Inventory estimation for inherently safer design
2018-11-08T10:16:54Z (GMT) by
Traditional approaches to safety in process plants tend to rely on 'added-on' safety measures as a means of minimising risk. During the design process the first stage at which safety is considered in detail is the HAZOP study. Inherent safety, where safety is designed into a plant has been found to have great benefits with regards to both safety performance and operating costs. In order to implement inherent safety fully it must be considered as early as possible in the design process, before decisions have been made which are fixed and costly to change. The major barrier to this is the lack of data available in the early design stage, which prevents different options being assessed for safety. The most important variable is that of inventory, as the quantity of material present is a major factor in determining the hazard posed by that material. The use of short-cut design methods together with simplifying assumptions was investigated to determine if they could be used in an inventory estimation study. It was found that such methods could be used. Although there are uncertainties in the available data it would be possible to use the methods to estimate the inventory of a process at the route selection stage of the design study. This would enable the comparison of different process routes in order to select the route that is the safest in relation to hazardous inventories and also to pinpoint which areas of a process have the greatest effect on safety. This would aid the design engineer to focus on the most hazardous items in a process plant and minimise that hazard.