10 replies to this topic

[mehul]

Dear all,

              Any body have any idea how to design Steam sparged Water Bath Vaporizer.

[breizh]

Hi,

Consider these resources to support your work .

Have a look at Perry's chemical engineers' handbook you may have some design .

Good luck

Breizh 

[Bobby Strain]

You refer to it as cryogenic. Cryogenic temperature starts at -150 C. So, what are the conditions for your application?

 

Bobby

[Pilesar]

I looked into large-scale LNG vaporizers previously but not actually designed one of these. What issues are you having? Based on vaporization capacity, you can determine the duty required with water as the intermediate fluid. Knowing the allowable pressure drop lets you design the pipe diameter and lengths. The hot-side duty lets you calculate the amount of steam required. I didn't see anything really tricky when I looked at this many years ago -- the water was held in an open tank or pit with the natural gas pipes passing through it. It would be best to have a go-by but I can't supply one.

[breizh]

Hi,

To add to my previous reply :

https://www.cryogasi...ated-vaporizers

 

More info using your favorite search engine .

Good luck

Breizh 

[mehul]

Thanks to all for your valuable input with given reference i will work out on it  

[ChEO]

Normally, the term cryogenic usually does not go very well with water, but it can be done, so long as you provide adequate surface area for heat transfer.

 

I've done this with a coil copper tube in a drum of water, for example, with the cryogenic liquid input going straight down to the bottom of a coil of copper tubing in a drum of water and the vaporized gas coming back up through the windings.

 

For the process side:

 

Total Heat load will be determined by heating requirements in three zones in the vaporizer - the liquid heating to the boiling point zone, the vaporization zone, and the vapor superheat zone, or required flow rate X (sensible heat gain of the liquid + heat of vaporization + sensible heat gain of the vapor).  The last zone could be the largest so it important to estimate what load is required in each zone.  Each zone will have a different heat transfer coefficient (depending on fluid properties and velocities) and a different required area for heat transfer (Az = Qz / Uz).  The required areas for heat transfer will correlate directly to lengths of tubing for each zone with a given diameter.  

 

Normally the tubing diameter can be selected based on the total vapor flow rate that has to be handled.  

 

For the water side:

 

You will need to feed enough steam such that the latent heat matches the process side heat load.  You will want to sparge steam into the bottom of the drum in such a way as to promote mixing of the water and maintain an uniform water temperature.  Otherwise, your tubing might ice up reducing the heat transfer surface area.  You have think about how to insure that the steam will condense in the water before it can reach the surface, otherwise it will not contribute to heating the water.

 

This should give you an idea of the principles that you should apply to your specific situation.  It is a good teaching problem because it forces you to evaluate multiple different heat transfer problems.

 

Good Luck.

[IGC]

Yes.  For liquified air gases, LNG, LPG, Ethylene... various others.  In fact, if you sent an RFQ via Breizh's link it may land on my desk

Edited by IGC, 15 February 2021 - 10:44 AM.

[mehul]

Normally, the term cryogenic usually does not go very well with water, but it can be done, so long as you provide adequate surface area for heat transfer.

 

I've done this with a coil copper tube in a drum of water, for example, with the cryogenic liquid input going straight down to the bottom of a coil of copper tubing in a drum of water and the vaporized gas coming back up through the windings.

 

For the process side:

 

Total Heat load will be determined by heating requirements in three zones in the vaporizer - the liquid heating to the boiling point zone, the vaporization zone, and the vapor superheat zone, or required flow rate X (sensible heat gain of the liquid + heat of vaporization + sensible heat gain of the vapor).  The last zone could be the largest so it important to estimate what load is required in each zone.  Each zone will have a different heat transfer coefficient (depending on fluid properties and velocities) and a different required area for heat transfer (Az = Qz / Uz).  The required areas for heat transfer will correlate directly to lengths of tubing for each zone with a given diameter.  

 

Normally the tubing diameter can be selected based on the total vapor flow rate that has to be handled.  

 

For the water side:

 

You will need to feed enough steam such that the latent heat matches the process side heat load.  You will want to sparge steam into the bottom of the drum in such a way as to promote mixing of the water and maintain an uniform water temperature.  Otherwise, your tubing might ice up reducing the heat transfer surface area.  You have think about how to insure that the steam will condense in the water before it can reach the surface, otherwise it will not contribute to heating the water.

 

This should give you an idea of the principles that you should apply to your specific situation.  It is a good teaching problem because it forces you to evaluate multiple different heat transfer problems.

 

Good Luck.

[mehul]

Nice Informative Insight but can we do this exercise in Aspen EDR or another simulation tools or need to develop own excel calculation.

[breizh]

Hi,

To add to my reply consider to dig in the thread attached :

 https://www.cheresou...porizer-design/

 

By the way why don't you ask vendor to size and quote the unit ? 

I don't see the point to anyone to design this type of equipment , you should rely on people dealing with this type of technology where empirical data are needed together with a know how (experience) .

My view 

Breizh