Farrel Corporation

Michael R Kearney

William H Swilling, Jr

Douglas E Mosher

Joseph R Piccolo, Sr

Stuart A Sardinskas

Mathew Mormino, Jr

Darren G Rhodes

Ian Lowe

Rotor zone cooling method for channeling liquid coolant flow in rotors in continuous mixers provides for predetermined zones along the lengths of the rotors to be cooled as may be desired and provides for other predetermined zones to remain neutral. A sequence of alternating cooling/neutral/cooling/neutral/cooling/neutral zones can be provided, including zones of various possible lengths, locations and numbers of such zones for tailoring or customizing these zones to optimize temperature conditions along a rotor depending upon mixing requirements and characteristics of plastic materials being mixed. A central coolant feed tube conveys coolant from an entrance into the bore to a discharge end of the feed tube positioned near the bore terminus in a first cooling zone. Coolant flow is diverted into isolation channels within isolation tubing sections spaced inwardly from the rotor bore wall for creating a neutral zone. Coolant flow is diverted outwardly from an isolation channel through ports into a cooling augmentation channel located closely adjacent to the rotor bore wall being confined outside of a cooling booster tubing sections. Coolant is diverted to flow outwardly from an isolation channel into an augmentation channel and thereafter coolant flow is diverted inwardly from the augmentation channel.

Rotor zone cooling method and apparatus for rotors in continuous mixers

Continuous mixers of plastic materials are equipped with greased journal bearing assemblies instead of bulky, expensive, pumped circulating-oil lubricating systems, usually involving oil-cooling heat exchangers with circulating water. Such pumped oil systems having traditionally been employed in the past for lubricating journal bearings of the two rotors in such mixers. Novel thermal isolation of the journals for the two rotors separates their bearing assemblies from the severe heat being generated during mixing of plastic materials by continuous rotation of the two rotors within the mixer barrel. Localized cooling provides heat sinks for the drive and driven journals of each rotor. The rotors are shown as three-piece assemblies with drive and driven journals separate from the main rotor body. Beneficial interactions of localized cooling for the drive and driven journals plus thermal isolation of the journals from the severe heat being generated in the mixer barrel advantageously enables the journal bearing assemblies to be lubricated by grease instead of by circulating oil. Each of the journal bearing assemblies shown and described comprises two axially spaced, spherical-type roller bearings each encircling a portion of a journal and each being equipped with a seal housing having a grease fitting. The outer races of these roller bearings are shown and described as mounted in respective end frames which are spaced farther away from the upstream and downstream ends of the mixer barrel than their usual spacing in the past.

Greased journal bearing assemblies with thermal isolation and cooling in

Quick-disconnect couplings for three-piece rotors in a two-rotor continuous mixer for plastic materials enable a main rotor section (or 'main rotor body') of each rotor to be uncoupled from a drive journal located at one end of the main rotor section and a driven journal located at the other end of the main rotor section. These quick-disconnect couplings as shown provide the following features: (a) piloted to maintain concentricity, (b) keyed to transmit torque, (c) enable quick assembly and disassembly of three-piece rotors, (d) maintain integrity of couplings bolted onto respective ends of each rotor section, (e) thus, a complete functional main rotor body is assembled with its quick-disconnect couplings at each end, (f) the disengageable interface between each coupling and each journal is supplied with both pilot and key, (g) concentricity and torque capabilities are built into the quick-disconnect coupling assemblies, (h) threaded locking collars captive on the journals serve to lock the disengageable interfaces together, (i) interface joints are pre-loaded by tightening the locking collars using spanner wrenches, (j) threaded locking collars do not become jammed, because torque is carried by keyed engagement at each interface, and (k) for disassembly the locking collars are backed off, and main rotor bodies together with their couplings are conveniently removed by separation at the piloted and keyed interfaces.

Quick-disconnect couplings for three-piece rotors in continuous mixers

Rotor zone cooling apparatus channels liquid coolant flow in rotors in continuous mixers of plastic materials for causing predetermined zones along the lengths of the rotors to be cooled as may be desired and for other predetermined zones to remain neutral, i.e. without significant cooling. A sequence of alternating cooling/neutral/cooling/neutral/cooling/neutral zones can be arranged, including zones of various possible length, various possible locations and various possible numbers of such zones. These zones are tailored or customized for optimizing temperature conditions along a rotor depending upon the mixing requirements and characteristics of plastic materials being mixed. Within an axial bore in a rotor is inserted a novel elongated cooling tubing assembly which rotates with the rotor. For creating a neutral zone, coolant flow is diverted inwardly into an isolation channel within an isolation tubing section spaced inwardly from the rotor bore wall. For creating a cooling zone, coolant flow is diverted outwardly from an isolation channel into a cooling channel located adjacent to the rotor bore wall. Coolant flow in such a cooling channel is located outside of a cooling booster tubing section. Isolation tubing sections and booster tubing sections are shown assembled in a versatile arrangement along a central tube. Rabbeted ring fittings have shoulders overlapping lips on adjacent support rings welded to respective tubing sections and hold seals in contact with the bore wall. A rotary joint near the bore entrance allows the whole coolant tubing assembly to rotate with the rotor.

Rotor zone cooling apparatus for rotors in continuous mixers of plastic

Flowable molten plastic material is fed downwardly into an adjustable converging hopper mounted on a horizontal extruder barrel. This hopper is positioned around an opening feeding down into the barrel for guiding and deflecting a descending 'rope' of plastic material into engagement with screw flights of a rotating feed screw extending along the axis of the extruder barrel. The hopper comprises a box-like structure open at top and bottom and having two opposed side walls which slope inwardly downwardly toward each other for providing a downwardly converging configuration with a pair of vertical parallel end walls interconnecting the side walls. A larger of the two sloping side walls extends downwardly farther than the other and is inclined to vertical at a large angle than the shorter side wall. An adjustable extension of this larger sloping side wall comprises an adjustable converging deflector having a compound-angled surface 'X', and this deflector is adjustable downwardly and upwardly along the larger sloping side wall toward and away from the feed screw. Multiple deflection faces on surface X serve to follow approximately a spiral approach to the extruder screw for allowing and enabling molten plastic material to convey against surface X as the extruder screw is rotating into the material. Thus, the molten plastic material can slide over the rotating feed screw and create drag against adjustable surface X. The configuration of this surface provides an undercut for molten plastic material to become drawn into the screw flights and into the extruder.

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Milford, CT, United States of America

Michael R Kearney