SPLIT FEED METHOD OF TREATMENT...AN EFFICIENT WAY TO

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D A R C O D E P A R T M E N T * A T L A S POWDER C O M P A N Y Dareo General Sales Offices —60 EAST 42nd STREET, NEW YORK 17, N. Y. ATLAS POWDER COMPANY, CANADA, LTD., BRANTFORD, CANADA

SPLIT FEED METHOD OF TREATMENT... AN EFFICIENT WAY TO USE ACTIVATED CARBON Purification Solution to be treated

accomplished

FIRST rREATING TANK J

HH

TILICK

I

D ARCO SECOND TREATING TANK

%Z4

FILTER

Purified Solution

4S42

activated

by several

The simplest is a one-shot treatment, in which all the Darco required to do the purifying job is mixed with the solution in a single application. Countercurrent treatment, the most economical method, consists of treating the solution first with Darco t h a t h a s been used once . . . then treating a second time with new Darco. I n plants where products are made at irregular intervals, counter-current treatment is not feasible because it is normally not practical to hold once-used carbon from one application over any appreciable length of time to b e used for the first treatment of the next batch. I n such cases worthwhile savings in carbon can still be realized by using the split treatment method. This consists of two successive treatments, each with new Darco . . . filtering and discarding the carbon after each step. As with counter-current treatment, the net savings in carbon secured by split

A simple method

A 50-lb. bag of Darco is placed on a rotating shelf in the hopper which a typical Darco customer built for his treating process.

with

for handling

bags of

Here's the bag locked in place. The operator slits the bag crisscross from corner to corner, then lowers the padded flanged lid to form a dustproof hopper.

carbon different

can be methods

treatment depend on the solution characteristics. As a rough rule, the countercurrent dosage in any particular case will range 50-75% of the split feed dosage. I n both cases, because of the divided dosage feature, a given amount of carbon removes more impurities than if all the carbon were used at once. The reason for this saving is that adsorption by activated carbon follows a logarithmic law. T h e carbon takes out the first portion of the impurity more readily than the remainder. By dividing the total carbon dosage needed into two steps, the carbon is used a t its greatest adsorptive efficiency. The most efficient division of dosage, incidentally, is not half-and-half—but should be determined for the individual application. If you'd like further information a b o u t this and other methods of treatment with Darco activated carbon, just -write for a copy of an article, "Adsorption from Solution by Activated Carbon."

DARCO

A few turns of the crank quickly shake the Darco out of the bag. A motorized screw conveyor meters the carbon into a slurry tank or treating tank.

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