Liquid sulfur gravity drain (rundown)

In a Claus sulfur recovery unit, sulfur is continuously produced in a series of condensers (typically 4 per train). These condensers operate at an elevated pressure (typically 1 to 8 psig). The sulfur is continuously drained from the condensers via the run‐down lines. These lines run from the condenser drain to a sealing device, and from the sealing device to a sulfur storage container.  Several design aspects should be considered when designing run – down lines. 

       1. Heating of the liquid sulfur to prevent sulfur freezing (using ControTrace heating system)
       2. Proper sealing device to keep vapors upstream in the sulfur condenser (using SxSeal 2000)
       3. Open channel flow to prevent vapor lock in piping (reference below whitepaper)
Use of crosses at changes to allow cleanout of hydrocarbon and catalyst carryover from sulfur condenser that can not be melted out after solidification 

Read more about preventing vapor lock in your sulfur run-down lines:

 Sulfur Run‐Down Liquid Level Prediction