scholarly journals Mixing optimization with inward flow configuration contra-rotating impeller, baffle-free tank

2021 ◽  
Vol 60 (4) ◽  
pp. 3759-3779
Author(s):  
P. Satjaritanun ◽  
J.R. Regalbuto ◽  
J.A. Regalbuto ◽  
N. Tippayawong ◽  
S. Shimpalee
Keyword(s):  
Flow Configuration ◽  
Rotating Impeller

Feasibility Study of Catheter-directed Thrombolysis with Recombinant Staphylokinase in Deep Venous Thrombosis

1998 ◽  
Vol 79 (03) ◽  
pp. 517-519 ◽  
Author(s):  
Stephane Heymans ◽  
Raymond Verhaeghe ◽  
Luc Stockx ◽  
Désiré Collen
Keyword(s):  
Deep Vein Thrombosis ◽  
Continuous Infusion ◽  
High Speed ◽  
Minor Bleeding ◽  
Vein Thrombosis ◽  
Catheter Directed Thrombolysis ◽  
Long Term Follow Up ◽  
Valve Function ◽  
Rotating Impeller ◽  
Deep Vein

SummaryThe feasibility of catheter-directed thrombolysis with recombinant staphylokinase was evaluated in six selected patients with deep vein thrombosis. The patients underwent intrathrombus infusion of recombinant staphylokinase (2 mg bolus followed by a continuous infusion of 1 mg/h). Heparin was given via the catheter as a bolus (5000 U) and as a continuous infusion (1000 U/h). Complete lyis was obtained in five patients and partial lysis in one patient. Complications consisted of minor bleeding in four subjects. Symptomatic reocclusion occurred in one. Debulking of the thrombus mass by a high speed rotating impeller (n = 1) and stenting (n = 3) were used as additional interventions. An underlying anatomical abnormality was present in two patients. Long term follow up revealed normal patency in all patients and normal valve function in four patients. Symptomatic venous insufficiency with valve dysfunction was present in the two with a second thrombotic episode.Thus catheter-directed infusion of recombinant staphylokinase in patients with deep vein thrombosis appears feasible and may be associated with a high frequency of thrombolysis. Larger studies to define the clinical benefit of this treatment appear to be warranted.

scholarly journals Effect of Flow Rate on Turbulence Dissipation Rate Distribution in a Multiphase Pump

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 886
Author(s):  
Zongliu Huang ◽  
Guangtai Shi ◽  
Xiaobing Liu ◽  
Haigang Wen
Keyword(s):  
Flow Rate ◽  
Dissipation Rate ◽  
Circumferential Direction ◽  
Outlet Section ◽  
Inlet Section ◽  
Distribution Characteristics ◽  
Rate Condition ◽  
Rate Distribution ◽  
Multiphase Pump ◽  
Rotating Impeller

The turbulence dissipation will cause the increment of energy loss in the multiphase pump and deteriorate the pump performance. In order to research the turbulence dissipation rate distribution characteristics in the pressurized unit of the multiphase pump, the spiral axial flow type multiphase pump is researched numerically in the present study. This research is focused on the turbulence dissipation rate distribution characteristics in the directions of inlet to outlet, hub to rim, and in the circumferential direction of the rotating impeller blades. Numerical simulation based on the RANS (Reynolds averaged Navier–Stokes equations) and the k-ω SST (Shear Stress Transport) turbulence model has been carried out. The numerical method is verified by comparing the numerical results with the experimental data. Results show that the regions of the large turbulence dissipation rate are mainly at the inlet and outlet of the rotating impeller and static impeller, while it is almost zero from the inlet to the middle of outlet in the suction surface and pressure surface of the first-stage rotating impeller blades. The turbulence dissipation rate is increased gradually from the hub to the rim of the inlet section of the first-stage rotating impeller, while it is decreased firstly and then increased on the middle and outlet sections. The turbulence dissipation rate distributes unevenly in the circumferential direction on the outlet section. The maximum value of the turbulence dissipation rate occurs at 0.9 times of the rated flow rate, while the minimum value at 1.5 times of the rated flow rate. Four turning points in the turbulence dissipation rate distribution that are the same as the number of impeller blades occur at 0.5 times the blade height at 0.9 times the rated flow rate condition. The turbulence dissipation rate distribution characteristics in the pressurized unit of the multiphase pump have been studied carefully in this paper, and the research results have an important significance for improving the performance of the multiphase pump theoretically.

scholarly journals Rheology of a dense granular bed penetrated by a rotating impeller

2021 ◽  
Vol 386 ◽  
pp. 60-69
Author(s):  
Wenguang Nan ◽  
Mehrdad Pasha ◽  
Mojtaba Ghadiri
Keyword(s):  
Granular Bed ◽  
Rotating Impeller

Effect of Flow Configuration on Nitrifiers in Biological Activated Carbon Filters for Potable Water Production

2020 ◽  
Vol 54 (22) ◽  
pp. 14646-14655
Author(s):  
Min Rui ◽  
Haoshen Chen ◽  
Yinyin Ye ◽  
Huiping Deng ◽  
Hong Wang
Keyword(s):  
Activated Carbon ◽  
Potable Water ◽  
Water Production ◽  
Biological Activated Carbon ◽  
Flow Configuration

Design of Cooling Towers by the Effectiveness-NTU Method

1989 ◽  
Vol 111 (4) ◽  
pp. 837-843 ◽  
Author(s):  
H. Jaber ◽  
R. L. Webb
Keyword(s):  
Heat Exchanger ◽  
Cooling Tower ◽  
Design Method ◽  
Design Methods ◽  
Parallel Flow ◽  
Basic Method ◽  
Cooling Towers ◽  
Flow Configuration ◽  
Heat Exchanger Design

This paper develops the effectiveness-NTU design method for cooling towers. The definitions for effectiveness and NTU are totally consistent with the fundamental definitions used in heat exchanger design. Sample calculations are presented for counter and crossflow cooling towers. Using the proper definitions, a person competent in heat exchanger design can easily use the same basic method to design a cooling tower of counter, cross, or parallel flow configuration. The problems associated with the curvature of the saturated air enthalpy line are also treated. A “one-increment” design ignores the effect of this curvature. Increased precision can be obtained by dividing the cooling range into two or more increments. The standard effectiveness-NTU method is then used for each of the increments. Calculations are presented to define the error associated with different numbers of increments. This defines the number of increments required to attain a desired degree of precision. The authors also summarize the LMED method introduced by Berman, and show that this is totally consistent with the effectiveness-NTU method. Hence, using proper and consistent terms, heat exchanger designers are shown how to use either the standard LMED or effectiveness-NTU design methods to design cooling towers.

Optimum Strain Gauge Application to Bladed Assemblies

2002 ◽  
Author(s):  
J. Szwedowicz ◽  
S. M. Senn ◽  
R. S. Abhari
Keyword(s):  
Strain Gauge ◽  
Element Model ◽  
Strain Gauges ◽  
Structural Components ◽  
Algorithm Optimization ◽  
Rotating Blades ◽  
Novel Approach ◽  
Present Technique ◽  
Optimization Function ◽  
Rotating Impeller

Optimum placements of the strain gauges assure reliable vibration measurements of structural components such as rotating blades. Within the framework of cyclic vibration theory, a novel approach has been developed for computation of the optimum gauge positions on tuned bladed discs regarding the determined sensitivity, orthogonality, gradient and distance criteria. The utilized genetic algorithm optimization tool allows for an effective numerical search of suitable solutions of the defined optimization function. A rotating impeller disc represented by a cyclic finite element model demonstrates the application of this method. The present technique can be easily applied to other structural components requiring optimal strain gauge instrumentation.

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