JP2001140759A - Oil separator and very low temperature refrigerating device equipped with oil separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably separate oil from helium gas (refrigerant) by an oil separator. SOLUTION: Plural kinds of nets gradually having coarser meshes along the flow direction of a refrigerant are disposed on the outlet side of glass wool 35 for the refrigerant, a baffle board 40 to prevent oil from being discharged from its upper part with its lower part opened is provided on the outflow side of the coarsest net. Thereby, oil in helium is reliably separated by these plural kinds of nets, and even if oil is discharged to the downstream side from the nets, the oil is not easily discharged from an oil separator 18 by the baffle board 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryogenic refrigeration apparatus used for a cooling device such as a superconducting magnet, a physical property test device or a cryopump at a cryogenic temperature, and an oil separator used for the cryogenic refrigeration device.

[0002]

2. Description of the Related Art Generally, a cryogenic refrigeration system is used for a cryopump that generates a high vacuum pressure by condensing or adsorbing gas molecules to a panel cooled to a cryogenic temperature, and cools the panel to a cryogenic temperature (for example, 10 Å). This is used for cooling a superconducting magnet or a sample to a cryogenic temperature (for example, 4K) by using it for cooling of a superconducting magnet or a physical property test device.

As shown in FIG. 5, such a cryogenic refrigeration system 1 includes a compression unit 3 having a compressor 2 and a refrigerator 4.
Are connected by a refrigerant pipe 5. In the refrigerant pipe 9 of the compression unit 3, a heat exchanger 6 is provided on the discharge side of the compressor 2, and a high-temperature and high-pressure refrigerant pressurized by the compressor 2 (hereinafter, referred to as “helium gas”). Is exchanged with high-pressure gas at room temperature. The high-pressure gas is supplied to the refrigerator 4 and adiabatically expanded, and the low-temperature end 4A of the refrigerator 4 is cooled to a very low temperature.

In FIG. 5, reference numeral 7 denotes an oil separator, reference numeral 8 denotes an adsorber, and reference numeral 50 denotes a buffer tank.

[0005] The oil separator 7 described above has a structure in which glass wool is incorporated in a shell and both sides thereof are held by metal fittings. Then, by flowing the helium gas discharged from the compressor 2 from one side of the shell via the heat exchanger 6, when the helium gas passes through the glass wool, the oil contained in the helium gas is removed by the glass wool. While being captured, only helium gas is allowed to flow out from the other end of the shell, and the oil captured by the glass wool and collected from the lower portion of the other end to the compressor 2 so as to suppress wear of the sliding portion inside the compressor 2. I have to.

[0006]

The state of the oil separator 7 into which the helium gas has flowed is considered to be as follows.

When the oil particles in the helium gas flowing into the oil separator 7 collide with the glass wool fibers, the oil particles adhere to the glass wool fibers.
Further, the next oil fine particles adhere to the oil fine particles adhered to the fiber of the glass wool, and the particles gradually increase in size, and eventually fall downward due to gravity. The glass wool near the inlet of the oil separator 7 is almost wet with oil, but as it goes to the outlet of the oil separator 7, almost no oil particles fall down on the way to the glass wool on the downstream side, and only helium flows from the outlet of the oil separator 7. get out.

The oil particles that have fallen downward due to gravity collectively become liquid and are discharged from the oil outlet.

However, when the flow rate of the helium gas flowing into the oil separator 7 increases or the mixing ratio of the oil particles in the helium increases, the helium cannot be separated within the glass wool and the oil adheres to the mesh of the glass wool on the downstream side. Resulting in.

If oil adheres to the entire surface of the mesh, the flow path of helium gas (glass wool mesh) is closed, and the flow rate of helium gas locally increases. The oil adhering to the mesh is blown off by the helium gas having a high flow rate, and scattered as oil particles in the space on the outlet side in the oil separator 7. It is conceivable that such an outflow of oil eventually enters the refrigerator 4, freezes inside the refrigerator 4, and causes the failure of the refrigerator 4.

When the amount of oil returning to the compressor 2 due to the outflow of oil from the oil separator 7 decreases, the oil shortage in the compressor 2 occurs, and the wear of the sliding portion inside the compressor 2 progresses. Therefore, it is considered that durability is inferior.

SUMMARY OF THE INVENTION The object of the present invention has been made in view of the above-mentioned circumstances, and an oil separator reliably separates helium gas (refrigerant) from oil to make it difficult for oil to enter a refrigerator. Therefore, it is possible to reduce the occurrence of defects in the refrigerator and to improve the durability of the compressor.

[0013]

According to the first aspect of the present invention,
In the oil separator that allows the refrigerant to flow in from one side of the shell in which the glass wool is stored, captures the oil contained in the refrigerant by the glass wool by passing through the glass wool, and allows the refrigerant to flow out from the other side of the shell. On the outlet side of the refrigerant of the glass wool, a plurality of types of nets each having a coarse mesh are sequentially arranged along the flow direction of the refrigerant, and a lower portion of the net is opened on the outflow side of the coarsest net, and this one-piece net is opened. A baffle plate for preventing oil from being discharged from the upper part of the coarse mesh is provided.

The first aspect of the present invention has the following effects. On the outlet side of the glass wool refrigerant, a plurality of types of nets having coarser meshes are sequentially arranged along the flow direction of the refrigerant, so that the oil in the helium is reliably separated by these types of nets. You.

According to a second aspect of the present invention, the baffle plate according to the first aspect has a lower portion opened to form an oil passage.

The second aspect of the present invention has the following operation. Since the lower portion of the baffle plate in the shell is open, the lower portion serves as an oil passage, and the oil flows smoothly in the shell.

According to a third aspect of the present invention, the baffle plate according to the first aspect is provided with a guide path for guiding oil hitting the plate to the inner wall of the shell.

The third aspect of the invention has the following operation. The baffle plate in the shell is provided with a guide path for guiding the oil hitting the plate to the inner wall of the shell, so that the oil hitting the baffle plate flows down smoothly along the inner wall of the shell.

According to a fourth aspect of the present invention, the other side of the shell according to the first aspect is provided with a refrigerant outlet at an upper portion thereof and an oil outlet at a lower portion thereof.

[0020] The invention described in claim 4 has the following operation. On the other side of the shell, the outflow portion of the refrigerant is provided at the upper portion and the outflow portion of the oil is provided at the lower portion, so that the oil and the helium gas can be reliably separated and taken out from the oil separator.

According to a fifth aspect of the present invention, there is provided a compression unit provided with a compressor for compressing and compressing a refrigerant, a refrigerator for realizing an extremely low temperature by the pressurized refrigerant from the compression unit,
Wherein the oil separator according to any one of claims 1 to 4 is disposed on the discharge side of the compressor.

The fifth aspect of the invention has the following operation. According to the fifth aspect of the present invention, since such an oil separator is disposed in the refrigerant circuit of the cryogenic refrigeration system, oil does not easily enter the refrigerator. Further, the durability of the compressor is improved.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a refrigerant circuit in an embodiment of a cryogenic refrigeration apparatus according to the present invention. The cryogenic refrigeration apparatus 10 according to this embodiment is a refrigeration apparatus used for a cryopump or the like and cooling to about 10K, and includes a compression unit 12 having a compressor 11 and a refrigerator 13. .

The compression unit 12 is such that a buffer tank 16 is arranged on the suction side of a refrigerant pipe 15 in which the compressor 11 is arranged, and a heat exchanger 17, an oil separator 18 and an adsorber 19 are arranged in order on the discharge side. The compressor 11 compresses the refrigerant (helium gas) into a high-temperature and high-pressure pressurized refrigerant.

The heat exchanger 17 exchanges heat with the high-temperature and high-pressure refrigerant from the compressor 11 and converts the high-temperature and high-temperature refrigerant at room temperature (for example, about 20
２１21 kg / cm2). Oil separator 18
Separates oil in the refrigerant used for lubrication and cooling in the compressor 11. Further, the adsorber 19 adsorbs the oil that has not been completely removed by the oil separator 18 and volatile components in the oil using activated carbon. The buffer tank 16 is provided with the refrigerator 1 as described later.
3 absorbs the pressure pulsation of the refrigerant generated by the suction and discharge of the refrigerant and guides the refrigerant to the compressor 11.

The refrigerating machine 13 is provided with a normal-temperature high-pressure refrigerant (for example, about 2 ° C.) from an adsorber 19 in the compression unit 12.
0-21 kg / cm 2) is introduced and the adiabatic expansion is repeated to cool the low-temperature end 60 to, for example, about 10K and the low-temperature end 70 to, for example, about 80K. These low-temperature ends 20 constitute a cryopump.

The refrigerator 13 is provided with a suction-side refrigerant pipe 21 and a discharge-side refrigerant pipe 22. Suction side refrigerant pipe 2
1 is connected to the compression unit 12 via the outgoing refrigerant pipe 23.
Is connected to the end of the refrigerant pipe 15 on the adsorber 19 side. As described above, the high-pressure refrigerant from the compressor 11 of the compression unit 12 is introduced into the refrigerator 13 through the outgoing-side refrigerant pipe 23 and the suction-side refrigerant pipe 21. The discharge-side refrigerant pipe 22 is connected to an end of the refrigerant pipe 15 of the compression unit 12 on the buffer tank 16 side via a return-side refrigerant pipe 24. The low-pressure refrigerant (for example, about 4 kg / cm 2) expanded in the refrigerator 13 is returned to the compressor 11 of the compression unit 12 by the discharge-side refrigerant pipe 22 and the return-side refrigerant pipe 24.

Here, the refrigerant pipe 1 of the compression unit 12
5. The suction-side refrigerant pipe 21 and the discharge-side refrigerant pipe 22, and the outgoing-side refrigerant pipe 23 and the return-side refrigerant pipe 24 of the refrigerator 13 form a circulation path through which the refrigerant circulates between the compression unit 12 and the refrigerator 13. Constitute.

The internal structure of the oil separator 18 is as follows.

In FIG. 2, a shell 30 includes a cylindrical central shell 31, a cap-shaped inlet (one side) shell 32,
A cap-shaped outlet (one side) shell 33 is provided, and openings on both sides of the central shell 31 are closed by welding with two inlet / outlet shells 32 and 33.

Numeral 34 denotes a refrigerant inlet pipe connected to the upper part of the inlet shell 32, which is connected to the heat exchanger 17.

Reference numeral 35 denotes a glass wool disposed on the central shell 31. Reference numeral 36 denotes an inlet side press fitting which is disposed at a portion serving as an inlet side of the helium gas and presses one side of the glass wool. is there. Reference numeral 37 denotes a first mesh having a fine mesh, which is disposed at a portion on the helium gas outlet side. 38 is the coarse second
And is disposed on the exit side of the first net 37. Approximately ten second nets 38 are stacked.

Reference numeral 39 denotes an outlet side press fitting which is disposed at a portion on the helium gas outlet side and presses one side of the second net 38, and is a so-called punching metal having a large number of holes formed therein.

Numeral 40 denotes a baffle plate, which is disposed on the exit side of the exit side holding member 39. As shown in FIGS. 3 and 4, the baffle plate 40 has a substantially circular shape, and its lower portion is cut out into a fan shape of about 150 degrees to form an opening 41.

Reference numeral 42 denotes a guide path provided along the upper side of the cut-out portion, which is bent in a substantially U-shape and is inclined so that the center is higher and becomes lower toward both ends. The baffle plate 40 is fixed in the shell 30 by welding the peripheral flange 43 of the baffle plate 40 to the inner wall of the central shell 31.

Reference numeral 44 denotes a refrigerant outlet pipe mounted on the upper part of the outlet shell, which is connected to the adsorber 19 (see FIG. 1). Reference numeral 45 denotes an oil discharge pipe attached to a lower portion of the outlet shell, which is connected to a suction side 80 of the compressor 11 (see FIG. 1).

Reference numeral 46 denotes a leg for fixing the oil separator 18.

The oil separator 18 having such a structure
Then, when helium gas flows in from the refrigerant inlet pipe 34,
The helium gas passes through the glass wool 35. At this time, the oil fine particles in the helium gas become glass wool 35.
These oil fine particles adhere to the fibers of glass wool when the fibers collide with the fibers. Further, the next oil fine particles adhere to the oil fine particles adhered to the glass wool fiber, and the particles gradually increase in size, and eventually fall downward due to gravity.

Accordingly, the glass wool near the refrigerant inlet pipe 34 (near the inlet holding member 36) is almost wet with oil due to this phenomenon. However, as the glass wool near the refrigerant outlet pipe 44 (near the outlet press fitting 39), the glass wool (on the downstream side) almost drops oil particles on the way, only helium becomes, and this helium flows from the hole of the outlet press fitting 39. Discharged. The discharged helium gas is guided to the inside of the outlet shell 33 through the opening 41 of the baffle plate 40, and then reaches the adsorber 19 through the refrigerant discharge pipe 44.

On the other hand, the oil adhering to the fibers of the glass wool 35 and dropping is collected in the lower part 47 of the oil separator 18, and goes to the glass wool 35 near the oil discharge pipe 45 (near the outlet holder 39).
And then returned to the compressor 11 via the oil discharge pipe 45.

However, if the amount of oil in the refrigerant flowing from the refrigerant inlet pipe 34 of the oil separator 18 increases extremely, or if the total amount of refrigerant flowing in increases, the oil cannot be completely separated by the above mechanism. Then, the oil adheres and stays on the surface of the fine mesh (first mesh) 37. When the oil stays in the fine mesh 37, the flow area of the refrigerant gas becomes narrow and the flow rate of the refrigerant increases, so that the oil attached to the fine mesh 37 is blown off. In the case of a conventional oil separator, oil that has become droplets may be discharged from the refrigerant outlet pipe 44 together with the refrigerant.

According to the present invention, however, the droplets blown off from the fine mesh 37 collide with the downstream coarse second mesh 37 due to the large size of the particles and fall downward due to gravity. Therefore, the helium gas and the oil are surely separated in the vicinity of the outlet holding member 39.

Further, even if the oil is discharged from the upper hole 49 of the outlet holding metal fitting 39 without being separated completely,
The oil falls down by hitting the baffle plate 40, is received by the guide path 42, flows on both sides thereof along the guide path 42 as shown by arrows in FIG. 3, travels along the inner wall of the oil separator 18, and passes through the lower portion 48 of the outlet shell 33. And is returned to the compressor 11 via the oil discharge pipe 45 together with the above-described oil.

Thus, the oil separator 18
The oil in the helium gas flowing into the compressor is reliably separated, the oil is returned to the suction side 80 of the compressor 11 (see FIG. 1) via the oil discharge pipe 45, and only the helium gas from which the oil has been removed is supplied to the adsorber 19. Flows to

[0045]

As described above, in the oil separator according to the first aspect, a plurality of types of nets having coarser meshes are sequentially arranged on the outlet side of the glass wool refrigerant along the flow direction of the refrigerant. In addition, a baffle plate is provided on the outflow side of the first coarse mesh to open the lower portion and prevent the oil from being discharged from the upper portion, so that the oil in the helium is reliably separated by these plural types of meshes. However, even if oil is discharged from the net downstream, the oil is hardly discharged from the oil separator by the baffle plate.

According to the second aspect of the present invention, since the lower portion of the baffle plate of the first aspect is opened to form an oil passage,
This lower portion serves as an oil passage so that the oil can be smoothly discharged through the inside of the shell.

According to the third aspect of the present invention, since the baffle plate according to the first aspect is provided with a guide path for guiding the oil hitting the plate to the inner wall of the shell, the baffle plate hits the baffle plate. The oil can smoothly flow down along the inner wall of the shell and be discharged.

According to a fourth aspect of the present invention, the other side of the shell according to the first aspect is provided with a refrigerant outlet at an upper portion thereof and an oil outlet at a lower portion thereof. Oil and helium gas can be separated and taken out.

According to a fifth aspect of the present invention, there is provided a compression unit having a compressor for compressing and pressurizing a refrigerant, a refrigerator for realizing an extremely low temperature by the pressurized refrigerant from the compression unit,
In the cryogenic refrigeration system having the oil separator, the oil separator according to any one of claims 1 to 4 is disposed on the discharge side of the compressor, so that oil does not easily enter the refrigerator.
The durability of the compressor is improved.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a cryogenic refrigeration apparatus provided with an oil separator according to the present invention.

FIG. 2 is an internal structure diagram of the oil separator shown in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view of a baffle plate of the oil separator shown in FIG.

FIG. 5 is a refrigerant circuit diagram of a conventional cryogenic refrigeration apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cryogenic refrigeration apparatus 11 Compressor 12 Compression unit 13 Refrigerator 18 Oil separator 30 Shell 35 Glass wool 37 First net 38 Second net 40 Baffle plate 42 Guide path (oil passage)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomonori Tamura 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. F-term (reference) 3H003 AC03 BH05

Claims (5)

[Claims] 1. A refrigerant is introduced from one side of a shell in which glass wool is stored, and the oil contained in the refrigerant is captured by the glass wool by passing through the glass wool, and the refrigerant flows out from the other side of the shell. In the oil separator to be made, on the outlet side of the refrigerant of this glass wool, a plurality of types of nets each having a coarse mesh are sequentially arranged along the flow direction of the refrigerant, and a lower portion is provided on an outflow side of the coarsest net. An oil separator characterized by having a baffle plate which is opened to prevent oil from being discharged from above the first coarse mesh. 2. A coolant flows in from one end of the shell in which the glass wool is stored, and the oil contained in the coolant is captured by the glass wool by passing through the glass wool, and the coolant flows out from the other side of the shell. In the oil separator, on the outlet side of the refrigerant of the glass wool, a plurality of types of nets each having a coarse mesh are sequentially arranged along the flow direction of the refrigerant, and a lower portion thereof is provided on an outflow side of the coarsest net. An oil separator having a baffle plate which is opened to prevent oil from being discharged from an upper portion of the first coarse mesh, wherein the baffle plate has a lower portion opened to form the oil passage; . 3. A coolant flows in from one end of the shell in which the glass wool is stored, and the oil contained in the coolant is captured by the glass wool by passing through the glass wool, and the coolant flows out from the other side of the shell. In the oil separator, on the outlet side of the refrigerant of the glass wool, a plurality of types of nets each having a coarse mesh are sequentially arranged along the flow direction of the refrigerant, and a lower portion thereof is provided on an outflow side of the coarsest net. A baffle plate which is opened and prevents oil from being discharged from the upper part of the coarse mesh is provided, and a guide path for guiding oil hitting the plate to the inner wall of the shell is provided in the baffle plate. An oil separator. 4. A refrigerant is introduced from one side of the shell in which the glass wool is stored, and the oil contained in the refrigerant is captured by the glass wool by passing through the glass wool, and the refrigerant flows out from the other side of the shell. In the oil separator to be made, on the outlet side of the refrigerant of this glass wool, a plurality of types of nets each having a coarse mesh are sequentially arranged along the flow direction of the refrigerant, and a lower portion is provided on an outflow side of the coarsest net. Is provided with a baffle plate for preventing oil from being discharged from the upper part of the first coarse mesh, and a refrigerant outlet at the upper part and an oil outlet at the lower part on the other side of the shell. An oil separator characterized in that: 5. A cryogenic refrigeration apparatus comprising: a compression unit having a compressor for compressing and pressurizing a refrigerant; and a refrigerator for realizing a cryogenic temperature by the pressurized refrigerant from the compression unit. 5. The cryogenic refrigeration apparatus according to claim 1, wherein the oil separator according to claim 1 is disposed on a discharge side of the cryogenic refrigerator.