FeedForward has recently completed a Dowtherm Vaporizer controls upgrade using Yokogawa hardware and software. The scope of work included upgraded digital controls for operation of the boiler, flash tank, condensate tank, fuel oil delivery and associated pumps and blowers. As part of the project, FeedForward implemented an improved control strategy which combusts air and fuel based upon pressure in the Flash Tank. The combustion controls use a metered cross-limiting function between fuel and air based upon BTU input. O2 trim is also employed in this function. FeedForward developed and programmed the equations to implement this regulatory control strategy in the new Yokogawa DCS. The scope also included a new operator MMI on graphic displays, and on-site startup and tuning support.

This batch project was for the modification of existing logic to include additional raw materials, addition of weight batch tanks to confirm mass flow meters, and new valve manifolds for five batch reactors on a Yokogawa MicroXL DCS. Batch logic and graphic panel modifications were required.