DK2952640T3

DK2952640T3 - DEVICE FOR ACTIVATING OR CLEANING BELLS

Info

Publication number: DK2952640T3
Application number: DK15001621.0T
Authority: DK
Inventors: Hermann-Josef Suelmann
Original assignee: Teftorec Gmbh
Priority date: 2014-06-02
Filing date: 2015-05-29
Publication date: 2019-01-07
Also published as: EP2952640B1; EP2952640A1; DE102014007812A1

Description

The invention relates to a device for activating or cleaning wells according to the preamble to Claim 1. In the production of filter rods in the ground for groundwater abstraction, it is necessary after completion of the well construction to remove filter gravel introduced into an annular space between the filter chamber and the edge of the borehole and contamination from the edge of the borehole and grains of sand of small diameter that are extractable by suffosion. The extraction of suchlike contamination or particles is referred to as activation. The aim of the activation of a well is to produce the largest possible pore space in the annular space of the filter and the ground adjacent thereto, in order to ensure that the flow resistance for the groundwater entering into the well is as small as possible, and that the groundwater-lowering of the pressure head resulting therefrom at and in the well remains as low as possible. Upon activation, it should also be possible for silt, fine sand and other small mineral or organic particles, which can be transported together with the flowing groundwater at a correspondingly high speed through the pores of the supporting grain skeletons from the adjoining layers of soil, to be introduced into the well and thus pumped away.

The regeneration of wells comprises all measures, which serve for the removal of mineral and/or organic deposits arising during a well operating time from the annular space of the well and the adjacent rock. The methods used for this purpose adhere to the principle of the separation or removal of deposits and adhesions from the filter material and the supporting grain skeleton of the adjacent rock and the extraction of these particles through the well filter. Various methods and devices for separation and removal are known, which avail themselves of hydromechanical, hydropneumatic and chemical operating principles .

For the extraction of deposited and/or loosened particles from the annular space of a well and the rock adjacent thereto, it is necessary to produce the highest possible flow velocities in the area to be cleaned. Known methods and devices used for that purpose reduce the well filter to be maintained to a single work step, by the introduction into the filter tube of a working chamber provided at its ends with seals. A suchlike working chamber is described in the prior art in German utility model 81 20 151, in which a so-called working chamber is formed between two shut-off bodies arranged at a distance from one another and one on top of the other and an inner wall of the filter tube. A delivery flow about 5 to 10 times higher than is the case in normal well operation through this part-section of the well filter is pumped through this working chamber, of which the height or length is comparatively short in relation to the overall length of the filter tube. Because of the so-called permeability contrast, according to which the water permeability in the gravel pack in the annular space of the filter is greater than that of the adjacent rock, the increased delivery flow has only a marginal influence on the flow velocity in the annular space and in the rock adjacent thereto. A further consideration is that the annular space at all times receives a flow radially from the adjoining rock over the entire length of the filter tube. The groundwater enters into the filter tube above and below the working chamber and flows in the annular space and in particular inside the filter tube in the direction of the working chamber, wherein the groundwater flowing into the filter tube flows around the shut-off bodies laterally in order to enter into the working chamber. As a result, the flow proportion of the well water in the annular space laterally or radially adjacent to the working chamber is decreased and its flow velocity is reduced, which has an adverse influence on the quality of cleaning.

Known removal chambers for intensive desanding are described in DVGW (Deutsche Vereinigang des Gas- und Wasserfaches e„V., German Technical and Scientific Association for Gas and Water) Technical Bulletin W 119. With regard to these removal chambers, an adequate radial incoming flow is received into the chamber opening. For the geometrical delimitation of the chamber opening in the filter tube, sealing bodies at its ends are required, which are formed either as sealing washers or as (inflatable) annular hoses of variable volume. As a result, no importance is attached to a longitudinal extent of these sealing bodies or their length in relation to the length of the open chamber. Instead, with regard to these sealing bodies, only their sealing effect inside the filter tube for the delimitation of the working chambers or removal chambers are rated as important.

Conventional devices for cleaning wells, for example according to DE 81 20 151, are subject to the disadvantage that, including at a significantly increased flow rate, the cleaning performance in the annular space and in particular in the rock adjacent thereto is not optimal. Further known devices, for example according to DE 40 17 013 C2 or also DE 38 44 499 Cl, are used for cleaning a gravel backfill and the adjacent rock in the radial surroundings of a drilled well, wherein, by the use of pumps and clearly distinct chambers, a circulation flow between a number of chambers is produced. The purpose of this is to bring about flushing of the pore chamber in the filter gravel and in the adjacent rock externally between the distinct chambers in the well filter tube, in order, by so doing, to remove any contamination and deposits adhering to the gravel granules. This can be accompanied, if required, by the addition of chemical cleaning means.

In all the removal chambers of known devices, a problem arises from the fact that the chamber delivery rate is not automatically divided at all times into two equally large proportions Qo and Qu as well as a smaller radially inflowing proportion Qr, regardless of the type of sealing bodies by which they are delimited. The division of the chamber delivery rate of the radially inflowing proportion Qr exclusively into two equally large proportions Qo = Qu occurs approximately autonomously only when the removal chamber is present precisely in the centre of a well filter, and, in addition, when the filter is also present in the centre of a hydraulically coherently acting aquifer stratum having approximately uniform permeability. A suchlike situation is represented in Fig. 1. It should be noted, however, that this situation essentially arises rarely or not at all. Basically, it must be assumed that natural aguifers, as a conseguence of their geological genesis, being stratified and accordingly in layers, are characterized at all times by different permeabilities. The length of well filters is usually selected depending on whether this is technically necessary for the extraction of the desired guantity of water. These filter lengths are then arranged appropriately in the area of the most permeable layers of the well. Only a part of an aguifer, through which the groundwater flows in a hydraulically coherent manner, is conseguently developed as a well filter, wherein a residual part of the aguifer remains undeveloped. In the extraction of groundwater through a suchlike well filter, also referred to as an "incompletely developed" well filter, the incoming flow arrives at differing intensity over its longitudinal extent. If a removal chamber is present in the centre of this filter, which chamber separates the water flow arriving in the upper section of the well filter from the water flow arriving in the lower section, wherein these partial flows are reunited only after the flow has passed around the boundaries of the chamber, it is self-evident that, because of the asymmetry of the flow spaces and also of the different permeabilities in the rock, these partial flows Qo and Qu differ from one another at all times. This situation is represented in Fig. 2. This difference between the partial flows Qo and Qu can adopt extreme values in the sense that one of the two partial flows in each case adopts a situation-specific maximum value and the value of the other partial flow approaches zero. A device for cleaning a filter tube well, which has a total of four volume bodies in the form of inflatable packers, is known from US 3945436. This device is interspersed for its entire length by a central tube, which is connected above ground to a high-pressure source for the purpose of supplying it with a cleaning fluid. The central tube - when viewed from above - is provided in each case with outlet openings, on the one hand between the first and second packers, and on the other hand between the third and fourth packers. Once the device has been introduced into the filter tube of a filter tube well and the packers have been inflated appropriately, the cleaning fluid is discharged during operation of the device from the aforementioned outlet openings of the central tube under high pressure radially outwards into the rock which surrounds the filter tube wells. A removal chamber is formed between the second and third packers of the device and the inner wall of the filter tube, into which chamber the cleaning fluid previously discharged under high pressure then flows once more. The cleaning fluid is then discharged vertically upwards from an upper outer front of the device through an annular gap, which is formed between said central tube and an external tube as a consequence of the pressure of the subsequent flow of cleaning fluid. A generic device for activating or cleaning filter tube wells, in which a removal chamber is formed between a first and a second volume body, from which chamber water from the filter tube wells can be discharged by means of a pumping device, is known from DE 10 2009 018 383 B4. This device is provided with a balance tube, which completely intersperses the removal chamber in the longitudinal direction of the device, wherein this balance tube produces a hydraulic connection between the areas which in each case adjoin the external outer fronts of the two solid bodies opposite the removal chamber. The hydraulic connection through the balance tube in the case of an uneven incoming flow to the device causes an automatic pressure or volumetric flow balance between the areas of the filter tube above and below the device. The device according to DE 10 2009 018 383 B4 has the disadvantage that a possible volumetric flow rate through the balance tube is limited, and the provision of a number of suchlike balance tubes is complicated and expensive in terms of their design.

Accordingly, the invention has as its object to make available a device for activating or cleaning wells, in which, by simple mechanical means, an automatic control of volumetric flows above and below a removal chamber is set with an improved volumetric flow.

This object is accomplished by a device having the characterizing features of Claim 1. Advantageous further developments of the invention are defined in the dependent claims .

An inventive device is used for activating or cleaning filter tube wells with a filter tube and comprises a first and a second volume body, which with their outer diameter can be adapted substantially to the inner diameter of the filter tube and on their outer peripheral surface in each case comprise sealing means, by means of which a sealing effect between the volume bodies and the inner wall of the filter tube can be adjusted. The device further comprises a removal chamber, which can be formed between the first and second volume body and the inner wall of the filter tube, when the device is introduced into the filter tube, wherein this removal chamber can be connected hydraulically to a pumping device. A hydraulic connection between the areas, which in each case adjoin the external outer fronts of the two volume bodies opposite the removal chamber, is provided for the device. An external tube and an internal tube arranged inside the external tube are provided, wherein the hydraulic connection extends at least through an annular space, which at least completely intersperses the removal chamber in the direction of a longitudinal axis of the device and is formed between the external tube and the internal tube, wherein the external tube and the internal tube are likewise part of the inventive device. The two volume bodies are each formed as a sleeve and are attached to an outer peripheral surface of the external tube.

The present invention is based on the significant finding that a hydraulic connection for the purpose of assuring a volumetric flow balance between the areas of the filter tube above and below the device, i.e. between the areas, which in each case adjoin the external outer fronts of the two volume bodies opposite the removal chamber, is formed by an annular space, which at least completely intersperses the removal chamber in the direction of the longitudinal axis of the device. A suchlike annular space exhibits, in comparison with a known balance tube according to the prior art, an increased cross-sectional area transversely to the longitudinal axis of the device, and as such permits a larger volumetric flow for an improved flow egualization. The embodiment of a suchlike annular space between the internal tube and the external tube is mechanically highly robust, furthermore, and can be implemented by simple and cost-effective means.

In an advantageous further development of the invention, the external tube can extend substantially along the entire longitudinal axis of the device. As a result, the external tube forms a structural or load-bearing component for the inventive device, to which further components can be attached, for example the internal tube and the two volume bodies.

In an advantageous further development of the invention, both the external tube and also the internal tube can each extend along the entire longitudinal axis of the device. For this purpose, the external tube and the internal tube are selected effectively with the same length. Concentric positioning of the internal tube inside the external tube is assured in this case by radial web elements or the like. A suchlike embodiment of the device has the advantage that, on the one hand, the internal tube is guided as far as the lower outer front of the external tube, so that further devices or eguipment for maintaining the filter tube well, for example an impulse generator or the like, can be attached to the lower outer front of the internal tube. Furthermore, supply lines for the impulse generator, for example, can be passed intentionally through the annular space.

In an advantageous further development of the invention, the device has a conveying pipe, which opens out into the removal chamber and can be connected hydraulically to a pumping device. A negative pressure can be produced in the conveying pipe by operating the pumping device, as a conseguence of which water is discharged from the filter tube well through the removal chamber. In this context, reference may be made to the fact that the pumping device is an optional component of the inventive device. If necessary, the pumping device can also be installed above ground, i.e. outside the filter tube well, which reduces the weight of the device and facilitates its operation inside the filter tube. In this case, a hydraulic connection is assured between the conveying pipe and the pumping device by suitable tube connections, lines or the like. These tube connections also ensure a length compensation when the device is moved or displaced in the longitudinal direction of the filter tube.

In an advantageous further development of the invention, the conveying pipe is constituted by the internal tube. In other words, the internal tube fulfils a dual function in this case. The internal tube is of hollow configuration, so that well water can be discharged through the internal tube, wherein the internal tube serves as a conveying pipe. At the same time, the internal tube with its outer peripheral surface forms an internal part inside the external tube, for the configuration of the annular space described above. In this embodiment of the invention, recesses, respectively at least one recess, are formed in the walls both of the internal tube and also of the external tube each adjacent to each other in the area of the removal chamber. A connecting channel leads radially outwards from the recess of the internal tube through the annular space to the recess of the external tube, whereby the conveying pipe - in the form of the internal tube - is hydraulically connected to the removal chamber and is hydraulically separated from the annular space at the same time. Because of this, it is possible for well water to make its way radially from the outside through the removal chamber and through the connecting channel into the conveying pipe in the form of the internal tube, and, hydraulically separated therefrom at the same time, for a volumetric flow to take place inside the annular space between the internal tube and the external tube in the direction of the longitudinal axis of the device.

Expediently, more than only a single recess, namely at least two recesses, preferably three, and more preferably also four recesses, are formed in the wall of the internal tube. In accordance with this, the conveying pipe in the form of the internal tube is then connected hydraulically to the removal chamber by two connecting channels, and, where appropriate, three or preferably also four connecting channels, wherein, as described, these connecting channels intersperse the annular space, in each case radially, and the recesses of the internal tube and the external tube that are adjacent to each other connect with each other. A preferred embodiment of the invention proposes four connecting channels in this context, wherein corresponding recesses for this purpose are formed in the walls of the internal tube and of the external tube, respectively every 90°, along the periphery.

Because the two volume bodies are formed as a sleeve, they can be slid onto an outer peripheral surface of the external tube. As a result, a height of the removal chamber or a distance of the two volume bodies relative to one another can be set in the direction of the longitudinal axis of the device, when at least one of the two volume bodies can be displaced relative to the external tube in the direction of the longitudinal axis of the device. After a suchlike displacement of this volume body for the purpose of setting a desired height of the removal chamber, this volume body can be secured or clamped once more to the external tube by appropriate fixing means, for example by a screwed connection or the like.

The embodiment of the invention referred to above, in which the two volume bodies are attached to the outer peripheral surface of the external tube, has the advantage of a robust and simple construction, which can also be implemented inexpensively. As a result, the external tube serves as a structural component for the device, to which the two volume bodies are attached as described.

In an advantageous further development of the invention, the sealing means on the outer peripheral surfaces of the volume bodies can comprise a flexible layer of a foam material. As a result, the foam material can be formed from an open-cell foam material or from a foam rubber. A suchlike nature of the sealing means, in interaction with the structure of the wrapped wire filter or of the filter tube of the filter tube well, leads to an intensive sealing effect, because the foam material is able to nestle into the spaces between the wrapped wires.

In an advantageous further development of the invention, the sealing means can have a variable volume. This means that the sealing means can be increased in respect of its volume by supplying a fluid, for example compressed air or water, and can be expended radially outwards in the process. This is appropriate for a stationary operation of the device inside the filter tube well, i.e. at an invariable and predetermined position inside the filter tube, because the desired sealing effect between the volume bodies and the filter tube is optimized by the radial expansion of the sealing means. By implication, this means that the extent of the sealing means in the radial direction is reduced by the discharge of fluid from the variable volume of the sealing means, whereby a subseguent actuation of the device in the longitudinal direction of the well is more easily possible.

An even further optimized sealing effect can be achieved both in that the sealing means comprise a variable volume, and in that a flexible layer of foam material is attached to its outer surface. This leads to overlapping of the above-mentioned advantage in respect of, on the one hand, the flexible layer of foam material and, on the other hand, a targeted expansion or reduction of the sealing means in the radial direction. An additional advantage for this combination is that an outer peripheral surface of the variable volume of the sealing means produced by the application of the flexible layer of foam material is less sensitive to damage if it comes into contact with the filter tube in conjunction with the supply of a fluid into the variable volume.

In an advantageous further development of the invention, the internal tube in the area of the upper first volume body can project beyond the external tube and can be eguipped at its outer front with first connecting means, which permit the connection of further pipelines or the like. This is of advantage in particular when, as described, the internal tube at the same time performs the function of a conveying pipe, through which well water is discharged during operation of the pumping device. In this case, tube connections, lines or the like, which are introduced from above ground or from the outside into the filter tube of the well, can be appropriately connected to the conveying pipe in the form of the internal tube.

It will be appreciated that the characterizing features already referred to above and still to be explained below are applicable not only in the respectively specified combination, but also in other combinations or in isolation, without departing from the scope of the present invention.

The invention is represented below schematically in the drawing on the basis of preferred embodiments, and is described in detail with reference to the drawing.

In the drawing:

Fig. 1 depicts flow characteristics for a conventional cleaning device under idealized conditions of a filter tube well,

Fig. 2 depicts the cleaning device in Fig. 1 under actual conditions of a filter tube well, when uneven flow characteristics are present,

Fig. 3.1 depicts a lateral exploded view of an inventive device,

Fig. 3.2 depicts a lateral exploded view of an inventive device according to a further embodiment,

Fig. 4 depicts a perspective view of an external tube of the device in Fig. 3.1 or Fig. 3.2,

Fig. 5 depicts a cross-sectional view along line A-A in

Fig. 5,

Fig. 6, Fig. 7 depicts side views of the device according to Fig. 3.1 or Fig. 3.2, in each case in a partially assembled state,

Fig. 8.1 depicts a cross-sectional view along line B-B in

Fig. 6 or Fig. 7,

Fig. 8.2 depicts a cross-sectional view along line C-C in

Fig. 6 or Fig. 7,

Fig. 9 depicts a side view of a device according to Fig. 3 or Fig. 4 in an assembled state,

Fig. 10 depicts a side view of the device in Fig. 9, with a reduced distance between the two volume bodies,

Fig. 11 depicts a cross-sectional view along line D-D in

Fig. 10,

Fig. 12 depicts a lateral sectional view of the inventive device in Fig. 3, when this is introduced into a filter tube well,

Fig. 13 depicts a further lateral sectional view of the inventive device in Fig. 12, with a modified sectional line,

Fig. 14 depicts a lateral sectional view of an inventive device, wherein flow proportions in a filter tube well are represented in an idealised manner, and

Fig. 15 depicts a lateral sectional view of an inventive device in a filter tube well, wherein practically relevant flow proportions are represented in the filter tube well. A basic design of preferred embodiments of an inventive device 1, which serves for activating or cleaning filter tube wells with a filter tube, is described in Fig. 3 to Fig. 8.

Fig. 3 depicts the device 1 according to a first embodiment with its essential component parts. The device 1 comprises a first volume body 12 and a second volume body 14, which are each of sleeve-shaped design. Annular discs 15 or the like are provided in each case on the external outer fronts of these volume bodies 12, 14, which have a somewhat larger diameter compared with the volume bodies themselves. The device 1 further comprises sealing means 16, which can be mounted on the respective volume bodies 12, 14. For a suchlike mounting of the sealing means 16 on the volume bodies 12, 14, the annular discs 15 ensure an exact positioning of the sealing means 16 in relation to a longitudinal axis of the volume bodies 12, 14, and, in so doing, prevent slipping of the sealing means 16 in the direction of this longitudinal axis. The design and the functionality of the sealing means 16 are additionally described below in detail.

The device 1 further comprises an external tube 26 and an internal tube 27. The diameter of the external tube 26 is selected so as to be larger than the diameter of the internal tube 27, for example twice as large. In any case, the difference between the diameters of these two tubes is dimensioned in such a way that the internal tube 27 can be accommodated inside the external tube 26 and, in the process, intersperses the external tube 26 in the direction of a longitudinal axis L of the device 1.

The representation in Fig. 3 makes clear that the internal tube 27 is of longer execution than the external tube 26. The axial length of the two volume bodies 12, 14 is smaller in each case than the length of the external tube 26, and amounts to one third thereof, for example. In this context, reference is made to the fact that the representations of the device 1 in the drawing are not true to scale, and that all the aforementioned length specifications or length ratios are intended to be understood only by way of example.

At least one recess 32a is formed in a central area of the external tube 26 in its wall Wa, through which a connection between an inner side and an outer side of the external tube 26 is present. Four suchlike recesses 32a are formed appropriately along the periphery of the wall Wa of the external tube 26. This is illustrated in the perspective view of the external tube 26 in Fig. 4, in connection with the cross-sectional view along the line A-A in Fig. 4, which is depicted in Fig. 5. Passages on all sides in the form of these four recesses 32a are defined uniformly for the external tube 26 along its periphery.

In the same way as for the external tube 26, the internal tube 27 is also provided with at least one recess 32i in its wall Wi. Expediently, and analogously to the external tube 26, a total of four suchlike recesses 32i are also provided for the internal tube 27, which passages are formed uniformly distributed over the periphery of the internal tube 27 and, in this respect, define passages between an inner side and an outer side of the internal tube 27 in all directions. A suchlike distribution of these recesses 32i in the internal tube 27 arises in the same way as for the external tube 26 in Fig. 4 and Fig. 5, so that reference may be made thereto in order to avoid repetitions.

With regard to the embodiment according to Fig. 3.1, it should be noted that the internal tube 27 is hollow in form, and that it exhibits a floor element 28 in a section below the recesses 32i. By means of this floor element 28, it is possible to ensure that the area of the internal tube 27 adjacent to the recesses 32i is hydraulically separated from the area of the internal tube 27, which is attached below these recesses 32i in the direction of the lower outer front 27u of the internal tube 27.

The internal tube 27 is of open configuration on its upper outer front 27o, and at that point possesses first connecting means 36 (Fig. 6) for the connection thereto of further tube connections, lines, hoses or the like. As already explained above, the internal tube 27 is of hollow configuration, wherein this cavity extends all the way to the aforementioned floor element 28. In this way, the internal tube 27 forms a conveying pipe 30, of which the functionality is additionally described below in detail.

Fig. 3.2 depicts a further embodiment of the inventive device 1. Insofar as their characterizing features and components correspond to those of the embodiment in Fig. 3.1, the same reference designations are used here and they are not described one more time. The embodiment according to Fig. 3.2 comprises an internal tube 27.2, which is of shorter axial embodiment in comparison with the internal tube 27 in Fig. 3.1. This means that the lower outer front 27u of the internal tube 27.2 is attached directly below the recesses 32i.

Figs. 6 to 8 illustrate a partial assembly of the device 1 according to Fig. 3.1 or Fig. 3.2.

Fig. 6 depicts a side view of the device 1 according to Fig. 3.1 in a partially assembled state. As a result, the first volume body 12 and the second volume body 14 are slid onto an outer peripheral surface of the external tube 26, and they are secured appropriately there. The external tube 26 is of open configuration on each of its two external outer fronts 26o, 26u. The internal tube 27 is introduced inside the external tube 26, and it thus intersperses the external tube 26 substantially along the entire longitudinal axis L of the device 1. As a result, the internal tube 27 is received in such a way inside the external tube 26 that an annular space 25 is formed between an outer peripheral surface of the internal tube 27 and an inner peripheral surface of the external tube 26. This annular space 25 is depicted in Fig. 8.1, which represents a cross-sectional view along the line B-B in Fig. 6. Concentric centring of the internal tube 27 inside the external tube 26 is assured by suitable radial webs or the like (not depicted) . The functionality of this annular space 25 is additionally described below in detail.

Fig. 7 depicts a side view of the device 1 according to Fig. 3.2, in a partially assembled state. The sole difference compared with the embodiment or the representation in Fig. 6 is that the internal tube 27, as described in Fig. 3.2, is shorter in form in the axial direction. Its lower floor element 28 is accordingly situated adjacent to an upper outer front of the second volume body 14. As a result, the external tube 26 is of hollow configuration along the second volume body 14 and, as such, also forms a part of the hydraulic connection between the two external outer fronts 22, 24 of the device.

Figures 8.1 and 8.2 illustrate the embodiment of the external tube 26 and the internal tube 27 with their recesses 32a, 32i. In particular, the external tube 26 and the internal tube 27 in Fig. 8.1 are depicted in a cross-sectional view along the line B-B in Fig. 6 or Fig. 7, and in Fig. 8.2 in a cross-sectional view along the line C-C in Fig. 6 or Fig. 7. The internal tube 27 is arranged concentrically inside the external tube 26, so that an annular space 25 is formed (Fig. 8.1) between these two tubes. In the central area of the external tube 26 and the internal tube 27, their recesses 32a, 32i are connected to one another in each case by connecting channels 34 (Fig. 8.2). These connecting channels 34 ensure that an external area of the external tube 26 that is separated from the annular space 25 is hydraulically connected to an internal area of the internal tube 27. In this way, water is able to flow in from outside through the recesses 32a, 32i and through the connecting channels 34 into the internal tube 27, but without making its way into the annular space 25 in the process. As a result, water is able to flow through the annular space 25 in the longitudinal direction of the internal or external tubes and thus in the direction of the longitudinal axis L of the device, but without becoming mixed with the water which makes its way radially from the outside through the recesses 32 and the connecting channels 34 into the internal tube 27 or into the conveying pipe 30 in the process.

The connecting channels 34 are provided with a ridge 35 (Fig. 8.2) adjacent to the first volume body 12 or adjacent to the second volume body 14, which stems from the fact that the recesses at their axial ends - as can be appreciated in the side view according to Fig. 6 or Fig. 7 - each comprise the form of an outwardly oriented triangle. The function and the purpose of this ridge 35 are additionally described below in detail.

Further details in respect of the positioning of the volume bodies 12, 14 on the external tube 26 and in respect of the embodiment of the sealing means 16 are described In Figs. 9 to 11.

Fig. 9 depicts a side view of the device 1 in an assembled state. As a result, the two volume bodies 12, 14 are attached to the external tube 26 in such a way that a distance hi is set between the opposite outer fronts of these volume bodies 12, 14. Because of this, the recess 32a is substantially fully released.

Fig. 10 depicts the device 1 in Fig. 9 in a modified operating position, when the upper first volume body 12 is displaced along the external tube 26 in the direction of the lower second volume body 14, so that a distance km between the opposite outer fronts of these two volume bodies is reduced. Because of this, the recess 32a is partially covered by the first volume body 12. A distance h between the two volume bodies 12, 14 can be changed in a desired manner by a displacement of the first volume body 12 along the external tube 26, as illustrated in Fig. 9 and Fig. 10. The attachment of the first volume body 12 to the external tube 26 after a suchlike displacement can be implemented by appropriate (and not depicted here) clamping means, for example by a screwed connection.

The sealing means 16, which are provided on an external periphery of the first and second volume body 12, 14, comprise a flexible layer 16.1 in the form of a foam material, which is applied to an outer peripheral surface of a variable volume 16.2. This is illustrated in Fig. 11, which depicts a cross-sectional view along the line D-D in Fig. 10. The variable volume 16.2 can be changed in respect of its volume by the supply or discharge a fluid, for example compressed air or water. In the simplest case, the variable volume 16.2 can be configured as a rubber body or the like. The variable volume 16.2 of the upper first volume body 12 is connected to a supply line 38 for the supply or discharge of a fluid. The variable volume 16.2 of the lower second volume body 14 is fed with the fluid via an additional line 39, which branches off from the variable volume 16.2 of the upper first volume body 12. In this way it is possible to expand the variable volume 16.2 of two volume bodies 12, 14 radially outwards by supplying a fluid, for example compressed air or water, through the supply line 38. The flexible layer 16.1 in this case is of sufficiently elastic configuration for it to adapt to a suchlike deformation of the variable volume 16.2.

Fig. 12 depicts a simplified representation of the device 1, when it is introduced into a filter tube well having a filter tube 10. The filter tube 10 of the filter tube well can consist of stainless steel and, as a rule, exhibits wrapped wires, which form a wall of this filter tube 10. Well water is able to flow in radially from the outside into the filter tube 10 through the spaces between these wrapped wires.

The internal tube 27 is centred inside the external tube 26 via a plurality of radial support webs 29 (Fig. 12) and is secured thereby inside the external tube 26. A removal chamber 18 is formed between an inner wall of the filter tube 10 and the first and second volume body 12, 14. A height h of the removal chamber 18, in the direction of the longitudinal axis L of the device 1, is defined by the distance of the two volume bodies 12, 14 relative to one another. The recesses 32 in the external tube 26 and the internal tube 27 are adjacent to the removal chamber 18, with the result that well water is able to flow into the internal tube 27 radially from the outside in the area of the removal chamber 18. As already explained, the internal tube 27 in this case serves as a conveying pipe 30, which is connected to a pumping device 20 by a connecting line 21, which is connected via the first connecting means 36 to the upper outer front 27o of the internal tube 27.

The section through the device 1 according to Fig. 12 is selected so that the recesses 32 in the wall of the external tube 26 and of the internal tube 27 are depicted in the central area of the device 1. In particular, these recesses 32a, 32i are symbolized in a simplified manner by broken lines in Fig. 12. In contrast, the device 1 in the representation in Fig. 13 is depicted in another sectional plane, which in the central area of the device 1 once again makes clear the annular space 25, which is formed between the external tube 26 and the internal tube 27 and completely intersperses the removal chamber 18 in the direction of the longitudinal axis L of the device. A flow of water in the longitudinal direction of the device 1 is possible through the annular space 25, namely between the two external outer fronts 22, 24 of the external tube 26.

Second connecting means 37 can be provided on the lower outer front 27u of the internal tube 27 (Fig. 6) or on an external outer front 26u of the external tube 26 (Fig. 7), to which further devices for the maintenance of the well can be attached, for example an impulse generator. In the case of a suchlike attachment of an impulse generator or the like to an under side of the device 1, the annular space 25 is of advantage, because a supply line can then be passed through the annular space 25 to the impulse generator, but without this influencing the radial flow of the water from the well through the removal chamber 18 and into the internal tube 27.

The passage of suchlike supply lines through the annular space 25 ensures that an outer front or a front end of suchlike supply lines slides on the ridge 35 in relation to the connecting channels 34 which radially intersperse the annular space 25 with their ridge. Getting caught or becoming stuck on the connecting channels 34 is prevented as a result of this. The use of the device 1 inside a filter tube well or its filter tube 10 and the flow characteristics resulting therefrom are described in detail below with reference to Fig. 14. For the sake of simplicity, the device 1 is represented in Fig. 14 only in a half-section along its longitudinal axis L.

In the representation in Fig. 14, the device 1 is introduced completely into a filter tube well or its filter tube 10. The filter tube 16 is surrounded by an annular space 40, which is filled with a gravel pack. The annular space area 40 is enclosed in turn by adjacent rock 42. The device 1 receives a water volume Zu as an incoming flow from the rock 42 above the first volume body 12. The same is true of an area below the second volume body 14, which receives a water volume Zo as an incoming flow from the rock 42. An egualizing flow Qar is produced inside the device 1 along its longitudinal axis L through the annular space 25 formed between the external tube 26 and the internal tube 27. A suchlike egualizing flow Qar intersperses the annular space 25 and - in the case of the embodiment according to Fig. 3.2 - also the lower area of the external tube 26 adjacent to the second volume body 14 and, in so doing, produces a hydraulic connection between the areas which adjoin the external open outer fronts of the volume bodies 12, 14. A flow takes place around the device 1, starting from the outer front areas 22, 24 of the external tube 26 along their longitudinal axis L in the direction of the removal chamber 30, wherein this circulation intersperses the filter gravel layer inside the annular spaces 40 and is designated in Fig. 14 by Qo or Qu. The circulation Qo and Qu along the volume bodies 12, 14 occurs because the flexible layer 16.1 on the outer peripheral surfaces of the volume bodies 12, 14 results in a sealing effect compared with an inner wall of the filter tube 10.

The hydraulic connection by means of the annular spaces 25 described above results in the flow proportions Qo (in relation to the circulation of the upper first volume body 12) and Qu (in relation to the circulation of the lower second volume body 14) adopting more or less identical values. This is the case in particular when different flow resistances are present in the aguifer in the area of the rock 42 above and below the removal chamber 30 because of an irregular rock composition, so that the water volumetric flows Zo and Zu are of different sizes.

The circulations Qo and Qu make their way into the removal chamber 18 after flowing past the two volume bodies 12, 14. In addition, a direct radial inflow Qr from the rock 42 makes its way through the annular space 40 into the removal chamber 18. A negative pressure is produced in the conveying pipe 30 by the pumping device 20 (Fig. 12, Fig. 13). As a result of this, an extraction flow Qk (Fig. 14) is extracted from the removal chamber 18 and is carried above the ground.

The annular space 25 between the external tube 26 and the internal tube 27 initiates an automatic suction flow control, according to which any water volumetric flows Zo and Zu of different sizes, which flow into the device 1 above or below the two volume bodies 12, 14, are divided into circulations Qo and Qu of identical size, which enter through the annular space 40 into the removal chamber 18 externally along the two volume bodies. This ensures an almost identical intensive cleaning effect in the area of the two volume bodies 12, 14. The guantity of water, which is available in its entirety in the filter tube 10, is thus divided approximately identically between the two partial flows in the form of the circulations Qo and Qu in every operating situation and in particular without additional measures .

The annular space 25 and the hydraulic connection associated therewith between the external outer fronts of the two volume bodies 12, 14 results in the further advantage that the device 1 can be introduced with a smaller resistance into the filter tube 10 of the filter tube well. As a result of the hydraulic connection, no piston function of the lower second volume body 14 actually occurs inside the filter tube 10, so that less water or no water at all in conjunction with displacement of the device 1 is displaced inside the filter tube 16. The same is true with respect to the upper first volume body 12 in the case of axial displacement of the device 1 upwards inside the filter tube 10, when the device 1 has already been introduced completely into the filter tube well. A movement of the device 1 inside the filter tube 10 thus takes place, not against a water resistance, but in particular only against a frictional resistance which results from the contact of the flexible layer 16.1 with the inner wall of the filter tube 10.

With regard to the representation in Fig. 14, it should be appreciated that the depicted water volumetric flows Zo and Zu are represented as being substantially identical in size only for the purpose of simplification. In practice, these water volumetric flows Zo and Zu generally adopt different values because of different resistances inside the aguifers in the form of the rock 42, so that, as described above, a pressure or flow egualization takes place through the annular space 25. With reference to Fig. 15, a description is given below of the how a pressure or flow egualization through the annular space 25 takes place in the presence of differently-sized water volumetric flows Zo and Zu.

The device 1 is depicted in Fig. 15 in a lateral cross-sectional view along its longitudinal axis, similar to the representation in Fig. 14 or Figures 12 and 13. Fig. 15 makes clear a pressure or flow egualization through the annular space 25 for the case in which, because of different resistances inside the aguifer in the form of the rock 42, for example, the water volumetric flow Zo above the upper volume body 12 is greater than the water volumetric flow Zu below the second volume body 14. A pressure or flow egualization accordingly takes place through the annular space 25 downwards, as is accordingly indicated in Fig. 15 by arrows. It can be appreciated from the example of the water volumetric flow Zo that, starting from the rock 42, this enters radially through the filter gravel annular space 40 into the filter tube 10, before then flowing vertically downwards in the filter tube 10 to the upper outer front of the volume body 12. A part of this water volumetric flow Zu now enters into the annular space 25 between the external tube 26 and the internal tube 27, in order, after flowing through the annular space 25, to re-emerge at the lower outer front 26u of the external tube 26. After only a short distance, this flow proportion then makes its way radially outwards through the filter tube 10 into the annular space 40, where it rushes upwards once more in the direction of the removal chamber 18, before cleaning with the other flow proportions (Qr, Qo, Qu) takes place in the removal chamber 18. Finally, the negative pressure in the conveying pipe 30 or the internal tube 27 produced by the pumping device 20 causes the well water to be discharged from the removal chamber 30 through the conveying pipe 30. It will be appreciated that the flow characteristics for the example described here, according to which the water volumetric flow Zo is larger than the water volumetric flow Zu, are also applicable mutatis mutandis in the opposite case, namely when the water volumetric flow Zo is smaller than the water volumetric flow Zu. A displacement of the device 1 inside the filter tube 10 into a further operating position is facilitated in that the variable volume 16.2 of the sealing means 16 can be reduced radially by draining off a fluid. Once a new operating position of the device 1 inside the filter tube 10 has been achieved, the variable volume 16.2 is increased radially once more by supplying fluid. In conjunction with this radial expansion, the flexible layer 16.1 in the form of the foam material is positioned tightly against the wrapped wire filter structure of the filter tube 10, wherein the foam material is also able to penetrate into the spaces between the wrapped wires. This results in an excellent sealing effect between the outer peripheral surface of the volume bodies 12, 14 and the filter tube 10.

As an alternative to a combined embodiment of the sealing means 16 with the flexible layer 16.1 and the variable volume 16.2, it is likewise possible for the present invention that the sealing means 16 are constituted only by a single flexible layer in the form of foam material or the like. This results in the advantage that the sealing means then act in a purely passive manner and do not necessitate the supply or discharge of a control fluid. The appropriate dimensioning of this foam material sealing means in respect of its diameter permits a good sealing effect in interaction with the filter tube 10, on the one hand, and an axial displaceability of the device 1 in the longitudinal direction of the filter tube well is also assured.

The inventive device 1 has the advantage that, for the described pressure or flow egualization between its external outer fronts 22, 24, the hydraulic connection has a sufficiently large flow cross section in the annular space 25, the conseguence of which is an advantageously large volumetric flow. The annular space 25 intersperses the removal chamber 18 in the direction of the longitudinal axis L of the device 1, wherein the connecting channels 34 between the recesses 32 of the external tube 26 and the internal tube 27 are separated hydraulically from the annular space 25. The axial length of this annular space 25, in the direction of the longitudinal axis L of the device 1, has no influence on this flow egualization.

Claims

An apparatus (1) for activating or purifying seepage wells with a filter tube (10) comprising a first and a second volume body (12, 14), which with their outside diameter can be substantially adapted to the inner diameter of the filter tube (10) and on their outer peripheral surface each has a sealing means (16) by means of which a sealing effect can be set between the volume bodies (12, 14) and the inner wall of the filter tube (10), a withdrawal chamber (18) which can be formed between the first and second volume bodies (12, 14) and the inner wall of the filter tube (10), the withdrawal chamber (18) being hydraulically coupled to a pump device (20), a hydraulic connection between the regions each adjacent to the outer end sides (22, 24) of the device facing the removal chamber (18), characterized in that an outer tube (26) and an inner tube (27) located inside the outer tube (26) are provided, the hydraulic connection extending at least through an annulus (25) which at least completely passes through the take-out chamber (18) in the direction of the longitudinal axis (L) of the device (1) and is formed between the outer tube (26) and the inner tubes (27) and the volume bodies (12, 14) are each formed as sleeves and can be slid onto an outer circumferential surface of the outer tube (26).

Device (1) according to claim 1, wherein the outer tube (26), respectively, at its respective outer end sides (26o, 26u) and the inner tube at its upper end side (27o) are open.

Device (1) according to claim 1 or 2, wherein the inner tube (27) and the outer tube (26) respectively extend along the entire longitudinal axis (L) of the device (1).

Device (1) according to claim 1 or 2, wherein the outer tube (26) extends substantially along the entire longitudinal axis (L) of the device (1), the inner tube (27) passing only through the device (1). in the region of the first upper volume body (12) and the withdrawal space (18).

Device (1) according to one of claims 1 to 4, wherein a transport line (30) on the device which can be connected to a pump device (20) opens into the withdrawal chamber (18).

Device (1) according to claim 5, wherein the conveyor line (30) is formed through the inner tube (27), in which at least one recess (32i; 32a) is formed in the region of the withdrawal chamber (18), each of which adjacent to each other, in the walls (Wi, Wa) of the inner tube (27) and the outer tube (26), a connecting channel (34) passing radially from the recess of the inner tube (32i) through the annulus (25) to the recess in the outer tube (32a), and the conveyor line (30) is thereby hydraulically connected to the take-out chamber (18) and is hydraulically separated from the annulus (25).

Device (1) according to claim 6, wherein at least two, preferably two, formed in the walls (Wi; Wa) of the inner tube (27) and the outer tube (26), each adjacent to each other. three, further preferably at least four recesses (32i; 32a), the conveying line (30) being hydraulically connected to the take-out chamber (18) by two, preferably by at least three, further preferably at least four connecting channels ( 34), each of which passes radially through the annulus (25) and connects the adjacent holes of the inner tube and the outer tube with each other.

Device (1) according to one of claims 1 to 7, wherein the first volume body (12) and / or the second volume body (14) can be displaced relative to the outer tube (26) in the direction of the longitudinal axis (L) of the device. and can be fixed in a predetermined position on the outer tube (26), whereby the height (h) of the withdrawal chamber (18) can be adjusted in the direction of the longitudinal axis (L) of the device (1).

Device (1) according to one of claims 1 to 8, wherein the sealing means (16) on the outer circumferential surfaces of the volume bodies (12, 14) have a flexible layer (16.1) of a foam material, in particular formed by a foam with open cells or of a foam rubber.

Device (1) according to one of claims 1 to 9, wherein the sealing means have a variable volume (16.2), whereby the sealing means can be increased radially outwardly by supplying a fluid into the volume (16.2).

Device (1) according to claims 9 and 10, wherein the flexible layer (16.1) of foam material is located on the outer casing surface of the variable volume (16.2).

Device (1) according to one of claims 1 to 11, wherein the inner tube (27) on its upper end side (27o) is provided with first connecting means (36) for connecting additional pipelines (42) or the like.

Device (1) according to one of claims 1 to 12, wherein the inner tube (27) on its lower end side (27u) or the outer tube in the region at its outer end side (26u) is provided with other connecting means (44) for to place additional apparatus for the well treatment.