JPH049724A - Measuring device for furnace temperature of hot hydrostatic pressure apparatus - Google Patents

Abstract

PURPOSE:To accurately measure a furnace temperature of a pressure apparatus to be operated under relatively low pressure without influence of pressure by forming a heat radiation incident surface opposed to the end of a closed end tube in a spherical surface with an objective point of measurement as its center. CONSTITUTION:An optical element 13 is hermetically sealed fixedly to a lower cover 3 through a sealing member 14, and its heat radiation incident surface 15 is formed in a spherical surface at a point 16 to be measured at its temperature of the end 10 of a closed tube as a center. A detector 17 for detecting the heat radiation is so associated with the cover 3 as to limit a visual field by a collimator 18, and its maximum visual field is so formed as to converge a focus at the point 16 through combination lenses 19, 20 and the element 13 to collect the radiated heat of a predetermined part. The heat radiated from the end 10 of the tube is condensed to an optical system 12 at the lower part of the tube 9, introduced to the detector 17 through an optical fiber, and a temperature in a furnace chamber 7 is measured. Thus, the temperature can be measured without influence of variation in the refractive index of gas upon variation of the pressure.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is for measuring the temperature inside a hot isostatic press (hereinafter abbreviated as HIP) device used under relatively low pressure. This invention relates to a furnace temperature measuring device.

(Prior art) A HIP device is a device that utilizes the synergistic effect of high temperature and high pressure to perform pressure sintering of powder, defect removal of sintered crystals and cast products, and diffusion bonding. Its industrial use is attracting attention, and recently its application has been focused on engineering ceramics at temperatures between 1700°C and 2100°C.
It has spread to the high temperature region of ``C.

In such equipment, controlling the temperature inside the high-temperature, high-pressure furnace is extremely important for the treatment efficiency, and therefore various temperature measurement means are installed to detect the temperature inside the furnace, and currently there are no closed ones. There is talk of adopting radiation temperature measuring means using end tubes.

FIG. 5 shows a known HI equipped with temperature measuring means in the furnace.
An example of a P device is shown.

That is, FIG. 5 uses a closed-end tube 31 and an optical fiber 32,
The closed-end tube 31 is connected to a high-pressure container 35 including a heater 33 and a heat insulating layer 34.
Furnace chamber 3 partitioned by the heat insulating layer 34 of P device
The radiation thermometer 40 A device connected to a measurement system consisting of
(Refer to Publication No. 7) In order to take in the emitted light from the closed-end tube 31 into the optical fiber 32, there is a method of directly inputting it into the optical fiber 32 as shown in FIG. 6, or a collimator using a lens 41 as shown in FIG. There is a method of projecting light onto the optical fiber 32 at 42.

However, in the HIP device, the location where the optical system is placed is usually around 300°C and 12,000 atmospheres, and the density of the gas such as Ar or N2 that forms the atmosphere is significantly different from that at room temperature and pressure. , and has a high density. In particular, the collimator in the apparatus shown in FIG.
(See FIG. 7) is located at a relatively low temperature, so the density is even higher.

As a result, the refractive index of the gas increases with increasing density and is greater than the value at room temperature and pressure, which improves the optical properties of lenses and optical fibers designed for use in air at room temperature and pressure, e.g. Changes in distance, numerical aperture of the optical fiber, etc. will affect the thermometer characteristics.

To explain this in more detail, the focal length of a lens is usually expressed as follows.

n l rz r+where, r, , rz : Radius of curvature L on both sides of the lens However, nL ; Absolute refractive index of the lens material n2i Absolute refractive index of the lens surrounding medium And, for gas at room temperature and normal pressure, n2 is almost equal to l , the lens is designed under these conditions.

However, as shown in the following table, the absolute refractive index of the gas changes depending on the pressure, and the focal length changes according to the above equation.

Of course, the density tends to decrease due to the high pressure and high temperature inside the IP device, and the refractive change rate is smaller than in the table above, but the state of the temperature measurement optical system changes (i.e., the pressure There is no change in the fact that

In order to solve these problems unique to HIP equipment,
A method disclosed in Japanese Unexamined Patent Publication No. 163935/1983 has already been invented, and as shown in FIG. , lenses 4 on the incident surface and the exit surface, respectively.
1, and a convex lens-shaped portion 46 with a high refractive index is a lens 41.
This can be achieved by setting it inside the .

(Problem to be Solved by the Invention) However, when the HIP device is operated under relatively low pressure, the above conventional configuration has problems such as the configuration of the lens system and the introduction of the optical fiber into the high-pressure container. However, it has the disadvantage of requiring advanced quality control.

In view of the above-mentioned problems, the present invention has a simple configuration to measure the temperature inside the furnace of an HTP device operated under relatively low pressure.
There is something that can be done accurately without being affected by pressure.

(Means for Solving the Problem) The technical means of the present invention for solving this technical problem is to provide a furnace chamber 7 provided in a high pressure chamber 4 formed by a high pressure vessel 1.
A closed-end tube 9 is installed, and the thermal radiation from the tip 10 of the closed-end tube 9 is collected by an optical system 12 and guided to a detector 17 to measure the temperature inside the furnace chamber 7. In the furnace temperature measuring device of the isostatic pressure pressurizing device, at least the optical system element 13 facing the closed-end tube tip 10 of the optical system 12 is fixed to the high-pressure vessel 1 in an airtight manner, and the optical system The thermal radiation incidence surface 15 facing the closed-end tube tip 10 of the system element 13 is formed into a spherical surface centered on the temperature measurement target point 16 of the closed-end tube tip 10.
The point is that the radiant energy from 6 is focused outside the high pressure chamber 4.

(Function) Thermal radiation from the closed-end tube tip 10 is focused on the optical system 12 located at the bottom of the closed-end tube 9, inputted directly or via the optical fiber 21 to the detector 17, and Furnace chamber 7 by
Temperature measurements are taken within the In this case, since the entrance surface 15 of the optical system element 13 in contact with the high-pressure gas in the high-pressure chamber 4 is configured as a spherical surface centered on the temperature measurement target point 16 and condenses light, the refraction of the gas due to pressure fluctuations occurs. Temperature measurement becomes possible without being affected by rate changes.

(Example) Hereinafter, the present invention will be explained according to the illustrated example.
In the figure, 1 is a high-pressure container, 2 is its upper lid, and 3 is its lower lid, and a high-pressure chamber 4 is formed by these. Note that the axial force acting on the upper lid 2 and the lower M3 is applied by a press frame, which is not shown.

Inside the high pressure chamber 4, a heat insulating layer 5 and a heating device 6 are disposed inside the heat insulating layer 5 to form a high temperature and high pressure furnace chamber 7. Reference numeral 8 denotes a sample stand provided at the bottom of the furnace chamber 7 and serving as a heat insulator.

A closed-end tube 9 is disposed in the furnace chamber 7 so that its tip 10 is placed at the temperature measurement site, and its lower end is fixed to the lower lid 3. A minute opening 11 is provided near the lower M3 at the bottom of the closed-end tube 9 to maintain pressure balance with the high pressure chamber 4.

12 is an optical system provided below the closed end tube 9 of the lower lid 3. This optical system 12 includes a closed-end tube tip 10 as shown in FIG.
It includes an optical system element 13 (lens) facing the , a combination lens 19 and 20, and a collimator 1B. The optical system element 13 is airtightly fixed to the lower lid 3 via a sealing member 14, and its thermal radiation incidence surface 15 is a spherical surface centered on the temperature measurement target point 16 of the closed-end tube tip 10. It is composed of A detector 17 for detecting thermal radiation is mounted on the lower lid 3.
are incorporated so that the field of view is limited by the collimator 18, and the maximum field of view is the combined lens 19.
20 and the optical system element 13 are configured to focus on the temperature measurement target point 16 and collect heat radiation in a prescribed portion.

Note that the lens 20 is configured as a convex lens-shaped portion with a high refractive index because it is necessary to bend the optical path inward inside the lens 20 . Further, regarding lenses 1.9.20, the function may be performed by a single lens (as long as it is a focusing optical system), and there is no need to provide the structure in contact with element 13. Regarding the element 13, if the object to be measured is placed at an infinite distance, the entrance surface 15 becomes a plane, and the blade exit surface may also be a plane and configured as a glass window.

FIG. 3 shows another embodiment, in which the thermal radiation from the optical system 12 is focused on the tip surface 21a of the optical fiber 21 (with the maximum field of view determined by the numerical aperture of the optical fiber 12, the object of temperature measurement is The optical fiber 21 is configured to guide the thermal radiation from the optical system 12 to the external detector 17 through the optical fiber 21. In other respects, the configuration is similar to that of the previous embodiment.

FIG. 4 shows another embodiment, in which the closed-end tube 9 and the optical system 12 are fixed to a mounting member 22, and this mounting member 22 is attached to a lower M3.
The temperature measuring system is airtightly attached using a sealing member 23, thereby making it possible to easily remove the temperature measuring system from outside the high pressure vessel 1.

Regarding the installation method of the closed-end tube 9 in the furnace chamber 7, it is possible to install it from the side by penetrating the heat insulating layer 5, but it is possible to install the closed-end tube 9 in the furnace chamber 7 from the side. Considering this, installation methods that can cause density changes in a plane perpendicular to the axis are undesirable, and therefore it is desirable to install them vertically.Furthermore, considering the thermal protection of the optical system 12, it is undesirable to install the optical system 12 from below. It is desirable to install it vertically.

(Effects of the Invention) According to the present invention, the optical system element 13 facing the closed-end tube tip 10 is airtightly fixed to the high-pressure vessel, and the closed-end tube tip 10 of the optical system element 13 and Since the opposing thermal radiation entrance surface 15 is formed into a spherical surface centered on the temperature measurement target point 16 of the closed-end tube tip 10, it is not affected by changes in the refractive index of the gas due to pressure fluctuations. It is possible to measure temperature accurately without any problems.

Moreover, most of the optical system 12 can be provided outside the high pressure chamber 4, and the design of the optical system I2 itself is simplified, which in turn increases the reliability of the temperature measuring system as a whole.

In addition, when the optical system element 13 and the closed-end tube 9 are fixedly airtightly fixed to the high-pressure vessel 1 as an integral component, the temperature measurement system can be easily removed from outside the high-pressure vessel 1.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view of the closed-end tube and optical system portion. FIGS. 3 and 4 are sectional views showing other embodiments, respectively. Fig. 5 is a sectional view showing the conventional example, Fig. 6 is a block diagram of the closed end tube and optical fiber section, Fig. 7 is a sectional view of the collimator section, and Fig. 8 is a block diagram of the optical system section. be. 1-High pressure vessel, 7-Furnace chamber, 9-Closed end tube, 10 Tip, 12.-Optical system, 15-Incidence surface, 16-Temperature measurement target point,
17-Detector. Patent Applicant: Kobe Steel, Ltd. Figure 2 Figure 7 'N1 Figure 8

Claims (2)

[Claims] (1) A closed-end tube (9) is installed in a furnace chamber (7) provided in a high-pressure chamber (4) formed by a high-pressure container (1). ) is focused by the optical system (12), and guided to the detector (17) and sent to the furnace chamber (7).
), in which the optical system (12) includes at least a closed-end tube tip (
The optical system element (13) facing the high pressure vessel (10)
), and a thermal radiation incidence surface (15) facing the closed-end tube tip (10) of the optical system element (13).
is formed into a spherical surface centered on the temperature measurement target point (16) of the closed end tube tip (10), and the radiant energy from the temperature measurement target point (16) is focused outside the high pressure chamber (4). A furnace temperature measuring device for a hot isostatic pressurizing device, characterized in that: (2) The hot static system according to item 1, wherein the optical system element (13) and the closed-end tube (9) are hermetically fixed to the high-pressure vessel (1) as an integral component. Furnace temperature measurement device for water pressure equipment.