Do High-Efficiency Thermocompressors Save Steam?
High-efficiency thermocompressors do offer a higher entrainment ratio which means a lower motive steam (high-pressure) flow is required to recompress the same amount of suction steam (low-pressure) flow or conversely pull a higher amount of suction flow for the same amount of motive flow for a given set of pressure condition.
A high-efficiency thermocompressor will offer an operating cost advantage if the source of the motive steam bypasses a cogeneration turbine or if the source of motive steam is produced on a high-pressure boiler separate from the source of low-pressure steam. In these cases, the motive steam will have a higher cost than the make-up steam. Minimizing the motive steam required will maximize the make-up steam flow and the power generation.
For tissue machine applications where the motive flow is limited to the Yankee's condensing rate, the higher entrainment ratio provides the benefit of increased blowthrough flow for the same amount of motive steam flow and for this reason, high-efficiency thermocompressors have become the industry standard for Yankee dryers.
On booster thermocompressor applications, a high-efficiency thermocompressor will reduce the ratio of motive to suction steam flow for a fixed discharge flow.