WO1998001260A1

WO1998001260A1 - Blasting device with pressure means, and method for the use thereof

Info

Publication number: WO1998001260A1
Application number: PCT/NL1997/000373
Authority: WO
Inventors: Adrianus Gerardus Van Houten
Original assignee: E B E Nederland BV
Current assignee: E B E Nederland BV
Priority date: 1996-07-05
Filing date: 1997-07-01
Publication date: 1998-01-15
Anticipated expiration: 1999-01-05
Also published as: NL1003522C2; JPH11512034A

Abstract

During the blasting of walls the blasting device is pushed away from the wall by the blasting agent, with the result that the gap between the wall and the jet nozzle (6) increases, which is undesirable because this pollutes the environment. The pressure force required for pushing the blasting device against the wall is created by tensioning a belt (18) along the wall, which belt runs along guide rollers (9, 12) fixed on the blasting device. By fixing the belt or the guide rollers resiliently, it is ensured that length changes in the belt, as a result of the movement of the device along the wall are taken up, and the pressure force always remains present to a sufficient degree.

Description

Blasting device with pressure means, and method for the use thereof

The invention relates to a blasting device for blasting more or less vertical walls, comprising drive means by means of which a blasting agent can be thrown at high speed through a jet nozzle against the wall, and hoisting means with which the device can be moved along the wall, guide means with which the jet nozzle can be guided more or less at a constant distance in a sealing manner along the wall, and pressure means for pressing the guide means with a pressure force against the wall. Such blasting devices are known, inter alia from

Dutch Application NL 1000576 (not a prior publication) of the same applicant. The known blasting device is moved along the steel wall, and during the movement the pressure force towards the wall is achieved by drawing the device towards the steel wall with magnets. Such a blasting device can be used only in the case of steel walls and in situations where the pressure force does not have to be great, for example if the wall is vertical.

This document also discloses devices in which the jet nozzle is pressed with spring force against the wall and in which the springs rest against a frame situated on a manipulator or the like. Owing to the limited dimensions of the frame, only a small part of the wall can often be worked, after which the manipulator has to be moved again, which leads to great loss of time.

The blasting device according to the invention aims to avoid the abovementioned disadvantages, and to that end the pressure means comprise a belt which is stretched along the wall between two attachment points and one or more guide rollers fixed to the device, the belt exerting a pressure force on the guide rollers.

Using a belt which pushes the device against the wall produces pressure means which are easy to fit and can be used in the case of concrete and other non-magnetic walls, and which can be fitted quickly. Such pressure means can also be useful in applications in which the magnetic force is too low to draw the blasting device against the wall, as is the case, for example, during blasting of the backward sloping faces of the bow of a ship. It is also possible to work smaller wall surfaces efficiently, because no complex constructions are used to achieve the pressure force.

According to an improvement of the invention, the belt and/or the guide rollers are resiliently fixed. This ensures that the blasting device is always pushed with a pressure force against the wall, even if the total distance from one attachment point to a guide roller, and possibly between individual guide rollers, and from a guide roller to the second attachment point, varies as a result of the movement of the blasting device along the wall.

According to a further improvement of the invention, the guide roller is fixed on an arm and can be pushed by a spring against the side of the belt facing the wall. By means of this design, great length changes in the distance between the guide rollers and the attachment points, arising as a result of the movement of the blasting device along the wall, are easily accommodated.

According to another embodiment of the invention, a spring is fitted between one end of the belt and an attachment point.

Fixing the belt to the wall with a spring means that sufficient tension can always be maintained on the belt, while sufficient length change to move the blasting device along the wall between the attachment points can still occur.

According to a preferred embodiment of the invention, an attachment point is fixed against the wall with a clamping strip. This ensures that if a pillar, for example a concrete supporting pillar of a motorway, has to be blasted the bottom supporting point can be fitted by simple means on the underside of the pillar, without fixing points having to be fitted for it in the pillar. This saves time and effort, and the work can be carried out more efficiently.

According to a further improvement of the invention, a hoisting cable and the top side of the belt are suspended from a hoisting bracket which can be supported against the wall.

This ensures that the blasting device can easily be moved along different parts of the wall, so that the latter can be worked easily over a large area. According to a further improvement of the invention, the hoisting bracket can be moved by means of a drive along a rail which can be supported against the wall.

This ensures that a stable, but movable attachment point is obtained, as a result of which accurate control of the blasting device along the wall is possible.

According to a further improvement of the invention, the hoisting bracket or the rail is supported against the wall by means of a mobile apparatus.

This makes the device easier to put into operation and more efficient in use, the mobile apparatus being easy to move along a wall or along the different sides of a pillar.

The invention also comprises a method for use of the blasting device, in which the latter is suspended in front of the wall, the belt is guided along the guide rollers and the pressure force is created by tensioning the belt with a belt buckle fixed at working height.

Tensioning the belt with a belt buckle which is fixed at working height ensures that a quick method for positioning the blasting device is achieved.

According to a further improvement of the method, the length of the belt is adjusted with the belt buckle during the movement along the wall.

This means that great length differences in the belt during movement along the wall can also easily be corrected.

The invention is explained below with reference to a drawing in which the invention is illustrated with reference to a number of exemplary embodiments. In the drawing, Figure 1 shows in side view a blasting device according to a first exemplary embodiment of the invention, by means of which a square pillar is blasted; Figure 2 shows in rear view the blasting device according to Figure 1;

Figure 3 shows in side view a blasting device according to the first exemplary embodiment of the invention which is adapted for blasting a round pillar; Figure 4 shows in top view the blasting device according to Figure 3 ;

Figure 5 shows in side view a blasting device according to a second exemplary embodiment, by means of which a wall is blasted; Figure 6 shows in rear view the blasting device according to Figure 5;

Figure 7 shows in front view the blasting device according to Figure 5;

Figure 8 shows in rear view a third embodiment of the invention, in which the blasting device can move along the belt in the horizontal direction during blasting;

Figure 9 shows in top view the blasting device according to Figure 8; and

Figure 10 shows an application of the blasting device according to Figure 5, such as is used for blasting the sloping faces of a ship.

In the various figures and exemplary embodiments corresponding parts are always indicated by identical reference numbers as far as possible. Figure 1 shows a blasting device 1 by means of which blasting agent is thrown at high speed against the surface of a pillar 22. The pillar 22 is a concrete column, in this case of square cross-section, the surface of which has to have paint, dirt or the like removed from it, and to this end the blasting device 1 is moved by a hoisting cable 13 along the surface.

The blasting device 1 is designed with a throwing wheel (not shown) which is driven by a throwing wheel motor 11, so that blasting agents stored in a stock tank 4 are transferred to the throwing wheel and subsequently thrown at high speed, by directing the throwing wheel downwards obliquely, through a throwing channel 5 against the wall to be blasted at the position of a jet nozzle 6. The blasting agent rebounding from the wall, with the entrained dirt, circulates through a return channel 7 and by way of a conveyor 3 back to the stock tank 4, while the dirt is removed therefrom in the meantime in a manner not shown. For this purpose, a vacuum cleaner (not shown) is present, as discussed in greater detail in the above- mentioned NL 1000576, in which the blasting device is discussed in detail, and which also forms part of this application.

A seal, by means of which dirt and dust are pre- vented as far as possible from reaching the environment, is fitted between the jet nozzle 6 and the wall. In order to make this seal function well, it is important that the distance from the jet nozzle 6 to the wall should be small and should vary as little as possible, and to this end a swivelling guide wheel 2 and a guide wheel 8 are fitted on the device.

The blasting device 1 is suspended from the hoisting cable 13, which is fixed to a hoisting bracket 14, and is moved in the vertical direction by a winch 10. The hoisting bracket 14 is suspended from a rail 23 shown in

Figure 2, which rail is suspended from a supporting bar 15. The supporting bar 15 is fixed to a mechanical shovel bucket 16, which is fixed by means of an arm 17 to a mobile apparatus (not shown) . The supporting bar 15 rests against the wall of the pillar 22, so that said bar is brought to a stable position, and so that the movement of the blasting device 1 with the winch 10 can be carried out accurately. In the embodiment shown, the winch 10 is placed in the blasting device 1, but it is also possible to place the winch 10, for example, on the ground, in which case the hoisting cable 13 of the winch 10 is guided to the blasting device 1 by way of a block fixed on the hoisting bracket 14.

The blasting device 1 is pushed away from the wall by the blasting agents thrown against the wall, which is undesirable because the gap between the jet nozzle 6 and the wall becomes unacceptably large and pollution of the environment occurs. For that reason, pressure means, consisting of a belt 18 which is fixed to the hoisting bracket 14 at the top and to a spring 20 by means of a belt buckle 19 at the bottom, is provided. The spring 20 is pulled against the pillar by a belt 21. The belt 18 presses against a top guide roller 12 and a bottom guide roller 9, which form part of the blasting device 1. Under the influence of the spring 20, the belt presses against the two guide rollers 9 and 12. The length of the belt 18 above the guide rollers is a, the distance between them is b, and the distance below them is c. The total length of a + b + c changes as a result of the movement along the wall under the influence of the winch 10, which length change is taken up by the spring 20.

Figure 2 shows the rear view of the pillar 22, and it can be seen how the blasting device 1 can be moved along the wall by movement of the hoisting bracket 14 along the rail 23 in a direction A.

Figures 3 and 4 show an embodiment in which the blasting device 1 is taken in front of the wall of a pillar 22 by means of a mobile mechanical shovel 24, and where the blasting device is adapted so that it can blast a pillar 22 with round cross-section. For this purpose, guide wheels 25 are fitted in such a way that the blasting device 1 can easily move in the horizontal direction. To this end, a driven guide roller 26 is also fitted. Figure 5 shows another embodiment of the blasting device 1, which device is suspended from the hoisting cable 13 which runs by way of cable pulleys 27 to the winch 10 and can therefore be moved in the vertical direction. In this embodiment the belt 18 is kept tensioned by means of guide rollers 9 and 12, which are fixed, each on a lever

28, to the blasting device 1 in such a way that they swivel about a swivel bearing 29. Owing to the fact that the levers 28 are of considerable length, greater length changes in the belt 18 as a result of the movement of the blasting device 1 along the wall are easily taken up.

Figure 6 shows the rear view of the blasting device 1 of Figure 5, and here it can be seen how the levers 28 are placed under spring tension by the springs 30. Figure 7 shows the front view of the same blasting device 1, and here the shape of the jet nozzle 6 and the position of the guide wheels 2 and 8 can also be seen.

Figures 8 and 9 show a blasting device 1 which is adapted to a horizontal main movement, in which the hoisting bracket 14 can move in the rail 23 by means of a horizontal drive 33. The belt 18 in this case is tensioned in the horizontal direction along a wall 34, guide rollers 31 which rotate about a vertical axis being fixed on the levers 28, and guide wheels 32 also having a vertical axis of rotation.

Figure 10 shows how the device according to Figure 5 can be used to blast a sloping ship's wall 35, in which the slope of the ship's wall 35 at the bow of the ship, as indicated on the right in Figure 10, is steeper than in the centre of the ship, as indicated in the left part of Figure 10. In a dock with a side wall 37 and a dock floor 38 a ship is positioned on supporting blocks 36. The belt 18 and the hoisting cable 13 are fixed at the top side to a mobile fixing point 39 which can move along the length of the ship if necessary. At the bottom side, the belt is fixed to the supporting block at a fixing point 40. If the springs 30 (not shown in Figure 10) are made sufficiently heavy, the blasting device 1 can be pressed with sufficient force against the wall, even where there is a very negative slope of the wall 35.

In addition to the embodiments shown, in which the blasting agents are thrown against the wall by a throwing wheel, it is, of course, also conceivable for the blasting agents to acquire sufficient speed in another way, for example by compressed air. The blasting agents selected, combined with the seal against the wall, in that case also can provide a dust-free seal during blasting of the wall.

Claims

1. Blasting device (1) for blasting more or less vertical walls, comprising drive means (11) by means of which a blasting agent can be thrown at high speed through a jet nozzle (6) against the wall, and hoisting means (10, 13) with which the device can be moved along the wall, guide means (2, 8; 25, 26; 32) with which the jet nozzle can be guided more or less at a constant distance in a sealing manner along the wall, and pressure means for pressing the guide means with a pressure force against the wall, characterized in that the pressure means comprise a belt (18) which is stretched along the wall between two attachment points (14, 19, 20) and one or more guide rollers (9, 12; 31) fixed to the device, the belt exerting a pressure force on the guide rollers.

2. Blasting device according to claim 1, characterized in that the belt and/or the guide rollers are resiliently fixed.

3. Blasting device according to claim 1 or 2, characterized in that the guide roller is fixed on an arm (28) and can be pushed by a spring (30) against the side of the belt facing the wall.

4. Blasting device according to claim 1, 2 or 3, characterized in that a spring (19) is fitted between one end of the belt and an attachment point.

5. Blasting device according to one of the preceding claims, characterized in that an attachment point is fixed against the wall with a clamping strip (21) .

6. Blasting device according to one of the preceding claims, characterized in that a hoisting cable (13) and the top side of the belt are suspended from a hoisting bracket (14) which can be supported against the wall.

7. Blasting device according to claim 6, characterized in that the hoisting bracket can be moved by means of a drive (33) along a rail (23) which can be supported against the wall.

8. Blasting device according to one of claims 6 or 7 , characterized in that the hoisting bracket or the rail is supported against the wall by means of a mobile apparatus (24).

9. Method for blasting a wall with a blasting device according to the invention, in which the blasting device is suspended in front of the wall, and the belt is then guided along the guide rollers and the pressure force is created by tensioning the belt with a belt buckle (20) fixed at working height.

10. Method according to claim 9, characterized in that the length of the belt is adjusted with the belt buckle during the movement along the wall.