Abstract:
The water treatment system, particularly pre-filtration unit of the water treatment system, comprising at least one chlorine sensor device, includes a salt-water treatment device which is connected to the chlorine sensor device, an electrolysis cell being disposed in the associated line, and thereafter a pump and a release valve.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention refers to a fluid system for quality/function monitoring and/or control of physically and chemically acting filter stages of a water pretreatment for the operation of a reverse-osmosis or another water treatment or water monitoring system. 
       BACKGROUND OF THE INVENTION 
       [0002]    Filter routes have the disadvantage that the remote diagnosis of chlorine and hardness and the monitoring of the degree of soiling of mechanical filters cannot be carried out or can only be carried out by taking great efforts. 
         [0003]    Moreover, it is necessary for reasons of safety, particularly in dialysis water treatments, that a time-consuming manual documentation of the water hardness and/or of the chlorine content should be carried out daily, especially in order to furnish evidence that the toxic chlorine has been removed from the liquid by the filters used. 
         [0004]    Existing chlorine sensors for online measurement are often not chlorinated at regular intervals and cannot provide any reliable measurement results in the absence of chlorine in the liquid. 
         [0005]    To remove hardly soluble salts, such as calcium and/or magnesium, from the water, softeners are often used. When softeners are used with acidic cation exchange resins, these must be regenerated by means of sodium chloride brine solution at regular intervals. 
         [0006]    This regeneration is normally carried out with sodium chloride solution which is provided in a so-called brine container in which salt is dissolved in a predetermined liquid amount. 
         [0007]    Failure of the regeneration process e.g. because of a missing sodium chlorine brine solution may lead to serious calcification of the downstream systems. 
         [0008]    Moreover, softeners tend to show a microbial growth with subsequent contamination of the liquid flowing therethrough because of the relatively large resin volume. 
         [0009]    Problems are posed by filter blocking because the resulting exchange of filter material is normally accompanied by operational interruption. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    The aim of the invention is the development of an actuator-sensor control which enables the user to evaluate the functionality of a system by online access and to obtain, on this basis, a remote diagnosis about the current operational state. 
         [0011]    To meet the normative and/or in-house requirements, the necessary documentation evidence can be furnished simultaneously together with the automatic recording by way of the connected electronic data processing system. 
         [0012]    It is possible on account of the desired system-specific evaluation by analysis and visualization of the operational parameters to achieve an acyclic distribution of the service operations and thus a reduction of the number of services. 
         [0013]    On this basis an economic and ecological procedure is possible as the deployment of trained stuff on site can thereby be coordinated in an improved way and failure caused by wear can be avoided in a targeted and preventive way. 
         [0014]    To avoid the aforementioned drawbacks and to comply with the objective, respectively, partial streams are passed under one aspect of the present invention to the corresponding sensor before and after the filter stages by means of switched valves and are evaluated by electronic measuring devices. These measuring devices may here also be an integral part of subsequent systems of a water treatment and/or also a control room, and a bidirectional operation for influencing actuators and sensors is here possible. 
         [0015]    Advantageously, with an electronic pressure sensor different mechanical filter stages are monitored online with respect to their degree of soiling by measuring the pressures and determining the pressure difference and an automatic backwashing program is also started in the case of suitable filters with a corresponding automatic backwashing system. 
         [0016]    Under another aspect of the invention, use is made of an online measuring chlorine sensor the safety-relevant function of which is checked according to the invention by supplying electrolytically produced chlorine of a known concentration to the sensor at regular intervals. The measurement result is electronically recorded and documented. The chlorine can be produced from an existing brine solution. 
         [0017]    The function of the softener, i.e. the filtration and reduction of the hardly soluble calcium and magnesium salts, can be monitored by an ion-sensitive calcium and/or magnesium sensor. 
         [0018]    The fill level of the salt water container and the residual volume of the salts in the brine container, respectively, have to be monitored in a simple way by means of a weighing device. To this end the brine container is placed on a constructional element with weighing cell. Since the constructional understructure can be used at any time independently of the brine container used, brine containers that are already in use can also be equipped with the monitoring device. It is possible to indicate the brine volume directly or as a signal-light solution with message color; transfer to and recording in a control room or a subsequent water treatment system, which may e.g. be configured as an RO system, is also possible. Inspection and documentation of the salt supply in the brine container which has to be carried out by the operating personnel every day can thus be dispensed with. 
         [0019]    A regular slight chlorination of the softener during regeneration by chlorine, which is electrolytically produced from the brine container of the softener, reduces the microbial growth in the softener resin and thereby ensures a more sterile liquid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0020]      FIG. 1  is a schematic diagram of a pre-filtration unit according to the invention. 
           [0021]      FIG. 2   a  is a cross-sectional view of a salt water container according to the invention. 
           [0022]      FIG. 2   b  is a top perspective view of a weighing platform according to the invention. 
           [0023]      FIG. 2   c  is a bottom perspective view of the weighing platform of  FIG. 2   b.    
           [0024]      FIG. 3  is a schematic of an alternate embodiment of a pre-filtration unit according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]      FIG. 1  shows a pre-filtration unit according to the invention with a mechanical-chemical filter stage  4 , an actuator-sensor monitoring unit  3 , an associated electronic evaluation unit  2 , and a possible electronic unit  5  pertaining e.g. to a downstream reverse osmosis system, wherein the electronic unit  2  may also be configured as a control-room electronic unit and may communicate with the electronic unit  5 . 
         [0026]    The mechanical-chemical filter stage  4  is only shown by way of example with respect to the selection of the arranged filter stages so to as to illustrate the function of the monitoring operation according to the invention. 
         [0027]    The exemplary arrangement of a water line  6   a  begins with the water inlet  6 , a shut-off valve  8 , and an automatically back-washable pre-filter  9  with drain valve and drainage connection. This is followed by a safety shut-off valve  10  which is activated by a leakage indicator  22   a  with liquid sensor  22   b.    
         [0028]    Further components may be a pipe separator  11  and a backflow preventer  12  for avoiding contamination of the water inlet  6 . 
         [0029]    At low water supply pressures it is possible to add a pressure increasing unit  13 . A further possible filter stage  14  may be configured as a cartridge filter  14   a,  sand filter ( 14   b ) or also as a hollow fiber filter (here not shown) in the nano or ultra-pore range. 
         [0030]    A softener  15 , e.g. illustrated as a twin softener, is normally filled with strongly acidic, cation-containing resin which upon exhaustion has to be regularly regenerated with NaCl solution from the salt water treatment  16 . It is here important to monitor the fill level of the salt in the salt water container  16 . This is done with a weighing device  17 , which is designed as an independent constructional understructure. 
         [0031]    According to  FIG. 2  the weighing device  17  consists of a weighing cell  46  the signal of which can be amplified by electronics  44  on the weighing platform  42 , electronically processed, or can be processed by electronics  2  and also by possibly successive electronics  5 . Preset weight limit values of the brine container can here be monitored and optically or acoustically indicated or remotely diagnosed by technical electronic data processing. The weighing cell  46  is fastened to the weighing platform  42  by means of screws  48  such that a third of the brine or salt weight weighs on the measuring foot  47 . Side boundaries  45  are mounted for the lateral guidance of the brine container. 
         [0032]    During the regeneration process of the softener  15  chlorine-containing solution can be formed with the help of an electrolysis device  18  from the salt water flowing towards the electrolysis cell  18 . It goes without saying that the chlorine concentration depends on the brine concentration, but substantially on the magnitude of the electrically supplied power to the electrolysis cell. The microbial growth in the softener resin is thereby strongly reduced. 
         [0033]      19  shows a twin carbon filter/dechlorination device which is used for the filtration of the chlorine. 
         [0034]    A filter stage  20  as a fine-filter stage can remove the smallest particles from the filter water  7  before it is e.g. supplied to a reverse osmosis system or a drinking water installation. 
         [0035]    The actuator-sensor unit  3  can be equipped with an electronic water meter  21  for recording and reporting the water consumption. 
         [0036]    For monitoring the chlorine content of the supplied liquid a chlorine sensor  30  is preferably positioned in a chlorine sensor chamber  29 , either for the measurement of the whole chlorine or of the free chlorine. The chlorine sensor chamber  29  has an inlet and a free outlet. A release valve  28  is directly positioned in front of the sensor chamber. Usually, the supplied liquid can be chlorinated by the water supplier with chlorine of different concentrations; depending on the hygienic state, a chlorine input may be temporarily missing. In such a case no statement can be made on the proper function of the sensor  30  without further measure. 
         [0037]    For regularly checking the chlorine sensor a test valve  27 , a brine suction valve  24 , and the release valve  28  are opened and the electrolysis cell  18  is switched on. The brine or the chlorine-containing solution is sucked in a selected concentration ratio from the brine container  16  via the adjustable brine suction valve  24  and a pump  23 , mixed with liquid via a flow throttle  25 , passed on to the measuring chamber  29 , recorded via the chlorine sensor  30  and evaluated with electronics  2  and  5 , respectively. 
         [0038]    The proper function of the measuring cell  30  can be ensured by this regular testing. It is within the scope of the present invention to provide and monitor the sodium chloride brine solution also exclusively for the purpose of chlorine sensor monitoring, independently of a softener or other filter stages. The suction line of the brine solution and the electrolysis cell for the electrolytic chlorine production are here made independent of a brine suction line and an electrolysis cell of the softener. 
         [0039]    Pump  23  is preferably shown as a venturi pump, but other pump types are possible for performing the function; in such a case the chlorine-containing solution is supplied in metered amounts by means of a pump (not shown) from line  24   a  into line  25   a.    
         [0040]    For monitoring the correct carbon filter function/dechlorination device  19  an upstream valve, e.g.  40  or  27 , may first be opened. Likewise, the release valve  28  is opened. If chlorine is contained in the supplied liquid, this is recorded via the previously verified chlorine sensor  30 . 
         [0041]    Thereupon, the valves  33  after the first filter stage,  31  after the second filter stage or also  32  after a filter stage  20  and the chlorine release valve  28  are successively opened. The filter stages of the carbon filter can thus be tested. If the chlorine sensor records the absence of chlorine, the checking of the filter is successfully completed. It is within the meaning of the present invention that this measurement can also be carried out independently and recorded technically by electronic data processing. 
         [0042]      FIG. 3  shows a further pre-filtration unit of the invention which differs from that of  FIG. 1  by the measures for ensuring a proper function of the chlorine measurement cell and for checking the same. Brine or chlorine-containing solution is sucked in a predetermined concentration ratio either from the brine container  16 , which is arranged for the regeneration of the softener  15 , or from a separately provided brine container  16   b.  The associated chlorine test line  24   a  terminates behind a shut-off valve  49  in a chlorine-test circulation circuit  50  in which in clockwise direction in which the sucked brine is circulated a pump  51 , an electrolysis cell  18   b  and a measurement chamber  29   b  with a chlorine sensor and a further shut-off valve  52  are installed one after the other. The chlorine measurement chamber  29   b  is connected to a free outlet  53  as is also the case in the embodiment of  FIG. 1 . In this embodiment the brine is sucked—in contrast to the embodiment of FIG.  1 —directly from the brine container  16  and is not branched off as a chlorine-containing liquid from the connection line  16   a  between the electrolysis cell  18  and the softener  15 . 
         [0043]    A small brine amount is here taken from the brine container  16  provided for the regeneration of the softener  15  or from an optionally available brine container  16   b  and circulated through the chlorine generator  18   b  and the chlorine measurement cell  29   b.  This is preferably done at regular time intervals to keep the chlorine measurement cell active and to perform a function control. The chlorine measurement cell or the chlorine sensor  30 , respectively, is here to indicate a measurement value within a predetermined range with a short, always identical switch-on period of the chlorine generator  18   b.  After this activation and detection the whole line towards the brine container is flushed free. The flushing interval is defined such that the brine amount taken is replenished. 
         [0044]    It is within the scope of the invention that, instead of the brine container  16   b,  a container with chlorine bleaching agent or chlorine dioxide or a similar chlorine-containing liquid is used. In this case the chlorine generator  18   b  is omitted. 
         [0045]    With the above-described activation of the chlorine measurement cell it is reliably prevented that this cell becomes passive. Only minimum amounts of NaCl are here consumed. 
         [0046]    Apart from the above-described features for activation and control of the chlorine measurement cell, the pre-filtration unit of  FIG. 3  corresponds to that of  FIG. 1 , so that the reference numerals thereof are also applicable to the embodiment of  FIG. 3 . The arrangement of the eight valves  37 ,  38 ,  39 ,  40 ,  27 ,  33 ,  31 ,  32  is shown in a purely schematic manner. These valves and their associated actuating members, which are also called actuators in the description, may be provided—other than shown in the drawings—also at the places where the associated branch lines branch off from the water line  6   a.    
         [0047]    For monitoring the filter stages  9 ,  14 ,  20  a pressure sensor  41  is acted upon selectively and successively before or after the filter stages with the pressures prevailing at the filter stages via the valves  37 ,  38 ,  39 ,  40 ,  31 ,  32  shown in  FIG. 1 . 
         [0048]    For instance, the pressure drop of the filter stage  9  is monitored by measuring the inlet pressure via the upstream valve  37  and the outlet pressure is monitored by the subsequent valve  38 . 
         [0049]    As an equivalent to the said measurement,  FIG. 1  shows the measurement of the pressure drops by switching the valves  39 / 40  for the filter stage  14  and the valves  31 / 32  for filter stage  20 . 
         [0050]    The determination of the pressure drops at the softening stage  15  and dechlorination stage  19  is also possible by way of a successive switching of the valves  40 ,  27 ,  33 ,  31 . 
         [0051]    An atmospheric relief of the pressure sensor  41  in general or between two measurements can be carried out via valve  34  and also  28 . 
         [0052]    By measurement of the flow through line  6   a  with water meter/flow meter  21  or also by a corresponding flow measurement in a subsequent treatment process, the pressure values measured on the filters can be calculated by means of electronics  2 ,  5  as standard or mean values and a warning, exchange, flushing or maintenance time can be predicted for preset pressure differences. 
         [0053]    Since the determination of the filter pressure differences normally regards relative measurements, the use of a single pressure sensor  41  is advantageous both in terms of costs and in terms of the calibration efforts. 
         [0054]    As a rule, the water inlet pressures on line  6   a,  e.g. on filter  9 , are known, so that the pressure sensor  41 , acted upon with a known pressure before the beginning of a measurement cycle, must be verified during maintenance or during inspection by a technician. 
         [0055]    An advantageous development of the pressure measurement is the determination of mean pressure values by means of electronics  2 ,  5  on the respective filters  9 ,  14 ,  15 ,  19 ,  20  in that e.g. 50 measurements are combined to form a mean value and are represented over an exemplary period of 1000 operating hours. Changes that are due to the service life end of the sensor  41  or the blocking of the aforementioned filters can be recognized technically by electronic data processing or predicted, respectively, and remotely inquired. 
         [0056]    To monitor the correct function of the softener  15 , valve  40  is first of all opened and hard water is supplied via a measuring chamber  35  to a calcium sensor  36  through the opened valve  34 . Subsequently, softened liquid is passed via the flow throttle  25  and valves  27 ,  34  into the measuring chamber  35  to the ion-sensitive calcium sensor  36 . 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Legend 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                  1. 
                 Pre-filtration with sensor package 
               
               
                   
                  2. 
                 Electronics sensor package 
               
               
                   
                  3. 
                 Actuator and sensor unit 
               
               
                   
                  4. 
                 Pre-filtration components 
               
               
                   
                  5. 
                 Electronics post-filtration 
               
               
                   
                  6. 
                 Water inlet 
               
               
                   
                  7. 
                 Filter water 
               
               
                   
                  8. 
                 Shut-off valve 
               
               
                   
                  9. 
                 Back-flushable pre-filter with cleaning valve 
               
               
                   
                 10. 
                 Safety shut-off valve 
               
               
                   
                 11. 
                 Pipe separator 
               
               
                   
                 12. 
                 Backflow preventer 
               
               
                   
                 13. 
                 Pressure increasing unit 
               
               
                   
                 14. 
                 Fine-filter stage 2 
               
               
                   
                 15. 
                 Softening stage 
               
               
                   
                 16. 
                 Salt water treatment/brine tank 
               
               
                   
                 17. 
                 Weighing unit 
               
               
                   
                 18. 
                 Electrolysis cell 
               
               
                   
                 19. 
                 Dechlorination stage/carbon filter 
               
               
                   
                 20. 
                 Fine-filter stage 3 
               
               
                   
                 21. 
                 Water meter/flow meter 
               
               
                   
                 22. 
                 Leakage indicator with sensor 
               
               
                   
                 23. 
                 Brine pump 
               
               
                   
                 24. 
                 Brine suction valve 
               
               
                   
                 25. 
                 Flow throttle 
               
               
                   
                 26. 
                 Backflow preventer 
               
               
                   
                 27. 
                 Chlorine sensor test valve/calcium check valve I 
               
               
                   
                 28. 
                 Chlorine sensor release valve 
               
               
                   
                 29. 
                 Chlorine sensor chamber 
               
               
                   
                 30. 
                 Chlorine sensor 
               
               
                   
                 31. 
                 Chlorine check valve II/fine-filter state 3 inlet pressure 
               
               
                   
                 32. 
                 Chlorine check valve III/fine-filter state 3 outlet pressure 
               
               
                   
                 33. 
                 Chlorine check valve I 
               
               
                   
                 34. 
                 Calcium sensor release valve 
               
               
                   
                 35. 
                 Calcium sensor chamber 
               
               
                   
                 36. 
                 Calcium sensor 
               
               
                   
                 37. 
                 Fine filter stage 1 inlet pressure 
               
               
                   
                 38. 
                 Fine filter stage 1 outlet pressure 
               
               
                   
                 39. 
                 Fine filter stage 2 inlet pressure 
               
               
                   
                 40. 
                 Fine filter stage 2 outlet pressure/calcium test valve 
               
               
                   
                 41. 
                 Pressure sensor 
               
               
                   
                  6a 
                 Lines 
               
               
                   
                  6b 
               
               
                   
                 16a 
               
               
                   
                 19a 
               
               
                   
                 24a 
               
               
                   
                 25a 
               
               
                   
                 42. 
                 Platform 
               
               
                   
                 43. 
                 Adjustable feet 
               
               
                   
                 44. 
                 Electronics 
               
               
                   
                 45. 
                 Side boundary 
               
               
                   
                 46. 
                 Weighing cell 
               
               
                   
                 47. 
                 Measurement foot 
               
               
                   
                 48. 
                 Mounting of weighing cell 
               
               
                   
                 49. 
                 Shut-off valve 
               
               
                   
                 50. 
                 Chlorine-test circulation circuit 
               
               
                   
                 51. 
                 Pump 
               
               
                   
                 52. 
                 Shut-off valve 
               
               
                   
                 53. 
                 Free outlet