Skids and Package Units
Discover the Building Blocks for Modular Plant Projects
Chemicals are Next for Skids and Modules
There is, however, still a long way to go. The chemical injection packages which companies like Lewa, Check Point and Stewart & Stevenson deliver to oil & gas fields are huge container modules capable of handling hundreds of cubic meters per hour, whereas smaller skids are the norm in the pharmaceutical, food and chemical industries. Products which combine mixers, dosing pumps and material handling equipment or multiple compressors with air dryers, filters, tanks and motors in a single module are commonly used in these industries.
The industry can deliver complete solutions for entire process steps either off the shelf or tailored to customer specifications. Four types of package units are very common:
- Simple remote boxes which have a remote I/O module but no controller/visualization
- Stand-alone boxes with interfaces to the control system
- Integrated solutions which contain a complex process module, for example a separation stage
- Modular boxes containing a complete process unit which has a series of configurable process modules
However, it is a big step up from a single unit to an entire facility. Good modular plant design depends on integration of modules from different suppliers to create a working production process. This goes beyond the actual material flows. If the skid as delivered is not a pure standalone solution, then it needs interfaces.
Data Exchange and Integration are Necessary
Data exchange is not the only consideration. Seamless integration into existing safety, automation and operating environments is equally important. Package units must communicate with each other, with the control system and with the operator.
Experts say that the solutions currently on offer have shortcomings in this respect. Many component manufacturers also quietly admit that on-board intelligence is often not regarded as important and is not really used. So a lot of work remains to be done. Even the ever-optimistic VDI believes that the future of modularization depends on interface standardization.