Method of removing solvent residues from aqueous paper pulps
AssigneeThe Dow Chemical Company
InventorJ. Frank Valle-Riestra
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Abstract
It has been found that solvent residues can be removed from aqueous paper pulps by stripping with economic volumes of gases. This can be done in conventional contacting equipment without reducing pulp consistencies below the levels typical of commercial paper-making operations. The solvents stripped out are recoverable and do not constitute a source of pollution.
Claims10
The method of removing residual amounts of volatile solvents from aqueous pulps of cellulosic fibers by gas stripping, wherein said pulp contains from about 0.4 to about 1.5 weight percent of said fibers comprising intimately contacting said pulp with n volumes of said gas under such conditions of agitation that the pulp consistency remains essentially uniform throughout, thereby removing at least a fraction of said solvent from said pulp,
- the ratio of n to the volumes of said gas required to remove the same fraction of solvent in the same manner, from the same volume of water containing the same initial amount of said solvent, being within the range of from about 1.5/l to about 6/l.
Dependencies are inferred from the claim text.