Rank: Newbie
Joined: 6/28/2010
Posts: 2
Location: Eastover SC 29044
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What types of flowmeters are used on 93% sulfuric to meter flow? We are having difficulty with mag meters. Thanks.
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Rank: Member
Joined: 10/15/2008
Posts: 16
Location: Canada
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My recommendation would have been a magflow meter but you appear to be having problems with yours. What seems to be the problem? Is it the electronics, installation, accuracy, reliability, etc?
What do you use the flow measurement for? Process indication only, alarming, interlock, loading, transfer, etc?
The selection of an alternate flow meter will depend on how you use the flow measurement. If the duty is acid loading then a coriollis flow meter might be a good alternative. If it is measuring the circulating flow over a drying tower then a simple orifice plate might be adequate. Accuracy won't be too important if you use it to alarm/interlock on low flow.
The choice of flow meter will also depend on how much space you have available and the piping arrangement.
It would be helpful if you could provide some more information.
Regards,
Douglas
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Rank: Newbie
Joined: 6/28/2010
Posts: 2
Location: Eastover SC 29044
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We meter (control) the flow to several locations in our ClO2 plants and bleach plants. The magmeters do not function well and have to be changed every 3 or 4 months. We have problems with one specific meter more than the others. It is on a long run of 1" SS piping and is in a vertical run so it is always flooded. It is outside on the south face of a large building. it is 3 feet above ground and is pumped up 20 feet into a 40 PSI line through a static mixer where it is diluted just before entering the process. The flow is erratic and spikes. We have had problems getting enough flow before but never had issue with the meters. It is indication mainly as the acid is added for pH control. Now we get enough flow but the meters fail. We are looking into other types or brands currently. We have considered massflowmeters but they are expensive. We use them on other costly chemicals. Also do you know if the heat would effect the flow or the measurement. We pump from a carbon steel tank using positive displacement gear pumps. We filter the acid from railcars with a 40 micron bag before storing it.
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Rank: Member
Joined: 10/21/2008
Posts: 13
Location: chesterfield, mo
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ClO2,
Ther could be some process line backflow 40 psig into the acid lines during intermittent flow conditions. The acid dilution would result in changing conductivity affecting mag meter accuracy performance. The corrosion attack of the mag meter probes would be faster with dilute acid. Is the frequent failure mag meter located closer to the acid injection point?
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Rank: Newbie
Joined: 2/9/2010
Posts: 2
Location: Houston
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This is not a flowmeter problem. You have a process design problem.
Doug Louie is a good consultant.
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