JP3216584U - Water quality analyzer - Google Patents

Abstract

A water quality analyzer capable of cleaning the inside of an atmosphere open port of a multi-port valve is provided. A water quality analyzer includes a measuring cell, a measuring unit for measuring the absorbance of sample water contained in the measuring cell, a syringe pump for sucking and discharging liquid, And multi-port valves 4 and 6 for switching a flow path communicating with the syringe pump, and configured to transfer the sample water sucked by the syringe pump to the measurement cell and perform absorbance measurement. The multi-port valve has an air release port connected to an air release channel 18 whose end is open to the atmosphere, and can communicate between the syringe pump and the air release channel. The air release flow path has an internal capacity for storing the liquid discharged from the syringe pump when a predetermined amount of liquid is discharged from the syringe pump in a state where the air release port and the syringe pump communicate with each other. It is what has. [Selection] Figure 1

Description

  The present invention relates to a water quality analyzer such as a total organic carbon measuring device (TOC meter) and a total phosphorus measuring device (TP meter).

  Water quality analyzers such as TOC meters and TP meters are equipped with a syringe pump that sucks and discharges liquid, and a multi-port valve for switching the flow path that communicates with the syringe pump. Each step necessary for measuring the absorbance is executed by driving the valve.

  For example, a TP meter generally includes a reactor for oxidizing a phosphorus compound in sample water and a measurement unit for measuring absorbance of sample water after being oxidized in the reactor. The operation like this is executed. After collecting the sample water with a syringe pump, a reagent such as potassium peroxodisulfate is further sucked with the syringe pump. After mixing the sample water and the reagent in the cylinder of the syringe pump, the sample water to which the reagent is added is transferred to the reactor. In the reactor, the phosphoric compound in the sample water is oxidized to produce orthophosphoric acid. The sample water that has been oxidized in the reactor is again sucked by a syringe pump, and further, ascorbic acid as a reducing agent and molybdic acid as a color former are sucked and mixed with the sample water, and then the sample water is transferred to the measuring section. In the measurement unit, the absorbance of the sample water is measured, and the phosphorus concentration in the sample water is obtained (see Patent Document 1).

JP 2003-014724 A

  As described above, in the water quality analyzer, the sample water and the reagent are mixed in the cylinder of the syringe pump. Mixing of sample water and reagent is performed by supplying sparge gas into the cylinder of the syringe pump. However, when supplying sparge gas into the cylinder of the syringe pump, the suction / discharge port of the syringe pump must be open to the atmosphere. is there. Therefore, one port of the multi-port valve is an air release port that is open to the atmosphere, and when the sparge gas is supplied into the syringe pump cylinder to mix the sample water and the reagent, the syringe pump and the air release port are opened. The multi-port valve is switched so as to communicate with the port.

  The multiport valve rotates the rotor to move the rotor groove for communicating between the ports to a desired position to switch the connection destination of the syringe pump. When the rotor rotates and the rotor groove passes through the air release port, if any liquid remains in the rotor groove, the liquid enters the air release port and precipitates, closing the air release port. I found out that When the air release port is closed, when the sample water and the reagent are mixed, a back flow of liquid that cannot be assumed in the normal state occurs, and the sample water and the reagent are mixed in the sparge gas supply line. Adversely affect

  In the conventional water quality analyzer, since the liquid cannot be passed through the atmosphere open port of the multiport valve, there is no way to remove the liquid when the liquid enters the air open port.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable the inside of an air release port of a multiport valve to be cleaned.

  The present invention has a measurement cell, and communicates with a measurement unit for measuring the absorbance of sample water stored in the measurement cell, a syringe pump for sucking and discharging liquid, and the syringe pump. The water quality analyzer includes a multiport valve for switching a flow path, and is configured to transfer the sample water sucked by the syringe pump to the measurement cell and perform absorbance measurement. In the present invention, the multi-port valve has an air release port connected to an air release channel whose end is open to the atmosphere, and can communicate between the syringe pump and the air release channel. The air release channel stores the liquid discharged from the syringe pump when a predetermined amount of liquid is discharged from the syringe pump in a state where the air release port and the syringe pump communicate with each other. It has an internal capacity.

  In the present invention, an air release flow path is connected to the air release port of the multi-port valve, and when a predetermined amount of liquid is discharged from the syringe pump in a state where the air release port and the syringe pump communicate with each other, the syringe pump The liquid discharged from the air is stored in the atmosphere open flow path. For this reason, even if liquid is discharged from the syringe pump in a state where the air release port and the syringe pump are in communication, the liquid does not overflow into the apparatus from the air release port, and the liquid in the air release flow path is discharged. It can be pulled back by a syringe pump. Therefore, the atmosphere opening port can be cleaned by discharging and sucking the cleaning liquid from the syringe pump in a state where the atmosphere opening port and the syringe pump are in communication.

  In a preferred embodiment of the present invention, a cleaning liquid flow path for supplying a cleaning liquid to one port of the multi-port valve is connected, and the syringe pump and the cleaning liquid flow path are connected to each other to connect the syringe pump. After the cleaning liquid is sucked in, the predetermined amount of the cleaning liquid is discharged from the syringe pump by communicating between the syringe pump and the air opening flow path, and the cleaning liquid stored in the air opening flow path In order to execute a cleaning operation for sucking the liquid into the syringe pump, it is preferable to include a cleaning operation unit configured to control the syringe pump and the multiport valve.

  As the cleaning liquid, a diluent for diluting the sample water by adding to the sample water can be used.

  Moreover, the said washing | cleaning operation part may be comprised so that the said washing | cleaning operation may be performed whenever the absorbance measurement of the sample water in the said measurement part is complete | finished once.

  In the water quality analyzer according to the present invention, when a predetermined amount of liquid is discharged from the syringe pump in a state where the air release port and the syringe pump communicate with each other, the liquid discharged from the syringe pump is stored in the air release flow path. Therefore, the inside of the atmosphere opening port can be cleaned by discharging and sucking the cleaning liquid from the syringe pump in a state where the atmosphere opening port and the syringe pump are in communication with each other.

It is a schematic block diagram which shows one Example of a water quality analyzer. It is a flowchart which shows an example of operation | movement of the Example. It is a flowchart which shows the other example of operation | movement of the Example.

  Hereinafter, an embodiment of a water quality analyzer according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the water quality analyzer of this embodiment mainly includes a syringe pump 2, two multi-port valves 4 and 6, a reactor 8, a measuring unit 10, and a calculation control device 24.

  The syringe pump 2 sucks and discharges liquid. The suction / discharge port of the syringe pump 2 is connected to the center port of the multiport valve 4 described later. The cylinder of the syringe pump 2 is connected to a sparge gas passage for supplying a sparge gas into the cylinder by the pump 22, and the liquid can be agitated in the syringe pump 2 by the sparge gas supplied by the pump 22. It is like that.

  The multi-port valve 4 has one central port and a plurality of selection ports, and can selectively connect the central port to any one selection port. The suction / discharge port of the syringe pump 2 is connected to the center port of the multiport valve 4. One selection port of the multiport valve 4 is connected to the central port of the multiport valve 6 through a flow path. One of the other selected ports of the multi-port valve 4 is an air release port, and an air release flow path 18 whose end is open to the atmosphere is connected. The air release channel 18 has an internal capacity that can store the liquid without overflowing when a predetermined amount of liquid is discharged from the syringe pump 2 with the syringe pump 2 and the air release port communicating with each other. It has a flow path.

  Each of the remaining selection ports of the multiport valve 4 is connected to six flow paths that lead to the containers for storing the reagents (1) to (6). Reagent (1) is sodium hydroxide solution, reagent (2) is potassium peroxodisulfate solution, reagent (3) is hydrochloric acid solution, reagent (4) is sulfuric acid solution, reagent (5) is molybdic acid solution, reagent (6) Is an ascorbic acid solution.

  The multi-port valve 6 also has one central port and a plurality of selection ports, and selectively connects the central port to any one selection port. One selection port of the multi-port valve 6 is connected to the reactor 8 via a flow path, and the other selection port of the multi-port valve 6 is connected to the inlet of the measurement cell 12 of the measurement unit 10 via the flow path. It is connected. The other selection port of the multi-port valve 6 is connected to a flow path leading to a container for storing a span solution, a diluting solution, and a standard solution, in addition to a water collection tube for collecting sample water.

  The reactor 8 is for oxidizing the sample water and has an ultraviolet irradiation lamp 9. Sample water oxidation treatment refers to sample water to which an oxidizing agent (for example, potassium peroxodisulfate solution) has been added, while supplying oxygen gas or air under a constant temperature condition (for example, 95 ° C.). Irradiation is a process for generating orthophosphoric acid by oxidizing and decomposing phosphorus compounds in sample water.

  The measurement unit 10 includes a measurement cell 12, a light source 14, and a light detection element 16. The outlet of the measuring cell 12 leads to the drain. The light source 14 generates light having a measurement wavelength (for example, 220 nm) toward the measurement cell 12, and is realized by, for example, a laser element. The light detection element 16 is for detecting the intensity of light from the light source 14 that has passed through the measurement cell 12, and is realized by, for example, a photodiode.

  The operation of this water quality analyzer is controlled by the arithmetic and control unit 24. The arithmetic and control unit 24 is realized by a dedicated computer or a general-purpose personal computer. The arithmetic and control unit 24 has a function of driving the syringe pump 2, the multiport valves 4 and 6, the measurement unit 10, and the like to execute a series of measurement operations from sampling of sample water to measurement of absorbance. An example of a series of measurement operations is as follows.

  First, after sample water is sucked into the syringe pump 2, a reagent necessary for the oxidation reaction of the sample water such as potassium peroxodisulfate is sucked into the syringe pump 2. By pulling the plunger of the syringe pump 2 to a predetermined position so that the sparge gas channel 20 communicates with the cylinder of the syringe pump 2 and supplying the sparge gas into the syringe pump 2, the sample water and the reagent in the syringe pump 2 are supplied. Mix. Thereafter, the sample water in the syringe pump 2 is transferred to the reactor 8 to oxidize the phosphorus compound in the sample water. The sample water oxidized in the reactor 8 is again sucked by the syringe pump 2, and further, ascorbic acid as a reducing agent and molybdic acid as a color former are sucked and mixed with the sample water, and then the sample water is transferred to the measurement cell 12. Then, the absorbance of the sample water is measured.

  The arithmetic and control unit 24 further includes a cleaning operation unit 26 configured to perform cleaning in the atmosphere release port of the multiport valve 4. The cleaning operation unit 26 is a function obtained by an arithmetic element such as a microcomputer executing a predetermined program. Washing in the atmosphere opening port is performed by discharging a predetermined amount of diluent from the syringe pump 2 with the syringe pump 2 connected to the atmosphere opening flow path 20 and then sucking out the discharged diluent. The cleaning operation in the atmosphere opening port may be configured to be performed at a desired timing based on the user input, but is configured to be automatically performed every time the above-described series of measurement operations is completed once. May be. In this embodiment, a diluent is used for cleaning the air release port. However, the present invention is not limited to this, and a dedicated cleaning solution for cleaning the air release port is separated from the diluent. It may be used.

  FIG. 2 is a flowchart showing an example of a series of operations from measurement to cleaning of the air release port.

  When the user inputs a measurement start instruction, the arithmetic and control unit 24 performs a series of measurement operations based on a preset program (step S1). After the series of measurement operations is completed, the cleaning operation unit 26 sucks the diluent through the syringe pump 2 (step S2). The syringe pump 2 is connected to the atmosphere release port (step S3), and a predetermined amount of diluent is discharged from the syringe pump 2 (step S4). The diluted solution discharged from the syringe pump 2 is stored in the air release channel 18 connected to the air release port. Thereafter, the diluent stored in the air release channel 18 is sucked by the syringe pump 2 (step S5). The syringe pump 2 is connected to the drain, and the diluted solution is discharged to the drain (step S6). Thereby, the inside of the air release port of the multi-port valve 4 is cleaned with the diluent.

  In addition, in order to improve the cleaning effect in the air release port, the discharge / suction of the diluent by the syringe pump 2 may be repeated a plurality of times. FIG. 3 is a flowchart showing an example of a cleaning operation in which the discharge / suction of the diluent is repeated a plurality of times.

  After the series of measurement operations (step S11) is completed, the cleaning operation unit 26 sucks the diluent through the syringe pump 2 (step S12). After the syringe pump 2 is connected to the atmosphere release port and a predetermined amount of diluent is discharged from the syringe pump 2 (step S14), the diluent stored in the atmosphere release channel 18 is sucked by the syringe pump 2 (step S15). ). After the discharge and suction operations of the diluent by the syringe pump 2 are repeated a predetermined number of times (step S16), the syringe pump 2 is connected to the drain and the diluent is discharged to the drain (step S17).

  As described above, in the water quality analyzer, after the series of measurement operations is completed, the air opening port of the multi-port valve 4 is cleaned, so that the air opening port due to deposition in the air opening port is used. Can be prevented from occurring.

2 Syringe pump 4, 6 Multiport valve 8 Reactor 9 Ultraviolet lamp 10 Measurement unit 12 Measurement cell 14 Light source 16 Photodetecting element 18 Atmospheric release channel 20 Sparge gas channel 22 Pump 24 Arithmetic control unit 26 Cleaning operation unit

Claims (4)

A measuring cell for measuring the absorbance of sample water stored in the measuring cell, a syringe pump for sucking and discharging liquid, and a flow path communicating with the syringe pump are switched. A water quality analyzer configured to perform absorbance measurement by transferring sample water sucked by the syringe pump to the measurement cell,
The multi-port valve has an open air port connected to an open air channel whose terminal end is open to the atmosphere, and is capable of communicating between the syringe pump and the open air channel,
The air release channel has an internal capacity for storing the liquid discharged from the syringe pump when a predetermined amount of liquid is discharged from the syringe pump in a state where the air release port and the syringe pump communicate with each other. A water quality analyzer that you have. A cleaning liquid flow path for supplying a cleaning liquid to one port of the multi-port valve is connected,
After the syringe pump and the cleaning liquid flow path are communicated to suck the cleaning liquid into the syringe pump, the syringe pump and the air release flow path are communicated to form a predetermined amount from the syringe pump. The syringe pump and the multi-port valve are controlled to execute a cleaning operation for discharging the cleaning liquid and sucking the cleaning liquid stored in the open air flow path into the syringe pump. The water quality analyzer according to claim 1, comprising a washing operation unit.   The water quality analyzer according to claim 2, wherein the cleaning liquid is a diluent for diluting the sample water by adding to the sample water.   The water quality analyzer according to claim 2 or 3, wherein the cleaning operation unit is configured to execute the cleaning operation every time the absorbance measurement of sample water in the measurement unit is completed once.

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