Nozzle pressure drop

The expanders also remove energy from the gas, using that energy to drive a centrifugal compressor for pipeline recompression. As gas expands through the expander s inlet nozzle, pressure drops from 90 bar (1,300 psig) to 55 bar (800 psig). Temperature drops as well, below the dewpoint, and the liquids formed can be separated from the main gas stream. 

The temperature is approximately 20°F below the 265°F temperature limit. The sections differ by less than 1 F. This is probably just luck because that good a balance is not really necessary. Also, it should be noted that to maintain simplicity the additional factors were ignored, such as the 10°F temperature pickup in the return stream due to internal wall heat transfer. Also, nozzle pressure drops for the exit and return were not used. Balance piston leakage was not used as it was in Example 5-3. When all the factors are used, the pressures for each section would undoubtedly need additional adjustment as would the efficiency. However, for the actual compression process, the values are quite realistic, and for doing an estimate, this simpler approach may be quite adequate,... 

Nozzle Pressure Drop, AP The pressure drop through a jet mixing nozzle is given by ... 

The pressure loss in the shell nozzles will normally only be significant with gases. The nozzle pressure drop can be taken as equivalent to velocity heads for the inlet and for the outlet, based on the nozzle area or the free area between the tubes in the row immediately adjacent to the nozzle, whichever is the least. 

Well within the specification, so no need to check the nozzle pressure drop. 

This is well within the specification, so there is no need to check nozzle pressure drops. The proposed thermal design is therefore satisfactory. As the calculated pressure drops are below that allowed, there is some scope for improving the design. 

Aqueous wastes contain oxidizable compounds within a liquid water stream and may be endothermic or exothermic depending on the concentration of oxidizable compounds. Proper atomization of fhe liquid stream is probably the most critical aspect of handling aqueous wastes. This is because the droplet must be small enough to be capable of completely evaporating within the thermal oxidizer chamber and still allow for sufficient residence time to oxidize the combustible compounds. The fluid nozzle, pressure drop, and atomization fluid (e.g., air or steam) demand (if dual fluid atomization is used) should be matched to what is used in the field to obtain a meaningful simulation. 

Toluene exit temperature = 257.4°F Styrene exit temperature = 175.9°F Tube-side tube pressure drop = 3.59 psi Tube-side nozzle pressure drop = 0.56 psi Toluene exit pressure = 85.85 psia Shell-side baffled pressure drop = 4.57 psia Shell-side nozzle pressure drop = 4.92 psia Styrene exit pressure = 40.52 psia Heat transfer area (tube outside) = 3,217 ft ... 

Each nozzle in fact is a tube with a restriction orifice at the bottom. The nozzle pressure drop is taken across the orifice but the nozzle tube is made long enough to contain the expanding gas jet. Since the jet now sweeps the whole cross-section of the tube, it becomes difficult for the catalyst to backflow into the header pipe where it would cause erosion problems. Air grid life is extended. Catalyst attrition is also minimized because, when the gas first contacts the bed of catalyst it is moving much slower than at the orifice (catalyst attrition varies with velocity cubed or worse). 

Need to supply a known flow distribution to the core Second priority reduce Nozzle-to-nozzle pressure drop... 

Reactor Nozzle-to-Nozzle Pressure Drop (dP/P) Indicates fraction of inlet pressures. Based on an evaluation envelope to include many reactor pressure boundary designs from the SNPP Heat Balance Section 6. 

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