Need Long Term Reliability? We’ve Got You Covered
Edwards Air Force Base in California’s Mojave Desert is well known for its numerous aerial high-speed breakthroughs, including Chuck Yeager’s first supersonic flight. Ten miles northeast of the Edwards runways lies a company known for a much slower form of transportation: the twenty-mule teams that U.S. Borax used in the 1880s to haul 30-ton loads of borax ore out of Death Valley and across 165 miles of desert to the nearest railroad spur.
Today Borax is part of the Rio Tinto Group of mining companies, the world’s largest mining corporation, and operates California’s largest open-pit mine in Boron, California, one of the plant’s two largest borate deposits and produces nearly half the world’s supply of industrial borates.
The ore processing facility requires both steam and electricity for its operations, so Borax installed a Siemens/Westinghouse 251B-10 turbine/generator set on site to meet those needs. The unit produces 49.2 MW (ISO) which is more that enough to meet plant needs, so the rest is sold to the grid. (A second plant in Boron, Mojave Cogeneration, also has 41 MW Westinghouse M33 condensing steam turbine. Mojave Cogen supplies medium pressure steam to Borax and sells power to Southern California Edision.)
While temperatures in Boron are relatively pleasant compared to the original Borax mine at Furnace Creek in Death Valley, daily highs still average in the 90’s for three months of the year, frequently peaking at over 100. The ore processing facility requires both steam and electricity for its operations and that ambient heat greatly spas the GT output. The facility had an evaporative cooler which helped, but did not fully cool the air to the desired degree.
“This increases the power output of the combustion turbine by 1MW,” said U.S. Borax Utilities Engineer. “This additional power output easily paid for the Meefog system within one year of its operation.”
The Meefog system has a three pump skid allowing the operators to select three stages of cooling depending on ambient conditions. The pumps send up to 9.72 gpm of 2000 psi water to a fogging array containing 216 impaction pin nozzles which convert the water into a fine mist that quickly evaporates before entering the compressor.
Long Term Reliability
The utilities engineer said that not only did the system provide a quick return on investment, but trouble free operation as well. In the fifteen years the system has been in operation, it has continued to deliver a reliable power boost.