The SPM-1700 Instrumentation III – Multi-Element Control Process Simulation consists of four independent process loops. Each one of these process loops demonstrates one of four basic multi-element control strategies.
The first process loop is Cascade Control, the second process loop is Bias Control, the third process loop is Ratio Control, and the fourth process loop is Auctioneering (Selector) Control.
Each of the four process loops consist of a mix tank where components A and B are to be mixed to a specified composition. The resulting mixture leaves the mix tank by gravity.
In each of the four process loops Feed A flow is controlled by FIC-X01 and Feed B flow is controlled by FIC-X02. Tank level is controlled by LIC-X02 and mixture flow is indicated by FI-X03. Feed A composition is indicated by AI-X01, Feed B composition is indicated by AI-X02, and mixture composition is indicated by AI-X03. In the Cascade Control Process and the Auctioneering (Selector) Control Process the mixture line is outfitted with a composition controller (AIC-X03). The Auctioneering (Selector) Control Process is also outfitted with a HIGH/LOW Output Selector Relay which decides whether the flow controller output or the mixture composition controller output should modulate the Feed B flow control valve.