Just as we must use the absolute temperature, we must also use the absolute pressure. We were given the pressure in psig, which is pounds per square in gauge. Gauge pressure is taken relative to the pressure of the atmosphere, which would be 14.7 psia at sea level, and it will have lower pressures at higher elevations. The correction from gauge to absolute pressure at sea level under the standard condition of 1 atmosphere is:
The velocity of the gas is equal to the volumetric flow rate divided by the cross-sectional area of the pipe, which remains constant in the furnace. Thus, the effect on the velocity is essentially equivalent to the increase in the volume of the gas due to the change of temperature and the total number of moles of gas when the ethane is cracked. Therefore, the ratio of the velocities will be:
Temperature Gauge Pro 2.35 Crack Mac Osx
The exact increase in velocity is needed when designing the ethane cracker to insure that there will be sufficient residence time. Also, if the residence time is too great, the ethylene product will continue to crack to carbon and hydrogen gas. However, the actual calculations of the effect on cracking are much more difficult as the increase of the gas volume and thus the velocity is over the length of the pipe, while the temperature increase that more than doubles the volume occurs near the start of the pipe. 2ff7e9595c
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