JP5201942B2 - Explosion-proof room pressurization system - Google Patents

Description

  The present invention relates to a pressurization system for an explosion-proof room, and is particularly useful when applied to a pressurization system for pressurizing a jetty monitoring room or the like installed in an explosion-proof area to prevent invasion of combustible gas.

  Various facilities for LNG processing, such as an LNG transfer pipeline, are arranged around a pier where an LNG ship that transports flammable gas is berthed. For this reason, a certain range around the pier is an explosion-proof region.

  Here, a pier monitoring room for monitoring the state of the pier is usually built in an explosion-proof area, and the room is used as a space for a monitoring person to perform a predetermined work or take a break. Therefore, there are many devices in the pier monitoring room that can serve as an ignition source for the invading LNG.

  In order to prevent the LNG from leaking into the environment, the inside of the pier monitoring room is pressurized to create a high-pressure atmosphere. The pressurization system pressurizes this type of jetty monitoring room, etc., and controls the driving of the fan to supply air into the jetty monitoring room by using this fan and pressurizes to a predetermined pressure. The pressure is monitored so as to be maintained at the predetermined pressure.

  In addition, the following patent document 1 can be mentioned as a well-known publication regarding explosion-proof of a pressurization chamber.

JP 2002-127073 A

  In the pressurization system according to the prior art, the fan is configured to be able to be driven independently even when other functions of the pressurization system such as monitoring of the indoor pressure are stopped in preparation for maintenance, inspection, etc. ing. When the fan is driven, a lamp indicating this is turned on.

  Therefore, the pressurization system is not always activated even if the lamp indicating the operation state of the fan is lit.

  As a result, there may be a case where the room such as the jetty monitoring room is not maintained at a predetermined pressure due to leakage of indoor air or the like even though the fan is operated. There is no lamp that indicates the activation / deactivation of the pressurization system. Functions such as monitoring of the indoor pressure by the pressure sensor are presumed to remain active, but this is noticed. Because there is no possibility.

  On the other hand, a lamp that indicates the start / stop of the pressurization system is not provided. Therefore, it is difficult to confirm the start / stop of the pressurization system, which hinders system operation monitoring.

  An object of the present invention is to provide a pressurization system for an explosion-proof room that can easily grasp the driving status of the pressurization system at the same time as the driving of the fan in view of the above prior art.

In order to achieve the above object, the first aspect of the present invention provides:
By supplying pressurized air into the room via a fan, the pressure inside the room is maintained at a high pressure, and air is prevented from entering the room from the surrounding environment. An explosion-proof room pressurization system configured to be able to start and stop even in an independent state without starting and stopping the system,
The start / stop of the fan is detected, the start / stop of the pressurization system is detected, and a lamp indicating this is turned on when both the fan and the pressurization system are in an active state. Control system,
The control system has a system start switch and a fan start switch for starting the pressure system,
When the system start switch is turned on, the system relay is energized and its first contact is closed, whereby the first relay and the second relay are energized, and at the same time, the first relay is energized. The second contact, which is a self-holding contact, is closed and the third contact for energizing the third relay for operating the fan is closed together with the self-holding of the first and second relays,
Further, the fan start switch is connected to the third contact in parallel so that the fan can be started independently without being a condition for starting the pressure system,
The second relay and the third relay are connected in series by a contact that is closed when the second relay is energized and a contact that is closed when the third relay is energized. The explosion-proof chamber pressurization system is characterized in that the lamp is turned on only when the lamps are simultaneously energized.

  According to the present invention, the lamp indicating this is turned on only when both the fan drive and the pressurization system drive are simultaneously established. As a result, the driving status of the pressurization system can be easily grasped simultaneously with the driving of the fan.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing an explosion-proof chamber pressurizing system according to an embodiment of the present invention. As shown in the figure, the pressurization system 1 pressurizes the explosion-proof chamber to form a high-pressure environment in order to prevent the gas from entering the explosion-proof chamber even if flammable gas such as LNG leaks into the environment. Is for. Specifically, the explosion-proof chamber is pressurized to a predetermined pressure by controlling the driving of the fan 2 and supplying air into the explosion-proof chamber. At the same time, control is performed to maintain the pressure in the explosion-proof chamber at a predetermined pressure or higher, such as monitoring whether the pressure in the explosion-proof chamber detected via the pressure sensor 3 is maintained at a set value or higher. As a result, when the pressure falls below the set value, an alarm is issued and this fact is sent to the central control room.

  Here, the fan 2 is configured to be able to start independently even when the pressurizing system 1 is stopped in preparation for maintenance, inspection, and the like.

  The pressurization system 1 includes a control system for controlling the driving of the fan 2 and maintaining the pressure in the explosion-proof chamber and issuing a necessary alarm.

  FIG. 2 is a circuit diagram showing a sequence circuit of a control system in the pressurizing system 1 according to the present embodiment. In the figure, PS is a push button switch for starting up the pressurizing system 1 (see FIG. 1, the same applies hereinafter), and PR is a push button switch for stopping the pressurizing system 1. Here, the relay R · S is energized by pressing the push button switch PS.

  In addition, although the code | symbol R * S in a figure is a coil of a relay correctly, in the following description including the code | symbol R1, R2, R3 and R * R in a figure, a coil of a relay is called like this.

  When the relays R and S are energized, the a contact rs1 is closed. As a result, the relay R1 is energized to close the a contact r11 and the a contact r12. As a result, even if the push button switch PS is released, the relay R1 is held by the closing of the a contact r11 and continues to be energized, and the relay R3 is also energized by the closing of the a contact r12. This state is continued. As a result, although not shown, all the functions of the pressurizing system 1, such as monitoring of the explosion-proof chamber pressure, a predetermined alarm function, etc. are activated and the driving state is continued.

  Here, the relay R3 activates the fan 2 (see FIG. 1; the same applies hereinafter) by its energization and stops it by deenergizing. Therefore, the fan 2 is also started when the push button switch PS is pressed, that is, when the pressurization system 1 is started, and the drive is continued together with the pressurization system 1 to pressurize the explosion-proof chamber.

  Further, the relay R2 is also energized at the same time when the a contact rs1 is closed by pressing the push button switch PS. As a result, the a contact r2 connected to the lamp L is closed. On the other hand, the a contact r3 connected in series with the lamp L to the a contact r2 is closed by the energization of the relay R3. As a result, the lamp L is turned on when the pressure system 1 is started together with the fan 2. On the other hand, the lamp L is not lit when any one of the a contact r2 to the a contact r3 is opened.

  The fan 2 is also activated by pressing the push button switch PF. Here, the push button switch PF has a structure in which the state is mechanically latched once pressed, and the latch is released by pressing again. Therefore, the fan 2 can also be activated by energizing the relay R3 by pressing the push button switch PF. That is, the pressurization system 1 can be started independently without being a condition. Thus, when only the fan 2 is driven independently, the a contact r3 is closed by energizing the relay R3, but the a contact r2 is closed on the condition that the pressurizing system 1 is activated. Since it is not made, the lamp L is not turned on.

  The pressurization system 1 is stopped by pressing the push button switch PR. This is because if the push button switch PR is pressed, the relays R and R are energized, and the relay R1 is deactivated by opening the b contact rr. That is, the a-contact r11 and the a-contact r12 are opened by the deactivation of the relay R1.

  According to this embodiment, the a contact r3 of the relay R3 functions as a detection unit that detects the start / stop of the fan 2, and the detection unit that the a contact r2 of the relay R2 detects the start / stop of the pressurizing system 1. Function as. Since the lamp L is lit when both the a-contact r3 and the a-contact r4 are closed together, the pressure system 1 is driven together with the fan 2 by the lighting of the lamp L. Can be easily confirmed.

As described above, the present embodiment can be realized by adding a single relay R2 to the control system of the existing pressurizing system 1 in a sequence circuit using a relay , and thus the object can be achieved inexpensively and easily. .

  INDUSTRIAL APPLICABILITY The present invention can be effectively used in the industrial field where manufacture, sales, operation, and maintenance of a pressurizing system that pressurizes a chamber for explosion prevention is performed.

It is a block diagram which shows the pressurization system of the explosion-proof room which concerns on embodiment of this invention. It is a circuit diagram which shows the sequence circuit of the control system in the pressurization system shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressurization system 2 Fan 3 Pressure sensor L Lamp PF, PR, PS Push button switch R * R, R * S, R1, R2, R3 Relay rs1, r11, r12, rr, r2, r3 Contact

Claims (1)

By supplying pressurized air into the room via a fan, the pressure inside the room is maintained at a high pressure, and air is prevented from entering the room from the surrounding environment. An explosion-proof room pressurization system configured to be able to start and stop even in an independent state without starting and stopping the system,
The start / stop of the fan is detected, the start / stop of the pressurization system is detected, and a lamp indicating this is turned on when both the fan and the pressurization system are in an active state. Control system,
The control system has a system start switch and a fan start switch for starting the pressure system,
When the system start switch is turned on, the system relay is energized and its first contact is closed, whereby the first relay and the second relay are energized, and at the same time, the first relay is energized. The second contact, which is a self-holding contact, is closed and the third contact for energizing the third relay for operating the fan is closed together with the self-holding of the first and second relays,
Further, the fan start switch is connected to the third contact in parallel so that the fan can be started independently without being a condition for starting the pressure system,
The second relay and the third relay are connected in series by a contact that is closed when the second relay is energized and a contact that is closed when the third relay is energized. A system for pressurizing an explosion-proof room, wherein the lamp is lit only when the two are simultaneously energized.

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