Stochastic model of the flow mechanically stirred solid-liquid system

1980 ◽  
Vol 45 (7) ◽  
pp. 2070-2084 ◽  
Author(s):  
Vladimír Kudrna ◽  
Václav Machoň ◽  
Vlasta Hudcová
Keyword(s):  
Diffusion Equation ◽  
Stochastic Model ◽  
Boundary Conditions ◽  
Stationary State ◽  
Flow System ◽  
Solid Phase ◽  
Liquid System ◽  
Ideal Mixing ◽  
Phase Liquid ◽  
Solid Liquid

An attempt is made to describe by use of the onedimensional stochastic model the flow system solid phase-liquid stirred by the mechanical rotary mixer. At the assumption that the solid phase is dimensionally homogenous a diffusion equation has been obtained which is solved under the boundary conditions, characterizing the method of withdrawal of the solid phase from the system. It is demonstrated that the model can express also the relations usually used for description of similar situations (ideal mixing, separation coefficients in stationary state etc.) like individual cases.

scholarly journals Solid-liquid equilibrium in liquid compound fertilizers

2018 ◽  
Vol 24 (1) ◽  
pp. 59-68
Author(s):  
Kristina Jancaitienė ◽  
Rasa Slinksienė
Keyword(s):  
Crystallization Temperature ◽  
High Speed ◽  
Solid Phase ◽  
Nitrogen Concentration ◽  
Multicomponent System ◽  
Liquid System ◽  
Insoluble Residue ◽  
Aqueous Salt Solutions ◽  
Calcium Magnesium ◽  
Solid Liquid

Liquid compound fertilizers (LCF) are aqueous salt solutions which nourish the soil. They contain nitrogen, phosphorus, potassium, sometimes calcium, magnesium and micronutrients. An LCF solution has practically no insoluble residue and contains the elements in a fully digestible form and is a high-speed, highly effective fertilizer. It is important to assess the equilibrium in the solid-liquid system when creating liquid compound fertilizers, since their basic properties, concentration and crystallization temperature, depend on it. The aim of the study was to determine properties of a liquid multicomponent (K+, NH4 +, Cl- and PO4 3-) system. This liquid multicomponent system, which was obtained as a by-product in the conversion of KCl and NH4H2PO4, can be used as a liquid fertilizer. This work investigates liquid fertilizers? chemical composition and their physicochemical properties, such as crystallization temperature, pH, density, viscosity and corrosivity. In order to increase nitrogen concentration, ammonium nitrate was added. Composition of the solid phase obtained by crystallization was identified by methods of chemical and instrumental analysis (radiography, infrared molecular absorption spectroscopy and optical microscopy). The results show that all properties of liquid fertilizers are best when the concentration of NH4NO3 in liquid solutions equals 8%.

scholarly journals Acid and enyzymatic hyrolysis of Solarium tuberosum L. Glycoalkaloids: Comparison results

2006 ◽  
Vol 12 (4) ◽  
pp. 241-245 ◽  
Author(s):  
Nada Nikolic ◽  
Mihajlo Stankovic ◽  
Milorad Cakic
Keyword(s):  
Liquid Phase ◽  
Enzymatic Hydrolysis ◽  
Acid Hydrolysis ◽  
Liquid System ◽  
Two Phase ◽  
Comparison Results ◽  
Phase Liquid ◽  
Comparison Of The Results ◽  
Solid Liquid ◽  
Hydrolysis Of

A comparison of the results of the acid and enzymatic hydrolysis of GA from potato haulm and tuber sprouts is presented in this paper. Different systems were used for acid hydrolysis: monophase liquid, two-phase liquid-liquid or solid-liquid and three-phase solid-liquid-liquid systems. Enzymatic hydrolysis was carried out by enzymes present in fresh haulm and fresh tuber sprouts and the fresh juice obtained from fresh plant material. The procedure of acid hydrolysis of GA from potato sprouts in a two-phase liquid-liquid system was selected as the optimal procedure for obtaining solanidine. The liquid-liquid system was composed of GA extract with hydrochloric acid as the first liquid phase and chloroform as the second liquid phase. A degree of GA hydrolysis of 96% and a solanidine yield of 1.50 g per 100 g of dried tuber sprouts after 90 minutes were then achieved.

scholarly journals Peloids as Thermotherapeutic Agents

2021 ◽  
Vol 18 (4) ◽  
pp. 1965 ◽  
Author(s):  
Francisco Maraver ◽  
Francisco Armijo ◽  
Miguel Angel Fernandez-Toran ◽  
Onica Armijo ◽  
Jose Manuel Ejeda ◽  
...  
Keyword(s):  
Solid Phase ◽  
Raw Materials ◽  
Liquid System ◽  
Mineral Waters ◽  
Heat Flow Rate ◽  
Psoriatic Arthropathy ◽  
Reduction Of Pain ◽  
Solid Liquid ◽  
Main Effects

The use of peloids as heat-providing therapeutic systems dates back to antiquity. Such systems consist of a liquid phase and an organic or inorganic solid phase. The latter facilitates the handling, preparation and stability of the solid–liquid system, modifying its organoleptic and phy-sicochemical properties, and improves its efficacy and tolerance. Peloids enable the application of heat to very specific zones and the release of heat at a given rate. The aims of this work are to study 16 reference peloids used in medical spa centers as thermo-therapeutic agents as well as to propose nine raw materials as a solid phase for the preparation of peloids. The physical properties studied are the centesimal composition, the instrumental texture and the thermal parameters. In conclusion, the peloids of the medical spas studied are used as thermotherapeutic agents in the treatment of musculoskeletal disorders, especially in knee osteoarthritis and to a lesser extent in back pain and psoriatic arthropathy. The clinical experience in these centers shows that the main effects of the application of their peloids are the reduction of pain, an increase in the joint’s functional capacity and an improvement in the quality of life. As thermotherapeutic agents, all the peloids of the me-dical spas studied and the pastes (raw materials with distilled water) examined showed a heat flow rate of up to four times lower than that shown by the same amount of water. The raw materials studied can be used as solid phases for the preparation of peloids with mineral waters.

A Circuit-Based Dynamic Characteristic Analysis on the Propelling Flow System in Liquid Rockets

2013 ◽  
Vol 765-767 ◽  
pp. 227-233
Author(s):  
Ming Yang ◽  
Zhi Chun Yang
Keyword(s):  
Boundary Conditions ◽  
Natural Frequency ◽  
Flow Parameter ◽  
Flow System ◽  
Mathematic Model ◽  
Liquid System ◽  
Accurate Solution ◽  
Point Of View ◽  
Characteristic Analysis ◽  
Network Function

To penetrate into the study of POGO vibration, by taking the LRC equivalent circuit analyzing method, based on two boundary conditions in document [, taking the flow pulse drive into consideration, this paper proposes four boundary conditions specific to the propelling flow system in liquid rockets, and at the same time, complements the mathematic model. Further, by way of network function, under the liquid system flow parameter, this paper infers transfer function expressions, and makes the accurate solution of the natural frequency under every boundary condition. At last, from the statistic point of view, by the method of correlation coefficient, this paper studies the influence that the flow parameter may have on the system natural frequency, and set the major influential liquid flow parameter to the system natural frequency of liquid propelling flow system in liquid rockets.

scholarly journals Estimating Just Suspension Speed for Stirred Reactors Using Power Measurement

2019 ◽  
Vol 2 ◽  
pp. 1-5
Author(s):  
Raja Shazrin Shah Raja Ehsan Shah ◽  
Baharak Sajjadi ◽  
Abdul Aziz Abdul Raman ◽  
Tiam You See ◽  
Shaliza Ibrahim ◽  
...  
Keyword(s):  
Power Consumption ◽  
Solid Phase ◽  
Liquid System ◽  
Solid Particles ◽  
Power Measurement ◽  
Internal Diameter ◽  
Rushton Turbine ◽  
Suspend Solid ◽  
Experimental Values ◽  
Solid Liquid

A simplified mathematical model was developed to predict the just suspended speed, NJS in a solid-liquid system by analyzing the net impeller power consumption to suspend solid particles. A fully baffled tank with an internal diameter of 400mm equipped with a standard Rushton turbine with a diameter of D=T/3 (133mm) was used in this work. Glass beads were used as the solid phase and distilled water was used as the liquid phase. Solid loadings were varied within the range of 0-27 wt%. Power consumption was measured using the shaft torque method. The predicted NJS values were in a good approximation to the experimental values using the Zwietering’s criterion with a deviation of 2 – 10%. The deviation was lower for higher solid concentrations.

scholarly journals Simulation of Formation of Icosahedral Structure in Solid-Liquid-Solid Phase Change Using Molecular Dynamics Methods

2017 ◽  
Vol 17 (1) ◽  
pp. 19 ◽  
Author(s):  
Nikodemus Umbu Janga Hauwali ◽  
Artoto Arkundato ◽  
Lutfi Rohman
Keyword(s):  
Molecular Dynamics ◽  
Phase Change ◽  
Solid Phase ◽  
Icosahedral Phase ◽  
Temperature Decrease ◽  
Icosahedral Structure ◽  
Cooling Temperature ◽  
Molecular Dynamics Methods ◽  
Phase Liquid ◽  
Solid Liquid

It has successfully conducted research to study the structure of the icosahedral formation in the event of change of the solid phase - liquid-solid using molecular dynamics method . The result showed that the percentage of the maximum icosahedral structure is obtained when the simulation is run at the start of the cooling temperature of 2875 K at a rate of temperature decrease of 0.064 K /step and at the beginning of the cooling temperature of 3000 K at a rate of temperature decrease 0.12 K/step. While icosahedral minimum percentage obtained when the simulation is run at a temperature of 2750 K with the initial cooling rate of temperature decrease of 0.069 K/step. Based on these results we can conclude that there is a relationship between the initial temperature of the cooling and the rate of temperature decrease of the icosahedral structure is formed. Keywords: Icosahedral, phase change, molecular dynamics

Stochastic model of nonideal mixer. Boundary conditions in batch system

1984 ◽  
Vol 49 (2) ◽  
pp. 490-505
Author(s):  
Vladimír Kudrna ◽  
Pavel Hasal ◽  
Jiří Vlček
Keyword(s):  
Experimental Data ◽  
Stochastic Model ◽  
Boundary Conditions ◽  
Closed System ◽  
Batch System ◽  
Ideal Mixer

The earlier proposed general approach for description of the non-ideal mixer is coupled with corresponding boundary conditions for the closed system. Some simplifications in this procedure result in relations which are in agreement with experimental data.

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