Control Using Wireless Devices – Field Results Part 2

The Separations Research Program was established at the J.J. Pickle Research Campus in 1984. This cooperative industry/university program performs fundamental research of interest to chemical, biotechnological, petroleum refining, gas processing, pharmaceutical, and food companies. CO2 removal from stack gas is a focus project for which WirelessHART transmitters were installed for pressure and steam flow control on a stripper column. A picture of the process is shown below.

Standard WirelessHART pressure and flow transmitters were installed to demonstrate and test control using WirelessHART and the PIDPlus. The control was modified to allow the operator to switch between control using WirelessHART and PIDPlus and the wired transmitters and PID. The stripper column pressure control is shown below for each manner of control.

The same dynamic control response was observed for SP changes as illustrated above. Original plant PID tuning was used for both wired and wireless control. The control performance for wireless vs. wired control is summarized in the following table.

Comparable control as measured by IAE was achieved using WirelessHART Measurements and PIDPlus vs. control with wired measurements and PID. However, the number of measurement samples with WirelessHART vs. Wired transmitter was reduced by a factor of 10X for flow control and 6X for pressure control – accounting for differences in test duration.