scholarly journals Flow regimes and pressure drop of a composite tridimensional rotational flow sieve tray under concurrent gas--liquid flow

2021 ◽  
Author(s):  
Shaofeng Zhang ◽  
Bingfang Liu ◽  
Hongkai Wang ◽  
Yan Liu ◽  
Dewu Wang ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Shooting Method ◽  
Structural Parameters ◽  
Operating Conditions ◽  
Rotational Flow ◽  
Difference Sequence ◽  
Sieve Tray ◽  
New Type ◽  
Gas Liquid Flow ◽  
Type Pressure

A new type of composite tridimensional rotational flow sieve tray is proposed. The flow pattern and operation domain of the tray were defined and divided by the image shooting method, combined with the standard deviation of the pressure difference sequence. There are membrane–drip column and foam–embolic flow in the TRST area of the internal packing–type tray, while bubbly and milk froth-ribbon flow are present in the packing area of the external packing-type tray. This study focused on the influence of the tray structure parameters on the pressure drop. Under the experimental operating conditions, the dry pressure drop was within 160 Pa, while the wet pressure drop was within 900 Pa. Under the same structural parameters, the internal packing–type pressure drop of the tray was higher than that of the external packing-type tray. A mathematical model of the pressure drop between dry and wet trays was established.

The Structure Design and Numerical Simulation Research on Downhole Hydrocyclone Desander

2014 ◽  
Vol 933 ◽  
pp. 434-438
Author(s):  
Yue Juan Yan ◽  
Yan Xu Shang ◽  
Zun Ce Wang ◽  
Mi Tian ◽  
Yue Wang
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Separation Efficiency ◽  
Structural Parameters ◽  
Production Capacity ◽  
Geometrical Model ◽  
Structure Design ◽  
Operating Conditions ◽  
Structure Parameters ◽  
Effect Of Structure

A new downhole hydrocyclone desander with spiral deflector and cyclone cone was designed to apply in downhole solid-liquid separation according to the downhole operating conditions, such as a high produced liquid viscosity, narrow radial working space and closed bottom flow, etc. The structure parameters were designed primarily based on the effect of structure size on pressure drop, production capacity and separation efficiency. Numerical simulation was conducted on the base of Mixture model and Reynolds stress (RSM) turbulent model by Fluent CFD software. The geometrical model of single inlet and single outlet was established. The simulation calculations were carried out to analysis the effect of structure parameters change on separation efficiency and pressure drop, obtained the influence rules. The optimum structural parameters were confirmed. The numerical simulation results lay the foundation for the next experimental study.

Flow characteristics of blade unit of a tridimensional rotational flow sieve tray under concurrent gas–liquid flow

AIChE Journal ◽  
2020 ◽  
Vol 66 (9) ◽  
Author(s):  
Hongkai Wang ◽  
Meng Tang ◽  
Dewu Wang ◽  
Yan Liu ◽  
Yishuo Zhang ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Flow Characteristics ◽  
Rotational Flow ◽  
Sieve Tray ◽  
Gas Liquid Flow

Experimental study and modeling development of pressure drop in concurrent gas-liquid columns with a tridimensional rotational flow sieve tray

2018 ◽  
Vol 191 ◽  
pp. 383-397 ◽  
Author(s):  
Meng Tang ◽  
Shaofeng Zhang ◽  
Dewu Wang ◽  
Yan Liu ◽  
Lusha Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pressure Drop ◽  
Rotational Flow ◽  
Sieve Tray

scholarly journals Flow characteristics of blade unit of a tridimensional rotational flow sieve tray under concurrent gas-liquid flow

Authorea ◽  
2020 ◽  
Author(s):  
Hongkai Wang ◽  
Meng Tang ◽  
Dewu Wang ◽  
Yan Liu ◽  
Yishuo Zhang ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Flow Characteristics ◽  
Rotational Flow ◽  
Sieve Tray ◽  
Gas Liquid Flow

The analysis on the influence of mixed sliding-rolling motion mode to precision degradation of ball screw

2021 ◽  
pp. 095440622098201
Author(s):  
Qiang Cheng ◽  
Baobao Qi ◽  
Hongyan Chu ◽  
Ziling Zhang ◽  
Zhifeng Liu ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Operating Conditions ◽  
Ball Screw ◽  
Rolling Motion ◽  
Degradation Model ◽  
Sliding Motion ◽  
Factors Analysis ◽  
Motion Mode

The combination of sliding/rolling motion can influence the degree of precision degradation of ball screw. Precision degradation modeling and factors analysis can reveal the evolution law of ball screw precision. This paper presents a precision degradation model for factors analysis influencing precision due to mixed sliding-rolling motion. The precision loss model was verified through the comparison of theoretical models and experimental tests. The precision degradation due to rolling motion between the ball and raceway accounted for 29.09% of the screw precision loss due to sliding motion. Additionally, the total precision degradation due to rolling motion accounted for 21.03% of the total sliding precision loss of the screw and nut, and 17.38% of the overall ball screw precision loss under mixed sliding-rolling motion. In addition, the effects of operating conditions and structural parameters on precision loss were analyzed. The sensitivity coefficients of factors influencing were used to quantitatively describe impact degree on precision degradation.

Flow Coefficient Evaluation of Poppet Valves Used in Reciprocating Compressors for LDPE

2008 ◽  
Author(s):  
Enzo Giacomelli ◽  
Massimo Schiavone ◽  
Fabio Manfrone ◽  
Andrea Raggi
Keyword(s):  
Pressure Drop ◽  
Time Pressure ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Flow Coefficient ◽  
Operating Life ◽  
High Fatigue ◽  
Strongly Connected ◽  
And Performance ◽  
Poppet Valves

Poppet valves have been used for a long time for very high pressure reciprocating compressors, as for example in the case of Low Density Polyethylene. These applications are very critical because the final pressure can reach 350 MPa and the evaluation of the performance of the machines is strongly connected to the proper operation and performance of the valve itself. The arrangement of cylinders requires generally a certain compactness of valve to withstand high fatigue stresses, but at the same time pressure drop and operating life are very important. In recent years the reliability of the machines has been improving over and over and the customers’ needs are very stringent. Therefore the use of poppet valves has been extended to other cases. In general the mentioned applications are heavy duty services and the simulation of the valves require some coefficients to be used in the differential equations, able to describe the movement of plate/disk or poppet and the flow and related pressure drop through the valves. Such coefficients are often determined in an experimental way in order to have a simulation closer to the real operating conditions. For the flow coefficients it is also possible today to use theoretical programs capable of determining the needed values in a quick and economical way. Some investigations have been carried out to determine the values for certain geometries of poppet valves. The results of the theory have been compared with some experimental tests. The good agreement between the various methods indicates the most suitable procedure to be applied in order to have reliable data. The advantage is evident as the time necessary for the theoretical procedure is faster and less expensive. This is of significant importance at the time of the design and also in case of a need to provide timely technical support for the operating behavior of the valves. Particularly for LDPE, the optimization of all the parameters is strongly necessary. The fatigue stresses of cylinder heads and valve bodies have to match in fact with gas passage turbulence and pressure drop, added to the mechanical behavior of the poppet valve components.

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