JP2021047112A - Liquid measurement device and water quality measurement apparatus - Google Patents

Abstract

To provide a liquid measurement device and a water quality measurement apparatus which can automatically and accurately measure a measurement object liquid even when the performance of a pump fluctuates.SOLUTION: A TOC measurement apparatus 1 comprises: a pump 16A which can switch between the normal driving of suctioning the air from a pipe line 22A and the reverse driving of feeding the air to the pipe line 22A; an optical sensor 51 which detects a sample in the pipe line 22A; and a control device. The control device performs the first control of controlling a valve device so as to permit the flow between pipe lines 21A, 22A and restrict the flow between pipe lines 22A, 23A and normally driving the pump 16A, the second control of reversely driving the pump 16A at the low speed on the basis of the detection of the liquid level of the sample by an optical sensor 51 during the first control, and the third control of controlling the valve device so as to restrict the flow between the pipe lines 21A, 22A and permit the flow between the pipe lines 22A, 23A on the basis of the re-detection of the liquid level of the sample by the optical sensor 51 during the second control and reversely driving the pump 16A.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid measuring device for measuring a liquid to be measured and a water quality measuring device including the liquid measuring device.

As a water quality measuring device, for example, a total organic carbon measuring device for measuring the concentration of organic carbon contained in water as a sample is known (see, for example, Patent Document 1).

In Patent Document 1, a predetermined amount of sample is injected into a reaction vessel using a microsyringe, a predetermined amount of an acid solution is injected into a reaction vessel using a metering pump, and a predetermined amount is further injected using another metering pump. A total organic carbon measuring device for injecting the oxidant solution of the above into a reaction vessel is described.

Japanese Unexamined Patent Publication No. 63-173962

However, in the configuration of Patent Document 1, it is necessary to measure the sample as the liquid to be measured using a microsyringe, and there is a problem that the sample cannot be measured automatically. Therefore, it is conceivable to measure the sample using a metering pump as in the case of the acid solution and the oxidizing agent solution, but there is a problem that the sample cannot be accurately measured when the performance of the metering pump deteriorates.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid measuring device and a water quality measuring device capable of automatically and accurately measuring a liquid to be measured even when the performance of a pump fluctuates. And.

In order to solve the above problems, the liquid measuring device according to claim 1 has a storage unit for storing the liquid to be measured, a primary conduit connected to the storage unit, and a measurement for measuring the liquid to be measured. A pump that can be switched between a pipeline, a secondary pipeline through which the liquid to be measured flows after measurement, a forward rotation drive that sucks air from the measurement pipeline, and a reverse rotation drive that sends air to the measurement pipeline, and the above. A valve device for controlling the flow of the liquid to be measured between the primary pipeline and the measuring pipeline and the flow of the liquid to be measured between the measuring pipeline and the secondary pipeline, and the weighing. The control device includes a sensor device that detects the liquid to be measured flowing in the pipeline and a control device that controls the pump and the valve device based on the detection result of the liquid to be measured by the sensor device. , (1) Allow the flow of the liquid to be measured between the primary pipe and the measuring pipe, and limit the flow of the liquid to be measured between the measuring pipe and the secondary pipe. Based on the first control of controlling the valve device and driving the pump in the forward direction, and (2) the sensor device detecting the liquid level of the liquid to be measured during the first control. The primary control is based on the second control in which the pump is reversely driven at a lower speed than the first control, and (3) the sensor device detects the liquid level of the liquid to be measured again during the second control. The valve device is provided so as to limit the flow of the liquid to be measured between the conduit and the measuring pipeline and to allow the flow of the liquid to be measured between the measuring pipeline and the secondary pipeline. It is characterized in that it controls and performs a third control for reversely driving the pump.

The liquid measuring device according to claim 2 further includes an intermediate line connecting the primary line and the measuring line in the liquid measuring device according to claim 1, and the intermediate line is provided with the intermediate line. It is characterized in that a bubble reducing portion formed by enlarging the inner diameter of the intermediate pipeline is provided.

The liquid measuring device according to claim 3 is the liquid measuring device according to claim 1 or 2, wherein as the storage unit, a sample storage unit that stores a sample containing organic carbon as the measurement liquid and a solute of an acid. An acid solution storage unit for storing the acid solution to be measured as the measurement liquid and an oxidant solution storage unit for storing the oxidant solution containing the oxidant as the solute as the measurement liquid are provided as the primary pipeline. A sample primary conduit connected to the sample storage portion, an acid solution primary pipeline connected to the acid solution storage portion, and an oxidant solution primary pipeline connected to the oxidant solution storage portion are provided. As the measuring pipeline, a sample measuring pipeline for measuring the sample, an acid solution measuring pipeline for measuring the acid solution, and an oxidizing agent solution measuring pipeline for measuring the oxidizing agent solution. The sensor device includes a sample sensor that detects the sample flowing in the sample measuring pipeline, an acid solution sensor that detects the acid solution flowing in the acid solution measuring pipeline, and an oxidizing agent solution weighing. It is characterized by including an oxidant solution sensor that detects the oxidant solution flowing in the pipeline.

The liquid measuring device according to claim 4 includes a diluted water storage unit for storing diluted water for diluting the sample as the liquid to be measured in the liquid measuring device according to claim 3. The sensor device is provided with a diluted water primary pipeline connected to the diluted water storage portion as the primary pipeline, and a diluted water measuring pipeline for measuring the diluted water as the measuring pipeline. The diluted water sensor for detecting the diluted water flowing in the diluted water measuring pipeline is provided.

The liquid measuring device according to claim 5 is the liquid measuring device according to claim 4, wherein the secondary line, the sample measuring line, and the diluted water measuring line are connected in series. It is a feature.

The liquid measuring device according to claim 6 is the liquid measuring device according to any one of claims 1 to 5, wherein the valve device includes the primary pipeline, the measuring pipeline, and the secondary pipeline. It is characterized by having a three-way solenoid valve connected to the valve.

The water quality measuring device according to claim 7 is characterized by including the liquid measuring device according to any one of claims 1 to 6.

According to the present invention, it is possible to provide a liquid measuring device and a water quality measuring device capable of automatically and accurately measuring a liquid to be measured even when the performance of a pump fluctuates.

It is a schematic diagram of the water quality measuring apparatus provided with the liquid measuring apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the bubble reduction part which concerns on the same embodiment. It is a block diagram of the schematic structure of the water quality measuring apparatus which concerns on the same embodiment. It is a flowchart which shows the flow of the measurement of total organic carbon by the water quality measuring apparatus which concerns on this embodiment. (A) to (D) are schematic views showing the flow of measurement and transfer of a sample according to the same embodiment. (A) to (D) are schematic views showing the flow of measurement and transfer of the acid solution according to the same embodiment. (A) to (D) are schematic views showing the flow of measurement and transfer of the oxidizing agent solution according to the same embodiment. (A) to (D) are schematic views showing the flow of measurement and transfer of wash water according to the same embodiment.

The liquid measuring device and the water quality measuring device according to the embodiment of the present invention will be described with reference to the drawings. The total organic carbon measuring device 1 (hereinafter referred to as “TOC measuring device 1”), which is a water quality measuring device, is an automatic measuring device for continuously or periodically measuring the concentration of total organic carbon (TOC) in water. Is. The TOC measuring device 1 has a built-in liquid measuring device that measures a liquid to be measured such as a sample.

As shown in FIG. 1, the TOC measuring device 1 includes a sample storage unit 11A, an acid solution storage unit 11B, an oxidant solution storage unit 11C, a washing water storage unit 11D, a span calibration liquid storage unit 11E, a mixing unit 12, and a heating unit. It includes 13, a water removing unit 14, a carbon dioxide detecting unit 15, pumps 16A and 16B, a carbon dioxide removing unit 17, a waste liquid storage unit 18, and a discharge pipe 19.

The sample storage unit 11A, the acid solution storage unit 11B, the oxidant solution storage unit 11C, the washing water storage unit 11D, and the span calibration liquid storage unit 11E have storage units (hereinafter referred to as “storage units 11”) for storing the liquid to be measured. It is configured.

The sample storage unit 11A is composed of a tank that stores water containing organic carbon, which is the target of water quality measurement, as a sample. Water is guided to the sample storage unit 11A via a flow rate adjusting valve (not shown), and water exceeding a predetermined amount is recirculated from the sample storage unit 11A.

The acid solution storage unit 11B is composed of a storage container for storing an acid solution for removing inorganic carbon (IC). The acid solution is an aqueous solution using pure water as a solvent and an acid as a solute, and as the acid, for example, an inorganic acid such as sulfuric acid, hydrochloric acid, or phosphoric acid is used. The concentration of the acid in the acid solution is adjusted in advance so that the hydrogen ion index (pH) of the sample is sufficiently lowered when the acid solution is mixed with the sample.

The oxidant solution storage unit 11C is composed of a storage container for storing the oxidant solution. The oxidant solution is an aqueous solution using pure water as a solvent and an oxidant as a solute, and as the oxidant, for example, sodium persulfate (sodium peroxodisulfate) or potassium persulfate (potassium peroxodisulfate) is used. The concentration of the oxidizing agent in the oxidizing agent solution is adjusted in advance so that the organic carbon in the sample can be sufficiently oxidized when the oxidizing agent is mixed with the sample and heated.

The wash water storage unit 11D is composed of a tank for storing wash water for cleaning the inner wall of the pipeline through which the sample passes, the inside of the solenoid valve, and the inside of the mixing unit 12. As the wash water, for example, tap water, ion-exchanged water obtained by an ion exchange method, or pure water such as RO water obtained by filtration using a reverse osmosis membrane is used. Pure water is preferably used when measuring low concentrations of total organic carbon.

The span calibration liquid storage unit 11E is composed of a storage container for storing the span calibration liquid for performing span calibration. The span calibration solution is an aqueous solution containing pure water as a solvent and potassium hydrogen phthalate as a solute.

The mixing unit 12 is a liquid storage unit, and is composed of a container for storing the liquid to be measured after measurement. Inside the mixing section 12, the sample after weighing and the acid solution after weighing are mixed, and after the inorganic carbon is removed by aeration treatment, the sample and the oxidizing agent solution after weighing are mixed. Further, the mixing unit 12 constitutes a flow path that guides the vapor of the sample generated in the heating unit 13 to the carbon dioxide detection unit 15.

The heating unit 13 is composed of an autoclave provided with a heating element 13A for heating a sample mixed with an oxidizing agent solution. The heating unit 13 oxidizes the organic carbon in the sample by heating the sample, and generates vapor of the sample containing carbon dioxide.

The water removing unit 14 is composed of a mist catcher. The water removal unit 14 removes water from the vapor of the sample sent to the carbon dioxide detection unit 15 by collecting liquid particles in the vapor.

The carbon dioxide detection unit 15 is composed of a non-dispersive infrared type (NDIR type) gas analyzer that detects carbon dioxide contained in the vapor of the sample. The carbon dioxide detection unit 15 measures the concentration of total organic carbon contained in the sample by detecting carbon dioxide from the vapor of the sample, and outputs the measurement result.

The pump 16A is composed of a peristaltic pump (so-called ironing pump) provided with a tube forming an air flow path. The pump 16A is generated when the rotor is rotationally driven to compress and relax the tube, and the rotor compresses (crushes) the tube to send air and relaxes (restores) the compressed tube. Inhale air by negative pressure. The capacity of the pump 16A to transfer air per unit time varies depending on the rotation speed of the rotor. Further, at least the pump 16A has a forward rotation drive for sucking air from the measuring pipe and the heating pipe (pipes 22A to 22D, 27 described later) by switching the rotation direction of the rotor, and the measuring pipe and the heating pipe. It is configured to be switchable to reverse drive that sends air to.

The pump 16B is composed of an electromagnetic air pump provided with a diaphragm. The pump 16B vibrates the diaphragm with an electromagnet and sends air into the measuring pipe and the heating pipe (pipes 22A to 22D, 27 described later) and the like.

The carbon dioxide removing unit 17 is composed of a carbon dioxide removing pipe that removes carbon dioxide from the air transferred by the pumps 16A and 16B. The carbon dioxide removing unit 17 includes, for example, soda lime as an absorbent that absorbs carbon dioxide.

The waste liquid storage unit 18 is composed of a tank that stores the residual liquid in the mixing unit 12 as waste liquid. The waste liquid collected in the waste liquid storage unit 18 is appropriately disposed of by a maintenance worker of the TOC measuring device 1.

The discharge pipe 19 is a pipe that discharges carbon dioxide derived from inorganic carbon generated in the mixing section 12, water collected by the moisture removing section 14, and residual liquid in the pipeline 24 described later.

Further, as shown in FIG. 1, the TOC measuring device 1 includes pipelines 21A to 21E, 22A to 22D, 23A to 23C, 24 to 27, bulbs 31 to 39, 41 to 47, and optical sensors 51 to 54. I have.

The pipelines 21A to 21E form a primary pipeline connected to the storage unit 11. The pipeline 21A is a sample primary pipeline connected to the sample storage unit 11A. The pipeline 21B is an acid solution primary pipeline connected to the acid solution storage unit 11B. The conduit 21C is an oxidant solution primary conduit connected to the oxidant solution storage portion 11C. The pipeline 21D is a primary rinse water pipeline connected to the wash water storage unit 11D. The pipeline 21E is a span calibration fluid primary pipeline connected to the span calibration fluid storage unit 11E. The pipelines 21A to 21E are connected to the corresponding valves 37, 35, 36, 34, 38 on a one-to-one basis (see FIG. 1).

The pipelines 22A to 22D form a measuring conduit for measuring the liquid to be measured, and have translucency. The conduit 22A is a sample measuring conduit for measuring a sample, and also serves as a span calibration liquid measuring conduit for measuring the span calibration liquid. Pipeline 22B is an acid solution measuring pipe for measuring the acid solution. The conduit 22C is an oxidant solution measuring conduit for measuring the oxidant solution. Pipeline 22D is a washwater measuring pipe for measuring wash water. The ends of the pipelines 22A to 22D on the pump 16A side are connected to the corresponding valves 34, 32, 33, 31 on a one-to-one basis, and the ends of the pipelines 22A to 22D on the mixing portion 12 side are connected. , Are connected to the corresponding valves 39, 35, 36, 34 on a one-to-one basis (see FIG. 1). Since the pipeline 22A and the pipeline 22D are connected in series via a valve 34, wash water flows through the pipeline 22A.

The pipelines 23A to 23C form a secondary pipeline connected to the mixing unit 12 through which the liquid to be measured flows. The pipe line 23A, the pipe line 22A, and the pipe line 22D are connected in series via valves 34 and 39, and the sample after measurement, the washing water, and the span calibration liquid flow through the pipe line 23A. The acid solution after weighing flows through the pipeline 23B. The oxidant solution after weighing flows through the conduit 23C. The pipelines 23A to 23C are connected to the corresponding valves 39, 35, 36 on a one-to-one basis (see FIG. 1), respectively.

The pipeline 24 constitutes an intermediate pipeline connecting the primary pipeline and the measuring pipeline. The pipeline 24 is connected to the valves 37 and 38 and is connected to the pipeline 22A at the connection point P. The pipeline 24 is provided with a bubble reducing portion 24A formed by enlarging the inner diameter of the pipeline 24. The bubble reduction unit 24A will be described later with reference to FIG.

The pipeline 25 is connected to the pumps 16A and 16B and the valves 31 to 33 and 41 in order to transfer the liquid to be measured such as the sample and the vapor of the sample. The pipeline 26 is connected to the mixing portion 12 and the valve 42. The pipeline 27 is a heating pipeline for heating the sample, is provided around the heating element 13A, and the ends of the pipeline 27 on the pump 16A and 16B sides are connected to the valve 41 and the pipeline 27 is connected to the valve 41. The end of the mixing portion 12 side is connected to the valve 42.

The valves 31 to 39 are valve devices that control the flow of the liquid to be measured between the primary pipe and the measuring pipe and the flow of the liquid to be measured between the measuring pipe and the secondary pipe (hereinafter, "" It constitutes a valve device 30 ").

The valves 31 to 33 are each composed of a two-way solenoid valve. The valve 31 controls the flow of fluid (air) between the pipeline 25 and the pipeline 22D. The valve 32 controls the flow of fluid (air) between the pipeline 25 and the pipeline 22B. The valve 33 controls the flow of fluid (air) between the pipeline 25 and the pipeline 22C.

The valves 34 to 36 are each composed of a three-way solenoid valve in which the primary pipeline, the measuring pipeline, and the secondary pipeline are connected. The valve 34 controls the flow of the fluid (washing water) between the pipeline 21D and the pipeline 22D, and also controls the flow of the fluid (washing water and air) between the pipeline 22D and the pipelines 22A and 23A. Control. The valve 35 controls the flow of the fluid (acid solution) between the pipeline 21B and the pipeline 22B, and controls the flow of the fluid (acid solution and air) between the pipeline 22B and the pipeline 23B. .. The valve 36 controls the flow of the fluid (oxidizing agent solution) between the pipeline 21C and the conduit 22C, and also controls the flow of the fluid (oxidizing agent solution and air) between the conduit 22C and the conduit 23C. Control.

The valves 37 to 39 are each composed of a two-way solenoid valve. The valve 37 controls the flow of fluid (sample) between the pipelines 21A and the pipelines 24 and 22A. The valve 38 controls the flow of fluid (span calibration liquid) between the pipeline 21E and the pipelines 24 and 22A. The valve 39 controls the flow of fluids (sample, wash water, span calibration fluid, and air) between the conduit 22A and the conduit 23A.

The valves 41 to 47 are each composed of a two-way solenoid valve. The valve 41 controls the flow of fluid (air) between the conduit 25 and the conduit 27, and the valve 42 controls the flow of the fluid (sample and air) between the conduit 26 and the conduit 27. To do.

The valve 43 controls the flow of the fluid (sample vapor) between the mixing section 12 and the moisture removing section 14, and the valve 44 controls the fluid (dioxide derived from inorganic carbon) between the mixing section 12 and the discharge pipe 19. Control the flow of (gas containing carbon). The valve 45 controls the flow of the fluid (residual liquid) between the mixing unit 12 and the waste liquid storage unit 18, and the valve 46 controls the flow of the fluid (residual liquid) between the pipeline 24 and the discharge pipe 19. Control. The valve 47 controls the flow of fluid (air) between the pump 16B and the pipeline 25 in order to prevent the air sent from the pump 16A from flowing into the pump 16B.

The optical sensors 51 to 54 constitute a sensor device (hereinafter referred to as “sensor device 50”) for detecting the liquid to be measured flowing in the measuring conduit. The optical sensors 51 to 54 each include a light emitting unit and a light receiving unit arranged so as to face each other across the measuring tube. The light emitting unit emits a predetermined amount of detection light, and the light receiving unit detects. It is configured to receive light. Each of the optical sensors 51 to 54 detects the liquid to be measured based on the light receiving result of the detected light by the light receiving unit.

The optical sensor 51 is a sample sensor that detects a sample flowing in the conduit 22A, and also serves as a span calibration liquid sensor that detects a span calibration fluid flowing in the conduit 22A. The optical sensor 51 is provided in the vicinity of the conduit 22A at a distance from the connection point P according to the measurement target value so that a predetermined amount of sample can be measured.

The optical sensor 52 is an acid solution sensor that detects an acid solution flowing in the conduit 22B. The optical sensor 52 is provided in the vicinity of the pipeline 22B at a distance from the bulb 35 according to the measurement target value so that a predetermined amount of the acid solution can be measured.

The optical sensor 53 is an oxidant solution sensor that detects the oxidant solution flowing in the conduit 22C. The optical sensor 53 is provided in the vicinity of the pipeline 22C at a distance from the bulb 36 according to the measurement target value so that a predetermined amount of the oxidant solution can be measured.

The optical sensor 54 is a wash water sensor that detects the wash water flowing in the conduit 22D. The optical sensor 54 is provided in the vicinity of the pipeline 22D at a distance from the bulb 34 according to the measurement target value so that a predetermined amount of washing water can be measured.

The operation of the bubble reducing unit 24A will be described with reference to FIGS. 2 (A) and 2 (B).
As shown in FIG. 2A, when the sample is transferred from the sample storage portion 21A to the conduit 22A, the sample may be formed like a thin film due to surface tension, so that air bubbles are formed at the head portion of the sample. May occur, and there are multiple sample liquid levels in a short interval. In the bubble reduction section 24A, the sample formed in the form of a thin film falls along the inner wall of the bubble reduction section 24A so as to merge with the sample below. The generated air bubbles can be eliminated. In this way, the bubble reduction unit 24A reduces the bubbles generated in the liquid to be measured (sample and span calibration liquid) flowing through the pipeline 24, and prepares the liquid level of the liquid to be measured.

Further, as shown in FIG. 3, the TOC measuring device 1 includes a heating unit 13, pumps 16A and 16B, and a control device 60 for controlling valves 31 to 39 and 41 to 47. The control device 60 controls the valve device 30 and the pump 16A based on the detection of the liquid to be measured by the sensor device 50 in order to measure the liquid to be measured.

In the above configuration, the liquid measuring device included in the TOC measuring device 1 of the present embodiment includes a storage unit 11, a pump 16A, pipelines 21A to 21E, 22A to 22D, 23A to 23C, a valve device 30, and a sensor. It is composed of a device 50.

An example of the flow of measurement of total organic carbon will be described with reference to FIG.
First, the TOC measuring device 1 measures the sample and transfers the sample to the mixing unit 12 (step S1). Specifically, the valve device 30 and the pump 16A so that the control device 60 transfers the sample from the sample storage unit 11A to the conduit 22A, and further transfers a predetermined amount of the sample from the conduit 22A to the mixing unit 12. To control.

The sample weighing operation in step S1 will be described in more detail with reference to FIG. The arrows in FIG. 5 indicate the flow of the sample. As shown in FIG. 5A, the control device 60 controls the valve 31 so that the pipelines 25, 22D, and 22A communicate with each other, and further, the sample between the pipelines 21A and the pipelines 24, 22A. The first control is to control the valve 37 so as to allow the flow and limit the flow of the sample between the pipe 22A and the pipe 23A, and to drive the pump 16A in the forward direction so as to suck air from the pipe 22A. Then, the sample is transferred from the sample storage unit 11A to the conduit 22A. When the forward rotation drive of the pump 16A is stopped based on the detection of the liquid level of the sample by the optical sensor 51, the liquid level of the sample becomes the optical sensor 51 due to the high-speed transfer of the sample as shown in FIG. 5 (B). Stay away from. Therefore, the control device 60 pumps to reduce the amount of the sample in the pipeline 22A as shown in FIG. 5C based on the fact that the optical sensor 51 detects the liquid level of the sample during the first control. The 16A is switched from the forward rotation drive to the low speed reverse rotation drive, the pump 16A is reverse-driven at a lower speed than the first control, and the second control is performed until the optical sensor 51 detects the liquid level of the sample again. The excess sample is transferred from the sample storage unit 11A to the sample storage unit 11A. Then, as shown in FIG. 5D, the control device 60 connects the pipelines 21A and the conduits 24 and 23A based on the fact that the optical sensor 51 detects the liquid level of the sample again during the second control. The valves 37 and 39 are controlled so as to limit the flow of the sample between the pipes 22A and allow the flow of the sample between the pipes 22A and the pipe 23A, and the pump 16A is reversely driven so as to send air into the pipe 22A. The sample is transferred from the pipeline 22A to the mixing unit 12 by performing the third control.

Next, the TOC measuring device 1 measures the acid solution and transfers the acid solution to the mixing unit 12 (step S2). Specifically, the valve device 30 is such that the control device 60 transfers the acid solution from the acid solution storage unit 11B to the pipeline 22B, and further transfers a predetermined amount of the acid solution from the pipeline 22B to the mixing unit 12. And control the pump 16A.

The measurement operation of the acid solution in step S2 will be described in more detail with reference to FIG. The arrows in FIG. 6 indicate the flow of the acid solution. As shown in FIG. 6A, the control device 60 controls the valve 32 and performs the first control to drive the pump 16A in the forward rotation so as to suck air from the pipeline 22C, from the acid solution storage unit 11B. The acid solution is transferred to the line 22B. When the forward rotation drive of the pump 16A is stopped based on the fact that the optical sensor 52 detects the liquid level of the acid solution, the liquid level of the acid solution is raised by the high-speed transfer of the acid solution as shown in FIG. 6 (B). Since the state is separated from the optical sensor 52, the control device 60 applies the acid solution in the conduit 22B as shown in FIG. 6C based on the fact that the optical sensor 52 detects the liquid level of the acid solution. In order to reduce the weight, the second control is performed in which the pump 16A is reversely driven at a lower speed than the first control, and the excess acid solution is transferred from the pipeline 22B to the acid solution storage portion 11B. Then, as shown in FIG. 6D, the control device 60 controls the valve 35 based on the fact that the optical sensor 52 detects the liquid level of the acid solution again during the second control, and enters the pipeline 22B. The acid solution is transferred from the pipe line 22B to the mixing unit 12 by performing the third control of reversely driving the pump 16A so as to send air.

Next, the TOC measuring device 1 performs aeration treatment to remove inorganic carbon contained in the sample (step S3). Specifically, the control device 60 controls the valves 41 and 42 so that the pipelines 25, 27, and 26 communicate with each other, and the pipes for passing the carbon dioxide-removed air through the sample in the mixing unit 12. The pump 16A is controlled so as to send air into the path 27, and the valve 44 is controlled so that the gas containing carbon dioxide generated in the mixing unit 12 is discharged.

Next, the TOC measuring device 1 measures the oxidant solution and transfers the oxidant solution to the mixing unit 12 (step S4). Specifically, the control device 60 transfers the oxidant solution from the oxidant solution storage section 11C to the conduit 22C, and further transfers a predetermined amount of the oxidant solution from the conduit 22C to the mixing section 12. It controls the valve device 30 and the pump 16A.

The measurement operation of the oxidizing agent solution in step S4 will be described in more detail with reference to FIG. 7. The arrows in FIG. 7 indicate the flow of the oxidant solution. As shown in FIG. 7A, the control device 60 controls the valve 33 and performs the first control to drive the pump 16A in the forward rotation so as to suck air from the pipeline 22C, and performs the first control to drive the oxidant solution storage unit 11C. The oxidant solution is transferred from the pipe to the line 22C. When the forward rotation drive of the pump 16A is stopped based on the fact that the optical sensor 53 detects the liquid level of the oxidant solution, as shown in FIG. 7 (B), the oxidant solution is transferred by high-speed transfer of the oxidant solution. Since the liquid level is separated from the optical sensor 53, the control device 60 is inside the conduit 22C as shown in FIG. 7C based on the fact that the optical sensor 53 detects the liquid level of the oxidant solution. In order to reduce the amount of the oxidant solution in the above, the pump 16A is reversely driven at a lower speed than the first control to perform the second control, and the excess oxidant solution is transferred from the conduit 22C to the oxidant solution storage portion 11C. To do. Then, as shown in FIG. 7 (D), the control device 60 controls the valve 36 based on the fact that the optical sensor 53 detects the liquid level of the oxidant solution again during the second control, and the pipeline 22C. The oxidant solution is transferred from the pipeline 22C to the mixing unit 12 by performing the third control of reversely driving the pump 16A so as to send air into the mixing section 12.

Next, the TOC measuring device 1 transfers the sample mixed with the oxidant solution from the mixing unit 12 to the heating unit 13 (step S5). Specifically, the control device 60 controls the valves 41 and 42 so that the pipelines 25, 27 and 26 communicate with each other, and controls the pump 16A to drive the pump 16A in the forward direction so as to suck the sample in the pipeline 27. As a result, the sample is transferred from the mixing unit 12 to the pipeline 27. Further, the control device 60 stops the drive of the pump 16A when the sample reaches the pipe line 27, limits the flow of the fluid between the pipe line 25 and the pipe line 27, and causes the pipe line 26 and the pipe line 27 to be connected to each other. The valves 41, 42 are controlled to limit the flow of fluid between them.

Next, the TOC measuring device 1 heats the sample so that the organic carbon in the sample becomes carbon dioxide (step S6). Specifically, the control device 60 controls the heating unit 13 so as to heat the sample at, for example, 120 ° C. for 30 minutes. At this time, since the pipeline 27 is closed by the valves 41 and 42, the sample in the pipeline 27 is pressurized and the oxidation of organic carbon is promoted. After heating the sample, the control device 60 maintains the state in which the conduit 27 is closed by the valves 41 and 42 for a predetermined time, and the inside of the heating unit 13 and the conduit 27 so that the sample reaches a predetermined temperature (about 60 ° C.). Cool the sample.

Then, the TOC measuring device 1 detects carbon dioxide contained in the vapor of the sample and measures the concentration of total organic carbon contained in the sample (step S7). Specifically, the control device 60 controls the valves 41 and 42 so that the pipelines 25, 27, and 26 communicate with each other, and the flow of sample vapor between the mixing unit 12 and the water removing unit 14 flows. By controlling the valve 43 as permissible and driving the pump 16A to send air into the pipeline 27, the vapor of the sample is sent to the carbon dioxide detection unit 15 via the mixing unit 12 and the water removing unit 14. To transfer. The carbon dioxide detection unit 15 measures the concentration of carbon dioxide contained in the vapor by detecting carbon dioxide from the vapor of the sample, and based on the concentration of the carbon dioxide, the concentration of all organic carbon contained in the sample. Is calculated.

Further, before the series of operations shown in FIG. 4 is performed, the TOC measuring device 1 cleans the inner walls of the pipelines 22A and 23A, the inside of the valve 39, and the inside of the mixing unit 12, and further removes carbon dioxide. Remove the residual liquid with free air. Specifically, the valve device 30 and the pump 16A so that the control device 60 transfers the wash water from the wash water storage unit 11D to the pipeline 22D, and further transfers the wash water from the pipeline 22D to the mixing unit 12. To control. Next, the valve 31 controls the valve 45 so that the control device 60 can transfer the residual liquid from the mixing unit 12 to the waste liquid storage unit 18, and further sends air to the pipelines 22A to 22D, 26, 27. ~ 33, 35, 36, 39, 41 to 43, 46, 47, pump 16B, etc. are controlled.

With reference to FIG. 8, the measurement operation of the washing water at the time of washing the pipelines 22A and 23A, the valve 39, and the mixing unit 12 will be described in detail. The arrows in FIG. 8 indicate the flow of wash water. As shown in FIG. 8 (A), the control device 60 controls the valves 31 and 34, performs the first control to drive the pump 16A in the forward rotation so as to suck air from the pipeline 22D, and performs the first control to drive the pump 16A in the forward rotation. The wash water is transferred from 11D to the pipeline 22D. When the forward rotation drive of the pump 16A is stopped based on the detection of the level of the wash water by the optical sensor 54, the level of the wash water is raised by the high-speed transfer of the wash water as shown in FIG. 8 (B). Since the state is separated from the optical sensor 54, the control device 60 uses the cleaning water in the conduit 22B as shown in FIG. 8C based on the detection of the cleaning water level by the optical sensor 54. In order to reduce the weight, the second control is performed in which the pump 16A is reversely driven at a lower speed than the first control, and the excess wash water is transferred from the pipeline 22D to the wash water storage unit 11D. Then, as shown in FIG. 8D, the control device 60 controls the valve 39 based on the fact that the optical sensor 54 detects the liquid level of the washing water again during the second control, and enters the pipeline 22D. The third control for reversely driving the pump 16A so as to send air is performed, and the washing water is transferred from the pipeline 22D to the mixing unit 12 via the pipelines 22A and 23A.

Further, in the TOC measuring device 1, instead of the operation in step S1, the control device 60 transfers the washing water from the washing water storage unit 11D to the pipeline 22D, and further, the cleaning water is transferred from the pipeline 22D to the mixing unit 12. By controlling the valve device 30 and the pump 16A so as to transfer the water, the pure water stored in the washing water storage unit 11D is used as the zero calibration solution to perform zero calibration. Further, the TOC measuring device 1 transfers the span calibration liquid from the span calibration liquid storage unit 11E to the mixing unit 12 instead of the operation in step S1 and performs the operations in steps S3 to S8 to perform span calibration. I do. The measurement operation of the span calibration liquid can be performed by controlling the valve 38 instead of the valve 37 in step S1.

In the above embodiment, the following effects can be obtained.
(1) Based on the detection result of the liquid to be measured (sample, acid solution, oxidizing agent solution, washing water, and span calibration liquid) by the sensor device 50, from the primary pipe (pipes 21A to 21E) to the measuring pipe. After the liquid to be measured is transferred to (pipes 22A to 22D), the excess liquid to be measured is discharged from the measuring pipe, and a predetermined amount of the liquid to be measured is discharged from the measuring pipe to the secondary pipe (pipeline 23A to 23A). Transferred to 23C). Therefore, even when the performance of the pump 16A fluctuates, the liquid to be measured can be automatically and accurately measured.

(2) Since the intermediate pipeline (pipeline 24) is provided with the bubble reducing portion 24A formed by enlarging the inner diameter of the intermediate pipeline, the liquid level of the liquid to be measured (sample and span calibration liquid) is provided. Can be adjusted, and the liquid to be measured can be measured more accurately.

(3) Since the secondary pipeline (pipeline 23A), the sample measuring pipeline (pipeline 22A), and the washing water measuring pipeline (pipeline 22D) are connected in series, the secondary pipeline (pipeline 22D) is connected to the secondary pipeline (pipeline 22D). The flow path to the pipeline and the flow path from the sample storage section to the secondary pipeline can be shared.

(4) The valve device 30 is a three-way solenoid valve in which the primary pipeline (pipeline 21B, 21C), the measuring pipeline (pipeline 22B, 22C), and the secondary pipeline (pipeline 23B, 23C) are connected. (Valves 35 and 36) are provided, so that the configuration of the valve device 30 can be simplified as compared with the case where the valve device 30 is composed of only the two-way solenoid valve.

The present invention is not limited to the above embodiment, and the above configuration can be changed. For example, the following changes can be made and implemented, or the following changes can be combined and implemented.

-The pump configuration may be changed as appropriate. That is, for example, pumps having different performances or uses from the pumps 16A and 16B may be further added, and the pumps 16A and 16B may be composed of one pump having those performances.

-The washing water may be used as dilution water for diluting the sample, the washing water storage portion 11D is used as the dilution water storage portion, the conduit 22D is used as the dilution water measuring conduit, and the optical sensor 54 is used as the dilution water sensor. May be used as. In this case, after step S1 and before step S2, the TOC measuring device 1 measures the diluted water and transfers the diluted aqueous solution to the mixing unit 12 (step S1.5). The operation of measuring the diluted water in step S1.5 is performed in the same manner as the operation of measuring the washing water described in the above embodiment. That is, the control device 60 controls the valves 31, 34, the pump 16A, and the like so as to transfer the diluted water from the wash water storage unit 11D to the pipeline 22D, and further, a predetermined amount of the diluted water is transferred from the pipeline 22D to the mixing unit 12. The valves 31, 39, pump 16A, etc. are controlled so as to transfer the diluted water.

-In step S1, the valve 46 is controlled so as to allow the flow of fluid between the pipeline 24 and the discharge pipe 19 without transferring the excess sample from the pipeline 22A to the sample storage portion 11A. Therefore, the excess sample may be transferred from the pipeline 22A to the discharge pipe 19.

-Pipe line 22A may be connected to valve 31. In this case, the wash water storage unit 11D, the pipeline 22D, the bulb 34, and the optical sensor 54 can be omitted.

1 Total organic carbon measuring device (water quality measuring device)
11A Sample storage section (storage section)
11B Acid solution storage unit (storage unit)
11C Oxidizing agent solution storage unit (storage unit)
11D Washing water storage unit (storage unit)
11E span calibration liquid storage unit (storage unit)
16A, 16B Pumps 21A-21E Pipeline (primary pipe line)
22A-22D pipeline (measuring pipeline)
23A-23C pipeline (secondary pipeline)
24 pipeline (intermediate pipeline)
24A Bubble reduction unit 25-27 Pipeline 31-39 Valve (valve device)
41-47 bulbs 51-54 optical sensor (sensor device)
60 Control device

Claims (7)

A storage unit that stores the liquid to be measured and
The primary pipeline connected to the storage section and
A measuring pipe for measuring the liquid to be measured and
The secondary pipeline through which the liquid to be measured flows after weighing, and
A pump that can be switched between a forward rotation drive that sucks air from the measuring line and a reverse drive that sends air to the measuring line.
A valve device that controls the flow of the liquid to be measured between the primary pipe and the measuring pipe and the flow of the liquid to be measured between the measuring pipe and the secondary pipe.
A sensor device that detects the liquid to be measured flowing in the measuring conduit, and
A control device for controlling the pump and the valve device based on the detection result of the liquid to be measured by the sensor device is provided.
The control device is
(1) To allow the flow of the liquid to be measured between the primary pipe and the measuring pipe and to limit the flow of the liquid to be measured between the measuring pipe and the secondary pipe. The first control that controls the valve device and drives the pump in the forward direction,
(2) A second control in which the pump is reversely driven at a lower speed than the first control based on the detection of the liquid level of the liquid to be measured by the sensor device during the first control.
(3) The flow of the liquid to be measured is restricted between the primary pipe and the measuring pipe based on the fact that the sensor device detects the liquid level of the liquid to be measured again during the second control. At the same time, the valve device is controlled so as to allow the flow of the liquid to be measured between the measuring pipe and the secondary pipe, and a third control for reversely driving the pump is performed. Liquid weighing device. An intermediate pipeline connecting the primary pipeline and the measuring pipeline is further provided.
The liquid measuring device according to claim 1, wherein the intermediate pipeline is provided with a bubble reducing portion formed by enlarging the inner diameter of the intermediate pipeline. As the storage unit, a sample storage unit that stores a sample containing organic carbon as the measurement liquid, an acid solution storage unit that stores an acid solution containing an acid as a solute, and an oxidizing agent as the solute. It is provided with an oxidant solution storage unit that stores the oxidant solution as the liquid to be measured.
As the primary pipeline, a sample primary pipeline connected to the sample storage unit, an acid solution primary pipeline connected to the acid solution storage unit, and an oxidant solution primary pipeline connected to the oxidant solution storage unit. Equipped with a pipeline,
The measuring line includes a sample measuring line for measuring the sample, an acid solution measuring line for measuring the acid solution, and an oxidant solution measuring line for measuring the oxidant solution. With
The sensor device includes a sample sensor that detects the sample flowing in the sample measuring tube, an acid solution sensor that detects the acid solution flowing in the acid solution measuring tube, and the oxidizing agent solution measuring tube. The liquid measuring apparatus according to claim 1 or 2, further comprising an oxidant solution sensor for detecting the oxidant solution flowing in the liquid. As the storage unit, a diluting water storage unit for storing the diluted water for diluting the sample as the liquid to be measured is provided.
As the primary pipeline, a diluted water primary pipeline connected to the diluted water storage unit is provided.
As the measuring pipe, a diluted water measuring pipe for measuring the diluted water is provided.
The liquid measuring device according to claim 3, wherein the sensor device includes a diluted water sensor that detects the diluted water flowing in the diluted water measuring pipeline. The liquid measuring device according to claim 4, wherein the secondary pipe, the sample measuring pipe, and the diluted water measuring pipe are connected in series. The valve device according to any one of claims 1 to 5, wherein the valve device includes a three-way solenoid valve in which the primary line, the measuring line, and the secondary line are connected. Liquid weighing device. A water quality measuring device including the liquid measuring device according to any one of claims 1 to 6.

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