KR102414181B1 - Total organic carbon analyzer - Google Patents

Abstract

A total organic carbon measuring device is provided. A total organic carbon measuring apparatus according to an aspect of the present invention includes: a first multi-channel valve for selectively providing an analysis sample and a reagent; an inorganic carbon removal unit for mixing the analysis sample and the reagent introduced from the first multi-channel valve, and removing inorganic carbon from the analysis sample and the reagent; an oxidation reaction unit oxidizing the analysis sample and reagent introduced from the inorganic carbon removal unit to generate carbon dioxide; a detector for measuring the carbon dioxide; and a switching valve disposed between the oxidation reaction unit and the detector and selectively communicating the high purity gas connection line and the oxidation reaction unit to selectively supply the carbon dioxide to the detector.

Description

Total organic carbon analyzer

The present invention relates to an apparatus for measuring total organic carbon of a high-temperature combustion oxidation method.

In the field of environmental management and process control, a total organic carbon (TOC) measuring device has been used to measure the amount of organic matter present in water. Various types of total organic carbon measuring devices have been developed depending on the method of oxidizing organic matter into carbon dioxide, such as high-temperature combustion oxidation method, ultraviolet (UV) oxidation method, wet oxidation method using an oxidizing agent with heat or ultraviolet light, ozone oxidation method, etc. come. In particular, compared to other methods, the total organic carbon measuring device of the high-temperature combustion oxidation method has the advantage of being able to oxidize even difficult-to-decompose organic substances and calculating the most accurate measurement values even from samples containing particulate matter.

The measuring step of the total organic carbon measuring device is generally 1) sample and reagent injection step; 2) removing inorganic carbon from the sample; 3) organic carbon oxidation step; 4) oxidized carbon dioxide (CO2) gas recovery step; 5) transferring the recovered carbon dioxide to a non-dispersive infrared (NDIR, Non-Dispersive Infra-Red) detector and detecting it, and then calculating total organic carbon; 6) It consists of sample discharging and washing steps.

In the case of the conventional high-temperature combustion oxidation type total organic carbon measuring device, it is composed of a sample and reagent injection unit, an inorganic carbon removal unit, a high-temperature oxidation reaction unit, a water trap, a detection unit, and an operation control unit to implement the above-mentioned measurement step. . In the conventional total organic carbon measuring device of the high-temperature combustion oxidation method, a carrier gas such as air or oxygen always passes from the oxidation reaction unit to the detection unit at a constant flow rate, and when the sample is injected into the high-temperature oxidation reaction unit, As the water turns into steam, explosive pulses are generated that change the flow rate. Since the oxidation reaction part is filled with catalyst, quartz wool, quartz beads, etc. in the combustion tube, whenever an explosive pulse occurs, a strong impact is given to the filling material to change the filling state or the catalyst It is broken and causes a change in the flow rate of the carrier gas. As water becomes steam in the combustion tube at a high temperature, the volume increases rapidly, so the pressure inside the combustion tube increases significantly. Vaporized steam passes through the catalyst bed at a very high speed and is discharged out of the combustion tube and condenses again in the water trap. will affect When the velocity of the carrier gas passing through the detector is changed, the shape of the peak of the detector is changed or the tail of the peak is lengthened, resulting in lowering the reproducibility and accuracy of the measurement. Therefore, it is necessary to improve the structure and function so that the measurement reproducibility and accuracy can be stably maintained no matter what changes occur inside the combustion tube of the high-temperature oxidation part during the operation of the total organic carbon measuring device.

The present invention provides an organic material in a gas sample ring tube in order to solve the problem that the flow rate of the carrier gas fluctuates due to the change in the state of the filling material in the combustion tube as water is changed to steam and an explosive pulse is generated whenever a sample is injected into the high-temperature oxidation unit. An object of the present invention is to provide a total organic carbon measuring device capable of maintaining the measurement reproducibility and accuracy of the total organic carbon measuring device by collecting the oxidized carbon dioxide and transferring it to the detection unit.

A total organic carbon measuring apparatus according to an aspect of the present invention for achieving the above object includes: a first multi-channel valve for selectively providing an analysis sample and a reagent; an inorganic carbon removal unit for mixing the analysis sample and the reagent introduced from the first multi-channel valve, and removing inorganic carbon from the analysis sample and the reagent; an oxidation reaction unit oxidizing the analysis sample and reagent introduced from the inorganic carbon removal unit at a high temperature to generate carbon dioxide; a detector for measuring the carbon dioxide; and a switching valve disposed between the oxidation reaction unit and the detector and selectively communicating the high purity gas connection line and the oxidation reaction unit to selectively supply the carbon dioxide to the detector.

In this embodiment, carbon dioxide generated in the high-temperature combustion oxidation reaction unit can be captured and quantitatively injected into the detector by using a gas sample ring tube connected to the switching valve, so It is possible to solve the problems of measurement reproducibility and accuracy.

1 is a block diagram of an apparatus for measuring total organic carbon according to an embodiment of the present invention;
2 is a graph of the peak shape obtained by the detector when the switching valve and the sample loop tube according to the prior art are not used;
3 is a graph of the peak shape obtained by the detector when carbon dioxide is collected and then transferred to the detector using the switching valve and the sample loop pipe according to the embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of the components may be selected between the embodiments. It can be used by combining or substituted with

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be generally understood by those of ordinary skill in the art to which the present invention belongs, unless specifically defined and described explicitly. It may be interpreted as a meaning, and generally used terms such as terms defined in advance may be interpreted in consideration of the contextual meaning of the related art.

In addition, the terminology used in the embodiments of the present invention is for describing the embodiments and is not intended to limit the present invention.

In the present specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when it is described as "at least one (or more than one) of A and (and) B, C", it is combined as A, B, C It may include one or more of all possible combinations.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only used to distinguish the component from other components, and are not limited to the essence, order, or order of the component by the term.

And, when it is described that a component is 'connected', 'coupled', or 'connected' to another component, the component is directly 'connected', 'coupled', or 'connected' to the other component. In addition to the case, it may include a case of 'connected', 'coupled', or 'connected' due to another element between the element and the other element.

In addition, when it is described as being formed or disposed on "above (above)" or "below (below)" of each component, "above (above)" or "below (below)" means that two components are directly connected to each other. It includes not only the case where they are in contact, but also the case where one or more other components are formed or disposed between two components. In addition, when expressed as "upper (upper)" or "lower (lower)", the meaning of not only an upper direction but also a lower direction based on one component may be included.

1 is a block diagram of an apparatus for measuring total organic carbon according to an embodiment of the present invention.

Referring to FIG. 1 , the apparatus for measuring total organic carbon according to an embodiment of the present invention includes a first multi-channel valve 20 , a metering pump 28 , an inorganic carbon removal unit 80 , and a second multi-channel valve 30 . ), syringe pump (10), oxidation reaction unit (60), water trap (70), switching valve (40), Peltier cooler (92), water storage unit (94), halogen scrubber (96), filter (97) , a detector 98 , a bubble detection sensor 22 , a mass flow controller (MFC) 52 , 54 , flow meters 55 , 58 , and solenoid valves 56 and 57 .

Each of the above-described components may be connected with a Teflon or stainless steel tube.

The first multi-channel valve 20 may introduce an analysis sample or reagent into the total organic carbon measuring device. The metering pump 28 may inject the analysis sample or reagent provided from the first multi-channel valve 20 into the inorganic carbon removal unit 80 .

The inorganic carbon removal unit 80 includes a glass tube, a mixer, a sample or reagent inlet, a gas inlet, and an inorganic carbon outlet, and after mixing phosphoric acid with the sample provided from the first multi-channel valve 20, aeration with zero air Thus, inorganic carbon can be removed. Inorganic carbon converted into carbon dioxide is discharged and removed through the inorganic carbon outlet. The inorganic carbon removal unit 80 may be disposed between the metering pump 28 and the second multi-channel valve 30 .

The second multi-channel valve 30 may provide an inorganic carbon removal sample to the inorganic carbon removal unit 80 , or may inject distilled water into the syringe pump 10 . To this end, the second multi-channel valve 30 may be connected to the inorganic carbon removal unit 80 and the syringe pump 10 . In addition, the second multi-channel valve 30 may be connected to the oxidation reaction unit 60 and the outlet.

The syringe pump 10 may be connected to the oxidation reaction unit 60 through the second multi-channel valve 30 . The syringe pump 10 may provide an inorganic carbon removal sample for the inorganic carbon removal to the oxidation reaction unit 60 .

The oxidation reaction unit 60 may use platinum or the like as a catalyst to oxidize a sample mixed with a reagent in a high-temperature environment. A combustion tube 61 made of quartz or ceramic is installed in the oxidation reaction unit 60 . A catalyst, quartz wool, quartz beads, and the like are filled in the combustion tube 61 . After the sample from which inorganic carbon is removed is injected into the combustion tube, the organic material is burned and oxidized at a high temperature to generate carbon dioxide, and the carbon dioxide concentration may be measured by the detection unit 98 to be described later.

The oxidation reaction unit 60 includes a heater for heating the combustion tube. The heater may provide a heat source of approximately 680 degrees or greater.

The water trap 70 cools and condenses the high-temperature steam before sending the carbon dioxide generated through high-temperature combustion oxidation in the oxidation reaction unit 60 to the detector 98 to separate the carbon dioxide from liquefied water to provide moisture. to remove

The switching valve 40 may include a sample loop pipe 42 . The switching valve 40 may be connected to the Peltier cooler 92 . The high-purity gas connection line 50a and the sample loop pipe 42 may be connected through the switching valve 40 . A high-purity gas for transporting carbon dioxide in the sample loop tube 42 and MFCs 52 and 54 may be connected. Accordingly, carbon dioxide can be transported at a constant flow rate. Carbon dioxide in the sample loop tube 42 may be provided to the Peltier cooler 92 .

The Peltier cooler 92 completely removes moisture from carbon dioxide generated after combustion and oxidation of the sample so that moisture does not flow into the detector 98 . The water storage unit 94 is connected to the Peltier cooler 92 and removes moisture contained in the transport gas through cooling in the Peltier cooler 92 .

The halogen scrubber 96 may be connected to the Peltier cooler 92 . The gas that has passed through the oxidation section contains halogen compounds, which are interfering substances that affect the detector. Halogen compounds are removed using pyrex, wool, copper, tin, or the like. To this end, the halogen scrubber 96 may remove halogen compounds in the gas provided from the Peltier cooler 92 .

The filter 97 may be disposed between the detector 98 and the halogen scrubber 96 to remove particulate matter and residual moisture. The filter 97 may include a porous membrane particle filter.

The detector 98 may measure the concentration of carbon dioxide that has passed through the filter 97 .

The bubble detection sensor 22 is disposed between the first multi-channel valve 20 and the metering pump 28 to detect whether the sample or reagent is normally injected.

The MFCs 52 and 54 control the flow rate of the high-purity gas so that the sample is injected into each component at an appropriate rate.

The MFCs 52 and 54 may include a first MFC 52 providing high-purity gas to the oxidation reaction unit 60 and a second MFC 54 providing high-purity gas to the switching valve 40 . have. Accordingly, the gas in the oxidation reaction unit 60 may be provided to the switching valve 40 , or carbon dioxide in the sample loop pipe connected to the switching valve 40 may be provided to the detector through the Peltier cooler 92 . have.

The flow meters 55 and 58 display the flow rate of carbon dioxide provided to the detector 98 and the flow rate of the inorganic carbon removal gas provided to the inorganic carbon removal unit 80 . , the solenoid valve 56 may be connected to the inorganic carbon removal unit 80 to supply or block high-purity gas.

Hereinafter, the operation of the total organic carbon measuring device will be described.

First, the first multi-channel valve 20 may operate to provide a sample and reagent for measurement to the inorganic carbon removal unit 80 through the metering pump 28 .

Next, a sample and a reagent for measurement may be mixed in the inorganic carbon removal unit 80 . At this time, the solenoid valve 58 is opened, so that the high-purity gas 50 may be injected into the inorganic carbon removal unit 80 . Accordingly, as the sample and the acid are mixed, the pH is lowered, and the inorganic carbon existing in the carbonate or bicarbonate state is changed to carbon dioxide, and the carbon dioxide gas that has become a gas by the aeration of the high-purity gas can be discharged through the inorganic carbon outlet.

In addition, the second multi-channel valve 30 may be operated to connect the inorganic carbon removal unit 80 and the second multi-channel valve 30 . Accordingly, the sample from which inorganic carbon has been removed in the inorganic carbon removal unit 80 may be moved to the syringe pump 10 . In addition, a predetermined amount of the sample in the syringe pump 10 may be repeatedly injected into the oxidation reaction unit 60 through the second multi-channel valve 30 .

Next, the switching valve 40 may be operated to connect the sample loop tube 42 . In this case, the high-purity gas may be provided to the oxidation reaction unit 60 through the first MFC 52 , and the high-purity gas may be provided to the detector 98 through the second MFC 54 . Meanwhile, the gas passing through the oxidation reaction unit 60 may be moved to the sample loop tube 42 through the water trap 70 .

Next, the operation of the first MFC 52 may be stopped, and the switching valve 40 may be operated to connect the high-purity gas connection line 50a and the sample loop pipe 42 . Accordingly, carbon dioxide in the sample loop tube 42 is provided to the detector 98 through the Peltier cooler 92, the halogen scrubber 96, and the filter 97, so that carbon dioxide is emitted through the detector 98. The carbon concentration can be measured.

When the measurement of the organic carbon concentration is completed, the operation of the second MFC 54 may be stopped, and the movement of the high-purity gas to the sample loop tube 42 may be stopped.

In addition, the first MFC 52 operates to provide high-purity gas to the oxidation reaction unit 60 , so that the oxidation reaction unit 60 may be cleaned.

The second multi-channel valve 30 opens a distilled water port through operation to provide distilled water to the syringe pump 10 , so that the syringe pump 10 can be washed. When washing in the syringe pump 10 is completed, the distilled water in the syringe pump 10 may be discharged through an outlet connected to the second multi-channel valve 30 .

The first multi-channel valve 20 opens the outlet, and the sample remaining in the inorganic carbon removal unit 80 may be discharged through the operation of the metering pump 28 . In addition, the first multi-channel valve 20 may provide distilled water to the inorganic carbon removal unit 80 through the metering pump 28 by opening a distilled water port. When the cleaning of the inorganic carbon removing unit 80 is completed with distilled water, the distilled water in the inorganic carbon removing unit 80 may be discharged through an outlet connected to the first multi-channel valve 20 .

According to the above configuration, carbon dioxide generated in the oxidation reaction unit can be collected and quantitatively injected into the detector in the sample loop pipe connected to the switching valve, so that even if a change in the flow rate of the gas passing through the oxidation reaction tank occurs, high measurement reproducibility and accuracy can keep

When the switching valve and the sample loop tube are not used as in the prior art, the peak shape obtained from the detector (FIG. 2) and the peak shape obtained from the detector when carbon dioxide is collected and transferred to the detector for measurement using the switching valve and the sample loop tube Comparing (FIG. 3), in the case of the conventional total organic carbon measuring device, the peak of the detector is asymmetrical and the tail is elongated, but when the switching valve and the sample loop tube are used, the peak of the detector is both based on the highest point. It can be seen that it appears in a symmetrical shape and the tail does not appear.

Through the above-mentioned structural improvement, it is possible to stably maintain the measurement reproducibility and accuracy even when the flow rate of the gas passing through the oxidation tank changes according to the change in the state of the filling material of the oxidation tank. In the case of an online total organic carbon measuring device that performs daily measurements, the reliability of the measurement data can be greatly improved.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can realize that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (10)

a first multi-channel valve for selectively providing an analyte sample and a reagent;
an inorganic carbon removal unit for mixing the analysis sample and the reagent introduced from the first multi-channel valve, and removing inorganic carbon from the analysis sample and the reagent;
an oxidation reaction unit oxidizing the analysis sample and reagent introduced from the inorganic carbon removal unit to generate carbon dioxide;
a second multi-channel valve disposed between the oxidation reaction unit and the inorganic carbon removal unit;
a syringe pump connected to the second multi-channel valve and quantitatively supplying the analysis sample and reagent provided from the inorganic carbon removal unit to the oxidation reaction unit;
a detector for measuring the carbon dioxide; and
a switching valve disposed between the oxidation reaction unit and the detector and selectively communicating the gas connection line and the oxidation reaction unit to selectively supply the carbon dioxide to the detector;
The oxidation reaction unit is a total organic carbon measuring device that oxidizes the analysis sample and reagent by providing a heat source through a heater.
delete The method of claim 1,
and a water trap disposed between the switching valve and the oxidation reaction unit to provide a quantitative amount of the carbon dioxide to the switching valve.
The method of claim 1,
A total organic carbon measuring apparatus including a first MFC for providing a gas to the oxidation reaction unit.
The method of claim 1,
and a Peltier cooler disposed between the detector and the switching valve to cool the carbon dioxide.
6. The method of claim 5,
and a halogen scrubber disposed between the Peltier cooler and the detector to remove halogen compounds in the carbon dioxide.
7. The method of claim 6,
A total organic carbon measuring device comprising a porous membrane particle filter disposed between the halogen scrubber and the detector.
delete The method of claim 1,
and a metering pump disposed between the inorganic carbon removal unit and the first multi-channel valve.
The method of claim 1,
The switching valve is a total organic carbon measuring device including a sample loop pipe for storing the carbon dioxide provided from the oxidation reaction unit.

Images