This is a photo of a very big shell and tube heat exchangers. "Outokumpu Stainless Tubular Products"
(OSTP) unit in Fagersta produces heat exchanger tubes for heat exchanger evaporators, condensers and other equipment. I don't bother counting how many tubes they are in the shell and tube heat exchanger, but I'm guessing there are almost 1000 tubes. Do you want to count? Photo adopted from
Chemicals-Technology.com.