Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a device for the aseptic
sampling of products accommodated in an aseptic enclosure
from that enclosure. The device in question is particular-
ly intended for use in the field of foods, more especially
for the sampling of fresh, refrigerated or long-life dairv
products, or in the pharmaceutical field, for example for
monitoring during the fillinq of flexible bags with prod-
ucts for enteral or parenteral administration.
FR-PS 2 374 629 already describes an aseptic sampling
device of the type in question. The disadvantage of this
device is that the valve through which the product is drawn
off forms between itself and the sampling enclosure a dead
zone in which the products stagnate, creating a serious
risk of bacterial growth. On the other hand, this device
is complicated and difficult to operate and is not partic-
ularly suitable for drawing off products containing solid
pieces.
The object of the present invention is to obviate the
disadvantages mentioned above by means of a simple device
which is easy to use and which minimizes the risks of
contamination.
The invention relates to a device for the aseptic
sampling of products accommodated in an aseptic enclosure
from that enclosure, comprising a valve for drawing off
products, an inlet pipe for steam and sterile air and a
product sampling pipe, in which the draw-off valve com-
prises a closure cone which, in the closed position, rests
on a valve seat, the plane of contact of the cone with tha
seat being situated substantially level with the surface of
the enclosure, the steam inlet pipe opens directly into the
head space of the valve and the product sampling pipe is in
the extension of the steam inlet pipe.
The enclosure from which the samples are taken may be
both a pipe and a reservoir. Unlimited volumes of sterile
products may be taken as samples. The device according to
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the invention may be used both for viscous liquid products
and even for products containing solid pieces.
The crucial feature of the invention is that the
closure cone of the valve is substantially in the plane
forming the surface of the enclosure. In this case, there
is no residual product to stagnate so that, on the product
side, there is virtually no risk of bacterial growth. On
that side of the closure cone which is not in contact with
the product in the closed position, i.e. in what is termed
the head space in the present specification, the steam is
directly introduced so that the head space can be steril-
ized. The steam thus purges the entire zone from the head
space to the product sampling pipe. In this way, the
device can be repeatedly used and re-sterilized after each
sampling.
The product to be sampled must be able to arrive under
light pressure in the sampling bottle, above all if it
contains solid pieces. To this end, the diameter of the
valve seat is substantially equal to twice the diameter of
the product sampling pipe.
To collect the product, a circular plate with a recess
in which the upper edge of the bottle to be filled slides
during sampling is provided at the end of the sampling
~ipe. The product may also be collected from a flexible
pipe.
When the device is not in use, the circular plate is
covered with a disc to keep the device as a whole sterile.
The device according to the invention and its mode of
operation are described in more detail in the following
with reference to the accompanying drawings, wherein:
Figure 1 is a partial section through the device
according to the invention before sampling.
Figure 2 is a partial section through the same device
during sampling.
An opening (2) is formed in the wall (1) of the
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enclosure from which the samples are to be taken. A draw-
off valve (4) is welded in the opening (2) at (3). This
valve comprises a valve body (5) with a valve seat (6)
which is closed by a closure cone (7) provided with a seal
(19). The cone (7) is integral with a guide rod (8)
designed to slide in a part (9) fixed to the valve body (5)
by a locking collar (10). The valve is sealed by a flex-
ible membrane (11) held between the closure cone (7) and
the rod (8) on the one hand and the valve body (5) and the
part (9) on the other hand. The valve is opened and closed
by a knob (12) fixed to a cylindrical sleeve (13) which is
formed internally with a screwthread (14) engaging in a
corresponding screwthread (15) of the part (9). The sleeve
(13) further comprises an annular protuberance (16) which
bears against stops (17) (18) to allow displacement of the
guide rod (8) when the knob (12) is rotated. The valve
body (5) additionally comprises a pipe (20) for the intro-
duction of steam through the valve (21) and sterile air
through the valve (22) and a product sampling pipe (23).
This pipe opens onto a circular plate (24) closed by a disc
(25) comprising a central bore (26) for the outlet of
sterile air to guarantee good sterilization conditions.
The mode of operation of the device is as follows:
Before the product (27) is sampled, the head space
(28) has to be sterilized. To this end, the valve (21) is
opened and steam at 120C and under an excess pressure of
approx. 1 bar is admitted for six minutes. The steam flows
along the p~pe (23) to the bore (2~). The valve (21) is
then closed and the valve (22) opened. Sterile air is
admitted to cool the system. This air is allowed to flow
for as long as a sample needs to be taken. Before samp-
ling, the disc (25) is unscrewed and a sterile product
recovery bottle (29) is placed in position (Fig. 2). The
top of the bottle is engaged in the recess ~30) of the cir-
cular plate ~24). With the valves (21) and (22) closed,
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the knob (12) of the draw-off valve is turned so that the
cylindrical sleeve (13) is displaced and the closure cone
(7) is removed from the valve seat (6). The product (27)
flows in the direction of the arrows in Fig. 2 and is
recovered in the bottle (29). When the bottle is full, the
knob (12) is turned in the opposite direction and the
closure cone is returned to the valve seat (6). The
flexible membrane (11) provides for effective sealing of
the draw-off valve (4) and for simple operation of the
device according to the invention.
The bottle (29) is removed, the system is freed by
rinsing from the condensed steam which has accumulated
therein and is then resterilized with steam and sterile air
is allowed to flow until the next sample needs to be taken.
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