Pipeline wear, pulverization of the material being transported, and hydraulic resistance in hydraulic transport

1966 ◽  
Vol 2 (2) ◽  
pp. 194-200
Author(s):  
V. V. Trainis ◽  
K. I. Yafarov
2021 ◽  
Vol 2094 (2) ◽  
pp. 022032
Author(s):  
N V Medved ◽  
E L Egorova ◽  
V N Morozov ◽  
V A Gron ◽  
A V Galaiko

Abstract The article presents the results of the dredger in a deep deposit of sand and gravel materials. It was found that when the diameter of the suction pipe exceeds the diameter of the inlet mixing chamber by 150 mm, the actual pressure from the ejector does not exceed one meter, and with an increase in the supply of the suction pump as a result of a sharp jump in hydraulic resistance, the vacuum is disrupted. It was also found that the effect on the calculated compression ratio of the jet apparatus increases with an increase in the injection coefficient and the input velocity of the injected stream.


2020 ◽  
Vol 7 (3) ◽  
pp. 37-44
Author(s):  
KONSTANTIN NAPREENKO ◽  
◽  
ROMAN SAVELEV ◽  
ALEKSEY TROFIMOV ◽  
ANNA LAMTYUGINA ◽  
...  

The article discusses methods for determining the hydraulic resistance of units of an accident-resistant fuel system. A detailed description of the need to create such fuel systems for modern helicopters is given. The development of such systems today is impossible without the use of the method of mathematical modeling, which allows to qualitatively solve problems arising in the design process. To obtain accurate research results, it is necessary to have a complete description of all elements and assemblies of the system. Methods for determining the hydraulic characteristics of AFS elements using the drag coefficient, reference literature and CFD codes are considered. As the investigated AFS units, a drain valve and burst fitting were studied in the article. A hydraulic calculation of these AFS elements ware performed, the simulation results are presented in the ANSYS CFX software package. Also as the calculation results of bursting fitting, the pressure distribution fields of full and static pressure, velocity and streamlines are also shown. An experimental setup for validating the results obtained using the mathematical modeling method is considered, as well as a methodology for conducting a full-scale experiment to determine the hydraulic resistance of the unit. Materials have been prepared for inclusion in a one-dimensional mathematical model of an accident-resistant fuel system.


2020 ◽  
pp. 123-126
Author(s):  
В.В. Кожемякин ◽  
Р.А. Иванов ◽  
Е.С. Игнатьева

Работа посвящена расчетно-теоретическому исследованию работы блока инжекторов. Рассмотрен пароводяной струйный аппарат, который применяется в качестве средства циркуляции теплоносителя первого контура. Подвод дополнительного потока осуществляется на цилиндрическом участке с внезапным расширением сечения через перемычку. Для достижения поставленной цели разработана программа для ЭМВ, в которой смоделирована зависимость давления от нагрузки в контуре, а также проведено расчетно-теоретическое исследование влияние гидравлического сопротивления на расход перемычки. В данной работе рассмотрены только рабочие режимы, т.е. все инжекторы работают как насосы. В ходе работы было установлено, что при нагрузке в 30% увеличиваются коэффициенты инжекции пароводяного струйного аппарата, но характер работы перемычек не меняется. Так же было установлено, что расход через перемычку меняется не пропорционально коэффициенту гидравлического сопротивления перемычки. The paper is devoted to the computational and theoretical study of the injector block operation. A steam-water jet apparatus is considered, which is used as a means of circulating the primary circle coolant. The additional flow is supplied on the cylindrical section with a sudden expansion of the cross-section through the bridge. To achieve this goal, a computer program was developed that modeled the pressure dependence on the load in the circuit, and also a theoretical study of the influence of hydraulic resistance on the flow of the jumper was conducted. In this paper, only operating modes are considered, i.e. all the injectors function as pumps. In the process of the research, it was found that at a load of 30%, the injection coefficients of the steam-water jet apparatus increase, but the nature of the work of the jumpers does not change. It was also found out that the flow rate through the jumper does not change in proportion to the coefficient of hydraulic resistance of the jumper.


2013 ◽  
Vol 8 (3-4) ◽  
pp. 342-349
Author(s):  
L. Andjelic ◽  
M. Pavlovic ◽  
B. Babovic

The thermal power plant ‘Morava’, with a productive force of 125 MW, is located on the right bank of the River Velika Morava, near the city of Svilajnac, Serbia. This power plant uses coal for production. Ash and slag from the coal are burned and go to a landfill by hydraulic transport. The ratio of the liquid/solid mixture is 10:1. Towards the reduction of water quantity taken from the Velika Morava river for hydraulic transport, it's provided to build a water recirculation system for overflow and drainage water from landfill to power plant. In this paper, the results of the hydraulic study of water balance in landfill is shown. The goal of this study is to assess the water quantity in landfill, which can then be reused for hydraulic transport. For dimensioning of drainage system and overflow building on landfill, it was necessary to perform detailed analysis of rainfall and filtration throw landfill. With results of water quantity in drainage system, and overflow water, all parts of the recirculation system of water, from landfill to power plant, was performed. Also, in this paper are the data of hydraulic transport of mixture of water and ash/slag.


2001 ◽  
Vol 1 (5-6) ◽  
pp. 215-220
Author(s):  
A. Gillighan ◽  
S.J. Judd ◽  
R. Eyres

The efficacy of ultrafiltration (UF) and microfiltration (MF) membranes was assessed for the concentration of actual waterworks sludges using crossflow tubular membranes operated at constant trans-membrane pressure. The MF membrane gave higher initial fluxes than the UF membrane but after 10 min of filtration the flux value and its decline tended to be very similar for both membranes operating under the same conditions. All membranes gave permeate product water of <0.2 NTU and <100ppb coagulant at all times. For both membranes mechanical cleaning, with sponge balls, was at least as effective as acid chemical cleaning, indicating that no significant permanent internal fouling occurred for these membrane materials. Hydraulic resistance data indicated a significant difference in the dynamic layer resistance between the two membranes. Whilst the UF membrane had a hydraulic resistance 3.7 times that of the MF membrane, the dynamic layer formed on the UF membrane during operation displayed a maximum hydraulic resistance almost nine times lower than that of the MF membrane operating under the same conditions. Correlation of cake resistance R versus feed solids concentration C for all the data generated for t>0 demonstrated reasonable agreement with the expression R∝ca where a=0.37 in the current study. This trend has been recorded in previous reported studies, a varying between 0.33 and 0.62 depending on sludge dewaterability.


2016 ◽  
Vol 11 (2) ◽  
pp. 210-217 ◽  
Author(s):  
A.T. Akhmetov ◽  
A.A. Valiev ◽  
A.A. Rakhimov ◽  
S.P. Sametov ◽  
R.R. Habibullina

It is mentioned in the paper that hydrodynamic conditions of a flow in blood vessels with the stenosis are abnormal in relation to the total hemodynamic conditions of blood flow in a vascular system of a human body. A microfluidic device developed with a stepped narrowing for studying of the blood flow at abnormal conditions allowed to reveal blood structure in microchannels simulating the stenosis. Microstructure change is observed during the flow of both native and diluted blood through the narrowing. The study of hemorheological properties allowed us to determine an increasing contribution of the hydraulic resistance of the healthy part of the vessel during the stenosis formation.


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