A SEPARATOR WITH BYPASS PROTECTION
20240216840 ยท 2024-07-04
Assignee
Inventors
- Reuben D'Orton-Gibson (Bristol, GB)
- Michael Lawrance-Owen (Bristol, GB)
- Reuben KETTLE AIERS (Bristol, GB)
- Fergal Feeney (Bristol, GB)
- Adam ROOT (Bristol, GB)
Cpc classification
B01D29/682
PERFORMING OPERATIONS; TRANSPORTING
B01D2201/081
PERFORMING OPERATIONS; TRANSPORTING
B01D2221/02
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A separator prevents microplastics from entering the environment by regenerating the pressure consumption of filters for removing microplastics in effluent from any source but in particular removing microfibers from washing machine wastewater. The separator separates microplastics from an effluent and includes: a chamber with an inlet and an outlet, a sieve structure forming a permeable barrier between the inlet and the outlet to filter the effluent, the sieve structure thus having an inlet side for unfiltered effluent and an outlet side for filtered effluent, wherein a bypass conduit is provided between the inlet and the outlet to provide an alternative route for effluent in the event that the flow of fluid is impeded.
Claims
1-15. (canceled)
16. A separator suitable for separating solid material from a fluid, the separator comprising: a chamber with an inlet and an outlet, a sieve structure forming a permeable barrier between the inlet and the outlet to filter the fluid, the sieve structure thus having an inlet side for unfiltered fluid and an outlet side for filtered fluid, the separator further comprising a filter pressure regeneration apparatus for dislodging filtered material from the sieve structure, wherein the filter pressure regeneration apparatus comprises a conduit and a nozzle assembly having at least one cleaning nozzle for directing fluid towards the outlet side of the sieve structure, wherein the separator is wherein the sieve structure has a circular cross-section, and wherein a channel is formed between the chamber and the sieve structure such that in use the fluid is guided circumferentially around the sieve structure through the channel, and wherein a bypass conduit having a valve is provided between the inlet and the outlet to provide an alternative route for fluid in the event that the flow of fluid is impeded.
17. The separator of claim 16, wherein the bypass conduit includes a pressure-activated valve.
18. The separator of claim 16, wherein the bypass conduit includes a gravity bypass tube.
19. The separator of claim 16, wherein the bypass conduit includes a Pitot tube.
20. The separator of claim 16, wherein the bypass conduit includes a venturi.
21. The separator of claim 16, wherein the bypass system includes an electronically controlled valve.
22. The separator of claim 16, wherein the nozzle assembly comprises a plurality of cleaning nozzles that are rotatable around the central axis of the sieve structure.
23. The separator of claim 16, having a pump in fluid communication with the outlet of the chamber.
24. The separator of claim 23, wherein the pump is arranged to recirculate the filtered fluid to the conduit of the filter pressure regeneration apparatus and/or to drain the separator.
25. The separator of claim 16, wherein an air vent is provided in a conduit between the pump and the filter pressure regeneration apparatus to introduce air into the conduit.
26. The separator of claim 16, wherein a one-way valve is provided such that in use, the one-way valve prevents fluid that has passed through the bypass conduit from returning to the chamber.
27. A washing machine with a separator as claimed in claim 16.
28. A method of operating the separator as claimed in claim 16, comprising the steps of; filtering fluid through a sieve structure, allowing the fluid to bypass the sieve structure when the pressure at an inlet of the sieve structure exceeds a predetermined threshold.
29. The method of claim 16 further comprising the step of allowing the fluid to bypass the sieve structure through a pressure-activated valve.
30. The method of claim 16, further comprising the step of detecting the pressure at the inlet using a sensor and controlling an electronic valve in a bypass conduit when the pressure differential reaches the predetermined threshold.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0072] While the description that follows focuses on washing machines for clothes, it is to be understood that the teachings herein are not limited to use in washing machines as they are equally suited to other processing appliances, such as but not limited to driers, such as wash-dryer combination machines, tumble driers, dyeing machines, cutting machines, recycling machines, dry cleaning machines and so on. The washing machines or other processing appliances could be domestic or commercial. The teachings herein could also be used in other industries in which microparticles may be generated as a result of processing of items. References to washing machines herein are therefore to be understood as comprising any similar appliance of the types contemplated herein.
[0073] The separator described herein may be installed within the appliance itself during manufacture as shown in
[0074] The separator system 1700 described above may be installed within a washing machine, as shown in
[0075] It will further be appreciated that the teachings herein are suited to any application which requires the removal of microplastics, including microfibers, from any effluent, including wastewater, within which such materials may be entrained.
[0076] It should be noted that wastewater from a washing machine, and other applications, contain a wide variety of compounds including microplastics. Although the filter is specifically suited to the capture of microplastic, due to the environment in which it operates, this system is also robust against the harsh and varied compounds the filter comes into contact with and is also suited to filtering out any solid material entrained in an effluent.
[0077] Effluent is understood to include wastewater from the sources mentioned above. It can also include the wastewater from Wastewater Treatment Plants. Effluent includes entrained dirt, detergent and micropollutants including microplastics, which include microfibers.
[0078]
[0079] In this embodiment the pressure activated valve may be designed with a cross sectional profile that enables the valve to invert and thus open, allowing the flow of effluent. Upon the reduction in pressure the valve would then automatically self-close and return to the original orientation.
[0080] The opening pressure threshold can be controlled through varying the flexibility or shore hardness of the flexible material from which the component is manufactured.
[0081] The bypass may be a binary mechanism which is either open or closed to fluid flow. Alternatively, the bypass may operate on a on a graduated basis where it allows varying amount of fluid to pass depending on the pressure applied to the bypass mechanism.
[0082] The bypass may be monitored to establish whether it is in an open or closed state. This sensing system that might include a fluid sensor, mechanical sensor, or pressure sensor. This would enable the bypass to be in communication with the washing machine.
[0083] In another embodiment a sensing system may be used to predict the operation of the bypass mechanism and inform the user ahead of a bypass event that the filter needs emptying.
[0084] Alternatively, the valve 406 may be of a type that can be electronically controlled. A pressure sensor that detects a pressure differential between the two sides of the sieve structure can control the valve, so that if the pressure differential reaches a predetermined level, the valve is operated and the bypass activated. In this embodiment a sensing system may be used to control the operation of the bypass by software logic.
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[0087] The above embodiments work by creating an obstruction to the flow of the effluent. This may be undesirable from the point of view of washing machine manufacturers who often stipulate that anything connected to the outlet of their machines must not cause an obstruction.
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[0089] The bypass may be used to both provide passage for effluent directly to the outlet of the device when the filter membrane becomes blocked and also when the device is opened by the user during disassembly for maintenance or emptying. The bypass is advantageous as it can be used to stop the flow of water from exiting the device through the disassembled product, which would otherwise result in a leak or flood.
[0090] Another benefit of the bypass is that it regulates the pressure seen by the filter system. If for example the opening pressure of the bypass is set to be 6 Kpa, this would also be the maximum pressure typically experienced by the filter mesh and regeneration system. By limiting this pressure, so is also limits the force at which effluent is applied to the mesh. This is advantageous as the regeneration system and wash fluid velocity can be optimised to work at this maximum application force.
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[0094] A cylindrical sieve structure is provided coaxially with the outer wall 1101. The sieve structure extends between the cap 1102 and the base 1103 and provides a seal beyond which unfiltered effluent cannot pass. The sieve structure comprises an open support scaffold to which is fixed a mesh of aperture 25 micrometers. Mesh sizes in the range 5-75 micrometers are also suitable. The mesh separates the solid material from the liquid component of the effluent. An interior dividing wall 1107 creates a channel for the effluent to flow around the sieve structure, starting at the inlet 1104. The chamber is divided horizontally into two parts by a partition 1108. The partition 1108 has an opening on the other side of the interior dividing wall 1107. The combination of the opening and the lower part of the chamber beneath the partition 1108 provide a trap 1109 within which waste material can accumulate. The outlet 1105 is connected to a scoop 1110 that collects filtered effluent that passes through the mesh. A central vertical conduit 1111 provides wash fluid to the nozzle assembly. The nozzle assembly includes propulsion nozzles 1112 mounted on a rotatable hub 1113. The nozzle assembly includes cleaning nozzles (not shown) mounted on the rotatable hub 1113. The cleaning nozzles extend radially out from the hub to be proximal to the filtered side of the sieve structure.
[0095] The separator unit is around 15 cm in diameter. However, it will be appreciated that larger or smaller diameters could be selected depending on the application. The size of the unit is selected on the flow rate of effluent to be filtered. A separator diameter of 15 cm is sufficient to process the effluent from a domestic washing machine flowing at a rate of 13 litres per minute.
[0096] The open area of the mesh that enables the passage of water at a given flowrate can be adjusted by changing either the surface area of the mesh or the mesh aperture. The mesh aperture effects the efficiency, so a smaller mesh aperture is generally preferable to provide greater efficiency. The mesh surface area is a function of the height and diameter, therefore a given area can be matched by increasing the height if the diameter is reduced, and visa versa. All variables can be adjusted to meet product packaging and efficiency specification requirements.
[0097] The bypass system 1115 connects the inlet to the outlet. It ensures that if the regeneration system fails for some reason, the entire wash load of effluent will not back up and cause a flood.
[0098] In another embodiment, the filtered effluent is used to wash the sieve structure.
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[0100] An electronically controlled diverter valve may be provided to recirculate the filtered effluent to the conduit of the filter pressure regeneration apparatus and/or drain the separator, so that only a single pump is required to drain the separator and to recirculate the waste water to the regeneration system.
[0101] It may be advantageous to be able to control the drainage of a separator unit and the pressure regeneration separately.
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[0103] A reservoir 1516 with a fluid detector 1517, which could be a float switch or a capacitative sensor may be provided beneath a separator unit, as shown in
[0104] A separator may be provided where the inlet feeds the interior of the sieve structure and the outlet collects filtered effluent from the outside of the sieve structure.
[0105] The separator housing may be opened to empty the trap when the effluent has been drained. An opening at the top of the sieve structure may be provided to avoid air locks.
[0106] An air inlet may be provided at the inlet of the separator to avoid syphoning all of the waste water out of a washing machine.
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[0108] A more detailed description of a stand-alone separator is provided below:
[0109] A separator unit for locating externally to a textile processing apparatus such as a domestic washing machine is shown in
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[0111] Located within the filter assembly of the jug is a pressure consumption regeneration apparatus comprising a rotatable nozzle assembly 2210 mounted on a hollow spigot 2211. The rotatable nozzle assembly is captive on the spigot by the filter assembly cap 2203b. The spigot is fed by a conduit that is routed through the unit to a recirculating pump 2216a, shown in
[0112] The jug 203 is provided with a moulding 2212 that collects the filtered effluent that has passed through the mesh. This moulding channels effluent to the jug outlet 2213. The jug outlet feeds two reservoirs; a recirculation reservoir 2214 and a drainage reservoir 2215. The recirculation reservoir is connected to the recirculation pump 2216a. The drainage reservoir is connected to a drainage pump 2216b, shown in
[0113] Upon drainage from the filter unit the reservoirs are arranged to prioritise filling of the recirculation reservoir before the drainage reservoir. This ensures that there is always a supply of wash fluid for recirculation and it is not removed by the drainage pump.
[0114] The volume of the recirculation reservoir is designed to ensure a supply of wash fluid that can provide constant recirculation without fully emptying the reservoir. It might be advantageous in some scenarios to limit this and only provide enough wash fluid for a burst as the reduction in this volume enables the product size to be reduced.
[0115] The volume of the drainage reservoir is designed to ensure any back flowing fluid from the outlet ducting and hose pipe can back fill into this chamber without overflowing. This ensures that the user can remove the filter jug when the product is installed close to the floor level and not result in any flooding.
[0116] The geometry of the reservoirs is designed with an angled base and centralized feed point for the pumps. This reduces sedimentation in the tank by removing static flow areas in the tank and creating a dynamic drainage environment that encourages particles to travel to the feed point and be removed by the pump along with any waste water.
[0117] The geometry and depth of the reservoirs is further designed to limit vortexing of the pumps which would otherwise reduce their ability to draw water into the pump and reduce their operational efficiency
[0118] The inlet 2201 and outlet 2219 of the unit 2100 are connected by a conduit 2220. A dispensing valve, 2221 is provided at the entrance to the conduit 2220. The dispensing valve opens at a predetermined pressure, so that if there is a fault in the unit and pressure builds up, the valve operates and effluent bypasses the filter section of the unit straight to the outlet. One-way valve 2222 is provided to prevent filtered effluent re-circulating and one-way valve 2223 is provided to prevent by-passing effluent to enter the reservoirs. In another embodiment of the design, the user can gain access to the bypass for maintenance, for example to remove a blockage.
[0119] An air valve 2224 is provided in the inlet to prevent the recirculation pump and/or the drainage pumps from drawing water out of a connected washing machine, to ensure that there is sufficient water left in the washing machine.
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[0121] The capacitive sensor is a type of fluid sensor; any other type could be used, such as a float switch.
[0122] The electronic system is arranged to operate the unit in numerous modes involving different combinations of sensors and software logic, to optimise the system operation or vary it for differing regional, user, functional or cost requirements. For example, only a capacitive sensor could be used (no pressure sensor) to reduce the number of components and cost. The following are examples of modes of use:
Example 1Capacitive Sensor and Pressure Sensor
Active Filtering:
[0123] If the capacitive sensor indicates that there is effluent present at the inlet (i.e. that the washing machine is emptying) and the pressure sensor indicates that the mesh has blinded over, then the drainage pump is activated to drain the unit and the recirculation pump is activated to spray the mesh to remove the debris and regenerate the pressure consumption. Active filtering may run for a set time once it has been triggered.
Passive Filtering:
[0124] If the pressure sensor indicates that the pressure differential is below a threshold and the capacitive sensor is triggered, then passive filtering is initiated. This is where the recirculation pump is turned off and only the drainage pump is operated.
Drainage Cycle:
[0125] If the capacitive sensor indicates that effluent at the input has ceased, then the recirculation pump is operated after a delay, which could be around 100 seconds, to clean the mesh; this delay can be adjusted. Shortly after, for example 2 seconds, the drainage pump is operated to drain the system. The recirculation pump is then turned off after, for example, a further 3 seconds and then the drainage pump is turned off after, for example, 10 seconds. If the capacitive sensor detects input effluent then the drainage cycle is interrupted and the filtering mode is initiated again.
Standby:
[0126] If the capacitive sensor is low, then the recirculation and drain pump are both turned off.
Example 2Capacitive Sensor Only
[0127] The capacitive sensor is provided on the inlet pipe. When water is detected the pumps are activated until water is not detected anymore. The pumps are programmed to overrun by a predetermined number of seconds to clean the mesh and drain the filter.
Example 3Capacitive Sensor with Current Monitoring on the Drainage Pump
[0128] The capacitive sensor is provided on the inlet pipe. When water is detected, the drain pump is turned on. If current on the drain pump is low while the fluid sensor is reading high, then the recirculation pump is turned on. The recirculation pump is turned off after a predetermined time while the drain pump is left on.
Example 4Integrated in Washing MachinePressure Sensor Only
[0129] The separator unit may be integrated into a washing machine or other textile processing apparatus. No fluid sensor is required as integration with the washing machine control logic enables the filter to know when water is being pumped into the filter. When fluid is pumped through the filter and the pressure sensor is low, the recirculation pump is not run, but the drain pump is activated. When fluid is being pumped through the filter and the pressure sensor is triggered, then the recirculation pump is run. The washing machine drain cycle can be paused at this point for a few seconds to increase the pressure consumption regeneration effectiveness.
[0130] The unit may be used to reduce the water consumption of an existing washing machine or other textile processing equipment, by recirculating the water from the output back into the washing machine. This is possible because the filter removes a high proportion of the debris from the effluent and is therefore very clean. A unit that is integrated into a washing machine could provide this functionality too.
[0131] The separator unit could be integrated into a washing machine and used to replace the conventional filter that is used to prevent debris from reaching and damaging the washing machine pump. Furthermore, by replacing an existing filter with the advanced filtering technology disclosed herein, a different washing machine pump could be used altogether, one that operates at a higher efficiency.
[0132] A bypass system is an important feature of the systems described above because of the complexity of the elements making up the systems. Should any of these fail then the bypass system ensures that the unit will not flood the owner's property. If, for example, the pressure regeneration system malfunctions, for example the nozzles become blocked, or the nozzle assembly stops rotating for any reason, the sieve structure will become blinded over and fluid will back up into the inlet. Without a bypass system, this backed-up fluid could overflow our of the unit and into the property causing a lot of damage.
[0133] As an alternative to regenerating the pressure of the separator unit, a disposable cartridge may be provided. The part of the separator that contains the filtering element, i.e. the sieve structure, could be provided as a cartridge, that is removed and disposed of and replaced with a new one. Alternatively, the cartridge could be sent for cleaning and then re-used.
[0134] Wastewater expelled from textile factories is contaminated with microfibers and it is not guaranteed it will be filtered at municipal facilities. When these facilities exist, they may remove up to 98% of microplastics, however what escapes still equates to millions of microfibers every day. Microfibers removed from water may then be passed to the environment as sewage sludge, spread on agricultural land as fertiliser. Ultimately microfibers are passed as pollutants into the natural environmentthey need to be stopped at source.
[0135] Wet-processing factories currently operate in a linear system, whereby microfibre resources are expelled as pollutants from the technical process into the biological environment. Use of the separator system described herein closes the loop into a continued cycle to retain the value of the microfibers within the technical process and stop damage to the biological environment.
[0136] An embodiment of the separator system can be retrofitted onto the existing wastewater outlet of wet-processing textile factories to enable microfibre capture at source before pollution of the natural environment can occur.
[0137] The separator system can be used to filter microplastics and other micropollutants from environmental drainage systems, such as roadside gullies. A lot of microplastics in the environment break down from larger items of plastic such as car tyres, road surfaces and road markings. After synthetic textiles, tyres are the largest source of microplastics and contain harmful materials such as mineral oils.
[0138] Catalytic converters are fitted on most cars and contain highly valuable materials such as platinum, palladium, copper and zinc. During use, small amounts of these metals are lost from cars and fragments are deposited on the road surface. While metal concentrations vary geographically, collection and recycling of these materials not only reduces environmental pollution but can also be a revenue stream in a circular economy.
[0139] A larger-scale embodiment of the invention can be applied to the treatment of effluent in Wastewater Treatment Plants. For example, the chamber of the separator could be 1 meter in diameter or 2 meters or greater.
[0140] Typical sewage networks are built along one of two designs: [0141] i) Combined sewers. These collect surface water and sewage together, meaning all waste water passes through a Wastewater Treatment Plant (WWTP). During heavy rainfall, it is common for sewers to overflow, releasing untreated sewage and pollution into waterbodies. [0142] ii) Separate sewers. These discharge surface water directly into waterbodies.
[0143] In both systems, roadside runoff, i.e. surface water from the roads, is released into the environment. Most roadside gullies have drains located at regular points and these drains have a sediment pot, which lets heavy materials like gravel and sand settle to prevent blockage. These hold some micropollutants, but the majority of microplastics and valuable metals are too small and are not retained.
[0144] An embodiment of the separation system of the present invention can be retrofitted as an insert into the sediment pot of a drain to filter micropollutants at source. It is designed to fit existing gullies and to be emptied using a mobile vacuum pump.
[0145] In another embodiment the system can be used as part of a filtration system for maritime waste disposal. At sea shipping vessels dump wastewater contaminated from activities on the ship, which include microplastic from various sources. The filter system can be applied to filter this effluent prior to disposal and thus combat this pollution source.