DK2334874T3

DK2334874T3 - Device and method for activation or cleaning the chambers

Info

Publication number: DK2334874T3
Application number: DK08843205.9T
Authority: DK
Inventors: Peter Nillert
Original assignee: Teftorec Gmbh
Priority date: 2007-10-23
Filing date: 2008-10-22
Publication date: 2016-06-13
Also published as: WO2009052791A3; EP2334874A2; EP2334874B1; DE102007050966A1; WO2009052791A2; DE202008014113U1

Description

The invention relates to a device for activating or cleaning wells according to the preamble of claim 1, and a corresponding method for the same intended use according to the preamble of claim 5.

During the manufacture of filter strands in the soil for pumping ground water, it is necessary after completing the well structure to bring out the impurities and sand grains of low diameter, which can be extracted through suffusion, from the filter gravel / rim placed in an annulus space between the filter chamber and borehole edge. The discharge of such impurities or particles is termed as activation. The objective of activating a well is to generate the biggest possible pore space in the filter annulus space and the adjacent soil so that the flow resistance to the ground water seeping in the well becomes preferably low and the lowering of the pressure level of the ground water in and around the well turns out to be as low as possible. During activation, silt, fine sand and other small mineral and organic particles from the adjacent soil layers, which can be transported with the flowing ground water through the pores of the supporting soil skeleton at the correspondingly high speed, can enter in the well and consequently be pumped out.

The regeneration of wells includes all measures, which help in removing the mineral and/or organic depositions from the well annulus space and the adjacent ground arising during the operation of a well. The methods used therefor follow the principle of separation or removal of depositions and adhesion of the filter material and the supporting soil skeleton of the adjacent ground and the discharge of these particles through the well filter. Different methods and devices are known for separation and removal, which make use of hydro-mechanical, hydro-pneumatic and chemical principles.

For discharging the deposited and/or dissolved particles from the annulus space and the adjacent ground, it is necessary to generate possibly high flow speeds in the area to be cleaned. Known methods and devices used therefor reduce the well filter to be handled to a work section by placing a working chamber with seals placed at both its ends in the filter tube. As per state-of-the-art technology, such a working chamber is described in the 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 each other and an inner wall of the filter tube. Through this working chamber, whose height/length is comparatively short as compared to the total length of the filter tube, about 5 to 10 times higher flow rate is pumped than in case of normal well operation via this sub-section of the well filter. Because of the so-called permeability contrast, according to which the water permeability in gravel filling in the filter annulus space is greater than that of the adjacent ground, the effect of the increased flow rate is only negligible on the flow speed in the annulus space and in the adjacent ground. In addition, water always flows in the annulus space over the entire length of filter tube radially from the adjacent ground. The ground water enters in the filter tube above and below the working chamber and flows in the annulus space and, in particular, within the filter tube in the direction of the working chamber, wherein the ground water flowing in the filter tube circulates at the sides of the shut-off bodies for entering in the working chamber. Through this, the flow portion of the well water in the annulus space area is reduced laterally or radially adjacent to the working chamber and its flow speed is reduced, which has a negative effect on the quality of cleaning.

Conventional devices, such as the ones according to DE 81 20 151, also have the disadvantage that even in case of a considerably high pumping rate, the cleaning efficiency is not optimum in the annulus space and, in particular, in the adjacent ground. A generic device with the features of the preamble according to claim 1 is known from US-A-2 288 233 and US-A-3 032 116. A generic method with the features of the preamble according to claim 5 is known from DE 40 17 013 Al, DE 285 159 A, US-A-2 512 801 and DE 973 316 C. A generic device with the features of the preamble according to claim 1 is similarly known from GB-A-2 347 702. Volume bodies are used in such a device, each of which consists of a rigid cylindrical body with a diameter smaller than a bore hole of a filter tube well and has a flexible layer on the outer periphery, whose diameter is greater than that of the filter tube. For achieving a sealing effect of the flexible layer vis-a-vis the filter tube an inner pressure is generated within the flexible layer, which presses this flexible layer against the filter tube and brings it in contact with its wall.

Accordingly, the object of the invention is to provide a device and a method for activating or cleaning wells, wherein for the device the sealing effect vis-a-vis the filter tube is realized by using robust and simple means, and wherein for the method the particle discharge is made more intensive and the working time necessary therefor is reduced with simple means.

The above object is solved by a device with the features of claim 1 and by a method with the features of claim 5. Advantageous further embodiments of the invention are defined in the dependent claims. A device according to the invention for activation or cleaning of filter tube wells includes a first and a second volume body, which each extend alongside the longitudinal axis of the well, with their outer diameter being adjusted to the inner diameter of the filter tube, and on their outer circumferential surface being formed in a flexible manner relative to the longitudinal axis of the well so that a sealing effect is achieved between the outer circumferential surfaces of the respective volume bodies and the inner wall of the filter tube. At least one of the two volume bodies is made up of a rigid, cylindrical body, the outer diameter of which is formed smaller than the inner diameter of the filter tube. Between the first and the second volume body and the inner wall of the filter tube, a removal space is formed, which can be connected hydraulically with the pumping device and whose height is determined by the distance between the two volume bodies. The longitudinal extension of the respective volume bodies in the direction of the longitudinal axis of the device corresponds to the height of the removal space. A flexible layer is arranged at the outer circumferential surface of the cylindrical body. The outer diameter of this flexible layer is slightly larger than the inner diameter of the filter tube. The flexible layer is made of foam material, in particular, of an open-cell foam material or of foam rubber.

The device according to the invention is characterized by the fact that both the volume bodies fulfil the function of a sealing piston, wherein the volume bodies enclose a central chamber arranged between then in the form of said removal space. In their function as sealing piston, the volume bodies ensure a sealing vis-a-vis the filter tube of the well along its entire length. In doing so, the sealing effect vis-å-vis the filter tube is established by the deformation of the foam material, of which the flexible layer is made, e.g. when introducing into the filter tube. When the device is inserted in the filter tube, the flexible layer adapts itself to the inner diameter of the filter tube and fully absorbs the water present in the well. This causes an adequate sealing between the outer circumferential surface of the cylindrical body and the inner wall of the filter tube, in order to seal the filter tube in this area.

The device according to the invention is equally suitable for use in vertical and horizontal filter strands of filter tube wells with filter gravel placed in the annulus space between the filter tube and the ground, as well as also for use in well structures without the incorporated filter gravel. Upon introducing the device into the filter tube, at first the second volume body comes in contact with the well water. The sealing pistons in the form of both the volume bodies seal the filter tube of the well on both sides of the removal space vis-a-vis the annulus space or the adjacent ground i.e. in the longitudinal direction of the well. The effect of this is that water flows into the removal space radially through the annulus space or from the adjacent ground in an increased manner, supplemented by parts of the well water, which flow in the area of the annulus space adjacent to the volume bodies axially with respect to the longitudinal axis of the well in the direction of the removal space and then enter in it. Accordingly, the volume bodies cause an inflow of the well water into the central open chamber in form of the removal space, wherein the inflow sets itself longitudinal or parallel to the longitudinal axis of the well vis-a-vis the sealing volume bodies. Both the volume bodies and the increased flow speed caused by these radially to the annulus space improve, on the one hand, the in-depth cleaning in the ground and, on the other hand, the cleaning in the annulus space adjacent to the volume bodies.

In an advantageous further embodiment of the invention, the distance between the volume bodies can be set such that length ratio between the height of the removal space and the longitudinal extension of the volume bodies can be changed. The smaller the height of the removal space with respect to the respective longitudinal extension of both the volume bodies is, the deeper is the cleaning effect in the adjacent ground. By adjusting the height of the removal space, an adjustment can be done to specific features of the well, without having to bring the device out of filter tube of the well in doing so. For instance, the distance between both the volume bodies can be achieved by means of a telescopic stamp or a similar device, which is adjustable in its length, by means of which the volume bodies are connected with each other through their opposite lying front faces.

In an advantageous further embodiment of the invention, a first or a second shut-off disc can be arranged at the volume bodies adjacent to the removal space, wherein both the shutoff discs are concentric and are essentially spaced parallel to each other and are adjusted with their outer diameter to the inner diameter of the filter tube. The shut-off discs improve the sealing effect of the volume bodies vis-a-vis the inner wall of the filter tube and a defined boundary of the volume bodies to the removal space.

In an advantageous further embodiment of the invention, the device may comprise a conveyor line, which can be connected with a pumping device and which is in fluid connection with the removal space. The conveyor line can cross the first volume body so that the first volume body encompasses the conveyor line. The conveyor line is adequately designed as tensile stress and pressure-proof so that the device can safely be shifted inside the filter tube. A loosening of the volume bodies in case of such a shifting is prevented by the fact that they could be fixed to the first or to the second shut-off disc, for instance, by means of welding, screw connection or something similar.

In an advantageous further embodiment of the invention, at least one of the two volume bodies can be placed in a sliding way on the conveyor line so that by shifting this volume body relative to the conveyor line along the longitudinal axis of the well, the distance to the respectively other volume body and hence the height of the removal space can be changed. The volume body sliding with respect to the conveyor line can be fixed on it by means of a locking mechanism, in order to ensure a defined and unchanging height of the removal space.

The form of the volume bodies as rigid, cylindrical bodies with the flexible layer made of foam, foam rubber, etc. at its outer circumferential surface is suitable for use in the so- called wire filters, wherein the characteristic relief structure of the inner wall of the filter tube is sealed suitably by the volume body against a water flow between the filter wire rods.

In an advantageous further embodiment of the invention, in case of the variant of the volume body with the flexible layer at the outer circumferential surface of the cylindrical body, this flexible layer can be replaced, if the cell structure of this layer gets damaged or destroyed because of frequently shifting the device along the longitudinal axis of the well.

In an advantageous further embodiment of the invention both the volume bodies can be made as one-piece from a ring-shaped cylinder, whose outer wall is designed as perforated at least in the region of the removal space. Consequently, both the volume bodies form the upper and the lower part of the device respectively. A lower part of the device i.e. the second volume body is closed at its lower front face, wherein an upper part of the device i.e. the first volume body shows an opening at its upper front face, in which the conveyor line enters or else is fixed in it. On the outer circumferential surface of the ring-shaped cylinder, adjacent to the removal space i.e. in an upper and lower area of the cylinder, sealing elements can be placed in form of the aforesaid explained flexible layer, which ensure a sealing against the inner wall of the well filter tube. In case the perforation of the ring-shaped cylinder extends over more than just its middle part, then the length of the outer wall of the ring-shaped cylinder adjacent to the removal space or its height can be set by a length of a sealing body placed on the outer circumferential surface of the ring-shaped cylinder.

In an advantageous further embodiment of the invention, the shut-off discs can be made respectively from two disc elements, between which a sealing disc is fixed, wherein the outer diameter of the disc element is less than the inner diameter of the filter tube and the outer diameter of the sealing disc is greater than the inner diameter of the filter tube. A respective sealing disc can be made from soft rubber or something similar, which is fixed between a shut-off disc and a further shim with a shut-off disc having a similar or the same diameter. In the variant of the volume body with a flexible layer at the outer circumferential surface of the cylindrical body, the sealing disc prevents a recirculation of the shut-off discs from the flexible layer inside in the removal space, which improves the cleaning of the adjacent annulus space.

In an advantageous further embodiment of the invention, the conveyor line can completely pass through the removal space and lead till the second shut-off disc, wherein the conveyor line is built as perforated within the removal space. This enables a simple and strong structure of the device, since the second shut-off disc can be fixed at a lower free front face of the conveyor line. A fluid connection between the conveyor line and the removal space is ensured by its perforation, wherein the perforation is selected as adequately large under consideration of the particles to be discharged.

In an advantageous further embodiment of the invention, the longitudinal extension of the first and the second volume body can be of equal length along the filter tube. This supports a uniform cleaning effect of the annulus space on both sides of the removal space. It is of further advantage, when the longitudinal extension of each volume body essentially matches the height of the removal space. In doing so, the complete length / height of the device is determined up to one-third through the height of the removal space and up to two-thirds through the longitudinal extension of the volume bodies. Such a design of the device enables an efficient cleaning / activation of the well, since each section of the filter tube, except the topmost and the lower most, is flowed-through respectively three times after a corresponding shifting of the device within the filter tube. In doing so, practically a precleaning, an in-depth cleaning and a post-cleaning of each filter section take place, wherein a measurement and control of the cleaning process can be traced integrally for all the three sections. A method according to the invention for activating or cleaning filter tube wells includes the following steps: a) Providing a device, in particular as explained above, wherein the device is operated by applying a suction pressure at the removal space by means of a pumping device so that water is conveyed from the removal space, and thus particles are discharged from the filter tube well, b) Introducing the device into a filter tube of a filter tube well, until the device is completely immersed in the well water, c) Operation of the device in an initial operational position, in which the device is arranged in a specific position with respect to the longitudinal axis of the well, d) Shifting of the device by a distance in another operational position, wherein the distance essentially corresponds to the height of the removal space, and e) Operation of the device in the other operational position.

Furthermore, in the method according to the present invention, the steps d and e are repeated once in a step f, before, in a step g, the device is shifted in a new operational position in the same direction along the length of the filter tube which is the same as three times the height of the removal space so that in the newly set operational position the front face of the second volume body facing away from the removal space is present in a position, in which the front face of the first volume body facing away from the removal space was present in the earlier operational position. Thereafter, in a step h, the device is operated in the new operational position according to step g, wherein a suction pressure is applied to the removal space.

The advantage of the method according to the invention is that after a first cleaning cycle the device is shifted into a new operational position essentially by the height of the removal space so that along with a continuous cleaning of the ground, a second, intensive cleaning of the same section of the annulus space also takes place. This takes place when the steps d) and e) are repeated according to an advantageous further embodiment of the invention. A shifting of the device into a further operational position can be done depending upon the measurement of the solid content of the particles contained in the water being pumped i.e. when this solid content falls short of a permissible limiting value. This indicates that the corresponding section of the well has been subject to an adequate cleaning.

Such a method is especially suitable for cleaning / activating a well filter with a developed filter gravel annulus space. Since flowing takes place in a section of the annulus space only once, a very quick cleaning of the well along its entire length can be done with this method with respect to the annulus space. In case such a method is carried out with a device, in which the height of the removal space essentially matches the respective longitudinal extension of both the volume bodies, this device can be shifted by a distance in step g, which corresponds to three times the height of the removal space.

The invention is shown below schematically in the drawing by means of various embodiments and is explained in detail with reference to the drawing. The figures of the drawing show as follows :

Fig. 1 a simplified longitudinal cross-sectional view of a device with its essential components,

Fig. 2 a longitudinal cross-sectional view of the device of Fig. 1 in a filter tube of a well with ring gravel filling, Fig. 3a to 3c the device of Fig. 2 in different operational positions,

Fig. 4 the device of Fig. 1 / Fig. 2 in an initial operational position and a further operational position within the filter tube,

Fig. 5 the device of Fig. 4 in a further operational position, when it is shifted in the filter tube in the same direction alongside of the filter tube,

Fig. 6 a longitudinal cross-sectional view of a device in another embodiment,

Fig. 7 a longitudinal cross-sectional view of a device according to the invention,

Fig. 8 a strongly simplified longitudinal cross-sectional view of a device according to the invention in another embodiment, in which the distance of both the shut-off discs can be adjusted respective to each other.

Fig. 9 a simplified longitudinal cross-sectional view of a device according to the invention in another embodiment, and Fig. 10 a simplified longitudinal cross-sectional view of a device according to the invention in still another embodiment.

With reference to Fig. 1 to 5, a first embodiment of a device 1 is explained in detail below along with its structure and intended use.

The device 1 includes a conveyor line 2, which can be introduced lengthwise in a filter tube of a well, which is explained further below by taking reference to Fig. 2. At the conveyor line 2, a first shut-off disc 3 and a second shut-off disc 4 are fixed in such a way that both the shut-off discs 3, 4 are concentric and are spaced parallel to each other. When the device 1 with its conveyor line 2 and both the shut-off discs 3, 4 is inserted in a well filter tube, which is shown in Fig. 1 by a dashed line and is marked with reference number 5, a removal space 6 is formed between the first and the second shut-off disc 3, 4, and the inner wall of the filter tube 5. The height h of this removal space 6 is determined from the distance between both the shut-off discs 3, 4.

Between both the shut-off discs 3, 4, the conveyor line 2 is formed with openings and hence perforated so that a fluid connection is present between the conveyor line 2 and the removal space 6. By applying a suction pressure on the conveyor line 2, water can be pumped out of the removal space 6, which is indicated by an arrow F in Fig. 1.

Above the first shut-off disc 3 and outside of the removal space 6, a first volume body 7 is arranged, through which the conveyor line 2 passes. A second volume body 8 is arranged below the second shut-off disc 4 and outside of the removal space 6. Both the volume bodies 7, 8 are made of a flexible material, which is indicated in Fig. 1 by wavy lines. As a result of the flexible material, both the volume bodies 7, 8 are radially flexible with respect to the longitudinal axis 9 of the well. The solid bodies 7, 8 are fixed respectively at the first / second shut-off disc 3, 4 and extend along the longitudinal axis of the well 9 opposite to the removal space 6. Both the volume bodies 7, 8 are essentially adjusted in their outer diameter R to the inner diameter of the filter tube 5.

Both volume bodies 7, 8 can be filled with a fluid, wherein their outer circumferential surface expands in the direction of the inner wall of the filter tube 5 through a rise in pressure. This is indicated in Fig. 1 by means of a dotted line. In case the outer circumferential surface of both the volume bodies 7, 8 comes in contact with the inner wall of the filter tube 5 owing to the aforesaid increase in pressure and gets pressed against it, a sealing effect arises between the two .

Fig. 2 shows a longitudinal cross-sectional view of the device of Fig. 1, when it is completely introduced into a filter tube 5 of a well. The well shows a bore hole edge 10, which encompasses an annulus space 11. The annulus space 11 is filled with filter gravel / sand, wherein outside of the annulus space 11 natural ground 12 or the groundwater reservoir is present. Inside the annulus space 11, the filter tube 5 is inserted, which is formed with slits for a necessary permeability of water. Parallel to the conveyor line 2 there is a supply line 13, which passes through the first volume body 7 as well as the second volume body 8. Within the volume bodies 7, 8, the supply line 13 is present with perforated sections 13a so that there is a fluid connection between the supply line 13 and an inner space of the respective volume body 7, 8. A directional valve 14 is present the front face of the second volume body 8, which is opposite to the removal space 6. The conveyor line 2 is built as perforated between both the shut-off discs 3, 4 i.e. in the form of an inlet sieve 2a.

Upon a first insertion of the device 1 in the filter tube 5, the second volume body 8 and with that also the directional valve 14 come at first in contact with the well water. In doing so, the directional valve 14 is opened so that the well water can flow from below through the supply line 12 or through its perforated sections 13a in the inner space of the first and the second volume bodies 7, 8. In case the device 1 is shifted within the filter tube 5 into an initial operational position, the directional valve 14 is closed again. If now, as indicated by the double arrow in Fig. 2, liquid (e.g. water) is pumped from top in both the volume bodies 7, 8 and this results in an increase in internal pressure of the volume bodies, the outer circumferential surfaces of the volume bodies 7, 8 expand radially outside and come in a sealing contact with the inner wall of the filter tube 5. For shifting the device 1 within the filter tube 5 into a new operational position, the inner pressure within the first and the second volume body 7, 8 is reduced suitable so that the outer circumferential surfaces of both the volume bodies 7, 8 lose their contact with the inner wall of the filter tube 5.

The length L of the device 1 is made up of the height h of the removal space 6 and the longitudinal extension of the respective volume bodies 7, 8. As shown in Fig. 2, the height of the removal space 6 and the respective longitudinal extensions of both the volume bodies 7, 8 form equal one- third. Accordingly, the device in this embodiment is known as "symmetric dual piston chamber".

With reference to the embodiments as per Fig. 1 / Fig. 2, it is clear that the shut-off discs 3, 4 are optional so that this embodiment can also work without the shut-off discs. In case the shut-off discs 3, 4 are omitted, the front faces of the volume bodies 7, 8 adjacent to the removal space 6 are designed as stiffened.

Given below is an explanation in detail of the device 1 and its interaction with the well with respect to a specific well section with the help of Fig. 3a to 3c. This section of the well is marked with a double arrow in the Fig. 3a to 3c.

With reference to Fig. 3a, it is assumed that here the device 1 is brought in an initial operational position and an excess pressure is set in both the volume bodies 7, 8 to such an extent that both the volume bodies are present at the inner wall of the filter tube 5 with a sealing effect. Thereafter, a suction pressure is applied at the conveyor line 2 so that well water is pumped out of the removal space 6. In the actual section of the well according to the double arrow of Fig. 3a, the filter tube 5 is blocked by the first volume body 7. For this reason, the well water flows through just this section of the well essentially parallel to the longitudinal axis of the well 9 from top in the direction of the removal space 6 of the device 1, which leads to a cleaning of the annulus space 11 in this area. The comparatively high flow velocity, which gets set in the named area of the annulus space 11, leads to a thorough discharge of dirt particles and the like.

After an operation of the device 1 in the operational position of Fig. 3a for an adequately long time, the device 1 is subsequently shifted in a further operational position of the filter tube 5, i.e. approximately by a distance, which is the same as the height h of the removal space 6. This is indicated in Fig. 3b. Upon a renewed operation of device 1, when after increasing the inner pressure in both the volume bodies 7, 8, a suction pressure is applied at the conveyor line 2, there is a distinct radial inflow of well water inside the removal space 6 in the section of the well marked by the double arrow. This is indicated in Fig. 3b through corresponding arrows. This is associated not only with a cleaning of the annulus space 11, but also with a cleaning in the groundwater reservoir 12 lying adjacent to the annulus space 11. The cleaning of the groundwater reservoir 12 is related to the increased flow speed in the section of the well under question, the reason for which is that owing to the blocking effect of the first and the second volume bodies 7, 8 adjacent to the removal space 6, the well water cannot flow directly out of the filter tube 5 and hence the portion of the flow in the area of the annulus space is increased radially adjacent to the removal space 6.

Starting from the operational position according to Fig. 3b, the device 1 is then shifted again within the filter tube 5 by a distance, which essentially matches the height of the removal space 6. This is shown in Fig. 3c. In case of a renewed operation of device 1, well water flows out of the section of the well marked by the double area from below through the annulus space 11 and enters upward in the removal space 6. This causes a renewed cleaning of the annulus space 11 of this section of the well. A comparison of Fig. 3a to 3c makes it clear that the section of the well indicated by the double arrow is cleaned twice with respect to its annulus space (Fig. 3a and Fig. 3c), and in the operational position of Fig. 3b, not only its annulus space, but also the adjacent groundwater reservoir is cleaned. The operational positions of Fig. 3a / Fig. 3c have the effect of a pre-cleaning and a post-cleaning of the well annulus space.

After ending the well cleaning / activation and before pulling the device out of the well, the directional valve 14 can be opened, in order to drain out water from both the volume bodies 7, 8 downward in the well. This reduces the weight of device 1 and makes it easy to pull out the device from the filter tube 5.

With reference to Fig. 4 and 5, a sequence is shown below, with which the well can be cleaned efficiently by means of the device according to Fig. 1 mainly with reference to its annulus space 11.

The Fig. 4 and 5 respectively show a longitudinal cross-section of the well and of the device 1. In Fig 4 on the left, the device 1 is shown in an initial operational position, similar to the position of Fig. 3a. Upon an operation of the device 1 in this position, the annulus space sections I are cleaned thoroughly, because in these sections well water essentially flows in parallel to the longitudinal axis 9 of the well (Fig. 1) into the removal space 6. The annulus space sections I border on the sides at the first / second volume bodies 7, 8. After the annulus space sections have been cleaned or activated adequately, the device 1 is shifted by a distance, which essentially is the same as the height of the removal space 6, in the filter tube 5, which is shown on the right in Fig. 4. In this new operational position, the annulus space sections II are then cleaned when the device 1 is operated again, which border on the sides at the first and the second volume bodies 7, 8.

Along with the cleaning of the annulus space sections I and II because of the axial flow of well water in the removal space 6, the annulus space II (in the operational position shown on the left in Fig. 4) or the annulus space I (in the operational position shown on the right in Fig. 4) are cleaned in addition by the radial flow of the well water, similar to the illustration of Fig. 3b.

Subsequent to an operation of the device in the position as shown in Fig. 4 on the right, the device 1 is shifted within the filter tube 5 in the same direction by a distance, which in general is the same as the complete length of the device or three times the height h of the removal space 6 for the embodiment according to Fig. 4, see Fig. 5. In this way, the front face of the second volume body 8, facing away from the removal space 6, reaches a position, at which the front face of the first volume body 7 facing away from the removal space 6 had been present in the previous operational position (Fig. 4 right). Starting from the new operational position of the device 1 shown in Fig. 5, the steps explained with the help of Fig. 4 are repeated. Such a shifting of the device 1 within the filter tube 5 avoids that a respective section of the annulus space is covered over multiple times by the volume bodies of the device 1. This enables a quick and efficient cleaning of the annulus space 11 of the well along its entire length .

With reference to Fig. 6, a further embodiment of the device 1 is explained. Same components explained above in the device of Fig. 1 or Fig. 2 are designated with the same reference signs and are not explained again in order to avoid repetitions.

The device of Fig. 6 comprises an axially shortened inlet sieve 2a', wherein the shut-off discs 3 and 4 have a shorter distance to each other. Accordingly, the height of the removal space 6 is shorter. The same also applies to the length L of the device, which is made up of the height h of the removal space 6 and the longitudinal extension of both the volume bodies 7, 8. The device as per Fig. 6 is termed as "shortened double piston chamber".

Owing to the low height h of the removal space 6, the radial flow to the side of the removal space 6 increases within the annulus space 11 and in the groundwater reservoir 12, when the device 1 is operated. This not only increases the cleaning within the annulus space 11 in this area, but instead also improves a cleaning with deep action within the ground or the groundwater reservoir 12. Upon shifting the device 1 within the filter tube 5, the offset of the device is restricted to the height of the removal space 6. The extra effort in operating the device resulting from this is contrasted by the explained deep action discharge of particles from the groundwater reservoir 12 adjacent to the annulus space 11.

With reference to the above embodiments according to Fig. 1-6, it is indicated that these do not fall under the scope of claim 1, but instead are meant only to explain the underlying functioning of the invention. In case of the embodiments according to Fig. 1-6, alternative to the fact that both the volume bodies are made of a flexible material and are filled with a liquid for a sealing against the inner wall of the filter tube 5, it can also be provided that both the volume bodies are formed in the shape of cylindrical rigid body, wherein a flexible layer is attached at the outer circumferential surfaces of both these volume bodies, which is made from an open-celled foam or foam rubber. With its outer diameter, the flexible layer is formed negligibly bigger than the inner diameter of the filter tube. The use of a foam-like flexible layer in the embodiments according to Fig. 1 to 6 is advantageous especially for operating the device, because a shifting of the device 1 within the filter tube 5 is possible without changing the inner pressure within the volume bodies 7, 8 and can accordingly be done faster. In the same way, all pressure lines, for instance, in the form of the aforesaid supply lines, which otherwise would be necessary for filling the volume bodies with a liquid, are not necessary.

With reference to Fig. 7, an embodiment of device 1 according to the invention is explained, which is especially suitable for use in wells without filter annulus space i.e. without the incorporated filter gravel filling. Fig. 7 shows a longitudinal cross-sectional view through the well design and the device 1, 5, whose structure is explained in detail below.

The device 1, according to the embodiment of Fig. 7, comprises a conveyor line 2, which ends in the first shut-off disc 3'. Below the first shut-off disc 3', a second shut-off disc 4' is fixed concentric and essentially parallel to it by means of duct spacers 15. The first volume body 7' is formed in the shape of a rigid cylindrical body. The conveyor line 2 passes through the first volume body 7', at which the first shut-off disc 3 is fixed. The second volume body 8' is similarly formed in the shape of a rigid cylindrical body, which is fixed below the second shut-off disc 4. Both the shut-off discs 3', 4', similar to the embodiment of Fig. 1, are adjusted with their outer diameter to the inner diameter of the filter tube 5. Both the volume bodies 7' , 8' are with their respective outer diameters slightly smaller than the inner diameter of the filter tube. At the outer circumferential surfaces of the first or the second volume body 7', 8' respectively a flexible layer 17 is fixed, which is made from an open-celled foam.

With its outer diameter, the layer 17 is formed slightly larger than the inner diameter of the filter tube 5.

Upon an introduction of the device of Fig. 7 in the filter tube 5, the flexible layers 17 at the first and the second volume body 7' , 8' are slightly pressed together that they tightly cling to the inner wall of the filter tube 5. Upon a contact with the well water, the pores of the flexible layer 17 get filled, which gives rise to a sealing effect between the outer circumferential surface of the first / second volume body 7', 8' and the inner wall of the filter tube 5.

With the conveyor line 2 ending in a corresponding opening of the first shut-off disc 3', a fluid connection is established between the conveyor line 2 and the removal space 6' formed between the first and the second shut-off discs 3', 4'.

Applying a suction pressure at the conveyor line 2 causes a pumping of well water out of the removal space 6', which simultaneously leads to a discharge of particles from the well. The height h of the removal space 6' is approximately 10% of the total length of device 1. Similar to the embodiment of Fig. 6, in the device of the embodiment given in Fig. 7 the annulus space area, which borders radially at the removal space 6', is cleaned with deep action including the neighbouring groundwater reservoir 12 because of the sealing effect of the volume bodies 7' , 8' . This is achieved by the high radial flow speed, in particular, in the adjacent ground in the area between the volume bodies 7', 8'.

The cleaning / activation of the well by means of the device of Fig. 7 is done in a continuous process, in which the device is continually shifted inside the filter tube 5 during its operation. The optimum shifting speed can be selected in such a way that particles that can be discharged can be transported from a place lying at a certain radial distance from the filter in annulus space to the removal space 6' during the period, in which the well water flow acts on this place. The particle discharge achieved can be measured continually and hence the efficiency of well cleaning / activation can be controlled. In case the particle discharge does not achieve the reference value, the operation of the device 1 can be repeated at this point of the well, wherein the speed of shifting the device within the filter tube 5 is consistent. Consequently, the deep action of the cleaning measure is regulated via the height of the feed rate.

The device according to Fig. 7 is called as "moving double piston split chamber" and is especially suitable for activating and regenerating the well systems without the incorporated filter gravel filling. Such a type of well is shown in Fig. 7, in which the ground or the groundwater reservoir 12 border directly at the bore-hole edge.

Fig. 8 shows a principally simplified representation of another embodiment of the device 1 according to the invention. In this case, the conveyor line 2 ends in a corresponding opening of the first shut-off disc 3". Below the first shutoff disc 3", a second shut-off disc 4" is fixed concentric and, in particular, parallel to it i.e. by means of a number of telescope stamps 18. Using this telescope stamp, the distance of both the shut-off discs 3", 4" can be set and hence the height of the removal space between both the shutoff discs can be changed. Fig. 8 shows a lower distance of both the shut-off discs to one another with thick continuous lines. The dotted line shows a changed position for the second shut-off disc 4", in which it has a higher distance to the first shut-off disc 3".

Two volume bodies 7", 8" are fixed respectively at the first and the second shut-off disc 3", 4", wherein the second shut off disc 8" is shown only partly for simplification. Upon introducing the device 1, the volume bodies 7", 8" seal the filter tube 5. The volume bodies 7", 8" can be covered with a flexible layer (see Fig. 7), which ensures an adequate sealing effect with the inner wall of the filter tube 5. The flexible layer enables a shifting of the device 1 within the filter tube 5 without making a regulation of the pressure medium necessary with reference to the volume body. Moreover, the flexible layer enables an adjustment of both the shut-off discs 4" to each other for changing the height of the removal space 6.

Fig. 9 shows another design of the device 1 according to the invention in a longitudinal cross-sectional view. As compared to the aforesaid embodiments, components of this embodiment -given in the same design or same function - are designated with the same reference signs. The first and the second volume bodies 7''', 8''' are both essentially formed as rigid cylindrical bodies, whose outer diameter is selected slightly smaller than the inner diameter of the filter tube 5. On the outer circumferential surfaces of the volume bodies 7' ' ' , 8' ' ' , sealing elements are placed in the form of flexible layers 17, similar to the explanation given for Fig. 7.

The first volume body 7''' is crossed by a passage opening 19. The conveyor line 2 passes through this passage opening 19, wherein the inner diameter of the passage opening 19 and the outer diameter of the conveyor line are adjusted to each other in such a way that the first volume body 7' ' ' can be shifted on the conveyor line 9 in longitudinal axis 9 of the well without hindrance and play. The second volume body 8' ' ' is fixed at a free end of the conveyor line 2 e.g. through welding, etc. The conveyor line 2 is formed in its area adjacent to the second 15 volume body 7' ' ' . In the same way, as in the case of the design according to Fig. 1, the removal space 6 is formed between the two volume bodies 7' ' ' , 8' ' ' , wherein the distance of both the volume bodies 7' ' ', 8' ' ' determines the height h of the removal space 6.

By shifting the first volume body 7''' relative to the conveyor line 2, the height h of the removal space 6 can be changed. A locking mechanism 20 is placed at the first volume body 7 ' ' ', by means of which the first volume body 7' ' ' can be fixed with respect to the conveyor line. The locking mechanism defines a position of the first volume body 7''' with reference to the conveyor line 2, which results in a predetermined height h of the removal space 6. Depending upon the condition of the well, in which the device 1 is used, the height h of the removal space 6 can either be increased or decreased. The flexible layers 17, which are fixed respectively to the outer circumferential surface of the volume bodies 7''', 8''', enable a shifting of the first volume body 7 ' ' ' with respect to the conveyor line 2 as well as a shifting of the device 1 within the filter tube 5, when the first volume body 7' ' ' is locked at the conveyor line. Alternative to the flexible layer, a pressure-controlled sealing body can be used at the outer circumferential surface of the volume bodies, which comes under pressure with a liquid, similar to the design according to Fig. 1, when a seal seat is required. Upon shifting the first volume body 7''' or the complete device 1, the inner pressure of the sealing body is reduced accordingly so that it releases in a suitable way from the inner wall of the filter tube 5. Suitable pressure control lines can be given in the sealing bodies for feeding a liquid in the sealing bodies. For an easier insertion / pull out of the device 1 in / out of the well, the second i.e. the lower volume body 8' ' ' can be equipped with a directional valve 14, similar to the design given in Fig. 2.

The device 1 in the design according to Fig. 9 is characterized by being simple and strong, wherein the height h of the removal space 6 can be changed by using simple means. The height h of the removal space can also be set when the device 1 has already been shifted inside the filter tube 5.

Although not shown in Fig. 9, shut-off discs can be arranged at the volume bodies 7''8''' bordering the removal space 6, similar to the design given in Fig. 1. Here, it is clear that the shut-off disc placed at the first volume body 7''' shows a passage opening, through which the conveyor line 2 passes, in order to enable a shifting of the first volume body 7 ' ' ' together with this shut-off disc.

Fig. 10 shows another embodiment of the device 1 in a longitudinal cross-sectional view. As compared to the aforesaid embodiments, components in this embodiment are designated, given in the same design or same function, with the same reference sign. The first and the second volume bodies 7' ' ' ' , 8' ' ' ' are made as a single piece from a ring- shaped cylinder 21, wherein the first volume body 7'''' forms the upper part of this cylinder 21 and the lower volume body 8' ' ' ' forms the lower part of this cylinder 21. The cylinder 21 is closed at its lower end i.e. at a lower front face of the second volume body 8 ' ' ' ' , and has an opening 22 at its upper end i.e. at an upper front face of the first volume body 7' ' ' ' . The cylinder 21 is designed as inside hollow and hence forms a removal space 6, wherein the outer wall of the cylinder 21 is designed as perforated in the area of its middle one-third. Through this perforation, well water can flow in the cylinder 21 from outside, which is shown in Fig. 10 through arrows.

At the outer circumferential surface of the cylinder 21, flexible layers 17 are placed respectively in its upper and lower areas, which ensure a sealing of the device 1 against the inner wall of the filter tube 5 in the same way as shown in the embodiment according to Fig. 9. The height or length of the removal space 6 can be set through the length of the flexible layers, which are placed on the outer circumferential surfaces of the cylinder 21. Perforated areas of the outer wall of the cylinder 5 can be sealed by the flexible layers 17. Alternative to the flexible layers 17, the outer circumferential surface of the cylinder 21 can be sealed in the area of the first and second volume body 7' ' ' ', 8' ' ' ' against the inner wall of the filter tube 5 also by means of inner-pressure controlled sealing bodies.

The conveyor line 2 is inserted from top through the opening 22 in the removal space 6 i.e. in the inner area of the cylinder 21 and is connected to a submersible motor pump 23. The submersible motor pump 23 is inserted within the cylinder 21 and essentially extends parallel to the longitudinal axis of the cylinder 21. The length of the submersible motor pump 23 or the number of its motor stages is adjusted to the necessary delivery rate of the device 1. The submersible motor pump 23 has an inlet sieve 24, which is arranged in front of an inlet of the conveyor line and acts as a filter. The submersible motor pump 23 is enveloped in a casing pipe 24, which is open at its lower front face, where the submersible motor pump 23 ends. The casing pipe 24 is firmly connected, adjacent to the inlet sieve 24, with the outer circumferential surface of the conveyor pipe 2. The casing pipe 24 essentially fulfils two tasks: on one hand, to conduct the water pumped by the submersible motor pump 23 specifically in the direction of the inlet sieve 24, and on the other hand, to ensure a cooling of the submersible motor pump 23 through the well water passing along it. For this, it is important that the casing pipe 24 reaches in its longitudinal extension till below the last stage of the submersible motor pump 23.

In the operation of the submersible motor pump 23, well water is sucked, as shown in Fig. 10, from outside through the perforation of the outer wall of the cylinder 21 into the removal space 6, wherein the well water subsequently flows to the lower open front face of the casing pipe 24. After entry in the casing pipe, the well water is pumped past the submersible motor pump 23 upward in the direction of the inlet sieve 24 and is finally pumped out of the well in the conveyor line 2, as shown by the arrow F.

The embodiment of the device 1 as per Fig. 1 is very robust and is economical to manufacture owing to the one-piece design of the first and the second volume bodies 7'''', 8'''' in the form of the cylinder 21. Alternative to the illustration of Fig. 10, the submersible motor pump 23 can also be arranged outside the cylinder 21 or the removal space 6, in particular, when the submersible motor pump 23 shows a larger diameter owing to the necessarily high pump efficiency.

The embodiments according to Fig. 9 and 10 can be operated for cleaning or activating a well in the same way as the designs according to Fig. 2 and Fig. 6, and have the same quality of the cleaning effect. For avoiding repetitions, please refer to the explanations given above for Fig. 2 to Fig. 6 regarding the operation of the device.

Claims

A device (1) for activating or purifying filter tube wells with a filter tube (5), comprising a first and a second volume body (7, 8), each extending along the longitudinal axis (9) of the well, with its outer diameter is adapted to the inner diameter of the filter tube (5) and on its outer circumferential surface is flexibly formed at least radially with respect to the longitudinal axis (9) of the well, so as to obtain a sealing effect between the outer peripheral surfaces of the respective volume bodies (7, 8). (5) inner wall, wherein at least one of the two volume bodies (7, 8) consists of a rigid cylindrical body, which with its outer diameter is formed quite a bit smaller than the inner diameter of the filter tube (5), an outer circumferential surface of the cylindrical body is provided with a flexible layer (17), the outer diameter of the flexible layer (17) being slightly larger than the inner diameter of the filter tube (5), where In the first and second volumes (7, 8) and the inner wall of the filter tube (5), a recess (6) is formed which can be hydraulically connected to a pump device and the height (h) is determined by the distance of the two volume bodies (7, 8) to each other, where the length extension of the respective volume bodies (7, 8) in the direction of the longitudinal axis of the device corresponds to the height (h) of the take-out space (6), characterized by the flexible layer (17) being made of a foam material, in particular a open cell foam material or a foam rubber.

Device (1) according to claim 1, wherein the distance between the volume bodies (7, 8) is adjustable so that the length ratio between the height (h) of the take-out space (6) and the length extension of the volume bodies (7, 8) is variable.

Device (1) according to claim 1 or 2, wherein on the volume bodies (7, 8) adjacent to the withdrawal space, each first and second shut-off discs (3, 4) are respectively arranged, wherein the two shut-off discs (3, 4) ) concentric and parallel spaced apart and with their outside diameter adapted to the inside diameter of the filter tube (5).

Device (1) according to one of claims 1 to 3, in which the shut-off discs (3, 4) are each formed by two disc elements, between which is provided a sealing disc, the outside diameter of the disc elements being smaller than that of the filter tube (5). ) internal diameter, and an outer diameter of the sealing disc is greater than the inner diameter of the filter tube (5), wherein a respective sealing disc is made of a soft rubber or the like, which is secured between a locking disc (3, 4) and a further disc of the same diameter such as the shut-off disc.

A method of activating or purifying filter tube wells, with the steps of: a) providing a device (1) according to one of claims 1 to 4, wherein operation of the device (1) is effected by applying a suction pressure to the take-out space (6) at by means of the pump device, so that water is transported out of the withdrawal space (6), and thus particles are withdrawn from the filter tube well, b) introducing the device (1) into a filter tube (5) into a filter tube well until the device (1) is completely submerged in c) operating the device (1) in an initial operating position in which the device (1) is positioned in relation to the longitudinal axis of the well (9); (d) displacing the device (1) by extending into a further operating position, which distance corresponds to the height (h) of the take-out compartment (6), and e) operation of the device (1) in the additional operating position, where steps d) and e) are repeated, characterized by the additional steps: f) repeating once of steps d and e, g) displacing the device (1) into a new operating position in the same direction along the filter tube (5) with a distance corresponding to the triple height of the withdrawal space (6) so that it from the withdrawal space ( 6) the front facing away from the second volume body (8) in the newly set operating position is at the location at which the front side facing away from the first room body (7) has been placed in the previous operating position; h) the device (1) in the new operating position according to step g.

The method of claim 5, wherein a displacement of the device (1) into a further operating position occurs when, at the previous operating position, a permissible solids content of particles contained in the transported water is undercut.

A method according to claim 5 or 6, wherein the device (1) before step d) is decommissioned, the pump device being switched off or the suction pressure applied to the withdrawal space (6) at least lowered.

A method according to any one of claims 5 to 7, wherein step f) is followed by step f).

The method of claim 8, wherein step f) is followed by step f as often as it corresponds to the length of the filter tube (5) of the well.