Prospectus

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OR-3 Heat Transfer in Empty Spray Sections in Vacuum Systems (Also, See MD-2, Possible Combine) Expected Benefit toMembers: Use in heat transfer sections of industrial columns, allowing reduction in pressure drop with increase in vaporization of distillates, reducing coke formation, maintenance and packing costs. Present Situation and Proposed Research: In 1987, FRI did experiments with empty spray sections. At that time, it was shown that sprays are very good heat transfer devices and that the heat transfer occurred in a short distance from the distributor. The proposed research is that analysis of the empty spray sections, by measurements of the pressure drop, heat transferred, height necessary and determination of the heat transfer coefficient. Sprays with different spray angles (90 and 120 degrees), different pressure drops (changing liquid reflux rates), and different types (full cone and hollow cone) will be tested. The studies may reproduce the same behavior of the pumparounds, that is, a subcooled reflux liquid that condenses the upper vapor (total or not) forming the liquid product of same composition of the reflux liquid. If possible, three other studies may be done: • Two streams and one spray distributor: these two streams would be pumped from two individual pumps into one sole header, upstream of the spray distributor. The streams would be of different volatility. The heavier one would play the role of the pumparound in an industrial vacuum column, whereas the lighter one would simulate a lighter sidecut from the crude column. The purpose of this case study is to observe the feasibility of introducing two different feeds into one spray distributor: how this affects the heat transfer coefficient and whether the cone collapses from the vaporizing lighter feed. • Two streams and two spray distributors: again, two streams of different volatility, this time would be pumped from two individual pumps into two individual spray distributors, placed one above the other. The same aspects as in the previous case study should be studied. • Two streams, one spray distributor and one gravitational distributor: again, two streams of different volatility, this time would be pumped from two individual pumps into two individual distributors, the heavier feed going to the spray distributor whereas the lighter one to the gravitational distributor, just above the former. The same aspects should be studied. In a paper by Cai and Kunesh presented at AIChE in 1999, a pan distributor was employed, and just as with sprays, the heat transfer took place in a short height. Developmental Research Idea

PROSPECTUS

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