JPH05117708A - Safety device of hot isostatic press - Google Patents

Abstract

PURPOSE:To simplify the structure of the safety device without need for a thermocouple, etc., and to prevent the overheating due to failure. CONSTITUTION:A rapid cooling passage 9 for circulating the high-temp. gas of the furnace chamber 6 in a heat-insulating layer 5 in cooling is formed at the upper part of the insulating layer 5 in a high-pressure cooling vessel 1, and a passage cleaning valve 10 for cleaning the W passage 9 when the inner surface of the vessel 1 is overheated is furnished. A temp. sensing ferromagnetic body 14 with the Curie point controlled to the overheating temp. of the inner surface of the vessel 1 is provided to the valve 10, and a magnet 16 is provided at the upper part of the vessel 1 to keep the valve open through the ferromagnetic body 14 and to close the valve 10 when the temp. of the inner surface of the vessel 1 exceeds the Curie point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a hot isostatic pressing device.

[0002]

2. Description of the Related Art Hot isotropic pressure for applying high isotropic pressure and high temperature by a gas to a material to be processed at the same time to perform pressure sintering of powder, defect removal of sintered products and castings, diffusion bonding of dissimilar materials, etc. A pressurizing device (hereinafter referred to as a HIP device) is conventionally configured as shown in FIG. That is, in FIG. 3, 1 is a high-pressure container, which is composed of a high-pressure cylinder 2 and upper and lower lids 3 and 4, and has a high gas pressure space inside. 5 is an inverted cup-shaped heat insulating layer, which is placed on the lower lid 4 in the high-pressure container 1,
The inside of this heat insulation layer 5 is a furnace chamber 6. 7 is a heater and 8 is a processing material.

Reference numeral 9 denotes a quenching passage formed on the heat insulating layer 5, which can be opened and closed by a passage closing valve 10. Flow path shutoff valve 10
Is driven to open and close by a hydraulic cylinder 11 mounted on the upper lid 3. Reference numeral 12 is a thermocouple that senses the temperature inside the high-pressure container 1, and is provided in the upper part of the high-pressure container 1. 13 is a controller. In the HIP processing process of the processing material 8, the inside of the furnace chamber 6 is maintained at a high temperature by the heater 7. Then, in the cooling process after the end of the processing process, the flow passage shut-off valve 10 is pulled up and opened by the hydraulic cylinder 11, and the high temperature gas in the furnace chamber 6 is rapidly cooled.
Rapid cooling is performed by circulating the inside and outside of the heat insulating layer 5 through 9 as indicated by the arrow A.

In this cooling process, what should be noted for the safety of the apparatus is excessive temperature rise of the inner surface of the high-pressure container 1. This causes an increase in thermal stress and reduces the fatigue strength of the high pressure vessel 1. Therefore, conventionally, the thermocouple 12 was installed at the position where the highest surface temperature rise was expected inside the high-pressure vessel 1, and when the temperature was excessively high, the flow passage shut-off valve 10 was opened and closed according to the output voltage of the thermocouple 12 to circulate. The flow rate is being adjusted.

[0005]

Increasing the size of the HIP device,
It is considered that as the application to ultra-high temperature expands, rapid cooling by circulating flow will increase in the cooling process. At this time, from the viewpoint of the safety of the high-pressure container 1, it is necessary to guarantee the overheating prevention of the inner surface of the high-pressure container 1 with a probability of 100%.

However, in the conventional HIP device, the thermocouple 12
By detecting the excessive temperature rise by the output voltage of, and opening and closing the flow path shutoff valve 10 via the controller 13 and the hydraulic cylinder 11, when there is an abnormality in the thermocouple 12, the controller 13, the hydraulic cylinder 11, etc., There is a possibility that the inner surface of the high-pressure container 1 may be overheated. The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a simple structure without the need for a thermocouple or the like, and to prevent an accident of excessive temperature rise due to a failure.

[0007]

[Means for Solving the Problems] According to the present invention, a furnace chamber 6 inside the heat insulating layer 5 is provided at the upper portion of the heat insulating layer 5 in the high pressure vessel 1 during cooling.
In the hot isostatic pressurizing device provided with a flow passage shut-off valve 10 for forming the quenching flow passage 9 for circulating the high temperature gas and closing the quenching flow passage 9 when the inner surface of the high-pressure container 1 is overheated, High pressure vessel
(1) A temperature-sensing ferromagnetic material (14) having an overheating point on the inner surface as the Curie point is provided in the flow path shut-off valve (10), and the flow path shut-off valve (10) is held in the open position via this ferromagnetic material (14) and a high-pressure container 1 The high pressure vessel 1 is provided with a magnet 16 for closing the flow path shutoff valve 10 when the inner surface exceeds the Curie point.

[0008]

[Operation] In the cooling process, the magnetic force of the magnet 16 causes the ferromagnetic material 14
The flow path shutoff valve 10 is held in the open position via the, and the high temperature gas in the furnace chamber 6 is circulated by natural convection through the quenching flow path 9. During this cooling, if the temperature of the inner surface of the high-pressure vessel 1 exceeds the excessive temperature rise point, that is, the Curie point of the ferromagnetic material 14, its saturation magnetic susceptibility decreases sharply, and the flow passage shutoff valve 10 closes the quenching flow passage 9. Therefore, it is possible to prevent the overheating of the high-pressure container 1.

Since the physical phenomenon in which the saturation magnetic susceptibility of the ferromagnetic material 14 sharply decreases at the Curie point is used as described above, the structure is simplified without the need for a thermocouple for temperature sensing, and the failure is accompanied by a failure. Accidents of excessive temperature rise can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows the entire HIP device, and its essential parts are shown in FIG. In FIGS. 1 and 2, the flow path shutoff valve 10 is made of, for example, iron, and is provided so as to be movable up and down so as to open and close the quenching flow path 9 of the heat insulating layer 5. And this flow path shutoff valve 10
A ferromagnetic material 14 for temperature sensing having an excessive temperature rise point on the inner surface of the high-pressure container 1, that is, a Curie point at an allowable limit temperature, is embedded therein.

On the other hand, in the upper lid 3 of the high-pressure container 1, a recess 15 into which the passage shutoff valve 10 is fitted from below and an electromagnet 16 are provided in the quench passage.
It is provided above and below corresponding to the 9 axis positions. electromagnet
Reference numeral 16 is composed of an iron core and a coil 17 wound around the core, and the coil 17 is connected to an external power source via a cable 18. The electromagnet 16 holds the flow path shutoff valve 10 in the open position for fitting into the recess 15 via the ferromagnetic body 14 when energized, and when the inner surface of the high-pressure vessel 1 exceeds the Curie point, it is ferromagnetic. The flow path shutoff valve 10 is closed by a rapid decrease in the saturation magnetic susceptibility of the body 14. 19 is a quench valve, which is a heat insulating layer 5
It is provided in the lower structure 20 of the furnace chamber at the lower end so as to be openable and closable.

Next, the operation will be described. Coil 17 of electromagnet 16
The magnetic flux 21 is always energized to generate a magnetic flux 21, and the magnetic force holds the flow path shutoff valve 10 in the open position. Therefore, the quenching flow path 9 is always open, and the space inside the furnace chamber 6 and the space outside the heat insulating layer 5 are in communication with each other. However, since the quench valve 19 at the bottom of the furnace chamber 6 is closed, no convection occurs inside or outside the heat insulating layer 5.

During the quenching process, when the quenching valve 19 is opened, the high temperature gas in the furnace chamber 6 passes through the quenching passage 9 and the quenching valve 19 and the heat insulating layer
Since the circulating flow A circulating by natural convection is generated inside and outside 5, the inside of the furnace chamber 6 is rapidly cooled. In this quenching process, if the temperature of the inner surface of the high-pressure vessel 1 rises excessively for some reason, it is detected by the ferromagnetic material 14, the flow path shut-off valve 10 is lowered to close the quenching flow path 9, and the circulation flow Shut off A.

That is, since the ferromagnetic material 14 whose Curie point is the permissible limit temperature Tc of the high-pressure container 1 is incorporated in the flow path shutoff valve 10 for temperature sensing, the temperature of the inner surface of the high-pressure container 1 is allowed during rapid cooling. When the temperature exceeds the limit temperature Tc, the saturation magnetic susceptibility of the ferromagnetic material 14 sharply decreases and its magnetic resistance becomes extremely large. Therefore, even if the current supplied to the coil 17 is not cut off, the flow path shut-off valve 10 falls to close the quenching flow path 9 and shut off the circulating flow A, so that the excessive temperature rise of the inner surface of the high-pressure vessel 1 is suppressed. You can

Since the ferromagnetic material 14 and the electromagnet 16 are combined in this way and the physical properties of the ferromagnetic material 14 itself are changed, the flow passage shutoff valve 10 is directly operated to suppress the circulating flow A.
In addition to simplifying the structure, it is possible to prevent accidents of excessive temperature rise due to failure, and ensure highly reliable operation from a safety standpoint. In the embodiment, the electromagnet 16 is used, but the invention is not limited to this, and a permanent magnet may be used.

[0016]

According to the present invention, a temperature-sensing ferromagnetic material 14 whose Curie point is an excessive temperature rise point on the inner surface of the high-pressure container 1 is provided in the flow path shutoff valve 10, and a flow is made through this ferromagnetic material 14. Since the high pressure vessel 1 is equipped with a magnet 16 that holds the path shutoff valve 10 in the open position and closes the flow path shutoff valve 10 when the inner surface of the high pressure vessel 1 exceeds the Curie point, a thermocouple or the like for temperature sensing is required. Not only that, the structure can be simplified, accidents of excessive temperature rise due to failure can be prevented, and highly reliable operation can be guaranteed from the safety aspect.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 High-pressure container 2 High-pressure cylinder 5 Insulation layer 6 Furnace chamber 9 Quenching flow path 10 Flow path shut-off valve 14 Ferromagnetic material 16 Magnet

Claims (1)

[Claims] 1. The upper part of the heat insulation layer (5) in the high pressure vessel (1),
A quenching channel (9) is formed to circulate the hot gas in the furnace chamber (6) inside the heat insulating layer (5) during cooling, and a quenching channel (9) is used when the inner surface of the high-pressure vessel (1) is overheated. In a hot isostatic pressurizer equipped with a flow path shut-off valve (10) for closing, a temperature-sensing ferromagnetic material (14) whose Curie point is the overheating point on the inner surface of the high-pressure vessel (1)
Is provided in the flow path shutoff valve (10), the flow path shutoff valve (10) is held in the open position through this ferromagnetic material (14), and the flow path is flown when the inner surface of the high pressure vessel (1) exceeds the Curie point. A safety device for a hot isostatic pressing device, characterized in that a magnet (16) for closing the shutoff valve (10) is provided in the high-pressure container (1).