JPH10220832A - Safety device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To emit reaction gas to the outside of a system at a sufficiently low concentration without using an expensive, large-sized maintenance power source, and to maintain the internal pressure of a container at an atmospheric pressure or less. SOLUTION: A safety device is equipped with a reaction container 11 to which stock and process gas are fed from a stock feeder to provide a reaction inside, an exhauster 13 which is connected with the reaction container 11 and exhausts the gas inside the reaction container 11, an eliminator 14 which eliminates a deleterious ingredient contained in the exhaust air in the exhauster 13, an ejector 20 which is connected to the line between the reaction container 11 and exhauster 13 to dilute the exhaust air and gas from the reaction container 11, and a nitrogen feeder 25 connected with the ejector. In the normal operation, the reaction container 11 is exhausted by means of the exhauster 13, and deleterious gas is eliminated by means of the eliminator 14 to be exhausted. In the emergency operation, nitrogen is fed to the ejector 20 from the nitrogen feeder 25 to generate the negative pressure at the throat part of the ejector 20 by the flow of nitrogen, thus exhausting the reaction gas from the reaction container 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device, and more particularly, to a safety device used for an exhaust system at the time of an emergency stop of a facility using toxic gas or high-temperature gas.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional exhaust device for a reaction vessel. Reference numeral 1 in the figure denotes a reaction vessel. The reaction vessel 1 is connected to a raw material supply device 2 for supplying a raw material and a process gas to the reaction vessel 1, and a reaction is performed in the reaction vessel 1. In the raw material supply device 2, the supply of the raw material is automatically stopped 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 a harmful component is contained in the reaction product and the process gas in the reaction vessel 1, the internal gas is exhausted by the exhaust device 3, and the harmful component contained in the exhaust gas is removed by the abatement device 4. Thereafter, the gas is released from the vent stack 5 to the atmosphere. Here, the exhaust device 3 exhausts the inside of the reaction vessel 1 and maintains the inside of the reaction vessel 1 at an atmospheric pressure or less.
It has a function of preventing leakage from the reaction vessel 1 to the outside.

A line connecting the reaction vessel 1 and the exhaust device 3 and a line connecting the abatement device 4 and the vent stack 5 are connected by a line 8 having a preliminary exhaust device 6 and a preliminary abatement device 7 interposed therebetween. ing. The preliminary exhaust device 6 and the preliminary abatement device 7 are installed to provide backup when the exhaust device 3 and the abatement device 4 fail. A safety power supply 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]

However, in the conventional exhaust apparatus for a reaction vessel, the exhaust apparatus 3, the abatement apparatus 4, the preliminary exhaust apparatus 6, and the uninterruptible power supply for driving the preliminary abatement apparatus 7 are provided. The security power supply 9 is large and expensive, and requires maintenance and inspection. In addition, a backup is required to ensure the reliability of the abatement device and the exhaust device including the mechanical drive unit.

The present invention has been made in view of such circumstances, and an ejector for exhausting a reaction vessel and diluting a reaction gas is provided so as to be connected to a line connecting the reaction vessel and an exhaust device. By using an ejector, it is possible to exhaust the reaction vessel and dilute the reaction gas without using a large and expensive maintenance power source as in the past, and discharge the reaction gas out of the system at a sufficiently low concentration. An object of the present invention is to provide a safety device capable of maintaining the internal pressure of a container at or below atmospheric pressure.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a reaction vessel in which a raw material and a process gas are supplied from a raw material supply device and a reaction is carried out therein, and a gas connected to the reaction vessel and exhausting the gas inside the reaction vessel. Exhaust device, an abatement device connected to the exhaust device for removing harmful components contained in exhaust gas in the exhaust device, and an exhaust device connected to a line connecting the reaction container and the exhaust device, and exhaust gas from the reaction container. An ejector for diluting gas and a nitrogen supply device connected to the ejector are provided. During normal operation, the inside of the reaction vessel is evacuated by an exhaust device, and after removing harmful gas by an exclusion device, exhaust is performed. During operation, the reaction gas is exhausted from the reaction vessel by supplying nitrogen to the ejector from the nitrogen supply device and generating a negative pressure in the throat of the ejector by the flow of nitrogen. It is a safety device.

(Operation) i) A nitrogen supply device using a liquid nitrogen tank can supply nitrogen gas stably without using power, and can exhaust and dilute the reaction gas even during a power failure. .

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 or below atmospheric pressure without power. iii) The 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 PREFERRED EMBODIMENTS A safety device according to one embodiment of the present invention will be described below with reference to FIG. Reference number 11 in the figure is a reaction vessel. The reaction vessel 11 is connected to a raw material supply device 12 for supplying a raw material and a process gas to the reaction vessel 11, and a reaction is performed in the reaction vessel 11. In addition, in the raw material supply device 12, the supply of the raw material is automatically stopped in an emergency by an interlock device. The reaction vessel 11 includes an exhaust device 13, an abatement device 14, a vent stack
Exhaust facilities such as 15 are connected sequentially.

A line connecting the reaction vessel 11 and the exhaust device 13
An ejector 20 is connected to 16 via a line 19 in which an exhaust flow control valve 17 and a container exhaust system closing valve 18 are sequentially provided. Here, the exhaust flow rate control 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 in which a normally open solenoid valve 21, a nitrogen flow control valve 22, and a pressure reducing valve 23 are interposed in this order from the ejector 20 side. Here, the nitrogen flow control valve 22 controls the flow rate of nitrogen, and the pressure reducing valve 23 controls the pressure of nitrogen. The solenoid valve 21 is closed during normal operation, and is opened during an emergency.

As described above, the safety device according to the above embodiment includes a reaction vessel 11 connected to a raw material supply device 12, an exhaust device 13, a detoxification device 14, and a vent stack 15 sequentially connected to the reaction container 11. An exhaust flow control valve 17, a container exhaust system closing valve 18, and an ejector 20 connected to a line 16 connecting the reaction vessel 11 and the exhaust device 13, an electromagnetic valve 21, a nitrogen flow control valve connected to the ejector 20, 22, a pressure reducing valve 23 and a nitrogen supply device 25 are provided. The operation of the safety device having such a configuration during normal operation and during an emergency such as a power failure
It is as follows.

I) During normal operation: The reaction vessel 11 is evacuated by the exhaust device 13, harmful gas is removed using the abatement device 14, and then exhausted by the vent stack 15. ii) Emergency: The raw material supply device 12 automatically stops supplying the raw material by the interlock device. Since the solenoid valve 21 is normally open, it is automatically opened in an emergency. When the solenoid 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 control valve 22, and the solenoid valve 21. A negative pressure is generated in the throat of the ejector 20 by the flow of the 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 reduced in advance by using a pressure reducing valve 23, the flow rate of nitrogen is controlled in advance by a nitrogen flow control valve 22, and the flow rate of exhaust from the reaction vessel 11 is controlled in advance by using an exhaust flow rate control valve 17. Adjust it. The container exhaust system closing valve 18 includes:
The line to the ejector 20 is kept closed during normal operation with the normally open solenoid valve 21, but is opened in an emergency, and the exhaust line to the ejector 20 is opened.

The safety device according to the above embodiment has the following effects. First, if the nitrogen flow rate is secured in the ejector 20, a negative pressure is generated in the throat and the reaction gas can be sucked out of the reaction vessel 11. When the ejector 20 is driven, since the driving nitrogen is supplied to the ejector 20 from the nitrogen supply device 25, the reaction gas is diluted by adjusting the nitrogen flow rate and the exhaust gas flow rate in advance. The downstream concentration can be kept low. Furthermore, by using the normally open solenoid valve 21, at the time of a power failure, the drive of the ejector 20 and the emergency exhaust line are automatically opened.
Exhaust can be performed without separately taking power outage countermeasures.

[0014]

As described above in detail, according to the present invention, an ejector for exhausting a reaction vessel and diluting a reaction gas is provided so as to be connected to a line connecting the reaction vessel and an exhaust device.
By using this ejector during an emergency operation, the reaction gas is exhausted from the reaction vessel and the reaction gas is diluted, and the reaction gas is discharged out of the system at a sufficiently low concentration without using a large and expensive maintenance power source as in the past. It is possible to provide a safety device capable of maintaining the internal pressure of the reaction vessel at or below the atmospheric pressure.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a safety device according to one 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 device, 13 ... exhaust device, 14 ... abatement device, 15 ... vent stack, 17 ... exhaust flow rate control valve, 18 ... container exhaust system closing valve, 20 ... ejector, 21 ... solenoid valve , 22 ... nitrogen flow control valve, 23 ... pressure reducing valve, 25 ... nitrogen supply device.

Claims (1)

[Claims] 1. A reaction container in which a raw material and a process gas are supplied from a raw material supply device and a reaction is performed therein, an exhaust device connected to the reaction container and exhausting gas inside the reaction container, and an exhaust device Connected to a detoxification device that removes harmful components contained in the exhaust gas in the exhaust device, and an ejector that is connected to a line connecting the reaction container and the exhaust device and dilutes exhaust gas and gas from the reaction container, A nitrogen supply device connected to the ejector. During normal operation, the inside of the reaction vessel is evacuated by an exhaust device, and after removing harmful gases by an elimination device, the reaction container is evacuated. A safety device for supplying nitrogen to an ejector and generating a negative pressure in the throat of the ejector by the flow of nitrogen, thereby exhausting a reaction gas from a reaction vessel.