10 replies to this topic

[Carol]

Good day to you all.

I am cunrrently doing my plant design of a refinary plant. I am facing problem of designing the steam sparger for my bleaching part vessel.

Based on MOTT corporation infomation given,

My steam mass flow that caluclated is only 0.87kg/hr. is it possible?

My vessel is around 2 * 4 meter square, operating at 110C and o.1bar. Heat needed to heat up my oil from 100 C to 110C is 124kW.

my sparger size of DN40, with 40 holes has velocity of steam from hole at 4m/s.

Is the velocity of my steam and mass flow of my steam acceptable?

Thank you for your time~

[ankur2061]

Carol,

Several open resources are available on the net for sparger design. Some of the links are given below:

http://www.eng-tips.....cfm?qid=188767

http://www.cheresour...ty-restriction/

Perry's Chemical Engineer's Handbook has also an excellent description of sparger design.

Additionally, I am uploading a design guide from MOTT for sparger design.

Hope this helps.

Regards,
Ankur

Attached Files

•  sparger_design_guide.pdf   1.15MB   801 downloads

[Carol]

Thanks a lot.. Really appreciate your help.

[ankur2061]

Carol,

Do you give a minus rating after thanking him for helping you?

Regards,
Ankur

[Carol]

I am sorry. I am new to this. Really sorry.

[Profe]

Hi Carol
About your query, I think that you are heating oil with direct injection of water steam. If this is true, well you have performed a mass and energy balance to determine the amount of steam required. You will also have steam conditions used for this purpose, such as pressure steam and temperature steam, and finally, the pressure of the system (or external pressure) which injects steam heating.
It’s this Ok?
Additionally, read the attached pdf file.

I Hope that will be useful

Good luck

Attached Files

•  Design gas distributors.pdf   1.02MB   482 downloads

Edited by Profe, 10 November 2011 - 09:15 AM.

[katmar]

Carol, You have been given plenty of resources already, so I won't confuse the issue by giving any more. But you have made some basic errors in your heat balance. 124 kW is certainly not equivalent to 0.87 kg/hour of steam. Your pipe size makes me think that maybe this is just a typo and your steam flow is actually 0.87 kg/second. But that flow rate is also not equal to 124 kW. Check your calculations and if you cannot find the error then post them here for comment.

[Carol]

Katmar,
Thank you for your attention and advice.

Yes there is error in my calculation. if 2 bar saturated steam is provided to the system, and the steam leave at 0.1 bar and 110C. 225.9kg/second of steam is needed to provide 124kw of heat.

However, the main problem is that, i cant imagine how a sparger should looks like in my vessel. Whether it should be a pipe sparger or ring sparger. Or it is just look like a jet nozzle which is in a round shape and having plenty holes on it.

Regarding sparger design, i have to admit that i dont really know lot about it. I just started to study it when designing my plant design project~ Excuse me for all the question i ask and thank you for all the infomation given by you all.

I do appreciate it.

[katmar]

It is difficult to formulate rules for the shape of a sparger. I have installed single pipes, rings, crosses and ladders. For your 2x4 m vessel maybe a ladder would be the best with a single pipe running across the center as a 4 m "spine" with branches at the 1.0, 2.0 and 3.0 m points.

Your application is not quite clear to me, but if you are decolorizing and deodorizing then it would probably better to have the sparger extending over the whole cross section (as I have described here) to encourage mass transfer.

One thing that I have found is that the material cost of the sparger is usually small compared with the design and fabrication costs and it is far better to design the sparger piping a bit larger in diameter to ensure that you have (approximately) the same pressure throughout the sparger. In this way you avoid having to vary the hole spacing along the length to ensure even distribution. This is described in the attached article by Knaebel (Chem Eng, March 9, 1981, p116). If the pipe diameter is getting too large then using a ring will allow you to design for half the flow in each direction.

Many experienced engineers discourage the use of "home made" spargers and prefer to use proprietary items from Spirax or Mott. However, I have worked with many of the "home made" variety and have had no problems. In fact, in one particular instance I helped out an engineer who had ordered a very elaborate and expensive proprietary distributor (not from either of the suppliers mentioned here) which was late in delivery by designing him a temporary ring distributor to use until the fancy one arrived. The ring sparger worked so well that he never installed the other one!

Please check your heat balance again. 124 kW is 124 kJ/second, or 4.46e5 kJ/hour. At 2 bar g the latent heat of steam is about 2160 kJ/kg, making the steam flow about 210 kg/hour. But this is for heating only. If you need steam for stripping the color and odor you will need more than this.
 Knaebel Sparger.pdf   122.19KB   462 downloads

[Carol]

Dear Sir,

Thank you for helping. My sytem is only a simple bleacher system that act to mix the adsorbent and palm oil. The main purpose is to remove impurities from palm oil. Hence, needed to maintain the mixture tmeperature and having agitation to allow well mixing. i will try to double check my calculation. Thank you for the information.

[breizh]

Hi Carol,

Consider this resource as well:
http://www.spiraxsar...m-injection.asp

Breizh