In the 2016 Chemical Engineering case study, in the afternoon, there was a net suction head for the pump – is it necessary to make corrections?
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The calculated value for NPSHa is 5.01 meters; the possible answers are 4.0 meters, 4.5 meters, and 4.9 meters, with the other option being unreliable. I took into account a 0.5-meter margin and chose 4.5 meters. It also comes closest to 5.01 - 0.5 when calculated. Is the term used in the question “net suction head” referred to as “NPSHr”? The proposer should specify how much of a correction is needed, 0.3 meters or 0.5 meters. "The net positive suction head of a pump is divided into the required net positive suction head (also known as the necessary net positive suction head), denoted as NPSHr (NPSH Required) or NPSHR, and the available net positive suction head (also known as the effective net positive suction head), denoted as NPSHa (NPSH Available)."
No correction is needed; with g=10, the result is 4.9
I got the same result as the original poster; I made corrections to get values that are closer to 4 and 5
This post was last edited by tjuliusuan on 2016-9-5 at 15:29; the value of 1000/9.8 is simply taken from that of a book
No correction is needed; if one is required, a margin value will be provided for you, as the association’s margin is 0.3M.
How did I get a result of 5? 01 then
I also got 5.01. I calculated it N times back and forth; I really don’t want to lose points on this type of question. In the end, 4.9 was chosen
I hope I won’t get another question wrong; oh no, my performance wasn’t that good to begin with
I also got 5.01, with each step accurate to four decimal places; the closest value is obtained by subtracting 0.5m. Hesitated for a long time between 4.9 and 4.5……
But in the association’s handbook, G is always set to 9.81 when doing calculations