Degassing device

Abstract

A degassing device is provided with: a degassing module having a pipe unit that has gas permeability and separates a fluid flow space from a pressure reduction space; a vacuum pipe connected to the degassing module and communicating with the pressure reduction space of the degassing module; and a discharge device configured so as to be connected to the vacuum pipe and to discharge the gas in the pressure-reduced space to the outside via the vacuum pipe, the vacuum pipe having: a suction pipe section that communicates with the pressure-reduced space and reaches the discharge device from the degassing module; and a buffer tube part branched from the suction tube part, the front end part of which is blocked.

Description

Technical Field The present invention relates to a degassing device. Background Art Patent Document 1 discloses a degasser used in a liquid chromatography apparatus or the like. Prior art literature Patent Literature Patent Document 1: International Publication No. 2007 / 094242 Summary of the invention Problem that the invention aims to solve The degassing device described in Patent Document 1 is configured such that the decompression space in the degassing module provided with the tube unit and the discharge device (pump) are connected by vacuum piping, and the liquid flowing in the tube unit is degassed by operating the discharge device. However, when the discharge device is operated, pulsation of the suction pressure will occur in the vacuum piping and the decompression space. In the degassing module, the tube unit is repeatedly expanded and contracted due to the pulsation, so that the volume of the tube unit increases and decreases, thereby causing disturbances in the flow rate and flow velocity of the liquid flowing in the tube unit. As a result, sometimes it will affect the inspection, etc. Therefore, an object of one aspect of the present invention is to provide a degassing device capable of reducing pulsation of suction pressure generated in a decompression space of a degassing module and suppressing disturbance of the flow rate and flow velocity of a liquid flowing in a pipe unit. Solutions for solving problems

[0001] A degassing device according to one technical solution of the present invention comprises: a degassing module having a pipe unit which is gas permeable and separates a fluid flow space from a decompression space; a vacuum pipe which is connected to the degassing module and communicates with the decompression space of the degassing module; and a discharge device which is configured to be connected to the vacuum pipe and discharge the gas in the decompression space to the outside via the vacuum pipe, wherein the vacuum pipe comprises: a suction pipe portion which is communicated with the decompression space and reaches the discharge device from the degassing module; and a buffer pipe portion which branches from the suction pipe portion, and the front end portion of the buffer pipe portion is blocked. In the degassing device, since the decompression space of the degassing module and the discharge device are connected via the suction pipe portion of the vacuum pipe, as the discharge device works, pulsation of the suction pressure will be generated in the suction pipe portion and the decompression space. However, since the vacuum pipe not only has a suction pipe portion that is connected to the decompression space and reaches the discharge device from the degassing module, but also has a buffer pipe portion that branches from the suction pipe portion and has a blocked front end, the pulsation of the suction pressure will also spread to the buffer pipe portion, thereby reducing the pulsation of the suction pressure generated in the suction pipe portion and the decompression space. Thus, the flow rate and flow velocity of the liquid flowing in the pipe unit of the degassing module can be suppressed. In addition, since the buffer pipe portion branches from the suction pipe portion, the buffer pipe portion can be set even if the suction pipe portion is not made longer. Thus, since the increase in the pressure loss of the gas reaching the discharge device from the decompression space can be suppressed, the discharge efficiency of the discharge device can be suppressed from decreasing. In addition, the arrangement of the suction pipe portion can be easily performed. Alternatively, [2] in the degassing device described in [1], a buffer branch portion where the buffer pipe portion branches off from the suction pipe portion is located on the downstream side of the degassing module in the flow direction of the gas from the degassing module to the discharge device. In this degassing device, by locating the buffer branch portion on the downstream side of the degassing module in the flow direction of the gas from the degassing module to the discharge device, the pulsation of the suction pressure generated in the suction pipe portion can be suppressed by the buffer pipe portion before the pulsation reaches the decompression space. As a result, the pulsation of the suction pressure generated in the decompression space can be further reduced. Alternatively, [3] in addition to the degassing device described in [1] or [2], the degassing device further comprises a detector for detecting the degree of decompression of the decompression space, and the vacuum pipe further comprises a detection pipe section that branches from the suction pipe section and is connected to the detector. In the degassing device, by connecting the detector for detecting the degree of decompression of the decompression space to the detection pipe section that branches from the suction pipe section, the degree of decompression of the decompression space can be appropriately detected. In addition, by providing the detection pipe section independently of the buffer pipe section, the position, shape, etc. of the buffer pipe section can be designed without being restricted by the detector. [4] In the degassing device described in [3], the detection branch portion where the detection piping portion branches off from the suction pipe portion may be located on the upstream side of the buffer branch portion where the buffer pipe portion branches off from the suction pipe portion in the flow direction of the gas from the degassing module to the discharge device. In this degassing device, by making the detection branch portion located on the upstream side of the buffer branch portion in the flow direction of the gas from the degassing module to the discharge device, the pulsation of the suction pressure generated in the suction pipe portion can be reduced by the buffer pipe portion before the pulsation reaches the detection piping portion. Thus, the detection accuracy of the detector can be improved. [5] In the degassing device according to any one of [1] to [4], the inner diameter of the buffer tube portion is the same as the inner diameter of the suction tube portion. In this degassing device, by making the inner diameter of the buffer tube portion the same as the inner diameter of the suction tube portion, the vacuum piping can be easily manufactured. [6] In the degassing device according to any one of [1] to [5], the length of the buffer pipe section is not less than 5% and not more than 30% of the length of the path of the suction pipe section from the degassing module to the discharge device. In this degassing device, by making the length of the buffer pipe section not less than 5% and not more than 30% of the length of the path of the suction pipe section from the degassing module to the discharge device, the buffer pipe section can be easily arranged, and the pulsation of the suction pressure generated in the suction pipe section can be appropriately reduced. [7] In the degassing device according to any one of [1] to [6], the length of the buffer tube section may be not less than 1000% and not more than 1600% of the inner diameter of the buffer tube section. In this degassing device, by making the length of the buffer tube section not less than 1000% and not more than 1600% of the inner diameter of the buffer tube section, the buffer tube section can be easily arranged, and the pulsation of the suction pressure generated in the suction tube section can be appropriately reduced. Alternatively, [8] in addition to the degassing device described in any one of [1] to [7], the degassing device further comprises a plug which can be detachably mounted on the front end of the buffer tube portion to block the front end of the buffer tube portion. In the degassing device, by providing the plug which blocks the front end of the buffer tube portion, the front end of the buffer tube portion can be easily blocked. In addition, when the suction tube portion is mistakenly connected to the exhaust port side of the discharge device during maintenance, etc., and the discharge device is operated in this state, the suction tube portion and the decompression space are pressurized to a relatively high pressure. When the suction tube portion and the decompression space are pressurized to a relatively high pressure, there is a possibility that a detector for detecting the decompression degree of the decompression space, the suction tube portion, etc., may be damaged, or the suction tube portion may fall off from the degassing module. However, since the plug can be detachably mounted on the front end of the buffer tube portion, when the suction tube portion and the decompression space are pressurized to a relatively high pressure, the plug may fall off from the front end of the buffer tube portion, and the suction tube portion and the decompression space may be opened to the atmosphere. Thus, by making the plug function as a safety valve, it is possible to suppress damage to the detector, the suction tube portion, and the like, and to suppress the suction tube portion from falling off from the degassing module. [9] In the degassing device described in [8], the plug may include an insertion portion that is pressed into the buffer tube. In this degassing device, the front end of the buffer tube can be appropriately plugged by providing the plug with an insertion portion that is pressed into the buffer tube. Alternatively,

[10] based on the degassing device described in [9], the degassing module includes a discharge nozzle portion pressed into the suction pipe portion, and the sealing force between the insertion portion and the buffer pipe portion is smaller than the sealing force between the discharge nozzle portion and the suction pipe portion. In this degassing device, by making the sealing force between the insertion portion and the buffer pipe portion smaller than the sealing force between the discharge nozzle portion and the suction pipe portion, it is possible to easily cause the insertion portion to fall off from the buffer pipe portion before the discharge nozzle portion falls off from the suction pipe portion when the suction pipe portion and the decompression space are pressurized to a higher pressure. Therefore, the function of the plug as a safety valve can be further improved. Alternatively,

[11] based on the degassing device described in [9] or

[10] , the degassing module has a discharge nozzle portion that is pressed into the suction pipe portion, and the outer circumference of the insertion portion is smaller than the outer circumference of the discharge nozzle portion. In the degassing device, by making the outer circumference of the insertion portion smaller than the outer circumference of the discharge nozzle portion, the sealing force between the insertion portion and the buffer pipe portion can be made smaller than the sealing force between the discharge nozzle portion and the suction pipe portion. Thus, when the suction pipe portion and the decompression space are pressurized to a higher pressure, it is easy for the insertion portion to fall off from the buffer pipe portion before the discharge nozzle portion falls off from the suction pipe portion. Alternatively,

[12] based on the degassing device described in any one of [9] to

[11] , the degassing module has a cylindrical discharge nozzle portion pressed into the suction pipe portion, the insertion portion is formed in a cylindrical shape, and the outer diameter of the insertion portion is smaller than the outer diameter of the discharge nozzle portion. In the degassing device, by making the outer diameter of the insertion portion smaller than the outer diameter of the discharge nozzle portion, the sealing force between the insertion portion and the buffer pipe portion can be made smaller than the sealing force between the discharge nozzle portion and the suction pipe portion. As a result, when the suction pipe portion and the decompression space are pressurized to a higher pressure, it is easy for the insertion portion to fall off from the buffer pipe portion before the discharge nozzle portion falls off from the suction pipe portion. Alternatively,

[13] in the degassing device described in any one of [9] to

[12] , the degassing module has a discharge nozzle portion that is pressed into the suction pipe portion, and the length of the insertion portion is shorter than the length of the discharge nozzle portion. In the degassing device, by making the length of the insertion portion shorter than the length of the discharge nozzle portion, when the insertion portion and the discharge nozzle portion are pressed into the buffer pipe portion and the suction pipe portion as a whole, the sealing force between the insertion portion and the buffer pipe portion can be smaller than the sealing force between the discharge nozzle portion and the suction pipe portion. Thus, when the suction pipe portion and the decompression space are pressurized to a higher pressure, it is easy for the insertion portion to fall off from the buffer pipe portion before the discharge nozzle portion falls off from the suction pipe portion. Alternatively,

[14] in the degassing device described in any one of [9] to

[13] , the degassing module includes a discharge nozzle portion that is pressed into the suction pipe portion, and the insertion length of the insertion portion relative to the buffer pipe portion is shorter than the insertion length of the discharge nozzle portion relative to the suction pipe portion. In the degassing device, by making the insertion length of the insertion portion relative to the buffer pipe portion shorter than the insertion length of the discharge nozzle portion relative to the suction pipe portion, the sealing force between the insertion portion and the buffer pipe portion can be made smaller than the sealing force between the discharge nozzle portion and the suction pipe portion. Thus, when the suction pipe portion and the decompression space are pressurized to a higher pressure, it is possible to easily cause the insertion portion to fall off from the buffer pipe portion before the discharge nozzle portion falls off from the suction pipe portion. Alternatively,

[15] in the degassing device described in any one of [1] to

[14] , at least a portion of the vacuum pipe is a resin composition containing polyolefin and styrene-type thermoplastic elastomer. In the degassing device, by making at least a portion of the vacuum pipe a resin composition containing polyolefin and styrene-type thermoplastic elastomer, excellent solvent resistance, chemical resistance and durability can be achieved. In addition, gas permeability can be reduced and the vacuum pipe can be prevented from falling off. Furthermore, due to the elasticity of the resin composition containing polyolefin and styrene-type thermoplastic elastomer, the suction pipe portion expands and contracts in accordance with the pulsation of the suction pressure generated in the suction pipe portion. As a result, the pulsation of the suction pressure generated in the suction pipe portion and the decompression space can be further reduced. Effects of the Invention According to an aspect of the present invention, it is possible to reduce the pulsation of the suction pressure generated in the decompression space of the degassing module and suppress the disturbance of the flow rate and flow velocity of the liquid flowing in the pipe unit. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a schematic plan view showing a degassing device according to one embodiment of the present invention. Figure 2 yes Figure 1 A schematic diagrammatic side view of a degassing device is shown. Figure 3 It means that it is installed on Figure 1 Schematic cross-sectional view of an example of a degassing module of the degassing device shown. Figure 4 Yes Figure 3 An enlarged cross-sectional view showing an enlarged view of the vicinity of a connector portion of the degassing module. Figure 5 Yes Figure 1 An enlarged cross-sectional view showing an enlarged view of the vicinity of a connection portion between a buffer tube portion and a plug of a degassing module. Figure 6 Yes Figure 1An enlarged cross-sectional view of the degassing module showing an enlarged view of the vicinity of a connection portion between the degassing module and the suction pipe portion. Figure 7 Yes means Figure 1 Schematic diagram of the degassing module, vacuum piping and exhaust device of the degassing device shown. Figure 8 Yes Figure 1 An enlarged cross-sectional view showing an enlarged view of the vicinity of a vibration-proof member of the degassing device shown. Fig. 9 It is a schematic side view showing another example of a degassing device. Fig.10 Yes Fig. 9 An enlarged cross-sectional view showing an enlarged view of the vicinity of a vibration-proof member of the degassing device shown. Fig.11 It is a schematic side view showing another example of a degassing device. DETAILED DESCRIPTION Hereinafter, the degassing device of the embodiment will be described in detail with reference to the drawings. In addition, in all the drawings, the same reference numerals are attached to the same or corresponding parts, and repeated descriptions are omitted. Figure 1 It is a schematic top view showing a degassing device according to one embodiment. Figure 2 yes Figure 1 A schematic side view of the degassing device is shown. Figure 1 and Figure 2 As shown, the degassing device 1 includes: a housing 5, a degassing module 10, 20, a vacuum pipe 40, a discharge device 50, an atmosphere opening pipe 60, an atmosphere opening valve 70, an adjustment valve 75 and a control unit 80, wherein the housing 5 has a bottom plate 2, a front plate 3 and a rear plate 4. The bottom plate 2 of the housing 5 divides the bottom of the degassing device 1, the front plate 3 of the housing 5 divides the front part of the degassing device 1, and the rear plate 4 of the housing 5 divides the rear part of the degassing device 1. The degassing device 1 is, for example, a degassing device for liquid chromatography, and is used to degas a fluid that is an inspection object of the liquid chromatography. Of course, the degassing device 1 can also be used for gas chromatography, a biochemical analysis device, an inkjet filling device, etc. The degassing modules 10 and 20 have, for example, Figure 3 The structure shown. Figure 3 It means that it is installed on Figure 1 FIG. 1 is a schematic cross-sectional view of an example of a degassing module of the degassing device shown. Figure 4 Yes Figure 3 The enlarged cross-sectional view of the vicinity of the connector portion of the degassing module shown in FIG. Figure 3 The structure of the degassing module 10 is shown, but the other degassing modules 20 have the same structure. Figure 3 and Figure 4 As shown, the degassing module 10 includes: a tube unit 12, which bundles a plurality of tubes 11 at both ends to define a fluid flow space S1 inside; a housing 13, which accommodates the tube unit 12; a cover 14, which hermetically seals an opening 13a of the housing 13; a connector 15 and a connector 16, which connect and fix the tube unit 12 passing through the cover 14; and a discharge nozzle 17 and an open nozzle 18, which protrude from the housing 13. A discharge port 17a communicating with the decompression space S2 is formed in the discharge nozzle 17, and an open port 18a communicating with the decompression space S2 is formed in the open nozzle 18. The degassing module 10 divides the interior of the housing 13 into a fluid circulation space S1 and a decompression space S2 by using a tube unit 12 as a gas permeable membrane having gas permeability. The fluid circulation space S1 is the internal space of each tube 11 of the tube unit 12, and the decompression space S2 is the space outside the tube unit 12. The fluid circulation space S1 is a region to which liquid is supplied, and the liquid introduced from the inlet 12a of the tube unit 12 is supplied to the outlet 12b. The decompression space S2 is a region into which gas is sucked. In addition, in the degassing module 10, liquid is supplied to the internal space of each of the plurality of tubes 11, i.e., the fluid circulation space S1, and gas is sucked from the decompression space S2 outside the plurality of tubes 11, thereby degassing the liquid supplied to the tube unit 12. Each tube 11 constituting the tube unit 12 is a tubular membrane (gas permeable membrane) that allows gas to pass but does not allow liquid to pass (see Figure 4 ). The raw material, film shape, film morphology, etc. of the tube 11 are not particularly limited. As the raw material of the tube 11, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ethylene copolymer resin) (ETFE), polytrifluorochloroethylene (PCTFE), amorphous fluorine-containing polymer (amorphous fluorine resin; AF), polyvinylidene fluoride (PVDF) and other fluorine resins, polypropylene (PP), polymethylpentene (PMP), silicone, polyimide, polyamide. As the amorphous fluorine-containing polymer, for example, Teflon (registered trademark) AF can be mentioned. Although two such degassing modules 10 and 20 are arranged in the degassing device 1, one degassing module may be arranged, or three or more degassing modules may be arranged. like Figure 1 and Figure 2 As shown in FIG. 1 , the vacuum pipe 40 is a member for discharging the gas in each decompression space S2 to the outside. The vacuum pipe 40 includes a suction pipe portion 41 , a discharge pipe portion 42 , a detection pipe portion 43 , and a buffer pipe portion 44 . The suction pipe section 41 is communicated with the decompression spaces S2 of the decompression modules 10 and 20 and connected to the decompression modules 10 and 20 and the discharge device 50 in order to deliver the gas in the decompression spaces S2 of the decompression modules 10 and 20 to the discharge device 50. The suction pipe section 41 includes discharge piping sections 45 and 46 connected to the discharge nozzle sections 17 of the decompression modules 10 and 20, a discharge collection section 47 that collects the discharge piping sections 45 and 46, and a piping section 48 that connects the discharge collection section 47 to the discharge device 50. The exhaust pipe 42 is connected to the exhaust device 50 to exhaust the gas sent to the exhaust device 50 to the outside of the degassing device 1. The end of the exhaust pipe 42 on the opposite side to the exhaust device 50 is attached to the front plate 3 and is open to the outside of the degassing device 1 in front of the front plate 3. The detection piping section 43 is branched from the suction pipe section 41 and connected to the detector 85 in order to detect the degree of decompression in each decompression space S2 of the degassing modules 10 and 20. As described later, the detector 85 is a pressure sensor for detecting the degree of decompression in each decompression space S2 of the degassing modules 10 and 20, and the detector 85 is provided in the control section 80. As will be described later, the buffer tube portion 44 branches off from the suction tube portion 41 , and a front end portion 44 a of the buffer tube portion 44 on the opposite side to the suction tube portion 41 is closed by a plug 90 . At least a portion of the suction pipe section 41 (discharge pipe sections 45, 46, discharge collection section 47 and pipe section 48), the discharge pipe section 42, the detection pipe section 43 and the buffer pipe section 44 constituting the vacuum pipe 40 is composed of, for example, a resin pipe. All or substantially all (for example, except for the connecting parts) of the components of the vacuum pipe 40 may also be composed of resin pipes. In other words, the vacuum pipe 40 may be constructed by connecting a plurality of pipes using connecting members or the like. Such a pipe is composed of a pipe that is resistant to solvents used in liquid chromatography, for example, the rubber hardness of the pipe is preferably within the range of 70±30 degrees and the oxygen permeability of the pipe is 6000cc (STP) cm / cm 2 / sec / cmHg×10 -10Below. The rubber hardness is preferably in the range of 70±30 degrees, but from the viewpoint of both the appropriate flexibility to prevent the loosening and falling off of the connecting part and the appropriate durability to suppress the deformation, crushing and clogging of the tube, the lower limit is more preferably above 50 degrees, further preferably above 55 degrees, and particularly preferably above 60 degrees, and the upper limit is more preferably below 95 degrees, further preferably below 80 degrees, and particularly preferably below 75 degrees. Among them, the rubber hardness represents Shore A, and can be measured, for example, using a durometer (type A) according to the method of JIS K 7312 (1996). In addition, from the viewpoint of excellent durability, the oxygen permeability may be preferably 6000cc (STP) cm / cm 2 / sec / cmHg×10 -10 Below, more preferably 3000cc (STP) cm / cm 2 / sec / cmHg×10 -10 Below, more preferably 1000cc(STP)cm / cm 2 / sec / cmHg×10 -10 Below, particularly preferably 500cc (STP) cm / cm 2 / sec / cmHg×10 -10 Below, and preferably 0.1cc (STP) cm / cm 2 / sec / cmHg×10 -10 More preferably 10cc(STP)cm / cm 2 / sec / cmHg×10 -10 Here, oxygen permeability refers to oxygen permeation rate, and can be measured by, for example, a method in accordance with ASTM D 1434 pressure method. The material of the tube constituting the vacuum pipe 40 is not particularly limited as long as it has the above-mentioned properties. For example, vinyl chloride, silicone rubber; polyamide (nylon) such as nylon 6, nylon 66, nylon 11, and nylon 12; polyurethane; polyethylene such as low-density polyethylene and linear low-density polyethylene, polyolefins such as polypropylene; fluororesins such as FEP, PFA, ETFE, and PTFE; thermoplastic elastomers such as polyester thermoplastic elastomers, styrene thermoplastic elastomers, and olefin thermoplastic elastomers, and one or more of them can be used. As the material of the tube constituting the vacuum pipe 40, a resin composition including polyolefin and thermoplastic elastomer among the above-mentioned materials is more preferred, and a resin composition including polyolefin and styrene thermoplastic elastomer is further preferred. The vacuum pipe 40 is composed of a resin composition including the above-mentioned polyolefin and thermoplastic elastomer, so that it not only has excellent solvent resistance, but also can reduce gas permeability. In addition, the vacuum pipe 40 is composed of a resin composition including the above-mentioned polyolefin and thermoplastic elastomer and has appropriate flexibility, which can also prevent loosening and falling off at the connection part of the discharge collection part 47 during the degassing operation, and can also suppress deformation, crushing, and clogging of the pipe, so the durability is also excellent. In addition, although the degassing device 1 of this embodiment has a plurality of degassing modules, and has a plurality of connection structures such as the connection part of the vacuum pipe 40 and the degassing modules 10, 20, and the connection part with other parts of the discharge collection part 47, it is composed of such a flexible and durable pipe, so that the long-term reliability as a degassing device can be improved. In addition, the styrene-based thermoplastic elastomer used in the vacuum pipe 40 is a copolymer having at least one styrene block (hard segment) and at least one elastomer block. As the elastomer block, vinyl-polydiene, polyisoprene, polybutadiene, polyethylene, polychloroprene or poly-2,3-dimethylbutadiene can be preferably used. The elastomer block can also use an elastomer block after hydrogen is added. If hydrogen is added to the elastomer block, the solvent resistance (solvent resistance) and chemical resistance have a better tendency, which is preferred. As specific examples of styrene-based thermoplastic elastomers, styrene-vinyl isoprene-styrene triblock copolymers (SIS), styrene-isobutylene diblock copolymers (SIB), styrene-butadiene-styrene triblock copolymers (SBS), styrene-ethylene·butylene-styrene triblock copolymers (SEBS), styrene-ethylene·propylene-styrene triblock copolymers (SEPS), styrene-ethylene·ethylene·propylene-styrene triblock copolymers (SEEPS), styrene-butadiene·butylene-styrene triblock copolymers (SBBS), etc. can be cited. Styrene-based thermoplastic elastomers can be used alone or in combination of two or more. Among them, styrene-vinyl isoprene-styrene triblock copolymers are preferably used because of their superior solvent resistance (solvent resistance) and chemical resistance. Preferred examples of such styrene-vinylisoprene-styrene triblock copolymers include "FG 1901G Polymer" and "FG 1924G Polymer" manufactured by Kraton, and HYBRAR 5127 manufactured by Kuraray Co., Ltd. In addition, HYBRAR 7311 manufactured by Kuraray Co., Ltd., which is obtained by adding hydrogen to a vinylisoprene block, can also be preferably used. Regarding the range of the content rate of the styrene block in the styrene-based thermoplastic elastomer (styrene content), the lower limit is preferably 1% by mass, more preferably 5% by mass, and further preferably 10% by mass relative to the total of the styrene block and the elastomer block. Within this range, there is a tendency to obtain better solvent resistance (solvent resistance) and chemical resistance. On the other hand, the upper limit is preferably 30% by mass, more preferably 20% by mass, relative to the total of the styrene block and the elastomer block. Within this range, there is a tendency to obtain better solvent resistance (solvent resistance) and chemical resistance. Regarding the range of the content of the styrene-based thermoplastic elastomer in the resin composition containing polyolefin and styrene-based thermoplastic elastomer, the lower limit is preferably 3% by mass, more preferably 5% by mass, and further preferably 10% by mass relative to the total of the polyolefin and the styrene-based thermoplastic elastomer, and within this range, there is a tendency to obtain good solvent resistance (solvent resistance) and chemical resistance. On the other hand, the upper limit is preferably 30% by mass, more preferably 25% by mass, and further preferably 20% by mass relative to the total of the polyolefin and the styrene-based thermoplastic elastomer, and within this range, there is a tendency to obtain good solvent resistance (solvent resistance) and chemical resistance. Furthermore, in the discharge collecting section 47, the connecting portion connecting the tubes to each other may be made of hard plastic (polypropylene) or the like. The exhaust device 50 is connected to the decompression space S2 of the degassing modules 10 and 20 via the suction pipe portion 41 of the vacuum pipe 40, and the exhaust device 50 exhausts the gas in each decompression space S2 to the outside based on the control instruction from the control unit 80. The exhaust device 50 is arranged above the bottom plate 2. The exhaust device 50 is configured to include, for example, a pump 51, a fixed plate 52 to which the pump 51 is fixed, and the like. The pump 51 is fixed to the upper surface 52a of the fixed plate 52 (the surface on the side opposite to the bottom plate 2). Therefore, the lower surface 52b of the fixed plate 52 (the surface on the bottom plate 2 side) becomes the lowermost surface of the exhaust device 50 (the surface closest to the bottom plate 2 side). The pump 51 includes: a motor 53 for discharging the gas in each decompression space S2 to the outside; an air intake port 54 connected to the piping portion 48 for sucking the gas in each decompression space S2; and an air exhaust port 55 connected to the exhaust pipe portion 42 for discharging the sucked gas to the outside of the degassing device 1. The motor 53 is driven to rotate based on a control instruction from the control unit 80, so that the gas in each decompression space S2 is discharged to the outside. As the pump 51, for example, a diaphragm pump such as a diaphragm type dry vacuum pump is used. The diaphragm pump is a vacuum pump that moves the diaphragm up and down by driving the motor to rotate, and moves the gas from the air intake port to the exhaust port by the up and down movement of the diaphragm. As the fixing plate 52, for example, a rectangular metal plate is used. When the pump 51 is operated to discharge the gas in each decompression space S2 to the outside, pulsation of the suction pressure is generated in the suction pipe section 41 connected to the discharge device 50. In addition, pulsation of the suction pressure is also generated in each decompression space S2 connected to the suction pipe section 41. The above-mentioned buffer pipe section 44 is used to suppress such pulsation of the suction pressure generated in the suction pipe section 410 and each decompression space S2. The buffer pipe section 44 branches from the discharge collection section 47 of the suction pipe section 41 and is connected to the suction pipe section 41. As a result, the buffer pipe section 44 increases the volume of the vacuum piping 40 connected to the suction pipe section 41 to suppress the pulsation of the suction pressure generated in the suction pipe section 410 and each decompression space S2. In addition, unlike the detection piping section 43, the detector 85 is not connected to the buffer pipe section 44. Figure 5 Yes Figure 1 An enlarged cross-sectional view showing an enlarged view of the vicinity of a connection portion between a buffer tube portion and a plug of a degassing module. Figure 6 Yes Figure 1 The enlarged cross-sectional view of the degassing module shown in FIG. Figure 5 and Figure 6 As shown, the inner diameter d1 of the buffer tube portion 44 is not particularly limited. For example, from the viewpoint of being able to easily manufacture the vacuum piping 40, the inner diameter d1 of the buffer tube portion 44 may be the same as the inner diameter d2 of the suction pipe portion 41. In other words, the inner diameter d1 of the buffer tube portion 44 may be the same as the inner diameter d2 of each of the discharge piping portions 45 and 46, the discharge collection portion 47, and the piping portion 48 of the suction pipe portion 41, except for the connection portion of the discharge collection portion 47 that connects the respective pipes to each other. Figure 7 Yes means Figure 1 The schematic diagram of the degassing module, vacuum piping and exhaust device of the degassing device is shown in FIG. Figure 7As shown, the length L1 of the buffer pipe section 44 is not particularly limited. For example, from the viewpoint of being able to appropriately suppress the pulsation of the suction pressure generated in the suction pipe section 41 and each decompression space S2, the length L1 of the buffer pipe section 44 is preferably, for example, 5% or more of the length L2 of the path R from the degassing modules 10 and 20 of the suction pipe section 41 to the discharge device 50, more preferably 7.5% or more of the length L2 of the path R, and further preferably 10% or more of the length L2 of the path R. The path R is, for example, the shortest path from the degassing modules 10 and 20 of the suction pipe section 41 to the discharge device 50. When the degassing module 10 is arranged on the downstream side of the degassing module 20 in the flow direction D of the gas from the degassing modules 10 and 20 to the discharge device 50, the path R is, for example, a path from the degassing module 10 arranged on the downstream side in the flow direction D to the discharge device 50. In addition, the length L1 of the buffer pipe section 44 being 5% of the length L2 of the path R means that the length L1 of the buffer pipe section 44 is 0.05 times the length L2 of the path R. On the other hand, from the viewpoint of being able to easily arrange the buffer pipe section 44, the length L1 of the buffer pipe section 44 is, for example, preferably 30% or less of the length L2 of the path R, more preferably 20% or less of the length L2 of the path R, and further preferably 15% or less of the length L2 of the path R. From these viewpoints, the length L1 of the buffer pipe section 44 is, for example, preferably 5% or more and 30% or less of the length L2 of the path R from the degassing modules 10 and 20 of the suction pipe section 41 to the discharge device 50, more preferably 7.5% or more and 20% or less of the length L2 of the path R, and further preferably 10% or more and 15% or less of the length L2 of the path R. like Figure 5 and Figure 7As shown, for example, from the viewpoint of being able to appropriately suppress the pulsation of the suction pressure generated in the suction pipe section 41 and each decompression space S2, the length L1 of the buffer pipe section 44 is preferably, for example, 1000% or more of the inner diameter d1 of the buffer pipe section 44, more preferably 1100% or more of the inner diameter d1 of the buffer pipe section 44, and further preferably 1200% or more of the inner diameter d1 of the buffer pipe section 44. In addition, the length L1 of the buffer pipe section 44 being 1000% of the inner diameter d1 of the buffer pipe section 44 means that the length L1 of the buffer pipe section 44 is 10 times the inner diameter d1 of the buffer pipe section 44. On the other hand, from the viewpoint of being able to easily arrange the buffer pipe section 44, the length L1 of the buffer pipe section 44 is preferably, for example, 1600% or less of the inner diameter d1 of the buffer pipe section 44, more preferably 1500% or less of the inner diameter d1 of the buffer pipe section 44, and further preferably 1400% or less of the inner diameter d1 of the buffer pipe section 44. From these viewpoints, the length L1 of the buffer tube portion 44 is, for example, preferably not less than 1000% and not more than 1600% of the inner diameter d1 of the buffer tube portion 44, more preferably not less than 1100% and not more than 1500% of the inner diameter d1 of the buffer tube portion 44, and further preferably not less than 1200% and not more than 1400% of the inner diameter d1 of the buffer tube portion 44. like Figure 1 and Figure 7 As shown in FIG. 1 , the portion where the buffer pipe section 44 branches from the suction pipe section 41 is referred to as the buffer branch section B1, and the portion where the detection pipe section 43 branches from the suction pipe section 41 is referred to as the detection branch section B2. In this case, the buffer branch section B1 and the detection branch section B2 may be at any position of the suction pipe section 41. For example, from the viewpoint of further reducing the pulsation of the suction pressure generated in the decompression space S2, the buffer branch section B1 is preferably located on the downstream side of the degassing modules 10 and 20 in the flow direction D of the gas from the degassing modules 10 and 20 to the discharge device 50. That is, on the path R of the suction pipe section 41 from the degassing modules 10 and 20 to the discharge device 50, the buffer branch section B1 is located on the discharge device 50 side relative to the degassing modules 10 and 20. In addition, from the viewpoint of improving the detection accuracy of the detector 85, the detection branch section B2 is preferably located on the upstream side of the buffer branch section B1 in the flow direction D of the gas from the degassing modules 10 and 20 to the discharge device 50. That is, on the route R of the suction pipe portion 41 from the degassing modules 10 and 20 to the discharge device 50 , the detection branch portion B2 is preferably located on the side opposite to the discharge device 50 relative to the buffer branch portion B1 . like Figure 1 , Figure 5 and Figure 7As shown, the plug 90 is detachably mounted on the front end portion 44a of the buffer tube portion 44 so as to fall off from the front end portion 44a of the buffer tube portion 44 when the suction tube portion 41 and the decompression space S2 are pressurized to a relatively high pressure. That is, the plug 90 is mounted on the front end portion 44a of the buffer tube portion 44 to block the front end portion 44a of the buffer tube portion 44, and the plug 90 falls off from the front end portion 44a of the buffer tube portion 44 to open the front end portion 44a of the buffer tube portion 44. The plug 90 includes an insertion portion 91 pressed into the buffer tube portion 44 and an expanded diameter portion 92 expanded in diameter relative to the insertion portion 91. The insertion portion 91 is pressed into the front end portion 44a of the buffer tube portion 44 to block the front end portion 44a of the buffer tube portion 44. The insertion portion 91 may be in any shape as long as it can block the front end portion 44a of the buffer tube portion 44 by being pressed into the front end portion 44a of the buffer tube portion 44. For example, the insertion portion 91 may be cylindrical. The outer circumference of the insertion portion 91 is longer than the inner circumference of the front end portion 44a of the buffer tube portion 44. When the insertion portion 91 is formed in a cylindrical shape, the outer diameter D1 of the insertion portion 91 is larger than the inner diameter of the front end portion 44a of the buffer tube portion 44. The inner diameter of the front end portion 44a of the buffer tube portion 44 does not refer to the inner diameter of the front end portion 44a of the buffer tube portion 44 that is enlarged by the insertion portion 91 being pressed in, but refers to the inner diameter of the front end portion 44a of the buffer tube portion 44 before the insertion portion 91 is pressed in. The diameter-enlarged portion 92 is enlarged relative to the insertion portion 91, thereby forming a step between the insertion portion 91 and the insertion portion 91. The diameter-enlarged portion 92 abuts against the end surface of the front end portion 44a of the buffer tube portion 44 via the step, thereby limiting the amount (the length) of the insertion portion 91 being pressed relative to the front end portion 44a of the buffer tube portion 44. In addition, the outer diameter of the diameter-enlarged portion 92 is larger than the outer diameter of the front end portion 44a of the buffer tube portion 44 that is enlarged by the insertion of the insertion portion 91, for example, so that the diameter-enlarged portion 92 also serves as a handle for pulling the insertion portion 91 out of the front end portion 44a of the buffer tube portion 44. like Figure 5 and Figure 6As shown, in the degassing device 1, the close fitting force between the insertion portion 91 and the buffer tube portion 44 is smaller than the close fitting force between the discharge nozzle portion 17 and the suction tube portion 41, so that when the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure, the plug 90 is easy to fall off from the buffer tube portion 44 before the discharge nozzle portion 17 falls off from the suction tube portion 41. As such a structure, for example, a structure in which the outer circumferential length of the insertion portion 91 is smaller than the outer circumferential length of the discharge nozzle portion 17 can be set. In addition, when the discharge nozzle portion 17 and the insertion portion 91 are formed in a cylindrical shape, a structure in which the outer diameter D1 of the insertion portion 91 is smaller than the outer diameter D2 of the discharge nozzle portion 17 can be set. In addition, when the insertion portion 91 and the discharge nozzle portion 17 are integrally pressed into the buffer tube portion 44 and the suction tube portion 41, a structure in which the length L3 of the insertion portion 91 is shorter than the length L4 of the discharge nozzle portion 17 can be set. In addition, it is possible to set a structure in which, when any portion of the insertion portion 91 and the discharge nozzle portion 17 are pressed into the buffer tube portion 44 and the suction tube portion 41, the insertion length L5 of the insertion portion 91 relative to the buffer tube portion 44 is shorter than the insertion length L6 of the discharge nozzle portion 17 relative to the suction tube portion 41. like Figure 1 and Figure 2 As shown, the discharge device 50 is supported on the bottom plate 2 of the housing 5 by means of four vibration-proof members 101. The four vibration-proof members 101 have the same structure, and therefore, except for the case where they are specifically described separately, they are described together as the vibration-proof members 101. The vibration-proof member 101 is a member for attenuating vibration and suppressing vibration transmission. The vibration-proof member 101 is interposed between the bottom plate 2 and the discharge device 50 (fixed plate 52) and supports the discharge device 50 relative to the bottom plate 2. The four vibration-proof members 101 are arranged at the four corners of the fixed plate 52 when viewed from above, and support the discharge device 50 (fixed plate 52) at the four corners of the fixed plate 52. The discharge device 50 is arranged at a position at a predetermined height from the upper surface 2a of the bottom plate 2 (the surface on the discharge device 50 side) by the vibration-proof member 101. The vibration-proof member 101 has, for example, Figure 8 The structure shown. Figure 8 Yes Figure 1 The enlarged cross-sectional view of the vicinity of the vibration-proof member of the degassing device shown in FIG. Figure 8As shown, the vibration-proof member 101 is interposed between the base plate 2 and the fixing plate 52, and supports the fixing plate 52 relative to the base plate 2. The vibration-proof member 101 has: a neck 101a, which is inserted into the through hole 52c of the fixing plate 52; an upper diameter-enlarged portion 101b, which extends from the neck 101a to the upper surface 52a side of the fixing plate 52 and expands in diameter; a lower diameter-enlarged portion 101c, which extends from the neck 101a to the lower surface 52b side of the fixing plate 52 and expands in diameter; and a through hole 101d, which passes through the neck 101a, the upper diameter-enlarged portion 101b, and the lower diameter-enlarged portion 101c. The upper diameter-enlarged portion 101b and the lower diameter-enlarged portion 101c are larger than the aperture of the through hole 52c of the fixing plate 52 to prevent the through hole 52c of the fixing plate 52 from passing through. Then, the screw 102 is inserted into the through hole 101d of the vibration-proof member 101 from the upper surface 52a side of the fixing plate 52, and is screwed into the screw hole 2c of the bottom plate 2. Thus, the upper enlarged diameter portion 101b and the lower enlarged diameter portion 101c clamp the fixing plate 52 from the upper surface 52a side and the lower surface 52b side, and the lower enlarged diameter portion 101c is pressed against the bottom plate 2, and the discharge device 50 is supported on the bottom plate 2 via the vibration-proof member 101. In addition, by making the lower enlarged diameter portion 101c a spacer between the fixing plate 52 and the bottom plate 2, the fixing plate 52 is arranged at a predetermined height from the bottom plate 2. like Figure 1 and Figure 2 As shown, the atmosphere opening piping 60 is a member that communicates with each decompression space S2 of the degassing modules 10 and 20 and is used to connect each decompression space S2 to the atmosphere opening valve 70. The atmosphere opening piping 60 includes open piping parts 61 and 62 connected to each open port 18a of the degassing modules 10 and 20, an open collection part 64 that collects the open piping parts 61 and 62, and a pipe 65 that connects the open collection part 64 to the atmosphere opening valve 70. The end 66 of the open collection part 64 of the atmosphere opening piping 60 on the side opposite to the pipe 65 is closed. The atmosphere opening piping 60 is made of the same material as the vacuum piping 40, for example, a resin pipe. More specifically, at least a part of the open piping parts 61 and 62, the open collection part 64, and the pipe 65 that constitute the atmosphere opening piping 60 is made of, for example, a resin pipe as described above. All or substantially all (for example, except for the connecting portion) of the constituent members of the atmosphere-release piping 60 may also be formed of resin pipes. That is, the atmosphere-release piping 60 may be formed by connecting a plurality of resin pipes using connecting members or the like. Such a resin pipe is formed of a pipe that is resistant to the solvent used in liquid chromatography, has a rubber hardness in the range of 70±30 degrees, and has an oxygen permeability of 6000cc(STP)cm / cm 2 / sec / cmHg×10 -10In addition, similar to the connection part of the discharge collection part 47, the connection part of the open collection part 64 may also be composed of hard plastic (for example, polypropylene) or the like. The atmosphere release valve 70 is a solenoid valve that is connected to one end of the atmosphere release pipe 60 and can introduce the atmosphere into each decompression space S2 of the degassing modules 10 and 20 at one go through the atmosphere release pipe 60 based on a control instruction from the control unit 80. For example, when the degassing process in the degassing modules 10 and 20 is completed, the atmosphere release valve 70 opens the solenoid valve from the closed state (CLOSE) to the open state (OPEN) within 5 seconds based on the control instruction from the control unit 80, so that each decompression space S2 (for example, a 1L container) is opened to the atmosphere within 1 minute. The adjustment valve 75 is an electromagnetic valve disposed between the degassing modules 10, 20 and the discharge device 50, and is used to adjust the degree of decompression of the decompression space S2. When the decompression space S2 is decompressed by the discharge device 50, the adjustment valve 75 opens the valve. On the other hand, when the degree of decompression of the decompression space S2 is within a prescribed range, the adjustment valve 75 closes the valve based on a control instruction from the control unit 80. At this time, the discharge device 50 can stop its discharge action. Afterwards, on the other hand, when the degree of decompression of the decompression space S2 is outside the prescribed range, the valve is opened based on a control instruction from the control unit 80. The atmosphere opening valve 70 and the adjustment valve 75 are both raised to a prescribed height from the bottom plate 2 of the housing 5 by a plurality of legs 71 and a plurality of legs 76. The control unit 80 controls the operation and stop of the pump 51 of the discharge device 50. In addition, the control unit 80 has a detector 85 for detecting the degree of decompression of the decompression space S2, and controls the operation of the discharge device 50 and the adjustment valve 75 based on the detected degree of decompression. In this control, the discharge of the atmosphere by the discharge device 50 is performed in such a way that the degree of decompression detected by the detector 85 becomes a prescribed value, and when the degree of decompression in the decompression space S2 is within a prescribed range, the adjustment valve 75 is closed and the operation of the discharge device 50 is stopped. When the degree of decompression detected by the detector 85 after closing the adjustment valve 75 is out of the prescribed range, the control unit 80 operates the discharge device 50 again to perform the discharge process. On the other hand, when the degassing process performed by the degassing modules 10 and 20 is completed, the control unit 80 controls the operation of the exhaust device 50 and the atmosphere opening valve 70 based on a stop instruction from the outside or the like. In this control, after the degassing process is completed, the atmosphere opening valve 70 is opened to open each decompression space S2 to the atmosphere at one go. After the degassing process is completed, control may be performed in the following manner: while the exhaust action of the gas performed by the exhaust device 50 is continued for a predetermined time (for example, several seconds), the atmosphere opening valve 70 is opened to open each decompression space S2 to the atmosphere at one go. As described above, in the degassing device 1 of the present embodiment, since the decompression spaces S2 of the degassing modules 10 and 20 and the discharge device 50 are connected via the suction pipe section 41 of the vacuum pipe 40, as the discharge device 50 operates, pulsation of the suction pressure is generated in the suction pipe section 41 and in the decompression spaces S2 of the degassing modules 10 and 20. However, since the vacuum pipe 40 not only has the suction pipe section 41 that is connected to the decompression spaces S2 and reaches the discharge device 50 from the degassing modules 10 and 20, but also has the buffer pipe section 44 that branches from the suction pipe section 41 and has a blocked front end 44a, the pulsation of the suction pressure also spreads to the buffer pipe section 44, thereby reducing the pulsation of the suction pressure generated in the suction pipe section 41 and in the decompression spaces S2. As a result, the turbulence of the flow rate and flow velocity of the liquid flowing in each pipe unit 12 of the degassing modules 10 and 20 can be suppressed. Furthermore, since the buffer pipe section 44 branches off from the suction pipe section 41, the buffer pipe section 44 can be provided without making the suction pipe section 41 longer. Thus, since the increase in the pressure loss of the gas reaching the discharge device 50 from each decompression space S2 can be suppressed, the reduction in the discharge efficiency of the discharge device 50 can be suppressed. In addition, the suction pipe section 41 can be easily arranged. In addition, in the degassing device 1, by locating the buffer branch portion B1 on the downstream side of the degassing modules 10 and 20 in the flow direction D of the gas from the degassing modules 10 and 20 to the exhaust device 50, the pulsation of the suction pressure generated in the suction pipe portion 41 can be suppressed by the buffer pipe portion 44 before the pulsation reaches each decompression space S2. As a result, the pulsation of the suction pressure generated in each decompression space S2 can be further reduced. In addition, in the degassing device 1, the decompression degree of each decompression space S2 can be appropriately detected by connecting the detector 85 for detecting the decompression degree of each decompression space S2 to the detection piping section 43 branched from the suction pipe section 41. In addition, by providing the detection piping section 43 independently of the buffer pipe section 44, the position, shape, etc. of the buffer pipe section 44 can be designed without being restricted by the detector 85. In addition, in the degassing device 1, by arranging the detection branch portion B2 upstream of the buffer branch portion B1 in the flow direction D of the gas from the degassing modules 10 and 20 to the exhaust device 50, the pulsation of the suction pressure generated in the suction pipe portion 41 can be reduced by the buffer pipe portion 44 before reaching the detection piping portion 43. Thus, the detection accuracy of the detector 85 can be improved. In addition, in the degassing device 1 , the vacuum pipe 40 can be easily manufactured by making the inner diameter d1 of the buffer pipe portion 44 and the inner diameter d2 of the suction pipe portion 41 the same. In addition, in the degassing device 1, by setting the length L1 of the buffer pipe section 44 to be 5% or more, 7.5% or more, or 10% or more of the length L2 of the path R of the suction pipe section 41 from the degassing modules 10 and 20 to the discharge device 50, the pulsation of the suction pressure generated in the suction pipe section 41 can be appropriately suppressed. On the other hand, by setting the length L1 of the buffer pipe section 44 to be 30% or less, 20% or less, or 15% or less of the length L2 of the path R of the suction pipe section 41 from the degassing modules 10 and 20 to the discharge device 50, the buffer pipe section 44 can be easily arranged. In addition, in the degassing device, by setting the length L1 of the buffer tube portion 44 to be 1000% or more, 1100% or more, or 1200% or more of the inner diameter d1 of the buffer tube portion 44, the pulsation of the suction pressure generated in the suction tube portion 41 can be appropriately suppressed. On the other hand, by setting the length L1 of the buffer tube portion 44 to be 1600% or less, 1500% or less, or 1400% or less of the inner diameter d1 of the buffer tube portion 44, the buffer tube portion 44 can be easily arranged. In addition, in the degassing device 1, the plug 90 for plugging the front end portion 44a of the buffer tube portion 44 can be easily plugged. In addition, when the suction tube portion 41 is connected to the exhaust port 55 side of the discharge device 50 by mistake during maintenance, etc., and the discharge device 50 is operated in this state, the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure. When the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure, there is a possibility that the detector 85 for detecting the decompression degree of each decompression space S2, the suction tube portion 41, etc. are damaged, or the suction tube portion 41 falls off from the degassing modules 10 and 20. However, since the plug 90 is detachably mounted on the front end portion 44a of the buffer tube portion 44, when the suction tube portion 41 and each decompression space S2 are pressurized to a relatively high pressure, the plug 90 is removed from the front end portion 44a of the buffer tube portion 44, and the suction tube portion 41 and each decompression space S2 are opened to the atmosphere. In this way, by making the plug 90 function as a safety valve, it is possible to suppress damage to the detector 85, the suction tube portion 41, etc., and to suppress the suction tube portion 41 from falling off from the degassing modules 10 and 20. In addition, by removing the plug 90 from the buffer tube portion 44, an additional degassing module (not shown) can be connected to the buffer tube portion 44, and thus the expandability is also excellent. In addition, in the degassing device 1 , since the plug 90 has the insertion portion 91 to be pressed into the buffer tube portion 44 , the front end portion 44 a of the buffer tube portion 44 can be appropriately plugged. In addition, in the degassing device 1, by making the close fitting force between the insertion portion 91 and the buffer tube portion 44 smaller than the close fitting force between the discharge nozzle portion 17 and the suction tube portion 41, when the suction tube portion 41 and each decompression space S2 are pressurized to a relatively high pressure, the insertion portion 91 can be easily removed from the buffer tube portion 44 before the discharge nozzle portion 17 is removed from the suction tube portion 41. As a result, the suction tube portion 41 and each decompression space S2 can be opened to the atmosphere at an earlier stage, and thus the function of the plug 90 as a safety valve can be further improved. In addition, in the degassing device 1, by making the outer circumferential length of the insertion portion 91 smaller than the outer circumferential length of the discharge nozzle portion 17, the close fitting force between the insertion portion 91 and the buffer tube portion 44 can be made smaller than the close fitting force between the discharge nozzle portion 17 and the suction tube portion 41. Thus, when the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure, the insertion portion 91 can be easily removed from the buffer tube portion 44 before the discharge nozzle portion 17 is removed from the suction tube portion 41. In addition, in the degassing device 1, by making the outer diameter D1 of the insertion portion 91 smaller than the outer diameter D2 of the discharge nozzle portion 17, the close fitting force between the insertion portion 91 and the buffer tube portion 44 can be made smaller than the close fitting force between the discharge nozzle portion 17 and the suction tube portion 41. Thus, when the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure, the insertion portion 91 can be easily removed from the buffer tube portion 44 before the discharge nozzle portion 17 is removed from the suction tube portion 41. In addition, in the degassing device 1, by making the length L3 of the insertion portion 91 shorter than the length L4 of the discharge nozzle portion 17, when the insertion portion 91 and the discharge nozzle portion 17 are integrally pressed into the buffer tube portion 44 and the suction tube portion 41, the close fitting force between the insertion portion 91 and the buffer tube portion 44 can be made smaller than the close fitting force between the discharge nozzle portion 17 and the suction tube portion 41. Thus, when the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure, the insertion portion 91 can be easily removed from the buffer tube portion 44 before the discharge nozzle portion 17 is removed from the suction tube portion 41. In addition, in the degassing device 1, by making the insertion length L5 of the insertion portion 91 into the buffer tube portion 44 shorter than the insertion length L6 of the discharge nozzle portion 17 into the suction tube portion 41, the close fitting force between the insertion portion 91 and the buffer tube portion 44 can be made smaller than the close fitting force between the discharge nozzle portion 17 and the suction tube portion 41. Thus, when the suction tube portion 41 and each decompression space S2 are pressurized to a high pressure, the insertion portion 91 can be easily removed from the buffer tube portion 44 before the discharge nozzle portion 17 is removed from the suction tube portion 41. In addition, in the degassing device 1, at least a part of the vacuum pipe 40 is a resin composition containing polyolefin and styrene-based thermoplastic elastomer, thereby making it possible to achieve excellent solvent resistance, chemical resistance and durability. In addition, the gas permeability can be reduced, and the vacuum pipe 40 can be suppressed from falling off. In addition, due to the elasticity of the resin composition containing polyolefin and styrene-based thermoplastic elastomer, the suction pipe part 41 expands and contracts according to the pulsation of the suction pressure generated in the suction pipe part 41. As a result, the pulsation of the suction pressure generated in the suction pipe part 41 and each decompression space S2 can be further reduced. As mentioned above, although embodiment of this invention is described, this invention is not limited to the said embodiment, It can change or modify suitably within the range of the summary of this invention. For example, the buffer tube portion may be blocked by a structure other than a plug. For example, the buffer tube portion may be blocked by clamping the buffer tube portion with a clamping member such as a clamp. In this case, the portion up to the position where the buffer tube portion is clamped and blocked by the clamping member such as a clamp is the buffer tube portion, and the vicinity of the position where the buffer tube portion is clamped and blocked by the clamping member such as a clamp is the front end portion of the buffer tube portion. In addition, for example, the vibration-isolating member may be attached to the housing and the discharge device via another member instead of being directly attached to the housing and the discharge device. Fig. 9 It is a schematic side view showing another example of a degassing device. Fig.10 Yes Fig. 9 An enlarged cross-sectional view showing the vicinity of the vibration-proof member of the degassing device. Fig. 9 and Fig.10 In the degassing device 1A shown, the vibration-proof member 103 is formed in a columnar shape such as a cylinder or a prism. An upper plate 104 having a thread groove 104a is connected to the front end, i.e., the upper end, of one side of the vibration-proof member 103, and a lower plate 105 having a thread groove 105a is connected to the front end, i.e., the lower end, of the other side of the vibration-proof member 103. The upper plate 104 is fixed to the fixing plate 52 by screwing a screw 106 inserted into the through hole 52d of the fixing plate 52 into the thread groove 104a of the upper plate 104, and the lower plate 105 is fixed to the bottom plate 2 by screwing a screw 107 inserted into the through hole 2d of the bottom plate 2 into the thread groove 105a of the lower plate 105. Thus, the vibration-proof member 103 is interposed between the bottom plate 2 of the housing 5 and the fixing plate 52 of the discharge device 50, and is in a state of supporting the discharge device 50 relative to the bottom plate 2 of the housing 5. In addition, for example, the vibration-isolating member may be attached to a pump of the discharge device instead of the fixing plate of the discharge device. Fig.11 FIG. 1 is a schematic side view showing another example of a degassing device. Fig.11In the degassing device 1B shown in FIG. 1 , the discharge device 56 has the same pump 51 as in the above embodiment, but does not have a structure corresponding to the fixing plate in the above embodiment. In addition, the vibration-proof member 109 is directly or indirectly attached to the pump 51 and the base plate 2. The shape of the vibration-proof member 109 and the mounting structure of the vibration-proof member 109 with respect to the pump 51 and the base plate 2 can be set to be, for example, Figure 8 The shape of the vibration-isolating member 101 and the mounting structure of the vibration-isolating member 101 relative to the fixing plate 52 and the base plate 2 are shown. Fig.10 The shape of the vibration-isolating member 103 shown and the mounting structure of the vibration-isolating member 103 with respect to the fixing plate 52 and the base plate 2 are the same. Industrial Applicability The present invention can be used as a degassing device used in liquid chromatography, gas chromatography, a biochemical analysis device, an inkjet filling device, and the like. Description of Reference Numerals 1. 1A, 1B, degassing device; 2. bottom plate; 2a. upper surface; 2c. threaded hole; 2d. through hole; 3. front plate; 4. rear plate; 5. shell; 10. degassing module; 11. tube; 12. tube unit; 12a. inlet; 12b. outlet; 13. shell; 13a. opening; 14. cover; 15. connector; 16. connector; 17. discharge nozzle; 17a. outlet; 18. open nozzle; 18a. open port; 20. degassing module; 40. vacuum piping; 41. suction pipe; 42, discharge pipe; 43, detection piping; 44, buffer pipe; 44a, front end; 45, 46, discharge piping; 47, discharge assembly; 48, piping; 50, discharge device; 51, pump; 52, fixing plate; 52a, upper surface; 52b, lower surface; 52c, through hole; 52d, through hole; 53, motor; 54, air intake; 55, exhaust port; 56, discharge device; 60, atmosphere open piping; 61, 62, open piping; 64, open assembly; 65, piping; 66 , end; 70, atmospheric release valve; 71, leg; 75, adjustment valve; 76, leg; 80, control unit; 85, detector; 90, plug; 91, insertion unit; 92, enlarged diameter unit; 101, vibration-proof member; 101a, neck; 101b, upper enlarged diameter unit; 101c, lower enlarged diameter unit; 101d, through hole; 102, screw member; 103, vibration-proof member; 104, upper plate; 104a, screw groove; 105, lower plate; 105a, screw groove; 106, screw member; 107, screw member; 109 , vibration-proof component; B1, buffer branch; B2, detection branch; D, flow direction; d1, inner diameter; d2, inner diameter; D1, outer diameter; D2, outer diameter; L1, length of the buffer tube; L2, length of the path of the suction tube from the degassing module to the discharge device; L3, length of the insertion part; L4, length of the discharge nozzle part; L5, the pressed length of the insertion part relative to the buffer tube; L6, the pressed length of the discharge nozzle part relative to the suction tube; R, path; S1, fluid flow space; S2, decompression space.

Claims

1. A degassing device, wherein: The degassing device has: A degassing module having a pipe unit having gas permeability and separating a fluid flow space from a decompression space; a vacuum pipe connected to the degassing module and communicating with the decompression space of the degassing module; and an exhaust device connected to the vacuum pipe and configured to exhaust the gas in the decompression space to the outside via the vacuum pipe, The vacuum pipe has: a suction pipe portion communicating with the decompression space and extending from the degassing module to the exhaust device; and A buffer pipe section is branched from the suction pipe section, and a front end portion of the buffer pipe section is blocked.

2. The degassing device according to claim 1, wherein: A buffer branch portion where the buffer pipe portion branches off from the suction pipe portion is located on a downstream side of the degassing module in a flow direction of the gas from the degassing module to the exhaust device.

3. The degassing device according to claim 1 or 2, wherein: The degassing device further comprises a detector for detecting the degree of decompression in the decompression space. The vacuum pipe further includes a detection pipe section that is branched from the suction pipe section and connected to the detector.

4. The degassing device according to claim 3, wherein: The detection branch portion where the detection pipe portion branches from the suction pipe portion is located upstream of the buffer branch portion where the buffer pipe portion branches from the suction pipe portion in the flow direction of the gas from the degassing module to the exhaust device.

5. The degassing device according to any one of claims 1 to 4, wherein: The inner diameter of the buffer tube portion is the same as the inner diameter of the suction tube portion.

6. The degassing device according to any one of claims 1 to 5, wherein: The length of the buffer pipe portion is not less than 5% and not more than 30% of the length of the path of the suction pipe portion from the degassing module to the exhaust device.

7. The degassing device according to any one of claims 1 to 6, wherein: The length of the buffer tube portion is greater than or equal to 1000% and less than or equal to 1600% of the inner diameter of the buffer tube portion.

8. The degassing device according to any one of claims 1 to 7, wherein: The degassing device further includes a plug that is detachably mounted on the front end portion of the buffer tube portion to close the front end portion of the buffer tube portion.

9. The degassing device according to claim 8, wherein: The plug has an insertion portion that is pressed into the buffer tube portion.

10. The degassing device according to claim 9, wherein: The degassing module includes a discharge nozzle portion that is pressed into the suction pipe portion. The close fitting force between the insertion portion and the buffer tube portion is smaller than the close fitting force between the discharge nozzle portion and the suction tube portion.

11. The degassing device according to claim 9 or 10, wherein: The degassing module has a discharge nozzle portion that is pressed into the suction pipe portion, The outer circumference length of the insertion portion is smaller than the outer circumference length of the discharge nozzle portion.

12. The degassing device according to any one of claims 9 to 11, wherein: The degassing module has a cylindrical discharge nozzle portion that is pressed into the suction pipe portion, The inserting portion is formed into a cylindrical shape, The outer diameter of the insertion portion is smaller than the outer diameter of the discharge nozzle portion.

13. The degassing device according to any one of claims 9 to 12, wherein: The degassing module has a discharge nozzle portion that is pressed into the suction pipe portion, The length of the insertion portion is shorter than the length of the discharge nozzle portion.

14. The degassing device according to any one of claims 9 to 13, wherein: The degassing module has a discharge nozzle portion that is pressed into the suction pipe portion, A length by which the insertion portion is pressed into the buffer tube portion is shorter than a length by which the discharge nozzle portion is pressed into the suction tube portion.

15. The degassing device according to any one of claims 1 to 14, wherein: At least a portion of the vacuum pipe is a resin composition containing a polyolefin and a styrene-based thermoplastic elastomer.

Images