Chlorobutyl Lining for Chemical Resistance Case Study: PotashCorp’s HPD Evaporators
Customer / Project: PotashCorp
Location: Aurora, North Carolina
PotashCorp is one of the world’s largest fertilizer enterprisers, producing nitrogen, phosphate and potash.
The company has 15 HPD evaporators used to process phosphoric rock for fertilizer production at its Aurora, NC facility. The company used a competitor’s rubber linings, but had issues with longevity. PotashCorp was searching for a rubber lining better suited for the extreme heat and wear environment. The evaporators operate at full vacuum. The equipment uses a steam injection vessel to boost the vacuum during the hot part of the summer when the cooling pond water temperature rises due to the increase in ambient temperatures.
The heavy wear areas were especially problematic, with corrosion and impingement damaging the lining. These troublesome areas included the:
- Bottom cone (outlet)
- Tangent inlet nozzle (liquid recirculation)
- Vapor nozzles that are subject to high-velocity gas
The company had to perform repeated repairs in these areas, as well as manway flanges that are opened for inspection and the liquid inlet flanges that are subject to damage by overtorquing.
Ultimately, PotashCorp wanted a material that could withstand the demanding environments found in the fertilizer production industry.
Blair Rubber Co. suggested its LS582 chlorobutyl lining which has exhibited great success in similar phosphoric acid applications, as well as other harsh-condition vessels like scrubber systems in coal-fired power plants.
LS582 is a soft, black chlorobutyl lining for general purpose chemical resistance. LS582 has a reliable service life of 8-10 years in phosphoric acid.
Blair Rubber Co. recommended that PotashCorp double line the equipment for better protection from physical damage and corrosion from gases introduced into the vessel.
PotashCorp agreed with Blair Rubber Co.’s recommendations and started double lining with the LS582 chlorobutyl lining. The double lining technique has now become the standard for evaporators.
Preliminary reports showed the chlorobutyl lining was performing well and exceeding expectations in the evaporator environment.
Since the installation of Blair Rubber Co.’s LS582, PotashCorp has had significantly less repair time. One evaporator has had the same LS582 lining since 2003.
“Our superior LS582 lining has served PotashCorp well over the years,” said Danny Lee, Blair Rubber Co.’s national sales manager.
“The configuration of our chlorobutyl linings withstand the extreme conditions that phosphoric acid production presents. It was especially important for PotashCorp to have a lining that could protect from wear.” All PCS evaporators are now completely double lined, not just in the heavy wear areas.
Equipment is inspected every 14-21 days. Blair Rubber Co.’s consultative technical support has made PotashCorp a long-standing customer. Should any issues arise, Blair Rubber Co. will perform an on-site joint inspection and analyze samples in its lab.
PotashCorp now exclusively uses the LS582 for its evaporators.