In-duct cleaning apparatus

Abstract: An in-duct cleaning apparatus comprises a travelling portion (3) and monitor/remote-control portion (4). The travelling portion (3) has a travelling truck (21) carrying a compressed-air ejector (50) and a video camera (25). The monitor/remote-control portion (4) is able to control remotely the travelling portion (3) while monitoring the front of the travelling portion (3) in accordance with the signal coming from the video camera (25). The compressed-air ejector (50) is equipped with a rotating nozzle (60) for ejecting compressed air toward the duct inside surface obliquely in front of the travelling truck (25).

Description: This invention relates to an apparatus for cleaning the surface inside a duct. Heretofore, for the purpose of cleaning the inside surfaces of a duct, a large robot has been used in the case of a large duct and ventilation through the duct has been used in the case of a medium or small sized duct. In most cases where such ventilation has been ineffective, manual work has been necessary. Where manual work is necessary, the cleaning has never gone well because of the difficulty of the work itself or preparing workers. Thus, mold and bacteria have grown or dust has accumulated in the duct, and the accumulation of such foreign substances has been considered to be a cause of, e.g. infection in a hospital or food poisoning in a restaurant. This problem will accumulate with the increase of small sized ducts. An known in-duct cleaning apparatus for cleaning duct inside surfaces comprises:- a travelling means drivable for moving forwards and backwards in the interior of a duct to be cleaned; a video camera carried by said travelling means; an image display means for displaying an image taken by said video camera to enable monitoring of the interior of the duct; a control means for controlling the travelling of said travelling means in accordance with an image displayed on said image display means; an air compressor; and a compressed air ejecting nozzle carried by said travelling means and connected for receiving compressed air from said compressor and for ejecting compressed air towards the interior of the duct; Such a known apparatus having a facility for cleaning the surface inside a duct is described in GB-A-2 149 051. This document describes an apparatus for applying a corrosion resistant paint to the inner surface of welded pipes. On the forward end of a self propelled vehicle there is mounted an operating unit for automatic grinding-cleaning or coating purposes. A radioactive source is provided on the vehicle so that gamma rays radiated therefrom pass to the outside of the pipe facilitating location of the vehicle within the pipe. Dust is purged in a direction opposite to the forward travel of the vehicle, i.e. towards the entrance through which the vehicle was inserted, by blowing compressed air through blowing ports provided in a cleaner attached to the rear lower part of the vehicle. However, the known apparatus does not purge dust evenly against the whole circumference of the inside surface of the duct and can not remove foreign substances and the like attached throughout the whole circumference of the duct inside surface. Neither does the known apparatus have the adaptability to preferentially clean certain areas of the inside surface of the duct according to different situations, for example where particular foreign substances and the like are clinging. It is an object of this invention to provide an in-duct cleaning apparatus which overcome the above existing faults. The present invention is characterised over the prior art in that said compressed air ejecting nozzle is provided on the travelling means to be rotatable through a predetermined angle around an axis substantially parallel to said duct and to be inclined at an angle to said axis of rotation of the compressed air ejecting nozzle. In this way, air is blown against the duct inside surface obliquely in front of the travelling means, successively in the duct circumferential direction. As a results, foreign substances such as trash and dust, accumulated on or attached to the duct insider surface, are successively cleaned out and the substances blown away are discharged out of a duct opening. In addition, the nozzle can be rotated continuously over the predetermined angle to enable compressed air to be blown successively and evenly against the inside surface of the duct. In one embodiment, the compressed air nozzle is rotatable through a predetermined angle of 360 degrees. Accordingly, the apparatus can clean out trash and dust through the whole circumference of the inside surface of the duct to provide even cleaning. In another embodiment, the compressed air ejecting nozzle is rotatable through a predetermined angle of 180 degrees. Accordingly, the apparatus can clean out efficiently and swiftly the lower half part inside the duct where trash and dust are liable to accumulate. In another embodiment, the rotation of the compressed air ejecting nozzle is capable of being stopped at any position of rotation. Thus, the apparatus can predominantly clean out a particular part, for example the left or right wall parts inside the duct. Conveniently, the compressed air ejecting nozzle rotates about the axis of the duct so that symmetrical cleaning is possible. Preferably, said compressed air ejecting nozzle is provided on the travelling means to be inclined at a particular angle to said axis of rotation of the compressed air ejecting nozzle whereby compressed air is ejected at an angle of substantially 45 degrees to that axis of rotation. In another embodiment, a further compressed air ejecting nozzle is carried by said travelling mean and is connected for receiving compressed air from said compressor and for ejecting compressed air in a substantially straight line. Accordingly, compressed air can be blown concentratedly against a narrow area of the inside of the duct to remove particular foreign substances and the like clinging to said narrow area. Preferably, the direction of said line of compressed air ejected from said further compressed air ejecting nozzle can be manually or remotely changed. In another embodiment, said travelling means comprises guide rollers for guiding the travelling means to travel precisely along the interior of the duct. This enables the travelling means to advance smoothly inside the duct without incurring any stagnation even at the duct curvatures and enables the driving motor thereof to be free of overloading reducing failure of the apparatus. Fig. 1. is an illustrative drawing showing a preferred embodiment of the present invention; Fig. 2 is a schematic block diagram showing the outline of a travelling portion controller on board a travelling portion and a monitor/remote-control portion remotely connected to said travelling portion controller in said preferred embodiment; Fig. 3 is a detailed side view showing the travelling portion in said preferred embodiment; Fig. 4 is a detailed plan view showing the travelling portion in said preferred embodiment; and Fig. 5 is a plan view showing the main shaft to a rotating nozzle and optical position detecting elements for detecting the rotating position of said main shaft in said preferred embodiment. The preferred embodiment of the in-duct cleaning apparatus of the present invention will be described in accordance with Fig. 1 to Fig. 5. Fig. 1 is an illustrative drawing showing a preferred embodiment of the present invention; Fig. 2 is a schematic block diagram showing the outline of a travelling portion controller on board a travelling portion and a monitor/remote-control portion remotely connected to said travelling portion controller in said preferred embodiment; Fig. 3 is a detailed side view showing the travelling portion in said preferred embodiment; Fig. 4 is a detailed plan view showing the travelling portion in said preferred embodiment; and Fig. 5 is a plan view showing a main shaft to the rotating nozzle and optical position detecting elements for detecting the rotating position of said main shaft in said preferred embodiment. In Fig. 1, 1 is a duct; 2 is an entry of equipment and materials to the duct 1; 3 is a travelling portion carried in through the entry 2; 4 is a monitor/remote-control portion having a first function to execute monitoring the front of the travelling portion 3 by using a TV 5 and a VTR 6 in accordance with the signal given by a video camera 25 on board the travelling portion 3 and having a second function, while executing the above monitoring, to execute remote-controlling of the travelling portion 3 by using a remote-control switch 7; 8 is a transceiver; 9 is a video amplifier; 10 is a power supply unit supplied with AC-100V, having a battery built-in to enable it to work for about 5 hours even when said AC-100V supply is interrupted; 11 is a compressor for generating compressed air; 12 is an antenna line for transmitting the signal sent out from the monitor/remote-control portion 4 to the travelling portion 3 and for transmitting the signal of the camera sent back from the travelling portion 3 to the monitor/remote-control portion 4; 14 is an air pipe for transmitting the compressed air generated by the compressor 11 to the travelling portion 3; 21 is a travelling truck, of the travelling portion 3, equipped with crawlers 20 as shown in Fig 3; 50 is a compressed-air ejector; and 64 is a direction in which the travelling portion 3 progresses inside the duct 1. Further explanation will be given referring to Figs. 2, 3, 4 and 5. 22 is an air joint to receive the compressed air transmitted through said air pipe 14; 23 is a rotating nozzle in said compressed-air ejector 50; 24 is a straight -ejective nozzle in the same compressed-air ejector 50; 25 is a video camera; 26 is a double illuminating lamp for helping the video camera 25 take pictures; and 13 is the central part of a travelling portion controller 27. Regarding the travelling portion controller 27 (as shown in Fig. 2) and the monitor/remote-control portion 4 connected remotely to said travelling portion controller 27 in the preferred embodiment, 4, 5, 6, 7, 8, 9, 10, 12 and 14 have already been described. Among them the transceiver 8 plays a pivotal role at the side of the monitor/remote-control portion 4 in exchanging signals between the travelling portion controller 27 via said antenna line 12. Said transceiver 8 firstly, receives a signal generated by the video camera 25 of the travelling portion controller 27 via a control substrate 30 and a signal converter 32 in the central part 13 of the same travelling portion controller 27; secondly, transmits the signal to the TV 5 and the VTR 6 in the monitor/remote-control portion 4, via a radio wave line 29 in the same monitor/remote-control portion 4 ; thirdly, makes "the scene inside the duct 1 and in front of the travelling portion 3 caught by the video camera 25" changed immediately into the images of the TV 5 and the VTR 6 ; fourthly, receives later-described operating signals 76 which an operator sends out by using the remote-control switch 7 in accordance with said images of the TV 5 and the VTR 6, via a radio wave line 28 ; fifthly, transmits said operating signals 76 to the control substrate 30, via the antenna line 12 and also via the signal converter 32 in the central part 13 of the travelling portion controller 27 ; and thereby, makes said control substrate 30 execute the control of each of the later-described several systems. 31 in the central part 13 of the travelling portion controller 27 is a voltage regulator for regulating "the voltage to the electric machinery or electric machineries of each of the later-described several systems", i.e., "the voltage to each load of the control substrate 30" ; 33 is a travelling system comprising electric motors 41 and 42 of DC 12V drive for propelling the travelling truck 21 of the travelling portion 3 ; 34 is a rotating nozzle rotating system comprising an electric motor 43 of DC 12V drive for rotating the rotating nozzle 23 ; 35 is a camera tilt system comprising an electric motor 44 of DC 12V drive for giving the video camera 25 an appropriate tilt angle (refer to Fig. 3) ; 36 is a video camera system comprising the video camera 25; 37 is an illuminating lamp system comprising a double DC 6V illuminating lamp 26 ; 38 is a straight -ejective nozzle system, comprising the straight -ejective nozzle 24, which executes ejection by receiving the compressed air transmitted through the air pipe 14 via an electromagnetic valve 39 of DC 12V drive ; and 40 is a rotating nozzle system, comprising the rotating nozzle 23, which executes ejection by receiving the compressed air transmitted through the air pipe 14 via an electromagnetic valve 39a. Further it should be added that when the aforementioned remote-control switch 7 is used, several operating signals 76 to effect the following can be sent out : putting on or off the control substrate 30 ; making the traveling truck 21 relating to said system 33 turn left or right, or go ahead or backward, or stop ; making the rotating nozzle 23 relating to said system 34 start or stop rotation ; making the video camera 25 relating to said system 35 tilt upward or downward ; turning on or off the illuminating lamp 26 relating to said system 37 ; and making the straight -ejective nozzle 24 and the rotating nozzle 23 start ejection of the compressed air through the operation of the electromagnetic valves 39 and 39a of said systems 38 and 40. The aforementioned rotating nozzle 23 is installed in the front part of the travelling portion 3, and is rotated with the electric motor 43 via a belted speed changer 61 (whose speed change ratio is determined by the ratio of the diameter of a belt pulley 80 to that of a belt pulley 81) while being supplied with the compressed air from the compressor 11 through the air pipe 14. And the rotating nozzle 23 is constructed such that it can make the compressed air ejected from a rotating nozzle tip part 60 bend by a fixed angle of, e.g., 45 degrees from the horizontal plane toward a cylindrical part 63 of the inside surface of the duct 1 with an appropriate ejection angle A, wherein said cylindrical part 63 is to be shifted successively in the progressive direction 64 of the travelling truck 3. The detailed plan view said rotating nozzle 23 is as shown in Fig.4. The aforementioned rotating nozzle 23 can be rotated continuously covering an angle of 360 degrees, so it enables the compressed air to be blown successively and evenly against the whole circumference of the inside surface of the duct 1. Besides, the rotating nozzle 23 may be made to rotate reciprocatively within the range of an angle of 180 degrees covering the lower half part inside the duct. For that purpose, the motor 43 itself may be made to rotate reciprocatively, or a part of the rotating nozzle system 40 may be equipped with a mechanism which can interchange 360 degrees' rotating motion with 180 degrees' reciprocative rotating motion. For instance, in order that the motor 43 itself may be made to rotate reciprocatively ; as shown in Fig.5, optical position detecting elements 84 and 85 horizontally and symmetrically positioned about the shaft center 83 of the main shaft 82 to the rotating nozzle 23 may be made to detect the rotating position of said main shaft 82 via a single blade-like projection 86 fixed to and movable with the main shaft 82 and may be made to transmit the position detection signal to the motor 43 to make its rotating direction reversed in every 180 degrees of rotation. As a result of such as the above, the lower half part inside the duct where trash and dust are liable to accumulate, except the ceiling part where no dust and the like are liable to accumulate, can be efficiently and swiftly cleaned out. Further, the rotation of the rotating nozzle 23 may be made to stop at either a leftward or a rightward horizontal position inside the duct. Such a stopping of the rotation of the rotating nozzle 23 may, for instance, be performed by transmitting the above position detection signal generated by the above optical position detecting elements 84 and 85 to the motor 43 and making the motor 43 stop. As a result of such as the above, the left and right wall surfaces inside the duct 1 can be predominantly cleaned out. The aforementioned straight -ejective nozzle 24 is installed separately from the aforementioned rotating nozzle 23; can be made, at need, to eject the compressed air concentratedly toward a specific area inside the duct 1 ; and constructed such that the direction of a straight -ejective nozzle tip part 62 can be changed manually or automatically by the operation at the monitor/remote-control portion 4 (the drawings in these embodiments illustrate the case of manual operation). Besides, the compressed air ejection angle of the tip part 62 is made to be so small that the compressed air is enabled to be blown concentratedly against a narrow area 65 inside the duct 1. The aforementioned travelling truck 21 is equipped with guide rollers 66, 67, 68, and 69. Said guide rollers 66, 67, 68 and 69 are provided with roller outer rings as shown by 70 made of, e.g., rubber and supported on vertical axes as shown by 71 at the four corners of the travelling truck 21 so as to be rotatable freely, with said roller outer rings being made to project out of the outer frame of the travelling truck 21. Accordingly, as shown in Fig.4, in case that the travelling truck 21 approaches, e.g., a vertical wall surface 74 inside the duct 1, i.e., the right-hand wall surface facing the progressive direction 64 (of the travelling truck 21) ; the outer rings of said guide rollers 66 and 68 become brought into contact with said vertical wall surface 74 at the points 72 and 73, roll and move on said wall surface 74, guide the progressive direction 64 of the travelling truck 21 running inside the duct 1, and thus enable the travelling truck 21 to advance inside the duct 1 smoothly. In case that the duct 1 is curved as shown in Fig.4, the function of the guide rollers as stated above becomes particularly effective. The in-duct cleaning apparatus of the present invention consists of the aforementioned structure, brings about the aforementioned operational effects, and consequently yields overall effects as follows. Firstly, said in-duct cleaning apparatus is equipped with the rotating nozzle which can be rotated under the operation of the monitor/remote-control portion and can eject the compressed air toward the duct inside surface in oblique front of the travelling truck, so that said apparatus can successively clean the duct inside surface in oblique front of the travelling truck as the truck advances and can remove foreign substances and the like attached to said duct inside surface. Secondly, said in-duct cleaning apparatus, in addition to the above first effect, can, by making the rotating nozzle rotate covering an angle of 360 degrees, blow the compressed air against the circumference of the duct inside surface, and can thereby clean out trash and dust evenly throughout the whole circumference of the duct inside surface. Thirdly, said in-duct cleaning apparatus, in addition to the above first effect, can, by making the rotating nozzle rotate reciprocatively within the range of an angle of 180 degrees covering the lower half part inside the duct, clean out efficiently and swiftly the lower half part inside the duct where trash and dust are liable to accumulate, except the ceiling part where no dust and the like are liable to accumulate. Fourthly, said in-duct cleaning apparatus, in addition to the above first effect, can, by enabling the rotating nozzle to stop at either a leftward or a rightward horizontal position inside the duct, clean out predominantly the left and right wall parts inside the duct. Fifthly, said in-duct cleaning apparatus, in addition to the above first effect, can, by being equipped with the straight -ejective nozzle which can eject the compressed air concentratedly toward the narrow area of the duct inside surface in front of the travelling truck under the operation of the monitor/remote-control portion, clean predominantly and powerfully said narrow area of the duct inside surface at need, and thus can remove particular foreign substances and the like clinging to said narrow area. Sixthly, said in-duct cleaning apparatus, in addition to the above first to fifth effect, can, by being equipped with the guide rollers attached to the travelling truck for guiding the progressive direction of the travelling truck by keeping contact with the duct inside wall surface, not only make the travelling truck advance smoothly inside the duct without incurring any stagnation even at the duct curvatures but also make the truck driving motor entirely free from being excessively overloaded with direct contact between the truck side surface and the duct inside wall surface, and can thereby bring about the effect that the failure of said apparatus will be made to be minimized. It can be summarized that the in-duct cleaning apparatus of the present invention can perform cleaning inside a duct too narrow for a man to enter ; can perform, taking the place of a man and more skillfully than a man, a dirty, dangerous and severe work inside a duct even if the duct allows a man to enter ; can serve to improve and to perform labour saving of said dirty, dangerous and severe job site ; and can, through in-duct cleaning, contribute to the improvement of environmental sanitation.

Claims: An in-duct cleaning apparatus for cleaning duct inside surfaces, said apparatus comprising:- a travelling means (3) drivable for moving forwards and backwards in the interior of a duct (1) to be cleaned; a video camera (25) carried by said travelling means; an image display means (5) for displaying an image taken by said video camera (25) to enable monitoring of the interior of the duct (1): a control means (4) for controlling the travelling of said travelling means (3) in accordance with an image displayed on said image display means (4); an air compressor (11); and a compressed air ejecting nozzle (23) carried by said travelling means (3) and connected for receiving compressed air from said compressor (11) and for ejecting compressed air towards the interior of the duct; characterised in that said compressed air ejecting nozzle (60) is provided on the travelling means (3) to be rotatable through a predetermined angle around an axis substantially parallel to said duct (1) and to be inclined at an angle to said axis of rotation of the compressed air ejecting nozzle. An in-duct cleaning apparatus according to claim 1 wherein said compressed air nozzle (23) is rotatable through a predetermined angle of 360 degrees. An in-duct cleaning apparatus according to claim 1 wherein said compressed air ejecting nozzle (23) is rotatable through a predetermined angle of 180 degrees. An in-duct cleaning apparatus according to any preceding claim wherein the rotation of said compressed air ejecting nozzle (23) is capable of being stopped at any position of rotation. An in-duct cleaning apparatus according to any preceding claim wherein said compressed air ejecting nozzle (23) rotates about the axis of the duct. An in-duct cleaning apparatus according to any preceding claim wherein said compressed air ejecting nozzle (23) is provided on the travelling means to be inclined at a particular angle to said axis of rotation of the compressed air ejecting nozzle whereby compressed air is ejected at an angle of substantially 45 degrees to that axis of rotation. An in-duct cleaning apparatus according to any preceding claim wherein a further compressed air ejecting nozzle (24) is carried by said travelling mean (3) and is connected for receiving compressed air from said compressor (11) and for ejecting compressed air in a substantially straight line. An in-duct cleaning apparatus according to claim 7 wherein the direction of said line of compressed air ejected from said further compressed air ejecting nozzle (24) can be manually or remotely changed. An in-duct cleaning apparatus according to any preceding claim wherein said travelling means (3) comprises guide rollers (66, 67, 68, 69) for guiding the travelling means to travel precisely along the interior of the duct (1).

Inventors: MATSUURA KENGI, TORITANI KATSUMI, MATSUURA, KENGI, TORITANI, KATSUMI
Applicants: ATAKA CONSTRUCTION & ENG, ATAKA CONSTRUCTION & ENGINEERING CO. LTD
Application year: 1993
Main classification: B08B9
IPC codes: B08B5, B08B9