【０００１】
【発明の属する技術分野】
この発明は、水の超臨界状態の水熱反応処理装置での水熱反応容器内の圧力を検出する圧力検出管の閉塞防止方法に関する。
【０００２】
【従来の技術】
３７４℃以上、２２．１ＭＰａ（２２０気圧）以上の超臨界状態で被処理物と、酸化剤を含んだ水とを反応させることにより水熱反応を生じさせ、被処理物中の有機物を短時間でほぼ完全に分解する水熱反応処理を行う際に、水熱反応の温度を、熱電対を使用して検出、制御しようとしても、被処理物に含まれている無機成分から種々な塩が生成され、これらの塩が金属の表面に付着し、高温であること、酸素が充分に存在することの相乗効果により金属を腐食させ、熱電対による温度計測を不可能にする。
【０００３】
【発明が解決しようとする課題】
このため、本特許出願人は、先願の特願２００２−１９７４９７号によって、熱電対をシース管で覆ったシース熱電対を保護管に収容し、この保護管に種々な改良を加え、水熱反応容器内の温度を熱電対で検出し、水熱反応の温度を制御可能にすることを提案した。この水熱反応を、より安全に制御し、安定して行うには水熱反応容器の内部の圧力を測定し、圧力を制御することが必要である。そのため、圧力計を取付けた圧力検出管を水熱反応容器の内部に突入させると、同様な理由で圧力検出管に塩が付着し、その塩が容器の内部に突入した圧力検出管の端部を閉塞し、水熱反応容器の内部の圧力の測定、その測定による水熱反応容器内の圧力制御を行うことを不可能にする。
【０００４】
【課題を解決するための手段】
この発明は上述した課題を解消するために開発されたもので、水の超臨界状態での水熱反応により分解を行う水熱反応容器の内部に、圧力計を取付けた圧力検出管を突入し、上記水熱反応容器の内部の圧力を計測する水熱反応処理装置での圧力検出管の閉塞防止方法として、請求項１の発明は上記水熱反応容器の内部下方に冷却水を注入して亜臨界水領域を形成し、上記圧力検出管の水熱反応容器内に突入した端部を亜臨界水領域に位置させることを特徴とし、請求項２の発明は、上記圧力検出管に、反応容器内の圧力以上の高圧流体の供給管を接続し、上記高圧流体を水熱反応容器内に突入した圧力検出管の端部から器内に吹き込むことを特徴とする。又、請求項３の発明は、上記圧力検出管を、水熱反応容器の内周沿いに旋回して内周に付着した析出固形物を剥離するスクレーパに対応して設けられたスクレーパ・バーと兼用させることを特徴とする。
【０００５】
【発明の実施の形態】
図示の各実施例において、１０は上壁１１と、漏斗形の下部１２とを有する上下方向に細長い円筒形の水熱反応容器で、上壁の中心には廃液等の被処理物や、水その他の必要な材料を器内に供給するノズル１４が設けてある。
【０００６】
図示の各実施例では、装置の全体の系統は図１（Ｂ）、図２（Ｂ）に示したように廃液などの被処理物と、反応助剤と、水とを夫々高圧ポンプＰで供給管１３に注入するほか、酸化剤として空気をエアコンプレッサから予熱器を通して供給管１３に注入し、これらをノズル１４から水熱反応容器の内部に混合して供給する。
【０００７】
廃液などの被処理物を除いて上記した原料を水熱反応容器に供給して器内に水熱反応を生じさせ、器内が所定の温度に上昇して超臨界状態になったら、廃液などの被処理物を器内に供給する。これにより固体を含む反応液が漏斗形の下部１２の下端の排出管１２′から冷却器１７を経て気液分離器１８に供給され、減圧弁Ｖを経て気体と、固体を含む液体とに分離して排出される。
【０００８】
このようにして被処理物を酸化剤と共に水熱反応容器１０内で水熱反応させたとき、被処理物が、例えば塩素を含有する有機性廃液であると、有機性廃液は水熱反応により、水、二酸化炭素、塩化水素の高温高圧流体、乾燥またはスラリー状の灰分や塩類等の固体からなる反応生成物が得られる。この際、塩化水素は塩化水素ガスとして存在するため、それほど腐食性を持たないが、水に溶けることにより塩酸となり、激しい腐食環境を形成するので注入した水、或いは水に添加した中和剤で中和する。
【０００９】
上記のようにして水熱反応処理を継続すると、前述したように被処理物に含まれる無機成分から種々の塩が生成される。そして、これらの塩は、金属の表面に付着し、高温であること、酸素が充分に存在することの相乗効果により、多くの場合、金属を腐食させる。
【００１０】
従って、水熱反応容器１０内の圧力を制御するため、上端に圧力計２０を取付けた圧力検出管２１を上壁から水熱反応容器１０内に突入し、その下端２１′が超臨界水領域中に位置していると、管２１の回りには析出した固形物が付着すると同時に、析出した固形物が管の下端を次第に塞ぐので水熱反応容器１０内の圧力を圧力計２０は示さなくなる。
【００１１】
このため、図１の請求項１の実施例では、漏斗形の下部１２の内部の直上に冷却水を冷却管１５で供給し、これにより器内の冷却管１５のレベルの直上に冷却流体水準１６を形成し、冷却流体水準から上の上壁１１までの間の超臨界水領域の下に亜臨界水領域を形成し、圧力検出管２１の下端２１′を亜臨界水領域中に位置させてある。従って、圧力検出管の超臨界水領域を貫通している部分の回りには析出した固形物が付着するが、その下端２１′は亜臨界水領域中に位置し、析出した固形物は溶解するので圧力検出管の下端２１′は閉塞されない。従って、圧力計２０によって水熱反応容器１０内の圧力を正確に知ることが可能なため、水熱反応の圧力を最適に制御することができる。
【００１２】
図２の請求項２の実施例、図３の請求項３の実施例では、水熱反応容器の内部全体は超臨界水領域であり、圧力計２０を上端に取付けた圧力検出管２１の下端２１′は超臨界水領域中に位置する。
【００１３】
このため、圧力検出管の下端２１′が析出した固形物で閉塞されるのを防ぐため、請求項２の実施例では、図２（Ｂ）に示したようにエアコンプレッサで供給管１３に注入される空気の一部を分岐管２２で分岐し、圧力検出管２１に注入するようにしてある。従って、圧力検出管２１の内部には空気が圧力検出管の下端２１′から水熱反応容器内に噴出するため、同様に水熱反応容器内の析出した固形物は圧力検出管の下端２１′を閉塞しない。さらに、分岐管２２に加熱管２３を設置し、加熱した高温空気を圧力検出管の下端２１′から噴出するとより効果的である。従って、この場合も水熱反応容器の内部の圧力を圧力計２０で正確に知ることができるため、水熱反応の圧力を最適に制御できる。
【００１４】
図２の実施例では水の臨界温度よりも高温に加熱した空気を圧力検出管２１に注入したが、空気に限らず、水など他の同様な高温の流体を注入してもよい。
【００１５】
水熱反応容器１０の内壁には析出した固形物が固着するので、通常は漏斗形の下端部にＹ字形断面のスクレーパ１９の下端部の軸を取付け、モータＭなどで回転させ、スクレーパで水熱反応容器１０の内壁に付着する固形物を剥脱除去する。そして、スクレーパ１９の内壁には除去した固形物の一部が付着するので、これを除去するため、固定したスクレーパ・バーを１本ないし複数本、スクレーパの内壁側に軸方向にスクレーパに対応した位置で接触させてある。
【００１６】
図３の請求項３の実施例ではスクレーパ・バー２４の１本を中空な圧力検出管２１にし、容器から外に突出した上端に圧力計２０を取付け、このスクレーパ・バー２４を圧力検出管と兼用させてある。スクレーパ・バーと圧力検出管とを兼用することにより、圧力検出管に付着する固形物がスクレーパで剥脱除去され、下端２１′が閉塞しにくくなる。更に、図１の実施例と同様に水熱反応容器の内部下方に冷却水を冷却管１５で供給し、これにより冷却管１５のレベルの直上に冷却流体水準１６を形成し、この冷却流体水準から下を亜臨界水領域にすると、ここでは前述したように、析出した固形物が溶解するので、スクレーパ兼用圧力検出管の下端２１′をこの亜臨界水領域に位置させておくと、下端２１′の閉塞をより確実に防止できて好ましい。従って、このスクレーパ・バー兼圧力検出管の下端は、析出した固形物で塞がれないため、水熱反応容器内の圧力を圧力計２０で検出することができる。またスクレーパ・バーと圧力検出管とを兼用することで反応容器内部の構造物を少なくできるため、反応容器内で析出した固形物の付着を軽減できる。
【００１７】
【発明の効果】
以上で明らかなように、本発明よれば水熱反応容器の内部の圧力を圧力計によって正確に知ることができるため、器内での水熱反応の圧力を最適に制御できる。
【図面の簡単な説明】
【図１】（Ａ）は請求項１の発明の水熱反応容器の一実施例の断面図、（Ｂ）は同上の水熱反応処理装置の概略図。
【図２】（Ａ）は請求項２の発明の水熱反応容器の一実施例の断面図、（Ｂ）は同上の水熱反応処理装置の概略図。
【図３】（Ａ）は請求項３の発明の水熱反応容器の一実施例の断面図、（Ｂ）は同上の横断面図。
【符号の説明】
１０ 水熱反応容器
１４ 原料注入用のノズル
２０ 圧力計
２１ 圧力検出管[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for preventing blockage of a pressure detection tube for detecting a pressure in a hydrothermal reaction vessel in a hydrothermal reaction apparatus in a supercritical state of water.
[0002]
[Prior art]
A hydrothermal reaction is caused by reacting an object to be processed with water containing an oxidizing agent in a supercritical state of 374 ° C. or higher and 22.1 MPa (220 atm) or higher, and an organic substance in the object is reduced for a short time. When performing a hydrothermal reaction process that is almost completely decomposed in, the temperature of the hydrothermal reaction is detected and controlled using a thermocouple, but various salts are formed from the inorganic components contained in the object to be treated. When formed, these salts adhere to the surface of the metal and corrode the metal due to the synergistic effect of the high temperature and the sufficient presence of oxygen, making it impossible to measure the temperature with a thermocouple.
[0003]
[Problems to be solved by the invention]
For this reason, the present applicant has disclosed a sheath thermocouple in which a thermocouple is covered with a sheath tube in a protective tube according to Japanese Patent Application No. 2002-197497, and made various improvements to the protective tube, It was proposed that the temperature inside the reaction vessel could be detected by a thermocouple and the temperature of the hydrothermal reaction could be controlled. To control this hydrothermal reaction more safely and stably, it is necessary to measure the pressure inside the hydrothermal reaction vessel and control the pressure. Therefore, when the pressure detection tube with the pressure gauge is inserted into the inside of the hydrothermal reaction vessel, salt adheres to the pressure detection tube for the same reason, and the end of the pressure detection tube at which the salt enters the inside of the container. And makes it impossible to measure the pressure inside the hydrothermal reaction vessel and control the pressure inside the hydrothermal reaction vessel based on the measurement.
[0004]
[Means for Solving the Problems]
The present invention has been developed to solve the above-described problem, and a pressure detection tube equipped with a pressure gauge is inserted into a hydrothermal reaction vessel that performs decomposition by a hydrothermal reaction in a supercritical state of water. As a method for preventing blockage of a pressure detection tube in a hydrothermal reaction apparatus that measures the pressure inside the hydrothermal reaction vessel, the invention of claim 1 includes injecting cooling water inside the hydrothermal reaction vessel below. The subcritical water region is formed, and the end of the pressure detection tube that protrudes into the hydrothermal reaction vessel is located in the subcritical water region. A supply pipe for a high-pressure fluid having a pressure equal to or higher than the pressure in the vessel is connected, and the high-pressure fluid is blown into the vessel from an end of the pressure detection pipe that has entered the hydrothermal reaction vessel. Further, the invention according to claim 3 is characterized in that the pressure detecting tube is provided along a scraper bar provided correspondingly to a scraper for turning the pressure detecting tube along the inner periphery of the hydrothermal reaction vessel to peel off deposited solid matter attached to the inner periphery. It is characterized by being shared.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
In each of the illustrated embodiments, reference numeral 10 denotes a vertically elongated cylindrical hydrothermal reaction vessel having an upper wall 11 and a funnel-shaped lower part 12, and the center of the upper wall has an object to be treated such as a waste liquid or water. A nozzle 14 for supplying other necessary materials into the vessel is provided.
[0006]
In each of the illustrated embodiments, the entire system of the apparatus uses a high-pressure pump P to process an object to be treated such as a waste liquid, a reaction aid, and water, as shown in FIGS. 1B and 2B. In addition to the injection into the supply pipe 13, air as an oxidant is injected into the supply pipe 13 from an air compressor through a preheater, and these are mixed and supplied from the nozzle 14 into the inside of the hydrothermal reaction vessel.
[0007]
The above-mentioned raw materials are supplied to a hydrothermal reaction vessel except for a substance to be treated such as a waste liquid to cause a hydrothermal reaction in the vessel, and when the inside of the vessel rises to a predetermined temperature to be in a supercritical state, a waste liquid, etc. Is supplied into the vessel. As a result, the reaction liquid containing the solid is supplied from the discharge pipe 12 'at the lower end of the funnel-shaped lower part 12 to the gas-liquid separator 18 via the cooler 17, and separated into the gas and the liquid containing the solid via the pressure reducing valve V. And is discharged.
[0008]
When the object to be treated is hydrothermally reacted with the oxidizing agent in the hydrothermal reactor 10 in this manner, if the object to be treated is, for example, an organic waste liquid containing chlorine, the organic waste liquid is subjected to a hydrothermal reaction. A reaction product comprising a high-temperature and high-pressure fluid of water, carbon dioxide, and hydrogen chloride, and a solid such as ash and salts in a dried or slurry state is obtained. At this time, since hydrogen chloride is present as hydrogen chloride gas, it does not have much corrosiveness.However, it dissolves in water to form hydrochloric acid, and forms a severely corrosive environment. Neutralize.
[0009]
When the hydrothermal reaction is continued as described above, various salts are generated from the inorganic components contained in the object to be treated as described above. These salts adhere to the surface of the metal and corrode the metal in many cases due to the synergistic effect of the high temperature and the sufficient presence of oxygen.
[0010]
Therefore, in order to control the pressure in the hydrothermal reaction vessel 10, a pressure detecting tube 21 having a pressure gauge 20 attached to the upper end is inserted into the hydrothermal reaction vessel 10 from the upper wall, and the lower end 21 'is in the supercritical water region. When it is located inside, the deposited solid adheres around the pipe 21 and the deposited solid gradually closes the lower end of the pipe, so that the pressure gauge 20 does not indicate the pressure in the hydrothermal reaction vessel 10. .
[0011]
For this purpose, in the embodiment of FIG. 1, the cooling water is supplied by the cooling pipe 15 directly above the inside of the funnel-shaped lower part 12, whereby the cooling fluid level is immediately above the level of the cooling pipe 15 in the vessel. 16 to form a subcritical water zone below the supercritical water zone between the cooling fluid level and the upper wall 11, and position the lower end 21 'of the pressure detecting tube 21 in the subcritical water zone. It is. Therefore, the precipitated solid adheres around the portion penetrating the supercritical water region of the pressure detecting tube, but the lower end 21 'is located in the subcritical water region, and the precipitated solid dissolves. Therefore, the lower end 21 'of the pressure detecting tube is not closed. Accordingly, since the pressure in the hydrothermal reaction vessel 10 can be accurately known by the pressure gauge 20, the pressure of the hydrothermal reaction can be optimally controlled.
[0012]
In the second embodiment of FIG. 2 and the third embodiment of FIG. 3, the entire interior of the hydrothermal reaction vessel is a supercritical water region, and the lower end of a pressure detecting tube 21 having a pressure gauge 20 mounted on the upper end. 21 'is located in the supercritical water region.
[0013]
For this reason, in order to prevent the lower end 21 'of the pressure detecting tube from being clogged with the deposited solid matter, in the embodiment of the present invention as shown in FIG. A part of the air to be blown is branched by a branch pipe 22 and injected into the pressure detection pipe 21. Accordingly, since air is blown into the hydrothermal reaction vessel from the lower end 21 ′ of the pressure detection pipe inside the pressure detection pipe 21, similarly, the precipitated solid matter in the hydrothermal reaction vessel is reduced to the lower end 21 ′ of the pressure detection pipe. Do not block. Further, it is more effective to install a heating pipe 23 in the branch pipe 22 and to blow heated high-temperature air from the lower end 21 'of the pressure detection pipe. Therefore, also in this case, since the pressure inside the hydrothermal reaction vessel can be accurately known by the pressure gauge 20, the pressure of the hydrothermal reaction can be optimally controlled.
[0014]
In the embodiment of FIG. 2, air heated to a temperature higher than the critical temperature of water is injected into the pressure detection tube 21, but the invention is not limited to air, and other similar high-temperature fluids such as water may be injected.
[0015]
Since precipitated solid matter adheres to the inner wall of the hydrothermal reaction vessel 10, the lower end of a scraper 19 having a Y-shaped cross section is usually attached to the lower end of the funnel and rotated by a motor M or the like. Solid matter adhering to the inner wall of the thermal reaction vessel 10 is exfoliated and removed. Since a part of the removed solid material adheres to the inner wall of the scraper 19, one or more fixed scraper bars are attached to the inner wall side of the scraper in order to remove the solid material. Contacted in position.
[0016]
In the embodiment of FIG. 3, one of the scraper bars 24 is a hollow pressure detecting tube 21, and a pressure gauge 20 is attached to the upper end protruding out of the container, and this scraper bar 24 is connected to the pressure detecting tube. It is also used. By also using the scraper bar and the pressure detecting tube, solid matter adhering to the pressure detecting tube is exfoliated and removed by the scraper, and the lower end 21 'is less likely to be closed. Further, cooling water is supplied to the inside of the hydrothermal reaction vessel below the cooling pipe 15 in the same manner as in the embodiment of FIG. 1, thereby forming a cooling fluid level 16 immediately above the level of the cooling pipe 15. If the lower part is placed in the subcritical water region, the precipitated solids are dissolved as described above, so that the lower end 21 'of the scraper / pressure detecting tube is located in this subcritical water region. 'Can be more reliably prevented from blocking. Therefore, since the lower end of the scraper bar and the pressure detecting tube is not closed by the precipitated solid matter, the pressure in the hydrothermal reaction vessel can be detected by the pressure gauge 20. In addition, since the structure inside the reaction vessel can be reduced by also using the scraper bar and the pressure detecting tube, the adhesion of solids precipitated in the reaction vessel can be reduced.
[0017]
【The invention's effect】
As apparent from the above, according to the present invention, the pressure inside the hydrothermal reaction vessel can be accurately known by the pressure gauge, so that the pressure of the hydrothermal reaction in the vessel can be optimally controlled.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view of one embodiment of the hydrothermal reaction vessel according to the first aspect of the present invention, and FIG.
FIG. 2A is a cross-sectional view of one embodiment of the hydrothermal reaction vessel according to the second aspect of the present invention, and FIG. 2B is a schematic view of the same hydrothermal reaction apparatus.
FIG. 3A is a cross-sectional view of one embodiment of the hydrothermal reaction vessel according to the third aspect of the present invention, and FIG.
[Explanation of symbols]
Reference Signs List 10 Hydrothermal reaction vessel 14 Nozzle 20 for material injection 20 Pressure gauge 21 Pressure detection tube
