Showing papers on "Diffuser (sewage) published in 2000"

An Analytical Solution of a Half‐Cell Model for PEM Fuel Cells

Abstract: A mathematical model for polymer electrolyte membrane (PEM) fuel cells is developed and rigorous analytical solutions of the model are obtained. The modeling domain consists of the cathode gas channel, gas diffuser, catalyst layer, and the membrane. To account for the composite structure of the gas diffuser and for its gradient in liquid water content, the gas diffuser is modeled as a series of parallel layers with different porosity and tortuosity. Starting from the oxygen transport equations and Ohm's law for proton migration, expressions for the oxygen mass fraction distribution in the gas channel, gas diffuser, and catalyst layer, and current density and membrane phase potential in the catalyst layer and membrane are derived. The solutions are presented in terms of the physical and thermodynamic parameters of the fuel cell. The polarization curve is expressed parametrically as a function of the surface overpotential. Expressions for cathode internal and overall effectiveness factors, active fraction of the catalyst layer, catalyst layer resistance, limiting current density, and the slope of the polarization curve are also presented. Due to the advantage of the closed-form solutions this model can he easily used as a diagnostic tool for a PEM fuel cell operating on H 2 and air.

Simulated neon light using led's

Abstract: A neon light is simulated using light emitting diodes as a light source. An elongated, translucent diffuser of circular cross-sections is mated with an elongated opaque tubular housing of constant cross-section with a lengthwise slot. The diffuser is held in longitudinally aligned abutment against the edges of the housing slot to form a chamber between the housing and the diffuser from which light may only be emitted through the diffuser. A plurality of light emitting diodes is aligned in a linear array in the chamber. The reflection and refraction of light by the tubular diffuser produces a neon-like glow or glare along the exposed surface of the diffuser. The housing has a maximum width not greater than the diameter of the diffuser, so that the housing is hidden behind the diffuser. The diodes may be electrically connected in patterns of alternating sequential activation to give a flashing, mono-chromatic effect and may be color coded according to the patterns of alternating sequential activation to give a flashing, color changing effect to the fixture. Preferably, the housing is sufficiently resiliently flexible to permit the diffuser to be disengaged from and reengaged with the housing so as to permit maintenance of the fixture without removal from its location. This LED simulation affords a durable, low voltage, low energy, non-gaseous, inexpensive, easy to install, easy to maintain, chromatically versatile, long life fixture which looks like neon light and demands the attention of the observer.

From a profiled diffuser to an optimized absorber

Abstract: The quadratic residue diffuser was originally designed for enhanced scattering. Subsequently, however, it has been found that these diffusers can also be designed to produce exceptional absorption. This paper looks into the absorption mechanism of the one-dimensional quadratic residue diffuser. A theory for enhanced absorption is presented. Corresponding experiments have also been done to verify the theory. The usefulness of a resistive layer at the well openings has been verified. A numerical optimization was performed to obtain a better depth sequence. The results clearly show that by arranging the depths of the wells properly in one period, the absorption is considerably better than that of a quadratic residue diffuser.

Non-metallic bioreactor and uses

Abstract: An autoclavable unicellular culture system comprising flexible, light transmitting walls, an internal oxygen diffuser (11) and a head plate (20) which has a plurality of aperture (19). The present invention also comprises a fish or shellfish rearing system incorporating the culture system.

Self cleaning filter

Abstract: A self cleaning filter which works in dead end mode consists of a plurality of membrane module placed in a tank of waste water with an air diffuser to bubble air up over the surface of the membrane, the filtered water permeates through the membranes and is led away and the air keeps the membrane surface clear.

Adjustable air diffuser and related methods

Abstract: Apparatus for a discharge vent on an air circulation system includes structures for controlling the direction and quantity of airflow. Filter elements may be provided to help reduce contaminants that might otherwise be discharged through the vent. Preferred methods for assembling and using the apparatus are disclosed.

Modeling the mixing of heated water discharged from a submerged multiport diffuser

Abstract: The mixing of heated water which is discharged from a submerged multiport diffuser was analyzed using the three-dimensional grid-based numerical model. The discharge momentum flux is properly incorporated into the model using the concept of a numerical slot diffuser, along with multi-jet theory. Plane or line patch was introduced to impose discharge momentum flux which plays an important role in mixing of the thermal effluent in the near field. The laboratory experimental work has been conducted to investigate mixing characteristics of the coflowing diffuser. A comparison of model simulations with laboratory experiments show that the proposed model properly simulates the shapes of thermal plumes and the distributions of excess temperature. The proposed model properly simulates velocity induced by a coflowing diffuser in proximity to a shoreline boundary, and this is confirmed by Lee's experiments.

Oil lamp with ceramic diffuser

Abstract: An oil lamp emitting a fragrance has a container including a fuel oil and a fragrance and a wick for drawing fuel oil out of the container for burning. A separate ceramic diffuser is positioned adjacent the top of the lamp, near the combustion end of the wick. The ceramic diffuser receives a combination of fuel oil and fragrance and diffuses the fragrance into the air. The diffusion is increased when the lamp is lighted. The lamp provides a scent to the surrounding air which is similar in strength to fragranced wax candles.

Flow diffuser to be used in electro-chemical plating system and method

Abstract: An apparatus comprising an electrolyte cell, an anode, and a porous rigid diffuser. The electrolyte cell is configured to receive a substrate to have a metal film deposited thereon. An anode is contained within the electrolyte cell. A porous rigid diffuser is connected to the electrolyte cell and extends across the electrolyte cell. The diffuser is positioned between a location that the substrate is to be positioned when the metal film is deposited thereon and the anode.

Portable griddle stove with dual cooking surfaces

Abstract: A portable griddle stove has two non-stick cooking surfaces, either of which can withstand being on the underside of the cooking surface in use and the heat applied to the underside surface. A heat shield and heat diffuser control the temperature applied to the underside of the cooking surface by providing radiant heat to the center portion of the cooking surface and cooling the combustion gas diffused to the perimeter of the cooking surface. Secondary air provided through openings in case the and heat shield assist in cooling the combustion gas.

The design and analysis of pipe diffusers for centrifugal compressors

Abstract: The geometry of the region between the impeller tip and diffuser throat is accepted as being very influential, little understood and crucial to the performance of centrifugal compressors. T...

Springbox for water remediation

Abstract: A method and apparatus for treatment of contaminated water is described. The apparatus includes a container divided into at least two chambers by a wall that partially separates the two chambers, the containing having an inlet at a first one of the chambers and an outlet at a second one of the chambers. The apparatus has a first microporous diffuser disposed in a first one of the chambers of the container and arranged to receive a decontaminating gaseous agent and a second microporous diffuser disposed in a second one of the chambers and arranged to receive air. Additionally, special microporous diffusers are described.

Diffuser for a wind turbine

Abstract: A Diffuser Augmented Wind Turbine has a nacelle (15) centrally supporting two or more rotor blades (not shown), the rotor blades being surrounded by a primary diffuser section (10) of substantially aerofoil shape when viewed in section and a much thinner aerofoil-like secondary diffuser (11) extending rearwardly from the trailing edge of the primary diffuser, wherein one or more slots (13) are arranged circumferentially around the diffuser assembly (10, 11) allowing the injection of air from the exterior surface into interior surface of the diffuser assembly (10, 11), the slots (13) further differentiating the primary and secondary diffuser sections (10, 11).

Porous air diffuser for treatment of liquids

Abstract: A porous diffuser is disclosed. The porous diffuser can be in the form of a hose or other structure, the wall of the hose or structure having many small and irregularly shaped channels and pores that allow gas to seep out of the hose into the liquid. The diffuser receives air, oxygen or other gasses, and releases these gasses as bubbles into the liquid through the channels and pores. As the bubbles migrate in the liquid, they diffuse their gas into the liquid, as well a mix the liquid. The porous diffuser also provides for convenient methods to purge the system of liquid that has seeped into the diffuser during normal use and to retrieve the diffuser when maintenance, repair or replacement is required. An anchoring system can be incorporated with the porous diffuser to overcome buoyancy problems associated with gas in a liquid environment which can reduce or prevent proper gas distribution.

Water circulation apparatus system and method

Abstract: The floating water circulation apparatus (10) is equipped with an impeller (18) that is larger than and tightly fitted over the top of the draft tube (22) through which the water from the pond or reservoir is drawn. The water drawn up and directed outwardly over a large diffuser plate (20) that is centrally located within the invention. The outer edge of the diffuser plate (20) is equipped with a laminar flow diffuser lip (21) which is specifically designed to inhibit the passage of water from the diffuser plate (20) to the open water as little as possible. Addifionally, a means of providing a floating water circulation apparatus (10) with the ability to operate effectively in weather conditions in which a layer of ice is likely to form over the diffusor plate (20) of the apparatus in the nighttime hours is provided. Finally, the present invention is equipped with an anchoring device that is designed in a manner that allows for its use in a body of water that is equipped with an impermeable liner.

Gas diffuser for aeration vessel of membrane assembly

Abstract: The invention concerns a gas diffuser constructed and arranged to disperse gas into a aeration vessel of a water treatment assembly from a blower. The gas diffuser includes main pipes, branch pipes extending between the main pipes and containing gas discharge ports, wherein the branch pipes have a smaller cross-sectional area than the cross-sectional area of the main pipes. The gas discharge ports are further sized, constructed and arranged to reduce the possibility or likelihood of sludge from blocking the ports or entering the branch pipes. This object is achieved either by placement of the ports on the bottom sides of the branch pipes or, alternatively, by construction of the ports to include conduit members, themselves having an arrangement of openings or coverings to prevent or reduce the likelihood of sludge from blocking the ports or entering the branch pipes.

Concentric air diffuser

Abstract: A concentric air diffuser for use with climate control systems to direct air to desired locations within the interior of a building and return air to the system includes a perforated plate between a supply inlet and supply vents The perforated plate assists in balancing air flow out of the vents Additionally, a baffle plate is located along the portion of the perforated plate below the supply inlet to assist in distributing air throughout the diffuser housing prior to allowing the air to flow through the clear area portion of the perforated plate and out through the vents

Reaction chamber for an epitaxial reactor

Abstract: Reaction chamer (10) for an epitaxial reactor comprising a belljar (14) made of insulating, transparent and chemically resistant material, a susceptor (24) provided with disk-shaped cavities (34a-n) for receiving wafers (36a-n) of material to be treated and having an insulating and chemically resistant plate (40) arranged above it, and a diffuser (54) consisting of a plurality of outlet pipes (106a-f) mounted on a cap (52) fixed to an upper opening (50) of the belljar (14).

Buoyant media filter with diffuser

Abstract: A water filtration system has a tank partially filled with a floating bead filtration media. A cylindrical diffuser is disposed in the tank and extends from the upper portion to the lower portion thereof. The diffuser in internally partitioned into a lower chamber and an upper chamber and each chamber has slots that communicate with the tank. An supply conduit delivers soiled water from a pond to the lower chamber of the diffuser. The soiled water flows through the openings in the lower chamber and into the tank, upwardly through the filtration media where it is filtered, and into the upper chamber through the openings formed therein. An return conduit delivers filtered water from the upper chamber of the diffuser back to the pond.

Metered material dispenser

Abstract: A dispenser is provided for sprinkling a preset quantity of granulated material, such as table salt. The dispenser comprises a granulated material reservoir, an enclosure, a metering cup, a cap, a collector and a diffuser. The reservoir has a side, a top and a bottom wall. The enclosure encases the reservoir side wall and is closed at one end by a cap adjacent to the reservoir bottom wall. The metering cup is positioned in the cap and an opening in the reservoir bottom wall communicates with and fills the metering cup. A collector is positioned adjacent to the top wall of the reservoir. A passageway formed between the reservoir sidewall and the enclosure communicates with the metering cup and collector. The diffuser is positioned adjacent to an opening in the collector and opposite the collector. When the dispenser is in the upright position, granulated material from the reservoir fills the metering cup. When the dispenser is inverted, the granulated material flows from the metering cup through the passageway to the collector. The collector directs the granulated material to the diffuser that sprinkles the granulated material over a desired area.

Method an apparatus for heating thin plastic sheet

Abstract: A method and apparatus heats a thin sheet of material prior to subjecting the sheet to a process for forming the sheet into a desired shape, such as by vacuum forming. The sheet is supported in a generally horizontal manner during transport through the apparatus, for example on a pair of conveyor chains or belts which carry and provide support to the longitudinal edges of the sheet by gripping same. The sheet is heated from above and below by heating elements and a diffuser plate is located between the upper and lower heating elements, and beneath the downwardly facing side of the sheet. The diffuser plate permits air flow therethrough from an air source and forms a film of heated air adjacent the downwardly facing side of the sheet to support the sheet and prevent excessive downward sagging thereof during heating thereof.

Hollow monolithic ceramic gas diffuser and method of manufacture

Abstract: A ceramic diffuser assembly containing a diffuser fitting integrally connected to a diffuser body, Wwhen the ceramic diffuser assembly is supplied with oxygen-containing gas at a pressure of from about 0.2 to about 80 pounds per square inch, the gas flows through it at a rate of from about 0.5 to about 50 standard cubic feet per minute, the plot of gas pressure versus flow rate is a straight line, and the slope of said straight line is from about 0.1 to about 4. The diffuser body contains a first ceramic layer, a second ceramic layer, and a recessed area disposed between the first and second layers.

Aerobic treatment tank

Abstract: PROBLEM TO BE SOLVED: To provide an aerobic treatment tank capable of being prevented from the lowering of treatment capacity accompanied by the deposition of a carrier. SOLUTION: Water 14 to be treated is stored in the aerobic treatment tank 10 and a carrier 16 having microorganisms fixed thereon is charged in the water 14 to be treated. The interior of the treatment tank 10 is divided into compartments 10A and 10B by a flow guide plate 22 and an air diffuser 24 is arranged in the compartment 10A. A rectifying plate 28 is provided under the air diffuser 24 and the deviation of the circulating flow of water to be treated is prevented by the rectifying plate 28.

Fuel air premixer having a diffuser assembly and upstream fuel manifold rings

Abstract: A premixer for an industrial type gas turbine engine wherein the premixer includes a diffuser ring assembly made up of annular concentric rings and upstream of the diffuser ring assembly in the airflow path is a corresponding fuel manifold ring assembly, each ring in the manifold ring assembly corresponding to a passageway formed between the diffuser rings, and each manifold ring includes a downstream channel for feeding the fuel to the air as the air passes by the ring.