scholarly journals Development of a Novel Shaft Dryer for Coal-Based Green Needle Coke Drying Process

2019 ◽  
Vol 9 (16) ◽  
pp. 3301
Author(s):  
Guowei Xie ◽  
Xinxin Zhang ◽  
Jiuju Cai ◽  
Wenqiang Sun ◽  
Ketao Zhang ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Moisture Content ◽  
Experimental Result ◽  
Vertex Angle ◽  
Needle Coke ◽  
Pressure Drops ◽  
Green Coke ◽  
Rotary Speed ◽  
Area Occupation ◽  
Average Vertex

The industry of coal-based green needle coke develops rapidly in recent years. The green coke produced by the delayed coking process usually has a moisture content of 10%–25%, which damages the calcining kiln and needle coke quality. A standing dehydration tank is currently used to reduce the moisture content of green coke. However, this process has several weaknesses such as unstable operation, large land area occupation, and low productivity. To solve this issue, a novel drying system with a shaft dryer proposed in this work is suitable for green coke drying. Moreover, the performances of the green coke are investigated to design the proposed shaft dryer. The experimental result shows that the average vertex angle of the pile of green cokes is 109.2°. The pressure drop of the dryer increases linearly with the green coke bed height, and the green coke with a larger size has a smaller pressure drop. The specific pressure drops are 5714, 5554, 5354, and 5114 Pa/m, with median green coke sizes of 26.85, 29.00, 30.45, and 31.80 mm, respectively. Tooth spacing is another important parameter which influences the mass of green coke leakage. The optimal tooth spacing and rotary speed of the rollers are determined by the required production yield.

scholarly journals Prediction of pressure drop through packed beds of granular materials: influence of moisture reduction and air velocity

2019 ◽  
Vol 22 ◽  
Author(s):  
Heitor Otacílio Nogueira Altino ◽  
Maria do Carmo Ferreira
Keyword(s):  
Energy Consumption ◽  
Pressure Drop ◽  
Moisture Content ◽  
Empirical Equations ◽  
Packed Beds ◽  
Moisture Removal ◽  
Air Velocity ◽  
Pressure Drops ◽  
Moisture Contents ◽  
Forchheimer’S Equation

Abstract The influence of the moisture content of the solids on the pressure drop through packed beds of soy, barley, lentils and oats was investigated. The properties of the grains and the packed beds were determined varying the moisture contents of the solids between the equilibrium moisture content and 0.24 g g-1 (mass of water per mass of dry solid). The pressure drops were measured as a function of the aeration velocity under different moisture contents of the solids. It was observed that a reduction in the moisture content caused a decrease in the particle dimensions but did not affect their shape. Due to the reduction in size caused by the moisture removal, the packed beds become denser and less permeable to the airflow, resulting in an increase in the pressure drop. In the moisture range investigated, the pressure drops increased by more than 39% for lentils, soy and barley, and by about 24% for oats, indicating that the energy consumption during aeration could rise significantly. The parameters of the Forchheimer’s equation were modified to take into account the influence of the moisture content of the solids on the pressure drops. For each particle, empirical equations were proposed and shown to be adequate to accurately predict the pressure drop of the packed beds as a function of the moisture content and aeration velocity.

Experimental Study on the Effect of Moisture Content on Hysteretic Behavior of Reinforced Concrete Columns

2018 ◽  
Vol 12 (1) ◽  
pp. 47-61
Author(s):  
Wenjuan Lv ◽  
Baodong Liu ◽  
Ming Li ◽  
Lin Li ◽  
Pengyuan Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Moisture Content ◽  
Early Stage ◽  
Damping Ratio ◽  
Concrete Columns ◽  
Hysteretic Behavior ◽  
Cyclic Test ◽  
Experimental Result ◽  
Reinforced Concrete Columns

Background: For reinforced concrete structures under different humid conditions, the mechanical properties of concrete are significantly affected by the moisture content, which may result in a great change of the functional performance and bearing capacity. Objective: This paper presents an experiment to investigate the influence of the moisture content on the dynamic characteristics and hysteretic behavior of reinforced concrete column. Results: The results show that the natural frequency of reinforced concrete columns increases quickly at an early stage of immersion, but there is little change when the columns are close to saturation; the difference between the natural frequencies before and after cyclic test grows as the moisture content rises. The damping ratio slightly decreases first and then increases with the increase of moisture content; the damping ratio after the cyclic test is larger than before the test due to the development of the micro-cracks. Conclusion: The trend of energy dissipation is on the rise with increasing moisture content, although at an early stage, it decreases slightly. According to the experimental result, a formula for the moisture content on the average energy dissipation of reinforced concrete columns is proposed.

Experimental and Computational Analyses of Pressure Differentials in Flexible Ducts With Different Bent Angles

2007 ◽  
Author(s):  
Ray R. Taghavi ◽  
Wonjin Jin ◽  
Mario A. Medina
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Complex Geometry ◽  
Analysis Data ◽  
Secondary Flows ◽  
Low Flow ◽  
Pressure Drops ◽  
Pressure Distributions ◽  
Geometrical Effects ◽  
Cfd Analyses

A set of experimental analyses was conducted to determine static pressure drops inside non-metallic flexible, spiral wire helix core ducts, with different bent angles. In addition, Computational Fluid Dynamics (CFD) solutions were performed and verified by comparing them to the experimental data. The CFD computations were carried out to produce more systematic pressure drop information through these complex-geometry ducts. The experimental setup was constructed according to ASHRAE Standard 120-1999. Five different bent angles (0, 30, 45, 60, and 90 degrees) were tested at relatively low flow rates (11 to 89 CFM). Also, two different bent radii and duct lengths were tested to study flexible duct geometrical effects on static pressure drops. FLUENT 6.2, using RANS based two equations - RNG k-ε model, was used for the CFD analyses. The experimental and CFD results showed that larger bent angles produced larger static pressure drops in the flexible ducts. CFD analysis data were found to be in relatively good agreement with the experimental results for all bent angle cases. However, the deviations became slightly larger at higher velocity regimes and at the longer test sections. Overall, static pressure drop for longer length cases were approximately 0.01in.H2O higher when compared to shorter cases because of the increase in resistance to the flow. Also, the CFD simulations captured more pronounced static pressure drops that were produced along the sharper turns. The stronger secondary flows, which resulted from higher and lower static pressure distributions in the outer and inner surfaces, respectively, contributed to these higher pressure drops.

Experimental Study of Evaporation Heat Transfer Characteristics and Pressure Drops of R410A and R134a in a Multiport Mini-Channel

2009 ◽  
Author(s):  
Jatuporn Kaew-On ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Transfer Coefficients ◽  
Pressure Drops ◽  
Heat Transfer Coefficients ◽  
Evaporation Heat ◽  
Evaporation Heat Transfer ◽  
R 134A

The evaporation heat transfer coefficients and pressure drops of R-410A and R-134a flowing through a horizontal-aluminium rectangular multiport mini-channel having a hydraulic diameter of 3.48 mm are experimentally investigated. The test runs are done at refrigerant mass fluxes ranging between 200 and 400 kg/m2s. The heat fluxes are between 5 and 14.25 kW/m2, and refrigerant saturation temperatures are between 10 and 30 °C. The effects of the refrigerant vapour quality, mass flux, saturation temperature and imposed heat flux on the measured heat transfer coefficient and pressure drop are investigated. The experimental data show that in the same conditions, the heat transfer coefficients of R-410A are about 20–50% higher than those of R-134a, whereas the pressure drops of R-410A are around 50–100% lower than those of R-134a. The new correlations for the evaporation heat transfer coefficient and pressure drop of R-410A and R-134a in a multiport mini-channel are proposed for practical applications.

scholarly journals Method of producing parboiled rice without steam by fluidized bed dryer

2020 ◽  
Vol 187 ◽  
pp. 01002
Author(s):  
Asadayuth Mitsiri ◽  
Somkiat Prachayawarakorn ◽  
Sakamon Devahastin ◽  
Wathanyoo Rordprapat ◽  
Somchart Soponronnarit
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Rice Yield ◽  
Experimental Result ◽  
Rice Starch ◽  
Parboiled Rice ◽  
Starch Gelatinization ◽  
Fluidized Bed Dryer ◽  
Head Rice ◽  
Head Rice Yield

A more simple methodology of producing parboiled rice is subject to be investigated in this work with proposed the method, the gelatinization of rice starch, commonly taking place at the steaming step in the traditional process, and drying are combined and replaced by a hot air fluidized bed dryer. A pilot-scale continuous fluidized bed, with a maximum capacity of 140-150 kg/h, has been designed, constructed and tested. Suphanburi 90 paddy variety with high amylose content was dipped into hot water at temperatures of 70, 80, 83°C for 4.0, 3.3, 3.2 h, respectively, to get the moisture content around 47-55% db and dried at 150-170°C using air speed of 3.5 m/s. The paddy bed depth within the dryer was 3 and 5 cm. In the dryer operation, the exhaust air was fully recycled and reheated again by 30 kW electrical heaters to the desired temperature. The experimental result has shown that parboiled rice with a different degree of starch gelatinization could be produced by this technique. The degree ranged between 80-100% as examined by differential scanning calorimeter. The exit moisture content was given in a range of 14-21% db, relying on the drying temperature and soaking time. The aforementioned exit moisture contents were not a detrimental effect on head rice yield although the tempering was not included. The head rice yield was given in the range of 59-66%, depending on the degree of starch gelatinization. The starch granules lost their original shape as revealed by scanning electron microscope.

Swirling Annular Flow in a Steam Separator

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Hironobu Kataoka ◽  
Yusuke Shinkai ◽  
Shigeo Hosokawa ◽  
Akio Tomiyama
Keyword(s):  
Pressure Drop ◽  
Annular Flow ◽  
Nuclear Reactor ◽  
Water Pressure ◽  
Interfacial Friction ◽  
Pressure Drops ◽  
Pressure Transducers ◽  
Ring Configuration ◽  
Film Flows ◽  
Steam Separator

Effects of pick-off ring configuration on the separator performance of a downscaled model of a steam separator for a boiling water nuclear reactor are examined using various types of pick-off rings. The experiments are conducted using air and water. Pressure drops in a barrel and a diffuser and diameters and velocities of droplets at the exit of the barrel are measured using differential pressure transducers and particle Doppler anemometry, respectively. The separator performance does not depend on the shape of the pick-off ring but strongly depends on the width of the gap between the pick-off ring and the barrel wall. The pressure drop in the barrel is well evaluated using the interfacial friction factor for unstable film flows. Carry-under can be estimated using a droplet velocity distribution at the exit of the separator.

Shellside Waterflow Pressure Drop Distribution Measurements in an Industrial-Sized Test Heat Exchanger

1988 ◽  
Vol 110 (1) ◽  
pp. 60-67 ◽  
Author(s):  
H. Halle ◽  
J. M. Chenoweth ◽  
M. W. Wambsganss
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Operating Cost ◽  
Power Requirement ◽  
Pressure Drops ◽  
Pressure Losses ◽  
Finned Tubes ◽  
Heat Exchanger Design ◽  
Isothermal Water

Throughout the life of a heat exchanger, a significant part of the operating cost arises from pumping the heat transfer fluids through and past the tubes. The pumping power requirement is continuous and depends directly upon the magnitude of the pressure losses. Thus, in order to select an optimum heat exchanger design, it is is as important to be able to predict pressure drop accurately as it is to predict heat transfer. This paper presents experimental measurements of the shellside pressure drop for 24 different segmentally baffled bundle configurations in a 0.6-m (24-in.) diameter by 3.7-m (12-ft) long shell with single inlet and outlet nozzles. Both plain and finned tubes, nominally 19-mm (0.75-in.) outside diameter, were arranged on equilateral triangular, square, rotated triangular, and rotated square tube layouts with a tube pitch-to-diameter ratio of 1.25. Isothermal water tests for a range of Reynolds numbers from 7000 to 100,000 were run to measure overall as well as incremental pressure drops across sections of the exchanger. The experimental results are given and correlated with a pressure drop versus flowrate relationship.

scholarly journals Grid convergence study of a cyclone separator using different mesh structures

2017 ◽  
Vol 23 (3) ◽  
pp. 311-320 ◽  
Author(s):  
R.A.F. Oliveira ◽  
G.H. Justi ◽  
G.C. Lopes
Keyword(s):  
Pressure Drop ◽  
Collection Efficiency ◽  
Fluid Dynamic ◽  
Two Phase ◽  
Mesh Structure ◽  
Pressure Drops ◽  
Regular Elements ◽  
Grid Convergence ◽  
Grid Convergence Index ◽  
Mesh Structures

In a cyclone design, pressure drop and collection efficiency are two important performance parameters to estimate its implementation viability. The optimum design provides higher efficiencies and lower pressure drops. In this paper, a grid independence study was performed to determine the most appropriate mesh to simulate the two-phase flow in a Stairmand cyclone. Computational fluid dynamic (CFD) tools were used to simulate the flow in an Eulerian-Lagrangian approach. Two different mesh structure, one with wall-refinement and the other with regular elements, and several mesh sizes were tested. The grid convergence index (GCI) method was applied to evaluate the result independence. The CFD model results were compared with empirical correlations from bibliography, showing good agreement. The wall-refined mesh with 287 thousand elements obtained errors of 9.8% for collection efficiency and 14.2% for pressure drop, while the same mesh, with regular elements, obtained errors of 8.7% for collection efficiency and 0.01% for pressure drop.

scholarly journals Pemodelan Penurunan Tekanan Brine di Dalam Pipa Injeksi pada Lapangan Panas Bumi Dieng

Jurnal MIPA ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 32
Author(s):  
Jeferson Polii
Keyword(s):  
Pressure Drop ◽  
Flow Line ◽  
Chemical Constituents ◽  
Temperature Drop ◽  
Fluid Pressure ◽  
Saturation Temperature ◽  
Geothermal Field ◽  
Chemical Pollution ◽  
Pressure Drops ◽  
Very High

Injeksi brine hasil dari fluida produksi panas bumi digunakan untuk mengisi volume pori batuan reservoir, mencegah penurunan tekanan batuan yang terlalu cepat, dan mencegah polusi panas dan polusi kimia pada lingkungan yang disebabkan oleh kandungan kimia tertentu pada brine. Pada pipa aliran brine terjadi penurunan tekanan fluida sepanjang aliran. Di lapangan panas bumi Dieng, konsentrasi silika sangat tinggi, sehingga penurunan temperatur saturasi memicu desposisi silika. Penurunan tekanan sepanjang pipa aliran brine dari pompa Vertikal Atas (VA) 7 ke pond di pad 29 di lapangan panas bumi Dieng akan menyebabkan penurunan temperatur saturasi, selain juga kehilangan panas secara alami. Perhitungan penurunan tekanan fluida brine berdasarkan perhitungan Harrison-Freeston dan metode dari Zhao, yang dikembangkan dengan algoritma menggunakan Macro Excel. Sehingga dengan memodelkan penurunan tekanan sepanjang pipa alir, dapat dikembangkan untuk perhitungan penurunan temperatur dan pengendapan silika di pipa aliran brine untuk injeksi panas bumi.Brine injection from geothermal production fluids is used to fill reservoir pore rock volumes, preventing rapid rock pressure drops, and preventing heat pollution and chemical pollution in the environment caused by certain chemical constituents in the brine. Decrease fluid pressure along the flow on the brine flow pipe. In the Dieng geothermal field, the silica concentration is very high, so the decrease in saturation temperature triggers the silica desposition. The pressure drop along the brine flow pipe from the Upper Vertical (VA) 7 pump to the pond in pad 29 in Dieng geothermal field will cause a decrease in saturation temperature, as well as natural heat loss. The calculation of the decrease in brine fluid pressure based on Harrison-Freeston calculations and methods of Zhao, developed with algorithms using Macro Excel. By modeling the pressure drop along the flow line, it can be developed for the calculation of temperature drop and deposition of silica in the brine flow pipe for geothermal injection

Experimental Investigation Into the High Altitude Relight of a Three-Cup Combustor Sector

2018 ◽  
Author(s):  
Michael J. Denton ◽  
Samir B. Tambe ◽  
San-Mou Jeng
Keyword(s):  
Pressure Drop ◽  
High Altitude ◽  
High Speed ◽  
Development Process ◽  
Recirculation Zone ◽  
Operating Conditions ◽  
Pressure Drops ◽  
High Speed Video ◽  
Air Jet ◽  
Flame Development

The altitude relight of a gas turbine combustor is an FAA and EASA regulation which dictates the successful re-ignition of an engine and its proper spool-up after an in-flight shutdown. Combustor pressure loss, ambient pressure, ambient temperature, and equivalence ratio were all studied on a full-scale, 3-cup, single-annular aviation combustor sector to create an ignition map. The flame development process was studied through the implementation of high-speed video. Testing was conducted by placing the sector horizontally upstream of an air jet ejector in a high altitude relight testing facility. Air was maintained at room temperature for varying pressure, and then the cryogenic heat exchanger was fed with liquid nitrogen to chill the air down to a limit of −50 deg F, corresponding with an altitude of 30,000 feet. Fuel was injected at constant equivalence ratios across multiple operating conditions, giving insight into the ignition map of the combustor sector. Results of testing indicated difficulty in achieving ignition at high altitudes for pressure drops greater than 2%, while low pressure drops show adequate performance. Introducing low temperatures to simulate the ambient conditions yielded a worse outcome, with all conditions having poor results except for 1%. High-speed video of the flame development process during the relight conditions across all altitudes yielded a substantial effect of the pressure drop on ignitability of the combustor. An increase in pressure drop was associated with a decrease in the likelihood of ignition success, especially at increasing altitudes. The introduction of the reduced temperature effect exacerbated this effect, further hurting ignition. High velocity regions in the combustor were detrimental to the ignition, and high area, low velocity regions aided greatly. The flame tended to settle into the corner recirculation zone and recirculate back into the center-toroidal recirculation zone (CTRZ), spreading downstream and likewise into adjacent swirl cups. These tests demonstrate the need for new combustor designs to consider adding large recirculation zones for combustor flame stability that will aid in relight requirements.

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