5 replies to this topic

[HadeerK]

Hello everyone.

 

I have to built a Temperature Swing Adsorber for compressed air drying. Actually its like over sizing the already working adsrober.

 

Currently the flow rate from compressor is 15 cubic meter per minute and for that adsrober with Height=12 feet and Diameter=1ft is working. One column of adsrober holds 175kg of activated alumina pellets. 

The new compressor will have 33.3 cubic meter per minute. The height of adsrober cannot be increased due to Utility room height.

 

I have scrubbed through a lot of literature but couldn't find anything useful. I would really some help in this matter.

I have attached two pictures. One approach gives amount of desiccant w.r.t flow rate and service time but it also need desiccant loading divided by moisture content in air.

 

Second one shows the diameter calculation on he basis of superficial velocity and pressure. But the diameter is calculated as 8.6 inch (lower than the current one) which doesn't make sense.

 

Best Regards

Attached Files

•  Capture2.PNG   38.3KB   1 downloads
•  Capture1.PNG   46.17KB   2 downloads

[breizh]

Hi ,

I don't think anybody will do this type of calculation in the real life .Go directly to vendor/manufacturer  of compressor and ask for the sizing and cost of the equipment providing the flow rate you want to treat , the moisture of the air and your specification at the outlet of the dryer (dew point ) .

Ask quotation from Big manufacturer like atlas Copco and others.

My 2 cents

Breizh

[HadeerK]

Thanks for replying. Actually the current adsorber was manufactured locally and we just want to get the diameter required for increased flow rate so that we can just get a pipe with that specification and use it as adsorber.

 

anyways thanks for your reply.

Hi ,

I don't think anybody will do this type of calculation in the real life .Go directly to vendor/manufacturer  of compressor and ask for the sizing and cost of the equipment providing the flow rate you want to treat , the moisture of the air and your specification at the outlet of the dryer (dew point ) .

Ask quotation from Big manufacturer like atlas Copco and others.

My 2 cents

Breizh

[Pilesar]

As I understand it, you have a working dryer that everyone is happy with. You have a need for a new dryer for a new service with a scaled-up flowrate and constraints on vessel length. You have calcs that indicate your existing dryer is oversized. I would approach the new dryer sizing this way: Scale up the volume of the existing drying bed in proportion to flowrate, constrain the length, and set the diameter to fit the bed volume, then round up the diameter to fit the next standard pipe size. Would my approach give an oversized dryer? yes. But it would be adequately sized and I would have a defensible method for the size. Who would complain? How much would the difference in cost between an 8 inch diameter dryer vessel and a 14 inch diameter dryer vessel matter to the project? Would my resulting design be perfect and the vessel be the exact right size? No. But I could complete the task and do other engineering that would matter. Sometimes getting done is more valuable than getting perfect results. The 'ask the vendor for sizing' method works also to avoid overthinking a minor piece of equipment.

[breizh]

Hi,

To add to my previous answer , consider the link attached where you can find pointers , if you insist to perform the design in house.

https://www.aiche.or...sics_part_1.pdf

Good luck

Breizh

[HadeerK]

Thank you everyone for answering. I got another related topic from "Unit Operations book by Mcabe". will study it and provide update.