The evaporator section is the part of the system, which does the actual cooling of a product. It is basically a cold surface of proper size to cool a product to the desired temperature. There are two general types we build for liquid chilling.
For gas chilling and drying applications, either a finned coil (similar to an air cooled condenser), or a shell-and-tube heat exchanger can be used. The type of gas to be cooled and its pressure may restrict the choice.