Note: Descriptions are shown in the official language in which they were submitted.
#4836
l This invention relates generally to high speed
liquid filling machines, and more particularly relates to a
method of and apparatus for sterilizing such machines without
disassembly and reassembly, to thereby effect substantial cost
savings and insure sterility.
Past practice in high speed filling machines, par-
ticularly involving applications where sterilization is re-
quired such as in the pharmaceutical industries, required that
the machine be shut down and that the components through which
the medium to be filled flowed be disassembled and sterilized,
and after sterilization be reassembled againO A serious
problem with that process is that after sterilization the
reassembling of the machine can and often does reintroduce
non-sterile conditions. An important aspect of the present
invention is that the prior process is modified so that the
machine does not have to be disassembled and reassembled.
It is sterilized in place witho~t disconnection, and there is
no possibility that after the sterilization process has taken
place any contaminants can be reintroduced into the system.
In the system according to the in~ention, sterilization is
carried out in place by a sterili~ing medium of pure saturated
steam at 250F (or 121C).
Basically, the system operates by first closing off
the normal functioning of the machine. In the system to be
illustrated and described the sterilizing steam is introduced
into the product dispensing manifold, and this can be done
through the product supply line with the product supply line
being at that point disconnected from the product source.
Typically that is done by valving off the product supply
and then disconnecting the product suppl~ line from the supply
,
and
1 source/coImecting it to the sterilizing steam source. Al-
ternatively, the sterilization process can be carried back
as far into the system as is desired. For example, i~ the
product supply tank has been emptied, the steam can be intro-
duced at some earlier point to clean out or sterilize theproduct supply tank itself and/or any portion of the line
between the tank and product dispensing manifold.
A very large time saving and/or dollar saving is ef-
fected by using the system according to the invention. For
example, the entire sterilization process can be carried out
within an hour and a half and the machine can be back on
line and in operation. The alternative method of taking the
dispensing heads apart, autoclaving them and then reassembling
them requires substantially longer times. For example, it
takes an hour for the autoclaving sterilization process, and
approximately forty-five minutes per head for disassembly,
cleaning and reassemblyO In a typical twenty head machine9
this would require fifteen man hours of labor for disassembly,
cleaning and reassembling the heads, whereas in the system
according to the invention, since none of that is required,
the entire set-up process takes fifteen minutes irrespective
of how many heads there are in the machine~ The time savings
are therefore substantial.
The only alternative to this would be for the
operator to have duplicate mach;nery so that when one
piece of machinery is taken of~ line the other one can
be put on line, and the cleaning and sterilizing process
carried out while the second machine is operating. This
obviously is hugely expensive, and where a large number
of machines are being run in a system would be economically
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1 prohibitive. This alternative also results in very large
; down times for half of the machinery because half of it is
being operated and half of it is not being operated because
it is being cleaned~ so that there is no way to avoid this
tremendous financial outlay. Accordingly, the advantages of
the system are really two-fold. ~ne of the major advantages
is in not having a recontamination problem after steriliza-
tion of the machine9 and the second large advantage is the
economic one in which very substantial monetary savings are
effected,
Accordingly? a primary object of the invention is to
provide a novel method of and apparatus for sterilization of
product filling machinery which eliminates disassembly and
reassembly of the machinery and thereby eliminates the possib-
ility of recontamination after sterilization and during re-
assembly.
Another object of the invention is to provide a novel
method of and apparatus for sterilization of product filling
machinery as aforesaid which effects substantial monetary
savings by drastically reducing t~e time necessary to carry
out a sterilization cycle.
A further object of the invention is to provide a
novel method and apparatus as aforesaid utilizing steam steri-
lization which incorporates a novel steam condensate purge
system and a novel autoclave structure.
; The foregoing and other objects of the in~ention willappear more fully hereinafter from a study of the following
description and the appended drawings, wherein:
Figure 1 is a diagrammatic view of a portion of the
system according to the invention;
1 Figure 2 is a diagrammatic view of another portion of
the system according to the invention showing the novel con-
densate purge system;
Figure 3 is an enlarged vertical cross section through
one of the novel autoclaves as would be seen when viewed along
the lines 3-3 of Figure 2;
Figure 4 is an enlarged view of the autoclave region
shown in the identified phantom circle on Figure 3;
Figure 5 is an enlarged view of the autoclave region
shown in the identified phantom circle on Figure 3;
Figure 6 is a cross section through the autoclave
structure as would be seen when viewed along the lines 6-6
of Figure 4;
Figure 7 is a cross section through the autoclave
structure as would be seen when viewed along the lines 7-7
of Figure 5; and
Figure 8 is a vertical cross section through a con-
densate purge valve as would be seen when viewed along the
lines 8-8 of Figure 2.
1 In the several figures, like elements are denoted by
like reference characters.
Figure 1 shows a part of a filling machine in dia-
grammatic form including one of the dispensing nozzles 10
held in its reciprocable frame 11 and connected to an air
actuatable filling head 12 by a flexible tube 137 the filling
. head 12 being connected by flexible tubing 14 to a product
manifold 15 which latter is connected to a source of product
supply by tubing 16. The filling heads 12, of which there
normally are a number, are connected to an air manifold 17
which is fed from an air tube 18 that transmits pressurized
air to the manifold under control of apparatus contained in
the base cabinet 19, Supported from the base cabinet 19 are
a plurality of autoclaves 20, one o~ which is shown, and a
three position control switch 21 which is used to control the
sterilization system. A steam and condensate line 22 extends
from the lower end of the autoclave 20, and a control line 23
extends from the switch 21.
The autoclave 20, as ~est seen ln Figures 3 to 7,
is formed with an elongated hollow cylindrical shell 24
within which are threadedly secured at the upper and lower
ends respectively7 a hollow open ended plug 25 and a hollow
open ended fitting 26. The plug 25 has peripherallysecured
to the lower end of its interîor open end the upper end of
a reversing tu~e 27, which latter extends downward within
: the shell 24 to a bottom end 2& which terminates somewhat
above the upper end of fitting 26. The very bottom of the
reversing tube 27 is provided with an aperture 29 through
which steam condensate can drip through the bottom fit-
ting 26 into the steam and condensate line 22 which is
_ 5 _
1 secured to the bottom fitting by a compression fitting 30.
The sidewall of the upper end of the reversing tube 27 is also
- apertured immediately below the lower end of the plug 25, as
shown at 31. The upper end of plug 25 is formed as an exter-
nally threaded compression sleeve 32 upon which is threaded
a compression nut 33.
Disposable within the autoclave 20 is the dispensing
tube 34 of the nozzle 10 with the upper end of the dispensing
tube peri~herally sealed and locked within the plug 25 by the
compression sleeve 32 and nut 33 and with its outside surface
spaced away from the inside surface of the reversing tube 27.
As best seen in Figure 3, the flow path of the sterilizing
steam is shown by the solid arrows and follows a path downward
through flexible tubing 13 into the top of the dispensing tube
34, downward through the inside of the dispensing tube to its
open ended bottom where it reverses and flows upward between
the inside face of the reversing tube 27 and the outside face
of the dispensing tube 34 to the series of holes 31 through the
sidewall of the reversing tube 27 at the elevation immediately
below the plug 25. The steam then comes out through the holes
31 and goes down between the outside face of the reversing
tube 27 and the inside face of the autoclave shell 24, thereo
after passing down into the steam and condensate line 22.
Any condensate which is formed within the dispensing
tube 34 as the steam travels downward drips out the bottom
of the dispensing tube and through the aperture 29 at the
bottom of the reversing tube 27. The aperture 29 is such in
size that while no condensation build-up can occur inside the
reversing tube 27, it is possible for the condensate to ef-
fectively seal the bottom of the reversing tube so that the
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_eam coming out of the bottom of the dispensing tube 34 willreverse flow upward between the dispensing tube and the reversing
tube as previously described.
As best seen in Figure 2 the steam and condensate line 22
connects to a temperature sensing thermocouple 35 which senses the
sterilizing temperature and generates electrical signals at leads
36 which correspond to the temperature. The leads 36 are returned
inside the base cabinet 19 to actuate a temperature indicator and
can also be used to activate automatically sequencing control equip-
ment if desired. The steam and condensate continue past the -thermo-
couple 35 to a steam and condensate line 37 which discharges into
the intake end of a back pressure and constant bleed valve 38 which
is shown in detail in Figure 8 to be subsequently described. The
discharge end of valve 38 is connected by a discharge line 39 to a
condensate manifold 40.
Connected to the valve body is the intake port of an impulse
purge valve 41 which has its discharge port connected by a line 42
to the discharge line 39. To the condensate manifold 40 are also
connected the discharge ends of all o~ the other bleed valves i~the
sterilizing system which receive steam and condensate from other
autoclaves, one such other valve being illustrated as 38A. The
purge valve 41 is actuated and deactuated during sterilization via
a control line 43 by a repeat cycle timer 44 under the control of a
step programmer 45, all of the other purge valves, such as 41A,
being similarly controlled via control lines 43A through 43E. The
cycle timer 44 could typically be an ATC (trade mark) series 342
timer, and the step programmer could be an ATC Model 1800. ATC is
a designation for equipment manufactured by Automatic Timing and
Controls Company of King of Prussia, Pennsylvania 19406. The
condensate manifold has its outlet connected to a three way valve
46 which is actuated by actuator 47 so that the manifold
, ~ ~
:
1 is connected to atmosphere when the sterilization system is
not operating and is connected to a waste line when the
sterilization system is in operation. Control of the valve
actuator 47, timer 44, programmer 45, and purge valves 41
during the Initial Purge operation, is effected from the base
cabinet switch 21 through control line 23.
Details of the valve 38 and purge system are shown in
- Figure 8 to which reference should be made. The intake of
the valve 38 empties into a small vertical passage 48 which
connects at its bottom to a horizontal passage 49 into which
; is threadedly engaged a valve stem 50 which may be advanced
and retracted by the valve handle 51 to variably open and
close the passage 49 to control the size of the opening be-
tween the passage 49 and the vertical exit passage 52 and
thereby control the back pressure in the steam line. The
intake vertical passage 48 also connects, near its junction
with the horizontal passage 49, to a horizontal passage 53
which couples to the intake port of purge valve 41 D the dis-
charge port being connected, as previously describe~ to the
discharge line 39 by the line 42.
The sequence of events that takes place in carrying
out the steam sterilization according to the invention is as
follows. First, the supply of product is cut off from the
product manifold 15 in whatever manner is convenien~ as for
example by valving. Next, the dispensing nozzles 10 are each
removed from their operatively held position for dispensing
product and are each inserted into and secured within a
separate autoclave 20 as previously described. In Figure 1
only one such nozzle is illustrated; but as schematically
shown in Figure 2 this process is carried out for all of the
1 nozzles in the entire apparatus. Assuming~that sterilizing
steam is availa~le ~t this point, the switch 21 on the base
cabinet 19 is moved from its "Off" (0) position to the
Initial Purge (IP) position. This causes the three-way valve
to change its position so that the condensate manifold which
had been connected to atmosphere is now connected to the
waste line.
Actuating pulses from control line 23 are simultan-
eously routed to all of the imp~se purge valves 41, 41A and
so forth, so that all of the valves are opened simultaneously
to by-pass each of the constant bleed valves 38. This allows
steam to flow through the entire system rapidly to quickly
purge out all of the air and non~condensable gases that are
in the system. At this initial point in the sterilization
cycle any steam temperature drop which oc~urs is ~ot critic-
ally important since it will be followed up with sterilizing
temperatures. This initial purge condition is maintained
until the thermocouples 35 sensing the temperatures in the
autoclaves 20 indicate that the system is coming up to tem-
perature. The actual time that this requires is a function ofthe size of the system, that is, how many heads are being
autoclaved, and whether just the dispensing nozzles are being
sterilized or whether some larger part of the system which
has more mass to it is being sterilized, such as the product
holding tank. In any event this allows the sy~tem to come up
to temperature much more rapidly than if the steam had to flow
through the back pressure and constant bleed valves 38~
It is desired that those valves 38 be initially ad-
justed and that they not have to be thereafter frequently re-
adjusted. The adjustment for back pressure is such that the
.
:
1 valves 38 will not be in maximum flow condition during normalsterilization cycle, and therefore the impulse purge valves
being all simultaneously opened allows a much faster steam
flow through the system~ and consequently a more rapid rise
` 5 in temperature within the system so that the sterilization pro-
cess can be started sooner.
~ hen the initial purge has been completed the switch
21 on the base cabinet 19 is moved from the "IP" position to
the "S" or sterilize position. This activates the cycle timer
44 and step programmer 45 via control line 23 f~ carrying out
a sequentially controlled purge process and discontinues the
simultaneous activation of the purge valves. The steaming
process goes on continuously during the sterilizakion time,
` and all of the nozzles of the system are simultaneously subjec-
ted to the sterilizing steam on a continuous basis. While
this continuous steaming process is going on there is also
a cyclic condensate purge process that is carried out, and this
purge process is carried out nozzle by nozzle in a timed
i sequence. The sequence is such that the purge for each nozzle
takes place for a selected time interval o~ perhaps up to two
seconds in length. The reason for purging on a sequential
basis is that if purging o~ all of the autoclaves were done
simultaneously the steam source would be depleted and would
result in a temperature drop below the required sterilization
temperature of 250F. In order to avoid this, the purge opera-
tion is carried out sequentially so that only one autoclave
at a time is being purged, not the entire group9 which could
be as many as thirty-two or more separate autoclaves.
The purpose of the purge operation is best understood
by reference again to Figure 8. From that showing it will be
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~z~
l clear that condensate which may puddle up in the internal
passages of the valve cannot bleed through to the discharge
condensate manifold 40 as rapidly as the steam or gas phase
can, and as a consequence condensate can start to build up in
that valve and back-up into the autoclave, thereby interfering
with the steam sterilization processigoing on therein. For
purposes of eliminating this problem the impulse purge valves
41 are provided. By means of the purge valve actuation for a
short time period whatever condensate may have collected at
the bleed valve passage 49 is rapidly by-passed to the larger
passageway 42 around the valve structure and into the conden-
sate manifold line. This eliminates the problem of condensate
build-up into the autoclave structures.
The impu~se purge valves 41 are controlled by timing
pulses from the cycle timer 44 which actuate the purge valves
to open under control of the step programmer 45. The cycle
timer 44 produces the selectable length of actuating pulse
that is desired, and this pulse, which is being repeatedly
generated, is distributed out to each of the impulse purge
valves in a timed sequence as controlled by the ste~ program-
mer 45. This sequence is continuous during the c-ourse of the
entire sterilization process. That is, while the steam steri~
zation may be going on for as long as forty-five minutes to an
hour, the impulse purge valves are being operated in sequence
for timed intervals of up to two seconds each) and this se-
quence is continuously repeating itself throughout the course
of the sterilization process.
Having now describéd the invention in connection with
particularly illustrated embodiments thereof, it will be ap-
preciated that variations and modifications of the invention
1 may now naturally occur from time to time to those personsnormally skilled in the art without departing from the essen-
tial spirit or scope of the invention, and accordingly it is
intended to claim the same broadly as well as specifically as
indicated by the appended claims.
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