The chemical industry covers a wide range of activities like designing equipment and developing processes for manufacturing new materials on a large scale. These materials are used in diverse sectors like aeronautical space, biotechnology and IT, among others. This is in addition to fine-tuning processes, which make existing processes more cost-effective.
The domain of chemical engineering not only includes converting the laboratory and pilot scale plants to commercial plants but also involves designing reactors, distillation columns, pumps, heat exchangers, etc. This helps in implementing the mass and heat transfer processes required to convert raw materials to the end products. In addition to designing individual pieces of equipment, the plant as a whole is designed keeping good engineering practices in mind as well as mandatory guidelines laid down by American Petroleum Institute and other Chemical Process Industry (CPI) governing bodies.
Further, the process involves preparation of the plot plan to position process areas, utility areas and tankages. This provides access to movement of man and machine for raw material inputs, movement of intermediate and finished products between and without plant areas as well as for construction and maintenance.
Piping design and routing remains a major plant engineering activity in all CPI projects. Pipelines provide the means of transfer of all fluid process and utility materials such as steam, cooling water, compressed air, etc. Design of piping (selection of material, size and routing) has a major bearing on plant activities.
The design method
The pre-automation phase see engineers manually preparing equipment assembly drawings, structural / civil general arrangements equipment layout drawings, piping general arrangement drawings - floor wise plans and elevations, pipe rack routing, isometrics, etc. While design of individual equipment and structure requires specific domain knowledge, piping requires a high level of spatial detailing in addition to piping knowledge.
More than any other aspect of plant engineering, piping is most prone to design changes due to the requirements governed by piping stress analysis. Results of pipe stress analysis cause changes to pipe routing that in-turn often lead to a cascade of changes. During installation at site, it is often seen that pipe routing as planned by piping designers leads to interferences between piping and structures, equipment either directly or indirectly due to pipes crossing access areas for operation and maintenance of equipment (opening of manhole and body flanges, accessibility for viewing, etc) or instruments (viewing of flow/level/pressure/temperature indicators, sight glasses, operating bypass valves on control valves, calibration and maintenance of instruments) and also operation of valves. This leads to rework and rerouting of pipelines, leading to usage of extra pipe material, man-hours of effort and eventually delay in production deadlines.
The automation era
The introduction of plant design systems has made all this, a thing of the past. The biggest benefit of plant design automation is that disciplines like piping, equipment, structures, electric raceway, etc are created under the same umbrella of plant design. The multidiscipline pace allocation avoids all possibility of clashes or site reworks. This not only saves costly, reworks at site but also takes care of modification/alteration in one discipline, which results in a cascading effect on related disciplines. Advance features like space claims (soft clash) for equipment maintenance area, etc are defined in advance so that necessary error messages are generated even in the case of faulty modelling.
Almost all chemical industries involve huge amount of piping to handle various working fluids. Engineering of a chemical plant involves maximum man-hour for creation of isometric drawings. Isometric drawings are the 3-dimensional view of the plant piping, thus making the plant erection simple and easy to interpret. It is imperative to reduce this cycle time for isometric creation. Plant design solution also creates isometric drawing automatically. However, company standards need to be customised at least once, to give the correct output. These drawings are also intelligent as they have a link with the parent model. Hence, whenever the model is edited, isometric drawings get updated automatically.
Plant design & internet
The World Wide Web has created a revolution in the corporate world. It is now a known fact that the client server- based applications have been redefined by incorporating web-based tools. This has resulted in the development of any user-friendly tools, which are ideal for design and development in federated environment. In the chemical industry too, large EPCs are now sub- contracting to other vendors and the whole project is getting merged in plant design environment. Besides, during the construction stage, the client is apprised of the nitty-gritty of the project progress, with web-based tools. The client then collaborates with the developers to get the plant as per his own choice. The scheduling of the project is also done on the same platform. This helps in planning for the required materials.
Thus, plant design automation is an integral part of the chemical industry. Moreover, the progress in this industry is totally dependent upon the kind of automation tools that are incorporated. Web-based technology has also played a major role in enabling plant designers to keep a strong control on the progress and scheduling of the projects.