Plastics piping systems. Fittings, valves and ancillaries. Determination of gaseous flow rate/pressure drop relationships

1998 ◽  
2019 ◽  
Vol 213 ◽  
pp. 02069
Author(s):  
Tomáš Polášek ◽  
Adam Bureček ◽  
Lumír Hružík

The article is focused on mathematical simulation of the temperature influence on the pressure drop at the pump suction line. It is evaluated pressure drop depending on mineral oil flow rate. The courses of individual dependencies are determined by mathematical simulation using the ANSYS CFD computing software. The temperature affects significantly physical properties of the flowing mineral oil. In a paper is also described the experimental measurement of a mineral oil sample and determination of its physical properties depending on temperature.


2020 ◽  
pp. 0958305X2094531
Author(s):  
Hebert Lugo-Granados ◽  
Lázaro Canizalez-Dávalos ◽  
Martín Picón-Núñez

The aim of this paper is to develop guidelines for the placing of new coolers in cooling systems subject to retrofit. The effects of the accumulation of scale on the flow system are considered. A methodology to assess the interconnected effect of local fluid velocity and fouling deposition is developed. The local average fluid velocity depends on the water flow rate distribution across the piping network. The methodology has four main calculation components: a) the determination of the flow rate distribution across the piping network, b) the prediction of fouling deposition, c) determination of the hydraulic changes and the effect on fouling brought about by the placing of new exchangers into an existing structure, and d) the calculation of the total cooling load and pressure drop of the system. The set of disturbances introduced to the system through fouling and the incorporation of new coolers, create network responses that eventually influence the cooling capacity and the pressure drop. In this work, these interactions are analysed using two case studies. The results indicate that, from the thermal point of view, the incorporation of new heat exchangers is recommended in series. The limit is the point where the increase of the total pressure drop causes a reduction in the overall volumetric flow rate. New coolers added in parallel create a reduction of pressure drop and an increase in the overall water flow rate; however, this increase is not enough to counteract the reduction of fluid velocity and heat capacity removal.


1983 ◽  
Vol 48 (12) ◽  
pp. 3356-3369 ◽  
Author(s):  
Vladimír Jiřičný ◽  
Vladimír Staněk

The paper gives a review of present approaches to the problem of a single- and two-phase flow in a packed bed. A new definititon has been given of the flooding point, which, as far as the theory is concerned, rigorously defines critical values of the quantities in the flooding point. At the same time, the definition enables a unambiguous experimental determination of the flooding point from experimental dependence sof the hold-up or pressure drop on the flow rate of phases. Based on extensive experimental data three alternative forms have been proposed of the versatile correlation of liquid hold-up on the velocity of liquid at the zero velocity of gas. The correlations have been formulated on the principle of automodel properties and define the appropriate relationships in terms of normalized variables related to the newly defined flooding point. The dependences on the geometry parameters of the packing and physical properties of liquid appear in the versatile correlations only implicitly. A new possibility has been shown of inverse utilization of the versatile correlations for the determination of the critical values (the flooding point) from two independent measurements of liquid hold-up in a real apparatus.


2001 ◽  
Vol 44 (10) ◽  
pp. 171-176 ◽  
Author(s):  
F.M. Tiller ◽  
W.P. Li ◽  
J.B. Lee

In accord with Darcy's law, the flow rate through a porous bed depends upon the pressure drop Δpc. In general, increasing Dpc leads to increased values of flow rate and average percentage solids in filtration operations. When cakes become super-compactible, their behavior undergoes an unexpected change in which both the flow rate and the percentage solids reach maximum values and thereafter are unaffected by increasing Δpc. The critical pressure drop ΔpcR is defined as that value at which the flow rate reaches 90% of its ultimate value. When Δpc is greater than DpcR and is doubled or tripled, the cake resistance approximately doubles or triples leaving the rate virtually unchanged. The super-compactibility problem is analyzed theoretically, and is verified by stepped pressure filtration experiments on different materials from Houston and Korea.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5933
Author(s):  
Pawel Sliwinski

A new methodology of determination of the theoretical and actual working volume of a hydraulic motor based on the characteristics of the delivered flow rate into hydraulic motor vs. the rotational speed at a constant pressure drop in the working chambers is described in this paper. A new method of describing the delivered flow rate into a motor per one shaft revolution as a nonlinear function of the pressure drop in the motor working chamber is proposed. The influence of the flowmeter location in the measurement system on the result of the theoretical and actual working volume calculation is described. It is shown that, in order to assess the energy losses (volumetric and mechanical) in the motor, the actual working volume must be a polynomial function (third degree) of its pressure drop in the working chambers. The result of the experimental tests of the satellite hydraulic motor confirmed the validity of the proposed method. The result of the calculation of the theoretical working volume of the motor according to the proposed method was compared with the results of calculations according to known methods.


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