JP3122287B2 - Double tube capacitance type density meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-tube capacitance type density meter used for measuring the density of slush fluid.

[0002]

2. Description of the Related Art Slush hydrogen is a type of hydrogen in which solids and liquids coexist, and has a larger amount of cold storage and a higher density than ordinary liquid hydrogen.

FIG. 5 shows an example of an apparatus for filling the produced slush hydrogen into another container, and shows the configuration thereof.

In FIG. 1, a transfer pipe 01 having a flow meter 02 from a storage tank 04 is connected to a filling container 05. A capacitance type density meter 03 is provided in the storage tank 04.

As shown in FIG. 6, a transfer pipe 01 is a double pipe of an outer pipe 1 and an inner pipe 3. The outer side of the inner pipe 3 becomes a vacuum layer 2, and slush hydrogen 06 flows inside the inner pipe 3.

In the example of FIG. 5, slush hydrogen storage tank 04 is pressurized so that slush hydrogen 06
The transfer pipe 01 is provided with a flow meter 02 so as to fill a required amount.

[0007] Filling containers and storage tanks are of various types, ranging from several tens of liters to several thousand liters, and the size of the inner tube 3 of the transfer pipe 01 is used from about 10 mm to several hundred mm.

[0008] The density of the slush hydrogen 06 in the slush hydrogen storage tank 04 is determined by the capacitance type density meter 0 installed in the tank.
Measured at 3.

The capacitance type densitometer 03 is composed of opposed flat electrodes. The capacitance C is given by equation (1).

C = 8.855 × 10 ⁻¹² ε _s A / L (1) where ε _s : relative permittivity (F / m) L: distance between electrodes (m) A: area of electrode (m ² ) By measuring C, ε _s is determined. On the other hand, since ε _s and the density of liquid hydrogen and solid hydrogen are known values, the density can be determined from the ratio of solid in slush hydrogen.

[0011]

The above-mentioned conventional apparatus has the following problems. (1) The density of the liquid coexisting in slush hydrogen is 7
7.0 gr / l, solids 86.5 gr / l. For this reason, if the stirring in the storage tank 04 is not good, the liquid and the solid may be separated, and it is doubtful whether the density of the slush hydrogen 06 filled through the transfer pipe 01 is equal to the density measured in the storage tank 04. (2) As the transfer tube 01 becomes longer, the heat of penetration increases, so that the solid dissolves during the transfer and the density decreases. (3) To accurately measure the flow rate, the density of the slush hydrogen passing through the flow meter 02 is required. (4) For the side using the filled slush hydrogen, the density and the filling amount are the initial data desired at a minimum.

[0012]

The present invention employs the following means to solve the above-mentioned problems.

That is, as a double-tube capacitance-type density meter, a double-tube transfer tube and a cylindrical tube having a cross-sectional shape substantially equal to the cross-sectional shape of the inner tube of the transfer tube are provided inside. Two joints having a cylindrical electrode support tube coaxially, two cylindrical insulating tubes made of an insulator having a cross-sectional shape substantially equal to the cross-sectional shape of the inner tube, and a cross-sectional shape of the inner tube. the absolute almost equal to the first electrode conductor made of a sectional shape was cylindrical, tubular shape with a substantially equal cross-sectional shape as the sectional shape of the electrode supporting tube
Two insulating inner cylinders made of an insulator arranged inside the edge cylinder ;
The electrode supporting tube cross section and the second good conductor made of arranged inside said first electrode substantially equal cross-sectional shape in the tubular
An electrode, wherein the joint, the insulating cylinder, the insulating inner cylinder, the first electrode and the second electrode are provided in the middle of the inner pipe of the transfer pipe in the axial direction.
Along the first joint, the first insulating cylinder and the inside thereof
The first insulating inner cylinder, the first electrode and the
The arranged second electrode, the second insulating cylinder and the inside thereof are arranged.
The second insulating inner cylinder which is location, are sequentially connected coaxially in the order of the second joint.

[0014]

In the above means, when a fluid is caused to flow into the inner pipe of the transfer pipe, the fluid flows through the inner pipe, the joint, the insulating pipe, the insulating inner pipe, and the first pipe.
It flows smoothly through the electrode and the second electrode portion.

Therefore, the capacitance between the first electrode and the second electrode is measured. If the relationship between the density of the fluid and the capacitance is determined in advance by measurement or calculation, the density of the passing fluid is determined.

In this way, the density of the fluid passing through the transfer tube can be determined immediately and accurately.

[0017]

【Example】

(1) An embodiment of the present invention will be described with reference to FIGS.
Note that portions described in the conventional example are assigned the same reference numerals and description thereof is omitted.

As shown in FIG. 1, a double tube capacitance type density meter (hereinafter referred to as a density meter) 01a is provided on the upstream side of a flow meter 02 of a transfer pipe 01 to a filling vessel 05. . Density meter 01a is 2, as shown in FIG. 3, the joint 6 the inner tube 3
A cylindrical of substantially equal cross-sectional shape to the cross-sectional shape of one end pixel
First and second joints respectively connected to the ends of the inner tube 3
6 . A cylindrical electrode support tube 9 is coaxially mounted on a support 10 via a support 10.
The insulating tube 5 is made of an insulating material such as a cylindrical glass having a cross-sectional shape substantially equal to the cross-sectional shape of the inner tube 3, and one end of each of the first and second insulating tubes 5 is provided .
And the other end of the second joint 6 and the other end thereof.
A first and a second connected to both ends of the first electrode 4 respectively.
That consists of an insulating cylinder 6. It is located inside the insulation tube 5
The insulating inner tube 8 is also made of an insulator such as a glass having a cross-sectional shape substantially equal to the cross-sectional shape of the electrode support tube 9, and has one end at each end.
The other end is connected to the end of the electrode support tube 9 and
First and second insulators connected to both ends of the second electrode 7.
That consists of the edge inner cylinder 8.

The other ends of the first and second insulating cylinders 6
First electrode 4 both ends are connected is metallic der of the tubular substantially equal cross-sectional shape to the cross-sectional shape of the inner tube 3 is, was or <br/>, is disposed inside the first electrode 4, First and second absolute
Edge tubular second electrode 7 which at both ends respectively connected to the other end of the 8 that is to that of the tubular substantially equal cross-sectional shape to the cross-sectional shape of the electrode supporting tube 9 made of metal.

In the middle of the inner tube 3, one end of a joint 6 is coaxially welded, and is insulated from the insulating cylinder 5 connected to the other end of the joint 6.
An insulating inner cylinder 8 disposed inside of the tube 5 is熔着with and coaxially to the joint 6. Further, the first electrode 4 and the inside thereof
A second electrode 7 disposed on the in the coaxial end of the insulating tube 5
And the other end of the insulating inner cylinder 8 . Hereinafter, similarly, the insulating cylinder 5, the insulating inner cylinder 8, and the joint are connected. That is, FIG.
As is clear from FIG.
Tube 3, first joint 6, first insulating tube 5, first electrode 4,
2 joint 6 and the inner pipe 3 in this order.
It is provided coaxially inside. On the other hand, the second electrode 7
Supported through the first electrode support 10 inside the joint
The first electrode support cylinder 9, the first insulating inner cylinder 8, the second electrode
7, via the second insulating inner cylinder 8 and the second electrode support
Are connected in the order of the second electrode support cylinder 9 supported by
Inside the system holding the first electrode 4 interposed in the cylinder 3
It is provided coaxially with the tube .

From the electrodes 4 and 7, a joint 6 and an outer tube 1 are provided.
Lead wire 12 via hermetic seal 11 provided in
Has been pulled out. And it is connected to a measuring device not shown.

As described above, the slush hydrogen 06 is transferred to the filling vessel 05 through the inner pipe 3. At this time, since the slush hydrogen 06 passes between the electrodes 4 and 7, the density of the slush hydrogen 06 is measured by measuring the capacitance.

In this way, the density of the slush hydrogen 06 entering the flowmeter 02 is measured with high accuracy just before the filling vessel 05. (2) A second embodiment of the present invention will be described with reference to FIG. First
A bowl-shaped cap 13 having a plurality of holes a is welded to the upstream end and the downstream end of the electrode support tube 9 of the embodiment.

In the above, since most of the slush hydrogen 06 passes between the electrodes 4 and 7, a more accurate density can be obtained.

[0025]

As described above, the present invention has the following effects. (1) The pressure loss of the transfer pipe is small because the second electrode, the insulating inner pipe, and the electrode support pipe installed inside the inner pipe through which the slush hydrogen flows are cylindrical. (2) Since the first electrode is sandwiched by a joint via an insulating cylinder and connected to each other, no special joint such as a flange is required, and the invasion heat is the same as the conventional one.

Since the first electrode has the same shape as the inner tube,
It can be finished with the same dimensions as the conventional transfer tube assembly. (3) The density can be measured accurately just before the filling path to the filling container.

[Brief description of the drawings]

FIG. 1 is an overall system diagram of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the double tube capacitance type density meter of the embodiment.

FIG. 3 is a view taken in the direction of arrows AA in FIG. 2 of the embodiment.

FIG. 4 is a sectional view showing the configuration of a second embodiment of the present invention.

FIG. 5 is an overall system diagram of a conventional example.

FIG. 6 is a sectional view of the transfer pipe of the conventional example.

[Explanation of symbols]

0 1 moves flue 01a density meter 1 outer tube 2 vacuum layer 3 inside pipe 4 first electrode 5 insulating tube 6 joint 7 the second electrode 8 insulated inner tube 9 the electrode supporting tube 10 electrode support 11 hermetically seal 12 leads

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-52776 (JP, A) JP-A-54-21399 (JP, A) JP-A-1-148854 (JP, U) 5480 (JP, B1) (58) Fields studied (Int. Cl. ⁷ , DB name) G01N 27/22 G01N 9/00-9/36 G01R 27/26

Claims (1)

(57) [Claims] 1. A double-tube type transfer tube, and two cylindrical tubes having a cross-sectional shape substantially equal to the cross-sectional shape of an inner tube of the same transfer tube and having a cylindrical electrode support tube coaxially inside thereof. Fittings and
Two insulating cylinders made of insulator and having a cross section substantially equal to the cross section of the inner tube; a first electrode made of a good conductor having a cross section substantially equal to the cross section of the inner tube; Two insulating inner cylinders made of an insulator disposed inside the insulating cylinder in a cylindrical shape having a cross-sectional shape substantially equal to the cross-sectional shape of the electrode supporting cylinder, and a cross-section substantially equal to the cross-sectional shape of the electrode supporting cylinder good guide to shape the the tubular is positioned within the first electrode
A second electrode made of a body , wherein the joint, the insulating tube, the insulating inner tube, the first electrode and the second electrode are provided along the axial direction of the first joint and the second electrode in the middle of the inner tube of the transfer tube . 1 insulating tube and
A first insulating inner cylinder, a first electrode, and
The second electrode disposed therein, the second insulating tube and its
Characterized by being connected coaxially sequentially in the order of a second insulating inner cylinder and a second joint arranged inside the double-walled capacitance type density meter.