GB2161520A

GB2161520A - Excavation apparatus for use in a pipe-driving operation

Info

Publication number: GB2161520A
Application number: GB08512678A
Authority: GB
Inventors: Wolfgang Paetow; Heinz Thiemann
Original assignee: Ed Zueblin AG
Current assignee: Ed Zueblin AG
Priority date: 1984-05-23
Filing date: 1985-05-20
Publication date: 1986-01-15
Also published as: DE3419158C2; GB8512678D0; GB2161520B; DE3419158A1

Abstract

The excavation apparatus is used when driving pipes (2) into the ground and has a pressure-tight bulkhead partition (4), which divides a pressure chamber (5) facing a drift face (3), from a back chamber (6) which is under atmospheric pressure. Both chambers (5, 6) are connected by a conveying device (9), by which the material excavated at the face (3) is conveyed through a lock opening which is able to be closed off by a drum (28) in a pressure-tight manner. Consequently it is no longer necessary for operators to enter the pressure chamber (5) and it is no longer necessary to bring the back chamber (6) to excess pressure. <IMAGE>

Description

SPECIFICATION Excavtion apparatus for use in a pipe driving operation The invention relates to an excavation apparatus, preferably a cutting edge, for use in a pipe driving operation of the type comprising at least one pressure resistant bulkhead partition which separates a pressurised chamber from a back chamber under atmospheric pressure, such bulkhead having an opening for discharge and supply pipes, and a lock door.

In pipe driving operations, individual pipe sections are driven into the earth by means of presses for the purpose of laying underground pipe lines. Located at the front end of this pipe line section in the feed direction is the excavation apparatus, by which the earth is excavated. In the case of suitable soil conditions, for example when the soil contains water, the working region of the cutting edge, namely the pressure chamber, must be placed under excess pressure. When the pipesare driven in hydraulically under compressed air, it is normal to restrict the pressure chamber to the front part of the cutting edge. For this purpose it is provided with the pressure-resistant bulkhead partition, which separates the pressure chamber from the back chamber.

Excavation at the drift face can be observed and controlled through inspection windows.

Supply pipes for water and suction pipes for example may be guided through the openings. The material excavated at the face is mixed with water and this mixture is sucked out of the pressure chamber by the suction pipe. In the rear portion of the pipe, by installing a lock arrangement, a working chamber is formed which is at atmospheric pressure under normal operating conditions.

Due to this it is possible under normal driving operation, to install the working personnel largely under atmospheric air conditions and to considerably reduce the risks when working with compressed air. If obstacles at the drift face occur, for example perched blocks, tree trunks and the like, then the latter cannot be removed by the suction pipe from the pressure chamber. It is then necessary for the operator to enter the pressure chamber and remove the obstacles. Also when repairs to the cutting edge are required, the operator must enter the pressure chamber. This is only possible if the working chamber is previously brought to excess pressure. In the pipe driving process, due to the geological conditions, it may happen very frequently that obstacles of this type occur in the driving region, so that it is frequently necessary to enter the pressure chamber.As long as the operator remains in the pressure chamber, the pipe driving process must be interrupted. These interruptions of the operation lead to a clear restriction of output and represent a considerable expenditure.

It is the object of the invention to construct an excavation apparatus of this type so that such obstacles which arise during the driving operation, can be removed from the pressure chamber without the operator having to enter the pressure chamber.

The invention provides excavation apparatus for use in a pipe-driving operation, with at least one pressure-resistant bulkhead partition, said partition separating a pressure chamber which is under excess pressure and which faces a drift face, from a back chamber which is under atmospheric pressure, said partition comprising at least one opening for discharge and supply pipes and at least one lock door, wherein the pressure chamber is connected to the back chamber by at least one conveying device operable to convey at least part of the material excavated at the drift face to said back chamber through a lock opening which is closable by said lock door in a pressuretight manner.

In the excavation apparatus according to the invention, the pressure chamber is connected to the back chamber by the conveying device. By means of the conveying device obstacles which appear during driving of the pipe section can be conveyed out of the pressure chamber which is under excess pressure, into the back chamber which is under atmospheric pressure. Since the lock opening, through which this material must be conveyed, can be closed off in a pressure-tight manner, this material can be removed through the lock opening without difficulties. As a result of the construction according to the invention, it is no longer necessary for the operator to enter the pressure chamber to remove the obstacles and the working chamber no longer needs to be brought to excess pressure.Due to this, it is possible to work with a high output and at low cost with the excavation apparatus according to the invention.

The invention is described in detail with reference to one embodiment thereof illustrated in the accompanying drawings, in which: Figure 1 shows an excavation apparatus in longitudinal section, Figure 2 shows the excavation apparatus of Figure 1, in plan view and in section, Figure 3 is a section on line Ill-Ill of Figure 1, Figure 4 is a section on line IV-IV of Figure 1.

The excavation apparatus illustrated in the drawings is constructed as a cutting edge known per se, which has a cylindrical shape and whereof the end face 1 has the shape shown in Figures 1 and 2. The cutting edge 1 is attached in manner known per se to a pipe section 2. Connected to this pipe section are further pipe sections which form the pipe line to be laid in the ground. The pipe sections and the cutting edge are driven into the ground by feed presses. Excavation is carried out with the cutting edge in known manner at a drift face 3 at the time of the feed.

The cutting edge is divided by a bulkhead partition 4 into a pressure chamber 5, which lies between the drift face 3 and the bulkhead partition and a back chamber 6. The bulkhead partition 4 located in a radial plane comprises an inspection window 7 and a lock door 8.

Through the inspection window 7 it is possible to observe from the back chamber 6 which is under atmospheric pressure, excavation at the face 3 in the pressure chamber 5.

It is possible to enter the pressure chamber 5, when it is brought to atmospheric pressure, through the lock door 8, for example in order to carry out repair work. The excess air pressure necessary in the pressure chamber 5 is built up in known manner.

Provided in the region below the inspection window 7 and the lock door 8 is a conveying device 9, by which larger parts of the excavated face material, such as perched blocks, tree trunks or the like, can be conveyed from the pressure chamber 5 into the back chamber 6, without it being necessary to enter the pressure chamber. The conveying device 9 has a partly cylindrical bearing part 10 attached to the bulkhead partition 4, which bearing part extends from the bulkhead partition into the back chamber 6 (Figure 1).The bearing part 10 extending at right angles to the longitudinal axis 11 of the cutting edge is closed off at both ends by side plates 1 2 and 1 3 (Figure 2), which are arranged symmetri cally with respect to the longitudinal axis 11 and extend beyond the bulkhead partition 4 slightly into the pressure chamber 5. Inside the pressure chamber 5, the side plates 12, 1 3 are bent at right angles towards each other. These bent edges 14, 1 5 lie on the cylindrical casing of the bearing part 19 as shown in Figure 1. The two edges 14, 1 5 define a rectangular inlet opening 1 6 in the bulkhead partition 4 (Figures 1 to 3).On the side located opposite the inlet opening 16, the bearing part 10 is provided with a socketlike projection 17, which defines an outlet opening 18, which in the embodiment has a rectangular shape (Figure 4). In the region of the outlet opening 18, the side plates 12, 1 3 are provided with thickened edges 1 9 and 20 extending one in the direction of the other, which define the outlet opening in the axial direction of the bearing part 10. The edges 19, 20 comprise a sliding guide 21 for a slide 22, by which the outlet opening 1 8 can be closed. It is preferably constructed as a hydraulically operated flat slide valve, which can be moved into the released position illustrated in Figure 1.

Like the bearing part 10, the side plates 12, 1 3 are connected to the bulkhead partition 4 so that a pressure-tight closure with respect to the back chamber 6 is ensured. In the region below the outlet opening 18, the bearing part 10 continues in a section 23' extending obliquely rearwards into the back chamber 6, which section 23' is connected to the base by way of a closure member 24 lying perpendicular with respect to the base 23 of the cutting edge. provided at the lower edge 25 of the inlet opening 1 6 is a plate 26 penetrating the bulkhead partition 4 and ascending from the end face 1 in the direction of the working chamber 6, on which the material excavated from the face 3 is supplied to the inlet opening 1 6 when the cutting edge is advanced.Located on the bearing part 10 is an inspection window 27, which is closed in a pressure-tight manner.

A drum 28 is mounted to rotate in the bearing part 10 and between the side plates 12, 1 3. In the filling position illustrated in Figure 1, a filling opening 29 in the drum casing is congruent with respect to the inlet opening 16, so that the material is able to enter the drum. It is arranged with a small clearance in the bearing part 10. The gap-like annular space 30 between the drum casing and the inner side of the bearing part 10 is sealed by two seals 31, 32, which extend between the side plates 12, 1 3 and are located in shaped recesses 33 and 34 in the bearing part.

In its drum casing, the drum 28 comprises a grating 35, which extends over the axial length of the drum and in the embodiment is constructed to be flat. In the filling position according to Figure 1, the grating 35 is located in the region above a collecting chamber 36, which is limited with respect to the pressure chamber 5 by the edge 25 and with respect to the back chamber 6 by the inclined member 23' and the closure member 24.

Laterally this collecting chamber 36 is limited by the side plates 1 2 and 1 3 and by the base 23 of the cutting edge. The drum casing is also provided with an inspection window 37, which in the filling position according to Figure 1 is located below the inspection window 27 in the bearing part 10. Due to this the filling operation of the drum 28 can be observed from the back chamber 6. Opening into the collecting chamber 36 is a suction pipe 38, which passes through the inclined member 23' and the closure member 24 in the region below the conveying device 9. The passage way is again closed off in a pressuretight manner. The suction pipe 38 leads to a pump unit 39 located behind the bulkhead partition 4 in the feed direction, with which the material located in the collecting chamber 36 is removed by suction and supplied to the outside from the pipe line by way of a return pipe 40.

A bearing 41 and 42 for the drum 28 is respectively attached to the remote outer sides of the side plates 12, 1 3. It is preferably set in rotation about its axis 43 hydraulically.

Guided through the side plate 1 3 is a water pipe 44, which opens axially into the drum 28. The water pipe 44 is guided outwards through the pipe line to be laid.

During operation, the drum 28 assumes the filling position illustrated in Figure 1, in which the filling opening 29 lies directly behind the inlet opening 16. The slide 22 assumes its closed position, in which it closes off the outlet opening 1 8 in an air-tight manner. An excess pressure is built up in known manner in the pressure chamber 5, whereas atmospheric pressure prevails in the back chamber 6. Since the pressure chamber 5 is connected by way of the inlet opening 16, the filling opening 29 and the grating 35 to the collecting chamber 36, the corresponding excess pressure also prevails in the collecting chamber. The sealing systems 31, 32 between the bearing part 10 and the drum 28 seal the pressure chamber 5 in the region of the conveying device 9 in a pressure-tight manner with respect to the back chamber 6.Also provided in the region of the edges 1 9 and 20 of the side plates 12, 1 3 is a peripheral seal 45, which seals the annular space 30 between the bearing part 10 and the drum 28 even in the region of the side plates. The bearing part 10 forms a substantially cylindrical body preferably consisting of steel, which serves as a rinsing container. During the feed of the cutting edge and the excavation at the face 3, water is sprayed by way of the water pipe 44 into the drum 28. The smaller components of the excavated material are mixed with the water and washed through the grate 35 into the collecting chamber 36, from which this mixture is sucked by the pump 39.

The larger constituents of the excavated material, which cannot drop through the grating 35, such as for example perched blocks, tree trunks and the like, settle on the grating 35 inside the drum 28. Larger constituents 46 of this type are illustrated in Figure 1. During the advance of the cutting edge, the excavated material passes by way of the inclined plate 26 into the drum. When the latter has been iilled with the larger constituents 46, it is rotated out of the filling position through approximately 180 until the filling opening 29 is located in front of the outlet opening 1 8 closed by the slide 22. The seals 31, 32, 45 seal the pressure chamber 5 of the cutting edge with respect to the outlet opening 1 8 in a pressure-tight manner.Before the slide 22 is opened, the annular chamber 30 between the bearing part 10 and the drum 28 in the region between the seals 31, 32 is vented.

Then the slide 22 is opened, so that the constituents located in the drum 28 can be removed. At the time of this removal there is no necessity to vent the pressure chamber 5.

After the removal, the slide 22 is reclosed and the drum 28 is rotated back to its filling position according to Figure 1.

In this excavation apparatus, the excavated material is separated by screening into material which can be flushed away and material which cannot be flushed away. The material which can be flushed away may have a grain size of up to approximately 60 mm, whereas larger grain sizes settle on the grating 1 5. The flushing chamber is formed by the collecting chamber 36 below the drum 28, from which the material which can be flushed away is removed by suction. The coarse-grained material collecting on the grating 35 and which cannot be flushed away is removed through the outlet opening 1 8 under atmospheric conditions. The maximum size of the material which cannot be flushed away depends inter alia on the size of the drum 28.An appropriate upper limit size for the material which cannot be flushed away is to be found at a diameter of 600 mm.

In place of the drum 28 it is also possible to use a travelling grate in the form of a suitable armoured conveyor, which comprises entrainment members arranged with a small spacing one behind the other for the accumulated larger constituents and by which these constituents are supplied to a removal point located behind the bulkhead partition and which can be bounded by bulkheads. This travelling grate is located in the base of the cutting edge. A central plate of the armoured conveyor is constructed so that the conveying material which can be flushed away is able to pass through. The armoured conveyor itself is encapsulated in a pressure-tight manner behind the bulkhead partition, for example by a steel pipe. Solely the accumulated material is removed by the travelling grate, whereas the material which is able to be flushed away is sucked out of the collecting chamber ior example. The removal of the accumulated larger constituents can be carried out during intervals between operation, when for example a new pipe section is added to the pipe line to be driven in.

Claims

1. Excavation apparatus for use in a pipedriving operation, with at least one pressureresistant bulkhead partition, said partition separating a pressure chamber, which is under excess pressure and which faces a drift face, from a back chamber which is under atmospheric pressure, said partition comprising at least one opening for discharge and supply pipes and at least one lock door, wherein the pressure chamber is connected to the back chamber by at least one conveying device operable to convey at least part of the material excavated at the drift face to said back chamber through a lock opening which is closable by said lock door in a pressure-tight manner.

2. Excavation apparatus according to Claim 1, wherein the conveying device comprises at least one conveying part operable to move between a filling and an emptying position.

3. Excavation apparatus according to Claim 2, wherein the conveying apparatus comprises a drum as the conveying part, which is operable to rotate between the filling and emptying positions.

4. Excavation apparatus according to Claim 3, wherein the conveying part is mounted to rotate in a housing-like bearing part.

5. Excavation apparatus according to Claim 4, wherein the bearing part is connected in a pressure-tight manner to the bulkhead partition.

6. Excavation apparatus according to Claim 4 or Claim 5, wherein in the region of the bearing part the bulkhead partition comprises at least one filling opening, which in the filling position of the conveying part aligns with at least one filling opening of the conveying part.

7. Excavation apparatus according to any one of Claims 4 to 6, wherein the lock opening is provided in the bearing part.

8. Excavation apparatus according to any one of Claims 4 to 7, wherein the lock opening can be closed off by a slidable lock door.

9. Excavation apparatus according to any one of Claims 4 to 8, comprising an intermediate chamber disposed between the bearing part and the conveying part and which is sealed in a pressure-tight manner.

10. Excavation apparatus according to any one of Claims 4 to 9, wherein the conveying part comprises a casing, through which finegranular material may pass, extending over at least a part of its periphery.

11. Excavation apparatus according to Claim 10, wherein part of the casing of the conveying part is formed by a grating.

1 2. Excavation apparatus according to Claim 10 or Claim 11, wherein located in the region below the conveying device is at least one collecting chamber for the fine-granular material, which is closed off in a pressuretight manner with respect to the back chamber.

1 3. Excavation apparatus according to Claim 12, wherein at least one removal pipe opens into the collecting chamber.

14. Excavation apparatus according to Claim 13, wherein said removal pipe is a suction pipe.

15. Excavation apparatus according to any one of Claims 4 to 14, wherein at least one water pipe opens into the conveying part.

1 6. Excavation apparatus according to any one of Claims 4 to 15, wherein the conveying device is located substantially completely in the back chamber.

1 7. Excavation apparatus according to Claim 1 or Claim 2, wherein the conveying device comprises a travelling grate located in the pressure chamber which is operable to supply the excavated material to a removal point located behind the bulkhead partition and which is bounded by bulkhead partitions.

18. Excavation apparatus according to any one of Claims 4 to 16, wherein the bearing part and the conveying part each comprise at least one inspection window.

19. Excavation apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.