Dust collection apparatus and cell wall drying system having the same

Abstract

The utility model provides a kind of dust collecting equipment and cell wall drying system with it, dust collecting equipment includes: powder storehouse, first communication port and second communication port are provided on the lateral wall of powder storehouse;Cyclone separator, the discharge port of cyclone separator is communicated with first communication port;Filtering device, filtering device has shell, sealing plate and multiple filter tubes, the import of shell is communicated with second communication port, sealing plate and filter tube are all arranged in shell, sealing plate is fixedly arranged in shell, and the circumference of sealing plate is sealed with shell, multiple connection ports are provided on sealing plate, multiple connection ports are set up one by one with multiple filter tubes, the open end of filter tube is connected with connection port, and the open end of filter tube is set towards the import of shell, filter tube is made of metal filter screen;Fan, fan is communicated with the outlet of shell, for providing negative pressure to powder storehouse. The technical scheme of the application can solve the problem of high cost of dust removal system in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of cell wall drying technology, specifically to a dust collection device and a cell wall drying system having the same. Background Technology

[0002] Currently, after the cell walls are dried and dehydrated to form dried matter, the fine dust in the dried matter is collected and removed to prevent the fine dust from being discharged directly into the atmosphere with the exhaust gas, thereby reducing air dust pollution and minimizing the adverse impact on the surrounding ecological environment.

[0003] In existing technologies, filtration equipment such as water curtain dust collectors or bag filters are typically used to effectively intercept dust and ensure that exhaust gases meet emission standards. However, in the scenario of collecting dust from yeast cell walls, water curtain dust collectors have limited efficiency in capturing fine dust, easily generating dusty wastewater containing organic matter, requiring supporting wastewater treatment facilities and posing a risk of secondary pollution. Bag filters, on the other hand, suffer from problems such as filter bags being prone to condensation or wear due to humidity fluctuations, resulting in a short lifespan; conventional filter media having limited temperature resistance; complex structure, large footprint, high operating resistance, and high energy consumption, leading to high costs and complex maintenance for existing filtration equipment. Utility Model Content

[0004] This invention provides a dust collection device and a cell wall drying system thereon to solve the problem of high operating costs of existing dust removal systems.

[0005] According to one aspect of this utility model, a dust collection device is provided, comprising: a dust silo, on the side wall of which a first connecting port and a second connecting port are provided; a cyclone separator, the outlet of which is connected to the first connecting port; a filter device, comprising a housing, a sealing plate, and multiple filter cylinders, the inlet of which is connected to the second connecting port, both the sealing plate and the filter cylinders being disposed within the housing, the sealing plate being fixedly disposed within the housing, and the periphery of the sealing plate being sealed to the housing, the sealing plate being provided with multiple connection ports, each of which corresponds to one of the multiple filter cylinders, the open end of the filter cylinder being connected to the connection port, and the open end of the filter cylinder facing the inlet of the housing, the filter cylinder being made of a metal filter screen; and a fan, the fan being connected to the outlet of the housing for providing negative pressure to the dust silo.

[0006] Furthermore, the filter device is also equipped with a cleaning component, which includes an air jet and an air source. The air jet is installed inside the housing and connected to the air source. The air jet is located on the side of the filter cartridge opposite to the second connection port and is positioned corresponding to the filter cartridge.

[0007] Furthermore, the jet component includes an air pipe and multiple nozzles. The air pipe is connected to an air source, and the multiple nozzles are all mounted on the air pipe. The multiple nozzles are also configured to correspond one-to-one with multiple filter cartridges.

[0008] Furthermore, the filter cartridge and the sealing plate are detachably connected.

[0009] Furthermore, the mesh size of the metal filter is between 5 and 15 mesh.

[0010] Furthermore, a third connecting port is provided on the housing, which is located upstream of the filter cartridge, and the air outlet of the cyclone separator is connected to the third connecting port.

[0011] Furthermore, a first shut-off valve is provided between the cyclone separator and the first connecting port, and a second shut-off valve is provided between the filter device and the second connecting port.

[0012] Furthermore, a first vibrating hammer is provided on the side wall of the cyclone separator, which is used to strike the side wall of the cyclone separator, and a second vibrating hammer is provided on the side wall of the powder bin, which is used to strike the side wall of the powder bin.

[0013] Furthermore, a fourth connecting port is provided at the bottom of the powder hopper, and the filtering device also includes a vibrating screen, which is located at and connected to the fourth connecting port.

[0014] According to another aspect of the present invention, a cell wall drying system is provided, which includes a drying tower and a dust collection device. The outlet of the drying tower is connected to the dust collection device, which is the aforementioned dust collection device.

[0015] This invention utilizes a metal mesh filter cartridge to precisely intercept residual fine dust. Compared to the limitations of water curtain dust collectors in capturing fine dust, this significantly improves overall dust removal efficiency and effectively prevents pollution and material waste caused by dust escape. Furthermore, the metal filter cartridge offers superior temperature resistance and wear resistance compared to baghouse dust collectors. It is less prone to condensation due to humidity fluctuations or wear from dust, making it suitable for the temperature conditions of the flue gas discharged from the drying tower and the physical characteristics of cell wall dust, thus significantly extending the service life of the filter components. Moreover, it eliminates the need for additional water supply, avoiding the problem of dust-laden wastewater generated by water curtain dust collectors. This eliminates the need for wastewater treatment facilities, reducing initial construction costs and preventing secondary pollution risks. The collected dust can be centrally recycled and reused in a dust silo, further improving material utilization. The metal filter cartridge is easy to clean and maintain, requiring minimal replacement. Combined with stable airflow driven by negative pressure, its operating resistance is far lower than that of baghouse dust collectors, significantly reducing fan energy consumption and long-term maintenance costs. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the structure of the dust collection device provided by this utility model is shown;

[0018] Figure 2 A schematic diagram of the filtration device provided by this utility model is shown.

[0019] The above figures include the following reference numerals:

[0020] 100. Powder hopper;

[0021] 110. Second oscillating hammer;

[0022] 120. Fourth connecting port;

[0023] 200. Cyclone separator;

[0024] 210. First shut-off valve;

[0025] 220. First oscillating hammer;

[0026] 300. Filter device;

[0027] 310. Shell;

[0028] 320. Sealing plate;

[0029] 330. Filter cartridge;

[0030] 340. Clean up components;

[0031] 341. Trachea;

[0032] 342. Sprayer head;

[0033] 350. Second shut-off valve;

[0034] 360° Vibrating screen;

[0035] 400. Fan. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0037] like Figure 1 and Figure 2 As shown in the figure, this utility model embodiment provides a dust collection device, which includes a dust hopper 100, a cyclone separator 200, a filter device 300, and a fan 400. The dust hopper 100 is used to collect cell wall powder dried in a drying tower. A first connecting port and a second connecting port are provided on the side wall of the dust hopper 100. The cyclone separator 200 is connected to the drying tower, and its outlet is connected to the first connecting port. Gas is used to introduce the cell wall powder into the dust hopper 100. The filtration device 300 has a housing 310, a sealing plate 320, and multiple filter cartridges 330. The inlet of the housing 310 is connected to the second communication port. The sealing plate 320 and the filter cartridges 330 are both disposed inside the housing 310. The sealing plate 320 is fixedly disposed inside the housing 310, and the periphery of the sealing plate 320 is sealed to the housing 310. The sealing plate 320 is provided with multiple connection ports, which are respectively provided with multiple filter cartridges 330. The open end of the filter cartridge 330 is connected to the connection port, and the open end of the filter cartridge 330 is set towards the inlet of the housing 310. The filter cartridge 330 is made of metal filter screen. The fan 400 is connected to the outlet of the housing 310 and is used to provide negative pressure to the powder silo 100.

[0038] Applying the technical solution of this application, the cell wall powder dried in the drying tower will undergo preliminary separation of most of the coarse particles by the centrifugal force of the cyclone separator 200. After preliminary separation, the cell wall powder enters the powder hopper 100 through the first connecting port. The fan 400 can then be turned on, and the negative pressure provided by the fan 400 will guide the cell wall powder in the powder hopper 100 to the filter device 300. The sealing plate 320 and the housing 310 of the filter device 300 are sealed together, and the dust can only flow through the filter cylinder 330 connected to the sealing plate 320. The fine dust filtered by the filter cylinder 330 can be introduced into the next process under the action of the fan 400. The layout design with the opening facing the inlet of the housing ensures that the dust-laden airflow can fully enter the interior of the filter cylinder. The high-precision filtration of the metal filter screen intercepts the fine dust, achieving secondary purification and preventing dust escape, thereby removing impurities from the cell wall powder.

[0039] The dust collection equipment provided in this application uses a metal filter cartridge 330 to precisely intercept residual fine dust. Compared to the limitations of water curtain dust collectors in capturing fine dust, this significantly improves overall dust removal efficiency and effectively avoids pollution and material waste caused by dust escape. Furthermore, the metal filter cartridge 330 has stronger temperature resistance and better wear resistance than the filter media in baghouse dust collectors. It is less prone to condensation due to humidity fluctuations or wear from dust, making it suitable for the temperature conditions of the flue gas discharged from the drying tower and the physical characteristics of cell wall dust, thus significantly extending the service life of the filter components. Moreover, no additional water supply is required, avoiding the problem of dust-laden wastewater generated by water curtain dust collectors. This eliminates the need for wastewater treatment facilities, reducing initial construction costs and preventing secondary pollution risks. The collected dust can be centrally recycled and reused through a dust silo, further improving material utilization. The metal filter cartridge is easy to clean and maintain, requiring no frequent replacement. Combined with stable airflow circulation driven by negative pressure, the operating resistance is much lower than that of baghouse dust collectors, significantly reducing fan energy consumption and long-term maintenance costs.

[0040] Furthermore, the filter device 300 is also provided with a cleaning component 340, which includes an air jet and an air source. The air jet is disposed inside the housing 310 and is connected to the air source. The air jet is located on the side of the filter cartridge 330 away from the second connection port and is disposed corresponding to the filter cartridge 330. High-pressure gas supplied by an air source is used to directionally spray air onto the side wall of filter cartridge 330. The impact force of the gas quickly removes yeast cell wall dust that has adhered to the filter over a long period of filtration, achieving online dust removal of the filter cartridge. Filtration performance can be restored without disassembling the equipment. This avoids the problems of increased airflow resistance and decreased filtration efficiency caused by dust residue, and eliminates the need for frequent shutdowns to replace filter bags or manual cleaning as required by baghouse dust collectors. This significantly reduces maintenance workload and downtime losses, ensuring continuous production. At the same time, during the dust removal process, the dust falls back into the dust hopper with the airflow for centralized collection, avoiding secondary dust pollution. Furthermore, the high-pressure gas impact does not damage the metal filter screen and extends the service life of filter cartridge 330. Combined with the environmental advantages of dry dust removal and the compact layout, this further enhances the adaptability, stability, and economy of the equipment in yeast cell wall dust collection scenarios, making the overall system more efficient and easier to maintain.

[0041] In some specific embodiments of this application, the jetting component includes an air pipe 341 and a plurality of nozzles 342. The air pipe 341 is connected to an air source, and the plurality of nozzles 342 are all disposed on the air pipe 341. The plurality of nozzles 342 are disposed in a one-to-one correspondence with the plurality of filter cartridges 330. With a one-to-one correspondence between nozzles and filter cartridges, the high-pressure gas delivered by the air source can be diverted through the air pipe 341 and precisely guided by each nozzle 342 to the inner wall of the corresponding filter cartridge 330. This achieves directional and point-to-point dust removal for each filter cartridge 330, avoiding the dust removal dead zones that may occur with a single jet structure. This ensures that the yeast cell wall dust adhering to the surface of the metal filter cartridge 330 can be completely and evenly removed, effectively maintaining the consistency of filtration efficiency for each filter cartridge. At the same time, this dispersed nozzle 342 design can be flexibly adapted according to the number and layout of the filter cartridges 330, ensuring that the impact force of the high-pressure gas is concentrated on the corresponding filter cartridge 330. This not only improves the dust removal efficiency but also avoids gas waste. Compared with a general jet structure, it is more adaptable to the design of filtration devices with multiple filter cartridges 330, further enhancing the convenience and effectiveness of online dust removal. Combined with the material characteristics of the metal filter cartridges 330 and the centralized recovery function of the powder hopper 100, the equipment maintains stable dust removal performance during long-term operation, resulting in lower maintenance costs and greater practicality.

[0042] Furthermore, the filter cartridge 330 and the sealing plate 320 are detachably connected. When the filter cartridge 330 experiences filter screen wear, severe clogging, or requires thorough cleaning after long-term use, it can be directly removed from the connection port of the sealing plate 320. This reduces the complexity and workload of maintenance operations. Compared to the cumbersome process of replacing filter bags in baghouse dust collectors and the difficulty in thoroughly cleaning fixed filter components, this not only saves maintenance time and reduces production downtime losses, but also ensures that the entire filtration device 300 maintains efficient and stable dust removal performance by selectively replacing or deeply cleaning damaged filter cartridges 330, thus reducing operation and maintenance costs.

[0043] Specifically, the mesh size of the metal filter is set between 5 and 15 mesh. When the mesh size is less than 5 mesh, the pore size is too large, resulting in insufficient structural strength of the filter cartridge 330. This makes it susceptible to damage due to the impact of high-pressure air jet cleaning and prolonged friction with dust. Conversely, when the mesh size is greater than 15 mesh, the pore size is too small, increasing the airflow resistance received by the filter cartridge 330 and affecting the overall operating resistance of the collection device. This application, by setting the mesh size of the metal filter between 5 and 15 mesh, ensures that the filter cartridge 330 possesses sufficient structural strength to withstand the impact of high-pressure air jet cleaning and prolonged friction with dust, preventing deformation or damage due to insufficient strength. Simultaneously, it achieves a reasonable pore size, enabling efficient interception while avoiding increased airflow resistance caused by an excessively high mesh size. Specifically, the mesh size of the metal filter can be set to 5, 10, or 15 mesh.

[0044] In some feasible embodiments of this application, a third connecting port is provided on the housing 310, located upstream of the filter cartridge 330, and the outlet of the cyclone separator 200 is connected to the third connecting port. With this design, the airflow containing fine dust after the cyclone separator 200 separates coarse particles can be directly introduced into the upstream area of ​​the filter cartridge 330 through the third connecting port, without the need for additional pipeline detours. This reduces resistance loss and dust deposition during airflow transport, allowing the dust-laden airflow to enter the filter cartridge more smoothly for fine filtration. Compared to the traditional layout where the separation equipment and filtration device are independently set up, this significantly improves the overall system's dust removal continuity. The residual kinetic energy of the airflow after cyclone separation assists dust in entering the filter cartridge 330, reducing the negative pressure drive load of the fan 400 and indirectly reducing energy consumption.

[0045] Specifically, a first shut-off valve 210 is installed between the cyclone separator 200 and the first connecting port, and a second shut-off valve 350 is installed between the filter device 300 and the second connecting port. Thus, a precise and controllable pipeline on / off adjustment mechanism can be formed through the first shut-off valve 210 and the second shut-off valve 350. The first shut-off valve 210 can flexibly control the discharge path from the cyclone separator 200 to the powder silo 100. When maintenance or cleaning of residual dust inside the cyclone separator 200 is required, closing the first shut-off valve 210 isolates the cyclone separator 200 from the powder silo 100, preventing dust leakage or reverse airflow impact on equipment components during maintenance. Simultaneously, the discharge rate can be controlled by adjusting the valves. The first valve is designed to adapt to the capacity of the powder hopper and the subsequent processing rhythm. The second shut-off valve 350 can precisely control the airflow channel between the powder hopper 100 and the filter device 300. When the filter device 300 needs to be cleaned online, the filter cartridge needs to be disassembled and replaced, or the inside of the housing needs to be cleaned for maintenance, closing the second shut-off valve 350 can isolate the filter device 300 from the powder hopper 100, preventing dust in the powder hopper 100 from entering the filter device during maintenance and causing secondary pollution. It also avoids the airflow from affecting the dust collection status in the powder hopper 100 during high-pressure cleaning.

[0046] In some feasible embodiments of this application, a first vibrating hammer 220 is provided on the side wall of the cyclone separator 200, which is used to strike the side wall of the cyclone separator 200. A second vibrating hammer 110 is provided on the side wall of the powder hopper 100, which is used to strike the side wall of the powder hopper 100. During the separation process of the cyclone separator 200, some coarse dust particles are easily attached to the side wall of the separator due to centrifugal force. The powder collected in the powder hopper 100 may also adhere to the hopper wall due to gravity settling, slight moisture absorption, etc., forming material accumulation. This application uses the vibration effect generated by mechanical striking to cause the dust adhering to the powder hopper 100 of the cyclone separator 200 to fall off and concentrate to the bottom of the hopper, avoiding the accumulation of material from affecting the hopper's capacity and the smoothness of subsequent unloading.

[0047] In some embodiments of this application, a fourth connecting port 120 is provided at the bottom of the powder silo 100, and the filter device 300 further includes a vibrating screen 360, which is located at and connected to the fourth connecting port 120. The dust collected in the powder silo 100 may contain a small amount of coarse particulate impurities or dust clumps that have not been completely separated by the cyclone separator 200. The vibrating screen 360 can perform secondary sieving of these materials through high-frequency vibration, accurately separating fine cell wall powder that meets the particle size requirements, effectively removing coarse impurities and clumps, improving the purity and uniformity of the final recovered material, and meeting the downstream production requirements for raw material particle size. This further enhances the practicality, purification effect, and smooth operation of the equipment in industrial yeast cell wall dust collection scenarios.

[0048] According to another aspect of this application, a cell wall drying system is provided, comprising a drying tower and a dust collection device. The outlet of the drying tower is connected to the dust collection device, which is the aforementioned dust collection device. By connecting the drying tower to the aforementioned dust collection device, after the drying tower completes the drying of the cell wall powder, the dust-laden airflow is directly introduced into the dust collection device. First, coarse particles are quickly separated by a cyclone separator 200, and then fine dust is intercepted by a metal filter cartridge 330. Combined with online dust removal by the jet assembly, material cleaning by the vibrating hammer, and secondary screening by the vibrating screen, this ensures thorough dust collection, avoids environmental pollution from dust after drying, and recovers high-purity, uniformly sized cell wall powder, reducing material waste, lowering operating costs, and facilitating maintenance.

[0049] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0050] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0051] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0052] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0053] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0054] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A dust collection device, characterized in that, The dust collection device includes: A powder hopper (100) has a first connecting port and a second connecting port on its side wall; Cyclone separator (200), the discharge port of the cyclone separator (200) is connected to the first communication port; A filtration device (300) has a housing (310), a sealing plate (320), and multiple filter cylinders (330). The inlet of the housing (310) is connected to the second communication port. The sealing plate (320) and the filter cylinders (330) are both disposed inside the housing (310). The sealing plate (320) is fixedly disposed inside the housing (310), and the periphery of the sealing plate (320) is sealed to the housing (310). The sealing plate (320) is provided with multiple connection ports, and the multiple connection ports are respectively provided with the multiple filter cylinders (330). The open end of the filter cylinder (330) is connected to the connection port, and the open end of the filter cylinder (330) is facing the inlet of the housing (310). The filter cylinder (330) is made of metal filter screen. A blower (400) is connected to the outlet of the housing (310) and is used to provide negative pressure to the powder silo (100).

2. The dust collection device according to claim 1, characterized in that, The filter device (300) is also provided with a cleaning component (340), which includes an air jet and an air source. The air jet is disposed in the housing (310) and communicates with the air source. The air jet is located on the side of the filter cylinder (330) away from the second communication port and is disposed corresponding to the filter cylinder (330).

3. The dust collection device according to claim 2, characterized in that, The jetting component includes an air pipe (341) and multiple nozzles (342). The air pipe (341) is connected to the air source. The multiple nozzles (342) are all disposed on the air pipe (341). The multiple nozzles (342) are disposed in a one-to-one correspondence with the multiple filter cartridges (330).

4. The dust collection device according to claim 1, characterized in that, The filter cartridge (330) and the sealing plate (320) are detachably connected.

5. The dust collection device according to claim 1, characterized in that, The mesh size of the metal filter is between 5 and 15 mesh.

6. The dust collection device according to claim 1, characterized in that, The housing (310) is provided with a third communication port, which is located upstream of the filter cylinder (330), and the air outlet of the cyclone separator (200) is connected to the third communication port.

7. The dust collection device according to claim 1, characterized in that, A first shut-off valve (210) is provided between the cyclone separator (200) and the first communication port, and a second shut-off valve (350) is provided between the filter device (300) and the second communication port.

8. The dust collection device according to claim 1, characterized in that, A first vibrating hammer (220) is provided on the side wall of the cyclone separator (200), and the first vibrating hammer (220) is used to strike the side wall of the cyclone separator (200). A second vibrating hammer (110) is provided on the side wall of the powder hopper (100), and the second vibrating hammer (110) is used to strike the side wall of the powder hopper (100).

9. The dust collection device according to claim 1, characterized in that, The powder hopper (100) is provided with a fourth connecting port (120) at its bottom. The filter device (300) also includes a vibrating screen (360), which is located at the fourth connecting port (120) and connected to the fourth connecting port (120).

10. A cell wall drying system, characterized in that, The cell wall drying system includes a drying tower and a dust collection device, wherein the outlet of the drying tower is connected to the dust collection device, and the dust collection device is the dust collection device according to any one of claims 1 to 9.

Images