1 reply to this topic

[MGS RN]

Hello All,

 

Myself Goutham and I am working professional in the Shell & Tube exchanger design and have around 5 years experience in this field. We have in house methods of sizing heat exchangers in our company. Recently I designed 1-2 TEMA NEN Heat exchanger with water in both sides. There are 4 exchangers in series and so they are arranged like a 2 x 2 matrix. As the connections in the bottom exchangers comes laterally (from sides), we needed to rotate the partion plate 90deg for the flow alignment with the nozzles. We use 45% cut horizontal baffles in the shell side. My question is should we need to rotate the shell side baffles too inline with the partition plates? Attached picture would explain the issue better. Heating surface is 4 x 480m2. Shell ID is 1.1m.

 

I hope the problem is explained clear. My thiking is if we dont rotate the baffles aligning with the parition plate, there could be uneven heat trasnfer (shell & Tube side fluid) which could reduce the heat trasnfer coeffecient. Noramlly baffles are not inclined, they are horizontal or vertical? Could there be any issues with the inclined baffles?

 

Experts. I need your help!  Any further details requied please let me know. Thanks!

 

 

 

[saeed.s]

 

Dear Goutham 

 

The chord should be vertical (usually with a large baffle cut) in condensers, vaporizers and units handling fluids containing suspended solids. This arrangement minimizes “pockets" which would trap vapors or sediment, reducing the effective surface area.

 

The baffle chord should be horizontal when sediment-free, single phase shell side fluid is being cooled or heated through a wide temperature range [200 to 300°F ( 110 to 165°C)] in one shell. This avoids fluid stratification.

 

The baffle chord can also be placed at a 45° angle to grade. This position is termed “on the bias". When sedimentation and stratification possibilities co-exist, a 45° chord at a suitable baffle cut provides a reasonable compromise solution to both problems. A 45°chord is also useful to prevent the accumulation of heavy components in an exchanger when a wide boiling range fluid is being partially vaporized. With horizontal pass partitions, the 45°chord mitigates the effect on heat transfer of fluid flow through the pass lanes.

 

 

Edited by saeed.s, 06 November 2019 - 08:32 PM.