Why is the design important? Condensers are designed to turn condensable vapor into liquid, which has a twofold benefit. Firstly, it helps remove load from the process stream and lowers loading to the downstream equipment, which improves efficiency. Secondly, it sets the pressure for the upstream piece of equipment. In many cases that upstream pieces of equipment is an ejector. Ejectors are designed for a certain maximum discharge pressure. When that discharge pressure is exceeded, the ejector’s suction pressure does not slowly degrade, the loss of vacuum is sudden as the critical operation of the ejector and its internal shockwave are disrupted. Failure to utilize a properly designed condenser greatly increases the risk of the upstream ejector breaking operation due to a higher than design backpressure.
In some vacuum systems, the first piece of equipment the process flows sees is a condenser. These systems are known as precondensing systems. In this case an improperly designed condenser can have a direct impact on the process vessels operating pressure. Any additional pressure drop across the precondenser above the design, directly translates to a poorer vacuum in the process vessel. This is undesirable in almost all instances.