JP2000146948A - Filter for water-quality measurement and turbidity removal apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a filter whose filtration efficiency is increased and by which sample water can be sent to a water-quality measuring part without changing the property of the sample water, by a method wherein the sample water is passed through a filter mesh inserted into a filter body and its turbid substance is removed. SOLUTION: A plurality of oval-shaped circulation holes are formed on the side face of a cylindrical case in a filter mesh 4 inserted into a filter body 2 at a filter 1. In addition, a screen is wound and bonded. A turbid substance is captured and removed by the screen. The bottom part is closed. An inflow port 6a for sample water to be filtered and an outflow port 6b used to take out filtrate are provided at a filter head 6 which is formed of a resin, and a pipe is screwed and connected to them, Then, the sample water flows into the inflow port 6a from the pipe, it is passed through the circulation holes and the screen from the inside (or the outside) of the filter mesh 4, the turbid substance is removed, and the sample water is passed through the outside (or the inside) of the filter mesh 4 so as to be taken out from the outflow port 6b as its filtrate. Since the filter body 2 is made of a transparent acrylic resin, the contamination degree of the screen can be confirmed visually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In the water supply and sewerage systems, water quality is measured continuously or intermittently for water quality management. The water quality is measured as a pretreatment introduced into a measuring unit for measuring the water quality. The turbidity in the sample water is removed. The present invention relates to a filter and a clarifier for the water quality measuring instrument.

[0002]

2. Description of the Related Art In the treatment of water supply and sewerage and the management of water quality, water quality is measured in the course of the treatment. As a pretreatment of a water quality measuring unit for measurement, turbidity in sample water to be measured is removed. Is done. As a method for removing the turbid matter, a sand filtration method and a filter paper filter method are often used.

[0003] Hereinafter, these conventional filtering methods will be described with reference to FIGS.

FIG. 11 is an explanatory view of the sand filtration method. In the figure, reference numeral 80 denotes a filtration water tank in which a predetermined layer of filtration sand 81 is settled at the bottom. 82 is a sample water introduction pipe, 83 is a filtered water discharge pipe, and a peristaltic pump 84 is provided. Reference numeral 85 denotes a washing water introduction pipe, 86 denotes a motor-operated valve provided on the washing water introduction pipe 85, and 87 denotes a discharge pipe for discharging overflowed sample water and washing wastewater.

The sample water to be measured is sent from a sample water inlet pipe 82 to a sand filtration tank 80 by gravity or the like. The sample water sent to the sand filter tank 80 is drawn out of the sand filter tank 80 through the filter sand 81 by the peristaltic pump 84, and the filtered water from which the turbid matter has been removed from the filtered water outlet pipe 83 is sent to the water quality measuring unit 88. The water quality is measured here.

[0006] The removal of turbidity is performed by passing the sample water through filter sand. Therefore, the turbidity adheres to the filter sand and the filtration function deteriorates. Therefore, it is necessary to wash (backwash) with washing water. There is.

[0007] In this backwashing, at regular intervals controlled by a timer or the like, the operation of the pump 84 is stopped, the electric valve 86 is opened, the washing water is pumped from the washing water introduction pipe 85 and adheres to the filter sand 81. The turbid matter thus washed out is drained from a drain pipe 87.

FIG. 12 is an explanatory view of the turbidity by the filter paper filter method. FIG. 12A is a conceptual diagram of the filter paper filter device.
(B) is an explanatory view of a filtering means using filter paper. In these figures, reference numeral 90 denotes a filtration water tank, and 91 denotes a filtering means using filter paper provided in the filtration water tank 90.
Is composed of a filtered water take-out drum 92, a filter paper 93 and a take-up device 94 which are disposed diagonally above and to the right and left in FIG. After the lower half of 92 is wound, it is wound up by a winder 94.

The sample water is introduced through a sample water introduction pipe 95, and the sample water filtered through a filter paper is supplied to a filtered water take-out drum 9
2 and is taken out of the filtrate water take-out pipe 96 and sent to the measuring device.

Reference numeral 97 denotes a used filter paper collection box, and 98 denotes an overflow drain pipe.

[0011]

The sand filtration method is a method of filtering a sample water with a filter sand. However, in order to increase the filtration efficiency and obtain sufficient turbidity removal, it is necessary to reduce the filtration speed. There is. When the filtration speed is reduced, organic matter and microorganisms adhere to the filter sand and propagate, changing the properties of the sample water,
An error occurs in the measurement in the water quality measurement unit at the latter stage of the filtration device.

When a large amount of filtrate is required, for example, in a case where a large amount of water is required for measurement, or when the same sample water is simultaneously measured with various types of water quality measurement devices, a large amount of filtrate is required. The water tank has a large capacity, and the pump also has a large size.

Furthermore, in the sand filtration method, the sample water is filtered, and the turbidity in the sample water is captured and removed between the filtered sand and the filtered sand. In this method, the turbidity to be removed is removed. It is difficult to specify the particle size, the filtrate after filtration,
Suspended substances may be mixed in, lowering the performance of water quality measuring instruments,
It may cause a failure.

Further, in the filter paper filter method, natural flow,
Since the filtration is carried out by the pressure of the water level, the filtration efficiency is greatly affected by the degree of adhesion of the turbidity to the filter paper, so that it is impossible to keep the amount of the filtrate flowing off constant. Therefore, in order to secure a certain amount of filtrate,
A large amount of sample water is required, and the filtration device becomes large.

[0015] Further, since the washing mechanism cannot be added, an organic substance or microorganisms such as nitrifying bacteria adhering to the filtered water tank may affect the properties of the sample water.
In order to eliminate this effect and maintain the properties of the sample water, maintenance such as cleaning of the filtration water tank is required. Furthermore,
Since the filter paper is a consumable item, periodic maintenance such as replacement of the filter paper is required.

In view of the above, it is an object of the present invention to provide a filter and a turbidity removing device which can increase the filtration efficiency and can send the solution to a water quality measuring section without changing the properties of the sample water. It is.

[0017]

SUMMARY OF THE INVENTION The present invention relates to a filter for removing turbidity of sample water supplied to a water quality measuring section for automatically measuring water quality in a water supply or sewerage treatment process, and a filter using the filter. It relates to a turbidity device. This filter can increase the filtration efficiency, and can specify the particle size of the suspended matter to be removed without changing the properties of the sample water.

As a specific configuration, a cylindrical filter mesh is inserted into a cylindrical filter body, and the sample water is passed through the filter mesh to remove the turbidity of the sample water and remove the turbidity. The filtrate is sent to a water quality measuring unit, and the filter mesh is a bottomed cylindrical shape having a flow hole on a side part, and a screen is wound around the outer periphery to form a filter.

With this configuration, it is possible to perform filtration while increasing the pressure of the sample water, thereby increasing the filtration efficiency and removing the size of the screen mesh wound around the filter mesh. The selection can be made according to the particle size of the turbid substance, and the turbid substance can be prevented from being mixed into the filtrate.

Next, the clarifier according to the present invention is implemented in various embodiments using this filter. Each embodiment is as follows.

In the first embodiment, the sample water is pumped up by a pump to increase the water pressure and is sent to a filter. The filter removes the turbidity of the sample water, and the filtrate from which the turbidity has been removed is supplied to a water quality measuring unit by a flow control valve. Adjust the flow rate to the required flow rate.

In the second embodiment, a backwash function using cleaning water and control of the cleaning function are added to the first embodiment. As a specific example, the filter of the first embodiment is used. On the outflow side, there is provided a washing valve which is normally closed and is opened at the time of back washing to supply washing water, and at the inflow side of the filter, there is provided a drain valve which is always closed and opened at the time of back washing to discharge washing water to the drain port.

In the third embodiment, a flow meter having an analog output function is provided in the second embodiment, and the backwashing is switched by detecting a decrease in the flow rate. Is provided with a flow meter having an analog output function on the outflow side of the filter, converts the analog signal of the flow meter into a flow rate value, compares it with a preset lower limit flow rate value, and sets the output side flow rate of the filtrate to the lower limit flow rate value. In the following cases, the pump is stopped and the cleaning valve and the drain valve are opened to clean the filter.

In the fourth embodiment, the piping flows of the first embodiment are connected in two systems so that the sample water can be continuously supplied to the water quality measuring section. That is, on the output side of the pump for increasing the water pressure of the sample water, an A system in which an A-line water valve and an A-line filter are connected in series, and a B system in which a B-line water valve and a B line filter are connected in series are arranged in parallel. Connect and connect the A line filter or B line filter to the flow control valve by selectively opening and closing the A line water flow valve or the B line water flow valve, and connect the filtrate to the flow rate required for the water quality measurement unit with the flow control valve. Adjust and send the solution.

In the fifth embodiment, the piping flows of the second embodiment are connected in two lines, and the supply of the sample water to the water quality measuring section can be performed stably and continuously. The quality can be distributed between the two filters. That is,
A cleaning auxiliary valve that is closed at the time of backwashing is provided on the outflow side of each filter of the A system and the B system, and a cleaning valve that is always closed and opened at the time of backwashing and supplies cleaning water to the filter is provided between the auxiliary valve and the filter. The filter is always closed at the inflow side of each of the filters and opened at the time of back washing so that the washing water after washing is discharged to the drain port.

In the sixth embodiment, a flow meter having an analog output function is provided in the fifth embodiment.
That is, a flow meter that measures the flow rate of the filtrate filtered by the A system or the B system is a flow meter having an analog output function, converts an analog signal of the flow meter into a flow value, and sets a predetermined lower limit flow value and In comparison, when the output side flow rate of the filtrate becomes lower than the lower limit flow rate value, the pump is stopped, and the washing valve and the drain valve are opened to perform back washing.

In the seventh embodiment, when backwashing the filter, the filtrate of another system is used as the wash water without using external wash water. That is, on the output side of the pump for increasing the water pressure of the sample water, an A-system in which an A-line water-flow valve and an A-line filter are connected in series, and a B-system in which a B-line water-flow valve and a B-line filter are connected in series, are formed. The outflow sides of these A-system and B-system filters are connected to a flow control valve via a cleaning auxiliary valve, and the system A or B system is selected by switching the water flow valve, and the filtered filtrate is passed through the flow control valve. When the liquid is sent to the water quality measurement unit and the backwashing of the system A or system B filter is closed, the auxiliary cleaning valve is closed, the backflow side system water supply valve is closed, and the drainage valve is opened. Is opened to supply the sample water to the filter, the filtrate filtered by the filter is supplied from the outflow side of the filter of the backwashing side system, and discharged to the drain port via the drain valve of the backwashing side system.

In the eighth embodiment, a flow meter having an analog output function is provided in the seventh embodiment.
That is, a flow meter that measures the flow rate of the filtrate filtered by the A system or the B system is a flow meter having an analog output function, and an analog signal of the flow meter is converted into a flow value and compared with a preset lower limit flow value. When the output flow rate of the filtrate falls below the lower limit flow rate value, close the water flow valve and cleaning auxiliary valve of the backwash side system, open the drain valve, and open the water flow valve of the other system side to connect the filter. Supply sample water,
The filtrate filtered by the filter is supplied from the outlet side of the filter on the backwashing side system to be washed.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration of the filter according to the present invention will be described. FIG. 1 is a front view of the filter of the present invention, and FIG. 2 is an exploded view.

In these figures, 1 is a filter, 2 is a filter body, which is made of transparent acrylic so that the inside can be seen through, and has a screw portion 2a at an upper portion and a drain valve 2b at a lower portion. Reference numeral 3 denotes an O-ring, 4 denotes a filter mesh, and a plurality of elliptical communication holes 4a are formed in the side surface of the inner cylindrical case.
Is provided, and the bottom is closed. Reference numeral 5 denotes an O-ring, reference numeral 6 denotes a filter head, which is formed of resin and has an inlet 6a through which a sample water to be filtered flows in, and an outlet 6b through which a filtered filtrate is taken out. The pipes can be connected by screw-in type. Further, a circular groove for fitting the filter mesh 4 and a screw with which the screw portion 2a of the filter body 2 is screwed around the mounting surface 6c of the lower part of the filter head 6 to which the filter mesh 4 is attached. Have been.

As shown in FIG. 2B, a screen 4b is wound and adhered to the filter mesh 4, and the screen 4b captures and removes turbid matter. Note that FIG.
(C) is a top view of the filter head.

As an assembling procedure, an O-ring 5 is fitted around the upper periphery of the filter mesh 4, a screen 4 b is wound around the outer periphery, and the filter mesh 4 is inserted into the filter body 2. Next, the filter head 6 is put on the upper part of the filter body 2, and the screw part 2 a of the filter body 2 and the screw part of the filter head 6 are screwed together with the O-ring 3 interposed therebetween to be integrally fixed. , Assembled in the state shown in FIG. Water tightness can be secured by the O-rings 3 and 5 by tightening the screw, and water leakage from the connection portion is completely prevented.

The sample water flows in from a pipe connected to the inlet 6a, passes from the inside (or outside) of the filter mesh 4, passes through the flow holes 4a and the screen 4b, passes through the outside (or inside) of the filter mesh 4, and flows out of the outlet 6b. Taken out. At this time, the turbid matter is captured and removed by the screen 4b, and is taken out as a filtrate.

Since the filter body 2 is made of transparent acrylic, the degree of contamination of the screen can be visually checked.

The drain valve 2b is normally closed at all times, and is opened when draining the sample water retained in the filter body 2 during maintenance such as replacement of the filter mesh or cleaning.

It is preferable to prepare several types of filter mesh 4 in which screens having different meshes are wound in advance, and to replace each filter mesh according to the particle size of the turbid substance. However, only the screen may be replaced. .

Although the case where the filter mesh is a cylinder has been described, the filter mesh does not necessarily need to be a cylinder and may be a square cylinder.

FIG. 3 is a flow chart of a water quality measuring turbidity device (hereinafter abbreviated as a turbidity device) of the present invention. The turbidity removing device 10 includes a pump 11 for applying pressure to the sample water and pumping it to the filter 1, a flow rate adjusting valve 12 for adjusting the filtrate filtered by the filter 1 to a flow rate required for the water quality measuring section, and managing and adjusting the filtrate. And a digital flow meter 13 used in the operation.

The sample water is taken in from the sample water inlet 14, the water pressure is increased by the pump 11, filtered by the filter 1, and the flow rate required for water quality measurement is adjusted by the flow rate adjusting valve 12 while watching the digital flow meter 13, and the filtrate outlet 15 From

As described above, by increasing the pressure of the sample water by the pump, the filtration rate of the filter can be increased,
The device can be downsized.

The first embodiment is used for pretreatment of an automatic water quality measuring instrument for measuring the quality of water in the clean water and the sewage treatment process in which the turbidity component of the sample water is very small (turbidity is 5 degrees or less). Suitable.

When the filter mesh of the filter 1 is replaced or maintenance is performed, the operation of the pump 11 is temporarily stopped, and the drain valve 2b is opened to remove the sample water remaining in the filter 1 into the drain port 16a. Perform after discharging from

FIGS. 4A and 4B are explanatory diagrams of a second embodiment of the present invention, wherein FIG. 4A is a flowchart of a turbidity removing unit, and FIG. 4B is a system configuration diagram of a clarifying device.

The second embodiment is obtained by adding a backwash function using external cleaning water and a control unit for the cleaning function to the first embodiment.

The same or corresponding parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description is omitted.
The same applies to the following.

In FIG. 4, reference numeral 20 denotes a water quality measurement and turbidity unit (hereinafter, abbreviated as a turbidity unit). As shown in FIG. , A washing valve 21, a drain valve 22 and a washing auxiliary valve 23 are added, and washing water flows in from the outlet side of the filter 1 through the washing water valve 21 and drains through the drain port 22 from the inlet side. Discharge to mouth 16.

That is, normally, the washing valve 21 and the drain valve 22 are closed and the washing auxiliary valve 23 is fully opened, and the sample water is pumped by the pump 11 as in FIG. The filtrate is sent from a filtrate outlet 15.

Next, in the case of back washing (supplying washing water to the filter from the opposite direction to wash the inside of the filter), the control unit 20
When the cleaning cycle set in advance by the cleaning cycle timer or the like in 1 is reached, the pump 11 is stopped and the cleaning valve 21 is stopped.
And the drain valve 22 is opened, and at the same time the auxiliary cleaning valve 23 is opened.
Close.

By this control, the washing water flows in from the outlet side of the filter 1, cleans the filter mesh 4 from the outside (or the inside), flushes the turbidity adhering to the inner surface (or the outer surface), and from the inlet side. The water is discharged from the drain port 16 through the drain valve 22.

As the washing water, tap water or a process liquid which has been treated to some extent is used.

In the second embodiment, there is a container for temporarily storing a filtrate, such as an adjustment tank, between the water quality measuring unit and the clarifier, or the water quality measuring device is an intermittent measuring method or a temporary measuring method. When there is no problem in the measurement even if the flow of the sample water to be measured is stopped, and the turbid substance concentration of the sample water to be filtered is higher than that in FIG. 3 (generally 30 degrees or less). Suitable.

FIG. 5 is an explanatory view of the third embodiment of the present invention. FIG. 5 (A) is a flowchart of a turbidity removing unit, and FIG. 5 (B) is a system configuration diagram of a clarifying device.

In the third embodiment, an analog output function is added to the digital flow meter 13 of the second embodiment.

In these figures, reference numeral 30 denotes a turbidity unit, and 31 denotes a flow meter with an analog output function to which an analog function is added. The flow rate of the filtrate is transmitted to the control unit 301 as an analog signal.

The flow rate of the filtrate that can be taken out of the turbidity reduction device decreases as the degree of adhesion of the turbidity component to the filter medium increases. Therefore, the second embodiment is an effective method when the fluctuation of the turbidity component to be removed due to a change with time is small and the cycle of the backwash can be approximately specified.

However, the concentration of the turbidity component of the sample water flowing in cannot be specified, and it may be difficult to specify the cycle of backwashing. In such a case, the method of the third embodiment is suitable.

That is, the flow rate of the filtrate is transmitted to the control unit 301 as an analog signal Sa by the flow meter 31 with an analog output function. The control unit 301 always receives the analog signal of the flow meter, converts the analog signal into a flow rate value, compares it with a preset lower limit flow rate value, and performs backwashing when the filtrate outlet side flow rate becomes lower than the lower limit set value. Let's get started.

In the third embodiment, it is possible to reduce the flow rate at the filtrate outlet side, that is, to perform backwashing in accordance with the degree of contamination of the filter mesh, and to minimize the amount of washing water used.

FIG. 6 is an explanatory view of a fourth embodiment of the present invention, in which (A) is a flowchart of a turbidity unit, and (B) is a system configuration diagram of a clarifier.

In the fourth embodiment, two systems of the piping flow of the first embodiment (FIG. 3) are provided. In the above embodiments, since there is only one filtration system, there is a container for temporarily storing the filtrate, such as an adjustment tank, between the water quality measurement unit and the clarifier, or the water quality measurement device is intermittent. This method is used when there is no problem in the measurement even if the flow of the sample water to be measured is temporarily stopped, but in the fourth embodiment, the sample water is continuously supplied to the water quality measuring unit. It is intended to be.

In FIG. 6, reference numeral 40 denotes a turbidity unit. The clarity unit 40 is composed of two systems A and B. A
The system is provided with a pump 11, an A-line filter 1A, a digital flow meter 13, a flow control valve 12, and an A-line flow valve 42, as in FIG.
The system shares a part with the system, and includes a pump 11, a B-line water flow valve 42B, and a B-line filter 1B.

These two systems are operated alternately at regular intervals according to an operation schedule preset by the control unit 401. During the operation of the A system, the B line water flow valve 42
When B is closed, the flow of the sample water to the B line filter 1B is stopped, and the switching time set by a timer or the like is reached,
The system switching is performed by closing the A-line water-flow valve 42A and opening the B-line water-flow valve 42B.

In this apparatus, the sample water can be continuously supplied to the water quality measuring instrument, and the turbid substance to be removed is dispersed in two filters, so that the life of the apparatus and the maintenance can be extended.

FIG. 7 is an explanatory view of a fifth embodiment of the present invention, in which (A) is a flowchart of a turbidity removing unit, and (B) is a system configuration diagram of a turbidity removing device.

In this embodiment, two systems of the piping flow of the second embodiment (FIG. 4) are provided. That is, a backwashing function using washing water and two systems A and B for controlling the washing function are provided, the filtrate is continuously fed, and the backwashing function using washing water is made possible.

The system A corresponds to FIG. 4A of the second embodiment.
Approximately the same as above, except that the A-line
Is provided. Note that the same parts as those in FIG. 4A are denoted by the same reference numerals, and “A” indicating the A system is added, and “B” is added to the B system.

That is, the system A is a washing line, and the pump 11-A line water flow valve 42A-A line filter 1
A-A line washing auxiliary valve 53A-Digital flow meter 13-Flow control valve 14;
The liquid is sent from 5.

A line cleaning valve 51 as a backwash line
A-A line filter 1A-A line drain valve 52A
The cleaning water is discharged from the drain port 16.

The washing line in the B system is provided with a pump 11
-B line water flow valve 52B-B line filter 1B-
B line cleaning auxiliary valve 53B-Digital flow meter 13
The backwash line is formed by a B line cleaning valve 51B-B line filter 1B-B line drain valve 52B.

The turbidity removing operation in the A system is performed in a state where the black-painted valve in FIG. 7A is closed. However, the drain valves 2bA and 2bB are always closed except for maintenance and the like.

When the system is switched to the system B and the system B is used for clarification, the A-line water supply valve 42A and the A-line cleaning auxiliary valve 53A are closed, and the B-line water supply valve 42B and the B-line cleaning auxiliary valve 53B are opened. Done.

Next, in the backwashing operation of the system A, the operation of the pump 11 is stopped from the state shown in FIG.
2A and the A-line cleaning auxiliary valve 53A are closed, the A-line cleaning valve 51A and the A-line drain valve 52A are opened, and the cleaning water is supplied to the A-line filter 1A from the opposite direction to clean the filter mesh in the filter. I do.

In the backwashing operation in the B system, the turbidity removing operation
From the state where the system is operating, the pump 11 is stopped, and the B-line water-flow valve 42B and the B-line cleaning auxiliary valve 53B
Is closed, and the B-line cleaning valve 51B and the B-line drain valve 52B are opened.

These operations are performed after the system is switched from the system A to the system B according to an operation schedule preset in the control unit 501, that is, the A-line water valve 42A.
After the A-line cleaning auxiliary valve 53A is closed, the A-system performs a back-washing step using cleaning water.

When the backwashing step is started, the A-line washing valve 51A and the A-line drain valve 52A are opened. After the washing water passes through the A-line filter 1A from the washing water inlet and passes through the filter mesh in the reverse direction, The water is drained from the drain port 16 through the A-line drain valve 52A.

The turbidity removing operation is continuously performed during a cleaning time set in the control unit 501 in advance.

Each time the A and B systems are alternately switched according to the operation schedule, the stopped system is backwashed.

This device can stably and continuously supply the sample water to the water quality measuring section, and has a backwashing function with washing water. The cleaning time can be shortened, the life of the apparatus can be prolonged, and maintenance can be prolonged.

FIG. 8 is an explanatory view of the sixth embodiment of the present invention, in which (A) is a flowchart of a turbidity unit, and (B) is a system configuration diagram of a clarifier.

In this embodiment, an analog output function is added to the digital flow meter of the fifth embodiment (FIG. 7).

In FIG. 8, reference numeral 60 denotes a clarification unit according to the sixth embodiment. As shown in FIG. 8A, a flow rate with an analog output function is added to the digital flow meter 13 shown in FIG. It is 61 in total. Other structures are almost the same as those in FIG.

In FIG. 8B, reference numeral 601 denotes a control unit. The control unit 601 has a cleaning cycle setting, a cleaning time setting, and a lower limit flow value setting function, and an analog flow signal Sa from a flow meter 61 with an analog output function. And outputs control signals for the pump and each valve in the clarification unit 60.

In the sand filtration method and the filter paper filter method shown in the conventional example of FIG. 11, and also in the fourth embodiment of the present invention, the flow rate of the filtrate that can be taken out from the turbidity removing device depends on the degree of adhesion of the turbid component to the filter medium. Decrease. Backwashing is performed to prevent this, but if this backwashing is performed at regular intervals,
The fifth embodiment (FIG. 7) is an effective method when the fluctuation of the turbidity component to be removed by the turbidity removing device due to the time change is small and the backwashing cycle can be approximately specified.

However, when river surface water is used as tap water as in the case of water supply, weather conditions and other influences such as an increase in turbidity of raw water due to rainfall. When the turbidity component concentration of the sample water flowing into the turbidity analyzer cannot be specified as described above, it is effective to use the flow rate of the filtrate as a trigger for performing the backwash.

In the sixth embodiment, a flow meter having an analog output function is attached to the subsequent stage of the filter, and the flow rate of the filtrate is transmitted to the control section as an analog signal Sa. The control unit always receives the analog signal of the flow meter, converts the analog signal into a flow value, compares it with a preset lower flow rate, and starts backwashing when the outlet flow rate of the filtrate falls below the lower flow rate.

[0087] This reduces the flow rate of the filtrate on the outlet side, that is, performs backwashing in accordance with the degree of contamination of the filter mesh, so that the amount of washing water used can be minimized.
Since the number of times of washing can be adjusted to an optimum value, effective backwashing is possible.

FIG. 9 is an explanatory view of a seventh embodiment of the present invention. FIG. 9 (A) is a flowchart of a turbidity removing unit, and FIG. 9 (B) is a system configuration diagram of a turbidity removing device.

In this embodiment, no external washing water is used for backwashing the filter, and another type of filtrate is used as washing water.

Reference numeral 70 denotes a turbidity removing unit according to the seventh embodiment. The A line cleaning valve 51A, the B line cleaning valve 51B, and the B line cleaning auxiliary valve 53B are removed from the fifth embodiment (FIG. 7). The A-line cleaning auxiliary valve 53A serves as a common cleaning auxiliary valve 71, and the respective outlet sides of the A-line filter 1A and the B-line filter 1B are directly connected.

A control unit 701 in FIG. 9B has a cleaning cycle setting function and a cleaning time setting function.

[0092] The normal operation is performed at regular intervals according to an operation schedule preset in the control unit 701.
The system is operated by alternately switching between the system and the B system.

In the operation of the A system, the A line
2A and the cleaning auxiliary valve 71 are open, and the A-line drain valve 52A, the B-line flow valve 42B, and the B-line drain valve 52B are closed.

At this time, the sample water is pressure-fed by the pump 11, is turbid by the A-line filter 1A, and is provided with the cleaning auxiliary valve 71, the digital flow meter 13 and the flow control valve 1
After passing through 4, water is sent from the filtrate outlet 15 to the water quality measuring section.

In the operation of the B system, the B-line water-flow valve 42B and the cleaning auxiliary valve 71 are opened, and the A-line water-flow valve 42A, the A-line drain valve 52A, and the B-line drain valve 52B are closed.

The sample water is pressure-fed by the pump 11, is turbid by the B-line filter 1B, and is sent from the filtrate outlet 15 to the water quality measurement section through the washing auxiliary valve 71, the digital flow meter 13, and the flow control valve 14. .

Next, in the case of the backwashing operation, the backwashing process is started after the system is switched from the system A to the system B or from the system B to the system A in the normal operation. When the system is switched from the A system to the B system, the backwashing process is performed using the B line
And the A-line drain valve 52A opens, and the A-line water flow valve 42A, the cleaning auxiliary valve 71, and the B-line drain valve 52B close. The sample water is clarified by the B-line filter 1B, passes through the A-line filter 1A, backwashes the filter mesh, and then drains from the drain port through the A-line drain valve 52A.

In the backwashing step when the system is switched from the B system to the A system in the normal operation, the A-line water-flow valve 42A and the B-line drain valve 52B are opened, and the B-line water-flow valve 42B, the cleaning auxiliary valve 71 and The A-line drain valve 52A is closed. The sample water is clarified by the A-line filter 1A, passes through the B-line filter 1B, backwashes the filter mesh, and then drains from the drain port through the B-line drain valve 52B.

This cleaning operation is continuously performed during a cleaning time set in the control unit 701 in advance. In this apparatus, the washing water pipe for backwashing and the valve for washing can be omitted, so that the apparatus can be reduced in size and cost, and the labor for maintenance can be reduced.

FIG. 10 is an explanatory view of an eighth embodiment of the present invention, in which (A) is a flowchart of a turbidity removing unit, (B) is a system configuration diagram of a clarifying device, and 80 is a clarifying unit. , 8
01 indicates a control unit. The control unit 801 has a cleaning cycle setting, a cleaning time setting, and a lower limit flow rate setting function.

In this embodiment, an analog output function is added to the digital flow meter of the seventh embodiment (FIG. 9) to provide a flow meter 81 with an analog output function, and an analog flow signal Sa is sent to the control unit 801. It is intended to be transmitted.

As described in the sixth embodiment, when the concentration of the turbidity component flowing into the clarifier cannot be specified and the backwashing cycle is difficult to determine, the filtrate is used as a trigger to execute the backwashing. It is more effective to use the amount of runoff.

The eighth embodiment is a modification of the seventh embodiment (FIG. 9). That is, a flow meter 8 having an analog output function is provided after the cleaning auxiliary valve 71.
1 is attached, and the flow rate of the filtrate is transmitted to the control unit as an analog signal. The control unit always receives the analog signal of the flow meter, converts it to a flow rate value, compares it with the preset lower limit flow rate set value, and performs backwash when the filtrate outlet flow rate falls below the lower limit flow rate set value. Start.

In this method, in addition to the features of the seventh embodiment, in order to reduce the flow rate of the filtrate on the outlet side, that is, to carry out backwashing in accordance with the degree of contamination of the filter mesh, the quality of the filtrate is measured at a stable flow rate. Can be supplied to

The control unit of each of the above embodiments has a state input signal relating to the operation of an electric valve, a pump, etc., a state output signal relating to the control of each device, an analog input function, an arithmetic function, and a storage function for setting values. Use a sequencer. A touch panel display is used to change the display of the set value and to display the current value of a timer or the like.

It is preferable to use a motor-operated valve that opens and closes the valve by rotating the valve with a motor. Since the orifice diameter of the valve portion of the electric valve is larger than that of the solenoid valve, the pressure loss can be suppressed low. Thereby, the liquid can be sent to the filter without lowering the sample water pressure.

The pump is used for feeding the sample water to the filter under pressure. The pump is used for the purpose of increasing the pressure of the sample water to increase the filtration efficiency of the filter, and to reduce the size of the apparatus. It is preferable to use a cascade pump. The pump is equipped with a thermal protector that automatically stops when the motor temperature rises due to filter clogging.

[0108]

As described above, according to the present invention, since the pressure of the sample water can be increased and the sample water can be filtered by the filter, the following effects can be obtained.

(1) A clarifier suitable for the measuring method and measuring system of the water quality measuring instrument can be selected.

(2) A stable water quality and amount can be ensured by the washing function.

(3) The frequency of maintenance and parts replacement can be prolonged.

(4) The volume and cost of the apparatus can be reduced.

(5) The amount of washing water used and the number of washings can be operated at optimum values.

(6) The particle size of the turbid matter to be removed can be specified by changing the mesh size of the screen.

[Brief description of the drawings]

FIG. 1 is a front view of a filter of the present invention.

FIG. 2 is an exploded view of the filter of FIG.

FIG. 3 is an explanatory diagram of the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a fourth embodiment of the present invention.

FIG. 7 is an explanatory view of a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram of a sixth embodiment of the present invention.

FIG. 9 is an explanatory view of a seventh embodiment of the present invention.

FIG. 10 is an explanatory diagram of an eighth embodiment of the present invention.

FIG. 11 is a configuration diagram of a conventional sand filtration device.

FIG. 12 is a configuration diagram of a conventional filter paper filter device.

[Explanation of symbols]

1, 1A, 1B ... filter 2 ... filter body 3, 5 ... O-ring 4 ... filter mesh 6 ... filter head 10 ... clarifier 11 ... pump 12 ... flow control valve 13 ... digital flow meter 14 ... sample water inlet 15 ... Filtrate outlet 16 ... Drain port 20, 30, 40, 50, 60, 70, 80 ... Denaturation unit 21 ... Cleaning valve 22 ... Drain valve 23 ... Cleaning auxiliary valve 31, 61, 81 ... Flow meter with analog output function 42A ... A line water flow valve 42B B line water flow valve 51A A line cleaning valve 51B B line cleaning valve 52A A line drain valve 52B B line drain valve 53A A line cleaning auxiliary valve 53B B line cleaning auxiliary valve 71: Cleaning auxiliary valve 201, 301, 401, 501, 601, 701, 8
01 ... Control unit

Claims (9)

[Claims] 1. A tubular filter mesh is inserted into a tubular filter body, sample water is passed through the filter mesh, turbidity of the sample water is removed by the filter mesh, and the filtrate from which the turbidity is removed is measured for water quality. To send the liquid to the
The filter for water quality measurement, wherein the filter mesh has a bottomed cylindrical shape, has a flow hole on a side part, and is wound around a screen around the outer periphery thereof. 2. The water pressure of the sample water is increased by a pump and sent to a filter. The filter removes turbidity in the sample water, and the filtrate from which the turbidity has been removed is adjusted to a flow rate required for the water quality measurement section by a flow rate control valve. And feed the solution,
A water quality measurement opacity apparatus, wherein the filter uses the filter according to claim 1. 3. A washing valve is provided on the outflow side of the filter, which is normally closed, and is opened at the time of backwashing to supply washing water. On the inflow side of the filter, the washing water is normally closed and opened at the time of backwashing, and a drain port is provided. 3. The turbidity measuring device according to claim 2, further comprising a drain valve for discharging water. 4. A flow meter having an analog output function is provided on the outflow side of the filter, an analog signal of the flow meter is converted into a flow rate value, and is compared with a preset lower limit flow rate value. 4. The turbidity measuring device according to claim 3, wherein the pump is stopped when the flow rate becomes equal to or less than the lower limit flow rate, and the filter is backwashed by opening the washing valve and the discharge valve. 5. An A system in which an A-line water-flow valve and an A-line filter are connected in series, and a B system in which a B-line water-flow valve and a B-line filter are connected in series, on the output side of a pump for increasing the water pressure of the sample water. Are connected in parallel, and the A-line filter or B-line filter is connected to the flow control valve by the selective opening and closing of the A-line flow valve or B-line flow valve, and the filtrate is required for the water quality measurement unit by the flow control valve. A turbidity measuring apparatus for water quality measurement, wherein the liquid is adjusted to a proper flow rate and the filters are used as the filters. 6. A cleaning auxiliary valve which is closed at the time of backwashing is provided on the outflow side of each of the filters of the A system and the B system, and is normally closed between each auxiliary valve and the filter and opened at the time of backwashing to supply cleaning water to the filter. 6. The turbidity meter according to claim 5, wherein a valve is provided, and a drain valve is provided on the inflow side of each of the filters, which is always closed and opened at the time of backwashing and discharges washing water after washing to a drain port. apparatus. 7. A flow meter for measuring a flow rate of a filtrate filtered by an A system or a B system is a flow meter having an analog output function, and an analog signal of the flow meter is converted into a flow value, and a predetermined lower limit is set. 7. The method according to claim 5, wherein the pump is stopped when the output side flow rate of the filtrate is equal to or less than the lower limit flow rate value, and the washing valve and the drain valve are opened to perform reverse washing. Turbidity analyzer for water quality measurement. 8. An output system of a pump for increasing the water pressure of the sample water includes an A system in which an A-line water valve and an A-line filter are connected in series, and a B system in which a B-line water valve and a B line filter are connected in series. The filter outflow side of the A system and the B system is connected to a flow control valve via a cleaning auxiliary valve, and the filtrate filtered by selecting the A system or the B system by switching the water flow valve is filtered. The liquid is sent to the water quality measurement unit via the, and when backwashing the A-system or B-system filter, the washing auxiliary valve is closed, the backwash-side system water flow valve is closed, and the drain valve is opened. Open the water flow valve to supply the sample water to the filter, supply the filtrate filtered by the filter from the outflow side of the filter in the backwashing system, and discharge it to the drain port through the drain valve in the backwashing system. To be In addition, the filters of both systems are claimed in claim 1
A turbidity measuring device for measuring water quality, comprising using the filter described in the above. 9. A flow meter for measuring a flow rate of a filtrate filtered by an A system or a B system is a flow meter having an analog output function, an analog signal of the flow meter is converted into a flow value, and a predetermined lower limit flow rate is set. When the output side flow rate of the filtrate falls below the lower limit flow rate value, the water flow valve and cleaning auxiliary valve of the backwashing system are closed, the drainage valve is opened, and the water flow valve of the other system is opened. 9. The water turbidity measuring apparatus according to claim 8, wherein the sample water is supplied to the filter by means of a filter, and the filtrate filtered by the filter is supplied from the outlet side of the filter of the backwashing side system and backwashed. .