Pressure drop axial distribution uniformity of the particle bed in the radial bed

2021 ◽  
Author(s):  
Tianhang Wu ◽  
Dewu Wang ◽  
Ruojin Wang ◽  
Bin Zhao ◽  
Meng Tang ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Axial Distribution ◽  
Distribution Uniformity ◽  
Particle Bed

Study on Filtration Performance of Rotary Disc Filter with Different Filter Discs

2012 ◽  
Vol 610-613 ◽  
pp. 1265-1269
Author(s):  
Jun Xia Hou ◽  
You Chen Zhang
Keyword(s):  
Pressure Drop ◽  
Filtration Efficiency ◽  
Field Configuration ◽  
Operation Condition ◽  
Know How ◽  
Velocity Magnitude ◽  
Filter Disc ◽  
Distribution Uniformity ◽  
The One ◽  
Triangular Type

Rotary disc filter is widely used in industrial water treatment. There are two methods to improving the filtration efficiency, which are the higher filtration velocity and lower filtration pressure drop; while the type of the filter disc plays an important role on the performance of filtration, In order to know how the filter disc affect performance of filtration, simplified model was used. On this basis, rectangular and triangular type was numerically simulated with the CFD software Fluent, DPM model, then the flow field configuration, velocity magnitude, pressure drop through the filter medium and the distribution of the particles were obtained. Then, the simulation results were analyzed and the conclusion was achieved that was under the same operation condition and porous parameters. Filter disc with a triangular type has greater advantages than the one with a rectangular type in the aspects of lower pressure drop, velocity distribution uniformity and particle distribution, which can highly improve the filtration efficiency.

scholarly journals Experimental Investigations of Cold Flow Mass Distribution and Pressure Drop Characteristics in a Structured Honeycomb Monolith Bed

2015 ◽  
Vol 9 (1) ◽  
pp. 302-311 ◽  
Author(s):  
Mingming Mao ◽  
Yongqi Liu ◽  
Ruixiang Liu ◽  
Bin Zheng ◽  
Jian Meng
Keyword(s):  
Pressure Drop ◽  
Mass Distribution ◽  
Total Pressure ◽  
Flow Resistance ◽  
Flow Reversal ◽  
Experimental Investigations ◽  
Test Rig ◽  
Cold Flow ◽  
Reactor Test ◽  
Distribution Uniformity

The thermal flow reversal reactor (TFRR) and catalytic flow reversal reactor (CFRR) can utilize the ventilation air methane (VAM) from coal mines effectively. The initial cold feed flow mass distribution uniformity in the monolith oxidation bed, the critical part of both reactors, has a great influence on the stability of methane oxidation process and conversation rate. So the emphases are put on the experimental investigations of the cold flow mechanics in the monolith bed based on a simplified reactor test rig. Firstly, the flow resistance coefficients of the monolith bed were calculated, and then the flow resistance mathematical model was built. It was found that the flow mass distribution uniformity was affected by the pressure drop distribution in the monolith bed, and obviously decreased with increasing inlet velocity. The pressure drop distribution was analyzed through a modified momentum equation. The total pressure loss in the lower header was evidently higher than that in the upper header or monolith bed. Additionally, the local losses at the inlet and outlet of the monolith bed were small, so they could be ignored. Finally, the formula of total pressure losses under different flow conditions was established based on the simplified reactor test rig.

Prediction of gas–solid bed hydrodynamics using an improved drag correlation for nonspherical particles

2015 ◽  
Vol 231 (10) ◽  
pp. 1826-1838 ◽  
Author(s):  
Md Rashedul H Sarker ◽  
ASM Raufur Chowdhury ◽  
Norman Love
Keyword(s):  
Pressure Drop ◽  
Power Plants ◽  
Packed Bed ◽  
Reynolds Numbers ◽  
Combined Cycle ◽  
Nonspherical Particles ◽  
Integrated Gasification Combined Cycle ◽  
Drag Measurement ◽  
Integrated Gasification ◽  
Particle Bed

Gas–solid beds are ubiquitous in industrial and energy production applications. Examples include fluidized beds, which are used in many systems such as in integrated gasification combined cycle power plants or in chemical looping systems. These examples and others involve complicated interactions between each phase of reactants in the system. The motivation of this work stems from the need for a better understanding of bed hydrodynamics in existing energy systems; results from this work can be used directly in software such as Fluent to more accurately predict flow behaviors of gas and solid phases. The experimental data are collected from two setups including an optically accessible drag measurement facility that was used to obtain the drag coefficient at various particle Reynolds numbers and a lab-scale gas–solid packed bed which was used to validate the computational correlation through pressure drop measurements across the packed bed. Results showed that the new correlation predicted drag coefficients as accurate as 10% and deviated by up to 15% for particles with sphericities less than 0.9. This is a significant improvement compared to existing correlations, which can deviate as much as 50% for the same range of tested values. Similar findings are observed when the drag correlation is implemented into Fluent. It was found that the model predicted pressure drop in a particle bed with nonspherical particles with an error as low as 5% and as high as 28% near the fluidization velocity.

scholarly journals Agglomeration of Particle Bed and Pressure Drop Variation in a Sinter Grate Furnace

1976 ◽  
Vol 13 (3) ◽  
pp. 121-126
Author(s):  
Mitsutaka KAWAMURA ◽  
Takeshi OHTAKE ◽  
Kunio UCHIDA ◽  
Shigeki TOYAMA
Keyword(s):  
Pressure Drop ◽  
Particle Bed

Preliminary Design of a Fuel Element With Divergent Hot Gas Channel In Particle Bed Reactor for Nuclear Thermal Propulsion

2021 ◽  
Author(s):  
Zhaoyu Liang ◽  
Yu Ji ◽  
Jun Sun ◽  
Chenrui Mao ◽  
Lei Shi
Keyword(s):  
Pressure Drop ◽  
Fuel Element ◽  
Specific Impulse ◽  
Flow Distribution ◽  
Momentum Equation ◽  
Heat Transfer Process ◽  
Maximum Temperature ◽  
Gas Channel ◽  
Hot Gas ◽  
Particle Bed

Abstract The nuclear thermal propulsion (NTP) system can shorten the travel time in deep space exploration and reduce the initial mass of the launch vehicle due to its superior characteristics including high specific impulse and large thrust. Particle bed reactor (PBR) is one of the most appropriate reactor concepts to equip the NTP systems. To make the best use of PBR, the thermal-hydraulic design of the fuel element should be carefully considered and a flow-power matching technology should be developed. In this paper, a novel design employing a divergent hot gas channel is proposed to achieve a uniform flow distribution with lower maximum temperature and pressure drop. Through the analysis of the 1D modified momentum equation in the inlet plenum and hot gas channel, the model of pressure drop is established. Then, the differential equation of the ideal cross-section of the hot gas channel is derived. At last, the flow and heat transfer process in the fuel element with divergent hot gas channel is simulated by using computational fluid dynamics (CFD) code, and the reduction of pressure drop and temperature verifies the theoretical model. This study shows that the proposed design of the divergent hot gas channel can provide a new idea for thermal-hydraulic optimization of the PBR fuel element.

New Cooling Scheme of First Wall in HCCB TBM and Related Performance Analysis

2013 ◽  
Author(s):  
Qijie Wang ◽  
Qixiang Cao ◽  
Zhou Zhao ◽  
Kaiming Feng
Keyword(s):  
Pressure Drop ◽  
Preliminary Analysis ◽  
First Wall ◽  
Radiation Load ◽  
Scheme Design ◽  
Nuclear Heat ◽  
Engineering Requirement ◽  
Distribution Uniformity ◽  
Related Stress ◽  
Stress Criteria

In the design and analysis for the ITER TBM, a key issue is the cooling of the First Wall. For safety, the First Wall FW must be designed to withstand the thermal radiation load from the plasma and the nuclear heat generated by nuclear reaction, and it should satisfy related stress criteria. For technology, it also should meet a pressure drop limits and other engineering requirement. The former cooling scheme design showed some shortcoming in temperature distribution uniformity and pressure drop, in order to improve it, a new cooling scheme has been designed and analyzed. The paper describes the detail of the new cooling scheme of FW, and a series related analysis was conducted to compare with former design. In the preliminary analysis, the new cooling scheme design showed much advantage to the former design. The working conditions of the analysis have been set to ITER design condition. The performances and the results obtained thermo-hydraulics and stress, are presented.

Spray irrigation on dairy pastures - efficient or not?

2006 ◽  
pp. 177-181
Author(s):  
S.M. Thomas ◽  
D. Bloomer ◽  
R.J. Martin ◽  
A. Horrocks
Keyword(s):  
Irrigation System ◽  
Groundwater Resources ◽  
Dairy Farmers ◽  
Large Variability ◽  
Irrigation Application ◽  
Irrigation Uniformity ◽  
Survey Results ◽  
Spray Irrigation ◽  
Use Efficiency ◽  
Distribution Uniformity

Applying water efficiently is increasingly important for dairy farmers and other users of surface and groundwater resources to maintain sustainable production. However, irrigation is rarely monitored. We used a questionnaire survey and measurements of five spray irrigation systems working in normal farm conditions to make observations on how efficiently irrigation is being managed. Survey results from 93 dairy farmers showed that, although the farmers believe they know how much water is being applied during irrigation, only 60% make measurements, and about 18% measure irrigation uniformity. Catch-can measurement of irrigation application depth for the different spray systems indicated large variability in application depths during irrigation, and field distribution uniformity ranged greatly between the different systems, decreasing in the order of centre pivots >travelling irrigators> K-line. Changes in irrigation system settings were sometimes made without considering application depths or uniformity. If our five case studies are typical, they may explain the large range of seasonal irrigation amounts recorded in the survey. We recommend that farmers monitor irrigation application depths and uniformity to help manage irrigation water efficiently and to help them estimate the value of irrigation to their enterprise. Keywords: distribution uniformity, water use efficiency, catch cans

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