DK180926B1

DK180926B1 - System for recycling drained water as toilet flush water

Info

Publication number: DK180926B1
Application number: DKPA202000579A
Authority: DK
Inventors: Fløe Vestergaard Morten
Original assignee: Gws Grey Water Solutions Aps
Priority date: 2020-05-14
Filing date: 2020-05-14
Publication date: 2022-06-29
Also published as: WO2021228918A1; EP4150166A1; DK202000579A1

Abstract

The present invention describes a system adapted for using collected fractions of wastewater for flushing a toilet.

Description

DK 180926 B1 System for recycling drained water as toilet flush water Technical field of the invention The present invention relates to a device intended for recycling of water or discarding of water not suitable to recycle for toilet flushing and wherein the device comprises a sensor system for measurement of water quality so that a decision of recycling or discarding can be performed by a control unit. The detected usable water is stored in a tank, for later use flushing the toilet. Background of the invention In many parts of the world, clean water is becoming a scarce commodity. Water treatment to remove contaminants can be effective, but is often costly, or uses technology that is not readily available. Areas of high-water consumption are the household toilet(s) and shower(s), where clean water is used and then discarded as wastewater.

WO 2019/164436 discloses a device intended for collecting or discarding wastewater and recirculating the collected fractions for another purpose, such as for flushing in a toilet. The device comprises a sensor system with an IR source and an IR receiver. The sensor system is connected to a control unit, which decides if water should be recycled or discarded in the point of separation based on the measurement of the water quality. However, there is no disclosure about how to use a collected fraction for flushing a toilet. US2010043129 discloses a method for processing greywater, comprising the following steps: a) supplying water to a reservoir of a greywater device; b) collecting the supplied water in the reservoir; c) conducting water out of the reservoir to at least one reservoir of a water consumer; d) monitoring the water quality; and e) flushing the water from the reservoir of the greywater device and/or the reservoir of the water consumer into a sewer drain when the water

> DK 180926 B1 quality drops below an acceptable level. EP1338709 discloses a device through which the wastewater is passed and that passes clear water into a gray water tank and dirty water into the sewer system. The wastewater flow is fed by a pump in the separation device and a sensor detects the degree of turbidity of the waste water and feeds this to an electronic circuit, which opens an outlet to the gray water tank until a certain degree of turbidity is reached.

Summary of the invention It is an object of the present invention to provide a method and system for using collected fractions of wastewater for flushing a toilet. As the toilet may be used at times where there is no access to recycled wastewater, it is problematic if the toilet is solely dependent of such a resource, as flushing of the toilet would otherwise only be possible at certain periods of the day where wastewater is generated. Furthermore, the amount of collected water may not be enough to fill the toilet cistern. Hence, the inventor of the present invention provides a system where wastewater may always be collected and saved until the cistern needs refilling. A first aspect relates to a system for recycling drained water as toilet flush water, the system comprising: - a water drain; - a pump well in wastewater communication with said water drain; - a pump positioned in said pump well; - a sensor unit positioned between said water drain and said pump well and adapted for continuously detecting the quality of said wastewater passing between said water drain and said pump well;

2 DK 180926 B1 - a water tank adapted for receiving water; wherein said pump is adapted for pumping wastewater into said water tank; and -a control unit configured for activating or deactivating said pump in response to data received from said sensor unit about the quality of said wastewater and preset threshold values of said wastewater quality. The sensor unit is positioned between said water drain and said pump well and wherein the quality of wastewater is qualified by the suitability for use in flushing a toilet without leaving a bad odor from the water in the toilet's water trap, as well as being suitable for storage for later use for flushing without too much growth of bacteria. The wastewater is preferably collected from a shower or bathtub water drain but could also be collected from a sink or pool drain.

Preferably, the collected wastewater is separated from a wastewater stream of varying water quality. In one or more embodiments, the water tank comprises a stirring system adapted for stirring wastewater within said water tank. The stirring system prevents the formation of biofilm on the inner surface sides of the tank and may be in the form of a rotating blade, vibration, aeration (preferably injection through jet nozzles) and/or water injection through jet nozzles. Preferably, a rotating blade is combined with fluid injection through jet nozzles.

In one or more embodiments, the quality of said wastewater passing between said water drain and said pump well is presented by the sensor unit as data representing the turbidity and/or pH of said wastewater at a given time or time period. Any suitable type of turbidity sensor system may be used, but a particular type is preferred that operates by performing e.g., turbidity measurements through a transparent pipe section through which the wastewater flows.

1 DK 180926 B1 In one or more embodiments, the sensor unit comprises a transparent pipe section with: - a first end adapted for being coupled to said water drain or to a pipe section downstream to said water drain; and - a second opposing end adapted for being coupled to said pump well or to a pipe section upstream to said pump well. This configuration allows all drained wastewater to pass through the sensor unit. Preferably, the transparent pipe section is mounted declining towards the pump well to avoid that wastewater stays within the transparent pipe, thereby minimizing biofilm formation.

In one or more embodiments, the sensor unit further comprises: - a light source positioned on a first side of said transparent pipe section and adapted for transmitting light through said transparent pipe section; and - a sensor positioned on a second opposing side of said transparent pipe section and adapted for quantifying the amount of light from said light source that is passed through said transparent pipe section at a given time or time period. In one or more embodiments, the sensor unit further comprises: - a light source positioned on a first side of said transparent pipe section and adapted for transmitting light through said transparent pipe section; - a mirror positioned on a second opposite side of said transparent pipe section and adapted for reflecting received light from said light source back through said transparent pipe section; and - a sensor positioned on said first side of said transparent pipe section and adapted for quantifying the amount of light from said light source that is reflected back through said transparent pipe section at a given time or time period. This embodiment increases the accuracy of the measurement. In one or more embodiments, the system further comprises a water flow and/or level indicator configured for: - activating said sensor unit when registering a water flow and/or level above a på DK 180926 B1 preset threshold; and - deactivating said sensor unit when registering a water flow and/or level below a preset threshold.

The sensor unit is preferably recalibrated each time it is activated. A baseline representing wastewater having the highest quality as possible may be generated from the wastewater passing through the sensor unit during the first minute after its activation. The baseline generated in this way accounts for the change in transparency over time of the transparent pipe section, e.g., due to the formation of biofilm. The data used for generating the baseline may be collected until a rapid change in the water quality is registered by the control unit.

In one or more embodiments, the water tank comprises an inlet adapted for receiving water from another source, i.e., tap water.

In one or more embodiments, the wastewater is subjected to UV (ultraviolet) light radiation prior to entering the water tank to neutralize organisms, such as bacteria or the like. Such UV light radiating means could be installed in the conduit between the pump and the water tank. Alternatively, or in combination, the wastewater is subjected to UV (ultraviolet) light radiation within the water tank to neutralize organisms, such as bacteria or the like. In this embodiment, the UV light radiating means is obviously placed in the tank.

Brief description of the figures Figure 1 shows a perspective view of a system in accordance with various embodiments of the invention; and Figure 2 shows a perspective view of a pump well in accordance with various embodiments of the invention.

. DK 180926 B1 Detailed description of the invention Referring to Figure 1, the general scheme of the invention is shown.

The system is exemplified collecting wastewater from a water drain 12 in a shower 10 but could also be used connected to other types of drains, such as a bathtub water drain, a sink or pool drain or the like.

The principle is to collect suitable fractions of the wastewater for storage and later use as toilet flush water.

The system comprises a pump well 200 in wastewater communication with the water drain 12 at one end and in wastewater communication with a sewer 300 at the other end.

A pump (not shown) is positioned within the pump well 200 and is adapted for pumping wastewater into a water tank 400. In order to select suitable fractions of the wastewater for later use as toilet flush water, a control unit 700 is needed to activate or deactivate the pump in response to received data about the quality of the wastewater and preset threshold values of said wastewater quality.

The control unit 700 can receive such data from a sensor unit 100 positioned between said water drain 12 and said pump well 200. The sensor unit 100 is adapted for continuously detecting the quality of the wastewater passing between said water drain 12 and said pump well 200. A preferred example of such a sensor unit 100 is here shown embodied with a transparent pipe section with a) a first end adapted for being coupled to a pipe section downstream to the water drain 12, and b) a second opposing end adapted for being coupled to the pump well 200. To avoid a high standby energy consumption, the system may be provided a water flow and/or level indicator (not shown). The water flow and/or level indicator is configured for activating the sensor unit 100 when registering a water flow and/or level above a preset threshold; and for deactivating said sensor unit 100 when registering a water flow and/or level below a preset threshold.

In this way, the sensor unit 100 is only active when there is enough wastewater flow present to collect from.

Hence, during a shower the wastewater from the shower enters the drain 12 and activates the level indicator (not shown). The water flow and/or level indicator activates the sensor unit 100. The sensor unit 100 may be

, DK 180926 B1 configured with a light source (not shown) positioned on a first side of said transparent pipe section and adapted for transmitting light through said transparent pipe section. A mirror (not shown) is positioned on a second opposite side of said transparent pipe section and adapted for reflecting received light from said light source back through said transparent pipe section. A sensor (not shown) positioned on said first side of said transparent pipe section and adapted for quantifying the amount of light from said light source that is reflected back through said transparent pipe section at a given time or time period. The received quantity of light is proportional to the turbidity of the passing wastewater. Based on these data, the control unit 700 can activate the pump to collect suitable fractions of the wastewater flow for storage and later use as toilet flush water. The sensor unit 100 is preferably recalibrated each time it is activated. A baseline representing wastewater having the highest quality as possible may be generated from the wastewater passing through the sensor unit 100 during the first minute after its activation. However, the first seconds may be subtracted due to large fluctuations in the dataset. The baseline generated in this way accounts for the change in transparency over time of the transparent pipe section, e.g., due to the formation of biofilm. The data used for generating the baseline may be collected until a rapid change in the water quality is registered by the control unit

700. Hence, the sensor unit 100 may comprise a timer configured for such use. The water flow and/or level indicator may also be configured to activate the pump and control unit 700, and further timers may therefore be necessary. The sensor unit 100 may be configured, during its calibration process, to take into account that the turbidity increases the during the first face of a shower, when a person is waiting to enter the shower (e.g., waiting for the water to temper). In this situation, the water comprises more air bubbles which affects its turbidity. When a person is taking the shower, the path that the water travels reduces the amount of air bubbles. Thus, a higher turbidity may be accepted during the first minutes, e.g., until the data fluctuations stabilize. Once the baseline/setpoint value is set,

0 DK 180926 B1 the system is ready to collect suitable wastewater fractions from the flow of wastewater. The control unit may be configured with programs of varying sensitivity, e.g., low, medium, and high, relative to one another. The pump may also be configured to stop the pump if large fluctuations occur.

The pump is only active when the wastewater is accepted by the control unit

700. Hence, fractions with large amounts of soap are discarded. When the pump is inactive, the wastewater will simply pass the pump well 200 and run through the sewer 300. An accepted wastewater fraction will be transported through the transport conduit 500 to the water tank 400. The transport conduit may be a pipe section, a hose or similar, suitable for transporting wastewater. The accepted wastewater fractions may be treated with ultraviolet light during its transport in the transport conduit 500. Alternatively, the water tank 400 may comprise means adapted for treating the collected wastewater with ultraviolet light within the tank water 400. This treatment aids in reducing the level of microorganisms in the wastewater. The water tank 400 may comprise a stirring system adapted for stirring the wastewater within said water tank. The tank may also comprise a water level indicator configured to inform the control unit about its water level status. If the water tank 400 is full, the control unit 700 may be configured not to activate the pump in the pump well 200. Alternatively, provided that the water tank 400 comprises an overflow conduit 505 in water communication with the sewer 300, excess water will simply leave the water tank via the overflow conduit 505 and into the sewer 300. This embodiment secures that the water in the tank is exchanged or diluted with freshly collected wastewater fraction, thereby reducing the risk of bad odor, i.e., bacterial growth. The tank 400 may also comprise an inlet 510 for tap water. The tap water may be used when there is a lack of wastewater in the tank 400 or for cleaning the tank 400 or to dilute the collected wastewater. The water tank 400 may also o DK 180926 B1 comprise a recirculation conduit 525 and a pump 520 adapted for recirculating the wastewater in the tank through the recirculation conduit 525. This embodiment may also be a means for stirring the wastewater within the tank.

The pump 520, or another pump, may also be adapted for actively pumping wastewater from the tank into the toilet cistern 600. The pump 520 may be controlled by the control unit 700 in response to a level indicator (not shown) positioned within the toilet cistern 600. The recirculation conduit 525 may in some embodiments be in water communication with the toilet cistern 600, thereby being able to clean both tanks at the same time.

DK 180926 B1 10 References 10 Shower 12 Drain 100 Sensor unit 200 Pump well

300 Sewage drain 400 Tank 500 Transport conduit 505 Overflow conduit

510 Fresh water supply 520 Pump 525 Recirculation conduit 600 Toilet cistern 700 Control unit

Claims

1 DK 180926 B1 PATENT CLAIM

1. System for recycling drained water as toilet flushing water, where the system comprises: - a water drain (12); - a pumping well (200) in waste water communication with the water drain (12); - a pump located in the pump well (200); - a sensor unit (100) adapted to continuously detect the quality of the waste water passing between the water drain (12) and the pumping well (200); - a water tank (400) adapted to receive water; wherein the pump is adapted to pump waste water into the water tank (400); and - a control unit (700) which is adapted to activate or deactivate the pump in response to data received from the sensor unit (100) about the quality of the waste water and preset threshold values of the waste water quality; characterized in that the sensor unit (100) is located between the water drain (12) and the pump well (200); where the quality of the waste water is qualified by its suitability for use when flushing a toilet without leaving a bad smell from the water in the toilet's water trap, as well as being suitable for storage for later use for flushing without too much bacterial growth.

2. System according to claim 1, wherein the water tank (400) comprises a stirring system which is adapted to stir waste water inside the water tank (400).

3. System according to any one of claims 1-2, wherein the quality of the waste water passing between the water drain (12) and the pumping well (200) is presented by the sensor unit (100) as data representing the turbidity and/ or pH of the wastewater at a given time or for a given period of time.

4. System according to any one of claims 1-3, wherein the sensor unit (100) comprises a transparent pipe section with:

12 DK 180926 B1 - a first end which is adapted to be coupled with the water drain or with a pipe section downstream from the water drain (12); and - another opposite end which is adapted to be coupled with the pumping well (200) or with a pipe section upstream from the pumping well (200).

5. System according to claim 4, wherein the sensor unit (100) further comprises: - a light source which is placed on a first side of the transparent pipe section and adapted to send light through the transparent pipe section; - a mirror which is placed on another opposite side of the transparent pipe section and adapted to reflect received light from the light source back through the transparent pipe section; and - a sensor which is located on the first side of the transparent pipe section and adapted to quantify the amount of light from the light source which is reflected back through the transparent pipe section at a given time or in a given period of time.

6. System according to claim 4, wherein the sensor unit (100) further comprises: - a light source which is placed on a first side of the transparent pipe section and adapted to send light through the transparent pipe section; and - a sensor which is placed on another opposite side of the transparent pipe section and adapted to quantify the amount of light from the light source which is passed through the transparent pipe section at a given time or in a given period of time.

7. System according to any one of claims 1-6, which further comprises a water flow and/or level indicator which is designed to: - activate the sensor unit (100) upon detection of a water flow and/or a level above a preset threshold; and - deactivating the sensor unit (100) upon detection of a water flow and/or a level below a preset threshold.

DK 180926 B1 13

A system according to any one of claims 1-7, wherein the sensor unit (100) is recalibrated each time it is activated, the recalibration process comprising generating a baseline representing wastewater of the highest possible quality from the wastewater passing through the sensor unit ( 100) during the first minute after its activation.