Help request: Single-loop flow ratio control
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In the figure, do 8151 and 8153 constitute a single-loop flow ratio control? What does reset mean for 8153, and what is its function?
I can only say that some people make decisions on a whim; I once met an expert in this field who designed a system to control two valves using a single temperature setting – it was purely arbitrary.
I’ve seen ones with a RESET button before
This is a “temperature – single-loop” variable ratio control system. The TIC—8153 outputs a value to the ratio controller, modifying its setpoint thereby adjusting the flow ratio.
This is a cascade-ratio control scheme, where the tower temperature TE-8153 is the primary variable and FT-8151 is the secondary variable. At the same time, the ratio of FT-8152 to FT-8151 constitutes a single-loop proportional control system; FT-8152 does not allow for flow control and serves as the main material, while FT-8151 is the secondary material that is required to adjust itself in accordance with changes in FT-8152. RESET is estimated to mean ratio reset.
Agree with this view; if the design is thorough enough, the drawings should include explanations of complex control circuits