JP7505098B2 - Control Panel Fire Suppression System - Google Patents

Description

The present invention relates to a control panel fire extinguishing system that detects and extinguishes fires that occur inside control panels such as server racks installed in data centers, etc.

Conventionally, control panel fire extinguishing systems have been installed to extinguish fires that break out indoors due to heat generation, smoke, or fire caused by abnormal current flow in electrical equipment within multiple control panels, such as server racks.

Conventional control panel fire extinguishing systems install sampling tubes in multiple control panels, and use ultra-sensitive smoke detectors to detect smoke particles in the air sucked in by a pump. When smoke is detected, a fire detection signal is sent out and extinguishing gases such as carbon dioxide or halon gas are released throughout the room to put out the fire.

However, in such conventional control panel fire extinguishing systems, extinguishing gas is released throughout the room when a fire is detected. In cooling systems where cooled air from an air conditioner is passed from under the floor through the server rack and then through to the ceiling, it is not possible to guarantee that the amount of extinguishing gas required to extinguish the fire will reach the rack where the fire has occurred. In addition, because extinguishing gas is released throughout the room, people cannot enter the room after the gas is released, making it difficult to take appropriate action afterwards.

To solve this problem, a control panel fire extinguishing system has been proposed in which, when an ultra-high sensitivity smoke detector detects smoke particles in the air sucked in by a sampling tube piped to multiple control panels and sends out a fire detection signal, ventilation for all server racks is stopped and the racks are sealed, and in this sealed state, the server rack in which a fire has occurred is identified based on a fire alarm signal output from a fire detector installed in the server rack, and a fire extinguishing device installed in the identified server rack is activated to extinguish the fire (Patent Document 2).

JP 2004-078807 A JP 2011-078468 A

However, in such conventional control panel fire extinguishing systems, the air inside the server rack is sucked in by an ultra-high sensitivity smoke detector through a sampling tube to monitor the overall fire. If the ultra-high sensitivity smoke detector detects a fire, the ventilation devices of all the server racks are closed to create a sealed state. In this state, the server rack on fire is identified based on a fire alarm signal from one of the fire detectors installed in each server rack, and the fire extinguishing system is activated. This results in a large time delay between the detection of a fire by the ultra-high sensitivity smoke detector and the identification of the server rack and the activation of the fire extinguishing system, leaving problems with early fire extinguishing.

In addition, if an ultra-high sensitivity smoke detector detects a fire, the ventilation of all server racks is stopped and they are sealed, causing the cooling function of server racks that are operating normally to be lost. In particular, in server racks equipped with a cooling structure that introduces cooling air from an air conditioning unit into the rack from under the floor and exhausts it out the ceiling, closing the intake and exhaust ports completely stops the cooling function, causing the temperature inside the server rack to rise rapidly, which could lead to secondary problems.

The present invention aims to provide a control panel fire extinguishing system that can monitor fires on a control panel basis, such as a server rack, and quickly and reliably extinguish fires without affecting other control panels.

(Control panel fire extinguishing system)
The present invention provides a control panel fire extinguishing system that detects and extinguishes a fire in a control panel to be monitored,
an air conditioning opening and closing device that is provided at an air conditioning inlet port at the bottom of the panel that introduces cooling air supplied from the air conditioning device into the panel and an air conditioning exhaust port at the top of the panel that exhausts the air inside the panel to the outside and is driven to open and close;
A suction pump is placed on the top of the panel and sucks and exhausts the air inside the panel.
A return pipe that returns the air discharged from the suction pump to the inside of the panel from the bottom of the panel,
A fire extinguishing device is installed under the panel and releases fire extinguishing gas into the panel to extinguish the fire.
a control device which, when receiving a fire detection signal, drives an air conditioning opening and closing device to seal the inside of the panel and releases extinguishing gas from a fire extinguishing device into the panel to extinguish the fire;
The present invention is characterized by comprising:

In addition, the control panel fire extinguishing system is equipped with a highly sensitive smoke detector that emits a fire detection signal when it detects a fire from smoke particles contained in the air sucked in from inside the panel by the suction pump.
2
(Fire extinguishing gas return)
The control device releases the extinguishing gas into the panel and circulates the air containing the extinguishing gas back into the panel from the suction pump via a return pipe.

(Coordinated control of air conditioning opening and closing devices and fire extinguishing devices)
The control device activates the fire extinguishing device while driving the air conditioning opening/closing device of the air conditioning inlet to close, and drives the air conditioning opening/closing device of the air conditioning exhaust outlet to close after a predetermined time has elapsed since the activation of the fire extinguishing device.

(Cylinder-type fire extinguishing system)
Fire extinguishing equipment:
A gas cylinder filled with fire extinguishing gas;
a fire extinguishing gas release valve that releases the fire extinguishing gas stored in the gas cylinder into the panel when opened;
Equipped with.

(Pipe-type fire extinguishing system)
Fire extinguishing equipment:
A fire extinguishing gas supply pipe that is drawn into the panel from the outside to supply fire extinguishing gas;
a fire extinguishing gas release valve that releases fire extinguishing gas into the panel through a fire extinguishing gas supply pipe when opened;
Equipped with.

(Fire detection and extinguishing activation notification)
The control device transmits a fire notification signal indicating a fire detection by the high-sensitivity smoke detector to an externally installed monitoring panel to notify of the occurrence of a fire, and also transmits a fire extinguishing start notification signal indicating the start of fire extinguishing by opening the fire extinguishing gas release valve to notify of the start of fire extinguishing.

(Effectiveness of control panel fire extinguishing system)
The present invention relates to a control panel fire extinguishing system for detecting and extinguishing a fire inside a monitored control panel, the system comprising: an air conditioning opening and closing device that is provided at an air conditioning inlet port at the bottom of the panel that introduces cooling air supplied from an air conditioning device into the panel, and an air conditioning exhaust port at the ceiling of the panel that exhausts air inside the panel to the outside, and is driven to open and close; a highly sensitive smoke detector that is provided at the top of the panel and detects a fire from smoke particles contained in the air sucked from inside the panel and emits a fire detection signal; a return pipe that returns the air exhausted from the highly sensitive smoke detector from the bottom of the panel to the inside of the panel; and a fire extinguishing device that is provided at the bottom of the panel and releases fire extinguishing gas into the panel to extinguish the fire. A control device is provided which, when it receives a fire detection signal from the high-sensitivity smoke detector, drives the air conditioning opening and closing device to seal the inside of the panel, releases fire extinguishing gas from the fire extinguishing device into the panel, and circulates the air containing the fire extinguishing gas back into the panel from the high-sensitivity smoke detector via the return piping, thereby making it possible to quickly detect a fire that occurs in the control panels of many server racks, etc. installed in a server room of a data center, etc., by the high-sensitivity smoke detector at an early stage, identify the control panel that has caused the fire, and release fire extinguishing gas such as CO2 gas into the rack, thereby quickly and reliably extinguishing the fire.

In addition, when a fire is detected, the air conditioning inlet and exhaust vent that cool the server rack are closed by the air conditioning opening and closing device, and extinguishing gas is released, ensuring that the fire is extinguished.

(Effect of fire extinguishing gas return)
In addition, the control device releases extinguishing gas into the panel and circulates the air containing the extinguishing gas back into the panel from the high-sensitivity smoke detector via a return pipe, which allows the extinguishing gas to be distributed evenly within the panel, making it possible to extinguish the fire more reliably.

(Effect of coordinated control of air conditioning opening and closing devices and fire extinguishing devices)
In addition, the control device activates the fire extinguishing device with the air conditioning opening and closing device at the air conditioning inlet driven in a closed state, and after a predetermined time has passed since the activation of the fire extinguishing device, it drives the air conditioning opening and closing device at the air conditioning exhaust outlet in a closed state.Therefore, when a fire is detected, the air conditioning inlet at the bottom of the panel is closed to block the introduction of cooling air from under the floor, and fire extinguishing gas is released into the panel from the bottom of the panel, pushing the air inside the panel out through the open air conditioning exhaust outlet in the ceiling of the panel, thereby efficiently diffusing and filling the panel with fire extinguishing gas in a short period of time, and after a predetermined time, the air conditioning exhaust outlet on the ceiling of the panel is closed to seal the inside of the panel, and the fire extinguishing gas released into the panel is efficiently filled therewith, thereby enabling quick and reliable extinguishing of the fire.

(Effect of cylinder-type fire extinguishing device)
In addition, since the fire extinguishing device is equipped with a gas cylinder filled with extinguishing gas and a fire extinguishing gas release valve that releases the extinguishing gas stored in the gas cylinder into the panel when opened, there is no need to install piping to supply extinguishing gas from the outside. Also, the gas cylinder can be a small one with a fire extinguishing gas release capacity corresponding to the internal volume of the panel, such as a server rack, and replacing the cylinder when the extinguishing gas is released is easy and low cost.

(Effect of piping type fire extinguishing system)
In addition, the fire extinguishing system is equipped with a fire extinguishing gas supply piping that is drawn into the panel from the outside to supply fire extinguishing gas, and a fire extinguishing gas release valve that releases fire extinguishing gas into the panel through the fire extinguishing gas supply piping when opened.Although it is necessary to install a fire extinguishing gas supply piping from the outside, the installed cylinder can be a small gas cylinder with a fire extinguishing gas release capacity corresponding to the internal volume of the panel, such as a server rack, and since it is only necessary to install a fire extinguishing gas release valve, such as an electromagnetic valve, inside the control panel, the amount of system equipment to be installed inside the control panel can be reduced, making it possible to reduce the installation space.

(Fire detection and extinguishing activation notification)
In addition, the control device sends a fire detection notification signal, indicating that a fire has been detected by the high-sensitivity smoke detector, to an external monitoring panel to notify of the occurrence of a fire, and also sends a fire extinguishing start notification signal, indicating that a fire has been started by opening the extinguishing gas release valve, to notify of the start of fire extinguishing.This makes it possible to check the fire detection and fire extinguishing start status by the fire extinguishing system installed on each control panel, such as a server rack, on the external monitoring panel, making it possible to respond appropriately to a fire in the control panel.

FIG. 1 is an explanatory diagram showing the elevation of a room in which a server rack equipped with a control panel fire extinguishing system according to the present invention is arranged. FIG. 2 is an explanatory diagram showing the plan of the room in FIG. 1; FIG. 1 is an explanatory diagram showing an embodiment of a control panel fire extinguishing system installed in a server rack. Diagram showing the outline of an ultra-high sensitivity smoke detector installed in a server rack Block diagram showing the functional configuration of the control device installed in the control panel fire extinguishing system Flowchart showing the control operation of the control panel fire extinguishing system

[Server Room Overview]
FIG. 1 is an explanatory diagram showing the elevation of a room in which a server rack equipped with a control panel fire extinguishing system according to the present invention is arranged, and FIG. 2 is an explanatory diagram showing the plan view of the room in FIG.

As shown in Figures 1 and 2, a server room 12 in a building such as a data center is partitioned by a floor unit 14 supported by free access pillars 15 and a ceiling unit 18. Inside the server room 12, multiple server racks 10 are arranged, and the server racks 10 house multiple servers used in the data center and provide various communication services.

An air conditioner 22 is installed adjacent to the server room 12, and the air conditioner 22 blows out cooled air into the free access space 16, which is the space under the floor of the floor unit 14, and introduces cooled air into the server rack 10 from the bottom of the rack. The air that passes through the rack is exhausted from the rack ceiling and enters the air conditioning duct space 20 behind the ceiling unit 18, is sucked in from the air conditioning duct space 20 by the air conditioner 22, and is blown out again as cooled air into the free access space 16, thereby realizing a structure that cools the inside of the server rack 10.

Each server rack 10 is equipped with system components of the control panel fire extinguishing system according to this embodiment, allowing fires to be detected and extinguished on a server rack 10 basis.

A monitoring panel 24 is installed in a room adjacent to the server room 12 and is connected by signal line 26 to the control device of the control panel fire extinguishing system installed in each server rack 10, making it possible to detect fires and activate fire extinguishing for each server rack 10. In addition, by connecting via signal line 28 to a management device installed in a monitoring center or the like via a LAN line, it is possible to detect fires and activate fire extinguishing for each server rack 10.

[Control panel fire extinguishing system]
FIG. 3 is an explanatory diagram showing an embodiment of a control panel fire extinguishing system installed in a server rack, in which FIG. 3(A) shows the internal structure as viewed from the front, and FIG. 3(B) shows the internal structure as viewed from the side.

(Air conditioning opening and closing device)
As shown in Figure 3, the server rack 10 has an air conditioning inlet 34 at the bottom of the panel that introduces cooling air supplied from an air conditioning unit into the panel, and an air conditioning exhaust 36 at the ceiling of the panel that exhausts air inside the rack to the outside. The air conditioning inlet 34 is provided with an inlet air conditioning shutter 38 that functions as an air conditioning opening and closing device, and the air conditioning exhaust 36 is provided with an exhaust air conditioning shutter 40 that functions as an air conditioning opening and closing device.

For example, a motor damper is installed as the inlet air conditioning shutter 38 and the outlet air conditioning shutter 40. The motor damper has a blade that rotates by a motor, and the opening can be closed by the rotation of the blade.

The inlet air conditioning shutter 38 and the outlet air conditioning shutter 40 are always open, and the cooling air blown out from the air conditioning device 22 shown in Figures 1 and 2 into the free access space 16 under the floor is introduced into the panel through the open inlet air conditioning shutter 38 to cool the servers 52 and hard disk drives 54 stored in the rack, and the heated air is discharged through the open outlet air conditioning shutter 40.

In addition, the inlet air conditioning shutter 38 and the outlet air conditioning shutter 40 are driven to close if a fire is detected, keeping the server rack 10 sealed.

(Ultra-sensitive smoke detector)
An ultra-high sensitivity smoke detector 30 is disposed in the upper part of the server rack 10. The ultra-high sensitivity smoke detector 30 draws in, from an intake port 32, a portion of the air that is exhausted to the outside through an exhaust port air conditioning shutter 40 that is open from an air conditioning exhaust port 36, detects a fire from the smoke particles contained in the drawn air, and exhausts the drawn air from an exhaust port 33.

The exhaust port 33 of the ultra-high sensitivity smoke detector 30 is connected to the upper part of the return pipe 45, which passes through the rear side of the rack and opens the lower exhaust port 45a into the rack, so that the air exhausted from the ultra-high sensitivity smoke detector 30 is returned to the inside of the rack from the bottom of the rack and returned.

Figure 4 is an explanatory diagram showing an overview of an ultra-high sensitivity smoke detector installed in a server rack, where Figure 4(A) shows the internal structure as viewed from above and Figure 4(B) shows the internal structure as viewed from the side.

As shown in FIG. 4, the ultra-high sensitivity smoke detector 30 uses a suction pump 62 to draw in air from inside the server rack 10 through the suction port 32, passes it through a space in which a laser diode (LD) 56 and a photodiode (PD) 58 are placed, and uses a signal processing unit 60 to perform a pulse count or integration of smoke particles generated by the laser light to determine whether a fire has occurred and transmit a fire detection signal, thereby detecting fires with high sensitivity.

The detection sensitivity of the ultra-high sensitivity smoke detector 30 is such that it can detect a fire with a light extinction density of, for example, 0.005%/m, compared to the 10%/m required for detecting a fire with a general smoke detector, making it approximately 2000 times more sensitive than a general smoke detector and capable of detecting even very faint smoke.

In addition, a return pipe 45 is connected to the exhaust port 33 of the suction pump 62 provided on the ultra-high sensitivity smoke detector 30, and the air exhausted from the exhaust port 33 is guided to the bottom of the rack by the return pipe 45 and released into the rack.

(Fire extinguishing device)
As shown in Fig. 3, a fire extinguishing device 42 is disposed under the server rack 10. The fire extinguishing device 42 of this embodiment stores, for example, two gas cylinders (fire extinguishing gas containers) 44 filled with fire extinguishing gas in a device box, and an electromagnetic valve, for example, is disposed as a fire extinguishing gas release valve 46 in the middle of the piping connecting the gas cylinders 44 to the head 48. CO2, N2, halon gas, FM-200, etc. are sealed in the gas cylinder 44 as a fire extinguishing gas, and the fire extinguishing gas release valve 46 is opened by a fire extinguishing start signal, and the fire extinguishing gas is released from the head 48 toward the upper part of the rack, filling the rack with the fire extinguishing gas evenly to extinguish the fire.

(Control device)
As shown in FIG. 3, a control device 50 is disposed on the upper portion of the server rack 10 .

FIG. 5 is a block diagram showing the functional configuration of a control device provided in the control panel fire extinguishing system.
5, the control device 50 includes a control unit 64, an input unit 66, an output unit 68, a reporting unit 70, and a transmission unit 72. The control unit 64 is composed of a computer circuit equipped with a CPU, a memory, and various input/output ports, and performs predetermined fire extinguishing control by executing a program.

The ultra-high sensitivity smoke detector 30 is connected to the input unit 66, which inputs a fire detection signal. The inlet air conditioning shutter 38, the outlet air conditioning shutter 40, and the fire extinguishing gas release valve 46 are connected to the output unit 68, which outputs a shutter open/close signal and a fire extinguishing activation signal. The monitoring panel 24 is connected to the reporting unit 70, which outputs a fire detection notification signal that identifies the server rack 10 and a fire extinguishing activation notification signal.

A management device 76 installed in a monitoring center or the like is connected to the transmission unit 72 by a signal line 28 via a LAN line. The management device 76 has, for example, a function of SNMP (Simple Network Management Protocol), and can monitor and control the control device 50 via the signal line 28, and receives and notifies at least a fire detection notification signal and a fire extinguishing activation notification signal that identify the server rack 10 from the control device 50.

When the control unit 64 receives a fire detection signal from the ultra-high sensitivity smoke detector 30, it outputs a shutter close signal to the inlet air conditioning shutter 38 and the outlet air conditioning shutter 40 to close the air conditioning inlet 34 and the air conditioning outlet 36 to seal the inside of the rack, and then outputs a fire extinguishing start signal to the fire extinguisher 42 to open the fire extinguishing gas release valve 46 and release the fire extinguishing gas.

The control unit 64 also controls the inlet air conditioning shutter 38 and the outlet air conditioning shutter 40 to close in sequence, and during that time, outputs a fire extinguishing start signal to the fire extinguisher 42 to open the extinguishing gas release valve 46 to release the extinguishing gas. That is, when the control unit 64 detects receipt of a fire detection signal from the ultra-high sensitivity smoke detector 30, it first outputs a shutter close signal to the inlet air conditioning shutter 38 to close the air conditioning inlet 34, then outputs a fire extinguishing start signal to the fire extinguisher 42 to open the extinguishing gas release valve 46 to release the extinguishing gas, and after a predetermined time has elapsed since the release of the extinguishing gas, it outputs a shutter close signal to the outlet air conditioning shutter 40 to close the air conditioning exhaust port 36.

[Control operation of the control panel fire extinguishing system]
FIG. 6 is a flow chart showing the control operation of the control panel fire extinguishing system, which is the control operation performed by the control unit 64 of the control device 50 shown in FIG.

As shown in FIG. 6, in step S1, the control device 50 determines whether or not a fire has been detected by receiving a fire detection signal from the ultra-high sensitivity smoke detector 30. If a fire is detected in step S1, the control device 50 proceeds to step S2, where it transmits a fire detection notification signal including the identification information of the server rack 10 to the external monitoring panel 24 and management device 76 to notify them of the fire detection.

Then, proceed to step S3, output a shutter close signal to the inlet air conditioning shutter 38 to close the air conditioning inlet 34 and stop the introduction of cooling air from the bottom of the rack. Then, proceed to step S4, output a fire extinguishing start signal to the fire extinguisher 42 to open the fire extinguishing gas release valve 46 to start it up and release the fire extinguishing gas, and in step S5, send a fire extinguishing start notification signal including the identification information of the server rack 10 to the external monitoring panel 24 and management device 76 to notify them of the start of the fire extinguishing.

As a result, extinguishing gas is released upward from the head 48 of the fire extinguishing device 42 located at the bottom of the server rack 10. Since the exhaust port air conditioning shutter 40 is in the open state at this time, the air pushed up by the release of the extinguishing gas from below escapes to the outside through the air conditioning exhaust port 36. The extinguishing gas can be released without increasing the internal pressure within the server rack 10, and the released extinguishing gas spreads efficiently and fills the server rack 10.

Next, in step S6, the process waits for a predetermined time to elapse, and when it is determined that the predetermined time has elapsed, the process proceeds to step S7, where a shutter close signal is output to the exhaust port air conditioning shutter 40 to close the air conditioning exhaust port 36. The predetermined time in step S6 is a time sufficient for the fire extinguishing gas to fill the server rack 10 after the fire extinguishing device 42 has released the fire extinguishing gas.

In this way, when a shutter closing signal is output to the exhaust air conditioning shutter 40 in step S7 to close the air conditioning exhaust 36, the server rack 10 becomes sealed and filled with fire extinguishing gas. At this time, the air inside the rack containing the fire extinguishing gas sucked in by the suction pump 62 provided in the ultra-high sensitivity smoke detector 30 shown in FIG. 4, which is placed at the top of the rack, is discharged into the return pipe 45, passes through the return pipe 45, and is released into the rack from the air outlet 45a located at the bottom of the server rack 10, creating a movement that circulates air inside the server rack 10. As a result, the released fire extinguishing gas is distributed evenly inside the server rack 10, making it possible to reliably extinguish a fire.

Next, in step S8, if it is determined that the fire has been restored through the operation of the manager, etc., the process proceeds to step S9, where the inlet air conditioning shutter 38 and outlet air conditioning shutter 40, which are in a closed state, are opened, cooling air is introduced through the air conditioning inlet 34 at the bottom, and the fire extinguishing gas that has filled the interior is exhausted through the air conditioning exhaust 36 at the ceiling, allowing repair work, etc., to be carried out safely on the equipment stored in the server rack 10, and the series of fire extinguishing controls is completed.

[Modifications of the present invention]
(control panel)
The above embodiment takes as an example a fire extinguishing system for a server rack having a cooling structure that introduces cooling air from the bottom and exhausts it to the ceiling side, but the present invention can be similarly applied to any appropriate control panel having a similar cooling structure.

(Pipe-type fire extinguishing system)
In addition, in the above embodiment, the fire extinguishing device 42 containing the gas cylinder 44 is placed inside the server rack, but it is also possible to provide a fire extinguishing gas release valve on the fire extinguishing gas supply pipe drawn into the server rack from an externally installed gas cylinder, and release the fire extinguishing gas from the head into the panel through the fire extinguishing gas supply pipe by opening the fire extinguishing gas release valve.

In this case, it is necessary to install fire extinguishing gas supply piping from the outside, but the gas cylinder to be installed can be a small gas cylinder with a fire extinguishing gas discharge capacity corresponding to the internal volume of the panel such as a server rack, and since it is only necessary to install a fire extinguishing gas discharge valve such as a solenoid valve inside the control panel, it is possible to reduce the amount of system equipment installed inside the control panel and save installation space.

(others)
Furthermore, the present invention includes appropriate modifications that do not impair the objects and advantages of the present invention, and is not limited to the numerical values shown in the above embodiment.

10: Server rack 12: Server room 14: Floor unit 16: Free access space 18: Ceiling unit 20: Air conditioning duct space 22: Air conditioning device 24: Monitoring panel 30: Ultra-high sensitivity smoke detector 32: Intake port 33: Exhaust port 34: Air conditioning inlet 36: Air conditioning exhaust port 38: Inlet air conditioning shutter 40: Exhaust air conditioning shutter 42: Fire extinguisher 44: Gas cylinder 45: Return piping 46: Fire extinguishing gas release valve 48: Head 50: Control device 62: Suction pump 76: Management device

Claims (3)

A control panel fire extinguishing system that detects and extinguishes a fire in a control panel to be monitored,
an air conditioning opening and closing device that is provided at an air conditioning inlet port at the bottom of the panel that introduces cooling air supplied from the air conditioning device into the panel and an air conditioning exhaust port at the top of the panel that exhausts the air inside the panel to the outside and is driven to open and close;
A suction pump is placed on the top of the panel and sucks and exhausts the air inside the panel.
a return pipe for returning the air discharged from the suction pump to the inside of the panel from the lower part of the panel;
A fire extinguishing device is installed under the panel and releases fire extinguishing gas into the panel to extinguish the fire.
a control device that, when receiving a fire detection signal, drives the air conditioning opening and closing device to seal the inside of the panel and releases the extinguishing gas from the fire extinguishing device into the panel to extinguish the fire;
A control panel fire extinguishing system comprising:
The control panel fire extinguishing system according to claim 1,
The control device releases the extinguishing gas into the panel and circulates the air containing the extinguishing gas from the suction pump back into the panel via the return piping.
The control panel fire extinguishing system according to claim 1 or 2,
A control panel fire extinguishing system characterized by comprising a highly sensitive smoke detector that emits a fire detection signal when it detects a fire from smoke particles contained in the air sucked in from inside the panel by the suction pump.

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