Product category:
Power Industry Process News
News Release from: Metrohm UK | Subject: 797 VA Computrace
Edited by the Processingtalk Editorial
Team on 15 July 2005
Determination of iron residues in boiler
waters
Low cost solution to the determination of iron in boiler waters using the Metrohm 797 VA Computrace: voltammetry is fast becoming the technique of choice, in preference to spectroscopic methods
Low cost solution to the determination of iron in boiler waters using the Metrohm 797 VA Computrace Iron in power station boiler waters can be a common problem with dark coloured deposits formed
This article was originally published on Processingtalk on 27 Feb 2008 at 8.00am (UK)
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Iron deposits in large amounts can inhibit the heat transfer - making the process less efficient - as well as causing corrosion problems, and thus there is a requirement to monitor their actual concentrations.
In the presence of dissolved oxygen any corrosion on the boiler tubing is intensified which may necessitate the system coming offline for essential maintenance.
From a commercial standpoint, power station boiler units need to be online as much as possible as power - along with revenue - is not being generated when the system is offline.
Further reading
Determination of trace metals (Tin) in effluent
Trace metal analyses including tin can be performed with the same or better sensitivity for the fraction of the cost of acquiring an AAS or ICP instrument using the technique of voltammetry
Sample processor for fully automated CVS analysis
With this new Sample Processor with the 797 VA Computrace it is possible to run the fully automated Cyclic Voltammetric Stripping (CVS) analysis of organic additives in electroplating solutions
The iron (and its deposits) can easily and reliably be measured in boiler (and any other) waters using the technique of voltammetry, a technique that has actually been around since 1922.
In recent years voltammetry has undergone something of a renaissance and for the analysis of water samples is fast becoming the technique of choice as it is not affected by particulate or saline samples that can cause problems for spectroscopic methods.
The 797 VA Computrace from Metrohm represents a modern voltammetric measuring instrument that connects to a PC directly via an USB connection.
The intuitive Windows XP based PC software controls the measurement, records the measuring data and allows full evaluation of the recorded information.
The boiler water sample and auxiliary solutions were added to the reaction vessel and the iron determined using adsorptive stripping voltammetry with the patented Metrohm Multi Mode Electrode (MME).
A typical sample from a UK based power station was analysed and found to contain 3.6micrograms per litre of iron, demonstrating the sensitivity of voltammetry for a fraction of the purchase cost, and just as importantly the running costs of spectroscopic techniques.
Calibration is performed on each and every sample using the technique of standard addition that takes into account any background matrix effects.
To enhance the accuracy and improve the sample throughput, the technique can be automated using Metrohm Dosinos (for the addition of the standard solutions) and a choice of autosamplers.
For further information on the low cost determination of iron in boiler waters (and other water sources) using the Metrohm 797 VA Computrace system please contact Metrohm. Request a free brochure from Metrohm UK ...
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