EP3154717B1

EP3154717B1 - Appliance for cleaning ducts

Info

Publication number: EP3154717B1
Application number: EP15739004.8A
Authority: EP
Inventors: Ronny REYGEL
Original assignee: Mobbit NV
Current assignee: Mobbit NV
Priority date: 2014-06-16
Filing date: 2015-06-15
Publication date: 2021-11-17
Anticipated expiration: 2035-06-15
Also published as: WO2015193793A1; BE1022236B1; EP3154717A1

Description

This invention relates to an appliance and to an assembly of a pipe system and an appliance for cleaning an inner wall of ducts of a pipe system, in particular an air ventilation system, the appliance comprising a covering provided to contact the inner wall and detach the dirt, and the appliance also including means for moving the appliance through the ducts, and to a method for cleaning a pipe system.
Over the last years, numerous measures have been taken to keep energy consumption in buildings as low as possible, inter alia through increasing insulation and sealing of any chinks and cracks present. While this is of benefit to the energy consumption, the natural ventilation in the building diminishes so that a need for an adequate air circulation system arises to ensure a healthy environment in the building. Indeed, in modern newly built houses, current legislation requires the presence of an air circulation system. Other applications in which air circulation is utilized are inter alia air conditioning systems or heating systems based on circulating air.
Air circulation is ensured by a system, present in the building, of mutually connected ducts or tubes along which fresh air is supplied and conveyed through the building and polluted air is carried off. Supply of fresh air to the duct system is ensured by one or more ducts that communicate with the outside air. Various filters are provided to limit entry of unwanted polluting particles into the duct system to a minimum. However, since the filters are unable to retain all impurities, all kinds of impurities are entrained with the air into the duct system and deposited on the inner walls. Examples of deposited impurities include inter alia dust, dirt, hairs of pets, fungi, moisture, and the like. Moisture present in the air transported through the ducts is conducive to the deposition and growth of microorganisms and fungi. These impurities are transported along with the air flowing through the ducts and pollute the air circulating through the building, giving rise to an unhealthy climate in the building. Regular cleaning of the filters through which the air flows into the building is consequently recommendable, but so is regular cleaning of the ducts through which the air flows, to prevent filters becoming overloaded and polluted air circulating through the building after all. To enable access to the duct system, in most cases one or more access hatches are provided. The number of access hatches, however, is mostly limited, inter alia because of the costs.
Various appliances have been designed for cleaning the ducts of an air circulation system. One system utilizes mechanically working brushes that loosen the dirt mechanically, and then exhaust the dirt. Less common are pneumatic appliances that loosen the dirt with compressed air, and chemically working methods whereby a liquid is sprayed under pressure against the wall of the ducts to loosen deposited dirt.
An appliance for cleaning the ducts is mostly introduced via an access hatch present in a room, and then moved through the ducts. A common problem during movement through the ducts is that the appliance gets stuck at one or more places in the ducts. Places entailing an increased risk of such an appliance jamming are, for example, bends and points where a duct splits up into two or more ducts. An attendant problem is that a building mostly includes only a limited number of access hatches, which makes releasing a jammed appliance complicated.
From AT331491 a device for cleaning chimneys is known which includes an upper and a lower clamping plate between which a pressure vessel is held. The upper and lower clamping plates are movable away from and towards each other by means of a spring. This movement causes a change of the diameter of the pressure vessel and a change of the pressure in the pressure vessel, so that the wall of the pressure vessel can be pressed against the chimney wall all the time. This device, however, exhibits the drawback that objects that protrude with respect to the inner wall of the chimney impede the movement of the pressure vessel and damage the wall of the pressure vessel. This device further exhibits the drawback that to enable a movement through bends in the chimney, the pressure in the pressure vessel needs to be lowered every time, and then readjusted again taking into account the diameter of the duct after the bend. This is time consuming. Moreover, there is a risk that at bends and places where a duct splits up into two or more ducts, the diameter of the pressure vessel needs to be reduced to the extent that contact with the wall is lost, so that wall cleaning is compromised.
US-A-4,261,073 describes an appliance for cleaning chimneys that comprises a plurality of tiltably interconnected members. Each member includes two disks disposed perpendicular to each other, one disk oriented diametrically and one oriented axially. Arranged along the edge of the diametrically extending disk is a cleaning cloth for cleaning the chimney. For cleaning the chimney, the appliance is vertically reciprocated through the chimney. This device, however, has the drawback that the cleaning effect is insufficient, since the contact between the cleaning cloth and the wall is limited to the edge of the disk and depends on the diameter of the diametrical disk. Moreover, the device is exclusively suitable for use in ducts whose diameter is greater than that of the diametrical disk. This device further exhibits the drawback that it readily gets stuck in ducts in which successive bends occur at a short mutual distance.
From US6,286,172 a portable appliance is known for cleaning ducts of a heating, ventilating or air conditioning system. The appliance includes an expandable bladder, one side of which is connected with an air supply to effect expansion of the bladder and contact with the duct wall during cleaning. A valve is provided for discharging air and compressing the bladder. The surface of the bladder that contacts the wall of the duct may be provided with a material that facilitates loosening of the dirt and that is capable of taking up a cleaning liquid, for example a structure promoting scrubbing, a brush, a sponge, etc. The bladder is introduced into the duct in the non-inflated condition, moved to the position that is to be cleaned, and filled with air until the outer wall of the bladder is in contact with the duct wall and can apply a pressure to the duct wall. Thereupon the bladder is moved back and forth in the duct to loosen and take up the dirt. As soon as cleaning is ended, the air pressure is let off, so that the bladder shrinks and can be removed from the duct.
The portable appliance known from US6,286,172 , however, exhibits the drawback that the bladder will lock in duct systems that include constrictions and/or several mutually closely consecutive bends or ramifications. As the number of duct system access hatches in a building is mostly limited, this has the consequence that certain parts of the duct system are not accessible and a cleaning of the whole duct system often is not possible. In the constrictions present in the ducts, the pressure in the bladder runs up considerably, so that the bladder locks and its movement is opposed. To enable movement through bends, the pressure in the bladder in each case needs to be lowered and thereafter readjusted again taking into account the diameter of the duct downstream of the bend. This is time consuming and entails the risk that the diameter of the bladder has to be reduced to the extent that contact with the wall is lost, so that wall cleaning is compromised. This device further exhibits the drawback that objects that protrude with respect to the inner wall of the chimney impede movement and damage the wall of the bladder. Ducts are often built up from a plurality of interconnected pipes, with the joint secured by e.g. screws or self-tappers protruding into the interior of the ducts.
Accordingly, there is a need for an appliance for cleaning ducts of a pipe system, in particular an air ventilation system, that locks less easily and that is suitable for use in a wide range of ducts, but also in duct systems having a more complicated structure, without necessitating unduly many manipulations. Examples of undesired manipulations are the opening of access hatches, removing the appliance and reintroducing it via another access hatch, and the like. A 'more complicated structure' is understood to mean also that objects can protrude into the interior of the ducts, that bends in the duct system may be at short mutual distances, and that in the duct system a split of a duct into two or more ducts may be followed or preceded by one or more bends.
The object of this invention accordingly consists in providing an appliance for cleaning ducts of a pipe system, in particular an appliance for cleaning ducts of an air ventilation system, that locks less easily and that is also movable through duct systems with a more complicated structure without necessitating unduly many manipulations, such as taking out the appliance and placing it again via another access hatch, and the like.
This is achieved according to this invention with an assembly that has the technical features of the characterizing portion of the first claim, and/or with an appliance according to claim 16, and/or with a method according to claim 17.
To this end, in the appliance of this invention the covering is implemented in a material that is permeable to gas, in particular air, and the covering surrounds an inner structure, the inner structure including a springy shaft with a first and a second end part mutually spaced apart a distance, while to the first end part a plurality of first fibers are attached which protrude radially with respect to the shaft for forming a first brush, and to the second end part a plurality of second fibers are attached which protrude radially with respect to the shaft for forming a second brush, the length of the first fibers being such that the diameter of the first brush in radial direction of the springy shaft is equal to or greater than the diameter of the duct to be cleaned, the length of the second fibers being such that the diameter of the second brush in radial direction of the springy shaft is equal to or greater than the diameter of the duct to be cleaned, the appliance being provided to move through a duct in axial direction of the springy shaft, in other words, in a direction running parallel to the springy shaft.
Thus, an appliance is provided which can easily deform in the desired direction or directions, for instance upon movement through one or more successive bends, also if the bends are disposed at a short distance from each other, and, for instance, upon movement through one or more bends that are disposed at a short distance from a place where a duct divides into two or more ducts. 'Short distance' in the context of this invention is understood to mean a distance that is less than the length of the springy shaft. In the appliance of this invention, the covering is permeable to gas, in particular permeable to air, so that the interior of the covering adjusts to the pressure of the environment and the covering exhibits high deformability.
As the diameter of the first and second brush is greater than or equal to the diameter of the ducts through which the appliance is moved, the outside of the covering is pressed against the inner wall of the duct, by the radially extending fibers of the first and second brush. As the diameter of the first and second brush is greater than or equal to the diameter of the duct, friction is created between the covering and the inner wall of the duct. The friction provides that contaminants can be scraped off the duct wall. As the friction is caused by radially extending fibers, the covering is pressed with some but slight pressure against the inner wall of the duct, so that the force needed to move the appliance through a duct can be kept low.
The radially extending fibers can be deformed or bent during the movement of the appliance through the duct, so that the friction is further increased. Owing to the fibers being capable of bending, the appliance is suitable for use in ducts of various diameters, but also for use in systems that include ducts of varying diameter, for example, systems in which a duct of greater diameter narrows to a duct of lesser diameter, or in systems in which the shape of the ducts varies. The appliance of this invention is able to accommodate such constrictions and changes in shape in that the fibers can bend to a greater or lesser extent. The appliance of this system is equally suitable for use in systems in which the ducts have bends and/or one duct divides into two or more ducts.
The presence of a springy shaft ensures a high deformability of the inner structure and makes it possible for the first and second end parts to be moved relative to each other in a great number of directions, so that the shaft is movable through ducts whose direction changes as a function of the length, for example, bent ducts.
Such an appliance is suitable for cleaning the inner wall of a duct or a unity of ducts in a wide range of applications. Such an appliance is for example suitable for cleaning the inner wall of a space in an apparatus where gas or air circulation takes place. Examples of this include ducts of an air ventilation system, an air or gas circulation system, an air or gas supply or exhaust system, ducts of an air conditioning or a heating system and the like. Such an appliance is also suitable for cleaning the inner wall of a space in an apparatus where liquid circulation takes place, for example the inner wall of ducts through which liquid flows, for example a water pipe, a drain pipe, a waste pipe and the like or any other system known to the skilled person that includes one or more ducts that are subject to pollution. The plurality of ducts may for instance be in an apparatus, for example, in a heating or cooling plant or apparatus, in a heat exchanger, in a heating or cooling spiral, in a housing for a fan, engines, etc., ducts that are in a housing in general or in a building, are incorporated in the walls of a building or arranged in the ground or in any other place. The plurality of ducts may for instance be in an apparatus, for instance a heating or cooling plant, but also the supply pipe and drain pipe of an apparatus, in a distributor of an apparatus, etc., in which forced or unforced circulation of a gas, air or a liquid takes place. Also a liquid flow may be forced or unforced.
The covering preferably forms a closable whole, for instance a bag provided with a closure, in which the inner structure can be received.
The first and second fibers extending radially with respect to the springy shaft are preferably grouped in bundles of a plurality of fibers, to provide a sufficient firmness of the fiber bundles and to create a greater local friction. The bundles of fibers are preferably arranged in a row extending radially around the springy shaft or around a part of the springy shaft. If the appliance is especially intended for cleaning ducts having a circular cross section, the fibers are preferably arranged symmetrically around the central springy shaft. If the appliance is especially intended for cleaning the inner wall of ducts having a cross section that, for instance, is asymmetrical, has a random shape, is rectangular, square or oval or of any other non-circular shape, the fibers may be disposed around the central shaft according to an asymmetrical geometric figure.
To ensure a sufficient deformability of the inner structure and hence of the appliance, the bundles of fibers are preferably arranged in a row that extends around the shaft in circumferential direction, or the bundles of fibers are disposed in a row that extends around a part of the circumference of the shaft. Optionally, successive bundles of fibers may be arranged in a staggered configuration, in two or more rows. Preferably, however, the number of rows of fibers is limited to guarantee a sufficient deformability of the internal structure.
To facilitate the movement of the appliance through the ducts and to guide the movement at constrictions, in bends or places where a duct divides into two or more ducts, there is preferably a first conical profile present on the first end of the springy shaft. Preferably, a conical profile is also present on the second end of the springy shaft.
The invention is further elucidated below on the basis of the appended drawings and the description of the drawings.

Figure 1 shows a cross section of the inner structure of the appliance of this invention.
Figure 2 shows a view of the inner structure of the appliance of this invention.
Figure 3 shows a cross section of the appliance of this invention.

The preferred embodiment of the appliance of this invention shown in Figure 3 comprises an outer covering 1 in which an inner structure 10 is received. The inner structure provides firmness to the appliance and provides that the appliance is deformable to enable a contact with the inner wall of the ducts to be cleaned. The outer covering 1 has an outer surface provided to contact the inner wall of the ducts to be cleaned, to detach the dirt and to enable removal of the dirt. The outer covering 1 has an inner volume in which the inner structure 10 is received.
The inner structure 10 includes a springy shaft 2, with a first and a second end part 5, 15. The shaft 2 can be substantially circular, in case the appliance is intended for use in ducts having a circular or square cross section. The shaft 2 can also be oval, for instance if the appliance is intended for use in oval or rectangular ducts. The springy shaft 2 can be made from a wide range of springy materials known to the skilled person, but is preferably made from spring steel. Spring steel is understood to mean steel that was treated to impart elastic properties and stretch. The springy shaft is preferably a spring made from spring steel. However, other, equivalent materials known to the skilled person may equally be used, for instance a synthetic with spring properties, for instance rubber or any other synthetic known to the skilled person. Such a springy shaft is capable of bending at angles of various magnitude, for example 30°, 45°, 60°, 90°, 120° or any other angle occurring in the duct system. Such a springy shaft is capable of bending in the length direction in one or two or more directions at the same time, to allow for the structure of the duct system.
To the first end part 5 of the springy shaft, a plurality of fibers 8 are attached which protrude radially with respect to the shaft 2 so that a first brush 3 is formed. To provide a greater contact surface with the inner wall of a duct, also to a second end part 15 of the springy shaft a plurality of fibers 18 are attached which protrude radially with respect to the shaft 2, so that a second brush 13 is formed.
The fibers can be made from any material considered suitable by the skilled person. Suitable materials are, for example, the materials that possess a sufficient stiffness and mechanical strength to be able to perform a scraping function on the inner wall of a duct, also through the material of the covering, in other words, when the material of the covering is between the fibers and the inner wall of the duct. Suitable materials at the same time possess a sufficient flexibility to be able to bend when the size of the duct is less than the size of the brush, in other words, when the diameter of the duct is smaller than the diameter of the brush. Suitable materials have a flexibility permitting the fibers to bend in multiple directions, so that the appliance can be moved through a duct in both the forward and the backward direction. Suitable materials are, for example, the materials from the group of synthetic fibers, in particular polyamide, polyvinyl chloride, polyethylene or polypropylene, or natural materials, in particular bahia, piassava, vegetable fibers, metal fibers, bassine, gomuti (arenga), or blends of two or more of these materials. The skilled person will preferably choose a material that is resistant to moisture or any other liquid the fiber may come into contact with, and does not degrade upon contact with moisture or such other liquid, and has a good mechanical strength, with a low risk of the fibers breaking or dust particles being released as a result of friction with the duct wall. The fibers of the first and second brushes 3, 13 can be made from the same or from a different material, but are preferably made from the same material.
The diameter of the fibers is not critical for this invention. Preferably, however, the diameter will be chosen such that the fibers exhibit a sufficient flexibility to be able to bend upon their movement through the ducts. Depending upon the nature of the material and the thickness of the fibers, the fibers may be provided as individual fibers, or as bundles of a plurality of fibers. This last is preferred, since a greater friction with the duct wall is created. The number of fibers per bundle can be chosen by the skilled person, taking the nature of the material and the thickness of the fibers into account.
The length of the fibers 8, 18 can vary within wide limits, but is chosen such that the diameter of the brush 3, 13 is equal to or greater than the diameter of the duct, taking the thickness of the covering 1 into account, so that friction with the inner wall of the duct is generated. Factoring in the diameter of the springy shaft, the fibers typically have a length of 3-10 cm, preferably 4-7.5 cm if the appliance is intended for use in ducts having a diameter of 10-25 cm. By using longer fibers, the appliance can also be made suitable for use in ducts having a greater diameter; by using shorter fibers the appliance can also be made suitable for use in ducts having a smaller diameter. Optionally, a blend of short and long fibers can be used, with the short fibers disposed in a particular position and the long fibers disposed in a particular position, to enable cleaning of ducts having a specific shape.
The fibers of the first and second brushes 3, 13 can have the same or a different length, but preferably have the same length.
The fibers preferably have the form of bundles of a plurality of fibers, so that maximum friction is ensured. The number of fibers in a bundle is chosen by the skilled person such that the fiber bundle exhibits a sufficient stiffness to be able to produce friction against the duct wall, and sufficient flexibility to be able to bend. The distance between successive bundles is not critical for this invention, but is preferably chosen such that on the one hand a sufficient friction is ensured and on the other hand a sufficient bendability of the fibers. A complicated structure of the system of ducts that is to be cleaned may require a greater flexibility of the fibers than a more simple structure.
In a preferred embodiment, the bundles of fibers 8, 18 are arranged in circumferential direction of the springy shaft, i.e., radially around the shaft 2, preferably on a radial line around the shaft 2. If the appliance is intended for use in ducts having a circular or square cross section, mostly an appliance will be used in which the fibers are arranged radially along the entire circumference of the springy shaft. If the appliance is intended for use in ducts having an oval or rectangular cross section, an appliance may be used in which the fibers are arranged along a part of the circumference of the springy shaft, for example an upper segment or half, or a lower segment or half.
The fibers may be attached to the springy shaft 2 directly. To simplify replacement of the brushes 3, 13, the bundles of fibers are preferably mounted on a ring 7, 17 which can be detachably attached to the springy shaft 2.
Depending upon the intended flexibility of the appliance and the intended contact surface in the length direction of the springy shaft 2, the fiber bundles 8, 18 may be arranged in one or more rows in circumferential direction of the springy shaft 2. In case multiple rows are provided, the fiber bundles are preferably disposed in a staggered arrangement. To guarantee a maximum flexibility, on the first end part, there are provided preferably five rows at a maximum, preferably three rows of fiber bundles at a maximum, more preferably one row (see Figures 1 and 2).
The brushes 3, 13 are spaced apart a distance in axial direction. The distance can be chosen by the skilled person taking into account the complexity of the structure of the duct system that is to be cleaned. A more complex system will generally require an appliance having a greater bendability. Generally, the distance between successive brushes 3, 13 will be 4-10 cm, preferably 4-7.5 cm.
The above-described inner structure which comprises a springy shaft on a first and second end part of which are mounted a first and a second brush of fiber bundles, respectively, is taken up in a covering 1.
In the appliance of this invention, any gas-permeable covering considered suitable by the skilled person can be used. A suitable covering is, for example, a cloth in a supple material, which is wrapped around the inner structure 10, or a covering having a layered structure containing a plurality of mutually overlying cloths, or a bag which has been pulled over the inner structure 10, or a sleeve. If use is made of a bag, the bag can contain a closure in radial direction of the appliance or in axial direction. The bag may be implemented in one piece or in two or more parts which are mutually connectable. A supple material is understood to mean that the material is deformable, that it is capable of deforming when being moved through the ducts, and that it is preferably capable of wholly or partly following the contours of the inner structure 10.
The covering 1 is preferably removable. This can be effected in any manner known to the skilled person.
The dimensions of the covering are not critical for this invention and are chosen taking into account the dimensions of the ducts to be cleaned and the dimensions of the brushes. Suitable dimensions are, for example, a length of 10-20 cm or 20-50 cm, and a diameter of 16-20 cm, or 10-12.5 cm or smaller still, down to 5 cm. A first end of the covering is preferably attached onto the first end part 5 of the springy shaft 2, between the first brush 3 and a first end piece 6. An open space 23 may be provided for receiving the covering.
The first end piece 6 is preferably detachably attachable onto the springy shaft 2. A second end of the covering is preferably attached onto the second end part 15 of the springy shaft 2, between the second brush 13 and the second end piece 16. The second end piece 16 is preferably likewise detachably attachable onto the springy shaft 2.
The first end piece 6 preferably has a rounded shape as shown in Fig. 1 and Fig. 2, since such a shape is able to guide the movement of the appliance through bends, forks and angles in the wall of the ducts and hence facilitate the movement of the appliance through the ducts. The second end piece 16 can have a different shape but preferably has the same shape as the first end piece 6 so that the appliance is symmetrical and can be used in opposite directions. The first and second end piece 6, 16 can have the shape of a truncate cone as shown in Fig. 1. More preferably, the first and second end piece 6, 16 have a conical shape as shown in Fig. 2.
The covering 1 may be made from a wide range of materials. The covering may be made from a material that has a good affinity for the pollution to be removed, present in the ducts, thus being able to take up a sufficiently large amount of it, or repels the pollution. Preferably, the covering is made of a material that is slightly elastic and sufficiently supple, so that it can stretch if necessary to overcome diameter differences, bends in the ducts, T-pieces, reducing pieces and other fittings in the ducts. Preferably, the covering has a good water uptake capacity, so that the covering can also be used wet, possibly together with detergents. If the appliance is intended for cleaning air ventilating ducts, the covering is preferably made in a material that is permeable to air and other gases, so that the pressure in the interior of the outer covering can adjust to the pressure prevailing in the duct through which the appliance is moving. If the appliance is intended for cleaning ducts through which a liquid flows, the covering is preferably made in a material that has a good uptake capacity for liquids. The covering may be made from a cloth in a natural material, e.g., cotton or linen, but also synthetics are suitable for this, e.g., polyester, polyamide, polypropylene, etc.
The covering is preferably made of microfibers. Microfibers are generally known to the skilled person. Mostly, they have sharp angles, so that they penetrate deeply into the dirt, much further than a round fiber can. Often, one of the polymers of the microfiber is lipophilic or oleophilic, so that they have a good absorbency of fat and oil. As a result of the fibers being closely packed together, the interstitial pores or voids exhibit capillary action. Microfibers have a thread that is mostly finer than one denier. Known microfibers are made from polyester, polyamide, e.g., nylon, Kevlar, Nomex, trogamide, or a conjugation of polyester, polyamide, and polypropylene (Prolen). Microfibers can be shaped and the covering can hence be manufactured as a mat, a knit, a woven, etc. Within the framework of this invention, the covering may be made of one material or from a combination of two or more materials.
The thickness of the covering is mostly negligible in comparison with the diameter of the brushes 3, 13. To create a largest possible contact surface with the wall, the covering is preferably made from a cloth whose outer surface that is in contact with the duct wall to be cleaned includes a plurality of protruding threads, pile bumps, loops or tufts or the like. Such threads, tufts or loops are able to penetrate into profiles, e.g., ribs, corrugations, wrinkles present in the wall of the ducts to be cleaned. Tubes used for making ventilating ducts do not always have a flat inner wall, but may have a flat or a profiled inner wall. Tubes may for instance be made from sheet metal, corrugated plastic and the like. Such threads, tufts or loops are further able to accommodate any unevennesses or obstructions protruding with respect to the inner wall of a duct, thereby minimizing the risk of the covering being pulled apart. If desired, the threads, bumps, loops or tufts or the like may be coated to provide optimum dirt and/or water absorbent or repellent properties, or be impregnated with one or more agents for killing off microorganisms present in the ducts.
To minimize the risk of the covering being pulled apart by protrusions that are on the inner wall of the ducts, both during the forward movement of the appliance through a duct provided with protruding obstructions, and during the backward movement, the protruding threads, loops or tufts or bristles preferably have a length of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm. This is because ducts are often made up of a plurality of interconnected tubes, with the joint secured by, e.g., screws or self-tappers protruding with respect to the inner wall of the ducts into the inner volume of the ducts.
The appliance of this invention preferably further includes first means 4 for moving it through the ducts, in the direction of the first end. The appliance of this invention preferably further includes likewise second means 14 for moving it through the ducts, in the direction of the second end. The movement means may be arranged to enable an automated movement, and may for instance comprise a drive, possibly electronically controlled, or controlled on the basis of imaging of the interior of the ducts, or in any other way considered suitable by the skilled person. The movement means may also be arranged to enable a manually controlled movement. The movement means may for example comprise a first pull cord 4 connected with the first end part 5 to enable a movement in a first direction. The movement means may also comprise a second pull cord 14 connected with a second end part 15, to enable a movement in a second direction. The first and second pull cords 4, 14 are preferably connected at the center of the springy shaft 2, so that the tractive force is exerted via the central axis of the springy shaft 2 and the center of the tractive force is fixed and the springy shaft 2 follows the axis of the ducts as well as possible. This is especially important upon movement through a bend or a fork to ensure that the covering remains in contact with the wall of the duct throughout its diameter at all times. A tractive force thus exerted is of equal magnitude in all directions radial with respect to the shaft 2.
In use, the appliance of this invention is introduced into a duct as is shown in Figure 4, and moved through the duct by pulling the cord 4 to enable movement in the direction of the arrow. If the appliance locks, it can be unlocked through a movement in the opposite direction, by pulling the cord 14.

Claims

An assembly of a pipe system comprising one or more ducts and a ducts cleaning appliance for cleaning a polluted inner wall of the one or more ducts, the appliance comprising a covering (1) provided to contact the inner wall and detach the dirt, the appliance also including means (4, 14) for moving the appliance through the ducts, characterized in that the covering is permeable to gas and in that the covering (1) surrounds an inner structure (10), the inner structure (10) including a springy shaft (2), having a first (5) and a second end part (15), mutually spaced apart a distance, while to the first end part (5) a plurality of first fibers are attached which protrude radially with respect to the shaft (2) for forming a first brush (3), and to the second end part (15) a plurality of second fibers are attached which protrude radially with respect to the shaft (2) for forming a second brush (13), the length of the first and second fibers being such that the diameter of the brushes (3, 13) in radial direction of the springy shaft (2) is equal to or greater than the diameter of the one or more ducts, the appliance being provided to move in axial direction of the springy shaft (2) through the one or more ducts.
An assembly according to claim 1, wherein the central shaft (2) is made from spring steel.
An assembly according to any one of the preceding claims, wherein the fibers are grouped in bundles (20) of a plurality of fibers (8, 18).
An assembly according to any one of the preceding claims, wherein the bundles of fibers are arranged in a row extending radially around the springy shaft (2) or around a part of the springy shaft (2).
An assembly according to any one of the preceding claims, wherein the fibers are disposed symmetrically around the central springy shaft, or according to an asymmetrical geometric figure.
An assembly according to any one of the preceding claims, wherein the fibers are made from a material chosen from the group of synthetic fibers, in particular polyamide, polyvinyl chloride, or natural materials in particular bahia, piassava, vegetable fibers, metal fibers, bassine, gomuti i.e. arenga, or blends of two or more of these materials.
An assembly according to any one of the preceding claims, wherein the covering is made from a cloth, with a plurality of protruding threads, loops or tufts, which preferably have a length of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm.
An assembly according to any one of the preceding claims, wherein the covering (1) forms a whole provided with means for closing it and in which the inner structure (10) is received, wherein the covering preferably comprises means to permit removing it from the inner structure .
An assembly according to any one of the preceding claims, wherein the covering is made from an elastic material.
An assembly according to any one of the preceding claims, wherein the covering is made from a material chosen from the group of natural fibers, in particular cotton or linen, or synthetic fibers, in particular polyester, polyamide or polypropylene.
An assembly according to any one of the preceding claims, wherein on a first end of the springy shaft (2) a conical profile (16) is present, which conical profile preferably comprises means which permit removing it from the first end of the springy shaft.
An assembly according to any one of the preceding claims, wherein on a second end of the springy shaft (2) a conical profile (6, 16) is present, which conical profile preferably comprises means which permit removing it from the first end of the springy shaft.
An assembly according to any one of the preceding claims, wherein the appliance further includes means for moving it through the ducts, in the direction of the first end part (5).
An assembly according to any one of the preceding claims, wherein the appliance further includes means for moving it through the ducts, in the direction of the second end part (15).
An assembly according to claim 12 or 13, wherein the movement means include a first cord (4) attached to the first end part (5) and a second cord (14) attached to the second end part (15).
An appliance comprising a covering (1) provided to contact the inner wall of one or more ducts and detach the dirt, the appliance also including means (4, 14) for moving the appliance through the ducts, characterized in that the covering is permeable to gas and in that the covering (1) surrounds an inner structure (10), the inner structure (10) including a springy shaft (2), having a first (5) and a second end part (15), mutually spaced apart a distance, while to the first end part (5) a plurality of first fibers are attached which protrude radially with respect to the shaft (2) for forming a first brush (3), and to the second end part (15) a plurality of second fibers are attached which protrude radially with respect to the shaft (2) for forming a second brush (13), the length of the first and second fibers being such that the diameter of the brushes (3, 13) in radial direction of the springy shaft (2) is equal to or greater than the diameter of the one or more ducts, the appliance being provided to move in axial direction of the springy shaft (2) through the one or more ducts, as part of the assembly according to any one of claims 1-15.
A method for cleaning a polluted inner wall of one or more ducts of a pipe system, wherein the pipe system comprises a ventilation system or a unity of ducts through which a liquid flows, wherein in an assembly according to any of claims 1 to 15, the appliance is moved through the one or more ducts in the direction of the first end part (5) and/or the direction of the second end part (15).