Measuring Blower Volume

[TJT]

Hello,
We are currently using a venturi for measuring our blower volume into our 2 Roasters. The average volume is 700 NM3/min. The differential of the transmitter is only 5.5" W.C. Periodically we have another group come in and, using a pitot tube, take samples and calculate the volume. We seem to be finding that the venturi reading vs. the pitot samples are differing by a greater amount. I would like to know if any one out there has had better success with an anubar or flowbar rather than a venturi for measuring a blower volume.
Thanks

 

[khan101]

Anubar has been used in these application successfully. Try to contact your local Emmerson application Engineer.

 

[automatic2]

check with your blower manufacturer. They will have a volume to inlet/outlet press. flow chart for your specific unit.

 

[pmover]

TJT,

you've obtain 2 different values for flow using 2 different instruments . . .

1) always check the flow test data and the instrument device used to determine flow (i.e. venturi and pitot tube). check flow measurement device (fmd) calcs with mfg. double check flow units of measurement.

2) not knowing the piping configuration may have an impact on flow test data. are there any flow disturbances upstream/downstream that are in close proximity of fmd.

3) is it possible to gather blower speed, inlet/outlet pressure and temps, motor voltage and current? if so, using motor current/voltage and making some assumptions for efficiency, the flow rate through the blower can reasonably be determined. compare with other flow test data. oh, it is beneficial to have blower performance curves from mfg. that include head (or delta p) & power vs. flow. be certain of flow measurement units.

something to work on . . .

good luck!
-pmover

 

[jsummerfield]

Look at the Veris Accelarabar and the Fluidic Techniques HHR FloPak.

http://www.veris-inc.com/Literature PDF's/Accelabar/Accelabar Brochure 11-04.pdf

http://www.fluidictechniques.com/flowpak/flowpak_main2.htm

John