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Cartridge Filtration
Published in Michael J. Matteson, Clyde Orr, Filtration, 2017
Tadeusz Jaroszczyk, Barry M. Verdegan, Kendall McBroom
Pleated elements (Figs. 9c, d, h, j, and k) are widely used for oil and air filtration. Filter media, such as cellulose paper, non woven fabrics, or flat membranes, can be pleated and oriented around a supporting center tube. Panel air filters are also often pleated; however, in this case the medium is supported by flat screen or perforated metal. The ends of the medium are typically held in end caps by an adhesive (plastisol or epoxy). When properly installed in a filter housing, the end caps and associated gasketing form a pressure seal against the housing’s sealing plates (refer to Section II, A).
Investigation on the sound absorption of cross-stitched fabric by airflow resistance and sound-induced vibration effects
Published in The Journal of The Textile Institute, 2022
Micro-perforated plate (MPP) has been widely used as sound absorber, and it was firstly proposed by Maa in the 1970s (Maa, 1975). Subsequently, both approximate and general theoretical models have been developed to predict the sound absorption properties. According to Maa’s model, this absorption plate can be made of any materials including cardboard, plastic, epoxy, wood, textiles, and metals, etc. (Maa, 1987, 1998). It is promising for noise reduction and control, and it has exhibited better structural stability and environmental friendliness than commercial porous materials (Chen et al., 2022; Laly et al., 2019; Zhang et al., 2022). However, it is still a limited and urgent problem to produce such sub-millimeter sized MPP economically on a large scale. In the past few decades, drilling method, infiltration method, laser method, micro-mechanical electrical method, and 3D printing method were utilized to fabricate MPP (Cobo & de Espinosa, 2013; Liu et al., 2017; Qian et al., 2015; Song et al., 2016). Furthermore, textile technique and structure optimization approaches have also gradually been developed for potential valuable topic in weaving flexible MPP fabric absorber with irregular pores (Shen et al., 2022; Witczak et al., 2021; Yan et al., 2022).
Additively manufactured dual-functional metamaterials with customisable mechanical and sound-absorbing properties
Published in Virtual and Physical Prototyping, 2022
Zhendong Li, Wei Zhai, Xinwei Li, Xiang Yu, Zichao Guo, Zhonggang Wang
The impedance of the micro-perforated plate is dominated by the micro-perforations on it. It can be expressed as where represents the ratio of the diameter of the perforation to the thickness of the viscous boundary layer and represents air density. and represent zeroth-order and first-order Bessel functions, respectively; denotes the dynamic viscosity and is the perforation porosity.
Burst pressure of perforated-steel strip composite pipe
Published in Ships and Offshore Structures, 2022
Qiang Q. Shao, Peng Cheng, Wen S. Liu, Wen X. Cai, Zhi P. Han, Yong Bai
The small hole on the perforated-steel strip becomes the most powerful ‘rivet’, which firmly holds the PE layer on both sides of the perforated-steel strip, making the PE layers and the perforated-steel strip as a whole, avoiding the peeling or separation of metal and plastic, solving the problem of insufficient strength and rigidity of pure plastic pipe, and controlling the linear expansion coefficient of plastic. The size of the hole diameter and the hole distance not only affects the bursting pressure of the pipe, but also affects the bonding ability of the PE layer and the perforated-steel layer. Therefore, the concept of density coefficient is introduced where L is the hole spacing and d is the hole diameter.