A closed cleaning device and method for non-structural air duct

Abstract

The present application discloses a closed cleaning device and method for a non-structural air duct, the method comprising the following steps: placing an airbag with internal vacuum in the non-structural air duct, the airbag being adapted to the size of the non-structural air duct; inflating the airbag, the airbag expanding until the outer surface of the airbag is in close contact with the inner wall of the non-structural air duct, so that the garbage in the non-structural air duct is squeezed between the outer surface of the airbag and the inner wall of the non-structural air duct, and the inner surface of the airbag forms a vent corresponding to the non-structural air duct; judging whether the airbag needs to be replaced by detecting the use status of the airbag, or replacing the airbag after a set interval of use time; the airbag replacement method is as follows: releasing the gas inside the airbag, taking out the airbag, and placing a new airbag in the non-structural air duct, and re-inflating it for use. The present application reduces the difficulty of cleaning the non-structural air duct and achieves the effect of cleaning the inside of the air duct.

Description

Technical Field

[0001] The present application relates to the technical field of shipbuilding, and in particular to a closed cleaning device and method for a non-structural air duct. Background Art

[0002] The ventilation system of existing ro-ro passenger ships is complex, and the branch pipes of the central air conditioner leading to each room are very narrow, making it impossible for personnel to enter for effective cleaning. Plastic film is only used temporarily for protection during the construction process, and it cannot be cleaned later until it is delivered for use. The existing protection methods are not effective in time, and the construction period of passenger ships is long. Even if effective vent protection is adopted, improper management and improper processes at various stages of construction will lead to serious pollution inside, and various modifications during the construction process will further aggravate the pollution in the air duct. The existing ro-ro passenger ships have extremely serious problems of this kind. Even a large amount of iron powder and iron filings generated during the construction process are mixed with rainwater and agglomerated in the air duct. Once the ventilation system is activated, all areas of the ship will be polluted, and there is a risk of damaging the fan. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a closed cleaning device and method for a non-structural air duct, which can solve the above-mentioned problems existing in the prior art, effectively reduce the probability of internal pollution of the air duct causing pollution to the entire ship during the production process, and can effectively ensure the cleanliness and safety of the air duct ventilation.

[0004] To achieve the above objectives, this application adopts the following technical solutions:

[0005] On the one hand, a closed cleaning method for a non-structural air duct is provided, comprising the following steps:

[0006] s1, an air bag with internal vacuum is placed in the non-structural air duct, and the size of the air bag is adapted to the size of the non-structural air duct;

[0007] s2, inflate the airbag until the outer surface of the airbag is in close contact with the inner wall of the non-structural air duct, so that the garbage in the non-structural air duct is squeezed between the outer surface of the airbag and the inner wall of the non-structural air duct, and the inner surface of the airbag forms a vent corresponding to the non-structural air duct;

[0008] s3, determine whether the airbag needs to be replaced by detecting the usage status of the airbag, or replace the airbag after a set usage time interval; the method for replacing the airbag is as follows: release the gas inside the airbag, take out the airbag, and put a new airbag into the non-structural air duct, and re-inflate it for use.

[0009] In some embodiments, during the step of inflating the airbag, an automatic inflation device is used to automatically inflate the airbag.

[0010] In some embodiments, during the process of the automatic inflation device inflating the airbag, when it is detected that the amount of air in the airbag reaches a preset inflation threshold, the automatic inflation device automatically stops inflating.

[0011] In some embodiments, a plurality of sensors are provided on the inner wall of the non-structural air duct, and the sensors are electrically connected to the automatic inflation device, and the sensors are used to detect whether the outer surface of the airbag abuts against the inner wall of the non-structural air duct; after the automatic inflation device starts to inflate the airbag, when the sensor detects that the outer surface of the airbag abuts against the inner wall of the non-structural air duct, a relevant control signal is sent to the automatic inflation device to control the automatic inflation device to stop inflating; when the sensor does not detect that the outer surface of the airbag abuts against the inner wall of the non-structural air duct, the automatic inflation device maintains continuous inflation action.

[0012] A closed cleaning device for a non-structural air duct, comprising: a non-structural air duct, an air bag and an inflating device, wherein the shape of the air bag corresponds to the internal shape of the non-structural air duct, and the air bag is detachably installed inside the non-structural air duct, the inflating device is arranged outside the non-structural air duct and connected to the air bag, the air bag has an initial state and an inflated state, when the air bag is in the initial state, the air bag is partially in contact with or not in contact with the inner wall of the non-structural air duct; when the air bag is in the inflated state, the outer surface of the air bag is completely in contact with the inner wall of the non-structural air duct, and the inner surface of the air bag forms a vent;

[0013] The closed cleaning device of the non-structural air duct is configured as follows: the airbag in the initial state is placed in the non-structural air duct, the airbag is inflated by the inflation device, the airbag gradually expands from the initial state to the inflated state, so that the outer surface of the airbag is completely against the inner wall of the non-structural air duct, and a vent is formed on the inner surface of the airbag.

[0014] In some embodiments, a plurality of the non-structural air ducts are provided, and the non-structural air ducts are detachably connected to form a main air duct, and the airbag is detachably installed in the main air duct.

[0015] In some embodiments, the cross-sectional area of ​​the airbag in the inflated state is a, the cross-sectional area of ​​the non-structural air duct is b, and the cross-sectional area ratio between the airbag and the non-structural air duct is c, where c=a / b, 1%≦c≦15%.

[0016] In some embodiments, the non-structural air duct is provided with an entrance for the airbag to be placed therein, and a door panel is hinged at the entrance.

[0017] In some embodiments, an air valve is also included, and the air valve is arranged on a pipe connecting the inflation device and the airbag.

[0018] In some embodiments, the airbag has a double-layer structure and is made of polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate.

[0019] The beneficial effects of the present application are as follows: pollutants in the non-structural air duct are squeezed between the outer surface of the airbag and the inner wall of the non-structural air duct by inflating the airbag, and a vent for normal ventilation is formed on the inner surface of the airbag. The airbag is arranged in the non-structural air duct to achieve the effect of closed cleaning without affecting the normal use of the non-structural air duct. The cleaning method effectively reduces the probability of internal pollution of the air duct causing pollution to the entire ship during the production process, and also reduces the labor cost invested in cleaning the narrow non-structural air duct. At the same time, the protection period of this method is longer. In addition, the damage of the air duct caused by modification is reduced, so that the damaged area is exposed to the risk of pollution and reduced service life caused by rust in the high humidity environment of the ocean. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present application is further described in detail below based on the drawings and embodiments.

[0021] Figure 1 A schematic flow chart of a closed cleaning method for a non-structural air duct according to an embodiment of the present application;

[0022] Figure 2 This is a schematic structural diagram of the closed cleaning device for the non-structural air duct described in an embodiment of the present application.

[0023] In the figure: 1. Non-structural air duct; 2. Airbag; 3. Inflator; 4. Vent. DETAILED DESCRIPTION

[0024] In order to make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0025] In the description of this application, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] like Figure 1 As shown, this embodiment provides a closed cleaning method for a non-structural air duct, comprising the following steps:

[0028] s1, placing an air bag 2 with internal vacuum in the non-structural air duct 1, the air bag 2 is adapted to the size of the non-structural air duct 1;

[0029] s2, inflate the airbag 2 until the outer surface of the airbag 2 is in close contact with the inner wall of the non-structural air duct 1, so that the garbage in the non-structural air duct 1 is squeezed between the outer surface of the airbag 2 and the inner wall of the non-structural air duct 1, and the inner surface of the airbag 2 forms a vent corresponding to the non-structural air duct 1;

[0030] s3, by detecting the use status of the airbag 2, determine whether the airbag 2 needs to be replaced, or replace the airbag 2 after a set use time interval; the method for replacing the airbag is as follows: release the gas inside the airbag 2, take out the airbag 2, and put a new airbag 2 into the non-structural air duct 1, and re-inflate it for use.

[0031] In the above cleaning method, before the airbag 2 is placed, there are already pollutants such as garbage in the non-structural air duct 1. After the airbag 2 is placed, the uninflated airbag 2 only occupies a very small part of the internal space of the non-structural air duct 1. After the airbag 2 is placed in the correct position, the airbag 2 begins to inflate and gradually expand. When the airbag 2 expands to the point where its outer surface has contacted the inner wall of the non-structural air duct 1, the inflation is stopped and the airbag 2 maintains the current state. In this state, the pollutants in the non-structural air duct 1 have been covered between the airbag 2 and the non-structural air duct 1, and the inner surface of the airbag 2 also forms a vent 4 of a size similar to that of the non-structural air duct 1, which achieves the goal of not affecting the ventilation volume and reducing ventilation pollution caused by improper cleaning in the later stage. The inflated airbag 2 has a ring structure that matches the size of the non-structural air duct 1. The preparation of the airbag 2 needs to deal with non-structural air ducts 1 of different sizes. After the airbag 2 has been used for a period of time, considering that the airbag 2 is contaminated or shrinks, resulting in a decrease in ventilation volume, the airbag 2 needs to be replaced in time. There are two main methods for determining whether it needs to be replaced. The first method is to detect the use status of the airbag 2, and the second method is to set a time, and the airbag 2 is replaced when the time comes. The first judgment method can be to detect whether the gas flow inside the airbag 2 has dropped significantly, or to detect whether the ventilation volume of the vent formed on the inner surface of the airbag 2 has dropped. The specific drop can be set to: if the gas flow inside the airbag 2 decreases by more than 15% compared with the initial flow, it is determined that the airbag 2 needs to be replaced, and if the ventilation volume decreases by more than 10% compared with the initial ventilation volume, it is determined that the airbag 2 needs to be replaced. The time set by the second judgment method can be ten days, or it can be adjusted up or down according to the specific situation of the airbag 2, and it can be judged and set based on previous usage experience.

[0032] In order to ensure the quality of the airbag 2 during use, the airbag 2 is preferably made of a high-density and lightweight polyester material and adopts a double-layer vacuum structure, and the shape needs to match the non-structural air duct 1.

[0033] In the step of inflating the airbag 2, there are two optional inflation modes: one is a self-inflation mode of the airbag 2, and the other is an external inflation mode. The self-inflation mode is to place the airbag 2 in the non-structural air duct 1, and then open the automatic inflation valve so that the airbag 2 is inflated and tightly covers the non-structural air duct 1.

[0034] The airbag structure in the self-inflation mode includes an airbag body, an airbag packaging bag, a gas generator and a linkage cable; the airbag body is a flexible, completely sealed bag-like object; the airbag body is arranged inside the airbag packaging bag, and both ends are fixedly connected to the airbag packaging bag; the gas generator and the linkage cable are arranged inside the airbag body; one end of the gas generator passes through the airbag body and is connected to the airbag packaging bag, and the switch on the other end is connected to one end of the linkage cable, and the other end of the linkage cable passes through the airbag body and is connected to the airbag packaging bag; the airbag packaging bag is a torn sealed bag. This solution adopts a structure in which the airbag body is set in the airbag packaging bag, making the product easy to store and carry, and preventing the airbag body from being scratched, stabbed or accidentally opened; since a gas generator is set in the airbag body to generate the gas required for airbag inflation, the airbag is in an airless, flat and folded state at the beginning and is inflated during use; a linkage cable is used so that the force of tearing the airbag packaging bag can be transmitted to the switch of the gas generator, so that the gas is released to inflate the airbag. The structure is simple and reliable, and the operation is convenient.

[0035] For the second airbag inflation method, an external automatic inflation device 3 is used to assist in automatically inflating the airbag 2, and the automatic inflation device 3 can be connected to the inflation port of the airbag 2 through an air pipe. By operating the automatic inflation device 3, the valve on the automatic inflation device 3 is opened, and the gas stored in the cylinder quickly enters the airbag 2 so that the airbag 2 can be rapidly inflated.

[0036] The scheme of inflating by using an external automatic inflating device 3 is supplemented. During the process of inflating the airbag 2 by the automatic inflating device 3, when the amount of air in the airbag 2 reaches the preset air threshold, the automatic inflating device 3 automatically stops inflating. Specifically, a switch valve can be set on the air pipe connecting the automatic inflating device 3 and the airbag 2. The switch valve sets an air threshold. When the amount of air transported through the air pipe reaches the air threshold during the process of the automatic inflating device 3 inflating the airbag 2, the switch valve automatically closes and cuts off the air supply channel, and stops inflating the airbag 2. The automatic closing method can prevent the airbag 2 from bursting due to excessive inflation, and also avoid unnecessary waste of resources. As for the set air threshold, it needs to be adjusted according to the size of the airbag 2. By testing the airbag 2, the data of how much air the airbag 2 needs to adhere to the inner wall of the non-structural air duct 1 is obtained, and then the air threshold is set according to the data. The air thresholds that need to be set for airbags 2 of different sizes are also the same, so the setting of the air threshold needs to be reasonably adjusted according to the actual situation.

[0037] Different from the above-mentioned scheme for controlling the termination of inflation, the present scheme adopts a scheme in which a plurality of sensors are arranged on the inner wall of the non-structural air duct 1, and the sensors are electrically connected to the automatic inflation device 3, and the sensors are used to detect whether the outer surface of the airbag 2 is in contact with the inner wall of the non-structural air duct 1; after the automatic inflation device 3 starts to inflate the airbag 2, when the sensor detects that the outer surface of the airbag 2 is in contact with the inner wall of the non-structural air duct 1, the relevant control signal is sent to the automatic inflation device 3 to control the automatic inflation device 3 to stop inflating; when the sensor does not detect that the outer surface of the airbag 2 is in contact with the inner wall of the non-structural air duct 1, the automatic inflation device 3 maintains continuous inflation action. The method of judging whether the inflation state of the airbag 2 meets the requirements by setting a sensor is more intuitive. Compared with the method of setting the air threshold, this solution is more direct and accurate. The purpose of inflating the airbag 2 is to make the outer surface of the airbag 2 close to the inner wall of the non-structural air duct 1 to shield the garbage. At the same time, it is also necessary to ensure that the ventilation volume of the vent 4 formed on the inner surface of the airbag 2 after inflation can meet the requirements. Under these two purposes, it is undoubtedly more accurate to use the sensor as the basis for judgment. Only when the sensor detects that the outer surface of the airbag 2 is against the inner wall of the non-structural air duct 1, it will send a command to stop inflation. In this solution, the sensor can be a photoelectric sensor, an infrared sensor, etc.

[0038] like Figure 2 As shown, the present embodiment provides a closed cleaning device for a non-structural air duct, comprising: a non-structural air duct 1, an airbag 2 and an inflating device 3, wherein the shape of the airbag 2 corresponds to the internal shape of the non-structural air duct 1, and the airbag 2 is detachably installed inside the non-structural air duct 1, the inflating device 3 is arranged outside the non-structural air duct 1 and connected to the airbag 2, the airbag 2 has an initial state and an inflated state, when the airbag 2 is in the initial state, the airbag 2 is partially in contact with or not in contact with the inner wall of the non-structural air duct 1; when the airbag 2 is in the inflated state, the outer surface of the airbag 2 is completely in contact with the inner wall of the non-structural air duct 1, and a vent 4 is formed on the inner surface of the airbag 2;

[0039] The closed cleaning device of the non-structural air duct is configured as follows: the airbag 2 in the initial state is placed in the non-structural air duct 1, and the airbag 2 is inflated by the inflation device 3. The airbag 2 gradually expands from the initial state to the inflated state, so that the outer surface of the airbag 2 is completely against the inner wall of the non-structural air duct 1, and a vent is formed on the inner surface of the airbag 2.

[0040] In the above solution, the airbag 2 is inflated by connecting the external inflator 3. Alternatively, the airbag 2 can be inflated automatically without connecting the external inflator 3. The specific structure is as described in the above solution and will not be described here.

[0041] Considering the complexity of the structure of the non-structural air duct 1, several non-structural air ducts 1 are provided in this solution, and each of the non-structural air ducts 1 is detachably connected to form a main air duct, and the airbag 2 is detachably installed in the main air duct. In this solution, one airbag 2 corresponds to multiple non-structural air ducts 1, and a certain part on the airbag 2 is matched according to the structure of each non-structural air duct 1. Since the airbag 2 has good elasticity, it can adapt to non-structural air ducts 1 of various shapes, and can also achieve the effect of sticking to the inner wall at the uneven air duct connection. Moreover, each non-structural air duct 1 is detachable, and a certain non-structural air duct 1 can be disassembled to facilitate subsequent maintenance or replacement. After disassembling the non-structural air duct 1, the airbag 2 can also be easily replaced. Specifically, the non-structural air duct 1 is provided with five smooth transition connections with the same structure. At this time, every fifth of the airbag 2 corresponds to a non-structural air duct 1. In addition, the installation relationship between the airbag 2 and the non-structural air duct 1 is also interchangeable. An airbag 2 can be set up separately for each non-structural air duct 1. Here, it refers to non-structural air ducts 1 with different structures. Such a setting can ensure that each airbag 2 matches each non-structural air duct 1 to the greatest extent, and the effect achieved is also more excellent. In addition, a non-structural air duct 1 can correspond to multiple airbags 2. This method is aimed at the situation where the structure of a single non-structural air duct 1 is very complex and it is impossible to use one airbag 2 to cover the inner wall of the non-structural air duct 1. For each special structure of the non-structural air duct 1, an airbag 2 is adaptively selected for installation, which can ensure that complex non-structural air ducts 1 can also be closed and cleaned in this way.

[0042] In order to further ensure the ventilation effect after the airbag 2 is installed in the non-structural air duct 1, the size between the airbag 2 and the non-structural air duct 1 needs to be rigorously designed. Specifically, the cross-sectional area of ​​the airbag 2 in the inflated state is a, the cross-sectional area of ​​the non-structural air duct 1 is b, and the cross-sectional area ratio between the airbag 2 and the non-structural air duct 1 is c, where c=a / b, 1%≦c≦15%. The airbag 2 in the inflated state will occupy a part of the ventilation area in the non-structural air duct 1. In order to ensure the ventilation volume, the cross-sectional area ratio c between the two needs to be controlled within a certain range. The preferred ratio is c=1%. Under this ratio, the airbag 2 occupies the smallest proportion in the non-structural air duct 1 and has the smallest impact on the ventilation volume; when the ratio c increases, the proportion of the airbag 2 in the non-structural air duct 1 will also increase, and the ventilation volume will also decrease, but the tolerance of the airbag 2 will increase. Therefore, a limit ratio c=15% is set. When the ratio c exceeds 15%, it is unusable and will have a great impact on the ventilation volume. Within this range, the ratio c can be set according to the ventilation volume requirements and the most appropriate ratio can be selected.

[0043] In some embodiments, the non-structural air duct 1 is provided with an entrance for placing the airbag 2, and a door panel is hinged at the entrance. The entrance is opened or closed by switching the door panel, and the airbag 2 can be placed in the entrance by opening the entrance. After the airbag 2 is placed and inflated, the door panel can be closed to seal the non-structural air duct 1. The door panel switch method is more convenient and safer.

[0044] For safety considerations of inflating the airbag 2, an air valve is provided on the pipe connecting the inflation device 3 and the airbag 2, so that the inflation of the airbag 2 can be stopped at any time to deal with dangerous emergencies.

[0045] Preferably, the airbag 2 is a double-layer structure, and the airbag 2 is made of polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate. The preferred material for making the airbag 2 is a high-density, lightweight polyester material, which can ensure that the airbag 2 has a longer service life in the non-structural air duct 1 and avoid frequent replacement. The above specific materials are only preferred but not limited to this.

[0046] In summary, compared with the existing technology, this new method can effectively reduce the pollution of the entire ship caused by the cleaning of the inside of the air duct during the production process. Secondly, it can reduce the labor for cleaning narrow non-structural air ducts and improve the effectiveness. Overall, it reduces the difficulty of cleaning non-structural air ducts and achieves the effect of cleaning the inside of the air duct; at the same time, it reduces the risk of damage to the air duct caused by modification, and the risk of pollution and reduced service life caused by rust in the damaged area exposed to the high humidity environment of the ocean, and completely isolates the air from contacting the surface of the ventilation duct.

[0047] In the description of this article, it should be understood that the terms "upper", "lower", "left", "right", etc., and other directions or positional relationships are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of this application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0048] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0049] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0050] The technical principles of the present application are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation methods of the present application without creative work, and these methods will fall within the scope of protection of the present application.

Claims

1. A closed cleaning method for a non-structural air duct, characterized in that: The following steps are involved: s1, an air bag with internal vacuum is placed in the non-structural air duct, and the size of the air bag is adapted to the size of the non-structural air duct; s2, the airbag is automatically inflated by an automatic inflation device, and the airbag expands until the outer surface of the airbag is in close contact with the inner wall of the non-structural air duct, so that the garbage in the non-structural air duct is squeezed between the outer surface of the airbag and the inner wall of the non-structural air duct, and the inner surface of the airbag forms a vent corresponding to the non-structural air duct; s3, judging whether the airbag needs to be replaced by detecting the use status of the airbag, or replacing the airbag after a set use time interval; the replacement method of the airbag is as follows: venting the gas inside the airbag, taking out the airbag, and putting a new airbag into the non-structural air duct, and re-inflating it for use; A plurality of sensors are arranged on the inner wall of the non-structural air duct, and the sensors are electrically connected to the automatic inflation device, and the sensors are used to detect whether the outer surface of the airbag abuts against the inner wall of the non-structural air duct; after the automatic inflation device starts to inflate the airbag, when the sensor detects that the outer surface of the airbag abuts against the inner wall of the non-structural air duct, a relevant control signal is sent to the automatic inflation device to control the automatic inflation device to stop inflation; when the sensor does not detect that the outer surface of the airbag abuts against the inner wall of the non-structural air duct, the automatic inflation device maintains continuous inflation action; Among them, the cross-sectional area of ​​the airbag in the inflated state is a, the cross-sectional area of ​​the non-structural air duct is b, and the cross-sectional area ratio between the airbag and the non-structural air duct is c, where c=a / b, 1%≦c≦15%.

2. The closed cleaning method of the non-structured air duct according to claim 1 is characterized in that: When the automatic inflation device inflates the airbag, when the amount of air in the airbag reaches a preset inflation threshold, the automatic inflation device automatically stops inflating.

3. A closed cleaning device for a non-structural air duct, characterized in that: include: A non-structural air duct, an airbag, and an inflating device, wherein the shape of the airbag corresponds to the internal shape of the non-structural air duct, and the airbag is detachably installed inside the non-structural air duct, the inflating device is arranged outside the non-structural air duct and connected to the airbag, the airbag has an initial state and an inflated state, when the airbag is in the initial state, the airbag is partially in contact with or not in contact with the inner wall of the non-structural air duct; when the airbag is in the inflated state, the outer surface of the airbag is completely in contact with the inner wall of the non-structural air duct, and the inner surface of the airbag forms a vent; The closed cleaning device of the non-structural air duct is configured as follows: the airbag in the initial state is placed in the non-structural air duct, the airbag is inflated by the inflating device, and the airbag is gradually expanded from the initial state to the inflated state, so that the outer surface of the airbag is completely against the inner wall of the non-structural air duct, and the inner surface of the airbag forms a vent; The cross-sectional area of ​​the airbag in the inflated state is a, the cross-sectional area of ​​the non-structural air duct is b, and the cross-sectional area ratio between the airbag and the non-structural air duct is c, wherein c=a / b, 1%≦c≦15%.

4. The closed cleaning device for non-structured air duct according to claim 3, characterized in that: A plurality of non-structural air ducts are provided, and the non-structural air ducts are detachably connected to form a main air duct, and the airbag is detachably installed in the main air duct.

5. The closed cleaning device for non-structured air duct according to claim 3, characterized in that: The non-structural air duct is provided with an entrance for the airbag to be placed therein, and a door panel is hinged at the entrance.

6. The closed cleaning device for non-structured air duct according to claim 3, characterized in that: It also includes an air valve, which is arranged on a pipeline connecting the inflation device and the airbag.

7. The closed cleaning device for non-structured air duct according to claim 3, characterized in that: The airbag has a double-layer structure and is made of polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate.

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