The present invention relates to a method for measuring one or more parameters in a water flow in a device intended for recycling of water, to a measuring unit intended for a water recycling device and to a water recycling device comprising such a measuring unit.
There are many different types of water recirculation systems. One such is shown in WO2013/095278, which describes a hybrid device for a recirculation shower, allowing purification and either recycling of water or discarding of water, wherein said hybrid device comprises a recirculation loop, a filter system with a nano-filter, at least one filter quality sensor, at least one pre-filter, and wherein the hybrid device is arranged to redirect the water from recirculation to drainage when the at least one filter quality sensor indicates the need thereof.
Furthermore, in WO2017/099663 there is also disclosed a water recirculation apparatus, wherein the apparatus comprises a light unit intended for neutralisation of organisms in said water flow, and wherein the light unit, such as a UV LED unit, is arranged in a dockable water treatment chamber.
The present invention also relates to water recirculation systems, e.g. such showers. The present invention is directed to providing an improved measuring method and a measuring unit intended for water recirculation systems.
The stated purpose above is achieved by a method for measuring one or more parameters in a water flow in a device intended for recycling of water, said method comprising directing part of the water flow to a liquid-stagnant space where the measuring is performed. The concept of the present invention is to ensure that the measuring is performed on a water amount which is stagnant. This has several advantages, Firstly, as the water amount is not in movement, there is no or a very little risk of air bubbles, which in themselves is an error source for the measurement. Secondly, as the water amount is stagnant, the present invention provides the control of measuring several parameters on one and the same water amount, not only once but also during several times if this is of interest, before a specific water amount is conversed and replaced. Both advantages mentioned above are important when measuring in a system where water is flowing, such as in a water recirculation system, e.g. in a recirculating shower.
The present invention is also directed to a device intended for recycling of water, said device comprising a flow path for recycled water, a fresh water inlet, a recirculation water inlet and a recirculation water outlet, a user outlet, a heater and a filter, and wherein the device also comprises an off-line bypass loop arrangement which comprises a liquid-stagnant space and which off-line bypass loop arrangement also comprises one or more sensors enabling measuring in the off-line bypass loop arrangement. One example of such a device is shown in
Below, specific embodiments of the present invention are disclosed. According to one specific embodiment of the present invention, the liquid-stagnant place is arranged as an off-line bypass loop arrangement comprising a quality measuring cell in the device intended for recycling of water. It should be noted that the present invention covers all systems where the liquid is led to liquid-stagnant space for measurement, however an off-line bypass arrangement is one preferred alternative. This off-line bypass arrangement is further discussed below.
According to yet another specific embodiment of the present invention, the step of directing part of the water flow to a liquid-stagnant space is performed cyclically. Cyclically should in this regard be linked to the sampling timing, implying that the method according to the present invention is performed repeatedly. The actual measuring may be performed linked to a minimum off-line regulation, i.e. measuring first after a certain time range when it is ensured that the water flow is stopped. Moreover, the actual measuring frequency for different parameters may vary so that certain parameters, e.g. turbidity, may be measured every sampling cycle, however other parameters, such as microbiological activity, may be measured only once a day or so.
As may be understood from above, the method may involve measuring one or more different parameters. According to one specific embodiment of the present invention, the measuring is performed on one or more of the parameters turbidity, conductivity, pH value, ultrasound and microbiological activity. It should be noted that any combinations of parameters above are possible, and according to one specific embodiment of the present invention, measuring is performed on at least turbidity, which may be a key parameter in several cases. Turbidity is of interest to measure the water quality, and may function as a quality measurement of a primary water quality measurement performed by measuring conductivity (with EC sensor(s)). pH value indicates another important parameter for water. Ultrasound is induced to remove air bubbles, e.g. by use of an ultrasonic transducer (see
Moreover, the present invention may also involve measuring other parameters not mentioned above, such as water hardness. Furthermore, the method according to the present invention may also involve adding a reagent to the liquid-stagnant space before measuring a certain parameter.
According to yet another specific embodiment of the present invention, measuring is performed on turbidity, and reference value is set as a start by measuring penetrated light through fresh water, and this is used as a reference, and wherein the turbidity then is measured by comparing liquid light penetration with reference, and as such enabling to determine water quality. This in itself is different than measuring turbidity according to the standard. According to the present invention, calibration may be performed for a water recycling device and the control system and operation method thereof during the production of the device by using what is known to be fresh water. As such, a reference value may be set, and therefore it may be enough to measure a difference to this reference value, and not an absolute value as is the standard. According to this embodiment of the present invention, the actual measurement is simplified as it is enough to measure the level of light penetrating from one side of a tank or quality measuring cell (see below) or the like containing the liquid-stagnant space.
The present invention also provides a device intended for recycling of water, where said device comprises an off-line bypass loop arrangement which comprises a liquid-stagnant space and which off-line bypass loop arrangement also comprises one or more sensors enabling measuring in the off-line bypass loop arrangement.
According to one specific embodiment of the present invention, the offline bypass loop arrangement comprises a quality measuring cell and a magnetic valve. The actual measuring is being performed in the quality measuring cell and the magnetic valve is provided to ensure a filling of a new measuring amount after emptying the same and when a new measurement is intended.
As is shown in
According to one embodiment of the present invention, the off-line bypass loop arrangement is arranged as a suction unit on the low pressure side of the device intended for recycling of water. One such alternative is shown in
The device according to the present invention may comprise one or several sensors. According to one specific embodiment of the present invention, the off-line bypass loop arrangement comprises sensors for measurement of at least one of the parameters turbidity, conductivity, pH value, ultrasound and microbiological activity. According to one specific embodiment, the off-line bypass loop arrangement comprises a turbidity sensor unit.
It should be noted that also other sensors may be arranged, e.g. for measuring the water hardness. The sensors are connected to a control system which is also connected to other sensors or data handling or sourcing units. The data may be used to analyse the incoming water as such, e.g. in the case of water hardness, but the mina purpose is for measuring the real-time water quality in a water recirculating system, such as a recirculating shower. Moreover, the data collected may also give input to decisions being made in the control system, such as with reference to if water should be recirculated or discarded or how often and when cleaning of the device should be performed etc. etc.
As is further discussed below, the off-line bypass loop arrangement may also comprise an ultrasonic transducer. This is further discussed below, also in relation to reducing the error source of air bubbles when using turbidity as a water quality parameter being measured.
In
Moreover, the device 1 also comprises a flow path 4 for recycled water, a fresh water inlet 5 (cold and hot water inlet), a recirculation water inlet 6 from a selection tank and a recirculation water outlet 7, a user outlet 8 (shower head), a heater 9 and a main filter 10 enabling the recycling feature. As seen in
Moreover, the off-line bypass loop arrangement 3 comprises a quality measuring tank 12 and a magnetic valve 13. The quality measuring tank 12 may be seen as a conversion tank, and can be a comparatively small unit, such as between 0.5 and 1.5 litres, e.g. between 0.5 and 1.0 litres, in case of recirculation shower as shown in
Several sensors 11 may be arranged in the off-line bypass loop arrangement 3, suitably in the quality measuring tank 12 as shown in
Moreover, and as shown in
Number | Date | Country | Kind |
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1750925-8 | Jul 2017 | SE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/SE2018/050734 | 7/4/2018 | WO | 00 |