NL1039131C2

NL1039131C2 - Method and device for measuring the water quality of shower water to control water management systems in recycle showers or swimming pools.

Info

Publication number: NL1039131C2
Application number: NL1039131A
Authority: NL
Inventors: Martinus Gerardus Antoinnette Keuten; Mateo Jozef Jacques Mayer
Original assignee: Coram Internat B V
Priority date: 2011-10-25
Filing date: 2011-10-25
Publication date: 2013-05-01

Description

Method and device for measuring the water quality of shower water to control water management systems in recycle showers or swimming pools

The present invention relates to a device and method for measuring the water quality of shower water, to control water quality management systems in recycle showers or 5 swimming pools, characterized by at least a sensor from the group of UV sensors or conductivity sensors, installed in the water flow collected from a shower, after having been in contact with a user of the shower and at least a control system for managing the water quality of a recycle shower or swimming pool comprising a dosing system of chemicals for water disinfection and / or a system to purge water. The technology according to the present 10 invention opens possibilities to pro-actively predict the quality of water in recycle showers or swimming pools, resulting in savings in water consumption and / or a reduced amount of chemicals required to safeguard water quality and / or a concentration of impurities in the shower water and / or swimming pool water that is lower than can be achieved with prior art technologies.

15

Introduction

Managing water scarcity is a world wide point of attention becoming increasingly important from a health, safety and environment point of view i.e., providing sufficient and save drinking water for everybody in a sustainable way.

20 A significant amount of drinking water is consumed for hygienic and wellness purposes e.g., in showers, bathrooms and swimming pools. A paradox in many countries is that there is an increasing water demand for so called wellness concepts i.e., relaxing, excersising, enjoying and recovering in bath rooms, jacuzzis, swimming pools and saunas on the one hand and a growing scarcity of drinking water on the other hand.

25 Hence there is a demand for sustainable technologies to combine wellness concepts with sustainability and responsible care for our environment.

The present invention relates to a method and device to implement sustainability and responsible care for our environment in wellness concepts.

30 Description of the technology according to the present invention

According to a first aspect, the present invention relates to at least one sensor from the group of UV sensors and conductivity sensors. More specifically, a UV sensor is defined in this patent application as a sensor comprising at least a light source with a wave length in the range from 200 nm to 400 nm and a light sensitive element that is at least sensitive for 35 light with a wave length in the range from 200 nm to 400 nm. Preferably, the sensor operates according to the light transmission principle i.e., the light source is transmitting light through the water to be investigated to the light sensitive element. The efficiency at 1039131 2 which the light is transmitted from the light source to the light sensitive element is measured by the light sensitive element and this efficiency is related to the level of impurities in the water concerned. It is noted that the UV sensor may work according to a transmission principle where the light travels in a straight line from the light source through the water to 5 the light sensitive element or according to a transmission principle based upon light dispersion i.e., dispersion of light because of, for example, particles or suspended insoluble liquid droplets in the water. In the latter case, the UV light source and the light sensitive element are preferably placed under such an angle relative to one another that hardly any or no transmission of light is recorded in absence of turbid material such as particles or 10 suspended insoluble liquid droplets in the solution. In this particular case, only the light that is dispersed by the particles or suspended insoluble liquid droplets is recorded by the light sensitive element resulting in a turbidity measurement. In a preferred embodiment of the technology according to the present invention, the UV sensor is based upon both the principle of direct transmission of light from the light source through the water to the light 15 sensitive element and the indirect transmission of light from the light source through the water to the light sensitive element i.e., through dispersion. Preferably this is realized by applying one UV light source and at least 2 light sensitive elements that are placed at different angles from the UV light source. More preferably, a UV sensor working according to the direct light principle is combined with a sensor to measure the turbidity of the water.

20 Based upon the turbidity signal and an algorithm, the signal produced by the UV sensor is corrected for turbidity of the water, resulting in a reliable measurement of water quality, even though turbidity is interfering with the UV absorption measurements.

According to a second aspect, the present invention relates to a conductivity measurement. The conductivity measurement is preferably executed through the classical principal of 25 measuring an (alternating) electric current between 2 conductive plates that are placed in the water to be investigated. It is noted that also the use of conductivity measurements according to principles where there is no direct contact between the water to be investigated on one hand and the sensitive elements on the other hand is part of the present invention. According to a third aspect, the present invention relates to a first water source that has 30 been in contact with a person taking a shower, resulting in the presence of impurities in the first water source that were previously present on the person taking the shower. The impurities may comprise micro-organisms and / or organic compounds and / or inorganic salts. According tot the present invention, the sensors defined in the first aspect and the second aspect of the present invention are placed in the first water source i.e., the water 35 that has been in contact with a person taking a shower.

According to a fourth aspect, the present invention relates to a device, preferably a microprocessor containing device including software, registering and / or storing and / or 3 interpreting the measurements performed by the sensor(s) described in the first and / or second aspect.

According to a fifth aspect, the present invention relates to control means for controlling the water quality of the first water source in a recycle shower or of a second source, the second 5 source comprising swimming pool water or jacuzzi water or any other water source a person will use after taking a shower, thereby producing the first water source.

Now a number of important aspects of the present invention have been explained, a number of non limiting preferred embodiments of the technology according to the present invention will be explained.

10 In a first preferred embodiment, the technology according to the present invention relates to a method and device to save water, and heating energy for that water, in a recycle shower while experiencing a large and intense water jet. For this purpose, at least one sensor according to the first and / or second aspect of the present invention is placed in the first water source of the recycle shower. In order to better explain the first preferred 15 embodiment, a non limiting description of a typical recycle shower configuration is now given. It is stressed that the following description of a recycle shower is one of many possible configurations and that the configuration explained in this patent application is just a non limiting example to better explain the details of the present invention. Typically a recycle shower consists of at least an inlet for water, equipped with valve(s) to open/dose and 20 to set temperature, that is connected to a shower head, a shower floor, on which the user of the shower stands, equipped with a water drain for guiding the water into a first water storage tank, a first drainage canal connected to the first water storage tank, a valve connected to the first drainage canal, first control means for closing the valve in the first drainage canal, at least a first recyle pump for recycling water in the first storage tank to the 25 shower head and second control means, switching on the first pump in order to switch the shower into recycle mode thereby reducing water and heat consumption and increasing the intensity of the water jet leaving the shower head. It is noted that the shower may be equipped with multiple shower nozzles in recycle mode on the top and side(s) of the shower. The side nozzles can be used for massage showering since the recycle mode has 30 an increased flow rate which is considerably higher than the normal (sustainable) showering flow rate of about 6 liters of water per minute.

The first water source, as defined previously in this patent application, relates to the water in the recycle shower after having been used by a person in the recycle shower e.g., water on the shower floor or water in the first storage tank or water in the first recycle pump or water 35 in the tubing or piping system to recycle water in the water shower or water in the first drainage canal. Preferably the sensor or sensors according to the first aspect and / or second aspect of the present invention are placed in the first water source e.g., in any of the 4 devices just mentioned in which the first water source is present. Preferably, the signal produced by the sensor according to the first and or second aspect of the present invention is translated into a quality parameter for the first water source. Preferably, the translation of the sensor signal into a quality parameter for the first water source is realized through at 5 least a microprocessor equipped with at least an analog to digital converter that is connected to at least one sensor according to the first or second aspect of the present invention. Preferably, the microprocessor is connected to control means for controlling the valve in the first drainage canal. Preferably, the microprocessor is also connected to control means for controlling the first recycle pump. Preferably, the microprocessor closes the valve 10 of the first drainage canal and starts the first recycle pump when the water quality of the first water source, as measured through the sensor(s) according to the first and / or second aspect of the present invention, is better (lower UV adsorption and lower conductivity) than a pre-defined value which is stored in the microprocessor. As a result, the recycle shower will automatically switch from a shower mode using exclusively fresh water to a shower mode at 15 which the water is recycled, thereby increasing the intensity of the water jet flowing out of the shower head and automatically saving water and energy. Summarizing, the recycle shower operates using exclusively fresh water short after the person in the shower starts washing himself or herself. At this stage, the sensor(s) in the first water source will detect a high concentration of impurities in the first water source i.e., a poor water quality. After this 20 relatively short period, the person taking the shower will be nearly clean so that the the sensors in the recycle shower will detect a high water quality. Based on this information, it is concluded that the recycle shower can be switched into recycle mode and to realize this mode, both the valve in the first drainage canal is closed and the first recycle pump is started. Optionally, the recycle shower is equipped with a heater to heat the water when it is 25 in recycle mode. In this way, cooling down of the water in the recycle shower system is prevented, increasing the time that the recycle shower can be effectively used without introducing any fresh water into the recycling system. Preferably, the shower is also equipped with a first person detection sensor detecting whether or not a person is present in the shower. This sensor can be a pressure sensor on the shower floor or any prior art 30 person detection sensor. In case a person is detected in the shower and also a water flow is detected, the water quality measurement system for analyzing the first water source is started. The person detection sensor is especially of added value to make sure that the shower is only switched into recycle mode if actually a person is present in the recycle shower. In this way, malfunction of the automatic recycling system because the person that 35 is about to take the shower is not yet present in the shower, is prevented. Additionally, the person detection sensor can be used in combination with the water heater in the recycle shower system: In order to prevent pathogens to end up e.g., legionella, the recycle shower 5 must be disinfected regularly. Away to disinfect the recycle shower system without the use of chemicals is to recycle warm water in the recycle shower i.e., water with a temperature higher than 60 degrees Celsius, preferably about 80 degrees Celsius. By the use of a person detection sensor, optionally with a sensor to make sure that the shower door is 5 closed, a safe disinfection mode for the recycle shower can be defined and activated, for example through a switch or remote control.

In a second preferred embodiment the technology according to the present invention is applied to improve the quality of water in swimming pools and / or to reduce the amount of disinfection chemicals for disinfection of swimming pool water and / or to reduce the total 10 water consumption figures to ensure the quality of the water in swimming pools. As will be explained in the following text, the technology according to the present invention especially relates to a strategy i.e., a method to pro-actively couple data collected at the showers of a swimming pool to the dosing strategy of chemicals in a swimming pool and / or the purge of swimming pool water and / or the intake of fresh water in swimming pools. The uniqueness 15 of the concept is that the data collected from data at the showers i.e., water quality data from a first water source, are used to predict what is going to happen to water quality in a second water source i.e., the swimming pool water, in spite of the fact that the first water source and the second water source are different water streams. The basic principle of this approach is now explained. A general rule in swimming pools is that a person has to take a 20 shower prior to entering the swimming pool. Basic idea is to wash of most of the impurities i.e., organic compounds and salts from a person before he or she is in contact with the swimming pool water. In this way, the amount of dirt i.e., impurities ending up in the swimming pool is reduced as compared to the situation that the person involved would not take a shower prior to his or her contact with swimming pool water. However, it is known 25 that the efficiency of showering is not optimum i.e., not all impurities are removed from the persons who take a shower. Also, it is known that, depending on for example the wheather conditions, the average amount of impurities on a person going to a swimming pool may be high or low. By analyzing the shower water of persons entering a swimming pool using the technology according to the present invention, i.e., by using sensors as described in the first 30 or second aspect according to the present invention, it is possible to analyze the amount of impurities that are washed off the persons that are about the enter the swimming pool. Assuming that an average wash efficiency is achieved during the showering of the persons entering the swimming pool, the amount of impurities found in the shower water of persons taking a shower prior to entering the swimming pool can be related to the amount of 35 impurities that will finally end up in the swimming pool. Hence, the dosing of disinfection chemicals can be adjusted pro-actively to a level that will neutralize the amount of impurities that are about to be introduced into the swimming pool water. Also, fresh water intake and 6 water purge can be adjusted according to the measurements executed in the water collected at the showers in the swimming pool. By adjusting the required swimming pool water treatment pro-actively, undesired fluctuations in swimming pool water quality, resulting in high chemical and water consumption figures, can be prevented. Preferably, the showers S in the swimming pool are connected to one central buffer tank in which the level of impurities in the water is measured. Preferably, the amount of shower water used is also measured by the use of a water meter. From the time averaged shower water flow and the measured impurity level in the water collected from the showers, a total load of impurities can be calculated. By multiplying this total load of impurities with (one minus the average 10 washing efficiency), a total load of impurities ending up in the swimming pool water can be calculated. Based upon the predicted total load of impurities ending up in the swimming pool, the dosing strategy of chemicals, fresh water and also the purge of swimming pool water is adjusted. Preferably, data analysis and subsequent process control through the dosing of chemicals and fresh water as well as the purge of swimming pool water are 15 automated using at least a microprocessor and software. In a preferred embodiment, the technology according to the present invention comprises also a automated showering showering system for swimming pools to avoid un-showered pool access. Preferably this is realized by the use of a walk trough shower where the door to enter the pool area is dosed until a sufficient level of deaning (removal of pollutants) is reached. Preferably, the door to enter the pool area is 20 automatically opened after said sufficient level of deaning (removal of pollutants) is reached.

Now the basic features of the technology according to the present invention have been explained, a number of preferred specific process conditions is mentioned.

From an extensive data analysis program of a first water source, i.e., water samples collected as a function of time while persons were taking a shower, it was concluded that 25 the performance of the UV sensor is optimum when the UV absorption measurements are executed at a UV light wavelength near 275 nm. Also it was found that most persons taking a shower can be considered clean after about 3 minutes of showering. After about 1 minute of showering, most of the impurities are already washed off. From these data it is concluded that, in case a recycle shower is applied, this shower usually can be switched to the recycle 30 mode rather quickly i.e., within 5 minutes. The technology according to the present invention will do this automatically and will prevent a person taking a shower from having too wait too long or from switching to recycle mode too quickly. The automatic switching of a recycle shower to the recycle mode after a showering time shorter than 5 minutes is part of the technology according to the present invention. Also a manual switching into recycle 35 mode based upon an advise given through, for example, a LED indicator is part of the present invention. It is also noted that air bubbles or particles present in the water may disturb the UV measurement. It is noted that the presence of air bubbles may be related to 7 the presence of surfactant (shampoo, shower gel) in the water and that the presence of particles means that the water is not yet clean. Hence a disturbance of the UV measurement can be used to conclude that the water is not (yet) clean.

Further, it is noted that in most cases, there is a strong relation between the amount of 5 impurities on a person and the total amount of salts on that person. Reason for this is that a person excretes salts in order to be able to sweat. Hence, it is possible to relate the total amount of impurities ending up in showering water to the conductivity of the showering water. Of course this relation is only valid in case no surfactant is applied since the surfactant (soap, shampoo) has also a significant conductivity. However since it is also not 10 desired to recycle surfactant in a recycle shower, since it binds dirt, a conductivity measurement appears to be surprisingly efficient to determine the right moment for switching to the recycle mode. Therefor, a conductivity sensor is part of the present invention.

In case the technology according to the present invention is applied in swimming pools, a 15 showering time i.e., the time that a person should take a shower before entering the swimming pool can be calculated from analyses with the technology according to the present invention. For this purpose, the amount of impurities in the water leaving the showers, as determined by the use of the technology according to the present invention, is used to calculate a desired showering time. By means of, for example, a LEO indication in 20 the showers, a person taking a shower can be signalled when he or she is clean and ready to leave the shower.

The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.

25 30 35 8

Clauses 1. Device to measure the water quality of shower water and to control the water quality of a water source characterized by • at least one sensor from the group of UV sensors or conductivity sensors 5 • installed in a first water source, said first water source having been in contact with a user of a shower • at least a control system for managing the water quality of either the first water source or a second water source.

2. Device according to clause 1 where the first water source comprises the water that 10 is recycled in a recycle shower.

3. Device according to clause 2, applied in a recycle shower characterized by • at least a shower head • a shower floor on which the user stands equipped with • a water drain for guiding the water to a first water storage tank, 15 • a first water storage tank, • a first drainage canal connected to the first water storage tank, • a valve installed in the first drainage canal, • at least a first water recycling pump for recycling water in the first water storage tank to the shower head 20 • first control means for closing the valve in the first drainage canal • second control means switching on the first water recycling pump in order to switch the shower into recycling mode thereby saving water and increasing the intensity of the water jet leaving the shower head, • at least a microprocessor and software to automate switching of the first and 25 second control means based upon water quality of the first water source as detected by the sensor from the group of UV sensors or conductivity sensors.

4. Device according to one of the previous clauses 2 or 3 equipped with a heater in the recycling system in order to keep the water in the recycle shower at a desired temperature.

30 5. Device according to one of the previous clauses 2-4 equipped with a sensor, sensing whether or not a person is present in the recycle shower.

6. Device according to one of the previous clauses 2-5 equipped with hardware and software to switch on a disinfection program of the recycle shower comprising the recycling of water at a water temperature above 60 degrees Celsius.

35 7. Device according to clause 1 whereby the second water source comprises swimming pool water and the first water source comprises water collected from the shower floor of showers in the swimming pool.

9 8. Device according to one of the previous clauses 1-7 where the sensor consists exclusively of a sensor from the group of UV sensors.

9. Device according to clause 8 where the UV sensor operates at a wavelength between 265 and 285 nm.

5 10. Device according to clause 9 where the UV sensor operates at a wavelength of 275 nm.

11. Device according one of the previous clauses 1-7 where the sensor consists exclusively of a sensor from the group of conductivity sensors.

12. Method for measuring the water quality of shower water and to control the water 10 quality of a water source characterized by a device according to one of the previous clauses 1-11.

15 20 25 30 35 1039131

Claims

Device for measuring the water quality of shower water and for controlling the water quality of a water source characterized by • at least one sensor from the group of UV sensors or conductivity sensors 5. installed in a first water source, characterized in that this first water source in has been in contact with a user of the shower • at least a control system for controlling the water quality of a first water source or a second water source.

2. Device as claimed in claim 1, wherein the first water source consists of the water that is recycled in a recycling shower.

3. Device as claimed in claim 2, used in a recycling shower characterized by • at least one shower head • a shower floor on which the shower user stands, equipped with • a drain to direct the shower water to a first water storage tank operatively connected to • a first water storage tank, • a first drain channel connected to the first water storage tank, • a first valve installed in the first drain channel, • at least a first water recycling pump for recirculating water from the first water storage tank to the shower head • a first control unit around the valve in the first water storage tank drain channel • a second control unit to switch on the first water recycling pump so that water is saved and the intensity of the water jet from the shower head increases 25. at least one microprocessor and software for automating the switching of the first control unit and the second control unit on the basis of of water quality such as commun by the sensor from the group of UV sensors and conductivity sensors.

4. Device as claimed in any of the foregoing claims 2 and 3 plus a heating element in the recycling system in order to keep the water in the recycling shower at the desired temperature.

Device as claimed in any of the foregoing claims 2-4 plus a sensor that detects whether a person is present in the shower.

6. Device as claimed in any of the foregoing claims 2-5 plus hardware and software for carrying out a cleaning program of the recycling shower in which the temperature of the recycled water is higher than 60 degrees Celsius. 1 0 3 9 1 3 1

Device as claimed in claim 1, wherein the second water source consists of swimming pool water and wherein the first water source consists of water originating from the shower floor of showers in the swimming pool.

Device as claimed in any of the foregoing claims 1-7, wherein the sensor 5 exclusively comes from the group of UV sensors.

The device of claim 8 wherein the UV sensor operates at a wavelength in the range of 265 to 285 nm.

The device of claim 9 wherein the UV sensor operates at a wavelength of 275 nm.

Device according to one of the preceding claims 1 to 7, wherein the sensor exclusively comes from the group of conductivity sensors.

12. Method for measuring the water quality of shower water and for controlling the water quality of a water source characterized by a device according to one of the preceding claims 1 to 11. 15 20 25 30 35 1039131