scholarly journals Influence of Particle Size, Structure, and Layer Thickness on the Back Discharge in Electrostatic Precipitators

2010 ◽  
Vol 82 (9) ◽  
pp. 1447-1447
Author(s):  
M. Majid ◽  
H. Wiggers ◽  
P. Walzel
2011 ◽  
Vol 415-417 ◽  
pp. 237-242
Author(s):  
Zhou Da Zhang ◽  
Xue Mei Chen ◽  
Guo Liang Qu

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.


Author(s):  
Vaishak Ramesh Sagar ◽  
Samuel Lorin ◽  
Johan Göhl ◽  
Johannes Quist ◽  
Christoffer Cromvik ◽  
...  

Abstract Selective laser melting (SLM) process is a powder bed fusion additive manufacturing process that finds applications in aerospace and medical industries for its ability to produce complex geometry parts. As the raw material used is in powder form, particle size distribution (PSD) is a significant characteristic that influences the build quality in turn affecting the functionality and aesthetics aspects of the product. This paper investigates the effect of PSD on the printed geometry for 316L stainless steel powder, where three coupled in-house simulation tools based on Discrete Element Method (DEM), Computational Fluid Dynamics (CFD), and Structural Mechanics are employed. DEM is used for simulating the powder bed distribution based on the different powder PSD. The CFD is used as a virtual testbed to determine thermal parameters such as heat capacity and thermal conductivity of the powder bed viewed as a continuum. The values found as a stochastic function of the powder distribution is used to analyse the effect on the melted zone and deformation using Structural Mechanics. Results showed that mean particle size and PSD had a significant effect on the packing density, melt pool layer thickness, and the final layer thickness after deformation. Specifically, a narrow particle size distribution with smaller mean particle size and standard deviation produced solidified final layer thickness closest to nominal layer thickness. The proposed simulation approach and the results will catalyze in development of geometry assurance strategies to minimize the effect of particle size distribution on the geometric quality of the printed part.


2006 ◽  
Vol 60 (29-30) ◽  
pp. 3548-3552 ◽  
Author(s):  
Yuqiu Qu ◽  
Haibin Yang ◽  
Nan Yang ◽  
Yuzun Fan ◽  
Hongyang Zhu ◽  
...  

2008 ◽  
Vol 97 (11) ◽  
pp. 4815-4829 ◽  
Author(s):  
Jennifer J. Sheng ◽  
Paul J. Sirois ◽  
Jennifer B. Dressman ◽  
Gordon L. Amidon

Nano LIFE ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1441014 ◽  
Author(s):  
Qi Liu ◽  
Weiping Hao ◽  
Yongguang Yang ◽  
Aurore Richel ◽  
Canbin Ouyang ◽  
...  

Nanocrystalline celluloses (NCCs) were separated from four commercial microcrystalline celluloses (MCCs) by an acid hydrolysis–sonication treatment. Transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectrum, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were conducted to investigate the NCCs. MCCs with different morphologies and particle sizes showed different aggregation degrees. The aggregation of MCCs followed the order MCC1 > MCC3 > MCC2 > MCC4, which is the same order of the heights of the resulting NCCs. The best uniformity and thermal stability were characterized for NCC3, which was produced by MCC3 with smallest original particle size and good dispersity among the four MCCs. This result suggests that both the original particle size and dispersity of MCCs had significant effects on separated NCCs.


1953 ◽  
Vol 26 (1) ◽  
pp. 127-135
Author(s):  
George E. Popp ◽  
Lynn Harbison

Abstract Carbon black, regardless of type, particle size, structure, and physical properties imparted, does not affect the rate or degree of checking or cracking in natural-rubber or low-temperature polymer compounds when subjected to weather or ozone exposure. Natural rubber will withstand much longer periods of exposure than the synthetic polymer studied. A pronounced degree of ozone and weather cracking and checking will result if no antioxidant is compounded into the synthetic polymer. An MAF black-synthetic polymer compound may be substantially improved in its resistance to ozone and weather resistance by selection and application of the proper antichecking ingredients.


Author(s):  
A. W. J. de Gee ◽  
A. Begelinger ◽  
G. Salomon

Friction and endurance of five powdered solid lubricants were studied on a pin and ring machine. Simple methods were developed to produce layers of constant thickness (1 μm). The ease of rubbing-in varies widely with structure and with particle size. Ease of layer formation is completely unrelated to endurance: NbSe2 is rubbed in readily, but is rubbed off directly on loading. Layers of constant thickness from MoS2, WS2, and WSe2 powders behave roughly similarly, but MoS2 has a much longer life. The lubricant films are gradually destroyed by oxidation and therefore endurance increases in the series oxygen, air, and nitrogen (with 100 p.p.m. oxygen). The process of lubricant degradation is the same for the synthetic crystalline powders as found previously for MoS2: blistering of the run-in film surface on release of loading. Oxygen accelerates this process, leading finally to descaling and the onset of seizure. The endurance of MoSe2 goes through a pronounced maximum in oxygen–nitrogen mixtures. It is suggested that oxygen plays a dual role, first by enhancing film formation, and second by causing oxidative embrittlement of the lubricant.


2011 ◽  
Vol 233-235 ◽  
pp. 2648-2653 ◽  
Author(s):  
Luo Fang Guo ◽  
Hong Li ◽  
Zi Quan Li ◽  
Yong Qing Li ◽  
Wen Chen Song ◽  
...  

Variations of decomposition rate and decomposition layer thickness of six spherical limestone particles with different sizes are calculated and compared with each other by the experiments and model of static decomposition of limestone under constant temperature. The results indicate that: the decomposition process of limestone can be explained by unreacted core model (UCM) when it is heated sharply; the decomposition rate of large particle is greater than that of small one; the smaller particle size, the larger decomposition layer thickness in unit time.


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