Southern Regional Wastewater Treatment Plant Oxygen System Upgrade (Design-Build),
HOLLYWOOD, FL
CLIENT OBJECTIVES
The cryogenic oxygen generation system at the Southern Regional Wastewater Treatment Plant was originally furnished by Union Carbide in 1975. The system required upgrades to modernize the process, replace aging equipment, and address capacity and reliability limitations.
SCOPE OF SERVICES
To upgrade the oxygen generation system, the City desired to replace the existing 1,250 horsepower (Hp) main air compressors with three 900 Hp units to allow for energy savings as well as improved reliability. The cold box houses several heat exchangers used for the cryogenic process. The main reversing heat exchanger was tested in June 2004, and it was determined that this unit required replacement. Replacement of other associated components were also incorporated into the scope, including the cooling tower and cooling water pumps, antiscalant and biocide feed systems, ambient air vaporizers, as well as the instrument air compressor and instrument air system.
In December 2007, the City of Hollywood requested qualifications from qualified Design-Build teams to provide design, permitting, and construction of the proposed improvements. In January 2008, the City selected the Design-Build team led by the Poole & Kent Company of Florida (P&K) to complete the project. Other team members included Air Products and Chemicals, Inc. (process design and major equipment supplier), McCafferty Brinson Consulting, LLC (civil, stormwater, mechanical, and structural design), and Norman F. Bray Electrical Engineers (electrical design). The City issued the authorization to proceed to P&K in November 2008.
SOLUTIONS
The design-build contract included preliminary and final design, permitting, and construction for the following project components:
- Replacement of the dual 1,250 HP air compressors with three 900 HP units to allow for energy savings as well as increased reliability, and installation of a sound-attenuating enclosure and metal canopy over the new compressors.
- Rehabilitation of the two existing liquid oxygen (LOX) storage tanks and piping.
- Rehabilitation of the existing cryogenic oxygen generation system, including rehabilitation of the cold box, replacement of the existing reversing heat exchanger, switch valve assembly, and expansion turbine, and replacement of the existing cooling water tower and cooling water pumps with a new cooling water tower, complete with an antiscalant and algaecide system, cooling water pumps, and associated piping, fittings, valves, gauges, and miscellaneous appurtenances.
- Installation of three new ambient air vaporizers and a new instrument air compressor and new instrument air piping system.
- Miscellaneous improvements, including replacement of the existing dual element thaw heater and replacement of the existing valves on the nitrogen gas blowdown silencer.
- Replacement of various piping systems with carbon steel, PVC, 316 stainless steel, and monel stainless steel, as appropriate for the service.
- Miscellaneous site work (service road paving and/or overlay, addition of sidewalks, equipment pads, etc.) and associated mechanical, structural, electrical, and instrumentation and control improvements.
BACKGROUND
The City of Hollywood owns and operates the Southern Regional Wastewater Treatment Plant (SRWWTP), which utilizes a pure oxygen activated sludge process rated at 48.75 million gallons per day (mgd). The 64 ton per day (TPD) capacity cryogenic oxygen generation system is one of the essential components of the plant.