Countercurrent liquid-solid contacting apparatus

An apparatus for purifying a liquid by countercurrent liquid-solid contact and for regenerating a purifying material used to purify the liquid, said apparatus comprising:

• a liquid treating column having a bed of purifying material in the form of a mass of purifying particles filled in said liquid treating column, the uppermost surface of said purifying bed being spaced a predetermined distance from the top of said liquid treating column to provide therebetween a vacant space;
• said liquid treating column having at the top and bottom thereof a material inlet and a material outlet, respectively;
• said liquid treating column having at respective lower and upper portions thereof a liquid inlet and a liquid outlet, said liquid inlet being positioned above said material outlet and adapted to be connected to a source of liquid to be purified, whereby said liquid to be purified is introduced through said liquid inlet into said purifying bed and passes upwardly therethrough while being purified, thereby forming purified liquid;
• liquid collector means, positioned within the liquid treating column and connected to said liquid outlet, for collecting said purified liquid and for withdrawing said purified liquid from the interior of said liquid treating column through said liquid outlet, but not permitting the passage of particles of said purifying material;
• said liquid collector means being completely embedded within said bed of purifying material within said liquid treating column, the amount of said purifying material within said liquid treating column being selected such that an upper portion of said purifying bed, situated above said liquid collector means, forms a settling layer which alone acts on the remaining lower portion of said purifying bed below the level of said liquid collector means to form means for preventing any possible fluidization and/or expansion of the purifying particles forming said remaining lower portion of said purifying bed during upward passage therethrough of said liquid;
• said liquid collector means and said liquid outlet being free of connection to said vacant space between said top of said liquid treating column and said uppermost surface of said purifying bed;
• a regenerating column having defined in top and bottom portions thereof a material inlet and a material outlet, respectively, for regenerating said purifying material after soiling thereof in said liquid treating column;
• connecting piping means, having a first end connected to said material outlet in said liquid treating column and a second end connected to said material inlet in said regenerating column, for transferring a soiled lower portion of said purifying material from said liquid treating column to said regenerating column;
• liquid discharge means in said regenerating column for withdrawing liquid to be used to wash said soiled purifying material from the interior of said regenerating column;
• an exhaust piping connected to said material outlet of said regenerating column;
• transport conduit means, having a first end connected to said exhaust piping and a second end connected to said material inlet of said liquid treating column, for transferring said purifying material, which has been regenerated within said regenerating column, through said material inlet of said liquid treating column;
• means for supplying compressed air into said regenerating column for a predetermined period of time for fluidizing said soiled purifying particles, which have been soiled by suspended solids separated from the liquid purified in said liquid treating column, and for causing said suspended solids to separate from said soiled purifying particles;
• means for supplying a washing liquid into said regenerating column for a predetermined period of time for fluidizing said soiled purifying particles to enhance the separation of said suspended solids therefrom, for then transporting the thus separated suspended solids upwardly through the fluidized bed of soiled purifying particles, and for washing said soiled purifying particles within said regenerating column, the thus separated suspended particles and washing liquid being discharged to the outside of said regenerating column through said liquid discharge means;
• and
• means, installed between said exhaust piping and said transport conduit means, for transporting the regenerated purifying material through said material inlet in said liquid treating column and onto the top of said purifying bed within said liquid treating column.