Drop , process flow, variables responses

Process Flow, Variables, and Responses Syrups, Suspension, and Drops Products... 

PROCESS FLOW, VARIABLES, AND RESPONSES SYRUP, SUSPENSION, AND DROP PRODUCTS... 

Process flow, variables, and responses syrups, suspension, and drops products... 

The constraints changed from one trial configuration of the reaction system to the next, but typically included things like the minimum coolant temperature to permit efficient utilization of the heat of reaction as process steam, the maximum allowable aldehyde concentration in the condensed crude product to avoid refining and product specification problems, and a prescribed reactor pressure drop to insure adequate flow distribution among the reactor tubes at a minimum energy cost. All of these are implicit constraints — they establish the maximum or minimum levels for certain response variables. Explicit constraints comprise the ranges for search variables. 

Flow is the manipulated variable as well as the controlled variable, so it seems as though the process is unity. But this is not the case. Opening a valve does admit flow, but the response is not quite instantaneous. If the fluid is gaseous, it is subject to expansion upon a change in pressure therefore the contents of a pipe vary somewhat with pressure drop, hence with flow. In a liquid stream, inertia is significant-flow cannot be started or stopped without accelerating or decelerating. To demonstrate the dynamic character of inertia, the time constant of a column of liquid in a pipe will be derived. 

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