| 摘要 |
<p>PROBLEM TO BE SOLVED: To dispense with steam to be supplied for evaporation and concentration by providing a heat exchanger for recovering heat from a heating medium on the midway to be fed to a heat recovering part from a re-heating part of a non-leak gas gas heater. SOLUTION: The heat exchanger 31 for recovering heat from the heating medium W to be fed to the heat recovering part 1a from the re-heating part 3 of the non-leak gas gas heater is provided. As a result, the heat exchanger 31 functions as a heater for a circulating slurry for the evaporation and concentration in an evaporator 13, a part of the heat energy of the flue gas is used for the evaporation and concentration and the requirement of the supply of steam is eliminated. That is, as the circulating quantity of the heating medium W is about 1,000 t/h and the temp. of the heating medium W is about 75-80 deg.C at the outlet in the case of a 100 MW thermal power plant, the circulating slurry composed of a desulfurization waste water is heated to about 59 deg.C and the temp. of the heat transfer surface is kept at <=70 deg.C to prevent the generation of gypsum scale.</p> |
