Abstract: Substrates for paperboard packing with improved internal sizing including the use of a combination of a dispersed rosin size (DRS) with an alkenylsuccinic anhydride size for reducing edgewicking with less use of the sizing agents.

Abstract: Substrates for paperboard packing with improved internal sizing including the use of a combination of a dispersed rosin size (DRS) with an alkenylsuccinic anhydride size for reducing edgewicking with less use of the sizing agents.

Abstract: Embodiments of an electrochemical flow cell stack are disclosed. A plurality of frame layers may each have a peripheral gasket channel configured to receive a gasket material. The gasket channel may surround a recessed area having a size and a structure configured to receive an insert layer. Each of the plurality of frame layers may include at least one void area defining a first half-cell chamber of a flow cell. A plurality of insert layers may each be nested within a corresponding frame layers. Each insert layer may include at least one void area defining a second half-cell chamber of the flow cell. A flow cell may be formed by one of the plurality of frame layers and one of the plurality of insert layers.

Abstract: A fuel cell is provided that includes a water transport plate separating an air flow field and a water flow field. The driving force for moving water across the water transport plate into the water flow field is produced by a differential pressure across a restriction. The restriction is arranged between an air outlet of the cathode water transport plate and a head of a reservoir that is in fluid communication with the water flow field.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).

Abstract: A fuel cell includes an electrode assembly having an electrolyte between a cathode catalyst and an anode catalyst, and a flow field plate having a channel for delivering a reactant gas to the electrode assembly. The flow field plate includes a channel having a channel inlet. A porous diffusion layer is located between the electrode assembly and the flow field plate. The porous diffusion layer includes a first region near the channel inlet and a second region downstream from the first region relative to the channel inlet. The first region includes a filler material that partially blocks pores of the first region such that the first region has a first porosity and the second region has a second porosity that is greater than the first porosity.

Abstract: A fuel cell (10) includes a cathode catalyst (26) for receiving a first reactant and an anode catalyst (24) for receiving an expected amount of a second reactant. The cathode catalyst (26) and the anode catalyst (24) respectively catalyze the first reactant and the second reactant to produce an electrochemical reaction that generates a flow of electrons between the cathode catalyst (26) and the anode catalyst (24) The amount of the first reactant consumed in the electrochemical reaction corresponds to a threshold amount of the second reactant needed to generate a forward flow of the electrons from the anode catalyst (24) to the cathode catalyst (26). A portion (42) of a fuel cell flow field includes a feature (54, 60, 80, W1, D1) that restricts consumption of the first reactant.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) cross sections having intersecting polygons or other shapes, obtuse angles including triangles and trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120), or (e) diverging channels (152).

Abstract: A fuel cell stack (31) includes a plurality of fuel cells (9) each having an electrolyte such as a PEM (10), anode and cathode catalyst layers (13, 14), anode and cathode gas diffusion layers (16, 17), and water transport plates (21, 28) adjacent the gas diffusion layers. The cathode diffusion layer of cells near the cathode end (36) of the stack have a high water permeability, such as greater than 3×10?4 g/(Pa s m) at about 80° C. and about 1 atmosphere, whereas the cathode gas diffusion layer in cells near the anode end (35) have water vapor permeance greater than 3×10?4 g/(Pa s m) at about 80° C. and about 1 atmosphere. In one embodiment, the anode gas diffusion layer of cells near the anode end (35) of the stack have a higher liquid water permeability than the anode gas diffusion layer in cells near the cathode end; a second embodiment reverses that relationship.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).

Abstract: An inlet fuel distributor (10-10d) has a permeable baffle (39, 54, 54a, 60) between a fuel supply pipe (11, 83) and a fuel inlet manifold (12, 53, 53a, 63) causing fuel to be uniformly distributed along the length of the fuel inlet manifold. A surface (53, 68) may cause impinging fuel to turn and flow substantially omnidirectionally improving its uniformity. Recycle fuel may be provided (25, 71) into the flow downstream of the fuel inlet distributor. During startup, fuel or inert gas within the inlet fuel distributor and the fuel inlet manifold may be vented through an exhaust valve (57, 86) in response to a controller (58, 79) so as to present a uniform fuel front to the inlets of the fuel flow fields (58).

Abstract: A fuel cell (10) includes a cathode catalyst (26) for receiving a first reactant and an anode catalyst (24) for receiving an expected amount of a second reactant. The cathode catalyst (26) and the anode catalyst (24) respectively catalyze the first reactant and the second reactant to produce an electrochemical reaction that generates a flow of electrons between the cathode catalyst (26) and the anode catalyst (24) The amount of the first reactant consumed in the electrochemical reaction corresponds to a threshold amount of the second reactant needed to generate a forward flow of the electrons from the anode catalyst (24) to the cathode catalyst (26). A portion (42) of a fuel cell flow field includes a feature (54, 60, 80, W1, D1) that restricts consumption of the first reactant.

Abstract: A PEM fuel cell power plant includes fuel cells, each of which has a cathode reactant flow field plate which is substantially impermeable to fluids, a water coolant source, and a fluid permeable anode reactant flow field plate adjacent to said water coolant source. The anode reactant flow field plates pass water from the coolant sources into the cells where the water is evaporated to cool the cells. The cathode flow field plates prevent reactant crossover between adjacent cells. By providing a single water permeable plate for each cell in the power plant the amount of water present in the power plant at shut down is limited to a degree which does not require adjunct water purging components to remove water from the plates when the power plant is shut down during freezing ambient conditions. Thus the amount of residual ice in the power plant that forms in the plates during shut down in such freezing conditions will be limited.

Abstract: Fuel cells (38) have water passageways (67; 78, 85; 78a, 85a) that provide water through reactant gas flow field plates (74, 81) to cool the fuel cell. The water passageways may be vented to atmosphere (99), by a porous plug (69), or pumped (89, 146) with or without removing any water from the passageways. A condenser (59, 124) receives reactant air exhaust, may have a contiguous reservoir (64, 128), may be vertical, (a vehicle radiator, FIG. 2), may be horizontal, contiguous with the top of the fuel cell stack (37, FIG. 5), or below (124) the fuel cell stack (120). The passageways may be grooves (76, 77; 83, 84) or may comprise a plane of porous hydrophilic material (78a, 85a) contiguous with substantially the entire surface of one or both of the reactant gas flow field plates. Air flow in the condenser may be controlled by shutters (155). The condenser may be a heat exchanger (59a) having freeze-proof liquid flowing through a coil (161) thereof, the amount being controlled by a valve (166).

Abstract: A fuel cell is provided that includes a water transport plate separating an air flow field and a water flow field. The driving force for moving water across the water transport plate into the water flow field is produced by a differential pressure across a restriction. The restriction is arranged between an air outlet of the cathode water transport plate and a head of a reservoir that is in fluid communication with the water flow field.

Abstract: Fuel cells (38) have minute water passageways (67) that provide water through one or both reactant gas flow field plates (74, 82) of each fuel cell, whereby the fuel cell is cooled evaporatively. The water passageways (67; 78, 85; 78a, 85a) may be vented by a porous plug (69), or by a microvacuum pump (89) that does not pump any water from the passageways, or simply vented (99) to atmosphere. A condenser (59) may have a contiguous reservoir (64); the condenser (59) may be vertical, such as a vehicle radiator (FIG. 1), or may be horizontal, contiguous with the top of the fuel cell stack (37, FIG. 5). The passageways may be grooves (76, 77; 83, 84) in the reactant gas flow plates (75, 81) or the passageways may comprise a plane of porous hydrophilic material (78a, 85a) contiguous with substantially the entire surface of one or both of the reactant gas flow field plates.

Abstract: A fuel cell power plant (19) has a stack of fuel cells (20) cooled by a mixture of water with a non-volatile, miscible fluid that sufficiently depresses the freezing point, such as polyethylene glycol (PEG). The water and fluid are mixed in a reservoir (21), a small pump (22, 60) flows the mixture through coolant channels (28) in or adjacent water transport plates (29); heat of the catalytic reaction warms the water transport plates causing water to evaporate therefrom thereby cooling the stack. The PEG is non-volatile at stack operating temperature and does not evaporate; concentrated PEG is returned (33) to the reservoir (21). Water in the process air flow channels (41), including evaporated process water, is recovered in a condensation-rate-controlled (53, 54)) condenser (46) in communication (48) with the reservoir (21) for remixture with the concentrated PEG solution. Hydrophobic gas diffusion layers (72) shield the proton exchange membrane (70) from the PEG.

Abstract: A plurality of cooler plates (9) are disposed between fuel cells (8) in a stack (7) and have protrusions (12, 13) which include coolant inlet and outlet channels (15). The protrusions are surrounded by an elastomeric sealant material (35, 36) which forms a seal with the manifold structures (27, 28) to form coolant inlet and outlet manifolds (17, 20). The sealant material prevents coolant from entering fuel cells along the edges thereof, thereby preventing the fuel cells from being poisoned by the coolant. The coolant inlet and outlet manifold structures (27, 28) also define reactant gas manifolds (18, 21).

Abstract: A PEM fuel cell assembly includes cooler plates (10) with internal coolant manifolds (25) isolated from the cell stack assembly by an isolation gap (28) to minimize the risk of contamination of the cells by antifreeze. The internal coolant manifolds are formed by seal assemblies (24), each disposed between inlet or outlet openings (14, 15) in projections (16) of each cooler plate extending outwardly from the fuel cell planform (20) to provide a gap (28), which may be used as an air turn manifold. Flanges (40) with through holes (41) may receive tie rods to assist assembly of a fuel cell stack with the cooler plate.

Abstract: In a fuel cell stack (11a), a larger number of fuel cells (18–21, 33–36) are interposed between successive cooler plates (13–15) without creating excessively high temperatures in those fuel cells (33–36) which are remote from the cooler plates, by virtue of increased air flow in air flow field channels (30a) which are deeper in fuel cells (30–36) remote from the cooler plates, compared with the flow field channels (30, 30b) which are in fuel cells (18–21) adjacent to the cooler plates. The thickness of air flow field plates (29b) may be increased to accommodate the increased depth of the air flow channels (30a). Fuel cells (18a) adjacent the cooler plate may have air flow field channels (30b) which are more shallow than normal whereby increased air utilization therein will be balanced by decreased air utilization in the cells (33–36, 33a) having deeper air flow channels (30a); in this case, the channels (30a) may be normal or deeper than normal.