Design of Sealed Shell & Tube Type Hex

You are making a lot of assumptions here....... There is more that one manufacturer of HEX's. And considering you evident lack of design knowledge, I suggest you contact another manufacture.

No pressure, no flow rate.... What's Libr solution?

LiBr is lithium bromide.

You could duplicate the original HEX.

Maybe consult a TEMA (Tubular Exchanger Manufacturers Association) design manual?

There is no clue in this thread as to the wetted materials.

The starting point is to select materials that will be corrosion-resistant to the fluid in contact with them at the temperatures and pressures to be expected. There are several ways to address this:

• Same materials as the connecting pipework
• Refer to corrosion chart and other databases
• Discuss the problem with heat exchanger vendors with a view to obtaining quotations

It is pointless continuing if one doesn't know whether the wetted materials are carbon, various alloys, maybe glass or even plastics, as the method of construction will be different in each case and this has a fundamental impact on design and selection.

If in doubt, consult a qualified Process Engineer.

kindly help me how to design sealed shell & tube type HEX for VAM.

You need not design it. You need to make only a procurement specification. Contact some HEX suppliers, they will help you.

LiBr is highly corrossive in contact with moisture. So any leak in the system will be dangerous. Normally, it will not allow you to plug the leaking tubes and reuse because water leak in LiBr side will almost destroy the HEX. This aspect should be taken care while designing (FOS may be higher).