Hello dear Sir.

i'm asking about another method to measure flow of air blower of pipe diameter about 24 inch instead of Target meter, because it is about of work now....

knowing that the pressure of blower is relatively low about 0.2 kg per cubic meter but flow is relatively high .

Best regard.

 

Hi,

Many years ago I was asked to do something similar for a mining flotation blower, The installation was very difficult as there was only a few feet of pipe and right next to a manual valve.

I came up with the idea of using a ventilation fan (like you would use to ventilate a control cabinet) which I mounted in the center of the line. A domestic cooling fan would work also. It acted just like a turbine, the output was a nice sign wave about 10 volts p-p at 0 - 30 Hz depending on valve position.

I made a simple frequency to mA converter. Apart from fabrication time the total installed cost was about $100.

I never bothered trying to calibrate it as we only needed it to set a control valve, the feedback was the operator observing the results.
Once installed it lasted for many years until the mine closed down without any maintenance.

I did think about mounting a length of pipe on the roof of the car and driving down the road to give me frequency against velocity but as I said wasn't necessary in our case.

BTW if you decide that you need a flow straightener in front of the turbine you can make one very easily by cutting a length of tubing into short lengths e.g. 1" EMT conduit, then just tack them all together in honeycomb arrangement.

Hope this gives you some inspiration.
Roy

 

A very interesting approach!

Great story, Roy!