Suspended matter concentration measurement device, suspended matter concentration measurement method, crystallization reaction system, and crystallization reaction method

Abstract

To provide a suspended matter concentration measurement device capable of stably measuring the concentration of a suspended matter in a liquid containing the suspended matter, thereby improving process stability, reducing the workload of operator managers, and ensuring safety.SOLUTION: A suspended matter concentration measurement device 2 comprises: a sampling pipe 30 for sampling a suspended matter-containing liquid; a first valve 20 installed in the sampling pipe 30; a measurement container 12 connected to the sampling pipe 30 and configured to store the suspended matter-containing liquid; an intake device 14 for creating negative pressure inside the measurement container 12; an intake pipe 32 connecting the measurement container 12 and the intake device 14; a second valve 22 installed in the intake pipe 32; and a concentration measurement device for measuring the concentration of the suspended matter in the suspended matter-containing liquid stored in the measurement container 12. The suspended matter concentration measurement device generates negative pressure inside the measurement container 12 by the intake device 14, samples the predetermined amount of suspended matter-containing liquid into the measurement container 12 by utilizing the negative pressure, and measures the concentration of the suspended matter in the suspended matter-containing liquid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a suspended matter concentration measuring device for measuring the concentration of suspended matter in a liquid containing suspended matter, a method for measuring the concentration of suspended matter, a crystallization reaction system including the measuring device, and a crystallization reaction method including the measuring method. [Background technology]

[0002] In a coagulation-sedimentation process in which a coagulant is added to raw water containing suspended solids to form flocs, and the sludge is then allowed to settle and separate in a settling tank, there is a method, as disclosed in Patent Document 1 for example, in which the sludge concentration in the settling tank is controlled and the sludge in the tank is recycled to improve the quality of the sedimentation-treated water.

[0003] However, when a sludge concentration meter or interface meter is submerged in the settling tank to control the sludge concentration in the settling tank, as in Patent Document 1, the sludge concentration in the settling tank may not be measured correctly due to dirt on the sensor part, etc.

[0004] Furthermore, for the purpose of reducing the fluorine concentration of hydrofluoric acid-containing wastewater discharged from semiconductor factories and the like to below the discharge standard or reusing the hydrofluoric acid as a valuable substance, a method of treating the wastewater by a crystallization reaction technique in which a calcium agent is added to the fluorine-containing water to be treated in a crystallization reaction tank to produce sparingly soluble calcium fluoride, as disclosed in Patent Document 2, is widely known.

[0005] In such a crystallization reaction, in order to increase the recovery rate of fluorine, it is necessary to control the slurry concentration in the crystallization reaction tank within a predetermined range by adjusting the amount of calcium fluoride crystals extracted, the amount of seed crystals added as crystallization nuclei, etc. In Patent Document 2, a crystal concentration meter is used to control the slurry concentration in the crystallization reaction tank within a predetermined range.

[0006] However, when measuring the slurry concentration using a crystal concentration meter, such as an ultrasonic concentration meter, as in Patent Document 2, there is a possibility that high-concentration slurries such as those used in crystallization reaction tanks will exceed the measurement range, or that the sensor will need to be frequently cleaned due to the formation of scale caused by calcium and the like. Patent Document 2 also describes a method in which an operator samples the slurry solution in a crystallization reaction tank using some method and measures the sedimentation volume of the crystals. However, there is a risk that the operator will handle a slurry solution containing hydrofluoric acid when sampling, and the measurement takes time, so it may not be possible to appropriately track the amount of crystals withdrawn or the amount of seed crystals added in response to fluctuations in the slurry concentration. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-045494 [Patent Document 2] Patent No. 5941329 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a suspended matter concentration measuring device and a suspended matter concentration measuring method, a crystallization reaction system equipped with the measuring device, and a crystallization reaction method including the measuring method, which can stably measure the concentration of suspended matter in a liquid containing suspended matter, thereby improving treatment stability, reducing the burden on operation managers, and ensuring safety. [Means for solving the problem]

[0009] The present invention provides a suspended matter concentration measuring device for measuring the concentration of suspended matter in a suspended matter-containing liquid, the device comprising: a liquid sampling pipe for sampling the suspended matter-containing liquid; a first valve installed in the liquid sampling pipe; a measurement container to which the liquid sampling pipe is connected and which stores the suspended matter-containing liquid; an intake device for creating a negative pressure inside the measurement container; an intake pipe connecting the measurement container and the intake device; a second valve installed in the intake pipe; and a concentration measuring device for measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container. The suspended matter concentration measuring device creates a negative pressure inside the measurement container using the intake device, and by utilizing this negative pressure, a predetermined amount of the suspended matter-containing liquid is sampled into the measurement container, and the concentration measuring device measures the concentration of suspended matter in the suspended matter-containing liquid in the measurement container.

[0010] The apparatus for measuring the concentration of suspended solids preferably further comprises a cleaning device.

[0011] It is preferable that the device for measuring a concentration of suspended solids further comprises a discharge pipe connected to the measurement container and for discharging the liquid containing suspended solids, and a third valve installed in the discharge pipe.

[0012] In the device for measuring the concentration of suspended solids, the liquid containing suspended solids is preferably water obtained from a water treatment facility that treats wastewater from a semiconductor factory.

[0013] In the device for measuring the concentration of suspended solids, it is preferable that at least a portion of the suspended solids in the liquid containing suspended solids is calcium fluoride.

[0014] The present invention is a crystallization reaction system that adds a calcium agent to fluorine-containing water to be treated to generate calcium fluoride crystals and recovers the calcium fluoride crystals, comprising: a crystallization reaction tank that adds the calcium agent to the fluorine-containing water to be treated to generate the calcium fluoride crystals; and a suspended solids concentration measuring device that measures the concentration of suspended solids in a suspended solids-containing liquid in the crystallization reaction tank.

[0015] The present invention is a method for measuring the concentration of suspended matter in a suspended matter-containing liquid, which includes a liquid collection step of creating a negative pressure inside a measurement container and using that negative pressure to collect a predetermined amount of the suspended matter-containing liquid into the measurement container, and a measurement step of measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container.

[0016] The method for measuring a concentration of suspended solids preferably further comprises a washing step.

[0017] In the method for measuring the concentration of suspended solids, the suspended solid-containing liquid is preferably water obtained from a water treatment facility that treats wastewater from a semiconductor factory.

[0018] In the method for measuring a concentration of suspended solids, it is preferable that at least a part of the suspended solids in the liquid containing suspended solids is calcium fluoride.

[0019] The present invention is a crystallization reaction method for generating calcium fluoride crystals by adding a calcium agent to fluoride-containing water to be treated, and recovering the calcium fluoride crystals, the crystallization reaction method comprising: a crystallization reaction step of adding the calcium agent to the fluoride-containing water to be treated in a crystallization reaction tank to generate the calcium fluoride crystals; and a method for measuring the concentration of suspended solids in a suspended solid-containing liquid in the crystallization reaction tank. [Effects of the Invention]

[0020] The present invention can provide a suspended matter concentration measuring device, a suspended matter concentration measuring method, a crystallization reaction system equipped with the measuring device, and a crystallization reaction method including the measuring method, which can stably measure the concentration of suspended matter in a liquid containing suspended matter, thereby improving treatment stability, reducing the burden on operation managers, and ensuring safety. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram illustrating an example of a crystallization reaction system including a suspended solids concentration measuring device according to an embodiment of the present invention. [Figure 2] 3 is a schematic diagram illustrating a standby step in the method for measuring the concentration of suspended solids according to an embodiment of the present invention. FIG. [Figure 3] FIG. 2 is a schematic diagram illustrating a blank measurement step in the method for measuring the concentration of suspended solids according to an embodiment of the present invention. [Figure 4] 1 is a schematic diagram illustrating an intake process in a method for measuring a concentration of suspended solids according to an embodiment of the present invention. [Figure 5] 1 is a schematic diagram illustrating a liquid sampling step in a method for measuring a suspended solids concentration according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram illustrating a measurement step in a method for measuring a concentration of suspended solids according to an embodiment of the present invention. [Figure 7] 1 is a schematic diagram illustrating a liquid washing step in a method for measuring a concentration of suspended solids according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram illustrating a second liquid washing step in the method for measuring the concentration of suspended solids according to the embodiment of the present invention. [Figure 9] FIG. 1 is a schematic diagram illustrating a first gas scrubbing step in a method for measuring a concentration of suspended solids according to an embodiment of the present invention. [Figure 10] FIG. 2 is a schematic diagram illustrating the second gas scrubbing step in the method for measuring the concentration of suspended solids according to the embodiment of the present invention. [Figure 11] FIG. 1 is a schematic diagram showing another example of a crystallization reaction system including a suspended solids concentration measuring device according to an embodiment of the present invention. [Figure 12] FIG. 1 is a schematic diagram showing another example of a crystallization reaction system including a suspended solids concentration measuring device according to an embodiment of the present invention. [Figure 13] FIG. 1 is a schematic diagram showing another example of a crystallization reaction system including a suspended solids concentration measuring device according to an embodiment of the present invention. [Figure 14] FIG. 2 is a diagram showing an example of a calibration curve used in the suspended solids concentration measurement device according to the embodiment of the present invention. [Figure 15] 1 is a schematic diagram illustrating an example of a measurement container in a suspended solids concentration measurement device according to an embodiment of the present invention. [Figure 16] 10 is a schematic diagram showing another example of the measurement container in the suspended solids concentration measurement device according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present invention. The embodiment is an example of implementing the present invention, and the present invention is not limited to the embodiment.

[0023] An example of a crystallization reaction system equipped with a suspended solids concentration measuring device according to an embodiment of the present invention is outlined in FIG. 1, and its configuration will be described.

[0024] The crystallization reaction system 1 is a crystallization reaction system that adds a calcium agent to fluorine-containing water to be treated to generate calcium fluoride crystals and recovers the calcium fluoride crystals. The crystallization reaction system 1 includes a crystallization reaction device 7 that includes a crystallization reaction tank 50 that adds a calcium agent to fluorine-containing water to be treated to generate calcium fluoride crystals, and a suspended solids concentration measuring device 2 that measures the concentration of suspended solids in the suspended solids-containing liquid in the crystallization reaction tank 50.

[0025] The suspended solids concentration measuring device 2 is a measuring device that measures the concentration of suspended solids in a suspended solids-containing liquid. The suspended solids concentration measuring device 2 is also a measuring device that can automatically measure the concentration of suspended solids in a suspended solids-containing liquid. The suspended solids concentration measuring device 2 includes a liquid sampling piping 30 that samples the suspended solids-containing liquid, a first valve 20 installed on the liquid sampling piping 30, a measuring container 12 to which the liquid sampling piping 30 is connected and which stores the suspended solids-containing liquid, an air intake device 14 that creates a negative pressure inside the measuring container 12, an air intake piping 32 that connects the measuring container 12 and the air intake device 14, a second valve 22 installed on the air intake piping 32, and a concentration measuring device that measures the concentration of suspended solids in the suspended solids-containing liquid in the measuring container 12, for example, a measuring device 10, a control device 16, and a computing device 18. In the suspended solids concentration measuring device 2, a negative pressure is created inside the measurement container 12 by the suction device 14, a predetermined amount of liquid containing suspended solids is sampled into the measurement container 12 by utilizing this negative pressure, and the concentration of suspended solids in the suspended solids-containing liquid in the measurement container 12 is measured by the measurement device 10, which is a concentration measuring device. Alternatively, in the suspended solids concentration measuring device 2, a negative pressure is created inside the measurement container 12 by the suction device 14, a predetermined amount of liquid containing suspended solids is sampled into the measurement container 12 by utilizing this negative pressure, and the concentration of suspended solids in the suspended solids-containing liquid in the measurement container 12 is automatically measured by the measurement device 10, which is a concentration measuring device.

[0026] The suspended solids concentration measuring device 2 may further include cleaning devices for cleaning the inside of the measurement container 12, the liquid sampling piping 30, etc., such as a gas supply piping 36 that supplies gas into the measurement container 12, a fourth valve 26 installed on the gas supply piping 36, a cleaning liquid supply piping 38 that supplies cleaning liquid into the measurement container 12, and a fifth valve 28 installed on the cleaning liquid supply piping 38. The suspended solids concentration measuring device 2 may further include a discharge piping 34 connected to the measurement container 12 and that discharges the suspended solids-containing liquid, and a third valve 24 installed on the discharge piping 34. The suspended solids concentration measuring device 2 is a measuring device that can also automatically clean the inside of the measurement container 12, etc.

[0027] The crystallization reaction tank 50 of the crystallization reaction apparatus 7 is equipped with an agitator 52 having an agitator blade and a motor for rotating the agitator blade with a rotating shaft, for agitating the liquid in the crystallization reaction tank 50. One end of the liquid sampling pipe 30 is immersed in the suspended solids-containing liquid in the crystallization reaction tank 50, and the other end of the liquid sampling pipe 30 is connected to the suspended solids-containing liquid inlet of the measurement container 12 via a first valve 20. An exhaust pipe 34 is connected to the outlet of the measurement container 12 via a third valve 24. The intake device 14 and the upper intake port of the measurement container 12 are connected by an intake pipe 32 via a second valve 22. A gas supply pipe 36 is connected to the intake pipe 32 between the second valve 22 and the connection portion of the intake port of the measurement container 12 via a fourth valve 26, and a cleaning liquid supply pipe 38 is connected to the intake pipe 32 via a fifth valve 28. A measuring device 10 is installed in the measurement container 12.

[0028] The measuring device 10, the control device 16, and the arithmetic device 18 are connected by electrical connections or the like to enable wired or wireless communication. The intake device 14, the control device 16, and the arithmetic device 18 are connected by electrical connections or the like to enable wired or wireless communication. The first valve 20, the second valve 22, the third valve 24, the fourth valve 26, and the fifth valve 28 are each connected by electrical connections or the like to the control device 16 and the arithmetic device 18 to enable wired or wireless communication.

[0029] [Method for measuring suspended solids concentration] As an example of the method for measuring the concentration of suspended solids according to this embodiment, an example in which the concentration of suspended solids in a liquid containing suspended solids in a crystallization reaction tank 50 of a crystallization reaction apparatus 7 is measured and a gravimetric measuring device is used as the measuring device 10 will be described below with reference to Figures 2 to 10. Table 1 is an operating process chart showing an example of the open / closed states of the first valve 20 (V1), the second valve 22 (V2), the third valve 24 (V3), the fourth valve 26 (V4), and the fifth valve 28 (V5) and the operating states of the intake device 14 and the measuring device 10 in each step.

[0030] [Table 1]

[0031] (1) Standby process (see Figure 2) The standby step is a step of waiting for a predetermined time between measurements of the concentration of suspended solids. For example, in the crystallization reaction apparatus 7, a crystallization reaction step is performed in which a calcium agent is added to fluoride-containing water to be treated in the crystallization reaction tank 50 to generate calcium fluoride crystals. In the standby step, for example, the control device 16 waits for a predetermined time between measurements of the concentration of suspended solids in the suspended solid-containing liquid in the crystallization reaction tank 50.

[0032] To more accurately grasp the change in the concentration of suspended solids in a suspended solid-containing liquid over time, the shorter the waiting time (interval between measurements of the suspended solids concentration), the better, but for example, once every hour to 24 hours is sufficient. The waiting time may be controlled by a timer or the like. After the predetermined waiting time has elapsed, proceed to the blank measurement step (2) below.

[0033] (2) Blank measurement process (see Figure 3) The blank measurement process is a process of measuring the weight (W0) of an empty measurement container 12. In the blank measurement process, for example, the control device 16 measures the weight (W0) of the empty measurement container 12 before the suspended matter-containing liquid is sampled using a weight measuring device as the measurement device 10, and outputs the weight measurement result to the calculation device 18.

[0034] The end point of the blank measurement step may be controlled, for example, by the timing when the signal (W0) output by the measurement device 10 is received by the calculation device 18, or by a timer.

[0035] (3) Intake stroke (see Figure 4) The suction process is a process in which gas such as air is sucked out of the measurement container 12 by the suction device 14, creating a negative pressure inside the measurement container 12. In the suction process, for example, the control device 16 opens the second valve 22 and causes the suction device 14 to suck out gas such as air from the measurement container 12 through the suction piping 32, creating a negative pressure inside the measurement container 12.

[0036] The intake step may be completed by closing the second valve 22. The end point of the intake step may be managed by a timer or the like. As shown in FIG. 12 (described later), a pressure measuring device 42 may be installed in the intake piping 32 connecting the measuring device 10 and the intake device 14, and the end point of the intake step may be determined to be the time when the pressure reading of the pressure measuring device 42 reaches the target pressure. The target pressure may be calculated from the amount of liquid sampled (the sum of the volumes of the measuring container 12 and the liquid sample piping 30) and the specific gravity of the suspended matter in the crystallization reaction tank 50.

[0037] (4) Liquid collection process (see Figure 5) The liquid sampling step is a step of utilizing the negative pressure within the measurement container 12 to sample a predetermined amount of the liquid containing suspended solids within the crystallization reaction tank 50 into the measurement container 12. In the liquid sampling step, the negative pressure within the measurement container 12 set in the "(3) Suction step" is utilized, and for example, the control device 16 opens the first valve 20 to sample a predetermined amount of the liquid containing suspended solids within the crystallization reaction tank 50 into the measurement container 12 through the liquid sampling piping 30.

[0038] In the liquid collection step, a predetermined amount, for example a predetermined volume, of liquid containing suspended solids is collected into measurement container 12. In order to collect a predetermined amount of liquid containing suspended solids, measurement container 12 may be configured to include a partition plate 70 as shown in Fig. 16 (described later), a liquid level measuring device 40 such as a water level gauge may be installed in measurement container 12 as shown in Fig. 11 (described later), or a pressure measuring device 42 such as a pressure gauge may be installed in measurement container 12 as shown in Fig. 12 (described later), or two or more of these may be combined.

[0039] The liquid sampling process may be completed by closing the first valve 20. As shown in Fig. 12, which will be described later, the end point of the liquid sampling process may be the time when the pressure indication value of the pressure measuring device installed in the intake pipe 32 reaches the target pressure. The target pressure may be calculated from the amount of liquid sampled (the sum of the volumes of the measurement container 12 and the liquid sampling pipe 30) and the specific gravity of the suspended matter in the crystallization reaction tank 50.

[0040] The predetermined amount of liquid containing suspended solids to be sampled may be in the range of 0.5 to 10 L in volume, for example 1 L, from the viewpoint of measurement error.

[0041] (5) Measurement process (see Figure 6) The measurement step is a step of measuring the concentration of suspended matter in the suspended matter-containing liquid collected in the measurement container 12. In the measurement step, for example, a conversion formula (e.g., a calibration curve) between the weight of the suspended matter-containing liquid and the suspended matter concentration is prepared in advance, and the concentration of suspended matter is calculated from the weight of the suspended matter-containing liquid collected in the liquid collection step using the conversion formula.

[0042] The procedure for measuring the concentration of suspended solids when a weight measuring device is used as the measuring device 10 in the measurement step will be described below. [1] The weight Wn of the sampled suspended solids-containing liquid is measured when the suspended solids concentration Cn is changed, and a calibration curve (suspended solids concentration Cn = a × Wn + b, where a is the regression coefficient and b is the intercept) such as that shown in Figure 14 is prepared in advance. The calibration curve is prepared using samples with varying suspended solids concentrations, with a volume equivalent to the predetermined amount of suspended solids-containing liquid sampled in the sample collection step. For example, the control device 16 stores this conversion formula (calibration curve) in the calculation device 18. [2] For example, the control device 16 measures the weight (W1) of the suspended matter-containing liquid collected in the measurement container 12 by the measurement device 10, and outputs the weight measurement result to the calculation device 18. [3] For example, the control device 16 calculates the suspended solids concentration Cn using the calibration curve created in [1] in the calculation device 18 using the following formula: The weight of the collected liquid containing suspended matter is Wn = W1 - W0 Suspended matter concentration Cn=a×Wn+b [4] When water containing multiple series of suspended solids is flowing in, the suspended solids concentration can be calculated using the following formula from the flow rate of each series and the calibration curve of sludge concentration of each series that has been prepared in advance. Cn=(a1×Q1+a2×Q2+···an×Qn) / (Q1+Q2+···Qn)×Wn+(b1×Q1+b2×Q2+···bn×Qn) / (Q1+Q2+···Qn) an is the regression coefficient for the n-series calibration curve bn is the intercept of the calibration curve for the n series Qn is the flow rate of n series n is an integer greater than or equal to 2

[0043] The unit of weight may be, for example, kg, and the unit of suspended solids concentration may be, for example, mg / L, v / v%, w / w%, etc.

[0044] After the measurement step is completed, the liquid containing suspended solids in the measurement container 12 may be returned to the crystallization reaction tank 50, which is the sampling point, through the liquid sampling pipe 30 by opening the first valve 20. If it cannot be returned to the sampling point, the liquid containing suspended solids in the measurement container 12 may be discharged from the measurement container 12 to the outside of the system through the discharge pipe 34 by opening the third valve 24.

[0045] (6) Liquid cleaning step 1 (see Figure 7) The liquid cleaning 1 step is a step in which a cleaning liquid such as cleaning water is used to drain and clean the liquid containing suspended matter mainly in the measurement container 12 and surrounding piping. In the liquid cleaning 1 step, for example, the control device 16 opens the fifth valve 28 to supply the cleaning liquid to the measurement container 12 through the cleaning liquid supply piping 38, and closes the first valve 20 and opens the third valve 24 to discharge the cleaning waste liquid from the measurement container 12 to the outside of the system through the discharge piping 34.

[0046] In the liquid washing 1 step, the first valve 20 may be closed, the fifth valve 28 may be open, and the third valve 24 may be open, and a washing liquid may be supplied to the measurement container 12 through the washing liquid supply pipe 38 while the washing wastewater is discharged from the measurement container 12 through the discharge pipe 34. Alternatively, the first valve 20 may be closed, the fifth valve 28 may be open, and the third valve 24 may be closed, and a predetermined amount of washing liquid may be supplied to and stored in the measurement container 12 through the washing liquid supply pipe 38. After a predetermined time has elapsed, the third valve 24 may be opened and the washing wastewater may be discharged from the measurement container 12 through the discharge pipe 34. Discharging the washing wastewater from the discharge pipe 34 to the outside of the system can prevent impurities that may be contained in the washing wastewater from being mixed into the crystallization reaction tank 50. In particular, when the suspended matter is calcium fluoride and crystals are to be recovered, it is desirable to discharge the washing wastewater from the discharge pipe 34 to the outside of the system because impurities in the washing wastewater may reduce the purity of the crystals.

[0047] The first liquid cleaning step can be completed by closing the fifth valve 28 and the third valve 24. The end point of the first liquid cleaning step can be managed by a timer or the like.

[0048] The liquid cleaning step 1 allows the liquid containing suspended matter in the measurement container 12 to be discharged, thereby reducing the influence on the next measurement. In particular, when the liquid containing suspended matter contains suspended matter with high sedimentation tendency, such as calcium fluoride produced by the crystallization reaction of hydrofluoric acid, it is preferable to provide the liquid cleaning step.

[0049] (7) Liquid cleaning process 2 (see Figure 8) The liquid cleaning 2 step is a step in which a cleaning liquid such as cleaning water is used to drain and clean the liquid containing suspended matter remaining mainly in the liquid sampling piping 30. In the liquid cleaning 2 step, for example, the control device 16 opens the fifth valve 28 to supply the cleaning liquid to the measurement container 12 through the cleaning liquid supply piping 38, and closes the third valve 24 and opens the first valve 20 to drain the cleaning waste liquid from the measurement container 12 through the liquid sampling piping 30.

[0050] In the liquid cleaning process 2, the third valve 24 may be closed, the fifth valve 28 may be open, and the first valve 20 may be open, and cleaning liquid may be supplied to the measurement container 12 through the cleaning liquid supply pipe 38 while the cleaning waste liquid is discharged from the measurement container 12 through the liquid collection pipe 30; alternatively, the third valve 24 may be closed, the fifth valve 28 may be open, and the first valve 20 may be closed, and a predetermined amount of cleaning liquid may be supplied to and stored in the measurement container 12 through the cleaning liquid supply pipe 38, and after a predetermined time has elapsed, the first valve 20 may be opened and the cleaning waste liquid may be discharged from the measurement container 12 through the liquid collection pipe 30.

[0051] The second liquid cleaning step can be completed by closing the fifth valve 28 and the first valve 20. The end point of the second liquid cleaning step can be managed by a timer or the like.

[0052] In the second liquid washing step, if the amount of washing wastewater in the second liquid washing step is small relative to the volume of the crystallization reaction tank 50, the washing wastewater may be returned to the crystallization reaction tank 50. For example, if the ratio of the amount of washing wastewater to the volume of the crystallization reaction tank 50 is 5 vol % or less, the washing wastewater may be returned to the crystallization reaction tank 50.

[0053] The first and second liquid washing steps may be performed simultaneously. The order of the first and second liquid washing steps may be reversed. One or both of the first and second liquid washing steps may be omitted. For example, if the ratio of the amount of waste washing liquid to the volume of the crystallization reaction tank 50 exceeds 5 vol%, the second liquid washing step may be omitted. A blow-off line may be provided in the liquid sampling piping 30 between the first valve 20 and the crystallization reaction tank 50 to discharge the waste washing liquid outside the system. Alternatively, the first liquid washing step may be omitted and only the second liquid washing step may be performed without using or providing the third valve 24 and the discharge piping 34. This allows the remaining liquid in the liquid sampling piping 30 to be blown out, improving the accuracy of the next measurement and suppressing sludge adhesion within the system.

[0054] (8) Gas cleaning process 1 (see Figure 9) The gas cleaning 1 step is a step in which a gas such as air is used to drain and clean the cleaning liquid remaining mainly in the measurement container 12 and surrounding piping. In the gas cleaning 1 step, for example, the control device 16 opens the fourth valve 26 to supply gas to the measurement container 12 through the gas supply piping 36, and closes the first valve 20 and opens the third valve 24 to exhaust the gas from the measurement container 12 to the outside of the system through the exhaust piping 34.

[0055] In the first gas cleaning step, the first valve 20 is closed, the fourth valve 26 is open, and the third valve 24 is open, and gas is supplied to the measurement container 12 through the gas supply pipe 36, while gas is discharged from the measurement container 12 through the discharge pipe 34.

[0056] The first gas scrubbing step can be completed by closing the fourth valve 26 and the third valve 24. The end point of the first gas scrubbing step can be controlled by a timer or the like.

[0057] If cleaning liquid remains in the measurement container 12, it may cause a measurement error the next time a measurement is performed. For this reason, it is preferable to provide a gas cleaning step.

[0058] (9) Gas cleaning process 2 (see Figure 10) The gas cleaning 2 step is a step in which a gas such as air is used to discharge and clean the cleaning liquid remaining mainly in the liquid sampling piping 30. In the gas cleaning 2 step, for example, the control device 16 opens the fourth valve 26 to supply gas to the measurement container 12 through the gas supply piping 36, and closes the third valve 24 and opens the first valve 20 to discharge the gas from the measurement container 12 through the liquid sampling piping 30.

[0059] In the gas cleaning step 2, the third valve 24 is closed, the fifth valve 28 is open, and the first valve 20 is open, and gas is supplied to the measurement container 12 through the gas supply piping 36, while gas is discharged from the measurement container 12 through the liquid sampling piping 30.

[0060] The second gas scrubbing step may be completed by closing the fourth valve 26 and the first valve 20. The end point of the second gas scrubbing step may be controlled by a timer or the like.

[0061] The first gas scrubbing step and the second gas scrubbing step may be performed simultaneously. The order of the first gas scrubbing step and the second gas scrubbing step may be reversed. One or both of the first gas scrubbing step and the second gas scrubbing step may be omitted. For example, if the remaining liquid in the liquid sampling piping 30 does not affect the next measurement, the second gas scrubbing step may be omitted. Furthermore, if the third valve 24 and the discharge piping 34 are not used or not provided as described above, and only the second liquid scrubbing step is performed without the first liquid scrubbing step, then it is sufficient to omit the first gas scrubbing step and perform only the second gas scrubbing step.

[0062] The above-described suspended solids concentration measuring device and method enable stable measurement of the concentration of suspended solids in a liquid containing suspended solids, thereby improving process stability, reducing the burden on the operation manager, and ensuring safety. Furthermore, the above-described suspended solids concentration measuring device and method, which control at least a portion of the process using, for example, a control device 16, enable stable and automatic measurement of the concentration of suspended solids in a liquid containing suspended solids, improving process stability, reducing the burden on the operation manager, and ensuring safety. In this case, the suspended solids amount measuring device 10, the intake device 14, the control device 16, the computing device 18, the first valve 20, the second valve 22, the liquid level measuring device 40, and the pressure measuring device 42 and turbidity measuring device 44 described below function as an automatic measuring means for automatically measuring the concentration of suspended solids in a suspended solid-containing liquid. Furthermore, the control device 16, the first valve 20, the second valve 22, the third valve 24, the fourth valve 26, the fifth valve 28, and the like function as an automatic cleaning means for automatically cleaning the interior of the measurement container 12.

[0063] In water treatment, understanding the concentration of solids in a liquid containing suspended solids is extremely important from the perspective of managing the treatment status and maintaining the equipment. The suspended solids concentration measuring device and method according to this embodiment are particularly effective as a method for measuring the concentration of suspended solids in corrosive wastewater, such as fluorine-containing wastewater. When sampling corrosive wastewater, corrosive gases, including wastewater mist, can corrode rotating equipment such as pumps, potentially causing malfunctions. The suspended solids concentration can be measured by creating a negative pressure in the measuring container using an air intake device, using this negative pressure to suck up the suspended solids-containing liquid from a tank such as a crystallization reaction tank, and measuring the weight per volume, for example. In the case of a crystallization reaction device for fluorine wastewater, understanding the sludge volume (SV, or suspended solids concentration) in the crystallization reaction tank is extremely important for determining the fluorine recovery rate and operational management.

[0064] The suspended solids concentration measuring device and measuring method according to the present embodiment also facilitates management of the amount of slurry extracted and replenished from a tank such as a crystallization reaction tank, making it possible to maintain a high recovery rate, which is susceptible to fluctuations depending on the slurry concentration.

[0065] In Patent Document 1, the sludge concentration in a settling tank is estimated using a sludge concentration meter or interface meter, and the amount of polymer flocculant added is controlled so that the estimated sludge concentration remains constant. In contrast, the suspended solids concentration measuring device and measuring method according to the present embodiment do not have a submerged sensor part like a sludge concentration meter, so there is no problem with measuring sludge concentration due to sensor contamination, etc., and stable treatment is possible.

[0066] Furthermore, Patent Document 2 uses a method for measuring the slurry concentration by installing a crystal concentration meter in a crystallization reaction tank or by having an operator sample the slurry solution in the crystallization reaction tank and measure the sedimentation volume of the crystals. In contrast, the suspended solids concentration measuring device and method according to the present embodiment can automatically and mechanically sample the slurry in the crystallization reaction tank and automatically measure the sludge volume (SV, or slurry concentration). Because a high concentration of hydrofluoric acid is stored in the crystallization reaction tank, automatic sampling reduces the workload of the operator. Furthermore, because the measured SV can be output as a numerical value, the SV output value can also be used for automatic control of the crystallization reaction based on the SV.

[0067] The suspended solids-containing liquid is not particularly limited as long as it is a liquid such as water or sludge containing suspended solids. A preferred example of the suspended solids-containing liquid is water obtained from a water treatment device that treats wastewater from a semiconductor factory. Because wastewater from a semiconductor factory contains few impurities and the suspended solids components change little, measurement accuracy (the accuracy of the calibration curve) can be improved. Examples of suspended solids include naturally occurring substances such as silica sand contained in river water or lake water, substances that insolubilize metal ions in wastewater, and organic substances such as excess sludge generated by biological treatment.

[0068] The suspended solids-containing liquid is preferably a suspended solids-containing liquid in a crystallization reaction tank of a crystallization reaction apparatus in which calcium agents such as calcium hydroxide or calcium chloride and calcium fluoride seed crystals (seed agents) that serve as crystallization nuclei are added to wastewater containing fluorine (hydrofluoric acid), causing calcium fluoride to crystallize on the surfaces of the seed crystals. In other words, it is preferable that at least a portion of the suspended solids in the suspended solids-containing liquid is calcium fluoride. To stabilize the calcium fluoride crystallization reaction and maintain high treatment performance, it is extremely important to understand the concentration of suspended solids that serve as the nuclei of the crystallization reaction. Furthermore, because hydrofluoric acid is highly corrosive, it is difficult to stably measure the suspended solids concentration using an immersion sensor. Furthermore, as mentioned above, when measuring suspended solids in a crystallization reaction tank, there is a high risk of workers coming into contact with hydrofluoric acid, making the operation highly dangerous.

[0069] The suction device 14 is not particularly limited as long as it can create a negative pressure (below atmospheric pressure) inside the measurement container 12, and examples thereof include an aspirator and a vacuum pump. When using a hydrofluoric acid-containing effluent as the suspended matter-containing liquid, a mist containing hydrofluoric acid may be generated, so a liquid-ring vacuum pump should be used to protect the pump. Specific examples of liquid-ring vacuum pumps include the liquid-ring vacuum pump (20LVSD6-04ZE) manufactured by Nikuni Co., Ltd.

[0070] The liquid sampling pipe 30 is a pipe for introducing the suspended matter-containing liquid into the measurement container 12. The material of the liquid sampling pipe 30 is not particularly limited as long as it is resistant to the suspended matter-containing liquid, and examples thereof include polyvinyl chloride (PVC) and steel pipe. When the suspended matter-containing liquid is a corrosive liquid such as hydrofluoric acid-containing effluent, the liquid sampling pipe 30 may be lined with a corrosion-resistant resin such as polyethylene.

[0071] Measurement container 12 is a container that stores the sampled suspended solids-containing liquid. The material of measurement container 12 is not particularly limited as long as it is resistant to the suspended solids-containing liquid, and examples include containers made of resin or metal. Measurement container 12 is only required to be able to sample a predetermined amount of suspended solids-containing liquid, and examples include containers made of transparent polyvinyl chloride or the like that allow the interior of measurement container 12 to be viewed. When a weight measuring device is used as measurement device 10, the piping connected to measurement container 12 should be flexible piping or other structure that has little effect on weight measurement.

[0072] An example of a measurement container 12 is shown in Figure 15. The measurement container 12a shown in Figure 15 has a bottom plate 60 raised above the bottom of the container, taking into account ease of cleaning the interior of the container and making it easy to drain suspended matter-containing liquid from the bottom of the container after measurement. A liquid sampling pipe 30 and a discharge pipe 34 run between the bottom of the container and the bottom plate 60, allowing suspended matter-containing liquid from a crystallization reaction tank or the like to be sampled into the measurement container 12a through the liquid sampling pipe 30 and discharged through the discharge pipe 34. Air can also be taken in through an air intake pipe 32 at the top of the container. In consideration of ease of maintenance, the top may be flanged to make it easier to open.

[0073] Another example of the measurement vessel 12 is shown in Figure 16. The measurement vessel 12b shown in Figure 16 has a shape that emphasizes quantitative measurement by providing a partition plate 70 inside the vessel. The partition plate 70 divides the interior of the measurement vessel 12b into equal halves of a predetermined volume, for example, and is installed vertically from the bottom of the vessel upward. A liquid containing suspended solids from a crystallization reaction vessel or the like is sampled through the liquid sampling pipe 30 onto one side of the measurement vessel 12b separated by the partition plate 70 until it overflows the partition plate 70. The liquid on the other side separated by the partition plate 70 is discharged through the discharge pipe 34, and the predetermined volume remaining on one side is used to measure the concentration of suspended solids in the suspended solids-containing liquid. Furthermore, the vessel is designed to allow for air intake through the intake pipe 32 at the top. For ease of maintenance, the top may be flanged for easy opening.

[0074] The amount of sampled liquid may be measured by installing a liquid level measuring device such as a guide pulse, laser, or ultrasonic water level gauge in the measurement container 12. An example of a suspended solids concentration measuring device having such a configuration is shown in Figure 11.

[0075] In the suspended solids concentration measuring device 3 shown in Fig. 11, a liquid level measuring device 40 is installed in a measuring container 12. The liquid level measuring device 40 is connected to a control device 16 and a computing device 18 by electrical connection or the like so as to enable wired or wireless communication.

[0076] In the liquid sampling process, the negative pressure in the measurement container 12 set in the "(3) Intake process" is utilized, and for example, the control device 16 opens the first valve 20 and samples a predetermined amount of the suspended matter-containing liquid in the crystallization reaction tank 50 into the measurement container 12 through the liquid sampling piping 30 until the liquid level in the measurement container 12 measured by the liquid level measuring device 40 reaches a predetermined height.

[0077] A pressure measuring device such as a pressure gauge may be installed in the measurement container 12, and the amount of sampled liquid may be measured using a signal from the pressure measuring device. An example of a suspended solids concentration measuring device configured in this way is shown in FIG.

[0078] 12, a pressure measuring device 42 is installed between the second valve 22 in the intake pipe 32 and the connection to the intake port of the measurement container 12. The pressure measuring device 42 is connected to the control device 16 and the computing device 18 by electrical connection or the like so as to enable wired or wireless communication.

[0079] In the liquid collection step, the signal from the pressure measuring device 42 may be used to control the end point of the liquid collection. The pressure measuring device 42 may also be used to detect abnormalities in devices such as the intake device 14.

[0080] An example of an operation for stopping the collection of fluid using the pressure measuring device 42 will be described below.

[0081] (i) The pressure P' required to suck up a predetermined volume of suspended solids-containing liquid from the crystallization reaction tank 50 or the like into the measurement container 12 by utilizing the negative pressure inside the measurement container 12 is confirmed in advance. For example, the control device 16 stores this pressure P'. (ii) For example, the control device 16 opens the second valve 22 and starts the intake device 14. (iii) For example, the control device 16 closes the second valve 22 and stops the intake device 14 at the timing when the measurement value of the pressure measuring device 42 becomes P′. (iv) For example, the control device 16 opens the first valve 20 and sucks up the liquid containing suspended matter into the measurement container 12 . (v) For example, the control device 16 closes the first valve 20 and stops collecting the liquid when the measurement value of the pressure measuring device 42 becomes atmospheric pressure (0 in gauge pressure).

[0082] The measuring device 10 is not particularly limited as long as it can measure the concentration of suspended solids, and examples thereof include a weight measuring device, a sludge concentration measuring device, etc. When a weight measuring device is used as the measuring device 10, a mechanism capable of sampling a predetermined volume, such as a weighing mechanism or a liquid level meter, may be installed, and the correlation between the SV and weight for the sampled volume may be determined in advance.

[0083] There are no particular limitations on the computing device 18, and it may be a programmable logic controller (PLC), personal computer (PC), or other device that can convert the signal from the measuring device 10 into a suspended solids concentration. The computing device 18 may also serve as the control device 16. When the measuring device 10 calculates the SV value based on the signal from the weight measuring device, the correlation between the SV and weight for the sample volume may be determined in advance.

[0084] The control device 16 is not particularly limited as long as it is a programmable logic controller (PLC), a personal computer (PC), or the like that can control the opening and closing of valves (first valve 20, second valve 22, third valve 24, fourth valve 26, fifth valve 28) and devices such as the measuring device 10. The control device 16 may also function as the computing device 18.

[0085] The cleaning device for cleaning the inside of the measurement container, etc., is composed of a liquid cleaning device including a pump that sends liquid from a liquid supply source such as water, a cleaning liquid supply pipe 38 that supplies the liquid to the measurement container 12, the liquid sampling pipe 30, etc., and a fifth valve 28 that controls the supply of liquid; and a gas cleaning device including a pump that sends gas from a gas supply source such as air, a gas supply pipe 36 that supplies the gas to the measurement container 12, the liquid sampling pipe 30, etc., and a fourth valve 26 that controls the supply of gas; and is a mechanism for cleaning the measurement container 12, the liquid sampling pipe 30, etc. The liquid supply source may be branched from facility water or the like installed in the facility. A gas supply source may be a cylinder or the like.

[0086] For liquid cleaning, water is usually used as the cleaning liquid. Alternatively, a chemical such as an acid or alkali may be added to water as the cleaning liquid. For gas cleaning, air is usually used as the cleaning gas. The cleaning liquid and cleaning gas used for cleaning can be discharged outside the system through the discharge pipe 34 connected to the measurement container 12. The cleaning liquid and cleaning gas used for cleaning can be discharged to the crystallization reaction tank 50 or a pellet storage tank that stores pellets crystallized in the crystallization reaction tank 50.

[0087] A sensor unit of a turbidity measuring device may be installed at the top of the measurement container 12, and the turbidity and suspended solids concentration (SS) of the supernatant water in the measurement container 12 may be measured. An example of a suspended solids concentration measuring device configured in this way is shown in FIG.

[0088] 13, a turbidity measuring device 44 is installed in a measurement container 12, and a sensor unit of the turbidity measuring device 44 is installed at the top or the like of the measurement container 12 so as to measure the turbidity of the supernatant water. The turbidity measuring device 44 is connected to the control device 16 and the computing device 18 by electrical connections or the like so as to enable wired or wireless communication.

[0089] The turbidity measuring device 44 is not particularly limited as long as it can measure the turbidity of the supernatant water in the measurement container 12, but examples include a light transmission type and a scattered light type.

[0090] The sensor of the turbidity measuring device 44 may be installed at any position so long as it can measure the turbidity of the supernatant water after it has been left to stand in the measurement container 12, for example, at a position above the center of the measurement container 12. The sensor of the turbidity measuring device 44 may be installed at any position so long as the detection part of the sensor comes into contact with the supernatant water after it has been left to stand, such as on the inner side or top of the measurement container 12.

[0091] For example, the quality of the treated water from the crystallization reaction tank 50 can be estimated by leaving the suspended matter-containing liquid collected from the crystallization reaction tank 50 in the measurement container 12 for a predetermined period of time (for example, 5 to 30 minutes) and measuring the turbidity of the supernatant water after leaving it there using the turbidity measuring device 44.

[0092] The fluorine concentration in the treated water in the crystallization reaction tank 50 may be estimated from the turbidity of the supernatant water after standing, measured by the turbidity measuring device 44. Alternatively, the fluorine recovery rate may be calculated from the fluorine concentration of the water to be treated in the crystallization reaction, the estimated fluorine concentration of the treated water, and the flow rate of the water to be treated in the crystallization reaction. The amounts of calcium agent and seed crystals to be added to the crystallization reaction tank 50 and the amount of pellets to be withdrawn from the crystallization reaction tank 50 may be controlled based on the calculated fluorine recovery rate.

[0093] The suspended solids concentration measuring device and method according to the present embodiment as described above can stably measure the concentration of suspended solids in a liquid containing suspended solids, thereby improving the stability of treatment, reducing the burden on the operation manager, and ensuring safety.Furthermore, the suspended solids concentration measuring device and method according to the present embodiment as described above can stably and automatically measure the concentration of suspended solids in a liquid containing suspended solids, thereby improving the stability of treatment, reducing the burden on the operation manager, and ensuring safety.

[0094] The present specification includes the following embodiments. [1] A suspended matter concentration measuring device for measuring the concentration of suspended matter in a suspended matter-containing liquid, a liquid sampling pipe for sampling the suspended matter-containing liquid; a first valve installed in the liquid collection pipe; a measurement container connected to the liquid sampling pipe and configured to store the suspended matter-containing liquid; an intake device for creating a negative pressure inside the measurement container; an intake pipe connecting the measurement container and the intake device; a second valve installed in the intake piping; a concentration measuring device for measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container; Equipped with A suspended matter concentration measuring device that creates a negative pressure inside the measurement container using the suction device, uses this negative pressure to collect a predetermined amount of the suspended matter-containing liquid into the measurement container, and measures the concentration of suspended matter in the suspended matter-containing liquid in the measurement container using the concentration measuring device.

[0095] [2] The suspended solids concentration measuring device according to [1], The apparatus for measuring the concentration of suspended solids further comprises a cleaning device.

[0096] [3] The suspended solids concentration measuring device according to [1] or [2], a discharge pipe connected to the measurement container and configured to discharge the suspended matter-containing liquid; a third valve installed in the discharge pipe; The suspended solids concentration measuring device further comprises:

[0097] [4] The suspended solids concentration measuring device according to any one of [1] to [3], The suspended solids concentration measuring device is configured such that the liquid containing suspended solids is water obtained from a water treatment facility that treats wastewater from a semiconductor factory.

[0098] [5] The suspended solids concentration measuring device according to any one of [1] to [4], A device for measuring a concentration of suspended matter, wherein at least a portion of the suspended matter in the suspended matter-containing liquid is calcium fluoride.

[0099] [6] A crystallization reaction system that adds a calcium agent to fluoride-containing water to be treated to generate calcium fluoride crystals and recovers the calcium fluoride crystals, a crystallization reaction tank in which the calcium agent is added to the fluorine-containing water to be treated to generate calcium fluoride crystals; The suspended solids concentration measuring device according to any one of [1] to [5], which measures the concentration of suspended solids in the suspended solids-containing liquid in the crystallization reaction tank; A crystallization reaction system comprising:

[0100] [7] A method for measuring the concentration of suspended matter in a suspended matter-containing liquid, comprising: a liquid collection step of creating a negative pressure inside a measurement container and collecting a predetermined amount of the suspended matter-containing liquid into the measurement container by utilizing the negative pressure; a measuring step of measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container; A method for measuring a concentration of suspended solids, comprising:

[0101] [8] [7] The method for measuring a suspended solids concentration according to A method for measuring a concentration of suspended solids, further comprising a washing step.

[0102] [9] A method for measuring the concentration of suspended matter in a suspended matter-containing liquid, comprising: a liquid sampling pipe for sampling the suspended matter-containing liquid; a first valve installed in the liquid collection pipe; a measurement container connected to the liquid sampling pipe and configured to store the suspended matter-containing liquid; an intake device for creating a negative pressure inside the measurement container; an intake pipe connecting the measurement container and the intake device; a second valve installed in the intake piping; a concentration measuring device for measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container; Using a suspended solids concentration measuring device comprising: A method for measuring the concentration of suspended matter, which creates a negative pressure inside the measurement container using the suction device, uses this negative pressure to collect a predetermined amount of the suspended matter-containing liquid into the measurement container, and measures the concentration of suspended matter in the suspended matter-containing liquid in the measurement container using the concentration measuring device.

[0103]

[10] [9] The method for measuring a suspended solids concentration according to The method for measuring a concentration of suspended solids, wherein the device for measuring a concentration of suspended solids further comprises a cleaning device.

[0104]

[11] The method for measuring a suspended solids concentration according to [9] or

[10] , The suspended solids concentration measuring device a discharge pipe connected to the measurement container and configured to discharge the suspended matter-containing liquid; a third valve installed in the discharge pipe; The method for measuring a concentration of suspended solids further comprises:

[0105]

[12] A method for measuring a suspended solids concentration according to any one of [7] to

[11] , A method for measuring the concentration of suspended solids, wherein the liquid containing suspended solids is water obtained from a water treatment device that treats wastewater from a semiconductor factory.

[0106]

[13] A method for measuring a suspended solids concentration according to any one of [7] to

[12] , A method for measuring a concentration of suspended matter, wherein at least a portion of the suspended matter in the suspended matter-containing liquid is calcium fluoride.

[0107]

[14] A crystallization reaction method for generating calcium fluoride crystals by adding a calcium agent to fluoride-containing water to be treated, and recovering the calcium fluoride crystals, a crystallization reaction step of adding the calcium agent to the fluoride-containing water to be treated in a crystallization reaction tank to generate calcium fluoride crystals; The method for measuring a concentration of suspended solids according to any one of [7] to

[13] , which measures the concentration of suspended solids in a liquid containing suspended solids in the crystallization reaction tank; A crystallization reaction method comprising: [Explanation of symbols]

[0108] 1 crystallization reaction system, 2, 3, 4, 5 measuring device, 7 crystallization reaction apparatus, 10 suspended solids amount measuring device, 12, 12a, 12b measuring container, 14 intake device, 16 control device, 18 calculation device, 20 first valve, 22 second valve, 24 third valve, 26 fourth valve, 28 fifth valve, 30 liquid sampling piping, 32 intake piping, 34 discharge piping, 36 gas supply piping, 38 cleaning liquid supply piping, 40 liquid level measuring device, 42 pressure measuring device, 44 turbidity measuring device, 50 crystallization reaction tank, 52 agitator, 60 bottom plate, 70 partition plate.

Claims

1. A suspended matter concentration measurement device for measuring the concentration of suspended matter in a suspended matter-containing liquid, comprising: a liquid sampling pipe for sampling the suspended matter-containing liquid; a first valve installed in the liquid collection pipe; a measurement container connected to the liquid sampling pipe and configured to store the suspended matter-containing liquid; an intake device for creating a negative pressure inside the measurement container; an intake pipe connecting the measurement container and the intake device; a second valve installed in the intake pipe; a concentration measuring device for measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container; Equipped with A suspended matter concentration measuring device characterized by creating a negative pressure inside the measurement container using the suction device, using this negative pressure to collect a predetermined amount of the suspended matter-containing liquid into the measurement container, and measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container using the concentration measuring device.

2. The suspended solids concentration measuring device according to claim 1, A device for measuring a concentration of suspended solids, further comprising a cleaning device.

3. The suspended solids concentration measuring device according to claim 1, a discharge pipe connected to the measurement container and configured to discharge the suspended matter-containing liquid; a third valve installed in the discharge pipe; The suspended solids concentration measuring device further comprises:

4. The suspended solids concentration measuring device according to claim 1, 10. A device for measuring the concentration of suspended solids, wherein the liquid containing suspended solids is water obtained from a water treatment facility that treats wastewater from a semiconductor factory.

5. The suspended solids concentration measuring device according to claim 1, A device for measuring the concentration of suspended solids, wherein at least a portion of the suspended solids in the liquid containing suspended solids is calcium fluoride.

6. A crystallization reaction system that adds a calcium agent to fluoride-containing water to be treated to generate calcium fluoride crystals and recovers the calcium fluoride crystals, a crystallization reaction tank in which the calcium agent is added to the fluorine-containing water to be treated to generate calcium fluoride crystals; The suspended matter concentration measuring device according to any one of claims 1 to 5, which measures the concentration of suspended matter in the suspended matter-containing liquid in the crystallization reaction tank; A crystallization reaction system comprising:

7. A method for measuring a concentration of suspended matter in a suspended matter-containing liquid, comprising: a liquid collection step of creating a negative pressure inside a measurement container and collecting a predetermined amount of the suspended matter-containing liquid into the measurement container by utilizing the negative pressure; a measuring step of measuring the concentration of suspended matter in the suspended matter-containing liquid in the measurement container; A method for measuring a concentration of suspended solids, comprising:

8. The method for measuring a suspended solids concentration according to claim 7, A method for measuring a concentration of suspended solids, further comprising a washing step.

9. The method for measuring a suspended solids concentration according to claim 7, A method for measuring the concentration of suspended solids, characterized in that the liquid containing suspended solids is water obtained from a water treatment facility that treats wastewater from a semiconductor factory.

10. The method for measuring a suspended solids concentration according to claim 7, A method for measuring the concentration of suspended solids, characterized in that at least a portion of the suspended solids in the suspended solid-containing liquid is calcium fluoride.

11. A crystallization reaction method for generating calcium fluoride crystals by adding a calcium agent to fluoride-containing water to be treated, and recovering the calcium fluoride crystals, comprising: a crystallization reaction step of adding the calcium agent to the fluoride-containing water to be treated in a crystallization reaction tank to generate calcium fluoride crystals; The method for measuring a concentration of suspended matter according to any one of claims 7 to 10, wherein the concentration of suspended matter in the suspended matter-containing liquid in the crystallization reaction tank is measured; A crystallization reaction method comprising:

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