Customer Name: The President Juárez Power Plant – Operated by CFE | Location: Rosarito, Baja California, Mexico
Background:
The President Juárez Power Plant in Rosarito, Baja California, Mexico, is operated by CFE – the government owned energy department of Mexico. Just 200 meters away from the Pacific Ocean, this site is surrounded by an average relative humidity of 90% in the autumn and winter seasons and faces intermittent conditions called the SantaAna winds.
Due to the plants close proximity to the ocean, it commonly has a high airborne marine salt concentration; this area is also subject to periodic dust storms caused by the SantaAna winds that blow toward the sea.
Problem:
Because of the constant high airborne moisture, the filter pressure drop rose quickly, power output decreased and forced outages, all requiring the change of filter elements. During scheduled shutdown inspections, operators found evidence of granule concentrations of salt, as well as water, on the floor of the clean air plenum and duct, downstream of the filters.
Expensive repairs were required as damage to the turbine compressor had occurred. The original inlet filter house, specified by the turbine OEM, was a small, simple 2-stage static filter that did not include features to handle the difficult local environment.
Solution:
Nederman Pneumafil analyzed the environment, including the site’s significant space constraints, and proposed a solution that included a self-cleaning pulse style primary filter, with back up static polishing filters. The filters would be able to handle the seasonal dust storms as well as pulse-off any accumulated moisture and dust.
The pulse filter elements used were the Pneumafil MATREX filter media, with a MERV 16 efficiency (higher than the original OEM filters), with 100% synthetic material – no cellulose fibers. These filter elements would ensure that no airborne moisture would be absorbed, eliminating a high pressure drop.
The Pneumafil MATREX media included a hydrophobic layer (highly water repellent) on the upstream side of the unit to prevent the salt in the air from dissolving into airborne moisture and wicking through the filters.
As a safety precaution, the final stage polishing filters were used in case any moisture with salt ever made its way through the primary filters. The filter elements and the filter mounting grids were constructed with stainless steel metal components to prevent corrosion.
The filter house was expanded and the total media area greatly increased, ensuring that the filter pressure drop would remain low for a longer duration and the filter life would be greatly extended. The filter house was specifically designed to fit in the available space – tall and narrow, while having the ability to withstand 100 mph winds and Seismic Zone 4 earthquake loads.
The main filter house was carbon steel, including multi-layer paint coatings specifically designed for coastal marine corrosive environments.
Results:
Nederman Pneumafil retrofitted the Baja California - President Juárez Power Plant, in partnership with Phi Energy, by designing and engineering the replacement filter house. Nederman Pneumafil supplied all the critical components – such as filter elements and pulsing controls – as well as provided on-site supervision and inspection by their own experienced service technicians during construction.
This solution eliminated compressor damage and costly repairs due to salt contamination. The plant has seen a significant decrease of derating and unplanned shutdowns, and in turn, an increase in the life of the filters.