AU2006246459A1 - Water recovery apparatus and method of water recovery - Google Patents

Description

I

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: WATER RECOVERY APPARATUS AND METHOD OF WATER RECOVERY Applicant: IPSO Pacific Pty Ltd The following statement is a full description of this invention, including the best method of performing it known to me: 1 6067 BGI CI WATER RECOVERY APPARATUS AND METHOD OF WATER RECOVERY 0 Z Field of the Invention The present invention relates to a water recovery apparatus and a method of Orecovering water. It will be convenient to describe the invention with particular reference to use in conjunction with a washing machine or other washing appliance, particularly a commercial laundry washing machine, although the Ninvention may have wider application.

Background of the invention Reducing consumption of water has become of significant concern in recent times. Increasing demand on finite natural resources has necessitated devising ways to increase the efficiency of appliances by reducing the amount of resources they consume. In particular, recovery and recycling of water has become a significant objective.

While many washing appliances may be connected to water recovery systems such as greywater storage and treatment tanks, such systems are generally separate and remote from the washing appliance. Considerable capital may need to be spent on designing and installing the infrastructure for these recovery systems, and unless built when the premises which they service are built, subsequent installation may involve significant inconvenience and cost.

Further, space available for an appliance, for example, in a laundry, may be predetermined and limited, and there may not be space for additional apparatus for water recovery or recycling to be added at a later date.

In addition, waste water recycling systems which are known utilize filters to filter particulates from the water being recovered. When a filter is used, there is a N 2 C need to periodically maintain and clean the filter. This requires a maintenance O schedule and resources to conduct the maintenance. If maintenance is not Z conducted adequately, there is a risk that the water recycling apparatus will either N not function to its optimum capacity, and/or there may be an increased risk of overflow due to water not being able to flow through a blocked filter.

It would be desirable to provide an appliance which has an integral waste water recycling system which does not take up floor space significantly in addition to Ithat which would ordinarily be taken up by the appliance. It would further be desirable to provide a water recycling system which can be retrofitted to an existing appliance without requiring major modification of the appliance. It would further be desirable to provide a waste water recycling system which improves the quality of the water being recycled without the consumption of additional resources.

It would further be desirable to provide a water recycling apparatus which does not incorporate a filter.

Summary of the Invention In accordance with one aspect of the invention there is provided a water recycling apparatus for an appliance with a water inlet and a waste water outlet connectable to a drain, the apparatus including: a support onto which said appliance may be mounted a tank having an inlet connectable to a waste water outlet of said appliance and an outlet, a diverter for selectively diverting flow of water from said waste water outlet between said drain and said tank, and pumping means for pumping water from the outlet of said tank to the inlet of said appliance.

J3 Preferably the apparatus does not include a filter. Particularly it is preferable that O the apparatus does not include a filter between the inlet of the tank and the inlet Z of the appliance.

The present invention is particularly suitable for use with appliances which use ozone in water to perform a washing function, most preferably commercial laundry washing machines.

Preferably, the apparatus can be provided to be fitted to an existing appliance either prior to installation or after commissioning of the appliance. It is desirable for the apparatus to be capable of being added to the appliance without requiring significant modification of the appliance.

The apparatus includes a support onto which an appliance may be mounted.

The support preferably has a depth and width substantially the same as the depth and width of the appliance which may be mounted thereon, so that the "footprint" or floor area occupied by the support is substantially the same or only marginally larger or smaller than the footprint of the appliance. The support may have a height suitable to raise the appliance to a level which is more convenient for loading or unloading. This is particularly important where the appliance is a commercial laundry washing machine. The support most preferably provides a platform to elevate the appliance to a desired height.

The support should be suitably stable and strong to adequately support the appliance during its operation, as will be appreciated by the skilled addressee.

The support may include features to facilitate fastening of the support to a floor, and/or fasteners of an appliance to the support.

The tank may be any suitable reservoir capable of holding a volume of wastewater. Preferably, the capacity of the tank is at least equal to the volume of water used by the appliance during a rinse function. For example, if the O 4 Sappliance generally uses 100 litres of water during a first rinse, then it is desirable o for the tank to have a capacity of at least 100 litres, so that it can store the entire Z volume of water discharged from the appliance at the end of that rinse function.

Preferably, the tank is located beneath the support and within the footprint of the Is support, or at least is substantially within the footprint of an appliance mounted \on the support.

The tank may include a cover comprising one or more separately openable lids to enable inspection of the contents of the tank if desired, even though there are no parts inside the tank which are likely to require maintenance.

The tank includes an inlet which is connectable to the wastewater outlet of the appliance. The inlet may be connectable to the wastewater outlet by means of a or junction in the wastewater outlet pipe of the appliance which can be retrofitted to the appliance. Thus the wastewater outlet stream of the appliance may be diverted either to the tank or to the drain. Preferably the tank includes an overflow outlet connectable to the drain to which the appliance is connected. It will be appreciated that the drain will generally be connected to a sewer, or other facility for disposal of wastewater. A non-return valve may be included between the overflow outlet and the drain to prevent backflow of water from the drain to the tank.

The apparatus includes a diverter for selectively diverting wastewater to the either the tank or the drain. In one embodiment, the diverter includes a first valve between the or junction and the drain, and a second valve between the or junction and the tank. Water can thus be directed to either the tank or the drain by opening of one and closing the other valve. In this embodiment, the first valve is preferably a valve which was supplied as original equipment of the appliance. In another embodiment a three-way valve may be utilized which is switchable between a first position where water is prevented from flowing from O3 C the appliance, a second position where water can flow from the appliance to the O drain, and a third position where water can flow from the appliance to the tank.

c, The tank also includes an outlet so that the contents of the tank can be transferred to the appliance for reuse. The outlet is preferably associated with a pump means which pumps water in the tank to the inlet of the appliance when required. The outlet may be located close to the bottom of the tank. Sensing means for monitoring the water level in the tank may be included. Preferably the IN sensing means senses when the water level in the tank is higher than an upper level. If water in the tank reaches the upper level, the sensing means may signal to a controller, which may be master controller associated with the appliance, to operate the diverter to prevent flow of water to the tank. The sensing means may also sense when the water level in the tank is below a lower level. The lower level is preferably higher than the outlet of the tank. When the sensing means senses that the water level in the tank is below the lower level, a signal is sent to a controller to prevent the pump means from pumping water from the tank. This may act to prevent running the pumping means dry. In addition the sensing means may signal to the appliance to allow filling of the appliance to an appropriate level using mains water.

The apparatus of the present invention is preferably associated with an appliance, more preferably with an appliance in which ozone is added to water entering the appliance.

In another embodiment of the invention there is provided a method of recycling water in a washing appliance with a water inlet and a water outlet, which uses water in one or more rinsing stages and is capable of performing successive washes, the method including: diverting water in said outlet used in at least one of said rinsing stages to a storage means; and C transferring water from said storage means to said inlet in a subsequent O washing or rinsing stage.

c Preferably, where the appliance has a first and second rinsing stage during each washing cycle, water used in said second rinsing stage is diverted to and stored o' in the storage means and is transferred to the water inlet for use in the first rinsing stage of a subsequent wash cycle. In addition, or alternatively water from a first rinsing stage may be diverted to and stored in the storage means and is Itransferred to the water inlet for use in the second rinsing stage of the same wash cycle.

The method of the present invention is particularly suitable for use with washing appliances which use ozone in water to perform the washing function. Washing appliances, particularly commercial laundry appliances used in for example hospitals, nursing homes, prisons or hotels, may, in addition to surfactants, detergents, bleaches and other water treatment chemicals, use ozone to sterilize, deodorize disinfect and cleans laundry. Ozone is generally generated close to the appliance and is injected into a water inlet stream in the form of bubbles, some of which dissolve in the water. Ozone has a very high oxidizing potential, and is an effective biocide and deodorizer and also is effective in breaking down particulate matter. Ozone is extremely unstable and decomposes to 02 rapidly.

The applicant has found that, at least for certain washing appliances, water which has been charged with ozone in a rinse stage of a washing cycle will still contain ozone at the end of the rinse stage. By storing that rinse water after the rinse stage has been completed, the remaining ozone will continue to act on the water for sometime afterwards, sometimes for as long as 20 minutes afterwards. Thus, the ozone generated and injected into the water stream entering the appliance at the start of the rinse stage for the purpose of cleansing the laundry in the appliance can perform the secondary function of purifying or at least improving the quality of the water which can then be stored and reused during a Ssubsequent rinse stage of the same wash cycle, or during another stage of a O subsequent wash cycle. In this way, not only does this method allow for recovery Z and recycling of water which would otherwise be discharged to the drain, it also Nutilizes the residual ozone to act on that water to at least partially purify it or improve its quality, thus maximizing the use of ozone which has been generated.

No additional ozone needs to be added to the waste water collected. Ozone is generally generated in an apparatus which consumes electricity, so by using as much of the ozone generated as possible, the efficiency of the process is Imaximized. Accordingly it is preferable that water is stored in the storage means for at least a minimum time, while the residual ozone acts on contaminants in the water.

Preferably, ozone is added to the water transferred from the storage means to the inlet when it enters the appliance.

It will now be convenient to describe the invention with reference to a preferred embodiment illustrated in the accompanying drawing. It is to be understood that the drawing and the following description relate to a preferred embodiment only, and are not intended to limit the scope of the invention.

Figure 1 is a schematic diagram of an appliance and water recycling apparatus of the present invention.

In Figure 1, appliance 1 is a front loading washing machine housed in a cabinet 3. Appliance 1 has a drum 5 for containing a articles to be washed, and a hatch 7 for loading and unloading those articles into and out of the drum 5. Drum 5 is driven by a motor 9 via a belt 11. Appliance 1 has a water inlet pipe 13 which may be connected to a mains water supply. Water inlet pipe 13 has a mains water outlet 15 which opens into dispenser 17, which has a port 19 which opens into drum 5. When in an opened position, mains valve 14 allows mains water to r

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Sflow to dispenser 17. Detergent, surfactants, bleaches or other chemicals may o be placed in dispenser 17 as required.

z C Appliance 1 has a waste outlet 21 which allows water to drain from drum 5 to waste pipe 23 via outflow 24. Waste pipe 23 may be connected to a sewer or other suitable utility for disposal of waste water. Drain valve 25 is switchable \between an open position, which allows water to flow along outflow 24 from the drum to the waste pipe 23, and a closed position.

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cIN Apparatus 1 also includes an overflow outlet 27 with an opening 29 towards the top of drum 5 to allow flow of water from the drum 5 to waste pipe 23 if the water level in the drum 5 reaches opening 29.

Ozone generator 31 has an ozone injector 33 which may inject ozone into a stream of mains water flowing along water inlet pipe 13. Controller 35 controls and co-ordinates the operation of ozone generator 31, valves 14 and 25, and motor 9.

Appliance 1 is mounted on plinth 37 which acts as a support, and may be bolted thereto by bolts 39a and 39b. Plinth 37 is preferably of a height h such that hatch 7 is of a desirable height above the floor (not shown) onto which plinth 37 is placed to enable easy loading and unloading of laundry into and out of drum Width w of plinth 37 is the same as the width of appliance 1, and the depth (not shown) of plinth 37 is preferably the same as the depth of the appliance, so that plinth 37 does not take up any significantly greater floor space than appliance 1.

Plinth 37 contains tank 41, which has two lids 43a and 43 b to allow inspection of the inside of tank 41. Tank 41 is capable of holding at least the volume of water normally used in drum 5 during, for example, a rinse phase of a wash cycle.

Tank 41 has an overflow outlet 45 connected to waste pipe 23 with a non-retum valve 47 between tank 41 and waste pipe 23 to prevent backflow of dirty water from waste pipe 23 into tank 41.

O Pump 49 although shown located schematically in the base section 50 of appliance 1, is preferably positioned at the rear (not shown) of tank 41 below the N level of overflow outlet 45 and has a return inlet 51 in tank 41 and a return outlet 53 at dispenser 17 at the end of return pipe 55, so that water from tank 41 can be pumped to dispenser 17. Pump 49 is preferably capable of pumping water which may have a proportion of particulate matter therein. Preferably pump 49 has wear surfaces made from ceramic or other hard wear resistant materials known N in the pump making art to enhance its durability.

Although not shown, pump 49 may include a priming line from mains valve 14, whereby a small quantity of mains water is allowed to flow into pump 49, as controlled by controller 35, to prime pump 49 prior to operation.

Ozone injector 56 may inject ozone into return pipe 55 when required.

Waste outlet 21 includes a branch 57, one side of which is directed to outflow 24, and the other side of which is directed to tank inflow 59. Tank valve 61 is switchable between an open position whereby water is able to flow from drum through tank valve 61 along tank inflow 59 and out of opening 63 into tank 41.

Sensor 65 includes a high level probe 67 to sense when the water level in tank 41 reaches an upper level, and a low level probe 69 to sense when the water level in the tank reaches a lower level and an earth rod 70 against which high level probe 67 and low level probe 69 measure against, and which extends from sensor 65 close to the base 72 of tank 61. Controller 35 controls and coordinates the action of pump 49 (and any priming arrangement) and tank valve 61, and receives and processes sensing data from sensor An initial washing cycle is performed by loading soiled laundry articles into drum through hatch 7, which is then closed and a start signal is sent to controller k -IU N Controller 35 signals for ozone generator 31 to commence producing ozone, and o to open mains valve 14 and for motor 9 to start agitation of drum 5. Motor 5 may Z be signaled by controller 35 to stop, start, spin, or agitate at various times during c different washing and/or rinsing stages as will be appreciated by the skilled addressee.

Ozone is injected through injector 33 into the stream of clean mains water flowing along water inlet pipe 13. Detergent, bleach and/or other laundry chemicals will Ihave been added previously to dispenser 17, and the ozone charged water flowing from mains outlet 15 washes those chemicals into drum 5. Drum 5 will continue to fill until a desired volume of water has been delivered, and controller will signal for mains valve 14 to be shut off, ozone generator 31 to stop.

Bacteria, biological waste, fats and oils, soils and solid particulate matter will then be washed from the soiled laundry.

After a programmed time, controller 35 will signal the opening of drain valve and the batch of soiled wash water will drain out of drum 5 through waste outlet 21, out of outflow 24 and into waste pipe 23 to travel to a sewer. Drain valve is then closed, and mains valve 14 is again opened and ozone generator 31 activated so that a first batch of clean ozone charged rinse water enters drum After agitation for a suitable time, controller 35 signals for drain valve 25 to again open, and the first batch of rinse water is allowed to flow out outflow 24 to the sewer. Drain valve 25 is then closed.

Mains valve 14 is then opened and ozone generator 31 activated and a second batch of clean, ozone-charged rinse water is allowed to flow into drum 5. After agitation for a suitable time, controller 35 signals to tank valve 61 to open, so water will flow from waste outlet 21 through branch 57 and valve 61 to tank inflow 59 and into tank 41 from opening 63. The contents of the drum, which may have been spun at least partially dry at the end of the second rinse stage, may the be removed from the drum 5 for further processing, eg, drying, pressing etc.

O Tank 41 is capable of holding all of the second batch of rinse water from drum Z Importantly, the water in tank 5 will still have therein an effective amount of ozone N to continue to break down particulate matter and have anti-bacterial activity. It has been found that effective amounts of ozone may still be present in such water for as much as 20 minutes after discharge into the tank 5 before it decomposes to 02. Accordingly, water in the tank will continue to be purified by the residual ozone for some time after the second rinse stage has been

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N completed.

In the next successive wash with the next batch of soiled laundry, the wash stage may be repeated in a manner identical to that described above. Upon commencement of the first rinse stage, the controller, after allowing a small volume of mains water to prime pump 49, signals pump 49 to operate to pump water from tank 41 up return inlet 51 and along retumrn pipe 55 and out return outlet 53. Simultaneously, ozone generator 31 is activated to inject ozone into that stream of water through injector 56. The quality of the water which has been stored in tank 41 from the previous wash cycle will generally be sufficiently high to be adequate to perform the first rinse. The first rinse is performed in the same way as the first rinse described above, and that batch of water may be discharged to waste pipe 23 at the end of that stage.

The second rinse may then be performed as described above, with the water used in the second rinse discharged into the tank 41 for storage and use in the first rinse of a subsequent wash cycle.

If at any stage there is a malfunction in the control of the various components, and the water level in the tank rises above an upper level, high level probe 67 will signal to controller 35, and controller 35 will not activate opening of tank valve 61 but instead will open drain valve 25 if water needs to be drained from drum Even if water in the tank 41 rises above the upper level, it will flow out overflow IND) 12 Soutlet 45 rather than spilling over the sides of tank 41. If the water level in tank O 41 falls below a lower level, low level probe 69 will signal to controller 35 to Z prevent operation of pump 49 so that pump 49 does not run dry. Instead i controller 35 will activate mains valve 14 to supply the desired volume of water to the drum By storing waste water which is charged with ozone, the energy and water efficiency of the washing process can be increased. Not only is water reused Iwhere it would otherwise be directed to a waste stream, but the amount of ozone generated for use during the rinsing stage serves to both treat the laundry being washed/rinsed and any residual ozone then acts to purify the waste water recovered. There is therefore a synergistic effect by using the present system with an appliance which uses an ozone washing system.

Alternatively, or in addition, the water used in a first rinse stage may be diverted and stored in the tank 41 for subsequent use in a second, or other rinse stage.

Further, water stored in the tank 41 may be used in a wash stage of a subsequent wash cycle. Controller 35 may be easily programmed for such variations. The quality of the water stored in the tank and at least partially purified by the action of the ozone will be the main factor determining the suitability of such reuse. It will be appreciated that water may be recovered during wash cycles using one, or more than two rinse stages without departing from the underlying principle of the present invention.

The apparatus of the present invention may be fitted to any suitable washing appliance either during the initial manufacture of that appliance, or most preferably fitted to the assembled appliance prior to installation. The apparatus may alternatively be fitted to an existing appliance which has already been installed and commissioned. The apparatus may be fitted to an appliance without needing substantial modification to the appliance. An appliance will generally not have a branch between waste outlet 21 and drain valve 25. A "T" IO 1 or junction thus would need to be substituted as shown as branch 57. Return o outlet 53 can be positioned relatively easily above dispenser 17. A wiring loom Z for connecting pump 49, tank valve 61, sensor 65 and ozone injector 56 to controller 35 may be added to the original wiring of the appliance.

I It can be seen that the apparatus of the present invention may not require any filtration means and this is highly desirable to avoid the maintenance and blockage problems of filtered systems. It is considered that the main concession ID to not requiring filtering means is that the pump is of a suitable design to be able to withstand a moderate level of particulate matter in the water to be pumped.

The parts of the apparatus may be made from any suitable materials known in the art. Preferably the plinth is made from steel. Preferably the tank is made from a durable polymeric material. Preferably the tank valve is a ball valve.

It is to be understood that various modifications, alterations and/or additions may be introduced to the parts previously described without departing from the spirit of the invention.

Finally, it is to be understood that various other modifications and/or alterations may be made without departing from the spirit of the present invention as outlined herewith.

Claims (16)

1. 2. A water recycling apparatus according to claim 1 wherein the apparatus does not include a filter.
2. 3. A water recycling apparatus for an appliance according to claim 1 or 2 wherein the tank is located within said plinth.
3. 4. A water recycling apparatus according to any one of claims 1 to 3 wherein the capacity of said tank is equal to or greater than the volume of water used by said appliance during a rinse function. A water recycling apparatus according to any one of claims 1 to 4 wherein said tank includes an overflow outlet connectable to said drain.
4. 6. A water recycling apparatus according to any one of claims 1 to including sensing means senses a water level in said tank higher than upper level, said diverter prevents flow of water from said waste water outlet to said tank. O c 7. A water recycling apparatus according to claim 6 whereby if said sensing o means senses a water level in said tank higher than an upper level, said diverter Z prevents flow of water from said waste water outlet to said tank.
5. 8. A water recycling apparatus according to claim 6 or 7 whereby if said Is sensing means senses a water level in said tank lower than a lower level, said pump means is prevented from pumping water.
6. 9. A water recycling apparatus according to any one of claims 1 to 8 wherein said diverter comprises: a three-way junction in said waste water outlet; and valve means. A water recycling apparatus according to claim 9 wherein said valve means comprises a first valve located between said three way junction and said tank, and a second valve between said three-way junction and said drain.
7. 11. A water recycling apparatus according to any one of claims 1 to wherein said tank includes an overflow outlet connectable to said drain.
8. 12. A water recycling apparatus according to any one of claims 1 to 11 wherein said appliance has a depth and a width, and said plinth has a depth and a width substantially equal to the depth and width of said appliance.
9. 13. An appliance having a filterless water recycling apparatus according to any one of claims 1 to 12.
10. 14. An appliance according to claim 13 wherein ozone is added to water entering said appliance via said water inlet. A method of recycling water in a washing appliance capable of performing O successive washes, which has a water inlet and a water outlet connected to a Z drain and which uses water in washing and one or more rinsing stages, the N method including: diverting water in said outlet used in at least one of said rinsing stages to a storage means; and transferring water from said storage means to said water inlet in a subsequent washing or rinsing stage.
11. 16. A method according to claim 15 wherein said washing appliance has a first and second rinsing stage, and water used in said second rinsing stage is diverted to and stored in said storage means, and is transferred to said water inlet for use in a first rinsing stage of a subsequent wash.
12. 17. A method according to claim 16 wherein water from a first rinsing stage is diverted to and stored in said storage means, and is transferred to said water inlet for use in said second rinsing stage of the same work.
13. 18. A method according to any one of claims 15 to 17 wherein ozone is introduced into water transferred to said water inlet.
14. 19. A method according to claim 18 wherein said water in said outlet diverted to said storage means contains ozone.
15. 20. A method according to any one of claims 15 to 19 wherein the washing appliance is in accordance with claim 13 or 14.
16. 21. A method according to any one of claims 15 to 20 wherein said water diverted to said storage means resides therein for at least a minimum duration.