Disposal of waste water from thermal salt bath treatment of metals - by evapn. and melting brine, withdrawing vapour in heated air

摘要

Waste water from thermochemical or thermal salt bath treatment of metals, esp. contg. hydroxides, in amt. of 5-40 l/h, is disposed of by an evapn. in a container, heating the waste water at below the level of the bath. In the 1st phase, the temp. of the water is below the b.pt. (95 deg.C) and in the 2nd phase, the remaining brine is melted at up to 650 deg.C, to skim off liq. salts. During both phases, the vapour forming is taken up in preheated air (5-20 deg.C above ambient temp.), and this air is removed by suction. ADVANTAGE - The firing is not affected e.g. is not corrosively attacked. The vapour contains few entrained particles. Encrustations are easily removed from the sides of the tank. The waste gases can be used as heat energy.