JP7534895B2 - Liquid Purification Equipment - Google Patents

Description

The present invention relates to a liquid purification device that can purify liquid to a high degree of purity.

An alcohol purification device that removes impurities from alcohol is disclosed. This alcohol purification device can remove ionic impurities from alcohol using ion exchange resins or the like. In this alcohol purification device, a back pressure valve is provided at the rear of an ion exchange tower filled with ion exchange resin. This applies a certain pressure to the alcohol flowing through the ion exchange tower, preventing air bubbles from forming in the ion exchange resin.

Patent No. 5739687 Special Publication No. 52-010107 Japanese Patent Application Publication No. 4-334503

However, in high-purity purification on the order of ppt, there is a problem that metal particles and metal ions eluted from the back pressure valve are mixed into the solvent such as alcohol, etc. For this reason, the above-mentioned conventional alcohol purification apparatus has a problem that it cannot be applied to high-purity purification on the order of ppt.
SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a liquid purification apparatus that can be applied to the purification of liquids to high purity on the order of ppt.

The above problems are solved by the present invention. That is, a liquid purification device according to the present invention (1) comprises:
A column filled with a porous adsorbent;
a supply unit provided upstream of the column for supplying a liquid into the column;
a resin orifice provided downstream of the column and configured to apply a pressure of at least a first predetermined value to the liquid passing through the column;
A switching valve provided at a position between the column and the orifice;
a second flow path extending from the switching valve and capable of passing the liquid at a flow rate greater than that of a first flow path including the orifice;
Equipped with.

The liquid purification apparatus of the present invention (2) is the liquid purification apparatus according to (1),
The orifice is made of a fluororesin.

The liquid purification apparatus of the present invention (3) is the liquid purification apparatus according to (2),
A relief valve is provided between the column and the supply section to maintain the pressure of the liquid in the column at or below a second predetermined value that is greater than the first predetermined value.

The liquid purification apparatus of the present invention (4) is the liquid purification apparatus according to (3),
The adsorbent has a first adsorption member,
The first adsorption member is made of one or more materials selected from the group consisting of ion exchange resins, zeolites, activated carbon, and synthetic adsorbents.

The liquid purification apparatus of the present invention (5) is the liquid purification apparatus according to (4),
The adsorbent has a second adsorption member,
The second adsorption member is composed of a filter capable of adsorbing fine particles generated from the relief valve.

The present invention provides a liquid purification device that can be used to purify liquids to high purity on the order of ppt.

1 is a system diagram showing an overall configuration of a liquid purification device according to an embodiment. 2 is a cross-sectional view showing an orifice and its surrounding structure in the liquid purification device shown in FIG. 1. 7 is a cross-sectional view showing an orifice and its surrounding structure in a liquid purification device of a second embodiment. FIG. 13 is a cross-sectional view showing an orifice and its surrounding structure in a liquid purification device of a third embodiment. FIG. 13 is a cross-sectional view showing an orifice and its surrounding structure in a liquid purification device of a fourth embodiment. FIG.

An embodiment of the liquid purification device will be described. The liquid purification device can be used, for example, to obtain ultrapure water, pure water, or treated water in a preliminary stage to obtain the pure water. The liquid purification device can be used, for example, to purify solvents such as IPA (isopropyl alcohol), PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), and PGEE (propylene glycol monoethyl ether). It can also be used to purify mixtures of the above solvents, solutions in which polymers or the like are dissolved in the above solvents, and aqueous acids and alkali solutions. Alternatively, the liquid purification device can be used, for example, as a household water purifier for obtaining purified water at home.

The liquid purification device includes a column filled with a porous adsorbent, a supply unit provided upstream of the column to supply liquid into the column, and a resin orifice provided downstream of the column to apply a predetermined pressure to the liquid passing through the column.

The inside of the column can be filled with various porous adsorbents (particles). The porous adsorbents can be, for example, ion exchangers, activated carbon, synthetic adsorbents, or zeolites. A particulate removal filter can also be installed at the outlet side of the column to remove particulates from the adsorbents (particles).

Examples of ion exchangers include granular ion exchange resins such as granular cation exchange resins, granular chelate resins, granular anion exchange resins, and combinations of granular cation exchange resins, granular chelate resins, and granular anion exchange resins; monolithic organic porous cation exchangers, monolithic organic porous chelate exchangers, monolithic organic porous anion exchangers, and monolithic organic porous ion exchangers such as combinations of monolithic organic porous cation exchangers, monolithic organic porous chelate exchangers, and monolithic organic porous anion exchangers; and combinations of granular ion exchange resins and monolithic organic porous ion exchangers. When the ion exchanger is a combination of a granular cation exchange resin, a granular chelate exchange resin, and a granular anion exchange resin, it may be used as a mixed bed in which the granular cation exchange resin, the granular chelate exchange resin, and the granular anion exchange resin are uniformly mixed, or it may be used as a double bed in which the upstream side of the ion exchanger-packed region is packed with a granular cation exchange resin and/or a granular chelate exchange resin, and the downstream side of the ion exchanger-packed region is packed with a granular anion exchange resin, or the upstream side of the ion exchanger-packed region is packed with a granular anion exchange resin, and the downstream side of the ion exchanger-packed region is packed with a granular cation exchange resin and/or a granular chelate exchange resin. In addition, when the ion exchanger is a combination of a monolithic organic porous cation exchanger and a monolithic organic porous anion exchanger, the upstream side of the ion exchanger packing region is filled with a monolithic organic porous cation and/or a monolithic organic porous chelate exchanger, and the downstream side of the ion exchanger packing region is filled with a monolithic organic porous anion exchanger, or the upstream side of the ion exchanger packing region is filled with a monolithic organic porous anion exchanger, and the downstream side of the ion exchanger packing region is filled with a monolithic organic porous cation exchanger and/or a monolithic organic porous chelate exchanger. When the ion exchanger is a combination of a granular ion exchange resin and a monolithic organic porous ion exchanger, the upstream side of the ion exchanger packing region is filled with a monolithic organic porous ion exchanger, and the downstream side of the ion exchanger packing region is filled with a granular ion exchange resin.

The granular cation exchange resin may be a strong acid cation exchange resin, a weak acid cation exchange resin, a chelating resin, or a combination of these. Examples of strong acid cation exchange resins include Orlite DS-1, Orlite DS-4, and XSC-1415HG. Examples of weak acid cation exchange resins include Amberlite (registered trademark) IRC76. Examples of chelating resins include Orlite DS-21 and DS-22. In order to reduce cationic impurities in the treated liquid, it is desirable to use the cation exchange resin in the H form.

The granular anion exchange resin may be a strongly basic anion exchange resin, a weakly basic anion exchange resin, or a combination of these. Examples of strongly basic anion exchange resins include Orlite DS-2, Orlite DS-5, and XSA-2415HG. Examples of weakly basic anion exchange resins include Orlite DS-6, and examples of boron-selective anion exchange resins with glucamine groups as functional groups include Amberlite (registered trademark) IRA743. In order to reduce anionic impurities in the treated liquid, it is desirable to use the anion exchange resin in the OH form. However, if carbonic acid does not become an impurity, it can be used in the carbonate or bicarbonate form.

The ion exchanger may also be a mixed bed ion exchanger. Examples of mixed bed ion exchange resins that are a mixture of granular strongly acidic cation exchange resins (cation exchange resins) and granular strongly basic anion exchange resins (anion exchange resins) include Orlite DS-3, Orlite DS-7, and XSM-N411HG.

The average particle size of the granular ion exchanger is not particularly limited, but is preferably 200 to 1000 μm, and particularly preferably 300 to 800 μm. The average particle size of the ion exchanger is a value measured by a laser diffraction particle size distribution measuring device.

There are no particular limitations on the monolithic organic porous ion exchanger, so long as the monolithic organic porous material has an ion exchange group introduced therein. For example, the monolithic organic porous ion exchanger shown below can be used.

Examples of monolithic organic porous ion exchangers include monolithic organic porous ion exchangers (hereinafter also referred to as the first form of monolithic organic porous ion exchanger) that are composed of a continuous skeleton phase and a continuous pore phase, the thickness of the continuous skeleton being 1 to 100 μm, the average diameter of the continuous pores being 1 to 1000 μm, the total pore volume being 0.5 to 50 mL/g, cation exchange groups or anion exchange groups being introduced, the ion exchange capacity per weight in a dry state being 1 to 6 mg equivalents/g, and the ion exchange groups being uniformly distributed in the organic porous ion exchanger.

The first form of monolithic organic porous ion exchanger may be a monolithic organic porous ion exchanger in which the air bubble-like macropores overlap each other, forming a continuous macropore structure with the overlapping portions forming openings with an average diameter of 30 to 300 μm, the total pore volume is 0.5 to 10 ml/g, cation exchange groups or anion exchange groups are introduced, the ion exchange capacity per weight in the dry state is 1 to 6 mg equivalents/g, the ion exchange groups are uniformly distributed in the organic porous ion exchanger, and in an SEM image of a cut surface of the continuous macropore structure (dried body), the area of the framework portion appearing in the cross section is 25 to 50% of the image area.

In addition, the first embodiment of the monolithic organic porous ion exchanger may be a monolithic organic porous ion exchanger having a bicontinuous structure consisting of a three-dimensionally continuous skeleton having an average thickness of 1 to 60 μm and made of an aromatic vinyl polymer containing 0.1 to 5.0 mol % of crosslinked structural units among all structural units to which ion exchange groups have been introduced, and three-dimensionally continuous pores having an average diameter of 10 to 200 μm between the skeletons, a total pore volume of 0.5 to 10 mL/g, cation exchange groups or anion exchange groups have been introduced, an ion exchange capacity per weight in a dry state of 1 to 6 mg equivalents/g, and ion exchange groups uniformly distributed in the organic porous ion exchanger.

When the particles are made of ion exchangers, the liquid to be treated is, for example, IPA (isopropyl alcohol), PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), PGEE (propylene glycol monoethyl ether), or NMP (N-methyl-2-pyrrolidone). An aqueous solution exhibiting acidity to alkalinity may be used as the liquid to be treated. Impurities to be removed from the liquid to be treated are, for example, metal ions such as Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Cd, and Pb, anions such as Cl, SO ₄ , NO ₃ , PO ₄ , CO ₃ , and HCO ₃ , organic acids such as formic acid, acetic acid, maleic acid, and propionic acid, and polymer compounds having positive or negative charges.

Activated carbon is commercially available activated carbon. The diameter of the activated carbon particles is arbitrary. Activated carbon has micropores with diameters of, for example, 0.7 nm to several tens of μm, and can physically remove organic impurities (organic acids, pigments, oils, etc.) from the liquid to be treated. In addition, the carbon component in the activated carbon can be used to decompose chlorine. Examples of activated carbon include carbonized phenolic resin.

Specific aspects of the liquid purification apparatus according to the embodiment will be described below with reference to the drawings.
[First embodiment]

The liquid purification device 11 of the first embodiment will be described with reference to Figures 1 and 2. The liquid purification device 11 can purify the liquid by passing the liquid to be purified through a column 13 and causing impurities to be adsorbed by the adsorbent in the column 13.

The liquid purification device 11 includes a column 13 (ion exchange tower) filled with a porous adsorbent 12, a supply unit 14 provided upstream of the column 13 to supply liquid into the column 13, a pressure gauge 16 provided upstream of the column 13, a first three-way valve 17 provided downstream of the column 13, a sampling line 18 that is a first flow path extending from the first three-way valve 17, a blow line 21 that is a second flow path extending from the first three-way valve 17, a resin orifice 22 provided midway through the sampling line 18 to apply a pressure of a first predetermined value or more to the liquid passing through the column 13, a relief valve 15 provided upstream of the column 13 to maintain the pressure of the liquid in the column 13 at a second predetermined value or less, and a first auxiliary three-way valve 23 and a second auxiliary three-way valve 24 provided upstream of the column 13.

The liquid purification device 11 includes a sampling clean booth 25 provided downstream of the orifice 22 in the sampling line 18, a glove box 26 provided downstream of the sampling clean booth 25 in the sampling line 18, a second three-way valve 27 provided in the sampling clean booth 25 in the sampling line 18, a first use point 28 branching off from the second three-way valve 27 and supplying the purified liquid, a third three-way valve 31 provided in the glove box 26 in the sampling line 18, and a second use point 32 branching off from the third three-way valve 31 and supplying the purified liquid.

The adsorbent 12 has a first adsorbent member 33 made of ion exchange resin and a second adsorbent member 34 made of a filter capable of adsorbing metal particles generated from the relief valve 15. The first adsorbent member 33 and the second adsorbent member 34 are arranged in series inside the column 13. The first adsorbent member 33 and the second adsorbent member 34 are examples of porous adsorbents. The column 13 is made of a fluororesin such as PFA.

The first adsorption member 33 is composed of an ion exchange resin filled inside the column 13. The second adsorption member 34 is composed of a nonwoven fabric filter formed into a flat plate shape. The second adsorption member 34 is disposed downstream of the first adsorption member 33, and can adsorb and remove fine particles generated from the relief valve 15 and the first adsorption member 33 (ion exchange resin).

The flow direction of the liquid in the column 13 may be any direction. That is, it may be a downflow type in which the liquid is supplied from above the column 13, refined in the column 13, and drained downward, or it may be an upflow type in which the liquid is supplied from below the column 13, refined in the column 13, and drained upward. The example in Figure 1 shows a downflow type.

The combination of the porous adsorbent 12 is not limited to the combination of the first adsorption member 33 made of ion exchange resin and the second adsorption member 34 made of a nonwoven fabric filter. The first adsorption member 33 may be one selected from the group consisting of ion exchange resin, zeolite, activated carbon, and synthetic adsorbent. Alternatively, the first adsorption member 33 may be composed of a combination of two or more types arbitrarily selected from the group consisting of ion exchange resin, zeolite, activated carbon, and synthetic adsorbent. That is, the ion exchange resin, zeolite, activated carbon, and synthetic adsorbent may be configured in the form of a cartridge housed in an individual case. The individual case is provided with a plurality of water passage holes through which liquid can pass, and any one of the ion exchange resin, zeolite, activated carbon, and synthetic adsorbent is housed inside the case. The first adsorption member 33 may be configured by appropriately combining two or more types of ion exchange resin, zeolite, activated carbon, and synthetic adsorbent configured in the form of a cartridge and arranging them in the column 13.

The second adsorption member 34, which is made of a filter, may be provided not only downstream of the first adsorption member 33, but also upstream of the first adsorption member 33, if necessary. The second adsorption member 34 may be omitted.

The supply unit 14 is a metal tank in which the liquid to be purified is stored. Nitrogen gas, which is an inert gas, is sent inside the supply unit 14. The supply unit 14 has a pump (not shown), and the liquid stored inside can be sent to the column 13 by driving the pump. For example, the liquid to be purified is stored inside the supply unit 14. The liquid to be purified can be any liquid, and may be water or an aqueous solution, or a solvent (non-aqueous liquid) such as IPA (isopropyl alcohol), PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), or PGEE (propylene glycol monoethyl ether). The liquid to be purified may be a mixture of water or a solvent, a solution in which a polymer or the like is dissolved in water or a solvent, or an acid or alkaline aqueous solution.

The relief valve 15 is provided at a position between the column 13 and the supply section 14. The relief valve 15 is composed of a general metal relief valve, and when the pressure in the column 13 becomes equal to or higher than a predetermined value (second predetermined value), it releases the liquid to the surroundings and plays a role in lowering the pressure around the column 13 to a predetermined value or lower. This prevents the column 13 and its surrounding structures (sleeve, three-way valve, etc.) from being damaged when the pressure becomes abnormally high. In other words, the relief valve 15 can regulate the pressure of the liquid inside the column 13 to a second predetermined value or lower. The second predetermined value is a predetermined value that is greater than the first predetermined value, which is the pressure of the liquid passing through the column 13, as determined by the orifice 22. The second predetermined value is, for example, 1 MPa, preferably 0.5 MPa, and more preferably 0.25 MPa, in terms of gauge pressure.

The first three-way valve 17 is made of a fluororesin such as PTFE or PFA, which has good chemical resistance. The first three-way valve 17 is an example of a switching valve provided at a position between the column 13 and the orifice 22. The first three-way valve 17 can switch the connection state between a state in which the column 13 is connected to a first flow path (sampling line 18) including the orifice 22, and a state in which the column 13 is connected to a second flow path (blow line 21) extending from the first three-way valve 17.

The second three-way valve 27 and the third three-way valve 31 are made of fluororesin such as PTFE or PFA. The pipe (tube) that constitutes the sampling line 18 is also made of fluororesin such as PTFE or PFA. The pipe that constitutes the blow line 21 may be made of any material, such as an iron pipe or a resin pipe. Unlike the sampling line 18, the blow line 21 (second flow path) does not have an orifice 22 interposed therebetween, and therefore can pass a significantly larger flow rate of liquid than the sampling line 18 (first flow path).

The first backup three-way valve 23 and the second backup three-way valve 24 are made of fluororesin such as PTFE or PFA.

In this embodiment, the orifice 22 is configured with an orifice sleeve made of resin. More specifically, the orifice 22 is configured with an orifice sleeve made of, for example, a fluororesin. Even more specifically, the orifice 22 is configured with an orifice sleeve formed of, for example, PTFE, PFA, etc.

As shown in FIG. 2, the orifice 22 has an orifice sleeve main body 35 and an adapter member 36 that is connected to the orifice sleeve main body 35 by screw engagement. Therefore, each of the orifice sleeve main body 35 and the adapter member 36 is formed of a resin, for example, a fluororesin (for example, PTFE, PFA, etc.). At least one of the orifice sleeve main body 35 and the adapter member 36 may be formed of a resin, for example, a fluororesin (for example, PTFE, PFA, etc.). Here, the concept of making each of the orifice sleeve main body 35 and the adapter member 36 out of a resin, for example, a fluororesin, includes coating the parts of each of the orifice sleeve main body 35 and the adapter member 36 that come into contact with the liquid passing through the inside (liquid-contacting parts) with a resin, for example, a fluororesin (for example, PTFE, PFA, etc.). The adapter member 36 has a male thread portion 36A. The adapter member 36 can be fixed to the orifice sleeve body 35 by engaging the male threaded portion 36A with the female threaded portion 35A formed on the inside of the orifice sleeve body 35. The adapter member 36 has a first connection portion 41 that is inserted into the inside of the orifice sleeve body 35, and a second connection portion 42 that is provided on the opposite side to the first connection portion 41. The second connection portion 42 is connected to the end of the tube that constitutes the sampling line 18.

The orifice sleeve body 35 has a joint portion 43, a cavity portion 44 provided inside the joint portion 43, and a narrowed portion 45 provided in the joint portion 43 and having an inner diameter that is extremely smaller than the inner diameter of the cavity portion 44. The end of the tube that constitutes the sampling line 18 is connected to the outside of the joint portion 43.

The inner diameter of the narrowed portion 45 can be set appropriately taking into consideration the desired back pressure (e.g., 0.05 MPa or more in gauge pressure), the inner diameter of the tube constituting the sampling line 18, the viscosity at room temperature of the liquid to be purified, the flow rate of the liquid flowing through the sampling line 18 and the narrowed portion 45, etc. This allows the orifice 22 (narrowed portion 45) to apply a pressure of at least a first predetermined value to the liquid passing through the column. The first predetermined value defined by the orifice 22 is 0.05 MPa in gauge pressure, and preferably 0.025 MPa.

The sampling clean booth 25, the first use point 28, the glove box 26, and the second use point 32 are installed, for example, in a semiconductor manufacturing factory. The liquid refined by the liquid refinement device 11 of this embodiment is used, for example, in the semiconductor manufacturing process. The sampling clean booth 25, the first use point 28, the glove box 26, and the second use point 32 may also be installed in a manufacturing factory for products other than semiconductors.

Next, the method of use and the action of the liquid purification device 11 of this embodiment will be described. The liquid purification device 11 of this embodiment can be switched between two modes: a purification mode in which liquid is produced, and a cleaning mode in which the column 13 and the like are cleaned. The switching between the purification mode and the cleaning mode can be performed by switching the connection state of the first three-way valve 17. That is, when the column 13 is connected to the sampling line 18 including the orifice 22, the purification mode is executed. Then, when the first three-way valve 17 is switched to connect the column 13 to the blow line 21, the cleaning mode is executed. Details of each mode will be described below.

The facility manager operates the first three-way valve 17 to connect the column 13 to the sampling line 18. In this state, the purification mode can be started by driving the pump. The driving force of the pump sends liquid such as IPA from the supply unit 14 to the column 13. The liquid passing through the column 13 is supplied to the sampling line 18 including the orifice 22 via the first three-way valve 17. At this time, an extremely large flow resistance is applied to the sampling line 18 due to the influence of the orifice 22. This flow resistance applies a back pressure to the column 13. The back pressure applied to the column 13 is, for example, 0.05 MPa or more in gauge pressure. This back pressure prevents the gas dissolved in the water in the ion exchange resin, which is the first adsorption member 33 of the column 13, from appearing as bubbles.

That is, the water-absorbed ion exchange resin contains 40 to 60% water by mass. Therefore, when a non-aqueous liquid such as IPA is passed through such an ion exchange resin, the water inside the ion exchange resin is gradually replaced with IPA or the like. In general, the saturation solubility of a gas in a mixed solvent is smaller than the saturation solubility of a gas in a single solvent. Therefore, when IPA or the like is passed through the ion exchange resin for the first time, the gas that was dissolved in the water inside the ion exchange resin exceeds the saturation solubility of the IPA-water mixed solvent, and gas bubbles are generated inside the column 13.

However, in this embodiment, a back pressure of 0.05 MPa or more is applied inside the column 13, so that the gas that could become bubbles under high pressure can be dissolved in IPA or the like. This prevents bubbles from being generated inside the column 13.

Furthermore, when the ion exchange resin is of the above-mentioned carbonate or bicarbonate type, _CO2 is generated during the reaction, causing air bubbles to form in the column 13. However, in the liquid purification apparatus 11 of the present embodiment, back pressure is applied to the inside of the column 13 by the orifice 22, so that the air bubbles caused by the _CO2 can be dissolved in the liquid. This prevents the generation of air bubbles in the column 13.

The back pressure applied to the liquid passing through column 13 does not exceed the second predetermined value due to the action of relief valve 15. This prevents the pressure inside column 13 from becoming too high, which could damage column 13 or its surrounding structure.

In the column 13, the liquid passes between the first adsorption member 33 (ion exchange resin) and the second adsorption member 34 (filter), and impurities are removed from the liquid. The first adsorption member 33 (ion exchange resin) adsorbs and removes ionic impurities from the liquid. The second adsorption member 34 (filter) adsorbs and removes metal particles leaking from the relief valve 15 and particles leaking from the first adsorption member 33 (ion exchange resin).

The liquid purified in the column 13 and passing through the sampling line 18 is supplied through the orifice 22 to the first use point 28 of the sampling clean booth 25 and the second use point 32 of the glove box 26, as shown in FIG. 1. At the first use point 28 and the second use point 32, the purified liquid is made available for practical use.

When the liquid purification device 11 is operated for a specified period of time, the impurity adsorption performance of the first adsorption member 33 (ion exchange resin) decreases. Therefore, after operating the liquid purification device 11 for a specified period of time, the facility manager can regenerate (clean) the adsorption performance of the ion exchange resin by performing a cleaning mode in which an aqueous solution containing acid is passed through the column 13.

Prior to the cleaning mode, the facility manager stops the pump to stop the supply of liquid to the column 13. The facility manager switches the first three-way valve 17 to connect the blow line 21 to the column 13. The facility manager switches the second backup three-way valve 24 to connect a cleaning liquid tank (not shown) that stores an acid-containing liquid to the upstream side of the column 13. When an aqueous solution containing acid is sent into the column 13 by driving a pump or the like, the first adsorption member 33 (ion exchange resin) in the column 13 is cleaned. This regenerates (refreshes) the ion exchange resin. By going through this cleaning mode, the ion exchange resin is again able to adsorb and remove ionic impurities in the liquid.

In addition, in the cleaning mode, since there is no need to consider the effects of air bubbles generated in the column 13, the blow line 21 is not provided with an orifice 22 for applying back pressure.

After the ion exchange resin in the column is washed for a predetermined time in the washing mode and the regeneration of the ion exchange resin is completed, the facility manager stops the sending of the acid-containing liquid from the washing liquid tank and ends the washing mode. The facility manager switches the first three-way valve 17 to connect the sampling line 18 to the column 13. The facility manager also switches the second auxiliary three-way valve 24 to connect the supply unit 14 to the column 13. To resume the purification mode, the facility manager drives the pump to send liquid from the supply unit 14 into the column 13. This replaces the moisture inside the ion exchange resin, which is the first adsorption member 33 in the column 13, with a liquid such as IPA. At that time, as in the previous purification mode, back pressure is applied to the column 13 by the orifice 22, preventing the generation of bubbles in the column 13. The liquid purified in the column 13 is actually used at the first use point 28 and the second use point 32 via the sampling line 18.

In this way, the facility manager can operate the liquid purification device 11 by switching between the purification mode and the cleaning mode at regular intervals. In this case, the purification mode and the cleaning mode can be switched quickly by switching the first three-way valve 17, and the switching takes almost no time. Of course, the purification mode and the cleaning mode can be switched at regular intervals using a computer. In this case, each of the first to third three-way valves 17, 27, 31 and the first and second spare three-way valves 23, 24 included in the liquid purification device 11 can be configured as a computer-controllable solenoid valve, for example.

In the following embodiment, differences from the first embodiment will be mainly described, and illustrations and descriptions of parts common to the first embodiment will be omitted.
[Second embodiment]

The liquid purification device 11 of the second embodiment will be described with reference to FIG. 3. The liquid purification device 11 of this embodiment has a different structure for the orifice 22.

The orifice 22 has a connecting pipe 53 having an upstream end 51 and a downstream end 52 that serve as connectors for connecting to the sampling line 18, and a sleeve-shaped orifice body 54 inserted inside the connecting pipe. The orifice body 54 is inserted into the inner piping of the connecting pipe 53 by press-fitting. The orifice body 54 has a narrowed section 45 whose inner diameter is extremely smaller than the inner diameter of the connecting pipe 53. The connecting pipe 53 and the orifice body 54 are made of, for example, a fluororesin. More specifically, the connecting pipe 53 and the orifice body 54 are made of, for example, PTFE, PFA, etc.

The inner diameter of the narrowed portion 45 can be set appropriately taking into consideration the desired back pressure (e.g., 0.05 MPa or more in gauge pressure), the inner diameter of the tube constituting the sampling line 18, the viscosity at room temperature of the liquid to be purified, the flow rate of the liquid flowing through the sampling line 18 and the narrowed portion 45, etc. This allows the orifice 22 (narrowed portion 45) to apply a pressure of at least a first predetermined value to the liquid passing through the column. The first predetermined value defined by the orifice 22 is 0.05 MPa in gauge pressure, and preferably 0.025 MPa.

Liquid refinement apparatus 11 having orifice 22 with the structure of this embodiment also provides the same effects as liquid refinement apparatus 11 of the first embodiment.
[Third embodiment]

The liquid purification device 11 of the third embodiment will be described with reference to FIG. 4. The liquid purification device 11 of this embodiment has a different structure for the orifice 22.

The orifice 22 is disk-shaped and held between the joint surfaces of a pair of flange pipe sections 55. The orifice 22 has a narrowed section 45 whose inner diameter is much smaller than the inner diameter of the flange pipe sections 55. The pair of flange pipe sections 55 are interposed in the middle of the sampling line 18. The flange pipe sections 55 are joined to each other with multiple bolts and nuts (the fastening positions of the bolts and nuts are shown by dashed lines) so that they are butted against each other with the orifice 22 in between.

The orifice 22 has a narrowed section 45 whose inner diameter is much smaller than the inner diameter of the flange pipe section 55.

The inner diameter of the narrowed portion 45 can be set appropriately taking into consideration the desired back pressure (e.g., 0.05 MPa or more in gauge pressure), the inner diameter of the tube constituting the sampling line 18, the viscosity at room temperature of the liquid to be purified, the flow rate of the liquid flowing through the sampling line 18 and the narrowed portion 45, etc. This allows the orifice 22 (narrowed portion 45) to apply a pressure of at least a first predetermined value to the liquid passing through the column. The first predetermined value defined by the orifice 22 is 0.05 MPa in gauge pressure, and preferably 0.025 MPa.

Liquid refinement apparatus 11 having orifice 22 with the structure of this embodiment also provides the same effects as liquid refinement apparatus 11 of the first embodiment.
[Fourth embodiment]

The liquid purification device 11 of the fourth embodiment will be described with reference to FIG. 5. The liquid purification device 11 of this embodiment has a different structure for the orifice 22.

In this embodiment, the orifice 22 is configured with an orifice sleeve made of resin. More specifically, the orifice 22 is configured with an orifice sleeve made of, for example, a fluororesin. Even more specifically, the orifice 22 is configured with an orifice sleeve formed of, for example, PTFE, PFA, etc.

As shown in FIG. 2, the orifice 22 has an adapter member 36 having a cylindrical portion 36A at its tip and a male threaded portion 36B formed on its outer circumferential surface, an orifice sleeve body 35 that is rotatably fitted and held inside the cylindrical portion 36A of the adapter member 36, and a nut member 61 having a female threaded portion 61A that engages with the male threaded portion 36B of the adapter member 36.

The adapter member 36 may be connected to the sampling line 18 at the other end opposite the tip, or may be bent in an elbow shape at the other end opposite the tip so as to be perpendicular to the tip side.

The orifice sleeve body 35 has a joint portion 43, a cavity portion 44 provided inside the joint portion 43, and a narrowed portion 45 provided in the joint portion 43 and having an inner diameter that is extremely smaller than the inner diameter of the cavity portion 44. The end of the tube that constitutes the sampling line 18 is connected to the outside of the joint portion 43.

The tube that constitutes the sampling line 18 is placed over the outside of the joint portion 43 of the orifice sleeve main body 35. The nut member 61 abuts against the outer peripheral surface of the sampling line 18 via the through hole portion 61B, and can hold the tube that constitutes the sampling line 18 so that it does not fall out of the orifice sleeve main body 35. The tube that constitutes the sampling line 18 is inserted and held by the inner surface of the cylindrical portion 36A of the adapter member 36.

The orifice sleeve body 35, the adapter member 36, and the nut member 61 are each formed of a resin, such as a fluororesin (e.g., PTFE, PFA, etc.). The orifice sleeve body 35 and the adapter member 36 may be formed of a resin, such as a fluororesin (e.g., PTFE, PFA, etc.), and the nut member 61 may be formed of another material. Here, the concept of making the orifice sleeve body 35 and the adapter member 36 from a resin, such as a fluororesin, includes coating the parts of the orifice sleeve body 35 and the adapter member 36 that come into contact with the liquid passing through them (liquid-contacting parts) with a resin, such as a fluororesin (e.g., PTFE, PFA, etc.).

The inner diameter of the narrowed portion 45 can be set appropriately taking into consideration the desired back pressure (e.g., 0.05 MPa or more in gauge pressure), the inner diameter of the tube constituting the sampling line 18, the viscosity at room temperature of the liquid to be purified, the flow rate of the liquid flowing through the sampling line 18 and the narrowed portion 45, etc. This allows the orifice 22 (narrowed portion 45) to apply a pressure of at least a first predetermined value to the liquid passing through the column. The first predetermined value defined by the orifice 22 is 0.05 MPa in gauge pressure, and preferably 0.025 MPa.

The liquid purification device 11 having the orifice 22 structure of this embodiment achieves the same effects as the liquid purification device 11 of the first embodiment.

According to the first to fourth embodiments, the following can be said. The liquid purification device 11 includes a column 13 filled with a porous adsorbent 12, a supply unit 14 provided upstream of the column 13 and supplying liquid into the column 13, and a resin orifice 22 provided downstream of the column 13 and applying a pressure of at least a first predetermined value to the liquid passing through the column 13.

According to this configuration, a back pressure can be applied to the column 13 by an extremely simple structure using a resin orifice 22. This allows air bubbles generated from the adsorbent 12 to be dissolved (absorbed) into the liquid passing through the column 13 under a first predetermined pressure value. That is, when the adsorbent 12 is made of ion exchange resin, there is a problem that air bubbles are generated in the column 13 when the type of solvent passing through the column 13 is changed. In that case, a one-way flow phenomenon occurs in which the liquid does not flow at the location where the air bubbles are generated in the column 13, and the column 13 cannot exhibit the originally planned impurity removal performance. With the above configuration, one-way flow is prevented and the impurity removal performance according to the design value can be exhibited.

In addition, because the orifice 22 is made of resin, it is possible to prevent metal particles or metal ions from leaking from the orifice 22 and becoming mixed into the generated liquid. Furthermore, the structure using the above-mentioned orifice 22 has the advantage that a narrowed section with a smaller inner diameter can be appropriately set compared to a structure using a resistance tube with a small inner diameter. Also, using the orifice 22 has the advantage that the flow path can be made shorter compared to a structure using a resistance tube, and it has good washability and high cleanliness.

In addition, when the adsorbent 12 is composed of activated carbon or the like, air may remain in the micropores of the activated carbon. With this configuration, by applying back pressure to the inside of the column 13 using the orifice 22, the air bubbles in the micropores of the activated carbon can be dissolved in the solvent under a first predetermined pressure value. This allows liquid to pass through the micropores of the activated carbon in the column 13, and impurity removal performance can be achieved as designed.

The orifice 22 is made of fluororesin. With this configuration, the orifice 22 can be formed from fluororesin, which has high chemical resistance. This eliminates the risk of the orifice 22 being invaded and swollen or eroded by the liquid being refined. In addition, this prevents the problem of fine particles generated from the orifice 22 being mixed into the refined liquid, making it possible to provide a refined liquid with high purity.

The liquid purification device 11 is provided with a relief valve 15 that is provided between the column 13 and the supply unit 14 and maintains the pressure of the liquid in the column 13 at or below a second predetermined value that is greater than the first predetermined value. With this configuration, the structure applies back pressure using the orifice 22, and if the pressure in the column 13 becomes abnormally high, the liquid can be discharged to the outside via the relief valve 15. This prevents the risk of the column 13, orifice 22, etc. being damaged by high pressure.

The adsorbent 12 has a first adsorption member 33, which is composed of one or more selected from the group consisting of ion exchange resin, zeolite, activated carbon, and synthetic adsorbents. With this configuration, in the first adsorption member 33, which is prone to trapping air bubbles, the air bubbles generated in the column 13 can be dissolved in the liquid by a simple structure that applies back pressure to the column 13 using the orifice 22. This prevents air bubbles from being generated in the column 13, prevents one-sided flow in the column 13, and allows the purification performance to be achieved as designed.

The adsorbent 12 has a second adsorption member 34, which is composed of a filter capable of adsorbing fine particles generated from the relief valve 15. With this configuration, the fine particles generated from the relief valve 15 can be adsorbed by the second adsorption member 34. This makes it possible to remove impurities generated from the relief valve 15, which are essential for the safety of the device, from the refined liquid.

The liquid purification device 11 includes a switching valve disposed between the column 13 and the orifice 22, and a second flow path extending from the switching valve and capable of passing the liquid at a flow rate greater than that of the first flow path including the orifice 22.

According to this configuration, for example, in a cleaning mode in which the adsorbent inside the column is cleaned, the inside of the column can be cleaned by flowing liquid at a flow rate that exceeds the flow rate that passes through the orifice. This improves the efficiency of cleaning the column in the cleaning mode. In addition, by adopting a structure via a switching valve, dust and fine particles are not mixed into the refined liquid when switching the above-mentioned mode, and the cleanliness of the liquid purification device 11 can be maintained at a high level.

The above-described embodiment can be implemented with various substitutions and modifications.

(Example 1) Ion exchange resin (wet)

Orlite DS-3, a mixed resin (ion exchange resin) of strong cations and strong anions, was mixed with IPA in a PFA beaker to prepare 500 ml of wet Orlite DS-3. The wet Orlite DS-3 was in a slurry state. This slurry-like wet Orlite DS-3 was packed into a PFA column. The column was sealed, a sampling line was connected to the outlet of the column, and a PTFE orifice with an inner diameter of 0.2 mm and a length of 2 mm was installed in the middle of the sampling line. Then, IPA was passed through the column at SV5 (SV indicates how many times the amount of liquid flows per unit time relative to the ion exchange resin on a volume basis). The pressure gauge located upstream of the column showed a gauge pressure of 0.05 MPa, and it was confirmed that back pressure was applied inside the column. No air bubbles were generated in the ion exchange resin during the liquid passing through.
(Comparative Example 1-1) Ion exchange resin (wet)

Orlite DS-3, a mixed resin (ion exchange resin) of strong cations and strong anions, was mixed with IPA in a PFA beaker to prepare 500 ml of wet Orlite DS-3. The wet Orlite DS-3 was in a slurry state. This slurry-like wet Orlite DS-3 was packed into a PFA column. The column was sealed, and a blow line (a flow path without an orifice) was connected to the outlet of the column. Then, IPA was passed through the column at SV5. The pressure gauge located upstream of the column showed normal pressure (atmospheric pressure). Air bubbles were generated in the ion exchange resin during the passage of the liquid.
(Comparative Example 1-2) Ion exchange resin (wet)

Orlite DS-3, a mixed resin (ion exchange resin) of strong cations and strong anions, was mixed with IPA in a PFA beaker to prepare 500 ml of wet Orlite DS-3. The wet Orlite DS-3 was in a slurry state. This slurry-like wet Orlite DS-3 was packed into a PFA column. The column was sealed, and a sampling line was connected to the outlet of the column. A PFA needle valve was provided in the middle of this sampling line. Thereafter, while passing IPA through the column at SV5, the inner diameter (cross-sectional area) of the flow path of the sampling line was narrowed while finely adjusting the needle valve until the column was subjected to a back pressure of 0.05 MPa or more in gauge pressure. Thereafter, the value of the pressure gauge located upstream of the column indicated a gauge pressure of 0.05 MPa, and it was confirmed that a back pressure was applied inside the column. No air bubbles were generated in the ion exchange resin during the liquid passing. However, it took 30 minutes to adjust the back pressure using the needle valve.
Example 2 Ion Exchange Resin (Dry)

A required amount of dried Orlite DS-3, which is a mixed resin (ion exchange resin) of strong cations and strong anions, was prepared. The weight of the dried Orlite DS-3 was measured in advance so that it would be 500 ml when wetted with a solvent, and the required weight of the dried Orlite DS-3 was packed into a PFA column. A sampling line was connected to the outlet of the column, and a PTFE orifice with an inner diameter of 0.2 mm and a length of 2 mm was installed in the middle of the sampling line. IPA was then passed through the column at SV5. The pressure gauge located upstream of the column showed a gauge pressure of 0.05 MPa, and it was confirmed that back pressure was applied inside the column. When IPA was filled into the column filled with the dried resin, air bubbles were confirmed between the dried Orlite DS-3 and inside the dried Orlite DS-3. However, when IPA was passed through for 3 hours with back pressure applied, the air bubbles disappeared.
(Comparative Example 2) Ion exchange resin (dried)

A required amount of dried Orlite DS-3, which is a mixed resin (ion exchange resin) of strong cations and strong anions, was prepared. The weight of the dried Orlite DS-3 was measured in advance so that it would be 500 ml when wetted with a solvent, and the required weight of the dried Orlite DS-3 was packed into a PFA column. The column was sealed, and a blow line (a flow path without an orifice) was connected to the outlet of the column. IPA was then passed through the column at SV5. The pressure gauge located upstream of the column showed normal pressure (atmospheric pressure). When the column was filled with IPA, air bubbles present between the dried Orlite DS-3 and inside the dried Orlite DS-3 were confirmed. These air bubbles did not disappear even after passing IPA through for 3 hours.
Example 3 Zeolite (Dry)

A required amount of A-type zeolite, Zeolum SA-500A (manufactured by Tosoh Corporation) was prepared. The weight of the dried Zeolum SA-500A was measured in advance so that the volume would be 500 ml when wetted with a solvent, and the required weight of the dried Zeolum SA-500A was packed into a PFA column. A sampling line was connected to the outlet of the column, and a PTFE orifice with an inner diameter of 0.2 mm and a length of 2 mm was installed in the middle of the sampling line. IPA was then passed through the column at SV5. The pressure gauge located upstream of the column showed a gauge pressure of 0.05 MPa, confirming that back pressure was applied within the column. When the column was filled with IPA, air bubbles present between the dried Zeolum SA-500A and inside the dried Zeolum SA-500A were confirmed. However, when IPA was passed through for 3 hours with back pressure applied, the air bubbles disappeared.
(Comparative Example 3) Zeolite (Dry)

A required amount of A-type zeolite, Zeolum SA-500A (manufactured by Tosoh Corporation) was prepared. The weight of the dried Zeolum SA-500A was measured in advance so that the volume would be 500 ml when wetted with a solvent, and the required weight of the dried Zeolum SA-500A was packed into a PFA column. The column was sealed, and a blow line (a flow path without an orifice) was connected to the outlet of the column. IPA was then passed through the column at SV5. The pressure gauge located upstream of the column showed normal pressure (atmospheric pressure). When the column was filled with IPA, air bubbles present between the Zeolum SA-500A and inside the Zeolum SA-500A were confirmed. These air bubbles did not disappear even after passing IPA through for 3 hours.
Example 4 Activated Carbon (Dry)

A required amount of carbonized phenolic resin (manufactured by MET Co., Ltd.) was prepared. At that time, the weight of the carbonized phenolic resin was measured in advance so that it would be 500 ml when wetted with a solvent, and the required weight of the carbonized phenolic resin was filled into a PFA column. A sampling line was connected to the outlet of the column, and a PTFE orifice with an inner diameter of 0.2 mm and a length of 2 mm was installed in the middle of this sampling line. Then, IPA was passed through the column at SV5. The pressure gauge located upstream of the column showed a gauge pressure of 0.05 MPa, and it was confirmed that back pressure was applied in the column. When the column was filled with IPA, air bubbles present between the carbonized phenolic resin and inside the carbonized phenolic resin were confirmed. However, when IPA was passed through for 3 hours with back pressure applied, the air bubbles disappeared.
(Comparative Example 4) Activated carbon (dry)

A required amount of carbonized phenolic resin (manufactured by MET Co., Ltd.) was prepared. The weight of the carbonized phenolic resin was measured in advance so that it would be 500 ml when wetted with a solvent, and the required weight of the carbonized phenolic resin was filled into a PFA column. The column was sealed, and a blow line (a flow path without an orifice) was connected to the outlet of the column. IPA was then passed through the column at SV5. The pressure gauge located upstream of the column showed normal pressure (atmospheric pressure). When the column was filled with IPA, air bubbles present between the carbonized phenolic resin and inside the carbonized phenolic resin were confirmed. These air bubbles did not disappear even after passing IPA through for 3 hours.
(Example 5) Metal elution from PTFE orifice

A PFA column with a capacity of 50 ml was connected to a PFA tube using a PTFE connector. A PTFE orifice was placed in the middle of the tube downstream of the column. Ultrapure water was passed through a test system consisting of a column, connector, tube, and orifice. The pressure gauge located upstream of the column showed a gauge pressure of 10 kPa, confirming that back pressure was applied within the column. After washing with ultrapure water overnight, ultrapure water was passed through at 300 ml/hour, and the metal concentration in the ultrapure water at the outlet of the orifice was measured. An ICP-MS8900 (manufactured by Agilent Technologies, Inc.) was used for metal concentration analysis. The results are shown in Table 1. All metal elution from the above test system was less than 5 ppt.
(Comparative Example 5) Metal elution from SUS back pressure valve

A PFA column with a capacity of 50 ml was connected to a PFA tube using a PTFE connector. A SLT type back pressure valve manufactured by SURPASS Kogyo Co., Ltd. was inserted in the tube downstream of the column. The back pressure valve has a body made of SUS316 stainless steel and a PTFE diaphragm. Ultrapure water was passed through a test system consisting of the column, connector, tube, and back pressure valve. The pressure gauge located upstream of the column showed a gauge pressure of 10 kPa, confirming that back pressure was applied within the column. After washing with ultrapure water overnight, ultrapure water was passed through at 300 ml/hour, and the metal concentration in the ultrapure water at the outlet of the back pressure valve was measured. An ICP-MS8900 (manufactured by Agilent Technologies, Inc.) was used for metal concentration analysis. The results are shown in Table 1. The metal elution from the above test system was 5 ppt or more except for Na.

11 Liquid purification device 12 Adsorbent 13 Column 14 Supply section 15 Relief valve 17 First three-way valve 18 Sampling line (first flow path)
21 Blow line (second flow path)
22 Orifice 33 First suction member 34 Second suction member

Claims (5)

A column filled with a porous adsorbent;
a supply unit provided upstream of the column for supplying a liquid into the column;
a resin orifice provided downstream of the column and configured to apply a gauge pressure of 0.025 MPa or more to the liquid passing through the column;
A switching valve provided at a position between the column and the orifice;
a second flow path extending from the switching valve and capable of passing the liquid at a flow rate greater than that of a first flow path including the orifice;
A liquid purification apparatus comprising: The liquid purification device according to claim 1, wherein the orifice is made of fluororesin. The liquid purification device according to claim 2, further comprising a relief valve disposed between the column and the supply section, for maintaining the pressure of the liquid in the column at 1 MPa or less in gauge pressure. The adsorbent has a first adsorption member,
4. The liquid purification apparatus according to claim 3, wherein the first adsorption member is made of one or more materials selected from the group consisting of ion exchange resins, zeolites, activated carbon, and synthetic adsorbents. The adsorbent has a second adsorption member,
5. The liquid purification apparatus according to claim 4, wherein the second adsorption member is formed of a filter capable of adsorbing fine particles generated from the relief valve.

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