A method of treating liquids

摘要

In operation of a contacting vessel, the valve 7 is closed and the inlet valve 11 is opened and discrete particles of a treating material 12 are introduced under pressure through the inlet pipe 9 until the tank is filled with compacted material to the level of the retaining screen 8. In the tank shown in Fig. 1, the portion of the bed located above the distributer 2 will tend to become more compacted than the portion disposed below, but in Fig. 3 the entire bed will become compacted substantially uniformly throughout. The valve 11 is now closed and an untreated liquid is fed under a predetermined pressure and in a predetermined volume into the bed. As the content of the liquid in the tank increases, it will pass through the bed and exit in the form of a purified effluent through the retaining screen 8 into the collecting chamber 13 and through the product outlet pipe 14. After a sufficient period of time, the bed 12 tends to become spent or exhausted with the material near the bottom of the column showing the greatest degree of exhaustion. To replenish the material, outlet valve 7 of Fig. 1 or outlet valve 18 of Fig. 3 and inlet valve 11 are opened simultaneously and fresh material is introduced under pressure through the inlet pipe 9 so as to simultaneously force the most exhausted material out through resin outlet pipe. It is important that the fresh material be introduced at a sufficient rate so that the exhausted material is forced out of the bed rather than allowed to drop by gravity so that the bed is maintained in its original compacted condition. The force pushing the absorbent through the tank may be varied and controlled by the inlet and outlet valves. Specification 1,012,507 is referred to.