Long-Term Noise Problem Solved at Chemical-Process Plant

A little over a year ago, CCI was challenged to provide a solution to a severe noise problem that had existed for many years with the turbine bypass system in a, multi-product, chemical-process plant in Westlake, Louisiana. Dangerous noise levels exceeded 120 dBA. In addition, an unusual system configuration required special replacement-valve and accessory designs. CCI met these challenges, and noise levels were reduced to well below industry standards.

As a direct result of CCI’s success in meeting these challenges, an additional order has now been received for HP and LP turbine bypass systems in a combined-cycle/process-steam configuration in their new facility. Here, two large gas-turbine generators exhausting into two heat-recovery steam generators (HRSGs) serve a single steam-turbine generator.

Each of the HP and LP turbine bypass systems consist of steam-pressure-reduction, spraywater-pressure-reduction, and water-pressure-reduction valve. In addition a process-steam conditioning valve and its spraywater valve are also included in this new order. These new systems, as was also the case with the previous noise-reducing replacements, use severe-service, multistage, pressure reduction DRAG® trim. This advanced technology trim employs stacks of disks, each containing multiple, tortuous flow paths, so that trim-exit fluid velocities are severely controlled. This, in turn, minimizes noise and vibration generation and prevents the trim erosion that could occur from high fluid velocities in these control valves.

The HP turbine-bypass valve for this new system handles flow as high as 1,100,000 lb/hr (675 kg/sec) at inlet pressures up to 1900 psig (130 BarG) and a temperature of 1053 F (570 C). The water-pressure-reduction valves in both systems handle inlet water pressures up to 2600 psig (180 BarG) with &Mac198;Ps as high as 2065 psi (142 Bar) at temperatures ranging to 330 F (166 C).

Published in SOLUTIONS Summer 2001