Improvements in Methods of Preventing the Bursting of Bottles and other Receptacles while Substances Enclosed therein are being Sterilised, and in Apparatus therefor.
Year: 1897

page_text: Date of Application, 17th July, 1897-Accepted, 11th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in Methods of Preventing the Bursting of Bottles and
other Receptacles while Substances Enclosed therein are being
Sterilised, and in Apparatus therefor.
喳
I, AXEL LEONARD ROCKSTROM of Norberg in the Kingdom of Sweden, Brewer,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to a method and apparatus for preventing the bursting of
vessels while substances enclosed in them are being starilised and to apparatus
employed therein.
The principle of the method is to maintain during the whole sterilising process,
both while heating and while cooling the substance, a pressure around the vessels
which always equals or slightly exceeds the pressure in the interior of the vessels.
This is accomplished in the following manner. The vessels are placed in a closed
receptacle, which is filled with a fluid; and by forcing into said receptacle or
drawing off from, it water or a gas during the heating or cooling operation the
vessels are subjected to an external pressure equalling or exceeding that which
simultaneously exists in their interior. The fluid under pressure may be supplied
or drawn off by hand or automatically. In the former case enough is supplied of
the fluid to obtain an external pressure equalling or slightly exceeding that which
has been found by previous investigation to exist in the interior of the vessels
during the operation. In the latter case the internal pressure itself is used for the
purpose of allowing it to act upon a valve or the like by which the communication
is opened or closed between a pressure generator, the open air or a reservoir and
the closed receptacle. During the heating operation the internal pressure rises,
and, owing to this increase in pressure the valve leading to the: pressure generator
is actuated so as to cause a corresponding quantity of pressure fluid to flow into
the receptacle and make the external pressure equal to that of the interior. While
cooling takes place and the pressure consequently is sinking, a valve is actuated
permitting of the discharge of the pressure fluid into the open air or into a reser-
voir or back to the pressure generator and thus causing the external pressure to
fall in the same degree as the internal one.
In the drawing the sterilising apparatus referred to is shown combined with an
automatic pressure regulator.
Figure is an elevation of the sterilising apparatus having a portion of the
closed receptacle removed so as to show the pressure regulator.
Figure 2 represents a vertical sectional view on an enlarged scale of the upper
portion of the pressure regulator.
1) is the closed receptacle which may be of any convenient shape and size and
may be heated and cooled either from within or from without and is provided with
an hermetically closing cover R through which the vessels are introduced and
removed. Above this receptacle D there is a smaller receptacle E. (preferably
having a volume equal to about 6 per cent. of the cubic contents of the receptacle D).

page_text: Said receptacle E¹ is provided with a pressure gauge O and a safety-valve P
and communicates through the pipes Q and e' with the receptacle D and through
the pipe with a pressure regulator S. This is so mounted that its lower por-
tion is in the interior of the receptacle while its upper portion projects outside the
latter. The regulator S through a pipe communicates with a holder containing
carbonic acid or with an air compressor or other pressure generator.
A is a bottle or other vessel having the same volume and coefficient of expansion
as the other vessels used. This vessel A at its upper portion is fitted hermetically
in the wall of the receptacle 1). When filled up to L it holds the same amount of
liquid as is ordinarily placed in a bottle or vessel of liquid to be treated.
Figure 2 shows in a sectional view the upper portion of the pressure regulator
which is outside the receptacle. dis the conduit communicating with the
pressure generator and arranged so as to be shut off from the latter by means of
valves I I¹ of equal size and covering valve openings of equal size. These valves
are mounted on a vertical spindle which is movable lengthwise and at the lower
end of which there is fixed between two round metal discs a disc F of rubber,
horn, thin flexible metal or the like. The disc is at its outer edge fastened to
the wall of the apparatus so that the latter will be hermetically divided horizon-
tally. C is a low pressure chamber the cross sectional area of which is many
times greater than that of the valve openings. Said chamber C communicates
through a passage K (shown in dotted lines in the drawings) with the chamber G.
B is a chamber of the same volume as the air space between the cork and the
liquid in a bottle filled to the ordinary extent. M is a discharge conduit from a
third valve-opening which may be closed by means of the double valve I. The
distance between the two upper valve-openings is not greater than such as to
allow of one being only slightly (about one m/m) open when the valve closes the
other.
'
up
After placing say bottles of beer in the receptacle D and closing it said
receptacle is filled with water which may be done through a cock arranged for the
purpose. The vessel A is filled with beer up to L and the pressure regulator S
is brought in communication at d¹ with the pressure generator and at c¹ with the
receptacle E. The receptacle D is then heated. As the pressure in the beer
bottles increases that in the vessel A will also increase, the pressure
under the flexible disc F consequently forcing the latter upward and
causing it to open the valves I and I¹ which will again close the
valve openings as soon as the pressure on the upper side of the disc
increases and the latter as a result thereof is forced downward. The valves again
open as soon as the pressure in the vessel A and consequently in the beer-bottles
increases. In this manner there is successively created in the apparatus around
the bottles a pressure which so to speak regulates itself in such a manner that it
will always correspond to the pressure generated in the bottles during the pasteur-
izing process, the bursting of the bottles and the blowing out of the corks being
thus prevented.
The temperature is observed by means of a thermometer N. When the cooling
is commenced, the communication with the pressure generator is shut off and the 4
cock in the discharge conduit M (see Figure 1) is opened. As the pressure in the
vessel A falls the higher pressure on the upper side of the disc F forces the latter
downward causing the third or top-valve to open and remain so until the external
and internal pressures become equal. Instead of the thin flexible membrane
there may be used a piston attached to the valve-spindle and arranged so as to be 5
moved when the internal and external pressures differ, said piston evidently
doing the same service as the flexible membrane.
The receptacle E¹ serves to receive the surplus of water accumulating during the
heating operation in the receptacle D, said surplus during the cooling again
descending into the latter receptacle which is thus kept filled during the whole 5
process.
If the external pressure is to be produced by forcing in cold water, the pipe e¹

page_text: The cold and
Figure 1 is shut off by means of the cock mounted in the same.
therefore heavier water forced in is thus prevented from entering directly into the
receptacle which would cause partial disturbances in the heating of the bottles
and when the differences of temperature are considerable cracks in the bottles
owing to the contraction of the glass. When cooling is to take place the cock in
the pipe el is again opened.
The portion of the pressure regulator S which is just above the receptacle D is
preferably surrounded by some heat-insulating material so as to prevent loss of
heat during the heating operation. As long as an excessively high pressure is not
used, the pressure regulator acts in a very sensitive manner, the differences of
pressure being brought about so suddenly that the disc and the valves I and I¹
are kept continually vibrating provided that heating and cooling continue without
interruption.
As mentioned the pressure may also be regulated by hand, the pressure
regulator described being then unnecessary. In this case the pressure in the
vessels must have been previously determined for different temperatures and a
table of these variations prepared so as to enable of finding the minimum pressure,
corresponding to a reading of the temperature on a thermometer, required outside
the vessels for producing equilibrium with the internal pressure. The pressure,
for greater surety, should preferably be kept somewhat higher than that indicated
by the table, this being accomplished by supplying to or drawing from the
receptacle a greater or less quantity of the pressure fluid.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is:-
:―
1. A method of preventing the bursting or loss of contents of bottles and other
vessels whilst sterilising substances or liquids enclosed therein, consisting in placing
the vessels containing the subtance or liquid to be pasteurised, in a closed recep-
tacle, filling the receptacle with water or other fluid and during both the heating
and the cooling operation, by forcing in or drawing off water or the like or a gas,
maintaining in said receptacle a. pressure equalling or slightly exceeding that
simultaneously existing in the vessels substantially as described.
2. For carrying out the process described an apparatus consisting of a closed
receptacle (as D) arranged to be heated and cooled and adapted to receive the
vessels containing the substance or liquid to be sterilised a smaller and likely closed
receptacle (as E) communicating with and located higher than the former, and a
pressure generator connected with the smaller receptacle substantially as described.
3. In combination with apparatus arranged as specified in Claim 2; a pressure
regulator consisting of a vessel having the same interior volume and co-efficient
of expansion as the vessels containing the liquid or material to be treated, said
vessel being enclosed in a receptacle (as D) and closed at its outer end by means of
a casing provided with a piston, or a thin flexible diaphragm, connected with
valves or the like which are actuated by the internal pressure acting upon the
piston or diaphragm, for the purpose of effecting the automatic regulation of the
external pressure by means of the internal pressure by causing the said valves to
open or close communication between the pressure generator, the open air or some
reservoir, and the closed receptacle (D) substantially as described.
4. The combination and arrangement of parts constituting the complete
apparatus for use in sterilising liquids or materials substantially as and for the
purpose described and illustrated in the accompanying drawings.
1
1
T 1007