DK3061875T3

DK3061875T3 - DEVICE AND PROCEDURE FOR ACTIVATING OR CLEANING WELLS

Info

Publication number: DK3061875T3
Application number: DK16000438.8T
Authority: DK
Inventors: Peter Nillert; David Nillert
Original assignee: Teftorec Gmbh
Priority date: 2015-02-26
Filing date: 2016-02-24
Publication date: 2019-01-07
Also published as: EP3061875A1; DE202015002482U1; DE102015002476A1; EP3061875B1

Description

The invention relates to a device for activating or purifying wells according to the preamble to Claim 1 and a corresponding method using a suchlike device.

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.

Furthermore, a bowl-shaped supporting granule filter should be produced in the transitional area from the filter particle bed installed in the annular space to the adjacent natural ground by flushing-out of the small granules from the ground in this annular zone, which bowl-shaped filter is composed of the coarser supporting granules of the ground which do not pass through the pore channels of the installed filter particle bed. It is desirable, in addition, behind the supporting granule filter to be produced, likewise to flush very small granules in the adjoining ground, being the granule sizes that are capable of so-called suffosion, from the largest possible radially surrounding area around the bore hole, which granule sizes, in the presence of sufficiently large transport forces, can be transported through the pore channels of the natural ground. Through these measures for the so-called well filter development or activation, a good permeability and a large pore volume should be achieved in the granule filter, in order to produce the lowest possible lowering of the water table in the case of groundwater extraction as a result of low flow resistances, with the intention of guaranteeing the lowest possible use of energy for groundwater mounding.

The filter particle bed produced in conjunction with the well construction must also be repeatedly cleaned or regenerated after periods of operating the well, in order once more to remove deposits of mineral and/or organic origin originating from the inflowing groundwater as well as sediment granules from the ground that have entered into the filter particle bed, which have accumulated in the granule filter pores. In order to achieve the necessary cleaning of the pores at all of the described sites of the filter particle bed, which surrounds the filter tube, sufficiently large thrust forces of the flowing groundwater must be generated at these sites in order to be able to transport the particles for flushing. In addition, the particle flow taking place with the groundwater flow through the pore channels must be stimulated by suitable measures, because the particles in the chaotically structured flow paths through the pores of the skeleton of the filter granules become caught continuously in the pore end angles and, as a result, the particle transport is impeded or comes to a standstill without special measures which make the trapped particles capable of being transported once more. Both aims are pursued by different measures and practised modes of action .

The regeneration of wells comprises all measures, which serve for the removal of mineral and/or organic deposits arising from the annular space of the well and the adjacent rock during a period of operating the well. 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 laterally around the shut-off bodies in order to enter into the working chamber. As a result, the flow proportion of 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 Vereinigung 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 is rated as important. Conventional devices for cleaning wells, for example according to DE 81 20 151, are subject to the disadvantage that the cleaning performance in the annular space and in particular in the rock adjacent thereto is not optimal, including at a significantly increased flow rate. 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 is produced between a number of chambers. 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.

Pore space stimulation can be achieved simultaneously with the delivery flow, by means of which the particles that become caught continuously in the pore end angles can be released and made capable of being transported. A suchlike pore space stimulation can be produced in various ways according to the prior art. The alternating reversal of the flow direction by brief interruptions of the delivery flow, for example by switching off the delivery pump, with the result that the water present in a riser pipe above the removal chamber flows back through the chamber into the pore space and forces the previously aspirated particles back again, is already familiar. Since a switching operation is characterized by a few minutes' pumping and an even shorter switch-off time, the frequency of the switching operations is about 0.1 to 0.3 Hz and requires correspondingly lengthy process times until a pore filter has been cleaned sufficiently. A further possibility for pore space stimulation exists in the continuous variation of the direction of flow from the filter particle bed into the removal chamber, by causing an appropriate device with its removal chamber to be moved continuously back and forth along the filter tube over a section of the filter tube. As a result of this, the inflow direction changes in relation to the chamber, which induces activation of possible particle transport paths in the chaotic granule filter. This kind of pore space stimulation does not require any additional technology in order to produce and input impulses and can be used with removal chambers with discs or pistons as boundaries.

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 aquifers, being stratified and accordingly in layers as a consequence of their geological genesis, 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 quantity 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 aquifer, through which the groundwater flows in a hydraulically coherent manner, is consequently developed as a well filter, wherein a residual part of the aquifer 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 generic device for activating or purifying 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. A device for activating or purifying filter tube wells with a filter tube is known from EP 2 952 640 Al. This device comprises a first and a second volume body, which are adapted in respect of their outer diameter substantially to the inner diameter of the filter tube and in each case exhibit sealing means on their outer circumferential surface, by means of which a sealing effect can be set between the volume bodies and the inner wall of the filter tube, a removal chamber, which is formed between the first and second volume bodies and the inner wall of the filter tube, wherein the removal chamber can be hydraulically connected to a pumping device. A hydraulic connection is present between the areas, which in each case adjoin the outer end sides of the two volume bodies opposite the removal chamber, in particular through an annular space, which at least completely intersperses the removal chamber in the direction of the longitudinal axis of the device and is configured between an external tube and an internal tube arranged inside the external tube. WO 2005/007980 Al discloses a well for the extraction, monitoring and/or lowering of groundwater, having a standpipe exhibiting at least one filter tube area and having at least one pump arranged in the standpipe. It is proposed for this well that a spraying device for spraying of the filter tube area and/or a well area is allocated to the filter tube area, which is adjacent to the filter tube area. The spraying device is connected to at least one pressure line, through which the spraying device is supplied with a medium for spraying. A generic device according to the preamble to Claim 1 is known from DE 34 45 316 Al.

The invention accordingly has as its object to make available a device and a method for activating or purifying wells and a corresponding method, in which an improved activation of purification performance is capable of being realized as a result of a larger radial penetration depth effect inside the groundwater line of the well.

This object is accomplished by a device having the characterizing features of Claim 1 and by a method having the characterizing features of Claim 15. Advantageous further developments of the invention are defined in the dependent claims .

An inventive device serves for activating or purifying filter tube wells with a filter tube and comprises a first volume body and a second volume body, wherein these volume bodies are adapted with their respective outer diameter substantially to the inner diameter of the filter tube, and on their outer circumferential surface each comprise a sealing means, by means of which a sealing effect with respect to the inner wall of the filter tube can be achieved. Furthermore, the device comprises at least one removal chamber, which is formed between the first and the second volume bodies and the inner wall of the filter tube. The removal chamber can be hydraulically connected to a pumping device, wherein water can be pumped from the removal chamber during operation of the pumping device. Two removal chambers in the form of an upper removal chamber and a lower removal chamber are formed between the first and the second volume bodies in the longitudinal direction of the device. These two removal chambers are hydraulically separated from each other and can each be connected to the pumping device by separate hydraulic connections. An external tube is provided along the longitudinal axis of the device, wherein the volume bodies are attached to an outer circumferential surface of the external tube. An intermediate tube is arranged coaxially inside the external tube, wherein an outer annular space is formed between the external tube and the intermediate tube. The mode of operation of this outer annular space is additionally described below in detail.

The present invention is based on the significant finding that a larger radial depth of penetration in the ground which adjoins the filter tube is possible by an interaction of the upper removal chamber and the lower removal chamber with respect to the extraction or pumping-out of water from the filter tube. In other words, the cylindrical effective zone of the radial depth effect in the drilling aureole is increased into the adjoining groundwater line. The two effective zones of the upper removal chamber and the lower removal chamber are practically combined in this radially more remote zone of pore cleaning into a coherent effective area with sufficiently large flow forces, which zone is able to extend over the entire axial length of the device. It is advantageous in this case for the upper removal chamber and the lower removal chamber each to be connected by separate hydraulic connections to the pumping device. The dimensions of these hydraulic connections are configured in such a way that a volumetric flow, which is extracted through a respective removal chamber, i.e. through the upper removal chamber and the lower removal chamber, essentially adopts the same value or is in alignment. In other words, half the volume of water in each case is pumped through a respective removal chamber in relation to the total quantity of water discharged from the filter tube.

The inventive device is intended especially to be used as a "displaced chamber", wherein it is moved continuously inside the filter tube of a filter tube well during operation of the pumping device. In this case, a pore space stimulation inside a filter particle bed of the well and of the adjacent rock can be improved by the provision of a third central volume body, which is arranged between the upper removal chamber and the lower removal chamber. The third volume body is adapted in respect of its outer diameter, in the same way as the first and second volume bodies, substantially to the inner diameter of the filter tube and exhibits sealing means on its outer circumferential surface, by means of which a sealing effect with respect to the inner wall of the filter tube is realized. In conjunction with a movement of the device along the filter tube, the flow direction changes by up to 180°at a defined location of the well. The result of this is that a large number of particles are transported through the pore channels of the filter particle bed or the adjacent rock in a shorter time .

In an advantageous further development of the invention, a third central volume body can be provided, which is arranged between the upper and lower removal chamber. The third volume body is adapted with its outer diameter substantially to the inner diameter of the filter tube, and it exhibits on its outer circumferential surface sealing means, by means of which a sealing effect with respect to the inner wall of the filter tube can be set. With regard to a hydraulically effective repeated change in the flow direction during a movement of the inventive device along the filter tube, it is of advantage if the third central volume body is configured in the axial direction of the device with more or less the same length as the first and second volume bodies.

In an advantageous further development of the invention, the respective volume bodies can be of segment-like configuration in the longitudinal direction of the device, e.g. in the form of disc-shaped segments. These segments of the respective volume bodies can be slid onto the external tube of the device and secured thereto in a predetermined position. In this case, a number of segments then defines an axial extent of a respective volume body along the longitudinal axis of the device .

In order to guarantee effective processing, even of wells of particularly unfavourable construction which are characterized by comparatively small well pipe diameters and by very large bore diameters, it is recommended that the radial depth penetration or the generation of sufficiently large flow forces is reinforced in the direction of the filter tube at a large radial distance. This is possible with the inventive device in that an axial length of the third central volume body is reduced, which in the case of the aforementioned segment-like embodiment is possible simply by the removal of a segment of the third volume body. The effects of the upper and lower removal chamber are superimposed or reinforced by a suchlike reduction in the axial length of the third central volume body, with the result that sufficiently large flow forces are also generated in the outer filtering zone and into the drilling aureole.

In an advantageous further development of the invention, it is possible for the upper removal chamber to be connected hydraulically either to the outer annular space or to the inside of the intermediate tube, and for the lower removal chamber to be connected hydraulically either to the inside of the intermediate tube or to the outer annular space, so that the outer annular space and the intermediate tube for the removal chambers in each case form separate hydraulic connections for the pumping device. In other words, on the one hand, the outer annular space, which is formed between the external tube and the intermediate tube, and, on the other hand, the inside of the intermediate tube, can be embodied thereby in each case as a hydraulic connection, through which a respective removal chamber is connected hydraulically to the pumping device. In this case, recesses are configured in the wall of the external tube adjacent to the removal chamber, which recesses extend parallel to the longitudinal axis of the external tube. Recesses are likewise configured in the wall of the intermediate tube adjacent to the upper removal chamber or the lower removal chamber, which recesses extend parallel to the longitudinal axis of the external tube and especially opposite to the recesses of the external tube. In this case, connecting channels lead from the recesses of the external tube radially through the outer annular space in each case to the opposite recesses of the intermediate tube, so that this removal chamber is connected hydraulically to the inside of the intermediate tube and is hydraulically separated from the outer annular space.

In order to guarantee a volumetric flow of similar size for water which is discharged through the respective removal chambers, it is expedient for the aforementioned embodiment if the dimensions of the outer annular space and the diameter of the intermediate tube are matched to one another in such a way that, during operation of the pumping device, an identical throughput is set for the upper and lower removal chamber. It is likewise of advantage if the intermediate tube and the external tube can be connected hydraulically to the pumping device at an upper end of the external tube via a common connection coupling.

In an advantageous further development of the invention, it is also possible for the outer annular space to serve as a hydraulic connection between the outer end sides of the external tube or to be part of a suchlike hydraulic connection. For this purpose, the external tube is of open configuration on its outer end sides. Water is thus able, in the event of a movement of the device along the filter tube, to pass through the annular space which is formed inside the external tube, which leads to a reduced flow resistance for the device in the event of movement inside the filter tube. In a similar manner, a pressure or volumetric flow balance between the areas of the filter tube above and below the device is assured by this hydraulic connection between the outer end sides of the external tube, including when the device is not moved inside the filter tube.

In the case of the aforementioned embodiment of the invention, it is of advantage, furthermore, if an internal tube, which also extends inside the intermediate tube, is arranged coaxially inside the external tube. An inner annular space is accordingly formed between the internal tube and the intermediate tube, wherein the upper removal chamber is connected hydraulically either to the inner annular space or to the inside of the intermediate tube, and wherein the lower removal chamber is connected hydraulically either to the inside of the intermediate tube or to the inner annular space. The inner annular space and the internal tube for the two removal chambers accordingly each form separate hydraulic connections to the pumping device.

In an advantageous further development of the invention according to the last-mentioned embodiment, recesses can be configured in the wall of the external tube adjacent to the removal chambers, which recesses extend parallel to the longitudinal axis of the external tube. Recesses can likewise be configured in the wall of the intermediate tube adjacent to the upper removal chamber, which recesses extend parallel to the longitudinal axis of the external tube and extend opposite to the recesses of the external tube. In this case, connecting channels lead from the recesses of the external tube radially through the outer annular space respectively to the opposite recesses of the intermediate tube, so that the upper removal chamber is connected hydraulically to the inner annular space and is separated hydraulically from the outer annular space.

In an advantageous further development of the invention, the internal tube can extend inside the external tube in the axial length of the device at least into the area of the lower removal chamber, wherein recesses are configured in the wall of the internal tube adjacent to the lower removal chamber, which recesses extend parallel to the longitudinal axis of the external tube and opposite to the recesses of the external tube. In this case, connecting channels then lead from the recesses of the external tube radially through the annular space formed between the internal tube and the external tube respectively to the opposite recesses of the internal tube, so that the lower removal chamber is connected hydraulically to the inside of the internal tube and is separated hydraulically from the annular space between the internal tube and the external tube.

The last-mentioned embodiment of the invention is characterized in that three tubes are inserted coaxially into one another, being in particular an external tube, an intermediate tube and an internal tube. As a result, as described, an outer annular space and an inner annular space are formed inside the external tube. The outer annular space, which is formed between the external tube and the intermediate tube, then serves in conjunction with an annular space between the external tube and the internal tube as a hydraulic connection between the outer end sides of the external tube. Furthermore, both the inner annular space and the interior of the internal tube in each case adopt the function of a separate hydraulic connection, in order to connect the upper or lower removal chamber to the pumping device. In this way, a technically simple and simultaneously robust tool can be realized with comparatively few component parts for use on the construction site in order to activate or to purify wells.

In an advantageous further development of the invention, the intermediate tube can intersperse the external tube from an upper end of the device up to approximately a central area thereof. Furthermore, the internal tube can intersperse the external tube substantially along its entire length. In this case, the intermediate tube in the axial direction of the device is only as long as is made necessary by the inner annular space, which is formed between the intermediate tube and the internal tube, in its function as a hydraulic connection for the upper removal chamber to the pumping device. It is also possible, as a result, furthermore, for the internal tube to be arranged adjacent to the lower removal chamber, so that through the recesses, which are configured in the walls of the external tube and of the internal tube, in conjunction with the connecting channels arranged in-between, the internal tube can serve as a hydraulic connection for the lower removal chamber to the pumping device.

In respect of the embodiment of the invention in which, as described, the three tubes, in particular an external tube, an intermediate tube and an internal tube, are inserted coaxially into one another, it is of advantage for the dimensions of the inner annular space and the diameter of the internal tube to be matched to one another in such a way that, during operation of the pumping device, a matching throughput is set for the upper and lower removal chamber. It is of advantage, furthermore, if the intermediate tube and the internal tube can be connected hydraulically to the pumping device at an upper end or an upper end side of the external tube via a common connection coupling.

In an advantageous further development of the invention, the respective volume bodies can be attached to an outer circumferential surface of the external tube, wherein the first, second and/or third volume bodies can be displaced relative to the external tube in the direction of a longitudinal axis of the device and can be fixed to the external tube in a predetermined position. Before putting the device into operation, a displacement of the volume bodies relative to the external tube in the direction of a longitudinal axis of the device is possible. After achieving a predetermined position, the volume bodies can be secured to the external tube by suitable clamping devices or the like.

In an advantageous further development of the invention, the first, second and/or third volume bodies can be configured in a segment-like manner in the longitudinal direction of the device, wherein the segments can be pushed onto the external tube and can be fixed thereto in a predetermined position, and preferably so that an axial extension of a volume body can be varied by the number of its segments.

In an advantageous further development of the invention, the upper and lower removal chamber can be configured more or less in a central area of the device, wherein the adjacent first and second volume bodies extend in the direction of the outer end sides of the external tube and are thus attached to the external tube at the end.

In an advantageous further development of the invention, an axial length of the recesses which are configured in the walls of the individual tubes, and an axial length of the adjacent connecting channels can be larger than an effective axial height of an adjacent removal chamber. These recesses and the associated connecting channels are preferably configured with a length in the axial direction of the device such that they adjoin one another in the symmetrical centre of the device, and from there lead to the respective end sides at the end of the device. In the event that the volume bodies are mounted on the external tube of the device, it is possible that a proportion of the recesses formed in the external tube is covered by the volume bodies. As a consequence thereof, only the proportion of the recesses formed in the external tube, and also, in the same way, the associated recesses in the intermediate tube or in the internal tube which are present between the volume bodies and accordingly are not covered, are accessible for a radial inflow of water. By desired positioning of the volume bodies on the outer circumferential surface of the external tube, the height of the upper and lower removal chambers can be set precisely or modified depending on a respective intended purpose. A predetermined positioning of the volume bodies on the outer circumferential surface of the external tube is possible by means of suitable spacers, preferably in the form of so-called annular baskets. In this way, a modification of the inventive device in all conceivable known types of intensive removal chambers is possible with the simplest mechanical means.

In an advantageous further development of the invention, the sealing means on the outer circumferential surfaces of the volume bodies can exhibit open-cell foam material or bristles for the purpose of providing a sufficient sealing effect with respect to the inner wall of the filter tube. The open-cell foam material or the bristles are in their nature configured in such a way that, in order to guarantee the desired sealing effect, on the one hand, they fill the space between the rods of a wrapped wire filter all the way into the filter slot and, on the other hand, they bear tightly against internally smooth filter tubes on the internal tube wall. Furthermore, the nature of the foam material or the bristles is selected in such a way that a sufficient resistance to wear exists and no excessive wear occurs when the device is moved along the filter tube. According to a preferred embodiment, the sealing means or the volume bodies can be configured so that they are formed from the open-cell foam material or from the bristles, or consist thereof.

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 subsequent 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 or brushes is attached to its associated outer surface. This leads to overlapping of the above-mentioned advantages in respect of, on the one hand, the flexible layer of foam material or bristles and, on the other hand, a targeted expansion or reduction of the sealing means or the volume bodies in the radial direction. An additional advantage for this combination is that an outer peripheral surface of the variable volume by the application of the flexible layer of foam material, or by the provision of the bristles, 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 external tube or the internal tube in the area of a lower end side of the device can be equipped with connection means, in order to attach further equipment to the device for well maintenance. Suchlike equipment may be an impulse generator, for example, by which hydromechanical impulses are introduced into the well. A high-pressure hose for supplying the impulse generator can, for example, be passed through the annular space between the external tube and the intermediate tube or the internal tube .

The invention likewise relates to a method for activating or purifying filter tube wells with a filter tube, wherein a device according to the aforementioned embodiments and possibilities is moved constantly upwards or downwards along the filter tube and, as a result, water is conveyed by means of the pumping device from the two removal chambers of the device and is discharged from the well.

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 in 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 depicts a lateral cross-sectional view along the longitudinal axis of an inventive device, when this is inserted into a filter tube well, wherein flow proportions in the filter tube well are represented in an idealized manner,

Fig. 4 depicts a perspective view of a part of an external tube of the device in Fig. 3, having spacers attached thereto in the form of annular baskets,

Fig. 5 depicts various views of a spacer in Fig. 4,

Fig. 6 depicts various views of an inventive device, in particular in a completely assembled state, being a lateral cross-sectional view along its longitudinal axis, and a number of cross-sectional views thereof,

Fig. 7 depicts various views of an external tube according to Fig. 2, being a side view thereof and a number of cross-sectional views,

Fig. 8 depicts a side view and a cross-sectional view of an intermediate tube, which finds an application for a device according to Fig. 3 or Fig. 6,

Fig. 9 depicts a side view and a cross-sectional view of an internal tube, which finds an application for a device according to Fig. 3 or Fig. 6,

Figs. 10, 11 depicts various views of rectangular tubes, which find an application for a device according to Fig. 3 or Fig. 6,

Fig. 12 depicts a top view of an annular disc, which finds an application in the device according to Fig. 3 or Fig. 6,

Fig. 13 depicts a lateral cross-sectional view along the longitudinal axis of an inventive device according to a modified embodiment, and

Fig. 14 depicts a simplified representation of practically relevant flow proportions in the ground adjacent to a filter tube well, when an inventive device introduced therein is taken into in operation.

Fig. 3 depicts a simplified representation of an inventive device 1 in a longitudinal section, when the device is introduced into a filter tube well having a filter tube 10. The filter tube 10 is configured in a manner known per se and makes it possible for water to flow radially from the outside through the filter tube 10, as indicated in Fig. 3 by the arrow R.

The device 1 comprises a first (upper) volume body 12 and a second (lower) volume body 13, which with their respective outer diameter are substantially adapted to the inner diameter of the filter tube 10. Sealing means 16 are provided in each case on the outer circumferential surfaces of the volume bodies 12, 13, by means of which a sealing effect with respect to the inner wall of the filter tube 10 can be achieved.

Two removal chambers, in particular an upper removal chamber 18.1 and a lower removal chamber 18.2, are configured between the first and second volume bodies 12, 13 in the longitudinal direction of the device. These two removal chambers 18.1, 18.2 are hydraulically separated from one another and are connected respectively by separate hydraulic connections to a pumping device 20. Specifically, the upper removal chamber 18.1 is connected by a hydraulic connection 22 to the pumping device 20, whereas the lower removal chamber 18.2 is connected by a hydraulic connection 24 to the pumping device 20. Details of these hydraulic connections between the respective removal chambers 18.1, 18.2. and the pumping device 20 are described additionally below in detail.

The device 1 has an external tube 26, which extends along a longitudinal axis L of the device 1. The first and second volume bodies 12, 13 are attached to an outer circumferential surface of the external tube 26 and are secured there in a predetermined position. For this purpose, a plurality of spacers 28 (Fig. 4) are attached to the outer circumferential surface of the external tube 26, which in each case are arranged to either side of a volume body and, as a result, secure the volume body in a predetermined axial position with respect to the external tube 26.

Recesses, in particular in the form of elongated slots, are formed in the wall of the external tube 26 along the longitudinal axis L of the device 1. These recesses A26 in the wall of the external tube 26 are provided especially in the area of the upper and lower removal chamber 18.1, 18.2 and permit a radial inflow of well water into the device 1. Details of this radial inflow are described additionally below in detail.

The device 1 can exhibit a third central volume body 14, which is attached to an outer circumferential surface of the external tube 2 6 in the same manner as the volume bodies 12, 13. In this case, the third central volume body 14 is present on the external tube 2 6 between the upper volume body 12 and the lower volume body 13. An effective height h of the upper removal chamber 18.1 is defined by an axial distance between the first upper volume body 12 and the third central volume body 14. The same is true of the lower removal chamber 18.2, of which the effective height h in the axial direction is defined by a distance of the third volume body 14 from the second volume body 13. In each case, the removal chambers 18.1, 18.2 with their respective heights h in the axial direction of the device 1 are of sufficiently large configuration permit a specific throughput of well water to be extracted or discharged from the filter tube 10 during operation of the pumping device 20.

An embodiment of the spacers 28 for positioning of the volume bodies on the external tube 26 is illustrated in Fig. 4, which depicts the external tube in a simplified perspective view. In this case, the volume bodies are omitted for the sake of simplicity. At a lower end side, the spacers can be configured in the form of a fixing clamp 29 or the like. In a central area of the external tube 26, in particular especially adjacent to the recesses A26 in the area of the upper and lower removal chamber, the spacers are configured in the form of so-called annular baskets 30. For the axial attachment of the volume bodies to the outer circumferential surface of the external tube 26 in a predetermined position, it is proposed that a respective volume body is supported to either side by an annular basket 30 or a fixing clamp 29. With regard to the embodiment depicted in Fig. 3, reference should be made to the fact that the central volume body 14 is present between two annular baskets 30 and, as a result, is secured in the axial direction to the external tube 26. The first volume body 12 and the second volume body 13 are present respectively between an annular basket 30 and a fixing clamp 29u arranged on a lower end side 27u of the external tube 26 and, as a result, are axially secured to the external tube 26.

Fig. 5 illustrates an embodiment of the annular cages 30. In

Fig. 5.1 an annular basket 30 is depicted in a side view, whereas Fig. 5.2 depicts an annular basket 30 along a section A-A in Fig. 5.1. Fig. 5.3 depicts the annular basket 30 in Fig. 5.1 in a perspective view. The annular basket 30 consists of two annular elements 32, which are separated from each other by a plurality of webs 34. An inner diameter of the annular element 32 is adapted to an outer diameter of the external tube 26, in such a way that the annular cages 30 can be pushed without jamming onto an outer circumferential surface of the external tube 26. It is possible, by the use of suitable clamping devices, to define an annular basket 30, and thus also a volume body, in a predetermined axial position of the external tube 26.

An overall view of Fig. 3, Fig. 4 and Fig. 5.3 illustrates that a spacing of the two annular elements 32 of an annular basket 30 defines a height h of a respective removal chamber, in each case for the embodiment according to Fig. 3. For this reason, it is also proposed, as shown in the representation in Fig. 4, that an annular basket 30 is attached to the external tube 26 in each case adjacent to the recesses A26. The consequence of this is that well water is able to flow in from the outside radially between the annular elements 32 into the external tube 26.

For the attachment of the volume bodies 12, 13, 14 and the annular cages 30 to the external tube 26, attention is drawn to the fact that these component parts are able to be pushed simply onto the outer circumferential surface of the external tube 26. Spacer discs 35 can be provided between the axial end sides of the volume bodies and the annular baskets 30 adjacent thereto. For the embodiment in Fig. 3, it will be appreciated that the upper volume body 12, an annular basket 30, the central volume body 14, a further annular basket 30 and finally the lower volume body 13 have then been pushed onto on the external tube 26, in particular in this sequence in the longitudinal axis of the device 1 when viewed from top to bottom. Spacer discs 35 are arranged in each case between the annular baskets 30 and the volume bodies. In this arrangement, the aforementioned component parts lie closely adjacent to one another, i.e. their respective end sides are in contact with one another. These component parts are then fixed or secured together in their respective position on the external tube 26 by means of the fixing clamp 29u (Fig. 4) and a fixing clamp 29o (Fig. 3) attached to the upper end side 27o of the external tube 26, wherein the fixing clamps 29o, 29u are arranged in each case on the outer end sides of the adjacent volume bodies. A suchlike fastening possibility has the advantage that no separate clamping devices are necessary for the individual component parts themselves, i.e. the volume bodies 12, 13, 14 and the annular cages 30, and in total only two fastening elements, in particular in the form of the fixing clamps 29o, 29u, are sufficient for securing all the component parts to the external tube 26.

The fixing clamps 29o, 29u can be clamped steplessly at arbitrary locations on the outer circumferential surface of the external tube 26, with the result that the volume bodies 12, 13, 14 and the annular cages 30 can be fixed in various predetermined axial areas of the external tube 26.

In Figs. 6 to 11, further details of the "internal workings" of the device 1 and the associated structural elements are described, by means of which the aforementioned separated hydraulic connections 22, 24 are implemented between a respective removal chamber 18.1, 18.2 and the pumping device 20 .

Fig. 6 depicts various views of the device 1 and of associated tube elements. Fig. 6.1 depicts the aforementioned external tube 26 in a side view, wherein the volume bodies are omitted for the sake of simplicity. The external tube 26 is also depicted again in Fig. 7, in particular in a side view (Fig. 7.1), in a cross-sectional view along the line A-A in Fig. 7.1 (Fig. 7.2), and in a cross-sectional view of the line B-B in Fig. 7.1 (Fig. 7.3) . The cross-sectional view according to

Fig. 7.2 illustrates that the recesses A26 along the circumference of the external tube 26 are configured in four segments, which in each case are spaced apart from one another by about 90°. Furthermore, the side view in Fig. 7.1 illustrates that the recesses A26 extend over a large part of the axial length of the external tube 26.

Fig. 6.2 depicts a longitudinally sectioned view along the line A-A- in Fig. 6.1. It can be seen that an intermediate tube 36, which extends approximately to the centre of the external tube 26, is accommodated inside the external tube 26. The intermediate tube 36 is likewise represented in Fig. 8, in particular in a side view (Fig. 8.1) and in a cross-sectional view along the line A-A in Fig. 8.1 (Fig. 8.2) . The cross-sectional view according to Fig. 8.2 illustrates that recesses A36 are likewise configured in a wall of the intermediate tube (36), in particular along the circumference of the intermediate tube 36 in four areas, which are spaced apart from one another by about 90°.

With the device 1 installed, an outer annular space 38 (see Fig. 6.5) is formed between the external tube 26 and the intermediate tube 36. The intermediate tube 36 is positioned inside the external tube 26 in such a way that its recesses A36 in each case are arranged opposite recesses A26, which are configured in the wall of the external tube 26. The recesses A26 and A36 arranged opposite to each other are connected to each other by connecting channels 40, in particular in the form of so-called rectangular tubes, which are accommodated inside the outer annular space 38.

The rectangular tubes 42K for the connection of the recesses A26 to the recesses A36 are represented in Fig. 10, in particular in a top view (Fig. 10.1), in an end side view (Fig. 10.2), in a side view (Fig. 10.3.) and in a perspective view (Fig. 10.4). With regard to this connecting channel 40 in the form of the rectangular tubes 42K, by which, as explained, the recesses A26 are connected to the recesses A36, attention should be drawn to the fact that these are separated hydraulically from the outer annular space 38. Furthermore, attention should be drawn to the fact that a height hi of the rectangular tubes 42K (see Fig. 10.3) is selected so as to be consistent with the radial height of the outer annular space 38, i.e. with the distance between the inner peripheral surface of the external tube 26 and the outer circumferential surface of the intermediate tube 36. A seamless connection between the recesses A26 and A36 is assured in this way. Furthermore, it will be appreciated that an axial length of the rectangular tubes 42K is selected so as to be substantially consistent with an axial length I of the recesses A26 (see Fig. 7.1).

The longitudinally sectioned view in Fig. 6.2 further illustrates that an internal tube 44 is likewise arranged coaxially inside the external tube 26, wherein the internal tube 44 extends inside the aforementioned intermediate tube 36. An axial length of the internal tube 44 is selected in such a way that it intersperses the external tube 26 substantially for its entire axial length. In the length section of the external tube 26, in which the internal tube 44 extends inside the intermediate tube 36, an inner annular space 46 (see Fig. 6.4) is formed between the internal tube 44 and the intermediate tube 36. In the length section of the external tube 26, which is not interspersed by the intermediate tube 36, a further annular space 48 (see Fig. 6.3) is formed between the internal tube 44 and the external tube 26. With regard to the inner annular space 46, reference should be made to the fact that the intermediate tube 36 at its free end 36u (Fig. 6.2) is closed to the outer circumferential surface of the internal tube 44. This is of significance for the hydraulic connection 22 between the upper removal chamber 18.1 and the pumping device 20, as additionally described below in detail.

The internal tube 44 is also depicted in addition in Fig. 9, in particular in a side view (Fig. 9.1), and in a cross sectional view along the line A-A in Fig. 9.1 (Fig. 9.2) . The last-mentioned cross-sectional view illustrates that recesses A44 are likewise configured in a wall of the internal tube 44, in particular along the circumference of the internal tube 44 in four areas, which are spaced apart from one another by about 90°. In a manner similar to the intermediate tube 36, the internal tube 44 inside the external tube 26 is arranged in such a way that the recesses A44 in the wall of the internal tube 44 in each case are opposite to the recesses A26 in the wall of the external tube. These opposite recesses A26, A44 are connected to one another by connecting channels 40, in particular by rectangular tubes 42L, which are represented additionally in Fig. 11. A rectangular tube 42L is depicted there in detail in a top view (Fig. 11.1), in an end side view (Fig. 11.2), in a side view (Fig. 11.3) and in a perspective view (Fig. 11.4). A height km of the rectangular tubes 42L (see Fig. 11.3) in this case corresponds precisely to a radial height of the annular space 48 between the internal tube 44 and the external tube 26. In this way, in the case of an arrangement of the rectangular tubes 42L inside the annular space 48, a tight hydraulic connection between the recesses A26 and A44 is possible, in order thereby also to achieve a hydraulic separation from the annular space 48.

The above-mentioned "interleaving" of the intermediate tube 36 and of the internal tube 44 respectively inside the external tube 26, according to which these three tubes are inserted into each other and are arranged coaxially in relation to each other, is likewise depicted in the cross-sectional views according to Fig. 6.3 - Fig. 6.6. These representations depict in detail a section along the line B-B in Fig. 6.2 (Fig. 6.3), a section along the line C-C in Fig. 6.2 (Fig. 6.4), a section along the line D-D in Fig. 6.2 (Fig. 6.5), and finally a section along the line E-E in Fig. 6.2 (Fig. 6.6) . These cross-sectional views also illustrate especially the position of the respective recesses in the tube elements relative to each other, and also the positioning of the rectangular tubes 42K, 42L inside the respective annular spaces, in order to guarantee a hydraulic connection between the respective opposite recesses of the tube elements.

At this point, reference should be made to the fact that all of the depicted representations of the respective tube elements and the further component parts are not true to scale, but are intended to be understood only in simplified respect for the interaction of these component parts.

The external tube 26 is of open configuration in each case at its upper end side 27o and at its lower end side 27u. The consequence of this is that a hydraulic connection exists between these end sides 27o, 27u of the external tube 26, which extends through the outer annular space 38 and the annular space 48 and is symbolized in Fig. 3 by broken lines HV. This hydraulic connection HV permits a balancing flow between the outer end sides of the external tube 26, in the event of an uneven incoming flow 1 arriving at the device on its upper side and on its underside in the radial direction. Attention should also be drawn in this respect to the fact that this hydraulic connection HV, which, as explained, extends through the outer annular space 38 and the annular space 48, and not through the rectangular tubes 42K and 42L, is impaired. The reason for this is that these rectangular tubes 42K and 42L are arranged with their longitudinal axis in each case parallel to the longitudinal axis L of the device 1, so that the hydraulic connection HV in each case extends parallel or adjacent to these rectangular tubes 42K, 42L and, as described above, is hydraulically separated.

The representations in Fig. 3 and Fig. 6.2 show clearly that both the intermediate tube 36 and the internal tube 44 are led out of the external tube 26 on its upper end side 27o, whereas the intermediate tube 36 and the internal tube 44 are then connected jointly to the pumping device 20 via a common connection coupling 50 and a connecting line 52. The connecting line 52 is preferably flexibly configured and constitutes a length compensation, in order to permit a movement of the device 1 inside the filter tube 10 along its longitudinal axis L and over larger distances, if required, without restriction.

At an upper end side 27o, perforations are formed in the wall of the external tube 26 along its periphery, in particular in the form of holes 54. These holes can be seen in the representation in Fig. 7, and especially in the cross-sectional view in Fig. 7.3. A spacer in the form of an annular disc 56, which is represented as a separate component part in a top view in Fig. 12, serves for the axial fixing of an upper edge of the first upper volume body 12 on the upper end side 27 o of the external tube 26. Recesses 58, which adjoin the holes 54 at the upper end side 27o of the external tube 26, are formed at an inner peripheral edge of this annular disc 56.

The above-mentioned holes 54 on the upper end side 27o of the external tube 26 serve the purpose, in conjunction with the annular disc 56 and its recesses 58, that particles, especially sand, sediments or similar granular contamination, are able to pass through there in order for them subsequently to drop downwards through the outer annular space 38 of the device 1. The particles entering and sinking in the well water above the device 1 are conveyed in this way together with the water flowing through the holes 54 from the outside through the device 1 and its outer annular space 38 downwards into the well sump. Because of the open embodiment of the external tube 26 at its lower end side 27u, these particles are then able to exit completely from the device 1 downwards. Particles are prevented in this way from accumulating on an upper side of the device 1.

The volume bodies 12, 13, 14 are configured in the form of segments S, i.e. in the form of disc-shaped elements, which can be laid one on top of the other in a plurality and then together constitute a respective volume body. In the representation in Fig. 3, the first volume body 12 is configured, for example, by two segments S12/1 and S12/2, which together are attached to the outer circumferential surface of the external tube 26 and adjoin one another in the longitudinal axis L of the device 1. A separate attachment of the two segments S12/1 and S12/2 at their boundary surface is not required, because the first volume body 12 as such is delimited from above by the annular disc 56 and from below by an annular basket 30 and is held together in this respect.

In the same way as for the first upper volume body 12, in the embodiment in Figure 3, the second lower volume body 13 can also be constituted by two segments, in particular by a segment S13/1 and S13/2.

The third central volume body 14 can also be configured in the form of individual segments in the same way as for the volume body 12, 13. In the embodiment in Fig. 3, the third volume body 14 consists of three segments, in particular the segments S14/1, S14/2 and S14/3. It is also true of these segments of the third volume body 14 that they are attached adjacent to each other on the outer circumferential surface of the external tube 26, wherein a separate connection to the boundary surfaces of these segments is not required, because the central volume body 14 is delimited on its end sides by annular cages 30 and is secured in this way to the external tube 26.

The number of segments for the respective volume bodies depicted in the drawing is intended to be understood only by way of example. This means that the individual volume bodies can also exhibit more segments than represented in the drawing. For example, the first volume body 12 and/or the second volume body 13 can also have three or more segments.

In the inventive device 1, it is possible to modify a position of the respective volume bodies 12, 13, 14 on the outer circumferential surface of the external tube 26 and, as a result, for example, to set a height h of the upper removal chamber 18.1 and/or of the lower removal chamber 18.2, depending on the intended purpose of the device 1 and the type of well to be maintained. A suchlike change in the position of the volume bodies on the external tube 26 in the axial direction of the device 1 can be achieved in a simple manner in that the volume bodies can be displaced parallel to the longitudinal axis of the device 1 on the external tube 26. This is also applicable in the same way for the spacers, in the form of the fixing clamp 29, the annular cages 30 and the annular disc 56. These spacers can likewise be displaced along the external tube 26 in its axial direction, wherein, after reaching a predetermined position for the volume bodies, these spacers are clamped to the external tube 26 in order subsequently to hold the volume bodies in their predetermined position with respect to the external tube 26. A change in a height of the upper or lower removal chamber 18.1, 18.2 can take place, as described, by a displacement of the volume bodies in the axial direction with respect to the external tube 26. In this context, it is also possible to modify an axial length of the respective volume bodies by the removal of segments therefrom or the addition of segments thereto. This is possible in a simple manner because of the aforementioned segmented construction of the volume bodies. A variable positioning, especially of the upper and lower volume bodies 12, 13, on the outer circumferential surface of the external tube 26 is also possible, especially because the recesses A26, A36 and A44 are configured with sufficient length along the longitudinal axis of the device 1. As a result, it is possible for the upper and lower removal chamber to be formed variably at locations on the external tube 26 which are not enclosed or covered by the volume bodies. In this way, the device 1 can be modified in a structurally simple manner in all conceivable known types of intensive removal chambers.

The embodiment of the device 1 according to Fig. 3 can be modified by the third central volume body 14 not being mounted on the external tube 26 and accordingly being omitted. A suchlike modification is depicted in the representation in Fig. 13, which illustrates a longitudinal section through the device 1 similar to Fig. 3, when the device is introduced into the filter tube 10 of a well. In the embodiment of the device 1 according to Figure 13, the upper removal chamber 18.1 and the lower removal chamber 18.2 overlap one another on the whole to form a common large removal chamber 18, which is configured between the end sides of the two volume bodies 12, 13 in the central area of the device 1. Securing of the two volume bodies 12, 13 and the in-between annular cages 30 to the external tube 26 in its axial direction is implemented in the same manner as in Fig. 3, in that these closely adjacent component parts are pushed onto the external tube 2 6 and are suitably clamped or held by the fixing clamps 290, 29u.

Moreover, the design of the embodiment in Fig. 13 corresponds to that of the embodiment in Fig. 3, wherein identical component parts are provided here with identical reference designations, and reference should be made to the above explanations for the avoidance of repetitions.

The function of the invention and a corresponding use of the device 1 inside the filter tube 10 of a well are explained as follows below:

The device 1 is introduced completely into a filter tube well or into its filter tube 10. This is illustrated, as described, in a simplified manner in Fig. 3 and in Fig. 13 for various embodiments of the device 1. The filter tube 10 is surrounded by an annular space area 62, which is filled with a gravel pack. In particular, the annular space area 62 immediately adjacent to the filter tube 10 comprises an inner backfill 62±, wherein an outer backfill 62a is provided radially adjacent thereto. In this respect, the annular space area 62 comprises a double backfill, wherein these backfills differ from one another in respect of their permeability. The annular space area 62 with its two backfills is also represented in a simplified manner in the representation in Fig. 14. The annular space area 62 is surrounded by adjoining rock 64.

The device 1 receives an incoming flow of a volume of water radially from the rock 64. As a consequence of the outer open end sides of the external tube 26, a hydraulic balancing flow is established automatically between the end sides of the device 1 through the outer annular space 38, in the event of the device 1 receiving an incoming flow of water volumes of different sizes at its end sides. In other words, the hydraulic connection HV causes an automatic suction flow control through the outer annular space 38, the consequence of which is that more or less the same quantities of water can enter into the upper removal chamber 18.1 and 18.2.

Operation of the pumping device 20 causes water to be sucked in through the connecting line 52. As described previously, both the inner annular space 46 and the internal tube 44 are connected jointly via the connection coupling 50 to the connecting line 52 and, as a result, to the pumping device 20. As a consequence of this, during operation of the pumping device 20, water is pumped out or discharged from the upper removal chamber 18.1 on the one hand, in particular through the hydraulic connection 22, which is formed by the rectangular tubes 42K and the internal annular space 46. It is important in this respect for the intermediate tube 36 at its lower end side 36u, and thus also the inner annular space 46, to be of closed configuration, as described, in relation to the outer circumferential surface of the internal tube 44, so that pumping of water from the inner annular space 46 is possible during operation of the pumping device 20.

In a similar manner, during operation of the pumping device 20, water is also pumped out or discharged from the lower removal chamber 18.2, in particular through the hydraulic connection 24 which is formed by the rectangular tubes 42L and the interior of the internal tube 44. These hydraulic connections 22, 24 are separated hydraulically from one another, wherein, by means of corresponding dimensioning of the tube elements concerned, it is possible to guarantee that water is pumped out from the upper removal chamber 18.1 and the lower removal chamber 18.2 at all times with an identical delivery rate. The entire water volume Q, which is pumped from the well by means of the device 1, is thus divided into identical parts Q/2 for the two removal chambers 18.1, 18.2.

The hydraulic connection HV, which is guaranteed through the outer annular space 38 of the device 1 between its end side, as described, brings about automatic self-control in relation to a balancing flow between the end sides of the device. Furthermore, as a result, an axial movement or displacement of the device 1 inside the filter tube 10 is simplified, because the flow resistance is reduced through the outer annular space 38 thanks to the hydraulic connection HV. In this context, reference may be made once more to the fact that a balancing flow inside the device 1 through its outer annular space 38 and pumping-out of water through the hydraulic connections 22, 24 can take place simultaneously and without mutual interference, because these flow channels are hydraulically separated from each other.

Various areas, in which the water flows from the rock 64 through the annular space area 62 in the direction of the removal chambers 18.1, 18.2, are indicated by the reference designations I and II in the representations in Fig. 3 and 13. In the areas I, the water flows approximately parallel to the longitudinal axis L of the device 1 in the direction of a respective removal chamber. In the areas II, a gentle change takes place in the direction of the water flow, in order finally to enter radially into a respective removal chamber 18.1, 18.2. At the height of the line U, a reversal of the water flow takes place in the opposite direction. The representation in Fig. 14 illustrates in a highly simplified manner the paths of the water flow in the direction of the device 1 and the resulting directional change of the water flow.

The device 1 is especially suitable as a so-called "displaced chamber", wherein it is moved constantly along the filter tube 10, while the pumping device 20 is in operation and, as a result, as described, water is pumped out from the two removal chambers 18.1, 18.2. A suchlike mode of operation of the device 1 results in highly effective pore space stimulation inside the backfills of the annular space areas 62 and of the rock 64, because the water flow, in relation to a specific point inside the rock 64 or the annular space filling 62, then varies by up to 180°. As a result, more particles can be discharged through the pore channels of the annular space filling 62 and of the rock 64. The aforementioned reversal of the direction of flow by 180° takes place especially in those areas II which are symbolized in the representations in Fig. 3 and Fig. 13.

Connection means 58 (see Fig.4), which permit the attachment of further equipment to the device for well maintenance, can be provided on the lower end side 27u of the external tube 26. For example, the connection means 58 can be configured as annular elements, as hooks or the like. Further equipment for well maintenance can include an impulse generator, by which hydromechanical impulses are introduced into the well. For the sake of simplicity, the connection means 58 are represented only in Fig. 4, and they are not depicted in Fig. 3 and Fig. 13.

Finally, reference may be made to the fact that, depending on the geometrical dimensions of the granule filter and of the granule sizes of a respective well, it is possible with the inventive device 1 in the simplest constructive manner, to set an axial height of the volume bodies and a respective height of the removal chambers variably, and thus to guarantee an optimal use of the device 1.

Claims

An apparatus (1) for activating or purifying seepage wells with a filter tube (10) comprising a first volume body (12) and a second volume body (13), the volume bodies (12; 13) having their respective outside diameter being substantially adjustable the inner diameter of the filter tube (10) and on their outer circumferential surface each have sealing means (16) by which a sealing effect can be obtained with respect to the inner wall of the file tube (10), and at least one removal chamber ( 18), which can be formed between the first and second volume bodies (12; 13) and the inner wall of the filter tube (10), the withdrawal chamber (18) being hydraulically connected to a pump unit (20), and where during operation of the pump unit ( 20) water can be pumped out of the withdrawal chamber (18), between the first and second volume bodies (12; 13) in the longitudinal direction of the device (1) two withdrawal chambers (18.1; 18.2) are formed in the form of an upper withdrawal chamber (1). 8.1) and a lower withdrawal chamber (18.2) which is hydraulically separated from each other and by separate hydraulic connections (22; 24) each can be connected to the pump unit (20), and an intermediate tube is arranged, characterized in that an outer tube (26) is provided along the longitudinal axis of the device (1), the volume bodies (12; 13) being able to is placed on an outer circumferential surface of the outer tube (26) and the intermediate tube (36) is positioned coaxially within the outer tube (26), forming an outer annulus between the outer tube (26) and the intermediate tube (36) (38).

Device (1) according to claim 1, characterized in that an inner tube (44) is disposed inside the outer tube (26) with the inner tube (44) extending inside the intermediate tube (36) and thereby forming an inner annulus (46) between the inner tube (44) and the intermediate tube (46), the upper withdrawal chamber (18.1) being hydraulically connected either to the inner annulus (46) or to the interior of the intermediate tube (36), and the lower take-out chamber (18.2) is hydraulically connected either to the interior of the intermediate tube (36) or to the inner annulus (46) so that the inner annulus (46) and the inner tube (44) each form separate hydraulic connections ( 22; 24) for the outlet chambers (18.1; 18.2) of the pump unit (20).

Device (1) according to claim 2, characterized in that recesses (A26) extending in parallel with the longitudinal axis (L) of the outer tube (26) adjacent to the removal chambers (18.1; 18.2) are formed. outer tubes (26), with grooves (A36) extending parallel to the longitudinal axis (L) of the outer tubes (26) and extending in the wall of the intermediate tube (36) adjacent to the upper removal chamber (18.1) so that they face the recesses (A26) of the outer tube (26), connecting channels (40) from the recesses (A26) of the outer tube (26) radially through the outer annular space (38) to the respective recesses (A36) ) in the intermediate tube (36) such that the upper take-out chamber (18.1) is hydraulically connected to the inner annular space (46) and is hydraulically separated from the outer annular space (38), preferably connecting channels (40) between the recesses (A) which are formed in the individual tubes, so d e are facing each other, each formed by square tubes (42K; 42L) which, with their longitudinal axis, extend parallel to the longitudinal axis (L) of the device (1) and extend radially between the facing recesses (A) to form a hydraulic connection therebetween.

Device (1) according to claim 2 or 3, characterized in that the inner tube (44) extends inside the outer tube (26) at axial length at least to the region of the lower withdrawal chamber (18.2), in the wall of the inner tube (44) adjacent to the lower take-out chamber (18.2) are formed recesses (A44) which extend parallel to the longitudinal axis (L) of the outer tube (26) and opposite to the recesses (A26) thereof. outer tubes (26), connecting channels passing radially (A26) in the outer tubing (26) radially through the annular space (48) formed between the inner tubing (44) and the outer tubing (26) to the respective recesses ( A44) in the inner tube (44) such that the lower take-out chamber (18.2) is hydraulically connected to the interior of the inner tube (44) and is hydraulically separated from the annulus (48) between the inner tube (44) and the outside tube (26), preferably the intermediate tube (36) passing through the outer tube (26) from an upper end of the device (1) to approximately a region in the center thereof, further preferred that the inner tube (44) passes through the outer tube (26) substantially along its entire length. length.

Device (1) according to one of claims 2 to 4, characterized in that the outer pipe (26) is open in its outer end sides (27o, 27u), the hydraulic connection (HV) between the outer end sides (27o, 27u) on the outer tube (26) extends through the outer annulus (38) and the annulus (48) formed between the inner tube (44) and the outer tube (26).

Device (1) according to one of claims 1 to 5, characterized in that the respective spacers (28) are arranged in the area of the removal chambers (18.1; 18.2) on the outer circumferential surface of the outer tube (26). which ensure a distance between the volume bodies (12; 13) relative to each other and thereby a radial inflow of water into the withdrawal chambers (18.1; 18.2), preferably that the spacers (28) can be displaced relative to the outer tube (26) in the direction with the longitudinal axis of the device (1) and can be fixed in a predetermined position on the outer tube (26).

Device (1) according to claim 6, characterized in that the spacers (28) are formed in the form of ring curves (30) which have two ring elements (32) spaced apart by means of struts (34) in axial position. direction of the device (1), a distance between the two ring elements (32) defining an axial height (h) of a respective removal chamber (18.1; 18.2).

Device (1) according to one of claims 1 to 7, characterized in that the wall of the outer tube (26) on its upper end side (27o) is provided with perforations (54) along the circumference, so that particles, in particular sand, sediments or the like may fall through the perforations (54) into the outer tube (26), thereby preventing deposits in an upper end side (27o) of the outer tube (26), preferably the perforations being formed by holes (54) or the like.

Device (1) according to one of claims 1 to 8, characterized in that a third volume body (14) is provided in the middle, which is located between the upper withdrawal chamber (18.1) and the lower withdrawal chamber (18.2), the third volume body (14) having its outer diameter substantially adapted to the inner diameter of the filter tube (10) and having on its outer circumferential surface sealing means (16) with which a sealing effect can be set with respect to the inner wall of the filter tube (10). ), preferably the third volume body (14) can be mounted on an outer circumferential surface of the outer tube (26).

Device (1) according to claim 3 or one of claims 3 to 9 with reference to claim 3, characterized in that an axial length (I) of the recesses (A) formed in the individual tubes and an axial length thereof adjacent connecting ducts (42K; 42L) are greater than the effective axial height (h) of an adjacent removal chamber (18.1; 18.2), a portion of the recesses (A) formed in the outer tube (26) can be covered by the volume bodies ( 12; 13) at the ends and / or of the volume body in the center (14).

Device (1) according to one of claims 1 to 10, characterized in that the first, second and / or third volume bodies (12; 13; 14) can be displaced relative to the outer tube (26) in the direction of a longitudinal axis. (L) on the device (1) and can be fixed in a predetermined position on the outer tube (26).

Device (1) according to claim 11, characterized in that the volume bodies (12, 13, 14) and at least one ring basket (30) are arranged adjacent one another on the outer tube (26) and thereby contact with one another with their axial end sides, whereby clamping devices (29o, 29u) which are in contact with the outer end sides of the first and second volume bodies (12, 13) can be arranged on the outer tube (26) thereby defining both the first and second volume bodies (12, 13) as well as at least one annular basket (30) and, where appropriate, additional parts located on the outer tube (26) between the first and second volume bodies (12, 13) with for an axial position on the outer tube (26).

Device (1) according to one of claims 1 to 12, characterized in that the sealing means (16) on the relevant outer circumferential surfaces of the volume bodies (12; 13; 14) or the volume bodies themselves (12; 13; 14) have open-foam foam material. cells or brushes to ensure a sufficient sealing effect with respect to the inner wall of the filter tube (10), preferably that the sealing means (16) or the volume bodies (12; 13; 14) consist of foam material with open cells or brushes.

Device (1) according to claim 13, wherein the sealing means and / or the volume bodies have a changeable volume, whereby the sealing means can be increased radially outwardly by the supply of a fluid in the volume.

A method of activating or purifying seepage wells with a filter tube (10), wherein a device (1) according to one of claims 1 to 14 is constantly moved upwards or downwards along the filter tube (10), and thereby by means of the pump unit ( 20) water is discharged and discharged from the two sampling chambers (18.1; 18.2) onto the device (1) simultaneously.