Velocity Pressure Calculation Help
Velocity Pressure Calculation Help
(OP)
Hello all, first time poster here
I am currently designing a wet coal scrubber for a longwall mining application. Right now I am doing some pressure calculations to get the total pressure in the ducts, but am a little confused.
I already know the static pressure, but running into problems when trying to get the velocity pressure, the variable in question is the density factor of the air. The air coming into the scrubber I know is going to full of coal dust, then once it enters the scrubber, the coal dust in the air will be soaked with 20 conical water sprays spraying at 35 psi.
The book I am reading about Industrial Ventilation is telling me to get the overall density factor, I need to calculate the elevation, duct pressure, temperature, and moisture density factors. I can calculate all of these except for the moisture density factor. The equation they give is (lbm H20)/(lbm dry air). How can I calculate these values? Will I be able to knowing the velocity of the air stream and the amount of water entering the air stream? Also, will I need to take into account the amount of dust in the air stream for an additional density factor?
One last question also. I am assuming that when I am calcuating the velocity pressure, I will be using a different density factor for the duct segments with only coal dust in the air stream than I will be using for the scrubber box that has air and coal in it. Am I correct in assuming this?
Any help or insight you can offer will be greatly appreciated. This is my first project out of school where I am designing something like this and it is a little frustrating.
Thanks again
I am currently designing a wet coal scrubber for a longwall mining application. Right now I am doing some pressure calculations to get the total pressure in the ducts, but am a little confused.
I already know the static pressure, but running into problems when trying to get the velocity pressure, the variable in question is the density factor of the air. The air coming into the scrubber I know is going to full of coal dust, then once it enters the scrubber, the coal dust in the air will be soaked with 20 conical water sprays spraying at 35 psi.
The book I am reading about Industrial Ventilation is telling me to get the overall density factor, I need to calculate the elevation, duct pressure, temperature, and moisture density factors. I can calculate all of these except for the moisture density factor. The equation they give is (lbm H20)/(lbm dry air). How can I calculate these values? Will I be able to knowing the velocity of the air stream and the amount of water entering the air stream? Also, will I need to take into account the amount of dust in the air stream for an additional density factor?
One last question also. I am assuming that when I am calcuating the velocity pressure, I will be using a different density factor for the duct segments with only coal dust in the air stream than I will be using for the scrubber box that has air and coal in it. Am I correct in assuming this?
Any help or insight you can offer will be greatly appreciated. This is my first project out of school where I am designing something like this and it is a little frustrating.
Thanks again





RE: Velocity Pressure Calculation Help
RE: Velocity Pressure Calculation Help
RE: Velocity Pressure Calculation Help
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Plymouth Tube
RE: Velocity Pressure Calculation Help
How do you know that you can disregard coal dust as an entrained contaminant?