WO1989012513A1

WO1989012513A1 - Apparatus for cleaning pipes

Info

Publication number: WO1989012513A1
Application number: PCT/SE1989/000334
Authority: WO
Inventors: Hans Norberg
Original assignee: Hans Norberg
Priority date: 1988-06-13
Filing date: 1989-06-13
Publication date: 1989-12-28
Also published as: SE8802205D0

Abstract

An apparatus (15) for cleaning the inside of a pipe (11) is capable of being connected to a pressure-liquid hose (10) for the purpose of driving a rotor (16) which carries cleaning devices. The rotor is journalled on a stator (19) by means of self-sealing ball bearings (20). The pressure-liquid ducts in the stator are provided with nozzles (29A) which are operative to direct liquid jets into the rotor ducts (31) for rotation of the rotor. The rotor ducts are disposed so close to one another that jets exiting from the nozzles of the stator ducts will always reach freely into the rotor ducts, such as to maintain in this way the smallest possible static pressure in the gap between the stator and the rotor, and therewith in the vicinity of the ball bearings.

Description

Apparatus for Cleaning Pipes

The present invention relates to apparatus intended for cleaning the insides of pipes, particularly the insides of water pipes, and being of the kind set forth in the preamble of the following main claim.

Examples of such apparatus are described in EP-A3-0087562 and SE-A-8206903-0.

A common feature of these known apparatus is that the rotor is joumalled in a slide bearing which receives the high-pressure water exiting from the gap defined between the stator and the rotor, where the outflow from the ducts in the stator is retarded in an annular collecting chamber on the inside of the rotor, whereafter the pressure water is lead through one or more ducts in the rotor and out to the nozzles, in which the velocity is increased.

However, it has been found that under certain load conditions, the water film in the slide bearing breaks up, which results in binding of the bearing.

The object of the invention is to eliminate this risk. This object is achieved with apparatus having the characterising features set forth in the characterising clause of the main claim.

In accordance with the invention it is possible to journal the rotor on the stator with the aid of ball bearings or roller bearings, by taking measures to reduce the pressure in the gap between the stator and the rotor to the lowest possible value. The pressure on the bearings and their respective seals will be lowered to a commensurate extent and to such a small value as to prevent damage to the seals, which in turn means that lubricating grease and oil in the bearings will not be washed away.

As background to the invention, it can be mentioned that the replacement of a slide bearing with a ball bearing for taking up large and heavy loads is an obvious ex¬ pedient. However, it has been found that when the slide bearings of the known apparatus are replaced with ball bearings, the water pressure on the bearing seals is so great as to damage the seals and to wash away the bearing lubricant.

For the purpose of avoiding this, the rotor and stator ducts, in accordance with the invention, are arranged so that the pressure water in the stator ducts will exit through the nozzles in the form of liquid jets at high velocity and at low static pressure, the inflow openings in the rotor being so large and lying so close together that the liquid jets will not be retarded, but will always pass directly into one of the rotor ducts and flow freely therethrough while deflecting the flow direction for driving the rotor.

In practice, a vehicle provided with a pump is used to generate water pressure in a long flexible hose, with a capacity of, e.g., 350 1/m at a pressure of 150 bars. Subsequent to attaching the inventive apparatus to the end of the hose, the apparatus is lowered down a manhole to the vicinity of the pipe concerned and is then dir¬ ected towards the sewage pipe to be cleaned. The pump is then started and the apparatus begins to draw itself into the pipe under the action of the rearwardly dir¬ ected water jets, which drive the apparatus forwards in the pipe. These rearwardly directed water jets are able to draw the apparatus through a distance of 150 along the pipe, and consequently a further manhole is provided within the span of this 150 m. At the same time as the apparatus begins to move along the pipe, the rotor starts to rotate, the rotor being driven by the water jets exiting through four holes in the stator and direc- ted towards the inflow openings in the rotor ducts.

Although the inventive apparatus is primarily intended for cleaning pipes from roots and deposits, it can also be used to clean the pipes of district heating systems or to clean pipes in the cellulose industry, or to wash and clean rubbish disposal chutes, or to clean pipes in the oil industry. In these cases it is not necessary to use clean water and any pressure water suitable for the purpose in question can be used.

These and other elements characteristic of the invention and the advantages afforded thereby will now be de¬ scribed in more detail with reference to the accom¬ panying drawings, which illustrate a suitable embodiment of apparatus constructed in accordance with the invention.

Figure 1 is a logitudinal sectional view of a pipe in which there is introduced a carriage-carried apparatus according to the invention; Figure 2 is a sectional view taken on the line 2-2 in Fig. 1; Figure 3 is an enlarged detail view of the inventive apparatus shown in Fig. 1 and illustrates elastic, flexible or bendable arms which are combined in pairs to form stirrup-like structures, the working positions of which are shown in full lines, whereas the broken lines illustrate the stirrup-like structures subsequent to said structures being worn in their centre region and therewith separated into two elastically bendable or flexible arms which lie against the inner surface of the pipe; Figure 4 is an enlarged illustration of the inventive apparatus in Figure 1 and shows the presence of two self-sealing ball bearings, the connection of the flexible hose to the apparatus and the elastic, bendable arms being shown in chain lines and the direction of water flow from the hose and through the various ducts and openings being shown by arrows;

Figure 5 is a front view of the apparatus shown in Fig.

4; Figure 6 is a longitudinal section through one main part of the rotor; and Figure 7 is a cross-sectional view which shows the rotor around the stator with the various ducts.

As illustrated in Figure 1, a flexible hose 10 is car¬ ried by a carriage 11 having three wheels 12, such that the carriage is able to roll forwards in a pipe 13, which in the illustrated embodiment has, e.g., a dia¬ meter of about 23 cm. The carriage 11 may be followed by a further carriage located at a distance from the car¬ riage 11 such that the intermediate length of flexible hose will form a flexible connection between the two carriages, so as to facilitate driving around the curved regions of the pipe or to enable stationary obstacles in the pipe to be negotiated.

Provided on the forward end of the hose is a coupling

14, which connects the hose to the illustrated apparatus 15.

The hose is connected to a liquid pump (not shown) which is located on the service vehicle and which delivers the requisite pressure fluid, such as water, to the appar¬ atus 15 for driving the apparatus along the pipe and for driving the rotor 16, which has mounted thereon a plura¬ lity of cleaning devices in the form of elastic, ben- dable or flexible arms 17. In the case of the illus¬ trated embodiment, the arms are mutually joined in pairs at their outer ends to form stirrup-like structures 18 which function as cleaning devices.

As shown in Figure 4, the apparatus comprises a stator 19 which rotatably supports a rotor 16 by means of two self-sealing roller bearings 20.

The stator is comprised of a backpiece 21, an inter- mediate part 22 welded to the backpiece, and a shaft 23 which is screwed into the intermediate part and which carries the ball bearings 20. The ball bearings used in each test apparatus were of the self-sealing type re¬ tailed under the designation FAG 6202.

The rotor comprises an annular part 24 to the front end of which there is mounted an attachment part 25 which carries the cleaning arms 17 and stirrup-like structures 18 respectively and which is tightly secured by means of a bolt 25a. The bolt is hollow such as to enable the insertion of a draw bolt (not shown) and screwing of said bolt in a screw-threaded hole 23A provided in the end of the stator. The outer end of the bolt has pro¬ vided thereon an eye or lug on which a pulling line can be affixed for assisting forward movement of the apparatus, should the need arise.

The pressure liquid is supplied to a chamber 26 and divided into two main streams, of which one is conducted through reawardly directed outflow openings 27 fitted with nozzles 27A, to produce liquid jets for forward propulsion of the apparatus in the pipe 13, and the other of which is conducted through ducts 28 to lat¬ erally directed channels 29. The channels 29 are pro¬ vided with nozzles 29A which direct the jets towards the annular part 30 of the rotor 16 and the outflow ducts 31 arranged in said part, these ducts having a position and a configuration such as achieve the desired drive of the rotor.

As will be seen from Figure 4, there is a small gap 32 between the rotor and the stator. The nozzles 29A direct four liquid jets of considerably reduced static pressure and of high velocity through the gap 32 between the rotor and stator, in a direction obliquely forwards in the direction of rotation of the rotor. The inflow openings for the rearwardly and obliquely extending rotor ducts 31 are located so close together and are of such size that the jets exiting from the nozzles 29A will always impinge on the wall of one of the rotor ducts 31, for deflection of respective jets and for exiting through said duct. Thus the gap will essentially only receive liquid which is substantially without pressure and consequently no pressurized liquid will reach the self-sealing bearings. These bearings are consequently not exposed to damage from liquid under pressure, which could otherwise destroy the bearing seals and wash away the bearing lubricant with sub¬ sequent failure of the bearings.

The smallest distance between mutually adjacent inflow openings for the ducts 31 is smaller than the largest cross-dimension or width of the openings in the direc¬ tion of rotation, suitably less than half, preferably a fifth of said width. The attachment part is provided with a plurality of holes 33 for receiving the inner ends of the elastic, flexible arms and the inner ends of the stirrup-like structures respectively. These ends are then locked firmly in the holes with the aid of lock screws 34 (Fig. 4).

Claims

CLAIMS 1. Pipe cleaning apparatus comprising a stator (22) having a cylinder part (23) which carries a rotatably joumalled rotor 16) provided with attachments (25) for a number of cleaning devices intended for removing from the pipe interior such obstructions as deposits, penetrating roots and the like, and a connection (14) located on the rear end of the stator for the connection of a flexible hose (10) which is carried by a carriage (11) and which is intended to deliver high-pressure liquid, such as water, to a number of rearwardly di¬ rected ducts (27, 27A) provided in the stator, for the purpose of generating reaction jets which propel the apparatus along the pipe, and also to a number of out- wardly directed ducts (29, 29A) provided in the stator and discharging adjacent the circumference of the cylin¬ der part such as to transfer liquid through the gap (32) located between the stator and the rotor and to inflow openings in ducts (31), said inflow ducts being disposed in a surrounding annular part of the rotor (30) and directed obliquely outwards and rearwards relative to the direction of rotation of the rotor, for driving the rotor, c h a r a c t e r i s e d in that the rotor is joumalled on the stator by means of at least one ball bearing (20) or roller bearing; that the stator ducts include nozzles (29A) which direct liquid jets of grea¬ tly reduced static pressure and of high velocity through the gap (32) between the stator and the rotor and in a direction obliquely forwards in the direction of rota- tion of the rotor; and in that the inflow openings for the obliquely and reawardly directed rotor ducts (31) in the rotor are disposed so close together and are of such size that the jets exiting from said nozzles will always impinge on the wall of one of the rotor ducts, for deflection of the jet and free passage thereof through said duct.

2 Apparatus according to claim 1, c h a r a c ¬ t e r i s e d in that the smallest edge-distance between mutually bordering inflow openings in the rotor is smaller than the largest width of the inflow openings in the direction of rotation, suitably less than half of said width, preferably about a fifth of said width.