How to set bin size

There are several considerations in determining the required size of a new bin. One of the first considerations is the mass of material that needs to be stored. This value may be set based on consumption rate of the bulk solid, frequency of incoming or outgoing shipments, production rate or frequency, and/or required residence time if the vessel is to be used for aging or some related purpose. All of these are process considerations that may set the desired mass. Another consideration involving mass is limitations of the foundation upon which the bin is to be placed. 

Once the desired mass has been chosen, the next step is to convert it into a volume. This involves estimating the bulk density of the solid to be stored. Unfortunately, bulk density is not a constant for most bulk solids and often varies over a wide range depending on consolidating pressure. 

Once the volume has been determined, the next step is to determine individual overall dimensions. In the case of a circular cylindrical vessel, this means setting the diameter and height of the cylinder section, since in most cases the majority of storage volume is contained therein. Whenever possible, it is desirable to fabricate the vessel in a shop because this is more economical than doing so in the field and also provides better quality control. The limit then becomes the size of vessel that can be transported from the shop to the plant 

Whether or not the bin is to be shop fabricated, plant space considerations usually need to be taken into account. For example, plant layout may limit the maximum bin diameter. Access within the plant may dictate the maximum size that can be transported to the location where the bin is to be placed. 

Another consideration regarding bin size involves obtaining a reasonable height-to-diameter ratio, H/D. Usually bins are most economical when this ratio is between roughly 1.5 and 4.0. While these are not firm limits, they do provide a good guideline for economical construction. Vessels with smaller H/D values have much of their volume in the hopper section, which is more expensive to fabricate than a cylinder. At the other end of the spectrum, vessels with large H/D values may be taller than necessary or be more subject to wind or seismic considerations than a shorter vessel. 

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