A computational fluid dynamics analysis of transient flow through a generic Chemical Biological Radiological and Nuclear respirator canister

Wood, Samuel G. A.; Chakraborty, Nilanjan; Smith, Martin W.; Summers, Mark

doi:10.1016/j.cherd.2018.11.028

Cited by 7 publications

(4 citation statements)

References 7 publications

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“…The dead zone normally occurred in the region of high-pressure drop as well as insufficient adsorption rate [12,19]. However, several researchers had done the simulation on the gas mask canister [7,10,20,24]. They reported that the results were in good agreement with the recent study, which provided the idea of the optimization process of the gas mask filter.…”

Section: Introductionmentioning

confidence: 60%

Analysis of Preferential Flow at the Front Mesh Cartridge of the Gas Mask Filter: Cases in Malaysia Climate Environment

Noraini¹,

Azmir

Taib

et al. 2022

ARASET

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A gas mask respirator is essential for human protection from the hazardous and toxic chemical environment. The gas mask filter should be regularly checked, and the filter must be changed abruptly based on the temporal exposure to the toxic environment. Furthermore, the filter is exposed to a highly humid climate, and the high gas concentration speeds up the expiry cycle of the gas mask filter. Thus, this study aims to investigate the preferential flow absorbed into the gas mask filter and predict the potential area that presents the dead zone. In this study, a three-dimensional model of the commercial gas mask filter was modeled using the computational aided design (CAD) software. Four different humidity ratios of 50%, 60%,70%, and 80% as well as Five different filter concentrations of 20ppm, 100ppm, 200ppm, 300ppm, and 1000 ppm were simulated. The computational fluid dynamic (CFD) method was governed by continuity and Navier-stokes equation to investigate the presence of the dead zone based on several flow parameters. The result showed that the effects of the pressure, velocity, temperature, humidity, and concentration on the gas mask filter were analyzed. The pressure drop is seen in the charcoal filter region which experiences high-velocity circulation. The highest effect on the pressure drop, humidity, and concentration was seen for the case V filter. The high humidity ratio with the pressure drop in the gas mask filter also decreases the efficiency of filter concentration even though the temperature is constant. The high humidity ratio in the mask filter will retain the heat inside the gas mask filter, thus reducing the life cycle of the filter.

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Section: Introductionmentioning

confidence: 60%

Analysis of Preferential Flow at the Front Mesh Cartridge of the Gas Mask Filter: Cases in Malaysia Climate Environment

Noraini¹,

Azmir

Taib

et al. 2022

ARASET

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“…However, k and ϵ are unclosed terms, and they are evaluated by solving their modeled transport equations, which are given by where σ k = 1.1, σ ϵ = 1.3, C ϵ1 = 1.44, and C ϵ2 = 1.92 are constants of the model. The near-wall behaviors of k and ϵ are modeled by means of a blended wall approach, which has previously been used in the modeling of carbon beds in which the domain is subdivided into a near-wall viscosity-affected region and a fully turbulent region according to the local turbulent Reynolds number, Re y : …”

Section: Experimental Methods and Resultsmentioning

confidence: 99%

“…C ϵ1 = 1.44, and C ϵ2 = 1.92 are constants of the model. The near-wall behaviors of k and ϵ are modeled by means of a blended wall approach, which has previously been used in the modeling of carbon beds28 in which the domain is subdivided into a near-wall viscosity-affected region and a fully turbulent region according to the local turbulent Reynolds number, Re y : the near wall region (Re y < 200) a one-equation model is employed in which the full transport of ϵ is no longer solved but is instead algebraically modeled as κ = 0.4. The turbulent viscosity in this region is then calculated as…”

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confidence: 99%

Combined Experimental and Numerical Investigation of Linear Driving Force Kinetics in Small Activated Carbon Beds

Wood

Chakraborty

Smith

et al. 2019

Ind. Eng. Chem. Res.

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A numerical model has been developed with the intention of better understanding the relationship between flow characteristics and adsorption behavior in small activated carbon beds. The model uses the Dubinin–Radushkevich adsorption isotherm with Linear Driving Force kinetics and has been validated against experimental data for the breakthrough of cyclohexane. Simulations have been carried out varying the inlet flow rate and the adsorption kinetic constant. The adsorption behavior has been analyzed by assessing the furthest point into the bed that a threshold concentration of a contaminant could be seen in the vapor phase. It was seen in all cases that the adsorption was a two-stage process with a rapid initial penetration into a certain bed depth followed by a relatively slow gradual progression of the front through the bed over time. The initial distance penetrated into the bed has been seen to be inversely proportional to the kinetic constant, the same trend as predicted from a plug flow mass balance analysis. The rate of steady front advancement after this showed a slight tendency to increase with decreasing adsorption kinetics, compared to the expected plug flow speed.

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“…Using pleated filters is advantageous because they have large filtration areas owing to their pleated geometry [1,2]. Thus, pleated filters are widely used in areas requiring air purification such as medical powered air purifying respirator (PAPR) [3], chemical biological radiological and nuclear (CBRN) masks [4,5], and so on [6]. Although collection efficiency is a significant factor for filters, reducing pressure drop is also important to curtail energy consumption for PAPRs and lower respiratory resistance for CBRN masks.…”

Section: Introductionmentioning

confidence: 99%

Pressure drop and optimization meta-models for arbitrary low-height pleated filter shapes and flowrates

et al. 2021

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A computational fluid dynamics analysis of transient flow through a generic Chemical Biological Radiological and Nuclear respirator canister

Cited by 7 publications

References 7 publications

Analysis of Preferential Flow at the Front Mesh Cartridge of the Gas Mask Filter: Cases in Malaysia Climate Environment

Analysis of Preferential Flow at the Front Mesh Cartridge of the Gas Mask Filter: Cases in Malaysia Climate Environment

Combined Experimental and Numerical Investigation of Linear Driving Force Kinetics in Small Activated Carbon Beds

Pressure drop and optimization meta-models for arbitrary low-height pleated filter shapes and flowrates

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