JP3911907B2 - Turbidity measuring device and measuring method - Google Patents

Description

【００３９】
この設定は、製作段階で、例えば、フローセル流量調整バルブ１１ｂは、設定圧力０．０３ＭＰａで、フローセル２１内の流量が１５０ｍｌ／ｍｉｎ程度に設定し、実際の設置場所で、状況に応じて更に調整するようにすれば良い。
【００４０】
この加圧調整槽１１内の圧力は、そのままフローセル２１へと伝えられるため、フローセル２１内に圧力がかかった状態となる。圧力が上がると、気泡の溶解度が上がるため、ごく微細な気泡は水中へ溶解し、濁度測定の際、微細気泡の影響を受けることなく高感度濁度測定が可能となる。
【００４１】
図３は上記の高感度濁度測定装置を浄水施設に設置して濁度を測定する濁度測定方法の説明図である。
【００４２】
濁度測定装置は、加圧調整槽およびフローセル内の圧力を所定の圧力に保持するためには、試水の送水圧力がそれより高くする必要がある。急速ろ過池においては、管類、弁、流量調節器等を収めるための管廊が設けられ、管廊内は、ろ過池水面から一般に５ｍ程度下にあるため、最大圧力０．０５ＭＰａをかけることができる。従って、ろ過池管廊内に設置するときは、図３に示すように浄水管３０に採水配管１２を接続して直接採水する。
【００４３】
このように直線採水することで、ポンプ等の加圧手段を用いることなく、自然の圧力を利用して微細な気泡を除去した高感度の濁度測定が可能となる。
【００４４】
濁度測定装置の設置場所はいろいろあり、上記のように水質試験室や、ろ過池管廊内に設置される。この設置場所によっては、試水の圧力が無いか、不足する場合がある。例えば、水質試験室がろ過池の水面とあまり変わらなかったり、又はろ過池管廊内がろ過池水面からあまり下がっていない場合等である。この状況下でも濁度測定ができるようにする必要がある。
【００４５】
図４はかかる状況下でも測定ができる濁度測定方法の他の実施の形態の説明図で、検水配管１２に切換弁Ｖを設け、この切換弁Ｖを介して採水配管１２と並列的に加圧手段、例えば揚水ポンプＰを設け、切換弁Ｖの操作により、浄水管３０からの試水を直接加圧調整槽１１に流入するようにし、また、切換弁Ｖを切り替えてポンプＰを運転することにより、加圧された試水を加圧調整槽１１に送水するようにする。
【００４６】
水質試験室に検水を導入して濁度を測定する場合、一般的には採水用のポンプにより採水するが、この時点で圧力が０．０５ＭＰａ程度であれば、そのまま採水すれば微細気泡の影響を受けにくい状態で濁度の測定ができるので切換弁Ｖを介して直接採水するようにする。しかし、何等かの事由で０．０５ＭＰａ以下の場合がある。同様にろ過池管廊内に設置した場合でも、最大圧力が０．０５ＭＰａに達しない場合がある。
【００４７】
かかる場合は、切換弁Ｖを切り替えてポンプＰを運転し、採水圧を上げて加圧調整槽１１に送水するようにする。
【００４８】
このようにすることで、濁度測定装置をいかなる場所に設置しても微細気泡の影響を受けない濁度測定が実現できる。
【００４９】
この加圧手段は、揚水ポンプに限らず、放流検水槽を設けてもよい。
【００５０】
【発明の効果】
以上のように、本発明の濁度測定装置においては、加圧調整槽を用いて流量、圧力の調整ができるようにし、フローセル内の流量および圧力を微細気泡の溶解する所定の流量、圧力に保持するようにしたので、気泡の溶解度が上がり、微細な気泡は水中に溶解されて無くなり、気泡の影響を受けない高感度濁度の測定が可能となった。また、この濁度測定装置をろ過池管廊内に設置して使用する場合は、自然の圧力を利用して気泡の影響を受けない高感度の濁度測定ができる。
【００５１】
また、採水配管に採水加圧手段を設けることにより、本発明の濁度測定装置をいかなる設置場所に設置しても、気泡の影響を受けない高感度温度測定が可能となる等の効果を奏する。
【図面の簡単な説明】
【図１】本発明の濁度測定装置の概念図。
【図２】本発明の加圧調整槽の上部説明図。
【図３】本発明の濁度測定システムの概念図。
【図４】本発明の他の濁度測定システムの概念図。
【図５】従来の高感度濁度測定システムの概念図。
【符号の説明】
１…加圧調整部
２…高感度濁度計
３…ろ過池
１１…加圧調整槽
１２…採水配管
１３…検水導入管
１４…検水導出管
１５…排水管
１６…圧力計
２１…フローセル
２２…演算・表示部
３０…浄水管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a turbidity measuring apparatus and a measuring method used for water quality control in a water purification plant and the like, and in particular, enables highly sensitive turbidity measurement to be continuously measured.
[0002]
[Prior art]
As a countermeasure against leakage of protozoa such as Cryptosporidium at the water purification plant, the Ministry of Health and Welfare has issued a notification as “Cryptosporidium Provisional Countermeasure Guidelines”. This notification indicates that the turbidity of the filter basin water is constantly monitored so that the turbidity is 0.1 degree or less.
[0003]
In response, manufacturers of turbidity measuring devices have developed high-sensitivity turbidimeters (or devices) that are 10 times more sensitive than conventional turbidimeters.
[0004]
The approximate measurement range of the high-sensitivity turbidimeter is a lower limit of 0.0001 to 0.001 degrees and an upper limit of 1 to 2 degrees, and the guideline value of the provisional countermeasure guideline is 0.1 degree. The focus is in the vicinity of 0.1 degree.
[0005]
The minimum detectable particle size is 0.1 μm to 0.5 μm. Such a highly sensitive turbidimeter is usually installed in a filter pond corridor or a water quality test room, and continuously measures the turbidity of the filter basin effluent.
[0006]
FIG. 5 is a conceptual diagram of a conventional high-sensitivity turbidity measurement system, and shows a case where the turbidity of filtrate effluent is constantly monitored in a water quality test room. In the same figure, 3 is a filtration pond, 30 is a water purification pipe for sending the purified water filtered by the filtration basin 3, and 31 is a part of the purified water in the water purification pipe 30 as sample water (hereinafter abbreviated as test water). The pump 32 to be taken indicates a water quality test chamber, and the water quality test chamber 32 is composed of an adjustment tank 33 and a highly sensitive turbidimeter 34.
[0007]
The turbidity is measured by using a part of the purified water in the purified water pipe 30 as test water and pumping it into the adjustment tank 33 by the pump 31. The pumped-up sample water to be measured is passed through the flow cell 34a as a detection unit of the high-sensitivity turbidimeter 34 through the pipe 35 as test water and discharged from the discharge pipe 36.
[0008]
In the flow cell 34a, for example, a pulsed light beam is projected from the laser diode into the test water, and the light reflected / scattered from the fine particles existing in the light beam is detected by a detector equipped in a direction perpendicular to the light beam to be converted into an electric quantity. The turbidity is calculated and displayed by the calculation / display unit 34b.
[0009]
The adjustment tank 33 overflows when the amount of water collected exceeds a predetermined level, and maintains a constant water level. The drain pipe 36 is installed at a position lower than the water level of the adjustment tank 33 by a pressure difference. Therefore, the sample water can flow.
[0010]
[Problems to be solved by the invention]
As described above, the high-sensitivity turbidimeter is often installed together with the adjustment tank 33 and the high-sensitivity turbidimeter 34 in the water quality test chamber 32 so as to save time during maintenance. When the turbidity is continuously measured with the high sensitivity turbidimeter 34, it is necessary to feed the test water from the water purification pipe 30 at the outlet of the filter basin 3 to the water quality test room 3 when the turbidity is measured.
[0011]
The sample water sent from the filtration basin passes once through the adjustment tank 33 installed in the water quality test chamber 32 in order to keep the amount of water flowing into the high sensitivity turbidimeter 34 constant and for the purpose of simple defoaming. Then, it is sent to the high sensitivity turbidimeter 34.
[0012]
In the case of measurement with a conventional low-sensitivity turbidimeter, there was no problem, but when measuring turbidity with high sensitivity, very fine bubbles that cannot be defoamed with a conventional adjustment tank are detected. Therefore, there is a problem that precise turbidity cannot be measured.
[0013]
The present invention has been made in view of such problems, and an object of the present invention is to provide an apparatus and a method that enable highly sensitive turbidity measurement by reducing the influence of fine bubbles on the turbidity measurement value. It is.
[0014]
[Means for Solving the Problems]
In the present invention, the means for solving the above-mentioned problems is that the sample water to be measured is introduced into the pressure adjustment tank via the intake flow rate adjusting means for adjusting the intake amount, and the introduced sample water is divided into two. The main stream is discharged through the drain pipe from the manifold part provided in the pressure adjustment tank, and other part of the sample water is sent to the inlet side of the flow cell of the high sensitivity turbidity meter as the test water, and from the outlet side of the flow cell. Through the flow cell flow rate adjusting means for adjusting the flow rate to the flow cell provided in the manifold section, the main flow joins the main flow and is discharged from the drain pipe. The flow rate and pressure are adjusted by the intake flow rate adjusting means and the flow cell flow rate adjusting means. The turbidity measuring apparatus is configured to measure turbidity with a highly sensitive turbidimeter in a state where fine bubbles in the test water in the flow cell are removed.
[0015]
And although the pressure (water pressure) of a test water is desirable about 0.05-0.1 MPa, when higher than that, it adjusts with a water intake flow volume adjustment means. The sample water pressure adjustment and the flow rate and pressure adjustment of the sample water in the flow cell are performed as follows.
[0016]
A sampling water open / close valve is provided in series with the intake flow rate adjustment means in the sampling pipe for introducing the test water into the pressure adjustment tank, and further, the test water is supplied to the test water introduction pipe for supplying the test water from the pressure adjustment tank to the flow cell. the use off valve provided in advance to close the test water for the opening and closing valve opens the water samples for closing valve, the test water closing when the pressure of the pressure adjusting tank becomes a predetermined pressure by adjusting the intake flow rate adjusting means The valve is opened, and the flow rate and pressure are set to predetermined values by adjusting the flow cell flow rate adjusting means. This pressure is preferably a pressure for removing fine bubbles, for example, 0.02 to 0.05 MPa.
[0017]
The flow rate adjusting means is preferably a needle valve, and the open / close valve is preferably a ball valve.
[0018]
When the turbidity measuring device according to the present invention is installed in filtration or in a duct, the duct is about 5 m below the surface of the filtration pond, so that water is collected directly from the water purification pipe using this water pressure. Water is sent to the measuring device. By doing in this way, highly sensitive turbidity measurement can be performed without being influenced by fine bubbles.
[0019]
In addition, when sample water is taken into the turbidity measuring device through the sampling pipe, there may be a case where there is no pressure or a small pressure in the sampling pipe. In such a case, a pressurizing means capable of pressurizing at least about 0.03 MPa is provided in the water sampling pipe. This pressurizing means can be realized by a pump or a water discharge water tank.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0021]
FIG. 1 is a conceptual diagram of a turbidity measuring apparatus according to the present invention, which is composed of a pressure adjusting unit 1 and a high-sensitivity turbidimeter 2 having the same function as that of the prior art.
[0022]
The pressure adjustment unit 1 includes a pressure adjustment tank 11, a water sampling pipe 12 for introducing sample water to be measured (hereinafter referred to as test water), and a highly sensitive turbidimeter from the lower part of the pressure adjustment tank 11. 2, a test water introduction pipe 13 that feeds water to the inlet of the flow cell 21, which is a detection unit 2, a test water lead-out pipe 14 that feeds water from the outlet of the flow cell 21 to the upper portion of the pressurization adjustment tank 11, and a drain pipe 15.
[0023]
The water sampling pipe 12 is provided with a water intake flow rate adjusting valve 12a as a means for adjusting the water intake amount and a test water opening / closing valve 12b. Is provided.
[0024]
The pressurizing adjustment tank 11 includes a water tank 11A at the lower part and a manifold part 11B at the upper part, and the manifold part 11B has a function of adjusting the flow rate to the flow cell 21.
[0025]
The manifold portion 11B is screwed at the dotted line and can be removed. FIG. 2 is a bottom view as seen from the screwed portion after removal, and has a hole and a connection port serving as a passage serving as a pipe inside.
[0026]
In FIG. 2, reference numeral 14 'denotes a test water passage connected to the test water outlet pipe 14, and 15' denotes a water discharge passage connected to the drain pipe 15. The drain passage 15 'and the test water passage 14' are communicated with each other. . 11a is a communication hole that communicates with the lower water tank 11A of the pressurizing adjustment tank 11, through which the test water from the lower water tank 11A passes and is discharged to the drain pipe 15 through the drain passage 15 '.
[0027]
Reference numeral 11b denotes a flow cell flow rate adjustment valve as a means for adjusting the flow rate of the flow cell 21, which is provided in the flow path of the test water passage 14 'so as to form an orifice at a portion indicated by a one-dot chain line.
[0028]
A pressure gauge 16 communicates with the lower water tank 11A through the communication hole 11d and indicates the pressure in the water tank.
[0029]
A needle valve is suitable for the water intake and flow cell flow rate adjustment valve, and a ball valve is suitable for the open / close valve.
[0030]
The high-sensitivity turbidimeter 2 is the same as the high-sensitivity turbidimeter 34 shown in FIG. 5 and includes a flow cell 21 that detects turbidity through test water and a calculation / display unit 22.
[0031]
The sample water is introduced from the water sampling pipe 12 and is fed to the water tank 11A of the pressure adjustment tank 11 through the intake flow rate adjusting valve 12a and the test water opening / closing valve 12b. The sample water entering the water tank 11A is divided into two directions, and the main flow is discharged from the discharge pipe 15 through the communication hole 11a (FIG. 2) of the upper manifold portion 11B.
[0032]
The other flows as test water from the inlet of the flow cell 21 via the test water opening / closing valve 13a and the test water introduction pipe 13 from the lower part of the water tank 11A, enters the manifold section 11B from the outlet of the flow cell 21, and sets the flow cell flow rate adjustment valve 11b. As a result, it joins the main stream in the drainage passage 15 ′ and is discharged from the drainage pipe 15.
[0033]
In order to measure turbidity, it is necessary to make the flow rate and pressure in the flow cell 21 constant. In particular, in the present invention, this pressure is adjusted and maintained at a predetermined pressure that dissolves fine bubbles in water. It is characterized by removing bubbles. The means is as follows.
[0034]
First, the test water opening / closing valve 13a is closed, the test water opening / closing valve 12b is opened, and the intake water flow rate adjusting valve 12a is gradually loosened (opened), so that the pressure indication of the pressure gauge 16 is 0.03 to 0.05 Mp. Adjust as shown. This pressure is in the water tank 11A and the flow cell.
[0035]
Next, the water detection opening / closing valve 13a on the inlet side of the flow cell 21 is opened, and the flow cell flow rate adjustment valve 11b of the manifold portion 11B is loosened. When this flow cell flow rate adjustment valve is loosened, an orientation is formed in the water sample flow passage 14 ', and this portion is decompressed by joining the main flow from the communication hole 11a, and the water sample flows.
[0036]
Thus, when the flow cell flow rate adjusting valve 11b is loosened, the test water flows into the flow cell 21 and the pressure decreases.
[0037]
The relationship between the pressure and the flow rate at this time is set as shown in Table 1, for example.
[0038]
[Table 1]

[0039]
This setting is made at the manufacturing stage, for example, the flow cell flow rate adjustment valve 11b is set at a set pressure of 0.03 MPa, and the flow rate in the flow cell 21 is set to about 150 ml / min, and further adjusted according to the situation at the actual installation location. You should do it.
[0040]
Since the pressure in the pressure adjusting tank 11 is transmitted to the flow cell 21 as it is, the pressure is applied to the flow cell 21. When the pressure increases, the solubility of bubbles increases, so that very fine bubbles dissolve in water, and high-sensitivity turbidity measurement can be performed without being affected by the fine bubbles when measuring turbidity.
[0041]
FIG. 3 is an explanatory diagram of a turbidity measuring method in which the above-described highly sensitive turbidity measuring apparatus is installed in a water purification facility to measure turbidity.
[0042]
The turbidity measuring device requires that the water supply pressure of the test water be higher than that in order to maintain the pressure in the pressure adjusting tank and the flow cell at a predetermined pressure. In the rapid filtration basin, there is a duct for accommodating pipes, valves, flow regulators, etc., and the inside of the duct is generally about 5 m below the surface of the filtration basin, so apply a maximum pressure of 0.05 MPa. Can do. Therefore, when installing in the filtration pond pipe corridor, as shown in FIG. 3, the water collection pipe 12 is connected to the water purification pipe 30 and water is collected directly.
[0043]
By taking water in a straight line in this way, it is possible to perform highly sensitive turbidity measurement by removing fine bubbles using natural pressure without using a pressurizing means such as a pump.
[0044]
There are various places to install the turbidity measuring device, and it is installed in the water quality test room and the filtration pond pipe as described above. Depending on the installation location, there may be no or insufficient sample water pressure. For example, the water quality test chamber is not so much different from the water surface of the filter basin, or the inside of the filter pond corridor is not much lowered from the water surface of the filter pond. It is necessary to be able to measure turbidity even in this situation.
[0045]
FIG. 4 is an explanatory diagram of another embodiment of a turbidity measuring method capable of measuring even under such a situation. A switching valve V is provided in the water inspection pipe 12 and is parallel to the water sampling pipe 12 via the switching valve V. Is provided with a pressurizing means, for example, a pumping pump P. By operating the switching valve V, the sample water from the purified water pipe 30 flows directly into the pressurizing adjustment tank 11, and the switching valve V is switched to turn the pump P on. By operating, the pressurized test water is supplied to the pressurizing adjustment tank 11.
[0046]
When turbidity is measured by introducing test water into the water quality test room, water is generally collected with a water sampling pump. If the pressure is about 0.05 MPa at this time, the water is collected as it is. Since turbidity can be measured in a state that is not easily influenced by fine bubbles, water is directly collected through the switching valve V. However, it may be 0.05 MPa or less for some reason. Similarly, the maximum pressure may not reach 0.05 MPa even when installed in the filter pond corridor.
[0047]
In such a case, the switching valve V is switched and the pump P is operated to increase the water sampling pressure and supply water to the pressurization adjustment tank 11.
[0048]
In this way, turbidity measurement that is not affected by fine bubbles can be realized regardless of where the turbidity measuring device is installed.
[0049]
This pressurizing means is not limited to a pumping pump, and a discharge water detection tank may be provided.
[0050]
【The invention's effect】
As described above, in the turbidity measuring apparatus of the present invention, the flow rate and pressure can be adjusted using the pressure adjustment tank, and the flow rate and pressure in the flow cell are adjusted to the predetermined flow rate and pressure at which fine bubbles are dissolved. Since it was held, the solubility of the bubbles increased, and the fine bubbles were dissolved in water and disappeared, making it possible to measure highly sensitive turbidity without being affected by the bubbles. In addition, when this turbidity measuring device is installed in a filter pond corridor and used, highly sensitive turbidity measurement that is not affected by bubbles can be performed using natural pressure.
[0051]
In addition, by providing a water sampling pressurization means in the water sampling piping, it is possible to perform highly sensitive temperature measurement without being affected by bubbles regardless of the installation location of the turbidity measuring device of the present invention. Play.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a turbidity measuring apparatus according to the present invention.
FIG. 2 is an upper explanatory view of a pressure adjusting tank of the present invention.
FIG. 3 is a conceptual diagram of a turbidity measuring system according to the present invention.
FIG. 4 is a conceptual diagram of another turbidity measuring system of the present invention.
FIG. 5 is a conceptual diagram of a conventional highly sensitive turbidity measuring system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pressurization adjustment part 2 ... High sensitivity turbidimeter 3 ... Filtration pond 11 ... Pressurization adjustment tank 12 ... Sampling piping 13 ... Sample introduction pipe 14 ... Sample extraction pipe 15 ... Drain pipe 16 ... Pressure gauge 21 ... Flow cell 22 ... Calculation / display unit 30 ... Purified water pipe

Claims (4)

The sample water to be measured is introduced into the pressure adjustment tank through the intake flow rate adjusting means for adjusting the amount of water intake, and the main water is drained from the manifold section provided in the pressure adjustment tank. A flow cell that discharges through the pipe and sends other sample water to the inlet side of the flow cell of the high sensitivity turbidimeter as test water, and adjusts the flow rate from the outlet side of the flow cell to the flow cell provided in the manifold section. In the state where the main flow is merged with the main flow through the flow rate adjusting means and discharged from the drain pipe, and the flow rate and pressure are adjusted by the intake flow rate adjusting means and the flow cell flow rate adjusting means to remove fine bubbles in the test water in the flow cell. A turbidity measuring apparatus characterized by measuring turbidity with a high sensitivity turbidimeter. A sampling water open / close valve is provided in series with the intake flow rate adjustment means in the sampling pipe for introducing the test water into the pressure adjustment tank, and further, the test water is supplied to the test water introduction pipe for supplying the test water from the pressure adjustment tank to the flow cell. the use off valve provided in advance to close the test water for the opening and closing valve opens the water samples for closing valve, the test water closing when the pressure of the pressure adjusting tank becomes a predetermined pressure by adjusting the intake flow rate adjusting means 2. The turbidity measuring apparatus according to claim 1, wherein the valve and the flow rate and pressure are set to predetermined values by adjusting the flow cell flow rate adjusting means. A turbidity measurement device is installed in the filtration pond corridor where the water purification pipe from the filtration pond is placed, and the sample water to be measured is directly collected from the water purification pipe in the duct through the sampling pipe. The sample water that has been fed is sent to the turbidity measuring device, introduced into the pressure adjustment tank through the intake flow rate adjusting means and the sample water opening / closing valve, and the introduced sample water is divided into 2 minutes. The main stream is discharged from the manifold section provided in the pressure adjustment tank through the drain pipe, and some of the other test water is sent to the inlet side of the flow cell of the high sensitivity turbidimeter as the test water through the open / close valve for the test water. Then, the flow is adjusted to flow from the outlet side of the flow cell to the flow cell provided in the manifold section through the flow cell flow rate adjusting means so as to merge with the main flow and be discharged from the drain pipe, and the test water open / close valve is closed. Open the test water on-off valve and adjust the intake flow rate. When the pressure in the pressure adjustment tank is adjusted to the predetermined pressure by the adjustment, open the water detection valve and set the flow rate and pressure to the predetermined values by adjusting the flow cell flow adjustment means to remove the fine bubbles in the water in the flow cell. A turbidity measuring method, wherein the turbidity is measured with a highly sensitive turbidimeter in a removed state. Connect the sample water to be measured to the water purification pipe to take out the purified water from the filtration pond and take out the sample water to be measured, and raise the pressure when the water pressure of the sample water is below the specified pressure in the water sampling pipe A pressurizing means is provided, the sampled water sample is sent to a turbidity measuring device, and introduced into the pressure adjusting tank through the intake flow rate adjusting means and the sample water opening / closing valve of the turbidity measuring device. The test water is divided into 2 parts and the main stream is discharged from the manifold provided in the pressure adjustment tank through the drain pipe, and the other part of the test water is highly sensitive turbidity as test water through the open / close valve for test water. The water is fed to the inlet side of the total flow cell and joined to the main flow through the flow cell flow rate adjusting means for adjusting the flow rate from the outlet side of the flow cell to the flow cell provided in the manifold section, and drained from the drain pipe. Close the water valve Open the test water opening and closing valve, open the water sampling opening and closing valve when the pressure in the pressure adjustment tank reaches the specified pressure by adjusting the intake water flow adjusting means, and adjust the flow cell flow adjusting means to set the flow and pressure A turbidity measuring method characterized in that the turbidity is measured with a highly sensitive turbidimeter in a state in which fine bubbles in test water in the flow cell are removed by setting the value.

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