JP7494464B2 - Sample water treatment unit, water quality measurement system, water quality measurement device, sample water treatment method, and water quality measurement method - Google Patents

Description

The present invention relates to a sample water treatment unit, a water quality measurement system, a water quality measurement device, a sample water treatment method, and a water quality measurement method used in water quality measurement.

As is well known, for example, if a sample of water for water quality measurement contains suspended solids (SS), it is necessary to remove the SS from the sample of water for water quality measurement and clarify the turbidity before measuring it with a water quality measuring device.

When removing SS or turbidity from sample water for measuring water quality that contains such SS, a device called a prefilter is generally used.
Known examples of such prefilters include settling tanks, sand filters, inclined screens, vibrating screens, bag filters, cartridge filters, hollow fiber filters, and various combinations of these.

For example, in the fields of paper and pulp manufacturing, where the concentration of SS such as pulp and ash is high, large-scale sand filters and various screens are installed on the production line to continuously remove SS and clarify the turbidity of the measurement sample water online.

In online water quality measurements in the paper and pulp manufacturing industries, a portion of the water system in the production line is used as the measurement sample water, and a small volume of the measurement sample water, for example about 1 to 60 liters/h, is bypassed and passed through the water quality measuring device, but the prefilters using the large, large-capacity screens and filters mentioned above are not suitable.

Therefore, conventionally, small-capacity cross-flow partial treatment type hollow fiber column filters with a capacity of, for example, about 10 liters per minute have been used as pretreatment devices for water quality measurement devices.

However, when sample water containing SS is supplied to the pretreatment device, the SS gradually adheres to the surface of the hollow fiber membrane, clogging the fine openings and gradually reducing the amount of water being treated, eventually causing the fine openings of the hollow fiber membrane to become blocked. The higher the SS concentration, the more likely the fine openings of the hollow fiber membrane are to become blocked, and the more frequently the cartridge and container must be cleaned and replaced.

If the fine openings in such hollow fiber membranes become clogged, the column must be disassembled and the surface of the hollow fibers must be cleaned with high-pressure water or alkali, which requires the measurement device to be shut down, making it difficult to measure water quality continuously.
As a result, it was difficult to operate the system continuously for long periods without maintenance.

Therefore, in order to prevent interruptions to water quality measurements, various technologies have been disclosed for improving the maintenance performance of pretreatment devices equipped with hollow fiber membranes (see, for example, Patent Document 1).

The pretreatment device described in Patent Document 1 is configured to perform air scrubbing cleaning of the hollow fiber membrane in order to efficiently remove deposits such as SS adhering to the hollow fiber membrane.
As a result, it has become possible to achieve a certain degree of continuous operation even when pretreating sample water for measurement from pulp mill wastewater systems.

Patent No. 6322882

However, the pretreatment device described in Patent Document 1 performs air scrubbing of the hollow fiber membranes intermittently, and furthermore, filtration must be interrupted when air scrubbing is performed.
Furthermore, when the amount of dirt such as SS increases, the pretreatment device described in Patent Document 1 is unable to adequately prevent dirt from adhering to the outer surface of the hollow fiber membrane, and may be unable to ensure a satisfactory continuous operating period.

Stopping the water collection line to clean or replace such cartridges will interrupt continuous water quality measurement, contributing to measurement value fluctuations and affecting the reliability of water quality measurement data.

Furthermore, with conventional technology, on-site maintenance was required once every few days to once a week, so even though water quality measurement was automated, labor costs were incurred for maintenance, making the cost of water quality measurement an issue.

Therefore, there is a need for a technology for sample water treatment that can reduce maintenance costs and enable long-term continuous operation at low cost when filtering raw water for water quality measurement samples, including bypass lines for water quality measurement, to produce filtered water by suppressing the residue of deposits on the outer surface of the hollow fiber membrane and enabling it to be used for long periods of time without maintenance, thereby reducing maintenance costs and enabling long-term continuous operation at low cost, thereby improving the reliability of water quality measurement.

The present invention has been made in consideration of these circumstances, and aims to provide a sample water treatment unit, a water quality measurement system, a water quality measurement device, a sample water treatment method, and a water quality measurement method that are capable of filtering a measurement sample without maintenance over a long period of time.

Therefore, the inventors have intensively studied a technique for suppressing adhesion of SS and the like to the outer surface of a hollow fiber membrane made of an external pressure type hollow fiber arranged in a container, and as a result, the inventors have found that it is possible to stably and efficiently suppress adhesion of dirt such as SS to the surface of the hollow fiber membrane by fixing the filtrate discharge hole side of the hollow fiber membrane to the lower part of a vertical container arranged vertically, supplying raw water as a measurement sample from the lower part of the vertical container and discharging it from the upper part of the vertical container, forming an upward flow of raw water in the vertical container, and stably filtering the raw water moving along the upward flow by the hollow fiber membrane by a cross-flow partial filtration method. In addition, when gas is supplied from the lower part of the vertical container to form bubbles in the upward flow, the bubbles rise along the upward flow and come into contact with the bubbles to scrub the hollow fiber membrane, and the hollow fiber membrane is not disturbed, and adhesion of dirt such as SS to the surface of the hollow fiber membrane can be stably and efficiently suppressed.
Furthermore, it was found that the adhesion of SS and the like can be further suppressed by allowing the hollow fibers to sway, and that the action and effect of the swaying can be further obtained by leaving the upper side of the hollow fiber membrane free and not fixed. Also, the formation of bubbles can be intermittent or not, and it was realized that the adhesion of SS and the like to the outer surface of the hollow fiber membrane can be suppressed while continuously filtering the raw water, and that the adhesion of the dirt can be peeled off.

In order to solve the above problems, the present invention proposes the following means.
The invention described in claim 1 is a sample water treatment unit for filtering raw water of a water quality measurement sample to produce filtered water, comprising: a vertical container formed along a vertical direction; a raw water supply section disposed at the bottom of the vertical container for supplying raw water into the vertical container; a hollow fiber membrane made of external pressure hollow fibers disposed inside the vertical container for filtering the raw water supplied from the raw water supply section to produce filtered water; a filtered water delivery section disposed at the bottom of the vertical container for delivering the filtered water produced by the hollow fiber membrane; and a filter for filtering the raw water, which is disposed at the bottom of the vertical container and provided separately from the raw water supply section. and a discharge section disposed at the upper part of the vertical vessel and discharging non-filtered water other than the filtered water filtered by the hollow fiber membrane to the outside of the vertical vessel. The hollow fiber membrane extends along the vertical vessel and has a lower part connected to the filtered water discharge section. The gas supplied from the scribing gas supply section is configured to form bubbles in the upward flow of the raw water supplied into the vertical vessel and to contact the outer surface of the hollow fiber membrane, and the size of the bubbles is 0.5 mm or more and 30 mm or less in diameter.

The invention described in claim 7 is a sample water treatment method for filtering raw water for a water quality measurement sample to produce filtered water, characterized in that a hollow fiber membrane made of external pressure hollow fibers is extended along the vertical container inside a vertical container formed along the vertical direction and connected to a filtered water discharge section arranged at the bottom of the vertical container, raw water is supplied from a raw water supply section arranged at the bottom of the vertical container into the vertical container to form an upward flow of raw water and filtered by the hollow fiber membrane, gas is supplied from a scribing gas supply section arranged at the bottom of the vertical container and provided separately from the raw water supply section to form bubbles with a diameter of 0.5 mm to 30 mm in the upward flow of raw water, the bubbles are brought into contact with the outer surface of the hollow fiber membrane to peel off any attached matter from the outer surface, and non-filtered water other than the filtrate water filtered by the hollow fiber membrane is discharged to the outside of the vertical container from a discharge section arranged at the top of the vertical container.

According to the sample water treatment unit and sample water treatment method of the present invention, a hollow fiber membrane made of external pressure type hollow fibers is extended along the inside of a vertical container, and the lower part of the hollow fiber membrane is connected to a filtered water discharge section arranged at the lower part of the vertical container. Raw water for a water quality measurement sample is supplied into the vertical container from a raw water supply section arranged at the lower part of the vertical container, and the upward flow of the raw water is partially cross-flow filtered by the hollow fiber membrane to produce filtered water.
In addition, gas is supplied into the vertical vessel from a scribing gas supply unit located at the bottom of the vertical vessel to generate bubbles with a diameter of 0.5 mm or more and 30 mm or less in the upward flow of the raw water, and the bubbles are brought into contact with the outer surface of the hollow fiber membrane.
Then, non-filtrate water (water other than filtrate water) that has not been filtered by the hollow fiber membrane is discharged to the outside of the vertical container from a discharge portion disposed at the top of the vertical container.
As a result, the bubbles generated in the upward flow of raw water come into contact with the outer surface of the hollow fiber membrane. Therefore, even if the raw water used for the water quality measurement sample contains SS or other substances that adhere to the outer surface of the hollow fiber membrane, the SS or other substances that have adhered to the bubbles can be peeled off from the outer surface of the hollow fiber membrane, preventing the adhesions from remaining on the outer surface of the hollow fiber membrane.

In addition, since the hollow fiber membrane is fixed at its lower part and arranged to extend along the vertical vessel, the hollow fiber membrane is prevented from being disturbed by the upward flow or bubbles formed within the upward flow, and the upward flowing raw water can be stably filtered.
As a result, measurement sample water can be stably filtered without maintenance for a long period of time.
Furthermore, since the sample water treatment unit can be used continuously for a long period of time, physical maintenance costs such as the number of man-hours required for maintenance (labor costs) and parts costs can be reduced.
Furthermore, since the sample water treatment unit can be used continuously for a long period of time, the measurement sample water can be efficiently filtered online.
In addition, since the hollow fiber membrane is fixed at its lower part and arranged to extend along the vertical container, the hollow fiber membrane is prevented from being disturbed by the upward flow or bubbles formed within the upward flow, and the raw water can be stably filtered.

Here, the vertical vessel formed along the up-down direction is not limited to the vertical vessel (perpendicular to the ground) but may be inclined within a predetermined range with respect to the vertical direction. Specifically, the vessel may be inclined within a range that allows the gas supplied from the scribing gas supply unit to move from below to above along the outer surface of the hollow fiber membrane.
Furthermore, the positions of the upper and lower parts of the vertical vessel can be set arbitrarily within a range in which bubbles formed in the upward flow can come into contact with the outer surface of the hollow fiber membrane.
Here, the parts other than the lower part of the hollow fiber membrane may be fixed or may be configured in a free state.

The invention described in claim 2 is the sample water treatment unit described in claim 1, characterized in that the hollow fiber membrane is configured to sway within the vertical container.

The invention described in claim 8 is the sample water treatment method described in claim 7, characterized in that the hollow fiber membrane wobbles in the vertical container.

According to the sample water treatment unit and sample water treatment method of the present invention, the hollow fiber membrane sways within the vertical container, thereby preventing dirt, solids, etc. contained in the measurement sample from adhering to the hollow fiber membrane.
In addition, the bubbles formed by the bubbling gas can come into efficient contact with the hollow fiber membrane.

The invention described in claim 3 is the sample water treatment unit described in claim 1 or 2, characterized in that the upper side of the hollow fiber membrane is freely swingable.

The invention described in claim 9 is the sample water treatment method described in claim 7 or 8, characterized in that the upper side of the hollow fiber membrane is freely swingable.

According to the sample water treatment unit and sample water treatment method of this invention, the upper side of the hollow fiber membrane is not fixed (restrained) but is free to swing, so bubbles formed in the upward flow of raw water are more likely to come into contact with the hollow fiber membrane, and deposits can be efficiently removed from the outer surface of the hollow fiber membrane.

The invention described in claim 4 is a sample water treatment unit described in any one of claims 1 to 3, characterized in that the raw water supply unit is connected to a water system whose water quality is to be measured, and is configured to supply raw water for the water quality measurement sample online into the vertical container.

The invention described in claim 10 is a sample water treatment method described in any one of claims 7 to 9, characterized in that the raw water supply unit is connected to a water system whose water quality is to be measured, and raw water for the water quality measurement sample is supplied online into the vertical container.

According to the sample water treatment unit and sample water treatment method of the present invention, by connecting the raw water supply unit to the water system whose water quality is to be measured and supplying raw water online into the vertical container, it is possible to efficiently and continuously supply and filter a sample for water quality measurement from the water system whose water quality is to be measured.

The invention described in claim 5 is a water quality measurement system comprising a sample water treatment unit described in any one of claims 1 to 4 and a water quality measurement device that measures the water quality of a water quality measurement sample, and is configured so that filtered water produced in the sample water treatment unit is transferred to the water quality measurement device.

The invention described in claim 6 is a water quality measurement device comprising a sample water treatment unit described in any one of claims 1 to 4 and a water quality measurement section that measures the water quality of a sample for water quality measurement, and is configured so that filtered water produced in the sample water treatment unit is transferred to the water quality measurement section.

The invention described in claim 11 is a water quality measurement method, characterized in that the filtered water produced by the sample water treatment method described in any one of claims 7 to 10 is transferred to a water quality measurement unit that measures the water quality of a sample for water quality measurement, and the filtered water is measured in the water quality measurement unit.

According to the water quality measurement system, water quality measurement device, and water quality measurement method of the present invention, the generated filtered water is transferred to a water quality measurement device or water quality measurement unit for measuring the water quality, so that water quality measurement can be performed efficiently.

The sample water treatment unit, water quality measurement system, water quality measurement device, sample water treatment method, and water quality measurement method of the present invention make it possible to filter the measurement sample without maintenance for a long period of time.

1 is a schematic diagram illustrating an example of the schematic configuration of a water quality measuring device according to one embodiment of the present invention. 1 is a schematic diagram illustrating an example of a schematic configuration of a sample water treatment unit according to an embodiment. FIG. 1 is a schematic diagram illustrating the operation of a sample water treatment unit according to an embodiment of the present invention; FIG. 2 is a conceptual diagram for explaining an outline of the operation of an external pressure type hollow fiber constituting a hollow fiber membrane according to one embodiment.

Hereinafter, a sample water treatment unit and a water quality measuring device according to one embodiment of the present invention will be described with reference to FIGS.
Fig. 1 is a schematic diagram illustrating an example of a water quality measuring device according to an embodiment of the present invention, Fig. 2 is a schematic diagram illustrating an example of a sample water treatment unit, Fig. 3 is a schematic diagram illustrating an outline of the operation of the water quality measuring device, and Fig. 4 is a conceptual diagram illustrating an outline of the operation of an external pressure type hollow fiber constituting a hollow fiber membrane.

In Figures 1 to 4, reference numeral 1 indicates a water quality measuring device, reference numeral 10 indicates a sample water treatment unit, reference numeral 100 indicates a vertical container, reference numeral 120 indicates a hollow fiber membrane, reference numeral 20 indicates a water quality measuring unit (water quality measuring section) 20, reference numeral 30 indicates an air pump unit (bubbling gas supply source), and reference numeral 40 indicates a measurement control section 40.

As shown in FIG. 1, the water quality measuring device 1 includes, for example, a sample water treatment unit 10, a water quality measuring unit (water quality measuring section) 20, an air pump unit (bubbling gas supply source) 30, and a measurement control section 40.

The water quality measuring device 1 is configured to automatically supply raw water for the water quality measurement sample to the sample water treatment unit 10 in response to instructions from the measurement control unit 40, filter the raw water in the sample water treatment unit 10 to produce filtered water, transfer the filtered water to the water quality measuring unit 20, measure the measurement items in the water quality measuring unit 20, and continuously measure the water quality of the water system online.

The sample water treatment unit 10 includes, for example, a vertical container 100, a raw water supply section 121, a scribing air supply section (scribing gas supply section) 122, a filtered water delivery section 123, a non-filtered water discharge section (discharge section) 131, and a hollow fiber membrane 140 arranged inside the vertical container 100.

In addition, the raw water supply unit 121 and the scribing air supply unit 122 are arranged at the bottom of the vertical vessel 100, and the non-filtrate water discharge unit (discharge unit) 131 is arranged at the bottom of the vertical vessel 100.
The raw water for the measurement sample supplied from the raw water supply unit 121 is filtered by the hollow fiber membrane 140 to produce filtered water.

The upright container 100 includes, for example, a container body 110, a lower cover member 120, and an upper cover member 130. The upright container 100 is disposed along the up-down direction (for example, the vertical direction).
The upright container 100 may be set in any orientation within a range where the functions and effects of the present invention are achieved, and may be disposed at an angle to the vertical direction. However, it is preferable to dispose it vertically.

The container body 110 is made of, for example, a resin material and has a cylindrical shape.
The material from which the container body 110 is formed can be set as desired, but it is preferable to form the container body 110 from a transparent resin such as acrylic.
The shape of the container body 110 may also be set arbitrarily. When the container body 110 is cylindrical, the inner diameter of the container body 110 is not particularly limited, but may be, for example, about 30 to 100 mm, about 40 mm, or about 60 mm.

The lower cover member 120 is disposed at the lower part of the container body 110 and is configured to be able to close the lower opening of the container body 110 .
In this embodiment, the lower cover member 120 includes, for example, a first member 120A that is directly attached to the container body 110, and a bottom member 120B that closes the bottom of the first member 120A.

The first member 120A is, for example, cylindrical with a bottom, having a cylindrical retaining wall portion that retains the outer peripheral surface of the container body 110, and a bottom wall portion that is connected to the lower end of the retaining wall portion and formed into a disk shape.
Furthermore, a screw hole (not shown) coaxial with the axis of the container body 110 is formed in the center of the bottom wall.

In this embodiment, for example, a raw water supply portion 121 that communicates between the inside and the outside of the upright container 100 is formed on the side surface of the first member 120A.
Furthermore, the raw water supply unit 121 is connected to, for example, a raw water supply tube 11 .

The raw water supply tube 11 is provided with a cock-equipped elbow 11A on the upstream side, which is fixed to the housing of the measuring device 1, and an elbow 11B on the downstream side.
As shown in FIG. 3, the upstream side of the cock-equipped elbow 11A is connected to, for example, a water system S0 of a pulp manufacturing facility.

The raw water S1 for the water quality measurement sample collected from the water system S0 of the pulp manufacturing facility is supplied to the vertical container 100 via the raw water supply tube 11 and the raw water supply section 121 as raw water sample water G1 for measurement.

In this embodiment, for example, a scribing air supply part (scribing gas supply part) 122 that communicates between the inside and the outside of the vertical vessel 100 is formed on the side surface of the first member 120A.
Further, for example, a scribing air supply tube 12 is connected to the scribing air supply unit 122 .

The scribing air supply tube 12 is provided with an elbow 11A on the downstream side that is connected to a scribing air supply section (scribing gas supply section) 122, and an air pump 30 is connected on the upstream side.
In addition, scribing air (scribing gas) G1 is supplied from the air pump 30 into the vertical container 100 through a scribing air supply unit (scribing gas supply unit) 122.

The scribing air G1 supplied into the interior of the vertical vessel 100 via the scribing gas supply unit 122 is configured to form gas (bubbles) in the upward flow of the raw water in the vertical vessel 100.
The size of the air bubbles G2 is preferably, for example, 0.5 mm to 30 mm in diameter, and more preferably 5 mm to 20 mm in diameter, because it is essential that the bubbles penetrate into the gaps between the individual hollow fiber membrane fibers and rub against the fiber surfaces, and the larger the bubble diameter, the faster the floating speed and the greater the rubbing force (friction force) on the fiber surfaces, and the less carryover to the treated water.

The bottom member 120B is formed in a multi-stage cylindrical shape that is coaxial with the axis of the container body 110, and has a male screw portion (not shown) formed on the outer circumferential surface of the upper portion.
This male screw portion can be attached to the first member 120A by screwing it into a screw hole in the first member 120A.
In addition, a filtered water delivery section 123 is formed in the bottom member 120B, which is disposed coaxially with the axis of the container body 110 and connects the inside of the upright container 100 to the outside.

As shown in FIG. 3 , the filtrate discharge portion 123 communicates with a filtrate discharge hole (not shown) of the hollow fiber membrane 140 .
As shown in FIG. 1, the filtered water delivery tube 13 is connected to the filtered water delivery section 123 .

As shown in FIG. 1, the filtered water supply tube 13 has, for example, an elbow 13A connected to the filtered water supply section 123 on the upstream side and an elbow 13B connected to the water quality measuring unit 20 on the downstream side.
The filtered water supply tube 13 is configured to supply the generated filtered water S3 from the filtered water supply section 123 to the water quality measuring unit 20.

Furthermore, a lower portion of a hollow fiber membrane 140 is fixed to the upper side of the bottom member 120B (the side positioned inside the vertical vessel 100) with a filtrate discharge hole (not shown) facing downward.
A hollow fiber membrane 140 is provided upright on the bottom member 120B.
In addition, a filtered water delivery section 123 that is coaxial with the axis of the upright container 100 is disposed on the bottom member 120B, for example.

The hollow fiber membrane 140 is made by arranging a large number (multiple) of external pressure type hollow fibers 141, each having a filtrate discharge hole formed at one end (lower end), and binding the external pressure type hollow fibers 141 at positions 1/3 and 2/3 from the lower end in the length direction with binding strings 142, for example.

In addition, although the external pressure type hollow fibers 141 of the hollow fiber membrane 140 are bound by binding strings 142, the external pressure type hollow fibers 141 can change shape relative to each other except at the points bound by the binding strings 142, and raw water and air bubbles can flow upward between the external pressure type hollow fibers 141.

As described above, the hollow fiber membrane 140 is fixed at the lower side to the lower cover member 120, and the upper side (the range from 2/3 of the way from the lower end to the upper end) is free to move without being fixed to the vertical container 100 or the like.
It is preferable that the upper end of the hollow fiber membrane 140 is not fixed but is a free end.

As a result, the upper ⅓ of the hollow fiber membrane 140 is configured so that the hollow fibers 141 can swing relative to each other.
In this embodiment, the upper side of the hollow fiber membrane 140 is freely swingable as a whole.

In addition, it is possible to arbitrarily set whether or not the external pressure type hollow fibers 141 are bound by a binding string 142 or the like, and the external pressure type hollow fibers 141 may be freely configured without being bound.
Furthermore, when bundling the external pressure type hollow fibers 141, the bundling means, the number of bundling points, and the bundling positions can be set arbitrarily.

The upper cover member 130 is disposed on the upper portion of the container body 110 and is configured to be able to close the upper opening of the container body 110 .
As shown in FIG. 2, in this embodiment, the upper cover member 130 includes, for example, a cylindrical retaining wall portion that retains the outer peripheral surface of the container body 110, and a conical wall portion that is connected to the upper side of the cylindrical retaining wall portion and has an approximately cone-like shape and whose diameter decreases toward the upper side.

Further, a non-filtrate water discharge portion (discharge portion) 131 that communicates between the inside and the outside of the vertical container 100 is disposed at the top of the conical wall portion.
In this embodiment, the non-filtrate water discharge portion 131 is connected to, for example, a non-filtrate water drainage tube 14 .

As shown in Figures 1 and 2, the non-filtered water drainage tube 14 has, for example, an elbow 14A with a cock connected to the non-filtered water discharge section 131 on the upstream side, and a socket 14B fixed to the housing of the water quality measuring device 1 on the downstream side.

The non-filtered water drainage tube 14 is configured to discharge the non-filtered water S4 discharged from the outlet 131 to the outside of the water quality measuring device 1.
In this embodiment, the non-filtered water drainage tube 14 is configured to discharge air bubbles (foam) G2 discharged from the measurement sample water treatment unit 10 together with the non-filtered water S4.

The water quality measurement unit (water quality measurement section) 20 may be a colorimetric analysis unit (for example, S.sensing B (manufactured by Kurita Water Industries Ltd.)) or any other unit having a variety of well-known configurations.
The water quality measurement unit (water quality measurement section) 20 is configured, for example, based on instructions from the measurement control section 40, to automatically distribute the filtered water of the water quality measurement sample transferred from the sample water treatment unit 10 to a column (not shown), and to sequentially inject reagents from reagent bottles 21, 22 containing reagents corresponding to the water quality measurement items, thereby measuring the water quality.
The water quality measuring unit 20 then transmits the measurement results to a computer (not shown) or the like.

As shown in FIG. 1 , the air pump (air source) 30 is connected to a scribing air supply unit 122 by a scribing air supply tube 12 .
The air pump (air source) 30 supplies scribing air G1 into the upright container 100 via the scribing air supply unit 122 based on instructions from the measurement control unit 40.

In this embodiment, the air pump (air source) 30 operates continuously based on instructions from the measurement control unit 40, for example while the sample water treatment unit 10 is filtering, to continuously supply scribing air G1 into the vertical container 100.

It is possible to arbitrarily set whether the air pump (air source) 30 is operated continuously or intermittently. In addition, the supply time and cycle in the case of intermittent supply may be arbitrarily set.
Also, instead of the air pump (air source) 30, compressed air supplied from a pressurized air source may be supplied into the upright container 100 by switching an electromagnetic valve or the like.

The operation of the water quality measuring device 1 will now be described.
(1) First, as shown in FIG. 3, for example, raw water S1 for water quality measurement is collected from the water system (the water system to be measured) S0 of the pulp manufacturing facility.

(2) Next, raw water S1, which is a sample for water quality measurement, is supplied to the sample water treatment unit 10 via the raw water supply section 121.
As a result, the raw water supplied from the raw water supply section 121 to the sample water treatment unit 10 forms an upward flow within the vertical container 100 flowing from the raw water supply section 121 toward the non-filtrate water discharge section 131 .

(3) Then, as shown in FIG. 4, raw water S2 of the water quality measurement sample forming an upward flow in the vertical container 100 is filtered by the hollow fiber membrane 140, and filtered water S3 is produced in the external pressure type hollow fiber 141.
The produced filtrate S3 is discharged from a filtrate discharge hole located at the lower end of the external pressure type hollow fiber 141.
As a result, the filtrate is discharged from the hollow fiber membrane 140 and sent out from the filtrate discharge section 123 .

(4) Next, the measurement control unit 40 supplies scribing air (air) G1 from the air pump unit 30 via the scribing air supply unit 122 into the upright container 100.
The scribing air G1 supplied from the scribing air supply unit 122 forms large bubbles (foam) G2 in the upward flow of the raw water S2.

Then, these air bubbles G2 flow toward the non-filtrate water discharge portion 131 along with the upward flow.
At this time, the air bubbles G2 come into contact with the outer surface of the hollow fiber membrane 140 as shown in FIG. 4, and peel off and remove the SS, dirt, etc. adhering to the outer surface of the hollow fiber membrane 140 from the outer surface of the hollow fiber membrane 140.
At this time, it is preferable that the hollow fiber membrane 140 sways, for example, in the direction of the arrow F as shown in Fig. 4. It is also preferable that the external pressure type hollow fibers 141 constituting the hollow fiber membrane 140 sway as shown by G at any position in the length direction, so that the external pressure type hollow fibers 141 sway relatively to each other.
In order to further enhance the effect of air scrubbing, it is preferable that one of the hollow fiber membranes of the filtering means 12 is not fixed.

(5) Of the raw sample water G2, non-filtered water (measurement sample other than filtered water) that was not filtered by the hollow fiber curtain 140 is discharged to the outside from the non-filtered water discharge section 131 located at the top of the vertical container 100.
In this embodiment, the SS, dirt, etc. removed from the outer surface of the hollow fiber membrane 140 are discharged to the outside of the vertical container 100 via the non-filtrate water discharge section 131 together with the non-filtrate water and air bubbles G2.

According to the sample water treatment unit 10 according to one embodiment, a hollow fiber membrane 140 is disposed inside a vertical vessel 100 so as to extend along the vertical vessel 100 and to be connected to a filtered water delivery section 141 disposed at the bottom of the vertical vessel 100, raw water is supplied from a raw water supply section 121 disposed at the bottom of the vertical vessel 100 to form an upward flow, which is filtered by the hollow fiber membrane 140 in a cross-flow partial filtration manner, and non-filtered water is discharged to the outside from a non-filtered water discharge section 131 disposed at the top of the vertical vessel 100. At this time, a gas G1 is supplied from a scribing air supply section 122 disposed at the bottom of the vertical vessel 100 into the vertical vessel 100 to form bubbles G2 in the upward flow, and the bubbles G2 are brought into contact with the outer surface of the hollow fiber membrane 140, thereby suppressing the adhesion of SS and the like to the outer surface of the hollow fiber membrane 140 and peeling off the dirt, SS, and other deposits attached to the outer surface of the hollow fiber membrane 140.
As a result, measurement sample water can be stably filtered without maintenance for a long period of time.
Furthermore, since the sample water treatment unit can be used continuously for a long period of time, the number of steps required for maintenance and the maintenance costs can be reduced.
Furthermore, since the sample water treatment unit 10 can be used continuously for a long period of time, the measurement sample water can be efficiently filtered online.

In addition, according to the sample water treatment unit 10 of one embodiment, the lower part of the hollow fiber membrane is fixed to the vertical container 100, and the hollow fiber membrane 140 is arranged to extend along the vertical container 100, so that the hollow fiber membrane 140 can be prevented from being disturbed by the upward flow or the formed bubbles G2.

In addition, according to the sample water treatment unit 10 of one embodiment, the hollow fiber membrane 140 is configured to sway within the vertical container 100, thereby suppressing adhesion of SS and the like to the outer surface of the hollow fiber membrane 140.
In addition, since the hollow fiber membrane 140 sways within the vertical vessel 100, the bubbles G2 and the hollow fiber membrane 140 can be brought into contact with each other efficiently.

According to the sample water treatment unit 100 of one embodiment, the upper side of the hollow fiber membrane 140 is not fixed (restrained) but is free to swing, so that the upper side of the hollow fiber membrane 140 is easily swingable, and the bubbles G2 formed in the upward flow are easily brought into contact with the outer surface of the hollow fiber membrane 140, so that SS and the like can be efficiently removed from the outer surface of the hollow fiber membrane 140.

According to the sample water treatment unit 100 of one embodiment, the raw water supply section 121 is connected to the water system (the water system to be measured for water quality) 2 of the pulp manufacturing facility, and the raw water sample for water quality measurement is supplied online into the vertical container 100, so that the raw water sample for water quality measurement can be efficiently supplied into the vertical container 100.

According to the water quality measuring device 1 of one embodiment, the generated filtered water is transferred to the water quality measuring unit (water quality measuring section) 20 for measuring the water quality, so that the water quality can be measured efficiently and continuously.

Examples of the present invention will now be described.
In the examples of the present invention, a conventional sample water treatment device was used as a comparative example, the sample water treatment device 10 according to the above-mentioned embodiment was used as an example of the present invention, and the effect of the sample water treatment device 10 was confirmed using a case where the sample water treatment device 10 was used without supplying bubbling air as a reference example.

(1) Comparative Example Pretreatment Device (Conventional Sample Water Treatment Unit)
The hollow fiber membrane is fixed at the top and extends downward (raw water flows upward).
Vertical container, inner diameter 40 mm x length 200 mm (made of polyvinyl chloride)
Raw water supply section: Placed at the bottom of the vertical container. Non-filtrate discharge section: Placed at the top of the vertical container. Hollow fiber membrane: Filtrate drain hole side is fixed to the top of the vertical container. Hollow fiber membrane: Manufactured by Kuraray Co., Ltd. Membrane material: PVDF
Membrane pore size: 0.1 μm, effective membrane area: 0.1 ^m2
Effective membrane length: 200 mm
Then, sample water (raw water) was supplied from the raw water supply section and discharged from the non-filtered water discharge section.

(2) Pretreatment device of the present invention and reference examples (sample water treatment unit according to one embodiment)
The hollow fiber membrane is fixed at the bottom and extends from top to bottom (raw water flows upward).
Vertical container, inner diameter 40 mm x length 200 mm (made of polyvinyl chloride)
Sample water (raw water) supply section: Inner diameter φ8mm
Scrubbing air supply part: Inner diameter φ4mm
Non-filtered water outlet: Inner diameter φ8mm
Hollow fiber membrane YHF-20CS (Yuasa Membrane Systems Co., Ltd.)
Membrane material: Polysulfone resin, hydroxypropyl methylcellulose Membrane pore size: 0.2 μm Effective membrane area: 0.1 ^m2
Effective membrane length: 200 mm
Sample water (raw water) collection rate: 2 liters/min. Filtered water outlet (for water quality analysis): 0.2 liters/min.

(3) Test Methods Test methods for the Comparative Examples, Inventive Examples, and Reference Examples are described below.

Comparative Example
In the comparative example, sample water (raw water) was supplied to the pretreatment device described in the comparative example (1) above to produce filtered water, and the contamination of the outer surface of the hollow fiber membrane was confirmed, and the free chlorine was measured using S.sensing B (manufactured by Kurita Water Industries Ltd.).

[Example of the present invention]
In the present invention examples, sample water (raw water) was supplied to the pretreatment device described in (2) Present invention examples and reference examples above to produce filtered water, and the fouling of the outer surface of the hollow fiber membrane was confirmed.
In the present invention, scrubbing air (supply amount: 2 liters/min) was continuously supplied from the scrubbing air supply unit. The size of the air bubbles was about 5 mm to 20 mm.

[Reference Example]
In the reference example, sample water (raw water) was supplied to the pretreatment device described in the above (2) Invention Examples and Reference Examples to produce filtered water, and the fouling on the outer surface of the hollow fiber membrane was confirmed.
In the reference example, scrubbing air was not supplied and filtration was performed without bubbles in the raw water.

(4) Test Conditions The test conditions for the Comparative Examples, Invention Examples, and Reference Examples are as follows.
Sample water (raw water) supply rate: 2 liters/min. Non-filtered water discharge rate: 1.8 liters/min. Filtered water production rate: 0.2 liters/min. Sample water (raw water) SS concentration: 30-50 mg/liter.

(5) Test Results The results of the comparative examples, the invention examples, and the reference examples are explained below.

Comparative Example
In the comparative example, batch cleaning was performed once a day using an air scribe to treat the measurement sample water.
As a result, the hollow fiber membrane became clogged in about 8 hours, and it became impossible to measure free chlorine using S.sensing B after 10 hours without being able to be cleaned.

[Example of the present invention]
In the present invention, free and residual chlorine, and ORP could be continuously measured using S.sensing B for more than one month without any maintenance.
It was confirmed that this would eliminate the need for disassembly maintenance once a week.
It was also confirmed that this technology makes it possible to capture undetectable fluctuations in water quality that previously occurred during interruptions in water quality measurements, thereby improving the reliability of continuous online water quality measurements.

[Reference Example]
In the reference example, the measurement sample water was treated continuously without cleaning with an air scribe.
As a result, the hollow fiber membrane became clogged in about 8 hours, and measurement of free chlorine using S. sensing B became impossible in 10 hours.

(6) Confirmation of water quality measurement results in the examples of the present invention In the examples of the present invention, the possibility of blockage of the fine holes in the hollow fiber membrane due to blowing in scribing air was examined. No reduction in filtration performance due to blockage of the fine holes in the hollow fiber membrane was observed for coarse bubbles with a size of 5 mm or more and 20 mm or less.
Furthermore, even when scribing air was blown continuously, no particular fluctuations (measurement errors) in water quality such as pH, electrical conductivity, and oxidation-reduction potential due to oxidation of the measurement sample water were observed.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.
For example, in the above embodiment, the raw water supply unit 121 is connected to a pulp manufacturing facility (the water system whose water quality is to be measured) and the raw water of the water quality measurement sample is filtered online to produce filtered water. However, whether or not the raw water supply unit 121 is connected to the water system whose water quality is to be measured can be set arbitrarily, and for example, the water quality measurement sample may be filtered by batch processing.

In the above embodiment, the sample water treatment unit 10 is connected to the water quality measurement unit 20 and used in the water quality measurement device 1 that measures water quality online. However, it is possible to arbitrarily set whether or not the sample water treatment unit 10 is connected to a water quality measurement unit or water quality measurement equipment, and it may be applied, for example, to measuring the water quality of filtered water by batch processing.

In addition, in the above embodiment, a case has been described in which air G1 is continuously supplied from the scribing air supply unit 122, but the supply timing of the gas supplied from the scribing air supply unit 122 can be set arbitrarily, and for example, it may be supplied intermittently.

In the above embodiment, air is supplied as gas G1 from the scribing air supply unit 122, but it is also possible to configure the scribing air supply unit 122 to supply an inert gas such as nitrogen gas.

In addition, in the above embodiment, the sample water treatment unit 10 is described as being used in a water quality measurement device 1 equipped with a water quality measurement section 20, but it may also be applied to a water quality measurement system equipped with, for example, an individual water quality measurement device (single or multiple) arranged separately from the sample water treatment unit 10.

In addition, in the above embodiment, the upper side of the hollow fiber membrane 140 is not fixed and is configured to be able to swing freely, but the upper side of the hollow fiber membrane 140 may be configured not to be fixed as long as dirt adhering to the outer surface of the hollow fiber membrane 140 can be peeled off by the bubbles G2.

In addition, in the above embodiment, the hollow fiber membrane 140 is configured to sway, but the hollow fiber membrane 140 may be configured not to sway within a range in which dirt adhering to the outer surface of the hollow fiber membrane 140 can be peeled off by the bubbles G2.

In the above embodiment, the hollow fiber membrane 140 is formed by bundling multiple external pressure type hollow fibers 141 with a bundling cord 143. However, it is possible to arbitrarily set whether or not to bundle the external pressure type hollow fibers 141 in two, and the hollow fiber membrane 140 may be formed without bundling them. Also, instead of multiple external pressure type hollow fibers 141, the hollow fiber membrane may be formed by a single external pressure type hollow fiber.

In the above embodiment, the water quality measuring device 1 is described as having one sample water treatment unit 10, but it may also be configured to have, for example, two or more sample water treatment units 10. The same applies to the water quality measuring system.

In the above embodiment, the water quality measuring device 1 was used to measure the water quality of the water system of a pulp manufacturing facility, but it may also be configured to measure the water quality of water systems of paper manufacturing facilities, general wastewater treatment facilities, etc.

In addition, in the above embodiment, a case was described where the water quality of the measurement sample water having a high concentration of SS was measured, but it is possible to arbitrarily set whether the measurement sample water contains SS and the SS concentration.

In addition, the water quality measurement items can be set arbitrarily without being limited to pH, electrical conductivity, redox potential, and free and residual chlorine.

The materials and shapes shown in the above embodiment are merely examples, and the materials and shapes can be set as desired.

The sample water treatment unit, water quality measurement system, water quality measurement device, sample water treatment method, and water quality measurement method of the present invention can filter measurement samples without maintenance for a long period of time, making them industrially applicable.

1 Water quality measuring device 10 Sample water treatment unit 11 Air supply tube 12 Scribing air supply tube 13 Non-filtered water discharge tube 20 Water quality measuring unit (water quality measuring section)
30 Air pump unit (scribing gas supply source)
11 Air supply tube 100 Vertical container 110 Container body 120 Lower cover member 121 Raw water supply unit 122 Scribing air supply unit (scribing gas supply unit)
123 filtrate water delivery section 130 upper cover member 131 non-filtrate water discharge section (discharge section)
140 Hollow fiber membrane 141 External pressure type hollow fiber 142 Filtrate water discharge part (one end of hollow fiber membrane)
143 Hollow fiber bundling section S0 Water system of pulp manufacturing facility (water system subject to water quality measurement)
S1 Raw water for sample water for measurement S2 Raw water for sample water for measurement (upward flow)
S3 Filtered water S4 Non-filtered water G1 Scribing air (scribing gas)
G2 Bubbles (foam)

Claims (11)

A sample water treatment unit for filtering raw water for a water quality measurement sample to produce filtered water,
A vertical container formed along a vertical direction;
A raw water supply unit disposed at a lower portion of the vertical container and supplying raw water into the vertical container;
A hollow fiber membrane made of an external pressure type hollow fiber that is disposed inside the vertical vessel and filters the raw water supplied from the raw water supply unit to produce filtered water;
a filtrate delivery section disposed at a lower portion of the vertical vessel and delivering the filtrate produced by the hollow fiber membrane;
A scribing gas supply unit is disposed in a lower portion of the vertical vessel and is provided separately from the raw water supply unit, and supplies gas into the vertical vessel during filtration of the raw water;
A discharge part is disposed at an upper part of the vertical container and discharges non-filtrate water other than the filtrate water filtered by the hollow fiber membrane to the outside of the vertical container;
Equipped with
The hollow fiber membrane extends along the vertical vessel and has a lower portion connected to the filtrate delivery section;
The gas supplied from the scribing gas supply unit is configured to form bubbles in the upward flow of the raw water supplied into the vertical vessel and contact the outer surface of the hollow fiber membrane,
A sample water treatment unit characterized in that the size of the bubbles is 0.5 mm or more and 30 mm or less in diameter. 2. The sample water treatment unit according to claim 1,
The hollow fiber membrane is
A sample water treatment unit configured to oscillate within the vertical container. 3. The sample water treatment unit according to claim 1 or 2,
A sample water treatment unit, characterized in that the upper side of the hollow fiber membrane is freely swingable. The sample water treatment unit according to any one of claims 1 to 3,
The raw water supply unit includes:
It is connected to the water system where the water quality is to be measured.
A sample water treatment unit characterized in that it is configured to supply raw water for a water quality measurement sample online into the vertical container. A sample water treatment unit according to any one of claims 1 to 4,
A water quality measuring device for measuring the water quality of the water quality measurement sample;
Equipped with
A water quality measuring system, characterized in that the filtered water produced in the sample water treatment unit is transported to the water quality measuring device. A sample water treatment unit according to any one of claims 1 to 4,
a water quality measurement unit that measures the water quality of a water quality measurement sample;
Equipped with
The water quality measuring device is configured so that filtered water produced in the sample water treatment unit is transferred to the water quality measuring section. A sample water treatment method for filtering raw water for a water quality measurement sample to produce filtered water, comprising the steps of:
A sample water treatment method comprising: a hollow fiber membrane made of external pressure hollow fibers extending along a vertical container formed along a vertical container and connected to a filtered water discharge section arranged at the bottom of the vertical container; a raw water supply section arranged at the bottom of the vertical container supplies raw water into the vertical container to form an upward flow of raw water, and the raw water is filtered by the hollow fiber membrane; a scribing gas supply section arranged at the bottom of the vertical container supplies gas from a scribing gas supply section arranged separately from the raw water supply section to form bubbles having a diameter of 0.5 mm to 30 mm in the upward flow of raw water, the bubbles being brought into contact with an outer surface of the hollow fiber membrane to peel off deposits from the outer surface; and a discharge section arranged at the top of the vertical container discharges non-filtered water other than the filtrate water filtered by the hollow fiber membrane to the outside of the vertical container. 8. The method for treating a water sample according to claim 7, further comprising:
A sample water treatment method, characterized in that the hollow fiber membrane is oscillated within the vertical container. 9. The method for treating a sample water according to claim 7 or 8,
A sample water treatment method, characterized in that the upper side of the hollow fiber membrane is freely swingable. The method for treating sample water according to any one of claims 7 to 9,
The raw water supply unit is connected to a water system whose water quality is to be measured,
A method for treating sample water, comprising the steps of: supplying raw water for a sample for water quality measurement online into said vertical vessel. A water quality measurement method, comprising: transferring filtered water produced by the sample water treatment method according to any one of claims 7 to 10 to a water quality measurement section that measures the water quality of a water quality measurement sample; and measuring the filtered water in the water quality measurement section.

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