Pressure Drop and Apparent Solids Concentration inside a Novel Multi-Regime Riser

2013 ◽  
Vol 709 ◽  
pp. 309-312
Author(s):  
Xiao Lin Zhu ◽  
Guo Wei Wang ◽  
Qiang Geng ◽  
Chun Yi Li ◽  
Chao He Yang
Keyword(s):  
Pressure Drop ◽  
Satisfactory Agreement ◽  
Total Pressure ◽  
Operating Conditions ◽  
Experimental Results ◽  
Circulation Rate ◽  
Empirical Correlations ◽  
Solids Concentration ◽  
Solids Circulation Rate ◽  
Measured Pressure

In this study, pressure drop across a novel CFB riser integrated with an enlarged bottom section was investigated under various operating conditions. Experimental results indicated that total pressure drop was much higher across the riser with larger diameter-enlarged section dimensions, consequently, resulting in lower solids circulation rate realizable in the riser. Based on the measured pressure drop across this novel riser, apparent solids concentrations of the diameter-enlarged section and the conveying section were obtained. Furthermore, empirical correlations for estimating overall average solids concentration in these two sections were established, respectively. And a satisfactory agreement between predictions and experimental results was observed.

Analysis of the Microscopic Flow Structure of a CFB Downer Reactor Using Solids Concentration Signals

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Samwel V Manyele ◽  
Jesse Zhu ◽  
Hui Zhang
Keyword(s):  
Time Series ◽  
Sampling Rate ◽  
Operating Conditions ◽  
Circulation Rate ◽  
Optical Fiber Probe ◽  
Solids Concentration ◽  
Solids Circulation Rate ◽  
Concentration Time Series ◽  
Spatial Locations ◽  
Downer Reactor

The microflow structure in a downer reactor was studied by measuring the solids concentration fluctuations at various elevations and radial positions, using an optical fiber probe, at a sampling rate of 970 Hz. The downer reactor (0.1 m i.d. and 10 m high) was operated at gas velocities ranging from 3.5 to 10.0 m/s and solids flux from 50 to 200 kg/m2s, with spent FCC catalyst of Sauter mean diameter of 67 mm and density of 1500 kg/m3. The analysis of solids concentration time series was performed using statistical, spectral and chaos techniques. Results from these analyses were compared and related to the operating conditions (gas velocity and solids circulation rate) as well as to the spatial locations (radial and axial positions) in the downer reactor. Different techniques of time series analysis gave similar results but with different sensitivity to changes in the dynamics. A combination of the three signal analysis techniques proved to be more useful in providing more insight understanding of the microflow structure.

Experimental Investigations of Pressure Drop in the Combustion Chamber of Gas Turbine

1989 ◽  
Author(s):  
Marek Dzida ◽  
Krzysztof Kosowski
Keyword(s):  
Pressure Drop ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Relative Pressure ◽  
Wide Range ◽  
Few Data

In bibliography we can find many methods of determining pressure drop in the combustion chambers of gas turbines, but there is only very few data of experimental results. This article presents the experimental investigations of pressure drop in the combustion chamber over a wide range of part-load performances (from minimal power up to take-off power). Our research was carried out on an aircraft gas turbine of small output. The experimental results have proved that relative pressure drop changes with respect to fuel flow over the whole range of operating conditions. The results were then compared with theoretical methods.

Analysis and Optimization Design of Pressure Compensated Flow Control Valves

2003 ◽  
Author(s):  
Duqiang Wu ◽  
Richard Burton ◽  
Greg Schoenau ◽  
Doug Bitner
Keyword(s):  
Pressure Drop ◽  
Flow Control ◽  
Flow Rate ◽  
Total Pressure ◽  
Optimization Design ◽  
Constant Pressure ◽  
Control Device ◽  
Operating Conditions ◽  
Flow Control Device ◽  
Linearized Model

A pressure compensated valve (PC valve) is a type of flow control device that is a combination of a control orifice and a compensator (often called a hydrostat). The compensator orifice modulates its opening to maintain a constant pressure drop across the control orifice. In other words, the PC valve is so designed that the flow rate through the valve is governed only by the opening of the control orifice and is independent of the total pressure drop across the valve. Because of the high non-linearities associated with this type of valve, it is impossible, in practice, to design such a valve where the flow rate is completely unaffected by the pressure drop across the valve. In this paper, the effect of the non-linerities on the performance of the PC valve is investigated. First, a generic non-liner model of a PC valve is developed. Using this model, all possible operating conditions can be determined. Then a linearized model is developed and used to analyze the dynamic behavior of the PC valve. The model can then be used to optimize the design and operation of the valve for specific applications.

scholarly journals Inlet and Exit-Header Shapes for Uniform Flow Through a Resistance Parallel to the Main Stream

1961 ◽  
Vol 83 (3) ◽  
pp. 361-368 ◽  
Author(s):  
Morris Perlmutter
Keyword(s):  
Experimental Study ◽  
Pressure Drop ◽  
Total Pressure ◽  
Experimental Results ◽  
Main Stream ◽  
Height Ratio ◽  
Large Length ◽  
Flow Through ◽  
Pass Through ◽  
Good Agreement

An analytical and experimental study of flow in headers with a resistance parallel to the turbulent and incompressible main stream has been made. The purpose was to shape the inlet and exit headers, which had a large length-to-height ratio, so that the fluid would pass through the resistance uniformly. Analytical wall shapes and estimated total pressure drop through the headers were compared with experimental results. Good agreement between analysis and experiment was found for the cases compared.

Prediction for the Riser’s Average Solids Concentration Based on the Least Square SVM Method

2011 ◽  
Vol 236-238 ◽  
pp. 672-675
Author(s):  
Xue Yao Wang ◽  
Yun Han Xiao
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Multiple Linear Regression Model ◽  
Least Square ◽  
Circulation Rate ◽  
Neural Net ◽  
Training Time ◽  
Solids Concentration ◽  
Solids Circulation Rate ◽  
Svm Model

The measurement for riser’s solids concentration is important but difficult. So, a high-efficiency and low-cost new predicted method based on the least square SVM method is proposed. The superficial operated gas velocity Ug and solids circulation rate εs are chosen as the effect factors of the solids concentration. Furthermore, the multiple linear regression model (Linear) and artificial neural net model (ANN) are also used to compare with the SVM model. By analyzing the training time and error, it is proved the SVM model has higher prediction accuracy and forecasting efficiency, which is a better choice for the riser’s solids concentration prediction.

scholarly journals OPERATIONAL INFLUENCE OF THE MONO-CHAMBER AERATION MODE IN THE LOOP SEAL OF A CIRCULATING FLUIDIZED BED

2020 ◽  
Vol 51 (1) ◽  
pp. 15-20
Author(s):  
Fernanda De Oliveira ◽  
Guilherme Santos Furquim ◽  
Vitor Otávio Ochoski Machado ◽  
Maria Regina Parise ◽  
Jhon Jairo Ramírez Behainne
Keyword(s):  
Pressure Drop ◽  
Fluidized Bed ◽  
Energy Demand ◽  
Static Pressure ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Sauter Mean Diameter ◽  
Solids Circulation Rate ◽  
Fluidization Regime ◽  
Superficial Gas Velocity

Fluidization numbers varying from 0.84 to 1.68 were used in the loop seal valve of a bench-scale circulating fluidized bed (CFB) system to analyze the influence of the mono-chamber aeration mode on both the solids circulation rate and the static pressure drop inside the solids recycle device. Runs were carried out using 4 kg of overall solids inventory and particles of 183 µm in Sauter mean diameter, which were kept under fast fluidization regime at superficial gas velocity of 4 m/s. Results showed that the choice of the chamber to be aerated can noticeably affect the gas-solid hydrodynamics. In this sense, the analysis of variance applied on the experimental data indicated that the aeration into the recycle chamber of the loop seal offers lower levels of solids circulation rate but also allows to control it within a wider range of fluidization numbers and with less pressure drop or energy demand.

A Simplified Method for the Design of Externally Pressurized Gas Lubricated Thrust Bearings

1972 ◽  
Vol 1 (4) ◽  
pp. 205-212
Author(s):  
E.H. Dudgeon ◽  
I.R.G. Lowe
Keyword(s):  
Pressure Drop ◽  
Satisfactory Agreement ◽  
Empirical Studies ◽  
Performance Estimation ◽  
Empirical Correlations ◽  
Thrust Bearings ◽  
Load Factors ◽  
Simplified Method ◽  
Simplified Procedure

A simplified procedure has been developed for the performance estimation of externally-pressurized gas lubricated thrust bearings. Both orifice-compensated and inherently-compensated bearings may be treated. Empirical correlations for the entry compensation pressure drop are combined with numerically determined flow and load factors for the clearance space flow. The analytical predictions are compared with empirical studies indicating satisfactory agreement for most design purposes.

Field-Testing of Biodiesel (B100) and Diesel-Fueled Vehicles: Part 4—Piston Rating, and Fuel Injection Equipment Issues

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Deepak Agarwal
Keyword(s):  
Pressure Drop ◽  
Large Scale ◽  
Fuel Injection ◽  
Field Trials ◽  
Operating Conditions ◽  
Experimental Results ◽  
Injection Equipment ◽  
Frictional Losses ◽  
Fuel Filter

Abstract This study investigated the use of biodiesel (B100) and baseline diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel's compatibility with modern common rail direct injection (CRDI) fuel injection equipment (FIE) and evaluate biodiesel's long-term durability/compatibility with engine components. Two identical vehicles were fueled with biodiesel (B100) and baseline mineral diesel for 30,000 km field-trials on highway under identical operating conditions. Exhaustive experimental results from this series of tests are divided into four segments. The fourth and the last paper of this series compares the effects of long-term usage of biodiesel on piston deposits and FIE components compared to baseline mineral diesel. A key challenge for improving engine performance and fuel economy is the reduction of frictional losses, primarily at the piston ring–liner interface, which accounts for majority of frictional losses. Piston rating was done for the two vehicles after the conclusion of field-trials and it revealed that rating of different piston sections was ∼5–15% superior in case of biodiesel-fueled vehicle compared to that of diesel-fueled vehicle. Performance of FIE components such as fuel filter, fuel injectors, and fuel pump was assessed after the conclusion of field-trials. Pressure drop at different fuel flow-rates across the fuel filter was measured for assessing the fuel filter blockage. Pressure drop across biodiesel filter was ∼30% higher than diesel filter after 10,000 km usage but almost twice after 15,000 km usage. These experimental results indicated that some additional technical measures should be taken by automotive manufacturers to offset these technical challenges before biodiesel is adapted on a large-scale in modern CRDI vehicles.

Experimental Investigation of Pressure Drop of Flow Boiling at Vertical Narrow Rectangular Channel

2008 ◽  
Author(s):  
Liang-Ming Pan ◽  
De-Qi Chen ◽  
De-Wen Yuan
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Flow Boiling ◽  
Rectangular Channel ◽  
Vertical Channel ◽  
Narrow Channel ◽  
Operating Conditions ◽  
Experimental Results ◽  
Two Phase ◽  
Modified Model

Narrow channel heat transfer element has been extensive adopted in engineering applications, especially at electronics technology, this kind of elements often be used to construct compact heat exchanger. Pressure drop of flow boiling at vertical channel with gaps of 1.7, 2.2 and 3.6 mm was experimentally investigated in this paper. The variation of the two-phase frictional multiplier vs. heat flux at various operating conditions was gotten experimentally, possible mechanism of the two-phase frictional multiplier trends of narrow channel were analyzed. Experimental results revealed that the two-phase frictional multiplier increased at lower flow rate and heat flux, as well as higher vapor quality, and dropped at wider flow gap. The multiplier can not be estimated by commonly used method for ordinary gap, thus a modified model of pressure drop for narrow channel was proposed considering the size effects of channel. The error of the predicted two-phase frictional multiplier is within ±15.4% compared with experimental results.

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