The Dow Chemical Company

Robert A Hay, Ii

Albert C Dowell

Oswald Bergman

Eugene R Moore

Hubert Stacy Smith, Jr

Edward V Dettmer

Brian W Krause

Harold E St Louis

John A DeBliek

Charles C Crugher, Iii

John S Boruszewski

A process for providing a seal around a reciprocating and/or rotating shaft as in an apparatus for manipulating a fluid at least in part by the rotary and/or reciprocal motion of the shaft, involving the insertion of substantially identically configured free-floating seal elements into the gap between the shaft and its housing, and the improved apparatus resulting therefrom.

Floating ring labyrinth-type dynamic shaft seal and process for using

This invention is a method and an apparatus for rapidly devolatilizing a product of a polymerization process containing at least one volatile material. The product is initially devolatilized in a high temperature zone, and the foamed devolatilized product is separated into a gas and a liquid polymer phase and rapidly removed therefrom to minimize depolymerization and degradation of the polymer. The partially devolatilized product is further devolatilized by feeding it into a rotatable chamber which is rotated at a sufficient angular velocity to create a high gravitational field to form a vapor and a polymer liquid pool.

Method for the devolatilization of thermoplastic materials

A devolatilization apparatus is provided which removes volatiles from a variety of polymer products utilizing centrifugal forces to control the residence time of the polymer in the devolatilizer. Volatiles are efficiently removed without degrading the polymer product. The devolatilizer includes a rotatable annular chamber having an inlet, a first outlet located at a first distance from the axis of rotation of the chamber, and a second outlet located at a second distance from the axis of rotation of the chamber. Means are also provided for supplying a polymer, in liquid form, to the inlet to the annular chamber. The portion of the chamber located between the first and second outlets forms an annular pocket or subchamber. The apparatus also includes means to rotate the annular chamber at a speed sufficient to cause the liquid polymer to flow through the first and second outlets and form liquid seals at each of the outlets. A vacuum source communicating with the annular pocket is provided for removing the volatile constituents from the liquid polymer.

Centrifugal devolatilizer

The invention is an apparatus that allows a motor to move in any one of three linear directions, but it restrains rotary motion of the motor housing. In practice, the motor is used for driving a pump or some other rotary motion device. The device includes a lever arm fastened to the motor housing and a hydraulic cylinder pivotally connected to each end of the arm and to a support member. Each cylinder is divided into two chambers by a piston head, and hydraulic lines connect the chambers of one cylinder to the chambers of the other cylinder. When the pump (or other rotary motion device) tends to cause rotational movement of the motor housing, and lever arm, each cylinder responds to this rotational load by trying to displace fluid (oil) from one cylinder to the other. Since each cylinder tries to displace an equivalent volume of oil toward the other cylinder, through a common conduit, displacement of the oil is not possible. This action restrains rotational motion of the motor housing and lever arm, but allows them to move in any one of three linear directions.

Apparatus for restraining rotary motion of a motor component

A waste disposal mixer is shown suitable for the encapsulation of radioactive wastes in synthetic resins. The mixer permits the selective discarding of the agitator member and of a drip pan selectively positionable to receive dripping material from the agitator. The agitator can be selectively replaced, all movements being controlled remotely.

Waste disposal apparatus

An improved heat transfer or chill roll is disclosed employing a static mandrel, and agitation within the roll together with longitudinal distribution of the heat exchange fluid provides increased uniformity of surface temperature.

Film casting apparatus including heat transfer roll

Improved shaft seal is provided wherein generally radially extending distendable diaphragms are used to adjust the sealed gap. A flushing lubricant is provided. The seal is particularly suited for use in gear pumps handling viscous materials such as heat plastified thermoplastics.

Seal assembly which is hydraulically actuated

Rigid plastic foam is flexibilized in an apparatus utilizing four sets of foam gripping belts. A first and second set of opposed belts traveling at a given speed forward the foam into the apparatus to a second and third set of opposed belts traveling at a slower speed than the first and second set of belts. The first and third and the second and fourth sets of belts are interdigitated in a region of foam crush.

Apparatus for the flexibilization of synthetic resinous foam

A tube perforator is provided which has a generally cylindrical mandrel which extends within a tube. The mandrel is hollow and has a passage therein which extends in angular relation to the axis of the mandrel and exits on one side thereof. A punch disposed in the passage can be driven against the tube wall to cause perforation thereof.

Tubing perforator

A heat exchange assembly is provided which employs concentric flat plate heaters, the heat exchange assembly having a common fixed tube sheet and floating tube sheet; the floating tube sheet comprising two concentric portions having frustoconical interface thereby, the frustoconical interface when projected has its apex in a plane containing the adjacent face of the fixed tube sheet in the axis of generation of the flat plate heater. Thermal stress on the floating tube sheet is thereby relieved. The heat exchanger is useful as a reactor particularly where the temperature profile of the material flowing therethrough is controlled or varied.

Flat plate heat exchange apparatus

Profiled heat seals in plastic film are provided by opposed profiled heat sealing platens supported on endless chains. The platens are heated by contact with associated heating drums.

Heat sealing apparatus and method

Laminated heating elements are provided which are suitable for joining synthetic resinous thermoplastic bodies particularly thermoplastic foams. The heating elements are of laminar structure having at least two oppositely disposed heating elements which electrically may be fed in parallel. A significant improvement in rigidity and resistance to mechanical abuse is achieved.

Heating elements for thermoplastic lamination

Thermoplastic foam bodies are readily generally continuously laminated together wherein the joint therebetween contains a reinforcing scrim. Friction on each of the foam bodies is generally equalized by positioning the scrim relative to both major faces of the heating element employed for the lamination to obtain a desired degree of curvature in the laminate.

Method for the lamination of foam including a reinforcing scrim

Forming plates for the extrusion of foam from a slot die are provided which are adjustable in relationship to a generally adjacent die face. A movable plate portion is disposed adjacent the die face. The movable portion has a semi-cylindrical groove disposed therein. A pivoting forming plate having half-round edges has one edge disposed within the movable plate. The opposed half-round edge of the pivoting plate rests in a semi-cylindrical groove within a fixed forming plate. A similar opposed plate arrangement is employed on the opposite side of the die slot.

Extruded plastic foam shaping apparatus

In a process for the admixture of radio-active waste with an encapsulating resin in a container which will accompany the waste to a disposal site, the improvement which comprises providing a generally annular deflectable foil at an upper open end of the container to minimize contamination by splashing.

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Midland, MI, United States of America

Robert A Hay, Ii