New Technology for Free Air Delivery(FAD) Metering : Week 2/15/2012

In the last article, we discussed about quantifying the cost of compressed air leakage. We also saw the reasons why one should meter the compressed air, if there are any benefits. In this article, we will discuss on how can we measure the accurate FAD at the discharge point of the compressor with on-line pressure & temperature compensation.

The technology:            
With the current methodology, one has to have several instruments to arrive at FAD at the discharge point of a compressor (See fig-1)


It is possible today to go for a FAD meter that offers integrated pressure and temperature compensation in 2-wire technology and also achieve the accuracy of 1% of measured value
This FAD meter can provide accurate measurement of operating, standard volumetric and mass flow of conductive and non-conductive liquids, gases and vapours even with fluctuating pressures and temperatures. (See Fig-2)
This FAD meter can be put downstream of your compressor. We can then know at every moment, exactly how much air is reaching your process. Plus, the software automatically compensates for your plant's relative humidity (RH) levels and rated shaft RPM, ensuring 100% reading accuracy. In addition, you can also get integral pressure sensing and compensation.

On the display, one can see:

1) Mass/Normalized/Volumetric flow,
2) Pressure,
3) Temperature,
4) Velocity,
5) Totalized flow and of course,
6) The Free Air Delivery (FAD)

With an accuracy of +/- 1% of measured value, this FAD meter with built-in software can help you reconcile air generation and consumption in compressed air energy. It is the best solution industry can have today.



As compressed air is 9 times costlier than electricity, or it is even costlier than steam, it is important to meter it properly & arrest the leakages across the plant. Since these leakages are not visible (unlike steam leakages), there is a risk of these leakages getting ignored, resulting in a very costly waste.

It is therefore important to measure the FAD of a compressor (at the discharge point), so that one can measure how much compressed air is delivered, how much is used & how much is getting wasted.

Now comes our next question. Is it possible to both measure & improve the FAD? In our next article, we will see how we can do this.

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