Vertical plate freezer apparatus

Plate freezer apparatus has a plurality of vertically disposed refrigerated plates separated from each other by spacer frames to define a plurality of open topped compartments to receive product to be frozen. The assembly of plates and spacer frames are held together by spring tensioned rods which apply a compressive force to the assembly. Each plate has a number of wedge surfaces and a plate separating device engages the wedge surfaces of an adjacent pair of plates to thereby separate those plates to enable the spacer frame and frozen material therebetween to be withdrawn. The frozen material is removed from the spacer frame which is then re-inserted between the separated plates and the separating device removed before the compartment is refilled with product to be frozen.

BACKGROUND OF THE INVENTION 
This invention relates to apparatus for freezing foodstuffs and relates 
particularly to apparatus for continuous freezing of foodstuffs and 
removal of the frozen material from the freezing apparatus. 
Plate freezers are well known and have hitherto been made in a great 
variety of designs and sizes. Such plate freezers comprise a plurality of 
refrigerated plates between which material, such as foodstuffs, is frozen. 
One form of plate freezer apparatus is that described in my Australian 
Pat. No. 530,424 filed Nov. 29, 1976. 
In plate freezer apparatus, it is desirable that the material to be frozen 
can be quickly loaded into the space between adjacent refrigerated plates 
and that frozen material can be relatively quickly and simply removed from 
the apparatus. 
It is also desirable that the filling and unloading of the apparatus be as 
automatic as possible. 
BACKGROUND ART 
Various forms of plate freezers have been proposed to improve the 
efficiency of operation of the plate freezing apparatus and to improve the 
throughput of product to be frozen. 
In U.S. Pat. No. 4,083,199 there is disclosed plate freezer apparatus 
comprising a plurality of vertical refrigerated plates spaced apart to 
define freezing spaces therebetween which accommodates product to be 
frozen. The plates are all movable together so as to increase the spacing 
therebetween to enable frozen product to be removed. An emptying device 
comprises a plurality of combs with teeth which extend into the freezing 
space and are locked into the product when frozen. When the plates are 
separated the combs are lifted as a unit to lift the frozen material from 
the spaces. 
This apparatus operates as a batch freezing system with all product frozen 
at one time and all frozen product being removed together prior to the 
freezing spaces being subsequently filled with further product to be 
frozen. 
U.S. Pat. No. 4,178,773 discloses another form of plate freezer in which a 
number of horizontally disposed freezer plates receive product to be 
frozen in pre-formed containers. With this form of apparatus the 
individual containers are covered by a spacer frame to facilitate movement 
of the product onto and off the respective refrigerated plates. 
This apparatus is designed specifically for use with special product 
containers thus necessitating particular forms of spacer frames which 
surround the containers. 
It is an object of the invention to provide improved plate freezer 
apparatus which can operate to continuously freeze product and wherein 
selected frozen product is simply removed from the apparatus. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided plate freezer 
apparatus comprising an assembly of a plurality of substantially parallel 
freezer plates spaced apart from each other by interposed spacer means, 
the freezer plates and spacer means defining a plurality of cells adapted 
to receive material to be frozen, each freezer plate being adapted to be 
supplied with refrigerant or coolant fluid, compression means to maintain 
said plates and spacer means of said assembly in engagement whilst 
enabling separation of at least one adjacent pair of plates to facilitate 
removal of the spacer means from therebetween, separation means to 
selectively separate the plates of at least one adjacent pair of plates, 
withdrawal means adapted to engage the spacer means between the separated 
plates and to withdraw said spacer means together with frozen material 
from between the separated plates and means for removing said frozen 
material from engagement with said spacer means. 
Preferably, said spacer means comprises a frame located between each 
adjacent pair of plates whereby separation of the plates enables removal 
of said spacer frame together with frozen material. 
In one form of the invention, the plate freezer apparatus comprises a 
single tier of a plurality of substantially vertically disposed freezer 
plates substantially equally spaced from each other and defining a 
freezing space between each adjacent pair of plates. A spacer frame is 
located in each freezing space and cooperates with the adjacent freezing 
plates to define one or more open top freezing spaces with the peripheral 
sides and bottom of the said freezing space being delimited by the spacer 
frame. 
The plurality of freezer plates and spacer frames are held together in 
compressive abutment by compression means. The compression means may 
comprise tension members or tie rods extending substantially at right 
angles to the plane of the freezer plates. One end of each tension member 
engages with spring means which act on an end freezer plate while the 
other end of said tension members acts on the other end freezer plate, 
preferably through another spring, whereby the spring pressure holds the 
freezer plates in compressive abutment with the spacer frames. If desired, 
additional hydraulic means may be provided whereby the compressive force 
may be maximized by use of said hydraulic means but which also permits 
separation of the freezer plates while said hydraulic means is inactive or 
operating at reduced pressure and the compressive force is applied by said 
spring means. 
It is also preferred that wedge means are provided on each freezer plate, 
said wedge means being adapted to cooperate with wedge spacers movable 
between wedge means of adjacent plates whereby said adjacent plates are 
separated. It will be understood that separation of the plates is intended 
to mean that the spacer frame located between the separated plates is no 
longer compressively engaged by the adjacent plates and consequently may 
be removed from therebetween. 
The invention also comprises removal apparatus for use in association with 
plate freezer apparatus as above described to remove frozen material from 
adjacent pairs of freezer plates. The removal apparatus comprises means 
for separating two adjacent freezer plates whilst maintaining the 
remaining freezer plates in compressive abutment, means for engaging the 
spacer frame between the separated plates, means for moving in a 
horizontal direction the spacer frame and frozen material from between the 
separated plates, means for separating the frozen material from the said 
spacer frame and means for relocating said spacer frame between the 
separated plates whereafter the plate separation means is removed and the 
plates are subjected to the compressive abutment force. 
In order that a selected spacer frame may be removed from between its 
associated pair of plates, the assembly of freezer plates is movable 
relative to the removal apparatus. Appropriate indexing means is provided 
to enable a selected spacer frame to be positioned adjacent the removal 
apparatus. Alternatively, the assembly of freezer plates may be fixed and 
the removal apparatus is movable relative thereto. In this arrangement, 
the removal apparatus is provided with appropriate indexing means. 
Preferably, a filling station for loading material to be frozen into an 
empty freezing space is located adjacent the plate separation means 
whereby, after said separation subsequent removal of the frozen material 
from between a pair of plates and relocation of the spacer means, an 
indexing movement locates the empty freezing space at said filling station 
so that said freezing space may be refilled with material to be frozen. 
In one form of the invention, the filling station is located above said 
plates and the freezing space is filled through the open top. 
In order that the invention will be more readily understood embodiments 
thereof will now be described with reference to the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring firstly to FIGS. 1A and 1B and 2A and 2B there is shown an 
assembly of freezer plates 2 having open topped freezer plate spacing 
frames 1 located therebetween. Freezer plates 2 are vertically extending 
hollow substantially rectangular plates which are arranged to be 
refrigerated by the passage of refrigerant or coolant therethrough. The 
assembly of plates 2 is carried on tie bars 4 extending through each of 
the corners of the plates 2. A compression spring 5 engaged on each end of 
each tie bar 4 acts to apply compressive forces to the plates 2 thereby 
compressively engaging the freezing frames 1 between adjacent plates 2. 
As is best seen in FIG. 3, the whole assembly is supported on a carriage 6 
provided with wheels 6A adapted to run on structural frame 7. Thus 
carriage 6 is arranged to be positioned by moving from left to right as 
seen in FIG. 3. The movement of carriage 6 is achieved by means of chains 
8 shown in ghosted lines in FIG. 3. The chains 8 are driven by a reduction 
gear box and motor 9 (details not shown) the position of which is 
indicated in FIG. 1B and 3. 
Referring again to FIG. 3, the motion of carriage 6 is intermittently 
controlled to provide a dwell period for each freezing frame 1 beneath a 
filling station 10. In the arrangement shown sequential filling of the 
space defined by the spacer frames 1 and adjacent freezing plates 2 is 
achieved by moving carriage 6 as previously described. Located immediately 
adjacent the filling station 10 is frame withdrawal means 10A. This 
location enables filling station 10 to fill one freezing space whilst the 
immediately adjacent freezing space to the left as seen in FIG. 3, is 
emptied so that advancing of carriage 6 i.e. indexing of carriage 6 from 
the left to the right after withdrawal of frozen material enables the 
space just emptied to be filled. In this manner carriage 6 moves 
intermittently from left to right until all freezing spaces are filled 
whereafter the carriage 6 may then be moved all the way back to the left 
recommence the emptying/filling cycle from left to right as above 
described. 
The cycle time is arranged so that suitable freezing of the material 
between adjacent plates 2 is achieved. It may be desirable for enabling 
rapid withdrawal of frames 1 to defrost or warm the all, or selected pairs 
of plates 2, for example, by circulating warm fluid therethrough, so 
eliminating or minimising any ice seal or the like which may develop 
between the spacer frames 1, slabs of frozen material and the plates 2. 
To enable the frozen material to be withdrawn from between the plates 2 at 
the withdrawal means 10A, a plate separating means is provided. As is best 
seen in FIGS. 1B and 2B, the plate separating means includes a plurality 
of wedge surfaces 11 on the top and bottom of each plate 2. The location 
of the wedge surfaces 11 is shown in FIGS. 1B and 2B, however, the 
operation thereof is shown in greater detail in FIGS. 6 and 7. 
A pair of hydraulic cylinders 12 are mounted on the structural frame 7, at 
the position of the withdrawal means 10A, above and below the freezer 
plates 2. Each cylinder 12 is double ended and a piston rod 13 extends 
from each end of each cylinder 12. The piston rods each carry a pair of 
wedge spacers 14 which include a pair of rollers 14A adapted to engage 
with the wedge surfaces 11 of opposed plates 2 located at the withdrawal 
station 10A. As can be appreciated by reference to FIG. 6 insertion of 
wedge spacers 14 in the direction of arrow A between adjacent wedge 
surfaces 11 effects separation of adjacent plates 2, whereas withdrawal of 
the wedge spacers 14 as indicated by arrow B in FIG. 7 allows the 
compressive force of springs 5 to re-engage plates 2 with the frame 1 
located therebetween. 
Whereas each of plates 2 is provided with wedge surfaces 11, the hydraulic 
cylinders 12 and piston rods 13 are only located in alignment with the 
withdrawal means 10A. As seen in FIG. 2B the upper and lower edges of the 
plates 2 are provided with slots 13A so as to enable free movement of 
plates 2 past the cylinders 12 and wedge spacers 14 during indexing of 
carriage 6. 
In operation, a dwell period is provided during the indexing of carriage 6 
during which frozen slabs are removed by withdrawal means 10A. During this 
dwell period cylinders 12 are activated so retracting rods 13 and drawing 
the rollers 14A into engagement with wedge surfaces 11 thereby forcing 
apart the two plates 2 located at withdrawal means 10A. Withdrawal of 
frame 1 is then effected, frozen slabs are removed therefrom, frame 1 is 
reinserted between plates 2, cylinder 12 is deactivated so releasing rods 
13 and the wedge spacers 14 and enabling springs 5 to reclamp frame 1 
between plates 2, whereafter indexing of carriage 6 may recommence. 
Withdrawal means 10A is supported by an extension 7A of structural frame 7, 
which extension 7A extends to the left of carriage 6 as seen in FIG. 2B. 
The means by which frames 1 are horizontally guided during withdrawal will 
now be described. 
FIG. 5 should be referred to in conjunction with FIGS. 2A and 2B. FIG. 5 is 
taken along section line D-D of FIG. 2B but additionally shows the 
configuration of plates 2 adjacent the frame 1. Along the bottom edges of 
plates 2 there are provided rails 3 upon which frame 1 rests after 
separation of the plates 2. Additionally frame 1 is provided with a side 
rail 3B which is received in a groove 3A in one of the adjacent plates 2, 
namely the left hand plate 2 as seen in FIG. 5. Rails 3 thus horizontally 
support frame 1 when plates 2 are parted by wedge spacers 14. 
Referring now to FIGS. 2A and 2B, it should be appreciated that frame 1 
consists of a bottom horizontal member 1A, a plurality of vertically 
extending tines 1B and frame side rail 3B. The cells so formed between the 
tines 1B are open-topped so enabling ingress of material to be frozen from 
filling station 10. At the left hand end of frame 1 the end tine 1C is 
provided with extension arms 1D having notches 1E. 
Withdrawal means 10A is provided with guides 18 at the top and bottom 
thereof and is further provided with two endless chains 15, one at the top 
and the other at the bottom of extension frame 7A. Each chain 15 is 
provided with a lug 16 which is adapted to be engaged with notch 1E after 
the frame 1 is indexed into position. A hydraulic motor 17 (indicated by 
ghosted lines in FIG. 2A) is arranged to intermittently drive chains 15 
whereby the lugs 16 withdraw frame 1 (in the direction of arrow C in FIG. 
2B) from between plates 2 which have been previously separated. Thus frame 
1 slides on the rails 3 from between plates 2 to a position between guides 
18 which guides 18 act to hold frame 1 in an upright (vertical) position. 
Frame 1 is withdrawn to a position where the first of the cells aligns 
with an ejection mechanism 19, where it dwells. 
As seen in FIGS. 1A and 1B and 2A and 2B, ejection mechanism 19 is located 
adjacent carriage 6 in line with withdrawal means 10A. A detailed view of 
ejection mechanism 19 is provided in FIG. 4. A pushing head 19A is 
supported by guide rods 20 and propelled by a hydraulic cylinder 21. In 
use, the pushing head 19A pushes a frozen slab from the cell of frame 1 
into a fenced tined receiver 22. Pushing head 19A is then retracted. 
Receiver 22 is pivoted at its lower portion 22A about which it is rotated 
by means of a hydraulic cylinder 23 connected to receiver 22 by rod 23A. 
Receiver 22 is rotated through an angle of greater than 90.degree., 
preferably about 95.degree. so lowering the frozen slab onto driven 
rollers 26. The slab is retained at the open end of the tines of receiver 
22 by a curved guard 24. Rollers 26 are positioned so that the tines or 
receiver 22 pass therebetween to a position (shown in ghosted lines in 
FIG. 4) below rollers 26 so depositing the frozen slab on to driven 
rollers 26 which then propels the slab away in the direction of arrow D in 
FIG. 1A. Receiver 22 is then raised back to the vertical position. 
The frame 1 is then withdrawn until the next adjacent cell aligns with 
ejector mechanism 19, where it dwells until the ejection cycle is 
completed. In like manner frozen material is ejected from each of the 
cells of frame 1 in turn, whereafter hydraulic drive 17 is reversed so 
sliding frame 1 back into position between the separated plates 2. The 
wedge spacers 14 are retracted, springs 5 again clamp frame 1 between 
adjacent plates 2 and the carriage 6 is indexed to align the next frame 1 
with withdrawal means 10A. This motion also serves to locate the frame 1 
just emptied beneath the filling station 10. Thus ejection and fill cycles 
occur simultaneously during indexed advancement of the carriage 6 to the 
right as seen in FIG. 3. 
It will be appreciated that in an alternative embodiment, not illustrated, 
withdrawal means, and/or the filling station may be indexed to move 
relative to the plate assembly, which may be fixed in position. With this 
construction, the plate separation apparatus and the withdrawal means 10A 
is mounted for indexed movement on rails to be sequentially aligned with 
each of the spacer frames 1 in turn. The filling station 10 can also be 
moved with the withdrawal means 10A or can be moved separately to fill 
empty cells as desired. 
Referring to the drawings a freezer plate assembly 110 comprises a 
plurality of substantially vertically extending freezer plates 111 which 
are supported in a framework comprising cross members 113 and 115, end 
members 124 and 125 and lower track supports 123. 
The cross member 113 and end member 125 are movable relative to the track 
supports 123. Tension rods 126 extend between end members 124 and 125 and 
engage through slots 127 on each end of each freezer plate 111. The 
freezer plates 111 are therefore able to slide relative to the tension 
rods 126. The lower edge of each freezer plate 111 is supported on each 
side on a track 121 carried by the track support 123. The freezer plates 
also are able to slide relative to the track 121. 
At one end of the plate assembly 110 (left hand end as viewed in FIG. 9), 
springs 129 are provided to apply tension between the tension rods 126 and 
the fixed freezer plate end member 124. At the other end of the plate 
assembly 10, hydraulic rams 131 are interposed between the end of the 
tension rods 126 and the movable end member 124 to apply a tension to the 
rods 126 in addition to that provided by the springs 129, and the tension 
generated is transferred as a compressive force applied to the plate 
assembly 111. 
A spacer frame 135 is provided between each adjacent pair of plates 111 of 
the plate assembly 110. The spacer frames 135 are held in compressive 
abutment with the associated plates 111. Each spacer frame 135 comprises a 
lower support member 136 carrying a bottom member 137 having a plurality 
of vertically extending finger members 139. Thus, each spacer frame 135 
delimits a freezing space the thickness of which is the thickness of the 
spacer frame 135 and the periphery of which is defined by bottom member 
137 and side finger members 139 and which is open at the top thereof. This 
open topped freezing space configuration enables the freezing space 
between adjacent plates to be filled from above. The plurality of fingers 
139 divides each freezing space into a plurality of compartments or cells. 
Each freezer plate 111 is provided on opposite side surfaces thereof with 
three plate wedges 133. The wedges 133 have an increasing thickness in the 
vertical direction, although horizontally disposed wedge formations may 
also be utilized as shown in the previous embodiment. 
The freezer plate assembly and support structure 117 is movable along rails 
141 on wheels 143 carried by the track support 123. The rails 141 are 
carried on a frame comprising upper members 145, lateral beams 147 and 
columns 149. Movement of the assembly 117 along the rails 141 is achieved 
by means of a geared motor 155 driving a pair of shafts 153 to each end of 
which are secured sprockets 151. A pair of chains 157 engages with each 
sprocket 151 and around idler sprockets 159 at the opposite end of the 
support structure, the ends of each chain being connected to the track 
supports 123. 
An unloading station is located substantially centrally of the support 
frame and includes a pair of hydraulic cylinders 163, a drive beam 165 
extending across the top of the plate assembly 110 and wedge spacers 161 
carried by the drive beam 165. The wedge spacers 161, which are normally 
supported above the plate assembly 110, are movable downwardly by 
operation of the hydraulic ram 163 so that the spacers 161 drive between 
adjacent wedges 133 of a pair of adjacent plates 111. The wedge spacers 
161 are preferably fitted with rollers (not shown) to reduce friction 
between the wedges 133 and the wedge spacers 161. The downward movement of 
the wedge spacers 161 is preferably interlocked with the operation of the 
rams 131 whereby the pressure exerted by the rams 131 is released prior to 
movement of the wedge spacers 161. Thus, the tension in the tension rods 
126 comprises only the tension applied by the springs 129. At this reduced 
tension, the wedge spacers 161 engaging with the wedges 133 act to 
separate the adjacent plates 111. 
As the wedge spacers 161 have a fixed location along the length of rail 
supports 145 indexing of the assembly 117 along the rails 141 is required 
to ensure separation of a desired pair of plates 111. When the desired 
freezer plates 111 are separated by operation of the wedge spacers 161, 
the spacer frame 135 located between these plates is no longer 
compressively abutted and may then be removed from between the plates. The 
unloading station further includes hydraulic rams 169 connected to a 
lifting beam 167. 
Referring particularly to FIG. 10, there is shown a spacer frame 135 which 
has been removed from between a pair of plates 111 to enable slabs of 
frozen material removed therewith to be deposited onto a conveyor 193 
(FIG. 9). The lifting beam 167 has a bottom hinge member 170 secured 
thereto and a top hinge member 173 is pivoted to the bottom hinge member 
170 by means of pivot pin 171. The top hinge member 173 is provided with 
an interlocking device 175 which is adapted to engage and interlock with 
the spacer frame support member 136. The locking device 175 has a pair of 
wedges 177 which engage wedge shaped surfaces (not shown) in a recess in 
the frame support member 136. When the locking device 175 has interlocked 
the hinge member 173 to the frame support member 136, the rams 169 are 
reversed thereby lowering the frame 135 from between the separated plates 
111. 
Referring to FIG. 9, when rams 169 are fully extended, a further ram 179 is 
activated to push lever 181 in an upward direction thereby rotating the 
top hinge member 173 about the pin 171. The interlocked frame 135 is 
thereby moved in the direction of arrow A in FIG. 9, from a substantially 
vertical position to the position illustrated. A ram 183 is activated to 
rotate a plurality of lifting plates 185 which are fixed to a shaft 187 by 
means of suitable levers 189. The slabs of frozen material 191 are thereby 
lifted from the spacer frame 135 and are enabled to slide down plates 185, 
in the direction of arrow B, on to the conveyor 193. 
The spacer frame may thereafter be replaced into the assembly 110, after an 
optional wash and rinse, by reverse operation of the rams 183, 179 and 
169. With the spacer frame in position between the adjacent freezer plates 
111, the wedge spacers 161 are removed so that the freezer plates and 
spacer frame are subjected to the compressive abutting forces exerted by 
the springs 129. Reactuation of the hydraulic rams 131 increases the 
tension in the rods 126 thereby substantially sealing the freezing space. 
The plate and support assembly 117 is thereafter indexed one spacer frame 
spacing along the rails 141 thereby moving the just emptied spacer frame 
to a position beneath an adjacent filling station (not shown). In so 
doing, the spacer frame 135 is moved onto support members 195 (refer FIG. 
10) which are fixed to the track supports 145 by means of cross members 
197. Low friction wear strips 199 are fixed to the supports 195 to reduce 
the friction between the bottom of the spacer frames 135 and the supports 
195. 
The next spacer frame 135 carrying frozen material is then ready for 
removal from the assembly 110 in the manner above described. 
In the preferred forms of the invention, the time taken to complete one 
cycle of emptying and filling the freezing space between the pairs of 
adjacent plates is the time necessary for the material to be frozen. 
Therefore, the apparatus of the invention operates in a continuous manner 
for freezing the material and extracting the slabs of frozen material for 
subsequent packaging.