JPS5973034A - Magnetic stirrer - Google Patents

Abstract

PURPOSE:To improve the conductivity, by a method wherein a stirring stand is formed of a non-conductive material while a stirring element is constituted from a conductive magnetic body and an induction coil for applying alternating magnetic flux to the stirring element and a high frequency power source are provided. CONSTITUTION:A stirring stand 10 comprises a non-conductive material such as ceramics and a container 3 having a solvent and a specimen 4 accommodated therein is placed on the stirring stand while a stirring elemet 11 made of a conductive magnetic body is put in the container 3. A ring shaped induction coil 12 is provided at a position where alternating magnetic fluxes (a), (b) thereof pierce the stirring element 11 through the stirring stand under the stirring stand 10. In addition, the high frequency power source 13 of the induction coil 12 is provided and a heat insulating material 14 is interposed between a rotary magnet 6 and a motor 7. The heat insulating material 14 prevents adverse influence to the motor 7 caused by the heating of the rotary magnet 6 generated by the alternating magnetic fluxes (a), (b) of the induction coil 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic stirrer for stirring a solvent solid or liquid sample so as not to dissolve it.

Figure 1 is a configuration diagram of a conventional magnetic stirrer, in which 1 is a hot plate, 2 is a heater for heating the hot brake 1~, and 3 is a sample container such as a beer plate placed on the plate 1~. , 4 is a container and sample placed in the sample container, 5 is a magnetic stirrer placed in the sample container,
6 is a magnet that applies magnetic force to the stirrer 5 through the hot plate 1 and rotates once.

7 is a motor that rotationally drives the rotating magnet 6; 8 is a magnetic stirrer housing that holds the plate 1 through a heat insulating material 9; With this configuration, by rotating the rotary magnet 6 with the motor 7, the magnetic force exerted by the magnet rotates the stirrer 5 in the solvent and sample to perform stirring. At this time, in order to promote dissolution of the sample in the solvent, heat is applied to the sample and the solvent from the hot plate 1 heated by the heater 2 through the bottom surface of the sample container 3.

Although the magnetic stirrer having the above structure is widely used today, it has the following drawbacks because it uses a hot plate to promote sample dissolution.

(1) The bottom of the sample container that comes into contact with the hot plate is generally not flat, but has a concave central part, so the contact surface between the hole 1 and the plate 1 is only around the bottom, which reduces heat conduction to the sample and solvent inside. not good.

(2) The surface temperature of the plate 1 to 1 is quite high, so there is a risk of getting burned if you touch it carelessly.

Therefore, the present invention aims to improve the above-mentioned drawbacks of the prior art, and its purpose is to provide a magnetic stirrer that is safe and has good heat conduction to the sample and solvent.

The features of the present invention for achieving this object include: a stirring table on which a sample container containing a sample is placed; a magnetic stirrer placed in the sample container; and a stirrer sandwiching the stirring table. In a magnetic stirrer that has a motor-driven rotating magnet that does not apply magnetic force to the sample container, and that stirs the sample by rotating a stirrer in a sample container according to the rotation of the rotating magnet, the stirring table is formed of a non-conductive material, and The stirrer is made of a conductive magnetic material,
Furthermore, the magnetic stirrer is equipped with an induction coil that applies an alternating magnetic flux to the stirrer and a high frequency power source that drives the coil, and uses the heat generated in the stirrer to heat the sample. The present invention will be explained in detail below with reference to the drawings.

FIG. 2 shows an embodiment of the magnetic stirrer according to the present invention, and the same reference numerals as in FIG. 1 indicate the same parts.

In the figure, reference number 1o is a non-conductive stirring table made of ceramic, for example, and a sample container 3 containing a solvent and a sample 4 is placed on the stirring table.

A stirrer 11 made of a conductive magnetic material is placed inside the sample container 3 . Reference numeral 12 denotes, for example, a ring-shaped induction coil, which directs its alternating magnetic flux (a
, b) is thus placed in a position that penetrates /υ子11. 13 is a high frequency power source for an induction coil, 14 is a rotating magnet 6
This is a heat insulating material interposed between the motor 7 and the motor. Insulation material 14
This is to prevent an adverse effect on the motor 7 due to the heating of the rotating magnet 6 caused by the alternating magnetic flux (a, b) of the induction coil 12. If so, there is no need to provide it.

With the above configuration, for example, 1 to 1 in 100 from the high frequency power supply 13.
When a high frequency of 7 is applied to the induction coil 12, the coil 12 generates an alternating magnetic flux shown by dashed lines a and b. As shown in the figure, the alternating magnetic fluxes a and b pass through the conductive magnetic stirrer 11, so that eddy currents are generated in the stirrer/υ element 11 and heat is generated due to the accompanying eddy current loss. Therefore, since the solvent and sample in the sample container 3 have a heat source inside, they are not affected by the bottom shape of the sample container or the thermal conductivity of the sample container itself. Moreover, since the stirring table 10 is non-conductive, it is not affected by alternating magnetic flux.

As explained above, according to the present invention, a conductive magnetic stirrer is used to heat the solvent and the sample by utilizing the heat generated by the eddy flow loss generated in the stirrer, so that the bottom surface shape of the sample container is It is possible to provide a magnetic stirrer that is not affected by the thermal conductivity of the container and does not require any risk of burns since the stirring table itself is not heated.

[Brief explanation of drawings]

FIG. 1 shows a conventional example of a magnetic stirrer, and FIG. 2 shows an embodiment of the magnetic stirrer according to the present invention. 10... Stirring table 11... Stirring plate 12
...Induction coil 13...When using high frequency power supply
Applicant A771 ~ Kagaku Co., Ltd. Figure 2 Procedure Neyama〒 [Book (Method) % Formula % 1, Indication of case 1981 Patent Application No. 181780 2, Title of invention Magnetic Stara 3, Stone for amendment Relationship to the incident Patent applicant address (residence) 2-9-5 Nihonbashi Honmachi, Chuo-ku, Tokyo
Name Yamato Scientific Co., Ltd. Representative α Tatsumi Kawa 6, Subject of amendment (1) Power of attorney (2) Specification (3) Drawing 7, Contents of amendment <1) Extrusion of power of attorney (2) Specification 8. Attached list of fvI layers

Claims (1)

[Claims] A stirring table on which a sample container containing a sample is placed, a magnetic stirrer placed in the sample container, and a rotating magnet 6 driven by a motor so that no magnetic force is applied to the stirrer sandwiched between the stirring table. In a magnetic stirrer that stirs a sample by rotating a stirrer in a sample container according to the rotation of the rotating magnet, the stirring table is made of a non-conductive material and the stirrer is made of a conductive magnetic material. , further comprising an induction coil that provides an alternating magnetic flux to the stirrer and a high frequency power source that drives the coil;
A magnetic stirrer characterized by heating a sample by utilizing the heat generated by the stirrer.