KR100798053B1 - Cod analyzer - Google Patents

Abstract

A water quality analyzing apparatus for analysis of COD(chemical oxygen demand) in water is provided to reduce the detection error and use amount of reagents and improve stability and accuracy of analysis by installing a channel portion for measuring samples and reagents accurately. A water quality analyzing apparatus for analysis of COD in water comprises: a plurality of reagent storage tanks(8a, 8b, 8c); a plurality of reagent detection devices(10a, 10b, 10c); a plurality of reagent introduction tubes(9a, 9b, 9c) for connecting the reagent storage tank with the reagent detection devices; air introduction tubes(46) connecting the reagent detection devices with an air tank(22) which is connected to a vacuum suction pump(AP1); and electronic suction valves(SV12, SV13, SV14) which are installed in the medium of air introduction tubes for control the introduction and detection of reagents.

Description

Water quality analyzer {COD ANALYZER}

1 is a schematic block diagram of a water quality analysis device for COD analysis according to an embodiment of the present invention;

2 is a block diagram of the inspection meter of FIG.

3 is a block diagram of the reagent meter of FIG.

4 is a measurement control flow chart of the present invention.

The present invention relates to a water quality measuring apparatus, and more particularly, to a water quality analyzing apparatus for analyzing chemical oxygen demand (COD) in water quality.

In recent years, along with the increase in demand for water resources, water pollution through industrial discharges and domestic discharges has become a major problem. Effluents such as sewage and wastewater discharged from factories, workplaces, and homes contain organic substances that are easily oxidized, which contaminates the water quality. Therefore, it is very important to continuously measure, monitor and supervise these organic substances in water.

Chemical oxygen demand (COD) in water quality is an indicator of the quality of contaminated water. When an aqueous solution oxidant such as potassium permanganate (KMnO ₄ ) or potassium dichromate (K ₂ Cr ₂ O ₇ ) is added to the water containing the organic substance, the organic substance is oxidized, and the amount of oxygen corresponding to the amount of the oxidant consumed is In mg / l or ppm is the chemical oxygen demand (COD).

Among these COD analysis methods, a COD analysis device using a chemical oxygen demand measurement method using potassium permanganate (KMnO ₄ ) has been developed in various forms, but the measurement results are often different depending on the internal environment or conditions of the device. For example, a malfunction may occur due to a complicated internal structure of the COD analyzer, and a measurement error may occur due to a change in the amount of the measurement liquid even when the measurement reagent is weighed. There are many disadvantages.

Accordingly, an object of the present invention is to provide a water quality analysis apparatus that implements a flow path portion to accurately measure a sample and a reagent in COD analysis of water quality to ensure the stability and reliability of the device.

In accordance with the above object, the present invention, in the water quality analysis apparatus for measuring the chemical oxygen demand, between a plurality of reagent reservoirs (8a) (8b) (8c) and reagent meters (10a) (10b) (10c) To each reagent introduction tube (9a) (9b) (9c), and the air introduction tube (46) connected to each of the plurality of reagent meter (10a) (10b) (10c) one vacuum suction pump (AP1) It is configured to be connected to the air tank 22 connected to the air inlet tube 46, the electromagnetic suction valve (SV12) (SV13) (SV14) is configured to be installed by vacuum suction pump (AP1) Each reagent stored in the reservoirs 8a, 8b, 8c is selectively introduced and metered into the corresponding reagent meters 10a, 10b, 10c.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted in the specification including the accompanying drawings.

1 is a schematic configuration diagram of a water quality analysis device for analyzing COD according to an embodiment of the present invention, which is an automatic measurement device based on a process test method using a COD measurement principle by potassium permanganate (KMnO ₄ ).

The water quality analysis device for COD analysis of FIG. 1 applied to the present invention collects a test sample at regular intervals, and dilutes, introduces, oxidizes, and titrates the test procedure according to a test procedure to provide a COD measurement value to a measurer. More specifically, the water quality analyzer for COD analysis adds a certain amount (10 ml) of potassium permanganate (KMnO ₄ ) to the collected water and heat-reacts it for a predetermined time (30 minutes) to oxidize the organic material in the water. COD is analyzed by calculating a detection value (mV) according to the redox potential corresponding to potassium permanganate consumed by a microprocess (not shown).

Water quality analysis apparatus according to an embodiment of the present invention implements a flow path portion to accurately measure the sample and reagent in the COD analysis of water quality. The flow path portion relates to the structure of the inspection-introducing rectifier tank 2 for introducing the inspection and the structure for introducing and metering the inspection sample and the reagent including the dilution water and the test liquid.

Inspection for COD analysis is configured to be always supplied to the inspection introduction rectifier (2) through the pump (P1). The inspection rectification tank 2 configures the reservoirs so that the introduced inspection flows in three steps in turn so that suspended matter and sediment are filtered out by the inspection rectification tank 2. The inspection introduction amount into the inspection introduction rectification tank 2 is set according to the installation conditions and adjusted to a value set through the plurality of valves BV1, BV2, and BV3. In the valves BV1, BV2, BV3, BV1 is an inlet valve installed in front of the primary reservoir, and BV2, BV3 are wastewater valves installed at the bottom of the primary and secondary reservoirs. The lower end of the inspection introduction tube 40 connected to the inspection meter 4 is configured to be underwater in the secondary reservoir.

The inspection introduced into the inspection introduction rectification tank 2 is introduced into the inspection meter 4 through the inspection introduction tube 40 provided with the solenoid valve SV6, and the dilution water and the test liquid are also inspected through the other tubes 42. Is introduced into the meter 4. The dilution water is hydraulically regulated via valve NV1 and introduced to check gauge 4 via solenoid valve SV8, and the test solution is required when zero setting or span drift is required. It is introduced to the inspection meter 4 through the solenoid valve SV9 (in the setting mode).

Reagent reservoirs (8a) (8b) (8c) store liquid sodium hydroxide (Na ₂ C ₂ O ₄ ), sulfuric acid (H ₂ SO ₄ ), and silver nitrate (AgNO ₃ ), which are the respective reagents. Among these reagents, sodium hydroxide (Na ₂ C ₂ O ₄ ) is the reducing agent, sulfuric acid (H ₂ SO ₄ ) and silver nitrate (AgNO ₃ ) are the oxidizing agents.

The first reagent reservoir 8a storing the sodium hydroxide (Na ₂ C ₂ O ₄ ) solution is connected to the first reagent meter 10a through the first reagent introduction tube 9a, and sulfuric acid (H ₂ SO ₄ ). The second reagent reservoir 8b for storing the liquid is connected to the second reagent meter 10b through the second reagent introduction tube 9b, and the third reagent reservoir 8c for storing the silver nitrate (AgNO ₃ ) solution is provided. The third reagent introduction tube 9c is connected to the third reagent meter 10c.

According to an embodiment of the present invention, the inspection introduction and metering into the inspection meter 4 and the reagent introduction and metering into the reagent meter 10a, 10b, 10c are performed by a vacuum suction pump AP1 connected to the air tank 22. It is made by vacuum suction.

One air tank 22 connected to the vacuum suction pump AP1 includes an air introduction tube 44 of the inspection meter 4 and an air introduction tube 46 of each of the plurality of reagent meters 10a, 10b, and 10c. Are connected to each air introduction tube (44, 46) is provided with each solenoid valve (SV12 ~ SV15).

Among the above-mentioned solenoid valves SV12 to SV15, the check suction solenoid valve SV12 is a valve which operates when the air is sucked to introduce the check, the dilution water, and the test water from the check introduction rectifier tank 2 to the check meter 4. When the inspection is introduced, it is interlocked with the solenoid valve SV6. In the solenoid valves (SV13 to SV15), 'SV13' is the sodium hydroxide intake solenoid valve, 'SV14' is the sulfuric acid intake solenoid valve, and 'SV15' is the nitric acid intake solenoid valve.

In the embodiment of the present invention by operating the vacuum suction using a single vacuum suction pump (AP1) and the air tank 22, the inspection introduction and metering to the check meter (4) and to the reagent meter (10a) (10b) (10c) Reagent introduction and metering are made accurately, and there is no metering deviation between each meter (4) (10a) (10b) (10c). In particular, the front end of the reagent meter (10a) (10b) (10c) to ensure that the reagent is accurately introduced without a separate valve can be within the error range of ± 5% of the meter reproducibility.

FIG. 2 is a specific configuration diagram of the inspection meter 4 of FIG. 1, and FIG. 3 is a specific configuration diagram of the reagent meters 10a, 10b and 10c of FIG. 1.

The metering in the check meter 4 of FIG. 2 and the reagent meter 8a, 8b, 8c of FIG. 3 is metered using the level electrode and atmospheric pressure by the levelers 50 and 52.

The inspection is introduced into the inspection meter 4 as shown in FIG. 2 and self-weighed and injected into the reactor 6 through the solenoid valve SV5, and the reagent is added to the corresponding reagent meter as shown in FIG. It is introduced into (8a), (8b) and (8c) and self-weighed, and it is inject | poured into the reaction tank 6 through each solenoid valve SV2 (SV3) and SV4 after that. The first reagent meter 8a is a meter of sodium hydroxide (Na ₂ C ₂ O ₄ ), the second reagent meter 8b is a meter of sulfuric acid (H ₂ SO ₄ ), and the third reagent meter 8c is a silver nitrate. It is a meter of (AgNO ₃ ).

Meanwhile, potassium permanganate (KMnO ₄ ) stored in the storage tank 14 is injected into the reaction tank 6 through the manganese introduction syringe pump 12 and the three-way solenoid valve SV1.

The reaction tank 6 contained in the oil bath 20 is reacted for 30 minutes while stirring by an indirect heating method by the silicone oil heated by the heater H, and the amount corresponding to the organic pollutants in the inspection is Potassium permanganate is consumed.

The symbol 'ORP (Oxidation Reduction Potential)' related to the reactor 6 is a redox potential sensor, TEMP1 is a temperature sensor of the reactor 6, and TMEP2 is a temperature sensor of the oil bath 20. The valve SV18 and the cooling tube CT1 connected to the air tank 22 operate for steam cooling during the heating reaction in the reactor 6. And the atmospheric release valve (SV17) connected to the air tank 22 is a valve for selectively sealing and opening the reaction tank (6) as necessary for the measurement process.

Injecting potassium permanganate (KMnO ₄ ) into the reactor (6) with a manganese-injected syringe pump (12), titrating excess sodium hydroxide to the electrode and displaying the COD concentration through arithmetic processing in a microprocessor (not shown). Done. The titration is performed by putting potassium permanganate (KMnO ₄ ) in the reactor 6 and automatically calculating potassium permanganate (KMnO ₄ ) consumed until the OPR sensor detects the end point.

 In FIG. 1, the valve 'SV7', which is not described, is a valve for discharging excess amount after dilution water measurement, and 'SV19 and SV20' are solenoid valves for discharging the measured waste liquid or washing water, and 'SV19' is always 'SV20' is used to drain only the measured waste liquid.

The pressure pump AP2 and the drainage air valve SV10 are pumps and valves for discharging the waste liquid and the washing liquid in the reaction tank 6 to the outside, and operate in conjunction with the solenoid valve SV19 (SV20) for discharging.

The measurement process in the COD analysis water quality analysis apparatus as described above is performed on a timely measurement every predetermined measurement time, it is measured through the same steps as the control flow chart as shown in FIG.

In the case of zero measurement or span drift, the test is carried out with the corresponding test solution instead of the inspection. If a certain amount of chlorine ions is present, the program is compensated. If chlorine ions are irregular, the silver nitrate measurement method is used. If the contamination is severe, it is washed with sodium hydroxide water.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, the present invention has the stability and reliability of the device and can automatically measure and analyze the COD.

Claims (3)

In the water quality analysis device for measuring the chemical oxygen demand, Connect a plurality of reagent reservoirs (8a) (8b) (8c) and reagent meters (10a) (10b) (10c) to each reagent introduction tube (9a) (9b) (9c), and The air induction tube 46 connected to each of the meters 10a, 10b, 10c is configured to be connected to the air tank 22 connected to the one vacuum suction pump AP1. Each of the reagents stored in the reagent reservoirs 8a, 8b, and 8c by the suction of the suction valves SV12, SV13, and SV14 is vacuum suctioned by the vacuum suction pump AP1. (10b) (10c) Water quality analysis device characterized in that it is selectively introduced and metered. The inspection introduction tube according to claim 1, further comprising a check introduction rectification tank (2) and a check gauge (4), wherein a solenoid valve (SV6) is provided between the check introduction rectification tank (2) and the check meter (4). (40), connecting the check gauge (4) and the air tank (22) by an air inlet tube (44) provided with an electromagnetic suction valve (SV12) to vacuum suction by the vacuum suction pump (AP1). Water quality analysis device characterized in that the inspection stored in the inspection rectification tank (2) is introduced and quantified. According to claim 2, wherein the check introduction rectification tank (2) constitutes the storage tank so that the introduced inspection flows in turn in three stages, and the inlet valve (front) of the primary storage tank of the check introduction rectification tank (2) BV1) is installed, and wastewater valves BV2 and BV3 are installed at the bottoms of the primary and secondary reservoirs, and in the secondary reservoir, the water inlet tube 40 is connected to the inspection meter 4. Water quality analysis device characterized in that the bottom is configured to be located.

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