U.S. patent application number 11/975976 was filed with the patent office on 2009-04-23 for cryogenic freeze chamber assembly.
This patent application is currently assigned to Lehigh Technologies LLC. Invention is credited to Anthony M. Cialone, Josef Fischer, Peter J. Waznys.
Application Number | 20090100846 11/975976 |
Document ID | / |
Family ID | 40562080 |
Filed Date | 2009-04-23 |
United States Patent
Application |
20090100846 |
Kind Code |
A1 |
Waznys; Peter J. ; et
al. |
April 23, 2009 |
Cryogenic freeze chamber assembly
Abstract
A cryogenic freezing chamber assembly provided with improved
stress resistance caused by thermal expansion and contraction,
improved cryogenic fluid utilization, better means for viewing
activity therein and easy assembly and disassembly.
Inventors: |
Waznys; Peter J.;
(Centerport, NY) ; Fischer; Josef; (Bobingen,
DE) ; Cialone; Anthony M.; (Naples, FL) |
Correspondence
Address: |
SCULLY SCOTT MURPHY & PRESSER, PC
400 GARDEN CITY PLAZA, SUITE 300
GARDEN CITY
NY
11530
US
|
Assignee: |
Lehigh Technologies LLC
Mineola
NY
|
Family ID: |
40562080 |
Appl. No.: |
11/975976 |
Filed: |
October 23, 2007 |
Current U.S.
Class: |
62/63 ;
62/381 |
Current CPC
Class: |
B29B 17/0408 20130101;
Y02W 30/62 20150501; F25D 3/11 20130101; Y02W 30/625 20150501 |
Class at
Publication: |
62/63 ;
62/381 |
International
Class: |
F25D 13/06 20060101
F25D013/06; F25D 25/04 20060101 F25D025/04 |
Claims
1. A cryogenic freezing chamber assembly comprising: an elongated
chamber; an inlet means for introducing feedstock into said
chamber; an inlet means for introducing cryogenic fluid into said
chamber; an outlet means for removing said solid particles below
the glass transition temperature of said feedstock; and fixed
mounting means disposed midway between the ends of said
chamber.
2. A chamber assembly in accordance with claim 1 wherein said
chamber is trough-shaped with removable flat top sections.
3. A chamber assembly in accordance with claim 2 wherein a pair of
fixed support brackets are affixed to said trough shaped portion of
said chamber assembly at the midpoint of said chamber assembly.
4. A chamber assembly in accordance with claim 1 comprising a
plurality of movable mounting means attached to said chamber
assembly.
5. A chamber assembly in accordance with claim 2 wherein a
plurality support brackets, movable in the horizontal direction,
are affixed to said trough-shaped portion of said chamber
assembly.
6. A cryogenic freezing chamber assembly comprising: an elongated
chamber; an inlet means for introducing feedstock into said
chamber; an inlet means for introducing a cryogenic fluid into said
chamber; an outlet means for removing said feedstock from said
chamber; and a plurality of view-ports disposed on a flat top of a
trough-shaped chamber, said view-ports provided with heating
means.
7. A chamber assembly in accordance with claim 6 wherein comprises
a mounted frame holding a heated glass cushioned by a gasket.
8. A chamber assembly in accordance with claim 7 wherein said
heated glass is double layered and covered with an insulated latch
cover wherein heating to said glass is introduced when said latch
cover is opened.
9. A cryogenic freezing chamber assembly comprising: an elongated
chamber; a rotating auger disposed in said chamber; an inlet means
for introducing feedstock into said chamber wherein said feedstock
is contained, transported and agitated by said rotating auger; a
cryogenic fluid introducing a cryogenic fluid into said chamber,
said introductory means being responsive to means provided on said
rotating auger for introducing cryogenic fluid into said chamber;
and a feedstock outlet means for removal of said feedstock, at a
temperature below the glass transition temperature, from said
chamber.
10. An assembly in accordance with claim 9 comprising serrated
agitators attached to an outer diameter of said blade of said auger
and a stationary switch disposed on said chamber housing wherein
said cryogen introductory means are responsive to activation by
said switch, said switch being activated by said serrated
agitators.
11. An assembly in accordance with claim 10 wherein said stationary
switch is a magnetic switch activated by a magnet embedded in said
serrated agitator.
12. An assembly in accordance with claim 9 wherein said cryogenic
fluid introductory means comprises a plurality of spray head
assemblies.
13. A chamber assembly in accordance with claim 9 wherein said
feedstock inlet means comprises ferrous metal removal means
provided in said introductory means.
14. A chamber assembly in accordance with claim 13 wherein said
ferrous metal removal means comprises a magnetic bar screen
assembly which includes at least one bar magnetic connected to a
removal drawer.
15. A chamber assembly in accordance with claim 14 wherein said
magnetic bar screen assembly comprises at least one view-port.
16. A chamber assembly in accordance with claim 9 wherein feedstock
enters said chamber through said feedstock inlet means through a
variable frequency drive rotary valve.
17. A chamber assembly in accordance with claim 9 wherein said
feedstock inlet means comprises an isolating feedstock delivery
slide gate.
18. A cryogenic freezing chamber assembly comprising: an elongated
chamber; a feedstock inlet means for introducing feedstock into
said chamber; a cryogenic fluid inlet means for introducing
cryogenic fluid into said chamber; and a feedstock outlet means for
removing feedstock below its glass transition temperature; and a
rotating auger, supported by and rotating about end bearing
assemblies, for transmitting said feedstock from said inlet means
to said outlet means.
19. A chamber assembly in accordance with claim 18 wherein said
rotating auger is removable from said chamber by detaching said
auger from said end bearing assemblies and vertically removing said
auger from said chamber.
20. A chamber assembly in accordance with claim 19 wherein said end
bearing assemblies comprise a front end bearing assembly and a
drive end bearing assembly, said front end bearing assembly
provided with a pull handle to accommodate auger removal.
Description
BACKGROUND OF THE DISCLOSURE
[0001] 1. Field of the Invention
[0002] The present invention is directed to a cryogenic freeze
chamber assembly. More specifically, the present invention is
directed to a cryogenic freezing chamber assembly which more
efficiently chills polymeric particles so that those particles can
be effectively comminuted.
[0003] 2. Background of the Prior Art
[0004] Cryogenic freeze chamber assemblies are extensively utilized
in the processing of solid materials which have high impact
resistance. That is, solids which resist fracture during
comminution processes represent a major obstacle to reprocessing of
solid materials. The reprocessing of solid materials is an ever
more important commercial and environment undertaking. A prime
example of such materials is vehicle tires. Tires, principally
formed of rubber, are excellent examples of impact resistant solids
whose comminution is difficult unless its temperature is reduced
below the glass transition point. The removal of used tires is very
important to good environmental practice and the comminution
product, crumb and powder rubbers, represent valuable commercial
products.
[0005] Although the utilization of cryogenic freeze chamber
assemblies has become more common with the advent of solid
comminution processing, present cryogenic freezing chamber
assemblies have certain inefficiencies that call for improved
design.
[0006] A major concern in the design of cryogenic freeze chamber
assemblies is to effectively cool impact resistant particles with
minimum use of cryogenic fluid. Indeed, the cost of the cryogenic
fluid is probably the major variable cost in the process of
comminuting solids. Thus, a design which results in significant
reduction in the utilization of cryogenic fluid represents a major
aim of artisans working in this art.
[0007] Another problem associated with cryogenic freeze chamber
assemblies known in the art is meeting the requirement of providing
adequate structural strength to withstand stress imposed on chamber
assemblies due to the effect of thermal expansion and contraction.
Obviously, the utilization of very cold temperatures makes this
design aspect of prime importance in the successful and continuous
operation of such an assembly.
[0008] Yet another problem associated with prior art chamber
assemblies is the difficulty of identifying blockages in the
continuous processing of solid materials. Oftentimes, plugging
occurs during that processing. Quick removal of such blockages by
rapid identification and elimination of the blockage is essential
to successful operation of cryogenic freeze chamber assembles.
[0009] Still an additional problem associated with operation of a
cryogenic freeze chamber assembly, common to the operation of major
processing assembles, is easy assembly and disassembly to permit
maintenance and repair. Thus, easier removal and reassembly of
internal components of the subassemblies that constitute a
cryogenic freeze chamber assembly is another concern in this
art.
[0010] Cryogenic freeze chamber assembles designs of the prior art
are used in association with redundant apparatus to remove foreign
particles present in the feedstock stream. This is due not only to
the difficulty of removing foreign particles from such assemblies
but, also, to be able to remove such foreign particles from the
chamber assembly once they are removed from the feedstock
stream.
[0011] These and other structural advantages are highly desired in
the art.
BRIEF SUMMARY OF THE INVENTION
[0012] A new cryogenic freeze chamber assembly has now been
developed which solves many structural and design problems
associated with cryogenic freeze chamber assemblies of the prior
art.
[0013] The newly developed cryogenic freeze chamber assembly
addresses the issue of structural integrity effectuated by thermal
expansion and contraction. The chamber assembly is fixed at its
center to allow movement toward each end rather than the prior art
design of concentrating total expansion and contraction at one end.
This fixing of the chamber assembly at its center allows for
movement toward each end thus minimizing the interfacial stress
between stationery interconnecting flexible joints and the chamber
assembly.
[0014] Another aspect of the cryogenic freeze chamber assembly of
the present invention is improved utilization of cryogenic fluid.
Cryogenic fluid is introduced into the freeze chamber assembly in
two distinct patterns. The first is a continuous or pulsating spray
directed upon the feedstock stream transmitted through the chamber
assembly. This spray is controlled as a function of the chamber
assembly operating temperature. The second spray is positioned and
directed at the multiple and distinct rivulets of falling feedstock
particles elevated by rotating agitators. As such, the second of
the two cryogenic fluid introductions is limited to specific
intervals of time when such introduction effectuates total contact
with the total particle surface, maximizing the cooling effect of
the cryogenic fluid.
[0015] Yet another major problem associated with cryogenic freeze
chamber assemblies, overcome by the chamber assembly of the present
invention, is the quick resolution of process downtime caused by
blockages in the chamber. In order to remove or otherwise address
blockages of solid particles moving through the freeze chamber
assembly it is critical that the chamber be capable of inspection
without interruption caused by disassembly of the Ofm.fal
[0016] Ofm.fal
[0017] ports which permits viewing of the immediate area about the
portion of the chamber within view of the port. Since these
view-ports are strategically placed throughout the length of the
chamber assembly, the total chamber assembly can be viewed during
operation. To insure effectiveness, means to prevent fogging,
caused by the cryogenic temperature, the view-ports are provided
with heating means in communication with the glass viewing area of
the view-port. This heating is automatically effectuated when the
view-port cover is opened for viewing.
[0018] Still another issue associated with prior art cryogenic
freeze chamber assemblies, addressed by the improved design of the
chamber assembly of the present invention, is ease of assembly and
disassembly of components of the overall chamber assembly. The
chamber assembly of this invention is designed to permit vertical
removal of interior components which simplifies repair and
maintenance by vertical replacement of components compared to the
horizontal removal of interior components required by freeze
chamber assemblies of the prior art.
[0019] Yet another advance associated with the present chamber
assembly is a self-contained means for removal of foreign materials
present in the feedstock. In this advance means are provided for
removal of foreign materials from the feedstock at the chamber
assembly inlet prior to freezing. This advance is especially
important when the feedstocks are obtained from processed tires or
other material which contains fugitive ferrous metal. The removal
of ferrous metal is important to the reliability and efficiency of
not only the freeze chamber assembly but also for the protection of
downstream equipment. This is accomplished by the inclusion of
magnetic means at the feedstock inlet to attract and remove ferrous
metal particles from the feedstock entering the chamber.
[0020] In accordance with the present invention cryogenic freezing
chamber assembly is provided. The assembly includes an elongated
chamber, an inlet means for introducing feedstock therein, an inlet
means for introducing a cryogenic fluid into the chamber and fixed
mounting means disposed midway between the ends of the elongated
chamber assembly.
[0021] In accordance with the another embodiment of the present
invention the chamber assembly includes an elongated chamber, a
cryogenic fluid inlet means, a feedstock inlet means, an outlet
means for removing feedstock from the chamber and a plurality of
view-ports disposed on the chamber surface wherein the view-ports
are provided with heating means to maximize clear viewing.
[0022] In yet accordance with another embodiment of the present
invention a cryogenic freeze chamber assembly is provided which
includes an elongated chamber, a rotating auger disposed in the
chamber, an inlet means for introducing feedstock onto the auger,
disposed in the chamber, wherein the auger contains, transports and
agitates the feedstock particles, cryogenic fluid introductory
means responsive to means provided on the rotating auger for
introducing cryogenic fluid into the chamber and feedstock outlet
means for removal of the feedstock from the chamber.
[0023] In still further accordance with the present invention a
cryogenic freeze chamber assembly is drawn to an elongated chamber,
a feedstock inlet means for introducing feedstock into the chamber,
a cryogenic fluid inlet means for introducing cryogenic fluid into
the chamber, a feedstock outlet means for removing feedstock below
its glass transition temperature from the chamber and a rotating
auger, supported by and rotating about end bearing assemblies for
transmitting the feedstock from the feedstock inlet means to the
feedstock outlet means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The instant invention may be better understood by reference
to the accompanying drawings of which:
[0025] FIG. 1 is a front sectional view of a cryogenic freeze
chamber assembly in accordance with the present invention;
[0026] FIG. 2 represents three views of a magnetic bar screen
assembly of the cryogenic freeze chamber assembly. FIGS. 2a, 2b and
2c provide plan, front elevation and side elevation cross-sectional
views, respectively, of the magnetic bar screen assembly;
[0027] FIG. 3 provides three views of a removable bar screen of the
magnetic bar screen assembly. FIG. 3a is a plan view, FIG. 3b is a
front elevation view and FIG. 3c is a side elevation view of the
removable bar screen;
[0028] FIG. 4 is a front sectional view of a rotary feed valve
assembly of the cryogenic freeze chamber assembly;
[0029] FIG. 5 is a sectional view of a drive end bearing assembly
of the cryogenic freeze chamber assembly;
[0030] FIG. 6 are two views of a front end bearing assembly of the
cryogenic freeze chamber assembly. FIG. 6a is a front view and FIG.
6b is a front sectional view of that assembly;
[0031] FIG. 7 is a front sectional view of a cryogenic spray head
assembly of the cryogenic freeze chamber assembly;
[0032] FIG. 8 is a front sectional view of a view-port assembly of
the cryogenic freeze chamber assembly;
[0033] FIG. 9 are two views of the auger agitator assembly. FIG. 9a
illustrates a typical serrated agitator positioned between auger
blades and FIG. 9b depicts the serrated agitator tripping magnet in
proximity of a sensor;
[0034] FIG. 10 is a sectional view illustrating triggering of
cryogenic fluid from the cryogenic spray assembly;
[0035] FIG. 11 is a sectional view illustrating a continuous
cryogenic fluid spray from the cryogenic spray assembly;
[0036] FIG. 12 is a front view, partially in section, illustrating
the positioning of expansion mount locations; and
[0037] FIG. 13 provides two views of a cryogenic freeze chamber
assembly support.
[0038] FIG. 13a is a sectional view and FIG. 13b is an exploded
view of a portion of that assembly illustrating expansion joint
details.
DETAILED DESCRIPTION
[0039] A cryogenic freeze chamber assembly 100 incorporates major
sub-assemblies which represent embodiments of the present
invention. These embodiments will be better understood by the
description of their operation.
[0040] Feedstock 6 is introduced into the chamber assembly 100 from
a feedstock storage silo 62 through an inlet means. The feedstock 6
may be any solid that is insufficiently brittle so that its
temperature must be reduced to below its glass transition point in
order to insure proper comminutability. Examples of feedstocks
within the contemplation of the present invention includes rubbers,
plants, soft polymers and the like. Of the feedstocks within the
contemplation of the present invention, rubber, such as that
provide by chopped vehicle tires, sterols and other plant material
are particularly preferred.
[0041] The feedstock inlet means of chamber assembly 100 is
provided with a slide gate 200 which is utilized when necessary to
change feedstocks, make mechanical adjustments or to clear the
chamber. Specifically, slide gate 200 is opened when feedstock 6
flow into chamber assembly 100 is desired and closed to stop
feedstock 6 flow therein.
[0042] In view of the importance of chopped vehicle tires as a
potential feedstock, a magnetic bar screen assembly 300 is provided
to capture any tramp ferrous metal traveling with feedstock 6 when
that feedstock is chopped tires or other feedstock containing
fugitive ferrous metal.
[0043] A magnetic bar screen assembly 300 is provided with two
stationery view-ports 4 which permit internal visual inspection of
the presence, if any, of captured ferrous metal. Metal removal is
accomplished by closing the slide gate 200, pulling out drawer 3,
by means of draw pull handle 2, and manually removing the captured
metal contaminates from at least one bar magnet 5 of assembly 300.
After removal of the metal contaminates, the drawer 3 is
repositioned by holding the drawer 3, by means of handle 2, and
repositioning the bar magnet assembly 300 into its position in
chamber assembly 100.
[0044] Once past the magnetic bar screen assembly 300, the
feedstock 6 is introduced, in a controlled manner, into the
cryogenic freeze chamber assembly 100 through a variable frequency
driven (VFD) rotary valve 400. The feedstock 6 rate of introduction
into chamber assembly 100 is a function of feedstock
characteristics and downstream process requirements. These
characteristics may be considered in the control of the VFD valve
400. VFD valve 400 controls the mass rate of feedstock into the
assembly 100 by its rotary speed. It also acts as an air lock to
prevent air from leaking into chamber assembly 100. The feedstock
exiting VFD valve 400 flows through a flexible bellows 19 into the
inner portion of the chamber 100.
[0045] It should be appreciated that bellows 19, as well as other
bellows, discussed below, are preferably stainless steel. However,
other flexible materials, such as those compatible with low
temperature operation, may be used. Bellows are utilized in order
to eliminate interfacial stress caused by chamber contraction and
expansion due to changes in the temperature of the chamber assembly
100 due to the presence or absence of cryogenic fluid. On average,
chamber assembly 100 contracts approximately 1 inch upon contact
with cryogenic temperature. To minimize this size reduction,
chamber assembly 100 is fixed at its center to reduce contraction
length at each end to approximately 1/2 inch. This arrangement
permits metered feedstock 6 to discharge through flexible bellows
19 directly into the freezing chamber assembly 100.
[0046] Conveyor means are provided in the interior portion of
chamber assembly 100. The conveyor means may be in the form of an
endless belt, a rotating auger or the like. In a preferred
embodiment illustrated in the drawings, conveyor means is provided
by a rotating auger 7. The rotating auger 7 is supported by and
rotates about two end bearing assemblies. The first of these, the
drive end bearing assembly 500, is mounted on the drive end
assembly insert 11. The insert 11 also serves as the drive end cap
of chamber assembly 100.
[0047] The drive end bearing assembly 500 also includes dual
bearings 61, two insulator end caps 10 and a pressure plate 9. The
end caps 10 are designed to accommodate "O" ring shaft seals 15 and
"O" ring chamber seal 59. A VFD rotor (not shown) is coupled to a
rotor drive shaft 14 and keyed with motor drive shear pin 13. The
motor drive shaft 14 is tapered to assist in the installation
alignment of a slotted male coupling 65 which is affixed to auger
drive shaft 7. A tapered tip of motor drive shaft 14 is equipped
with a drive key 18 which, when engaged with slotted male coupling
65, drives auger driver shaft 7. The male coupling slot
accommodates expansion and contraction of the auger drive shaft 7.
This arrangement allows for coupling in tight areas without the
needs for bolts. A stationery feedstock barrier 8 prohibits
feedstock 6 from infiltrating the coupling area 60.
[0048] The other end of the auger shaft 7 terminates in a front end
bearing assembly 600. Specifically, shaft 7 is attached to a front
end auger shaft connector 30 and a front end bearing shaft 28
supported by front end bearing 27 as part of a front end bearing
block 26. The front end bearing assembly 600 includes a front end
assembly insert 25 provided with two insulated "O" ring support
seals 32 which are bolted together with insulator support assembly
bolts 34. The entire insert 25 is connected to an insulated auger
trough 24 by means of a multiplicity of front end assembly insert
bolts 33. The front end bearing assembly 600 includes a front end
rotating bearing shaft 28 which is sealed by means of "O" ring
seals 29. The insulated chamber constituting the front end bearing
assembly 600 is itself sealed by means of an "O" ring 59. The
assembly 600 further includes a pull handle 31 to assist in the
assembly or disassembly of the auger shaft 7 within the insulated
trough 24. Front end leaving shaft 28 is extended a distance "G,"
as shown in FIG. 6, to compensate for contraction changes.
[0049] The purpose of chamber assembly 100, to reduce temperature
of the feedstock 6 to below the glass transition point, is
accomplished by spraying the feedstock 6 with a cryogenic fluid.
The cryogenic fluid, usually a cryogenic liquid, is chemically
inert whose vaporization temperature is cryogenic at atmospheric
pressure. Examples of cryogens within the contemplation of the
present invention include argon, carbon dioxide, nitrogen and other
inert gases. Of these, the most effective, in terms of cryogenic
temperature, inertness and low cost, is liquid nitrogen.
[0050] Contact between the feedstock 6 and the cryogen is
effectuated by means of a multiplicity of cryogen spray head
assemblies 700. Each cryogen spray head assembly 700, which is
preferably constructed of stainless steel or the like, includes a
cryogen feed pipe 36 welded to a tapered plug 37, which fits into a
matching tapered threaded plug receiver 39. The tapered plug
receiver 39 is welded to a support pipe 40 which, in turn, is
welded to the top of the cryogenic freezing chamber assembly 100.
The top of the assembly 100 constitutes a plurality of flat trough
covers 23. FIG. 7 illustrates covers 23c which are provided in
assemblies 700. A screw cap 38 is utilized to hold the tapered plug
37 in position so that each spray nozzle can be accessed, inspected
and oriented. Two alignments identifiers 64 are positioned on the
centerline of a cryogen freeze pipe 36. Identifier 64 aids in
properly directing the cryogen spray from nozzles 41 and 42, one
located above tapered plug 37 and the other above a jam nut 63. Jam
nut 63 serves to lock the nozzles' position. The spray nozzle type
utilized in each spray head assembly 700 depends on the function of
the cryogenic spray. A directional nozzle 41 is illustrated in FIG.
7. However, a 45.degree. nozzle may be utilized depending upon its
location. The discharge pressure and velocity of the cryogenic
fluid emitting from nozzle 41 can be varied depending upon the type
and mass flow rate of feedstock 6.
[0051] It is common to encounter feedstock blockages during
operation. Even in the absence of blockages and other operational
problems, verification of feedstock movement and conditioning is
vital in controlling operating parameters in chamber assembly 100.
Thus, strategically located heated view-port assemblies 800 are
included in chamber assembly 100. These view-port assemblies 800
are welded to the trough covers 23, specifically covers 23a and
23b. As such, they provide visual access, from the top of the
assembly 100, to activities occurring in the interior of
trough-shaped chamber 24. Each view-port assembly 800 includes a
mounting frame 46, holding double-layered heated glass 44 cushioned
between a gasket 45, which, in a preferred embodiment, is silicone
rubber. Each view-port assembly 800 is protected by an insulated
latch cover 43. When the latch cover 43 is opened for viewing, heat
is supplied to insure the absence of clouding or frosting. This is
accomplished by including a heating element (not shown) in the
double glass 44 component of the view-ports assemblies 800. The
heating element is activated by a switch turned on by the opening
of latch cover 43. The heating element is switched off by the
closing of latch cover 43. It is emphasized that the disposition of
the view-port assemblies 800 in the figures is illustrative and
actual disposition of those view-port assemblies are function of
the design and operation of chamber 100.
[0052] As stated above, a preferred conveyor means for transporting
feedstock 6 through the insulated trough 24 of chamber assembly 100
is a rotating auger. More specifically, an auger agitator assembly
900, preferably employed as the conveyor means in chamber assembly
100, includes an auger drive shaft 7 to which auger blades 47 are
attached. The auger blades 47 are uniquely connected, preferably by
welding, to serrated agitators 48. The serrated agitators 48,
attached to auger blades 47, follow an orbital path as they first
intersect and pass through feedstock 6 at the bottom of the trough
24 portion of the chamber assembly 100. Continued auger drive shaft
7 rotation elevates feedstock 6 from its safe angle of repose to a
level where it begins to slide off serrated agitator 48. Because
the feedstock 6 is discharged from a gear tooth-shaped edge, it
flows in rivulets and feedstock 6 is thus easily and effectively
sprayed with the cryogenic fluid as it falls free from serrated
agitator 48. Spray is directed from the cryogenic spray head
assembly 700, from nozzles 41 or 42. Specifically, directional
nozzles 41 are employed in spraying feedstock 6 as it moves
horizontally along the bottom of the trough 24 as illustrated in
FIG. 11. The 45.degree. nozzles 42 are utilized in spraying
feedstock 6 as it falls in rivulets from serrated edges 48, as
illustrated in FIG. 10.
[0053] It is emphasized that cryogenic spray is activated only when
serrated agitator 48 embedded magnetic 49 triggers a stationery
magnetic switch 50 mounted on the side of insulated auger trough
24. Timing between switch activation and cryogenic fluid spray
initiation can be varied or turned off entirely depending upon
feedstock requirements. It is emphasized that transported feedstock
6 is also subjected to cryogenic fluid contact from spray-head
assemblies 700, by means of directional nozzles 41, as it traverses
along the bottom of the insulated trough-shaped chamber 24. The
directional nozzles 41 also serve to maintain set operational
temperature.
[0054] To better explain the expansion features of chamber 100 it
is again emphasized that a typical cryogenic freezing chamber
assembly 100 will contract about 1 inch when exposed to cryogenic
temperature, which approximates -346.degree. F. To compensate for
this contraction, and thus reduce undue stress on connecting
equipment, flexible bellows are used at the inlets and outlets of
feedstock flow. To further mitigate temperature-induced stress,
chamber assembly 100 includes a fixed mounting at its center so
that maximum thermal contraction is approximately 1/2 inch at each
end. Because of differential temperatures, insulated auger trough
64 and auger drive shaft 7 expansions and contractions are not
equal and must be compensated. Thus, the front end of auger drive
shaft 7 is free to float with thermal expansions within the front
end bearing assembly 600. This is illustrated by gap G. That is,
rotating shaft 28 can move, due to thermal expansion, by a length
G, as illustrated in FIG. 6b.
[0055] Externally, the insulated auger trough 24 is supported on
multiple mounts. As illustrated in FIG. 12, all but one of those
mounts is provided by expansion mount assembly 1000. Each assembly
1000, as illustrated in FIG. 13a, includes a pair of support
brackets 51 and a brace bracket strap 57 to connect the support
brackets 51 for additional stability. The support brackets 51 are
fastened to the auger trough 24 portion of the chamber assembly
100, preferably by welding, providing expansion and contraction
mobility.
[0056] Expansion and contraction capability of the chamber assembly
100 is provided by the chamber support assembly 1000 and expansion
joint arrangement 1000a. Expansion joint subassembly 1000a is
depicted in FIGS. 13a and 13b. Each support bracket 51, connected
to the auger trough 24 portion of chamber assembly 100, is free to
move horizontally depending on the expansion and contraction of the
assembly 100. Each support bracket 51, is welded to a pressure
plate 53, which is bolted to an upper slip plate 54. A lower slip
plate 55 is bolted to cross-mounting plate 56 which is bolted to a
platform structural steel support. Vertical and lateral movement of
the chamber assembly 100 is limited by a pair of "Z" brackets 52
affixed to cross-mounting plate 56. Horizontal movement of brackets
51 attached to trough 24, however, are permitted free movement
between upper and lower slip plates 54 and 55. A fixed mounting
support 58 is welded to a pressure plate 53 which is bolted to
cross-mounting plate 56, as shown in FIG. 13c. The cross mounting
plate 56, affixed to platform structural steel support, restrains
the center of chamber assembly 100 allowing expansion and
contraction to occur at either end.
[0057] The solid particles, entering the chamber assembly 100
through rotary valve feeder assembly 400, are removed as feedstock
product 22, below its glass transition temperature, through product
discharge 21. Discharge device 21 is again preferably provided by
flexible bellows.
[0058] The above description and embodiments are given to
illustrate the scope and spirit of the present invention. These
embodiments will make apparent, to those skilled in the art, other
embodiments and examples. These other embodiments and examples are
within the contemplation of the present invention. Therefore, the
present invention should be limited only by the appended
claims.
* * * * *