Traditional process loops for cooling water control in steel mills consist of a globe vale, flowmeter, and pressure and temperature sensor. The valves in such older installations for the production of rolled-steel are still often hand-operated and the efficiency very much dependent on the experienced operators who have good understanding of the process needs. However, as many of these plants have come of age and require upgrades to accommodate higher production output, use of pneumatically control globe valves and their integration into DCS is becoming common and necessary to ensure uniform quality of the rolled steel. Such upgrades, however, are expensive and undergo a typical project cycle from design engineering, procurement of latest equipment, to ramp-up of process loop that is optimized to provide desired performance and output.
This project was ideal for the consideration of FOCUS-1 solution that integrates control with measurement of process variables flow, pressure, and temperature. Upon discussion of the process boundaries and process performance expectations with the customers, a thorough review of the traditional loop was undertaken and an alternative with FOCUS-1 presented. During the technical comparison of individual components with the specifications of DN80/PN40 FOCUS-1, it was shown that all the functionalities of desired control of cooling water flow and measurement of its process parameters were ideally matched. In addition, FOCUS-1 provided novel form of control, that is Flow as a setpoint.
The advantages of this approach over the traditional process loop design were :
– reduced engineering efforts
– lesser flanges owing to a single FOCUS-1 device replacing four (4) components
– smaller footprint due to shorter piping as FOCUS-1 demands inlet run (4 D) and outlet run (0 D)
– simpler and less complex DCS because novel control philosophy is put to whereby flow is given setpoint (4/20mA analog IN)
– increased transparency of the process owing to multi-parameter output (4/20mA OUT + HART)
– faster view of the process by utilizing real-time asset management on the device or at DCS level enable by Ethernet connectivity
A simple Cost of Ownership (CoO) calculator helped convince the plant engineering and operations teams that FOCUS-1 can provide considerable savings over the entire life-cycle in such applications over traditional installations. However, for this it is imperative that this disruptive multi-parameter control and measurement device is considered early in the plant design phase.
We can demonstrate that for this application and many others, the savings from design/engineering to installation/ramp-up phase alone can be up to 33%. And creating visibility of process conditions to optimize loop performance is where the potential savings can be further increased.
