JPH04190842A - High temperature and high pressure apparatus for supercritical or subcritical fluid - Google Patents

Abstract

PURPOSE:To obtain the title apparatus easy to control temp. and pressure by providing a heating member to a solute holding part and providing a member controlling the quantity of the heat charged to said heating member to the outside of the high temp. and high pressure apparatus and connecting both of them in an airtight state. CONSTITUTION:The high pressure chamber of a vertical high pressure container 1 covered with and protected by a heat insulating layer 12 is divided into a solute holding part 3 and the storage part 2 of a fluid having a solute dissolved therein. An undissolved solute 4 and a heating member 10 are received in the holding part 3 and both terminals of a heater are drawn out to the outside to be connected to a charging quantity-of-heat control member 13. By this constitution, since the solute holding part can be directly heated, the time required in the dissolution of the solute can be shortened. Further, the control of the temp. of the high pressure container from the outside, in its turn, the control of the pressure thereof becomes easy.

Description

[Detailed Description of the Invention] [Industrial Application Field] It is known that a solvent in a supercritical state or a subcritical state exhibits an excellent ability to dissolve solutes such as organic solutes and inorganic solutes. Using this phenomenon, from the supercritical or subcritical high concentration solution formed, by pressure control or temperature control, ■ precipitate the solute, ■ grow a single crystal, ■ extract and separate the substance, and ■ fine particles. 2) or conducting various other reactions and treatments are being considered. The present invention relates to a high-temperature, high-pressure device for performing these operations.

[Prior Art] Conventionally used high-temperature and high-pressure equipment is equipped with a heating mechanism for controlling the temperature described above, but this heating mechanism heats the entire high-pressure container from the outside of the high-pressure chamber. This is a so-called external heating type that heats the fluid inside the high pressure chamber using the amount of heat given to the chamber. Therefore, it is said that there are problems as described below.

(1) High-pressure containers are generally thick-walled and large, so they have a large heat capacity and require a long time to heat. Therefore, the time it takes to raise the internal fluid to a predetermined temperature becomes even longer, and the time it takes to reach the predetermined amount of solute dissolved must become considerably longer.

(2) Large-sized high-pressure vessels can reach an outer diameter of 1 m or more and a total length (height) of 10 m or more (in the case of hydrothermal synthesis of crystals), making it extremely difficult to freely set the internal temperature. It is. In particular, since it is thick, the amount of heat transferred in the length (height) direction is large, making it more difficult to provide an accurate temperature difference in the length (height) direction.

For example, FIG. 9 is a conceptual diagram showing an apparatus used for hydrothermal synthesis of quartz crystal. Below the vertical high-pressure passenger unit 1 is a solute holding section 3 in which scrap quartz crystal 4 is housed. and baffle 5
The upper part on both sides constitutes a fluid reservoir 2 filled with a solvent such as a supercritical fluid or a subcritical fluid (water 6 in the figure), and a crystal seed crystal 7 is stored in the fluid reservoir 2. ing.

The high pressure vessel 1 configured as described above has an internal pressure of 1400
The pressure is controlled to be as high as atmospheric pressure, and the whole is completely housed in a heating furnace 8, and the solute holding section 3 is heated to a temperature (approximately 400° C.) necessary for melting the scrap crystal 4. On the other hand, seed crystal 7
The temperature of the fluid reservoir 2 in which the fluid 6 is stored must be at a temperature that does not dissolve the seed crystal 7 and at which the solute (crystal) in the fluid 6 precipitates, and is adjusted to, for example, about 360°C. When such a temperature gradient is applied, the fluid 6 that has dissolved the scrap crystal 4 in the solute holding section 3 rises by convection and enters the fluid storage section 2 through the baffle 5, where it is cooled and folds the crystal onto the seed crystal 7. Compare. The thus cooled fluid 6 descends again and enters the solute holding section 3 where it is heated to 400.degree. C. and dissolves the scrap crystal 4. As is clear from these explanations, an accurate temperature difference must be formed in the length direction (height direction in the figure, hereinafter referred to as axial direction) within the high-pressure vessel 1; Such temperature control is extremely difficult with external heating methods such as .

(3) Pressure control when operating the quartz crystal hydrothermal synthesis apparatus illustrated does not involve raising or lowering the pressure by operating valves, but rather by A method (pressure control method) is adopted in which the filling rate of the solvent is determined in advance (the volume of space after subtracting the amount of space), the chamber is sealed after being filled with the solvent, and the pressure inside the high pressure chamber is increased by heating (temperature control). That is, pressure is indirectly controlled by temperature. However, as mentioned in the previous section, the accuracy of temperature control in the above conventional technology is insufficient, and it is required to provide a temperature difference within a large container.Therefore, the pressure inside the container must be set strictly based on the temperature. I must say that this is extremely difficult. Due to such circumstances, if control fails as originally planned, the temperature of the high-pressure vessel must be lowered and the process must be repeated, which requires a huge amount of time and energy. Become something.

(4) Since the heating means is placed in the outside air, for example, the heat radiation area of the heating furnace becomes large, and the thermal efficiency inevitably becomes low accordingly.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned circumstances, and is directed to an ultra-high-temperature heating system that does not cause the drawbacks described in (1) to (4) above. The present invention aims to provide a high-temperature, high-pressure device for critical (including subcritical, hereinafter the same) fluids.

[Means for Solving the Problems] The high-temperature and high-pressure device of the present invention that can achieve the above object comprises a solute holding section for organic solutes or inorganic solutes, and a supercritical fluid storage section in which the solute is dissolved. In what you have prepared,
A heating member is provided in the solute holding part, and a member for adjusting the amount of heat input to the heating member is provided outside the high temperature and high pressure device, and the adjusting member for adjusting the amount of heat input and the heating member are connected in an airtight manner. This is a summary.

[Function] According to the device of the present invention having the above configuration, since the heating member is provided in the solute holding portion, the solute holding portion can be directly heated. That is, unlike the conventional method, it is not necessary to heat the entire high-pressure container, so the amount of heat required can be significantly reduced, and temperature control can be achieved in a short time. In addition, a member for adjusting the amount of heat input to the heating member is provided outside the high-temperature and high-pressure device, and these are connected in an airtight manner, so the temperature can be freely adjusted from the outside without adversely affecting the pressure maintenance of the high-pressure chamber. It has become possible to perform various operations with precise temperature control.

[Example] FIG. 1 is an explanatory diagram showing a typical example apparatus equipped with the concept of the present invention. is baffle 5
A solute holding part 3 and a storage part 2 for a fluid containing dissolved solute
It is divided into

In the holding part 3, an undissolved solute 4 is stored, and a heating member (in the figure, a resistance heating type electric heater) 10, which is a feature of the present invention, is stored. Both terminals of the electric heater 10 are led out through the wall of the high-pressure container 1 through conductive wires in an airtight manner, and are connected to the input heat amount adjusting member 13 .

In the figure, reference numeral 14 denotes a temperature sensor installed at various locations, and the input heat amount is controlled using the measured temperature value, and its output terminal is electrically connected to the input heat amount adjustment member 13 to automatically provide feedback. It may be configured so that it can be controlled. Sho 1
Reference numeral 5 indicates a fluid inlet/outlet, and 11 and 16 are heaters for heating the entire container 1, which can serve as auxiliary means when controlling the fluid temperature within the container 1.

When using the resistance heating type electric heater 10, it is recommended that it be of a sheath type as shown in FIG. That is, a sheath tube 17 made of a heat-resistant and pressure-resistant material such as Inconel is filled with an insulator 18 made of zirconia powder, magnesia powder, etc., and a heater wire 19 is inserted therethrough in an insulating manner, thereby providing a cooling water passage 20. It is attached to the bottom of the high pressure vessel 1 via a holding member 21 and attachment bolts 22. On the mouth side, a tapered sealing surface 23 is formed at the tip of the holding member 21 and comes into contact with the tapered sealing surface on the high-pressure container 1 side, and a welded portion 24 is further formed to ensure airtightness within the container. Further, in FIGS. 1 and 2, the structure is such that the device is inserted through the bottom side wall surface of the high-pressure vessel 1, but it can also be configured so that the device is inserted through the side wall surface or the ceiling wall surface.

A heat exchanger type heater can also be used as the heating member, and FIG. 3 shows a case where a multi-tube heat exchanger 25 is provided, and FIG. 4 shows a case where a spiral tube heat exchanger 26 is provided. Alternatively, according to the present invention, these may be combined as appropriate, or the fluid storage portion 2 may be provided with a similar configuration like the heater 11 in FIG. 1 to further precisely control the temperature distribution within the high pressure chamber. covered within the technical scope. Note that the heater 16 provided in the heat insulating layer 12
is effective in preheating the high-pressure vessel 1 to a predetermined temperature or maintaining the temperature, and is recommended to be provided in order to shorten the start-up time and help stabilize the processing temperature. .

Although the configuration of the temperature sensor is not particularly limited, a thermocouple type or resistance wire type is generally used. In either case, it is recommended to adopt a configuration similar to that of the electric heater 10 (see Figure 2) to ensure electrical insulation from the fluid, and also to ensure electrical insulation from the high-pressure vessel through the wall of the high-pressure vessel. Therefore, a configuration similar to that shown in FIG. 2 can also be adopted.

The solute holding section 3 is not limited to the structure partitioned by the baffle 5, but may be structured so that the solute is wrapped in a flexible steel material or the solute is stored in an appropriate cage.In short, the heater 10
Any method can be adopted in the present invention as long as the solute is dissolved in the fluid by the amount of heat such as, and the fluid in the dissolved state is not prevented from moving to the fluid storage section 2. Note that mW is not limited to a solid state, and may be a liquid such as oil or a slurry state.

The fluid that has been heated by the heater 10 and dissolved the solute in the m-quality holding section 3 forms an upward flow as the temperature rises and moves to the fluid storage section 2, while the fluid that was present in the fluid storage section 2 descends. Convection occurs here. The degree of convection is controlled by temperature control by each heater 10, 11.16. The temperature of the rising fluid decreases in the storage section 2, and the dissolved solute becomes supersaturated and precipitates on a seed crystal (not shown), producing purified crystal.

Figure 51 Figure 6 shows another embodiment of the device of the present invention, in Figure 5 a cylinder 27 is arranged coaxially with the high pressure vessel 1, and the solute holding part 3 is housed in the lower part of the cylinder 27. . Therefore, the fluid that has been heated in the solute holding part 3 and has dissolved the solute rises inside the cylinder 27, and the fluid that was present in the upper part of the cylinder 27 is pushed out over the peripheral wall of the cylinder 27 and into the cylinder. It moves to the outside of the body 27 and descends on the outside of the cylinder body 27. Therefore, the inside of the cylindrical body 27 becomes a rising passage for the fluid, and the outside becomes a descending passage for the fluid.

The cylindrical body 28 in FIG. 6 has a chimney-like appearance by widening only the solute holding portion 3 at the bottom and narrowing the upper part. Therefore, the ascending passage of the fluid becomes narrower and the descending passage becomes wider.

In the case of a structure in which such cylinders 27 and 2B are provided, since the convection passage is specified compared to the structure shown in FIG. 1, not only is the convection itself stabilized, but also
If a configuration is added in which the upper opening of the rising passage is controlled to be wider or narrower by its vertical movement, the flow rate of convection can be auxiliary controlled by means other than temperature control.

FIG. 8 is a diagram showing still another embodiment, in which a high pressure vessel is
A and lb make up one set, with the high-pressure container 1a placed on the solute holding section 3 side and the high-pressure container 1b placed on the fluid storage section 2 side.Furthermore, the upper parts of each container 1a and lb are connected, and the upper side The communication passage 29 is used as a passage for temperature increasing fluid, and the lower side communication passage 30 is used as a passage for temperature decreasing fluid. Therefore, temperature control of each part becomes more precise, and chemical operability using supercritical fluid becomes even higher.

[Effects of the Invention] Since the present invention is configured as described above, the following effects can be obtained.

(1) Since the solute holding portion is directly heated, the time required to dissolve the solute is shortened.

(2) Since the temperature can be controlled from the outside of the high-pressure container, even if the temperature control is relatively rough compared to the conventional case where the entire container is heated and a predetermined temperature difference is created inside the container. The temperature control accuracy inside the high-pressure vessel becomes extremely high.

(3) Ease and accuracy of temperature control leads to ease and accuracy of pressure control within the high-pressure vessel.

(4) Good convection can now be formed within the high-pressure chamber, which previously required the installation of a stirrer inside the high-pressure chamber and the need to overcome issues such as insertion space, material, and sealability. Compared to this, significant benefits can be obtained in terms of equipment costs, etc.

[Brief explanation of drawings]

Figure 1.5.6.8 is an explanatory diagram showing the overall concept of each embodiment of the device of the present invention, Figure 2 is an explanatory diagram showing the mounting structure of the heater, and Figure 3.4 is an explanatory diagram showing another embodiment of the heating member. Explanatory diagram,
FIG. 7 is an explanatory diagram showing the principle of convection control using a valve stem, and FIG. 9 is an overall conceptual diagram of a conventional device. 1... High pressure container 2... Fluid storage section 3...
Solute holding part 4... Solute 5... Baffle
10.11.16... Heater 13... Heating controller

Claims (1)

[Claims] In order to dissolve an organic solute or an inorganic solute in a supercritical fluid or a subcritical fluid, a solute holding part for the organic solute or inorganic solute, etc., and a fluid storage section for the supercritical fluid or subcritical fluid in which these solutes are dissolved are provided. In a high-temperature and high-pressure device for supercritical or subcritical fluids, the solute holding portion is provided with a heating member, and an external part of the high-temperature and high-pressure device is provided with a member for adjusting the amount of heat input to the heating member, 1. A high-temperature, high-pressure device for supercritical or subcritical fluid, characterized in that a heat amount adjusting member and the heating member are connected in an airtight manner.