Static Pressure Drop Research Articles

Detection of damage of a filter by visualization of filtration process

This paper deals with testing of filters on the basis of visualization of filtration process. A filtration material can be damaged by flow of the filtered medium, high pressure drop and long-term adverse conditions. These negative effects can cause extensive damage of the filtration textile and filtration efficiency decreases. The filter can be also fractured during manufacturing, processing or by improper manipulation. A testing of a purposely damaged filtration textile is described in the article. Experiments were performed on the filtration setup which permits an optical entrance to the position where a sample of filter is placed. A laser sheet is directed into this place. Scattered light from seeding particles in front of and behind the filter is captured by a digital camera. Images from the camera are analyzed and the filtration efficiency versus time and also versus position can be obtained. Measuring chain including light scattering theory and measuring of light intensity by a digital camera are also discussed in the article.

Expert-Based-Computer Aided Design and Component Selection for Dust Collection Systems

Environmental regulations regarding industrial pollution are getting tougher to keep high air quality. The design of proper system to meet specific requirements relays on selection of different filtration components. Components are available in a wide range of designs to meet various requirements of air filtration level, quantity, and characteristics of the contaminants to be removed. An expert system package for the selection of dust collectors' components is developed. The developed package utilizes database as well as knowledge base to aid the selection process based on practice and past experience. Industrial case studies are demonstrated to test the developed package and compare its results against the current systems design. The developed package in one case study estimated a minimum air flow rate of 60000 m 3 /hr, which is 30% higher than the existing value and a static pressure drop due to ducts of about 1900 Pa which is 30 % lower than the current value leading to improved air quality. In another case study the package results indicated the need to minimize the value of air flow to be 2300 m 3 /hr, which is 50% lower than the current value and increase the external static pressure to 1700 Pa which is 70% higher than the existing design value leading to better filtration efficiency.

Thermal Performances in Ribbed Rectangular Convergent and Divergent Channels

The rectangular convergent/divergent channels with one sided ribbed surface only have the inclination angles of 0.72oand1.43o at which the ribbed wall is manufactured with a fixed rib height ( e) =10 mm and the ratio of rib spacing (p) to height ( e) =10. The comparison shows that among the four channels (Dho/Dhi =0.67, 0.86, 1.16, and1.49) the divergent channel of Dho/Dhi =1.49 has the highest thermal performance at the identical mass flow rate, and the divergent channel of Dho/Dhii =1.16 has the highest at the identical pumping power and static pressure drop.

Effect of divergence ratio on heat transfer and friction factor in the ribbed rectangular channel

The local heat transfer and pressure drop of turbulent flows developed in stationary ribbed rectangular divergent channels are experimentally investigated. The rectangular divergent channels with a one sided ribbed surface only have inclination angles of 0.72° and 1.43°. The ribbed wall is manufactured with a fixed rib height (e) of 10 mm and rib spacing (p) to height (e) ratio of 10. The measurement was conducted within a Reynolds number range of 15,000 to 89,000. The local heat transfer characteristics of the rectangular divergent channels are quite different from those of the square straight channels because of the streamwise flow deceleration. The thermal performances of the ribbed rectangular divergent channels are compared with those of the ribbed square straight channels under three constraints: identical mass flow rate, identical pumping power, and identical pressure drop. The comparison shows that between the two channels D1 (Dho/Dhi = 1.16) and D2 (Dho/Dhi = 1.49), the divergent channel D2 (Dho/Dhi = 1.49) has the higher thermal performance at identical mass flow rate, and the divergent channel D1 (Dho/Dhi = 1.16) has the higher thermal performance under the constraints of identical pumping power and static pressure drop.

Optimizing Structure about Strong Base ASP Flooding Molecule Weight Adjusting Mechanism

Daqing oilfield ASP flooding drive target gradually changes from the first reservoir to the second and third reservoir,which leads to the unequal of the reservoirs producing extent, and seriously affects the developing for ASP flooding molecule weight. On the basis of that, we optimum the Molecule Weight Adjusting Mechanism of low permeability reservoir, and use the method of control variables to change the nozzle angle of diffuser section, cylinder length, diffuser angle, nozzle angle to establish 81 models. At the same time, we simulate flow field characteristics of these models with the help of Fluent. Ultimately, the models of low pressure drop and high stick loss rate could be found. Through analyzing and contrasting large of models, we found that shrinkage angle is 30 degree models under the same pressure drop condition the stick loss rate relativity high. Simultaneously, these models are suitable for the field requirements, and can provide theoretical basis for molecular weight adjusting and optimizing structure.

Thermal management of a multiple mini-channel heat sink by the integration of a thermal responsive shape memory material

In this paper, a novel application of a thermo-responsive shape memory polymer (SMP) is proposed to smart-control the forced flow of water in a multi mini-channel heat sink. In particular, it is reported that millimeter-sized cylinders made of SMP could be used to smartly obstruct the fluid flow by adapting the flow cross section to the heat load to be removed. By integrating the sensing, the control and the actuation functions within a unique, millimeter-sized device, these micro-valves, unlike the traditional actuators normally used for flow control, could be easily embedded into small heat sinks, with significant space and energy saving, useful, in particular, in systems where several miniaturized components have to be cooled concurrently, such as the modern mainframes or the concentrated photovoltaic solar cells.Two possible configurations for the SMP were considered in this study: an “open” configuration, without any obstruction of the water flow free and an “obstructed” configuration, with the millimeter-sized cylinder partially occupying the mini-channel. A numerical, steady state analysis was carried out with water in single-phase forced convection, to determine the effect of these two states on the internal fluid flow characteristics under different conditions of heat flux and pressure drop and to evaluate the overall thermal behavior of the smart-controlled multiple mini-channel heat sink in terms of ability to control the temperature of the system and to reduce the energy consumption.

Improving Khangiran gas turbine efficiency by two standard and one novel inlet air cooling method

Turbine air inlet cooling is one of many available commercial methods for increasing the performance of a gas turbine. The method that has different configurations could be applied for nearly all gas turbines. This paper offers a comparison between two standard and one exquisite inlet air cooling method, which are used to improve the performance of a gas turbine located at the Khangiran refinery in Iran. These methods have been applied to one of the gas turbines located at the Khangiran refinery. Two common air-cooling methods are based on fogging systems and absorption chillers. The idea behind the novel method is to utilize the potential cooling capacity of the refinery natural gas pressure drop station. The research is part of a plenary program developed to enhance the efficiency of the gas turbine used at the Khangiran gas refinery. Considering the results, it is found that the new method is the most feasible in economic terms, so it has been recommended to be used for improving the performance of the Khangiran refinery gas turbines.

Heat Transfer and Friction in Rectangular Convergent and Divergent Channels with Ribs

The local heat transfer and pressure drop of developed turbulent flows in the stationary ribbed rectangular convergent/divergent channels have been investigated experimentally. The rectangular convergent/divergent channels with one-sided ribbed surface only have the inclination angles of 0.72 deg and 1.43 deg at which the ribbed wall is manufactured with a fixed rib height and the ratio of rib spacing () to height . The measurement was conducted within the range of Reynolds numbers from 15,000 to 89,000. Because of the streamwise flow acceleration or deceleration, the local heat transfer characteristics of the rectangular divergent/convergent channels are quite different from those of the square straight channel. Thermal performance of the ribbed rectangular divergent/convergent channels is compared with the ribbed square straight channel under three constraints: identical mass flow rate, identical pumping power, and identical pressure drop. The comparison shows that among the four channels of C1 (), C2 (), D1 (), and D2 (), the divergent channel of D2 has the highest thermal performance at the identical mass flow rate, and the divergent channel of D1 has the highest at the identical pumping power and static pressure drop.

Heat Transfer and Airflow Analysis in the Upper Part of Electrolytic Cells Based on CFD

A CFD model of the top part of an electrolytic cell used in the primary aluminum industry is presented. The model is used to determine average heat transfer coefficients on the main surfaces, under different ventilation rates. Correlations have been developed for the heat transfer coefficient and pressure drop versus pot draft condition. Nonuniformity of the heat transfer coefficient is studied. Finally, the relative importance of natural convection versus forced convection is revealed by the analysis. The knowledge developed in this article is useful for the heat transfer design and analysis of electrolytic cells, which is crucial in this industry.

Effect of free air inflow method on fine particle classification of gas-cyclone

The effect on particle separation performance using a free air inflow cyclone at the upper plate was examined by experiment and CFD simulation. The 50% cut size with the free air inflow cyclone is smaller than that without the free air inflow cyclone under the same pressure drop condition. The optimum flow ratio defined by the free air inflow rate to main flow rate is 0.4. The four slit inlet cyclone shows better particle separation performance compared to other types. For a flow ratio greater than 0.4, the 50% cut size increases again due to the decrease of the main flow rate.From the simulation results, the rotational and downward flow velocity in the upper cylindrical part with the free air inflow cyclone is greater than that without the free air inflow cyclone. In the case of the free air inflow cyclone, a particle trajectory simulation indicated that particles entering the cyclone tend to move to the circular wall region smoothly. The experimental and simulation results indicate higher particle separation performance for the free air inflow cyclone.

Perda de pressão estática em uma coluna de grãos de quinoa

Objetivou-se, neste trabalho, avaliar os efeitos do fluxo de ar sobre a queda da pressão estática em massa granular de quinoa, cultivar Real, com diferentes teores de impurezas; ajustar os modelos matemáticos aos dados experimentais obtidos e selecionar o modelo que melhor represente o fenômeno. Inicialmente, o produto estava isento de impurezas e com teor de água de 17% base seco. Foram feitas adições de impurezas nos percentuais de 1, 2, 3, 4 e 5. Utilizando-se um equipamento devidamente projetado e construído e fluxos de ar variando de 0,1 a 0,4 m³ s-1 m-2, foram determinadas as pressões estáticas da quinoa limpa e com impurezas. Os dados experimentais de perda de carga foram ajustados às equações comumente utilizadas para descrever o fenômeno. Os resultados permitiram concluir que: a) a pressão estática em uma coluna com grãos de quinoa aumenta com o incremento de fluxo de ar; b) O aumento do nível de impureza provocou redução da queda de pressão estática; c) As equações que melhor representam os dados experimentais da queda de pressão no interior do leito com grãos de quinoa, sem e com impurezas, foram as equações de Shedd e de Guimarães, respectivamente.

Numerical Simulation on Convective Heat Transfer in Microchannels of Two-Stage Y-Branch Bifurcation Structures

Convective heat transfer in microchannels of two-stage Y-branch bifurcation structures at different inlet velocities and branch angles were simulated, and the temperature, static pressure drop as well as the relationship between Reynolds Number (Re) and Nusselt Number (Nu) of fluid were compared and analyzed. The results indicate that the flow in microchannels with 30° branch angle has the minimum pressure drop for the velocities from 0.5 m/s to 2.5 m/s, while it comes at 60° for the velocities from 2.5 m/s to 3.5 m/s. It can also be found that the laminar-turbulent transition comes in advance compared with the common round channels. The critical Reynolds Number is found to be in 1997-2224, which is smaller than the known value of 2300. The Nu increases with increasing Re with a same trend for the different branch angles.

Microfluidics and Coagulation Biology

The study of blood ex vivo can occur in closed or open systems, with or without flow. Microfluidic devices, which constrain fluids to a small (typically submillimeter) scale, facilitate analysis of platelet function, coagulation biology, cellular biorheology, adhesion dynamics, and pharmacology and, as a result, can be an invaluable tool for clinical diagnostics. An experimental session can accommodate hundreds to thousands of unique clotting, or thrombotic, events. Using microfluidics, thrombotic events can be studied on defined surfaces of biopolymers, matrix proteins, and tissue factor, under constant flow rate or constant pressure drop conditions. Distinct shear rates can be generated on a device using a single perfusion pump. Microfluidics facilitated both the determination of intraluminal thrombus permeability and the discovery that platelet contractility can be activated by a sudden decrease in flow. Microfluidic devices are ideal for multicolor imaging of platelets, fibrin, and phosphatidylserine and provide a human blood analog to mouse injury models. Overall, microfluidic advances offer many opportunities for research, drug testing under relevant hemodynamic conditions, and clinical diagnostics.

A Modeling Study of the Role of Hydrothermal Processes in the Formation of Production Reservoirs in Volcanogenic Rocks

The paper describes the role of hydrothermal fluid circulation in the creation of porous reservoirs bounded by low–permeability layers in volcanogenic rocks, which can accumulate fluids of different origin and phase conditions. The Rogozhnikovsky oil-bearing volcanogenic production reservoir in west Siberia, hosted in Triassic rhyolite tuffs and lavas, and the Mutnovsky high temperature geothermal reservoir hosted in recent rhyolites and andesites, are considered as benchmark examples. TOUGHREACT modeling scenarios show that formation of production reservoirs due to hydrothermal circulation may result from chemical fluid-rock interactions. The model shows short- term pressure drop conditions in the early stage of circulation (favorable for fluid migration into the reservoir), followed by reservoir self-sealing at the last stage of hydrothermal circulation (favorable for fluid trapping and formation of mineral resource deposits).

Flow‐Field Designs of Bipolar Plates in PEM Fuel Cells: Theory and Applications

AbstractA generalized model developed by Wang was modified for flow field designs of the most common layout configurations with U‐type arrangement, including single serpentine, multiple serpentine, straight parallel, and interdigitated configurations. A direct and quantitative relationship was established among flow distribution, pressure drop, configurations, structures, and flow conditions. The model was used for a direct, systematic, and quantitative comparison of flow distributions and pressure drops among the most common layout configurations of interest. The straight parallel configuration had the lowest pressure drops but suffered the most possibility of the uneven flow distribution across the channels. The single serpentine had the best flow distribution but had the highest pressure drops. The flow distribution and the pressure drop in the multiple serpentine was between the straight parallel and the single serpentine. Finally, we suggested basic criteria of the flow field designs of bipolar plates for the industrial applications. This provides a practical guideline to evaluate how far a fuel cell is from design operating conditions, and measures how to improve flow distribution and pressure drop.

Producing Electrical Power in Addition of Heat in Natural Gas Pressure Drop Stations by ICE

Natural gas (NG) must be preheated before pressure reduction takes places at City Gate Stations (CGS). It ensures that gas remains above the hydrate-formation zone and dew point, so no pipeline blockage occurs. The preheating consumes a considerable amount of NG as fuel. In order to operate the CGS more efficiently, a new idea is proposed in this study. The idea is to utilize a Combined Heat and Power (CHP) system in which an Internal Combustion Engine (ICE) acts as a prime mover. The ICE is driving a generator in addition of providing heat for preheating NG. To show the advantage of the proposed system, Mashhad CGS has been chosen as a case study. Results show that a CHP system with two 2.8 MW ICEs is the most appropriate system. The system has the minimum fuel consumption and payback period. Based on the Iranian natural gas consumption of 377 × 106 (m3/day) and by assuming the similar conditions for the other CGSs in Iran, the total amount of extractable electrical power from the CHP systems is predicted to be nearly 91.5 MW. That is equivalent to 802.14 GW.hr/year in 2010 with a yearly benefit about 45 million dollars. According to average annual growing rate of 2.4% of gas consumption in Iran, the predictions are performed until 2035.

Structure of bubble holdups in a viscous slurry bubble column with low surface tension media

The structure of bubble holdups was investigated in a viscous slurry bubble column (0.105m ID×1.5m in height) with low surface tension media. It was found that the bubble holdup was composed of three kinds of holdups of bubbles such as large, small and fine bubbles. The individual holdups of three kinds of bubbles were measured by using the static pressure drop (SPD) and dynamic gas disengagement (DGD) methods simultaneously. Effects of gas velocity (UG), solid content in the slurry phase (CS) and viscosity (μL) and surface tension (σL) of liquid media on the holdups of three kinds of bubbles were determined.The bubble size demarcating the fine and small bubbles was found to be in the range of 2.5–3.0×10−3m within these experimental conditions. The total bubble holdup measured by means of DRP method was lower than that obtained by using the SPD method but higher than that using the DGD method. The holdup of fine bubbles increased with increasing UG, but decreased with increasing CS, σL of μL. The holdups of large, small and fine bubbles were well correlated in terms of operating conditions, respectively.

REALISTIC OPTIMIZATION OF WELL LENGTH FOR HORIZONTAL DRILLING

Evaluation of optimal drain-hole length for horizontal wells in the past, under the condition of pressure drop between the toe and heel of the well, has neglected some vital variables. These include drain hole diameter as a parameter in the objective function, diameter of vertical section for well deliverability consideration, and the composite pressure drop of the well as a system. The length was optimized based on net present value as the objective function (Case-1), flow rate (Case-2) and vertical well pressure drop with constant bottom-hole flowing pressure (Case-3). Optimizing drain-hole length requires more than adjusting variables that improve inflow performance to maximize return-on-investment. The optimization process demands the observation of spectrum of variables/events that are influenced by the dynamic nature of production as relates to fluid property and composite pressure of the entire well and reservoir system. A holistic approach, considering the inflow (entire horizontal section acting as oil inflow source) and vertical lift performance is paramount, focusing on flow resistivity in the drain hole.

Numerical analysis of the gas flow rate uniformity in the molten carbonate fuel cell (MCFC) under various conditions

The gas distribution uniformity between anode channels in an indirect internal reforming type molten carbonate fuel cell (MCFC) is a crucial design parameter that influences both the electrical performance and durability. In this paper, a three-dimensional computational fluid dynamics (CFD) analysis was performed to investigate flow characteristics in the anode channels and manifold where shape, pressure drop and channel temperature conditions were varied. The combined mesh consists of a hexahedral mesh in the channels and a polyhedral mesh in the manifold. Results indicate that rotational flow develops at the left and right sides of the anode manifold that induces an uneven mass flow rate distribution in the anode channels. Gas flow rate uniformity is enhanced as the depth of the manifold decreases, as the pressure drop in the anode channels increases and as the temperature difference between the indirect internal reforming (IIR) channels and anode channels decreases.

Evaluation of Stirling cooler system for cryogenic CO2 capture

In previous research, a cryogenic system based on Stirling coolers has been developed. In this work, the novel system was applied on CO2 capture from post-combustion flue gas and different process parameters (i.e. flow rate of feed gas, temperature of Stirling cooler and operating condition) were investigated to obtain the optimal performance (CO2 recovery and energy consumption). From the extensive experiments, it was concluded that the cryogenic system could realize CO2 capture without solvent and pressure drop condition. Meanwhile, the results showed that for post-combustion, the novel SC system can capture above 80% CO2 from flue gas with 3.4MJ/kg CO2.