3 replies to this topic

[dixit]

Hello, 

 

 I am attempting to size an intrusive pipe line sparger as according to the fourth page of the following document: http://www.mottcorp....esign_guide.pdf

 

The design is to mix ethylene oxide gas through a porous metal sparger into a water pipeline, before entering into a reactor. 

 

The specifications are as follows (obtained from Aspen HYSYS simulation):

 

Ethylene Oxide Gas Flowrate: 32050 kg/hr

Pressure: 2500 kPa (362.59 psig)

Temperature: 290 C (554 F)

Volumetric Flow: 21.11 m³/min (obtained from gas equation with compressibility factor of z = 0.93)

 

Water Flowrate: 264200 kg/hr 

Pressure: 2500 kPa (362.59 psig)

Temperature: 48.44 C (77.432 F)

Volume: 4.37 m³/min

Gallon per Minute (GPM): 1155.15

 

I determined the SCFM to be 10002.71

ACFM = 402.79

 

I used the following site to size the water pipeline: http://www.tlv.com/g...-velocity.html 

 

Yielding the following results:

 

Pipe length: 100 m

Pipe ID: 0.2604 m

Water Velocity: 1.37 m/s

Flow Rate: 262.36 m3/hr

 

Based on the water pipeline, I assumed a sparger diameter of 1 inch, hence determining the liquid linear velocity to be 652.72 FPS (according to the provided equation in the first document linked).

 

The high FPS indicates a gas exit velocity designed to be 50 FPM but for a maximum of 150 FPM.

 

Using this maximum, the sparger area I calculated is then 2.6 feet² , but when I try to match my area with a suitable size from the tables provided, it would seem that it is too big. Is it simply a case of an inline sparger not being sufficient for my given process?

 

My excel file is attached for reference, though the layout may be a bit messy.

 

Any help would be appreciated. 

 

Cheers. 

 

Attached Files

•  Sparger Design UPDATED.xlsx   295.19KB   38 downloads

[Bobby Strain]

Well, sparging EO into water is not the method for producing Ethylene Glycol. The EO is absorbed into water in a contacting tower, then sent to the pipe reactor.

 

Bobby

[dixit]

Well, sparging EO into water is not the method for producing Ethylene Glycol. The EO is absorbed into water in a contacting tower, then sent to the pipe reactor.

 

Bobby

 

 

Thanks for your reply, but may I know exactly why a sparging unit cannot be employed? It is something to do with the mass transfer rate not being sufficient?

 

Otherwise, I may just have to design an absorber instead. 

[Bobby Strain]

Ethylene glycol is usually produced at an EO facility. The EO is already in water, which is fed to a pipe reactor. So, someone must have mislead you about the process.

 

Bobby