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Ergun Equation reulting to zero pressure ratio 
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#1
Sep1613, 12:09 AM

P: 78

I was trying to emulate a packed bed reactor, and apparently the pressure midway at the packed column became zero, until my numerical method failed altogether (as the pressure variable in the Ergun is at the denominator).
I'd like to be enlightened about one thing  does this phenomena (zero pressure midway the packed column) has something to tell me at what will happen at the end? No gas flow or something, perhaps? Thanks. EDIT: Sorry for the title spelling error, it's 'resulting', not reulting. 


#2
Sep1613, 11:44 AM

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Chet 


#3
Sep1613, 04:11 PM

P: 78

I was toying around the flowrate, Vo. When I assign increasing values for Vo, I found out that the pressure is going down.



#4
Sep1613, 06:06 PM

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Ergun Equation reulting to zero pressure ratio



#5
Sep1713, 03:22 AM

P: 78

I'm really sorry, I didn't understand the question :
Actually what's happening is that, the inlet pressure is at 7.5MPa, and I am using the Ergun equation to find out the outlet pressure. What's happening is that if I toy around the Vo by increasing it (volumetric rate), the pressure decreases rapidly until it approaches a certain high Vo value and the pressure approaches 0. I was wondering if this is equivalent to a physical phenomenon when the exit pressure becomes zero (ie. the gas won't flow anymore, the packings get destroyed, or something). 


#6
Sep1713, 06:50 AM

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#7
Sep1713, 08:25 AM

P: 78

Uh, I do know that the pressure should go down, but what I mean is that the pressure ratio at the end given a certain high flowrate is zero; does this signify something as a physical phenomenon? No effluent or something?
This is my first time to see a zero pressure ratio in my calculations, I'm sorry. XD 


#8
Sep1713, 11:01 AM

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#9
Sep1813, 12:59 AM

P: 78

I mean P/Po is going towards zero. The P there at the denominator is continually decreasing, causing the entire thing to approach zero apparently.
I was wondering what does this have to do as a physical phenomenon, when the exit pressure is zero. 


#10
Sep1813, 06:21 AM

P: 78

Arr, nevermind. Fluidization velocity is what I was looking for, apparently. Thanks.



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