Could someone please help me with a mass flow equation to calculate the flow of steam? I have an E&H Deltabar Transmitter giving me the Differential pressure on my steam line. I have the following info on the installation.
1. Pipe Diameter ID and OD
2. Orifice Plate ID.
3. Differential Pressure
4. Steam Pressure before the Orifice
5. Steam Temperature.

All Units are in Metric
dP = mm H20
Dimensions in mm

Thanking You in Advance.

 

See re calibration of flowmeter using dp posted on the 14th also. As I told them it is not an easy calculation, however you seem to have more info. I find it curious that you have all that info on the installation and yet nothing on the readout you are after. I would contact a salesperson or the manufacturer with this info and they can let you know. If this meter has been installed for awhile perhaps you need to enter the menus and see if the display of units you would like are there. It may be reading out the differential pressure where you can ask it for a rate in kg/hr or ft3/hr or whatever rate you are after.

 

I have the differential.pressure(16mmH2o) but I need to calculate mass flow with temperature and static pressure compensation.The instrument does not have this feature

 

I am assuming you have all the primary measuring instruments (pressure, temp and flow). The pressure, differential pressure and temperature analog signals all need to be input into a math unit to do the calculations, which will then produce an analog output, this output needs to be run through a square root extractor to linearize the signal and be sent to a controller for the readout. Check your controller, alot of them can do all these functions for you and you wil;l just input all the signals to the controller and then program the controller for the mass flow calculations. You should only have to tell it you want a mass flow and which input is what parameter. The algorithum should already be in the controller.

idtmemberdoug

 

Formulas can be found at the engineeringtoolbox website

http://www.engineeringtoolbox.com/flow-coefficients-d_277

You will need to manipulate the formulas for mass flow. The Cv coefficient is needed from the orifice supplier. Cv takes into account the ID and the shape and flow resistance of the orifice.

 

Thanks for your Input. All my Analogue signals are going to a Siemens S7 PLC . There isn't a Mass Flow Computer installed on the system .I was hoping to obtain the same result with a PLC that is why i need the Forular to wite the code.

Thanks.

 

Use US1000 controller from Yokogawa. It has very good capability for mass flow computation.

 

You can receive the same result with your Siemens S7, but you will have to enter the flow and compensation formula. The program flowcalc http://www.controlengineering.se/flowcalc/flowcalceng.htm can be used to find the complete flow formula, there is a description in the maual about how to do it.

Hope this helps.