Procedure 2-16 Optimum Vessel Proportions

This procedure specifically addresses drums but can be made applicable to any kind of vessel. The basic question is What vessel proportions, usually expressed as L/D ratio, will give the lowest weight for a given volume The maximum volume for file least surface area, and weight, is of course a sphere. Unfortunately, spheres are generally more expensive to build. Thus, spheres are not the most economical option until you get to very large volumes and for some process applications where that shape is required. 

For vessels wifliout pressure, atmospheric storage vessels, for example, file optimum L/D ratio is 1, again using the criteria for file maximum volume for the minimum surface area. This optimum L/D ratio varies with file following parameters  

In Process Equipment Design, Brownell and Young suggest that for vessels less than 2 in. in thickness, the optimum L/D ratio is 6 and for greater thicknesses is 8. However, this does not account for the parameters just 

Although this refinement is an improvement, it still does not factor in all of the variables. But before describing the actual procedure, a brief description of the sizing of drums in general is warranted. Here are some typical types of drums  

Typically the sizing of drums is related to a process consideration such as liquid holdup (surge), storage 

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