Automated Fuel Polishing Facts

2015

www.criticalpower.com © Ron Lenz 2015

Diesel Fuel Contamination: Generator Engines may be exercised regularly and operate properly and to specification. However inside the fuel tank, out of sight, free and emulsified water is slowly accumulating from condensation and even fuel deliveries with high water absorption. As the evening temperature falls the water begins to condense out of the fuel and build inside of the tank. If any water is on the storage tank bottom colonies of filter clogging bacteria and fungus will grow at the fuel/water interface. The by product of these colonies is acidic sludge. When the fuel/water interface grows high enough to reach the engines fuel supply tube which may be inches above the tank bottom; the filter clogging microbes will be drawn into the fuel system and stop the engine. 99% of all fuel contaminates; including water, are heavier than fuels and will be found on the storage tank bottom. Remove the tank bottom water and the micro-organisms will die. Therefore it is imperative that the fuel polishing systems intake supply tubes be located on the lowest portion of the storage tank bottom. Failure to do so may result in unexpected engine shutdown.

The fuel polishing system must be independent of the engines fuel supply. A properly installed Fuel Polishing System will prevent the emergency generators from becoming the Emergency.

Microbes found in diesel fuel Virtually all diesel fuel contains some moisture. Additional water accumulates in tanks as atmospheric moisture condenses. Moisture accumulates in diesel tanks as condensate droplets on exposed tank surfaces, as dissolved water in the fuel and as water bottoms beneath the fuel microbes depend on this water for growth. Additionally, microbes depend on the organic and inorganic molecules in diesel fuel for nutrition. Consequently, some species attack the fuel directly, growing at the expense of hydrocarbons and nonhydrocarbon fuel components. The biodegradation of fuel, in support of microbial growth, is a direct impact of contamination. Color, heat of combustion, pour point, cloud point, detergent and anti-corrosive properties change as microbes selectively attack fuel components. Sulfur-containing molecules are metabolized by a series of species, leading ultimately to the production of high concentrations of hydrogen sulfide. In addition to creating new cells, many microbes produce metabolites which promote further attack. Surfactants facilitate the emulsification of fuel, leading to the formation of a cloudy, invert-emulsion layer above the fuel/water interface. Polysaccharide slimes create microenvironments wherein mixed populations (consortia) of bacteria and fungi carry out biodegradation reactions that would be impossible for a single species outside the microenvironment. The slime also serves as a barrier, protecting the microbes from preservatives. A variety of organic acids (primarily 2 - 4 carbon atoms) are also produced as by-products of bacterial and fungal growth.

Diesel Fuel

Fungal growth

Water

Fueltec’s Polishing Systems exceed the engine manufacturers recommended ISO 18/16/13 cleanliness target. ISO Fuel Requirements The standard established by ISO (International Organization for Standardization) provides a common measurement system that engine and fuel system manufacturers use to designate acceptable particle levels in the fuel system. Determining fuel cleanliness requirements includes the measurement of both particle size and count. ISO 4406 utilizes a series of three numbers (18/16/13) to identify the particle count per milliliter at 4, 6 and 14 micron sizes. Engine manufacturers recommend ISO 18/16/13 or better as the cleanliness target in fuel tanks.

A micron is a metric measure equal to one millionth of a meter, or 1/25,000th of an inch. The smallest particle visible to the naked eye is 40 microns across. A human hair is 80 microns in diameter, and a single grain of talcum powder is 15 microns. © Ron Lenz 2014

Step #1 Getting to the fuel tank contamination

The flexible Fuel Polishing System supply tube’s intake nozzle is in contact with the storage tank bottom to remove all water and contaminates eliminating microbe growth.

The Fueltec Primary Filter Fueltec’s Polishing Systems Primary Filter • Removes solid and microbial contamination to one to five microns • Is in place before the systems pump offering protection from solid particulates • Housing manufactured from stainless steel

The Fueltec Fuel Pump Draws fluid from the storage tank bottom through the primary filter under a vacuum, under pressure through the water separator, then back to the tank.

Pump housings and gears are made of top quality bronze, shafts are 303 stainless steel. Bearings are made of high performance carbon-graphite material selected for wear resistance and long service life. Gear pumps are positive displacement pumps. Each shaft revolution displaces a definite amount of liquid relatively unaffected by the back pressure in the discharge line. Shaft speed and flow are directly proportional.

FEATURES Bronze Construction with Stainless Steel Shafts Positive Spring Loaded Lip Seal made from fluoroelastomer Available with Motor Adapter and Hardware Easy Field Assembly to Motors Self-Lubricating Carbon Bearings Consult Factory for Special Motors DRIVE The pump is driven directly from the electric motor shaft by means of a flexible coupling. An aluminum adapter connects the pump to the motor.

The Fueltec Water Separator Coalescer The micro-glass coalescer, originally designed for aircraft jet fuel, is an excellent coalescer for diesel fuels. The cartridge is made up with a pleated cellulose inner filter, polyester glass fibers which remove tiny water droplets from the fuel and cause them to grow in size, and an outer cotton sock which further increases the size of the water droplets.

Stainless Steel/Teflon Water Separator After passing through the micro-glass coalescer the flows through the hydrophobic water separator cartridge which repels the now enlarged water droplets. The clean dry fuel is returned to the storage tank and the separated water falls to the bottom of the separator housing.

The Fueltec HMI/PLC System Controller A) Programmable: date, time, tank selection, run time B)Compatibility: MODBUS, ETHERNET, GSM/GPRS C) Display: (1) Low water in trap (2) Vacuum at primary filter (filter change instructions) (3) Pressure at final filter (filter change instructions) (4) High water in trap (drain separated water) (5) System on (6) Tank selected for filtration (7) Day selected for filtration (8) Run time selected for filtration (9) Time of day D) Alarms: (1) High water in trap (2) High vacuum (service primary filter) (3) High pressure (service final filters) (4) Fluid in system sump (5) No fluid flow