Question 125General Subjects - Assistant Engineer70% to pass
While circulating heated sulfuric acid through a feed water heater of a flash evaporator for the purposes of scale removal, what would be the indication of the continued presence of scale?
AI Explanation
The correct answer is A) No change in color (remaining at red with a pH of 2.0) and no more venting of carbon dioxide gas.
The continued presence of scale in the feed water heater would be indicated by the heated sulfuric acid remaining red in color with a pH of 2.0. This is because the scale, likely composed of calcium or magnesium compounds, would not have been fully dissolved or removed, and the acid would not have become neutralized. Additionally, the lack of carbon dioxide venting would suggest that the scale was not reacting with the acid.
The other options are incorrect because a change in color to orange with a pH of 4.0 (option D) would indicate that the acid had been neutralized, signaling the removal of the scale. Options B and C do not provide accurate indications of the continued presence of scale in this scenario.
Related Questions
#123 Which of the following fresh water generators has an operating principle that evaporates pre-heated sea water by causing it to undergo a pressure drop into a vacuum? #124 In a flash evaporator, scale as a result of higher than normal temperatures is most likely to occur in the _______________. #126 When securing a flash-type evaporator for an extended period of time, you should _______________.#127 When should mechanical cleaning of feed water heater tubes be accomplished? #128 What procedure can be used to reduce the rate of scale formation on the heating surfaces of a flash evaporator while still maintaining the desired rate of distillate production?