JP3801286B2 - Safety device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety device, and more particularly to a safety device used for an exhaust facility at the time of emergency stop of a facility that uses harmful gas or high-temperature gas.
[0002]
[Prior art]
Conventionally, the example shown in FIG. 2 is known as an example of an exhaust device for a reaction vessel.
Number 1 in the figure is a reaction vessel. The reaction vessel 1 is connected to a raw material supply device 2 for supplying raw materials and process gas to the reaction vessel 1, and a reaction is performed in the reaction vessel 1. The raw material supply device 2 is configured to automatically stop the supply of raw materials in an emergency by an interlock device. Exhaust equipment such as an exhaust device 3, an abatement device 4, and a vent stack 5 are sequentially connected to the reaction vessel 1. When the reaction product and the process gas in the reaction vessel 1 contain harmful components, the exhaust device 3 exhausts the internal gas, and the removal device 4 removes the harmful components contained in the exhaust. Then, it is discharged from the vent stack 5 to the atmosphere. Here, the exhaust device 3 has a function of exhausting the inside of the reaction vessel 1 and keeping the inside of the reaction vessel 1 at atmospheric pressure or lower to prevent leakage from the reaction vessel 1 to the outside.
[0003]
A line connecting the reaction vessel 1 and the exhaust device 3 and a line connecting the detoxifying device 4 and the vent stack 5 are connected by a line 8 having a pre-exhaust device 6 and a pre-detoxifying device 7 interposed therebetween. The preliminary exhaust device 6 and the preliminary abatement device 7 are installed for backup when the exhaust device 3 and the abatement device 4 fail. A safety power source 9 such as an uninterruptible power supply is connected to the exhaust device 3, the abatement device 4, the preliminary exhaust device 6, and the preliminary abatement device 7 so that these devices are driven even during a power failure.
[0004]
[Problems to be solved by the invention]
However, in the conventional reaction vessel exhaust device, the safety power source 9 such as an uninterruptible power source for driving the exhaust device 3, the abatement device 4, the preliminary exhaust device 6, and the preliminary abatement device 7 is large and expensive. In addition, maintenance and inspection are required. In addition, a backup is necessary to ensure the reliability of the abatement device including the mechanical drive unit and the exhaust device.
[0005]
The present invention has been made in consideration of such circumstances, and an ejector for exhausting the reaction vessel and diluting the reaction gas is provided so as to be connected to a line connecting the reaction vessel and the exhaust device, and this ejector is used during an emergency operation. Therefore, without using a large and expensive maintenance power source as in the past, the reaction vessel can be exhausted and the reaction gas diluted, and the reaction gas can be released out of the system at a sufficiently low concentration. An object of the present invention is to provide a safety device that can keep the pressure below atmospheric pressure.
[0006]
[Means for Solving the Problems]
The present invention provides a reaction vessel in which a raw material and a process gas are supplied from a raw material supply device and a reaction is performed inside, an exhaust device connected to the reaction vessel and exhausting the gas inside the reaction vessel, and the exhaust device A detoxification device connected to remove harmful components contained in the exhaust gas in the exhaust device, an ejector connected to a line connecting the reaction vessel and the exhaust device, and for diluting the exhaust gas from the reaction vessel and the gas; A nitrogen supply device connected to the ejector, and a normally open solenoid valve interposed in a line connecting the ejector and the nitrogen supply device, and during normal operation, the reaction vessel is evacuated by an exhaust device, evacuated after removing harmful gases by scrubbing apparatus, emergency operation, the nitrogen from nitrogen supply device is supplied to the ejector to generate a negative pressure in the throat of the ejector by the flow of nitrogen More, a safety device, characterized by evacuating the reaction gas from the reaction vessel.
[0007]
(Function)
i) A nitrogen supply device using a liquid nitrogen tank can stably supply nitrogen gas without using power, and can exhaust and dilute the reaction gas even during a power failure.
[0008]
ii) By using an ejector, an exhaust system can be configured without mechanical driving only by supplying nitrogen for dilution, and the pressure in the reaction vessel can be maintained at atmospheric pressure or lower without electric power.
iii) Equipment can be simplified by using a nitrogen supply system using an ejector and a liquid nitrogen tank as backup equipment in an emergency.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a safety device according to an embodiment of the present invention will be described with reference to FIG.
Reference numeral 11 in the figure is a reaction vessel. The reaction vessel 11 is connected to a raw material supply device 12 for supplying raw materials and process gas to the reaction vessel 11, and the reaction is performed in the reaction vessel 11. In the raw material supply device 12, the supply of the raw material is automatically stopped in an emergency by an interlock device. Exhaust equipment such as an exhaust device 13, an abatement device 14, and a vent stack 15 are sequentially connected to the reaction vessel 11.
[0010]
An ejector 20 is connected to a line 16 connecting the reaction vessel 11 and the exhaust device 13 via a line 19 in which an exhaust flow rate control valve 17 and a vessel exhaust system closing valve 18 are sequentially provided. Here, the exhaust flow rate adjusting valve 17 adjusts the exhaust flow rate from the reaction vessel 11. A nitrogen supply device 25 is connected to the ejector 20 via a line 24 having a normally open solenoid valve 21, a nitrogen flow rate adjustment valve 22, and a pressure reducing valve 23 in order from the ejector 20 side. Here, the nitrogen flow rate adjusting valve 22 adjusts the nitrogen flow rate, and the pressure reducing valve 23 adjusts the nitrogen pressure. In addition, the solenoid valve 21 is closed during normal operation and opened in an emergency.
[0011]
As described above, the safety device according to the embodiment includes the reaction vessel 11 connected to the raw material supply device 12, the exhaust device 13, the detoxification device 14 and the vent stack 15 sequentially connected to the reaction vessel 11. Exhaust flow rate control valve 17 connected to line 16 connecting reaction vessel 11 and exhaust device 13, vessel exhaust system closing valve 18 and ejector 20, electromagnetic valve 21 connected to this ejector 20, nitrogen flow rate control valve 22, decompression The valve 23 and the nitrogen supply device 25 are provided. The operation of the safety device having such a configuration during an ordinary operation or an emergency such as a power failure is as follows.
[0012]
i) During normal operation: The reaction vessel 11 is evacuated by the exhaust device 13, the harmful gas is removed by using the abatement device 14, and then exhausted by the vent stack 15.
ii) Emergency: The raw material supply device 12 is automatically stopped by the interlock device. Since the solenoid valve 21 is normally open, it is automatically opened in an emergency. When the electromagnetic valve 21 is opened, nitrogen is supplied from the nitrogen supply device 25 to the ejector 20 through the pressure reducing valve 23, the nitrogen flow rate adjusting valve 22, and the electromagnetic valve 21. A negative pressure is generated in the throat of the ejector 20 due to the flow of nitrogen, and the reaction gas is exhausted from the reaction vessel 11. In order to keep the concentration of exhaust gas in nitrogen low, the pressure of nitrogen is preliminarily adjusted using the pressure reducing valve 23, the flow rate of nitrogen is controlled by the nitrogen flow rate adjusting valve 22, and the exhaust flow rate from the reaction vessel 11 is previously set using the exhaust flow rate adjusting valve 17. Adjust it. The container exhaust system closing valve 18 is a normally open solenoid valve 21 that is closed during normal operation, and closes the line to the ejector 20, but is opened in an emergency and opens the exhaust line to the ejector 20. To do.
[0013]
The safety device according to the embodiment has the effects described below. First, if the nitrogen flow rate is ensured, the ejector 20 generates negative pressure in the throat and can suck out the reaction gas from the reaction vessel 11. Further, when driving the ejector 20, since the driving nitrogen is supplied from the nitrogen supply device 25 to the ejector 20, the reaction gas is diluted by adjusting the flow rate of nitrogen and the flow rate of exhaust gas in advance. The downstream concentration can be kept low. Furthermore, by using the normally open solenoid valve 21, the drive of the ejector 20 and the emergency exhaust line are automatically opened in the event of a power failure, so that exhaust can be performed without taking measures against power failure separately. .
[0014]
【The invention's effect】
As described above in detail, according to the present invention, an ejector for exhausting the reaction vessel and diluting the reaction gas is provided so as to be connected to a line connecting the reaction vessel and the exhaust device, and this ejector is used during emergency operation. Without using a large and expensive maintenance power supply as in the past, exhausting the reaction vessel and diluting the reaction gas can discharge the reaction gas outside the system at a sufficiently low concentration, while increasing the internal pressure of the reaction vessel. It is possible to provide a safety device that can be maintained below atmospheric pressure.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a safety device according to an embodiment of the present invention.
FIG. 2 is an explanatory view of a conventional exhaust device for a reaction vessel.
[Explanation of symbols]
11 ... reaction vessel,
12 ... Raw material supply equipment,
13 ... exhaust system,
14 ... abatement equipment,
15 ... Vent stack,
17… Exhaust flow control valve,
18 ... Vessel exhaust system closing valve,
20 ... Ejecta,
21 ... Solenoid valve,
22… Nitrogen flow control valve,
23 ... pressure reducing valve,
25 ... Nitrogen supply device.

Claims (1)

A raw material and a process gas are supplied from a raw material supply device, and a reaction vessel in which a reaction is performed is connected, an exhaust device connected to the reaction vessel and exhausting the gas inside the reaction vessel, connected to the exhaust device, and An abatement device that removes harmful components contained in the exhaust gas in the exhaust device, an ejector that is connected to the line connecting the reaction vessel and the exhaust device, and that performs exhaust and gas dilution from the reaction vessel, and is connected to this ejector A nitrogen supply device, and a normally open solenoid valve interposed in a line connecting the ejector and the nitrogen supply device ,
During normal operation, the reaction vessel is evacuated with an exhaust device, exhausted after removing harmful gases with an abatement device,
A safety device characterized in that during emergency operation, nitrogen is supplied from a nitrogen supply device to the ejector and a negative pressure is generated in the throat of the ejector by the flow of nitrogen, thereby exhausting the reaction gas from the reaction vessel.

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