Steam Jet Thermocompressors

Steam jet thermocompressors or steam boosters are used to boost or raise the pressure of low pressure steam to a pressure intermediate between this and the pressure of the motive high pressure steam. These are useful and economical when the steam balance allows the use of the necessary pressure levels. The reuse of exhaust steam from turbines is frequently encountered. The principle of operation is the same as for other ejectors. The position of the nozzle with respect to the diffuser is critical, and care must be used to properly position all gaskets, etc. The thermal efficiency is high as the only heat loss is due to radiation [5]. 

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Freneau, Philip, Steam-Jet Thermocompressors Supply Intermediate-Pressure Processes, PotfCT Jan. 1945, Feb. 1945. 

Thermal compression is the term used to describe the application of a steam jet ejector or thermocompressor to an evaporator in order to increase the steam economy. A typical system is illustrated in Figure 18-1. Steam jet thermocompressors can be used with either single or multiple-effect evaporators. As a rule-of-thumb, the addition of a thermocompressor will provide an improved... 

A steam-jet thermocompressor is employed when low-pressure steam is used for the evaporation and the available steam pressure is high. The Jet compressor essentially replaces the existing pressure regulator or reducing valve that controls the steam pressure (and temperature) for evaporation and can be applied easily to single-effect and multi-effect units under the right conditions. 

The variability in energy savings and capital costs still depends on the existing evaporator conditions. For existing multi-effect units in which the total amount of first-effect vapor is now used in the second effect, the choice and location of the steam-jet thermocompressor are more complicated because the heat balances and heat-transfer rates are affected for each evaporator reaction. The economics may still be favorable to justify the technical evaluation and modification. Since the limitations of steam-jet thermocompressors are a compression ratio below 1.8 and new heat-transfer rates, the first effect normally becomes the best location. 

Thermocompressors are steam jet ejectors used to boost low pressure or waste steam to a higher intermediate pres-... 

The thermocompressor design is very similar to that of steam jet ejectors used for producing vacuum. The standard types of ejectors used for thermal compression are shown in Figure 18-2. Each ejector consists of three basic... 

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