JP5575623B2 - Insulator used for pressure vessel sensor for dielectric property measurement - Google Patents

Description

  The present invention relates to an insulator used for a small pressure vessel sensor for measuring dielectric characteristics of various fluids such as food.

  Since substances have inherent dielectric properties, they can exhibit dielectric polarization when placed in an electric field, and can know capacitance, dielectric constant, dielectric loss, dielectric relaxation, and the like. These characteristics directly reflect the state of motion of atomic groups and molecules. Therefore, measuring the dielectric characteristics is an effective means for detecting the molecular state of the constituent component in the measurement sample and its change.

  Since the measurement of dielectric properties is an effective means that can be directly measured under nondestructive conditions, it has been widely applied in the fields of food, medicine, chemistry, and the like. Application examples include the moisture content and the state of deterioration of edible oil (for example, Patent Document 1), the quality control of seasonings such as sauces from a macroscopic viewpoint, and the monitoring of the number of cells at the fermentation site. Can be mentioned. In the medical field, a method for non-invasively measuring blood glucose level from the skin has been devised (Patent Document 2). It is also applied to the measurement of alcohol content in mixed fuel.

  In the extraction of food materials and functional substances from natural products, it is necessary to select an appropriate solvent for the target solute. Conventionally, extraction processes using solubility parameters as an indicator of dissolution behavior have been studied. ing. The solubility parameter is defined by the latent heat of vaporization, and it is empirically known that the closer the solubility parameter value between the solute and the solvent is, the higher the compatibility is, and it is used as a guideline for judging the solubility. However, it is difficult to fit between materials having high hydrogen bonding properties.

  On the other hand, it is possible to actually measure the overall dielectric characteristics of each substance in an electric field, not only in a single phase but also in a mixed phase. When measuring the change in dielectric properties, when a dielectric (measurement sample) is inserted in an electric field region where the electrode surface area (S) and the distance between electrodes (d) are constant, the dielectric constant (ε) and the electric capacity (C) Is represented by C = ε (S / d). Therefore, since the electric capacity (C) can be easily measured by using an impedance analyzer or an LCR meter, a change in dielectric constant of the measurement sample can be measured as a change in electric capacity. Further, since it is reported that the smaller the dielectric constant difference between the solute and the solvent is, the higher the mixing property is, like the solubility parameter, it is possible to select an appropriate solvent by measuring the electric capacity.

  In this way, measuring the dielectric properties of various fluids such as foods has the great advantage of being able to directly observe these physical changes and properties in a non-destructive manner. From this point of view, there is a tendency that the measuring apparatus is enlarged and the structure needs to be changed depending on the properties of the fluid to be measured. For this reason, there has been a demand for the development of a highly versatile measuring instrument for simply measuring the dielectric properties of a wide range of fluids.

JP 2005-515436 A JP 2010-188135 A

  The present invention is widely applied to various fluids such as food (gas, liquid, various fluids such as supercritical fluid under high temperature and high pressure, and samples dissolved in fluid), and easily measures dielectric properties in a small space. It is an object of the present invention to provide a highly versatile measuring instrument and a suitable configuration thereof.

  In order to achieve the above object, as a result of intensive studies, the present inventors have developed a small pressure vessel sensor for measuring dielectric characteristics having the following configuration. The following (1) to (5) correspond to the respective symbols in FIG.

  A cylindrical cylindrical pressure vessel (2) serving as an electrode and an upper and lower pressure vessel lid (1), and a columnar or cylindrical electrode (3) serving as a pair of pressure vessel electrodes is disposed in parallel at the center of the vessel. A pressure-resistant container for measuring dielectric characteristics, characterized in that the columnar or cylindrical electrode (3) is installed via (4) and is led to the outside of the pressure-resistant container via a conducting wire (5). sensor.

  Further, the present inventors have further developed the following insulator used for the dielectric container for pressure characteristic measurement.

(I) The dielectric property measurement pressure vessel sensor is an insulator for use in insulation between electrodes, and has pores, and is in close contact with the cylindrical pressure vessel and the upper and lower pressure vessel lids. An insulator having a shape to be sealed, and thereby fixing a columnar or cylindrical electrode at the center of the container from above and below.
(II) The insulator according to (I), wherein a sample pocket is provided.
(III) The insulator according to (II), wherein a plurality of (for example, 4 to 5) pores and sample pockets are provided.

  ADVANTAGE OF THE INVENTION According to this invention, an electrode can be fixed maintaining a fixed distance, insulating the counter electrode of the pressure-resistant container sensor for dielectric property measurement of various fluids, such as foodstuffs. This makes it easier to continuously measure dielectric properties of various fluids including high pressure liquids. Further, by providing a sample pocket in the insulator, it is possible to provide a field for dissolving the sample in the dielectric container for pressure measurement.

Sectional drawing of an example of the pressure-resistant container sensor for dielectric property measurement is shown. The example of the insulator structure for fixing a counter electrode is shown. The upper and lower stages are top and rear views, and the middle stage is a cross-sectional view.

  The pressure-resistant container of the pressure-resistant container sensor for measuring dielectric characteristics is composed of a cylindrical shape and lids that are upper and lower nuts. One of the characteristics is that the container itself plays a role as an electrode by using a metal material such as stainless steel. As a result, it is not necessary to install a plate electrode or a cylinder-type electrode that has been conventionally used in the pressure vessel, and the size of the vessel and the simplicity of the design are realized. In particular, by using a material having high corrosion resistance and high heat resistance such as SUS316 as a material, it can be applied to a severe reaction field such as a supercritical fluid. The columnar or cylindrical electrode inside the container that forms a pair with this is installed in parallel with the cylindrical pressure-resistant container via an insulator. About the material of this columnar or cylindrical electrode, it is preferable to use the same material as the pressure vessel electrode.

  The container volume is about 20 to 30 mL, and the thickness of the cylinder is about 6 mm. Thereby, it is small and can hold | maintain high pressure | voltage resistance. The outer surface of the pressure vessel is preferably coated with an insulating material having excellent heat resistance and chemical resistance, such as polytetrafluoroethylene (PTFE), in order to protect it from external electrical interference.

  The columnar or cylindrical electrode is led to the outside of the pressure vessel through a lead wire such as Pt covered with an insulator such as Teflon (registered trademark) resin. Such a dielectric property measurement container is placed under an appropriate temperature condition with a heater or an oven, and the fluid and the measurement sample are allowed to flow in with a pump or the like, and an appropriate pressure condition is achieved with a back pressure valve or a regulator. To measure the desired dielectric properties. For example, the dielectric characteristics are measured by connecting an LCR meter or an impedance analyzer to the dielectric characteristics of the dielectric in the low frequency to high frequency range of 10 Hz to 100 MHz.

  The insulator of the present invention preferably uses Teflon (registered trademark) resin or the like so that it can be easily processed into a structure corresponding to various situations. The insulator also serves as a seal for the contact surfaces of the cylinder of the pressure vessel electrode and the upper and lower lid nuts, and assists the sealed state in the vessel. And the said insulator makes it possible to measure the dielectric properties of various fluids more simply and easily by providing pores. Moreover, this pore can also be used as a conducting wire path for connecting a columnar or cylindrical electrode to the outside.

  Further, the insulator can provide a field for dissolution of the sample in the dielectric measurement container by providing a sample pocket of an appropriate size. This makes it possible to know the dissolution behavior, solubility and the like of the polar component, and to perform quality control and the like. For example, although four pockets are shown in the example of FIG. 2, these are volumes that can sufficiently saturate the sample components in the fluid filled in the container.

  The fluid to be measured includes all solvents such as water, methanol, ethanol, acetone, n-hexane, phenol, chloroform, dichloromethane, acetonitrile, carbon dioxide, mixed solvents thereof, and supercritical fluids thereof. With respect to the solute component, polar components such as hydrocarbon compounds such as terpenoids and fatty acids, polyphenols, and carbohydrates are mainly targeted. In addition, the food itself composed of these solvents and solutes is also an object to be measured, and is characterized by being able to measure fluids having various viscosities.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

  FIG. 1 shows a cross-sectional view of an example of the configuration of a dielectric container measuring pressure vessel sensor for simply measuring dielectric characteristics in a small space. In FIG. 1, a metallic cylindrical pressure vessel (2) and upper and lower pressure vessel lids (1) constitute a pressure vessel electrode, and a columnar or cylindrical electrode (3 ) Are installed in parallel via an insulator (4), and a pair of columnar or cylindrical electrodes (3) are led to the outside of the pressure vessel via a lead (5) in an insulated state. The surface of the pressure vessel is provided with an insulating coating (6).

  Next, FIG. 2 shows an example of the configuration of an insulator for fixing the counter electrode of the dielectric container for measuring dielectric characteristics according to the present invention. In this example, five pores (shown as fluid passages) and four sample pockets are provided. The horizontal portion is also provided with a pressure-resistant container seal having a shape in which the cylindrical pressure-resistant container and the upper and lower pressure-resistant container lids are in close contact with each other to seal and fix them.

  The present invention is summarized as follows.

  It is an object of the present invention to provide a versatile measuring instrument that can be widely applied to various fluids such as foods and simply measure dielectric properties in a small space, and to provide a suitable configuration thereof. To do.

  And it is provided with a pore and has a shape that tightly seals and seals the cylindrical pressure vessel and the upper and lower pressure vessel lids of the dielectric property measurement pressure vessel sensor. An insulator that fixes the columnar or cylindrical electrode in the center of the sensor's container from above and below is used in a pressure-resistant container sensor for measuring dielectric properties, so that the electrode is fixed at a constant distance while insulating the counter electrode. can do.

Claims (2)

It has a metal cylindrical pressure vessel electrode and an upper and lower pressure vessel lid, and a columnar or cylindrical electrode which is a pair of the cylindrical pressure vessel electrode is installed in parallel at the center of the vessel , and the columnar or cylindrical electrode Is a dielectric container for measuring dielectric properties, which is led to the outside of the container in an insulated state via a conducting wire, and is an insulator for use in insulation between electrodes, provided with a pore and a sample pocket , and a cylinder Insulator characterized in that it has a shape that tightly seals and seals the mold pressure vessel electrode and the upper and lower pressure vessel lids, thereby fixing the cylindrical or cylindrical electrode at the center of the vessel from above and below .     2. The insulator according to claim 1, wherein a plurality of pores and sample pockets are provided.

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