JP2005342600A - Pressure-balanced reaction apparatus and its operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-balanced reaction apparatus having such a structure that the predetermined constitution can be kept without damaging a reaction vessel when a great pressure difference arises suddenly between the inside and outside of the reaction vessel since the operation is not controlled desirably or the reaction condition is changed, and to provide its operation method. <P>SOLUTION: This pressure-balanced reaction apparatus has a double-vessel structure that the reaction vessel is arranged in a pressure-resistant vessel so that the first pressure in the reaction vessel is balanced with the second pressure in the space between the pressure-resistant vessel and the reaction vessel. A communicative passage is arranged for communicating the inside of the reaction vessel with the space between the pressure-resistant vessel and the reaction vessel when the differential pressure between the first pressure and the second pressure reaches the predetermined or higher value. A rupture disk which ruptures when the differential pressure between the first pressure and the second pressure reaches the predetermined or higher value and opens the communicative passage is arranged in the communicative passage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure balance type reaction apparatus and a method for operating the same, and in particular, a pressure balance type capable of performing a reaction under a high pressure such as a hydrothermal reaction in the presence of supercritical water under more desirable apparatus conditions. The present invention relates to a reaction apparatus and an operation method thereof.

  As a reaction apparatus for performing a reaction under high pressure, a reaction vessel is provided in a pressure vessel to form a double vessel structure, and the reaction vessel is balanced with the pressure in the reaction vessel and the pressure between the pressure vessel and the reaction vessel. There is known a pressure balance type reaction apparatus in which a large internal / external differential pressure is not applied to itself. In such a structure, since a large deformation force is not applied to the reaction vessel, a relatively thin wall structure can be adopted, and the material cost can be reduced even when an expensive corrosion-resistant material is required. Since the pressure vessel only needs to have a structure that can satisfy only pressure resistance performance, relatively inexpensive materials can be selected, the entire device can be configured at low cost, and each part of the device can easily have sufficiently high required performance. It becomes possible to make it.

  Such a pressure balance type reaction apparatus is effective for, for example, a hydrothermal reaction in the presence of high-temperature high-pressure water. In recent years, attention has been paid to attempts to decompose and detoxify environmental pollutants using a hydrothermal oxidation reaction in the presence of high-temperature and high-pressure water, particularly supercritical water. In particular, due to supercritical water oxidation utilizing the high reactivity of supercritical water, harmful and difficult-to-decompose organic substances, such as PCB (polychlorinated biphenyl), dioxin, and organic chlorine, which were difficult to be decomposed by the prior art. Attempts have been focused on decomposing organic substances and converting them into harmless products such as carbon dioxide, nitrogen, water and inorganic salts. The supercritical water means water in a supercritical state, that is, water in a state exceeding the critical point of water. Specifically, it is at a temperature of 374.1 ° C. or higher and under a pressure of 22.04 MPa or higher. Says water in a state. Supercritical water has a high ability to dissolve organic substances, and can completely dissolve non-polar substances that are abundant in organic compounds. Conversely, the ability to dissolve inorganic substances such as metals and salts is extremely low. Supercritical water can be mixed with a gas such as air, oxygen, or nitrogen at an arbitrary ratio to form a single phase. When the pressure balance type reactor is applied to such hydrothermal reaction including supercritical water oxidation using supercritical water, particularly hydrothermal reaction using high-temperature high-pressure water having a temperature of 180 ° C. or higher and a pressure of 1 MPa or higher, It is possible to configure a predetermined continuous or batch hydrothermal reactor at low cost.

  As hydrothermal reactors to which a pressure balance type reactor is applied, in Patent Documents 1 to 3, a reaction vessel is provided in a pressure vessel, and the pressure outside the reaction vessel (between the pressure vessel and the reaction vessel). A pressure-balanced Bessel-type reactor in which a fluid for maintaining balance (balance fluid) is circulated is disclosed.

  Such pressure balance type reactors can be broadly classified into batch reactors and continuous reactors. FIG. 5 shows an example of a batch type apparatus. In the apparatus shown in FIG. 5, an object 111 to be processed is filled in a reaction vessel 112, and water or supercritical water 113 forming a reaction environment and a reaction fluid are used. The air 114 is introduced into the reaction vessel 112 and the reaction is performed in the reaction vessel 112. When the reaction is completed, the processing fluid 115 is discharged through the processing fluid discharge pipe 116 and is sent to a predetermined destination through, for example, the cooler 118 that has passed the cooling water 117 and the processing fluid pressure reducing valve 119. A balance fluid is supplied from a system different from such a reaction system. In this example, an air supply pipe as a reaction fluid supply pipe is branched, and air is used as a balance fluid 120 between the reaction vessel 112 and the pressure vessel 121. And discharged through the balance air pressure reducing valve 122. The balance fluid 120 is isolated from the reaction container fluid by the reaction container 112. Usually, the pressure of the balance fluid 120 is controlled so that the balance fluid pressure is slightly higher than the pressure in the reaction vessel. Although not shown, a check valve is provided in the line flowing into the reaction vessel 112 and the pressure vessel 121 to prevent backflow.

FIG. 6 shows an example of a continuous apparatus. In the apparatus shown in FIG. 6, the fluid 101 to be treated is introduced into the reaction vessel 103 together with, for example, supercritical water via the nozzle 102, and the reaction fluid 104 (this In this case, air is introduced and the reaction is performed in the reaction vessel 103, and the processing fluid 105 is discharged from the processing fluid discharge pipe 106. The air supplied as the reaction fluid 104 is also used as a balance fluid 107 for pressure balance. The balance fluid 107 flows between the reaction vessel 103 and the pressure vessel 108 and the reaction vessel 103 and the nozzle 102. Into the reaction vessel 103 through the gap. In this structure, since the inside and outside of the reaction vessel 103 communicate with each other through the opening of the reaction vessel 103, basically there is a pressure difference due to a small pressure loss due to the fluid flow, but basically the balance fluid and the inside of the reaction vessel The fluid pressure is the same. Although not shown in FIGS. 5 and 6, in order to detect the pressure difference between the inner side and the outer side of the reaction vessel, for example, a line for measuring the differential pressure between the reaction air and the balance air line is provided. It can be detected.
JP 2003-340261 A JP 2003-340262 A JP-A-9-85075

  However, in the batch type reactor structure as shown in FIG. 5, since the balance fluid and the fluid in the reaction vessel are isolated from each other, both of them are pressure-controlled in order to balance the pressure. When one of the pressure controls is unsatisfactory, it is assumed that a pressure difference between the inside and outside occurs and exceeds the design pressure of the reaction vessel. Furthermore, in the batch type apparatus, there is a temperature increase / pressure increase process (for example, Patent Document 2), and it is necessary to control the balance fluid pressure in accordance with the pressure increase accompanying the temperature increase in the reaction vessel. If there is a sudden rise, it is assumed that the balance air pressure cannot be controlled, and that a pressure difference between the inside and outside is generated and exceeds the design pressure of the reaction vessel. In addition, even when a sudden reaction occurs in the reaction vessel and the pressure suddenly rises or a sudden leak occurs in the device, the balance fluid pressure cannot be controlled, resulting in a difference in pressure between the inside and outside of the vessel. It is assumed that the pressure will be exceeded.

  Further, even in a continuous reactor structure as shown in FIG. 6, if salts are mixed in the fluid to be treated, it is deposited in the reaction vessel, and in some cases, also deposited in the gap between the reaction vessel and the nozzle. And the gap disappears. In this case, when the pressure adjustment of the fluid in the reaction vessel becomes unstable or when the pressure in the reaction vessel is reduced after the operation is finished, the fluid pressure in the reaction vessel decreases, but due to the effect of a check valve (not shown). Since the back flow of the balance fluid is prevented and the balance fluid pressure does not decrease, it is assumed that a pressure difference exceeding the design pressure of the reaction vessel is generated inside and outside the reaction vessel.

  Therefore, the object of the present invention is to pay attention to the above-mentioned problems, particularly when a sudden and excessive change in the internal / external pressure difference of the reaction vessel occurs due to a malfunction of control or a change in reaction conditions. It is an object of the present invention to provide a structure and an operation method that can maintain a predetermined configuration of a pressure balance type reactor without giving the pressure.

  In order to solve the above problems, a pressure balance type reaction apparatus according to the present invention has a double container structure in which a reaction vessel is provided in a pressure vessel, and the first pressure, the pressure vessel and the reaction vessel in the reaction vessel. A pressure balance type reaction apparatus that balances the second pressure between the first and second pressures when the differential pressure between the first pressure and the second pressure exceeds a predetermined value. And a communication passage that communicates between the pressure vessel and the reaction vessel, and the communication passage is ruptured when the pressure difference between the first pressure and the second pressure exceeds a predetermined value. It consists of what is provided with the rupture disk which opens a channel | path.

  The rupturable plate may have a structure in which a single rupturable plate is provided in the communication path, or may have a structure in which a rupturable plate that operates only in one direction is provided in both directions in parallel. .

  Further, it is preferable that a buffer tank is provided in the communication path.

  In such a pressure balance type reaction apparatus, a high-pressure reaction, for example, a hydrothermal reaction is performed in the reaction vessel. Examples of the hydrothermal reaction include a supercritical water oxidation reaction.

  The operation method of the pressure balance type reactor according to the present invention uses the pressure balance type reactor as described above, and bursts when the pressure difference between the first pressure and the second pressure becomes a predetermined value or more. It consists of a method of rupturing the plate to make the communication path communicate and stopping the apparatus.

  In the conventional pressure balance type reaction apparatus, when a pressure difference between the inside and outside of the reaction vessel occurs, the apparatus is only stopped as a countermeasure, and means for eliminating the pressure difference other than adjusting the pressure by each control valve is provided. There wasn't. Therefore, when the pressure difference between the inside and outside of the reaction vessel suddenly rises, the pressure balance cannot be adjusted with the control valve alone, and the design pressure of the reaction vessel is exceeded, and the reaction vessel may be deformed or damaged. However, in the pressure balance type reaction apparatus according to the present invention, when the internal / external differential pressure of the reaction vessel exceeds a predetermined value, the rupture plate provided in the communication passage is ruptured, and the communication that connects the inside and the outside of the reaction vessel is established. A passage (equal pressure equalization line) is opened, and the inside and outside of the reaction vessel are communicated to eliminate the differential pressure applied to the reaction vessel. Therefore, an excessive differential pressure is not applied to the reaction vessel, and the possibility of deformation or breakage is eliminated.

  According to the pressure balance type reactor and the operation method thereof according to the present invention, even when the internal and external pressure difference of the reaction vessel suddenly increases due to an unexpected situation or the like, an excessively high differential pressure with an extremely fast operation of rupture of the rupture disc Therefore, it is possible to prevent the reaction vessel from being deformed / damaged and to stably maintain a predetermined configuration of the pressure balance type reactor.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a pressure balance type reaction apparatus according to the first embodiment of the present invention, and particularly shows a hydrothermal reaction apparatus suitable as a batch type supercritical water oxidation apparatus. The pressure balance type reactor 1 shown in FIG. 1 has a double container structure in which a reaction vessel 3 is provided in a pressure vessel 2, and the first pressure in the reaction vessel 3 is between the pressure vessel 2 and the reaction vessel 3. It is comprised in the pressure balance type | mold reaction apparatus which balanced the 2nd pressure of this. The object to be processed 4 is filled in the reaction vessel 3 in a batch manner, water or supercritical water 5 and a reaction fluid 6 (in this case, air) are introduced, and the reaction is performed in the reaction vessel 3, and the treatment fluid 7 is discharged from the processing fluid discharge pipe 8. In the present embodiment, the discharged processing fluid 7 is cooled by the cooler 10 through which the cooling water 9 has been passed, and is appropriately depressurized by the processing fluid pressure reducing valve 11 and discharged to a predetermined destination. The air supplied as the reaction fluid 6 is also used as a balance fluid 12 for pressure balance, and the balance fluid 12 flows between the reaction vessel 3 and the pressure vessel 2 and is isolated from the reaction vessel 3. In this state, the fluid is discharged via the balance fluid discharge pipe 13 and the balance fluid pressure reducing valve 14.

  Then, when the pressure difference between the first pressure in the reaction vessel 3 and the second pressure between the pressure vessel 2 and the reaction vessel 3 becomes a predetermined value or more, 3 is provided with a communication passage 15 that allows communication between the inner side of 3 and the pressure vessel 2 and the reaction vessel 3. The communication passage 15 is provided with a rupture plate 16 that opens the communication passage 15 when the differential pressure between the first pressure and the second pressure becomes a predetermined value or more. The communication passage 15 is opened by the rupture of. In this embodiment, the rupturable plate 16 can be ruptured in both directions in the extending direction of the communication passage 15, but as shown in FIG. 2, rupturable plates 16 a and 16 b that operate only in one direction are arranged in parallel. A structure provided in both directions (so that the burst directions are opposite to each other) may be employed. In the structure shown in FIG. 2, the operating directions of the rupturable plates 16a and 16b are set to different directions, so that it is possible to accurately cope with either pressure increase. In the rupturable plate 16 shown in FIG. 1, one pressure (first pressure) is larger than the other pressure (second pressure) with the rupturable plate 16 as a boundary in the communication path 15, and the differential pressure is predetermined. A rupture disc that ruptures from the high pressure side to the low pressure side when the value is exceeded can be used.

  The rupture disk 16a shown in FIG. 2 is provided with, for example, a rupture portion that is convexly curved in the direction of the arrow at the center of the rupture disk. It is possible to use a rupturable plate that becomes large and breaks when the pressure difference exceeds a predetermined value, and does not break even if the pressure in the direction opposite to the arrow increases. Needless to say, the rupturable plate 16b is operated in the direction opposite to that of 16a.

  In the pressure balance type reactor 1 configured as described above, the communication passage 15 is provided, and the rupture plate 16 (or the rupture plates 16 a and 16 b) is provided in the communication passage 15, so that the pressure difference between the inside and outside of the reaction vessel 3 is increased. When the pressure changes abruptly and the differential pressure exceeds a predetermined range, the rupturable plate bursts quickly to open the communication passage 15 and the internal / external pressure difference of the reaction vessel 3 can be eliminated. Therefore, even when an unforeseen situation or the like occurs and the pressure difference between the inside and outside of the reaction vessel 3 suddenly increases, pressure equalization by rupture of the communication path 15 (equal pressure line) and the rupture plate provided therein, The pressure difference can be eliminated very quickly, and the configuration of the predetermined pressure balance type reactor 1 can be stably maintained without damaging the reaction vessel 3.

  In the illustrated example, water or supercritical water is introduced into the reaction vessel 3 as a line (communication path 15) provided with a rupturable plate 16 that senses the pressure difference between the inside and outside of the reaction vessel 3 and equalizes the pressure. In addition, the balance air pipe inlet is selected, but any other combination from the following points can be used. For example, the internal pressure sensing position of the reaction vessel 3 includes (1) reaction vessel inlet, (2) processing fluid outlet, (3) differential pressure detection dedicated line (not shown) derived from the reaction vessel, etc. As the external pressure sensing position of the container 3, (1) a balance air inlet, (2) a balance air outlet, (3) a differential pressure sensing dedicated line (not shown) derived from the pressure vessel, etc. may be selected. . In FIG. 1, the inlet side of water or supercritical water is basically supplied with water that does not contain impurities, and has the lowest risk of salt precipitation / clogging. preferable.

  In addition, the workpiece to be put into the reaction vessel may be corrosive, but normally the pressure vessel is not subjected to special corrosion countermeasures, so when the pressure inside the reaction vessel rises and the rupture disk is activated If the object to be processed (processed fluid) in the reaction container reaches the outside of the reaction container and is in contact with the pressure container, the pressure container may be corroded. Therefore, as shown in FIG. 3 with respect to the apparatus of FIG. 1, by providing a buffer tank 21 in the pressure equalizing line (communication path 15), even when the rupture plate 16 is activated due to an increase in the pressure in the reaction vessel, the reaction vessel The internal fluid does not reach the outside of the reaction vessel. In FIG. 3, the buffer tank 21 is provided in front of the rupturable plate 16, but it may be provided at the rear or one at the front and rear. As shown in FIG. 3, the buffer tank 21 is configured so that the connection side with the inside of the reaction vessel is led to the lower portion of the tank and the connection side with the outside of the reaction vessel is connected to the upper portion of the tank, as shown in FIG. It is preferable. Note that a buffer tank can be similarly provided for the apparatus shown in FIG.

  The present invention is suitable for a batch-type pressure balance reactor as shown in FIG. 1, but the present invention can also be applied to a continuous pressure balance reactor. FIG. 4 shows a pressure balance type reaction apparatus according to the second embodiment of the present invention, and particularly shows a hydrothermal reaction apparatus suitable as a continuous supercritical water oxidation apparatus. The pressure balance type reaction apparatus 31 shown in FIG. 4 has a double container structure in which a reaction vessel 33 is provided in a pressure vessel 32, and the first pressure in the reaction vessel 33 is between the pressure vessel 32 and the reaction vessel 33. It is comprised in the pressure balance type | mold reaction apparatus which balanced the 2nd pressure of this. The fluid 34 to be treated is introduced into the reaction vessel 33 together with, for example, supercritical water through the nozzle 35, the reaction fluid 36 (in this case, air) is introduced, and the reaction is performed in the reaction vessel 33, and the treatment fluid 37 Is discharged from the processing fluid discharge pipe 38. The air supplied as the reaction fluid 36 is also used as a balance fluid 39 for pressure balance. The balance fluid 39 flows between the reaction vessel 33 and the pressure vessel 32 and the reaction vessel 33 and the nozzle 35. And into the reaction vessel 33 from the gap 40. In the present embodiment, a brine water inlet 41 and a brine water outlet 42 are provided for the reaction vessel 33, and a liquid level detector 44 that detects the level of the brine water 43 in the reaction vessel 33 includes: The lower detection line 45 and the higher detection line 46 are connected to each other.

  When the pressure difference between the first pressure in the reaction vessel 33 and the second pressure between the pressure vessel 32 and the reaction vessel 33 becomes equal to or greater than a predetermined value, 33 is provided with a communication passage 47 that allows communication between the inner side of the pressure vessel 33 and the side between the pressure vessel 32 and the reaction vessel 33. In this communication passage 47, a differential pressure between the first pressure and the second pressure is a predetermined value. A rupture plate 48 is provided that opens the communication passage 47 by its own rupture when the above is reached. Even in this pressure balance type reaction device 31, even when an unexpected situation occurs and the pressure difference between the inside and outside of the reaction vessel 33 suddenly increases, the communication path 47 (equal pressure line) and the rupture disc provided there The pressure equalization by the rupture of 48 can eliminate the pressure difference very quickly, and the configuration of the predetermined pressure balance type reactor 31 can be stably maintained without damaging the reaction vessel 33.

  In FIGS. 1 and 4, the air used for the reaction is branched and supplied as a fluid for maintaining the pressure balance between the pressure vessel and the reaction vessel, but the pressure balance between the pressure vessel and the reaction vessel is shown. It is also possible to supply a fluid such as nitrogen, for example, as a separate fluid that keeps the temperature constant.

  The pressure balance type reactor according to the present invention and the operating method thereof can be applied to any double vessel type pressure balance type reactor, particularly in a batch type pressure balance type reactor, particularly in the presence of supercritical water. It is suitable for hydrothermal reaction under high pressure such as supercritical water oxidation.

It is a schematic equipment system diagram of a pressure balance type reaction device concerning the 1st embodiment of the present invention. It is a partial equipment system diagram which shows another structural example of the rupturable plate of the apparatus of FIG. FIG. 2 is a partial equipment system diagram when a buffer tank is provided in the apparatus of FIG. 1. It is a general | schematic apparatus system diagram of the pressure balance type | mold reaction apparatus which concerns on the 2nd embodiment of this invention. It is a schematic equipment system diagram of a conventional batch type pressure balance type reactor. It is a schematic equipment system diagram of a conventional continuous pressure balance type reactor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,31 Pressure balance type reaction apparatus 2,32 Pressure-resistant container 3,33 Reaction container 4 To-be-processed object 5 Water or supercritical water 6,36 Air as reaction fluid 7,37 Processing fluid 8,38 Processing fluid discharge pipe 9 Cooling water 10 Cooler 11 Processing fluid pressure reducing valve 12, 39 Air as balance fluid 13 Balance fluid discharge pipe 14 Balance fluid pressure reducing valve 15, 47 Communication path (equal pressure equalization line)
16, 16a, 16b, 48 Rupture plate 21 Buffer tank 34 Processed fluid 35 Nozzle 40 Gap 41 Brine water inlet 42 Brine water outlet 43 Brine water 44 Liquid level detector 45 Low side detection line 46 High side detection line

Claims (6)

  A pressure balance type reactor having a double vessel structure in which a reaction vessel is provided in a pressure vessel and balancing the first pressure in the reaction vessel and the second pressure between the pressure vessel and the reaction vessel And providing a communication path for communicating the inside of the reaction vessel and the space between the pressure vessel and the reaction vessel when the differential pressure between the first pressure and the second pressure exceeds a predetermined value, A pressure balance type reaction apparatus comprising a rupture plate that ruptures and opens the communication path when the differential pressure between the first pressure and the second pressure exceeds a predetermined value.   The pressure balance type reactor according to claim 1, wherein a rupturable plate that operates in only one direction is provided in parallel as the rupturable plate.   The pressure balance type reactor according to claim 1 or 2, wherein a buffer tank is provided in the communication path.   The pressure balance type | mold reaction apparatus in any one of Claims 1-3 which performs a hydrothermal reaction within reaction container.   The pressure balanced reactor according to claim 4, wherein the hydrothermal reaction is a supercritical water oxidation reaction.   The pressure balanced reactor according to any one of claims 1 to 5, wherein when the differential pressure between the first pressure and the second pressure becomes a predetermined value or more, the rupturable plate is ruptured to communicate with the communication path. The operation method of the pressure balance type reaction apparatus which makes the apparatus stop while communicating.

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