Total organic carbon on-line analyzer
Through high-temperature and high-pressure digestion and ultraviolet catalytic oxidation, combined with multi-stage dilution and filtration, the system safety and detection accuracy issues of the total organic carbon automatic analyzer are solved, and efficient analysis and error elimination of low-concentration samples are achieved.
Patent Information
- Application Number
- CN202422119224.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-08-30
AI Technical Summary
Existing total organic carbon automatic analyzers require carrier gas, which makes the system bulky and unsafe, has a high detection limit, makes it difficult to analyze low-concentration samples, has a limited detection range, and cannot eliminate interference from the external environment on the optical system.
High temperature and high pressure digestion and ultraviolet catalytic oxidation are used instead of high temperature combustion, combined with multi-stage dilution and multi-stage filtration, and silicon thermopile detectors and reference sensors are used to eliminate system errors, and the optical path is increased through mirror reflection on the inner wall of the gas chamber.
It reduces the risk and operation and maintenance costs of the instrument, expands the detection range, improves the detection limit, eliminates systematic errors, and achieves accurate analysis of low-concentration samples.
Smart Images
Figure CN223400893U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automatic water quality monitoring, in particular to a total organic carbon online analyzer. Background Art
[0002] Total organic carbon (TOC) is a comprehensive indicator that characterizes the total amount of organic matter in water. Compared with chemical oxygen demand (COD), the measurement process causes less pollution and is not affected by chloride ions and other factors. Therefore, it has replaced the COD indicator in many application scenarios. The determination of TOC in water bodies is usually divided into two steps: the first step is to acidify the water sample to remove inorganic carbon; the second step is to oxidize the organic carbon in the water sample and convert it into carbon dioxide gas for detection, generally using a non-dispersive infrared (NDIR) sensor.
[0003] The main problems with the existing total organic carbon automatic analyzer when in use are as follows: 1. Carrier gas is required, which means that the instrument needs to be equipped with a gas cylinder, resulting in a large volume of the entire system, and bringing about safety issues in the use of gas cylinders and increased operation and maintenance costs; 2. The detection limit is high, which makes it difficult to meet the analysis needs of low-concentration total organic carbon; 3. The detection range is limited and cannot measure ultra-high concentration water samples; 4. Using single optical path detection, it is impossible to calculate real-time absorbance, and it is impossible to eliminate the interference of the external environment on the optical system and the drift of the optical system itself; for this reason, we propose a total organic carbon online analyzer to solve the above problems. Utility Model Content
[0004] The purpose of the present invention is to provide an online total organic carbon analyzer to solve the problems raised in the above background technology.
[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a total organic carbon online analyzer, comprising a metering system, an oxidation reaction system, a gas circuit system and a detection system, wherein the metering system comprises a sampling pump, a multi-way valve, a pipeline and a liquid detector;
[0006] The oxidation reaction system includes a reaction unit, which includes a quartz glass tank, a photocatalytic substance is provided in the quartz glass tank, an ultraviolet lamp is provided on the outside of the quartz glass tank, and high-pressure solenoid valves are fixedly installed at the upper and lower ends of the quartz glass tank. A first three-way valve is provided at the upper end of the reaction unit, and a second three-way valve is provided at the lower end of the reaction unit;
[0007] The air circuit system includes an air pump, a first filter is fixedly mounted on the end of the air pump, a second filter is fixedly mounted on the upper end of the first filter, an electronic flow meter is fixedly mounted on the lower end of the second filter, and the air circuit system also includes a third filter, a fourth filter is fixedly mounted on the top end of the third filter;
[0008] The detection system includes an air chamber, one end of which is provided with a light source, a detection sensor and a reference sensor are provided on the side of the air chamber away from the light source, and the input port of the air chamber and the lower end of the fourth filter are fixedly installed.
[0009] Preferably, the normally open end of the first three-way valve is connected to air, the normally closed end of the first three-way valve is connected to the third filter, and the common end of the first three-way valve is connected to the high-pressure solenoid valve at the upper end of the quartz glass tank.
[0010] Preferably, the normally open end of the second three-way valve is connected to the multi-way valve in the metering system, the normally closed end of the second three-way valve is connected to the electronic flow meter, and the common end of the second three-way valve is connected to the high-pressure solenoid valve at the lower end of the quartz glass tank.
[0011] Preferably, the first filter is filled with alkaline solution, with air entering from the bottom and exhausting from the top; the second filter is filled with alkaline dry matter, with air entering from the top and exhausting from the bottom; the third filter is filled with acidic solution, with air entering from the bottom and exhausting from the top; the fourth filter is filled with copper wire, with air entering from the top and exhausting from the bottom.
[0012] Preferably, the detection sensor and the reference sensor are both composed of a silicon thermopile detector and a bandpass filter, the detection sensor detects a wavelength of 4.3 μm, and the reference sensor detects a wavelength of 3.9 μm.
[0013] Preferably, the oxidation reaction system further comprises a fan for cooling, the outer surface of the quartz glass tank is wound with a resistance wire, and a temperature sensor is embedded in the quartz glass tank.
[0014] Compared with the prior art, the beneficial effects of the present invention are:
[0015] 1. High-temperature and high-pressure digestion and ultraviolet catalytic oxidation replace high-temperature combustion above 680°C, reducing the danger of instrument operation and the cost of oxidation devices. Multi-stage filtration of the air completely removes carbon dioxide from the air, eliminating the need for carrier gas to purge carbon dioxide.
[0016] 2. The total reflection of the infrared beam by the mirror material on the inner wall of the air chamber effectively increases the optical path without increasing the volume of the air chamber, making the instrument have a lower detection limit.
[0017] 3. The multi-stage dilution method can dilute high-concentration samples to lower concentrations for detection, expanding the detection range.
[0018] 4. The 4.3μm wavelength sensor provides a detection signal, and the 3.9μm wavelength sensor provides a reference signal, which can eliminate the interference of the external environment on the optical system and the system error caused by the drift of the optical system itself. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0020] Figure 1 This is a schematic diagram of the structure of the utility model.
[0021] In the figure: 1. Metering system; 2. Reaction unit; 3. Quartz glass tank; 4. Photocatalytic substance; 5. Ultraviolet lamp; 6. First three-way valve; 7. Second three-way valve; 8. Air pump; 9. First filter; 10. Second filter; 11. Electronic flow meter; 12. Third filter; 13. Fourth filter; 14. Gas chamber; 15. Light source; 16. Detection sensor; 17. Reference sensor. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0023] Example: Figure 1 As shown, the utility model provides a total organic carbon online analyzer, including a metering system 1, an oxidation reaction system, a gas circuit system and a detection system. The metering system 1 includes a sampling pump, a multi-way valve, a pipeline, and a liquid detector;
[0024] The sampling pump is a syringe pump, a plunger pump, a piston pump, etc.; the pipeline is corrosion-resistant and high-temperature resistant pipeline; the liquid detector is an optical sensor, a capacitance sensor, etc., which can detect whether the sample or reagent is drawn;
[0025] The oxidation reaction system includes a reaction unit 2, which includes a quartz glass tank 3. The quartz glass tank 3 contains a photocatalytic substance 4, which is made of platinum and titanium as main active components. An ultraviolet lamp 5 is provided on the outside of the quartz glass tank 3. The ultraviolet lamp 5 can emit ultraviolet light with a wavelength lower than 185nm, which passes through the quartz glass tank 3 and acts on the liquid inside. High-pressure solenoid valves are fixedly installed at the upper and lower ends of the quartz glass tank 3. The high-pressure solenoid valves are mainly used to create a high-pressure environment during the oxidation reaction process. A first three-way valve 6 is provided at the upper end of the reaction unit 2, and a second three-way valve 7 is provided at the lower end of the reaction unit 2.
[0026] The oxidation reaction system also includes a fan for cooling. The outer surface of the quartz glass tank 3 is wrapped with a resistance wire. A temperature sensor is embedded in the quartz glass tank 3. The heating temperature is controlled by a PID algorithm.
[0027] Metering system 1 can perform multi-stage dilution to dilute high-concentration water samples to the basic range. The steps are as follows:
[0028] S1, the sampling pump extracts a certain amount of water sample through the multi-way valve and injects it into the quartz glass tank 3, then extracts a certain amount of pure water and injects it into the quartz glass tank 3; then extracts a certain amount of air and injects it into the quartz glass tank 3, and mixes the water sample and pure water through bubbles;
[0029] S2. The sampling pump extracts the mixed first dilution liquid from the quartz glass tank 3 through the multi-way valve and discharges it into the dilution pipeline connected to the multi-way valve for temporary storage; then the sampling pump extracts pure water to clean the quartz glass tank 3.
[0030] S3. The sampling pump extracts a certain amount of the first dilution liquid from the dilution pipeline through the multi-way valve and injects it into the quartz glass tank 3. Then, it extracts a certain amount of pure water and injects it into the quartz glass tank 3. Then, it extracts a certain amount of air and injects it into the quartz glass tank 3. The water sample and pure water are mixed by bubbles to complete the second dilution.
[0031] S4. Repeat steps S2 and S3 to continue diluting until the total organic carbon concentration in the water sample is diluted to within the measuring range.
[0032] The air circuit system includes an air pump 8, a first filter 9 is fixedly mounted on the end of the air pump 8, a second filter 10 is fixedly mounted on the upper end of the first filter 9, an electronic flow meter 11 is fixedly mounted on the lower end of the second filter 10, and the air circuit system also includes a third filter 12, a fourth filter 13 is fixedly mounted on the top end of the third filter 12;
[0033] The electronic flow meter 11 can be linked to control the air pump 8 to keep the gas flow constant;
[0034] The detection system includes an air chamber 14, a light source 15 is provided at one end of the air chamber 14, a detection sensor 16 and a reference sensor 17 are provided on the side of the air chamber 14 away from the light source 15, and the input port of the air chamber 14 and the lower end of the fourth filter 13 are fixedly installed;
[0035] The inner wall material of the air chamber 14 is high-purity silicon dioxide, which provides a light reflection surface; the outer wall material of the air chamber 14 is metal or plastic, which provides a light isolation surface and external protection;
[0036] The infrared light beam emitted by the light source 15 enters the gas chamber 14 at a certain inclination angle, is reflected multiple times in the gas chamber 14, and reaches the detection sensor 16 and the reference sensor 17. The light signal is converted into a current signal, and is processed by the signal amplifier to convert it into a suitable detection signal voltage signal and reference signal voltage signal for calculating the total organic carbon concentration.
[0037] The normally open end of the first three-way valve 6 is connected to the air, the normally closed end of the first three-way valve 6 is connected to the third filter 12 , and the common end of the first three-way valve 6 is connected to the high-pressure solenoid valve at the upper end of the quartz glass tank 3 .
[0038] The normally open end of the second three-way valve 7 is connected to the multi-way valve in the metering system 1, the normally closed end of the second three-way valve 7 is connected to the electronic flowmeter 11, and the common end of the second three-way valve 7 is connected to the high-pressure solenoid valve at the lower end of the quartz glass tank 3.
[0039] The first filter 9 is filled with alkaline solution, with air entering from the bottom and exhausting from the top; the second filter 10 is filled with alkaline dry matter, with air entering from the top and exhausting from the bottom; the third filter 12 is filled with acidic solution, with air entering from the bottom and exhausting from the top; the fourth filter 13 is filled with copper wire, with air entering from the top and exhausting from the bottom.
[0040] The detection sensor 16 and the reference sensor 17 are both composed of a silicon thermopile detector and a bandpass filter. The detection sensor 16 detects a wavelength of 4.3 μm, and the reference sensor 17 detects a wavelength of 3.9 μm.
[0041] The oxidation reaction steps of the gas system and the oxidation reaction system are as follows:
[0042] S1. Open the upper and lower high-pressure solenoid valves of the quartz glass tank 3, add the water sample to the quartz glass tank 3 through the metering system 1, and then add the acid reagent; open the second three-way valve 7 and the air pump 8, so that the air passes through the first filter 9 and the second filter 10 to absorb carbon dioxide, and then enters the quartz glass tank 3 after the flow is adjusted by the electronic flow meter 11, and the inorganic carbon in the water sample is blown off into the air;
[0043] S2. Turn off the air pump 8 and the second three-way valve 7, add the oxidant to the quartz glass tank 3 through the metering system 1, and close the upper and lower high-pressure solenoid valves of the quartz glass tank 3. Heat the mixed liquid through the resistance wire wrapped around the outer surface of the quartz glass tank 3. At the same time, turn on the ultraviolet lamp 5. Through the combined action of heating and ultraviolet light catalysis, all organic carbon in the water sample is converted into carbon dioxide. After the oxidation is completed, the liquid in the quartz glass tank 3 is cooled to below 60°C by a fan;
[0044] S3. Open the first three-way valve 6, the second three-way valve 7 and the air pump 8, so that the air passes through the first filter 9 and the second filter 10 to absorb carbon dioxide, and the carbon dioxide generated by the oxidation of organic matter is cooled and dehydrated through the third filter 12, and then passes through the fourth filter 13 to absorb chlorine and other oxidizing halogen gases before entering the detection system.
[0045] The oxidant is a mixture of ferrate and sulfuric acid.
[0046] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A total organic carbon online analyzer comprising a metering system (1), an oxidation reaction system, a gas path system, and a detection system, characterized in that: The metering system (1) includes a sampling pump, a multi-way valve, a pipeline, and a liquid detector; The oxidation reaction system comprises a reaction unit (2), the reaction unit (2) comprises a quartz glass tank (3), a photocatalytic substance (4) is provided in the quartz glass tank (3), an ultraviolet lamp (5) is provided on the outside of the quartz glass tank (3), high-pressure electromagnetic valves are fixedly installed at the upper and lower ends of the quartz glass tank (3), a first three-way valve (6) is provided at the upper end of the reaction unit (2), and a second three-way valve (7) is provided at the lower end of the reaction unit (2); The air circuit system comprises an air pump (8), a first filter (9) is fixedly mounted on the end of the air pump (8), a second filter (10) is fixedly mounted on the upper end of the first filter (9), an electronic flow meter (11) is fixedly mounted on the lower end of the second filter (10), and the air circuit system further comprises a third filter (12), a fourth filter (13) is fixedly mounted on the top end of the third filter (12); The detection system comprises an air chamber (14), a light source (15) is provided at one end of the air chamber (14), a detection sensor (16) and a reference sensor (17) are provided on a side of the air chamber (14) away from the light source (15), and an input port of the air chamber (14) and a lower end of a fourth filter (13) are fixedly mounted.
2. The total organic carbon online analyzer according to claim 1, characterized in that: The normally open end of the first three-way valve (6) is connected to air, the normally closed end of the first three-way valve (6) is connected to a third filter (12), and the common end of the first three-way valve (6) is connected to a high-pressure solenoid valve at the upper end of the quartz glass tank (3).
3. The total organic carbon online analyzer according to claim 1, characterized in that: The normally open end of the second three-way valve (7) is connected to the multi-way valve in the metering system (1), the normally closed end of the second three-way valve (7) is connected to the electronic flow meter (11), and the common end of the second three-way valve (7) is connected to the high-pressure solenoid valve at the lower end of the quartz glass tank (3).
4. The total organic carbon online analyzer according to claim 1, characterized in that: The first filter (9) is filled with an alkaline solution, with air entering from the bottom and exhausting from the top; the second filter (10) is filled with an alkaline dry substance, with air entering from the top and exhausting from the bottom; the third filter (12) is filled with an acidic solution, with air entering from the bottom and exhausting from the top; the fourth filter (13) is filled with a copper wire, with air entering from the top and exhausting from the bottom.
5. The total organic carbon online analyzer according to claim 1, characterized in that: The detection sensor (16) and the reference sensor (17) are both composed of a silicon thermopile detector and a bandpass filter. The detection sensor (16) detects a 4.3 μm wavelength, and the reference sensor (17) detects a 3.9 μm wavelength.
6. The total organic carbon online analyzer according to claim 1, characterized in that: The oxidation reaction system also includes a fan for cooling.
7. The total organic carbon online analyzer according to claim 1, characterized in that: The outer surface of the quartz glass tank (3) is wound with a resistance wire, and a temperature sensor is embedded in the quartz glass tank (3).