Developing a 1D-3D model to investigate the effect of entrapped air on pressure surge during the rapid filling of a pipe

Brownstock washing is a complex, dynamic process in which dirty wash water or weak black liquor (dissolved organic and inorganic material obtained from the pulp cooking process) is separated from pulp fibers. The use of material balance techniques is of great importance to identify potential problems and determine how well the system is operating. The kraft pulping industry was the first known to combine pulp washing with the recovery of materials used and produced in the wood cooking process. The motivation behind materials recovery is economic, and more recently, environmentally driven. The chemicals used in the kraft process are expensive as compared to those used in the sulfite process. For the kraft process to be economically viable, it is imperative that a very high percentage of the cooking chemicals be recovered. To reach such high efficiency, a variety of washing systems and monitoring parameters have been developed. Antifoam additives and processing aids have also played an important role in increasing washing effectiveness. Antifoam materials help attain washing effectiveness by preventing entrapped air from forming in the system, which allows for an easier, unimpeded flow of filtrate through the screens and washers.

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A Numerical and Experimental Approach for Modeling Porosity Due to Entrapped Air and Volatiles Off-gassing During Manufacturing of Composite Structures

10.33599/nasampe/s.19.1627 ◽

2019 ◽

Author(s):

Curtis Hickmott ◽

Alireza Forghani ◽

Victoria Hutten ◽

Evan Lorbiecki ◽

Frank Palmieri ◽

...

Keyword(s):

Composite Structures ◽

Experimental Approach ◽

Entrapped Air

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Evaluation of geometrical benchmark artifacts containing multiple overhang lengths fabricated using material extrusion technique

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.3.2020.28.0573 ◽

2020 ◽

Vol 14 (3) ◽

pp. 7296-7308

Author(s):

Siti Nur Humaira Mazlan ◽

Aini Zuhra Abdul Kadir ◽

N. H. A. Ngadiman ◽

M.R. Alkahari

Keyword(s):

3D Model ◽

Laser Scanner ◽

Dimensional Accuracy ◽

Fused Deposition Modelling ◽

Layer By Layer ◽

Fused Deposition ◽

Layer Technique ◽

Subtractive Manufacturing ◽

Manufacturing Features ◽

Layer Problem

Fused deposition modelling (FDM) is a process of joining materials based on material entrusion technique to produce objects from 3D model using layer-by-layer technique as opposed to subtractive manufacturing. However, many challenges arise in the FDM-printed part such as warping, first layer problem and elephant food that was led to an error in dimensional accuracy of the printed parts especially for the overhanging parts. Hence, in order to investigate the manufacturability of the FDM printed part, various geometrical and manufacturing features were developed using the benchmarking artifacts. Therefore, in this study, new benchmarking artifacts containing multiple overhang lengths were proposed. After the benchmarking artifacts were developed, each of the features were inspected using 3D laser scanner to measure the dimensional accuracy and tolerances. Based on 3D scanned parts, 80% of the fabricated parts were fabricated within ±0.5 mm of dimensional accuracy as compared with the CAD data. In addition, the multiple overhang lengths were also successfully fabricated with a very significant of filament sagging observed.

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