Secondary lint trap for residential laundry dryer

A secondary lint trap couplable between a laundry dryer and a building-embedded vent duct. The trap has an elongate housing. Aligned inlet and outlet apertures are formed in bottom and top sides of the housing's rearward ends. A tray is removably insertable within the housing. A screened aperture in the tray is aligned between the inlet and outlet apertures when the tray is inserted within the housing. The housing is mountable above the dryer such that the inlet and outlet apertures extend rearwardly of the dryer. This facilitates coupling of the dryer's exhaust outlet to the inlet aperture through one 90° elbow via a first short, substantially straight, elbowless conduit; and facilitates coupling of the vent duct to the outlet aperture through one other 90° elbow collar via a second short, substantially straight, elbowless conduit.

TECHNICAL FIELD

This disclosure concerns a secondary lint trap for use with laundry dryers in residential building suites.

BACKGROUND

Modern multiple-suite high-rise residential buildings have ventilation systems with floor or ceiling-embedded vent ducts. Each suite has one or more vent ducts. Exhaust conduits are used to connect exhaust air sources within the suite to one of the vent ducts. Bathroom fans, range hood fans and laundry dryers are typical exhaust air sources. For example, one exhaust conduit may be connected between the exhaust outlet of a bathroom fan and a vent duct, a second exhaust conduit may be connected between the exhaust outlet of a range hood fan and a vent duct, a third conduit may be connected between the exhaust outlet of a laundry dryer and a vent duct, etc. Exhaust air is expelled into the conduits and exhausted from the building through the vent ducts.

Conventional residential laundry dryers have built-in primary lint traps. However, a dryer's damp, warm exhaust air may contain a substantial amount of excess lint which is not trapped by the dryer's primary lint trap. A secondary lint trap can be coupled between the dryer's exhaust outlet and the building's vent duct to reduce the accumulation of lint in the vent duct.

A stackable laundry washer/dryer unit10(FIG. 1) incorporating a dryer12stacked atop a washer14is often used to conserve space in a high-rise building suite.FIG. 1depicts two alternative prior art configurations for coupling dryer12to one or the other of prior art secondary lint traps16A,16B. As shown to the right inFIG. 1, dryer12's exhaust outlet18can be coupled through conduit20A, 90° elbow22A and conduit24A to the inlet26A of prior art secondary lint trap16A. Secondary lint trap16A's outlet28A is coupled through conduit30A and 90° elbow32A to ceiling-embedded vent duct34A. Alternatively, as shown to the left inFIG. 1, dryer12's exhaust outlet18can be coupled through conduit20B, 90° elbow22B, conduit21B, 90° elbow23B and conduit24B to the inlet26B of prior art secondary lint trap16B. Secondary lint trap16B's outlet28B is coupled through conduit30B and 90° elbow32B to ceiling-embedded vent duct34B.

It is generally recommended that no more than two 90° elbows and no more than 15 feet of conduit be used to connect a laundry dryer's exhaust outlet to a building-embedded vent duct. Otherwise, air pressure in the exhaust conduit(s) and vent duct is reduced, resulting in inefficient operation of the dryer and potentially necessitating installation of an inline fan (not shown) to increase air pressure in the exhaust conduit(s) and vent duct. The prior art configuration shown to the right inFIG. 1is somewhat preferable to the configuration on the left, because the configuration on the right has only two 90° elbows22A,32A whereas the configuration on the left has three 90° elbows22B,23B,32B. The configuration on the right is also preferable if the combined length of conduits20A,24A and30A is less than the combined length of conduits20B,21B,24B and30B; particularly if the combined length of conduits20B,21B,24B and30B exceeds 15 feet.

It is not always possible to adopt a 2-elbow configuration like that shown to the right inFIG. 1, nor is it always possible to adopt a configuration requiring no more than 15 feet of conduit to connect a dryer's exhaust outlet to a suite's built-in vent duct. This is problematic because if moisture-laden air is not efficiently exhausted, moisture may accumulate inside the elbows, exhaust conduit(s), vent duct, etc. potentially causing water damage. Moreover, if a prior art secondary lint trap is mounted in a location which is difficult to reach, the suite's occupant(s) may be unable or may be disinclined to remove accumulated lint from the secondary lint trap with sufficient frequency. Lint may accordingly accumulate in the secondary lint trap to a point which further reduces the dryer's efficiency. In an extreme case, accumulated lint can pose a fire hazard.

DESCRIPTION

As best seen inFIGS. 3 and 4, secondary lint trap46includes an elongate housing56which slidably receives a flat, elongate removable tray58through frontal opening60. Housing56may be formed by fastening the side and rear edges62,64,66of a channel-shaped, sheet metal top part68to the corresponding side and rear edges72,74,76of a flat, sheet metal bottom part78. Top part68can be fastened to bottom part78by button-locking top part68's side and rear edges62,64,66to bottom part78's side and rear edges72,74,76respectively.

Inlet collar44's flanged rim80is circumferentially fastened around bottom part78's downward-facing inlet aperture82so that collar44protrudes downwardly from the bottom side of housing56's bottom part78. Inlet collar44and rim80are formed of sheet metal. Rim80may be welded around inlet aperture82.

Outlet collar48's flanged rim84is circumferentially fastened around top part68's upward-facing outlet aperture86so that collar48protrudes upwardly from the top side of housing56's top part68. Outlet collar48and its rim84are formed of sheet metal. Rim84may be welded around outlet aperture86.

Housing56is mounted atop dryer12such that inlet and outlet collars44,48extend rearwardly of dryer12's rear wall88. Such rearward extension facilitates coupling of dryer12's exhaust outlet18(which protrudes horizontally and rearwardly from dryer12's rear wall88) to inlet collar44through one 90° elbow40having an upward-facing outlet aligned with inlet collar44via one short, substantially straight, elbowless conduit42. Such rearward extension also facilitates coupling of vent duct54to outlet collar48through one 90° elbow52having a downward-facing outlet aligned with outlet collar48via another short, substantially straight, elbowless conduit50. Double-sided foam tape can be used to mount housing56atop dryer12.

Tray58is sized and shaped for snug-fit, slidably removable insertion through housing56's frontal opening60. An aperture92is formed near the rearward end94of tray58. Aperture92is aligned between apertures82,86which are aligned with one another when top and bottom parts68,78are assembled to form housing56. Aperture92is thus aligned between inlet and outlet collars44,48when tray58is fully inserted within housing56. A stainless steel mesh screen96is mounted in aperture92by fastening apertured frame98over screen96and to the underside of tray58, such that frame98circumferentially surrounds aperture92. A handle100is provided on the forward end102of tray58. The length of housing56and tray58(i.e. the displacement between housing56's rear edges66,76and the forward end102of tray58) is sufficient to allow handle100to protrude slightly forwardly of dryer12's front wall104when tray58is fully inserted within housing56. This allows handle100to be easily grasped for removal of tray58from housing56as explained below.

During operation of dryer12, lint-laden exhaust air is expelled horizontally and rearwardly through dryer12's exhaust outlet18into and through 90° elbow40, through conduit42, through secondary lint trap46's inlet collar44, and through mesh screen96—which traps lint. Lint-filtered exhaust air which passes through screen96flows through secondary lint trap46's outlet collar48, through conduit50, through 90° elbow52, into and through ceiling-embedded vent duct54which exhausts the air from the building.

As previously mentioned, a stackable laundry washer/dryer unit is often used to conserve space in a high-rise building suite. Sometimes, a relatively narrow closet is provided to house the washer/dryer unit. The closet may have insufficient room for mounting prior art secondary lint trap16A or16B in a conveniently accessible position within the closet. However, if prior art secondary lint trap16A or16B is mounted outside the closet, it may be necessary to use additional 90° elbows, or additional conduit, or both, to connect dryer12's exhaust outlet18through prior art secondary lint trap16A or16B to a building-embedded vent duct, thus exacerbating the aforementioned inefficient dryer operation problem. Secondary lint trap46overcomes these shortcomings because secondary lint trap46can be mounted inside a narrow closet in a conveniently accessible position atop a stackable laundry washer/dryer unit housed inside the closet.

While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof For example, although it may be convenient to mount housing56atop dryer12, housing56may alternatively be mounted above dryer12provided inlet and outlet collars44,48extend rearwardly of dryer12's rear wall88to facilitate coupling of dryer12's exhaust outlet18through one 90° elbow to inlet collar44via one short, substantially straight, elbowless conduit; and facilitate coupling of outlet collar48through one other 90° elbow to vent duct54via another short, substantially straight, elbowless conduit50. As another example, although it may be convenient for handle100to protrude slightly forwardly of dryer12's front wall104when tray58is frilly inserted within housing56, handle100need only be sufficiently near front wall104to facilitate removal and reinsertion of tray58within housing56. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.