JP2007253025A - Operation method of filtration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep treated water quality in a filtration system removing impurities such as non-dissolvable matter contained in raw water by a filter medium. <P>SOLUTION: In this operation method of the filtration system 1 with a raw water line 3 and a treated water line 4 connected to a filtration means 2 removing impurities contained in raw water by the filter medium, turbidity or chromaticity of treated water is detected, and feed of the treated water to the downstream side of the treated water line 4 is stopped, when the detected value exceeds a given turbidity or chromaticity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of operating a filtration system that removes impurities such as non-dissolved substances contained in raw water with a filter medium.

  Filtering systems that remove impurities such as non-dissolved substances contained in raw water using filter media include iron removal systems that remove iron as non-dissolved substances contained in raw water, and iron removal and manganese removal that remove iron and manganese. There is a system, and there is a sand filtration system for removing non-dissolved substances such as dust contained in raw water (for example, see Patent Documents 1 and 2).

The filtration system includes a filtering unit that removes non-dissolved substances contained in the raw water with a filter medium. The raw water is supplied to the filtering unit from a raw water line connected to the filtering unit, and the non-dissolved substance is removed by the filter medium. The water is captured and removed, and the water is collected from the treated water line connected to the filtering means.
JP-A-9-239361 JP 2003-265906 A

  By the way, in the said filtration system, when the said filter medium obstruct | occludes with the non-dissolved substance removed from raw | natural water, a non-dissolved substance cannot fully be removed and the quality of treated water will deteriorate. Therefore, in order to recover the processing capacity of the filter medium, a regeneration operation is performed at predetermined intervals.

  The regeneration operation is performed before the processing capacity of the filter medium is exceeded. However, the filter medium may exceed the treatment capacity before the regeneration operation due to, for example, deterioration of raw water quality or a rapid increase in the amount of treated water. In this case, non-dissolved substances leak to the treated water side and the treated water quality deteriorates.

  The present invention has been made in view of such circumstances, and the problem to be solved is to maintain the quality of treated water in a filtration system that removes impurities such as non-dissolved substances contained in raw water with a filter medium. It is to be.

  This invention was made in order to solve the said subject, and the invention of Claim 1 connected the raw | natural water line and the treated water line to the filtration means which removes the impurity contained in raw | natural water with a filter medium. A method of operating a system, wherein the turbidity or chromaticity of treated water is detected, and when the detected value exceeds a predetermined turbidity or chromaticity, supply of treated water to the downstream side of the treated water line is performed. It is characterized by stopping.

  Furthermore, the invention according to claim 2 is directed to the treated water when the detected value of the turbidity or chromaticity of the treated water exceeds the predetermined turbidity or the predetermined chromaticity and the supply of the treated water is stopped. It is characterized by supplying makeup water.

  According to the first aspect of the present invention, when the detected value of turbidity or chromaticity of treated water exceeds a predetermined turbidity or chromaticity, supply of treated water to the downstream side of the treated water line is stopped. By doing so, treated water having a high impurity concentration is not supplied, and the quality of the treated water can be maintained.

  According to the invention described in claim 2, when the detected value of the turbidity or chromaticity of the treated water exceeds the predetermined turbidity or the predetermined chromaticity and the supply of the treated water is stopped, the makeup water is supplied to the treated water. Therefore, the amount of treated water can be secured while maintaining the quality of treated water.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic explanatory diagram showing the configuration of an example of an embodiment of a filtration system according to the present invention.

  A filtration system 1 shown in FIG. 1 includes a filtration means 2, a raw water line 3 that supplies raw water to the filtration means 2, and a treated water line 4 that collects treated water from the filtration means 2.

  The filtration means 2 is a means for removing iron contained in the raw water as impurities such as non-dissolved substances, and the filtration system 1 of this embodiment is an iron removal system. The filtration means 2 includes a tower-type filtration unit 5 that performs filtration with a filter medium layer (not shown) formed of anthracite, filtration sand, and the like, and a control valve 6. Here, the filtering means 2 may be provided with a manganese removal capability by adding manganese zeolite or the like into the filter medium layer.

  The raw water line 3 and the treated water line 4 are connected to the control valve 6, and the raw water supplied to the filtration unit 5 through the control valve 6 is filtered and included in the raw water. Iron is removed, and this water flows through the control valve 6 to the treated water line 4.

  The raw water line 3 is provided with a raw water supply pump 7. In addition, an oxidant addition means 8 and a flocculant addition means 9 are connected to the raw water line 3 on the downstream side of the raw water supply pump 7 as chemical injection means for use in removing impurities.

  The oxidant addition means 8 includes an oxidant reservoir 11 connected to the raw water line 3 through an oxidant supply line 10. In this oxidant storage part 11, sodium hypochlorite is stored as an iron oxidant in the raw water, and this sodium hypochlorite is supplied to the oxidant supply line 10. It is added to the raw water line 3 by a pump 12.

  The flocculant addition means 9 includes a flocculant reservoir 14 connected to the raw water line 3 via a flocculant supply line 13. The flocculant stored in the flocculant reservoir 14 is added to the raw water line 3 by a flocculant supply pump 15 provided in the flocculant supply line 13.

  A water quality detection means 17 is connected to the treated water line 4 via a sample solution introduction line 16. This water quality detection means 17 detects the turbidity or chromaticity of treated water, and specifically includes an optical measuring device described in Japanese Patent Application No. 2005-347405. Although not shown in the drawing for the detailed configuration of this optical measuring device, the light from the light emitting element is irradiated to the sample liquid in the measurement chamber provided in the measurement cell through the first light guide unit, and the light from the sample liquid is also emitted. An optical measurement device that detects light with a light receiving element through a second light guide, the flow channel being formed in the measurement cell and introducing a sample liquid into or out of the measurement chamber, and the measurement cell And a flow control unit that opens and closes the flow channel unit, and a filter unit that is connected to the measurement cell and communicates with the measurement chamber. By configuring in this way, it is possible to realize a compact optical measuring device in which a sample liquid collecting mechanism and a cleaning liquid generating mechanism for cleaning the light transmission window in each light guide unit are integrated. Further, it is possible to realize an optical measuring device that can perform nozzle cleaning without reducing the supply pressure of the cleaning liquid. As a result, it is possible to perform installation and maintenance in the field in a short time, and further, it is possible to effectively remove the dirt component adhering to the light transmission window and maintain a predetermined measurement result. It has become.

  Further, the treated water line 4 is provided with a treated water supply valve 18 on the downstream side of the water quality detecting means 17, and a treated water storage part 19 is connected to the downstream side of the treated water supply valve 18. ing. The treated water storage unit 19 includes a water level sensor 20, and a treated water distribution line 21 and a makeup water supply unit 22 are connected to each other.

  The makeup water supply means 22 supplies makeup water such as clean water or purified water from another system to the treated water reservoir 19 when the detection value of the water quality detection means 17 exceeds a predetermined turbidity or a predetermined chromaticity. It is supposed to be. The makeup water supply means 22 includes a makeup water supply line 23 connected to the treated water reservoir 19 and a makeup water supply valve 24 provided in the makeup water supply line 23.

  The raw water supply pump 7, the oxidant supply pump 12, the flocculant supply pump 15, the water quality detection means 17, the treated water supply valve 18, the water level sensor 20, and the makeup water supply valve 24 include a signal line 25, Are connected to the control means 26 via 25,. This control means 26 is based on the signal input from the water quality detection means 17 or the water level sensor 20 via the signal line 25, and the raw water supply pump 7, the oxidant supply pump 12, the coagulant supply pump. 15. The treated water supply valve 18 and the makeup water supply valve 24 are controlled (a specific control method will be described later).

  In the filtration system 1, when the water level sensor 20 detects that the water level in the treated water storage unit 19 is equal to or lower than a predetermined water supply start water level, the control unit 26 controls the raw water supply pump. 7 is operated to supply raw water to the filtering means 2 at a predetermined set flow rate, and the treated water supply valve 18 is opened to supply treated water to the treated water storage unit 19. At this time, the control means 26 also operates the oxidant supply pump 12 and the flocculant supply pump 15 to operate the sodium hypochlorite in the oxidant reservoir 11 and the flocculant reservoir 14. Are added to the raw water line 3 respectively.

  When the sodium hypochlorite is added to the raw water line 3, the iron content in the raw water is oxidized to become insoluble ferric hydroxide. Then, when raw water in which ferric hydroxide is agglomerated by the flocculant flows into the filtration unit 5 through the control valve 6, ferric hydroxide is captured by the filter medium layer (not shown). The water is removed and flows out to the treated water line 4 through the control valve 6. The treated water that has flowed out to the treated water line 4 is stored in the treated water storage unit 19.

  During operation of the filtration system 1, turbidity or chromaticity is detected by the water quality detection means 17, and the detection result is input to the control means 26 via the signal line 25. Here, when the filtration means 2 exceeds the treatment capacity, the iron concentration of the treated water becomes high. The control means 26 stops the raw water supply pump 7 when the detection value of the water quality detection means 17 exceeds a predetermined turbidity or a predetermined chromaticity, and closes the treated water supply valve 18 to close the process. The supply of treated water to the water reservoir 19 is stopped.

  When the supply of treated water to the treated water storage unit 19 is stopped, the control unit 26 opens the makeup water supply valve 24 to open water from the makeup water supply line 23 to the treated water storage unit 19. Supply makeup water such as clean water. When the water level in the treated water storage unit 19 reaches a predetermined water supply stop water level, the control means 26 closes the makeup water supply valve 24 and supplies the treated water storage unit 19 with makeup water. Stop.

  According to the filtration system 1, when the detected value of turbidity or chromaticity of treated water exceeds a predetermined turbidity or chromaticity, by stopping the supply of treated water to the treated water storage unit 19, The treated water having a high iron concentration is not stored in the treated water reservoir 19, and the quality of the treated water in the treated water reservoir 19 can be maintained.

  Further, when the detected value of the turbidity or chromaticity of the treated water exceeds the predetermined turbidity or the predetermined chromaticity and the supply of the treated water is stopped, the makeup water is supplied to the treated water storage unit 19, so that the treated water A predetermined amount of treated water can be secured while maintaining the water quality.

  Here, a modified example of this embodiment will be described. In this embodiment, the filtration system 1 is an iron removal system in which the filtration means 2 is an iron removal means. However, the filtration system 1 is a sand filtration means that removes dust and the like from the filtration means 2. The sand filtration system may be used. In this case, the filtration unit 5 is configured to perform filtration with a filter medium layer (not shown) formed of anthracite, filtration sand, or the like.

  In this modified example, the flocculant added by the flocculant adding means 9 causes dust or the like in raw water to aggregate, and the aggregate is removed by the filter medium layer. Here, in this sand filtration system, since it is not necessary to oxidize the iron content in the raw water, it is not necessary to provide the oxidizing agent adding means 8, but the raw water supplied to the filtering means 2 is sodium hypochlorite. In order to sterilize with a sterilizing agent such as a sterilizing agent, a sterilizing agent adding unit including a sterilizing agent storage unit, a sterilizing agent supply pump, and a sterilizing agent supply line (not shown) is provided at the position of the oxidizing agent adding unit 8.

  Now, in this modification, when the said filtration means 2 exceeds processing capacity, the density | concentrations, such as refuse, will become high in treated water. When the detected value of the water quality detection means 17 exceeds a predetermined turbidity or a predetermined chromaticity, the supply of the treated water to the treated water storage unit 19 is stopped so that the treated water having a high concentration of dust or the like is The treated water is not stored in the treated water reservoir 19 and the treated water quality in the treated water reservoir 19 can be maintained.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, when the detection value of the water quality detection unit 17 exceeds a predetermined turbidity or a predetermined chromaticity and the supply of the treated water to the treated water storage unit 19 is stopped, the water level in the treated water storage unit 19 is a predetermined level. The makeup water may be supplied by the makeup water supply means 22 only when it is below the water level.

1 is a schematic explanatory diagram illustrating a configuration of an example of an embodiment of a filtration system according to the present invention.

Explanation of symbols

1 Filtration system 2 Filtration means 3 Raw water line 4 Treated water line

Claims (2)

An operation method of a filtration system in which a raw water line and a treated water line are connected to a filtering means for removing impurities contained in raw water with a filter medium,
Filtration characterized by detecting turbidity or chromaticity of treated water, and stopping the supply of treated water to the downstream side of the treated water line when the detected value exceeds a predetermined turbidity or chromaticity How to operate the system.   The supply water is supplied to the treated water when the detected value of the turbidity or chromaticity of the treated water exceeds a predetermined turbidity or a predetermined chromaticity and the supply of the treated water is stopped. How to operate the filtration system.

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