Question 460Motor Plants - Assistant Engineer

The correct answer is A) The rate of evaporation will decrease. The wearing of the rings in device '7' will affect the flow of water to the evaporation unit labeled '23'. As the rings wear, the pump's efficiency will decrease, reducing the amount of water flowing to the evaporation unit. This decreased water flow will directly impact the evaporation rate, causing it to decrease. The other answer choices are incorrect: B) The evaporation rate is dependent on the water flow, not just the vacuum level. C) Device '7' is likely a centrifugal or other type of pump that does use wearing rings. D) The standby pump '8' would not be used unless the primary pump '7' failed completely.