Confirmation of The Fouling Phenomena in CDI Process and The Establishment of Its Removal Process Conditions

2019 ◽  
Vol 29 (5) ◽  
pp. 276-283 ◽  
Author(s):  
Tae Yeong Kim ◽  
Ji Won Rhim
Keyword(s):  
Process Conditions ◽  
Removal Process

Removal Process Technology of Precision Grinding for Complicated Surface Part of High Performance Hard and Brittle Materials

2007 ◽  
Vol 359-360 ◽  
pp. 123-127
Author(s):  
Tian Ji ◽  
Dong Ming Guo ◽  
Gui Hong Bian
Keyword(s):  
High Performance ◽  
Screening Method ◽  
Brittle Materials ◽  
Precision Machining ◽  
Grinding Wheel ◽  
Process Conditions ◽  
Process Technology ◽  
Removal Process ◽  
Hard And Brittle Materials ◽  
Complicated Surface

Some key parts used in such area as the national defence are made of high performance hard and brittle materials, and they should meet not only the requirement of geometry accuracy but also that of specified physical performance in manufacturing. The Radome is one of such key parts in the active homing guidance weapon, with a typical complicated surface. In order to meet the electric thickness requirement, a controlled removal grinding point-by-point is needed for the radome during its precision machining. A special 3-coordinates equipment with spherical diamond grinding wheel is adopted; the grinding paths are generated in the planes normal to the cutter axis with a Z-level profile machining method; the feed step is determined by step screening method; and the stepping between layers is carried out according to the remaining scallop crest height. Process conditions including the grinding depth and the workpiece speed are determined through experiments, and the process errors under different processing conditions are analyzed to put forward an optimized processing tactics. As a result, a basis for precision removal process of any other part of high performance hard and brittle materials with complex surface is established, and a technology support for precision machining of key parts in the national major projects is provided.

The Deposition and Removal Process for Micro Machining Based on Electrical Discharge

2012 ◽  
Vol 472-475 ◽  
pp. 2448-2451
Author(s):  
Zi Long Peng ◽  
Yi Nan Li
Keyword(s):  
Electrical Discharge ◽  
Deposition Process ◽  
Process Conditions ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Discharge Process ◽  
Micro Edm ◽  
Micro Machining ◽  
Removal Process ◽  
Micro Structures

Based on the analysis of electrical discharge process characteristics, the principle of achieving deposition process and removal process using micro EDM is proposed. By controlling the tool electrode wear in one micro EDM system, it is easy to achieve the different machining type of deposition or removal process. Centering on the problem of tool electrode wear, the process conditions of the deposition and removal including machining polarity, machining dielectric medium, discharge parameters and the tool electrode rotation are researched detailedly. Results show that under the discharge phenomena between electrodes, metal material can be deposited to form micro structures, and the transfer strategy from deposition to removal process can be controlled easily. The machining procedure for fabrication of micro structures based on depostion and removal process are put forward. And finally, some examles with well shape and dimension accuracy are given to validate the processing ability for micro machining.

Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

Innovative electrotechnological systems to provide the temperature modes of technological pipelines

2019 ◽  
Vol 2 (1) ◽  
pp. 29-39 ◽  
Author(s):  
S. G. Konesev ◽  
P. A. Khlyupin
Keyword(s):  
Induction Heating ◽  
Thermal Exposure ◽  
Heating System ◽  
The Arctic ◽  
Process Conditions ◽  
Heating Systems ◽  
Fluid Properties ◽  
Low Efficiency ◽  
Extreme North ◽  
Induction Heating System

Introduction: the systems of thermal effects on thermo-dependent, viscous and highly viscous liquids under conditions of the Arctic and the Extreme North are considered. Low efficiency and danger of heating systems based on burned hydrocarbons, heated liquids and steam are shown. Electrothermal heating systems used to maintain thermo-dependent fluids in a fluid state are considered. The evaluation of the effectiveness of the application of the most common electrothermal system — heating cables (tapes). The most effective electrothermal system based on induction technologies has been determined. Materials and methods: considered methods of thermal exposure to maintain the fluid properties of thermo-dependent fluids at low extreme temperatures. Results: presents an induction heating system and options for its implementation in the Extreme North and the Arctic. Conclusions: induction heating system to minimize loss of product quality, improve the system performance under changing process conditions, eliminate fire product, to reduce the influence of the human factor.

Corrosion monitoring and root cause identification in high solids concentrators

TAPPI Journal ◽  
2016 ◽  
Vol 15 (7) ◽  
pp. 467-477
Author(s):  
PASI NIEMELAINEN ◽  
MARTTI PULLIAINEN ◽  
JARMO KAHALA ◽  
SAMPO LUUKKAINEN
Keyword(s):  
Paper Industry ◽  
Black Liquor ◽  
Construction Materials ◽  
Open Circuit ◽  
Process Conditions ◽  
Potential Range ◽  
Corrosion Monitoring ◽  
General Corrosion ◽  
High Solids ◽  
Passive Area

Black liquor high solids (about 80%) concentrators have often been found to suffer from aggressive corrosion. In particular, the first and second effect bodies are susceptible to corrosion attacks resulting in tube leaks and wall thinning, which limit the availability and lifetime of evaporator lines. Corrosion dynamics and construction materials have been studied extensively within the pulp and paper industry to understand the corrosion process. However, it has been challenging to identify root causes for corrosion, which has limited proactive measures to minimize corrosion damage. Corrosion of the first phase concentrator was studied by defining the potential regions for passive area, stress corrosion cracking, pitting corrosion, and general corrosion. This was achieved by using a technique called polarization scan that reveals ranges for the passive area in which the equipment is naturally protected against corrosion. The open circuit potential, also known as corrosion potential, and linear polarization resistance of the metal were monitored online, which allowed for definition of corrosion risks for stainless steel 304L and duplex stainless steels 2205 and SAF 2906. An online temperature measurement added insight to the analysis. A process diagnostics tool was used to identify root causes of the corrosion attacks. Many of the root causes were related to process conditions triggering corrosion. Once the metal surface was activated, it was difficult to repassivate the metal naturally unless a sufficient potential range was reached.

Study on the Chemical Modification Process of Jute Fiber

TAPPI Journal ◽  
2010 ◽  
Vol 9 (2) ◽  
pp. 23-29 ◽  
Author(s):  
Wei-ming Wang ◽  
Zai-sheng Cai ◽  
Jian-yong Yu
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Treatment Time ◽  
Jute Fiber ◽  
Process Conditions ◽  
Silicate Concentration ◽  
Sodium Hydroxide Concentration ◽  
Liquor Ratio ◽  
Degumming Process ◽  
Selection Of

Degumming of pre-chlorite treated jute fiber was studied in this paper. The effects of sodium hydroxide concentration, treatment time, temperature, sodium silicate concentration, fiber-to-liquor ratio, penetrating agent TF-107B concentration, and degumming agent TF-125A concentration were the process conditions examined. With respect to gum decomposition, fineness and mechanical properties, sodium hydroxide concentration, sodium silicate concentration, and treatment time were found to be the most important parameters. An orthogonal L9(34) experiment designed to optimize the conditions for degumming resulted in the selection of the following procedure: sodium hydroxide of 12g/L, sodium silicate of 3g/L, TF-107B of 2g/L, TF-125A of 2g/L, treatment time of 105 min, temperature of 100°C and fiber to liquor ratio of 1:20. The effect of the above degumming process on the removal of impurities was also examined and the results showed that degumming was an effective method for removing impurities, especially hemicellulose.

Conversion of fructose into methyl lactate over SnO2/Al2O3 catalystin flow regime

2020 ◽  
pp. 43-47
Author(s):  
S.V. Prudius ◽  
◽  
N.L. Hes ◽  
A.M. Mylin ◽  
V.V. Brei ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Practical Interest ◽  
Dimethyl Acetal ◽  
Racemic Mixture ◽  
Process Conditions ◽  
Impregnation Method ◽  
Aqueous Methanol ◽  
Methyl Lactate ◽  
Al2o3 Catalyst ◽  
Target Reaction

In recent years, numerous researchers have focused on the development of catalytic methods for processing of biomass-derived sugars into alkyl lactates, which are widely used as non-toxic solvents and are the starting material for obtaining monomeric lactide. In this work, the transformation of fructose into methyl lactate on Sn-containing catalyst in the flow reactor that may be of practical interest was studied. The supported Sn-containing catalyst was ob-tained by a simple impregnation method of granular γ-Al2O3. The catalytic ex-periments were performed in a flow reactor at temperatures of 160-190 °C and pressure of 3.0 MPa. The 1.6-9.5 wt.% fructose solutions in 80% aqueous methanol were used as a reaction mixture. It was found that addition to a reac-tion mixture of 0.03 wt.% potassium carbonate leads to the increase in selec-tivity towards methyl lactate on 15% at 100% conversion of fructose. Prod-ucts of the target reaction С6Н12О6 + 2СН3ОН = 2С4Н8О3 + 2Н2О were ana-lyzed using 13C NMR method. The following process conditions for obtaining of 65 mol% methyl lactate yield at 100% fructose conversion were found: use of 4.8 wt.% fructose solution in 80% methanol, 180 °С, 3.0 МПа and a load on catalyst 1.5 mmol C6H12O6/mlcat/h at contact time of 11 minutes. The cata-lyst productivity is 2.0 mmol C4H8O3/mlcat/h and the by-productі are 1,3-dihydroxyacetone dimethyl acetal (20%) and 5-hydroxymethylfurfural (10%). It should be noted that a racemic mixture of L- and D-methyl lactates has been obtained by conversion of D-fructose on the SnO2/Al2O3 catalyst. The SnO2/Al2O3 catalyst was found to be stable for 6 h while maintaining full fruc-tose conversion at 55–70% methyl lactate selectivity. After regeneration the catalyst completely restores the initial activity.

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