if you want to carry this percentage , with drum measures, calculates the total volume of the drum and the partial volume subtracting this height, as I say the drums are designed to leave a empty space between 30 to 20 feet (area without fill called outage), this is independent of the height or diameter of the drum, this is considered a safe space to avoid dragging or entraiment of coke or foam to the header line, these velocity in the drum must be less than 0.7 ft / sec, the ideal 0.3 ft / sec
Im sorry for my english Espana2005
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