Process for thermal treatment of crude phthalic acid
AssigneeDavy Powergas GmbH
InventorsHelmut Saffran, Lothar Sterck
Life of this patent
Estimating the term…
Abstract
There is disclosed a process and apparatus for the thermal treatment of crude phthalic anhydride. The process is conducted in a system with an inner chamber and outer chamber positioned therearound and the chambers have a common wall. The outer chamber may be divided into a plurality of sub-chambers and the flow of the phthalic anhydride undergoing treatment may be substantially reversed in successive ones of the sub-chambers. The system provides for more efficient use of heat and equipment.
Claims17
A process for the thermal treatment of crude liquid phthalic anhydride to enhance purification of said liquid which comprises passing said liquid through a portion of a thermal treating path, passing said liquid from said portion through another portion of said path, one of said portions being positioned substantially completely around said other portion and in adjacent, indirect heat exchange relationship therewith, and heating said liquid as it passes through said path to a temperature of about 190.degree. to 285.degree. C.
A process for the thermal treatment of crude liquid phthalic anhydride to enhance purification of said liquid which comprises passing said liquid through a first portion of a thermal treating path, passing said liquid from said first portion through another portion of said path in which the liquid therein is at a higher temperature than in said first portion, one of said portions being a central portion and another of said portions being positioned substantially completely around said central portion and in adjacent, indirect heat exchange relationship therewith, heating said liquid passing through said path, said liquid passing through said portion positioned substantially completely around said central portion being in indirect heat exchange flow with respect to said central portion to transfer heat from said liquid which is at a higher temperature to liquid in said path at a lower temperature, and withdrawing thermally treated liquid from said path.
Dependencies are inferred from the claim text.