used for measuring air flow in bag filterbag filter
Joseph Riley
Joseph Riley••The simplest way is to The simplest way is to install a hot wire anemometer, either install a hot wire anemometer, either permanently installed orpermanently installed or portable insertion style, in the inlet ducting to the filter. You will have to find a location where the gas portable insertion style, in the inlet ducting to the filter. You will have to find a location where the gas flow is approximately evenly distributed in the ducting. Depending on your
flow is approximately evenly distributed in the ducting. Depending on your filter design, you may have afilter design, you may have a hard time finding a good location if you want to find out the gas flow
hard time finding a good location if you want to find out the gas flow in each compartment. In this case,in each compartment. In this case, it is easiest to use the location at the outlet of each compartment, just after the outlet poppet valve, and it is easiest to use the location at the outlet of each compartment, just after the outlet poppet valve, and before the gases join together.
before the gases join together. Alternately, you could use a pitot
Alternately, you could use a pitot tube, but it tube, but it requires some expertise.requires some expertise. Bart Van Roon
Bart Van Roon••I allways use a pitot-tube in I allways use a pitot-tube in the duct to the chimney. The electronic versions you havethe duct to the chimney. The electronic versions you have these days calculate directly to m/s airflow. So
these days calculate directly to m/s airflow. So it it's easy to it it's easy to recalculate to m³/hr. Because you take therecalculate to m³/hr. Because you take the duct to the chimney (behind the bagfilter) the air is clean and easy to measure. Air in (m³/hr) = Air out duct to the chimney (behind the bagfilter) the air is clean and easy to measure. Air in (m³/hr) = Air out (m³/hr)
(m³/hr)
Joseph Riley
Joseph Riley••Where you measure is going to be governed by how accurate your want to be with yourWhere you measure is going to be governed by how accurate your want to be with your measurement and the purpose of your measurement.
measurement and the purpose of your measurement. If you try to measure the flow out of the
If you try to measure the flow out of the filter, you could be measuring false air intake from the filterfilter, you could be measuring false air intake from the filter hoppers and the outlet ducting. If
hoppers and the outlet ducting. If you need to refer the you need to refer the gas flow measurement back to gas flow measurement back to normalizednormalized conditions, in addition to the false air potential, measuring after the filter will also bring the added error conditions, in addition to the false air potential, measuring after the filter will also bring the added error of measuring the gases at a different pressure and temperature, which will cause a skew in your gas flow of measuring the gases at a different pressure and temperature, which will cause a skew in your gas flow when reported in normal conditions.
when reported in normal conditions.
Jagat Singh Rathee
Jagat Singh Rathee••The stainless steel pitot tubes are available in two The stainless steel pitot tubes are available in two configurations ,namely ,L-shapedconfigurations ,namely ,L-shaped and the S-shaped .L-shaped pitot tubes are
and the S-shaped .L-shaped pitot tubes are used for the flow measurements through tubes used for the flow measurements through tubes , ducting for, ducting for clean air ,gases without dust, and the S-shaped pitot tubes are used for the measurement of the dust clean air ,gases without dust, and the S-shaped pitot tubes are used for the measurement of the dust laden gases / air flow.
laden gases / air flow. There are standard coefficients / constants for these stainless steel pitot There are standard coefficients / constants for these stainless steel pitot tubes ,astubes ,as given by the designers /
These pitot tube / instruments are
These pitot tube / instruments are available with the dealers ,dealing in process measurementavailable with the dealers ,dealing in process measurement instruments like anemometer , pressure gauges ,manometers ,portable gas
instruments like anemometer , pressure gauges ,manometers ,portable gas analyzers , thermo-couplesanalyzers , thermo-couples etc.etc. including dealers in scientific instruments ,in
etc.etc. including dealers in scientific instruments ,in almost all metropolitan cities.almost all metropolitan cities.
Er. Abinash Rath
Er. Abinash Rath••actually I am in Qatar so I do not know where to actually I am in Qatar so I do not know where to find these . Can you tell me the flukefind these . Can you tell me the fluke model or any other company name to find in the site
model or any other company name to find in the site John Kline
John Kline••I think it is appropriate to ask what do you wI think it is appropriate to ask what do you want to use the air flow measurement for.ant to use the air flow measurement for. Knowing that you can decide on the best approach to measure it. Without knowing the end use, the Knowing that you can decide on the best approach to measure it. Without knowing the end use, the instrument choice may not be correct.
instrument choice may not be correct. Pamarthi S.S.Prasad
Pamarthi S.S.Prasad••Dear Mr.Abinash RathDear Mr.Abinash Rath Kindly contact this gentleman, may help you in
Kindly contact this gentleman, may help you in measurement and as well details.measurement and as well details. Best regards
Best regards
================================================= ================================================= Sultan Ahmad Mallick
Sultan Ahmad Mallick Technical Manager Technical Manager Envirozone LLC Envirozone LLC PO Box # 39230 PO Box # 39230 Abu Dhabi, UAE Abu Dhabi, UAE Tel : +971 2 5501320 Tel : +971 2 5501320 Fax : +971 2 5501321 Fax : +971 2 5501321 Mobile : +971 503277547 Mobile : +971 503277547 E-mail
E-mail : : samallick@[email protected] <mailto:[email protected]>one.ae <mailto:[email protected]> Web site:
Web site: www.envirozone.aewww.envirozone.ae
GPS Coordinate - N: 24° 19' 16.90'' E: 54° 28' 41 GPS Coordinate - N: 24° 19' 16.90'' E: 54° 28' 41.66''.66''
Er. Abinash Rath
Er. Abinash Rath••@ pamarth sir@ pamarth sir
I need to check the flow not the oxygen carbon dioxide like that I need to check the flow not the oxygen carbon dioxide like that John Kline
John Kline••Assuming that you are mAssuming that you are measuring on the clean side of teasuring on the clean side of the baghouse. I would suggest a cleanhe baghouse. I would suggest a clean pitot tube traverse in an area with as straight a
pitot tube traverse in an area with as straight a duct run as you could find. If you can measure oxygen atduct run as you could find. If you can measure oxygen at the same point, you m
the same point, you might double check gas volume versus combustion calculations.ight double check gas volume versus combustion calculations. Er. Abinash Rath
Er. Abinash Rath••http://www.chevrierinhttp://www.chevrierinstruments.com/Anglaistruments.com/Anglais/Pdf/Cat/F-018.ps/Pdf/Cat/F-018.pdf df can i use above instrument
can i use above instrument Daniel Raju Alamanda
Daniel Raju Alamanda••Yr Question; Can anybody tell me the Yr Question; Can anybody tell me the process instruments used for measuringprocess instruments used for measuring air flow in bag filter. (I hope you are not talking of
air flow in bag filter. (I hope you are not talking of which Brand of the measuring instruments...??)which Brand of the measuring instruments...??) For types of instruments:
For types of instruments:
My first advice is to know the total gas flow using "S' type pitot tube
My first advice is to know the total gas flow using "S' type pitot tube at BF inlet. 'L- type would be aat BF inlet. 'L- type would be a disaster as it is high dust laden gas stream.
disaster as it is high dust laden gas stream. Also get the dust
Also get the dust loading= gm/Nm3 using thimble sample train.loading= gm/Nm3 using thimble sample train. If there is provision fr dust drop test, pl do it
If there is provision fr dust drop test, pl do it to check the above value.to check the above value.
Then if the BF has Air Distributio Grid, then try the Annemometer for correct distribution or adjustment Then if the BF has Air Distributio Grid, then try the Annemometer for correct distribution or adjustment of baffles if any. try at diffrent % of
of baffles if any. try at diffrent % of dampers or RPM of fan.dampers or RPM of fan. Then again at BF outlet you can measure air flow by Pitot tube. Then again at BF outlet you can measure air flow by Pitot tube. Take the actual power drawn
Take the actual power drawn by fan & check with calculated theoritical power for by fan & check with calculated theoritical power for measured gas flow, if measured gas flow, if you know the fan curves.
you know the fan curves. Also take the dust
Also take the dust entrained in clean gas by Thimble sample train entrained in clean gas by Thimble sample train (mg/Nm3).(mg/Nm3). To measure the moisture content, use cooling rack
To measure the moisture content, use cooling rack for flue gases then for flue gases then a moisture absorbant chamber.a moisture absorbant chamber. (potash or silica crystals) wt before & after to get % moisture/Nm3
(potash or silica crystals) wt before & after to get % moisture/Nm3 Finally to get the false air across the bF, use O2 meter.
Finally to get the false air across the bF, use O2 meter.
To get the compressed air consumption in BF, note the time to discharge the tank from unloading to To get the compressed air consumption in BF, note the time to discharge the tank from unloading to loading condition of compressor.
loading condition of compressor.
You can also determine the dew point at inlet & outlet if your clever enough to use wet bulb/ dry bulb You can also determine the dew point at inlet & outlet if your clever enough to use wet bulb/ dry bulb temperatures.
temperatures.
can you please check this link can i
can you please check this link can i use thisuse this Er. Abinash Rath
Er. Abinash Rath••http://www.chevrierinhttp://www.chevrierinstruments.com/Anglaistruments.com/Anglais/Pdf/Cat/F-018.ps/Pdf/Cat/F-018.pdf df can you please check this link can i
can you please check this link can i use thisuse this
Joseph Riley
Joseph Riley••This instrument has an operating temperature limit of 50 deg C and the pitot tube is onlyThis instrument has an operating temperature limit of 50 deg C and the pitot tube is only 12" long. If your gas temperature is lower than that, and the
should be able to use it. This instrument is mainly used for HVAC, not for process gas streams. should be able to use it. This instrument is mainly used for HVAC, not for process gas streams.
Normally a cement plant has a pitot tube and a vane anemometer in it's toolbox. The pitot tube is used Normally a cement plant has a pitot tube and a vane anemometer in it's toolbox. The pitot tube is used for hot gas streams, such as kiln gas
for hot gas streams, such as kiln gas fan, and the vane anemometer is used for clean air, where the fanfan, and the vane anemometer is used for clean air, where the fan inlet is accessible, such as in a
inlet is accessible, such as in a clinker cooler fan. The pitot tube has tclinker cooler fan. The pitot tube has to be long enough to o be long enough to penetrate thepenetrate the ducting as close to m
ducting as close to mid point as possible (sometimes this is not id point as possible (sometimes this is not possible due to size of ducting).possible due to size of ducting).
For the air slide blowers, you would use either a vane anemometer on the intake of the blower and then For the air slide blowers, you would use either a vane anemometer on the intake of the blower and then correct for temperature and pressure to
correct for temperature and pressure to arrive at standard conditions, or arrive at standard conditions, or you can purchase a permanentyou can purchase a permanent insertion flow meter (such as an
insertion flow meter (such as an Annubar) or an thermal Annubar) or an thermal anemometer (Sierra Steeltrak or FCI unit).anemometer (Sierra Steeltrak or FCI unit). I know that everyone here is pushing pitot tubes for the gases, and you can find several of them out I know that everyone here is pushing pitot tubes for the gases, and you can find several of them out there, however, as I stated previously, if you want a fully bulletproof unit that you don't have to worry there, however, as I stated previously, if you want a fully bulletproof unit that you don't have to worry about fouling or correcting, you
about fouling or correcting, you should use a thermal anemometer such as tshould use a thermal anemometer such as the Kurz insertion flow meterhe Kurz insertion flow meter http://kurz-instruments.com/products/2445.htm
http://kurz-instruments.com/products/2445.htm..
Joseph Riley
Joseph Riley••For permanent installation insertion thermal mass flow meter:For permanent installation insertion thermal mass flow meter: http://kurz-instruments.c
http://kurz-instruments.com/products/454FTB.hom/products/454FTB.htmhttp://kurz-instruments.ctmhttp://kurz-instruments.com/products/K-om/products/K- BAR2000B.htmhttp://www.fluid
BAR2000B.htmhttp://www.fluidcomponents.com/Incomponents.com/Industrial/Products/dustrial/Products/MassFlowMeters/ProdSMassFlowMeters/ProdST98B_ANT98B_AN .asphttp://www.sierrainstruments.com/products/670s.html
.asphttp://www.sierrainstruments.com/products/670s.html For permanent installation of the fluidizing air
For permanent installation of the fluidizing air blower piping:blower piping: http://www.fluidcomp
http://www.fluidcomponents.com/Induonents.com/Industrial/Products/MassFstrial/Products/MassFlowMeters/ProdSTlowMeters/ProdST75.asphttp://www.fluid75.asphttp://www.fluid components.com/I
components.com/Industrial/Products/Mndustrial/Products/MassFlowMeters/ProdSassFlowMeters/ProdST50.asphttp://www.sierrainsT50.asphttp://www.sierrainstruments.cotruments.co m/products/640.htmlhttp:/
m/products/640.htmlhttp://www.sierrainstruments.c/www.sierrainstruments.com/products/quadratheom/products/quadratherm/640i.htmlrm/640i.html
Wolfgang Linke
Wolfgang Linke••Can we go back to Can we go back to your original question? Can you please describe what problem youyour original question? Can you please describe what problem you encounter in your plant. Then you will get a wealth of ideas how to solve it.