Nitrogen purification device

Abstract

The purpose of the present invention is to provide a nitrogen gas purification device capable of removing foreign gases that are difficult to remove at room temperature. The present invention provides a nitrogen gas purification device comprising an adsorption unit, an introduction passage leading to the adsorption unit, and a discharge passage connected to the adsorption unit, and a discharge passage for discharging the nitrogen gas from the adsorption part to the discharge passage, the nitrogen gas being purified by adsorbing an impurity gas in the nitrogen gas introduced into the adsorption part from the introduction passage having a heat exchanger for cooling the nitrogen gas by heat exchange with liquid nitrogen.

Description

Technical Field

[0001] This invention relates to a nitrogen purification device. Background Technology

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

[0003] (Existing technical documents)

[0004] (Patent Documents)

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-146628 Summary of the Invention

[0006] (The problem that the invention aims to solve)

[0007] The nitrogen purification device described above can remove impurities such as moisture, but it is difficult to remove impurities such as hydrocarbons.

[0008] Therefore, the object of the present invention is to provide a nitrogen purification device that can remove impurity gases that are difficult to remove at room temperature.

[0009] (The measures taken to solve the problem)

[0010] One aspect of the present invention is described below. [1]

[0012] A nitrogen purification device includes: an adsorption section; an inlet passage leading to the adsorption section; and an outlet passage connected to the adsorption section, wherein the purified nitrogen, which has been adsorbed by impurity gases in the nitrogen introduced into the adsorption section from the inlet passage, is discharged from the adsorption section to the outlet passage.

[0013] The inlet passage includes a heat exchanger that cools the nitrogen gas by utilizing heat exchange with liquid nitrogen. [2]

[0015] According to the nitrogen purification device described in [1], the inlet passage has an auxiliary heat exchanger closer to the upstream side than the heat exchanger, the auxiliary heat exchanger cooling the nitrogen flowing in the inlet passage by means of heat exchange with the nitrogen flowing in the outlet passage. [3]

[0017] According to the nitrogen purification device described in [2], the nitrogen purification device has a constant temperature bath, and the constant temperature bath has a constant temperature chamber surrounded by a vacuum insulation part.

[0018] The adsorption unit and the heat exchanger are located inside the constant temperature chamber.

[0019] The auxiliary heat exchanger is located inside the vacuum insulation section. [4]

[0021] According to the nitrogen purification device described in [3], the nitrogen purification device has 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 specified part of the constant temperature chamber is above -160°C and below -100°C. [5]

[0023] A nitrogen purification system, comprising:

[0024] Nitrogen purification device (A) as described in any one of [1] to [4];

[0025] Nitrogen purification device (B) as described in any one of [1] to [4];

[0026] A common inlet path, which branches into an inlet path (A) of the nitrogen purification device (A) and an inlet path (B) of the nitrogen purification device (B); and

[0027] The common exhaust passage is formed by the merging of the exhaust passage (A) of the nitrogen purification device (A) and the exhaust passage (B) of the nitrogen purification device (B).

[0028] The nitrogen gas is purified by alternately using the nitrogen purification device (A) and the nitrogen purification device (B) to introduce nitrogen gas from the common inlet passage and discharge nitrogen gas to the common outlet passage.

[0029] (The effect of the invention)

[0030] According to the present invention, a nitrogen purification device is provided that can remove impurity gases that are difficult to remove at room temperature. Attached Figure Description

[0031] Figure 1 This is a schematic diagram illustrating a nitrogen purification system according to one embodiment of the present invention. Detailed Implementation

[0032] Hereinafter, embodiments of the present invention will be described by way of example with reference to the accompanying drawings.

[0033] like Figure 1As shown, in one embodiment of the present invention, the nitrogen purification device 1 has an adsorption section 2, an inlet passage 3 leading to the adsorption section 2, and an outlet passage 4 connected to the adsorption section 2. The nitrogen purification device 1 discharges purified nitrogen gas, which has been adsorbed in the adsorption section 2 by impurity gases (e.g., oxygen, carbon monoxide, carbon dioxide, hydrogen, hydrocarbons, moisture, etc.) from the nitrogen gas introduced into the adsorption section 2 from the inlet passage 3, from the adsorption section 2 to the outlet passage 4. The inlet passage 3 has a heat exchanger 5 that cools the nitrogen gas through heat exchange with liquid nitrogen. Furthermore, the direction of nitrogen gas flow is as follows... Figure 1 As shown by the thick arrow in the image.

[0034] According to the above structure, under the action of the heat exchanger 5 provided in the inlet passage 3 leading to the adsorption section 2, the nitrogen gas is cooled by heat exchange with liquid nitrogen. As a result, the nitrogen gas can be easily made into a low temperature state that prevents the nitrogen gas from liquefying, for example, above -160°C and below -100°C. Therefore, impurity gases such as hydrocarbons that are difficult to remove at room temperature can be adsorbed in the adsorption section 2.

[0035] The inlet passage 3 has a secondary heat exchanger 6 located closer to the upstream side than the heat exchanger 5. This secondary heat exchanger 6 cools the nitrogen flowing in the inlet passage 3 by means of heat exchange with the nitrogen flowing in the outlet passage 4. According to the above structure, under the action of the secondary heat exchanger 6, the nitrogen flowing in the inlet passage 3 can be efficiently cooled by using the low-temperature nitrogen discharged from the adsorption section 2 and flowing in the outlet passage 4.

[0036] The auxiliary heat exchanger 6 has one or more (five in this embodiment) multi-tube structure sections 6a. Each multi-tube structure section 6a has a first tube body 6a1 and a second tube body 6a2 surrounding the first tube body 6a1. Nitrogen gas in one of the inlet passage 3 and the outlet passage 4 (outlet passage 4 in this embodiment) flows radially inward to the first tube body 6a1, while nitrogen gas in the other of the inlet passage 3 and the outlet passage 4 (inlet passage 3 in this embodiment) flows radially outward to the first tube body 6a1 and radially inward to the second tube body 6a2. According to this structure, the thermal efficiency of the heat exchange can be improved by the action of the multi-tube structure sections 6a.

[0037] The multi-tube structure 6a allows nitrogen gas in the inlet passage 3 and the outlet passage 4 to flow in opposite directions. Based on this structure, the thermal efficiency of heat exchange can be further improved.

[0038] The inlet passage 3 and outlet passage 4 (multi-tube structure 6a) in the auxiliary heat exchanger 6 can be straight-lined structures, but considering space efficiency, they can also be curved structures such as coils.

[0039] The auxiliary heat exchanger 6 is not limited to the structure described above; it can be any structure that cools the nitrogen flowing in the inlet passage 3 by utilizing heat exchange with the nitrogen flowing in the outlet passage 4. Furthermore, there are no particular limitations on the heat exchanger 5; it can be any structure that cools the nitrogen by utilizing heat exchange with the liquid nitrogen. It can be the same structure as the auxiliary heat exchanger 6, or it can be another structure.

[0040] The nitrogen purification device 1 has a constant temperature bath 7, which has a constant temperature chamber 7b surrounded by a vacuum insulation section 7a. An adsorption section 2 and a heat exchanger 5 are disposed within the constant temperature chamber 7b, and a secondary heat exchanger 6 is disposed within the vacuum insulation section 7a. According to this structure, under the action of the constant temperature chamber 7b, the adsorption section 2 and the heat exchanger 5 can be maintained at a temperature suitable for adsorbing impurity gases. Furthermore, by placing the secondary heat exchanger 6 within the vacuum insulation section 7a, it is possible to prevent the low-temperature nitrogen flowing through the discharge passage 4 in the secondary heat exchanger 6 from being heated by the external air, thereby enabling more efficient cooling of the nitrogen flowing through the inlet passage 3. The constant temperature bath 7 has an outer shell material 7c and an inner shell material 7d, with the vacuum insulation section 7a formed between the outer shell material 7c and the inner shell material 7d. For example, an insulating material such as perlite can be placed in the vacuum insulation section 7a. Liquid nitrogen, such as... Figure 1 As indicated by the white hollow arrow, the liquid is supplied from the outside towards the constant temperature chamber 7b through the outer shell material 7c and the inner shell material 7d to the heat exchanger 5, and then... Figure 1 As indicated by the white hollow arrow, it is discharged from the constant temperature room 7b to the outside.

[0041] The nitrogen purification device 1 includes a control unit 8, which regulates the flow rate and temperature of liquid nitrogen introduced into the heat exchanger 5 to ensure that the temperature of a designated portion within the constant temperature chamber 7b is above -160°C and below -100°C (preferably above -145°C and below -110°C, more preferably above -130°C and below -120°C). According to this structure, the temperature of the constant temperature chamber 7b can be easily adjusted using the computer-configured control unit 8.

[0042] The adsorption section 2 has an adsorbent for adsorbing impurity gases in nitrogen gas, such as activated carbon or zeolite. More specifically, the adsorption section 2 has multiple (three in this embodiment) adsorption devices 2a, each having a housing and adsorbent material filled within the housing, the housing having an inlet and an outlet. In this embodiment, the multiple adsorption devices 2a are fluidly connected in series, but this is not a limitation; they can also be fluidly connected in parallel, for example. The adsorption section 2 may also have a structure with a single adsorption device 2a.

[0043] In this embodiment, the nitrogen purification system 9 includes: a nitrogen purification device (A) 1A, a nitrogen purification device (B) 1B, a common inlet passage 10 branching into an inlet passage (A) 3A of the nitrogen purification device (A) 1A and an inlet passage (B) 3B of the nitrogen purification device (B) 1B, and a common outlet passage 11 formed by the merging of an outlet passage (A) 4A of the nitrogen purification device (A) 1A and an outlet passage (B) 4B of the nitrogen purification device (B) 1B, and the nitrogen purification device (A) 1A and the nitrogen purification device (B) 1B are used alternately to purify the nitrogen introduced from the common inlet passage 10 and discharged to the common outlet passage 11. According to the above structure, by simply switching the flow of nitrogen from the common inlet passage 10 to either inlet passage (A) 3A or inlet passage (B) 3B, the nitrogen purification devices (A) 1A and (B) 1B can be used alternately for purification (adsorption of impurity gases). Therefore, while nitrogen is being purified in one of the nitrogen purification devices (A) 1A or (B) 1B, the adsorption section 2 can be regenerated (desorption of impurity gases) in the other of the nitrogen purification devices (A) 1A or (B) 1B by heating, for example. Therefore, purified nitrogen can be continuously obtained through the common outlet passage 11.

[0044] The nitrogen purification system 9 includes: an inlet path switching unit 12 for switching nitrogen flow from a common inlet path 10 to either inlet path (A) 3A or inlet path (B) 3B; and an outlet path switching unit 13 for switching nitrogen flow from either outlet path (A) 4A or outlet path (B) 4B to a common outlet path 11. Both the inlet path switching unit 12 and the outlet path switching unit 13 can be constructed, for example, by one or more valve bodies provided in the flow path. The flow path switching operation performed by these valve bodies (inlet path switching unit 12 and outlet path switching unit 13) can be controlled, for example, by a control unit 8.

[0045] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. Various modifications can be made to the above embodiments without departing from the spirit of the present invention.

[0046] (Explanation of the labels in the attached diagram)

[0047] 1: Nitrogen purification device; 1A: Nitrogen purification device (A); 1B: Nitrogen purification device (B); 2: Adsorption unit;

[0048] 2a: Adsorption device; 3: Inlet channel; 3A: Inlet channel (A); 3B: Inlet channel (B);

[0049] 4: Discharge passage; 4A: Discharge passage (A); 4B: Discharge passage (B); 5: Heat exchanger;

[0050] 6: Secondary heat exchanger; 6a: Multi-tube structure; 6a1: First tube body; 6a2: Second tube body;

[0051] 7: Thermostatic bath; 7a: Vacuum insulation section; 7b: Thermostatic chamber; 7c: Outer shell material; 7d: Inner shell material;

[0052] 8: Control unit; 9: Nitrogen purification system; 10: Common inlet passage; 11: Common outlet passage;

[0053] 12: Import path switching unit; 13: Discharge path switching unit.

Claims

1. A nitrogen purification device comprising: an adsorption section; an inlet passage leading to the adsorption section; and an outlet passage connected to the adsorption section, wherein nitrogen purified by adsorbing impurity gases in nitrogen introduced into the adsorption section from the inlet passage is discharged from the adsorption section to the outlet passage, characterized in that, The inlet passage has a heat exchanger that cools the nitrogen gas by utilizing heat exchange with liquid nitrogen.

2. The nitrogen purification device according to claim 1, wherein, The inlet passage has an auxiliary heat exchanger located closer to the upstream side than the heat exchanger, which cools the nitrogen flowing in the inlet passage by means of heat exchange with the nitrogen flowing in the outlet passage.

3. The nitrogen purification device according to claim 2, wherein, The nitrogen purification device includes a constant temperature bath, which has a temperature-controlled chamber surrounded by a vacuum insulation layer. The adsorption unit and the heat exchanger are located inside the constant temperature chamber. The auxiliary heat exchanger is located inside the vacuum insulation section.

4. The nitrogen purification device according to claim 3, wherein, The nitrogen purification device has 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 specified part of the constant temperature chamber is above -160°C and below -100°C.

5. A nitrogen purification system, characterized in that, have: The nitrogen purification device (A) according to claim 1; The nitrogen purification device (B) according to claim 1; A common inlet path, which branches into an inlet path (A) of the nitrogen purification device (A) and an inlet path (B) of the nitrogen purification device (B); and The common exhaust passage is formed by the merging of the exhaust passage (A) of the nitrogen purification device (A) and the exhaust passage (B) of the nitrogen purification device (B). The nitrogen gas is purified by alternately using the nitrogen purification device (A) and the nitrogen purification device (B) to introduce nitrogen gas from the common inlet passage and discharge nitrogen gas to the common outlet passage.

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