Patent Abstract:
The method is for monitoring water quality in a water system. A water pipe is provided for conveying water therein. A particle sensor is in operative engagement with the water pipe. The particle sensor continuously counts particles in the water of the water pipe. The particle sensor triggers the taking of a water sample only when the particle count reaches a predetermined level.

Full Description:
PRIOR APPLICATION 
     This application is a U.S. national phase application based on International Application No. PCT/US2006/060760, filed 10 Nov. 2006, claiming priority from U.S. Provisional Patent Application No. 60/736,343, filed 14 Nov. 2005. 
    
    
     TECHNICAL FIELD 
     The method of the present invention is for monitoring water quality in a water system. An on-line method to capture water samples in real time when the water quality deteriorate or contaminates. More particularly, a particle sensor device senses or counts particles. This is the event that may trigger further analysis of the water. 
     BACKGROUND OF INVENTION 
     The currently available water quality monitoring systems are quite ineffective since they often measure the water quality at predetermined time intervals such as several times a day, once a week or once in a month. This means the actual testing may occur long after pollutants and other undesirable particles are already in the water flow on their way to the consumers. One problem is that the timing of the testing is not directly correlated to the actual event of the occurrence of the undesirable particles in the water flow. Another problem is that various micro-organisms and bacteria are of about the same size as other harmless microscopic particles in the water which makes it difficult to filter out such microorganisms and bacteria. There is a need for a method that effectively monitors the water quality and automatically collects the desired sample volume for further analyze when water quality/cleanness deteriorates. 
     SUMMARY OF INVENTION 
     The method of the present invention provides a solution to the above-outlined problems. More particularly, the method of the present invention is designed so that the testing and analysis of the water quality is event driven based on a continuous sensing or particle count of the water. The system has an on-line automatic microprocessor based testing system that is associated with a refrigerator or another cooled space. Regarding the water system of the present invention, a water pipe is provided for conveying water therein. A particle sensor is in operative engagement with the water pipe. The particle sensor continuously counts particles and classified in different fractions according to their sizes or size distribution in the water of the water pipe. The particle sensor triggers a taking of a water sample only when a particle count reaches a predetermined level of any of particles size and concentration. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
         FIG. 1  is a schematic view of the monitoring system of the present invention; 
         FIG. 2  is a schematic view of graph showing number of particles over a time period; and 
         FIG. 3  is a schematic view of the system of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows one embodiment of the water monitoring system  100  of the present invention. The system  100  has a pressurized water pipe  102  and a first diverting pipe  104  and a second diverting pipe  119  in fluid communication therewith. The monitoring system of the present invention may be used for both treated and un-treated water. A particle sensor  106  is in operative engagement with the water pipe  102  via a pipe segment  107  to continuously counts and determines size of microscopic particles  116  that flow in the water. Thanks to the two diverting pipes  104  and  119  it is possible to take water samples upstream and downstream of the particle sensor  106 . In this way, it is possible to smooth out any variations that may occur in the water samples taken. 
     Undesirable particles in the water may include, for example, microorganisms, bacteria and parasites such as Cryptosporidium and Giardia or other organic contamination. The particles may also be indications of chemical and radioactive contamination. Bacteria are often in the range of 0.5-10 micrometers, Cryptosporidium 2-7 micrometers and Giardia particles are often in the range of 7-20 micrometers. 
     The diverting pipe  104  also has a first branch pipe  109  and a second branch pipe  111  connected thereto. The branch pipe  109  is in fluid communication with a flow regulator  113  and the branch pipe  111  is in direct communication with a cooled device or a refrigerator  108  that contains a plurality of containers  115  for storing water samples  126 . The containers may store water from 0.1 liter to 100 liter. Of course, the containers may be used to store any suitable amount of water such as 1-2 liters. 
     In this way, it is possible to analyze water that has not passed through the particle sensor  106 . A pipe  117  extends between the particle sensor  106  and the flow regulator  113 . One function of the flow regulator is to more accurately set the flow of water by creating a water pillar to ensure that the correct amount of water enters the particle sensor  106  via the pipe  117 . The regulator  113  may also be used to remove undesirable air bubbles from the water before the water enters the particle sensor  106 . The mechanical flow controller can be replaced by an electronic flow controller. 
     An important feature of the present invention is the realization of the strong connection between the amount of microscopic particles and the quality of the water because many of the microscopic particles carry contaminants. The particle sensor  106  may be used to count particles both from water conveyed in the pipe  107  and water that has passed through the water regulator  113  and then through the pipe  117  and/or  119 . 
     As indicated earlier, water may be diverted from the water pipe  102  via a second diverting pipe  119  and directly into the refrigerator  108 . In this way, it is possible to analyze downstream water that has not passed through the particle sensor  106  and possibilities will be there to connect via the flow regulator  113 . These water samples may then be compared to water samples that come from the particle sensor  106  via the pipe  129 . As indicated earlier, the device  106  automatically produces water samples, for storage in the refrigerator, when the particle count reaches certain critical values. 
     The device  106  may count particles using a light scattering technique, light extinction technique or any other suitable technique for counting particles in flowing water. The device  106  may be set to register particles in the range of 0.1-500 micrometers, more preferably in the range of 0.5-100 micrometers. Preferably, the device  106  may classify the particles in the following size ranges: 0.5-1 micrometers, 1-2 micrometers, 2-7 micrometers, 7-20 micrometers and 20-100 micrometers. Of course, the device may be set to classify other suitable size ranges. Most preferably, the device  106  counts particles in the size range of 1-25 micrometers which includes most if not all bacteria and other microorganisms of particular interest for water quality monitoring. 
     A microprocessor  112 , such as a programmable logic configuration (PLC) device, is in operative engagement with the counting device  106 , the flow regulator  113 , the diverting pipe  104  and the second diverting pipe  119  via signal connections  121 ,  123 ,  125  and  127 , respectively, to open and close valves connected to the counting device  106 , the flow regulator  113  and the water pipes  104 ,  119  of the water system  100 . The microprocessor  112  is in communication with an operator  114  of the water monitoring system  100 . The signal  125  may control valves  142 ,  144 ,  146 ,  148 . The signal  127  may control the valve  150  of the second diverting pipe  119 . The signals  121 ,  123  control the flow of water in the pipe  117 . The microprocessor may store all the particle counts for further analysis. 
     In operation, the particle sensor  106  continuously counts particles  116  that flow in the water pipes. 
     When the particle count reaches a critical value over a time period, such as well over 50 particles/ml, an alert or water-testing signal  128  is triggered. In general, the particle count should not exceed 20%, or more preferably 10%, more than the normal base count of particles in the water flow. The particle sensor  106  automatically obtains a water sample  126  for further testing and analysis by the operator  114 . The diverting pipe may be connected to a valve to divert water from the main water pipe  102  in order to obtain the water sample  126 . The processor may be programmable to arrange for different testing volumes of water. The water samples  126  are preferably automatically kept in the refrigerator  108  to prevent further contamination. As indicated above, the microprocessor  112  activates valves so that a predetermined testing volume of the water sample flows into the containers  115  disposed in the refrigerator  108 . The operator  114  may then analyze the water samples  126  in the containers  115 . All the events are continuously logged in the processor and/or monitor and/or USB memory and/or flash card. 
     The alert signal  128  may also be sent to the operator  114  of the water plant. If the particle count reaches a crisis value then a crisis signal  130  may be sent to a crisis contact  132 . However, to avoid unnecessary panic, the crisis signal  130  may only be sent after a water test of a sample confirms the very high contamination. 
     The water may be further analyzed by taking additional water samples such as at locations  134 ,  136 ,  138 ,  140  or any other suitable location. The operator may first do a quick analysis to check the water for cloudiness, color, chlorine, pH, transparency, conductivity, coliform, E-coli or any other suitable parameter. The operator may also check to make sure the rise in particle count is not the result of an internal problem within the water plant itself before an alarm signal is sent out externally. 
     As shown in  FIG. 2 , the particle count may gradually increase as shown by the graph  150  and reach a peak value  152  relative to a normal base value  158  of the particle count and then decline. The graph  150  may be designed to show all particles sizes and/or only particles predefined particle size ranges such as 0.5-1 micrometers, 1-2 micrometers, 2-7 micrometers and 7-20 micrometers. By classifying the particle count into size ranges the operator may obtain information about which microorganism type might have contaminated the water. Water testing prior to reaching the peak value  152  may be considered as primary testing  154  and testing subsequent to the peak value may be considered secondary testing  156 . One object of the primary testing  154  is to trigger the water testing procedure and alerting the necessary personnel. One purpose of the secondary testing  156  is to make sure no additional peak values or substantial increase in the particle count is occurring. 
     The particle sensor could be placed anywhere in the process where it is necessary to control the water quality. Another reason for placing the particle sensor in a suitable place is because bio-film may get loosened from the water pipes to contaminate the water. It is therefore very important to capture the water sample at that point. 
     With reference to  FIG. 3 , a system  200  of an embodiment of the present invention is shown. Water  202  to be tested is conveyed via the manifold  201  into a discovery device  203  for discovering or sensing contamination of the water with a particle sensor. It is possible to convey water into the system from various points and the system may include reference water i.e. water that is not contaminated. The water is characterized in a characterizing device  204  and information is sent to a microprocessor monitor  205 . The current quality status of the water may be shown in a monitor  211 . The microprocessor  205  may evaluate and compare the analysis with information stored in an internal or external database  208 . If the analysis determines that a sample should be taken, information from the microprocessor  205  is sent to the sampling and storage device  206  for carrying out water sampling. At the same time, the microprocessor  205  sends instructions to the operator  209  that water samples have been taken and the operator  209  sends confirmation to the microprocessor that the message has been received. The operator  209  then carries out a manual quick analysis  207 . The quick analysis  207  may include analysis related to pH, transparency, conductivity, chlorine, color, bacteria, heavy metals, oxygen, temperature, ORP, identification of micro-organisms with PCR technology, TOC, TON, PyGC/MS, UV-VIS and other suitable test parameters. The results are sent to the microprocessor  205  for evaluation with the assistance of the database  208 . The information is thereafter sent to the operator  209  that decides whether a detailed laboratory analysis  212  should be carried out. The analysis  212  may include analysis of parameters related to bacteria, parasites, organic substances and other suitable parameters. The operator  209  may then inform a risk management group  214  that a sample has been taken and sent away for detailed laboratory analysis  212 . The result of the detailed analysis  212  is sent to the microprocessor  205  for evaluation with the assistance of information stored in the database  208 . A signal is sent to a report and evaluation unit  213  and the microprocessor  205  provides suggestions to the risk management group  214  regarding steps to be taken. When the contamination is severe, it is possible to quickly trigger an ozone desinfecting unit  218  to treat the contaminated water with an ozone desinfecting treatment. Alarms of an alarm unit  210  for different levels and risks may be sent by the microprocessor  205  to the operator  209  and the risk management  214 . It is possible to obtain information from the microprocessor  205  and the database  208  via a communication device  217  that may include GSM, satellite, Internet or any other suitable communication device or technology. It is also possible to periodically activate or on-line activation of a processing unit  216  for cleaning with automatic flushing, desinfecting, calibration control, validation, sensitivity/precision evaluation, maintenance of the sensor  203  and of the sampling and storage unit  206 . As an option, it is also possible to include other on-line measuring instruments  215  for an automatic on-site analysis that may be carried out or be located at the customer or in the system  100 . The automatic analysis in the instrument  215  may include analysis of parameters such as image-recognition, cell counter with automatic microscopic observation, TOC/COD, DNA identification, Colifast, toxicity, radioactivity and UV-VIS. 
     While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims.

Technology Classification (CPC): 2