and a guard member;
The housing has a gas introduction space that communicates with the gas working part of the oxygen gas sensor,
The guard member has a diameter larger than the diameter of the opening of the gas introduction space, is fixed in the skirt portion of the housing, and is disposed to face the opening of the gas introduction space.
The gas inlet formed by the gap between the guard member and the housing and the gas action part of the oxygen gas sensor are communicated by a bent gas flow path and are not opposed to each other along a straight line. Oxygen gas detector for liquid fuel storage tank. The housing has a guard member holding portion formed so as to protrude radially inward, and the guard member is fixed by a holding screw attached so as to penetrate the guard member holding portion. 2. The oxygen gas detector for a liquid fuel storage tank according to claim 1, wherein a head portion thereof is disposed on an inner surface side of the guard member holding portion .

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