Nitrogen gas purification apparatus

Abstract

To provide a nitrogen gas purification apparatus capable of removing impurity gases that are difficult to remove at room temperature.SOLUTION: A nitrogen gas purification apparatus has an adsorption part, an introduction path to the adsorption part, and a discharge path from the adsorption part. The apparatus discharges the nitrogen gas, which is purified by adsorbing impurity gases in the nitrogen gas introduced from the introduction path to the adsorption part at the adsorption part, from the adsorption part to the discharge path. The introduction path has a heat exchanger that cools the nitrogen gas through heat exchange with liquid nitrogen.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a nitrogen gas purification device.

Background Art

[0002] A nitrogen gas purification device having an adsorption device that adsorbs impurity gases in the introduced nitrogen gas at room temperature is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above nitrogen gas purification device can remove impurity gases such as moisture, but it is difficult to remove impurity gases such as hydrocarbons.

[0005] Therefore, an object of the present invention is to provide a nitrogen gas purification device capable of removing impurity gases that are difficult to remove at room temperature.

Means for Solving the Problems

[0006] One aspect of the present invention is as follows.

[0007] [1] A nitrogen gas purification device having an adsorption unit, an introduction path to the adsorption unit, and a discharge path from the adsorption unit, and discharging the purified nitrogen gas from the adsorption unit to the discharge path by adsorbing impurity gases in the nitrogen gas introduced from the introduction path in the adsorption unit, wherein the introduction path has a heat exchanger that cools the nitrogen gas by heat exchange with liquid nitrogen.

[0008] [2] The nitrogen gas purification device according to [1], wherein the introduction path has a secondary heat exchanger upstream of the heat exchanger for cooling the nitrogen gas flowing through the introduction path by heat exchange with the nitrogen gas flowing through the discharge path.

[0009] [3] It has a thermostatic bath having a thermostatic chamber surrounded by a vacuum heat insulation part, The adsorption part and the heat exchanger are provided in the thermostatic chamber, The nitrogen gas purification device according to [2], wherein the secondary heat exchanger is provided in the vacuum heat insulation part.

[0010] [4] The nitrogen gas purification device according to [3], which has a control part for adjusting the flow rate and temperature of the liquefied nitrogen introduced into the heat exchanger so that the temperature of a predetermined part in the thermostatic chamber is -160°C or higher and -100°C or lower.

[0011] [5] The nitrogen gas purification device (A) according to any one of [1] to [4], The nitrogen gas purification device (B) according to any one of [1] to [4], A common introduction path that branches into an introduction path (A) of the nitrogen gas purification device (A) and an introduction path (B) of the nitrogen gas purification device (B), A common discharge path in which a discharge path (A) of the nitrogen gas purification device (A) and a discharge path (B) of the nitrogen gas purification device (B) merge, A nitrogen gas purification system that purifies the nitrogen gas introduced from the common introduction path and discharged to the common discharge path by alternately using the nitrogen gas purification device (A) and the nitrogen gas purification device (B).

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a nitrogen gas purification device capable of removing impurity gases that are difficult to remove at normal temperature.

Brief Description of the Drawings

[0013]

Figure 1

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be exemplarily described with reference to the drawings.

[0015] As shown in FIG. 1, in one embodiment of the present invention, the nitrogen gas purification apparatus 1 has an adsorption unit 2, an introduction path 3 to the adsorption unit 2, and a discharge path 4 from the adsorption unit 2. The nitrogen gas purification apparatus 1 adsorbs impurity gases (for example, oxygen, carbon monoxide, carbon dioxide, hydrogen, hydrocarbons, moisture, etc.) in the nitrogen gas introduced from the introduction path 3 into the adsorption unit 2 by the adsorption unit 2, and discharges the purified nitrogen gas from the adsorption unit 2 to the discharge path 4. The introduction path 3 has a heat exchanger 5 that cools nitrogen gas by heat exchange with liquefied nitrogen. Note that the direction of the flow of nitrogen gas is indicated by a thick arrow in FIG. 1.

[0016] According to the above configuration, by cooling the nitrogen gas by heat exchange using liquefied nitrogen by the heat exchanger 5 provided in the introduction path 3 to the adsorption unit 2, it is possible to easily bring the nitrogen gas into a low temperature state of, for example, -160°C or higher and -100°C or lower without liquefying the nitrogen gas. Therefore, impurity gases such as hydrocarbons that are difficult to remove at normal temperature can be adsorbed by the adsorption unit 2.

[0017] The introduction path 3 has a secondary heat exchanger 6 that cools the nitrogen gas flowing through the introduction path 3 by heat exchange with the nitrogen gas flowing through the discharge path 4 on the upstream side of the heat exchanger 5. According to the above configuration, the secondary heat exchanger 6 can efficiently cool the nitrogen gas flowing through the introduction path 3 by using the low-temperature nitrogen gas discharged from the adsorption unit 2 and flowing through the discharge path 4.

[0018] The auxiliary heat exchanger 6 has one or more (five in this embodiment) multi-tube structure portions 6a each having a double or more multi-tube structure including a first tube body 6a1 and a second tube body 6a2 surrounding the first tube body 6a1. The nitrogen gas in one of the introduction path 3 and the discharge path 4 (the discharge path 4 in this embodiment) flows inside the first tube body 6a1 in the radial direction, and the nitrogen gas in the other of the introduction path 3 and the discharge path 4 (the introduction path 3 in this embodiment) flows outside the first tube body 6a1 in the radial direction and inside the second tube body 6a2 in the radial direction. According to the above configuration, the heat exchange thermal efficiency can be improved by the multi-tube structure portion 6a.

[0019] The multi-tube structure portion 6a causes the nitrogen gas in the introduction path 3 and the nitrogen gas in the discharge path 4 to flow facing each other. According to the above configuration, the heat exchange thermal efficiency can be further improved.

[0020] The introduction path 3 and the discharge path 4 (the multi-tube structure portion 6a) in the auxiliary heat exchanger 6 may be configured to extend linearly, but may also be configured to extend in a curved shape such as a coil shape in consideration of space efficiency and the like.

[0021] The auxiliary heat exchanger 6 is not limited to the above configuration, and any configuration may be used as long as it cools the nitrogen gas flowing through the introduction path 3 by heat exchange with the nitrogen gas flowing through the discharge path 4. Further, the heat exchanger 5 is not particularly limited as long as it is configured to cool the nitrogen gas by heat exchange with the liquefied nitrogen, and may have the same configuration as the auxiliary heat exchanger 6 or other configurations.

[0022] The nitrogen gas purification apparatus 1 has a thermostatic chamber 7 having a thermostatic chamber 7b surrounded by a vacuum heat insulation section 7a. The adsorption section 2 and the heat exchanger 5 are provided in the thermostatic chamber 7b, and the auxiliary heat exchanger 6 is provided in the vacuum heat insulation section 7a. According to the above configuration, the thermostatic chamber 7b can keep the adsorption section 2 and the heat exchanger 5 at a temperature suitable for the adsorption of impurity gases. Further, by providing the auxiliary heat exchanger 6 in the vacuum heat insulation section 7a, it is possible to prevent the low-temperature nitrogen gas flowing through the discharge path 4 in the auxiliary heat exchanger 6 from being warmed by the outside air, and the nitrogen gas flowing through the introduction path 3 can be cooled more efficiently. The thermostatic chamber 7 has an exterior material 7c and an interior material 7d, and the vacuum heat insulation section 7a is partitioned between the exterior material 7c and the interior material 7d. A heat insulating material such as perlite may be arranged in the vacuum heat insulation section 7a. The liquefied nitrogen passes through the exterior material 7c and the interior material 7d in a liquid state toward the thermostatic chamber 7b as shown by the white arrow in FIG. 1 and is supplied to the heat exchanger 5, and then is discharged from the thermostatic chamber 7b to the outside as shown by the white arrow in FIG. 1.

[0023] The nitrogen gas purification apparatus 1 has a control unit 8 that adjusts the flow rate and temperature of the liquefied nitrogen introduced into the heat exchanger 5 so that the temperature of a predetermined portion in the thermostatic chamber 7b is -160°C or higher and -100°C or lower (preferably -145°C or higher and -110°C or lower, more preferably -130°C or higher and -120°C or lower). According to the above configuration, the temperature of the thermostatic chamber 7b can be easily adjusted using the control unit 8 configured by a computer.

[0024] The adsorption section 2 has an adsorbent such as activated carbon or zeolite that adsorbs impurity gases in nitrogen gas within the adsorption section 2. More specifically, the adsorption section 2 has a plurality (three in this embodiment) of adsorption devices 2a having a housing with an inlet and an outlet and an adsorbent filled in the housing. In this embodiment, the plurality of adsorption devices 2a are fluid-connected in series, but are not limited thereto, and may be fluid-connected in parallel, for example. The adsorption section 2 may be configured to have a single adsorption device 2a.

[0025] In this embodiment, the nitrogen gas purification system 9 includes a nitrogen gas purification device (A) 1A, a nitrogen gas purification device (B) 1B, a common introduction path 10 that branches into an introduction path (A) 3A of the nitrogen gas purification device (A) 1A and an introduction path (B) 3B of the nitrogen gas purification device (B) 1B, and a common discharge path 11 where a discharge path (A) 4A of the nitrogen gas purification device (A) 1A and a discharge path (B) 4B of the nitrogen gas purification device (B) 1B merge. The purification of the nitrogen gas introduced from the common introduction path 10 and discharged to the common discharge path 11 is performed by alternately using the nitrogen gas purification device (A) 1A and the nitrogen gas purification device (B) 1B. According to the above configuration, by a simple operation of switching whether to flow the nitrogen gas through the introduction path (A) 3A or the introduction path (B) 3B from the common introduction path 10, the nitrogen gas purification device (A) 1A and the nitrogen gas purification device (B) 1B can be alternately used for purification (adsorption of impurity gas). Therefore, while one of the nitrogen gas purification device (A) 1A and the nitrogen gas purification device (B) 1B is purifying the nitrogen gas, the other of the nitrogen gas purification device (A) 1A and the nitrogen gas purification device (B) 1B can be regenerated (desorbing the impurity gas) by, for example, raising the temperature of the adsorption unit 2. Thus, the purified nitrogen gas can be continuously obtained through the common discharge path 11.

[0026] The nitrogen gas purification system 9 includes an introduction path switching unit 12 that switches whether to flow the nitrogen gas through the introduction path (A) 3A or the introduction path (B) 3B from the common introduction path 10, and a discharge path switching unit 13 that switches whether to flow the nitrogen gas from the discharge path (A) 4A or the discharge path (B) 4B to the common discharge path 11. Each of the introduction path switching unit 12 and the discharge path switching unit 13 can be configured by, for example, one or more valve bodies provided in the flow path. The switching operation of the flow path by these valve bodies (introduction path switching unit 12 and discharge path switching unit 13) can be controlled by, for example, the control unit 8.

[0027] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be variously modified without departing from the gist of the present invention.

Explanation of Reference Numerals

[0028] 1 Nitrogen gas purification device 1A Nitrogen gas purification device (A) 1B Nitrogen gas purification device (B) 2 Adsorption section 2a Adsorption device 3 Introduction path 3A Introduction path (A) 3B Introduction path (B) 4 Discharge path 4A Discharge path (A) 4B Discharge path (B) 5 Heat exchanger 6 Sub-heat exchanger 6a Multi-tube structure section 6a1 First tube body 6a2 Second tube body 7 Constant temperature bath 7a Vacuum insulation section 7b Constant temperature chamber 7c Exterior material 7d Interior material 8 Control section 9 Nitrogen gas purification system 10 Common introduction path 11 Common discharge path 12 Introduction path switching section 13 Discharge path switching section

Claims

1. A nitrogen gas purification apparatus having a suction part, an introduction path to the suction part, and a discharge path from the suction part, and discharging the purified nitrogen gas, which is obtained by adsorbing impurity gases in the nitrogen gas introduced from the introduction path to the suction part by the suction part, from the suction part to the discharge path, The nitrogen gas purification apparatus, wherein the introduction path has a heat exchanger that cools the nitrogen gas by heat exchange with liquid nitrogen.

2. The nitrogen gas purification apparatus according to claim 1, wherein the introduction path has a secondary heat exchanger that cools the nitrogen gas flowing through the introduction path by heat exchange with the nitrogen gas flowing through the discharge path, upstream of the heat exchanger.

3. having a thermostatic bath having a thermostatic chamber surrounded by a vacuum heat insulation part, wherein the suction part and the heat exchanger are provided in the thermostatic chamber, The nitrogen gas purification apparatus according to claim 2, wherein the secondary heat exchanger is provided in the vacuum heat insulation part.

4. The nitrogen gas purification apparatus according to claim 3, further comprising a control unit that adjusts the flow rate and temperature of the liquid nitrogen introduced into the heat exchanger so that the temperature of a predetermined part in the thermostatic chamber is -160°C or higher and -100°C or lower.

5. A nitrogen gas purification apparatus (A) according to claim 1, A nitrogen gas purification apparatus (B) according to claim 1, a common introduction path that branches into an introduction path (A) of the nitrogen gas purification apparatus (A) and an introduction path (B) of the nitrogen gas purification apparatus (B), and a common discharge path in which a discharge path (A) of the nitrogen gas purification apparatus (A) and a discharge path (B) of the nitrogen gas purification apparatus (B) merge, A nitrogen gas purification system that purifies the nitrogen gas introduced from the common introduction path and discharged to the common discharge path by alternately using the nitrogen gas purification apparatus (A) and the nitrogen gas purification apparatus (B).

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