MICROPLASTIC FILTER FOR WASHING MACHINES OR OTHER APPLIANCES

A microplastic filter includes a housing including an inlet configured to receive water. The microplastic filter also includes a fine filter disposed to rotate within the housing and configured to filter residues from the water. The microplastic filter further includes an inside wiper disposed within the fine filter. The inside wiper includes a center post disposed along a rotational axis of the fine filter and a helical curved wall spirally extending between the center post and the fine filter, where the helical curved wall is configured to guide a portion of the water to backflow through the fine filter and force away at least some filtered residues from pores of the fine filter to prevent fouling or clogging of the fine filter. In addition, the microplastic filter includes an outside wiper spirally disposed around the fine filter and configured to dislodge other filtered residues from the fine filter as the fine filter rotates.

TECHNICAL FIELD

This disclosure relates generally to filtering devices and processes. More specifically, this disclosure relates to a microplastic filter for washing machines or other appliances.

BACKGROUND

Microplastic pollution is an unaddressed problem within the appliance industry. For example, in washing machines, microplastics from clothing can be dislodged during cleaning and can be released into the sewage system when the washing effluent is drained. This may allow microplastic contamination to enter wastewater treatment systems or other water-related systems or the environment.

SUMMARY

This disclosure provides a microplastic filter for washing machines or other appliances.

In a first embodiment, a microplastic filter includes a housing including an inlet configured to receive water. The microplastic filter also includes a fine filter disposed to rotate within the housing and configured to filter residues from the water. The microplastic filter further includes an inside wiper disposed within the fine filter. The inside wiper includes a center post disposed along a rotational axis of the fine filter and a helical curved wall spirally extending between the center post and the fine filter, where the helical curved wall is configured to guide a portion of the water to backflow through the fine filter and force away at least some filtered residues from pores of the fine filter to prevent fouling or clogging of the fine filter. In addition, the microplastic filter includes an outside wiper spirally disposed around the fine filter and configured to dislodge other filtered residues from the fine filter as the fine filter rotates.

In a second embodiment, an appliance includes a drain configured to output water and a microplastic filter. The microplastic filter includes a housing comprising an inlet configured to receive the water. The microplastic filter also includes a fine filter disposed to rotate within the housing and configured to filter residues from the water. The microplastic filter further includes an inside wiper disposed within the fine filter. The inside wiper includes a center post disposed along a rotational axis of the fine filter and a helical curved wall spirally extending between the center post and the fine filter, where the helical curved wall is configured to guide a portion of the water to backflow through the fine filter and force away at least some filtered residues from pores of the fine filter to prevent fouling or clogging of the fine filter. In addition, the microplastic filter includes an outside wiper spirally disposed around the fine filter and configured to dislodge other filtered residues from the fine filter as the fine filter rotates.

In a third embodiment, a method includes receiving water through an inlet of a housing. The method also includes filtering residues from the water using a fine filter rotating within the housing. The method further includes guiding a portion of the water to backflow through the fine filter using an inside wiper disposed within the fine filter. The inside wiper includes a center post disposed along a rotational axis of the fine filter and a helical curved wall spirally extending between the center post and the fine filter, where the helical curved wall guides the portion of the water to backflow through the fine filter and forces away at least some filtered residues from pores of the fine filter to prevent fouling or clogging of the fine filter. In addition, the method includes using an outside wiper spirally disposed around the fine filter to dislodge other filtered residues from the fine filter as the fine filter rotates.

As used here, the phrase “configured (or set) to” may be interchangeably used with the phrases “suitable for,” “having the capacity to,” “designed to,” “adapted to,” “made to,” or “capable of” depending on the circumstances. The phrase “configured (or set) to” does not essentially mean “specifically designed in hardware to.” Rather, the phrase “configured to” may mean that a device can perform an operation together with another device or parts.

DETAILED DESCRIPTION

FIGS.1through3, described below, and the various embodiments of this disclosure are described with reference to the accompanying drawings. However, it should be appreciated that this disclosure is not limited to these embodiments and all changes and/or equivalents or replacements thereto also belong to the scope of this disclosure.

As noted above, microplastic pollution is an unaddressed problem within the appliance industry. For example, in washing machines, microplastics from clothing can be dislodged during cleaning and can be released into the water supply when the washing machine is drained. This may allow microplastic contamination to enter wastewater treatment systems or other water-related systems or the environment.

This disclosure addresses filtration of microplastics. More specifically, this disclosure provides a filter for performing microplastic filtration using a rotary cylindrical filter screen and wipers positioned outside and inside of the rotating cylindrical filter screen. The one or more wipers outside of the rotating cylindrical filter screen can continuously clean the filter screen and direct the resulting filtrate to a targeted storage area. The one or more wipers inside of the rotating cylindrical filter screen that can create continuous backflow to prevent the filter screen from clogging or fouling. In this way, the filter is able to effectively remove a large amount of microplastics from a washing machine or other appliance. The filter can also achieve a high filtration rate while avoiding clogging or fouling, which may be necessary or desirable in a washing machine or other appliance. For instance, the filter can be used in a washing machine without substantially increasing the drain time or washing cycle time of the washing machine.

FIG.1illustrates an example appliance100including a microplastic filter102in accordance with this disclosure. In this particular example, the appliance100takes the form of a washing machine. However, this is for illustration and explanation only. The microplastic filter102may be used in or with any other suitable appliance or any other suitable device or system in order to provide microplastics filtering.

Since the appliance100here represents a washing machine, the appliance100can be used to wash objects, such as clothing, towels, or bed sheets. Water is supplied to the appliance100at a beginning of a washing cycle and at different times during the washing cycle. During the washing cycle, the appliance100can clean the objects, causing microplastics attached to the objects to mix with the water. At different times during the washing cycle, the water is pumped into a drain104and passes through the microplastic filter102. The microplastic filter102can thereby filter microplastics before the water is output into a wastewater supply, such as a sewer system. One example embodiment of the microplastic filter102is shown inFIGS.2A and2B, which are described below.

AlthoughFIG.1illustrates one example of an appliance100including a microplastic filter102, various changes may be made toFIG.1. For example, while the microplastic filter102is shown inFIG.1as being disposed externally from the appliance100, the microplastic filter102can be implemented inside a housing or other portion of the appliance100. Also, the microplastic filter102can be used in or with any other suitable appliance or other device or system, such as those using liquid as a medium for fabric treatment.

FIGS.2A and2Billustrate an example microplastic filter102in accordance with this disclosure. For ease of explanation, the microplastic filter102may be described as being used with the appliance100. However, the microplastic filter102may be used in or with any other suitable appliance or other device or system, such as those using liquid as a medium for fabric treatment. As shown inFIGS.2A and2B, the microplastic filter102can include an inlet200, a housing202, a fine filter204, a rotational shaft206, an impeller208, a motor210, an inside wiper212, an outside wiper214, a waste collector216, and an outlet218. The inlet200of the microplastic filter102is configured to receive incoming water to be filtered, such as water received from or provided to the drain104of the appliance100. The water can flow through the inlet200into the housing202of the microplastic filter102. The inlet200can be sized based on the amount and rate of water being filtered, which (as described below) can maintain a pressure of the water to rotate the fine filter204. The housing202of the microplastic filter can contain the fine filter204, the rotational shaft206, the impeller208, the motor210, the inside wiper212, and the outside wiper214. The housing202can define a flow path between the inlet200and the outlet218. The housing202may be formed using any suitable material(s) and in any suitable manner.

The fine filter204can filter residues from the water entering the microplastic filter102via the inlet200, such as the water received from or provided to the drain104of the appliance100. Examples of residues can include microplastics and other materials. The fine filter204may have a substantially cylindrical shape or a shape with a constant diameter across a cross section in a plane perpendicular to a rotation axis of the fine filter. For example, the fine filter204can be formed in a conical shape. The fine filter204can be formed using a mesh with a spacing in a range from 5 microns to 100 microns. The spacing of the fine filter204determines a water flow through rate and a size of microplastics to be filtered. For a specified thickness mesh and specified size of the fine filter204, a water flow through rate decreases as the spacing is reduced. The design of the fine filter204can be based a flow through rate of the fine filter204being at or above a flow rate through the inlet200.

The fine filter204can rotate within the housing202, and the fine filter204can be designed to rotate clockwise or counterclockwise. The fine filter204can be connected to the rotational shaft206, and the rotational shaft206can be coupled to an impeller208and a motor210. The impeller208can be positioned within the housing202adjacent to the inlet200. In some embodiments, the impeller208can be rotated by the water flowing through the inlet200, which causes the impeller208to rotate the fine filter204. The motor210can also be utilized to rotate the fine filter204. The motor210can be designed to rotate the rotational shaft206when operated and to allow the rotational shaft206to freely rotate when not operated. For example, a non-operation state of the motor210may not impact an ability of the impeller208to rotate the rotational shaft206.

As water is passing through the fine filter204, microplastics and other debris are filtered from the water, such as when the microplastics or other debris get stuck in the openings or pores of the fine filter204. The inside wiper212can be stationary and positioned within the fine filter204. The inside wiper212can include a center post220and one or more helical curved walls222. The center post220can be positioned along the rotational axis of the fine filter204, and the one or more helical curved walls222can extend from the center post220to a trailing edge224in a convex curve in relation to the rotation direction of the fine filter204. In some embodiments, the convex curve can be an arch. Also, in some embodiments, there may be a uniform spacing between adjacent helical curved walls222. The convex curve directs a portion of the water to backflow through the fine filter204, where the water can put pressure on and loosen any microplastics or other debris stuck in the fine filter204. The trailing edge224spirals around the center post220in a rotational direction of the fine filter204in relation to the outlet218, and the trailing edge224can contact the fine filter204.

The outside wiper214can be formed as a helical ramp, which spirals around an outside of the fine filter204. The outside wiper214includes a leading edge226that spirals in a rotational direction of the fine filter204in relation from the outlet218. The leading edge226is offset in the rotational direction from the trailing edge224of the helical curved wall(s)222. For example, the leading edge226can be offset in a range from about 1° to about 20° in the rotational direction from the trailing edge224in relation to a plane perpendicular to the rotation axis of the fine filter204. The leading edge226of the outside wiper214can be spaced apart from the fine filter204. An angle of the outside wiper214in relation to a plane perpendicular to the rotational axis of the fine filter204may be substantially equal to an angle of the inside wiper212in relation to the plane perpendicular to the rotational axis of the fine filter204.

In some embodiments, the inside wiper212can include first and second helical curved walls222spirally extending between the center post220and the fine filter204. The first and second helical curved walls222can extend from opposite sides of the center post220. The outside wiper214can also include first and second helical outside wipers214spirally extending around the fine filter204within the housing202. The first and second outside wipers214can have leading edges226respectively extending in a rotational direction downstream of the trailing edges224of the first and second helical curved walls222.

The outside wiper214can impact and remove microplastics or other debris caught in the openings or pores of the fine filter204. The microplastics and other debris removed from the openings or pores of the fine filter204can be guided by the outside wiper214to the waste collector216. In some embodiments, the waste collector216can be removably coupled at a base of the housing202. The waste collector216can collect the microplastics and other debris removed from the water by the fine filter204. The waste collector216can be removed or accessed in order to clear the collected microplastics and other debris. In some embodiments, the waste collector216does not have an outlet. In other embodiments, the waste collector216can have an outlet separate from the outlet218. Any outlet of the waste collector216may not be connected to a wastewater supply, such as a sewer system, in order to prevent reintroduction of the microplastics or other debris into the water.

The outlet218outputs the filtered water, such as to a sewer system. In some embodiments, the outlet218can be connected to the housing202or separately connected to the appliance100. The water that is released through the outlet218may contain little if any microplastics or other debris having a size greater than the minimum opening or minimum pore of the fine filter204. For example, in some cases, the microplastic filter102can filter microplastics or other debris having a diameter or other size that is at least about 5 microns to about 100 microns.

AlthoughFIGS.2A and2Billustrate one example of a microplastic filter102, various changes may be made toFIGS.2A and2B. For example, the number and placement of various components of the microplastic filter102can vary as needed or desired. Also, the microplastic filter102can be used in any other suitable appliance filtering process or other process and is not limited to the specific processes described above.

FIG.3illustrates an example method300for filtering microplastics in accordance with this disclosure. For ease of explanation, the method300ofFIG.3is described as being performed using the microplastic filter102ofFIGS.1,2A, and2B. However, the method300may be used with any other suitable filter and in any other suitable system.

As shown inFIG.3, water is received from an appliance100(or other source) through an inlet200of the microplastic filter102at step302. For example, the water can represent water drained from a washing machine or other appliance100. The water can contain microplastics and other debris that would pollute the environment if released into a wastewater supply. In some cases, the inlet200can protrude from a housing202of the microplastic filter102at a first end and can be coupled to a hose or pipe, such as one extending from a drain104of the appliance100.

The water passes through the fine filter204between the inlet200and the outlet218of the housing202at step304. For example, the housing202can provide a flow path from the inlet200to the outlet218through the fine filter204. The fine filter204can be designed to filter microplastics that are a minimum size, such as a minimum size within a range from about 5 microns to about 100 microns. The filtered water can be routed through the housing202to the outlet218.

An inner wiper212causes a portion of the water to backflow through the fine filter204at step306. For example, the fine filter204can be implemented to rotate within the microplastic filter102. The rotation can be controlled, such as by using a motor210or an impeller208positioned at the inlet200of the housing202. The rotation of the fine filter204can cause water to rotate within an interior of the fine filter204. The inner wiper212can be shaped to guide or divert a portion of the rotating water to backflow through the microplastic filter102. The diversion of the water can cause microplastics or other debris stuck in the fine filter204to be dislodged. In some cases, the inner wiper212can include a center post220and one or more helical curved walls222. The helical curved wall(s)222can cause the rotating water to pass backwards through the fine filter204, and the trailing edge(s)224of the helical curved wall(s)222can spirally extend along an inside surface of the fine filter204.

An outer wiper214can dislodge at least some of the microplastics or other debris not dislodged by the backflow of the water at step308. For example, microplastics or other debris not forced out by the backflow of the helical curved wall(s)222may be dislodged by a leading edge226of the outer wiper214. The leading edge226of the outer wiper214can be spaced apart from the fine filter204so as to not interfere with the rotation of the fine filter204. An angle of the leading edge226of the outer wiper214can be substantially aligned with and slightly offset from an angle of the trailing edge224of the inner wiper212. The leading edge226of the outer wiper214can be offset in a rotational direction of the fine filter204from the trailing edge224of the inner wiper212. The angles of the leading edge226and the trailing edge224can be defined in relation to a plane extending perpendicularly to a rotation axis of the fine filter204.

In some embodiments, the inner wiper212can have first and second helical curved walls222spirally extending along an inside surface of the fine filter204. The first and second helical curved walls222can extend in a symmetrical manner in relation to the center post220. The second helical curved wall222can guide a second portion of the water to backflow through the fine filter204to force at least some of the filtered microplastics from the fine filter204. A second outer wiper214can dislodge additional filtered microplastics from the fine filter204that remain after passing the trailing edge of the second helical curved wall222.

The microplastics or other debris can be guided by the outer wiper214to a waste collector216at step310. In some embodiments, the waste collector216can be a waste storage that is removably coupled to the housing202, such as when the waste collector216can be removed from the housing202in order to remove the collected microplastics or other debris from the waste collector216. The waste collector216may not have an outlet or may have an outlet that is not connected to the outlet218or a wastewater supply.

AlthoughFIG.3illustrates one example of a method300for filtering microplastics, various changes may be made toFIG.3. For example, while shown as a series of steps, various steps inFIG.3may overlap, occur in parallel, occur in a different odder, or occur any number of times.