Effect of changing the downcomer size on acid spray volume
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The inner diameter of the liquid inlet pipe in the 93% acid drying tower of our company is 400 mm. There are a total of 854 downcomers in the set of 304 stainless steel tank-type acid separation equipment. Given that the original stainless steel downcomers (19*2 mm) were severely corroded, they have now been replaced with ones of 19*3 mm size. However, there is concern that this change may not ensure an adequate flow of acid, which could lead to acid overflowing in the acid separation tank. I ask the experts to help clarify this.
The acid drop due to gravity isn’t at full level in the pipe, so it should not be a serious problem
The trough-type acid dropping pipe isn’t filled to capacity; by increasing it by just 0.5mm, there’s no problem. Nevertheless, it is still recommended to pay more attention to the corrosion of the acid drainage pipes, as the wear caused by gravity and empty pipes occurs quite rapidly
I misread it; yours has the inner diameter reduced from 15 to 13. It would be best if you could provide the amount of acid used in each cycle as well as the number of acid application points per square unit, so that I can help calculate whether it’s feasible
The circulating acid volume is around 450 m3, with a spray density of approximately 43 points/m2, for a total of 854 points
After doing the calculations for you, the flow velocity inside the tube when the inner diameter is changed to 13 is 1.1 m/S, which is still acceptable. However, considering the gravitational acceleration of the sulfuric acid in the acid drop pipe, the flow velocity at the final outlet is likely to reach 3.8 m/S or even higher; therefore, care must be taken to prevent erosion and corrosion during production
It was specifically made thicker to prevent corrosion; does it seem that this was actually a mistake?
Since it’s already been changed, just use it for now and pay more attention to checking it