Nitrogen Gas Purification Equipment

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 technology]

[0002] BACKGROUND ART Nitrogen gas purification devices are known that have an adsorption device that adsorbs impurity gases in introduced nitrogen gas at room temperature (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-146628 Summary of the Invention [Problem to be solved by the invention]

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

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a nitrogen gas purification apparatus capable of removing impurity gases that are difficult to remove at room temperature. [Means for solving the problem]

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

[0007] [1] A nitrogen gas purification device comprising an adsorption unit, an introduction path to the adsorption unit, and an exhaust path from the adsorption unit, wherein the nitrogen gas purified by adsorbing impurity gases in nitrogen gas introduced into the adsorption unit from the introduction path is exhausted from the adsorption unit to the exhaust path, The nitrogen gas purifying device, wherein the introduction path has a heat exchanger that cools the nitrogen gas by heat exchange with liquefied nitrogen.

[0008] [2] The nitrogen gas purification apparatus according to [1], wherein the inlet path has a secondary heat exchanger located upstream of the heat exchanger, which cools the nitrogen gas flowing through the inlet path by heat exchange with the nitrogen gas flowing through the exhaust path.

[0009] [3] a thermostatic chamber having a thermostatic chamber surrounded by a vacuum insulation section; the adsorption unit and the heat exchanger are provided in the temperature-controlled chamber, The nitrogen gas purification apparatus according to [2], wherein the secondary heat exchanger is provided within the vacuum insulation section.

[0010] [4] The nitrogen gas purifying apparatus according to [3], further comprising a control unit that adjusts the flow rate and temperature of the liquefied nitrogen introduced into the heat exchanger so that the temperature of a predetermined portion in the temperature-controlled chamber is not lower than -160°C and not higher than -100°C.

[0011] [5] The nitrogen gas purification apparatus (A) according to any one of [1] to [4], The nitrogen gas purifying apparatus (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 exhaust path where the exhaust path (A) of the nitrogen gas purifier (A) and the exhaust path (B) of the nitrogen gas purifier (B) join together; A nitrogen gas purification system in which the nitrogen gas introduced through the common inlet path and discharged to the common discharge path is purified by alternately using the nitrogen gas purification device (A) and the nitrogen gas purification device (B). [Effects 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 room temperature. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating a nitrogen gas purification system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

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

[0015] 1, in one embodiment of the present invention, the nitrogen gas purification apparatus 1 has an adsorption section 2, an inlet path 3 to the adsorption section 2, and an outlet path 4 from the adsorption section 2. The nitrogen gas purification apparatus 1 is configured to adsorb impurity gases (e.g., oxygen, carbon monoxide, carbon dioxide, hydrogen, hydrocarbons, moisture, etc.) in nitrogen gas introduced into the adsorption section 2 from the inlet path 3, and discharge the purified nitrogen gas from the adsorption section 2 to the outlet path 4. The inlet path 3 has a heat exchanger 5 that cools the nitrogen gas by heat exchange with liquefied nitrogen. The direction of the flow of the nitrogen gas is indicated by a thick arrow in FIG. 1.

[0016] According to the above configuration, the nitrogen gas is cooled by heat exchange using liquefied nitrogen in the heat exchanger 5 provided in the introduction path 3 to the adsorption section 2, and the nitrogen gas can be easily brought to a low temperature, for example, above -160°C and below -100°C, without liquefying, so that impurity gases such as hydrocarbons that are difficult to remove at room temperature can be adsorbed in the adsorption section 2.

[0017] The inlet path 3 has a secondary heat exchanger 6 upstream of the heat exchanger 5, which cools the nitrogen gas flowing through the inlet path 3 by heat exchange with the nitrogen gas flowing through the discharge path 4. According to the above configuration, the secondary heat exchanger 6 can efficiently cool the nitrogen gas flowing through the inlet 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 structures 6a each having a first tubular body 6a1 and a second tubular body 6a2 surrounding the first tubular body 6a1, and the nitrogen gas in one of the inlet path 3 and the outlet path 4 (the outlet path 4 in this embodiment) flows radially inside the first tubular body 6a1, while the nitrogen gas in the other of the inlet path 3 and the outlet path 4 (the inlet path 3 in this embodiment) flows radially outside the first tubular body 6a1 and radially inside the second tubular body 6a2. With this configuration, the multi-tube structure 6a can improve the thermal efficiency of heat exchange.

[0019] The multi-pipe structure 6a allows the nitrogen gas in the inlet path 3 to flow in an opposing direction to the nitrogen gas in the outlet path 4. According to the above configuration, the thermal efficiency of heat exchange can be further improved.

[0020] The inlet path 3 and the outlet path 4 (multi-pipe structure 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, taking into consideration space efficiency, etc.

[0021] The auxiliary heat exchanger 6 is not limited to the above configuration, but may have any configuration as long as it cools the nitrogen gas flowing through the inlet path 3 by heat exchange with the nitrogen gas flowing through the outlet path 4. Furthermore, the heat exchanger 5 is not particularly limited as long as it cools the nitrogen gas by heat exchange with liquefied nitrogen, and may have the same configuration as the auxiliary heat exchanger 6 or another configuration.

[0022] The nitrogen gas purification apparatus 1 includes a thermostatic chamber 7 having a thermostatic chamber 7b surrounded by a vacuum insulation section 7a. The adsorption section 2 and heat exchanger 5 are provided within the thermostatic chamber 7b, and the auxiliary heat exchanger 6 is provided within the vacuum insulation section 7a. According to the above configuration, the thermostatic chamber 7b can maintain the adsorption section 2 and the heat exchanger 5 at temperatures suitable for adsorption of impurity gases. Furthermore, by providing the auxiliary heat exchanger 6 within the vacuum insulation section 7a, the auxiliary heat exchanger 6 prevents the low-temperature nitrogen gas flowing through the discharge path 4 from being heated by the outside air, thereby more efficiently cooling the nitrogen gas flowing through the introduction path 3. The thermostatic chamber 7 includes an outer casing 7c and an inner casing 7d, and a vacuum insulation section 7a is defined between the outer casing 7c and the inner casing 7d. A heat insulating material such as perlite may be provided within the vacuum insulation section 7a. The liquefied nitrogen passes through the outer casing 7c and the inner casing 7d in a liquid state toward the temperature-controlled chamber 7b as shown by the white arrows in FIG. 1 and is supplied to the heat exchanger 5, and then is discharged from the temperature-controlled chamber 7b to the outside as shown by the white arrows in FIG. 1.

[0023] The nitrogen gas purification device 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 inside the temperature-controlled chamber 7b is −160° C. or higher and −100° C. or lower (preferably −145° C. or higher and −110° C. or lower, and more preferably −130° C. or higher and −120° C. or lower). According to the above configuration, the temperature of the temperature-controlled chamber 7b can be easily adjusted using the control unit 8 configured by a computer.

[0024] The adsorption unit 2 has an adsorbent, such as activated carbon or zeolite, that adsorbs impurity gases in the nitrogen gas within the adsorption unit 2. More specifically, the adsorption unit 2 has a plurality of adsorption devices 2a (three in this embodiment) each 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 fluidly connected in series, but this is not limiting and they may also be fluidly connected in parallel, for example. The adsorption unit 2 may also be configured to have a single adsorption device 2a.

[0025] In this embodiment, the nitrogen gas purification system 9 includes a nitrogen gas purification apparatus (A) 1A, a nitrogen gas purification apparatus (B) 1B, a common inlet path 10 that branches into an inlet path (A) 3A of the nitrogen gas purification apparatus (A) 1A and an inlet path (B) 3B of the nitrogen gas purification apparatus (B) 1B, and a common exhaust path 11 where an exhaust path (A) 4A of the nitrogen gas purification apparatus (A) 1A and an exhaust path (B) 4B of the nitrogen gas purification apparatus (B) 1B converge, and the nitrogen gas introduced from the common inlet path 10 and discharged to the common exhaust path 11 is purified by alternately using the nitrogen gas purification apparatus (A) 1A and the nitrogen gas purification apparatus (B) 1B. According to the above configuration, the nitrogen gas purifiers (A) 1A and (B) 1B can be alternately used for purification (adsorption of impurity gases) by simply switching whether the nitrogen gas flows through the inlet path (A) 3A or the inlet path (B) 3B from the common inlet path 10. Therefore, while nitrogen gas is being purified in one of the nitrogen gas purifiers (A) 1A and (B) 1B, regeneration (desorption of impurity gases) can be performed in the other of the nitrogen gas purifiers (A) 1A and (B) 1B by, for example, raising the temperature of the adsorption section 2. Therefore, purified nitrogen gas can be continuously obtained through the common exhaust path 11.

[0026] The nitrogen gas purification system 9 has an inlet path switching unit 12 that switches whether nitrogen gas flows from the common inlet path 10 to an inlet path (A) 3A or an inlet path (B) 3B, and an outlet path switching unit 13 that switches whether nitrogen gas flows from an outlet path (A) 4A or an outlet path (B) 4B to the common outlet path 11. Each of the inlet path switching unit 12 and the outlet path switching unit 13 can be configured, for example, by one or more valve bodies provided in the flow path. The flow path switching operation by these valve bodies (inlet path switching unit 12 and outlet path switching unit 13) can be controlled, for example, by 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 modified in various ways without departing from the gist of the present invention. [Explanation of symbols]

[0028] 1. Nitrogen gas purification equipment 1A Nitrogen gas purification device (A) 1B Nitrogen gas purification device (B) 2 Adsorption part 2a Adsorption device 3. Introduction route 3A Introduction Route (A) 3B Introduction route (B) 4. Discharge route 4A Discharge route (A) 4B Emission route (B) 5 Heat exchanger 6. Secondary heat exchanger 6a Multi-pipe structure 6a1 First pipe 6a2 Second pipe 7 Temperature bath 7a Vacuum insulation section 7b Constant temperature room 7c Exterior material 7d interior material 8 Control Unit 9. Nitrogen gas purification system 10 Common introduction pathway 11 Common Emission Pathways 12 Introduction path switching section 13 Discharge path switching section

Claims

1. A nitrogen gas purification device comprising an adsorption unit, an introduction path to the adsorption unit, and an exhaust path from the adsorption unit, wherein the nitrogen gas purified by adsorbing impurity gases in nitrogen gas introduced into the adsorption unit from the introduction path is exhausted from the adsorption unit to the exhaust path, the introduction path includes a heat exchanger that cools the nitrogen gas by heat exchange with liquefied nitrogen, and a secondary heat exchanger that is located upstream of the heat exchanger and cools the nitrogen gas flowing through the introduction path by heat exchange with the nitrogen gas flowing through the discharge path, The nitrogen gas purification device has a thermostatic chamber having a thermostatic chamber surrounded by a vacuum insulation part, the adsorption unit and the heat exchanger are provided in the temperature-controlled chamber, The nitrogen gas purification device, wherein the secondary heat exchanger is provided within the vacuum insulation section.

2. 2. The nitrogen gas purifying apparatus according to claim 1, further comprising a control unit that adjusts the flow rate and temperature of the liquefied nitrogen introduced into the heat exchanger so that the temperature of a predetermined portion in the temperature-controlled chamber is −160° C. or higher and −100° C. or lower.

3. The nitrogen gas purification apparatus (A) according to claim 1; The nitrogen gas purification apparatus (B) according to claim 1; a common introduction path branching 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 exhaust path where the exhaust path (A) of the nitrogen gas purifier (A) and the exhaust path (B) of the nitrogen gas purifier (B) join together; A nitrogen gas purification system in which the nitrogen gas introduced through the common inlet path and discharged to the common discharge path is purified by alternately using the nitrogen gas purification device (A) and the nitrogen gas purification device (B).

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