4 replies to this topic

[chaupradip]

Hi all,

 

I need to cool a hot gas inside a duct. Although I can use dilution air to bring down the temperature of the gas but it will un-necessary increase the volume of the gas and size of downstream equipment. Instead I was thinking if I use some parallel plates placed inside the duct I can reduce the temperature as well as the volume as the plates will be absorbing the heat from the gas.. Since the generation of the gas is a batch process, I can have enough time to regenerate the plates for my next operation by ambient air..

 

Can anyone throw some light on how to proceed for designing. I need to know the area required, time for heating up the plates and time required for cooling of the plates.

 

Thanks in advance

 

chau

[Art Montemayor]

Chau:

 

You are not telling us the whole story.  Why is it that students request help - but under the condition(s) that they give us a minimum of basic data but yet expect a maximum of help?

 

Out forum members can guide you towards a successful solution only if you tell us ALL of the basic data.  For example, we can't tell you if you will need shoes to travel the road you propose to use if you don't tell us that the road is rocky, inclined, level, or slippery.  Our members need to know the entire description of what you are assigned to do (assuming this is an academic assignment) in order to guide you.

 

That is all our members should do: guide you and advise you on what you should do to attack and resolve this problem.  They will not do your work for you.  If you need advice, part of your job is to communicate your problem to others in a clear, detailed, and accurate manner.  That is what engineering is about.

 

So give our members a chance to guide you by helping them help you.  If you fail to communicate, you fail to get help.

[chaupradip]

Dear Art,

 

I am attaching a sketch of the conceptual system and hope that all the data required are given.

 

 

Regards,

 

chau

Attached Files

•  Scheme.pdf   14.63KB   39 downloads

[Dazzler]

Hello Chau

A few thoughts:

• For a new installaton, the fan would be better on the inlet side of the process in cool air. The fan will therefore be cheaper materials of construction.
• To cool flue gas or recover heat you could investigate WHRU (Waste Heat Recovery Unit) which is often a tube bank heat exchanger in the duct which can create hot water or hot oil or even preheat the combustion air (air preheater) for the furnace.
• Watch out that the flue gas is not cooled too low as it may reach the water or sulphur dew point.  Particularly if there is sulphur in the fuel. This condensation can lead to corrosion in the coler duct and stack and fan.

Dazzler

[gegio1960]

600 km3/h is a considerable quantity: anyway, the m3/h are at conditions (ie 300°C, P=?) or Normal?

if you want to apply your idea, you need, at least, to say how long the discharge will last: more time more material.

also, the gas composition would help.

good luck!