Q. How is the length of a shell determined in case of a heat exchanger?

A:

The length of the shell in heat exchanger is determined from the tube length under “Bundle” tab.

 

Example - For the BEU type exchanger, the entered value of tube length is 2800 mm

 

 

The value of shell length is kept blank:

 

 

The user can specify a value of the shell but it is not necessary as software calculates it. However please make sure that the shell length is consistent in case you are entering it.

The tube length field is mandatory and a value must be entered.

The length of the tube (2800 mm) is only the length of the straight portion of the tube.

The length of the shell is calculated by the program by taking into account many parameters as per the following (generate the 2d drawing to see more details):

1. The length of the bend portion of the tube, the largest U-Tube centerline is aligned with the tangent line

 

2. The straight length of the tube (2800 mm in this case

3. The length of the body flange and flange gasket assembly

4. The gasket thickness

5. The tubesheet thickness, and how it is assembled with the flange

6. The tube extension, as specified in the tubesheet

 

After factoring all these the length of the shell is calculated as 2876 mm in this case

 

 

 

The tangent reference line is taken as the beginning of the straight portion so it may not be the shell to head junction.

In the attached case there is a 50 mm straight flange portion for the head so the reference line is basically the location where the straight flange portion of head meets the curved portion of the head.