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Showing papers on "Diffuser (sewage) published in 2017"


Journal ArticleDOI
TL;DR: In this article, the authors demonstrated the performance of an integrated bio-cathode osmotic microbial fuel cell (OsMFC) capable of recovering electricity and water using forward osmosis in a double-chambered baffled channel reactor.

45 citations


Journal ArticleDOI
TL;DR: Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3mg/L, and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions, as indicated by the oxygen half-saturation constant and nitrification ability.
Abstract: In wastewater treatment plants (WWTPs) using the activated sludge process, two methods are widely used to improve aeration efficiency - use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics (such as concentrations of mixed liquor suspended solids (MLSS) and microbial communities) and operating conditions (such as air flow rate and operational dissolved oxygen (DO) concentrations). Moreover, operational DO is closely linked to effluent quality. This study, which is in reference to WWTP discharge class A Chinese standard effluent criteria, determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3mg/L, and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions, as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model (determined using different air flow rate (Q'air) and mixed liquor volatile suspended solids (MLVSS) values), theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however, operating at low DO and low MLVSS could significantly reduce energy consumption. Finally, a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed, which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology.

42 citations


Journal ArticleDOI
TL;DR: In this article, the emission of the bioaerosols from an urban wastewater treatment plant in spring and summer in different locations and downwind of the plant adopting an extended mechanical aeration system was investigated.
Abstract: Wastewater that enters wastewater treatment plants contains lots of pathogenic and nonpathogenic microorganisms which can become bioaerosols during treatment processes and pose health hazard to workers and nearby residents The emission of the bioaerosols from an urban wastewater treatment plant in spring and summer in different locations and downwind of the plant adopting an extended mechanical aeration system was investigated Samples of bacteria and fungi were collected within 6 months at 10 selected points by an Anderson one-stage impactor The highest concentration of bacteria (mean 1373 CFU/m3, 741–2817 CFU/m3) and fungi (mean 1384 CFU/m3, 212–1610 CFU/m3) was found in downwind of the aeration basins Statistical analysis showed a significant relationship between concentration of bacterial bioaerosols at downwind side of the aeration basins and wind speed (p value <005) and temperature (p value <005) Also, in the spring and summer, between the number of bacteria and fungi inside the plant and outside the plant (downwind) a significant correlation was observed (p value ≤005) The concentrations of bacteria at a distance of 500 m downwind were much higher than those at the background (upwind) point in spring and summer The processes of wastewater treatment especially using mechanical equipment to create turbulence can be considered as a major source of spreading airborne microorganisms to ambient air of wastewater treatment plants, and the bioaerosols can be dispersed to downwind distances affecting the nearby neighboring Therefore, in order to decrease the bioaerosols emission, doing some course of actions such as covering the surface of aeration basins, changing the aeration methods and aeration equipment (e g using diffuser aerator) may be effective

35 citations


Journal ArticleDOI
TL;DR: This research systematically studied the behavior of aeration diffuser efficiency over time, and its relation to the energy usage per diffuser, to help utilities gain more insight into process mechanisms and design better energy efficiency strategies at existing facilities to reduce energy consumption.

30 citations


Journal ArticleDOI
01 Apr 2017
TL;DR: In this paper, a vaned diffuser optimization was proposed to improve the efficiency of a high-power centrifugal pump by solving the three-dimensional Reynolds-averaged Navier-Stokes equations with a shear stress transport turbulence model.
Abstract: The diffuser plays a significant role in the performance of a centrifugal pump, especially for a high-power centrifugal pump. Therefore, to improve the efficiency of a centrifugal pump, optimization of a vaned diffuser is proposed in this work. The steady simulations were carried out by solving the three-dimensional Reynolds-averaged Navier–Stokes equations with a shear stress transport turbulence model. The numerical head and efficiency were validated by the experimental results of the original pump, and the results show that the predicted performance of the numerical simulation is in good agreement with the experimental results. Four design variables of the diffuser including the diffuser inlet diameter D3, diffuser inlet width b3, diffuser inlet angle α3, and diffuser wrap angle ϕ2 were selected to design by the CFturbo 9.0. The diffusers under test were selected using the orthogonal experiment method using the orthogonal array L16(44). The effect of the four variables on the pump’s efficiency was inve...

28 citations


Journal ArticleDOI
TL;DR: A comprehensive dynamic aeration system model has been developed that captures both air supply and demand and enables engineers to trouble-shoot the entire aeration systems including process, equipment and controls.

27 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of the angle and length of the diffuser, and wall temperature have been explored on heat and fluid flow, methanol conversion, hydrogen production, carbon monoxide reduction, as well as estimated net power of fuel cell with the same catalyst volume and entrance condition.

18 citations



Patent
30 May 2017
TL;DR: In this article, a heat diffuser (100) for use with an electrically-operated aerosol-generating device (300) was provided, with the diffuser being configured to be removably couplable to the aerosol generator.
Abstract: There is provided a heat diffuser (100) for use with an electrically-operated aerosol-generating device (300), the heat diffuser (100) being configured to be removably couplable to the aerosol-generating device (300). The heat diffuser (100) includes a non-combustible porous body (110) for absorbing heat from an electric heating element (330). The porous body (110) is formed from a heat storage material such that, in use, air drawn through the porous body (110) is heated by the heat absorbed by and stored in the porous body (110). A heated aerosol- generating article (400) and an aerosol-generating system, both comprising the heat diffuser (100), are also provided.

15 citations


Journal ArticleDOI
TL;DR: In this article, the authors employed an air curtain to prevent moisture entering into a purged front-opening unified-pod (FOUP) when its door is opened in a minienvironment.

14 citations



Journal ArticleDOI
TL;DR: In this article, the authors found that specific surface area of bubbles, aeration intensity, and diffuser submerged depth had a positive effect on the oxygen transfer coefficient (k L a ), while some mixed liquor characteristics such as the mixed liquor suspended solids (MLSS) concentration and apparent viscosity exerted negative function on it.

Patent
15 Dec 2017
TL;DR: In this article, an oral cleansing device with illumination features is described. But the device does not have an external lighting array and the illumination is transmitted to an exterior of the housing by traveling around the blocking member and through the diffuser.
Abstract: The present disclosure relates to an oral cleansing device with illumination features. In one example, the device includes a housing including an aperture, such as a button aperture, defined therethrough, a diffuser connected to the housing and configured to span over the aperture. The device also includes a blocking member positioned over a portion of the diffuser and connected thereto and a lighting array received within the housing and at least partially aligned with the blocking member such that light emitted from the lighting array is transmitted to an exterior of the housing by traveling around the blocking member and through the diffuser.



Patent
27 Apr 2017
TL;DR: A rear-end diffuser arrangement for a motor vehicle has at least one flap (16, 18, 32) mounted on a body part of the motor vehicle (2) so as to be movable from a retracted state into a deployed state and vice versa as mentioned in this paper.
Abstract: A rear-end diffuser arrangement for a motor vehicle has at least one flap (16, 18; 32) mounted on a body part (10) of the motor vehicle (2) so as to be movable by at least one drive device (38) The flap (16, 18; 32) is movable from a retracted state into a deployed state and vice versa The at least one flap (16, 18; 32) has a concavely curved surface facing toward the vehicle rear end (20)

Patent
30 May 2017
TL;DR: In this article, the authors provided a heated aerosol-generating article (100) for use with an electrically-operated aerosol generating device (200), the article having a mouth end (170) and a distal end (160) upstream from the mouth end.
Abstract: There is provided a heated aerosol-generating article (100) for use with an electrically-operated aerosol-generating device (200), the article having a mouth end (170) and a distal end (160) upstream from the mouth end. The article includes a heat diffuser (110) at the distal end of the article, and an aerosol-forming substrate (126) downstream of the heat diffuser. The heat diffuser comprises a non-combustible porous body (112) for absorbing heat from an electric heating element such that, in use, air drawn through the aerosol-generating article from the distal end to the mouth end is heated by the heat absorbed in the porous body.

Journal ArticleDOI
TL;DR: No significant impact of the RF treatment in preventing a decrease in alpha-fouling of the fine pore diffusers, over time in operation was observed, and reverse flexing potentially saves blower energy.

Proceedings ArticleDOI
05 Jun 2017
TL;DR: In this article, a spanwise array of oscillating jets that are placed just upstream of the separation domain is used to alter the spacing and diminishes the strength of the base flow streamwise vortices.
Abstract: Losses and flow distortions in a supersonic-inlet aggressive offset diffuser (Mthroat < 0.64) that are induced by closed, separated flow domains on the diffuser’s concave surfaces and by pairs of dynamically coupled counter-rotating streamwise vortices are mitigated using fluidic actuation. While pressure recovery is primarily limited by the separation in each of the diffuser’s turns, the distortion is governed by counter-rotating streamwise vortices that advect low-momentum fluid from the wall region into the core flow. The present investigations have shown that the secondary vortices are engendered by concentrations of streamwise vorticity that form in the outboard segments of the separated flow domains. Therefore, fluidic control of the scale and topology of the trapped vorticity within the internally-separated flow can be leveraged to control the structure and strength of the ensuing secondary vortices and thereby significantly reduce flow distortion and losses. In the present investigations, fluidic control is effected by a spanwise array of oscillating jets that are placed just upstream of the separation domain. The actuation alters the spacing and diminishes the strength of the base flow streamwise vortices by forming and adjoining streamwise vorticity concentrations of opposite sense. The spanwise distribution of the actuator array can be optimized to reduce the average circumferential distortion by as much as 60% at actuation to diffuser mass flow rate ratio of 0.4%.


Patent
09 May 2017
TL;DR: A sleep and wake environment apparatus includes an aromatherapy diffuser, a speaker, a light source, a clock, and a user interface with controls and a display as discussed by the authors, which can be controlled automatically and without contemporaneous user input.
Abstract: A sleep and wake environment apparatus includes an aromatherapy diffuser; a speaker; a light source; a clock; and a user interface with controls and a display. Each of these elements are in communication with a control computing device configured to control the aromatherapy diffuser, the speaker, the light source, and the clock automatically and without contemporaneous user input.

Patent
27 May 2017
TL;DR: In this article, a water treatment device of the present invention uses an air diffuser equipped with a branched pipe, in which the pipe has a turn section at which the air diffusers can be divided.
Abstract: The present invention addresses the problem of providing a water treatment device that is easy to maintain. A water treatment device of the present invention uses an air diffuser equipped with a branched pipe. Moreover, a water treatment device of the present invention uses an air diffuser in which the branched pipe has a turn section at which the air diffuser can be divided.

Journal ArticleDOI
TL;DR: In this article, a transient liquid crystal measurement technique has been used to investigate the performance of laidback hole and laidback fan-shaped hole film cooling under small and large blowing ratios, respectively.
Abstract: Abstract Film cooling performances of laidback hole and laidback fan-shaped hole have been investigated using transient liquid crystal measurement technique. For film cooling of laidback hole, the increase of inclination angle reduces the film cooling effectiveness under small blowing ratio, while produces better film coverage and higher film cooling effectiveness under larger blowing ratios. Heat transfer coefficient is higher in the upstream region of laidback hole film cooling with large inclination angle, while laidback hole with small inclination angle has relatively higher heat transfer coefficient in the downstream region. The increase of inclination angle reduces the film cooling effectiveness and heat transfer coefficient of laidback fan-shaped hole film cooling, especially in the upstream region. Increase of inclination angle is beneficial to the thermal protection of laidback hole film cooling under large blowing ratio. Film hole with large inclination angle has larger discharge coefficient due to smaller aerodynamic loss in the hole.

Patent
10 Aug 2017
TL;DR: A dual-chamber ultrasonic essential oil diffuser or nebulizer as mentioned in this paper is a diffuser having a reservoir or first chamber specifically for distilled water, a second air transfer chamber having a replaceable aroma cartridge and the diffuser being capable of mixing the nebulized water mist and essential oil aroma away from the transducer.
Abstract: A dual chamber ultrasonic essential oil diffuser or nebulizer or more specifically to a diffuser having a reservoir or first chamber specifically for distilled water, a second air transfer chamber having a replaceable aroma cartridge and the diffuser being capable of mixing the nebulized water mist and essential oil aroma away from the transducer.


Journal ArticleDOI
TL;DR: Multiport diffusers are used in many environmental applications to distribute a discharge flow uniformly through a number of jet nozzles into the same or another fluid as mentioned in this paper, such as water, air, or soil.
Abstract: Multiport diffusers are used in many environmental applications to distribute a discharge flow uniformly through a number of jet nozzles into the same or another fluid. For example, a sewag...

Journal ArticleDOI
TL;DR: Any changes in terms of oxygen transfer parameters (KLa and SOTE%) were specifically founded by causing to the repeated on/off switching of diffuser membranes in the intermittent aeration process of the urban wastewater treatments.

Patent
17 Aug 2017
TL;DR: In this paper, a diffuser plate where a plurality of microlenses are placed on a principal surface, wherein a phase difference generation part is inserted between the plurality of macrolenses and the principal surface is presented.
Abstract: The present invention provides a diffuser plate and a method for producing a diffuser plate that can improve variations in luminance of transmitted light or reflected light in a simple structure and that enable easy design and production. The diffuser plate according to the present invention is a diffuser plate where a plurality of microlenses are placed on a principal surface, wherein a phase difference generation part is inserted between the plurality of microlenses and the principal surface, the plurality of microlenses have two or more types of lens shapes, and the number of microlenses having the two or more types of lens shapes is determined so that a quantity ratio of the two or more types of lens shapes is a specific value, each of the lens shape types is selected corresponding to each of coordinates on the principal surface in which centers of undersurfaces of the plurality of microlenses are placed, and an angle range in which the diffuse light intensity is substantially uniform is in a range of +10% to −10% of a desired angle range.

Patent
Tomoyoshi Koyama1, Fukuda Tetsuya1
24 Aug 2017
TL;DR: In this article, a fuel gas diffuser is accommodated in an attachment hole of a body and an injector is provided upstream of the diffuser through an attachment, where a vibration absorption member made of elastic material is provided between a proximal end of a large diameter portion of this diffuser and a distal end of the main body in the attachment.
Abstract: In a fuel gas circulation apparatus, a diffuser is accommodated in an attachment hole of a body. An injector is provided upstream of the diffuser through an attachment. A vibration absorption member made of elastic material is provided between a proximal end of a large diameter portion of this diffuser and a distal end of a main body in the attachment, and a ring member is provided adjacent to the vibration absorption member.

Journal ArticleDOI
30 Nov 2017
TL;DR: In this article, a 5-blade louver face diffuser with 60° blade angle and horizontal lip was compared with a diffuser model with 45° and 65° blade angles with horizontal lip.
Abstract: The objective of the present work is to investigate the airflow characteristics inside a room through a 5-blade square louver face ceiling air diffuser using CFD to improve occupant’s thermal comfort. Several blades angles (45°, 60° and 65°) and lip angles (0°, 5°, 10°, and 15°) were installed inside the room model. The realizable k–ε turbulence model was used to simulate all the 3D cases. In the paper, the results of 5blade louver face diffuser with 60° blade angle and horizontal lip are compared with 5-blade louver face diffuser with 45° and 65° blade angles with horizontal lip. Then, the effect of lip angle is investigated and compared with the results from a diffuser with a 60° and horizontal lip. The results showed that the diffuser with a 65° blade angle provides jet air velocity higher than 60° beside air patterns cling with room ceiling, which enhances the surface (Coanda) effect and provides lower temperature gradients than 60°. Therefore, it is suitable to install in larger spaces in order to reduce drafts on space occupants and reduce installation costs. On the other hand, the results indicated that the diffuser model with a 45° blade angle and 0° lip angle provides cone-shaped air patterns without any being attached to the room ceiling, therefore this type is preferable for installation in rooms with larger height or inside areas that require relatively low noise levels. Moreover, increasing the diffuser lip angle to 15° allows air patterns relatively to leave the room ceiling, and reach thermal comfort conditions without draft faster than the 0° lip angle.