Analysis issues regarding water-coal slurry concentration
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The method we use in our laboratory to analyze the concentration of water-coal slurry is an infrared moisture meter; the concentration in Mill A is 62.8%, in Mill B it is 62.7%, and in the high-pressure coal slurry pump it is 62.5%. Then the manager asked us what was going on with these numbers Why is the concentration of the high-pressure coal slurry pump lower than that of mills A and B? I’m really puzzled; isn’t this normal? I also would like to ask all you experts: how should this kind of similar problem be explained?
I believe there is no necessary connection between the concentration in the large tank (high-pressure coal slurry pump) and that in mills A and B; just because the concentration in mills A and B is high, it does not necessarily mean that the concentration in the large tank is higher, and vice versa. I think this large tank reflects the overall condition of the water-coal slurry, and it shouldn’t be determined solely based on the water-coal slurry in the mill. Is my understanding correct? I hope to get some guidance from all of you experts.
1. All detection data contain deviations and errors; such differences require patient, straightforward explanations for those who are not familiar with analysis and testing procedures. 2. The uniformity of the samples as well as the representativeness of the samples at the measurement points also have a significant impact on the measurement results. Given the accuracy limitations of infrared moisture analysis, I think the above data is quite good – the relative deviations are all below 1%, so there should be no issues with the quality of the data.
In my coal chemical industry, we also use infrared rapid moisture analyzers for analysis. They are very easy to use and cost-effective. The data obtained has been compared with that from oven drying. It turns out that the coal-water slurry isn’t necessarily very homogeneous, even though there is stirring in the slurry tank. It’s not clear whether there is a slurry tank in front of your slurry pump; it is here that the final concentration is determined. Infrared moisture meters can provide accuracy up to 0.1%, and it is necessary to compare the results with those obtained using the oven method.
Mm-hmm, yes, we have compared them and there are no issues. The main issue is that the management now believes the concentration in the slurry tank should not be this low; the slurry concentration in mills A and B is both over 62.7%, so why is it only 62.5% for the high-pressure slurry pump? They think it should also be above 62.7%.
Sometimes we’re really frustrated by the analysis of the concentration of this water-coal slurry. We conduct analyses twice per shift, using 4-5 parallel samples each time; yet even so, the managers will ask, \"This value shouldn’t be this high...\" or \"If the gas flow doesn’t change, why has the concentration of the coal slurry decreased?\" Ah! I still have to struggle with deciding on the total number to report...
Instrument errors and operational errors are all objectively present. For domestic infrared instruments, a difference of 0.1% is quite normal. If it is imported, the two digits after the decimal point remain unchanged.