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Restricted Venting of Metal Drums

IP.com Disclosure Number: IPCOM000019901D
Publication Date: 2003-Oct-08
Document File: 2 page(s) / 28K

Publishing Venue

The IP.com Prior Art Database

Abstract

A solution to the problem of collapsing drums for activated adsorbents is proposed. The solution involves use of restricted venting, allow pressure equalization with limited adsorption of moisture.

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Restricted Venting of Metal Drums

 

Abstract

A solution to the problem of collapsing drums for activated adsorbents is proposed. The solution involves use of restricted venting, allow pressure equalization with limited adsorption of moisture.

Problem: Many porous inorganic materials such as zeolites, aluminas or other high surface area molecular sieve adsorbents are packaged while still hot as they come from an activation step, and are put into 55 gallon metal drums. Occasionally the drums suffer a structural collapse. This normally happens as the products cool in the sealed containers as they sit in a warehouse or when shipped to colder climates. The collapse does not seem to be due to excessive stacking weight or other external factors. Even when the drums collapse, they tend to maintain the integrity of their seal, however, the physical appearance of the container and safety concerns make them unacceptable for delivery to the customer. Repackaging costs, customer dissatisfaction, increasing occurrences, and safety were the main causes prompting a detailed study into this situation.

Solution: First to be studied was the structural integrity of the drum itself and the collapsing forces involved. It was found that under ambient conditions the drums collapsed at a vacuum of about 15 in. Hg. Slightly increasing the drum’s wall thickness or adding different types of reinforcing rings increased the drum’s vacuum capacity to about 20 in Hg. From previous tests on drums containing product, it was found that vacuums greater than that could be developed as the drums were subjected to cold temperatures. This vacuum was only partially a result of the air volume change due to temperature. The remaining vacuum, which caused the collapse, was created due to the product’s affinity for nitrogen. Additionally, these type modifications were deemed to be cost prohibitive.

Other physical changes to the drum were investigated which included the use of vacuum relief valves in the drum’s vent hole, plastic plugs placed in the vent hole, placing “breathable” material over the drum’s vent hole, etc. Along with some other technical problems, thes...