Oxygen Analyser calibration and slope Checking

R

Thread Starter

Ravindra

Dear Forum Members,

As we have ABB make ZFG2 model Oxygen analyser in our factory Boiler. As we are located in the remote place and remote country, which we could not able to procure Known Mixure Gasses(Spent Gasses)
As we calibrated the Oxygen Analyser by putting in the Nitogen Container as a Zero Value , and by keeping the Instrument in the Ambient Atmosphere adjusted as Span (20.9) twenty point nine.
And we did not checked the intermediate Values.
The reason as said we don't have Known Mixure Gasses
The question is we are operating the Boiler at 3 to 4 Oxygen, does we beleve this Instrument Readings.
Please Share your experiences.

And also one more question not related to the Automation, but i am asking.Sorry for giving inconvience.
As we encounter tremendous ash accumulation in the Bagasse Fired Boiler(Sugar cane waste after extracted Juice from the cane)at the convection path, super heater coils and boiler walls. Does any Forum Instrumentation Engineers Noticed this phenomenon in their operating Boilers. Please share your ideas what you did to fix the problems.
Thanks to the Forum and thanks to the Worldwide Instrumentation Engineers.

Thanks & Best Regards,
Ravindra
[email protected]
[email protected]
 
A
Hi Ravindra,
The world is a tiny village.
There are no longer remote places with hotmail addresses!

Using of ordinary N2 cylinders for calibrating analyzers is not recommended and not correct. I will not argue with you if you say that it still works. It is necessary to get proper calibration gas cylinders and work in the proper operating pressures, if you are using analyzers.

If your company is cutting costs and trimming the incorrect areas, then you need to explain the importance of having proper calibration gases to your management. The oxygen in the stack gas is a reading that can be used by you to save costs later on, but only if that reading is accurate and reliable.

If you are in India, then Calibration gases are available from vendors in almost all corners and centers in India. If you are from the Sugar belt,
then Pune, Nashik and Mumbai, all have manufacturers and/or agents of Calibration Gases.
Please use a proper Calibration gas for calibrating.

Regards,
Anand
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Dear Mr.Anand,

Thanks for your reply. I am In Vietnam. We find the Oxygen gas manufacturing units over here. The Supplier is agreed togive Spent gasses in the Cylinders. But he quoted accuracy is 1.0 %.
I may be wrong, using nitogen as a Zero Calibration, and agrees with yours energy saving point. We will try to import these Cylinders from India. Could you please provide me the Pressures recommended for this calibrations.
The Manual is saying the gas flow is to be 3000CC/Minute(approximately 3liter per minute).

And also could you please give some agents fax numbers for me either in Bomay/Madras.

Regards,
Ravindra.
 
A
Hi Ravindra,

My apology for assuming that you are in India.

If pressure is not specified, better use process pressure (mmwc at o2 measuring point).

Using 1% accuracy will be incorrect as you rightly point out. Of course, you could analyze the cylinder in a lab and then perform a check on the analyzer, with this known gas. Thus you can get very good accuracy. Gases in cylinders can drift with time. So do not store calibration cylinders for long duration of times or perform analysis at regular intervals.

You can check at the following websites.

BOC India http://www.boc-india.com/business_area/speciality.htm

Speciality Gas Co. Ltd.
SPECIALITY GAS CO.LTD.Z905131
Activities: Industrial Gases, Analytical Instruments, Gas Pressure Regulators
Address: D-273,TTC Indl.Area,MIDC,Turbhe,Navi Mumbai-400705
Tel.No: (022)7616328
Fax No: (022)7686635
E-Mail:

That no. could now be 0091-22-27616328 as now there is a new 2 prefixed to all old Mumbai numbers.

Do a web search with 'speciality gases for calibration' in google to get more results.

Regards,

Anand
 
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