EP0918575A1

EP0918575A1 - Nozzle for interior cleaning and/or painting of pipe lines

Info

Publication number: EP0918575A1
Application number: EP97929646A
Authority: EP
Inventors: Johan Faxon
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-06-27
Filing date: 1997-06-13
Publication date: 1999-06-02
Also published as: SE506851C2; AU3365797A; WO1997049505A1; SE9602534L; SE9602534D0

Abstract

Nozzle (1, 11) for interior cleaning and/or painting of pipe lines intended to be connected to a supply conduit (2, 12) for a first gaseous cleaning medium (compressed air), comprising one or more first exhaust passages (6, 14.1) for the first cleaning medium, comprising one or more second exhaust passages (4.4, 15.1) for a second cleaning medium and/or a paint. The second cleaning medium preferably consists of a compressed air-borne blasting medium. The nozzle (1, 11) comprises separate exhaust passages for the second cleaning medium or for the paint. One or more first exhaust passages (6, 14.1) are directed backwards towards the supply conduit (2, 12).

Description

NOZZLE FOR INTERIOR CLEANING AND/OR PAINTING OF PIPE LINES

TECHNICAL FIELD The present invention relates to a nozzle for interior cleaning and/or painting of pipe lines, intended to be connected to a supply conduit for a gaseous cleaning medium (compressed air). The nozzle comprises one or more exhaust passages for the first cleaning medium which may be directed outwards from the nozzle both backwards towards the supply conduit, perpendicular to the centre line of the nozzle and forward towards the front part of the nozzle. The nozzle thereby may be caused to move inside the pipe line by the forces of reaction which results from the escaping cleaning medium whilst cleaning and/or painting the interior wall of the pipe line. DESCRIPTION OF THE INVENTION

The object of the present invention is to achieve a nozzle according to the preamble which admits interior cleaning av pipe lines, in particular air vent pipes with various cleaning media as e.g. compressed air, or mixed with solvents or merely solvents, steam and other gaseous media and also compressed air or other gaseous media mixed with sandblasting means. Thus the term cleaning comprises dry as well as wet cleaning of the pipe line. The nozzle admits even interior painting of pipe lines, the term cleaning then comprises every application of a coating to the interior walls of the pipe line. The invention is not confined to pipe lines only, it lies also within the scope of the invention to use the nozzle for interior cleaning of different kinds of pipes and containers as well as hot-air pans, boilers or central heatings. The nozzle according to the invention comprises one or more exhaust passages for a first gaseous cleaning medium (compressed air) and is characterized in that it shows one or more exhaust passages for a second cleaning medium and/or a paint. At that the first exhaust passages are preferably intended to move the nozzle by means of forces of reaction from the escaping first gaseous medium and for dry cleaning of loose dust and loosening of dirt from the interior wall of the pipe line. The second exhaust passages are preferably intended for the appli¬ cation of a solvent to the pipe wall and for blasting and painting of the pipe wall. In interior treatment of a pipe line the nozzle according to the invention may be inserted through an orifice in a pipe line which is connected to an exhaust device for dust (vacuum cleaner) but otherwise closed towards the environment. When a first cleaning medium (compressed air) is caused to escape through the first exhaust passages which preferably are directed backwards towards the supply conduits the nozzle with the supply conduit is caused to move into the pipe line by forces of reaction from the escaping first cleaning medium. The nozzle then may be caused to move linearly along the pipe line as well as helically but also to treat certain spots of the pipe line where dirt remains especially tight. The first exhaust passages may also be directed perpendicu¬ larly outwards from the centre line of the nozzle and towards its front part as well.

It lies within the scope of the invention to be able to vary between the above mentioned directions in one and the same nozzle and thereby cause the nozzle to move in different directions within the pipe line. When the first exhaust passages are directed forward towards the front part of the nozzle the supply conduit favour¬ ably may consist of a rigid hose which allows that the nozzle compulsorily is slid into the pipe line against the force of reaction from the cleaning medium which escapes forwards.

The second cleaning medium is preferably a com¬ pressed air-borne blasting agent which in its turn may consist of conventional blasting sand or another occurr¬ ing blasting matter. It may be favourable if the blasting agent is of a very low specific gravity when cleaning sensitive pipe lines as e.g. pipe lines consisting of glass fibre armoured plastics or asbestos. A heavy blasting agent may cause damages to the interior walls of the pipe line. With pipe lines of that kind it is favour¬ able, too, to provide its interior wall with a relatively smooth surface layer which then facilitates an easier cleaning with merely e.g. compressed air and if necessary a solvent for adhering grease or the like. In using a compressed air-borne blasting agent it is favourable, too, to ensure that the exhaust passages are kept in a distance from the pipe wall to be cleaned. For that reason the nozzle according to the invention may be provided with support members which may be fixed or adjustable and which admit an adjustment of the desired distance between the exhaust passages and the pipe wall. Further details and features concerning the present invention are evident from the description to the drawings subsequently and from the patent claims. DESCRIPTION TO DRAWINGS

The invention is described subsequently as an example of an embodiment in connection with the enclosed drawings.

Fig. 1 shows a nozzle attached to the end of a supply conduit which is stiffened with a metal wire.

Fig. 2 shows separately a distributor for cleaning and/or painting media, centrally arranged in the nozzle.

Fig. 3 shows a cross section along line I-I of the distributor shown in fig. 2.

Fig. 4 shows a cross section along line II-II of the distributor shown in fig. 2. Fig. 5 shows a feeding device for media to the cleaning nozzle according to fig. 1.

Figs. 6 and 7 show an alternativ embodiment of the cleaning nozzle according to the invention.

A nozzle 1 shown in fig 1 comprises a distri¬ butor 3 arranged on a first supply conduit 2 for cleaning media and which supports a fixed back piece 4 and a rotary front piece 5. The back piece 4 shows an outer conical surface 4.1 whereas the front piece 5 shows a corresponding inner conical surface 5.1. In assembled condition an annular gap 6 is formed between those conical surfaces and is connected with the first supply conduit 2 via four first ducts 3.1 and four first orifices 3.2 in the distributor 3. A first cleaning medium e.g. in the form of compressed air is fed through the first supply conduit 2 and streams through the first ducts 3.1, escapes through the first orifices 3.2 in the distributor 3 towards an annular chamber 4.2 which is formed between the back piece 4 and the front piece 5 and continues through the annular gap 6.

The front piece 5 is freely rotatable round an axle 3.3 which is formed of the inner end of the distributor 3 and is kept in place by means of a screw 5.2 which is screwed into a threaded hole in the end of the distributor 3. Furthermore the front piece 5 is provided with a rubber or plastic ring 7 arranged along its periphery which bears on the interior wall of the pipe during the cleaning operation. The back piece 4 is provided with an inner threading and is screwed onto the distributor 3 which shows a corresponding outer thread¬ ing. The back piece 4 shows an inner ring-shaped slot 4.3 which runs round the opening in the back piece 4 and which is connected to an exhaust duct 4.4 ending in the outer conical surface 4.1 In an alternative embodiment a corresponding ring-shaped slot may be arranged in the casing surface of the distributor and in connection with the exhaust duct 4.4 instead. In assambled condition the ring-shaped slot 4.3 in the back piece 4 is connected to a second duct 3.3 and two second openings 3-4 in the distributor 3, the second duct 3.3 in its turn being connected with a second supply conduit 2.1 for a blasting medium e.g. a compressed air-borne blasting agent or a paint for painting.

In order to furthermore reinforce the cleaning results a solvent may be added with the compressed air which escapes from the ring-shaped slot 6 or through the exhaust duct 4.4 which also is intended for a blasting medium or paint. The cleaning may be executed in stages so that to begin with unattached dust is removed from the pipe line by means of compressed air from the gap 6 while dust simultaneously is evacuated whereupon the pipe wall may be coated with a solvent and a repeated cleaning with compressed air may be done. Then a blasting may be done followed by a painting. Alternatively the second supply conduit 2.1 may be arranged on the outside of the first supply conduit 2 and connect to a separate connection on the back piece 4 which is connected to the exhaust duct 4.4. Alternatively both supply conduits 2, 2.1 may be arranged in one and the same conduit casing.

In cleaning a pipe line by blasting the exhaust duct 4.4 is kept directed towards the pipe wall to be cleaned by the centre line of the nozzle 1 constituting an angle to the longitudinal direction of the supply conduit 2 which in this example of an embodiment is established by means of one at the end of the supply conduit 2 fastened metal wire 8 which has been bent in a desired angle and which when fastened to the connecting section on the distributor 3, too, provides the desired angular setting. The exhaust duct 4.4 for blasting medium is kept directed towards the pipe wall by keeping the nozzle 1 in a position in which the centre line of the distributor 3, the metal wire 8 and the exhaust duct 4.4 are mainly in a level which is perpendicular to the tangent plane of the pipe by the point of contact of the nozzle 1 to the interior wall of the pipe. In this position the nozzle 1 strives to move linearly along the longitudinal direction of the pipe by force of reaction from the escaping compressed air from the annular gap 6. Simultaneously the blasting medium is caused to escape through the exhaust duct 4.4 and continues through that part of the annular gap 6 which is nearest to the interior wall of the pipe and cleans it by the blasting effect in the blasting agent.

In rotating the supply conduit round its longitudinal axis the plane through the centre line of the distributor 3, the metal wire 8 and the exhaust duct 4.4 are caused to incline towards the tangent plane through the point of contact, the nozzle 1 being caused to move along the interior circumference of the pipe, too, while the front piece 5 of the nozzle 1 rolls freely towards the interior wall of the pipe. By this rotation the nozzle 1 may be set into helical motion through the pipe .

Blasting agent is fed to the nozzle 1 by means of a feed device 9 shown in fig. 5. The feed device 9 comprises a tank 9.1 for blasting agents which is connected with the second supply conduit 2.1 via a feed pipe 9.2. Compressed air is fed into the feed pipe 9-2 via a branch pipe 9-3 provided with a first cut-off valve 9-4 for a fluidization vessel 9.5 arranged between the tank 9.1 and the feed pipe 9.2. The branch pipe 9-3 is connected to the first supply conduit 2 via a distance piece 9-6. A second cut-off valve 9.7 is arranged in front of the distance piece 9.6 in the first supply conduit 2. In operation the second cut-off valve 9-7 e.g. may be opened solely, the nozzle 1 being acted on by compressed air only which escapes through the annular gap 6 and drives the nozzle onwards or helically onwards in the pipe. In pipe sections where the dirt shows hard to remove solely by means of the escaping compressed air the first cut-off valve 9-4 may be opened as well and by that means cause blasting medium to reach and escape from the nozzle 1. The feeding of blasting medium may be cut off when the desired cleaning effect has been achieved.

In an alternativ embodiment of the nozzle 1 according to the invention shown in fig. 6 the nozzle 11 consists of a homogeneous body. The nozzle 11 is rotary symmetrical and conically tapering towards its front part. A connection pipe 13 is screwed into its back part and in its turn stuck into a first supply conduit 12 which via the connection pipe 13 is connected with a first chamber 14 which extends centrally in the nozzle 11. The chamber 14 is closed with a tap 15 which is screwed into the front part of the nozzle 11. The chamber 14 is connected with exhaust ducts 14.1 or 14.2 which are arranged radially an sloping outwards towards the back part of the nozzle 11. As is evident from fig. 7 sex primary ducts 14.1 are arranged within a sector of 162 at that part of the nozzle 11 which is intended to be closest to the pipe wall to be cleaned and three secondary ducts 14.2 arranged within the remaining part of the circumference. Within the primary ducts 14.1 exhaust pipes 15.1 with smaller external diameter than the interior diameter of the primary ducts 14.1 are arranged so that a gap is formed between the wall of the primary ducts 14.1 and the external wall of the exhaust pipes 15.1 and connected with a second chamber 15.2 arranged centrally within the tap 15. The second chamber 15-2 is closed with an adjusting screw 15-3 running in a threaded hole within the front part of the tap 15 and which at its inner end supports a valve body 15.4. By driving in the adjusting screw 15.3 the mediaflow through the exhaust pipes 15.1 may be restricted. As mentioned above this medium may consist of a solvent, a blasting medium or a paint.

It may be favourable to let the nozzle 11 be at a distance from the surface to be cleaned especially by means of a compressed air-borne blasting agent but even in painting the surface concerned. This is achieved e.g. as shown in figs. 6 and 7 by means of support members in the shape of two wire bows 16 which are arranged at that side of the nozzle 11 which due to the shanted first supply conduit 12 is nearest to the pipe wall and in connection to the primary ducts 14.1 with the exhaust pipes 15.1 for blasting medium or paint. The invention is not limited to this embodiment of the support members 16 which may be performed in many different ways and be an integrated part of the nozzle 11 as well.

It lies within the scope of the invention to let the exhaust passages shown in the shape of an annular gap 6 in fig. 1 and in the shape of fan-shaped exhaust ducts 14.1 in fig. 6, be directed in an angle backwards towards the supply conduit 2, 12, perpendicular to the centre line of the nozzle 1 , 11 or in an angle forwards towards the front part of the nozzle 1, 11 as well as in a combination of these directions. In varying the medium escape between these escape directions the nozzle 1 , 11 may be caused by forces of reaction from the escaping medium to move forwards within the pipe line carrying the supply conduit 2, 12 or backwards by drawing the conduit or get shoved compulsorily from out into the pipe line against the forces of reaction from a medium escaping forward .

Claims

1. Nozzle (1 , 11) for interior cleaning and/or painting of pipe lines intended to be connected to a supply conduit (2, 12) for a first gaseous cleaning medium (compressed air) comprising one or more first exhaust passages (6, 14.1) for the first cleaning medium, c h a r a c t e r i z e d in that it comprises one or more second exhaust passages (4.4, 15.1) for a second cleaning medium and/or a paint.

2. Nozzle according to claim 1, c h a r a c ¬ t e r i z e d in that the second cleaning medium consists of a compressed air-born blasting medium.

3. Nozzle according to claim 1 or 2, c h a r a c t e r i z e d in that it comprises separate exhaust passages for the second cleaning medium or for the paint.

4. Nozzle according to any of the claims 1-3, c h a r a c t e r i z e d in that one or more first exhaust passages (6, 14.1) are directed backwards towards the supply conduit (2, 12) .

5. Nozzle according to any of the claims 1-4, c h a r a c t e r i z e d in that one or more second exhaust passages (4.4, 15.1) are arranged inside of or connected to the first exhaust passages (6, 14.1) whereby the first cleaning medium exerts an ejector suction effect upon the second cleaning medium or the paint.

6. Nozzle according to any of the claims 1-5, c h a r a c t e r i z e d in that support members (16) are arranged at least at the second exhaust passages (4.4, 15.1) whereby the nozzle is kept at a distance from the pipe wall to be cleaned.