Is there such a thing as a 6000 tube heat exchanger?
What is the tube length. The shell diameter. Can it be made in multiple shells. These are the questions you should ask to come up with the best design. If you allow about 1 square inch for each tube then you would end up with a 7.28 foot diameter tube sheet. Large but not uncommon. Depending on the shell pressure requirements you might need to make it into two shells. High pressure shells need to have a small a diameter as possible for cost considerations.