Question 59General Subjects - 1st Asst/Chief

The correct answer is A) brine density is too low. The efficiency and output capacity of a low pressure distilling plant will be reduced if the brine density is too low in the last effect shell. This is because the brine density affects the heat transfer rate in the distillation process. If the brine density is too low, it will result in lower heat transfer, reducing the overall efficiency and output capacity of the distilling plant. The other options are incorrect because: B) and C) are not related to the brine density, which is the key factor affecting the distilling plant's efficiency. D) is incorrect because there is no specific requirement for the brine density to exceed 1.5/32nd.