Note: Descriptions are shown in the official language in which they were submitted.
~3~
BAC~ P~SSU~ .~D~ALUS
This invention relates to a back pressure apparatus
for high temperature sterili~ing the inside of an aseptic
processing and filling system for foods or medicines
5 ~hereinafter merely called as ~system~), which is adapted
to be connected to a filler nozzle of the system to
maintain sterilizing steam inside the system
at a predetermined pressure during the sterilization of the
system.
In general, when aseptic processing the products such
as foods or medicines, it is necessary to make an àseptic
condition an aseptic processing and filling system
including various apparatus covering from a sterilizing
apparatus to a filling apparatus, a delivery pump, pipes
15 valves and the like to which the products tend to directly
contact, prior to the production and filling operation of
the system. To this end, there are several conventional
methods, for example, of passing sterilizing agents through
tbe system; of heating water to a high temperature by a
~Oheat-sterilizing apparatus and introducing the hot water
into the system: and of introducing steam through a steam
supply piping into the system to heat sterilize it.
However, the method of using the sterilizing agents has
been hardly used, since the agents sometimes would be
~5remained in the system and be mixtured into the products,
which would cause undesirable sanitary problems.
B
~3~
Accordingly, the heat-sterilizing methods using hot water
or steam have been acutally adopted for the system.
The heat-s~erilizing method above mentioned has been
usually carried out under the conditions; sterilizing timeo
20~45 minutes, and sterilizing temper~ature. 120-140Co In
this case, the hot water or steam in the inside of the
system should be held at a pressure above the atmospheric
pressure ~i.e. pressure for suppressing the boiling of
water; this pressure is called as Wback pressureR in the
present specification.) in order to maintain the hot water
or steam at a temperature above 100C. Fur~hermore, it is
required that the hot water or steam continues to flow
through the system without being stayed therein, since if
they would be stayed in the system, their temperature is
lowered, due to the heat radiation from the inside o~ the
system to the atmosphere, to the extent that the
steriliza~ion of the inside of the system would become
insufficient.
Meanwhile, filler nozzles have been designed to have
20 different shapes depending on the properties of the
products to be filled, in general, that in the fi1ling
process, any of the nozzle is arranged that it is opened to
fill one of sontain2rs with the product and tben the nozzle
is fully closed to interrupt the filling until the next
conteiner is conveyed in placeO Because of the unction of
the conventional filler nozzles as described above,
therefore, it is impossible to maintain the hot water or
steam in the system at a pressure above the atmospheric
~3~
--3--
pressure enough to provide a temperature required for
sterilization while permitting a continuous flow of heated
water and vapour through the system when the heat
sterilization of tbe system is carried out prior to the
filling production.
An attempt has been heretofore made to mount device
sterilizing the interior on the filler nozzle an attachment
device which is connected to back pressure device, such as
a pressure control valve or a steam trap, by means of a
pipe to establish enough pressure of ~he hot water or s~eam
in the system to sterilize it while permitting the flow of
hot water or steam through the system. However, there has
been a complicatedness and difficulty in manually mounting
the above attachment device on the ~iller nozzle in view of
the fact that a number of parts are commonly mounted in the
vicinity of the filler nozzle.
In addition, since the filler nozzle and the
attachment device become hotter, it is impossible to
manually remove the attachment device immediately after the
interior of the ~ystem has been heat sterilized, they must
be left for about thirty minutes to cool them to the
ambient temperature.
Furthermore, during removal of the attachment device
after cooling down as described above, the attachment
device must be carefully handled so as to avoid any
contamination of the tip and the inner surface of the
sterilized filler nozzle with a microorganism such as a
germ. In general, there is a need for disinfection of the
B
handst and it is practical to spray on sterilizing agent to
the nozzle portion of the filler after removal of the
atachment device.
~owever, in spite of such procedures, there has been
the problem that a filling chamber may be contaminated by
contacting with the environment since the shield door
provided to keep the filling chamber in a sterile condition
is opened to permit removing of the attachment device.
An object of the present invention is to provide an
apparatus capable of conveniently heat sterilizing an
entire aseptic processing and filling system including the
iller which is to be in contact with the product, without
causing the above-mentioned problems.
It is an object of the present invention to provide a
back pressure apparatus which is adapted to be connected to
the filler nozzle of the system and enables to maintain the
inside of the system under a predetermined pr,essurization
at a temperature above lOO~C while avoiding any stagnation
of the heating medium in the system.
It is another object of the present invention to
provide a back pressure apparatus which is detachably
connected to the filler nozzle of the syste~ without any
troublesome handling and preparatory time for the operation
thereof and without destroying the sterile condition of the
filler nozzle and the inside of the filler having been
sterilized.
According to the present inven~ion, it is possible to
completely sterilize the inside of the system with heating
B
medium at high temperature by connecting to the filker
nozzle a cap having a flow restricting means for
discharging the heating medium to maintain the pressure
of the heating medium upstream of the filler nozzle of
the system at a prede~ermined level and hy passing the
heating medium through the system after the connection
of the cap. Furthermore, it is possible, according to
the present invention, to pass the heating medium
through the system with any stay thereof in the system.
According to the present invention, the cap of the back
pressure apparatus is designed to be compact in
construction and therefore this makes it possi~le to
convey the cap to a position directly below the filler
nozzle by a conventional conveyor or the like and to
connect the cap to the filler nozzle with any suitable
means by which the mount and demount of the cap to the
filler ~ozzle are easily carried out without destroying
the sterile condition of the filLer nozzle and the
inside of the system.
According to the present invention, there is
provided a back pressure apparatus for maintaining a
predetermined pxessure within an aseptic filling system
to sterilize the inside of the aseptic filling system,
comprising:
`2~ a filler nozzle for filling a previously
sterilized food into containers under an aseptic
condition;
a cap adapted to be cbnnected in a liquid-tight
manner to said filler nozzle and including a steam trap
for continuously discharging steam condensate while
maintaining the inside of the aseptic filling system
upstream of the filler nozzle at the predetermined
pressure for sterilization;
lift means for moving vertically the cap to
connect or disconnect the cap to or from said filler
nozzle;
~3~
seal means for achieving a liquid-tight connection
between said filler nozzle and said cap; and
transfer means for transferring said cap to or
from a position just below said filler nozzle.
The present invention will become more apparent
from the following description of preferred embodiments
thereof with reference to the accompanying drawings in
which;
Figure 1 is a cross-sectional view of an
io embodiment of a back pressure apparatus attached to a
filler nozzle and constructed in accordance with the
- present invention; and
Figure 2 is a view similar to Figure 1 but showing
a modification of the invention.
Referring to Figure 1 of the drawings, there is
shown a preferred embodiment of a back pressure
apparatus according to the present invention comprisiny
a cap 2 adapted to be connected to a nozzle 1 of a
filter in an aseptic processing and filling system.
The filler nozzle 1 extends through a fixed plate 8
below which a filling chamber is definedO A lifting
device is provided for lifting the cap 2 toward the
filler nozzle 1 for connection therewith and includes
bolts 4 inserted in apertures in the fixed plate 8 and
adapted to be threadedly received in tapped holes 12 in
a flange 7 formed on the side wall of the cap 2.
Rotation of the bolts 4 causes the cap 2 to lift
upwardly the filler nozzle 1 into engagement with its
tip. An O-ring S is fitted in an annular groove in the
flange 7 to form a seal between the cap 2 and the tip
of the filler nozzle 1. The cap 2 is provided with a
partition 2a for defining a compartment 2b therewithin
and a conduit 2c extending from the partition through
the side wall of the cap 2 and terminating at an outlet
6. A steam trap 3 is provided in the conduit 2c within
the compartment 2b of the cap 2 to selectively
~2~
--7--
discharge steam condensate through the outlet 6 without
- any escape of steam from the aseptic processing system
so that the heating medium in a portion of the system
upstream of -the cap 2 can be maintained at a
predetermined pressure
Prior to carrying out a heat sterilization of the
aseptic processing and filling system, the cap 2 is
first located on a chain conveyor 9 adapted to run
through the filling chamber and to convey containers
which are filled with a product during a su~sequent
filling operation. The chain conveyor 9 is operated to
convey the cap 2 to a position where it is located
directly below the filler nozzle 1. Thenl the bolts 4
are inserted into the apertures in the fixed plate 8 to
threadedly engage the tapped holes 12 in the flange 7
of the cap 2. The cap 2 is lifted upwardly toward the
filler nozzle 1 by turning the bolts ~ in the tapped
holes 12 so that it is moved away from the chain
conveyor 9 until the cap 2 sealingly engages the tip of
the filler nozzle 1 with the O-ring 5 interposed
therebetween.
The heat sterilization of the sterile processing
and filling system is carried out by introducing
saturated stream from its source through a piping into
the system and passing the steam through the filler
nozzle 1 to the cap 2 through the stream trap 3 of
which the steam condensate is intermittently discharged
to the exterior~ The steam trap 3 in the cap 2 serves
to maintain the saturated steam in the portion of the
aseptic processing and filling system of the steam trap
3 at a predetermined pressure required to obtain a
temperature sufficient to sterilize the system. The
intermittent discharge of the steam condensate from the
steam trap 3 through the outlet 6 permits the steam to
constantly flow from the steam supply piping through
the system to the filler nozzle l. Thus, the system
B
~ ~3~
-8-
can be sterilized with the steam at the desired
temperature for a required time of sterilization.
Upon completion of the sterilization within the
- system as mentioned abov~, the bolts 4 are loosened so
that the cap 2 can be lowered from the filler nozzle to
the chain conveyor 9 which is then operated to convey
the cap 2 outside of the filling chamber. In this
case, -there are no possibilities of bacteria
contaminating the tip of the filler nozzle 1 and its
interior, and of ruining the sterilized condition
within the filler because the removal and conveyance of
the cap 2 can be perfor~ed without manual handling.
In addition, a sealing device which is disposed
downstream of the filler is not in operation during the
conveyance of the cap 2, so that it is possible to
convey the cap 2 out of the filling chamber without any
damage to the cap 2 and conversely, the filler is not
damaged by the cap 2.
After the cap 2 has been removed from the filler
nozzle 1, it is necessary to remove the fastening bolts
4 from the apertures in the fixed plate 8 because these
bolts 4 interfere with the incoming containers during
the subsequent filling operation. In this case, it is
possible to prevent bacteria or the like from entering
the filling chamber through the apertures by
introducing sterilized air, an inert gas or superheated
steam thereinto to maintain the filling chamber at a
positive pressure somewhat higher than the atmosphere
whereby the sterilized condition therewithin can be
maintained. It is preferable to close the apertures in
the top plate 8 by any suitable means after removal of
the bolts 4.
The steam drain is discharged out of the ~illing
chamber by connecting a pipe or the like to the outlet
port 6, especially in the case where it is undesirable
to discharge the steam condensate into the ~illing
,r
- 9 -
cham~er.
- The conveyance of the receiver forming part of the
back pressure apparatus according to the invention may
be performed by any suitable conveyor ~eans other than
the chain conveyor as described in the above
embodiment. In the case where it is d:ifficult to
convey the cap along a path of conveyance of the
product containers, -the ~hain conveyor may be reversely
driven to convey the cap through the exit side of the
filling chamber to the position direct:Ly below the
filler nozzle in a direction opposite to the direction
of the conveyance of the product containers.
Instead of the bolts threadedly received in the
tapped holes in the flange of the cap as shown in the
drawings, any suitable lifter means may be employed to
lift the cap from the chain conveyor toward the filling
nozzle 'or connection therewith.
Figure 2 shows another embodiment of the back
pressure apparatus in which a cap 2 similar to that of
the first embodiment as described with reference to
Figure 1 of the drawings is used except that the cap 2
is bought into contact with the fixed plate 8 to
surround the filler nozzle 1`. There is provided a
lifte~ 14 for lifting the cap 2 from the chain conveyor
9 toward the fixed plate 8. Gaskets of synthetic
resin, rubber or the like are interposed between the
periphery of the filler noz~le I and fixed plate 8 and
between the upper end of the cap 2 and the lower
surface of the fixed plate 8, respectively to prevent
any heating medium from escaping through therebetween.
The cap ~ay be formed from any suitable material,
such as stainless steel, ceramics synthetic resin or
the like which can resist the heat sterilizing
operation of the system.
It will be noted from the foregoing that by
connection the cap having the flow restricting means to
~,
:~3~2~
--1 o--
the fil.ler nozzle, the steam in the system can be
maintained under the pressurization to make it possible
to heat sterilize the inside of the system at high
temperature without any stagnation of the heating
medium in the system. It will also be noted that the
cap is simple and compact in construction and can ~e
removably connected to the filler nozzle without any
contamination of the nozzle with microorganisms
affecting the sterile condition within the system.
20 .
