DE4133531A1 - Deep well water regeneration - has pulsed flow of medium through the filter w.r.t. pH values and filter resistance with independent action on separate sections - Google Patents

Abstract

For the combined mechanical/chemical regeneration of a deep well, an acid or an acid mixt. with a given pH value is pumped to the working zone (13) in a sufficient vol. to give a mixt. with the well water of a required pH value. The working zone (13) is subjected to air or cleaning water pressure at a level w.r.t. the filter resistance and/or the constantly measured pH or electrical or chemical values at the suction stage (15), the regenerating medium is compressed into the gravel layers. The feed and dosage of the regenerating medium is controlled w.r.t. the constantly measured values and the filter resistance, and interrupted w.r.t. the nominal values. During feed interruption, the suction pump maintains its action until the constantly measured values register the min. requirements for the well water quality. ADVANTAGE - The separate working sections of the filter stretch can be operated individually within the deep well to be cleaned with good sealing of the working section. The regenerating medium has an in-depth effect through the pulsation compression/suction through the filter gravel and neighbouring layers. The filter resistance is measured objectively, and the operating periods are reduced by monitoring important pH and other process parameters. The chemical consumption is reduced to a min.

Description

The invention relates to a method for combined mechanical / chemical well regeneration using a well cleaning device with the in the preamble of Features specified claim 1, and a device to carry out the procedure.

From DE-PS 9 72 254 is a device for cleaning and disinfect cylindrical deep wells by means of Compressed air is known in the case of a in a filter tube movable up and down and opposite the filter tube wall an upper and lower edge sealable cleaning body Cleaning liquid through the filter slots in the filter gravel is pressed in, the possibly solid, liquid or gaseous cleaning agents and disinfectants be buried. The movable cleaning body is at the top and provided at the bottom with a rubber hose, which at Movement is empty and during the work process by filling adjusts the unevenness of the filter tube with compressed air and thereby completely sealing and holding the otherwise movable cleaning body on the filter tube wall conditionally. The chamber area thus formed is the Working section of the well cleaning device.

A well cleaning device, as it is in connection with the generic method is used is from the DE-PS 9 73 316 known. The well cleaning device for Regeneration, cleaning or disinfection of deep wells according to this document has three chambers if the hoses on the separators  Cylinders are inflated. There are two chambers as Working sections formed and the intermediate Chamber provided as a suction chamber through which in the Working section introduced regrind after the Penetrate the filter walls and the ones behind existing gravel layers of the well is suctioned off. During suction, the mechanical / chemical cleaning. Through the dividers with the respective filter surface is limited. In this is pressed in or in air or water Interaction pushed in by the suction pump. The Submersible pump is in the tier in the middle chamber firmly anchored so that the cleaning flows are optional are achievable.

Furthermore, a well cleaning device for the generic method known from DE 29 47 282 A1, which has two chambers, which are separated by three are formed, of which the middle partition element one has a medium breakthrough for a reversible pump, so that a flow of well water, added with Cleaning liquid from one chamber to the other is pumped, which simultaneously causes the well water mixture through the filter walls and the ones behind Filter gravel layers of the well flows and the Cleaning effect. For sealing the separating elements the rubber hoses with well water a pump provided in the rack. The Contaminated dirty water can then be pumped upwards will.  

Against the use of compressed air when working through a Fountains have significant concerns because of the Ventilation the iron and manganese in the underground will fail and this even more hinders the water passages or even can be blocked.

It is known from water treatment technology to aerate water containing Fe / Mn in order to bring it into a filterable form in order to be able to consciously let out iron and manganese fractions. In the groundwater, e.g. B. a well water, which is free of oxygen O ₂ , iron and manganese are present as soluble compounds divalent. If oxygen is added to the water, the iron is oxidized to the trivalent and the manganese to the tetravalent. This produces poorly soluble substances, so-called oxide hydrates, which are initially coloidally dissolved and after a certain time flocculate as fine turbidity. This mechanism also runs when compressed air is used to blow through the filter walls, that is, to mechanically clean the filter walls and the gravel layers. In order to remove deliberately deposited Fe / Mn particles again in a sand filter in a waterworks, it is necessary that such sand filters be backwashed once or twice a week in the water treatment plant. Basically, the same can also be achieved by reversing the direction of flow in a deep well with the well cleaning device, after which the contaminated well water mixture must be pumped out. The deposition process can, however, proceed very quickly, especially if iron and manganese deposits have already led to the filter wall and the gravel being closed in crystalline form. In such cases there is not much to do with a reversal of the flow direction in the case of cleaning with compressed air. A cleaning effect, even with the addition of rinsing liquid, can only be optimized more or less empirically with the known methods. Is z. B. acid entered as a cleaning agent and pumped out during the cleaning process of well water with the impurity particles and the regrind mixture and the pH value in a settling tank and correspondingly added via a feed line concentrate after the measured value acquisition, this means that the cleaning effect based on the pH value always can only be measured when the pH value of the mixture pumped out of the well is determined, in comparison to the pH value of the mixture in the inflow line. If, as a result of the cleaning process, it is found that the pH value of the pumped-out well water mixture corresponds to a certain target value, which signals the optimal cleaning, i.e. that the pH value is approximately the same as that of the cleaning liquid added via the inflow line, this is an indication that the cleaning process is complete. In this case, the supply of further regrind is switched off and the regrind and the water contaminated with crystalline deposits are pumped out of the well, which must be disposed of as acidic water and cannot be easily entered into the surface drainage system. It goes without saying that, for. B. in deep wells, which a lot of well water that is contaminated with the regrind must be pumped out, since the regrind contained therein still flows through the long inflow pipe. Likewise, the pH value of the pumped mixture can only be detected with a longer time delay, since the water is pumped out of the well via the long lines and is fed into a settling tank, in which the pH value of the well fluid is constantly checked. This also means that considerably more quantities of contaminated well water have to be pumped off and disposed of than would be necessary in the deep well due to the cleaning process.

The invention has for its object a method for combined mechanical / chemical well regeneration develop with which more efficient cleaning can be achieved that enables and avoids faster reactions, that unnecessarily much well water, that with dissolved and crystalline deposits after the cleaning process and with supplied regenerate is mixed, must be pumped out. A device for carrying out the method is also intended can be specified.

To solve the problem are in the characterizing part of claim 1 five procedural steps specified, adhering to them optimal cleaning effect with short Response times regarding the supply of regenerate and Pressure is given.

Entering the regrind before pressurization for the cleaning process in the working section With regard to the flocculation and crystalline formation of Fe / Mn the advantage that the rate of oxidation is reduced. It gets smaller the lower the Is pH. When using z. B. hydrochloric acid with a PH value of 2 to 3 in the work area is therefore also at Pressurization with compressed air causes oxidation to exclude. This also applies if rinsing liquids, e.g. B. mixed with oxidizing agents instead of compressed air  can be entered. On the other hand, the Pressurizing the cleaning effect in known Way significantly increased because of the mechanical cleaning the flow circulation of the well water - with the Regenerate offset - through the filter wall and the Gravel layers for faster removal of the crystalline Deposits. The constant or intermittent addition of regenerates ensures that even with prolonged Cleaning process, e.g. B. using compressed air, it Oxidation does not occur, even if the Flow direction is maintained on one side.

The cleaning effect can be achieved in different ways be measured and checked. One method is the filter resistance of the filter wall and the gravel layer through the reference pressure measurement method when applied with Determine pressure medium. The method to be used for this is z. B. from the earlier patent application P 40 32 118.5-25 known. The pressure measuring device is in one Connection line between a reference pressure line, the opens into the work area, and the pressure line via which the pressure medium is entered in the work area and provided behind a valve or in parallel arranged to the connecting line shunt pipe. At other reference pressure measuring devices only the normal water pressure in the rack and this is compared with the applied air pressure and in Depending on this, the filter volume resistance is determined. Even if the slots in the filter wall of the filter tube are closed by crystalline deposits by means of the pH value measurement or alternatively or additionally intended conductivity measurement or the iron ion measurement in the neighboring chambers to the working section of this  found so that a higher concentration of acid, which is added as regrind can be entered to to dissolve the crystalline deposits so that for the combined mechanical / chemical cleaning process the pressure medium the cleaning fluid through the slots in the filter wall and the layer of gravel behind it can flow. The change in chemical or electrical quantities continuously recorded with the measuring probes. These values also give the efficiency of the Cleaning process.

The prerequisite for the process is that a hermetic Sealing the work area from the Neighboring areas is ensured. Brush, lip or In this respect, disc sealers can only be used to a limited extent. The specified sealant, however, guarantee on everyone If the measurements are not falsified and the Depth effect is achieved.

Advantageous developments of the method are in the dependent claims 2 to 10 indicated.

Devices for performing the method in the different expansion stages are in claims 11 to 16 specified.

In the event that the method and an apparatus so is formed that intermittently after insertion of the regenerate the pressure medium is applied, so to speak creates a brief alternating flow, at which one increased mechanical cleaning effect in addition to chemical is achieved. The cleaning process can be significantly shortened. At the end of the  Cleaning process, if it is found that the Measured values of the measuring probes are optimal, both the Regenerative supply stopped as well Pressurization so that without delay and without further reflow of regenerate with well water and dissolved sediment contaminated Well water can be sucked off. The crowd is there compared to known methods much lower, so that also the disposal problems of acidic wastewater are lower.

The pressurizing agent causes the regenerate with greatest possible intensity through the filter wall and the Filter gravel is pressed. At a depth of 80 m, e.g. B. Working pressures of 35 bar with a working section volume of 20 l usual. The pH in the work section should be 2 amount and the fountain in the area of Be completely acidified cleaning section, d. H. it becomes sufficiently acidic before the cleaning process Regenerate introduced.

The advantages over known methods can be as summarize as follows:

• - Individual processing of the individual work sections within the filter section of the Deep well
• - optimal sealing of the working section  
• - the best possible depth effect of the regenerate pulsating pressing and suction of the Regenerate / well water mixture in or out of the Filter gravel and the adjacent layers
• - Objective measurement of the filter resistance in the Working section by capturing the in the rinsing process resulting pressure difference in the working section
• - Shortening the processing time of the individual Cleaning sections by measuring more important Process parameter (e.g. pH value) within the Working section
• - minimal use of chemicals through permanent Measurement of pH and other chemical parameters.

The invention is explained in more detail below with the aid of the well cleaning device shown schematically in FIG. 1 and the flow chart indicated in FIG. 2.

The well water collects in the well shaft 6 . In the well shaft 6 , a well cleaning device is introduced, which consists of a lower, elongated working cylinder 9 , designed as a double separating element, and which has a first sleeve at the top and a second sleeve 10 , 11 at the bottom. The cuffs 10 and 11 , the z. B. consist of armored or of a thick-walled rubber, form the sealing device of the working section 13 , that is, a chamber of the multi-chamber rack. You will have a pressure line 1 , z. B. a high pressure fabric hose, inflated with compressed air so that a chamber is formed between them and the outer surface of the working cylinder 9 and the shaft wall, which forms the working section 13 . In the working section 13 , compressed air for the gravel flushing and the flushing of the penetration openings 14 is pressed in the shaft wall 7 via a high-pressure line 24, or cleaning water mixed with air and cleaning agent is also supplied, which flows through the penetration openings 14 and the gravel layers 8 under high pressure and into the chamber 15 located above flows in the suction area. The suction area 15 is formed by the working cylinder 9 with the sleeve 10 and by the upper separating element 16 . This separating element 16 also has a sleeve 17 which is drawn onto the cylinder and which is inflated with compressed air via the pressure line 1 via an opening branch, so that it lies sealingly against the inner wall of the filter tube 7 . In an extension to the pressure line 1 , the connecting pressure line 12 to the sleeves 10 and 11 to the working cylinder 9 is shown.

It can be seen that the working cylinder 9 can also be formed from individual separating elements. The method according to the invention and the execution device do not only extend to the illustrated embodiment. The water that flows from the working area 13 when pressurized and mixed with regrind flows into the suction area 15 and is pumped to the outside via a discharge line 5 by an injector pump (not shown), which is pressurized with compressed air via the connection 2 . Part or all of the pumped amount is fed via the outflow line 18, which is also shown above, to a settling tank 19 , from which the well water mixture mixed with regrind is removed and fed to the rainwater supply line 3 via a pump 20 in a connecting line and via a shut-off valve 21 and into the working section 13 is pumped.

Furthermore, a pH value probe 22 is provided in the suction section 15 . The measurement display device 23 is located in the apparatus set up on the floor or is part of a measurement detection device, not shown here, which also performs control functions. Furthermore, an inflow line 24 is provided, via which pressure medium, preferably compressed air, is pressed into the working section 13 . Furthermore, a reference pressure line 4 is provided, by means of which the pressure built up in the working section 13 is determined. It is assumed that the reference pressure line 4 is pressurized with compressed air, so that no well water or flushing liquid can rise in the pressure line. The measured pressure, which can also be measured in other ways, e.g. B. by means of pressure sensors in the working section 13 can be determined. Now, depending on the determined pressure, which is a size of the filter flow resistance, the compressed air can be controlled with compressed air via the supply line 24 , for example.

The operation of the device including the procedural steps are briefly below described:

The multi-level frame lowered into the deep wells with the sleeves forming the chambers is fixed in the filter tube for the operation by inflating the sleeves. Then acidic regrind is pumped into the working section 13 via the feed line 3 via a concentrate container. The amount pumped in should be at least so large that it corresponds to the working volume of the working section. If the filter slots 14 are not yet completely closed by crystalline deposits, the regenerate already penetrates into the adjacent gravel layers 8 when it is introduced and thus also reaches the suction section 15 , in which the measuring probe 22 is located to determine the pH value. On the basis of the measured and displayed pH value in the measuring device 23 , it can thus be determined whether changes in the pH value already occur when the regenerate is introduced for the first time. Compressed air is now applied to the work area via the pressure medium supply line 24 , so that the well water mixture enriched with regenerate is pressed out of the work area 13 through the filter wall 14 into the gravel layer, thereby triggering the chemical and mechanical cleaning process. The beige added regrind causes a chemical cleaning, that is, the crystalline deposits are detached or dissolved and thus pass into the well water mixture is pumped via the suction pipe 5 into the storage container 19 alternately with the rinse cycle and is supplied again with the addition of replenisher to the circulation.

By pulsing the application of pressure medium via the supply line 24 , it is also achieved that the gravel layers are moved to a certain extent in a pulsating manner, the pulse frequency should be selected such that no compression of the gravel layers is effected.

The pH value changes drastically in the course of the cleaning process and almost reaches the pH value of the regenerated mixture which is supplied via the feed line 3 when the cleaning process ends. When this state is reached, the valve 21 is closed immediately, so that no regrind or regrind mixture can get into the well. The contaminated water is then pumped off and the pressure medium is switched off. This process can be carried out fully automatically via a corresponding measurement recording and control device, whereby the measurement of the pH value in the well, alternatively the measurement of the resistance of the contaminated well water or the measurement of the iron ion content can be used for the sequence control. In addition to this, it is expedient to also detect the filter flow resistance and use it for the control. In any case, the control options provide that the well water is controlled as a function of the measured value (PH value) and / or filter flow resistance and / or iron ion content and / or conductivity determined during the cleaning process. After the cleaning process has been completed, the well water contaminated by the regenerate and thus impaired in the water quality must of course be pumped out until the desired water quality is reached again, which enables the intended use of the well water. Due to the fact that the measured value in the suction area is determined directly in the rack, a quick reaction is possible, so that the supply of the regenerate can be stopped immediately and there is no further contamination of the well water. The pumped-off water enriched with acid can then be disposed of in smaller amounts than is possible according to the known methods.

Because the measured value acquisition of both the pH value or of the alternative values in the tier rack the cleaning process on site is also ongoing controllable and no time delay given, so that Well cleaning using the invention Method and an apparatus for performing this Procedure as described here, a faster and more efficient cleaning of the well enables.

The workflow is exemplified in a flow chart in FIG. 2.

Claims (16)

1. Method for combined mechanical / chemical well regeneration using a well cleaning device with a tier arrangement that can be moved in a well shaft made of filter walls and consists of separating elements that run transversely to the longitudinal axis of the shaft with sealing devices for forming one or more chambers arranged in series, which sealing devices consist of one or more on the circumferential surface area of cylinders on cuffs, hollow tires or tubes made of elastic material that are inflatable or inflatable with a pressure medium and thereby press sealingly against the inner surfaces of the filter wall, at least one chamber forming a working section into which a regrind can be introduced, and at least one further chamber or the area above or below is provided as a suction section from which the well water, enriched with regrind and dissolved and removed crystalline deposits, can be extracted is characterized by the following process steps:

• a) In the working section ( 13 ) an acid or an acid mixture is pumped as regrind with a certain pH in such an amount that the mixture of well water and regrind assumes an approximately certain desired pH.
• b) The working section ( 13 ) is acted upon by a pressure medium, such as flushing water or compressed air, the pressure of the pressure medium being controlled as a function of the filter passage resistance determined during the pressurization and / or of the values determined according to process step c), the regenerate is pressed deep into the gravel layers.
• c) In the suction section ( 13 ) or in a further chamber ( 15 ), the pH value or other electrical or chemical variables, such as iron ion concentration, of the well water mixture is measured continuously.
• d) The supply and metering of the regenerate is controlled as a function of the measured values after process step c) and the supply is interrupted as a function of predefined setpoints of the variables and / or predefined setpoints of the filter resistance.
• e) Depending on the interruption of the supply of the regenerate, the suction pump is controlled and remains switched on at least until the values determined continuously after process step c) correspond to the minimum requirements for the well water quality.

2. The method according to claim 1, characterized characterized in that the regenerate during the Pressurizing medium continuously or in pulses is added controlled, the amount and duration of Injection of the measured pH value, the conductance and / or the iron content and / or the measured filter resistance can be set. 3. The method according to claim 1, characterized in that the working area ( 13 ) is repeatedly acted upon with pressure medium for a limited time. 4. The method according to claim 3, characterized in that the regenerate is introduced only during the time in the working sections ( 13 ) in which no pressure medium is applied. 5. The method according to claim 3 or 4, characterized characterized that the Pressurizing the work area cyclically and in pulses. 6. The method according to any one of the preceding claims, characterized in that the Filter resistance measurement through the reference pressure measurement at Pressurization by the pressure medium takes place continuously. 7. The method according to any one of the preceding claims, characterized in that the feed of the regenerate with minimal filter resistance interrupted and the pressure medium supply switched off becomes.   8. The method according to any one of the preceding claims, characterized in that compressed air is used as the pressure medium and is pressed at about 35 bar into the working area ( 13 ). 9. The method according to claim 1, characterized in that when measuring a pH value which corresponds approximately to the desired pH value in the working section, the inflow line of the regenerate ( 3 ) is blocked. 10. The method according to any one of the preceding claims, characterized by the use in conjunction with a well cleaning device, in which from a chamber which forms the working area ( 13 ) in a second chamber ( 15 ) through the filter walls ( 14 ) reversible pumps well water Pump with regenerate in one direction or with an alternating direction through a controllable pump inserted between the chambers ( 13 , 15 ) in the partition, the set delivery rate forming the pressure medium supply or a further pressure medium supply by integrating a pressure medium supply line ( 24 ) is provided. 11. The device for performing the method according to claim 1, characterized in that in the work area ( 13 ) opens an inflow line ( 3 ) for the regenerate and a pressure medium supply line ( 24 ) for the pressure medium, and that for metering the regenerate and for exposure to Pressure medium controllable valves ( 21 ) are provided in the supply lines ( 3 , 24 ), and that a pH measuring sensor ( 22 ), a conductance measuring sensor or an iron ion measuring device are provided in a further chamber ( 15 ) or or half or below the working section ( 13 ) and / or a reference pressure measuring device with a reference pressure measuring line ( 4 ) is provided. 12. The apparatus according to claim 10, characterized in that the measured values are fed to a measurement detection device ( 23 ) which, based on a control program, as a function of the measured values:

• a) the pressure in the pressure medium supply line;
• b) controls the dosage of the regenerate;
• c) depending on the pH value, the conductivity or the iron ion concentration, switch off the suction pump after the cleaning process has ended when the well water is almost deacidified or corresponds to the quality before the cleaning process.

13. The apparatus of claim 11 or 12, characterized characterized in that the controllable valve in the supply line of the regenerate in the area of Exit of the regrind supply line before Working section is provided. 14. Device according to one of claims 11 to 13, characterized in that the well water mixture drawn off from the suction section ( 13 ) is fed to a mixing container ( 19 ) and concentrated regrind is added to the mixture, and that the regrind mixture set to a specific pH value is pressed into the working section ( 13 ). 15. The apparatus according to claim 12, characterized in that a visual display is provided on the measurement detection device ( 23 ), which displays the measured values measured. 16. Device for performing the method according to Claim 10 in conjunction with claims 11 to 15, characterized in that a Control device is provided which the pump in the Bridges between two adjacent chambers, by which one forms, controls and during operation, the suction pump only with minimal Performance works or is out of order or something is set to support the effect of the suction pump becomes.