JP2011257381A - Thermal hydrolysis device and analysis system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal hydrolysis device capable of stably performing a thermal hydrolysis reaction of a sample while preventing water droplet consisting of steam condensate from attaching to a sample boat, and an analysis system using the same.SOLUTION: The present invention comprises: a combustion tube 23 to store a sample subject to thermal hydrolysis inside; a steam supply mechanism 22 to supply steam into the combustion tube 23; an inner pipe 211 which is connected to one end portion of the combustion tube 23 as well as to the steam supply mechanism 22 and has one or a plurality of through-holes 213 formed on a lateral peripheral wall thereof; and a steam introduction section 21 which forms a double pipe structure with the inner pipe 211 by placing the same inside the steam introduction section 21 and has an outer pipe 212 provided with a drain 214. A halogen element or other element which vaporizes at a low temperature equal to or less than 700 K contained in the sample is extracted into water.

Description

  The present invention relates to a thermal hydrolysis apparatus capable of stably performing a thermal hydrolysis reaction of a sample and an analysis system using the same.

  Conventionally, in order to quantify a halogen element contained in an inorganic substance or an organic substance, first, a halogen element is extracted into water by a thermal hydrolysis method (pyrohydrolysis), and then the obtained extracted water is used. Analysis by various known analysis methods is performed (Patent Document 1, Patent Document 2).

JP-A-6-308111 JP-A-2-92802

  For this reason, although water vapor is introduced into the combustion tube of the thermal hydrolysis apparatus, water droplets composed of condensed water generated by condensation of the water vapor are likely to be generated on the inner wall surface of the water vapor introduction portion.

  The step of inserting the sample boat on which the sample is placed into the combustion pipe is performed after the water vapor starts to be stably generated, but when water droplets generated on the inner wall surface of the water vapor introducing portion adhere to the sample boat, The water droplets are rapidly heated in the high-temperature combustion tube and vaporized explosively. As a result, the blown-off sample boat may collide, and the combustion tube may be damaged or the sample may be scattered.

  Therefore, the present invention is directed to a thermal hydrolysis apparatus capable of stably performing a thermal hydrolysis reaction of a sample by preventing water droplets made of condensed water of water vapor from adhering to the sample boat, and an analysis system using the same. Is intended to provide.

  That is, the thermal hydrolysis apparatus according to the present invention is connected to a combustion tube containing a sample to be thermally hydrolyzed inside, a steam supply mechanism for supplying steam into the combustion tube, and one end of the combustion tube. The water vapor supply mechanism is connected, and an inner tube having one or more through holes formed in a side peripheral wall thereof, and the inner tube is accommodated inside to constitute the inner tube and a double tube structure, And a water vapor introducing portion comprising an outer tube provided with a drain, and is characterized in that a halogen element contained in a sample or a low-temperature vaporized element vaporized at 700 K or less is extracted into water. Here, the low-temperature vaporizing element that vaporizes at 700 K or less is a metal element that melts at a low temperature of 700 K or less, and examples thereof include Hg, As, Cd, Pb, Sn, and Zn.

  In such a case, since the water vapor introducing portion has a double tube structure composed of an outer tube and an inner tube, the inner tube that does not directly contact the external air has a temperature outside the outer tube as compared with the outer tube. It is not easily affected, and the inside of the inner pipe communicates with the inside of the high-temperature combustion pipe, so that condensation does not easily occur on the inner pipe surface. Also, even if water droplets due to condensation occur on the inner peripheral surface of the inner tube, it flows out from the through hole formed in the side peripheral wall of the inner tube into the gap between the inner tube and the outer tube, and is provided in the outer tube. Since it is discharged from the drain to the outside, a large amount of water does not accumulate in the water vapor inlet. Therefore, when the sample boat on which the sample is placed is inserted into the combustion tube, water droplets generated on the inner wall surface of the water vapor introducing portion adhere to the sample boat, and the water droplets rapidly in the high temperature combustion tube. As a result, it is possible to satisfactorily prevent the combustion tube from being damaged or the sample from being scattered by the sample boat that has been heated and explosively vaporized and collides with the combustion tube wall.

  In addition, water droplets formed by condensation of water vapor adhere to a wide range on the inner wall surface of the water vapor introducing portion, so that the water vapor introducing portion is formed of a single tubular body, and the tubular body is simply provided with a drain. However, it is difficult to sufficiently prevent water from accumulating in the water vapor introducing portion.

  The sample to be provided to the thermal hydrolysis apparatus according to the present invention is not particularly limited, and may be an inorganic substance such as ceramics or an organic substance such as a biological sample, and may be a solid or a liquid. Also good. When the sample used for the thermal hydrolysis apparatus according to the present invention is a liquid, the sample placed on the sample boat is heated outside (for example, on a hot plate), and the residue obtained by evaporating the liquid is used as the sample. In addition, when the sample to be provided to the thermal hydrolysis apparatus according to the present invention is an organic substance, there is a temperature gradient between the center part and the end part of the combustion tube of the thermal hydrolysis apparatus, so the sample placed on the sample boat is heated. After placing it at a temperature suitable for decomposition, insert it into the center of the combustion tube.

  The water vapor supply mechanism and the water vapor introduction unit may be connected so that water vapor is directly introduced into the inner pipe from the water vapor supply mechanism, but the water vapor supply mechanism is connected to the outer pipe. Also good.

  If it is such, even if a part of the steam supplied from the steam supply mechanism to the gap between the outer tube and the inner tube is condensed on the inner peripheral surface of the outer tube, the other is the side wall of the inner tube From the through-hole formed in the inner pipe into the inner pipe. And the water droplet which arose on the inner peripheral surface of an outer tube | pipe is discharged | emitted outside from the drain provided in the outer tube | pipe. Also, water droplets generated on the outer peripheral surface are discharged to the outside from the drain provided in the outer tube.

  As a result of the study by the present inventors, it has been found that increasing the amount of steam supplied into the combustion tube improves the recovery rate of the target element such as halogen. However, if a large amount of water vapor is supplied, condensed water is likely to be generated up to the high temperature portion of the combustion tube. For this reason, when supplying a large amount of steam, it is preferable to keep the temperature between the steam supply mechanism and the vicinity of the upstream end of the combustion pipe at 100 ° C. or higher. On the other hand, the insertion port of the sample boat is preferably 100 ° C. or less in terms of safety. However, when water vapor is introduced into the water vapor introduction part cooled to 100 ° C. or lower, the water vapor is condensed on the inner wall surface to generate water droplets. If the sample boat is to be inserted into the combustion tube from the side of the water vapor introducing portion where water has accumulated, water tends to adhere to the sample boat when passing through the water vapor introducing portion. In addition, if the sample boat is to be inserted into the combustion tube from the water vapor introducing portion side, the flow of water vapor at about 100 ° C. is hindered by the sample boat, so that condensed water easily adheres to the sample boat at this time as well. When the sample boat to which water is attached is inserted into the combustion tube, explosive water vaporization occurs, and the combustion tube and the sample boat are easily damaged. For this reason, when the sample boat is inserted into the combustion tube from the water vapor introducing portion side, it is necessary to perform an operation for completely wiping the condensed water adhering to the water vapor introducing portion, which takes time. In addition, if the sample boat is temporarily retained near the upstream end in the combustion pipe and the condensed water adhering to the sample boat is gradually evaporated, depending on the sample, it may be vaporized, and decomposition products will remain in the water vapor inlet. Further, it takes more time to collect the stayed decomposition product with a downstream cooling pipe or the like.

  On the other hand, the temperature in the vicinity of the downstream end of the combustion tube into which water vapor that has passed through the center of the combustion tube at 1000 ° C. or higher flows also helps the heat conduction effect of the combustion tube, so that the upstream end of the combustion tube It is hotter than the vicinity. For this reason, condensed water hardly occurs in the vicinity of the downstream end portion of the combustion pipe.

  Therefore, if a boat insertion port for inserting a sample boat into the combustion tube is connected to the end of the combustion tube opposite to the side to which the water vapor introducing portion is connected, 1000 ° C. The sample boat can be inserted from the downstream side of the heated steam flow (as described above, it is difficult for condensed water to be generated in this region), and even temporarily on the surface of the sample boat. Even if a small amount of condensed water is generated, it immediately vaporizes and becomes water vapor, so that it is possible to satisfactorily prevent condensation from adhering to the sample boat. Further, if the sample boat can be inserted into the combustion tube from the side opposite to the side where the water vapor introducing section is connected in this way, a large amount of water vapor can be obtained without worrying about the generation of condensed water in the water vapor introducing section. Therefore, the thermal hydrolysis efficiency can be increased and the recovery rate of the target element can be improved.

  When the sample to be provided to the thermal hydrolysis apparatus according to the present invention is an organic substance, when the sample is burned using pure oxygen gas, an explosive combustion reaction occurs, and as a result, the blown off sample boat collides. The combustion tube may be damaged or the sample may be scattered. For this reason, a nitrogen gas supply source is also provided in addition to an oxygen gas supply source as a carrier gas supply source of water vapor, and oxygen gas and nitrogen gas are used in combination as carrier gases to gradually increase the oxygen gas concentration in the carrier gas. In this case, it is possible to prevent an explosive combustion reaction of the sample, which is preferable.

  In the present invention, the water from which the halogen element or the low temperature vaporizing element is extracted may be water vapor.

  An analysis system comprising such a thermal hydrolysis apparatus according to the present invention and a detector for detecting the halogen element or the low-temperature vaporized element in the obtained extracted water is also provided by the present invention. One.

The detector used in the analysis system according to the present invention is not particularly limited. For example, ions that selectively react with various halogen ions such as F ⁻ , Cl ⁻ , Br ⁻ , and I ⁻ and various ions of the low-temperature vaporization element. An electrode, an inductively coupled plasma emission spectrometer (ICP), an atomic absorption spectrometer (AAS), etc. can be mentioned. The ion electrode may be a composite type integrated with the reference electrode, or a monopolar type in which the reference electrode is a separate body.

  In the analysis system according to the present invention, when a flow hydrolysis analysis is performed by connecting a thermal hydrolysis apparatus and a detector through a flow path, and an ion electrode is used as the detector, the ion electrode is It is preferable that the extracted water is disposed at a position where the extracted water drops on the electrode surface through a flow path connected to the thermal hydrolysis apparatus with the electrode surface facing obliquely upward. If this is the case, a part of the electrode surface of the ion electrode and the liquid junction of the comparison electrode are immersed in the extraction water, and the electrical connection between the internal liquid of the comparison electrode and the extraction water, and the liquid junction Since the other part of the electrode surface is exposed on the surface of the extracted water and the extracted water can be dropped on the electrode surface one by one, ensuring electrical communication between the electrode and the electrode surface. Even when the amount of the extracted water is small, the concentration of a halogen element or the like can be measured for each very small amount of extracted water, and high-accuracy analysis is possible.

  Moreover, the time for which the solution containing the target element dropped on the electrode surface of the ion electrode is charged on the electrode surface is within a few seconds, and new extracted water is always in contact with the electrode surface. And since the electric potential turns into the electric potential of extraction water, a quick response is attained with respect to the density | concentration change of the extracted target element.

  Part of the electrode surface of the ion electrode and the liquid junction of the reference electrode are immersed in the extraction water, and the other part of the electrode surface is exposed on the surface of the extraction water, and the extraction water is dropped on the electrode surface. In order to make it possible, the electrode surface side end of the ion electrode is accommodated in an extracted water storage container capable of storing therein the extracted water dropped on the electrode surface. In addition, it is preferable that the container includes a discharge port that is formed so that when the extracted water in the container exceeds a predetermined amount of liquid, the excess extracted water flows out.

  In this case, the extracted water in which a part of the electrode surface of the ion electrode and the liquid junction of the comparative electrode are immersed in the container is a liquid mainly composed of a buffer solution in which the concentration of the target element has been measured. This is to ensure conductivity between the electrode surface of the ion electrode and the reference electrode.

  As described above, according to the present invention, it is possible to prevent the water droplets composed of the condensed water of water vapor from adhering to the sample boat and perform the thermal hydrolysis reaction of the sample stably.

1 is an overall configuration diagram of an analysis system according to a first embodiment of the present invention. The longitudinal cross-sectional view which shows typically the structure of the water vapor | steam introduction part in the embodiment. The whole block diagram of the analysis system concerning a 2nd embodiment of the present invention. The longitudinal cross-sectional view which shows typically the structure of the water vapor | steam introduction part in the embodiment. The whole block diagram of the analysis system concerning a 3rd embodiment of the present invention. The whole block diagram of the analysis system which concerns on other embodiment. The whole block diagram of the analysis system which concerns on other embodiment.

<First Embodiment>
A first embodiment of the present invention will be described below with reference to the drawings.

  The analysis system 1 according to this embodiment is for performing flow injection analysis for extracting halogen or low-temperature vaporized elements contained in a sample into water and detecting these elements contained in the obtained extracted water. As shown in FIG. 1, a thermal hydrolysis apparatus 2 for extracting halogen or low-temperature vaporized element into water and an ion electrode 3 for detecting halogen or low-temperature vaporized element in the obtained extracted water are provided.

Each part will be described below.
The thermal hydrolysis apparatus 2 includes, from the upstream side, a water vapor introduction part 21 to which a water vapor supply mechanism 22 is connected, a combustion pipe 23, and a cooling pipe 24.

  The water vapor introducing portion 21 is made of, for example, quartz or the like, and has a double tube structure including an inner tube 211 and an outer tube 212 that accommodates the inner tube 211 as shown in FIG. A plurality of through holes 213 having a diameter of about 1 mm, for example, are formed in the upper and lower portions of the side peripheral wall, while the steam supply pipe 222 of the steam supply mechanism 22 is connected to the lateral side of the outer pipe 212. In addition, a drain 214 is provided below the drain 214. In FIG. 2, in order to facilitate understanding of the structure of the water vapor introduction part 21, the connection position of the water vapor supply pipe 222, the installation position of the drain 214, and the formation position of the through-hole 213 are respectively introduced with water vapor. Although shown so as to coincide with each other in the axial direction of the portion 21, the positions in the axial direction do not necessarily have to coincide with each other. Further, the water vapor supply pipe 222 may be connected to the upper part of the outer pipe 212 of the water vapor introduction part 21. An S-shaped tube 215 is connected to the downstream side of the drain 214, and condensed water generated by condensation of water vapor contacting the inner peripheral surface of the outer tube 212 flows into the drain 214, and the S-shaped tube 215. Is returned to the water storage container 221 to be described later.

  The downstream end portion of the water vapor introducing portion 21 is connected to the combustion pipe 23, while the upstream end portion is closed by a cap 216 made of, for example, silicone. In order to insert the sample boat 232 into the combustion pipe 23, the sample boat 232 is inserted from the upstream end of the water vapor introducing portion 21 opened by removing the cap 216, and an insertion rod (not shown) is inserted. Is pushed into the combustion tube 23.

  A sample boat 232 insertion opening that can be opened and closed is formed in the upper portion of the combustion tube 23, and the sample boat 232 may be inserted into the combustion tube 23 from the insertion port.

  The water vapor supply mechanism 22 includes a water storage container 221 that contains water therein, and the water storage container 221 heats the water storage container 221 and a water vapor supply pipe 222 that communicates the water storage container 221 and the water vapor introduction unit 21. A steam heater 223 is provided. For example, a flask or the like is used as the water storage container 221, while a mantle heater or the like is used as the water heater 223, for example. The steam supply pipe 222 is connected to the outer pipe 212 of the steam introduction part 21 from the lateral direction, and when the water stored in the water storage container 221 is heated by the steam heater 223 to generate steam, the steam is Then, it is supplied to the water vapor introducing part 21 through the water vapor supply pipe 222. Note that when the amount of water in the water storage container 221 changes, the amount of water vapor generated also fluctuates, and the generation rate of extracted water also changes accordingly. However, as described above, the condensed water discharged from the drain 214 passes through the S-shaped tube 215. By being returned to the water storage container 221 via the change in the amount of water in the water storage container 221 can be mitigated, and as a result, fluctuations in the generation rate of the extracted water can be suppressed.

  In addition, an oxygen gas supply source 224 made of, for example, an oxygen cylinder or the like is connected to the water storage container 221 via an oxygen supply pipe 225, and water stored in the water storage container 221 is supplied from the oxygen gas supply source 224. The supplied oxygen functions as a carrier gas for water vapor. A pressure gauge 226 and a flow meter 227 are provided on the oxygen supply pipe 225, and the amount of oxygen gas supplied from the oxygen gas supply source 224 is adjusted by the pressure gauge 226 and the flow meter 227. . The downstream end of the S-shaped tube 215 is connected to the oxygen supply tube 225, but the condensed water accumulated in the S-shaped portion functions as a plug, so that oxygen gas flows into the drain 214. There is no.

  The combustion tube 23 is a tubular body made of alumina or quartz, for example, and its upstream end is fitted and connected to the downstream end of the water vapor introducing portion 21 so that the inside of the combustion tube 23 and the water vapor introducing portion 21 are connected. The pipe 211 is configured to communicate with the inside of the pipe 211, while the downstream end is connected to a cooler 24 described later. The connected body of the steam introduction part 21 and the combustion pipe 23 is inclined toward the downstream end part of the combustion pipe 23 with the upstream end of the steam introduction part 21 as the topmost part, and is introduced from the steam introduction part 21. The water vapor is configured to easily flow into the combustion pipe 23. Further, in the connecting portion between the steam introduction part 21 and the combustion pipe 23, a step is formed on the inner peripheral surface, and even if water droplets adhere to the inner peripheral surface of the inner pipe 211 of the steam introduction part 21, It is configured so that it does not easily flow into the combustion pipe 23. Around the combustion tube 23, there is provided a heating furnace 231 composed of an electric furnace or the like capable of raising the temperature in the combustion tube 23 to a predetermined temperature, for example, up to about 1200 ° C. 23 is made of, for example, nickel, platinum or the like, and a sample boat 232 for placing a sample thereon is inserted. The heating furnace 231 is provided with a temperature controller 233, whereby the temperature of the heating furnace 231 is adjusted.

  The combustion pipe 23 and the cooling pipe 24 are connected via a connecting pipe 25. The downstream end of the combustion pipe 23 is fitted into the upstream end of the connecting pipe 25, and the downstream end of the connecting pipe 25 is fitted into the upstream end of the cooling pipe 24. Also in the connection part, it is comprised so that water may not accumulate easily. The connecting pipe 25 is provided with a fan (not shown) for sending air from the side surface to cool the air and condense water vapor at a position facing the outer peripheral surface. Further, the connecting pipe 25 is formed with a small diameter in order to prevent water droplets adhering to the inner peripheral surface from remaining without flowing down.

  The cooling tube 24 is for cooling the water vapor containing the halogen or the low-temperature vaporized element extracted from the thermally hydrolyzed sample to obtain the extracted water to be supplied to the ion electrode 3. It consists of a flowing Graham condenser. In the present embodiment, the extracted water obtained by the cooling pipe 24 is collected by a graduated cylinder 26 with a cock, and then stored in a suction cup 27 provided therebelow, and a pump 29 such as a peristaltic pump is provided. It is supplied to the ion electrode 3 through the extracted water supply pipe 28 provided. In addition, a water level sensor can be attached to the female cylinder 26 with a cock, and an electric valve can be opened and closed by the function of the sensor. Furthermore, it is well known to measure the amount of extracted water with an electronic balance.

  The ion electrode 3 is of a composite type integrated with the reference electrode, and the electrode surface side end is a container capable of storing extracted water with the electrode surface 31 facing obliquely upward. It is inserted in the lower part of 33. An extraction water supply pipe 28 is connected to the upper part of the extraction water storage container 33, and the extraction water dropped from the extraction water supply pipe 28 falls on the electrode surface 31 of the ion electrode 3, and then the container 33 is stored. The extraction water storage container 33 further has a discharge port 331 formed at a predetermined position (predetermined height represented by the line AA ′), and the extraction water in the container 33 has a predetermined liquid amount (AA ′ line). Exceeding extracted water flows out from the discharge port 331 and exceeds a portion of the electrode surface 31 of the ion electrode 3 and the liquid junction 32 are always immersed in the extracted water, The other part of the electrode surface 31 is always exposed on the surface of the extracted water. If the entire electrode surface 31 is configured to be immersed in the extraction water, the halogen element or the like to be detected is diluted in the extraction water. It becomes difficult to detect elements and the like. Further, even when a small amount of a new extract is dropped on the electrode surface 31, it is affected by the ion concentration contained in the remaining liquid. Extracted water that flows out from the discharge port 331 of the extracted water storage container 33 flows into the waste liquid tank 4 via the discharge pipe 34 connected to the discharge port 331, is stored therein, and then is appropriately discarded.

  In addition, in order to add a reference liquid for adjusting the pH of the extracted water to a predetermined value, the reference liquid supply container 35 that stores the reference liquid is a pump including a peristaltic pump or the like. 37 is connected via a reference liquid supply pipe 36 provided. More specifically, the reference solution is a buffer solution containing ions such as halogen elements to be measured, and the conductivity between the ion electrode and the reference electrode is ensured with the buffer solution in order to increase the response speed. The sensitivity change due to the pH of the extract is reduced. The pump 37 provided in the reference liquid supply pipe 36 is controlled so as to operate in synchronization with the pump 29 provided in the extraction water supply pipe 28.

  In addition, an internal liquid supply container 38 containing the internal liquid is connected to the ion electrode 3 via an internal liquid supply pipe 39 in order to supply an internal liquid made of, for example, a KCl saturated solution. The internal liquid supply container 38 is disposed above the liquid junction 32 in the vertical direction. By providing the internal liquid supply container 38 at such a position, the ion electrode 3 is installed so that the electrode surface 31 and the liquid junction portion 32 face up, contrary to the normal use state. However, since the internal liquid is continuously supplied to the ion electrode 3, the outflow of the internal liquid from the liquid junction part 32 is not delayed, and the fluctuation of the liquid potential difference between the internal liquid and the extracted water can be suppressed satisfactorily. .

  The ion electrode 3 is further transmitted from the ion logger main body 5, the data logger or AD converter 6 for recording measurement data obtained by the ion meter main body 5 in time series, and the data logger or AD converter 6. An information processing apparatus 7 that performs arithmetic processing on the measurement data is connected.

Next, a procedure for measuring the concentration of fluorine element using CaF ₂ as a sample using the analysis system 1 configured as described above will be described. Here, as the ion electrode 3, a fluoride ion electrode 3 that selectively reacts with F ⁻ is used.

First, the combustion tube 23 is heated to about 1000 ° C. by the heating furnace 231, the water storage container 221 containing water is heated by the steam heater 223, water vapor is generated, and the water vapor is combined with oxygen gas to the combustion tube 23. Supply in. Next, the cap 216 fitted to the upstream end portion of the water vapor introducing portion 21 is removed, and a sample boat 232 on which a predetermined amount of CaF ₂ is placed is inserted and installed in the combustion tube 23.

The following reaction occurs in the combustion tube 23 in which the sample boat 232 is installed.
First, the water vapor supplied into the combustion tube 23 is thermally dissociated, thereby generating H ⁺ and OH ⁻ .
2H ₂ O → 2H ⁺ + 2OH ⁻
Next, thermal hydrolysis of CaF ₂ occurs with H ⁺ and OH ⁻ .
CaF ₂ + 2H ⁺ + 2OH ⁻ → Ca + 2HF + 2OH ⁻ → Ca (OH) ₂ + 2HF →
CaO + H ₂ O (g) ↑ + 2HF (g) ↑

Extracting water in which HF is dissolved can be obtained by cooling the water vapor mixed with HF with the cooling pipe 24. In the extracted water, HF is separated into F ⁻ and H ⁺ .

Then, the F ⁻ concentration in the extracted water obtained is measured by the ion electrode 3. Furthermore, by performing predetermined calculation processing by the information processing device 7 using the measured F ⁻ concentration, the total volume of the extracted water, and the mass data of the sample subjected to analysis, the fluorine element in the sample The concentration can be determined.

  Therefore, according to the analysis system 1 according to the present embodiment configured as described above, the water vapor introducing portion 21 has a double tube structure including the outer tube 212 and the inner tube 211, and thus is directly connected to the external air. The inner tube 211 that is not in contact is less susceptible to external temperature than the outer tube 212, and the inner tube 211 communicates with the high-temperature combustion tube 23, so that condensation is unlikely to occur on the surface of the inner tube 211. . For this reason, even if a part of the water vapor supplied from the water vapor supply mechanism 22 to the gap between the outer tube 212 and the inner tube 211 is condensed on the inner peripheral surface of the outer tube 212, the other is the side peripheral wall of the inner tube 211. From the through-hole 213 formed in the inner pipe 211 and into the combustion pipe 23. Then, water droplets generated on the inner peripheral surface of the outer tube 212 are discharged from the drain 214 provided in the outer tube 212 to the outside. Even if water droplets due to condensation occur on the side peripheral surface of the inner tube 211, the water droplets generated on the outer peripheral surface are discharged to the outside from the drain 214 provided in the outer tube. On the other hand, water droplets generated on the inner peripheral surface of the inner tube 211 flow out into the gap between the inner tube 211 and the outer tube 212 from the through hole 213 formed in the side peripheral wall of the inner tube 211, and similarly the outer tube 212. Since the water is discharged to the outside from the drain 214 provided on the inner pipe 211, even if water droplets are formed on the inner peripheral surface of the inner pipe 211 due to condensation, a large amount of water does not accumulate in the water vapor introducing portion 21. Therefore, when the sample boat 232 on which the sample is placed is inserted into the combustion tube 23, water droplets generated on the inner wall surface of the water vapor introducing portion 21 adhere to the sample boat 232, and the water droplets are hot. Rapidly heated and explosively vaporized in the combustion tube 23. As a result, the combustion tube 23 is prevented from being damaged or the sample is scattered by collision of the blown-off sample boat 232. can do.

  The ion electrode 3 is disposed at a position where the extracted water dropped from the extracted water supply pipe 28 falls on the electrode surface 31 with the electrode surface 31 facing obliquely upward, and the electrode surface of the ion electrode 3 The side end portion is accommodated in an extracted water storage container 33 that can store the extracted water dropped on the electrode surface 31, and the extracted water in the container 33 is a predetermined liquid. When the amount (the height of the line AA ′) is exceeded, the discharge port 331 is formed so that the excess extracted water flows out. For this reason, a part of the electrode surface 31 of the ion electrode 3 and the liquid junction 32 are immersed in the extraction water, and electrical communication between the internal liquid of the comparison electrode and the extraction water, and the liquid junction 32 and the electrode surface 31 are performed. The other part of the electrode surface 31 is exposed on the surface of the extracted water, and the extracted water can be dropped on the electrode surface 31 drop by drop.

  For this reason, even if the amount of sample is small and the amount of extracted water to be obtained is small, the concentration of a halogen element or the like can be measured for each very small amount of extracted water, and high-precision analysis becomes possible. . Further, the solution containing the target element such as halogen dropped on the electrode surface 31 of the ion electrode 3 stays on the electrode surface 31 within a few seconds, and new extracted water is always in contact with the electrode surface 31. And since the electric potential becomes the electric potential of extraction water, it becomes possible to respond promptly to the concentration change of the extracted target element.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to the drawings. In the following, differences from the first embodiment will be mainly described, and the same points as in the first embodiment will be omitted by using the same reference numerals in the drawings.

  In the analysis system 1 according to the present embodiment, as shown in FIG. 3, the water vapor supply pipe 222 passes through the cap 216 inserted in the upstream end of the water vapor introduction part 21 and directly the inner pipe 211 of the water vapor introduction part 21. The water vapor is inserted into the water vapor introducing portion 21 from the upstream end portion.

  Further, as shown in FIG. 4, a through hole 213 is formed in the lowermost portion of the side peripheral wall of the inner pipe 211 of the water vapor introducing portion 21.

  Further, a waste liquid tank 217 is provided on the downstream side of the drain 214, and condensed water generated by condensation of water vapor contacting the inner peripheral surface of the inner pipe 211 is connected to the inner pipe 211 from the through hole 213. The liquid flows into the gap with the outer pipe 212, is further discharged to the waste liquid tank 217 via the drain 214, is stored therein, and is appropriately discarded.

  Thus, in this embodiment, unlike the first embodiment, the condensed water discharged from the drain is discarded without returning to the water storage container 221, but for example, a large amount of the target element is contained in the sample, When the target element is rapidly generated as a gas in the combustion tube 23, the target element diffuses throughout the combustion tube 23, and a part of the target element may be taken into the condensed water and discharged from the drain 214. When the target element is taken into the condensed water discharged from the drain 214 in this way, when the condensed water is returned to the water storage container 221, water vapor contaminated with the target element is supplied into the combustion tube 23, and the sample Even when the target element is not contained therein, the target element in the water vapor is detected as a blank, and when the value is sequentially changed according to the number of analyzes, the uncertainty of the analysis value increases. Therefore, when a large amount of water vapor is supplied to improve the recovery rate of the target element, it is preferable not to reuse the discharged water from the drain 214 in order to prevent such contamination.

  Further, the oxygen supplied from the oxygen gas supply source 224 is directly supplied into the water vapor filled in the upper space of the water storage container 221. Instead of supplying oxygen to the water stored in the water storage container 221 as in the first embodiment, even if oxygen is supplied directly into the water vapor filled in the upper space of the water storage container 221 in this way, the supply The generated oxygen can function as a carrier gas for water vapor.

  Further, the connecting pipe 25 is formed in a substantially T-shape, and a branch pipe 25 a branched from the middle and extending downward is fitted into the upstream end of the cooling pipe 24, while the downstream end of the connecting pipe 25 is provided. The part 251 is closed by a cap 252 made of, for example, silicone. The cap 252 is provided with a through-hole into which an O-ring 254 is inserted, and an insertion rod 253 for pushing the sample boat 232 into the combustion tube 23 is inserted into the through-hole. In order to insert the sample boat 232 into the combustion tube 23, the downstream end 251 of the connection tube 25 opened by removing the cap 252 is used as an insertion port of the sample boat 232, and from here the sample boat 232 is inserted. After inserting 232, the downstream end 251 is sealed with the cap 252, and then the sample boat 232 is pushed into the combustion tube 23 using the insertion rod 253 provided on the cap 252.

  According to the analysis system 1 according to the present embodiment configured as described above, the water vapor supplied to the gap between the outer tube 212 and the inner tube 211 is provided on the side peripheral wall of the inner tube 211 as in the first embodiment. Since a large amount of water vapor can be efficiently introduced into the inner tube 211 of the water vapor introducing portion 21 as compared with the case where it is introduced into the inner tube 211 through the through-hole 213, the thermal hydrolysis efficiency is increased and the target element is increased. The recovery rate can be improved.

  Further, when the supply amount of water vapor is increased, condensation may easily occur on the inner peripheral surface of the inner tube 211, but if the through hole 213 is formed at the lowermost portion of the side peripheral wall of the inner tube 211, Even if water droplets due to condensation occur on the inner peripheral surface of the inner tube 211, the water droplets flow out of the through hole 213 into the gap between the inner tube 211 and the outer tube 212, and further, a drain provided in the outer tube 212. Since 214 is discharged to the outside, a large amount of water does not accumulate in the water vapor introducing portion 21.

  Furthermore, by inserting the sample boat 232 into the combustion tube 231 from the downstream end 251 of the connecting tube 25, there is a problem caused by water droplets adhering to the sample boat 232 when inserted into the combustion tube 23. Can be resolved. This is because the water vapor that has passed through the combustion pipe 23 heated to 1000 ° C. or higher does not become 100 ° C. or lower even if it is cooled in the connecting pipe 25 to some extent. is there. Further, with this configuration, when the sample boat 232 is inserted into the combustion tube 23, even if condensed water adheres to the inner peripheral surface or the like of the inner tube 211 of the water vapor introducing portion 21, this is wiped off. Since no work is required, the analysis time can be shortened.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to the drawings. In the following, differences from the first and second embodiments will be mainly described, and the same points as those in the first and second embodiments will be described by using the same reference numerals in the drawings. Is omitted.

  In the analysis system 1 according to the present embodiment, as shown in FIG. 5, an inductively coupled plasma emission spectrometer (ICP) 8 is used as a detector for detecting a target element such as halogen. An opening end portion of the branch tube 25b branched from the middle of the connecting tube 25 and extending upward is disposed so as to face the opening end portion of the sample introduction tube 811 of the plasma torch 81 having a substantially bowl-shaped cross section, for example. Yes.

  In the present embodiment, since the target element vaporized in water vapor is supplied to the inductively coupled plasma optical emission spectrometer (ICP) 8, unlike the first and second embodiments, a cooling pipe for obtaining extracted water 4 is not necessary.

<Other embodiments>
The present invention is not limited to the above embodiment.

  For example, the detector used in the present invention is not limited to the ion electrode 3 or the inductively coupled plasma emission spectrometer (ICP) 8, but may be an atomic absorption spectrometer (AAS) or the like, for example.

  When the sample to be analyzed is an organic substance, when it is burned using pure oxygen gas, an explosive combustion reaction occurs, the sample boat 232 collides, the combustion tube 23 is damaged, or the sample is scattered. There are things to do. Therefore, as shown in FIG. 6, a nitrogen gas supply source 228 is also provided together with the oxygen gas supply source 224, and oxygen gas and nitrogen gas are used in combination as carrier gases to gradually increase the oxygen gas concentration in the carrier gas. Therefore, it is preferable to prevent an explosive combustion reaction of the sample.

  In order to more effectively suppress the generation of water droplets due to condensation, the water vapor introducing portion 21 is provided with a heater that can heat the double pipe portion to 100 ° C. or more around the outer pipe 212. May be. Further, a heater capable of heating to 100 ° C. or more may be provided around the water vapor supply pipe 222. Keeping the water vapor supply pipe 222 and the water vapor introduction part 21 at 100 ° C. or higher in this way is particularly suitable for supplying a large amount of water vapor.

  In each of the above-described embodiments, the steam inlet 21, the combustion pipe 23, and the connection pipe 25 formed as separate bodies are connected and used. However, the steam introduction section 21, the combustion pipe 23, and the connection pipe 25 are integrated in advance. It may be formed.

  When the sample boat 232 is inserted into the combustion pipe 23 from the downstream side of the water vapor flow as in the second embodiment or the third embodiment, condensed water is generated on the inner peripheral surface of the inner pipe 211 of the water vapor introducing portion 21. However, since the condensed water adheres to the sample boat 232 and causes explosive vaporization in the combustion tube 23, the problem that the combustion tube 23 and the sample boat 232 are damaged does not occur. From a specific point of view, the water vapor introducing portion 21 does not have to have a double tube structure, and may be a single tube as shown in FIG.

  In addition, it is needless to say that the present invention may appropriately combine some or all of the above-described embodiments and modified embodiments, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Analytical system 2 ... Thermal hydrolysis apparatus 21 ... Steam introduction part 211 ... Inner pipe 212 ... Outer pipe 213 ... Through-hole 214 ... Drain 22 ... Steam supply Mechanism 23 ... Combustion tube 3 ... Ion electrode 8 ... Inductively coupled plasma optical emission spectrometer (ICP)

Claims (8)

A combustion tube containing a sample to be thermally hydrolyzed inside;
A steam supply mechanism for supplying steam into the combustion pipe;
Connected to one end of the combustion tube and connected to the water vapor supply mechanism, an inner tube having one or more through holes formed in a side peripheral wall thereof, and the inner tube accommodated therein A water vapor introducing part comprising an inner pipe and a double pipe structure, and comprising an outer pipe provided with a drain; and
A thermal hydrolysis apparatus, wherein a halogen element contained in a sample or a low-temperature vaporized element vaporized at 700K or less is extracted into water.   The thermal hydrolysis apparatus according to claim 1, wherein the water vapor supply mechanism is connected to the outer pipe.   The boat insertion port for inserting the boat for a sample in the said combustion pipe is continuously provided in the edge part on the opposite side to the side to which the said steam introduction part of the said combustion pipe is connected. Thermal hydrolysis equipment.   The thermal hydrolysis apparatus according to claim 1, 2 or 3, comprising an oxygen gas supply source and a nitrogen gas supply source as a carrier gas supply source of water vapor.   The thermal hydrolysis apparatus according to claim 1, 2, 3, or 4, wherein the water from which the halogen element or the low-temperature vaporizing element is extracted is water vapor. The thermal hydrolysis apparatus according to claim 1, 2, 3, 4 or 5,
And a detector for detecting the halogen element or the low-temperature vaporized element in the obtained extracted water. The detector is an ion electrode;
The ion electrode is disposed at a position where the extracted water drops on the electrode surface through a flow path connected to the thermal hydrolysis apparatus in a state where the electrode surface is obliquely upward. 6. The analysis system according to 6.   The electrode surface side end of the ion electrode is housed in an extracted water storage container capable of storing the extracted water dropped on the electrode surface, and the container is extracted in the container. The analysis system according to claim 7, further comprising a discharge port formed such that when the amount of water exceeds a predetermined amount, the excess extracted water flows out.