Residual Pressure Drop Using ePTFE Micro-Filtration Membrane as Filter Medium

2006 ◽  
Vol 11-12 ◽  
pp. 701-704
Author(s):  
Jun Teng Liu ◽  
Zhong Qi Ren ◽  
Wei Dong Zhang ◽  
De Qiang Jiang ◽  
Jian Chun Zhang ◽  
...  
Keyword(s):  
Pressure Drop ◽  
High Efficiency ◽  
Filter Medium ◽  
Dust Removal ◽  
Residual Pressure ◽  
Air Filtration ◽  
Filtration Membrane ◽  
Surface Filtration ◽  
Residual Pressure Drop ◽  
Filtration Medium

Filtration medium is one of the most important parts of air-filtration. A Micro-filtration membrane made by expanded poly-tetra-fluoric-ethylene (ePTFE) was introduced in the dust removal process in our previous work. Compared with conventional fabric media, ePTFE membrane has many advantages, such as low residual pressure drop and high efficiency of dust removal, etc., because of its characteristics of micro-porous structure and slippery surface. More importantly, the useful life of ePTFE membrane is longer and the operating costs are lower during the surface-filtration process. In this paper, the residual pressure drop of the ePTFE micro-filtration membrane and conventional needle-felts fabric filtration medium were compared. The results clearly show that the residual pressure drop of the conventional filter medium increases after several filtration cycles, but that of the ePTFE membrane remains constant.

Evaluation of Air Filtration Options for an Industrial Gas Turbine

2015 ◽  
Author(s):  
Christopher A. Perullo ◽  
Josh Barron ◽  
Dale Grace ◽  
Leonard Angello ◽  
Tim Lieuwen
Keyword(s):  
Pressure Drop ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
High Efficiency ◽  
Air Filtration ◽  
Unit Output ◽  
Almost All ◽  
The Cost ◽  
The Impact ◽  
Unit Performance

Gas turbines ingest large quantities of air during operation. As a result, large quantities of foreign particles ranging in size from smoke (0.01 to 1.0 micron) to pollen (10 micron) enter the unit and can contribute to both fouling and erosion depending on particle size. Fouling and erosion both lead to reductions in unit output and efficiency resulting in increased operational cost. Operators have historically combatted fouling through a combination of online water washes, more effective off-line water washes, and air filtration. As is the case with almost all engineering problems, the trade-off between the cost and effectiveness of these methods must be evaluated. Online washing is somewhat effective but has led to first stage blade erosion and unit trips in some cases. Off-line washing is more effective at cleaning the unit, but requires the unit to be shut down for extended periods of time. Air filtration can help prevent foreign particles from entering the unit, but higher efficiency filters are generally associated with a larger inlet pressure drop, leading to decreased unit output; this is balanced against reduced fouling rates. These tradeoffs between the costs associated with higher efficiency filters and the frequency of compressor washing need to be evaluated on a plant-by-plant basis to determine the best combination of air filtration and compressor washing programs. This paper presents a field study carried out to determine the effectiveness of high efficiency filters in preventing compressor fouling. Fourteen units at four sites were monitored over a 9 month to 3 year time period to determine the changes in unit performance and the impact of water washes on unit performance for both pre and final filters of lower and higher efficiency ratings. Results to date indicate that higher efficiency filters are effective at reducing the need for off-line water washes and potentially reduce life-cycle cost. Reduced output from the higher pressure drop, high efficiency filters is offset by the better performance retention offered from reduced fouling rates.

Evaluation of the Deposition of Nanoparticles in Fibrous Filter

2014 ◽  
Vol 802 ◽  
pp. 174-179 ◽  
Author(s):  
Priscila Martins de Barros ◽  
Samirys Sara Rodrigues Cirqueira ◽  
Mônica Lopes Aguiar
Keyword(s):  
Pressure Drop ◽  
Specific Resistance ◽  
Filter Medium ◽  
Fibrous Filter ◽  
Filter Performance ◽  
Particle Penetration ◽  
Before And After ◽  
Filtration Stage ◽  
Surface Filtration ◽  
Cellulose Filter

This study aimed to evaluate the deposition of NaCl nanoparticles during filtration in a cellulose filter medium (HEPA). The diameter of the generated polydisperse particles was between 6 and 800nm. Deposition was evaluated with the curves of pressure drop as a function of time. The permeability of the filter medium was determined and, after the deposition of particles, specific resistance of the formed cake was obtained. Filter performance was evaluated by counting particles before and after the filter medium and the pressure drop was monitored in order to obtain the filtration curve. Filtration velocity was kept at 0.06 m/s, and the concentration of the solution generated at a rate of 0.0042 L /min in a commercial inhaler was of 5 g/L. The results showed that this filter showed two steps during the deposition of particles, an internal filtration stage and a surface filtration stage. Although this filter is highly efficient in removing particles in the range evaluated, roughly 100%, particle penetration was observed in the range between 50 and 200nm.

scholarly journals Simulation of C-CP Fiber-Based Air Filtration

2008 ◽  
Vol 3 (2) ◽  
pp. 155892500800300
Author(s):  
Christopher L. Cox ◽  
Philip J. Brown ◽  
John C. Larzelere
Keyword(s):  
Pressure Drop ◽  
Brownian Dynamics ◽  
High Efficiency ◽  
Fiber Spinning ◽  
Dynamics Simulation ◽  
Air Filtration ◽  
Brownian Dynamics Simulation ◽  
Cross Sectional ◽  
Significant Difference ◽  
Total Cross Sectional Area

The overall goal of this project is to develop High Efficiency Particulate Air (HEPA) filter media, using conventional fiber spinning techniques, with lower pressure drop than current media through the use of shaped fibers. Capillary-channeled polymer (C-CP) fibers are gaining interest for use in a range of separations applications. This paper focuses on modeling air filtration where the filter consists of C-CP fibers. A variety of numerical tools are being used in this effort, including a finite element flow solver and Brownian dynamics simulation. Aspects of these techniques in relation to the problem at hand will be described, and simulation results including comparisons to round-fiber filters will be presented. The primary result presented here is the significant difference in predicted pressure drop between a prototype C-CP filter and a round-fiber filter with equal total cross-sectional area.

Explore on Pressure-Drop Performance of Nanofibrous Filtration Membrane

2011 ◽  
Vol 236-238 ◽  
pp. 1885-1888
Author(s):  
Han Wang ◽  
Zuo Yi Yang ◽  
Jin Yong Liu ◽  
Gao Feng Zheng ◽  
Ling Min Chen
Keyword(s):  
Pressure Drop ◽  
Membrane Filtration ◽  
Filtration Efficiency ◽  
Nanofibrous Membrane ◽  
Air Filtration ◽  
Fibrous Filter ◽  
Filtration Membrane ◽  
Filtration Area ◽  
Change Trend ◽  
Resistance Performance

High filtration efficiency of nanofibrous membrane has been proved in air filtration area, but, in addition to filtration efficiency, pressure drop is another important characteristic of fibrous filter. Because pressure-drop is related to energy wastage of filtration, it’s necessary to study. While there are not enough studies dedicated to pressure-drop of nanofibrous membrane filters. Here, different thickness PVA nanofibrous membranes were made by electrospinning, and they deposited on cotton scaffolds to form nanofibrous filter samples. Through testing these samples, we found as thickness of nanofibrous membrane increased, pressure-drop rose almost linearly, while filtration efficiency presented a different change trend. When thickness of nanofibrous membrane reaching a point, filtration efficiency attained extreme limit, even if increasing thickness nanofibrous membrane, filtration efficiency only rose limitedly, but pressure-drop still increased rapidly. At the same time, we found despite the thickness of nanofibrous membrane was thinner than conventional fibrous filter, pressure-drop of nanofibrous filter was obviously higher than conventional fibrous filter. So it’s remarkable phenomena. Through theoretical analysis and simulation, the causation of high pressure-drop of nanofibrous filter was discussed and provided. Decreasing diameter of fiber caused resistance performance change. It’s necessary to carry on a further research.

scholarly journals Awareness of aerosol-related transmission of COVID-19 among the dentists of Nepal

BDJ Open ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Nashib Pandey ◽  
Buddha Bahadur Basnet ◽  
Sushmit Koju ◽  
Anju Khapung ◽  
Alka Gupta
Keyword(s):  
Social Sciences ◽  
Particle Size ◽  
High Efficiency ◽  
Emergency Services ◽  
Uv Light ◽  
Ventilation System ◽  
Age Groups ◽  
Air Filtration ◽  
Online Questionnaire ◽  
Dental Practitioners

Abstract Objective To access the awareness of dental practitioners of Nepal towards COVID-19 transmission through aerosols. Materials and methods The study involved 384 dentists from all over Nepal and was conducted for a period of 3 months. A self-reported online questionnaire was developed using Google forms and the link was shared. It emphasized the awareness related to the aerosol and ventilation system in their daily practices was prepared. The data were analyzed in Statistical Package for Social Sciences version 20.0 software. Results The majority of participants were female 52.9% (n = 203) and within the age groups of <30 years 57% (n = 219). Participants from Bagmati Province were 60.4% (n = 232), with least from Sudurpaschim Province 0.5% (n = 2). 60% of participants provided only emergency services during the COVID-19 pandemic and few (7%) provided consultations via telephone. The current ventilation system used was a well-ventilated room with open windows 65.4% (n = 251). However, 52.8% (n = 203) preferred specialized operatory incorporating high-efficiency particulate air (HEPA) filters and ultraviolet (UV) light. More than 60% of respondents were unaware of the particle size of the aerosol. Conclusions The obtained results signify the need for the proper ventilation system with appropriate air filtration systems in dental clinical setups.

Research and Application of High-Efficiency Multi-Cyclone Dust Removal

2011 ◽  
Vol 109 ◽  
pp. 400-404
Author(s):  
Yan Hong Yang ◽  
Da Fu Ni
Keyword(s):  
Structural Design ◽  
High Efficiency ◽  
Dust Removal ◽  
Working Principle ◽  
Selection Of

Performance and working principle of high-efficiency multi-cyclone were analyzed, and the structural design shortage of original high-efficiency multi-cyclone was pointed out. Its structure was researched and designed, including determination of setting chamber and pipe number, selection of material and the design of cyclones.

Development of composite filters with high efficiency, low pressure drop, and high holding capacity PM2.5 filtration

2019 ◽  
Vol 212 ◽  
pp. 699-708 ◽  
Author(s):  
De-Qiang Chang ◽  
Chi-Yu Tien ◽  
Chien-Yuan Peng ◽  
Min Tang ◽  
Sheng-Chieh Chen
Keyword(s):  
Pressure Drop ◽  
High Efficiency ◽  
Low Pressure
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