Designed and manufactured by CSV Containment, which deals with R&D within CSV Life Science, DIT (Drum Iris Technology) has a double iris valve interface system, which guarantees the function of a pass box, not allowing the volume of the drum to enter in the loading chamber, avoiding drum contamination. First DIT realizations have obtained confirmations in terms of operating costs, operability and ergonomics, performance and safety.
Recently CSV Containment has introduced a technology to contain reactor-charging operations. In order to manipulate the powders under controlled conditions, the company has developed a (DUM, Drum Unloading Machine) containment system with the aim of proposing a turnkey solution based on proprietary and innovative CSV know-how, that allows to confine operations of reactor loading. This technology immediately proved to be an innovative solution for contained drum handling in general.
Critical issues in Bag In / Bag-Out Procedure
In chemical/pharmaceutical, industry is often necessary to contain the loading phases of the equipment (i.e. reactor) by drums, passing through a dedicated flange (seldom) or through the hatch/ manway. Generally, drum transfers are contained using Bag-In / Bag-Out procedure; due to the difficulties, required time and consumables cost, operators feel a certain reticence, if not dissatisfaction. The BIBO technique consists in closing the corridor between the drum and the isolation chamber with a polyethylene bag ‘squeezed’ around the head of the drum (or the outer bag commonly already present in the drum packaging) and coupled at the interface (circular and provided with grooves acting as seats for the needed O-rings) provided on the isolation chamber. The operation, in itself rather cumbersome, provides for the introduction of consumable elements (O-rings, twin clamps, wire ties, etc.) and, especially on large drums, the use of lifts and, above all, the involvement of two operators. The phase of separation, equally laborious, requires a “manual” compression of the plastic that closes the corridor and its separation by means of a double clamp or with the so-called “crimping” systems.
Drum Iris Technology (DIT)
Therefore, CSV decided to create a system that had the function of a pass box, but at the same time did not allow the drum to enter the loading chamber, thus making it unnecessary to clean the drum, as it was not exposed to the contaminant. For this purpose, the company has designed and implemented a double iris interface system, positioned as in a pass box, instead of the classic folding doors. The result is a cylindrical pass box (rather than square or rectangular, usually done), without folding doors, but with opening and closing ends at full diameter by means of an elastic diaphragm made of elastomer (iris).
Luca Vietri, Containment Expert of CSV Life Science, comments: “Initially we thought we could make the interface through commercial valves, but faced with the need to use diameters and materials not available on the market and, moreover, a mechanism useful for coupling the two iris to the ends of a sealed tube interfaced to the chamber. We decided to create a proprietary device, designed and built entirely in our workshop. The double elastic barrier allows to minimize the contact surface of the drum with the inner contaminated chamber atmosphere and eventually to automate, without introducing consumables, the drum insertion and extraction operations itself. Furthermore, a negative or positive pressure difference (pressure cascade) can be generated between the double iris pass box and the adjacent rooms (external or internal chamber).
At the moment we are able to make iris interfaces from 4”/DN100 to the most common 12”/DN350, or 22”/DN560, for Kraft drums of all types up to 27” / DN700 mm opening useful for 200 l drums of solvents or liquids. The body material ranges from steel to alloy to POM, while typically the elastomers used are EPDM (black or white conductive), FKM or silicone. “