Off-Line Data Logging for NPK Plants

An off-line data-logging system has been introduced to Shellstar’s N.P.K. and ammonium nitrate plants.

The system uses an IBM 370 computer. Data input is by cards, using plant log-sheets as punching instruction documents. Data extract is mostly on demand. The key data extraction program is known as the Generalised Extract Request program, and it enables the requester to specify the data to be retrieved. This program also incorporates graph plotting routines, and the ability to transfer data to another computer, the Univac 1108. Using the latter computer comprehensive statistical analysis of N.P.K. data is possible.

The system also incorporates certain specialised programs: a mass balance program; one that traces period of manufacture for bagging batches, and so on.

The original objective for introducing the system was as an aid to solving certain process problems. Several of the problems that justified the system have been solved. Others yet remain, but the system has clearly demonstrated its usefulness and is considered justified.

In an appendix, the application of demand processing to the control of an N.P.K. plant is considered. Examples of use are formulation control and plant performance checking.

I K Watson, Shellstar Ltd (now Kemira Ince), Ince, Chester, UK.

31 pages, 13 figures, 2 refs.