Distillation: processes – separatory – Adding material to distilland except water or steam per se
Reexamination Certificate
1994-05-02
2001-06-26
Manoharan, Virginia (Department: 1764)
Distillation: processes, separatory
Adding material to distilland except water or steam per se
C159S047300, C159SDIG001, C159SDIG002, C203S093000, C203S094000, C203S098000, C203S100000, C203SDIG002
Reexamination Certificate
active
06251228
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention pertains to a photopolymer washout fluid solvent distillation apparatus and method. In particular, the present invention pertains to an apparatus used in distilling and recovering a desired solvent from waste photopolymer washout fluid and to the method of the apparatus' operation. The apparatus adds a surrogate solvent to the photopolymer waste fluid as the desired solvent is distilled from the waste fluid, thereby enabling recovery of a greater percentage of the desired solvent from the waste fluid while maintaining the liquidity of the waste fluid.
(2) Description of the Related Art
Known prior art methods of producing printing plates from acrylic elastomer resins and synthetic rubber plates include photoengraving and chemical milling of plate material to produce the printing plates. In these prior art processes, a layer of photoresist is applied over a surface of the plate material. The photoresist layer is then exposed to light through a photographic film or a masking stencil having a pattern formed therein corresponding to a desired pattern to be formed on the printing plate.
Exposure of the layer of photoresist to the electromagnetic radiation through the stencil or photographic film alters the susceptibility of the photoresist layer to removal by a photopolymer plate washout fluid. Applying the photopolymer plate washout fluid to the photoresist layer and the plate material removes the resist and etches away the plate material in a reverse pattern corresponding to the stencil or photographic film. The acrylic elastomer or synthetic rubber particles etched from the plate making material are washed away with the waste photopolymer washout fluid.
In order to more efficiently produce printing plates according to the process described above, it is desirable to recover the solvent employed as the photopolymer plate washout fluid by removing the acrylic elastomer particles and other foreign particles from the washout fluid. Until recently, a dominant washout fluid used in the plate making industry was alcohol-perchloroethylene. Older solvent distillation units, designed and installed without a vacuum assist, could recover and recycle these low boiling point “perc” solvents. New regulations, however, have led washout solution suppliers to develop new “safe solvents”. These high-boiling point solvents require a vacuum assist distillation system in order to recover the solvents, and almost all prior art recovery systems cannot be adapted for vacuum assist.
In addition, most prior art solvent recovery distillation systems have small capacities that are unable to service larger plate processors that produce wider plates and a greater amount of waste washout fluid. In these prior art distillation systems, a flexible bag is typically suspended inside a distillation tank. The waste photopolymer washout fluid is then supplied into the bag and the desired solvent is distilled from the washout fluid while it is in the bag. The washout fluid is distilled until it is reduced to an amorphous solid. When the distillation process reaches this point, the bag containing the amorphous solid is removed from the distillation tank and disposed of. In this prior art method of distilling desired solvents from waste photopolymer washout fluids, it is possible to recover about 85% of the desired solvent from a sample of waste washout fluid. Because the bags containing the reduced amorphous solid waste are removed from the distillation tank interior by the operator of the apparatus, the capacities of the system must be kept small to enable the bag containing the amorphous solid to be removed from the tank interior.
What is needed to overcome disadvantages associated with prior art photopolymer waste washout fluid recovery systems is a photopolymer waste fluid distillation system that is capable of processing large amounts of waste fluid and recovering more than 85% of the desired solvent from the waste fluid, while facilitating the disposal of the waste residue left after the desired solvent has been recovered. The distillation system should reduce emissions from the waste fluid processed and reduce the incidence of operator contact with the waste fluid being processed. What is also needed is a desired solvent recovery apparatus that is constructed in a manner that enables it to be easily connected with existing plate processors of various types to receive waste photopolymer washout fluid from the existing plate processor equipment and return recovered solvent to the equipment.
SUMMARY OF THE INVENTION
The photopolymer washout fluid solvent distillation apparatus of the present invention overcomes disadvantages found in solvent distillation systems of the prior art by providing an apparatus that is completely enclosed in a transportable enclosure having a Class 1, Division 2 rating, enabling the enclosure to be directly connected to existing plate making equipment without any modifications to the plate making equipment or the plate making room in which it is installed. The apparatus of the invention is capable of receiving waste photopolymer washout fluid directly from a plate processor on a continuous basis, recovering the desired solvent from the waste washout fluid, and supplying the recovered solvent directly back to the plate processor. The solvent distillation apparatus of the present invention distills a desired solvent from waste photopolymer washout fluid by a novel method that recovers a substantially greater percentage of the desired solvent from waste washout fluid than has been heretofore possible with prior art distillation systems.
The photopolymer washout fluid solvent distillation apparatus of the present invention is generally comprised of a waste washout fluid storage container that receives waste fluid directly from a plate processor, a distillation tank that is supplied with waste fluid from the waste fluid storage container, a distilled solvent container that receives distilled solvent from the distillation tank, a washout residue container that receives from the distillation tank the washout residue separated from the desired solvent, a surrogate solvent container that supplies a surrogate solvent to the distillation tank to replace the desired solvent distilled from waste washout during the distillation process, a plurality of valves and pumps that interconnect and control communication between the component parts of the invention, a control panel that enables an operator of the apparatus to control the solvent distillation process performed by the apparatus, and numerous sensors and controllers that provide for safe operations of the apparatus.
Each of the component parts of the invention described above are contained in a single cabinet enclosure that is transportable. The transportable cabinet enclosure enables the apparatus of the invention to be easily positioned relative to an existing plate processor in a plate making room. The apparatus of the invention is connected in communication with the plate processor by fluid conduits conducting waste washout fluid from the processor to the apparatus, and fluid conduits conducting distilled desired solvent from the apparatus back to the plate processor.
The apparatus of the invention distills a desired solvent blend from photopolymer waste washout fluid supplied to the distillation tank, and draws the distilled desired solvent blend to the desired solvent container of the apparatus where it is stored for continuous reuse in the plate processor. As the apparatus of the invention distills the desired solvent blend from the waste washout fluid, the apparatus supplies a surrogate solvent to the distillation tank. The surrogate solvent replaces the desired solvent distilled from the waste washout fluid. The surrogate solvent has a higher boiling point temperature than the desired solvent and maintains the liquidity of the waste washout fluid as the desired solvent blend is separated from the washout fluid. This enables the apparatus of the invention to r
Fluchel Donald G.
Marks Daniel B.
Howell & Haferkamp LC
Manoharan Virginia
LandOfFree
Photopolymer washout fluid solvent distillation apparatus... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photopolymer washout fluid solvent distillation apparatus..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photopolymer washout fluid solvent distillation apparatus... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2482338