Pulps. Determination of mass fraction of fines

2011 ◽  
Keyword(s):  
Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Bartosz Gil ◽  
Anna Szczepanowska ◽  
Sabina Rosiek

In this work, which is related to the current European Parliament Regulation on restrictions affecting refrigeration, four new three-component refrigerants have been proposed; all were created using low Global Warming Potential(GWP) synthetic and natural refrigerants. The considered mixtures consisted of R32, R41, R161, R152a, R1234ze (E), R1234yf, R1243zf, and RE170. These mixtures were theoretically tested with a 10% step in mass fraction using a triangular design. The analysis covered two theoretical cooling cycles at evaporating temperatures of 0 and −30 °C, and a 30 °C constant condensing temperature. The final stage of the work was the determination of the best mixture compositions by thermodynamic and operational parameters. R1234yf–R152a–RE170 with a weight share of 0.1/0.5/0.4 was determined to be the optimal mixture for potentially replacing the existing refrigerants.


We have measured the kinematic viscosity of glycerol-water mixtures, for glycerol mass fractions ranging from 0 to 1, in the temperature range 10-50 °C. The measurements were made by using a series of Ubbelohde viscometers. Apart from comprehensiveness and comparative accuracy the present measurements expose serious errors in the limited data that were earlier available on such mixtures. It is shown that all the data can be reasonably represented by the empirical correlation (In ν m - In ν w )/(In ν g - In ν w ) = x g [1 + (1 - x g ) { a + bx g + cx g 2 }], where ν w , v g and ν m are the kinematic viscosities of water, glycerol and the mixture respectively and x g is the mass fraction of glycerol in the mixture. The constants a, b and c are tabulated in the paper as functions of temperature. This correlation can now be used at a given temperature to tailor make a mixture of prescribed kinematic viscosity. While this paper is addressed, principally, to fluid dynamicists these results should be of interest to physicists studying the liquid state and physical chemists interested in mixtures.


2019 ◽  
Vol 9 (10) ◽  
pp. 2001
Author(s):  
Vladimir Kochemirovsky ◽  
Svetlanav Kochemirovskaia ◽  
Michael Malygin ◽  
Alexey Kuzmin ◽  
Maxim Novomlinsky ◽  
...  

The development of an algorithm to automate the process of measuring the magnetic properties of macroscopic objects in motion is an important problem in various industries, especially in ferrous metallurgy and at factories where ferrous scrap is a strategic raw material. The parameter that requires work control is the hidden mass fraction of a non-magnetic substance that is present in the ferromagnetic raw material. The solution to this problem has no prototypes. In our work, a simple measuring device and a mathematical algorithm for calculating the mass fraction of the non-magnetic fraction in a strongly magnetic matrix were developed. The device is an inductance coil, in which the angle of the electromagnet losses is related to the mass of the magnetic material moving the coil. The magnitude of the instantaneous values of the lost angle integral was compared with the result of weighing the object on scales. This allowed us to calculate the proportion of the magnetic and non-magnetic fractions. The use of this prototype is herein illustrated. The experimental results of the determination of the magnetic-fractional composition depending on the mass of scrap metal and its bulk and the magnetic characteristics are presented.


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