Good day to All,
I am a budding Chemical Engineer recently been given an assignment to design a PFD for one our new project.
Generating a PFD for our packages is usually quite simple; however for this particular job I am finding it difficult because the dosing is by gravity. I have read and understood Art Montemayor’s workbook about gravity flow but still I need some guidance about sizing the control valve from you all.
We have a storage tank, the inlet flowrate is 10 m3/hr and the outlet flow rate is 10 m3/hr. There will always be an ample amount of product left in the tank because we are maintaining a 5 minutes residence time to disentrain Hydrogen present in the product. Therefore the discharge line is always be flooded (A level transmitter monitors the level inside the tank, when a low level is detected, dosing will be stopped). Dosing flow control is by means of a proportional flow control valve- mag. flowmeter loop.
Our scope ends after the control valve; we don’t have any details about the piping layout after our limits. However, we have been informed that the dosing point is 15 m below the tank outlet.
My question is about sizing the control valve. Could anyone help me to determine the ∆P for the following two cases? (please see attached schematics)
1. Discharge pipe submerged in water
2. Dosing at sea level
Product density:1028 kg/m3
dynamic viscosity:1.37 cP
Product temp: 12 deg C
Many thanks
AR