In this process, maple syrup is heated as it passes through a steam heat exchanger, then enters an evaporator where the water boils off. The purpose of this is to raise the sugar concentration of the syrup, making it suitable for use as a food topping. A level control system (LT, LIC, and LV) maintains constant syrup level inside the evaporator, while an analytical control system (AT, AIR, AC, and AV) monitors the sugar concentration of the syrup and adjusts steam flow to the heat exchanger accordingly.
Suppose the steam tubes inside the heat exchanger become coated with residue from the raw maple syrup, making it more difficult for heat to transfer from the steam to the syrup. This makes the heat exchanger less efficient, which will undoubtedly affect the process.
Describe in detail the effect this heat exchanger problem will have on the performance of the analytical control system.
More Questions :
- Suppose the operations personnel of this maple syrup processing facility wished to have an automatic method for detecting heat exchanger fouling. What variable(s) could be measured in this process to indicate a fouled heat exchanger?
- What economic effect will this fouling have on the process? In other words, does the process become more or less profitable as a result of the heat exchanger fouling?
The analytical control system should still be able to maintain sugar concentration at setpoint, unless the heat exchanger fouling is so extreme that even a wide-open steam valve does not heat the incoming syrup enough to sufficiently concentrate it.
Follow-up question: suppose the heat exchanger fouling really is this bad, but we cannot fix the heat exchanger with the tools we have available. What would you recommend the operator do to make this system produce on-spec syrup?
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