Improvements in and relating to processes and apparatus for softening boiler feed water

摘要

502,526. Softening water. CHEMISCHE FABRIK BUDENHEIM AKT.-GES. July 2, 1938, No. 19689. Convention date, July 3, 1937. [Class 46] In a method of softening boiler feed water using blowdown boiler water for presoftening and a chemical softening agent for completing the softening, the entire softening process takes place in a cascade or tower apparatus from which the softened water is conducted to a filter. The apparatus shown is provided with plates 2 arranged horizontally or obliquely. The crude water enters the tower 1 through an inlet 3, blow-tlown boiler water enters through an inlet 4, and a solution of softening chemicals is supplied through an inlet 6. Steam may be supplied through an inlet 7 and the supply of steam or boiler water may be controlled by means of a thermostat 14. The softened water flows through filtering gravel 9 in a filter provided with a back-flushing device 11, an outlet 12 for flushing water, and an overflow pipe 13. Gases evolved in the tower escape through a pipe 5. In a modified apparatus the tower is under pressure, the pipe 5 communicating with the tower through a valve adapted to be opened at a predetermined pressure. The tower is connected to the filter chamber by a pipe. The softening chemicals may be tri-sodium-phosphate, or aluminates, soda, caustic soda, or combinations thereof.