KR20230155868A - Chemical Supply Unit and Central Chemical Supply System Including the Same - Google Patents

Abstract

The present invention relates to a chemical supply unit and a central chemical supply system including the same. The chemical supply unit according to one embodiment receives chemicals supplied from the outside or a storage tank and supplies them to the user where they are needed. A chemical supply unit supplying a booth, which defines an internal space in which pipes are placed, and has an exhaust port connected to an exhaust line on the ceiling; and an exhaust damper installed in the exhaust port to open and close the exhaust port, wherein the exhaust damper is an electric exhaust damper that can be automatically opened and closed. According to the present invention, the opening and closing operation of the exhaust damper can be conveniently and safely performed, and a chemical supply unit and a central chemical supply system capable of smooth and stable exhaust can be provided.

Description

Chemical supply unit and central chemical supply system including the same {Chemical Supply Unit and Central Chemical Supply System Including the Same}

The present invention relates to a chemical supply unit and a central chemical supply system including the same, and particularly to an exhaust structure of the chemical supply unit.

In semiconductor factories or chemical factories that use large amounts of various chemicals, a central chemical supply system (hereinafter simply referred to as CCSS) is provided to supply desired chemicals to process lines that require them and to recover waste liquid. In addition to general piping equipment such as piping, valves, fittings, filters, and pumps, these CCSS include storage tanks, mixers that dilute chemicals to the desired concentration or mix them with other chemicals, and hoses that transport chemicals transported in tank trucks to storage tanks. It includes various facilities such as the ACQC (Auto Clean Quick Coupler) unit, which is a connection system, a drum coupler for transferring chemicals stored in drums to a storage tank, and sampling equipment for collecting and inspecting supplied chemicals.

Here, chemicals mainly mean things in a liquid state, including various acids, alkaline solutions, ultrapure water, etc., but also things in a slurry or paste state with solid particles dispersed in liquid, and also things in a gaseous state such as nitrogen, oxygen, and air. It is a concept that includes fluids that can flow through pipes.

Meanwhile, CCSS installed in large-scale factories are often unitized or modularized according to the type of chemical or processing line. By unitizing the CCSS in this way, it is possible to respond flexibly and quickly to expansion or changes in the process line.

Typically, unitized CCSS units are in the form of a booth. Specifically, a typical CCSS unit consists of a roughly rectangular-shaped booth, and the interior of the booth is divided into several areas by partition walls.

Meanwhile, inside such a booth, especially in the piping area where piping, fittings, valves, etc. that exchange chemicals between the inside and outside of the booth are complexly arranged, there may be chemical fume leaking from connection parts of the pipes. Accordingly, an exhaust port is formed in the booth, an exhaust damper that can be opened and closed is used to communicate the exhaust line inside the booth and the factory, and an exhaust pump is used to exhaust the inside of the booth. By providing such an exhaust system, it is possible to exhaust chemical fumes that may be generated inside the booth and create an appropriate negative pressure inside the booth to prevent chemical fumes from leaking out of the booth.

However, since the exhaust damper is usually installed on the ceiling of the booth, in order to open and close the exhaust damper or adjust the opening and closing amount, it is inconvenient and a safety issue to have to climb up a booth at a considerable height (e.g., more than 2 m high) and work at height. there is.

The present invention was made in consideration of this situation, and solves the inconvenience and safety problems of opening and closing the exhaust damper, and provides a chemical supply unit (CCSS unit) and a central chemical supply system (CCSS) that enable smooth and stable exhaust. The purpose is to provide

The chemical supply unit according to one aspect of the present invention for achieving the above object is a chemical supply unit that receives chemicals supplied from the outside or from a storage tank and supplies them to the required user, and has an internal piping installed inside. A booth with limited space and an exhaust port connected to an exhaust line on the ceiling; and an exhaust damper installed in the exhaust port to open and close the exhaust port, wherein the exhaust damper is an electric exhaust damper that can be automatically opened and closed.

Here, the opening degree of the exhaust damper may be adjustable.

According to an embodiment, the chemical supply unit further includes a supply tank configured to receive and store chemicals from an external or storage tank via piping within the booth, and to supply the chemical to the user via piping within the booth. And, the exhaust port includes a first exhaust port for exhausting air in the interior space of the booth, and a second exhaust port for exhausting gas inside the supply tank, and the supply tank passes through the second exhaust port and the second exhaust damper. The exhaust path of the internal gas is independent of the exhaust path of the interior space of the booth via the first exhaust port and the first exhaust damper, so that the gases exhausted through the two exhaust paths do not mix with each other inside the booth.

In this case, the supply tank may be configured to supply the chemical to the place of use by pumping the chemical through the pressure of a high-pressure inert gas, and the gas exhausted through the second exhaust port and the second exhaust damper includes the chemical. The inert gas charged in the supply tank may be included.

Meanwhile, the inside and outside of the booth are blocked by an outer wall and/or a door, and a vent through which air can pass may be formed in the outer wall and/or the door. In this case, the vent may be equipped with a filter that filters out dust or foreign substances in the air.

In addition, according to an embodiment, the chemical supply unit includes a sensor installed in the interior space of the booth to detect chemical fume; and a control unit operably connected to the sensor and the exhaust damper, wherein when chemical fume is detected in the booth interior space by the sensor, the control unit opens the exhaust damper to exhaust the booth interior space. Can be configured to run.

In addition, in this case, the outer wall of the booth is provided with a door that is opened and closed so that workers can enter and exit the booth, and is equipped with a door lock, the control unit is operably connected to the door lock, and the control unit is connected to the sensor. When chemical fume is detected in the interior space of the booth, the exhaust damper is opened to exhaust the interior space, and then, when the chemical fume detected by the sensor falls below a standard value, the door lock can be configured to unlock. there is.

In addition, the central chemical supply system according to another aspect of the present invention is achieved by installing a plurality of any of the above-described chemical supply units. At this time, the exhaust line is a common exhaust line that communicates with each exhaust port of the plurality of chemical supply units, and a common exhaust pump is installed in the common exhaust line.

According to the present invention, the opening and closing operation of the exhaust damper can be conveniently and safely performed, and a chemical supply unit and a central chemical supply system capable of smooth and stable exhaust can be provided.

In addition, according to the embodiment, a chemical supply unit and a central chemical supply system that can be operated without side effects such as contaminating or corroding internal components of a gas containing a relatively high concentration of chemical fume can be provided.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention described later, so the present invention includes the matters described in such drawings. It should not be interpreted as limited to only .
Figure 1 is a perspective view schematically showing a CCSS unit according to an embodiment of the present invention.
FIG. 2 is a perspective view schematically showing the internal configuration of the CCSS unit shown in FIG. 1.
Figure 3 is a perspective view schematically showing the exhaust damper of the CCSS unit shown in Figure 1, where (a) shows a closed state and (b) shows a half-open state.
Figure 4 is a diagram showing the results of exhaust flow analysis by an exhaust damper according to Example (a) and Comparative Example (b) of the present invention.
FIG. 5 is a cut-away perspective view of the internal configuration of the CCSS unit shown in FIG. 1 viewed from a different direction than that of FIG. 2.
FIG. 6 is a piping diagram schematically showing the connection relationship of piping related to the second exhaust damper in the CCSS unit shown in FIG. 1.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms or words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, so at the time of filing the present application, various alternatives may be used to replace them. It should be understood that equivalents and variations may exist.

In the drawings, the size of each component or specific part constituting the component is exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect the actual size. If it is determined that specific descriptions of related known functions or configurations may unnecessarily obscure the gist of the present invention, such descriptions will be omitted.

As used herein, the terms 'coupled', 'mounted', 'fixed' or 'connected' refer to cases where one member is directly coupled, mounted, fixed or connected to another member, as well as when one member connects an intermediate member. It also includes cases where it is indirectly coupled, mounted, fixed, or connected to another member.

Additionally, in this specification, terms indicating direction such as up, down, left, right, front, back, etc. are used, but these directions may vary depending on the direction in which the object is placed and the direction of observation. However, in the following description, for convenience, the view from the direction of arrow A in FIGS. 1 and 2 will be described as the front (front).

Figure 1 is a perspective view schematically showing a CCSS unit according to an embodiment of the present invention, and Figure 2 is a perspective view schematically showing the internal structure and exhaust damper, omitting the outer wall and ceiling of the booth.

Referring to Figures 1 and 2, the chemical supply unit (CCSS unit) 1 according to this embodiment receives chemicals supplied from the outside or a storage tank (not shown) and supplies them to a point of use (Point of Use) that requires them. ) is a CCSS unit supplied. The CCSS unit (1) may only serve to relay (transmit) chemicals supplied from outside to the point of use, but usually supplies them to the point of use after pre-processing the chemicals supplied from outside, such as mixing, dilution, and filtering. It is composed.

The CCSS unit (1) is in the form of a booth (10). The booth 10 defines an internal space in which the pipes 30 and the like are placed. The booth 10 may have a substantially rectangular shape including a frame 11, an outer wall 12, and/or a door 14, and the inside and outside of the booth 10 includes an outer wall 12 and/or a door 14. ) can be blocked. Additionally, a vent 15 through which air can pass may be formed in the outer wall 12 and/or the door 14. In this case, a filter that filters out dust or foreign substances in the air may be installed in the vent 15.

In addition, the booth 10 is provided with an exhaust port 16, and this exhaust port 16 is connected to the factory exhaust line (not shown) to exhaust the air in the interior space of the booth 10. Specifically, in this embodiment, the exhaust port 16 may be provided on the ceiling of the booth 10, and one or more exhaust ports 16 may be provided, and in this embodiment, two exhaust ports 16a and 16b may be provided.

In addition, an exhaust damper 40 is installed in the exhaust port 16 to open and close the exhaust port 16, so that the exhaust port 16 can communicate with the exhaust line through the exhaust damper 40. The exhaust damper 40, especially when installed at the top of the booth 10, which is difficult for workers to access, as in this embodiment, is preferably made of an electric exhaust damper that can be automatically opened and closed, and can be opened so that the exhaust amount can be adjusted. It is more desirable to be able to adjust the (degree of opening). The exhaust damper 40 applied to this embodiment will be described in detail later.

Meanwhile, the internal space of the booth 10 is divided into several areas 20, and equipment necessary to process and supply the pipe 30 and/or chemicals is placed in each area 20. At this time, the areas 20 may be physically isolated by the partition wall 13 or may be simply spatially (conceptually) divided without the partition wall. Zone 20 may typically include a piping zone 21, a filter zone 22, a pneumatic zone 23, an electrical zone 24, etc.

The piping area 21 is a core area of the CCSS unit 1 and is allocated wider and larger than other areas and can be allocated to the center of the booth 10. In the piping area 21, a piping 30 and a valve 31 are disposed to receive chemicals supplied from a storage tank or from outside and to export the chemicals to the point of use.

The filter area 22 is an area where one or more filters F are placed to filter out impurities contained in chemicals supplied from the outside of the booth 10 or from the storage tank via the piping area 21 or particles of a specified size or larger. , may be assigned to one side (left side in this embodiment) of the booth 10 adjacent to the piping area 21.

The pneumatic area 23 is equipped with compressors, valves, piping, etc. to receive gases such as high-pressure inert gas (e.g., nitrogen), air, and clean dry air (CDA) from the outside and supply/block them to necessary facilities. As an area where elements are arranged, it can be allocated adjacent to the piping area 21 (in this embodiment, in the lower front right corner of the booth 10). High-pressure inert gas or air can be used to transport chemicals by pushing the chemicals stored in the tank by gas pressure, as will be described later. In addition, clean dry air can be used to clean the inside of pipes, etc. with ultra-pure water and then dry it, and can be blown into the interior space of the booth 10 and exhausted together with the air or chemical fume in the interior space.

The electrical area 24 controls the distribution board for supplying/blocking power to elements driven by power inside the booth 10, such as compressors, electromagnetic valves, and sensors, various switches, and even the overall operation of the CCSS unit 1. This is an area where a circuit board (not shown) including a control unit, an operation panel 29, etc. are placed, and may be allocated to one side of the booth 10 (in this embodiment, the upper part of the pneumatic area 23).

In addition, depending on the special specifications, requirements, or chemistry of the CCSS unit 1, elements other than the above-mentioned elements may be arranged, and if necessary, additional areas 25 other than the above-mentioned areas 21 to 24. This can be assigned. In this additional area, for example, when the chemical handled by the CCSS unit 1 is slurry, particle counters (not shown) or electronic valves may be placed to manage particles of a specified size or larger contained in the slurry. Of course, this additional area 25 is optional and may be omitted if unnecessary.

Additionally, doors 14 that can be opened and closed to allow workers access to maintain facilities such as the pipes 30 arranged in each area may be installed in these areas 21 to 25. In particular, the door 14 installed in the piping area 21 is relatively large to allow workers to enter and exit the booth 10, and the door 14 may be provided with a door lock.

Meanwhile, the exhaust damper 40 applied to the CCSS unit of this embodiment may be implemented as an electric exhaust damper in which the aperture 42 is opened and closed by the drive motor 41, as shown in FIG. 3. In particular, the drive motor 41 may be a servo motor, and the opening degree of the aperture 42 can be arbitrarily adjusted between a fully closed state ((a) in FIG. 3) and a fully open state (not shown) (see FIG. 3). (b) is half-open).

In this way, by configuring the exhaust damper 40 as an electric exhaust damper, manual opening and closing operations by the operator are unnecessary, thereby solving the inconvenience of working at heights and safety problems.

Furthermore, by using the aperture-type electric exhaust damper shown in Figure 3, even and smooth exhaust inside the booth 10 is possible, and the overall height of the booth 10 can be lowered compared to a conventional manual damper, allowing the booth to be transported to the factory. The upper space is secured when carrying in and out, making it convenient to install or remove the booth.

Specifically, referring to FIG. 4 showing the results of exhaust flow analysis by the exhaust damper according to Example (a) and Comparative Example (b) of the present invention, it is a manual butterfly valve type, that is, a disk-shaped inside of a cylindrical duct. Compared to the exhaust damper 40' according to the comparative example of a type in which the disk 42' opens and closes while rotating around the center line of the disk plane, in the case of the electric exhaust damper 40 according to the present embodiment, the exhaust flow rate It can be seen that this is evenly distributed and the overall height is much smaller.

Meanwhile, the CCSS unit 1 according to this embodiment receives and stores chemicals supplied from the outside or a storage tank (not shown), and supplies the chemicals to the point of use via the pipe 30 in the booth 10. It may further include a configured supply tank (50; see FIG. 6). Here, the storage tank is a large-capacity tank that stores a large amount of chemicals supplied from the outside through tank trucks or drums without special treatment, and the supply tank 50 is tailored to the time and amount required for each process line (use), and further It is a relatively small-capacity tank that stores chemicals for supply after necessary processing (filtering, mixing, dilution, etc.).

When the CCSS unit includes such a supply tank 50, especially when the chemicals are filtered by a filter (F) and then supplied to the point of use as in this embodiment, chemicals are supplied from the outside or a storage tank and supplied to the supply tank ( The process of storing the chemical in 50, the process of filtering the chemical, and the process of supplying the chemical from the supply tank 50 to the point of use are all carried out via the piping 30 in the piping area 21 under the control of the CCSS unit 1. You can. Here, the supply tank 50 may store chemicals after filtering or chemicals before filtering. In this embodiment, the chemicals before filtering are stored in the supply tank 50 and are then stored in the filter (F) when supplied to the point of use. After filtering, it is supplied to the point of use. In addition, a pump may be used to supply chemicals from the supply tank 50 to the place of use, but in this embodiment, the chemical is pumped by the gas pressure of an inert gas such as nitrogen supplied through the pneumatic area 23 described above. It consists of

Hereinafter, the configuration including the supply tank 50 will be described in detail with reference to FIGS. 5 and 6.

In this embodiment, two supply tanks 50 (50a, 50b) are installed outside the booth 10. Of course, only one supply tank or three or more supply tanks may be installed, or they may be installed inside the booth 10.

The booth 10 and the supply tank 50 include charging pipes 51a and 51b for charging chemicals supplied from an external source or a storage tank into each supply tank 50a and 50b, respectively, and supply tanks 50a and 50b. ) supply pipes 52a, 52b for supplying chemicals supplied from the supply tank 50a, 52b to the point of use, and an inert gas (e.g. nitrogen) for transporting the chemicals stored in each supply tank 50a, 50b to each supply tank 50a. , 50b) are fluidly connected by inert gas piping (53a, 53b).

In addition, inside the booth 10, booth internal inert gas pipes 33a and 33b are provided, which communicate with the inert gas pipes 53a and 53b through a valve 34. The ends of the booth internal inert gas pipes 33a and 33b opposite to the booth external inert gas pipes 53a and 53b are connected to the above-mentioned pneumatic area 23, and high-pressure nitrogen is supplied. In addition, the booth internal inert gas pipes 33a and 33b branch into exhaust pipes 35a and 35b, respectively, inside the booth and communicate with the second exhaust port 16b through the valve 36 and the exhaust duct 45.

Meanwhile, although not shown in Figure 6, in the booth 10, a pipe 30 and a valve 31 connected to the booth 10 side ends of the filling pipes 51a and 51b and the supply pipes 52a and 52b. etc. are provided so that chemicals can be exchanged with the external or storage tank, filter (F), and user.

The process of supplying chemicals from the supply tank 50 to a user using the supply tank 50 and piping configured as described above and the process of filling the supply tank 50 with chemicals will be described.

First, in order to supply the chemicals charged in the supply tank 50 to the point of use, the valve 34 of the inert gas pipes 33a and 33b inside the booth is opened, and the valve 36 of the exhaust pipes 35a and 35b is opened. Close and supply high-pressure inert gas to the supply tank 50 through the inert gas pipes 33a, 33b and 53a, 53b. Then, the chemicals inside the supply tank 50 due to the gas pressure of the inert gas pass through the supply pipes 52a and 52b to the outside of the booth 10 via the pipe 30 and the filter F inside the booth 10. It is supplied to the place of use.

Meanwhile, in order to fill the supply tank 50 with chemicals, the valve 31 of the pipe 30 inside the booth connected to the supply pipes 51a and 51b is opened to allow chemicals from the outside or the storage tank to enter the pipe inside the booth. (30) and supply pipes (51a, 51b) to supply to the supply tank (50). At this time, the valves 34 of the inert gas pipes 33a and 33b inside the booth are closed, and the valves 36 of the exhaust pipes 35a and 35b are opened, so that the gas filling the inside of the supply tank 50, that is, chemical fume, is closed. This contained inert gas is discharged from the factory via the inert gas pipes (53a, 53b and 33a, 33b), exhaust pipes (35a, 35b), exhaust duct (45), second exhaust port (16b), and second exhaust damper (40b). It is exhausted to my exhaust line (not shown).

As such, in this embodiment, the exhaust port 16 is divided into a first exhaust port 16a that exhausts the air in the interior space of the booth 10 and a second exhaust port 16b that exhausts the gas inside the supply tank 50. , the exhaust path of the gas inside the supply tank 50 via the second exhaust port 16b, the exhaust duct 45, and the second exhaust damper 40b, and the first exhaust port 16a and the first exhaust damper 40a. ) and is independent of the exhaust path of the interior space of the booth 10 passing through the booth 10, so that the gases exhausted through the two exhaust paths do not mix with each other inside the booth 10.

According to this configuration, the exhaust system of the CCSS unit 1 can be operated without side effects such as gas containing a relatively high concentration of chemical fume contaminating or corroding the internal components of the booth 10.

Meanwhile, a drain pipe 37 and a valve 38 may be provided at the lower part of the exhaust duct 45 to discharge chemicals generated by condensation of chemical fume or overflowed from the supply tank 50.

Meanwhile, the CCSS unit 1 according to this embodiment may be installed in the interior space of the booth 10 and may further include a sensor (not shown) that detects chemical fume. In this case, the sensor is operably connected to the control unit, wired or wirelessly, and can transmit detection results to the control unit according to instructions from the control unit or on its own initiative. Additionally, in this case, it is preferable that the electric exhaust damper 40 is also operably connected to the control unit.

In this case, when chemical fume is detected in the interior space of the booth 10 by the sensor, the control unit may control the exhaust damper 50 to be opened to exhaust the interior space.

Furthermore, as described above, especially if a door lock is provided on the door 14 through which workers can enter the booth 10, this door lock can also be operably connected to the control unit in addition to the sensor and exhaust damper 50 described above. there is.

In this case, when chemical fume is detected in the internal space of the booth 10 by the sensor, the control unit opens the exhaust damper 50 to exhaust the internal space, and then the chemical fume detected by the sensor is set to the standard value. When the value falls below, the door lock can be controlled to be unlocked. By doing this, the safety of workers entering the booth 10 for maintenance can be promoted.

Meanwhile, a central chemical supply system (CCSS) according to another aspect of the present invention can be achieved by installing a plurality of CCSS units 1 as described above. In this case, the above-described exhaust line becomes a common exhaust line communicating with each exhaust port 16 of the plurality of CCSS units 1, and a common exhaust pump (not shown) is installed in this common exhaust line. . This CCSS has the same configuration and advantages of the aforementioned CCSS unit (1), enabling smooth and stable exhaust of the entire CCSS.

Preferred embodiments of the present invention have been described above with reference to the attached drawings. However, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, so at the time of filing the present application, there are various options that can replace them. It should be understood that equivalents and variations may exist.

1: Chemical supply unit (CCSS unit)
10: Booth
11: frame
12: Exterior wall
13: Bulkhead
14: door
15: Ventilation hole
16, 16a, 16b: exhaust port
20: area
21: Piping area
22: Filter area
23: Pneumatic area
24: Electrical area
25: Additional area
30: Plumbing
31: valve
40, 40a, 40b: exhaust damper
50, 50a, 50b: supply tank

Claims (8)

As a chemical supply unit that receives chemicals supplied from outside or from a storage tank and supplies them to the required user,
A booth that defines an internal space where pipes are placed and has an exhaust port connected to an exhaust line on the ceiling; and
It includes an exhaust damper installed in the exhaust port to open and close the exhaust port,
A chemical supply unit, wherein the exhaust damper is an electric exhaust damper that can be automatically opened and closed. According to paragraph 1,
A chemical supply unit, characterized in that the opening degree of the exhaust damper is adjustable. According to paragraph 1,
The chemical supply unit further includes a supply tank configured to receive and store chemicals from an external or storage tank via piping within the booth, and to supply the chemicals to the user via piping within the booth,
The exhaust port includes a first exhaust port for exhausting air from the interior space of the booth, and a second exhaust port for exhausting gas inside the supply tank,
The exhaust path of the gas inside the supply tank via the second exhaust port and the second exhaust damper is independent of the exhaust path of the interior space of the booth via the first exhaust port and the first exhaust damper, and is provided through two exhaust paths. A chemical supply unit characterized in that the exhausted gases are not mixed with each other inside the booth. According to paragraph 3,
The supply tank is configured to supply the chemical to the user by pumping the chemical through the pressure of a high-pressure inert gas,
A chemical supply unit, wherein the gas exhausted via the second exhaust port and the second exhaust damper includes the inert gas charged in the supply tank. According to paragraph 1,
The inside and outside of the booth are blocked by an exterior wall and/or door,
The outer wall and/or door are formed with ventilation holes through which air can pass,
A chemical supply unit, characterized in that the ventilation hole is equipped with a filter that filters dust or foreign substances in the air. According to paragraph 1,
A sensor installed in the interior space of the booth to detect chemical fume; and
Further comprising a control unit operably connected to the sensor and the exhaust damper,
The control unit is configured to open the exhaust damper to exhaust the booth interior space when chemical fume is detected in the booth interior space by the sensor. According to clause 6,
The outer wall of the booth is provided with a door that opens and closes to allow workers to enter the booth and is equipped with a door lock,
The control unit is operably connected to the door lock,
The control unit, when chemical fume is detected in the interior space of the booth by the sensor, opens the exhaust damper to exhaust the interior space, and then, when the chemical fume detected by the sensor falls below the standard value, the A chemical supply unit configured to unlock a door lock. It is achieved by installing a plurality of chemical supply units according to any one of claims 1 to 7,
The exhaust line is a common exhaust line communicating with each exhaust port of the plurality of chemical supply units,
A central chemical supply system, characterized in that a common exhaust pump is installed in the common exhaust line.

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