Question

In a feedback control of milk heat exchanger:

• A. A thermometer measures the temperature of the milk coming out of the heat exchanger and sends to the controller a measurement signal
• B. Temperature of the milk is not measured through feedback control of milk heat exchanger
• C. A thermometer measures the temperature of the milk entering the heat exchanger and sends a measurement signal to the controller.
• D. A thermometer measures the temperature of the milk entering the heat exchanger first and then measure temperature coming out of the heat exchanger

Hint:

In a typical feedback control loop for heat exchangers, the key measurement is the temperature of the fluid leaving the system. This ensures that the controller can adjust the system based on the actual temperature of the fluid exiting the process.

Answer 1

The Correct Option is A

In a feedback control system, the temperature of the milk exiting the heat exchanger is measured using a thermometer. This temperature is used as a feedback signal for the controller, which regulates the heat exchanger's operation. The controller adjusts the temperature by responding to the measurements taken at the exit of the heat exchanger to ensure the milk's temperature remains at the desired setpoint. This process is crucial in maintaining consistent product quality during pasteurization or other thermal processes.
- Option (2) Temperature of the milk is not measured through feedback control of milk heat exchanger is incorrect as feedback control relies on the temperature measurement to adjust the system.
- Option (3) A thermometer measures the temperature of the milk entering the heat exchanger and sends a measurement signal to the controller. is incorrect because the input temperature isn't typically measured for the feedback loop.
- Option (4) A thermometer measures the temperature of the milk entering the heat exchanger first and then measure temperature coming out of the heat exchanger is incorrect as feedback control focuses on the output (exiting) temperature.
Thus, the correct answer is option (1): A thermometer measures the temperature of the milk coming out of the heat exchanger and sends to the controller a measurement signal.