Comparison of Combustion Models in Cleanroom Fire
9
Citation
12
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract In this paper, the cleanroom fire simulation in a semi-conductor factory is investigated by using the commercial computational fluid dynamics (CFD) code. We using three different combustion models in the fire simulation. The combustion models including the volume heat source (VHS) model, the eddy break-up (EBU) model and the presumed probability density function (prePDF) model are considered to predict the cleanroom fire. The turbulence models coupled with different combustion models, while the radiation model is coupled with the turbulent combustion processes. Additionally, the discrete transfer radiation method (DTRM) is used in the global radiation heat exchange. For the fire simulation, the different combustion models are evaluated for their performance and compared with the experimental data from the literature to verify. Thus, these numerical simulations can be adopted as a useful tool to design and optimize the smoke control strategy in cleanroom fire.Keywords:
Cleanroom
Large-Eddy Simulation
This chapter contains sections titled: Introduction Definition of a cleanroom Classes of cleanroom Occupancy states The meaning of the cleanroom classification US Federal Standard 209 E British Standard 5295 >209< Classification of airborne particles according to ISO 14644-1 Cleanliness testing within cleanrooms Classification of pharmaceutical clean room Different types of cleanrooms Cleanrooms and clean zones Working in clean zones Conclusions
Cleanroom
Clean water
Cite
Citations (0)
Cleanroom
HEPA
Contamination control
Cite
Citations (0)
Large-Eddy Simulation
Lean burn
Cite
Citations (67)
The existing standard for cleanrooms is based on an unoccupied state where there are no people or furniture inside the room. However, the distribution of airflow and particles in a cleanroom may differ significantly in an occupied state with the presence of people and furniture. This paper first validates a numerical model for simulating the air distribution in a locally concentrated cleanroom. Then the indoor airflow and the pollutant concentration in a locally concentrated bio-clean operation room (BCOR) are simulated at both occupied and unoccupied states by the validated model. The comparison of results shows the environment is very different between the two cases. Thus, human bodies and furniture should be properly considered when evaluating the environment in the locally concentrated cleanroom.
Cleanroom
Indoor air
Cite
Citations (5)
As devices become faster and feature sizes decrease, sensitivities to ESD and contamination increase. This workshop will focus on the roles that grounding methods, materials, cleanrooms and ionization play in controlling ESD and contamination in the modern cleanroom manufacturing environment. Several industry experts will share their experiences and will answer questions related to current ESD and Contamination control issues, such as selecting ESD and cleanroom safe materials, electrostatic attraction, the use of ionization and various other related topics.
Cleanroom
Contamination control
Cite
Citations (0)
Numerical simulation is the main method to solve turbulence problems. As one of the three methods which are commonly used in large-eddy simulation model (LES) is the most effective and promising research method. The basic idea of large-eddy simulation is that the large scale turbulent motion is directly simulated and we use the sub-grid scale model to simulate small-scale turbulent motion. Continuing alternative load exists in aero-engine combustion chamber during operation. This coupling phenomenon is an important reason to the combustion chamber fatigue failure. In this paper, the large-eddy simulation methods are described and applied in researching aero-engine combustion chamber multi-physics field coupling analysis. By comparing with the experimental results we verify the feasibility of this method and there is great significance of actual project.
Large-Eddy Simulation
Cite
Citations (0)
Using a modified dispersal chamber, the authors have studied the protective efficacy of cleanroom clothing systems. Study results show that the state of a cleanroom clothing system-new or much used-influences the protection efficacy of the system. Suitable combinations of cleanroom underwear and cleanroom garments also improve the protection of the clean environment against airborne contaminants from people.
Cleanroom
Cite
Citations (2)
A sampler that detects and counts viable particles in the air of cleanrooms in real-time was studied. It was found that when the sampler was used to monitor airborne particles dispersed from a number of materials used in cleanrooms, including garments, gloves, and skin, the number of viable particles dispersed from these materials was greater than anticipated. It was concluded that a substantial proportion of these viables were of a non-microbiological origin. When the sampler was used to monitor a non-unidirectional airflow cleanroom occupied by personnel wearing cleanroom garments, it was found that the airborne viable concentrations were unrealistically high and variable in comparison to microbe-carrying particles simultaneously measured with efficient microbial air samplers. These results confirmed previously reported ones obtained from a different real-time sampler. When the real-time sampler was used in a workstation within the same cleanroom, the recorded viables gave results that suggest that the sampler may provide an effective airborne monitoring method, but more investigations are required. LAY ABSTRACT: The airborne concentrations measured by a real-time microbial air sampler within an operational, non-unidirectional airflow cleanroom were found to be unrealistically high due to a substantial numbers of particles of non-microbiological origin. These particles, which resulted in false-positive microbial counts, were found to be associated with a number of materials used in cleanrooms. When the sampler was used within a cleanroom workstation, the counts appeared to be more realistic and suggest that this type of real-time airborne microbial counter may provide a useful monitoring method in such workstations, but further investigations are required.
Cleanroom
Cite
Citations (5)
A experimental setup has been designed for boron particles ignition and combustion. A sampling system with sampling devices has been developed and used to collected condensed combustion products during the tests. The boron combustion products in different test axial locations were sampled and analysed by SEM, EDS and XRD. Agglomeration was formed during heating and combusting and became small while combustion in the secondary chamber. Three products of particles, squamas and protonemas presented orderly. KEYWORD: Boron Combustion; Condensed Production; Secondary Chamber
Combustion products
Cite
Citations (0)
Prevention of airborne contamination has become an important factor in biotechnology; however, conventional laminar-airflow cabinets (LAF-cabinets) are no longer sufficient as a countermeasure against nano-sized airborne contaminants in the laboratory. Here we present a bench-top extra-cleanroom classified as ISO-1 that can prevent contamination from airborne nanoparticles. This bench-top extra-cleanroom consists of a novel clean-zone-creating system that is equipped with nanofibrous, nonwoven filters. In addition, the cleanroom is also equipped with an ionizer to prevent plasticware from collecting dust by electrostatic charge attraction. This combination of features allows the cleanroom to prevent DNA contamination derived from airborne nanoparticles. Our extra-cleanroom with ionizer could be useful in various areas of biotechnology that are easily affected by airborne contaminants.
Cleanroom
Human decontamination
Cite
Citations (9)