Shell Chooses CCI Lo-noise Advanced Technology for New Cogeneration Plant

For their new Athabasca Oil Sands cogeneration facility in Alberta, Shell Canada has selected a range of CCI control valves and atmospheric resistors for severe-service applications. These valves range in size from 8-in. to 24-in. (200-mm to 600-mm) and include process steam pressure-reducing valves with spraywater desuperheaters for several different sources of varying process steam pressure levels, deaerator steam-feed control valves, and atmospheric vent control valves.

The many different operating conditions required range as high as 926,000 lb/hr (420,000 kg/hr) at inlet pressures up to 630 psig (4350 KPaG) with &Mac198;Ps of 140 psi (970 KPa) at temperatures of 932 F (500 C).

The pressure-reducing control valves employ DRAG® trim consisting of stacks of individual disks which incorporate multiple, tortuous-path flow passages having many right-angle turns. The resulting pressure reduction configuration limits velocity heads (Hv = &Mac198;V2/2g) at trim exits to less than 70 psi (4.8 Bar). This assures the required noise levels of <85 dBA.

Also included in series with the vent control valves are atmospheric resistors (noise attenuators) which employ the same DRAG® technology as used in the pressure-reducing control valves. Instead of merely reducing venting noise, as would be the case in bulky, heavy mufflers, these atmospheric resistors actually prevent the creation of the noise.

Published in SOLUTIONS Summer 2001