Thermocompressor

Can a thermocompressor be used to increase steam pressures from waste heat ... 

Eig. 7. Schematic flow diagram of a basic horizontal-tube vapor compression (VC) desalination plant, shown (a) with a mechanical, motor-driven compressor and (b) with a thermocompressor, using an ejector, where (------) represents vapor (—), brine and (-), product. 

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

Steam jet thermocompressors or steam boosters are used to boost or raise the pressure of low pressure steam to a pressure intermediate bettveen 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 posidon all gaskets, etc. The thermal efficiency is high as the only heat loss is due to radiation [5]. 

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

Figure 8.16. Some types of evaporators, (a) Horizontal tube, (b) Calandria type, (c) Thermocompressor evaporator, (d) Long tube vertical, (e) Falling film, (f) Forced circulation evaporator-crystallizer, (g) Three types of Oslo/Krystal circulating liquid evaporator-crystallizers.

Do the steam systems operate at the needed pressure rather than at the available boiler pressure Too large a pressure leads to a higher condensation temperature for steam. This causes an unnecessarily large temperature differential for heat transfer. Fouling and other problems arise as a consequence, reducing the energy efficiency. In other words, use utilities at the lowest practical temperature. A simple solution to reduce the steam temperature is the use of a thermocompressor. This device uses high-pressure steam to increase the pressure of low-pressure steam to form steam at a desired intermediate pressure. 

Figure 3. Double-effect evaporator with thermocompressor flowsheet. Courtesy of Crown Iron...

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