JP2006272055A - Micro-wave chemical reaction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new apparatus uniformly performing a chemical reaction of an object to be reacted at a high efficiency by flowing the object to be reacted along a central axis of a rectangular wave-guide pipe for transmitting a micro-wave of TE10 mode. <P>SOLUTION: The chemical reaction apparatus is provided with the rectangular wave-guide pipe for transmitting the micro-wave of TE10 mode; and a circulation passage 2 arranged in the wave-guide pipe for circulating the fluid reaction object 3, in which passage the chemical reaction is performed. The circulation passage 2 is made of a material for permeating the micro-wave and extends in an axial direction of the wave-guide pipe 1. It is a rectangular shape in which a side parallel to an electric field is longer than a side perpendicular to the electric field in a cross section of the circulation passage 2 and the most in a longitudinal direction is arranged near the central axis of the wave-guide pipe. The reaction object is made flowing from an upstream end of the circulation passage and the reaction object is irradiated with the micro-wave to generate the chemical reaction during flowing from a downstream end. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a chemical reaction apparatus that promotes a chemical reaction by irradiating a microwave, and without using a cavity resonator, a chemical reaction target such as a liquid, a gas, and a powder can be made highly efficient and almost uniform. The present invention relates to a microwave chemical reactor that can be heated.

Microwaves are widely used as a heat source for industrial heating furnaces including microwave ovens. Microwave not only heats water contained in a substance, but also acts on a dielectric material with polarity to directly and selectively heat it, so that the object to be heated from the outside like conventional heating means Compared to a device that heats, it has the feature that it can be heated efficiently in a short time.
In recent years, when a substance to be subjected to a chemical reaction (hereinafter referred to as “reaction target”) is irradiated with microwaves, a phenomenon that can greatly accelerate the chemical reaction has been found, and the chemical reaction is not limited to a simple heating device. The application to the chemical reaction apparatus to perform is opening up greatly.
Currently, most microwave chemical reaction devices are at the experimental equipment level, and their application to plants is still immature, and development is now underway.
Chemical reaction experimental devices are roughly classified into a matching waveguide type in which a matching load is connected to the terminal, a short-circuited waveguide type in which the terminal is short-circuited, and a cavity resonator type using a cavity resonator.
In general, a chemical reaction experiment is performed by placing a reaction object in these apparatuses. In order to perform a chemical reaction uniformly, a uniform electric field distribution is required. In general, most of the containers for containing substances are test tubes and flasks. In the case of a waveguide type, these containers are arranged in a limited part in the axial direction of the waveguide. For this reason, there is usually a problem that efficiency is lowered. As the matching waveguide type chemical reaction experimental apparatus, those described in Patent Document 1 and Patent Document 2 are known. The short-waveguide-type chemical reaction experimental device is a device that replaces the matching-waveguide-type non-reflective terminator with a short-circuit, compared to the fact that the matched-waveguide-type can only use traveling wave energy. In the short-circuit type, since the energy of the reflected wave can be used, the efficiency increases. However, in order to increase the efficiency, it is necessary to maximize the standing wave in the vicinity of the reaction target. For this reason, since the short-circuit position must be adjusted, there is a problem in that it is troublesome in use. The cavity type multi-reflects microwaves on the cavity wall, so that the absorption of microwaves is increased, resulting in higher efficiency, but it is necessary to be tuned. However, there is a defect that it takes time to use. It is not always necessary to tune in a cavity type device that uses multi-mode, but in order to average the peaks and valleys in the electromagnetic field distribution in the space where microwaves are excited. In addition, microwaves are irradiated while moving the reaction target on the turntable, and a rotating reflector called a stirrer is placed in a part of the space where the microwaves are excited to equalize the space. A method is used in which a spiral thin tube is provided in the inside and the reaction target is made to flow in the tube to make it uniform. In either case, there is a problem that the apparatus becomes complicated accordingly. When a single mode cavity is used, there is an advantage that the electric field distribution is relatively uniform. However, tuning is essential, and there is a disadvantage in that not only the mechanism is complicated but also the use is troublesome.
JP 2002-79078 A JP-A-2005-13901

  This invention combines the high efficiency characteristics of a short-circuited waveguide type and a cavity resonator type with the simplicity of a matching waveguide type, and is particularly suitable for a plant, with a simple structure and simple use. The object is to provide a highly efficient chemical reaction apparatus.

  In the invention described in claim 1, in order to solve the above-described problem, the electric field of TE01 transmitted in the rectangular waveguide acts on the reaction target flowing in the flow path disposed in the waveguide. And promote the chemical reaction. The flow path has a rectangular shape in which the side parallel to the electric field is longer than the side perpendicular to the electric field in the cross section, and is arranged so that most of the length direction is located near the central axis of the waveguide.

  In the microwave chemical reaction device according to the first aspect, the chemical reaction proceeds in the microwave chemical reaction device according to the first aspect by passing the short-circuit portion of the waveguide and leading the flow path out of the waveguide. Provide a means for safely extracting reaction targets while preventing radio wave leakage.

  According to a third aspect of the present invention, in the microwave chemical reaction device according to the first or second aspect, the flow path to be reacted is vaporized by a chemical reaction with at least a part of the waveguide opened upward. A configuration is employed in which an exhaust device for exhausting the gas to the outside of the waveguide is attached.

  The invention described in claims 4 and 5 is the microwave chemical reaction device according to claim 1 or 2, wherein a suction device or a delivery device for mechanically sucking or forcing the reaction object in the downstream portion of the flow path. A configuration in which a device is attached is adopted.

  In the first aspect of the present invention, the chemical reaction of the reaction target is allowed to proceed substantially uniformly, and most of the microwaves transmitted particularly when the length of the flow path through which the reaction target flows is sufficiently long can be absorbed. I made it. It is possible to provide a microwave chemical reaction apparatus that promotes an almost uniform chemical reaction with high efficiency without synchronization.

  According to the second aspect of the present invention, it is possible to provide a simple device that hardly causes radio wave leakage.

  In the invention described in claim 3, unnecessary reaction products can be efficiently removed, and thereby the reaction can proceed more efficiently.

  In the inventions described in claims 4 and 5, the retention of the flow of the reaction object due to the increase in viscosity due to the chemical reaction is corrected, and the reaction object can be allowed to flow out without stagnation.

  An embodiment of the present invention will be described with reference to the drawings. 1 is a side view showing the basic structure of the chemical reaction apparatus of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 1, FIG. 6 is a cross-sectional view showing a chemical reaction apparatus according to another embodiment, and FIG. 7 is a cross-sectional view showing another embodiment of the flow path to be reacted. 8 and 9 are explanatory views showing an embodiment of a delivery device to be reacted.

  In FIG. 3, there is a rectangular tubular flow passage 2 substantially at the center of a rectangular waveguide 1, and a reaction object 3 flows therein. The flow path 2 is made of a dielectric material that absorbs less microwaves, and has a rectangular cross section that is long in the short side direction (left-right direction) of the rectangular waveguide 1 and short in the long side direction (up-down direction). When nothing is inserted into the rectangular waveguide 1, the electromagnetic wave mode transmitted therein is TE 10, the electric field of this mode is directed in the short side direction (left-right direction) of the rectangular waveguide 1, and the intensity is It changes in a sinusoidal shape with respect to the long side direction (vertical direction), and takes zero at the side walls 1c and 1d of the waveguide 1 and a maximum value at the center. The intensity does not change in the left-right direction. When a dielectric or the like is inserted into the rectangular waveguide 1, the electric field distribution usually changes slightly, but in the arrangement shown in FIG. 3, the upper and lower boundary surfaces of the reaction object 3 that is a dielectric, that is, the flow Since the upper and lower surfaces of the path 2 are parallel to the electric field, the magnitude of the electric field inside and outside the dielectric is the same. As a result of satisfying this boundary condition, when a dielectric is inserted, a slight change occurs in the electric field. However, when electromagnetic analysis is performed, unless the vertical thickness of the reaction target 3 that is a dielectric is too large, As a whole, it can be seen that the electric field inside the dielectric does not make a large difference from the electric field without inserting the dielectric. Since the electric field distribution in the reaction target 3 is almost uniform, it is important that a uniform chemical reaction can be expected. Needless to say, when the boundary condition is inappropriate, the electric field distribution inside and outside the dielectric body is greatly disturbed, and the strength of the electric field inside the dielectric body is also lowered.

  As a result, the intensity of the microwave electric field inside the reaction target 3 is substantially uniform in the left-right direction in FIG. The intensity of the microwave electric field inside the reaction target 3 changes in a sine wave shape in the vertical direction, but since the reaction target 3 is located at the approximate center of the waveguide 1 in the vicinity of the maximum value, its thickness in the vertical direction. Is substantially uniform when is sufficiently smaller than the vertical dimension of the waveguide 1.

  Note that the center of the flow path 2 does not necessarily coincide with the center of the rectangular waveguide 1, and may be slightly decentered as necessary. Although the electric field strength slightly changes, the uniformity is not so hindered when the degree of eccentricity is small. Further, the central axis of the flow path 2 and the central axis of the waveguide 1 do not necessarily have to be parallel. The point is that the upper and lower side walls 2c, 2d of the flow path 2 are parallel to the electric field, and most of the flow path 2 is in the vicinity of the central axis of the waveguide where the electric field is maximized. is there.

The reaction object 3 flowing in the flow passage moves to the left in FIGS. Since the microwaves are also transmitted in this direction, both flow toward the downstream while being translated from each other. Since the propagation speed of the microwave is much faster than the moving speed of the reaction target 3, the reaction target 3 receives microwave irradiation of the same intensity on the average in the flow direction, and the chemical reaction proceeds uniformly in the flow direction. To do. The energy of the microwave is consumed by the reaction target 3 as it advances in the axial direction, and most of the energy is consumed when it reaches the outflow portion of the reaction target 3. Alternatively, a short-circuit plate that blocks and reflects the microwave may be provided in the vicinity of the outflow portion so that most of the microwave energy is consumed before the microwave is reflected and returns to the upstream end.
The above description is made on the assumption that the waveguide 1 and the flow path 2 extend in a straight line, but the waveguide 1 has the flow path 2 built in even if both are bent somewhat. As long as you have, there is no problem.

  The reaction object 3 flows into the upstream end of the flow passage 2 through the inflow pipes 4 and 5. In the illustrated embodiment, the inflow pipes 4 and 5 have an oval shape whose cross section is flat in the vertical direction. With the inflow pipe having such a shape, there is no possibility that the reaction object 3 stays at the upstream end of the flow passage 2. However, the cross-sectional shape of the inflow pipes 4 and 5 is not limited to this. The portion of the inflow tubes 4 and 5 located in the waveguide 1 is usually made of a dielectric material with low microwave loss, while the portion located outside the waveguide 1 is made of metal or microscopic. It is covered with a tubular metallic part shaped so that the waves are cut off.

An example of the outflow part of the reaction object 3 is shown in FIG. Most of the microwave is consumed while translating with the reaction target, and it is considerably weak at the end. The waveguide 1 is short-circuited by a flat short-circuit plate 6 at the terminal end. The short-circuit plate 6 has a rectangular opening 6a through which the flow passage 2 passes. Since the microwave is cut off, if the thickness of the short-circuit plate 6 is appropriate, the leakage of the microwave can be suppressed to a level that does not cause any problem for safety. Although the microwave reflected by the short-circuit plate 6 propagates upstream, the energy is absorbed by the reaction object even in this process, and when it reaches the upstream end, it becomes a weak value without a problem. That is, it means that an extremely efficient chemical reaction apparatus can be provided.
The flow path 2 is led out from the waveguide 1 through the short-circuit plate 6, and guides the reaction target 3 that has finished the reaction to a required place.

FIG. 6 shows another embodiment of the flow passage 2. In this embodiment, the flow passage 2 has a groove-type cross section having an open top and a width dimension larger than a depth dimension. Note that most of the bottom surface is arranged in parallel with the electric field due to the boundary condition.
In chemical reactions, unnecessary products such as reaction water often occur. The generated reaction water becomes water vapor and is discharged into the waveguide 1 from the upper part of the flow path 2. In order to discharge gas such as water vapor in the waveguide 1, an exhaust pipe (not shown) is provided so as to penetrate the short-circuit plate 6 or, for example, the waveguide upper wall 1 c, and is connected to an exhaust pump for suction. . The exhaust pipe and its penetrating part are designed so as to satisfy the cutoff condition for microwaves.

In many cases, the viscosity increases as the chemical reaction progresses. In that case, there is a possibility that stagnation occurs in the flow of the reaction target, so that it is necessary to forcibly promote and improve the flow. Arranging the waveguide 1 and the flow path 2 so as to be inclined is one option, but it is often insufficient.
When stagnation occurs, the liquid level rises. Therefore, as shown in FIG. 7, the upper part of the groove-type flow passage 2 is covered with a lid 7. As a result, the downstream side (arrow tip side) end of the flow passage 2 has a tubular shape that is closed vertically and horizontally. Suction is performed by a pump so that the reaction target is integrally discharged at the downstream end. If balanced well, the reaction target having increased viscosity can be taken out by such a method.

  8 and 9 show another embodiment in which the reaction object flows at a speed that should flow. The reaction target 3 having increased viscosity is mechanically swept away by the delivery device 8 with a spatula blade. In FIG. 8, the delivery device 8 includes a plurality of water wheels 9. Moreover, in FIG. 9, the delivery apparatus 8 is comprised with the endless belt 10 with the blade board hung around the pulley. The extruded reaction target 3 flows into the storage tank 11. The endless belt 10 passes through the short-circuit plate 6 of the waveguide 1, but since the opening 6a is set to a size that can cut off the microwave, the thickness of the short-circuit plate 6 is effectively increased. If this is the case, the problem of electromagnetic wave leakage does not occur. The point of these embodiments is to attach a delivery device 8 that mechanically pushes out a reaction target. The delivery device 8 is composed of a dielectric material having a low microwave loss and a low dielectric constant, at least most of which is located in the waveguide 1. In the vicinity of the downstream end portion of the waveguide 1 to which the delivery device 8 is attached, the microwave is considerably weak. For example, the blade plate and its main support mechanism are made of quartz, and the bearing is partially Metal may be used. Since the temperature rises considerably, a certain amount of ingenuity is required for heat resistance and wear resistance.

  Since a compact chemical reaction apparatus can be configured, a large installation space is not required even if the system is upgraded so that a larger amount of reaction objects can be processed by arranging a plurality of them in parallel as necessary.

  The present invention can be used in a chemical reaction apparatus for industrially efficiently performing a chemical reaction of a relatively large amount of fluid.

It is a side view which shows the basic structure of the chemical reaction apparatus of this invention. It is II-II sectional drawing in FIG. It is III-III sectional drawing in FIG. It is IV-IV sectional drawing in FIG. It is VV sectional drawing in FIG. It is sectional drawing which shows the chemical reaction apparatus of other embodiment. It is sectional drawing which shows other embodiment of the flow path of reaction object. It is explanatory drawing which shows embodiment of the delivery apparatus of reaction object. It is explanatory drawing which shows other embodiment of the delivery apparatus of reaction object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rectangular waveguide 2 Flow path 3 Reaction object 4 Inflow pipe 5 Inflow pipe 6 Short circuit board 6a Opening 7 Lid 8 Feeding device 9 Water wheel 10 Endless belt 11 Storage tank

Claims (5)

A rectangular waveguide that transmits TE10 mode microwaves, and a flow path that is arranged in the waveguide to circulate a fluid reaction target that causes a chemical reaction,
The flow path is made of a material that transmits microwaves, extends in the axial direction of the waveguide, has a rectangular shape with a side parallel to the electric field in a cross section perpendicular to the axis and longer than a side perpendicular to the electric field, and has a length. Arranged so that most of the direction is located near the central axis of the waveguide,
A microwave chemical reaction device that causes a chemical reaction to occur by irradiating the reaction target with microwaves while flowing the reaction target from the upstream end of the flow passage and flowing out from the downstream end.   The waveguide is short-circuited on the downstream side of the flow path so that microwave leakage is sufficiently suppressed, and the flow path is led out from the waveguide through the short-circuit portion. The microwave chemical reaction apparatus according to claim 1.   The flow path is opened upward in at least a part of the waveguide, and the waveguide is exhausted to discharge gas vaporized from a reaction target in the flow path to the outside by a chemical reaction. The chemical reaction apparatus according to claim 1, wherein an apparatus is attached.   The chemical reaction device according to any one of claims 1 to 3, wherein the flow passage is formed in a rectangular tube shape at least on the downstream side, and a suction device for sucking a reaction target is attached to the downstream end. .   4. A delivery device made of a microwave low-loss material for mechanically pushing the reaction target downstream is attached to the downstream side of the flow passage. The chemical reaction apparatus according to 1.

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