Challenge

This Northwest Fab had space limitations when looking at upgrading its UPW system.  Siemens Water Technologies was requested to increase makeup and polishing supply flows to utilize the same limited space without the need of an additional building.  Minimizing costs and increasing reliability of the system were additional considerations.

Solution

The system was mathematically modeled on the WinCPD® design program to allow system optimization.  This resulted in:

• A UF was utilized on the UF Reject to recover water to reduce the load on the makeup system.
• A brine recovery RO was converted to a float RO to be used as a 1st pass or 2nd pass RO.
• The 2nd pass ROs were upgraded from 365 sq.ft. to 400 sq.ft. membranes to provide more flow.
• Pump impellers were upsized not requiring new motors.  Where larger impellers could not be supplied, additional parallel pumps were installed.  Piping was reconfigured to match the hydraulics of the pumps, DPs, and improved the process.
• A polishing MVD was installed in place of the conventional VDG, thereby improving the reliability of the degasification process.

Results

Tie-ins were installed during a Christmas shutdown to allow installation and reconfiguration of the equipment changes with minimal impact on the process.  The system became a much more reliable with lower maintenance requirements and over 25% increase in capacity.