US3481688A - Method and apparatus for autoclaving product-containing flexible pouch constructions or the like - Google Patents

Description

Dec. 2, 1969 F. A. CRAIG ET AL 3,481,688

METHOD AND APPARATUS FOR AUTOCLAVING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Filed Nov. 16, 1966 6 Sheets-Sheet 1 INVENTORS FRANCIS A. CRAIG MERLE LALBRIGHT THEIR ATTORNEYS FlGalA 2. 1969 F. A. CRAIG ET AL 3,481,688

METHOD AND APPARATUS FOR AUTOCLAVING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Filed Nov. 16, 1966 6 Sheets-Sheet 2 INVENTORS FRAN IS A. CRAI MERL L.ALBRlgHT THEIR ATTORNEYS Dec. 2. 1969 F. A. CRAIG ET AL 3,481,688

METHOD AND APPARATUS FOR AUTOOLAVING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Filed Nov. 16, 1966 e Sheets-Sheet 5 INVENTORS FRANCIS A. CRAIG MERLE L. ALBRIGHT THEIR ATTORNEYS Dec. 2. 1969 F. A. CRAIG ET AL 3,481,688

METHOD AND APPARATUS FOR AUTOCLAVING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Filed Nov. 16, 1966 6 Sheets-Sheet A INVENTORS FRA A.

F A MEA E' LAL B AA HT THEIR ATTORNEYS Dec. 2. 1969 F. A. CRAIG ET A 3,481,688 METHOD AND APPARATUS FOR AUTOCLAVING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Filed Nov. 16, 1966 6 Sheets-Sheet 5 l I WW 5 "'Y'JL lg WM mwrm 1 8 1, 1 z I l 1 1 no.5 34 34 Fmawswme m if MERLE ALBRIGHT F l G I 6 THEIR ATTORNEYS Dec. 2. 1969 F. A. CRAIG ET AL 3,481,688

METHOD AND APPARATUS FOR AUTOCLAVING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Filed Nov. 16, 1966 6 Sheets-Sheet 6 vge'eyo [[8 Z; r 2 5 I FITTCIEIEIZ Z INVENTORS J0 FRANClS A. came 27 g MERLE L.ALBRIGHT r" 9 BY 244m, FIGJO FIG. haw M THEIR ATTORNEYS United States Patent ()ifice 3,481,688 Patented Dec. 2, 1969 3,481,688 METHOD AND APPARATUS FOR AUTOCLAV- ING PRODUCT-CONTAINING FLEXIBLE POUCH CONSTRUCTIONS OR THE LIKE Francis A. Craig and Merle L. Albright, Richmond, Va., assignors to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Filed Nov. 16, 1966, Ser. No. 594,928

Int. Cl. A611 1/00 US. Cl. 21-56 21 Claims ABSTRACT OF THE DISCLOSURE It is well known that food products and the like can be packaged in rigid metallic containers or the like and, thereafter, be subjected to an autoclaving operation to kill harmful bacteria in the food products so that the productcontaining rigid metallic containers will maintain the food product in a preserved condition for a relatively long period of time before the ultimate consumer opens such containers for product consumption purposes.

However, this invention relates to a method and apparatus for autoclaving product-containing non-rigid container means, such as flexible metallic foil containing pouch constructions formed in a'manner hereinafter set forth, wherein the autoclaving operation does not adversely affect the non-rigid container means even though internal forces are created inside such non-rigid container means during lhe autoclaving operation that would normally tend to burst or other Wise adversely affect the sealed closed condition of the non-rigid container means.

In particular, one feature of the method and apparatus of this invention is to provide means for counterbalancing the adverse internal pressures created within the non-rigid container means during the autoclaving operation by pressurizing the autoclaving chamber in a manner hereinafter set forth.

Another feature of this invention is to provide means for effectively killing the harmful bacteria during the autoclaving operation without destroying the unharmful enzymes of the product means, the destroying of the unharmful enzymes adversely affecting the taste of the product means when subsequently consumed by the ultimate consumer.

In the embodiment of the invention hereinafter set forth, the pouch constructions are introduced into an autoclaving chamber of a housing means and are continuously moved therein by a rotatable member or rotor while a combination of pressurized steam and compressed air is substantially continuously introduced into the autoclaving chamber to autoclave such pouch constructions, the housing means having vent control means for substantially continuously venting the autoclaving chamber to the atmosphere during the autoclaving operation. Thereafter, the pouch constructions are cooled to the desired temperature in the autoclaving chamber before the same are removed therefrom for subsequent shipping, storing and merchandising thereof or the like.

Accordingly, it is an object of this invention to provide a method for autoclaving non-rigid product-containing pouch constructions or the like, the method of this invention having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an apparatus for autoclaving non-rigid product-containing pouch constructions or the like, the apparatus of this invention having one or more of the novel features set forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIGURES 1A and 1B schematically illustrate the apparatus and method of this invention with FIGURES 1A and 1B being adapted to be placed together along the respective lines 1A1A and 1B1B to fully illustrate the mechanical and fluid system of this invention.

FIGURE 2 is a schematic diagram of the electrical control system for controlling the apparatus of FIGURES 1A and 1B.

FIGURE 3 is an'enlarged, fragmentary, cross-sectional view of the housing means of FIGURE 1B and is taken on line 3-3 thereof.

FIGURE 4 is a fragmentary, cross-sectional view taken substantially on line 44 of FIGURE 3.

FIGURE 5 is a fragmentary, cross-sectional view taken substantially on line 55 of FIGURE 3 and illustartes in full lines an initial step in loading the rotor of the apparatus and in phantom lines the full loaded position of the rotor.

FIGURE 6 is an enlarged, fragmentary, cross-sectional view taken on line 66 of FIGURE 5 and illustrates one embodiment of the material for forming the flexible pouch constructions of this invention.

FIGURE 7 is a perspective view of a typical configuration of a pouch construction of this inventtion.

FIGURE 8 is an enlarged view of one of the plate means of the rotor for carrying the pouch constructions in the apparatus of this invention.

FIGURE 9 is a cross-sectional view taken on line 9-9 of FIGURE 8.

FIGURE 10 is a fragmentary, cross-sectional View taken on line 10-10 of FIGURE 3.

FIGURE 11 is a fragmentary, cross-sectional view taken on line 11-11 of FIGURE 3.

FIGURE 12 is a schematic graph illustrating the temperature relationships in the apparatus of this invention by full lines and a temperature relationship therein by dotted lines if an improved feature of this invention is not utilized.

While the various features of this invention are hereinafter illustrated and described as being particularly adaptable for autoclaving product-containing flexible pouch constructions formed of metallic foil or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide autoclaving means for other types of non-rigid pouch constructions formed of other types of suitable material.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGURES 1A and 1B, the improved method and apparatus of this invention is generally indicated by the reference numeral 20 and includes a housing means or retort 21 for autoclaving product-filled and nonrigid container means, such as the flexible pouch constructions generally indicated by the reference numeral 22 in FIGURE 7 and throughout the drawings, such autoclaving operation taking place in an autoclaving chamber 23 provided within the housing means 21.

As illustrated in the drawings, the housing means 21 includes a cylindrical body member 24 having opposed end walls 25 closing the opposed ends of the cylindrical body member 24, one of the end closures 25 forming an access door for placing the pouch construction 22 in the autoclaving chamber 23 and for removing the same therefrom.

In particular, a rotatable member or rotor 26 is disposed in the autoclaving chamber 23 of the housing means 21 and is rotatably mounted therein by shaft means 27,

the rotatable member 26 having two spaced and aligned arcuate outer bands 28 and 29 respectively supported from the shaft means 27 by cross brace means 30, FIG- URES 3, 4 and 11, and to each other by inverted V-shaped cross pieces 31, the cross pieces 31 being uniformly spaced about the rotor 26 and intermediate the adjacent cross braces 30 as illustrated in FIGURE 3 for a purpose hereinafter described. In addition, the adjacent cross braces 30 carry transversely disposed guide members 32 with each pair of guide members 32 cooperating with an aforementioned V-shaped member 31 in a manner hereinafter described and being connected together by an end plate means 33 for a purpose hereinafter described.

Such rotatable member or rotor 26 is adapted to carry or support the product-filled flexible pouch constructions 22 in such a manner that the pouch constructions 22 can be continuously rotated within the autoclaving chamber 23 during the entire operation of the apparatus 20 for a purpose hereinafter described.

In the embodiment illustrated in the drawings, it can be seen from FIGURES 5, 6 and 7 that each pouch construction 22 is formed from sheet material 34, FIGURE 6, having an outer layer of metallic foil 35, such as aluminum-containing metallic foil or the like, laminated to an inner heat scalable layer 36, such as polyvinylchloride or the like, with the sheet material 34 being folded and arranged into the rectangular configuration illustrated in FIGURE 7 and having the facing heat sealable layer 36 thereof heat sealed to itself to define a completely sealed closed outer peripheral side edge means 137 of the pouch construction 22 outboard of an internal chamber 37 therein which contains the desired product means 38, such as food or the like.

In this manner, the product means 38 is substantially hermetically sealed within each pouch construction 22 by the aforementioned heat scalable layer means 36 while the entire pouch construction 22 is substantially flexible and non-rigid whereby the subsequent steam created within the sealed closed chamber 37 of each pouch construction 22 during the autoclaving of the pouch construction 22 within the autoclaving chamber 23 of the housing 21 at a required autoclaving temperature, such as 250 F. or the like, would completely rupture or otherwise adversely affect the non-rigid sheet means 34 so that the aforementioned hermetically sealed relationship could not be provided unless the teachings of this invention are followed in a manner hereinafter set forth.

A plurality of plates 39, FIGURES 8 and 9, are provided for carrying the pouch constructions 22 in the rotatable member or rotor 26 of the apparatus 20 of this invention, each plate 39 having one or more substantially rectangular slots or recesses 40 passing therethrough and each being of a size to permit at least half of the chamber defining portion 37 of a pouch construction 22 to be fully received in the recess 40 while the sealed closed peripheral area 137 thereof will abut against the non-slotted portion of the plate 39 in the manner illustrated in FIGURE at all four sides of the particular pouch construction 22. One side of each plate 39 carries a perforated member or screen 41 to close off the slot means therein while permitting fluid flow therethrough.

In this manner, one or more product-filled flexible pouch constructions 22 can be disposed in the non-screened side of a plate 39 and have the non-screened side of another plate 39 disposed over the same in the manner illustrated in FIGURE 5 so that the cooperating plates 39 clamp the sealed areas 137 of the pouch constructions 22 firmly therebetween at all four sides of each pouch construction 22 while the outboard screen means 41 of the cooperating pair of plate means 39 substantially prevent movement of the non-clamped portions of the pouch constructions 22 relative to the plate means 39 whereby no bumping and tearing of the pouch constructions 22 can take place while the same are being rotated in the autoclaving chamber 23 by the rotor 26 and whereby a substantially uniform autoclaving of the product means will be provided as the product means is stabilized in the pouch constructions and cannot compact into one end of the pouch constructions.

The plates 39 each have a V-shaped cutout 42 at the bottom thereof as well as a plurality of openings 43 passing therethrough to permit the plates 39 to be arranged in stacked relation on pin means 44 having nuts 45 or the like threaded on one end 46 thereof in the manner illustrated in FIGURE 5, each pair of cooperat ing plate means 39 being adapted to be spaced from adjacent pairs of cooperating plate means 39 by suitable spacer means 47 telescoped on the pin means 44 in the manner illustrated in FIGURE 5. After a particular set of pin means 44 have been loaded with the desired number of cooperating plate means 39 in the manner illustrated in FIGURE 5, other nut means 48 can be threaded on the other end 49 of the pin means 44 to tightly compact the plate means 39 and spacers 47 together between the cooperating nut means 45 and 48 so that the sealed peripheral areas 137 of the held pouch constructions 22 will be firmly clamped between their respective pair of cooperating plate means 39.

The stacked and pinned plate means 39 are adapted to be loaded into the rotatable member or rotor 26 of the apparatus 20 by axially moving the stacked plate means 39 into the areas between adjacent cross members 30 of the rotor 26 while being guided and supported along a respective V-shaped member 31 at the aligned V-shaped cutouts 42 of the plate means 39, the arcuate guide members 32 guiding and maintaining such telescoping relationship until the stacked plate means 39 abut against the end member 33 of a cooperating pair of guide members 32 in the manner illustrated in phantom lines in FIGURE 5.

Thus, it can be seen that a plurality of product containing flexible pouch constructions 22 can be loaded into the rotor 26 of the apparatus 20 in stacked units and be removed therefrom in a relatively simple manner while permitting such pouch constructions 22 to be firmly held and stabilized by the clamping plate means 39 so that no banging or bruising of the pouch constructions 22 and product means 38 can take place and the product means cannot readily shift in the pouch constructions during the rotation of the pouch constructions 22 within the autoclaving chamber 23 by the rotatable member 26.

In general, once the rotatable member or rotor 26 of the housing means 21 has been loaded with the desired number of product-containing flexible pouch constructions 22 in the manner previously described, the housing means 21 is sealed closed and the pouch constructions 22 are first autoclaved therein at the desired temperature for the desired length of time in a manner hereinafter set forth while the member 26 is rotating relative to the housing means 21 and, thereafter, the temperature of the autoclaved pouch constructions 22 is reduced to a desired temperature by a cooling operation of the apparatus 20 in a manner hereinafter set forth so that at the end of the cycle of operation of the apparatus 20 of this invention,

sealed closed condition of the flexible pouch constructions 22 has not been adversely affected by the steam created therein during the autoclaving operation because of the following features of this invention.

In particular, during the autoclaving operation the autoclaving chamber 23 is pressurized with an overriding pressure that fully counterbalances and offsets the internal pressure created in the chambers 37 of the pouch constructions 22 so that no bursting or adverse effects are placed on the hermetically sealing flexible sheet material 34 of the pouch constructions 22 and the product means 38 has not been overcooked so as to destroy the taste producing enzymes thereof because the processing time for the autoclaving operation previously described in greatly reduced over prior known autoclaving times as will be apparent hereinafter.

After the retort or housing means 21 has been loaded with the product-containing flexible pouch means 22 in the manner previously described, the operator pushes downwardly on the start button 50, FIGURE 2,. to bridge a contact 51 with a contact 52 to energize a latching coil 53 of a pneumatic valve 54, FIGURES 1A and IE, to supply control air from a conduit means 55 interconnected to a source of compressed air (not shown) to a temperature recorder 56 that supplies the control air to a combined liquid level recorder-controller and cook pressure recorder-controller 57, the button 50 placing the coil 53 across the power source lead L and L because the contact 51 is interconnected to the lead L by leads 58 and 59 and the contact 52 is interconnected to one side 60 of the coil 53 by a lead 61, control output switch 62, normally closed contact means 63 of a relay 64 and a lead 65 with the other side 66 of the coil 53 being interconnected to the lead L by a lead 67.

The closing of the push button 50 against the contact 52 also energizes a coil 68 of a pneumatic valve 69 to supply control air from the compressed air supply conduit 55 to a come-up pressure controller 70 as one side 71 of the coil 68 is interconnected to the contact 52 through normally closed contact means 73 of the relay 64 and, thus, to power source lead L while the other side 74 of the coil 68 is interconnected to the lead 75 interconnected to the power source lead L by a lead 76.

The pushed-in start button 50 also energizes a coil 77 of a solenoid operated valve 78 through the previously described normally closed contact means 73 of the relay 64 to cause the solenoid operated valve 78 to supply control air to open a large valve 79 in a conduit means 80 leading from a steam boiler (not shown) to the autoclaving chamber 23 of the housing 21 to introduce steam under pressure into the autoclaving chamber 23. The energized solenoid operated valve 78 also supplies control air to a pneumatically operated valve 81 to open the valve 81 and interconnect a vent conduit 82 leading from the autoclaving chamber 23 to the atmosphere at point 83, the energized solenoid operated valve 78 also supplying control air to a pneumatically operated valve 84 to close the valve 84 to prevent the conduit 82 from being interconnected to the atmosphere at point 83 through the valve 84 for a purpose hereinafter described.

As the pressure in the autoclaving chamber 23 of the housing means 21 increases to a predetermined point as sensed by the come-up pressure controller 70 through a sensing probe conduit means 85, the increased sensed pressure in the conduit 85 closes a pressure switch 86 connected to the conduit means 85 to interconnect at contact 87 with a contact 88 to energize a relay coil 89 to start the running operation of a come-up timer 90 as the energized relay coil 89 closes normally opened relay contact means 91.

When the set point on the come-up controller 70 is reached by the opened steam conduit raising the pressure within the autoclaving chamber 23 to the set point of the recorder 70, such as 22 p.s.i.g. for a purpose hereinafter described, the recorder 70 terminates the supply of control air to the solenoid operated valve 78 to cause the large pressure operated valve 79 in the steam conduit 80 to close, the valve 81 in the vent conduit 82 to close and the valve 84 in the vent conduit 82 to open to now interconnect the vent conduit 82 to the atmosphere at point 83.

. When the temperature in the autoclaving chamber 23 of the housing means 21 reaches a set point, such as 275 F. for a purpose hereinafter described, as determined by the temperature recorder-controller 56, the temperature recorder-controller 56 causes the pressure switch 62 to break the electrical connection to the normally closed contact means 63 of the relay 64 while placing the relay coil 92 across the power source L and L to close the normally open relay contact means 93 of the relay 64 while opening the normally closed contact means 63 thereof to start the running operation of a cook timer means 94 and energize a cycle light means 95 to indicate to the operator that the cook or autoclaving cycle has begun.

When the come-up timer 90 times out, the same opens pressure switch 86 so that the come-up pressure controller 70 becomes inoperative. However, the closing of the contact means 93 by the pressure switch 62 will permit a relay coil 136 to be placed across the power source leads L and L to close normally open contact means 137' when the pressure switch 62 returns to the position of FIGURE 2 by the temperature recorder-controller 56 sensing a drop in temperature in the chamber 23 to a set point in a manner hereinafter described whereby a coil 138 of a solenoid valve 139 would be energized, such energized valve 139 being adapted to direct control air to the cook pressure part of the controller 57 which would then be adapted to direct control air to a pressure operated valve in the compressed air conduit 55 and to the vent valve 84 through a normally opened part of a solenoid operated valve 103.

Since the pressure in the autoclaving chamber 23 is now higher than the cook pressure set point for the cook.

pressure controller 57, the cook pressure controller 57 causes the vent valve 84 to open to bring the retort or autoclaving pressure down to the set cook point, such as 20 p.s.i.g. for a purpose hereinafter described, so that when the retort pressure reaches the set cook point as determined by the cook pressure controller 57, such set cook point pressure is now maintained in the autoclaving chamber 23 of the housing 21 by the cook pressure controller 57 directing control air in a cycling manner to open and close the vent valve 84, the cook pressure manner to open and close the valve 195 in the compressed air line 55 so that compressed air can be delivered into the autoclaving chamber 23 when the temperature recordercontroller 56 senses that the chamber 23 has its temperature dropped to the set point of 250 F. or the like.

The vent valve 84 is so constructed and arranged that the same will be supplied with low pressure control air at all times by the cook pressure controller 57 so that the same is at least partially open during the entire autoclaving cycle after the temperature set point has been reached and will be further regulated between such partially open condition and a full open condition by the controller 57 so as to maintain the set point cook pressure in the autoclaving chamber 23.

When the temperature in the autoclaving chamber 23 drops to the controlled set point of approximately 250 F., the temperature controller 56 causes the pressure switch 62 to move back to the position illustrated in FIGURE 2 sasress to interconnect the lead L to the now closed but normally open contact means 93 and, thus, energize a coil 95A of the relay 64 to open the normally closed contacts 73 of the relay 64 to deenergize the coils 68 and 77 whereby the valve 69 closes and the solenoid operated valve 78 closes so that the pressure in the autoclaving chamber 23 is no longer controlled by the cook pressure controller 70 and the large steam valve 79 is closed.

The interconnecting of the power source lead L to the now closed contact means 93 of the relay 64 by the temperature controller 56 also causes energizing of a coil 96 of a solenoid operated valve 97 to direct control air from the temperature controller 56 to a pressure operated small valve 98 in the steam line 80 to open the valve 98 to permit a lesser amount of steam to be by-passed around the valve 79 in the steam line 80 and be directed to the autoclaving chamber 23 of the housing means 21, the interconnecting of the power source lead L to the closed contact means 93 of the relay 64 also energizing a coil 99 of the relay 64 to close normally open-ed contacts 100 of the relay 64 to provide a holding circuit for maintaining the coil 96 of the solenoid operated valve 97 and the coil 138 of the solenoid operated valve 139 energized.

From the above, it can be seen that compressed air is now adapted to be supplied by the valve 195 to the autoclaving chamber 23 simultaneously with steam being adapted to be supplied around the closed large valve 79 by the small valve 98 so that a combination of steam and air can be maintained in the autoclaving chamber 23 with the vent valve 84 continuously venting the autoclaving chamber 23 during the entire autoclaving cycle in the chamber 23, the compressed air valve 195 and vent valve 84 being controlled by the pressure controller 57 and the steam valve 98 being controlled by the temperature controller 56.

In particular, during this autoclaving or cook cycle, the vent valve 84 and air valve 195 control the pressure in the autoclaving chamber 23 because the pressure controller 57 causes the vent valve 84 to open when the pressure in the chamber 23 is high to reduce such pressure and causes the air valve 195 to open when the pressure in the chamber 23 is low to increase such pressure by condensing the steam in the chamber 23. The small steam valve 98 controls the temperature in the autoclaving chamber 23 because the temperature controller 56 opens the valve 98 when the temperature is low to add more steam in the chamber 23.

Thus, during the entire cook or autoclaving cycle in the chamber 23, the temperature is maintained at approximately 250- F. and the pressure in the chamber 23 is maintained at aproximately 20 p.s.i.g. of p.s.i.g. thereof is caused by the steam at 250 F. and the remaining 5 p.s.i.g. is caused by the compressed air.

When the cook timer 94 times out after the autoclaving cycle has taken place in the above manner for the particular food product 38, the timing out of the timer 94 causes the start button 50 to move to the timed out position of FIGURE 2 and close normally open contact means 101 of the relay 64 to energize coil 102 of the solenoid operated valve 103 which causes a water pump 104 in a water source conduit 105 to begin operating and directs a full supply of control air to the vent valve 84 to completely close the vent valve 84. The timing out of the timer 94 also causes the contacts 63 of the relay 64 to return to their normally closed position and causes the contacts 93 to return to their normally open position which deenergizes coil 95A to deenergize the cook timer 94 and turn off the cook light 95.

The contacts 100 of the relay 64 also return to their normally open position to deenergize coil 96 of the solenoid operated valve 97 whereby the small steam valve 98 closes.

At this time, coil 133 of a solenoid operated valve 134 is energized by a normally closed time delay relay 135 whereby the solenoid operated valve 134 directs control air to a pressure operated valve 106 in the water line to open the valve 106 so that Water can be directed into the autoclaving chamber 23 of the housing 21. However, the flow of water through the valve 106 is delayed further by low pressure control air due to a needle valve 107 in advance of the valve 106 and the filling of an accumulator 108.

When the time delay relay 135 times out, the relay 135 deenergizes the coil 133 of the solenoid operated valve 134. However, control air is still supplied to the water valve 106 through a normally opened port means of the solenoid operated valve 134 to fully open the valve 106 and permit water to be continuously fed and sprayed into the autoclaving chamber 23 to tend to reduce the temperature of the autoclaved pouch constructions 22 therein, the air valve 195 supplying compressed air to the chamber 23 during the cooling operation to maintain the pouch constructions 22 under pressure.

When the temperature in the autoclaving chamber 23 of the housing 21 reaches a predetermined set point, such as 120 F., a pneumatically operated switch 109 bridges the contacts 110 and 111 and through closed contacts 137, which contacts 137' have been previously closed by the previously energized coil 136 when the contacts 93 of the relay 64 were closed by the pressure switch 62, energizes the end of the cooling cycle light 114.

When the light 114 is energized in the above manner, the cycle of operation of the system 20 of this invention can be terminated at the option of the operator.

For example, the operator can now push the end of cooling cycle button 115 to bridge the contacts 116 and 117 whereby the trip coil of the pressure operated valve 54 and trip coil 113 of the relay contact means 137 are energized to stop the water pump 104, close the Water valve 106, open the pressure operated valve 118 in a drain conduit 119 to drain the water from the chamber 23 of the housing means 21, open the vent valve 84 and close the air valve 195 whereby the entire cycle of operation of the system 20 is terminated until the start button 50 is again pushed to repeat the entire cycle of operation in the manner set forth above, the pressure operated drain valve 118 being supplied control air to open the same when a pressure operated switch 141 of a temperature transmitter 142 senses a temperature in the autoclaving chamber below 215 or the like to bridge a contact 143 with a contact 144 to energize coils 145 and 146 of solenoid operated valves 147 and 148.

From the above detailed cycle of operation of the system 20 of this invention, it can be seen that one embodiment of an automatic control system has been provided whereby it is to be understood that other types of control systems and operating procedures can be followed according to the teachings of this invention which will fall within the scope of the accompanying claims because the above detailed description is not intended to be a limitation on this invention but is merely to set forth the best known mode of automatic operation for the autoclaving procedure.

In particular, it can be seen that the system 20 of this invention generally comprises the following steps.

The autoclaving chamber 23 of the housing means 21 is loaded with the product-containing flexible pouch constructions 22 in the manner previously described to be continuously rotated in the autoclaving chamber 23 by the rotatable member 26 during the entire cycle of operation of the system 20 so that each pouch construction 22 Will be rotated in the autoclaving chamber 23 to minimize the effect of any cold or hot spots in the chamber 23, the rotatable member 26 being rotated when the cycle of operation is initiated by the pushin of the start button 50 and terminating when the end of cycle button 115 is pushed by the operator.

When the start button 50 is pushed to start the cycle of operation of the system 20, the large steam valve 79 is opened to rapidly bring up the steam pressure in the autoclaving chamber 23 to approximately 22 p.s.i.g. or above in order to rapidly raise the temperature of the pouch constructions 22 in the autoclaving chamber 23.

For example, this high pressure of steam in the autoclaving chamber 23 can be held for a predetermined time, such as about 1% to 1% minutes so that the temperature of the pouch constructions 22 rapidly approach the desired temperature of 250 F. for the subsequent autoclaving thereof.

As illustrated in FIGURE 12, a schematic graph 120 is provided wherein the vertical axis 121 represents increase in temperature from the point 122 and the horizontal axis 123 represents increase in time from the point 122. The full line 124 represents the temperature in the autoclaving chamber 23 being increased by this initial introduction of steam at 22 p.s.i.g. or above to rapidly raise the temperature in the autoclaving chamber 23 above the desired autoclaving temperature of 250 F., the high point of the temperature in the autoclaving chamber 23 being around 275 F. or above so that the temperature of the pouch constructions 22 will rapidly rise as represented by the full line 125 on the graph 120 to approximately 250 in a relatively short period of time whereby when the temperature in the chamber 23 is brought down to approximately 250 F. by the system 20 in the manner previously described, the period of time required for the overall autoclaving operation of the pouch constructions 22 at the 250 level is greatly reduced over the time required to normally bring the temperature in the autoclaving chamber 23 to the desired autoclaving temperature and, thereafter, maintain the same at the autoclaving temperature for the required amount of time to kill the harmful bacteria.

7 For example, the dotted line 126 on the graph 120 represents the temperature in the autoclaving chamber 23 if the temperature in the autoclaving chamber 23 is merely brought up to 250 by the introduction of steam at 250 F. (at a pressure of approximately 20 p.s.i.g.) whereby the temperature of the pouch constructions 22 will slowly rise to the temperature of 250 F. as represented by the dash line 127 on the chart 120 so that it can be seen that a relatively long period of time is required to bring the pouch constructions 22 to the desired temperature of 250 if the steam being introduced initially into the chamber is also at only 250 F.

From the above, it has been found that when the overall time that the pouch constructions 22 of this invention are being maintained in the autoclaving chamber 23 at temperatures above 120 or the like, the taste producing enzymes are more likely to be adversely afiected than if the autoclaving period of time is maintained as close as possible to only that time required to kill the harmful bacteria. Thus, by initially raising the temperature in the autoclaving chamber 23 well above the desired autothe chart 120 whereby the taste producing enzymes in the pouch constructions 22 being autoclaved by the method and apparatus of this invention are not adversely affected. Further, since the entire amount of time required for elevated temperatures in the autoclaving chamber 23 of this invention is relatively short, it can be seen that the autoclaving costs are greatly reduced over the autoclaving costs when the temperature of the pouch constructions 22 are being controlled along the line 127 of the graph 120.

During this initial introduction of steam into the autoclaving chamber 23 of the housing means 21 by the opening of the large steam valve 79, the chamber 23 is interco-nnected to the atmosphere at point by the opening of the vent valve 81. However, the vent valve 81 does not open initially until the temperature in the autoclaving chamber 23 has risen to some predetermined point, such as F. whereby when the vent valve 81 opens, it only remains fully open for a relatively short period of time to permit purging of the initial cold air in the chamber 23 by the incomin compressed air and steam whereby the valve 81 then partially closes to permit the raising of the pressure in the autoclaving chamber 23.

As previously stated, the initial pressure in the autoclaving chamber 23 is permitted to raise until the same reaches a high point above normal autoclaving pressure, such normal autoclaving pressure being approximately 20 p.s.i.g. to produce the autoclaving temperature of 250 F., with this high point being approximately 22 p.s.i.g. or above so that the temperature in the auto-claving chamber 23 is initially around 275 F. to rapidly raise the temperature of the pouch constructions 22 for the purposes previously described.

However, once this high pressure is reached, the pressure controller 57 controls the introduction of the compressed air by modulating the valve with the temperature controller 56 controlling the introduction of the steam through the smaller steam valve 98 with the large steam valve 79 being closed, the vent valve means 84 also being controlled by the pressure controller 57 to tend to maintain a constant steam pressure of approximately '15 p.s.i.g. and a constant air pressure of approximately 5 p.s.i.g. in the chamber 23 because such combined pressure in the autoclaving chamber 23 is approximately 20 p.s.i.g. and maintains the desired 250 F. autoclaving temperature therein. Since steam at 15 p.s.i.g. alone will produce the 250 F. in the autoclaving chamber 23, the additional 5 p.s.i.g. of compressed air in the autoclaving chamber 23 is an overriding pressure which will prevent the pouch constructions 22 from bursting or otherwise adversely atfect the sealed condition of the product means 38 therein because without this overriding pressure of 5 p.s.i.g., the internal pressure created in the pouch constructions 22 would burst the non-rigid sheet means 34.

Thus, the temperature controller 56 controls the introduction of the steam into the autoclaving chamber 23 and the pressure controller 57 controls the introduction of the compressed air and modulation of the vent valve means 84 to maintain the constant autoclaving pressure and temperature previously described until a desired cooking or autoclaving time has been accomplished, such as being automatically terminated by the timer 94 timing out.

When the autoclaving timer 94 has timed out, the small steam valve 98 is now closed as well as the vent valve 84. However, the compressed air now rushes into the autoclaving chamber 23 to fully maintain the desired 20 p.s.i.g. in the autoclaving chamber 23 even though no more steam is being introduced therein.

Once the time delay relay 135 energizes the coil 133 of the solenoid operated valve 134, and through the previously described further delay of needle valve 107 and accumulator 10 8, the water valve 106 opens to supply cooling water at a constant pressure and volume by the pump 104 into the autoclaving chamber 23 to be sprayed against the rotating pouch constructions 22 to reduce the temperature thereof from the previously described autoclaving temperature of 250 F. to a desired lower temperature, such as the previously described 120 F.

During the spraying of the water into the autoclaving chamber 23, the drain valve 118 is so constructed and arranged that the same maintains the resulting Water level in the bottom of the autoclaving chamber 23 to just below the pouch constructions 22 as the same are being rotated therein by the rotatable member 26.

Since the pressure in the autoclaving chamber 23 is being maintained at 20 p.s.i.g. during this cooling operation by the admission of the compressed air, the liquid level of water in the bottom of the autoclaving chamber 23 acts as a pressure seal so that the pressure will not be vented through the drain valve 118.

When the temperature of the pouch constructions 22 falls below 212 F., whereby the internal pressures created inside the pouch constructions 22 is terminated, the vent valve means 84 can again open to gradually reduce the pressure in the autoclaving chamber 23, the cooling operation taking place until a desired lower temperature is reached in the manner previously described.

Since the pouch constructions 22 are being rotated by the rotor or rotatable member 26 in the autoclaving chamber 23 during the previously described autoclaving and cooling operation, the rotor 26 rotating at approximately 8 revolutions per minute, not only are the effects of cold and hot spots in the autoclaving chamber 23 reduced to a minimum, but also the agitation effect of the rotating pouch constructions 22 results in a faster comeup temperature of the pouch constructions 22 as represented by the line 125 on the graph 120 of FIGURE 12.

Also, it can be seen from FIGURE 12 that since the temperature of the pouch constructions 22 is rapidly rising to the aforementioned autoclaving temperature or other preselected sterilization temperature, a more consistent starting point for the predetermined period of time of autoclaving is established so that the harmful bacteria will be completely destroyed during the autoclaving period of time and with this faster come-up temperature of the pouch constructions 22, the taste producing enzymes are not adversely affected by an over cooking thereof as would be the case if the come-up time was a relatively long period of time as represented by the dash line 127 on the graph 120 for the reasons previously described.

In addition, the pouch constructions 22 are so held by the clamping plate means of the rotor 26 that the product means 38 of each pouch construction 22 has a substantially uniform thickness throughout the respective pouch chamber 37 and cannot readly shift and compact therein during the rotation of the rotor whereby a substantially uniform heating and cooling of the product means 38 in all of the pouch constructions 22 takes place which would not be provided if the product means 38 could shift and compact in the ends of the pouch constructions 22 so that the resulting increased thickness and density of the product means 38 would not permit the center or core areas thereof to be heated at the necessary autoclaving temperature for the required length of time unless the cooking period of time is increased to compensate for the core areas whereby an over cooking of the outer areas of the product means 38 would take place. Thus, by stabilizing the product means 38 in the pouch constructions 22 to prevent the shifting and compacting of the product means 38, the temperature of the entire product means 38 can be raised to the desired autoclaving temperature at a faster rate so that the overall length of time that the product means 3-8 remain at elevated temperatures can be held at a minimum for the reasons previously set forth.

In view of the above, it can be seen that this invention provides a method and apparatus for effectively autoclaving non-rigid product-containing container means in an improved manner which not only prevents adverse bursting of the non-rigid container means during the autoclaving operation, but also assures that the harmful bacteria will be completely killed during the autoclaving period of time as a consistent starting point for the autoclaving operation is assured and the taste producing enzymes in the product means will not be over cooked and, thus, destroyed because the overall period of time for heating the pouch construction is held to an absolute minimum.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

'1. A method for autoclaving product-containing flexible pouch constructions and the like comprising the steps of disposing said pouch constructions in an autoclaving chamber of a housing means, introducing an autoclaving fluid into said chamber to autoclave said pouch constructions at a predetermined temperature, pressurizing said chamber with a pressure to prevent the internal pressure created in said pouch constructions during the autoclaving thereof from adversely affecting said pouch constructions, causing relative movement between said housing means and said pouch constructions therein during said autoclaving step to minimize the effect of any cold and/or hot areas in said autoclaving chamber, continuously moving said pouch constructions in said chamber by moving means in said chamber, and clamping the seam areas of said pouch constructions with said moving means to substantially stabilize the product within said pouch constructions for uniform autoclaving thereof.

2. A method as set forth in claim 1 wherein said clamping step includes the step of clamping all four side edge areas of each pouch construction for said stabilization purpose.

3. Apparatus for autoclaving product-containing flexible pouch constructions and the like comprising a housing means having an autoclaving chamber therein for receiving said pouch constructions, means for introducing an autoclaving fluid into said chamber to autoclave said pouch constructions at a predetermined temperature, means for pressurizing said chamber with a pressure to prevent the internal pressure created in said pouch constructions during the autoclaving thereof from adversely affecting said pouch constructions, means for causing relative movement between said housing means and said pouch constructions therein during said autoclaving of said pouch constructions to minimize the effect of any cold and/or hot areas in said autoclaving chamber, said means for causing relative movement includes means for continuously moving said pouch constructions in said chamber, said moving means including means for clamping the seam areas of said pouch constructions to said moving means to substantially stabilize the product means within said pouch constructions for uniform autoclaving thereof.

4. Apparatus as set forth in claim 3 wherein said clamping means of said moving means includes areas for clamping all four side edge means of each pouch construction for said stabilization purpose.

5. Apparatus for autoclaving product-containing flexible pouch constructions and the like comprising a housing means having an autoclaving chamber therein for receiving said pouch constructions, means for introducing an autoclaving fluid into said chamber to autoclave said pouch constructions at a predetermined temperature, and means for pressurizing said chamber with a pressure to prevent the internal pressure created in said pouch constructions during the autoclaving thereof from adversely affecting said pouch constructions, said means for introducing said autoclaving fluid into said chamber initially introduces said autoclaving fluid into said chamber to create a temperature in said chamber greater than said predetermined temperature to rapidly raise the temperature of said pouch constructions and, thereafter, introduces said autoclaving fluid into said chamber to maintain said lower predetermined temperature.

6. Apparatus as set forth in claim 5 wherein said means for pressurizing said chamber pressurizes said chamber with a pressure in excess of the said created internal pressure.

7. Apparatus as set forth in claim 5 and including means for maintaining said autoclaving temperature at pp ox mately 8. Apparatus as set forth in claim and including means for substantially continuously venting said autoclaving chamber during the period of time that said means introduces said autoclaving fluid into said chamber.

9. Apparatus as set forth in claim 8 wherein said vent ing means controls the change from said higher temperature to said predetermined temperature.

10. Apparatus as set forth in claim 5- Wherein said means for introducing autoclaving fluid into said chamber and said means for pressurizing said chamber includes means for introducing pressurized steam and compressed air into said chamber.

11. Apparatus as set forth in claim 10 and including means for substantially continuously venting said chamber during the period of time that said steam and said air are being introduced therein.

12. Apparatus as set forth in claim 5 and including means for cooling said pouch constructions in said chamber after the introduction of said autoclaving fluid into said chamber has been terminated and while said chamber is pressurized.

13. Apparatus as set forth in claim 12 wherein said means for cooling said chamber includes means for introducing water into said chamber.

14. Apparatus as set forth in claim 5 and including means for causing relative movement between said housing means and said pouch constructions therein during said autoclaving of said pouch constructions to minimize the effect of any cold and/or hot areas in said autoclaving chamber.

15. Apparatus as set forth in claim 14 wherein said means for causing relative movement includes means for continuously moving said pouch constructions in said chamber.

16. Apparatus as set forth in claim 15 wherein said said pouch constructions, and means for rotating said rotatable member in said chamber.

17. Apparatus as set forth in claim 5 wherein said means for pressurizing said chamber includes said means for introducing said autoclaving fluid into said chamber and means for additionally introducing another fluid into said chamber.

18. Apparatus as set forth in claim 17 wherein said autoclaving fluid is steam.

19. Apparatus as set forth in claim 18 wherein said means for introducing said steam introduces said steam into said chamber with a pressure of approximately 15 p.s.1.g.

20. Apparatus as set forth in claim 17 wherein said other fluid is compressed air.

21. Apparatus as set forth in claim 20 wherein said means for introducing said other fluid into said chamber introduces said other fluid with a pressure of approximately 5 p.s.i.g.

References Cited UNITED STATES PATENTS 1,544,304 6/1925 Fenn 99'-214 2,536,115 1/1951 Wilbur.

2,660,513 11/1953 Ball 21-56 2,816,841 12/1957 Kaap 99-214- 3,093,449 6/1963 Kotarski et al. 2l-56 XR 3,181,692 5/1965 Menacci 99 -214 XR 3,348,905 lo /196 7 Reveley 21-56 3,366,442 1/1968 Neiss 2l56 XR MORRIS O. WOLK, Primary Examiner BARRY S. RICHMAN, Assistant Examiner US. Cl. X.R.

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