Flowrates of gases

The reactor feed may be preheated and the feed pressure may alter. The volumetric flowrate of gases depends on the reactor temperature and pressure at fixed mass flowrate. In many cases, the feed is liquid at room temperature, while the reaction mixture is a gas at the higher temperature in the reactor. In these instances, the performance of the reactor is represented as conversion and selectivity against the liquid hourly space velocity (LHSV). This is defined as... 

Over a 30 m length of a 150 mm vacuum line carrying air at 295 K, the pressure falls from 0.4 kN/rrr to 0.13 kN/m2. If the relative roughness e/d is 0.003 what is the approximate flowrate It may be noted that flow of gases in vacuum systems is discussed fully by Griffiths 11. 

STEAM MAY be produced by cooling the nitrous process gases leaving the ammonia reactor/converter. These gases leave the reactor at 645°C and 1035 kPa, and at a flowrate of 31 706 kg/h. 

The flow rates of all the gases used were metered by a four channel mass flow controller. The electronic flow controller was equipped with a specially designed circuitry which permitted to increase and/or decrease linearly the flowrates of a specific reactant to perform "concentration programming reaction" or CPR experiments. The concentration of CO, and NO were measured at the reactor outlet via infrared analyzers. 

Compressors are used to move gases. The compressor increases the pressure of the gases. A mixtme of natural gas (Ci, C2, C3, i-C4, n-C4, i-Cs, n-Cs, n-Ce, at 100°C and 1 bar is fed into a compressor that has only 30% efficiency. The flowrate of the natural gas is 100 kgmole/h and its outlet pressure from the compressor is 5 bar. Using Peng-Robinson equation of state as a fluid package, determine the outlet temperature of the natural gas. 

Materials are usually transferred between different parts of a chemical plant in the fluid state. Large quantities of gases, liquids and fluidized solids may be easily and economically transported by pumping along a network of pipes. In process design and analysis it is necessary to determine pump duties, pipe sizes, pressure drops, flowrates etc. This section reviews the basic principles of fluid mechanics on which such calculations depend. 

Table 8.1. Composition and flowrates of feed and products for separation flowsheet of hydrocarbon gases... 

Calculation of the flowrate of reactant gases entering the cell... 

Calculation of the molar and then mass flowrate of water at cell input As the gases are ideal and the mixture of gases is ideal, we can write ... 

Flowrates of detector gases, split-vent gas flowrates, and the septum purge gas flowrates. 

For releases of gases through pipes, either adiabatic or isothermal flow models are available (Levenspiel, 1984 Growl and Louvar, 1990). For releases of gases at the same source temperature and pressure, the adiabatic flow model predicts a larger, i.e., conservative, flowrate, while the isothermal model predicts a smaller flowrate. The actual flowrate is somewhere in between these values. For many problems, the flowrates calculated by each approach are dose in value. 

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