Dehumidifier and membrane cartridge for dehumidifier

Abstract

A membrane cartridge for a dehumidifier has a cartridge frame having an internal cavity and opposing face openings in fluid communication with the internal cavity. The frame has an edge with an edge opening in fluid communication with the internal cavity and the face opening. An insert having a perforated surface aligned with the face opening is bounded by a boundary adjacent to the face opening. A membrane is attached to the cartridge frame over the insert and face opening, and the membrane is sealed to the face opening. A dehumidifier that can employ the membrane cartridge has a housing with an opening that allows gas flow therethrough, and the membrane cartridge is parallel to the gas flow. A compressible seal is located between the edge of the frame and the housing, and a fastener between the housing and the membrane cartridge is configured to pull the membrane cartridge toward the housing to compress the seal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 406,426, filed September 14, 2023, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] FIELD OF THE INVENTION This application relates to the dehumidification of gas streams, and more particularly to dehumidifiers and membrane cartridges useful in dehumidifiers. [Background technology]

[0003] Graphene oxide (GO) membranes are selectively permeable to water, making them attractive for water separation applications such as dehumidifying air streams. However, the fragility of GO membranes presents challenges for their use in commercial dehumidification devices.

[0004] Therefore, there remains a need for dehumidifiers and membrane cartridges that can effectively utilize GO membranes for dehumidifying air streams. Summary of the Invention

[0005] A membrane cartridge for a dehumidifier includes a cartridge frame having an internal cavity and a first face opening and a second face opening in fluid communication with the internal cavity, the cartridge frame further having an edge, the edge including one or more edge openings in fluid communication with the internal cavity and the two face openings; a first insert having a first perforated surface aligned with the first face opening, the first perforated surface being bounded by a first boundary adjacent to the first face opening; a second insert having a second perforated surface aligned with the second face opening, the second perforated surface being bounded by a second boundary adjacent to the second face opening; a first membrane attached to the cartridge frame over the first insert and the first face opening, the first membrane being sealed to the first face opening; and a second membrane attached to the cartridge frame over the second insert and the second face opening, the second membrane being sealed to the second face opening.

[0006] The dehumidification device includes a housing having an opening that allows gas flow therethrough, a membrane cartridge parallel to the gas flow and having an edge adjacent to the housing, a compressible seal between the edge of the membrane cartridge and the housing, and a fastener between the housing and the membrane cartridge that is configured to pull the membrane cartridge toward the housing to compress the seal.

[0007] The dehumidifier system includes the dehumidifier described above and / or the membrane cartridge described above.

[0008] The membrane cartridge comprises a cartridge frame. The cartridge frame can be any suitable peripheral shape into which the dehumidifier is fitted. For example, the cartridge frame can be polygonal (e.g., rectangular, square, etc.), circular, or oval. Many dehumidifiers are fitted to rectangularly shaped membrane cartridges, and therefore the cartridge frame is preferably rectangular. The cartridge frame bounds a volume defined by the inner length and width of the frame element, together with the thickness, and therefore the frame element, surrounding the cartridge frame. The bounded volume is an internal cavity surrounded by the cartridge frame and the opposing face openings of the cartridge frame.

[0009] The cartridge frame has a rim with one or more edge openings that are in fluid communication with the internal cavity and the two face openings. The edge openings extend through apertures that fluidly connect the internal cavity to the exterior around the membrane cartridge. Fluids (e.g., water vapor and condensed water) that collect in the internal cavity during operation of the membrane cartridge of the dehumidifier are discharged from the interior through the one or more edge openings. The edge of the cartridge frame may also have one or more positioning apertures that can be aligned with one or more corresponding indexing pins on the dehumidifier to properly align the membrane cartridge when it is installed in the dehumidifier. In some embodiments, the edge openings and the positioning apertures are on the same edge of the cartridge frame.

[0010] A semi-permeable membrane, e.g., a graphene oxide membrane, covers each face opening of the cartridge frame, thereby enclosing the internal cavity. The membrane is attached and sealed to the cartridge frame. The membrane can be attached to the frame by any suitable method, for example, by adhesive, clamps, staples, screws, etc. The membrane can be sealed to the frame by one or more seals (e.g., gaskets, etc.) or by a sealant (e.g., adhesive, caulking, etc.). Preferably, the membrane is attached and sealed to the frame by an adhesive. The adhesive is preferably water-insoluble. Epoxy-based adhesives are particularly preferred.

[0011] Because the membranes are flexible and somewhat fragile, each membrane is supported by a respective insert disposed between the two membranes in the internal cavity and aligned with the face opening. The inserts have perforated surfaces to allow fluids (e.g., water vapor and condensed water) to pass through the membranes from outside the internal cavity and into the internal cavity. The inserts have a peripheral boundary disposed adjacent to the face opening. The insert boundary is a peripheral portion that is substantially free of protrusions, such as perforations, pins, and posts, that decorate most of the insert's interior-facing surface. The inserts may be attached to each other within the internal cavity, to the cartridge frame, to the cartridge frame and to each other, or neither, and may be held in place by the membranes.

[0012] The inserts may be attached to one another in one or more ways; for example, the inserts may be glued together, screwed together, clamped together, or some combination thereof. In some embodiments, the inserts are clamped together. In some embodiments, the clamping may be achieved using a snap-lock mechanism. In some embodiments, the snap-lock mechanism includes a plurality of pins extending from one or both drilled surfaces of the inserts into the internal cavity and a corresponding plurality of receiving apertures on one or both opposing inserts, whereby the pins are inserted into and secured in the receiving apertures. The pins may extend from one of the inserts into the receiving apertures of the other insert, or both inserts may have pins and receiving apertures corresponding to the receiving apertures and pins of the other insert. In some embodiments, the receiving apertures may be formed in a plurality of posts extending from one or both drilled surfaces of the inserts into the internal cavity. The pin may have a head that is sized and shaped to be pressed into the receiving aperture, and the receiving aperture is sized and shaped to allow insertion of the pin while preventing or inhibiting withdrawal of the pin once inserted.

[0013] The inserts may be unattached to the cartridge frame or may be attached to the cartridge frame in one or more ways, such as with adhesive, screws, nails, rivets, clamps, or some combination thereof. Furthermore, the cartridge frame may be configured to engage with the inserts in one or more different ways. In some embodiments, the cartridge frame includes one or more recesses into which the boundaries of one or both inserts engage. The cartridge frame may include a recess adjacent one or both of the face openings. In some embodiments, the periphery of the recess engages the boundary of one of the inserts. In some embodiments, one or both of the membranes may be provided with a membrane frame attached to the cartridge frame. The membrane frame may have an outer lip that accommodates the insert when the insert is placed in a frame element of the cartridge frame. Thus, the boundary does not require a recess in the cartridge frame but may still seat flush in the cartridge frame while remaining held below the membrane covering the face opening.

[0014] The membrane cartridge allows for the use of graphene oxide (GO) membranes within the dehumidifier to separate water vapor from a gas (e.g., air) stream. In some embodiments, one or both of the membranes can be graphene oxide.

[0015] The dehumidification device includes a housing. The housing may include various walls, including, for example, a vacuum plate, a side plate, a guide plate, and a cover. The housing preferably has openings, preferably opposing openings, through which gas (e.g., humid air) is directed during operation of the device. At least one membrane cartridge, preferably multiple membrane cartridges, is disposed within the housing so that gas flows across the membrane surface, i.e., the membrane cartridges are parallel to the gas flow. The multiple membrane cartridges are preferably configured within a cartridge assembly in which the membrane cartridges are arranged parallel to one another with gas flow channels between them. The gas flow channels preferably have the same width and profile for consistent permeation of water vapor into the membrane cartridges across the cartridge assembly. Air flow through the housing past the membrane cartridges can be achieved using any suitable device, such as a fan, that can be mounted on the device or as part of a larger dehumidification system.

[0016] The water vapor and any condensed water collected inside the membrane cartridge can be discharged into the membrane cartridge through one or more edge openings. To assist in the discharge, the apparatus preferably includes a vacuum system in fluid communication with the interior of the membrane cartridge. In some embodiments, the vacuum system includes a vacuum chamber, e.g., a vacuum manifold, in fluid communication with the edge of the membrane cartridge, particularly with one or more edge openings of the membrane cartridge, the one or more edge openings providing through apertures fluidly connecting the interior of the membrane cartridge to the vacuum chamber.

[0017] A vacuum plate forming part of the housing, preferably the bottom of the housing, can act as an interface between the vacuum chamber and the membrane cartridge. The membrane cartridge is preferably mounted to the housing, preferably the vacuum plate, so that the edge of the membrane cartridge is adjacent to the housing, particularly the vacuum plate. In some embodiments, the vacuum plate includes one or more vacuum channels aligned with the edge openings of the membrane cartridge, thereby providing both support for the membrane cartridge and a fluid connection to the vacuum chamber. An airtight fluid seal can be provided between the vacuum chamber and the vacuum plate and between the vacuum plate and the edge of the membrane cartridge. In particular, the seal between the vacuum plate and the edge of the membrane cartridge is compressible to pull the membrane cartridge into the housing, preferably toward the vacuum plate, compressing the seal and providing a better seal. One or more fasteners, e.g., bolts, clamps, etc., can be used between the membrane cartridge and the housing to pull the membrane cartridge toward the housing and compress the seal. In some embodiments, one or more fasteners are located within the vacuum chamber.

[0018] To properly mount and position the membrane cartridge on its edge within the housing, the housing preferably includes one or more indexing pins. The one or more indexing pins engage with positioning apertures on the edge of the membrane cartridge. When the device includes multiple membrane cartridges, the housing includes multiple indexing pins to assist in positioning the membrane cartridges parallel to one another when stacked within the device. The indexing pins are preferably located on the upper surface of the vacuum plate. In some embodiments, guide plates located on opposite edges of the membrane cartridge from the edge opening are utilized to assist in proper positioning of the membrane cartridge. Furthermore, when multiple membrane cartridges are utilized, the device may include cartridge spacers to properly space the membrane cartridges so that they are parallel to one another and spaced apart as desired.

[0019] In some embodiments, one or more of the membrane cartridges is a membrane cartridge as defined above. The edge of the membrane cartridge is an edge of a cartridge frame that includes one or more edge openings.

[0020] Additional features will be described or will become apparent during the course of the following detailed description. It should be understood that each feature described herein can be utilized in any combination with any one or more of the other described features, and that each feature is not necessarily dependent on the presence of another feature, unless otherwise apparent to one of ordinary skill in the art. [Brief explanation of the drawings]

[0021] For a clearer understanding, preferred embodiments will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

[0022] [Figure 1A] 1 shows an exploded view of a first embodiment of a membrane cartridge. [Figure 1B] 1B shows a perspective view of the membrane cartridge of FIG. 1A. [Figure 1C] 1B depicts a cross section of the membrane cartridge of FIG. [Figure 1D] FIG. 1C depicts a side view of the membrane cartridge of FIG. 1B. [Figure 1E] FIG. 1D depicts a cross-sectional view through AA of the membrane cartridge of FIG. [Figure 2A] 10 depicts an exploded view of a second embodiment of a membrane cartridge. [Figure 2B] 2B shows a perspective view of the membrane cartridge of FIG. 2A. [Figure 3A] 10 depicts an exploded view of a third embodiment of a membrane cartridge. [Figure 3B] 3B shows a perspective view of the membrane cartridge of FIG. 3A. [Figure 4A] 1 shows an exploded view of a dehumidifier. [Figure 4B] 4B shows a first perspective view of the dehumidifier of FIG. 4A. [Figure 4C] 4C shows a bottom view of the dehumidifier of FIG. 4B. [Figure 4D]4D shows a cross-sectional view through BB of the dehumidifier of FIG. 4C. [Figure 4E] 4B shows a second perspective view of the dehumidifier of FIG. 4A. [Figure 4F] 4E shows a cross-sectional side view of the dehumidifier of FIG. 4E. [Figure 5A] 5B illustrates an exploded view of the dehumidifier system of FIG. 5A utilizing the dehumidifier of the present invention. [Figure 5B] 5B depicts a schematic diagram of sensor placement in the dehumidifier system of FIG. 5A using a membrane cartridge module housing three membrane cartridges of the present invention for a total of six membranes. [Figure 6A] 5C depicts a graph of Integrated Energy Factor (IEF, L / kWh) for different inlet conditions (relative humidity (RH, %) and temperature (T, °C)) and flow rate (CFM)) summarizing performance results for the dehumidifier system of FIG. 5B. [Figure 6B] 5C depicts a graph showing relative humidity and temperature at different flow rates in a high moisture environment for the dehumidifier system of FIG. 5B. [Figure 6C] 5C depicts a graph showing relative humidity and temperature at different flow rates in a low moisture environment for the dehumidifier system of FIG. 5B. [Figure 7A] 5B depicts graphs of integrated energy coefficient (L / kWh) and mixing ratio (GPP) versus inlet temperature (°C) at various temperatures from 20°C to 52°C summarizing the dehumidification performance at a flow rate of 250 CFM of the dehumidifier system of FIG. 5A comprising two membrane cartridge modules each housing 15 membrane cartridges of the present invention for a total of 30 membranes per module. [Figure 7B] 7B depicts a graph of Integrated Energy Coefficient (L / kWh) versus Inlet Mixing Pair (GPP) at a constant temperature of 20° C., showing dehumidification performance at a flow rate of 250 CFM for the same dehumidifier system that produced the results of FIG. 7A. [Figure 7C] 7B presents a graph of Integrated Energy Coefficient (L / kWh) and Mixing Ratio (GPP) versus Inlet Temperature (°C) at various temperatures from 20°C to 43°C summarizing dehumidification performance at a flow rate of 250 CFM for the same dehumidifier system that produced the results in FIG. 7A. [Figure 7D] 7B depicts a graph of Integrated Energy Coefficient (L / kWh) versus flow rate (CFM) at a constant temperature of 30° C. versus inlet mixing ratio (GPP), showing dehumidification performance for the same dehumidifier system that produced the results of FIG. 7A. [Figure 7E] 7B depicts a graph of differential pressure (D / F, Pa) versus total flow rate (CFM) showing how the differential pressure across the membrane cartridge module increases with increasing flow rate for the same dehumidifier system that produced the results of FIG. 7A. DETAILED DESCRIPTION OF THE INVENTION

[0023] 1A-1E, a first embodiment of a membrane cartridge 1 comprises a rectangular cartridge frame 3 having four edges 5 (only two of which are labeled) that define an internal cavity 7, with the cartridge frame 3 having opposed face openings 9, 10 into the internal cavity 7. One of the edges 5 of the cartridge frame 3 is specifically labeled 5a and includes a plurality of edge openings 11 (only one of which is labeled) that are in fluid communication with the internal cavity 7 and the opposed face openings 9, 10. The edge openings 11 are formed through the cartridge frame 3 between the outer and inner edge portions of edge 5a so that fluids, e.g., water vapor or liquid, that collect within the internal cavity 7 can be removed from the internal cavity 7 during use of the membrane cartridge 1. The membrane cartridge 1 comprises opposing perforated rectangular inserts 13, 15 in the form of rectangular plates having peripheral boundaries 14, 16 and a plurality of perforations, the insert 13 being aligned with a face opening 9 on one side of the cartridge frame 3 and the insert 15 being aligned with a face opening 10 on the opposite side of the cartridge frame 3.

[0024] The cartridge frame 3 includes peripheral recesses 17 on the inner edge portion of the rim 5, one of which surrounds the face opening 9 and the other of which (not shown) surrounds the face opening 10. Borders 14, 16 of the inserts 13, 15 engage with respective recesses 17 in the rim 5 of the cartridge frame 3 adjacent the respective face openings 9, 10. The inserts 13, 15 thus cover the face openings 9, 10, respectively, and bound the internal cavity 7 between the rim 5 and between the inserts 13, 15. The recesses 17 have a depth that allows the inserts 13, 15 to fit into the cartridge frame 3 such that the outer surfaces of the inserts 13, 15 are flush with the opposing surface of the cartridge frame 3. Each of the inserts 13, 15 includes a plurality of locking pins 19 that extend into the internal cavity 7 and a plurality of posts 20 with receiving apertures that also extend into the internal cavity 7. The locking pin 19 of the insert 13 is aligned with the post 20 of the insert 15 so that the locking pin 19 can be inserted into the receiving aperture of the post 20 to secure the two inserts 13, 15 together in a snap-fit ​​manner, thereby securing the cartridge frame 3 between the inserts 13, 15 without attaching the boundaries 14, 16 of the inserts 13, 15 to the cartridge frame 3.

[0025] The membrane cartridge 1 further includes opposed rectangular graphene oxide semipermeable membranes 21, 23 supported on and covering the inserts 13, 15, respectively. The membranes 21, 23 are attached to and sealed at the edges 5 of the cartridge frame 3 by annular beads of epoxy-cyanoacrylate adhesive 25, 27 (e.g., Loctite™ 4090). The membrane cartridge 1 further includes two positioning apertures 29 at the same edge 5a as the edge opening 11, which are alignable with one or more corresponding indexing pins on the dehumidifier to properly align the membrane cartridge 1 when it is installed in the dehumidifier. The membrane cartridge 1 further includes a plurality of fastener receptacles 28 (only one of which is labeled), e.g., bolt holes, at the same edge 5a as the edge opening 11, which are configured to engage fasteners (e.g., bolts) to secure the membrane cartridge 1 to the dehumidifier.

[0026] During use in a dehumidifier, as a moist gas stream (e.g., moist air) passes through the graphene oxide semi-permeable membranes 21, 23, at least a portion of the water vapor in the gas stream passes through the membranes 21, 23 and then through the perforations in the inserts 13, 15 into the internal cavity 7, thereby dehumidifying the gas stream. The water vapor and condensed liquid water can be vented through the edge openings 11 in the cartridge frame 3 to prevent water accumulation within the membrane cartridge 1.

[0027] 2A and 2B, a second embodiment of membrane cartridge 41 is similar to membrane cartridge 1 and includes a rectangular cartridge frame 43, rectangular perforated inserts 53, 55, and graphene oxide semipermeable membranes 61, 63, whereby membranes 61, 63 are supported on inserts 53, 55 and connected together in the same manner as membrane cartridge 1. Membrane cartridge 41 differs from membrane cartridge 1 in that cartridge frame 45 does not have a recess. Instead, inserts 53, 55 are free-floating together within the inner marginal portion of edge 45 of cartridge frame 43, and membranes 61, 63 are attached to cartridge frame 43 by annular beads of adhesive 65, 67, which seal and hold inserts 53, 55 in place within cartridge frame 43. As can be seen by comparing FIG. 2B with FIG. 1B, the fully assembled membrane cartridge 41 appears identical in appearance to the fully assembled membrane cartridge 1.

[0028] 3A and 3B, a third embodiment of a membrane cartridge 71 is similar to membrane cartridge 41 and includes a rectangular cartridge frame 73, rectangular perforated inserts 83, 85, and graphene oxide semipermeable membranes 91, 93, whereby the membranes 91, 93 are supported on the inserts 83, 85. Membrane cartridge 71 differs from membrane cartridge 41 in that the inserts 83, 85 are not connected together with receiving apertures by pins and posts. Instead, the inserts 83, 85 are glued together. The inserts 83, 85 still float freely together within the inner edge portion of the edge 75 of the cartridge frame 73, and the membranes 91, 93 are attached to the cartridge frame 73 by annular beads of adhesive 95, 97, which seal and hold the inserts 83, 85 in place within the cartridge frame 73. As can be seen by comparing FIG. 3B with FIG. 1B, the fully assembled membrane cartridge 71 appears identical in appearance to the fully assembled membrane cartridge 1.

[0029] 4A-4F, a dehumidification apparatus 100 is shown that can utilize membrane cartridges 1, 41, and 71. The apparatus 100 includes a housing 101 having a vacuum plate 103 at the bottom 101 of the housing, a pair of opposed side plates 105 attached to and extending upwardly from the vacuum plate 103, a guide plate 121 at the top 101 of the housing to which the side plates 105 are connected, and a cover 107 connected to the top of the guide plate 121. The side plates 105 are attached to the vacuum plate 103 by angle brackets 106. The housing 101 has opposed front and rear openings 109 and 111, each of which allows gas flow through the housing 101.

[0030] The apparatus 100 further comprises a cartridge assembly 113 mounted on the vacuum plate 103, the cartridge assembly 113 comprising a plurality of spaced apart parallel membrane cartridges 114 (only one is labeled) arranged such that there are a plurality of parallel gas flow channels 115 between the faces of the membrane cartridges 114. The membrane cartridges 114 and gas flow channels 115 are aligned such that the membrane cartridges 114 are parallel to the gas flow between the front opening 109 and the rear opening 111, and gas flows in the gas flow channels 115 through the housing 101 between the faces of the membrane cartridges 114. The edges of the membrane cartridges 114 abut the housing 101, a lower edge abuts the vacuum plate 103, and an upper edge abuts the cartridge spacer 117. The lower edge of the membrane cartridge 114 includes a locating aperture that aligns with and can be inserted over front and rear indexing pins 119 (only one is labeled), which are formed in front and rear rows and spaced apart in the rows to properly align and position the membrane cartridge 114 when it is installed within the housing 101. The cartridge spacer 117 includes a series of channels in which the upper edge of the membrane cartridge 114 seats to further assist in aligning, positioning, and securing the membrane cartridge 114 within the housing 101. Additionally, a guide plate 121 includes a single large aperture therein and is located at the top of the cartridge assembly 113 to help guide the individual membrane cartridges 114 into position when they are installed within the housing 101.

[0031] The vacuum plate 103 includes a series of vacuum channels 127 aligned with the edges of the membrane cartridges 114. The vacuum channels 127 are in fluid communication with edge openings at the edges of the membrane cartridges 114, which are in fluid communication with the respective internal cavities of the membrane cartridges 114, as described above in connection with membrane cartridge 1. A first compressible airtight seal 129 (e.g., an elastomeric gasket) is located between the edges of the membrane cartridges 114 and the vacuum plate 103. A plurality of fasteners 131 (only one will be labeled), e.g., bolts, inserted through the vacuum channels 127 are aligned with fastener receivers, e.g., bolt holes, at the edges of the membrane cartridges 114, such that engagement of the fasteners 131 with the fastener receivers is configured to pull the membrane cartridges 114 toward the vacuum plate 103 and, therefore, the housing 100, compressing the seal. The apparatus 100 also includes a vacuum manifold 125 located below the vacuum plate 103 and secured to the vacuum plate 103 by additional fasteners 133 (only one of which is labeled), e.g., bolts. A second compressible airtight seal 135 (e.g., an elastomeric gasket) is located between the vacuum manifold 125 and the vacuum plate 103. The vacuum manifold 125 includes a port 137 connectable to a vacuum system to apply a vacuum to the vacuum manifold 125, which is ultimately in fluid communication with the interior cavity of the membrane cartridge 114.

[0032] During operation, humid gas (e.g., humid air) flowing through the dehumidification apparatus 100 between the front opening 109 and the rear opening 111 flows through the gas flow channels 115 between the membrane cartridges 114. Water vapor in the gas selectively passes through a selectively permeable membrane (e.g., a graphene oxide membrane) and enters the internal cavity of the membrane cartridge 114. Water within the internal cavity of the membrane cartridge 114 is expelled through an edge opening with the assistance of a vacuum applied within the vacuum manifold 125, which is ultimately in fluid communication with the internal cavity of the membrane cartridge 114. Thus, the gas exiting the apparatus 100 is drier compared to the humid gas entering the apparatus 100.

[0033] 5A and 5B, a dehumidifier system 200 is shown including a dehumidifier 150 of the present invention. The dehumidifier 150 is shown with a width that can accommodate three membrane cartridges (having a total of six membranes), but the dehumidifier 150 could be wider if more membrane cartridges were desired. The system 200 includes a housing 201 in which the dehumidifier 150 is mounted. An inlet adapter 203 is mounted over the front opening 159 of the dehumidifier 150 to allow fluid communication between the front opening 159 of the dehumidifier 150 and a blower fan 205 that draws moist air through an inlet duct 207 in which the fan 205 is mounted to deliver moist air to the dehumidifier 150 through the inlet adapter 203. Also mounted within the housing 201 is an inlet duct 207 that is in fluid communication with the external environment through an open front window 209 in the front wall of the housing 201, the front window 209 being covered by an inlet filter 211 that filters out particulate matter from the moist inlet airflow. An outlet duct 213 is mounted over the rear opening 161 of the dehumidifier 150 to allow fluid communication between the rear opening 161 of the dehumidifier 150 and the external environment through an open rear window 215 in the rear wall of the housing 201. The drier outlet airflow from the dehumidifier 150 exits through the open rear window 215, which is covered by an outlet filter 217 that prevents particulate matter from entering the dehumidifier 150 through the outlet duct 213.

[0034] The bottom of dehumidifier 150 is in fluid communication with vacuum pump 221 through vacuum manifold 225 (see FIG. 5B ), which assists in pumping water vapor from dehumidifier 150 in the manner described above. The water vapor and pumped heat are exhausted through exhaust outlet 223 connected to vacuum pump 221. Exhaust outlet 223 may be connected to a drain. Enclosure 201 also includes air ports 224 in the walls of enclosure 201 to allow the air pressure within enclosure 201 to equalize with the air pressure of the external environment. Air ports 224 are covered by air port filters 226 to help prevent particulate matter from entering enclosure 201. Dehumidifier system 200 includes an electrical cabinet 227 that houses an electronic controller 228 for dehumidifier system 200, including a programmable logic controller (PLC), and a display 229 capable of displaying system parameters.

[0035] 5B is a schematic diagram of dehumidifier system 200 having a module 164 housing three membrane cartridges within dehumidifier 150 and showing the placement of various sensors 230, including humidity sensor 231, temperature sensor 232, and differential pressure sensor 233. Fan 205, vacuum pump 221, and electronic controller 228 all receive power through power meter 235 for their respective operation.

[0036] Example 1 In one experiment, two dehumidifier systems 200 were constructed, each with three membrane cartridges and a rated airflow rate of 63 CFM. Each system had a PLC that recorded data every 30 seconds and could retain data for up to one month. Each system was connected to the internet, allowing users to monitor the system in real time. After commissioning the systems at the test site, an external humidifier was brought in to simulate higher humidity conditions to ensure the systems performed as expected due to the very dry ambient conditions. Both systems were operated continuously in dehumidification mode for an indefinite period of time to collect lifetime data. Figures 6A-6C show the results.

[0037] Figure 6A summarizes the results. The dehumidifier system can handle more air volume and water vapor as the flow rate increases, which significantly improves the energy efficiency of the system. The dehumidifier system performs best at higher relative humidity and inlet temperatures and can exceed the performance of conventional dehumidifiers.

[0038] Figure 6B provides a plot of artificially generated higher humidity, with relative humidity levels ranging from 70% to 90% at temperatures ranging from 10°C to 20°C. Under these conditions, the dehumidification system was able to reduce the relative humidity by 15% to 25%, depending on the ambient humidity and temperature during the test. The system performed better at higher temperatures and higher relative humidity conditions. However, at a flow rate of 280 CFM, the difference in normalized relative humidity (RH) was larger, which is considered anomalous given the very low mixing ratio at the higher temperatures.

[0039] Another set of tests, the results of which are shown in Figure 6C, involved a realistic scenario in which the humidifier was turned off and the dehumidifier unit was exposed to a dry environment to evaluate the system's moisture removal capability. The relative humidity at the time of testing averaged 26%, which is considered very low. However, the dehumidifier system was still able to reduce the relative humidity by 5% at an inlet temperature of 16°C. Another test was conducted by carefully evaluating the humidity removal performance at different flow rates. The flow rate was increased from 2 to 4 times the design flow rate of 63 CFM, and a decrease in relative humidity removal was observed.

[0040] Example 2 In another experiment, the performance of two dehumidifier systems 200 was studied at various flow rates, temperatures, and humidity levels. The dehumidifier systems consisted of cartridge modules with 30 membranes rated at 125 CFM per cartridge module and a 375 m² dehumidifier with a Roots booster and vacuum pump. 3 The test chamber was equipped with a 1000W / hr vacuum pump system and a vacuum pump PLC with variable frequency drive (VFD) control for the Roots booster. Experiments were conducted in a test chamber with two air heaters, two humidifiers, one large blower fan box, two Accuvalve™ dampers at the inlet, and pressure, temperature, and humidity sensors located before and after the cartridge module and in the vacuum line.

[0041] The test chamber allows the user to independently control the inlet conditions for each channel and cartridge module. However, for all tests performed, the inlet conditions for both channels were kept the same to ensure consistency between both cartridge modules. Different inlet conditions for the cartridge modules can result in unbalanced vacuum levels for each cartridge module, which can affect the overall power efficiency for a given set of inlet conditions.

[0042] All tests were performed in the following order: The blower fan is started and the heater is turned on to increase humidity. Data is collected at different humidity levels and a fixed flow rate. While maintaining the flow rate, the temperature is increased and the humidity level is changed. The above is repeated until the desired temperature is reached, while recording the moisture removal and energy efficiency. Specific temperature and humidity levels are selected and flow rates are varied to evaluate moisture removal performance.

[0043] Key performance metrics for the dehumidifier system were obtained and are summarized in Figure 7A. As the mixing ratio increases, the difference between the inlet and outlet (D / F) increases with increasing IEF. This indicates that the performance of the system improves significantly at higher mixing ratios, which can be achieved with higher inlet temperatures.

[0044] The plot in Figure 7B shows how dehumidification performance is enhanced as the mixing ratio increases at a constant temperature of 20°C. At an inlet mixing ratio of 53 GPP, the IEF is 0.3 L / kWh, and at an inlet mixing ratio of 98 GPP, the IEF is 0.7 L / kWh. This results in a 133% increase in IEF from baseline to higher moisture content.

[0045] As Figure 7B shows, increasing the mixing ratio at a fixed temperature can improve the IEF of the system. The plot in Figure 7C shows the improvement in dehumidification performance with increasing temperature. At an inlet mixing ratio of 76 GPP, the IEF is 0.5 L / kWh, and at an inlet mixing ratio of 285 GPP, the IEF is 1.9 L / kWh. This results in a 280% increase in IEF from 20°C to 43°C.

[0046] The dehumidifier system was designed to operate at a rated flow rate of 250 CFM. However, the test chamber was capable of increasing the flow rate up to 650 CFM. The plot in Figure 7D shows that as the flow rate increases, the mixing ratio D / F between the inlet and outlet decreases, but the IEF increases as more air is processed by the cartridge module. From 250 to 650 CFM, the mixing ratio D / F decreases from 56 GPP to 32 GPP, resulting in a 43% decrease in moisture removal. Considering the same flow rate, the IEF increases from 0.91 to 1.29 L / kWh, a 42% improvement over the rated flow rate.

[0047] The plot in Figure 7E shows how the differential pressure across the cartridge module increases with increasing flow rate. The experimental pressure D / F indicates the pressure measured across each cartridge module and compares the data with the calculations and computational fluid dynamics (CFD) predictions. The experimental pressure D / F is 18 Pa at a flow rate of 250 CFM; the calculation is 37% lower than the experimental data, but the CFD model predicts it 8.4% lower. At the highest flow rate of 700 CFM, the experimental pressure D / F is 81 Pa; the calculation is 23% lower than the experimental data, but the CFD model predicts it 30% higher. The CFD model tends to overpredict the pressure D / F due to the selected k-ε turbulence model, and this discrepancy increases with increasing flow rate as the turbulent kinetic energy of the system increases. However, in most cases, the calculated pressure D / F is underpredicted because the module geometry is not taken into account, resulting in an ideal case for the flow traveling through the air channels.

[0048] The novel features will become apparent to those skilled in the art upon examination of this specification. However, it should be understood that the scope of the claims should not be limited by the embodiments, but should be accorded the broadest interpretation consistent with the language of the claims and the entire specification.

Claims

1. A membrane cartridge for a dehumidifier, comprising: a cartridge frame having an internal cavity and having a first face opening and a second face opening in fluid communication with the internal cavity, the cartridge frame further having an edge, the edge including one or more edge openings in fluid communication with the internal cavity and the two face openings; a first insert including a first drilling surface aligned with the first face opening, the first drilling surface being bounded by a first boundary adjacent the first face opening; a second insert including a second drilling surface aligned with the second face opening, the second drilling surface being bounded by a second boundary adjacent the second face opening; a first membrane attached to the cartridge frame over the first insert and the first face opening, the first membrane being sealed to the first face opening; a second membrane attached to the cartridge frame over the second insert and the second face opening, the second membrane being sealed to the second face opening.

2. 2. The cartridge of claim 1, wherein the first insert comprises a plurality of pins extending from the first perforated surface into the internal cavity, and the second insert comprises a plurality of receiving apertures into which the plurality of pins are inserted and secured.

3. The cartridge of claim 2 , wherein the second perforated surface comprises a plurality of posts extending from the second perforated surface into the internal cavity, the plurality of posts comprising the plurality of receiving apertures.

4. 4. The cartridge of claim 3, wherein the second perforated surface comprises another plurality of pins extending into the internal cavity, and the first perforated surface comprises another plurality of posts comprising another plurality of receiving apertures into which the other plurality of pins are inserted and secured.

5. the frame includes a first recess surrounding the first face opening, the first boundary engaging the first recess; The cartridge of any one of claims 1 to 4, wherein the frame includes a second recess surrounding the second face opening, and the second boundary engages with the second recess.

6. The cartridge of claim 5 , wherein the frame is unattached to the first boundary and the second boundary.

7. A cartridge according to any preceding claim, wherein the first and second membranes are attached and sealed to the frame by an adhesive.

8. 8. A cartridge according to any one of claims 1 to 7, wherein the edge comprises one or more positioning apertures alignable with one or more corresponding indexing pins on the dehumidifier to properly align the cartridge when the cartridge is installed in the dehumidifier.

9. The cartridge of any one of claims 1 to 8, wherein the first membrane, the second membrane, or both the first membrane and the second membrane comprise graphene oxide.

10. A dehumidification device, a housing having an opening therein to allow gas flow therethrough; a membrane cartridge parallel to the gas flow, the membrane cartridge having an edge adjacent to the housing; a compressible seal between the edge of the membrane cartridge and the housing; a fastener between the housing and the membrane cartridge, the fastener configured to pull the membrane cartridge toward the housing and compress the seal.

11. The apparatus of claim 10 , further comprising a vacuum chamber in fluid communication with the edge of the membrane cartridge, the fastener being located within the vacuum chamber.

12. 12. The device of claim 10 or 11, wherein the membrane cartridge is one of a plurality of membrane cartridges, and the housing comprises a plurality of indexing pins to assist the membrane cartridges in positioning parallel to one another in a stacked state within the device.

13. 13. The apparatus of claim 10, wherein the membrane cartridge is a membrane cartridge as defined in any one of claims 1 to 10, and the edge of the membrane cartridge is the edge of the cartridge frame that includes the one or more edge openings.

14. A dehumidifier system comprising a device according to any one of claims 10 to 13.

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