| 摘要 |
PURPOSE:To recover washing waste water as clear water and recycle a salt bath component dissolved in the waste water by washing away a carburizing component stuck to a material with a neutral salt bath after carburizing, hardening the material, cooling and washing it, and further washing it with water. CONSTITUTION:A material is carburized with carburizing salt bath A, dipped in neutral salt bath B to wash away the stuck carburizing component, hardened with isothermal salt bath C, cooled and washed in back washing vessel 1, and further washed with water in washing vessels 2, 3. Water of high salt concn. overflowing from vessel 1 is stored in waste water tank E once and fed into evaporation salt bath H equal to bath C in component and heated to 140-400 deg.C at a constant flow rate after being heated with heat exchanger G. Thus, the water is evaporated immediately. This steam is supplied to exchanger G, used as a heat source, condensed with condenser J, recovered in clear water tank L, and recycled. On the other hand, a salt bath component enriched excess of bath H is allowed to overflow, allowed to stand, dehydrated, and separated from undissolved components, etc. in standstill salt bath tank I heated to 200-500 deg.C. The super natant liq. is recycled to vessel C. |
