Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to a packaying system and me-thod of
packaging. Steam aseptic packaging systems and metho~s have been
used commercially for many years. The substitution of o-ther
heated gases ~including air) for steam is noted in literature
(e.g. U.S. Paten-t No. 2,5~9,216, issued on April 17, 1951 to
Martin and No. 2,631,768, issued on April 17, 1953 to Martln.
The use of hot air as con-trasted with steam offers a number of
impor-tant advantages.
One of the most important advantages is the saving in energy
required to vaporize wa-ter to create steam, with a consequent
saving in fuel expenses. It has been found that at somewhat
increased volumes -the letha]ity of hot air is comparable to that
of superheated steam. Within the sterilizing sections of the
system, the heated air is recirculated providing for increased
energy conservation and savings.
A second important advantage of the use of hot air is a lessening
of deterioration o~ ~arts which have heretofore been attacked by
the steam and also a lessening of the satura-tion of the insulation
of the casings occasioned by condensation of water in such insula-
tion, lessening its thermal efficiency.
Still another advantage of the present invention is the fact thatwhen steam is used in the headspace of a container, because of
condensation, there is a tendency to collapse the walls of the
container. Using hot air eliminates this tendency and therefore
permits the use of thinner walls of metal and glass containers and
also makes the use of Eiber and plastic containers practical,
along with other con-tainers constructed with less rigid material.
A further feature of the present invention is the reduction in the
required floor space of the packaging facility.
A still further feature of the invention is an additiona] reduction
in energy requirements by recirculation of air in the container and
lid sterilizing and other portions of the system.
Another feature of the invention is the cooling of the containers
to about 75-90F. prior to being filled and their being filled
with a pre-sterilized product which has been cooled. By
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sterilizing and then cooling containers and by steriliziny and
then cooling -the air which exist at greater -than a-tmospheric
pressure in -the fi]ler area, pre~s-terillzed and cooled product
may be filled into the containers at a much lower ternperature
is possible than where steam is employed, thereby avoiding the
deterioration at elevated temperatures which otherwise occurs.
Furthermore, containers made of product such as fiber are less
likely to be damaged under the conditions heretofore set forth.
This reduces degradation of the product.
An improved filler is hereinafter described in detail, -this filler
being a modification of one commercially used. Among -the features
of the filler are the fact that the slit through which product is
discharged is interchangeable, the width of the slit determining
the volume of product dispensed. Merely by substituting parts
having slits of different widths, this adaptability of a standard
filler to different rates of product flow is achieved.
Another feature of the filler hereinafter described is its adjust-
ability for different heights and widths of containers. The
filler tube in which the slit heretofore mentioned is installed
is supported in the filler chamber in such manner that it may
readily be raised and lowered to accommodate different container
heights. Additionally, the guides which maintain straight line
travel of the containers may be moved apart or together to
accommodate different container widths.
~ t7~ ~
Another feature of the filler is the fact that, if
desired, cooling water may be sprayed on the sides of the
containers prior to filling to reduce the temperature of
same. At least one of the guides heretofore men-tioned may
consist of a tube having spray holes through which sterile,
cooled water may be sprayed on the containers as they pass
therealong.
Still another feature of the invention is the use
of a valve installed between the pump or gravity feed of the
product and the filler to prevent overflow of product, which
might otherwise clog the filler and require the line to be
shut down until the overflow is cleaned and also to maintain
the product being forced into the filler at a uniform pressure.
Another feature of the invention is the use of pres-
surized air to prevent introduction of non-sterile air from
the atmosphere into the system after the container and lids
have been sterilized.
An additional advantage of the invention is that many
of the components of the system comprise adaptions o~fstandard
pieces of equipment, thereby making unnecessary large scale
redesign of these components and large inventories of spare
parts.
Still another feature of the invention is the provision
of continuous visual inspection of the product, containers and
lids through windows provided in the various components.
In accordance with the present invention there is
provided a filler for use with a hot air aseptic packaaing
system comprising a tunnel, a straight-line conveyor in said
tunnel receiving sterile, empty containers at a first end and
discharging said containers filled with sterile product at a
second end, a filler in said tunnel positioned above said
conveyor, first means for delivering said sterile product to
said filler, second means for delivering sterile air under
pressure to said tunnel, support means supportiny said filler
from said tunnel, said filler comprising a casing ex-tendina
:Longitudinally above the path of said containers as -they are
moved along said conveyor, said casing being formed a-t its
bottom with an elongated longi-tudinal first s]it, a tube of
lesser diameter than the interior of said casing disposed
within said casing perforated at its top and connected to said
first means, said tube being separated from said casing by a
space, an elongated insert formed with a second slit disposed
in said first slit, and deta_hable means securing said insert
to said casing, whereby said insert may be replaced with
another insert having a second slit of different width, product
received by said tube flowing into said space between said tube
and said casing, thence out through said second slit and into
said containers.
~ 4a -
,, ~
Other objects of the present invention will become apparen-t upon
reading -the following specification and referring to the
accompanying drawings in which similar characters of reference
represent corresponding parts in each of the several v:Lews.
In the drawings:
Fig. 1 is a schematic perspective view of the system in accordance
wlth the presen-t invention;
Fig. 2 is a -top plan view of the container sterilizer portion of
the inventlon;
Fig. 3 is a side elevational view of the structure of Fig. 2
partly broken away in section to reveal internal cons-truction;
Figs. 4A and 4B are a composite top plan view of the container
tunnel and filler portion of the apparatus;
Figs. SA and 5B are a composite side elevational view of the
structure of Figs. 4A, 4B;
Fig. 6 is a transverse sectional view taken substantially along
the line 6--6 of Fig. 4A;
Fig. 7 is a fragmentary sectional view taken substantially along
the line 7--7 of Fig. 6;
Fig. 8 is a perspective view of the container lid feed and
sterilizer;
Fig. 9 is an enlarged sectional view -through a portion of Fig. 8;
Fig. 9A is a schematic plan view of Fig. 9;
Fig. 10 is a transverse sectional view taken substan-tially along
the line 10--10 of Fig. 9;
Fig. 11 is a schematic top plan view of a portion of a container
closing machine with parts omitted for clarity and also showing a
por-tion oE the filler and tunnel;
Fig. 12 is a sectional view taken substantially along the line
12-~12 of Fig. 11;
Fig. 13 is an enlarged elevational view, partly broken away, in
section, of a valve which may be used in the system;
Fig. 14 is a sectional view similar to Fig. 6 of a modification;
Fig. 15 is an enlarged sectional view of a portion of Fig. 14;
Fig. 16 is a view similar to Fig. 13 of a modified valve.
Directing attention to Fiy. 1, the essential components of the
system are set forth. Containers 19 having -top flanges 20 and
which may be metal, fiber, glass, plas-tic or other ma-terial are
fed into a con-tainer sterilizer 21 where they are hea-ted -to a
temperature of up to appro~imately 500F by hot air. The con-
-tainers then pass through a straightline conveyor 22 which
includes a filler section 23 where a pre-sterilizecl, cooled
liquid or semi-liquid product is filled into the containers.
From the conveyor 22 the containers pass into a closing machine
24 which is a modified, enclosed adapta-tion of a well-known
commercially available machine. Meanwhile the lids 18 for the
containers, deposited in a lid storage magazine 26 pass through
a lid sterilizer 27 and -thence up an inclined lid conveyor 28 to
the closer 24. In the closer 24 the lids are attached to the
container. The components of the system will be described in
detail.
CONTAINER STERILIZER
The container sterilizer 21 shown in some detail in Figs. 2 and 3
has a double walled casing 31 filled with a heat insulation
material 32. In the walls of the casing 31 at convenient inter-
vals are observation windows 33. The containers 19 are fed into
sterilizer 21 through the container inlet 34 preferably in double
file. From the bottom of the inlet 34 the containers, s-till in
double file, pass onto a conveyor belt 36 which passes around and
over the power driven intake pulley 37. The conveyor belt 36
passes in a helical upward path around a central primary drum 38.
A helical trackway 39 supports the belt 36 in its path. The con-
tainers pass down through a discharge chute 41 and out of the
casing 31. The belt 36 is directed by end pulley 42 and additional
pulleys 43 back to the intake pulley 37. The structure herein
illustrated is a modification of a commercially available con-
veying system such as -that shown in U.S. Patent No. 3,348,659,
issued on October 24, 1967 to Roinestad.
Mounted at a convenient location such as the top of the sterilizer
21 is a heater 46 which may be electric, gas or oil fired. In a
preferred device a resistance electric heater is used. A blower
47 forces controlled air up from the air re-turn duct 48 -through
duct 51 which contains the heater 46 and then down -through inlet
--6--
'7~
duct 49 which leads into the casiny 31. The air is preferably
at a suitable temperature such as 300 for fiber containers which
is sufficient to sterilize containers when they are subjected
to such a temperature for a period of about 60 to 240 seconds,
normal time for containers 19 to pass throuyh the sterilizer 21.
For me-tal and glass containers ~50F. is suitable. The resident
time in the container sterilizer may be varied by increasing or
decreasing the speed of the conveyiny system.
CONTAINER TUNNEL AND FILLER
Communicatiny with the lower end of the discharge chute 41 is a
horizontally disposed tunnel 61. Continuously moving within the
tunnel 61 is a conveyor chain 62 and onto the horizontal top
stretch of the chain 62 the containers pass in single file.
Pulley 63 designates the driver pulley at the proximal end of the
tunnel 61.
About midway of the tunnel 61 is an idler pulley 66 around which
the chain 62 passes and returns to pulley 63.
Containers 19 are restrained as they are discharged from chain 62
and received in helix 71 by guide 68. Guide 68 carries horizontal
rods 226 which slide in holes in U-shaped brackets 227 and are
biased inwardly by springs 228. Brackets 227 are adjustably held
by bolts 229 threaded into the wall of tunnel 61. The heads of
bolts 229 are externally accessible for adjustment.
Mounted horizontally within the distal path of the tunnel 61 is
helix 71. Helix 71 has at its proximal end flights 72 which are
uniformly spaced apart slightly less than -the diameter of the
flanges 20 of the containers 19 being handled. It will be under-
stood that for different size containers 19 different helices 71
are required. At the distal end of the helix 71 the flights 73 are
spread apart, for a purpose which hereinafter appears. Shaft 74 of
helix 71 is mounted in bearings 75 at either end. The containers
19 discharged oEf chain 62 are supported partially by horizon-tal
plate 76 and partially by the vertical flange 78 of horizontal bar
77. There are holddown bars 79 mounted horizontally to engage the
top flanges of 20 of the containers 19. Bars 79 are supported by
brackets 81. As best shown in Fig. 6 the bars 79 may be moved in
and out to accommodate containers of different sizes. The con-
tainers 19 are partially supported and are driven by the flights
--7--
72, also as best shown in Fig~ 6. The containers are kept in con-
tact with the helix 71 by means of horizontally disposed vertically
spaced apart tubes 82. Tubes 82 preferably perform an additional
function in that sterile cooling water may be pumped therethrough
and the tubes are formed with spray holes (not shown) which spray
water against the sides of the containers 19, cooling and
cleaning the same. The spray water drains from the tunnel 61
through drain 83.
Helix 71 is driven from a power take-off 86 of the closer 24.
Thus the take-off sprocket 86 drives chain 87 which is connected
to sprocket 88 on the shaft 74 of helix 71. Idler sprocket 89
maintains the chain 87 tight. Shielding 91 functions as a guide
for containers 19 at one sideO
There are windows 92 along the length of the tunnel 61 through
which the attendant can observe the containers 19 as they pass
under the filler which is to be described. A cover 93 is hinged
by hinge 94 so that in case of malfunction the operator may obtain
access to the interior of the tunnel 61. Within the tunnel 61 is
a distributor 96 having air holes 96A which distributes air
throughout the interior of the tunnel. There is a duct 97 along-
side the tunnel 61 communicating at intervals with distributors
96. It will be understood that the tunnel 61 is preferably of
double-walled construction and the space between the walls is
filled with insulation 98 which may be a ceramic fiber. The
materials of which the walls are constructed are preferably stain-
less steel both inside and out.
To sterilize the air within the tunnel 61 and also, importantly,
to prevent the ingress of non-sterile atmospheric air, blower 101
is installed in a convenient location such as -the top of the
sterilizer 21 adjacent the blower 47. Blower 101 communicates
with a heater 102 which heats the air to a temperature of about
400F, thence to a horizontal duct 103 along the top of the
sterilizer 21 and thence down through a vertical duct 104 to a
horizontal duct 106 which communicates with the duct 97. At
start-up, air is preferably at 450-500F and -then reduced.
Where it is desirable, a heat exchanger 107 may be installed in
the vertical duct ]04. The hea-t exchanger 107 has a coolant
inlet 108 and a coolant outlet 109. Within the heat exchanger
107 are ccils (not shown, bu-t of a common commercia] -type)
around which the hot air in the duct 104 circulates and by which
its temperature is materially reduced. Some produc-ts deteriora-te
rapidly at high tempera-tures. Accordinyly, it :Ls desirable to
cool the air emit-ted through duct 106, while maintaininy its
pressure above atmospheric. Such sterile air, cooled but above
atmospheric pressure, is introduced in the filler 111. The
pressure of the air prevents ingress of non-sterile air from the
surrounding atmosphere. Since both the containers and the pro-
duct have been pre-sterilized, contamination of the product in
the containers is avoided. Low temperatures - if necessary, as
low as 70F - may be used, a condition which is never achievable
with the use of steam as contrasted with air.
In the modification of Fig. 1~, the filler 111 shown is a modi-
Eication of a commercially known structure. I-t is mounted above
the path of the containers 19 by means of horizontally outwardly
extending brackets 251 spaced at intervals along the length of
the filler 111. Each bracket 251 is received in a clamp 252 which
is, in turn, supported from a vertical support 253 on the side of
the filler by means of bolts 25~. By raising and lowering the
clamp 252 - i.e., by inserting the bol-ts 25~ through different
holes in the support 253, the filler casing 116 may be raised and
lowered.
The containers 19 are supported against latera:l displacement by
guides 256 fixed to brackets 257. Threaded rods 258 are -threaded
into the vertical flanges of brackets 257. These rods 258 pass
through one of several vertically spaced holes in vertical support
259 and are fixed in place by means of nuts 261. Accordingly, by
turning threaded rods 258, the brackets 257 and hence the guides
256 may be moved inward and outward so that the guides engage the
walls of the containers 19 as they pass under the filler. By
raising or lowering rods 258 and inserting same through differen-t
holes in support 259, guides may be positioned near the tops of
containers 19. The lower edges of the containers 19 are guided
by bottom guides 262.
Filler 111 has a horizontally disposed casing 116 formed with a
_g_
sl~
continuous slit 117 along its bottom edge. Interchangeable
inserts 266 of Tef]on or other suitable material are attached to
the slit 117 by means of brackets 267 held by bol-ts 268 into
casing. The width of the slits 269 in the inser-t de-termines -the
rate of flow of product. By replacing the inser-t 266 different
produc-t flow may be obtained.
A curtain of product is discharged -through the slit 269 in the in-
sert 266 immediately above the path of the containers 19 as -they
are rnoved along by the helix 71. Pre-sterilized, cooled product
is pumped or otherwise forced into a tube 118 within the casing
116~ Tube 118 has holes 119 at intervals at its top so that the
liquid or semi-liquid product is forced out through the holes 119
and into the interior of the casing 116. The product is fed
through an inlet 112 at one end of tube 118. This structure of
filler 111 has been found to promote more even distribution of
product. The pitch of the flights 72 below the filler 111 is
such that -the containers 19 are Eorced together so that the
flanges 20 partially overlap. Hence, there is a minimum of spill-
age of product discharged through slit 269.
Directing attention to Fig. 13, a valve 191 which may be used toby-pass flow of product into filler 111, particularly where
multiple fillers are used in a particular installation, is shown.
Pre-sterilized, cooled product is pumped by a pump (not shown) in
the product processing plant which is separated from the installa-
tion shown in Fig. 1 in many instances by a partition 192. A pipe
194 connects with the pipe 193 extending through the partition,
the pipe 194 having a flange 196, which is fastened -to -the
partition 192. Pipe 194 may be connected to an elbow 197. Used
throughout the installation are quick-connect couplings 199 of
conventional construction. Elbow 19/ is connected to an intake
198 of the valve 191. Discharge port 201 of valve 191 is connected
to a -tee 202. The opposite end of tee 202 may be connected to a
pipe 203 which leads to another filler. However, it may be con-
sidered that the discharge or vertical leg 204 of the tee 202 is
connected by means of pipe 206 to the inlet 112 of the filler 111.
~ther means of connection may, of course, be employed.
Within the body 198 of valve 191 is sleeve 211 having a reduced
diameter portion 212 and an enlarged diameter portion 213. I'he
~uncture of the portions 212 and 213 are formed with a seat 214,
--10--
'f-~
preferably conical. Valve head 216 is formed at one end with a
taper 217 which matches the seat 214. Head 216 is connected to
stem 21$ which is hiased by means of spriny 219 in-to seating
engagement. A fitting 221 is connec-ted to -the sleeve 211 and
such Eitting 221 has a discharge port 222 which leads back to -the
source of product. I'emperature sensor 224 is connected -to the
body 201 to sense the temperature oE product discharyed therefrom.
In the use of the valve, the product is pumped by means not shown
through the pipe 193. Normally, the head 216 is seated and pro-
duct flows out through reduced diameter portion 212 to the right
as viewed in Fig. 13 and thence through tee 202 and pipe 206 to
the filler 111. In the event -that the line is shut down or if
the volume of product being pumped through the pipe 193 is exces-
sive, the pressure within the reduced diameter portion 212 in-
creases to the point where it overcomes the Eorce of the spring
219 and the head 216 moves to the left as viewed in Fig. 13.
Surplus product then flows out of the discharge port 222 back to
the source of product. It will be noted that the discharge port
222 is preferably on the same side of the partition 192 as is the
pipe 193.
A modification of -the valve heretofore described is illustrated in
Fig. 16. In certain respects the valve of Fig. 16 resembles that
shown in Fig. 13 and the same reference numerals followed by the
subscript a are used to designate corresponding parts.
Product under pressure Erom a pump or gravity is introduced to one
end of tee 236. By quick-connect clamps 194a, the end of tee 236
opposite that through which produc-t is introdllced is connected -to
a pipe 193a by means of quick~connect clamps 194a or other means.
The pipe 193a passes through partition 192a and is secured there-
to by flange 196a. On the prvduct preparation side of partition
192a is a pressure relief valve 237. When the ou-tlet of pipe 193a
is closed (by means hereinafter explained) the pressure relief
valve 237 opens to permit product to be discharged through port
222a back to the source of product, thereby preventing waste.
Valve 237 has a T-shaped casing 238 formed with a seat 239.
Reciprocable within the casing 238 is a valve head 241 which seats
on seat 239, having a stem 242 which ex-tends exteriorly of casing
238 and is biased by an adjustable spring 243. In normal opera-
tion, the head 241 seats on the seat 239. However, when the pres-
--11--
sure exceeds the force of spring 243, head 241 unseats - i.e.,
moves -to -the righ-t as viewed in Eig. 16, permitting excess pro-
duct to flow out through -the filler 111 through inle-t 112. A
sleeve 211a is installed in the in-take arm of -the valve l91a,
this sleeve having a conical sea^t 21Aa against which head 216a
may seat. Steam 218a of head 216a ex-tends exteriorly of valve
]9la -to a valve actuator 246. ~alve actuator 246 determlnes the
,_
opening and closing of -the valve l91a and -the amount of opening
thereof -to maintain the desired pressure wi-thin the filler 111
into which the valve l91a discharges. Where closure of the head
216a creates an excessive pressure in the pipe 193a, the pressure
relief valve 237 unseats and excess product is discharged back
to the source of product.
Erom the tunnel 61, containers 19 are transferred to the closer
24.
As seen par-tially in Fig. 11, closer 24 has an inlet chain 1]6
which passes around a sprocket 117 at the distal end of the
tunnel 22. Chain 116 has horizontal fingers 118 which are spaced
apart a proper distance to feed containers into the turret of the
closer (hereinafter described) and such spacing of fingers 118 is
the same as the spacing of the spread flights 73. Guides 119
transfer the containers 19 discharged from the helix 71 into the
spaces between the fingers 118.
CONTAINER LID FEED AND STERILIZER
In addition to the container 19 and product being sterilized and
-the packing and lid closing being performed in a sterile atmos-
phere, it is also necessary that the container lids 18 be s-teri-
lized. In a preferred form of the present invention, a modifica-
tion of a Fleetwood Systems, Inc., lid feeder and conveyor 26 is
used. One form of such Fleetwood apparatus is shown in U.S.
Patent No. 4,000,709. Details of the operation of such apparatus
are set forth ln the aforesaid patent. ~enerally, a magazine 136
is provided having a plurality of cover stack chutes 137 mounted
so that the empty chutes are accessible to the attendant for
filling with stacks of lids 18 obtained from the container manu-
facturing facility. The chutes 137 are mounted so that they are
moved in a rotary path to one end 138, whereupon the lids 18 in
that particular chute are moved outward into a vertically disposed
transfer s-tation 139 which connec-ts with guides 141 which cause
-12-
the lids to make a 90 degree curve bend 140 and assume a hori-
zontal position. As the covers reach the lower end of -the bend
140, they are deposited to rest upon a pair of stainLess steel
chains 142 driven around sprockets 143 a-t ei-ther end oE -the hori-
zontal path~ The chains 142 move the lids 18 along -the hor:izon-
-tal path above horizontal partition 146. The return stretch of
the chains 142 is below partition 146. Af-ter leaving the hori-
zontal stretch, the lids are transferred to an upward inclined
elevator 148 which has a similar chain 149 drive. At the upper
end of the elevator 148 is a second 90 degree arcuate bend 151
which communicates with the top of the cover stack of closer 24,
hereinafter described. Where steel lids are used, magnetic hold-
downs 152 are used to prevent lids from being forced out of the
stack, as well understood in the industry. Non-steel lids are
retained in position by mechanical means not illustrated herein,
but understood in the art.
Casing 147 is provided around the lower end of the transfer
station 139 and continues around the horizontal lower stretch
and the inclined elevator 148 and the bend 151 which leads to the
closing machine. The casing 147 preferably has double walls 156
with heat insulation material 157 between the walls 156. Mounted
near the machine is a blower 161, the discharge 162 of which con-
nects to a heater 163, which may be of various types, typically
may be of the electric resistance type. From the heater 163 there
is a duct 164 leading to an entrance duc-t 166 preferably located
near the proximal end of the casing 147. As the lids 18 move
through the horizontal and inclined stretches, hot air circula-tes
around the lids and sterilizes them. Sterility is maintained
until the lids enter the closer 24. Return air is recirculated
through return duct 166 below partition 146. Closer 161 draws air
from return duct 166. As hereinafter appears, the closer 24 is
also in a sterile atmosphere with non-sterile atmospheric air
excluded by reason of the pressure inside the enclosure of the
closer.
CLOSING MACHINE
The closer 24 shown particularly in Figs. 11 and 12 is an adapta-
tion of the enclosed closer illustrated and described in U.S.
Patent No. 3,349,542, issued on October 31, 1967 to Guckel/ except
that steam is not used therein. An enclosure 171 which com-
munica-tes with the tunnel 71 feed and filler is double-walled
and provided with insulation 172 completely encloses the closer
24. Since s-terile air is forced into the enclosure, -the pres-
sure is grea-ter than atmospheric and this ensures that non-
sterile air cannot enter the enclosure. Duct 97 which extends
alongside the conveyor 22 is Eormed with a bend 173 which com-
municates with a distributor 174 inside the enclosure adjacent
the discharge of the seamed containers.
The sterilized lids 18 which have been deposited into the closer
from the lid s-terilizer 27 heretofore described are fed one at a
time into pockets 176 in the lid turret 177. Further, containers
19 are advanced by the fingers 118 of the conveyor chain 116 and
are fed into the pockets 178 of the main -turret 179 of the
closer. The lids 18 on the lid turret 177 are brought into
position over the containers 19 by timed rotation of the lid
turret 177~ By means well known in the seamer art, the lifters
181 of the main turret lift each container 19 into contact with
a lid 18 and thereupon seaming rolls (not shown) attach the lid
to the container. The completed container 182 is then trans-
ferred into the discharge star wheel 183 and thence guided byguides 184 out of the system. The details of the closing
machine are not herein illustrated, being of any of several well-
known types. The preferred form herein illustrated is the
Angelus model 60L seamer which is shown partially in said U.S.
Patent No. 3,349,542, issued on October 31, 1967 to Guckel.
One of the features of the closer apparatus is -the provision of
vertical pipes 186 and 187. Pipe 186 sprays s-terile cool water
through holes onto the lid push fingers (not shown) to keep them
clean. Sprays 188 of pipe 187 are in a vertical line and spray
sterile, cooled liquid on the container lifter 183 and also on
the seaming rolls (not shown) to prevent build-up of product
thereon.
Although sterile air in the closer 24 is -the preferred way of
preventing ingress of atmospheric air, nitrogen or steam (in
accordance with conventional practice) may be used.
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