Purge gas flow rate

Minimum purge gas flow rate required to prevent tip degradation when operating at mm down condition, even under maximum wind velocity,... 

Velocity seals are more recent developments in air seal design. They use conical baffles to redirect and focus the purge gas flow field just below the flare tip to sweep air from the flare stack. Some velocity seal designs can reduce the purge gas flow rate requirement to about 1/10 of the rate needed without the seal. Also, some velocity seal designs reportedly require only about 25 to 33 percent of the purge gas used in diffusion seals (AICliE-CCPS, 1998). More details about air (purge reduction) seals may be found in API RP 521 (2007). 

Figure 3. Recoveries of selected compounds as a function of purge gas flow rate...

Figure 15. Time evolution of cell HFR at different cell temperatures and for various purge gases. The purge gas flow rate was 4.5 L/min. (reproduced with permission from Tajiri et at.33)...

Figure Conversion Shift at T=721 K and 70 std cc/nain Purge Gas Flow Rate...

For PQ-USY and EX20P, the larger the purge gas flow rate, the higher the purity was obtained and the lower the yield was observed. 

Purge Gas Flow Rate. The purge gas flow rate can be adjusted up to about 220 ml of argon per minute. Normally the flow rate of the argon... 

A final experimental condition that has not yet received widespread consideration within the pharmaceutical sciences is the flow rate of the purge gas. A study by Kitaoka et al. (38) discusses marked differences in the melting behavior of dehydrated levofloxacin hemihydrate, depending on the experimental conditions used (described in more depth in the following section). These differences may be ascribed to a number of factors including the efficiency of removal of water of dehydration and differences in the thermal conductivity of the purged cell. Irrespective of the explanation, the choice of purge-gas flow rate (and indeed the gas itself) is an experimental parameter that needs to be considered. 

This relationship not only provides a convenient method for determining the heat of volatilization processes, but also explains the response of volatilization peaks in DTA curves to changes in purge-gas flow rates exhibited in dynamic-gas DTA systems. Under dynamic flow conditions, increasing the flow rate generally reduces the peak temperature at which volatilization occurs when the purge gas is noninteracting with the sample (and is different... 

In pressurization and depressurization steps, the amount of gas leaving or entering is determined by the pressure change which was set at a constant rate. The flow rate during the adsorption step determines the conversion range and was set to ensure a low conversion. The purge gas flow rate is expressed relative to the adsorption gas flow rate. 

Tosti et al. evaluated Pd-Ag membrane reactors in pilot plant environment [7]. The tests carried out during several months of operation have simulated the WGS reaction. Operating conditions are temperature of 325 °C, feed pressure of 100 kPa, shell pressure of 100 kPa and nitrogen (purging gas) flow rate of 2.74 X 10 " mol/s. They tested membrane reactor in different feed compositions with different CO feed flow rates. The results are presented in Figure 6.6. As expected increase in the CO feed flow rate decreases the CO conversion. Also increase in the water quantity increases the CO conversion. Introduction of CO2 in the feed decreases the CO conversion. 

The gas flow rate influences the characteristics of the instrument baseline. When the flow rate is too high the instrument baseline becomes unstable. Fluctuations in the flow rate alter the baseline gradient. A purge gas flow rate in the range 20-50 ml/min is recommended. Measurements under reduced pressure are generally only performed with simultaneous TG-DTA instruments and are discussed in... 

K min dashed line, 20 K/min. (B) DTA curves recorded simultaneously. Experimental conditions amount of sample, 5 mg dry N2 purge gas flow rate, 20 ml/min... 

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