Dos and Donts for Liquid Inlets into Gravity Distributors

9 Dos and Dont s for Liquid Inlets into Gravity Distributors 

Feed velocities leaving the feed pipe or feed sparger should not exceed 10 ft/s (305) and preferably be less than 4 to 5 ft/s (111). High velocities may disturb the liquid surface or cause excessive aeration in the distributor or parting box. 

When the inlet pipe directly feeds the distributor, the incoming liquid should be fed into the center of the distributor in order to ensure uniform head over all the orifices (111, 305). The feed pipe should be located about 2 to 8 in above the top edge of the distributor pan (305). It is important to ensure the feed flows into the distributor and does not enter the vapor risers. In one case (150a) poor column separation resulted from distributor feed being directly introduced into an open riser. 

It is best to ell the pipe down and continue it vertically downward for a short distance (Fig. 3.7c) to prevent feed from entering the vapor risers (Fig. 3.7d). The distributor should be inspected for absence of risers directly beneath the pipe outlet. 

The liquid fall height from the inlet pipe or sparger to the parting box or distributor should be minimized to prevent excessive 

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