High air flow rates

Activated carbon showed an auto-ignition temperature in flowing air of 452-518°C. Presence of 5% of the base ( triethylenediamine ) adsorbed on the carbon reduced the AIT to 230-260°C. At high air flow rates an exotherm was seen at 230-260°, but ignition did not then occur until 500°C. 

To overcome the weaknesses of the column fermenter, several alternative designs have been proposed. A tapered column fermenter [Figure 6.21 (b)] can maintain a high air-flow rate per unit area at the lower section of the fermenter where the cell concentration is high. 

Figure 4 shows the actual dilution system. The tower at left is the primary chamber. Its large volume is important for use with aerosols because even at high air flow rates the velocity is low, which allows time for solvent evaporation when wet aerosol droplets are introduced. Low velocity also helps prevent impaction of particles with the chamber walls. 

The Aerosol Sampling Station ASS-500 (produced by the Central Laboratory for Radiological-Protection, Warsaw, Poland) is used for routine environmental air monitoring. The station is a stand-alone, all-weather instrument for continuous air aerosol collection. The high air-flow rate (up to 550 m h ) through a chlorinated vinyl... 

The superficial air velocity is an important parameter that affects the performance of a fluidized-bed dryer, both in terms of the energy consumption and uniformity of the moisture content of dried paddy. Using high air flow rate does not enhance the drying rate of paddy, but instead leads to large energy consumption. 

Catalytic systems are best suited to low flow, low solvent concentration streams which do not contain catalyst poisons. Thermal oxidation is generally better for high concentrations and high air flow rates. 

Therefore, stacks with longer channels at lower air flow rates and/or higher stack currents are more prone to instability. In contrast, stacks with short air channels and high air flow rates are expected to be more stable. Note also that the larger characteristic temperature T lowers the time fj and hence it facilitates the growth of instability at the channel outlet. 

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