A few years ago, thermal oil oxidation became a problem for a food processor when it fouled the plant’s process equipment and increased fluid acidity.
few years ago, thermal oil oxidation became a problem for the Abergavenny Fine
Food Co., in Blaenau Gwent, South Wales, U.K., when it fouled the plant’s process
equipment and increased fluid acidity. Oxidation occurs when an oil temperature
greater than 149°F (65°C) meets air in the same space, starting a chemical
process from the reaction with oxygen.
Abergavenny header tank was in excess of 212°F (100°C) and had no nitrogen-blanketing
system to protect the overheated oil from the air above it.
oil “was frequently damaging oil circulation pumps,” says Paul Sanders, Abergavenny’s
site engineering manager, explaining that the thermal oil indirectly heats
fryer oil for the company’s breaded party-foods line.
a solution, Abergavenny contacted Global Heat Transfer Ltd., Staffordshire, U.K.
Engineers found a buildup of carbon around the piping because the oil had not
been tested or maintained for a number of years, according to Sanders. “The
carbon was coming loose and damaging the seals in the circulation pump,” he
Heat Transfer drained, flushed, cleaned and refilled the system, then set up
monthly oil testing and analysis to comply with the Dangerous Substances and
Explosive Atmospheres Regulations 2002, which requires employers to control the
risks to safety from fire and explosions.
“when we carry out our monthly analysis, we can pick up an issue before it
starts to cause problems,” Sanders says. “We can monitor the carbon content and
pick up any excess buildup of carbon, as well as the acid levels, which can
cause corrosion if they go over a certain level.
“We can also keep an eye on the flashpoint as well, which was very
low in this case. When I joined the company, the oil had not been analyzed or
changed for seven years prior to Global Heat Transfer getting involved. By that
time, the damage had been done from the carbon buildup in the pipework, tubes
operates from a 40,000 ft² facility producing snack foods, ready meals, dairy
and desserts. The plant has seen boiler efficiency improve significantly,
Sanders says, and there has been a 50 percent drop in heatup time.
Hot Oil Oxidation Damages Process Equipment
July 11, 2012