Moisture removal device and method

Abstract

A device for removing moisture from within an enclosure associated with a heat source is disclosed. The device includes a desiccant material within a chamber and a first port between the chamber and an external environment. The device includes a second port between the chamber and the enclosure, a first barrier extending across the second port, including an air impermeable water vapor permeable moisture transport layer, and a second barrier extending across the second port. During use, moisture vapor within the enclosure permeates through the moisture transport layer and enters the chamber where it is adsorbed by the desiccant material. The desiccant material may be regenerated by heating the device using an associated heat source. Pressure within the chamber promotes the flow of moisture through the first port. Heat is conducted through the second barrier to the first barrier to prevent or reduce condensation.

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to a device and method for removing moisture from enclosures, particularly electrical enclosures that house electrical components such as those used in automotive applications. [Background technology]

[0002] 2. Background of the Invention Many articles are susceptible to damage caused by excess moisture. For example, electrical and electronic articles may be damaged by excess moisture, or may have a shortened functional life or become moisture sensitive in operation. Enclosed components that undergo thermal cycling, such as those contained in housings, are similarly susceptible to moisture-related problems.

[0003] An enclosure may be thermally cycled due to changes in ambient conditions or may be thermally cycled during normal operation. For example, the enclosure may contain or be located near a heat source, such as one or more electrical components, the operation of which causes the enclosure to thermally cycle. Examples of enclosures susceptible to undesirable moisture include electronic devices contained in sealed housings, such as, for example, automobile headlamp units, vehicle LIDAR sensor devices, and other systems where moisture accumulates due to the on / off cycling of a heat source within the enclosure.

[0004] One way to remove moisture from such enclosures is to increase airflow across or through the enclosure. However, it can be difficult to ensure sufficient airflow when the components are in a sealed housing. Large openings also allow more entry of dust, dirt, oil, and other undesirable contaminants into the enclosure.

[0005] It is also known to use desiccants or desiccant materials within the enclosure to manage moisture within the enclosure, however, the desiccants have a limited capacity to adsorb moisture and require "regeneration," or removal of the adsorbed moisture, in order to continue to function as a means of removing moisture from the air within the enclosure.

[0006] Removal of excess moisture within the enclosure has been accomplished by an active moisture pump, such as that disclosed in WO2016 / 201045 or WO2018 / 067944 by WL Gore & Associates, Inc. Such moisture pumps include a desiccant material contained within a chamber in communication with the enclosure, and a vent valve to the outside environment. The vent valve can be opened during a regeneration event such that the net effect of the moisture pump is to remove moisture from the enclosure. However, the cost and relative complexity of such devices may not be suitable for certain applications.

[0007] U.S. Patent No. 6,709,493 (WL Gore & Associates, Inc.) describes a venting device in which a desiccant is disposed in a chamber located within an enclosure in close proximity to a vehicle headlamp or other enclosed electrical equipment that generates heat. The chamber is provided with a moisture-permeable, air-impermeable membrane to facilitate the transmission of water vapor into the chamber for adsorption onto the desiccant. The chamber is provided with a port into the enclosure and a vent to the outside environment. Heat generated by the headlamp regenerates the desiccant, causing air to flow into the chamber through the port and out of the chamber through the vent, resulting in a net flow of moisture out of the enclosure. The venting device relies on there being a net flow of air out of the enclosure through the vent, which does not exist in many applications. Summary of the Invention

[0008] Thus, there remains a need for improved moisture reduction devices that address one or more of the aforementioned problems.

[0009] Summary of the Invention An aspect of the invention relates to a device for removing moisture from within an enclosure associated with a heat source, the device comprising: a housing defining a chamber and a desiccant material within said chamber; Including, a first portion of the housing including a first port between the chamber and an environment external to the housing; a second portion of the housing including a second port between the chamber and an environment external to the housing; The second port includes a barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, an exterior of the moisture transport layer in fluid communication with an environment outside the housing and an interior of the moisture transport layer in fluid communication with the chamber.

[0010] The second port is further provided with an arrangement for heating or flowing heat to a barrier, such as an outer barrier as disclosed in further detail herein.

[0011] The second port includes a first barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, where an outer side of the moisture transport layer is in fluid communication with an environment outside the housing and an inner side of the moisture transport layer is in fluid communication with the chamber, and a second barrier extending across the second port, the second barrier configured to conduct heat to the first barrier.

[0012] In use, the device is placed with the enclosure, with the second port in communication with the interior of the enclosure and the first port in communication with the environment outside the enclosure. Water vapor within the enclosure permeates through the moisture transport layer into the chamber where it is adsorbed by the desiccant material. The desiccant material can be regenerated by heating the device using an associated heat source. Pressure within the chamber promotes the flow of vapor through the first port. Heat is conducted through the second barrier to the first barrier, preventing or reducing condensation inside the moisture transport layer. If condensation occurs, the condensed water within the chamber cannot be evacuated through the first port and is then reabsorbed by the desiccant material, which can inhibit or hinder the function of the device.

[0013] An "air impermeable" layer refers to a layer that inhibits mass air flow, particularly convective air flow. One of ordinary skill in the art will appreciate that some materials, such as polymeric materials, can still be considered air impermeable, but can tolerate the diffusion of small amounts of gaseous species over extended periods of time. The air impermeable layers disclosed herein exhibit essentially 0 liters / hour air flow when subjected to conventional air flow test protocols with an air pressure differential across the layer of about 1 psi, or 7 kPa. One of ordinary skill in the art will appreciate that diffusion through the material of the air impermeable layer can exceed 10% for some materials useful as air impermeable, water vapor permeable, moisture transport layers. -3 ~10 0 It will be appreciated that this may occur on the order of ml / hr or less.

[0014] On the other hand, "water vapor permeability" means a water vapor permeability of at least about 10% under ambient conditions of 22°C and 50% relative humidity. 0 ~10 2 mg / day / cm 2 This refers to a layer that is specially engineered to allow water vapor transmission at rates of up to 100%.

[0015] The second barrier can be attached to the housing. The first barrier can be attached to the housing and / or the second barrier. Each barrier can be attached to the housing, for example, around the second port.

[0016] The first barrier can be an inner barrier and the second barrier can be an outer barrier.

[0017] A device for removing moisture from within an enclosure coupled to a heat source, a housing defining a chamber and a desiccant material within said chamber; may include a first portion of the housing including a first port between the chamber and an environment external to the housing; a second portion of the housing including a second port between the chamber and an environment external to the housing; The second port is an inner barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, an outer side of the moisture transport layer being in fluid communication with an environment outside the housing and an inner side of the moisture transport layer being in fluid communication with the chamber; and an outer barrier adjacent an outer side of the moisture transport layer; Including, The inner barrier is movable between a first position in which the inner barrier is spaced apart from the outer barrier and a second position in which at least a portion of the outside of the inner barrier contacts the outer barrier in response to a pressure change in the chamber caused by heating of the device.

[0018] The terms "inside" and "outside" are used herein relative to the frame of reference of the chamber.

[0019] The first port on the first portion of the housing and the second port on the second portion of the housing can be positioned relative to each other such that, when in use with the enclosure, the first port can communicate with an environment outside the enclosure and the second port can communicate with the interior of the enclosure.

[0020] In use, the device is placed with the enclosure, with the second port communicating with the interior of the enclosure and the first port communicating with an environment outside the enclosure. For example, the device can be placed through an opening in a wall of the enclosure. Water vapor within the enclosure permeates the moisture transport layer and enters the chamber where it is adsorbed onto the desiccant material. The desiccant material can be periodically regenerated by heating the device using an associated heat source. When the device is heated, water vapor desorbed from the desiccant material passes to the external environment via the first port. During heating, pressure increases within the chamber, promoting the flow of vapor through the first port. The increase in pressure (i.e., pressure difference between the chamber and the enclosure) brings the inner barrier into contact with the outer barrier. Heating increases the temperature of the housing and one or more surfaces of the outer barrier that contact the inner barrier. This prevents or reduces condensation within the chamber. In particular, heat transferred through the outer barrier to the moisture transport barrier reduces or eliminates condensation on the second side of the moisture transport barrier that would impede or prevent device function. Additionally, when the inner barrier contacts the outer barrier, the surface area of ​​the inner barrier that is in fluid communication with the enclosure is also reduced, resulting in a reduced rate of vapor transmission from the chamber to the enclosure during desiccant regeneration.

[0021] The device is simple in construction and contains few moving parts, in some embodiments only one, and can be designed to be cost-effective and compact.

[0022] A device for removing moisture from within an enclosure associated with a heat source, comprising: a housing defining a chamber and a desiccant material within said chamber; may include a first portion of the housing including a first port between the chamber and an environment external to the housing; a second portion of the housing including a second port between the chamber and an environment external to the housing; the second port includes a first barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, an exterior of the moisture transport layer being in fluid communication with an environment exterior to the housing and an interior of the moisture transport layer being in fluid communication with the chamber, and a second barrier fixedly attached to the first barrier; The second barrier is configured to conduct heat to the first barrier.

[0023] The first barrier can be an inner barrier and the second barrier can be an outer barrier (or vice versa in some embodiments). The outer barrier can be fixedly attached to the outside of the inner barrier, with fluid communication to the moisture transport layer being provided through the outer barrier.

[0024] The second barrier includes one or more apertures that provide fluid communication to the moisture transport layer. The second barrier may be perforated.

[0025] The second barrier can be at least partially embedded within the first barrier.

[0026] The second barrier can be in thermal contact with the housing. The second barrier can include a thermally conductive material, such as a metal (e.g., aluminum, copper, steel).

[0027] The first barrier may be formed from any of the materials or by any of the methods disclosed herein for the inner barrier.

[0028] In another aspect, the invention extends to an enclosure including a device for removing moisture from the enclosure, said device comprising: a housing defining a chamber and a desiccant material within said chamber; Including, a first portion of the housing including a first port providing fluid communication between the chamber and an environment external to the enclosure; a second portion of the housing including a second port between the chamber and the enclosure; the second port includes an air impermeable, water vapor permeable moisture transport layer extending across the second port, an exterior of the moisture transport layer in fluid communication with the enclosure and an interior of the moisture transport layer in fluid communication with the chamber; The enclosure includes or is associated with a heat source configured to elevate the temperature of the device, desorb at least a portion of the adsorbed water from the desiccant material, and elevate the temperature inside the moisture transport layer to reduce or eliminate condensation within the chamber.

[0029] The heat source may also increase the temperature of the interior walls of the chamber.

[0030] The second port includes a first barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, where an exterior of the moisture transport layer is in fluid communication with an environment exterior to the housing and an interior of the moisture transport layer is in fluid communication with the chamber, and a second barrier extending across the second port, where the second barrier is configured to conduct heat to the first barrier. The heater can be configured to increase a temperature of the second barrier.

[0031] The first barrier can be an inner barrier and the second barrier can be an outer barrier.

[0032] The enclosure including a device for removing moisture from the enclosure, a housing defining a chamber and a desiccant material within said chamber; Including, a first portion of the housing including a first port providing fluid communication between the chamber and an environment external to the enclosure; the second portion of the housing includes a second port between the chamber and the enclosure. The device may include The second port is an inner barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, an outer side of the moisture transport layer being in fluid communication with the enclosure and an inner side of the moisture transport layer being in fluid communication with the chamber; and an outer barrier adjacent an outer side of the moisture transport layer; Including, the enclosure includes or is associated with a heat source operable to increase the temperature of the device, desorb at least a portion of the adsorbed water from the desiccant material, and increase the pressure within the chamber; The inner barrier is movable between a first position in which the inner barrier is spaced apart from the outer barrier and a second position in which at least a portion of the outer surface of the inner barrier contacts the outer barrier under the action of a pressure change in the chamber caused by heating the device using the heat source.

[0033] the enclosure including a device for removing moisture from within the enclosure coupled to the heat source; a housing defining said chamber, and a desiccant material within said chamber; Including, a first portion of the housing including a first port between the chamber and an environment external to the enclosure; the second portion of the housing includes a second port between the chamber and the enclosure. The device may include the second port includes a first barrier extending across the second port and including an air impermeable, water vapor permeable moisture transport layer, an exterior of the moisture transport layer being in fluid communication with an environment exterior to the housing and an interior of the moisture transport layer being in fluid communication with the chamber; and a second barrier fixedly attached to the first barrier; Including, The second barrier is configured to conduct heat from the heat source to the first barrier.

[0034] The device may be a device of the other aspects of the invention and may include any of the further or optional features thereof.

[0035] As used herein, the term "moisture" refers to water, whether in liquid or vapor form, that diffuses or condenses from the surrounding atmosphere.

[0036] As used herein, the terms "external environment" or "environment outside a chamber or enclosure" refer to the volume or space outside the chamber or enclosure, as the case may be. The external environment may be at ambient conditions or may be disturbed in some way, for example, by other mechanical or electrical devices (e.g., a vehicle engine).

[0037] It will be appreciated that the inner barrier can be movable between a range of first and second positions. For example, in response to pressure in the chamber, a larger or smaller area of ​​the outer surface of the inner barrier, or its moisture transport layer, can be moved into contact with the outer barrier, thereby defining a range of second positions. Similarly, in response to pressure in the chamber, the distance from the outer barrier and the curvature of the inner barrier can change, thereby defining a range of first positions.

[0038] At least a portion of the inner barrier can be flexible. In some embodiments, the entire inner barrier is flexible. At least a portion of the inner barrier can be elastically extensible. In some embodiments, the entire inner barrier is elastically extensible.

[0039] At least a portion of the outer barrier can be flexible or movable, with the movement or flexing of the outer barrier being less than the movement of the inner barrier.

[0040] For example, in some embodiments, when the inner barrier is moved to the second position, the outer barrier can flex under the action of the inner barrier, such flexing can, for example, allow the outer barrier to conform to the shape of the inner barrier and improve the contact area therebetween.

[0041] The outer barrier can be a fixed barrier.

[0042] During use, the device can be periodically heated by a heat source associated with the enclosure to at least partially regenerate the desiccant material (i.e., desorb at least a portion of the adsorbed water from the desiccant material). The heat source can be an electrical device within the enclosure, e.g., a car headlamp. The enclosure can, in some circumstances, be located sufficiently close to a heat source external to the enclosure, e.g., a vehicle engine, exhaust pipe, radiator, etc., that the device can be periodically heated during normal operation of the heat source.

[0043] The heat source may be present within the enclosure adjacent to or in thermal contact with the device. The heat source may be present outside the enclosure in thermal contact with the device. Thus, the invention in some aspects extends to an apparatus (such as a vehicle or electronic device) that includes an enclosure of the invention aspects and a heat source adjacent to or in thermal contact with the device, optionally within the enclosure. The apparatus may be, for example, a vehicle LIDAR apparatus in an enclosure mounted on an automobile. The apparatus may be a vehicle lighting unit including one or more light vehicle lights and associated equipment such as transformers / drivers within the enclosure.

[0044] The heat source can be a dedicated heat source for periodically heating the device. The enclosure may contain a heat source. The device can include a heat source.

[0045] A device may increase in temperature due to the flow of heat, either conductively and / or radiatively, from a heat source.

[0046] Any suitable heat source may be used. The heat source is preferably configured to raise the temperature of the desiccant material to greater than 100° C., greater than 120° C., greater than 140° C., or greater than 150° C. One skilled in the art will appreciate that particular desiccant materials have particular desorption characteristics. Desorption of certain desiccant materials, for example, occurs more rapidly above a particular threshold temperature, which may vary from desiccant material to desiccant material.

[0047] The heat source may be configured to raise the temperature of the inner walls of the chamber, or the inner walls of the chamber defined by the housing or enclosure, to greater than 50°C, greater than 70°C, greater than 90°C, or greater than 100°C during a regeneration event (i.e., when the desiccant material rises to a temperature of greater than 100°C, greater than 120°C, greater than 140°C, or greater than 150°C).

[0048] The heat source can be configured to raise the temperature inside the chamber beyond a maximum expected dew point within the chamber. The maximum expected dew point can depend on factors such as, for example, the amount of desiccant material, the regeneration rate, the pressure rise within the chamber and thus the size and movement of the internal barrier, the volume of the chamber, and the flow area of ​​the first port. The maximum expected dew point can be determined empirically.

[0049] The heat source may be configured to raise the temperature of the outer barrier (or at least its interior) to greater than 50°C, greater than 70°C, greater than 90°C, or greater than 100°C during a regeneration event (i.e., an event in which the desiccant material is at least partially regenerated by desorbing at least a portion of the adsorbed water).

[0050] The heat source is conveniently an electric heater that includes one or more heating elements that increase in temperature when an electric current is imposed thereon.

[0051] The heat source can be self-regulating, for example, a positive temperature coefficient (PTC) heater. As is known in the art, PTC heaters have temperature resistance characteristics that facilitate rapid initial heating, which can be configured to limit current flow as the temperature approaches a desired temperature.

[0052] The heat source can be an induction heater proximate to the device, the induction heater operable to inductively heat one or more conductive components of the device.

[0053] The housing can incorporate a heat source. For example, in some embodiments, the housing is a metallic structure and the heat source is coupled to the housing such that heat generated by the heat source is conducted to the housing and conducted and / or radiated to the desiccant and fixed barrier. In some embodiments, the housing or a portion thereof acts as the heat source. For example, in some embodiments, the housing can be resistively or inductively heated by imposing an appropriate electrical current or electric field.

[0054] The heat source may be disposed within the chamber. The heat source may be adjacent to, relative to, around, or embedded within the desiccant material.

[0055] The heat source may be controlled by any suitable control system.

[0056] As used herein, the terms "desiccants," "desiccant materials," or "drying agents" are intended to refer to any material capable of adsorbing water vapor from air or a carrier gas, thereby reducing the moisture in the air or carrier gas within an enclosure. The desiccant materials or desiccants can release the adsorbed water vapor upon undergoing a regeneration event, such as heating. The term carrier gas does not include water vapor, but can include gases such as nitrogen, hydrogen, helium, or argon.

[0057] Any desiccant material or combination of desiccant materials can be used in connection with the devices and methods disclosed herein. Examples of desiccant materials include, but are not limited to, oxides such as Al2O3 or CaO, chlorides such as CaCl2, CoCl2, ZnCl2, sulfates such as CaSO4, MgSO4 or Na2SO4, inorganic salts including carbonates such as K2CO3, molecular sieves such as zeolites, aluminophosphates, metal organic frameworks, activated carbon, gels or aerogels such as silica gel, clays such as bentonite, etc. The choice of desiccant material and the amount of desiccant used can vary depending on the particular purpose, such as the device, the environment to which the device will be exposed, the size of the enclosure, the material of the enclosure, how tightly the enclosure is sealed, etc. For example, some material enclosures, such as polycarbonate vehicle lamps, can be made from materials that allow water to penetrate the walls of the enclosure. Some enclosures can be made by gluing or sealing multiple pieces of material together, such as to seal an access panel to the enclosure. Seals (such as O-ring seals) or seams (such as glued seams) may be prone to leaks. Moisture ingress through material selection or leaks may also be a factor in the amount and / or type of desiccant material used. Automotive headlamp units, for example, have an enclosure volume of about 12-22 liters and require a desiccant capacity (i.e., mass of water available for adsorption) of about 500-1000 mg and must be able to adsorb this amount of moisture over the course of a day. In contrast, enclosures for vehicle sensors such as LIDAR sensors, by virtue of their metallic housing, have much lower leak rates and require desiccant capacities of about 10 mg or less per day.

[0058] The desiccant material may be provided in any suitable solid form, but is advantageously provided in particulate form, for example a powder or granules, with a high specific surface area.

[0059] The particulate desiccant may be mixed with additional materials, such as binders, to maintain the desiccant in a bulk shape or form. The desiccant material may be provided on a support material, such as a high surface area oxide, or may be distributed within a matrix, such as a porous or permeable polymer matrix. The desiccant material may be mixed with a thermally or electrically conductive material, such as a metal powder. The thermally or electrically conductive material may be combined with an appropriate heat source, as disclosed herein, to facilitate heat transfer to the desiccant material.

[0060] The desiccant material may be contained within a porous or water vapor permeable container, such as a pouch or bag (or multiple thereof). The desiccant material may in some embodiments be contained within a water vapor permeable, water impermeable container, such as a hydrophobic porous material, e.g., ePTFE.

[0061] The desiccant material may be distributed within the chamber in any suitable manner, however, in some embodiments, a shaped desiccant form (e.g., imposed by a desiccant container, binder or matrix) may be placed in thermal or physical contact with the interior walls of the chamber.

[0062] One or more interior walls of the chamber may be coated or lined with a desiccant material.

[0063] The desiccant material can substantially fill the chamber (at least when the flexible barrier is in the first position). The desiccant material can have a shape shaped to provide a flow path around or through at least a portion of the desiccant material, for example to provide for the flow of water vapor to the outlet channel.

[0064] The second port defines a second region and the inner barrier extends across the flow region. The second port can include an aperture in the housing.

[0065] The inner barrier extends across the second region. The inner barrier can have a larger area than the second region.

[0066] The inner barrier may define an interior surface of the chamber, such as all or a portion of the interior wall of the chamber.

[0067] The moisture transport layer can extend across the second region (some regions of which, in some embodiments, can be impermeable as disclosed below). The moisture transport layer can define an interior surface of the chamber, such as all or a portion of the interior wall of the chamber.

[0068] In the second position, at least a portion of the moisture transport layer may be in contact with the outer barrier, and in the first position, at least a portion of the moisture transport layer is spaced from the outer barrier.

[0069] The inner barrier may include one or more low permeability or impermeable regions. The low permeability regions may be less permeable to water vapor than the moisture transport layer. The impermeable regions may be substantially impermeable to air / carrier gas and water vapor.

[0070] One or more low-permeability or impermeable regions can be disposed between the inner and outer barriers. For example, a low-permeability or impermeable layer can be disposed between the inner and outer barriers. The low-permeability or impermeable layer can be spaced apart from the inner barrier when the inner barrier is in a first position and in contact with both the inner and outer barriers when the inner barrier is in a second position.

[0071] The or each reduced permeability region may be positioned to contact the outer barrier and block a flow path through or from around the outer barrier to the outer surface of the moisture transport layer when the inner barrier is in the second position, and when the inner barrier is in the first position, the or each reduced permeability region is spaced from the outer barrier and the device includes a flow path through or from around the outer barrier to the outer surface of the moisture transport layer.

[0072] The outer barrier may include a moisture transport layer laminated to a low-permeability or impermeable layer over one or more regions of the inner barrier. For example, the low-permeability region may be formed using one or more additional layers of moisture transport layer material. The low-permeability or impermeable region may be formed using one or more layers of a support layer or foil imbibed with a low-permeability plastic material.

[0073] The inner barrier may be laminated over some or all of the area of ​​the inner barrier.

[0074] The inner barrier can include a support layer. The support layer can be porous or permeable to air and water vapor. The support layer can include a flexible mesh, fabric, electrospun membrane, or porous membrane.

[0075] The support layer may comprise a plastic or polymeric material. The support layer may comprise an expanded polymeric membrane, such as an expanded polyethylene or fluoropolymer membrane, such as an ePTFE membrane. Expanded porous polymeric membranes are known in the art and typically comprise a porous microstructure that includes an interconnected fibrillar network. The fibrils may be interconnected by nodes.

[0076] Alternative support layers include acrylic copolymer membranes (e.g., membranes cast onto a nonwoven layer, e.g., Versapor® membranes from Pall Corporation, New York, USA) or polyvinylidene fluoride membranes (e.g., Durapore® membranes from Millipore Sigma, Massachusetts, USA) or other microporous membrane materials known in the art.

[0077] The support layer can be a fibrillating polymer membrane prepared from a fibrillizable polymer such as polyolefin, fluoropolymer, polyurethane, polyester, polyamide, polylactic acid, or any combination thereof. Specific examples of fibrillizable polymers suitable for use as the support layer include, but are not limited to, ultra-high molecular weight polyethylene (UHMWPE) (Sbriglia, U.S. Pat. No. 10,577,468), polylactic acid (PLLA, Sbriglia, U.S. Pat. No. 9,732,184), copolymers of vinylidene fluoride and tetrafluoroethylene or trifluoroethylene (e.g., VDF-co-(TFE or TrFE) polymers, Sbriglia, U.S. Pat. No. 5,732,184), and copolymers of vinylidene fluoride and tetrafluoroethylene or trifluoroethylene (e.g., VDF-co-(TFE or TrFE) polymers, Sbriglia, U.S. Pat. No. 5,732,184). No. 10,266,670), poly(ethylene tetrafluoroethylene) (ETFE, Sbriglia, U.S. Pat. No. 9,932,429), polyparaxylxylene (PPX, Sbriglia, U.S. Pat. App. Pub. No. 2016-0032069), and polytetrafluoroethylene (PTFE, Gore, U.S. Pat. No. 3,315,020; Gore, U.S. Pat. No. 3,953,566; and Baille, U.S. Pat. No. 7,083,225).

[0078] The material of the support layer may be selected to withstand the temperatures and conditions encountered within the enclosure during use, or the elevated temperatures required, for example, to regenerate the desiccant.

[0079] The inner barrier is elastically extensible in one direction or in two orthogonal directions such that movement between the first and second positions can be affected by elastically expanding and contracting the inner barrier.

[0080] The support layer may be elastically extensible in one direction or in two orthogonal directions and may comprise an elastic fabric or membrane.

[0081] Elastically stretchable porous membranes can be produced by forming an expanded polymer membrane and then shrinking the membrane by heat or solvent treatment.

[0082] The heat or solvent shrinkage can be at a rate that causes most or substantially all of the fibrils to assume a serpentine or more serpentine shape (i.e., curvature in two or more different directions), thereby providing the membrane with elastically extensible properties. Such membranes and methods for their manufacture are disclosed, for example, in US 2013 / 0183515 and US 2014 / 0172066 to WL Gore & Associates, Inc., each of which is incorporated herein in its entirety. The expanded porous polymer membrane can also be compressed or mechanically densified to impart elastically extensible properties. U.S. Patent No. 5,026,513 to WL Gore & Associates, Inc., discloses a method for making rapidly recoverable PTFE, the contents of which are incorporated herein in their entirety. The microstructure of the porous PTFE material is composed of nodes interconnected by fibrils, with substantially all of the fibrils having a curved or wavy appearance. The PTFE is first expanded by stretching, then manually compressed in the direction of the fibrils, and then restrained in the compressed state and heated. Those skilled in the art will appreciate that these methods are also applicable to other expanded polymer membranes, such as, but not limited to, polyethylene membranes. EP3061598 to WL Gore & Associates, Inc. discloses another method for producing elastically expandable porous membranes, the contents of which are incorporated herein in their entirety. An elastic substrate is expanded into a desired shape (such as a dome shape) and the expanded porous polymer membrane is peelably laminated thereto. The substrate is contracted, thereby reconstructing the microstructure of the porous polymer membrane.

[0083] The air impermeable, water vapor permeable moisture transport layer can comprise an air impermeable, water vapor permeable material such as a silicone material, a polyurethane material, an ionomer material such as perfluorosulfonic acid ionomer, a polyvinyl material such as polyvinyl chloride, a polyamide material such as nylon, or a polystyrene or styrene copolymer material such as sulfonated poly(styrene-isobutylene-styrene).

[0084] The air impermeable, water vapor permeable moisture transport layer can comprise an air impermeable, water vapor permeable material selected from a silicone material, a polyurethane material, an ionomer material, or a polyvinyl material.The air impermeable, water vapor permeable moisture transport layer can comprise an air impermeable, water vapor permeable material selected from a silicone material or a polyurethane material.

[0085] The moisture transport layer may include a support layer and an air impermeable, water vapor permeable material.

[0086] The air impermeable, water vapor permeable material may be provided as a layer laminated to the support layer. Alternatively or additionally, the air impermeable, water vapor permeable material may at least partially penetrate the support layer.

[0087] For example, the support layer can be porous (e.g., a fabric, or an electrospun or expanded polymer membrane) and the air-impermeable, water vapor permeable material can be present within at least some of the pores of the support layer. The porous support layer can be imbibed with the air-impermeable, water vapor permeable material (e.g., a suspension or solution thereof can be applied to the support layer and cured or dried). The layer of air-impermeable, water vapor permeable material can be compressed (optionally at an elevated temperature) with the porous support layer such that at least some of the air-impermeable, water vapor permeable material flows into the pores of the support layer.

[0088] Although reference is made herein to a porous support layer having its pores imbibed or otherwise filled with an air-impermeable, water vapor permeable material to render the moisture transport layer air-impermeable and water vapor permeable, it will be understood that the underlying structure or microstructure of the support layer which provides the porosity in the absence of the air-impermeable, water vapor permeable material is not substantially altered, so that water molecules can diffuse or permeate through the moisture transport layer via the air-impermeable, water vapor permeable material.

[0089] The outer barrier may be connected to the housing (eg, by an adhesive, one or more fasteners, welding, etc.) or may be integrally formed with the housing.

[0090] The outer barrier may include a bridge over or across the vapor port, where one or more flow paths are defined around the outer barrier (e.g., between the outer barrier and the housing) and / or through the outer barrier. The outer barrier may include a plate, such as a metal plate. "Plate" refers to a typically rigid or substantially rigid portion of the outer barrier that provides a continuous or nearly continuous surface. The nearly continuous surface of the plate provides a corresponding continuous or nearly continuous area of ​​contact with the inner barrier or its moisture transport layer at the second location. When the outer barrier becomes hot during use, heat flow to the moisture transport layer is optimized. As a result, the risk of condensation on the inner surface of the moisture transport layer that may inhibit or hinder the functioning of the device is reduced.

[0091] The plate can be generally flat. The plate may be provided with a profile that complements the shape or configuration of the moisture transport barrier when the inner barrier is in the second position. For example, the inner barrier or its moisture transport layer may assume a "dome-shaped" shape when moved to the second position (e.g., the inner barrier is elastically stretchable). Thus, the plate may be provided with a corresponding dome-shaped or truncated dome-shaped inner surface to improve contact with the inner barrier.

[0092] The plate is of smaller area than the second port and is connected across the second port by a connecting portion, thereby defining one or more flow paths between a periphery of the plate and the connecting portion. The plate can be offset from the housing and connected to the housing by the connecting portion.

[0093] The outer barrier may be provided with one or more apertures, or an array of apertures, such that, in use, as disclosed herein, the apertures are disposed adjacent to corresponding impermeable portions of the inner barrier such that, in use, the impermeable portions can occlude the one or more apertures when the inner barrier is in the second position.

[0094] The outer barrier may be in the form of a mesh or lattice, such as a metal mesh or lattice. The lattice may be generally rigid or may be somewhat flexible.

[0095] The second port may include a check valve.

[0096] The second port may include a check valve member disposed between the outer barrier and the inner barrier.

[0097] The check valve member is operable to block or restrict fluid communication between the enclosure and the outer surface of the moisture transport layer when the inner barrier is in the second position and to provide fluid communication between the enclosure and the outer surface of the moisture transport layer when the inner barrier is in the first position.

[0098] The outer barrier may form part of a check valve. As disclosed herein, the outer barrier may include one or more apertures therethrough or one or more spaces or gaps may extend around a portion of the outer barrier. The check valve member may be operable to occlude and space from said apertures or gaps.

[0099] The check valve member may be operatively coupled to the second port or housing, e.g., actively hinged, and disposed between the inner and outer barriers such that the check valve member may press against the outer barrier to block an aperture through or a gap around the outer barrier when the inner barrier is moved to the second position, and may be deflected away from the outer barrier to open a flow path to the outer surface of the moisture transport barrier when the inner barrier is moved to the first position.

[0100] The check valve member can be coupled to the inner barrier, e.g., one or more regions of its outer surface, and can be operable to press against the outer barrier to block an aperture through or a gap around the outer barrier when the inner barrier is moved to the second position, and to move away from the outer barrier to open a flow path to the outer surface of the moisture transport barrier when the inner barrier is moved to the first position.

[0101] The check valve member can be operatively coupled to the housing or the second port via a thermo-mechanical actuator that can include a shape memory material, such as one or more components formed from a nickel-titanium alloy, and can be configured to contract, bend, or stretch to close the check valve when the device is heated.

[0102] The check valve member may be electromechanically actuated. For example, the device may include a motor operable to open and close the check valve. The check valve member may be magnetically actuated and operable to open and close when an electric current is imposed on a region of the check valve. For example, in use, an electric current may be imposed on the outer barrier to magnetically attract the check valve member and close the check valve during a regeneration event.

[0103] The check valve member may, for example, be operable as a flapper valve. The check valve member may be formed from a thermally conductive material, as disclosed herein.

[0104] The check valve may be configured as a poppet valve.

[0105] The first port can be configured to limit a mass transport rate of water vapor into the chamber through the first port to less than a mass transport rate of water vapor into the chamber through the second port.

[0106] In use, water vapor enters the chamber through the first port by diffusion, and the first port may be configured to limit the rate of diffusion, for example by selecting the size of a first region of the path along or through the first port. The length of the flow path through the first port may also be selected in some embodiments to limit or reduce mass transport of water vapor into the chamber by diffusion.

[0107] The first port can take the form of a simple opening through a wall of the housing and / or enclosure. The first port can define or extend to an outlet channel. The outlet channel can include a convoluted path. A restricted or elongated flow path along the outlet channel and / or a convoluted path can further reduce diffusion into the chamber while maintaining a compact device configuration.

[0108] In some embodiments, the convoluted outlet channel may be defined by a separation layer. The separation layer may include an embossed open channel on one side thereof, the separation layer being positioned against an inner wall of the chamber, the outlet channel being defined by the open channel and the inner wall. The separation layer may include an aperture into the chamber at an end of the open channel, and the wall of the housing or enclosure may include an aperture that aligns with the other end of the open channel. In some embodiments, the embossed open channel is provided on an outer surface of the housing, such that a closed outlet channel is defined between the housing and the enclosure when the housing is secured to the enclosure.

[0109] The outlet channel may include a curved or convoluted diffusion tube.

[0110] The first port or outlet channel can extend to an outlet cavity, or can extend to multiple outlet cavities fluidly connected in series. The or each outlet cavity can have a larger flow area than the first port or outlet channel. The one or more outlet cavities can further reduce flow or diffusion into the chamber through the first port.

[0111] One or more of the first port, the outlet channel and the outlet cavity may include a vent cover. A vent cover may be provided over or across the second port or the outlet channel. The outlet cavity may include a vent cover. The outlet cavity may include a vent cover over an open end or aperture of the outlet cavity.

[0112] The vent cover can be present to reduce ingress of contaminants, water, and the like. The vent cover can function to limit diffusion and therefore the mass transport rate of water vapor into the chamber through the first port. The vent cover can be gas permeable (such gases include water vapor) and water impermeable. The vent cover can include a film or membrane. The vent cover can include a film of the same membrane material as the support layer disclosed herein. The vent cover can include an expanded polymer membrane, such as an expanded polyethylene membrane or expanded polytetrafluoroethylene membrane (or other expanded fluoropolymer).

[0113] The vent cover may include one or more low-permeability or impermeability regions. The or each vent cover low-permeability or impermeability region may be positioned to contact a corresponding outlet aperture of the first port, outlet channel or vent cavity, thereby blocking a flow path through said aperture. The vent cover may be displaceable by the action of gas flow from the chamber (caused by a pressure difference between the chamber and the external environment) to move the low-permeability or impermeability region away from the respective aperture.

[0114] The vent cover can be, for example, elastically stretchable as disclosed herein with respect to the support layer, such that the vent cover is biased to a position where the or each low-permeability or impermeable region blocks the respective aperture.

[0115] The device can include multiple vent covers, for example, the vent covers can extend over multiple portions of the flow path defined by the first port and optionally the outlet channel and one or more optional outlet cavities.

[0116] The first port may include a check valve operable to open during heating of the device. The first port check valve may include a check valve member operably coupled to the first port or the housing, for example via a thermo-mechanical actuator.

[0117] The first port may also be configured to restrict flow through the first port to increase pressure in the chamber during regeneration of the desiccant. The first port may comprise a flow area selected to restrict flow through the first port and facilitate increasing pressure in the chamber. The first port may include a flow restriction configured to restrict flow through the first port and facilitate increasing pressure in the chamber. For example, in some embodiments, a vent cover restricts flow through the first port.

[0118] The device may include a plurality of first ports or outlet channels.The device may include a plurality of second ports.

[0119] The device may not include any ports or openings between the chamber and an environment external to the chamber other than the first port and / or the second port, respectively. In particular, during use, the device may not include any ports or openings or any other means of fluid communication between the chamber and the interior of the enclosure.

[0120] The housing can have any size or configuration suitable for the particular size of the enclosure, moisture transport rate, etc. However, the chamber defined by the housing is preferably small compared to the enclosure, e.g., less than 10% of the volume of the enclosure. -2 Less than 10 -3 Less than or 10 -4 has a volume less than

[0121] A portion of the housing may include or be formed from a wall of the enclosure.

[0122] The housing can be coupled to or adapted to be coupled to the enclosure. The housing can be coupled to or adapted to be coupled to the interior of the enclosure. The enclosure can be provided with a wall port or aperture and, in use, the housing can be arranged to position the outlet conduit adjacent the wall port or aperture. The housing can also be coupled to or adapted to be coupled within or through an aperture in a wall of the enclosure.

[0123] For example, in use, the housing may be coupled to the enclosure by an adhesive or one or more fasteners. The housing may be threadedly coupled to the enclosure. The aperture or port of the enclosure may be, for example, female-threaded and the housing portion may be male-threaded. In alternative embodiments, there may be an interference fit between the housing and the aperture through the wall of the enclosure.

[0124] The housing may be sealed to the enclosure by, for example, an O-ring (which may be held in compression between the housing and the enclosure wall), or an adhesive or sealant may be used.

[0125] The housing may be of any suitable shape, hi some embodiments, the housing is generally circular in cross-section.

[0126] The housing may be formed from any suitable material or materials. Advantageously, the housing material is selected to allow for effective heating of the interior walls of the chamber.

[0127] The housing may include or be formed of a thermally conductive material such as metal (aluminum, steel, etc.). The housing may include or be formed of a thermally conductive plastic material that can be used at the temperatures required to regenerate the desiccant (e.g., about 150° C. or higher), such as polysulfone, polybutylene terephthalate (PBT), or polyetherimide (PEI). The housing may include or be formed of a composite material that includes a reinforcing material or filler in a matrix (such as a thermosetting or thermoplastic matrix), where the reinforcing material or filler is selected to enhance thermal conductivity. For example, glass fiber or powder or metal powder, mesh, or fabric can enhance thermal conductivity. Thermally conductive coatings such as metallized polymers (polymers with a metal coating or paint) may also be used.

[0128] The housing may include or be formed from one or more conductive materials. The one or more conductive materials may be susceptible to resistive (ohmic) or inductive heating. For example, a metallic housing, or a housing including a metal mesh, filler, or fabric composite, may be resistively or inductively heated.

[0129] The housing may be insulated. An insulating outer housing may be provided between the housing and the enclosure.

[0130] The heat source may be disposed within an insulating outer housing.

[0131] According to a further aspect of the present invention there is provided a method of removing moisture from an enclosure, the method comprising: During the first period, transporting water vapor from the enclosure to the chamber through an air impermeable water vapor permeable moisture transport layer; adsorbing at least a portion of the water vapor onto a desiccant material within the chamber; and During the second period, applying heat to elevate the temperature of the desiccant material and desorb at least a portion of the adsorbed water from the desiccant material; increasing the temperature of the interior walls of the chamber and the moisture transport layer to reduce or eliminate condensation within the chamber; and passing at least a portion of the water vapor from the chamber to an environment external to the enclosure; Includes.

[0132] The first period of time can be longer than the second period of time.

[0133] The second period of time can be, for example, from about 10 seconds to 60 minutes, whereas the first period of time can be from about 1 hour to 7 days.

[0134] The second period of time can be from about 10 seconds to 30 minutes, from about 10 seconds to 10 minutes, from about 1 to 10 minutes, from about 4 to 10 minutes, from about 5 to 7 minutes, or from about 6 minutes.

[0135] The first period can be at least about 10, 50, 100, or 200 times the length of the second period. The first period can be at least about 300, 400, or 500 times the length of the second period. The first period can be about 100 to 600, or about 200 to 500, or about 300 to 500 times the length of the second period. For example, the second period can be about several minutes (e.g., 1 to 10 minutes, 2 to 8 minutes, about 2 to 5 minutes, or about 3 minutes), and the first period can be about several hours (e.g., 10 to 30 hours, or 20 to 30 hours). In some embodiments, for example, the second period is performed once a day for about 1 to 10 minutes, or 2 to 8 minutes, or about 2 to 5 minutes, or about 3 minutes.

[0136] The first period of time may be considered to be an adsorption period during which the desiccant material adsorbs water, and the second period of time may be considered to include a regeneration period or event, during which water is desorbed from the desiccant material and the desiccant material is at least partially regenerated, during at least a portion of the second period of time.

[0137] The method can include passing water vapor from the chamber to an environment external to the enclosure through a first port. The method can include transporting water vapor from the enclosure to the chamber through a second port, the moisture transport layer being disposed across the second port.

[0138] The method can include increasing the temperature of the moisture transport layer by flowing heat from the second barrier to a first barrier attached to the second barrier and including the moisture transport layer.

[0139] The method can include increasing the temperature of the moisture transport layer by moving the inner barrier, including the moisture transport layer, into contact with the outer barrier during a second period of time, where the outer barrier, or at least the inner surface of the outer barrier in contact with the inner barrier, is at a higher temperature than the inner barrier. The method can include increasing the temperature of the moisture transport layer by moving the moisture transport layer into contact with the outer barrier during a second period of time.

[0140] The process of applying heat can increase the temperature of the outer barrier.

[0141] The method can include moving the inner barrier from a first position in which the inner barrier is spaced from the outer barrier to a second position in which at least a portion of an outer surface of the inner barrier contacts the outer barrier.

[0142] The method may include moving the moisture transport layer from a first position in which the moisture transport layer is spaced from the outer barrier to a second position in which at least a portion of an outer surface of the moisture transport layer is in contact with the outer barrier, It will be appreciated that moving the inner barrier causes the moisture transport layer to move.

[0143] The method can include increasing the pressure in the chamber, thereby displacing the inner barrier. The step of applying heat can increase the pressure in the chamber.

[0144] The method can include elastically stretching the inner barrier and / or moisture transport layer when moving from the first position to the second position.

[0145] The inner barrier can include one or more reduced-permeability or impermeable regions, and the method can include using the reduced-permeability or impermeable regions to block or restrict one or more flow paths from the enclosure to the moisture transport layer around or through the outer barrier when the inner barrier is in the second position.

[0146] The method may include moving the inner barrier from a first position to a second position, thereby moving a check valve member to block or restrict one or more flow paths around or through the outer barrier, and / or moving the check valve member away from the inner barrier to open one or more flow paths around or through the outer barrier.

[0147] The method can include cooling or allowing to cool the desiccant material, the interior walls of the chamber, and, in some embodiments, the outer barrier. The cooling or allowing to cool can occur during at least a portion of a first period of time. The method can include multiple first periods and second periods of time. The method can be performed with multiple cycles of heating and cooling or allowing to cool.

[0148] The chamber may be defined by a housing, and the method may include applying heat using a heat source adjacent to or integrated within the housing.

[0149] The method can include applying heat using a heat source within the enclosure.

[0150] The method can include applying heat using a heat source within the chamber.

[0151] The heat source can be used to apply heat directly to the desiccant material. For example, heat can be applied via a heater adjacent to the desiccant material, a heater relative to the desiccant material, a heater around the desiccant material, or a heater embedded within the desiccant material.

[0152] The method may include increasing the temperature of the desiccant material to greater than 100°C, greater than 120°C, greater than 140°C, or greater than 150°C during a second period of time.

[0153] The method can include increasing the temperature of the inner wall of the chamber, or the inner wall of the chamber defined by the housing or enclosure, to a temperature greater than 50°C, greater than 70°C, greater than 90°C, or greater than 100°C during a second time period (i.e., during the regeneration event) when the desiccant material is elevated to a temperature greater than 100°C, greater than 120°C, greater than 140°C, or greater than 150°C.

[0154] The method can include increasing a temperature of an interior wall of the chamber above a dew point within the chamber during a second period of time. The method can include increasing a temperature within the chamber above a maximum expected dew point within the chamber.

[0155] The method may include increasing the temperature of the fixed barrier to greater than 50°C, greater than 70°C, greater than 90°C, or greater than 100°C during a second period of time.

[0156] The or each step of increasing the temperature may include heating the inner wall, the outer barrier, or the desiccant material, as the case may be, by radiation, conduction, induction, or convection.

[0157] The method may include imposing an electric current on the housing or an electrically conductive portion thereof to increase the temperature of the housing.

[0158] The method may include imposing an electric current on a heat source, such as a resistive heater or an inductive heater.

[0159] The method can include increasing the pressure in the chamber. The pressure can be increased by applying heat.

[0160] The method can include flowing water vapor from the chamber to an exterior of the enclosure during a second period of time. The flow of water vapor from the chamber can be caused or increased by an increase in pressure within the chamber (e.g., by expansion of water vapor and / or air within the chamber). Thus, the step of applying heat can further include increasing the pressure within the chamber to flow water vapor from the chamber through the first port conduit to an environment exterior to the enclosure, and / or increasing the pressure within the chamber to move the flexible barrier from the first position to the second position.

[0161] The method can include passing water vapor from the chamber to the outside environment by diffusion. The method can include inducing or increasing such diffusion by applying heat. Diffusion can be increased by increasing the amount of water vapor (i.e., by desorption from a desiccant material) and / or by increasing the thermal energy of the water vapor and air in the chamber.

[0162] The method may include the use of an enclosure or device of any of the aspects or embodiments disclosed herein.

[0163] Further features of each aspect of the invention correspond to further features of the other aspects of the invention. For example, a description of the features of an enclosure or device disclosed herein and its operation or use corresponds to further features of the method disclosed herein. Conversely, the enclosure and device may include any feature required by a step of the method disclosed herein. [Brief description of the drawings]

[0164] Description of the drawings Non-limiting exemplary embodiments will now be described with reference to the following figures:

[0165] [Figure 1]Figures 1(a) and 1(b) show exploded perspective views of a device for removing moisture from an enclosure. Figure 1(c) shows a perspective view of the assembled device. Figure 1(d) shows an alternative embodiment of region A of Figure 1(a).

[0166] [Diagram 2] FIG. 2 shows a schematic cross-sectional view of an alternative device for removing moisture from an enclosure. [Diagram 3] FIG. 3 shows a schematic cross-sectional view of an alternative device for removing moisture from an enclosure. [Figure 4] FIG. 4 shows a schematic cross-sectional view of an alternative device for removing moisture from an enclosure. [Diagram 5] FIG. 5 shows a schematic cross-sectional view of an alternative device for removing moisture from an enclosure.

[0167] [Figure 6] FIG. 6 shows a plan view of the separation layer of the device of FIG. [Figure 7] FIG. 7 shows a schematic cross-sectional view of an alternative device for removing moisture from an enclosure.

[0168] [Figure 8] FIG. 8 shows the desorption data for the desiccant material in the vent cavity.

[0169] [Figure 9] 9(a)-(d) show images of the test devices and enclosures, and FIG. 9(e) shows dew point versus time data taken from enclosures A and B (from FIGS. 9(c) and (d)) and the laboratory reference dew point versus time data.

[0170] [Figure 10] FIG. 10 shows moisture removal data from a humidity-controlled enclosure for test devices with and without a fixed barrier.

[0171] [Figure 11] FIG. 11 shows the moisture vapor transfer rate (MVTR) of air impermeable films under various environmental conditions, and the ratio of the MVTR under simulated adsorption and desorption conditions.

[0172] [Figure 12] 12(a) and 12(b) show exploded views of yet another device for removing moisture from an enclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0173] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 1(a)-(c) show a device 1 for removing moisture from an enclosure. The device includes a housing 10 defining a chamber 12. A portion of the housing 10 is provided with a first port 17 in the form of an aperture extending through the housing 10 from the chamber 12 to the exterior of the housing (and the exterior environment in use). In another portion of the housing, an open face of the chamber 12 defines a second port 20. The second port 20 includes an inner barrier 30 and an outer barrier 40. In the embodiment shown, the inner barrier 30 is flexible and the outer barrier 40 is fixed. A block 50 of desiccant material is disposed within the chamber. The desiccant material block 50 is sized to fit within the chamber 12 and is attached in contact with the wall 14 of the chamber. The desiccant material 50 substantially fills the chamber 12 and is flush with or 1-2 mm below the peripheral wall 16 of the chamber.

[0174] The outer barrier 40 includes a center plate 42 and a connecting portion 44 that secures the outer barrier to the housing. In the embodiment shown, a friction fit is used between the inner sides 45 of tabs 46 extending from the connecting portion 44, although in other embodiments the outer barrier can be secured by, for example, welding or fasteners. In the perspective view of the assembled device in FIG. 1(c), an optional insulating cover 43 is shown clipped onto the outer barrier 40.

[0175] 1(d), device 1 may optionally further include an impermeable polymer layer 36 in the form of an annular ring disposed between inner barrier 30 and outer barrier 40. Layer 36 may in some embodiments be laminated to the inner barrier and move with the inner barrier between the first and second positions. Alternatively, layer 36 may be separate from the inner barrier such that it is slightly spaced from the inner barrier when the inner barrier 30 is in the first position and is sandwiched between the inner barrier 30 and outer barrier 40 when the inner barrier is in the second position.

[0176] An inner surface 48 of the plate 42 is provided with a truncated dome shape, as will be further described below. The inner surface of the plate is also spaced from the housing 10 (in this embodiment, as indicated by a protrusion 47 on the connecting portion 44) and provides a circumferential slot 60 between the outer barrier 40 and the housing 10.

[0177] The housing is adapted to be mounted through an aperture in the enclosure via a flange (not shown for clarity), with the second port 20 facing into the enclosure. In use, the second port 20 is located between the enclosure (not shown) and the chamber 12. The outer side 32 of the inner barrier 30 communicates with the enclosure. The inner side 34 of the inner barrier 30 communicates with the chamber 12. A slot 60 provides a flow path around the plate 42 of the outer barrier 40 between the enclosure and the inner barrier 30.

[0178] The terms "inner" and "outer" in this context are used relative to the chamber.

[0179] The flexible inner barrier 30 is comprised of an air impermeable, water vapor permeable, moisture transport layer formed from a semi-permeable ePTFE membrane imbibed with a water vapor permeable silicone. The inner barrier 30 is secured to the exterior surface 21 of the housing 10 by an adhesive around the perimeter of the vapor port 20. This allows the moisture transport layer to extend across and seal the entire flow area of ​​the second port 20.

[0180] The ePTFE membrane of the moisture transport layer is elastic, the elasticity being provided by heat or solvent shrinkage, or controlled compression as disclosed herein. The inner barrier 30 is movable under the action of fluid pressure within the chamber 12 to bring the outer surface 32 into contact with the inner surface 48 of the outer barrier 40. The elastically stretchable inner barrier 30 forms a dome-like shape, and the dome-like profile of the inner surface 48 of the outer barrier 40 increases the contact surface area therebetween in use (e.g., compared to a flat surface 48).

[0181] When there is no pressure differential between the chamber 12 and the enclosure, the inner barrier 30 is relatively flat, with the inner surface 34 being approximately level with the outer surface 21 of the housing 10 and therefore with the desiccant material 50 .

[0182] In the embodiment shown, the inner barrier 30 consists of a moisture transport layer, however, in alternative embodiments, the moisture transport layer is secured to and forms part of an inner barrier that includes additional components such as structural support or one or more low-permeability or impermeable regions, examples of which are described in more detail below.

[0183] The device 1 further includes a heat source 70. The heat source includes a resistive PTC heating element 74 and an electrical connection 72 connected through an intervening portion of the housing 10. The heating element 74 is mounted in a recess 76 in the housing 10 and is in thermal contact therewith. When a voltage is applied across the electrical connection, current flows through the PTC heating element 74 and the housing 10, resistively heating the device 1. As the temperature increases, the resistivity of the PTC element increases and limits the flow of current, thereby regulating the temperature to a desired maximum temperature of approximately 155°C.

[0184] The desiccant material 50 is molded with a notch 52 so that there is always a flow path to the first port 17. An opening (not visible) at the opposite end of the port 17 is fitted with a vent cover 18, which in the illustrated embodiment is made of ePTFE material.

[0185] The housing 10 and outer barrier 40 are of aluminum construction to promote efficient heat flow from the heat source 70 to other portions of the device 1. Other materials may be used as disclosed herein.

[0186] The device 1 further includes an optional insulated outer housing 80 formed from an insulating plastic or foam material to help conduct heat from the heat source 70 to the housing, the outer barrier, the inner barrier and the desiccant material during use. The outer housing 80 is formed to fit snugly around the housing 10 but leave the outer barrier 40 and the inner barrier 30 (which are in fluid communication with the enclosure during use) exposed. The insulated outer housing 80 has a larger diameter opening 82 through the housing from the inside surface adjacent the first port 17. The opening 82, together with the * of the housing 10, defines an outlet cavity that communicates with the first port 17 through the vent cover 18. Moisture condensed within the cavity is prevented from entering the chamber 12 by the vent cover 18. The housing optionally includes a further opening 84 therethrough which acts as a passageway to the enclosure during use and in some applications regulates the pressure within the enclosure. The opening 84 has an additional outer vent cover 86 that traverses the opening 84. The vent cover 86 prevents the ingress of water or particles from the outside environment.

[0187] In use, the device 1 is secured through a wall of an enclosure, such as an enclosure for a vehicle LIDAR system. During a first period of time, water vapor within the enclosure passes through the moisture transport layer (inner barrier 30) and permeates the air impermeable water vapor permeable silicone material present within the pores of the ePTFE support layer. Water vapor entering the chamber 12 is adsorbed by the desiccant material 50. The first period of time can be any suitable period of time, for example, a period of time that allows for equilibrium of humidity within the chamber 12 and the enclosure. In connection with any aspect or embodiment disclosed herein, the first period of time can instead be a shorter period of time, for example, selected such that the overall adsorption rate of the desiccant material during the first period of time is high.

[0188] During a second period of time, heat is applied to the device by passing an electrical current through the electrical connector 72 and the heating element 74. The temperature of the desiccant material 50 is raised, typically to above 100° C. or up to about 150° C., to desorb moisture from the desiccant material. The interior walls of the chamber 12 defined by the aluminum housing 10 also increase in temperature to prevent the desorbed water vapor from condensing thereon.

[0189] During the second time period, the pressure within chamber 12 also increases. The increased pressure creates a pressure differential between chamber 12 and the environment outside the enclosure, encouraging desorbed water vapor to exit chamber 12 through first port 17. In the embodiment shown, vent cover 18 also restricts exit from the chamber through first port 17, facilitating the pressure increase within the chamber without unduly restricting the flow area of ​​first port 17.

[0190] As the pressure increases, the inner barrier 30 also moves from a first position, where it is approximately parallel with the outer surface 21 of the housing 10 , to a second position in which it contacts the outer barrier 40 .

[0191] The outer barrier 40 is in good thermal contact with the housing 10 and is of aluminum construction. Thus, during heating, the temperature of the fixed barrier also increases. Thus, when the inner barrier 30 contacts the outer barrier 40, the temperature of the relatively less thermally conductive inner barrier increases or is maintained above 100° C. This temperature increase prevents condensation on the inner wall 34 of the inner barrier 30, which would otherwise not be able to flow out of the first port 17. Such condensation remains in the chamber and is then reabsorbed by the desiccant material, impairing the functioning of the device.

[0192] The inner barrier 30 is elastically deformed and therefore tends to become dome-shaped. The inner surface 48 of the outer barrier is truncated dome-shaped, with a concave area to increase the contact area between the inner barrier 30 and the outer barrier 40.

[0193] This contact of the inner barrier 30 with the outer barrier 40 in the second position also reduces the surface area of ​​the inner barrier 40 in communication with the enclosure, thereby reducing the rate of vapor transmission from the chamber 12 to the enclosure during desiccant regeneration.

[0194] In the second position of the inner barrier 30 of the embodiment shown in FIG. 1( d ), the impermeable layer 36 further reduces or blocks fluid communication between the enclosure and the outer surface 32 of the inner barrier 30 via the circumferential slots 60 .

[0195] The device 1 can be cycled, either at regular intervals or when moisture is detected within the enclosure. For a further period, the heat source 70 is switched off and the device 1 is allowed to cool. Passage through the inner barrier 30 occurs again and the desiccant material 50 adsorbs any water vapor that enters the chamber, after which another heating and desiccant regeneration event is initiated.

[0196] 2-7 and 12 show further embodiments of devices for removing moisture from an enclosure.

[0197] The device 100 of FIG. 2 has a housing 110 and a chamber 112. The device 100 is mounted through an aperture in the wall 101 of the enclosure 102. A block 150 of desiccant material is disposed within the chamber 112. An electric heater 170 is mounted to the housing 110. A first port 117 extends from the chamber 112 to the environment 103 outside the enclosure 102. The enclosure is also provided with an optional vent passage 104, which may be required in some applications, such as to regulate pressure within the enclosure. The first port 117 and the vent passage 104 are covered by a vent cover 118. A flexible inner barrier 130 is sealed to the housing 110 across the flow area of ​​the vapor port (generally shown as 120), as described above with reference to the device 1. The device 110 includes a stationary outer barrier 140 with through holes or apertures 160 therethrough that provide a flow path through the outer barrier 140 to the exterior surface 132 of the inner barrier 130 .

[0198] 3 shows a further example of a device 200 for removing moisture from an enclosure 202. The device 200 has a housing 210 defining a chamber 212. The device 200 is mounted through an aperture in a wall 201 of the enclosure 202. A block 250 of desiccant material is disposed within the chamber 212. An electric heating element 272 of a heat source, generally designated 270, is mounted to the housing 210 and extends into the chamber 212. The heating element 272 is embedded within the desiccant material block 250.

[0199] A first port 217 extends from the chamber 212 to the environment 203 external to the enclosure 202 and includes a vent cover 218. A flexible inner barrier 230 is sealed to the housing 210 across the flow area of ​​the second port (generally designated 220), as described above with reference to device 1. The device 200 includes a fixed outer barrier 240 with a through hole or aperture 260 therethrough to provide a flow path through the outer barrier 240 to the outer surface 232 of the inner barrier 230.

[0200] The inner barrier 230 includes a moisture transport layer 230, the central portion of which is laminated to a low permeability polymer layer 236. In other embodiments, foils can be used or, instead, one or more additional layers of air impermeable, water permeable material can be used. In a first position, shown in FIG. 2, the inner barrier 230 is spaced from the outer barrier 240. When the desiccant material 250 is heated and the pressure in the chamber 212 increases (as shown in FIG. 4), the inner barrier 230 moves to a second position where the low permeability or impermeable region 236 contacts the outer barrier 240 and blocks the aperture 260. This closes or restricts the flow path through the outer barrier 240 to the outer surface 232 of the moisture transport layer 230. In this way, the transmission of vapor from the chamber 212 to the enclosure 202 is reduced during the second heating and desiccant regeneration period.

[0201] 5 shows another device 300 for removing moisture from an enclosure 302. The device is mounted through an aperture in the enclosure wall 301 as previously described. The device 300 has a housing 310 defining a chamber 312. A block 350 of desiccant material is disposed within the chamber 312. A heat source electric heating element 372 is disposed relative to the desiccant material 350. Electrical connectors have been omitted for clarity of illustration. A thermal insulation layer 380 is disposed across the entire exterior surface of the device 300 that faces the external environment 303.

[0202] The device 300 includes a convoluted exit channel 317 defined by the separation layer 390 and the inner surface 312a of the cavity 312. An aperture 317a aligned with the end of the channel 317 is provided through the housing 310 and the insulation 380 to the external environment 303. A top view of the separation layer 390 is shown in FIG. 6, which shows the channel 317 embossed into the surface 392 of the separation layer 390. One end of the embossed channel 317 extends through the separation layer from aperture 317b, providing communication with the chamber 312. The opposite end of the channel 317 is aligned with aperture 317a.

[0203] The device 300 includes a stationary outer barrier 340 with holes or apertures 360 therethrough that provide a flow path through the outer barrier 340 to the outer surface 332 of the inner barrier 330 .

[0204] FIG. 7 shows another device 400 for removing moisture from an enclosure 402. The device is mounted through an aperture in the enclosure wall 401 as described above. The device 400 has a housing 410 defining a chamber 412. A block 450 of desiccant material is disposed within the chamber 412 and a heat source, an electric heating element 472, is embedded therein. For clarity of illustration, electrical connectors have been omitted. The device 400 includes a flexible inner barrier 430 and a fixed outer barrier 440 provided with a through hole or aperture 460. The aperture 460 provides a flow path through the outer barrier 440 to the outer surface 432 of the inner barrier 430 when the inner barrier 430 is in a first position, and a low or impermeable region 436 blocks the aperture 460 as described above.

[0205] The device 400 includes a plurality of first ports 417 defined by apertures through the housing 410. An ePTFE elastically stretchable vent cover 418 (formed by any of the methods disclosed herein) is provided with a low or non-permeable region 419. The region 419 is positioned to cover the port 417 in the housing when the chamber 412 is at or near the ambient pressure of the external environment 403 and the vent cover 418 is not elastically stretched. This reduces the diffusion of water vapor from the external environment 403 into the chamber 412. The vent cover 418 is stretchable away from the port 417 when pressure within the chamber increases (such as when the desiccant 450 is heated and the flexible barrier is in the second position as shown in FIG. 7), allowing water vapor to flow out of the chamber 412 while the device is being heated. An outlet cavity 482 is defined between the housing 410 and the insulated perforated layer 490.

[0206] Figures 12(a) and 12(b) show another device 500 for removing moisture from an enclosure. Features in common with device 1 are given similar reference numerals incremented by 500.

[0207] The device 500 includes a housing 510 defining a chamber 512. A first port 517 is provided in one portion of the housing 510 in the form of an aperture extending through the housing 510 from the chamber 512 to the exterior of the housing (and the external environment, in use). In another portion of the housing, an open face of the chamber 512 defines a second port 520. The second port 520 includes an inner barrier 530 and an outer barrier 540. An optional insulating cover 543 may also be provided.

[0208] The inner barrier 530 is flexible and the outer barrier 540 is fixed. A block 550 of desiccant material is disposed within the chamber and is sized to fit within and substantially fill the chamber 512 and to be attached against the wall 514 thereof.

[0209] The outer barrier 540 includes a central plate 542 and a connecting portion 544, which secures the outer barrier to an insulating outer housing 580. The connecting portion 544 has an inward projection 545 at the end of a protruding tab 546 that engages and "snap-fits" into a slot 581 in the outer housing. When assembled, the inner annular surface 547 of the outer barrier 540 abuts the annular outer surface 521 of the housing 510, with the inner barrier 530 therebetween, and the housing 510 is mounted between the outer barrier 540 and the outer housing 580.

[0210] The housing 510 is adapted to be mounted through an aperture in the enclosure via flange 588, with the second port 520 oriented within the enclosure. In use, the second port 520 is disposed between the enclosure (not shown) and the chamber 512.

[0211] This device does not have a circumferential slot between the housing and the outer barrier of the previously described device 1. Instead, the outer barrier 540 is provided with a central aperture 560, which provides a flow path between the enclosure and the inner barrier 530 through a central plate 542 of the outer barrier 540.

[0212] The terms "inner" and "outer" in this context are used in relation to the chamber.

[0213] The inner barrier 530 further includes an impermeable region in the form of a polymer layer 536 laminated to the outer surface 532 and aligned with the aperture 560. The layer 536 presses against the outer barrier 540 and covers the aperture 560 when the inner barrier 530 is in the second position.

[0214] In common with device 1, in device 500, inner surface 548 of plate 542 is provided with a dome-shaped profile, with aperture 560 provided in the inwardly extending area of ​​the dome. Optional insulating cover 543 is similarly constructed.

[0215] The flexible inner barrier 530 similarly includes an air impermeable, water vapor permeable moisture transport layer formed from a semi-permeable ePTFE membrane imbibed with water vapor permeable silicone. The inner barrier 530 is secured to the annular outer surface 521 of the housing 510 by an adhesive such that the moisture transport layer extends across and seals the entire flow area of ​​the second port 520.

[0216] When there is no pressure differential between the chamber 512 and the enclosure, the inner barrier 530 is relatively flat. In use, when pressure increases in the chamber 520, the inner barrier 530 resiliently deforms into a dome-like shape and engages the dome-shaped profile of the inner surface 548 of the outer barrier 540 in the second position.

[0217] Device 500 further includes a heat source 570 including electrical connections 572 and a resistive PTC heating element 574 mounted between and in thermal contact with housing 510 and outer housing 580. PTC heating element 574 is operable to resistively heat device 500.

[0218] The desiccant material 550 is in a molded form with a notch 552 that provides a flow path to the first port 517. An O-ring 583 is disposed between and seals the port 517 and an opening 582 through the outer housing 580, and a vent cover 586 is disposed across the exterior surface of the opening 582.

[0219] In common with the embodiments disclosed herein, the housing 510 and outer barrier 540 are typically of metallic construction, such as aluminum, to promote efficient heat flow from the heat source 570 .

[0220] In use of the device 500, during a first period of time, water vapor within the enclosure passes through the moisture transport layer (inner barrier 530) and permeates the air impermeable, water vapor permeable silicone material present in the pores of the ePTFE support layer. Water vapor entering the chamber 512 is adsorbed by the desiccant material 550. During a second period of time, heat is applied to the device by passing an electrical current through the electrical connector 572 and the heating element 574, causing the water to desorb from the desiccant material. During the second period of time, pressure increases within the chamber 512. As a result, pressure increases within the chamber 512, promoting the outflow of desorbed water vapor from the chamber 512 through the first port 517. As the pressure increases, the inner barrier 530 also moves from a first position that is generally level with the exterior surface 521 of the housing 510 to a second position in contact with the outer barrier 540. In the second position, the impermeable region 536 covers the aperture 560, substantially blocking fluid communication between the enclosure and the air impermeable, water vapor permeable silicone material.

[0221] The outer barrier 540 is in good thermal contact with the housing 510 and therefore also increases in temperature during heating, preventing condensation on the inner wall 534 of the inner barrier 530 that would otherwise occur.

[0222] It will be understood that the various examples shown in Figures 1-7 and 12 are exemplary devices according to the present invention and may include additional or alternative features as disclosed herein. For example, the first port configuration, outlet channel configuration, heat source configuration, and second port configuration are interchangeable. EXAMPLES

[0223] experiment Example 1 To demonstrate proof of concept of the desorption or regeneration period of the device to remove moisture from the enclosure, an aluminum housing was provided with a chamber of approximate dimensions of about 19 mm diameter x 2.5 mm depth. A PTC heater (155 °C) was fixed to the outer wall of the housing with electrically and thermally conductive epoxy. The outer wall of the housing was also provided with a 1 mm diameter outlet channel with a length of 3-4 mm. An ePTFE membrane vent with an inner diameter of 5.5 mm was placed above the outlet of the outlet channel.

[0224] A 19 mm diameter, 2 mm thick block of Gore silica gel desiccant material was placed inside the chamber and attached to the chamber wall with adhesive. The open side of the chamber was sealed with an aluminum plate using a silicone pressure sensitive adhesive.

[0225] The housing was heated using a PTC heater for a specified time and the mass of the device was measured. The experiment was repeated for specified times of 3, 5, 15 and 30 minutes.

[0226] Figure 8 shows the results of mass change and heater energy usage per mg of mass change. Mass change is normalized between 0% and 100% of adsorbed water, which corresponds to the initial and maximum mass of the device, and the final equilibrium mass was achieved after about 30 minutes. Mass loss per kJ of electrical heating peaked at about 5 minutes.

[0227] These data demonstrate that heating the housing can effectively and rapidly desorb water vapor from the hydrated desiccant within the sealed chamber through the outlet channel and vent cover.

[0228] material ePTFE / Silicone Material 1 Expanded polytetrafluoroethylene (ePTFE) membranes were made generally according to the teachings of U.S. Pat. No. 3,953,566, the contents of which are incorporated herein in their entirety. The ePTFE membranes had an average mass / area of ​​0.5 g / m 2and had an average thickness of less than 1 μm. The ePTFE membrane was compressed in both the transverse direction (TD) and machine direction (MD) by peelably laminating the ePTFE membrane in an elastically stretched state into a dome-shaped configuration as taught in Example 4A of EP3061598A1 by Zaggl et al. The substrate was relaxed into a planar configuration and the shrunken ePTFE membrane was removed. Both treatment ratios were 50% at room temperature (approximately 20° C.) and a speed setting of 2 m / min.

[0229] The compressed porous ePTFE membrane was placed onto a polyethylene terephthalate (PET) release layer (Janus® PET1120).

[0230] The ePTFE membrane / release layer stack was placed on a glass plate and then inserted into an automatic film applicator (model ZAA 2300, Zehntner GmbH Testing Instruments, Schissach, Switzerland).

[0231] The elastomer was obtained by providing an injectable, addition-curing, two-component silicone rubber (ELASTOSIL® LR6320F (Wacker Chemie AG, Munich, Germany) and crosslinker SX) and mixing the LR6320F and crosslinker SX components in a 10:1 ratio using a SPEEDMIXER™ DAC 150.1 FVZ-K (FlackTek Inc., Landrum, South Carolina) at 1500 rpm and a mixing time of 20 seconds.

[0232] The mixed components were poured onto a densified porous ePTFE membrane placed on a PET release liner. A universal applicator, type ZUA 2000 (Zehntner GmbH Testing Instruments), was used to evenly distribute a thin elastomer film onto the ePTFE membrane using a speed of 5 mm / s at 20°C.

[0233] The applicator gap was set at a distance of 40 μm from the PET release layer. The elastomer film was cured in an oven at 160° C. for 5 minutes.

[0234] (2) ePTFE / Silicone Material 2 Expanded polytetrafluoroethylene (ePTFE) membranes were prepared generally according to the teachings of U.S. Patent No. 3,953,566. The ePTFE membranes had an average thickness of about 1 μm.

[0235] The membrane film was first wound up in a continuous process through rubber and chrome nip rollers while applying a pressure of 90 psi at approximately 2.4 m / min.The membrane was then passed through two consecutive 4 ft infrared ovens (55A) where the membrane temperature was approximately 160°C.

[0236] Dow SYLGARD™ 184, a clear two-component polydimethylsiloxane elastomeric encapsulant (10 to 1 mix ratio), was hand mixed in a jar and poured between the rubber and chrome nip rollers.

[0237] The finished film was wound onto a plastic core upon exiting the oven.

[0238] (3) ePE / Polyurethane Porous polyethylene membranes were produced by mixing polyethylene materials with hydrocarbon liquids and other additives according to the teachings of U.S. Patent Nos. 5,248,461, 4,873,034, 5,051,183, and 6,566,012, each of which is incorporated herein by reference. The mixture was extruded into a sheet, biaxially stretched, and the hydrocarbon liquid drained off.

[0239] The resulting expanded polyethylene membrane was then imbibed with a polyurethane elastomer material as described above for ePTFE / silicone Material 2.

[0240] Example 2 Two test devices were prepared similar to the device of Example 1. Instead of an aluminum plate, each housing was sealed with an air impermeable, water vapor permeable layer of ePTFE / silicone material 2.

[0241] Device A was then provided with a fixed perforated aluminum outer barrier spaced apart from an air impermeable, water vapor permeable layer attached across the housing with a gap of approximately 0.3 mm as shown in Figure 9(a) and Device B was provided with an outer barrier configured as a flat plate with connecting portions attached to the housing with a gap of approximately 1 mm as shown in Figure 9(b).

[0242] Each device was fixed through the aperture into a 12 L enclosure. Each enclosure was provided with a 1 mm diameter, 3 mm long aluminum diffusion tube outlet for pressure equalization, but was otherwise sealed. An ePTFE vent cover was placed over the diffusion tube outlet. The outlet channel and vent port faces of each device were placed in communication with the external environment, and a fixed barrier and a flexible barrier (air impermeable, water vapor permeable layer) were placed inside Enclosure A and Enclosure B, respectively. Outside each enclosure, the exposed portion of each device housing was covered with hand-cut foam insulation (Figures 9(c) and 9(d)).

[0243] Each enclosure was fitted with a capacitive temperature and humidity sensor (Ahlborn FHA646-R).

[0244] Devices A and B were then subjected to six 6 minute thermal cycles at 24 hour intervals, and the dew point within the enclosure was constantly monitored. The results are shown in Figure 9(e). Line A shows the dew point within enclosure A. Line B shows the dew point within enclosure B. Line C shows the dew point in the laboratory environment, which remained fairly constant throughout. The laboratory temperature was also measured to be fairly constant throughout the test period, varying between a minimum of about 21.1°C and a maximum of about 22.3°C.

[0245] These data demonstrate that Devices A and B are capable of removing moisture from Enclosures A and B, respectively, upon repeated heating cycles.

[0246] During each heating cycle, a temporary increase in dew point occurred, consistent with water vapor desorbed from the desiccant in the chamber of each of Devices A and B permeating through the moisture transport layer into the respective enclosure. During each intermediate period, a decrease in dew point was observed, consistent with water vapor permeating out of each of the enclosures through the moisture transport layer. The gradual decrease in dew point in each of the enclosures during successive thermal cycles indicates that the desorbed water vapor exiting the outlet channels of each of Devices A and B exceeds the back permeation into the respective enclosures.

[0247] The data for Enclosure B shows a greater overall reduction in dew point than Enclosure A. This observation indicates that the contact area between the fixed barrier and the moisture transport layer in Enclosure B is greater than in Enclosure A.

[0248] After the final heating cycle, the dew point was monitored for an additional 7 days. For approximately 36 hours, the dew point in each of the enclosures, A and B, decreased. Thereafter, the dew point gradually increased, which is consistent with the complete hydration of the desiccant in each of the devices, A and B, followed by the diffusion of water vapor into each enclosure through the outlet channels and moisture transport barriers. This process was shown to be significantly slower than the rate at which moisture was exiting each enclosure during the previous six heating / adsorption cycles.

[0249] Example 3 Device B was used to conduct experiments demonstrating pumping from an enclosure maintained at a higher relative humidity than the external humidity ("downhill pumping"), and pumping from an enclosure maintained at a lower relative humidity than the external humidity laboratory ("uphill pumping"). The experimental protocols generally correspond to those disclosed in WO2021118558 (WL Gore & Associates, Inc.), the contents of which are incorporated herein by reference.

[0250] In some experiments, Device B was equipped with an inner barrier of ePTFE / silicone material 1. In some experiments, Device B was equipped with an inner barrier of ePTFE / silicone material 2.

[0251] Device B was placed in a 50 L sealed enclosure as described in Example 2 above. A balance with data logging capabilities was placed inside the enclosure. The enclosure was placed in a temperature and humidity controlled environmental chamber maintained at 50% RH and 30° C. A second humidity and temperature probe was placed inside the environmental chamber to monitor chamber conditions.

[0252] All access panels to the enclosure were opened, thereby exposing the interior of the enclosure to the chamber environment.

[0253] The temperature and humidity probes in the enclosure and environmental chamber, and the balance were connected to a data logger and data logging was initiated. The enclosure and balance were allowed to equilibrate for 67 hours.

[0254] A 14 cm diameter Petri dish holding a supersaturated salt bath (magnesium chloride hexahydrate) was placed on top of the balance. Supersaturated salt solution was provided in a volume sufficient to maintain approximately 35% relative humidity at 35° C. within the enclosure. All enclosure access panels to the enclosure were closed, creating a sealed environment. The enclosure containing the balance and supersaturated salt solution was allowed to equilibrate for an additional 70 hours, with data logging from the temperature and humidity probe and balance maintained throughout.

[0255] Device B was then heated to 155° C. for 6 minutes and allowed to cool for 23 hours and 54 minutes, and this cycle was repeated five times.

[0256] The experiment was repeated by selecting a supersaturated salt bath to bring the relative humidity inside the enclosure to 56% (using a magnesium nitrate hexahydrate salt bath) and again to 83% (using a sodium chloride salt bath).

[0257] Device B was then removed from the enclosure and a device without a fixed barrier was installed. This device had an ePTFE / silicone membrane only across the second port. The "uphill" and "downhill" experiments were then repeated.

[0258] The average mass of water removed from the enclosure per day is plotted in Figure 10, including data with a fixed barrier in place (data marked "Fixed Barrier") and without a fixed barrier in place (data marked "No Fixed Barrier"). Also shown in Figure 10 are data obtained using an ePTFE / Silicone Material 1 internal barrier and data obtained using an ePTFE / Silicone Material 2 internal barrier.

[0259] Although "downhill" pumping from an enclosure with 83% relative humidity to a laboratory with 51% relative humidity was possible with or without a fixed outer barrier, device B, which included a fixed barrier, was shown to be able to pump approximately twice as fast as the device with the fixed barrier removed.

[0260] Device B removed moisture at a slower rate from an enclosure at near ambient relative humidity (ie, from an enclosure at 56% relative humidity to a laboratory room at 51% relative humidity).

[0261] Device B was shown to be able to remove moisture from an enclosure with a relative humidity of 35%, even when the ambient humidity was higher. However, after the fixed barrier was removed, such "uphill" pumping was not possible, demonstrating the role of the fixed barrier.

[0262] Example 4 Moisture vapor transmission rate data was obtained for a variety of air impermeable, moisture vapor permeable materials.

[0263] In addition to using the bare porous ePTFE material, ePTFE / silicone materials 1 and 2 described above, data was also obtained for an expanded ePE / polyurethane material.

[0264] Method (a) Desiccant method A 10 g desiccant pack (MgCl2 / MgO desiccant in a non-woven PET pouch) was placed inside a glass canning jar (100 cm high, 7 cm diameter).

[0265] Steel lid has 2.62 cm 2 An aperture (8.7x29.3mm) was made and a sample of the membrane material was placed across it and secured in place using a silicone pressure sensitive adhesive. A corresponding aperture was made in a steel blank plate and the blank plate was placed over the membrane.

[0266] The jar was then sealed using a lid.

[0267] A control sample was prepared using aluminum tape instead of the membrane.

[0268] The jars were placed in an environmentally controlled laboratory at a temperature of 22°C and a relative humidity of 50%.

[0269] The mass of the jar was measured daily and linear regression was performed to obtain the MTVR. MVTR data was plotted against the control sample data in mg / day / cm. 2 was converted to.

[0270] Method (b) High-temperature water desorption A glass canning jar (height 100 cm, diameter 7 cm) was filled with 100 ml of distilled water. 2 A circular aperture (diameter 19.05 mm) was provided and a sample of the membrane material was placed across the aperture and secured in place using a silicone pressure sensitive adhesive.

[0271] The lid was also fitted with a polypropylene diffusion tube measuring 1 mm in diameter and 3 mm in length, and an ePTFE membrane vent cover was secured over the outlet of the diffusion tube.

[0272] The jar was then sealed using a lid.

[0273] The jars were placed in an environmental chamber maintained at 90° C. and relative humidity of 2% and 50%, respectively.

[0274] The mass of the jar was measured daily and a linear regression was performed to obtain the MTVR. The MVTR data was converted to mg / day / cm 2 was converted to.

[0275] A control sample was prepared using a non-perforated lid.

[0276] Method (c) E96 water method -25℃ and 45℃ Experiments were also carried out using the water test method described in section (b) above, where the jars were placed in an environmental chamber (Gintronic Gravitest 6300) maintained at 50% relative humidity and the experiments were carried out at 25°C and 45°C, respectively. Air flow across the membrane was maintained according to ASTM E96 standard.

[0277] result The MVTR results are shown in Figure 11 and Table 1. MVTR ratio values ​​were calculated from the results performed using methods (a) and (b).

[0278] [Table 1]

[0279] The MVTR data for method (a) shows the performance of the membrane material during adsorption conditions, which typically require the transmission of water vapor through a relatively low humidity chamber for a relatively long period of time.

[0280] The MVTR data for method (b) shows the performance of the membrane material during desorption conditions, which typically require the escape of water vapor from a relatively humid chamber at high temperature for a relatively short period of time.

[0281] When used in a device to remove moisture from an enclosure, a moisture barrier must exhibit a sufficiently high MTVR under both adsorption and desorption conditions, however the MTVR required under desorption conditions is lower than the MVTR required under adsorption conditions.

[0282] This is reflected in the lower MVTR ratios. The MVTR ratio data in Table 2 and Figure 11 show that both the ePE / polyurethane absorbent film and the ePTFE / silicone Material 1 and 2 films exhibit lower MVTR ratios than the air permeable, water vapor permeable bare ePTFE.

[0283] The MVTR data for method (c) shows a variety of materials that exhibit water vapor transport rates suitable for use as moisture barrier materials in devices according to the invention.

Claims

1. 1. A device for removing moisture from within an enclosure coupled to a heat source, comprising: a housing defining a chamber and a desiccant material within said chamber; Including, a first portion of the housing including a first port between the chamber and an environment external to the housing; a second portion of the housing including a second port between the chamber and an environment external to the housing; The second port is a first barrier extending across the second port and including an air impermeable, water vapor permeable, moisture transport layer; and a second barrier extending across the second port; Including, an exterior of the moisture transport layer in fluid communication with an environment outside the housing and an interior of the moisture transport layer in fluid communication with the chamber; The device, wherein the second barrier is configured to conduct heat to the first barrier.

2. the first barrier is an inner barrier and the second barrier is an outer barrier; an exterior of the moisture transport layer in fluid communication with an environment outside the housing, and an interior of the moisture transport layer in fluid communication with the chamber; the outer barrier is adjacent to an outer side of the moisture transport layer; 2. The device of claim 1, wherein the inner barrier is movable between a first position in which the inner barrier is spaced apart from the outer barrier and a second position in which at least a portion of the outside of the inner barrier is in contact with the outer barrier under the action of a pressure change in the chamber caused by heating of the device.

3. The device of claim 1 or 2, wherein the device includes a heat source operable to desorb at least a portion of the sorbed water from the desiccant material.

4. The device of claim 3 , wherein the housing contains a heat source or the heat source is disposed within the chamber.

5. 1. An enclosure including a device for removing moisture from the enclosure, comprising: The device comprises: a housing defining a chamber and a desiccant material within said chamber; Including, a first portion of the housing including a first port providing fluid communication between the chamber and an environment external to the enclosure; a second portion of the housing including a second port between the chamber and the enclosure; The second port is a first barrier extending across the second port and including an air impermeable, water vapor permeable, moisture transport layer; and a second barrier extending across the second port. Including, the second barrier is configured to conduct heat to the first barrier; The enclosure includes or is associated with a heat source operable to raise the temperature of the device, desorb at least a portion of the adsorbed water from the desiccant material, and raise the temperature of the moisture transport layer to reduce or eliminate condensation within the chamber.

6. the first barrier is an inner barrier and the second barrier is an outer barrier; an outer side of the moisture transport layer in fluid communication with the enclosure, an inner side of the moisture transport layer in fluid communication with the chamber, and the outer barrier adjacent to the outer side of the moisture transport layer; the heat source is operable to increase a temperature of the device and increase a pressure in the chamber; 6. The enclosure of claim 5, wherein the inner barrier is movable between a first position in which the inner barrier is spaced apart from the outer barrier and a second position in which at least a portion of an outer surface of the inner barrier is in contact with the outer barrier under the action of a pressure change in the chamber caused by heating of the device using the heat source.

7. 10. A device as claimed in claim 2 or claim 3 or 4 when dependent on claim 2, or an enclosure as claimed in claim 6, wherein the inner barrier comprises one or more low-permeability or impermeable regions which are impermeable to air or water vapour, and when the inner barrier is in the second position the or each low-permeability or impermeable region is arranged to contact the outer barrier and block a flow path through the outer barrier to the outer surface of the moisture transport layer, and when the inner barrier is in the first position the or each low-permeability or impermeable region is spaced from the outer barrier and the device comprises a flow path through or around the outer barrier to the outer surface of the moisture transport layer.

8. A device as claimed in claim 2 or 7 or claim 3 or 4 when dependent on claim 2, or an enclosure as claimed in claim 6 or 7, wherein at least part of the inner barrier is flexible and / or the outer barrier is a fixed outer barrier.

9. A device or enclosure according to any preceding claim, wherein the second port defines a flow region and the moisture transport layer extends across the flow region.

10. The device or enclosure of any preceding claim, wherein the moisture transport layer comprises a porous support layer and an air impermeable, water vapor permeable material present within at least some of the pores of the support layer.

11. The device or enclosure of claim 10 , wherein the support layer comprises an expanded polymeric membrane having a porous microstructure comprising an interconnected fibrillar network.

12. 12. A device or enclosure as claimed in claim 10 or 11, wherein the porous support layer is imbibed with an air impermeable, water vapour permeable material.

13. A device or enclosure according to any one of claims 10 to 12, wherein the support layer is elastically extensible.

14. A device or enclosure according to any one of claims 1 to 13, wherein the air impermeable, water vapour permeable material is selected from a silicone material, a polyurethane material or a perfluorosulfonic acid ionomer material.

15. A device as claimed in claim 2 or any one of claims 3, 4 or 7 to 14 when claimed as dependent on claim 2, or an enclosure as claimed in claim 6 or any one of claims 7 to 14 when claimed as dependent on claim 6, wherein the outer barrier comprises a bridge over or across the second port, and one or more flow paths are defined around and / or through the outer barrier.

16. 16. The device or enclosure of any one of claims 1 to 15, wherein the first port has a smaller flow area and / or a longer flow path than the second port, such that permeation or diffusion of water vapor into the chamber through the second port exceeds diffusion or flow of water vapor from the external environment into the chamber through the first port.

17. 17. The device or enclosure of any one of claims 1 to 16, wherein the first port defines an outlet channel or the first port extends to an outlet channel, the outlet channel comprising a curved or convoluted path.

18. 1. A method for removing moisture from an enclosure, comprising: The method comprises: During the first period, transporting water vapor from the enclosure to the chamber through an air impermeable water vapor permeable moisture transport layer; adsorbing at least a portion of the water vapor onto a desiccant material within the chamber; and During the second period, applying heat to elevate the temperature of the desiccant material and desorb at least a portion of the adsorbed water from the desiccant material; increasing the temperature of the interior walls of the chamber and the moisture transport layer to reduce or eliminate condensation within the chamber; and passing at least a portion of the water vapor from the chamber to an environment external to the enclosure; A method comprising:

19. 20. The method of claim 18, comprising moving an inner barrier including the moisture transport layer from a first position in which the inner barrier is spaced apart from an outer barrier to a second position in which at least a portion of an outer surface of the inner barrier is in contact with the outer barrier.

20. 20. The method of claim 19, comprising moving the moisture transport layer from the first position in which the moisture transport layer is spaced from the outer barrier to the second position in which at least a portion of an outer surface of the moisture transport layer contacts the outer barrier.

21. 21. The method of claim 19 or 20, comprising increasing the temperature of the moisture transport layer by moving the inner barrier into contact with the outer barrier during the second period of time, the outer barrier being at a higher temperature than the moisture transport layer.

22. A method according to any one of claims 18 to 21, comprising moving the inner barrier by increasing the pressure in the chamber, and wherein the step of applying heat increases the pressure in the chamber.

23. The method of any one of claims 18 to 22, comprising raising the temperature inside the chamber during the second period of time to a temperature above a dew point or a maximum expected dew point within the chamber.

24. The method of any one of claims 18 to 23, wherein the first period of time is longer than the second period of time.

25. 25. The method of claim 24, wherein the first period of time is at least about 10, 50, 100 or 200 times longer than the length of the second period of time.

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