SERVICES
SigmaClean™
Advanced HRSG Waterside Preparation Technology
Proven methodology for flushing and passivating Heat Recovery Steam Generator internal surfaces using operational chemistry — eliminating hazardous waste while simultaneously testing Boiler Feed Pumps to baseload
Comprehensive HRSG Waterside Preparation
SigmaClean™ prepares critical Heat Recovery Steam Generator (HRSG) waterside systems for optimal operational performance through advanced surface conditioning and concurrent equipment commissioning.
Systems Prepared for Operation:
Primary Components:
- Boiler Feedwater Pumps
- HP/LP Economizers
- HP/LP Evaporators and Drums
- Condensate Systems
- Boiler Feedwater Systems
- IP: HP/IP/LP Economizers. HP/IP/LP Evaporators and Drums
Fully Passive Drum Internals
Revolutionary Surface Passivation Technology
FQE Power's proven SigmaClean methodology transforms reactive iron surfaces into a passive state equivalent to surfaces after extended normal operation. This breakthrough process circulates demineralized water with all volatile chemistry at elevated temperatures to optimally condition HRSG watersides.
Advanced Magnetite Formation Process
The all-volatile chemistry creates an elevated pH and oxygen-depleted environment that promotes formation of magnetite — the passive form of iron oxide. Magnetite, an inorganic polymer, exhibits extremely low solubility in demineralized water, providing superior long-term protection.
Additional Benefits:
- High pH effectiveness in removing light oils from manufacturing and assembly processes
- Complete compatibility with all system components, including Boiler Feed Water (BFW) pumps
- Environmentally safe chemistry identical to normal HRSG operational requirements
The elevation of temperature is created by operating the BFW pump at full or near full operating flow and pressure. The mechanical energy transferred to the fluid by the pumps will raise the temperature of the circulating solution to above 212°F (100°C). Operating the BFW pumps at these conditions enables the commissioning of these pumps concurrently with the SigmaClean process, significantly earlier than normal, off the critical path and before steam operation of the HRSG.
A temporary filtration system is also provided to remove contaminants present in the waterside components of the HRSG. Combined with the high rate of circulation and elevated temperatures, it is particularity effective in cleaning the tubes and lower headers .
Once elevated temperatures are achieved in the HRSG by circulation, it is maintained along with chemistry for a minimum of 24 hours and is not stopped until the following is achieved:
- Full conversion of the internal surfaces to magnetite is verified by analytical methods
- BFW pump suction strainers return no particulate
SigmaClean has been proven effective in eliminating the requirement for aggressive chemical cleaning where acids or chelants are applied, generating waste streams that require offsite disposal.
Critical Evaluation Questions
Project Assessment Criteria:
❓ What is the amount of mill scale or deposits on your new HRSG?
❓ What specification is established on your project for acceptable deposits on the boiler when purchased?
❓ Is it possible your new HRSG, as received at the project site, came with <20 g/m² of mill scale? Professional Consultation These critical questions determine the optimal approach for your specific project requirements. FQE Power's technical team provides comprehensive analysis to ensure the most effective and economical solution for your HRSG preparation needs.
SigmaClean Eliminates Need For:
❌ Large staging areas — No elaborate pumping equipment, heat exchangers, steam generators, piping, or hoses
❌ Extensive flushing operations — Only two boiler volumes of demineralized water required
❌ Chemical disposal requirements — Uses identical all-volatile chemistry as normal HRSG operation
❌ Hazardous waste generation — Produces waste similar to concentrated blowdown only
❌ Frac tank staging — No extensive battery requirements for chemical handling
The Result: an HRSG with clean and passivated watersides that produces no BFW strainer trips during the steam blow.
Chemistry is easily achieved and maintained during operation due to the superior passivation provided by SigmaClean.
Contact us to discover how SigmaClean technology can deliver superior surface conditioning and concurrent equipment commissioning for your power generation project.
