JPS647302Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric furnace for thermal analysis with an observation window that allows observation of the state of a sample.

Conventionally, as this type of electric furnace, one is known in which a wire heater is wound around a base material and its outer periphery is surrounded by a heat insulating material such as refractory brick, but synthetic resin deforms due to constant temperature, Even if you try to observe a sample that has changed color etc. from the outside, it is difficult to see it in detail because it is blocked by the support base material of the heater and the heat insulating material.

The purpose of the present invention is to eliminate such inconveniences, and to provide an electric furnace for thermal analysis that can rapidly raise the temperature of a sample and make the temperature distribution uniform. A strip-shaped heater is made to surround the sample and support itself, and a reflector made of a translucent cylindrical base material whose inner surface is coated with a gold layer thick enough to be seen through is disposed on the outside of the heater. do.

FIG. 1 shows an embodiment of the present invention applied to a thermobalance. In the figure, 1 is a translucent sample container;
The sample container 1 is connected from its bottom to a balance via a bar 2, and is housed in a soaking tube 3 made of quartz glass. 4 is a cylinder made of quartz glass through which an inert gas or the like flows. The heater 5 surrounding the cylindrical body 4 is made of a strip heater made of, for example, an iron-chromium alloy and formed into a mesh shape by photo-etching.As clearly shown in FIGS. 2 and 3, the strip heaters are arranged in parallel. A plurality of strips 6 are connected in series by connecting each of the strips 6 at both ends to adjacent strips 6, and a claw piece 7 provided at the connecting portion
It is self-supported by disks 8, 8 which are fixedly mounted above and below. Reference numeral 9 denotes a reflector made of a transparent cylindrical base material such as quartz glass, the inner surface of which is coated with a gold layer 10 thick enough to be seen through by plating or the like;
The radiant heat from the heater 5 is reflected by the gold layer 10 surface, thereby blocking the radiant heat from leaking to the outside.

In FIG. 1, 11 is a transparent protective cylinder made of Pyrex or the like, and 12 is a thermobalance unit on which the present electric furnace is mounted.

Next, the operation of the heater 5 will be described.
is fixed at its upper and lower parts to the disks 8, 8 so as to be self-supporting, and is formed into a mesh-like shape by photoetching. The reflector 9 is thick enough that the gold layer 10 can be seen through, and uses a translucent cylindrical base material. Therefore, when viewed from the outside of the reflector 9, the shape, color, etc. of the sample placed in the atmosphere brightened by the red heat of the heater 5 can be closely observed.

The heater 5 has a large thermal resistance because it is formed into a fine mesh shape by photo-etching.
The temperature gradient is small and the temperature distribution is almost uniform.
Since this heater 5 is not disposed on a support member and is self-supporting, its heat capacity is small, and the reflector 9 transfers outward radiant heat from the heater 5 to the gold layer 1.
The heat capacity is small because it is reflected by zero and blocks heat from the outside. In this way, the temperature of the sample can be raised rapidly, and it can also be lowered rapidly.

In this heater 5, current flows in opposite directions between one strip 6 and the adjacent strip 6, so the magnetic flux generated by the current cancels each other and becomes non-inductive, thus eliminating the influence of magnetic lines of force. This heater is suitable for samples that are undesirably exposed. FIG. 4 shows rising and falling temperature characteristics of the electric furnace of the present invention (solid line) and the conventional electric furnace (dashed line) that uses a wire heater and is provided with a heat insulating material such as refractory tiles. The electric furnace of the present invention achieved a rapid heating rate of 100°C/min, compared to 20°C/min for conventional products.

In this way, according to the present invention, a heater formed in a mesh shape by photo-etching is made to surround the sample and support itself, and a light-transmitting heater coated with a gold layer thick enough to transmit light on the inner surface is placed on the outside of the heater. Since a reflector made of a flexible cylindrical base material is provided, it is possible to closely observe the shape, color, etc. of the sample during thermal analysis from the outside, and also has the effect of rapidly increasing the temperature of the sample and making the temperature distribution uniform.

[Brief explanation of drawings]

Fig. 1 is a sectional view of one embodiment of the present invention applied to a thermobalance, Fig. 2 is a sectional view taken along the line - - of Fig. 1,
FIG. 3 is a partial exploded view of the heater, and FIG. 4 is a rise/fall temperature characteristic diagram of electric furnaces of the present invention and a conventional example. 1...Sample container, 5...Heater, 9...Reflector, 10...Gold layer.

Claims (1)

[Scope of utility model registration request] A band-shaped heater formed into a mesh shape by photo-etching surrounds the sample and is self-supporting, and a reflector made of a translucent cylindrical base material whose inner surface is coated with a thick gold layer that can be seen through is placed on the outside. An electric furnace for thermal analysis with an observation window.