Abstract:
A batch sterilization system is disclosed having a plurality of retorts mounted on at least one indexable turret which sequentially and simultaneously indexes one retort with a loader for receiving containers to be sterilized, while a second retort with sterilized containers therein is indexed with an unloader for unloading. A second embodiment includes a pair of loader/unloaders for loading and unloading a first product in first retorts and a second product in the other retorts.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present invention is similar to my application entitled Batch Sterilization System, Ser. No. 07/346,443 filed on Apr. 24, 1989. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to sterilizing systems and more particularly relates to a plurality of batch type retorts mounted on an indexable turret for simultaneously moving one retort into position to receive container filled cars to be sterilized from a loader, and to simultaneously discharge sterilized containers from a second retort into an unloader. 
     2. Description of the Prior Art 
     Batch type sterilizers or retorts such as that disclosed in Mencacci U.S. Pat. No. 4,164,590 are well known in the art and are adapted to receive and discharge a plurality of containers within supporting cars through a door at one end of each retort. 
     A continuous pressure cooker and cooler is disclosed in Mencacci U.S. Pat. No. 4,196,225 and illustrates container filled cars or carts which are moved from one end to the other end of a continuous cooker and cooler while cooking and thereafter cooling containers being processed. 
     Commercially available batch type sterilizers such as FMC Model CFS are also used for sterilizing food products in cans, jars, pouches, plastic trays and other product filled containers. 
     European Patent Application Publication No. 0075531 discloses a sterilizing system which includes means for filling and sealing articles in containers, loading trays with the sealed articles therein into stacks, and then conveying the stacks through a sterilizer and thereafter removing the sterilized containers with the aid of a conveying system. 
     Conventional container receiving cars, loaders, unloaders, and car conveying means are disclosed in Creed et al U.S. Pat. No. 4,646,629. 
     Piegza U.S. Pat. No. 3,776,257 discloses the use of water as a heating medium in retorts and the use of power means for opening and closing retort doors. 
     Certain faults are present in the sterilizing industry primarily due to demand for more and more containers to be sterilized. An increase in the use of sterilized food products or the like indicates that sterilization systems should be designed to conserve space and also be automated. Although the containers have usually been loaded and unloaded from cars automatically, at the present time the cars are usually transported between these loaders/unloaders and the retorts by fork lifts or automatically guided vehicles. As the prior art sterilization system becomes bigger, this transport function becomes quite complex and labor intensive. It also becomes difficult to keep track of sterilized and unsterilized containers in the plurality of cars after they have been removed from present prior art systems. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, the above faults are rectified by mounting a plurality of radially disposed retorts on an indexable, rotatable turret that is indexed in alignment with conventional loaders and unloaders. Water, steam, air, hydraulic fluid, and electrical services are connected to the retorts through rotary couplings concentric with the axis of rotation of the turret. The retorts are arranged so that adjacent retorts will simultaneously index with adjacent loaders and unloaders when held stationary. If batches of containers have two or more products which require different processing temperatures and pressures are being sterilized in the retort, two or more loader/unloaders are provided to feed different products into different retorts supported on the turret. This permits processing two different products at the same time and at different temperatures and pressures without danger of mixing the two products together. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic plan of a first embodiment of the invention. 
     FIG. 2 is a perspective diagrammatically illustrating a loader, an unloader, and conveyors in positions to move unprocessed containers within cars into one retort and to receive processed containers from another retort for unloading by the unloader. 
     FIG. 3 is a diagrammatic vertical section taken along lines 3--3 of FIG. 1 diagrammatically illustrating conventional drive means for indexing the retort; and further illustrating means for controllably directing water, steam, air, hydraulic fluid and electrical services into the retorts, only two retorts being illustrated. 
     FIG. 4 is a diagrammatic plan of a second embodiment of the invention which processes and maintains two different products segregated while feeding, sterilizing and discharging sterilized containers. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A first embodiment of the turret sterilizer 20 (FIGS. 1-3) of the present invention includes a plurality of equally spaced retorts 22 mounted on an indexable turret 24 supported by bearings 26 (FIG. 3) on a floor 28 and driven by a motor M and drive train 29. Each retort 22 includes a tubular body having its inner end closed by an end closure 30 and having an outer end which is adapted to be opened or closed by a door 32 which is actuated by a hydraulic cylinder 34. A conventional loader L is provided to load containers CT into cars C; and a conventional unloader UL is provided to unload processed containers CT from the cars C. 
     The conventional loader L, unloader UL, trays T, and cars C may be of the type illustrated by Assignee&#39;s Creed et al U.S. Pat. No. 4,666,722 which issued on Nov. 19, 1987. 
     The loader L (FIG. 2) receives trays T of containers CT to be loaded into empty cars C. After the cars are loaded the cars are conveyed into one of the open retorts 22 at a feed station by a screw conveyor 35 which engages a set of pins 36 on opposite sides of each car C (only one set of pins being shown in FIG. 2). A gear motor 38 drives the screw conveyor 35 and first advances the filled trays T into position to be loaded into the cars C. After the cars C are loaded, they are advanced along a V-shaped track 40 and a flat track 42 into the open retort 22. Similar driven screw conveyors (not shown) are positioned in each retort 22 for moving the cars along tracks 44,46 into the retort 22. Thereafter an open door 32 on the retort 22 is closed by a hydraulic cylinder 34. 
     When one retort 22 is being loaded, another retort is being unloaded by a driven screw conveyor (not shown) similar to the screw conveyor 35. Each car C is intermittently moved onto a cart 56 which is connected to a hydraulic cylinder 58 which moves the car C into position to have a set of pins 36 mesh with a screw conveyor 60 which is driven by a gear motor 62. The gear motor 62 intermittently advances the car C into the unloader UL at which time the processed containers CT are removed from the car C and the empty cars are moved onto a cart 64 that is alternately moved by a hydraulic cylinder 66 from a receiving position adjacent the unloader UL to a position adjacent the loader L, and thereafter repeats the cycle. 
     Steam, air and water are controllably directed into the several retorts 22 at predetermined time intervals. The different components of the turret sterilizer 20 are preferably controlled by the computer CP or programmable controller with the aid of conventional sensors and controls. 
     More particularly, steam may be directed into the several retorts 22 from a source of steam (not shown) through a swivel joint 76 (FIG. 3), through on-off valves 78 and temperature control valves 80 under the control of the computer CP. The computer closes the on-off valve 78 when the retort gates 32 are opened to receive or discharge container filled cars; and also closes the valves 78 and gates 32 when the retorts are in their cooling cycles. When the containers are in their sterilizing cycle, the on-off valves 78 are opened and the temperature controlled valves 80 are controlled by the computer CP to first control the gradual rise in temperature, to then retain the steam at sterilizing temperature during cooking, and will thereafter gradually decrease the flow of steam into the retorts 22 prior to cooling at which time the on-off valves are closed. 
     During sterilization and initial cooling, it may be desirable to use a steam-air mixture rather than saturated steam as the heating medium depending upon the type of containers CT being used, for example, plastic or glass containers, and the product within the containers. A high pressure source of air is directed through a swivel joint 84 through air conduit systems 86 (only two being shown), each having an on-off air valve 88 and a pressure control valve 90 therein. When air is used, the on-off air valve 88 is open during sterilization and may remain open during cooling until the pressure within the containers being processed is below atmospheric pressure. The on-off air valve 88 and the pressure control valve 90 are controlled by the computer CP and conventional electrical controls and sensors (not shown). It will also be understood that sprays of hot water followed by sprays of cooling water may be used as the heating and cooling mediums, and that air or steam/air mixtures can be used to provide an overriding pressure. 
     Electrical energy is directed into the several electrically controlled components by a rotary electrical coupling 94 and conduits 96,98 which direct the electrical energy into the different controls, only two conductors being illustrated. 
     After the contents of the containers have been sterilized, cooling water is directed into the closed retorts 22 from a source of water directed into a conduit 100 and controllable valve 102 through a swivel joint 104 into a plurality of headers 106, each of which directs cooling water through branch conduits 108 into associated retorts 22. Each header has a control valve 110 therein to regulate the volume of cooling water entering the retorts 22 and cars C therein. The cooling water is discharged from the retorts into a trough 112 through conduits 114 having control valve 116 therein which are controlled by the computer to maintain the proper level of coolant in the cars C until the containers are adequately cooled. 
     When it is desired to open and close the retort doors 32, hydraulic fluid is directed through a swivel joint 118 and directional control solenoid valve 120 which receives signals from the computer CP to direct hydraulic fluid into the cylinders 34 to open and close the doors when in alignment with the two retorts 22 indexed with the loader L and unloader UL (FIG. 2). 
     Having reference to FIG. 4, which diagrammatically illustrates a sterilizer 20a which is capable of sterilizing two different products which may require different temperatures and pressures. Since the turret sterilizer 20a includes components similar to that of the first embodiment of the invention, the components of the turret sterilizer 20a which are equivalent to those of the first embodiment will be assigned the same numerals followed by the letter &#34;a&#34;. 
     The turret sterilizer 20a includes a plurality of rotorts R1-R8, each having a door 32a mounted on an indexable turret 24a. As illustrated in FIG. 4, a first loader/unloader 156 is similar to that illustrated in FIGS. 1 and 2, but is provided to sterilize first containers CTa which are fed into rotorts R1, R2, and R5, R6 when at station A and are discharged from said retorts when at station H. A second loader/unloader 158 is provided to handle second containers CTa&#39; filled with a different product which may or may not require different sterilizing temperatures and pressures. The second product is loaded into and unloaded from retorts R3, R4 and R7, R8, respectively. The loading of containers CTa&#39; takes place at station C, and the sterilized containers CTa&#39; are discharged at station B. 
     When starting the sterilization operation it will be assumed that all retorts R1-R8 are empty and that the retort door 32a at inlet stations A and C are open. A plurality of cars Ca filled with a first batch of containers CTa are then conveyed into retort R1 at station A and the retort door 32a of retort R1 is closed and a sterilizing medium such as hot water, steam, or a steam-air mixture is directed into retort R1 through circuits similar to those illustrated in FIG. 3. Sterilization and thereafter cooling of the containers in retort R1 continues until retort R1 is indexed to station H at which time door 32a is opened and the processed containers Ca are discharged into the unloader ULa. 
     At the same time that retort R1 is being loaded at Station A, a plurality of containers CTa&#39; in cars Ca&#39; are conveyed into retort R7 at station C, and the associated door is closed, at which time sterilization of the containers CTa&#39; begins. 
     The turret 24a is then indexed one step in the direction of the arrow thereby positioning empty retort R2 at station A for receiving cars Ca filled with containers CTa. The associated door 32a is then closed and sterilization followed by cooling will then occur in retort R2. At the same time empty retort R8 is indexed at station C and recovers cars Ca&#39; filled with said second batch of containers CTa&#39;. The associated retort door 32a is then closed permitting sterilization and thereafter cooling of the second batch of containers CTa&#39; before subsequent discharge at station B. 
     Thus, the single step indexing of turret 24a sequentially fills retorts R1, R2,-R5, R6 with the first product at station A and subsequently discharges the first product at station H. Similarly, indexing of the turret sequentially fills retorts R7, R8 and R3, R4 at station C with containers CTa&#39; filled with a second product to be sterilized at station C and subsequently discharges the sterilized and cooled second product at station B. 
     Thus, after all retorts R1-R8 have been initially filled with their associated products CTa or CTa&#39;, each indexing movement of the turret 24a will move retorts handling containers CTa into station H to discharge cars Ca with the sterilized and cooled containers CTa therein, and to receive cars Ca filled with containers CTa to be sterilized at station A. At the same time the second cars CA&#39; with the second containers CTa&#39;  to be sterilized therein are loaded into the retort at station C, and the sterilized containers CTa&#39; are discharged at station B. Thus, sterilization and subsequent cooling of the containers CTa and CTa&#39; takes place during all indexing movements except during one indexing movement of the turret. With eight retorts on the turret as illustrated in FIG. 4, sterilizing followed by cooling occurs during 315° of rotation of the turret. 
     As in the first embodiment of the invention, the heating medium may be steam, a steam/air mixture, or sprays of hot water may be used as the heating medium. Air or a steam/air mixture can be used to provide the necessary overriding pressure to prevent damage to the containers. 
     A computer CPa and circuitry similar to that disclosed in FIG. 3 of the first embodiment controls the movement of the turret 24a and processing fluids and times. 
     From the foregoing description it is apparent that the turret sterilizers of the present invention are capable of minimizing floor space by using a plurality of retorts mounted at evenly spaced intervals on an indexable turret. Cars containing the containers to be sterilized are moved into the retorts by conveying systems. A heating medium such as hot water, steam, or a steam-air mixture is directed into the retorts and may be subjected to an overriding air pressure during sterilization for controlling the pressure within the retorts and within the contents of the containers. The containers are then cooled by flooding or spraying cooling water thereon prior to the discharging of the containers from the retorts, and the processed containers are thereafter removed from the cars. In the second embodiment of the invention two different products may be sterilized in different retorts on the turret sterilizer. If a very large volume of containers, or two or more types of products are to be sterilized, two or more turret sterilizers may be mounted above each other on different floors so that the most desirable cooking times, pressures, and temperatures can be used for sterilizing each product. 
     Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent that modification and variation may be made without departing from what is regarded to be the subject matter of the invention.