scholarly journals PROSPECTS FOR THE DEVELOPMENT AND USE OF WATER-COOLED FUEL (REVIEW)

Author(s):  
A.S. Makarov

The perspective of obtaining fuels based on different degrees of metamorphism coals and organic waste has been considered. Coal-water fuel is a highly concentrated dispersed system consisting of a highly dispersed coal fraction and water with additives of plasticizers and stabilizers. Using these additives in the slurry gives possibility to reduce their viscosity, as well as to provide aggregative and sedimentation stability at higher concentrations of the solid phase. To ensure the ecological safety of combustion products in suspension, if it is necessary, products are added such as desulfurizers, corrosion inhibitors. The resulting slurry fuels are highly caloric and environmentally friendly. The suspension fuel caloric content can reach and even exceed the coal energy intensity. Due to this, as one of the components of dispersion medium industrial waste can be used. All harmful organic components decompose and burn at high temperatures (above 1200 °C). Bibl. 25.

2021 ◽  
Vol 12 (1) ◽  
pp. 32-39
Author(s):  
A. S. Makarov ◽  
◽  
R. E. Klishchenko ◽  
A. I. Egurnov ◽  
I. V. Kornienko ◽  
...  

Man-caused load on sources of industrial and domestic water supply, which causes the discharge of insufficiently treated wastewater, is one of the great environmental problems in Ukraine. The traditional way of solving this problem, associated with the disposal of such waters by adsorption, membrane or catalytic technologies, has a number of disadvantages associated with large volumes and a wide range of pollutants, traditional methods often require preparatory measures, time-consuming, scarce materials and expensive equipment. It would be ideal to create waste-free circulating water supply technologies, but these options are still far from being mass-produced. A promising way to solve these problems is to organize such production cycles, where the disposal of toxic wastewater will be combined with recovery technologies. Industrial and domestic wastewater often contains a significant proportion of the organic component. These are oil products, by-products of organic synthesis, spent lubricating and cooling suspensions, waste from the food, alcohol and pulp and paper industries, dyes and pigments, etc. All this waste is energy saturated and can be separated and used as fuel. However, due to low concentrations in most wastewater, their separation is economically unprofitable. A method is proposed for neutralizing toxic organic wastewater by using it as a dispersion medium for composite coal-aqueous fuel (CAF). The possibility of priming carbon microparticles obtained by preliminary plasma-chemical treatment of an organic dispersion medium to stabilize composite coal-water fuel were investigated. Waste cutting fluid (JCL) was used as an organic dispersion medium; anthracite served as the dispersed phase. A CAF sample was obtained based on anthracite from Ukrainian deposits with a solid phase (W) content of 70 mass. %, and studied its electrokinetic and rheological properties. It has been found that the preliminary plasma-chemical conversion of organic wastewater used as a dispersion medium for composite water-coal fuel significantly improves the operational properties of CAF. The growth of sedimentation stability and the optimization of the effective viscosity are achieved mainly through the implementation of the structural and mechanical factor by increasing the number of contacts with the introduction of a highly dispersed fraction of carbon microparticles and increasing the electrostatic repulsion of the elements of the suspension structure. Thus, the sedimentation stability of the obtained CAF is significantly improved in comparison with conventional anthracite suspensions in organic wastewater and reaches 2 days without the addition of stabilizers. In the future, it is planned to further improve the properties of CAF by introducing stabilizing reagents and dispersants into its composition.


2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Kiril Hristov Kolikov ◽  
Dimo Donchev Hristozov ◽  
Radka Paskova Koleva ◽  
Georgi Aleksandrov Krustev

We introduce a close packing model of the particles from the disperse phase of a liquid dispersion. With this model, we find the sediment volumes, the emergent, and the bound dispersion medium. We formulate a new approach for determining the equivalent radii of the particles from the sediment and the emergent (different from the Stokes method). We also describe an easy manner to apply algebraic method for determining the average volumetric mass densities of the ultimate sediment and emergent, as well as the free dispersion medium (without using any pycnometers or densitometers). The masses of the different components and the density of the dispersion phase in the investigated liquid dispersion are also determined by means of the established densities. We introduce for the first time a dimensionless scale for numeric characterization and therefore an index for predicting the sedimentation stability of liquid dispersions in case of straight and/or reverse sedimentation. We also find the quantity of the pure substance (without pouring out or drying) in the dispersion phase of the liquid dispersions.


1989 ◽  
Vol 28 (04) ◽  
pp. 120-123 ◽  
Author(s):  
J. A. Siegel ◽  
L. Mortelmans ◽  
E. van Cutsem ◽  
V. van den Maegdenbergh ◽  
M. de Roo ◽  
...  

In this study, we have evaluated the effect of the caloric content of a physiological test meal on the gastric emptying kinetics of solids and liquids. 22 healthy male volunteers were studied in two groups matched for age. After an overnight fast, each volunteer underwent the same test procedure; in the first group (G I), 10 volunteers received a meal consisting of bread,111In-DTPA water and 1 scrambled egg labeled with 99mTc-labelled sulphur colloid; in the second group (G II) 12 volunteers were given the same meal but with 2 labeled eggs in order to increase the caloric content of the solid phase meal. Simultaneous anterior and posterior images were recorded using a dualheaded gamma camera. Solid and liquid geometric mean data were analyzed to determine the lag phase, the emptying rate and the half-emptying time for both solids and liquids. Solid and liquid gastric half-emptying times were significantly prolonged in G II compared to G I volunteers. For the solid phased, the delay was accounted for by a longer lag phase and a decrease in the equilibrium emptying rate. The emptying rate of the liquid phase was significantly decreased in G II compared to G I. Within each group, no statistically significant difference was observed between solid and liquid emptying rates. We conclude that the caloric content of the solid portion of a meal not only alters the emptying of the solid phase but also affects the emptying of the liquid component of the meal.


2015 ◽  
Vol 1095 ◽  
pp. 53-57
Author(s):  
Xin Wang Ouyang ◽  
Zhang Yong Wu ◽  
Zi Yong Mo

The water-based nanoTiN fluids were prepared by nanoTiN particles, dispersion medium and dispersant using a two-step method. The dispersion and rheology of nanoparticles in water-based fluid were studied under different preparation conditions. The dispersion and rheology of prepared nanoTiN fluids were evaluated and analyzed from the mass fraction of nanoparticles, mass fraction of dispersant and type of dispersion medium respectively by using the analysis of sedimentation stability and rheological properties. The results show that the above-mentioned factors all have different degree of influence on nanofluids’ dispersion and rheology. The viscosity of nanofluids increases with mass fraction of nanoparticles. A balance amount of mass fraction of dispersant will improve nanofluids’ dispersity and fluidity. The dispersion effect of deionized water is the best when the nanoparticles dispersed in different dispersion medium.


Author(s):  
Yu. E. Pivinskii

The features of the rheological behavior of CFRC matrix systems are considered as highly concentrated dispersed systems. They are characterized by a dilatative, thixotropic and thixotropic-dilatant nature of the flow, depending on the composition, concentration, dispersion, and a number of other factors. The equation of the concentration dependence of the viscosity of suspensions (Pivinskii equation) is proposed. It is shown that the determining factor is the content of a kinetically free dispersion medium in them. The effect of the content of grain aggregate on the rheological properties of foundry systems is characterized. The significant effect of polydispersity of the particles of the solid phase and the temperature on the rheological properties of the HCBS with the dilatant nature of the flow is shown. The data on the effect of defloculation and stabilization of matrix systems on their rheological properties, which determine the reeterological properties of molding systems to obtain CFRC. Ill. 13. Ref. 50. 


2021 ◽  
pp. 104-112
Author(s):  
Mikhail Egorov ◽  
◽  
Dmitry Egorov ◽  
Sergey Egorov ◽  
◽  
...  

The article presents the results of numerical calculations of the dynamics of in-chamber processes in the cruise missile's second-stage cruise missile propulsion system, taking into account the distributed space-three-dimensional and time-varying flight overloads, obtained using the previously developed calculation method and the application software package created on its basis. The value of the flight overload of a cruise missile, in projections along the coordinate axes, is determined depending on the mass, speed and trajectory of the rocket, mass flow and thrust of the rocket engine. The external aerodynamic effect on the in-chamber process in the SRM is neglected. The results of the calculations are given in comparison-without taking into account and taking into account the effect of flight overload. Two main stages of the rocket engine operation are considered: entering the operating mode and the main operating mode. At the stage of entering the SRM operation mode, the overload affects the redistribution of the temperature of the gas phase of the combustion products in the area of the front bottom of the combustion chamber. On the March operation of the SRB as a result of the flight of an overload, an increase of the particle density (liquid drops) small and large diameter of the solid phase of the combustion products in the wall of the back plate and pre-exhaust gas flue, and the degree of change in the distribution density of the particles (liquid droplets) that are larger than large. The results of the numerical study are in good agreement with the experimental data – the results of bench tests of the rocket engine and the results of flight tests of the cruise missile, which includes the considered SRM.


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