cleanroom

By using the technique of turbulent large eddy simulation (LES) and finite element method (FEM) of computational fluid dynamics (CFD), the three dimensional flow fields in vector flow clean-room under empty state and static state condition were predicted. The partly expanded Taylor-Galerkin discretization scheme cooperated with implicit stream-upwind diffusion effect was used to deduce the finite element formulation of basic equations through Gauss filtering. The subgrid model of vortex viscosity was adopted in the numerical simulation.

States that the layout of the production line in any clean rooms is likely to change in accordance with the production process, and that this poses a problem for post clean room maintenance. One of the many problematic issues often found in the clean room environment is air velocity, and the ongoing problem should be addressed at upgrade time. The paper looks at the characteristics of airflow distribution within a clean room, as a result of changes to the production process. The study was conducted for a class 100 clean room at a manufacturing firm for disk drives.

A self contained guide to all aspects of cleanroom design, construction, testing and operation. Also examines cleanroom clothing requirements, as well as practical advice on the cleaning of cleanroom facilities. Supplemented by information on the latest sources, recommended practices, journals, books and internet sites.

This paper describes the development of software for simulating the air-conditioning environment in a computer room. This software uses a finite volume method combined with a rectangular structured mesh system and a k-£ two-equation model for turbulence. Some special modeling techniques are also used. This software has two purposes: (1) to optimize the layout of a computer room, thus minimizing the electric power used for air conditioning, and (2) to reproduce the situation in which an accident is caused by an air-conditioning problem and to assist in an investigation of the problem.

Airflow behavior inside a cleanroom with vertical unidirectional flow has been investigated. The design parameters, such as porosity and height of raised floor, width of clean room and inlet velocity profile, which affect the uniformity of air velocity distribution inside the cleanroom have been studied computationally. The Reynolds-averaged Navier-Stokes equations governing the flow are solved using a finite-volume code ST AR-CD. The standard k-e turbulence model has been used.

Future information age technology will demand cleaner and more cleanrooms for the manufacture, assembly and repair of electronic components. Many special processes can be very sensitive to trace contaminants which are not removed by conventional air conditioning, filtering and distribution. High efficiency particulate air filters, high velocity streamline air flows, relatively dry air, clean ducts and plenums, cooling, noise reduction and perhaps disinfection are needed.

This study has the objective of applying the "age of air" concept and tracer gas techniques in the evaluation of ventilation characteristics of workplaces equipped with a general ventilation system. A Class I OK cleanroom was selected for this study and C02 was used as a tracer gas. After the tracer gas was released in the form of a pulse into the cleanroom, its concentration was measured as a function of time at various locations by non-dispersive infrared photometers. The average age of air at each location was then calculated from the C02 concentration data.