Improving the flow sheet of slip preparation

1986 ◽  
Vol 43 (5) ◽  
pp. 206-208
Author(s):  
V. I. Goncharov ◽  
V. I. Akimov ◽  
K. P. Belous
Keyword(s):  
Flow Sheet ◽  
Slip Preparation

Comparative Study of GaN Growth Process by MOVPE

1999 ◽  
Vol 572 ◽  
Author(s):  
Jingxi Sun ◽  
J. M. Redwing ◽  
T. F. Kuech
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Gas Phase ◽  
Residence Time ◽  
Gas Flow ◽  
Flow Sheet ◽  
Flow Zone ◽  
High Quality ◽  
Phase Temperature ◽  
High Temperature Gas

ABSTRACTA comparative study of two different MOVPE reactors used for GaN growth is presented. Computational fluid dynamics (CFD) was used to determine common gas phase and fluid flow behaviors within these reactors. This paper focuses on the common thermal fluid features of these two MOVPE reactors with different geometries and operating pressures that can grow device-quality GaN-based materials. Our study clearly shows that several growth conditions must be achieved in order to grow high quality GaN materials. The high-temperature gas flow zone must be limited to a very thin flow sheet above the susceptor, while the bulk gas phase temperature must be very low to prevent extensive pre-deposition reactions. These conditions lead to higher growth rates and improved material quality. A certain range of gas flow velocity inside the high-temperature gas flow zone is also required in order to minimize the residence time and improve the growth uniformity. These conditions can be achieved by the use of either a novel reactor structure such as a two-flow approach or by specific flow conditions. The quantitative ranges of flow velocities, gas phase temperature, and residence time required in these reactors to achieve high quality material and uniform growth are given.

Circulation technology for slip preparation

1978 ◽  
Vol 35 (6) ◽  
pp. 344-347
Author(s):  
Z. A. Denyakin
Keyword(s):  
Slip Preparation

Correlation of a Volcanic Ash bed in Pleistocene Deposits near Mount Blanco, Texas, with the Guaje Pumice Bed of the Jemez Mountains, New Mexico

1972 ◽  
Vol 2 (4) ◽  
pp. 554-578 ◽  
Author(s):  
Glen A. Izett ◽  
Ray E. Wilcox ◽  
Glenn A. Borchardt
Keyword(s):  
New Mexico ◽  
Volcanic Ash ◽  
Fission Track ◽  
Major Elements ◽  
Flow Sheet ◽  
Chemical Analyses ◽  
Sedimentary Deposits ◽  
Jemez Mountains ◽  
Bandelier Tuff ◽  
Minimum Age

A rhyolitic volcanic ash bed about 0.3 m thick is exposed in a roadcut along Texas Highway 193 near Mount Blanco in the upper part of a sequence of Pleistocene sedimentary deposits at the type locality of the Blanco Formation, about 59 km northeast of Lubbock, Texas. This ash, here named informally the Guaje ash bed, has chemical and petrographic characteristics closely resembling those of the rhyolitic air-fall tephra (Guaje Pumice Bed) that directly underlies ash flows of Pleistocene age in the Jemez Mountains of northern New Mexico. The Guaje Pumice Bed and the ash flows belong to the Otowi Member of the Bandelier Tuff. Properties common to the Guaje ash bed and the Guaje Pumice Bed include: refractive index of glass, 1.497–1.498; microphenocrysts of quartz, sanidine (Or42–44), ferrohedenbergite (Fe51Ca42Mg7), chevkinite, allanite, zircon, and magnetite. Chemical composition of the glass of the Guaje ash bed matches that of the Guaje Pumice Bed for all major elements except K and Na and for trace elements determined by standard chemical analyses, atomic absorption, and neutron activation. Paleomagnetic measurements indicate that the ash has reverse depositional remanent magnetization. Glass shards of the ash have a fission-track age of about 1.4 ± 0.2 m. y. Sanidine from the Guaje Pumice Bed and its genetically related ash-flow sheet in the Jemez Mountains was K-Ar dated at about 1.4 m. y. by R. R. Doell and his colleagues in 1968. Correlation of the Guaje ash bed with the radiometrically dated Guaje Pumice Bed establishes a minimum age of about 1.4 m. y. for the Blanco Formation.

scholarly journals Combined Vapor Permeation and Continuous Solid-State Distillation for Energy-Efficient Bioethanol Production

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2266
Author(s):  
Hongshen Li ◽  
Hongrui Liu ◽  
Yufang Li ◽  
Jilin Nan ◽  
Chen Shi ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Efficient ◽  
Simulation Software ◽  
Separation Performance ◽  
Flow Sheet ◽  
Bioethanol Production ◽  
Permeate Flux ◽  
Rectification Column ◽  
Vapor Permeation ◽  
Wide Range

Extracting ethanol by steam directly from fermented solid-state bagasse is an emerging technology of energy-efficient bioethanol production. With continuous solid-state distillation (CSSD) approach, the vapor with more than 25 wt% ethanol flows out of the column. Conventionally, the vapor was concentrated to azeotrope by rectification column, which contributes most of the energy consumption in ethanol production. As an alternative, a process integrating CSSD and vapor permeation (VP) membrane separation was tested. In light of existing industrial application of NaA zeolite hydrophilic membrane for dehydration, the prospect of replacing rectification operation with hydrophobic membrane for ethanol enriching was mainly analyzed in this paper. The separation performance of a commercial PDMS/PVDF membrane in a wide range of ethanol–water-vapor binary mixture was evaluated in the experiment. The correlation of the separation factor and permeate flux at different transmembrane driving force was measured. The mass and energy flow sheet of proposed VP case and rectification case were estimated respectively with process simulation software based on experimental data. Techno-economic analysis on both cases was performed. The results demonstrated that the additional VP membrane cost was higher than the rectification column, but a lower utilities cost was required for VP. The discount payback period of supplementary cost for VP case was determined as 1.81 years compared with the membrane service lifetime of 3 years, indicating that the hybrid CSSD-VP process was more cost effective and energy efficient.

Processing Technogenic Raw Materials-Phosphorus Slags with the Production of Precipitated Nanosilica and Simultaneous Recovery of Valuable Components

2021 ◽  
Vol 316 ◽  
pp. 637-642
Author(s):  
Yelena G. Bochevskaya ◽  
Zaure B. Karshigina ◽  
Aynash S. Sharipova
Keyword(s):  
Specific Surface ◽  
Raw Materials ◽  
Nitric Acid Concentration ◽  
Process Conditions ◽  
Flow Sheet ◽  
Process Duration ◽  
Precipitated Silica ◽  
Component Content ◽  
Slag Processing ◽  
White Soot

The paper provides a flow sheet of the phosphorus slag processing to produce precipitated silica (white soot). The process conditions for opening phosphorus slag at the I stage of leaching have been selected: the nitric acid concentration is 3.5 mol/dm3; the ratio S:L = 1:3.5; the temperature is 60 oС; and the process duration is 1 hour. The parameters of the white soot production II stage have been determined: the HNO3 concentration is 6.5 mol/dm3; the ratio S:L = 1:3.5; the temperature is 50 oС; and the process duration is 1 hour. The temperature effect on the white soot structure and the specific surface have been established. At optimal process parameters, the white soot batches have been obtained with the main SiO2 component content of 88.2 and 90.5 %, and a specific surface of 170 and 182 m2/g, respectively. The through recovery of silicon into a commercial product is 98.0 % of its initial content in slag.

scholarly journals DISTILLATION OF BINARY TWO-PHASE MIXTURES WITH VARIOUS PHYSICO-CHEMICAL PROPERTIES: NORMAL MODE AND DEVIATIONS FROM IT

2016 ◽  
Vol 11 (4) ◽  
pp. 15-25
Author(s):  
L. A. Serafimov ◽  
K. A. Morozov
Keyword(s):  
Energy Consumption ◽  
Binary Mixtures ◽  
Normal Mode ◽  
Chemical Properties ◽  
Flow Sheet ◽  
Multicomponent Mixtures ◽  
Two Phase ◽  
Independent Variables ◽  
Physico Chemical ◽  
Key Indicators

In this article, the normal continuous mode of distillation is considered using an example of binary two-phase mixture distillation. In practice, there are often deviations from the normal mode. It has been proved that the deviation leads to an increase in energy consumption for the ongoing process. In the industry, columns separating binary mixtures are normally the finishing apparatuses in the flow-sheet separation of multicomponent mixtures, which are obtained in the reactor as a result of main reactions as well as by-reactions. The distillation of binary mixtures is relatively simpler than that of multicomponent mixtures. In this regard, the fundamental parts of monographs especially in the thirties-forties of the last century started with the study of binary mixtures, although multicomponent mixtures were the main focus. The aim of analyzing this complex and the highly energy-intensive process is to facilitate the choice of a mathematical model for the process and the determination on its basis variance. Variance is a set of independent variables that allow calculation of a process only after taking into account the number of independent equations related to these variables. A case of deviation from the normal distillation regime where an under-heated liquid enters the column feed has been revised. This leads to an increase in energy consumption during distillation. Key indicators of the normal regime relative to the level of feed and the temperature of the liquid are shown in the text.

Research on Improving the Classification-Gravity Concentration Technology Based on an Anshan-Type Low-Grade Hematite Ore

2012 ◽  
Vol 454 ◽  
pp. 256-260 ◽  
Author(s):  
Bao Yu Cui ◽  
De Zhou Wei ◽  
Rui Yang Zhang ◽  
Si Yao Zhang
Keyword(s):  
Size Distribution ◽  
Magnetic Separation ◽  
Low Grade ◽  
Flow Sheet ◽  
Gravity Concentration ◽  
Mineralogical Characteristics ◽  
Hematite Ore ◽  
Iron Grade

The beneficiation of Anshan-type low-grade hematite ores attracts more and more attention. Complicated beneficiation flow sheets are necessary to deal this type of ores. Classification-gravity concentration technology is used widely in these flow sheets because of its characteristics. In this paper, grinding characteristics and classification-gravity concentration tests were carried out based on the ore’s mineralogical characteristics. When the ground size of the ore was 75% -0.071mm, through beneficiation by the flow sheet of classification-gravity concentration-middle intensity magnetic separation discarding, a satisfactory concentrate assaying 67.58% Fe, 47.51% recovery was obtained, and the iron grade and yield of the tailings were 5.93% and 39.77% respectively. The controlling of the size distribution and the behavior of finer hematite grains is important and efficiency in beneficiation of Anshan-type hematite ores.

Plagioclase zoning in the setogawa ash-flow sheet of the Nohi rhyolite complex, central Japan

1974 ◽  
Vol 45 (3) ◽  
pp. 187-196 ◽  
Author(s):  
Tsuyoshi Morohashi ◽  
Shohei Banno ◽  
Masao Yamasaki
Keyword(s):  
Flow Sheet ◽  
Central Japan ◽  
Plagioclase Zoning

A Cancer Detection Flow Sheet

JAMA ◽  
1969 ◽  
Vol 208 (2) ◽  
pp. 361
Author(s):  
Richard D. Scott
Keyword(s):  
Cancer Detection ◽  
Flow Sheet
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