Our client in Pakistan required a propane refrigeration plant to mechanically cool the natural gas temperature of 48MMSCFD from 30F to -10F. To accommodate effective shipping, Startec's team of engineers optimized the design to have the chiller and suction scrubber at the same elevation. This updated design also resulted in a substantial reduction in structural steel supports and site assembly.
Because the control panel (UCP) had to control part of the gas processing equipment, Startec hosted constructive meetings and HAZOP sessions with the client to determine the better way to communicate with the main plant's PLC and respective compressor panels and UCP. These efforts ensured the plant would function with the proper safety protocols and operating philosophy. A further Layers of Protection Analysis Study was conducted to determine the required Safety Integrity (SIL) for Safety Instrumented Systems to conclude SIL calculations and an extra panel for trips were not required, further reducing project complexity and cost to our client. A few project highlights include:
- Galvanized structure for corrosive ambient environment by Karachi, Pakistan.
- Structure designed for local high seismic zone.
- Plant designed in consideration of hot ambient conditions as well as outdoor operator features including panel sunscreens and rolling staircase for condenser motor access.
- Skids designed for at-site jacking and grouting prior to pouring concrete pads.
- Piperack, condenser supports, and off-skid pipe supports designed with minimizing client assembly at site. Also designed so anchor bolts comply with local standards and designed for concrete piles.
- Electrical designed to meet IEC requirements.
- Cable tray utilized on all skids.
- Pre-assembly of plant completed at local shop before being crated to send to the shipping ports to load into the respective sea containers.
- Function testing of individual compressor panels and plant UCP panel respectively as well as function testing the program logic between compressor panels and plant UCP.
Description of Equipment Provided:
(3) 50% screw compressors; each driven by 750hp electric motors (each compressor able to supply approx. 150 TR)
(1) Refrigerant Condenser aerial cooler with (3) bays; each bay with a duty of 2098 MMBTU/hr and (3) 15hp motors
(1) Glycol cooler aerial cooler with a duty of 0.733 MMBTU/hr and (2) 10hp motors
(1) Scrubber and economizer skid with extended platform (skid included a plant UCP panel)
(1) Fully dressed accumulator with a platform on a skid (skid and platform able to ship in a 40ft high-cube sea container)
(1) Piperack design