The Experts below are selected from a list of 2265 Experts worldwide ranked by ideXlab platform

Ilpo Kulmala - One of the best experts on this subject based on the ideXlab platform.

  • local ventilation for powder handling combination of local supply and Exhaust air
    American Industrial Hygiene Association Journal, 1996
    Co-Authors: Kimmo Heinonen, Ilpo Kulmala, Arto Saamanen
    Abstract:

    The performance of a modified local ventilation unit equipped with local supply and Exhaust ventilation was evaluated during the manual handling of flour additive powder. The investigation tested five different configurations to study the effects of the Exhaust Opening location and local supply air on worker exposure. The measurements were done under controlled conditions in a test room. The breathing zone (BZ) dust concentration was measured by gravimetric sampling and real time monitoring. The different local ventilation configurations were also modeled numerically using computational fluid dynamics. Without local ventilation the average BZ dust concentration was 42 mg/m3. With local Exhaust only the exposure was reduced below 1 mg/m3. The addition of local supply air further reduced the exposure to below 0.5 mg/m3. The lowest results were achieved by locating two Exhaust Openings on either side of the contaminant source combined with local supply air. With this configuration the average BZ exposure was...

  • Air flow near an unflanged rectangular Exhaust Opening
    Energy and Buildings, 1996
    Co-Authors: Ilpo Kulmala, Pentti Saarenrinne
    Abstract:

    Abstract Turbulent air flow fields for an unflanged rectangular Opening were calculated numerically using the standard k-e turbulence model. The accuracy of the calculations was verified by experimental laser Doppler anemometer velocity measurements and by comparison with previous empirical centre-line velocity equations. The results show that the air flow into an unobstructed Exhaust hood can be predicted quite accurately provided that the calculation grid and the calculation domain are properly chosen.

  • Local Ventilation For Powder Handling—Combination of Local Supply and Exhaust Air
    American Industrial Hygiene Association Journal, 1996
    Co-Authors: Kimmo Heinonen, Ilpo Kulmala, Arto Saamanen
    Abstract:

    The performance of a modified local ventilation unit equipped with local supply and Exhaust ventilation was evaluated during the manual handling of flour additive powder. The investigation tested five different configurations to study the effects of the Exhaust Opening location and local supply air on worker exposure. The measurements were done under controlled conditions in a test room. The breathing zone (BZ) dust concentration was measured by gravimetric sampling and real time monitoring. The different local ventilation configurations were also modeled numerically using computational fluid dynamics. Without local ventilation the average BZ dust concentration was 42 mg/m3. With local Exhaust only the exposure was reduced below 1 mg/m3. The addition of local supply air further reduced the exposure to below 0.5 mg/m3. The lowest results were achieved by locating two Exhaust Openings on either side of the contaminant source combined with local supply air. With this configuration the average BZ exposure was...

  • Numerical simulation of the capture efficiency of an unflanged rectangular Exhaust Opening in a coaxial air flow
    The Annals of Occupational Hygiene, 1995
    Co-Authors: Ilpo Kulmala
    Abstract:

    Numerical simulations were used to determine the capture efficiency of an unflanged rectangular Exhaust Opening in a uniform flow parallel to the hood centre-line. The simulations were performed by the FLUENT computer code based on the finite volume method, using the standard k-e turbulence model. After calculating the turbulent air flow field, a large number of submicrometre particles were released in different locations in front of the Exhaust Opening and the destination of the particles was determined. The capture efficiency was calculated as the ratio of the number of the particles captured by the Exhaust hood to the number of the particles released. The calculations were verified by tracer gas measurements. The calculated capture efficiencies were in satisfactory agreement with the experimental values. The results show also that a uniformly directed airflow may be used to enhance the capture efficiency of Exhaust hoods.

  • Numerical calculation of an air flow field near and unflanged circular Exhaust Opening
    1995
    Co-Authors: Ilpo Kulmala, Pentti Saarenrinne
    Abstract:

    Turbulent air flow fields for an unflanged circular Opening were calculated numerically using the FLUENT computer code based on the finite volume method. The turbulence models used in the simulations were the standard two-equation k-e turbulence model and an algebraic stress model (ASM). The accuracy of the calculations was verified by experimental laser-Doppler anemometer velocity measurements and by comparison with previous measurements. The results show that the agreement between simulation and experiment was satisfactory with the k-e turbulence model and good with the ASM-model

Rong-ben Chiu - One of the best experts on this subject based on the ideXlab platform.

  • Validation of cross-contamination control in biological safety cabinet for biotech/pharmaceutical manufacturing process
    Environmental Science and Pollution Research, 2015
    Co-Authors: Angus Shiue, Han-yang Liu, Rong-ben Chiu
    Abstract:

    For class II, type A2 biological safety cabinets (BSC), NSF/ANSI Standard 49 should be conformed in cabinet airflow velocity derivation, particle contamination, and aerodynamic flow properties. However, there exists a potential problem. It has been built that the cabinet air flow stabilize is influenced by the quantity of downflow of air and the height above the cabinet Exhaust Opening. Three air downflow quantities were compared as an operating apparatus was placed from 20 to 40 cm above the bench of the cabinet. The results show that the BSC air downflow velocity is a function of increased sampling height, displaying that containment is improvingly permitted over product protection as the sampling height decreases. This study investigated the concentration gradient of particles at various heights and downflow air quantity from the bench of the BSC. Experiment results indicate that performance near the bench was better than in the rest of the BSC. In terms of height, the best cleanliness was measured at a height of 10 cm over the bench; it reduced actually with add in height. The empirical curves accommodate, founded on the concentration gradient of particle created was elaborated for evaluating the particle concentration at different heights and downflow air quantity from the source of the bench of the BSC. The particle image velocimetry system applied for BSC airflow research to fix amount of airflow patterns and air distribution measurement and results of measurements show how obstructions can greatly influence the airflow and contaminant transportation in a BSC.

F M Rosano - One of the best experts on this subject based on the ideXlab platform.

  • assessment of velocity fields in the vicinity of rectangular Exhaust hood Openings
    Building and Environment, 2001
    Co-Authors: Furio Cascetta, F M Rosano
    Abstract:

    Abstract In this paper new empirical formulas for the prediction of the air velocity in front of rectangular (slot) Openings (both plain and flanged) are presented. The new equations here introduced are inferred from an Exhaustive experimental study carried out by the authors on one of the most common and widespread shape of local Exhaust Opening (slot). The new empirical formulas presented here describe the three-dimensional velocity field near a rectangular Exhaust hood, providing the velocity gradients (decays) along suitable directions, parallel to the slot axis. These formulas have been tested and show an accurate fitting of the experimental data. The suggested equations are simple and can be friendly used by the designer, in order to predict the air velocity in front of a suction Opening, and therefore to dimension correctly a local Exhaust ventilation system.

Angus Shiue - One of the best experts on this subject based on the ideXlab platform.

  • Validation of cross-contamination control in biological safety cabinet for biotech/pharmaceutical manufacturing process
    Environmental Science and Pollution Research, 2015
    Co-Authors: Angus Shiue, Han-yang Liu, Rong-ben Chiu
    Abstract:

    For class II, type A2 biological safety cabinets (BSC), NSF/ANSI Standard 49 should be conformed in cabinet airflow velocity derivation, particle contamination, and aerodynamic flow properties. However, there exists a potential problem. It has been built that the cabinet air flow stabilize is influenced by the quantity of downflow of air and the height above the cabinet Exhaust Opening. Three air downflow quantities were compared as an operating apparatus was placed from 20 to 40 cm above the bench of the cabinet. The results show that the BSC air downflow velocity is a function of increased sampling height, displaying that containment is improvingly permitted over product protection as the sampling height decreases. This study investigated the concentration gradient of particles at various heights and downflow air quantity from the bench of the BSC. Experiment results indicate that performance near the bench was better than in the rest of the BSC. In terms of height, the best cleanliness was measured at a height of 10 cm over the bench; it reduced actually with add in height. The empirical curves accommodate, founded on the concentration gradient of particle created was elaborated for evaluating the particle concentration at different heights and downflow air quantity from the source of the bench of the BSC. The particle image velocimetry system applied for BSC airflow research to fix amount of airflow patterns and air distribution measurement and results of measurements show how obstructions can greatly influence the airflow and contaminant transportation in a BSC.

Pentti Saarenrinne - One of the best experts on this subject based on the ideXlab platform.

  • Air flow near an unflanged rectangular Exhaust Opening
    Energy and Buildings, 1996
    Co-Authors: Ilpo Kulmala, Pentti Saarenrinne
    Abstract:

    Abstract Turbulent air flow fields for an unflanged rectangular Opening were calculated numerically using the standard k-e turbulence model. The accuracy of the calculations was verified by experimental laser Doppler anemometer velocity measurements and by comparison with previous empirical centre-line velocity equations. The results show that the air flow into an unobstructed Exhaust hood can be predicted quite accurately provided that the calculation grid and the calculation domain are properly chosen.

  • Numerical calculation of an air flow field near and unflanged circular Exhaust Opening
    1995
    Co-Authors: Ilpo Kulmala, Pentti Saarenrinne
    Abstract:

    Turbulent air flow fields for an unflanged circular Opening were calculated numerically using the FLUENT computer code based on the finite volume method. The turbulence models used in the simulations were the standard two-equation k-e turbulence model and an algebraic stress model (ASM). The accuracy of the calculations was verified by experimental laser-Doppler anemometer velocity measurements and by comparison with previous measurements. The results show that the agreement between simulation and experiment was satisfactory with the k-e turbulence model and good with the ASM-model