JPH0226923Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a vacuum degassing device in a vacuum degassing device for degassing a solution such as molten steel and degassing in a vacuum refining facility. .

[Prior Art] In recent years, degassing treatments such as dehydrogenation and deoxidation of molten steel have been actively carried out in order to improve the yield and quality of products. Such degassing treatment is carried out by circulating the molten steel in a true tank, and the pressure of the vacuum tank is reduced by a vacuum device via a canopy duct and a gas cooler.

[Problems to be solved by the invention] However, in the conventional device described above, the vacuum chamber and the gas cooler are in communication via the canopy duct, so when the degassing device is not in operation, the air inside the gas cooler is Cold air entered the canopy duct, lowering the temperature of the inner wall surface of the canopy duct, and heat dissipation (radiation) from the canopy duct to the gas cooler was also large. For this reason, when the degassing device is restarted, the molten steel splash adheres to the inner wall surface of the canopy duct whose temperature has been lowered, solidifies, and gradually grows and blocks the passage, leading to an increase in pressure loss.
This had the problem of deteriorating the degree of vacuum reached to the vacuum chamber.

The present invention focuses on the above-mentioned conventional problems, and by making it possible to isolate between the gas cooler and the canopy duct, the inner wall surface of the canopy duct is prevented from being cooled by the cold air from the gas cooler during non-operation. The purpose of the present invention is to prevent the above-described shutoff operation from occurring inside the gas cooler, thereby facilitating gas seal measures.

[Means for Solving the Problems] The present invention is an attempt to solve the above technical problems, and provides a vacuum degassing device in which a vacuum chamber, a canopy duct, a gas cooler, and a vacuum device are connected in series. A cutoff valve for opening and closing communication between the canopy duct and the gas cooler is provided at a position on the side of the canopy duct inside the gas cooler, and a valve driving device for opening and closing the cutoff valve is provided above the gas cooler. The present invention relates to a vacuum degassing device characterized by being provided with a valve housing chamber.

[Operation] Therefore, in the present invention, when vacuum degassing is not in operation,
By blocking the communication between the canopy duct and the gas cooler using the shutoff valve, it is possible to prevent the inner wall surface of the canopy duct from being cooled by the cold air from the gas cooler. It is possible to prevent splashes from adhering to and growing on the wall surface. Further, since the cutoff valve is provided inside the gas cooler, gas sealing measures for installing the cutoff valve can be easily taken, and the structure can be simplified.

[Examples] Examples of the present invention will be described below based on the drawings.

The drawing shows an example of the present invention applied to degassing molten steel.
immersion tube 4 is inserted, and the upper part of the vacuum chamber 3 is
It is connected to a gas cooler 6 via a canopy duct 5, and the gas cooler 6 is further connected to a vacuum device 7. In the figure, reference numeral 8 denotes a heating device that is installed in the vacuum chamber 3 and keeps the inside of the vacuum chamber 3 and the canopy duct 5 warm.

In the above configuration, a cutoff valve 9 capable of cutting off communication between the canopy duct 5 and the gas cooler 6 is provided at a position on the side of the canopy duct 5 inside the gas cooler 6, and a cutoff valve 9 is provided at the top of the gas cooler 6. A valve accommodating chamber 10 is formed in which the shutoff valve 9 can be stored, and the shutoff valve 9 is
A valve driving device 12 is provided outside the valve housing chamber 10 and is configured to open and close by raising and lowering the valve. In the figure, reference numeral 13 indicates an opening/closing lid that opens and closes a ventilation hole 14 formed in the valve housing chamber 10;
indicates a splash.

When degassing the molten steel 2, the immersion tube 4 is immersed in the molten steel 2, and the pressure inside the vacuum chamber 3 is reduced by the vacuum device 7, so that the molten steel 2 is sucked through the immersion tube 4 to a desired position and degassed naturally. Circulate. At this time, the cutoff valve 9 is pulled up into the valve housing chamber 10 by the valve driving device 12 as shown by the solid line, and communicates with the canopy duct 5 and the gas cooler 6.

When degassing is not in operation, communication between the canopy duct 5 and the gas cooler 6 is cut off by lowering the cutoff valve 9 to the dotted line position. By shutting off the canopy duct 5 and the gas cooler 6 with the shutoff valve 9 in this way, the inner wall surface of the canopy duct 5 is prevented from being cooled by the cold air from the gas cooler 6, and the heating device 8 is prevented from being cooled by the cold air from the gas cooler 6. By keeping the temperature inside the vacuum chamber 3 and the canopy duct 5 at a high temperature, the splash 15 will adhere to the inner wall surface of the canopy duct 5 when the shutoff valve 9 is opened and degassing is restarted. can be prevented. Further, by shutting off the shutoff valve 9, the heat radiated from the canopy duct 5 is prevented from entering into the gas cooler 6. Therefore,
Maintenance work for the gas cooler 6, such as removing clogging caused by dust and splash, can be performed safely. Also, at this time, if you want to lower the temperature of the walls of the gas cooler 6 in a short time to clean it, you can cool it by opening the opening/closing lid 13 and sucking the air through the ventilation holes 14. Cleaning work can be done quickly and safely.

Furthermore, as described above, since the cutoff valve 9 is provided inside the gas cooler 6, there is no need to take measures for gas sealing, and even if gas leaks from the cutoff valve 9 into the gas cooler 6, No problem will occur because the problem will be dealt with by restarting the gas cooler 6.

The present invention is not limited to the illustrated and described embodiments, and the shape of the valve housing chamber, the driving method of the valve driving device, etc. can be variously modified, and degassing other than molten steel can be carried out. It can also be applied to

[Effects of the invention] As described above, according to the vacuum degassing apparatus of the invention, the communication between the gas cooler and the canopy duct is opened and closed by the shutoff valve provided inside the gas cooler, so that the degassing operation can be easily performed. When the gas cooler is shut off from the canopy duct, the inner wall surface of the canopy duct can be prevented from being cooled by the cold air from the gas cooler, and therefore, when degassing is restarted, splash is generated on the inner wall surface of the canopy duct. It is possible to prevent adhesion and solidification and growth, and since the shutoff valve is installed inside the gas cooler, gas sealing measures for installing the shutoff valve can be easily taken and the structure can be simplified. It can produce excellent effects.

[Brief explanation of drawings]

The drawings are explanatory diagrams showing one embodiment of the present invention. 2 is molten steel, 3 is a vacuum chamber, 5 is a canopy duct, 6 is a gas cooler, 7 is a vacuum device, 8 is a heating device, 9
10 indicates a shutoff valve, 10 indicates a valve housing chamber, and 12 indicates a valve driving device.

Claims (1)

[Scope of utility model registration request] In a vacuum degassing device in which a vacuum chamber, a canopy duct, a gas cooler, and a vacuum device are connected in series, a cutoff valve for opening and closing communication between the canopy duct and the gas cooler is provided at a position on the canopy duct side inside the gas cooler. A vacuum degassing device characterized in that a valve housing chamber is provided above the gas cooler and includes a valve driving device for opening and closing the shutoff valve.