hello friends... i m krunal shah, i m new person of instrument maintenance. i want (1) flow rate at 8 kg/cm2 pressure, (2) differential pressure with the help of that calculated flow rate.

friends i have following data for 3T BOILER:

pipe size ID: 105.05 mm

For flow transimmiter,primary element: orifice plate

BITA ratio for orifice plate: 0.43

maximum flow range for 3T boiler: 3T/H

required pressue P1= 8 KG/CM2 T1= 169.4 C
P2= 13 KG/CM2 T2=191 C
maximum pressure P3= 15 KG/CM2 T3=198 C

(pressure and temperature data are according to steam table)

if possible then please tell the formula / equation for calculating flow rate at 8 kg/cm2 pressure and also formula for calculating differential pressure.

Thanking you.

 

Dear,

What I get from your question is that you want to calculate flow and difrential pressure on the basis of static pressure but as far as I have worked the basic flow equation is

FLOW RATE IS PROPOTIONAL TO SQUARE ROOT OF DP

the constant of propotionality is depends upon Static pressure and temperature and if you have constant static pressure and temprature then you can put a constant then you can get good working results.

I have tried to find out some simple equations which can relate static pressure and temperature to his equation but the functions available are really complex.

 

Dear Mr. Shah,

You can refer Flow Measurement Hand Book from ISA to get the right formula. Why don't you also look at Flowel Software for orifice designing & DP calculation.

I would recommend using VERABAR Flow Element for the said application as its a maintainance free device generating very low PPL thereby saving huge cost on energy.

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