Unloading a tank can be a challenging process. Since most general-purpose rail cars have little if any slope to the drain or unloading tube area, some of the product hauled can be left behind. Called “heel” the left-behind residue can vary significantly in viscosity, melting point, density, polymerization and impurity content.
Other factors that determine the amount of heel is the amount of heat applied at unloading, the time required to unload the car and the amount of time since the last thorough cleaning.
Best Industry Practice
Some residues are also left behind after a more comprehensive fogger wash. Our team carefully removes these residues using hand tools, water blasters that deliver pressures up to 20,000 psi to problem areas and specialized vacuum equipment. When interior coatings are present, we take extra care in our work. We’ve learned and use best industry practices to recycle recovered oils and fats. Our experience in this area reduces waste and keeps disposal costs low.