Self-cleaning lint filter for combination washing and drying machine

Abstract

An autonomously cleanable lint filter assembly disposed in a closed air loop for a combination washing and drying machine includes a housing disposed upstream of a fan configured to pull airflow through the lint filter assembly from an air outlet of the combination washing and drying machine, two or more mesh filters spaced apart and disposed within the housing, a spring loaded axle extending through the housing and receiving thereabout the two or more mesh filters, three or more drain holes disposed within a lower half of the housing, two or more annular flanges disposed on an inner surface of the housing configured to receive thereon in a reversible face seal mating under force imparted by airflow one of the two or more mesh filters, and at least two spray nozzles disposed within the housing configured to deliver sprays of liquid to one of the two or more mesh filters.

What is claimed is: 
     
         1 ) An autonomously cleanable lint filter assembly disposed in a closed air loop for a combination washing and drying machine comprising:
 a housing disposed upstream of a blower configured to pull an airflow through the lint filter assembly from an air outlet of the combination washing and drying machine;   two or more mesh filters spaced apart and disposed within the housing such that an upstream mesh filter of the two or more mesh filters comprises a less dense mesh than a downstream one of the two or more mesh filters in a direction of airflow;   an axle configured to extend through a length of the housing between an airflow inlet and an airflow outlet and receive thereabout the two or more mesh filters, the axle being spring loaded at at least one end for bidirectional movement along a longitudinal axis;   three drain holes disposed within a lower half of the housing in alignment with three or more volumes partitioned by the two or more mesh filters;   two or more annular flanges disposed on an inner surface of the housing and extending inward radially, each of the two or more annular flanges being configured to receive thereon in a reversible face seal mating one of the two or more mesh filters under an application of force imparted by an airflow through the housing; and   at least two spray nozzles disposed within the housing adjacent the two or more mesh filters, each of the at least two spray nozzles being configured to deliver a spray of liquid to one of the two or more mesh filters.   
     
     
         2 ) The autonomously cleanable lint filter assembly of  claim 1 , further comprising at least one controller in operative communication with the blower and at least one actuator of the at least two spray nozzles, wherein the at least one controller is configured to instruct the at least one actuator to spray liquid upon receiving a signal indicative of completion of a drying cycle and shutdown of the blower. 
     
     
         3 ) The autonomously cleanable lint filter assembly of  claim 2 , wherein the at least one controller is configured to instruct the at least one actuator to deliver 200-400 cubic centimeters of water in each of two or more bursts during the drying cycle based on one or more of: receiving a signal indicative of at least one of the blower shutting down at an end of a drying cycle, the blower shutting down periodically at one or more timed intervals during the drying cycle, and a measured airflow velocity within the closed air loop being at or below a threshold value during the drying cycle. 
     
     
         4 ) The autonomously cleanable lint filter assembly of  claim 1 , wherein the three or more drain holes are configured to drain a combined spray liquid and lint solution into a collective drain channel disposed along a bottom of the housing, and wherein the collective drain channel drains the combined spray liquid and lint solution into a collective drain outlet. 
     
     
         5 ) The autonomously cleanable lint filter assembly of  claim 4 , wherein the collective drain channel comprises an upper channel portion affixed to the housing and a removable lower portion comprising a slanted bottom angled downward toward the collective drain outlet and wherein a grommet is disposed between rims of the upper channel portion and lower channel portion for watertight sealing. 
     
     
         6 ) The autonomously cleanable lint filter assembly of  claim 1 , further comprising a pair of hub and spoke assemblies configured to engage the housing at an airflow inlet end and an airflow outlet end, the hub and spoke assemblies being configured to support each end of the axle. 
     
     
         7 ) The autonomously cleanable lint filter assembly of  claim 6 , wherein each end of the axle is supported non-rotationally and wherein the two or more mesh filters comprise annular disc filters each one of which is configured to engage a rotational bearing disposed on the axle for spinning freely about the axle under an application of force from a spray of liquid. 
     
     
         8 ) The autonomously cleanable lint filter assembly of  claim 1 , further comprising at least one spring disposed in mated engagement with the at least one end of the axle configured to compress under the application of force imparted by the airflow on the two or more mesh filters thereby translating the axle in along its longitudinal axis until the two or more mesh filters engage corresponding faces of the two or more annular flanges in the reversible face seal mating. 
     
     
         9 ) The autonomously cleanable lint filter assembly of  claim 8 , wherein the at least one spring is configured to expand in an absence of the application of force imparted by the airflow on the two or more mesh filters thereby translating the axle in along its longitudinal axis in a second direction opposite the direction of airflow until the two or more mesh filters separate from the two or more annular flanges by a distance of at least between about 5 mm and 10 mm. 
     
     
         10 ) The autonomously cleanable lint filter assembly of  claim 8 , wherein the two or more mesh filters are affixed to the axle, the axle is supported on either end by linear bearings, and the axle and two or more mesh filters affixed thereto spin passively within the linear bearings under the application of force of an impinging spray on the two or more mesh filters. 
     
     
         11 ) The autonomously cleanable lint filter assembly of  claim 1 , wherein the airflow inlet of the housing is lower than the airflow outlet such that the housing is tilted from horizontal at an angle comprising a range of between about 5 to 40 degrees. 
     
     
         12 ) The autonomously cleanable lint filter assembly of  claim 1 , wherein the housing comprises a portion of the closed air loop between an air outlet of the combination washing and drying machine and a cold side heat exchanger. 
     
     
         13 ) The autonomously cleanable lint filter assembly of  claim 12 , wherein the at least two spray nozzles are configured to deliver the spray of liquid onto the side of each of the two or more mesh filters facing the airflow inlet which receives air from the air outlet of the combination washing and drying machine. 
     
     
         14 ) The autonomously cleanable lint filter assembly of  claim 13 , wherein the spray of liquid is configured to impinge on the mesh filter of the two or more mesh filters in an area disposed aside a vertical centerline, the spray of liquid is configured to impinge the mesh filter at least one of on and about a horizontal centerline, and the spray of liquid hits the mesh filter at an angle comprising a range of between about 35 and 55 degrees from the longitudinal axis of the axle. 
     
     
         15 ) The autonomously cleanable lint filter assembly of  claim 1 , further comprising at least two fluid conduits extended through openings in the housing, the at least two fluid conduits terminating at the at least two spray nozzles for delivering the spray of liquid to the two or more mesh filters. 
     
     
         16 ) A method of autonomously cleaning a lint filter disposed in a closed air loop of a combination washer and dryer comprising:
 receiving at at least one controller one or more sensor signals indicative of an airflow velocity;   determining, based on at least one of the received one or more sensor signals and a time interval, lint filter cleaning is required;   instructing, based on a determination that lint filter cleaning is required, a fan to shut off airflow within the closed air loop;   instructing, following shutting off the fan, two or more spray nozzles to spray two or more mesh filters affixed to a rotatable axle extending through a central axis of an elongated outer housing of the lint filter; and   instructing the fan to restart pulling airflow through the closed air loop following a period of spraying.   
     
     
         17 ) The method of  claim 16 , further comprising instructing the two or more nozzles to spray fluid on the two or more mesh filters when airflow is reduced by a range of between about 5-15% of an airflow velocity measured at a start of a drying cycle. 
     
     
         18 ) The method of  claim 16 , wherein the controller is configured to instruct the fan to stop airflow and spray at a time interval of every between about 9-15 min throughout a drying cycle. 
     
     
         19 ) The method of  claim 18 , wherein each incident of spraying imparts a range of 200-300 cubic centimeters of total fluid on the two or more mesh filters. 
     
     
         20 ) The method of  claim 18  wherein each time interval for spraying lasts in a range of between about 5-10 seconds. 
     
     
         21 ) The method of  claim 16 , further comprising instructing the fan to stop pulling airflow and instructing the at least two spray nozzles to spray lint off the at least two mesh filters at end of a drying cycle. 
     
     
         22 ) The method of  claim 16 , wherein the axle is retained at both ends by rotatable linear bearings disposed in hubs of hub and spoke assemblies radially attached to the outer housing and the axle is spring loaded at one end such that that under application of airflow force, the axle linearly translates and two or more mesh filters affixed thereto compress against annular flanges mounted to an interior of the outer housing to form a reversible seal. 
     
     
         23 ) The method of  claim 22 , further comprising three or more drain holes disposed through a bottom of the outer housing, the three or more holes being configured to drain into a collection channel disposed along a bottom of the housing to drain collected lint laded fluid into a drainpipe.