Abstract:
A batch sterilization system is disclosed for first loading containers to be sterilized into cars, transferring the loaded cars into one of a plurality of retorts arranged in horizontal rows and vertical columns, sterilizing the containers while in the retorts and discharging the containers from the cars, discharging the cars from the retort, unloading the cars and thereafter repeating the cycle. The system includes a plurality of single or double door retorts in horizontal and vertical rows thereby minimizing floor spaced. Different horizontally and vertically spaced retorts may process products requiring different sterilization times in the retorts. A programmable computer is preferably used for performing the several functions of the sterilization system and for keeping track of the location of the containers during and after processing. A second embodiment of the invention includes first and second double door retorts and first and second elevators with the unloader being positioned close to the second elevator.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to sterilizer systems and more particularly relates to a plurality of horizontal and/or vertically spaced batch type retorts with a conveying system for selectively moving groups of containers within at least one car into the sterilizers. 
     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. It will also be understood that doors may be provided on both ends of the retorts if desired. 
     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 of 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. Patent No. 3,776,257 discloses the use of water as the heating medium in retorts and the use of power means for opening and closing retort doors. 
     When a demand for more containers to be sterilized increases, more container supporting cars and more sterilizing units or retorts are required. Usually the containers are loaded and unloaded into the cars automatically, with conventional loader/unloader devices. At the present time cars are usually transported between these loaders/unloaders and the retorts by fork lifts or automatically guided vehicles. As the prior art sterilizing systems become 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 order to conserve floor space, the retorts may be supported in a plurality of levels with a plurality of retorts in each level. One or more vertically and horizontally movable carriers, and one or more adjustable bridges are provided to move one or more container filled cars into selected ones of said retorts and to move the cars and sterilized containers from the retorts onto a conveying system. The loaders move containers or other articles to be sterilized into empty cars, and the unloaders remove the sterilized containers or articles from the cars. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic plan of the batch sterilizer system of the present invention illustrating a vertical sterilizer. 
     FIG. 2 is a section taken along lines 2--2 of FIG. 1, rotated 90°, illustrating a plurality of horizontally and vertically spaced retorts with one retort door in the fourth level being opened. 
     FIG. 3 is a diagrammatic operational view in elevation of the batch sterilizing system of FIG. 1 illustrating a carrier having three cars thereon in a lowermost position and further illustrating a bridge in a raised inoperative position. 
     FIG. 4 is a diagrammatic elevation similar to FIG. 3 but illustrating the carrier fully loaded with cars at the elevation of a higher retort to be loaded. 
     FIG. 5 is an operational view similar to FIG. 4 except that the cars filled with containers to be sterilized are shown being conveyed over the bridge into an open retort. 
     FIG. 6 is a diagrammatic perspective of an elevator, an elevator frame supporting a transversely movable carrier, and a pair of bridges in loading position. 
     FIG. 7 is an enlarged diagrammatic perspective of the elevator and carrier illustrating drive means in position to load a batch of cars into a retort. 
     FIG. 8 is a diagrammatic perspective illustrating a drive system for driving the cars onto one of a plurality of bridges into and out of the retort. 
     FIG. 9 is a diagrammatic plan of a second embodiment of the invention illustrating double door vertically and horizontally spaced retorts for receiving containers through one door and discharging processed containers out of the other door. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A batch sterilization system of the present invention is diagrammatically illustrated in FIGS. 1-8. Cars C which are received from a conveyor 18 and a conventional unloader 20, are conveyed by conventional conveyors 22, 24 and 26 into conventional loader 28 which loads containers to be processed into the cars C and discharges the cars onto a conveyor 29. 
     The batch sterilization system is in the form of a vertical sterilizing system 30 (FIGS. 1-5) which is controlled by a computer CP (FIG. 1) or programmable controller with the aid of conventional sensors and other controls. The new features of the vertical sterilizer system includes a plurality of retorts 32 mounted on a frame 34 in vertical rows and horizontal columns, only two vertical columns and four horizontal rows being illustrated. Each retort includes a door 36 pivoted to one end and has its other end sealed by an end closure 38. The doors 36 are opened and closed by power means such as hydraulic cylinders 40 as is conventional in the art. A generally rectangular elevator housing 42 has a lower rectangular opening (not shown) in a front wall and a rear opening (not shown) that are large enough to allow retort cars C to enter the housing 42 at a predetermined elevation, preferably at a low elevation; and to be discharged through a large rear opening (not shown) to permit the cars to be moved into any one of the retorts. 
     As best shown in FIGS. 6 and 7, a generally rectangular vertically movable elevator frame 50 within the housing 42 is connected to four endless chains 52, 54, 56, and 58, with the lower ends of the chain trained around sprockets 60 keyed to shafts 62 (only two being shown). A chain drive 64 interconnects the two lower shafts 62, and a second chain drive 66 connects one of said lower shafts to a reversible elevator motor 68 thereby raising or lowering the elevator frame 50 to desired elevations. 
     As shown in FIG. 7, the rectangular elevator frame 50 has a pair of tracks 70 and an intermediate rack 72 extending transversely thereof. A transversely movable carrier 74 is supported by two pair of freely rotatable wheels 76 (only two wheels being shown in FIG. 7) which wheels ride on the tracks 70. A reversible motor 78 is secured to the carrier 74 and has a pinion 80 on its drive shaft which meshes with the teeth of the rack 72 thereby selectively moving the carrier 74 transversely into alignment with the selected vertical rows of retorts 32 as indicated by the double headed arrow 82 (FIGS. 1 and 7). As best shown in FIG. 7, each car C is preferably supported on freely rotatable wheels 84 with one pair of wheels 84 being adapted to ride on V-shaped tracks 85. Each car C has a plurality of pins 86 (FIG. 7) projecting outwardly from both side walls of the car in a direction parallel to the axis of the wheels 84. The cars C are transferred onto the carrier 74 and are moved off the carrier by means of an elongated screw 88. The screw is journaled on the carrier 74 and is driven by a motor 90 and chain drive 92. The above type of screw drives are old in the art and are similar to those described in Creed et al U.S. Pat. No. 4,646,629. 
     It will be understood that similar screw drives are provided within the several retorts 32 and along the several conveyors to be described hereinafter. 
     A plurality of bridges 100 (only two being shown in FIGS. 7 and 8) are aligned with the vertical rows of retorts 32 and are pivotally mounted on the rectangular elevator frame 50 (FIG. 8) by a pair of hinges 102. Each bridge includes a rectangular frame 104 having a central rib 106, a V-shaped track 108 and a flat track 110 for movably supporting the cars C. A helical screw 112 is rotatably supported on the bridge 100 and is driven by a reversible motor 114 connected thereto by a chain drive 116 for driving the cars into or out of the retorts 32. A helical screw 117 within the retort is driven by means (not shown) and cooperates with the screw 112 to move the cars into or out of the retorts 32. The bridge 100 is pivoted between an upwardly inclined inoperative position illustrated in FIGS. 3 and 4, and an operative position illustrated in FIGS. 5-8 by power means such as a hydraulic cylinder 118 pivotally connected between the bridge 100 and the elevator frame 50. 
     In operation of the batch sterilization system 30 of the first embodiment of the invention, empty cars C (FIG. 1) are received from the unloader 20 which has unloaded a previously sterilized batch of containers from loaded cars C. The empty cars are then conveyed by conveyors 22, 24 and 26 into the loader 28 which loads containers to be processed into cars C. The loaded cars are then moved by conveyor 29 and the elongated screw 88 (FIG. 7) into the elevator housing 42 and onto the transversely movable carriers 74 (FIGS. 6 and 7). Appropriate sensors and controls (not shown) are responsive to the controllable computer CP (FIG. 1) which determines which retort of a plurality of retorts is empty and has its door 36 (FIG. 8) open, or is waiting to be opened, in response to the computer actuating the appropriate hydraulic cylinder 40. Simultaneously or sequentially therewith, the computer CP will send signals to elevator motor 68 which will raise the elevator frame 50 and carrier 74 to the elevation of the retort 32 to be loaded, and will activate motor 78 (FIG. 7) which drives the carrier 74 transversely to a position in alignment with the open retort. After the carrier 74 has been moved into position to move the car C thereon into the open retort 32, the computer actuates a hydraulic cylinders 118 (FIG. 8) which lowers the associated bridge 100 that is in alignment with the retort 32 to be loaded. The motor 114 then drives the screw 112 by means of the chain drive 116, and a similar motor (not shown) is connected to an elongated screw 117 within the retort 32 for advancing the cars fully into the selected retort. The screws 112 and 117 are activated by the computer CP (FIG. 1) for moving a plurality of loaded cars C fully into the selected retort 32. 
     Thereafter the computer CP controls the raising of the bridge 100 by actuating cylinder 118 and thereafter closing the retort door 36 by actuating the hydraulic cylinder 40. The elevator frame 50 and components supported thereon may then be lowered by actuating motor 68 (FIG. 6) in the frame lowering direction to pick up another plurality of filled cars C for insertion into another empty retort 32 as described above. Alternately, the elevator frame 50 may be raised or lowered and the carrier 74 may be moved transversely to pick up a sterilized batch of container filled cars C. The sterilized cars are then transferred over the bridge when lowered onto the carrier 74 and thereafter be lowered to the level of the conveyor 18 (FIG. 1). The carrier motor 78 would then be activated by sensors and the computer CP to move the carrier 74 to the left (FIG. 7) into alignment with the conveyor 18 (FIG. 1) and unloader 20 which empties the cars and transfers the empty cars onto the conveyors 22, 24 and 26 to again be loaded with containers (not shown) to be sterilized. Although not fully illustrated in the drawings it will be understood that the preferred drive system for moving the cars C (FIG. 1) between the retorts 32, the loader 28 and unloader 20 are generally of the type illustrated in Assignee&#39;s Creed et al U.S. Pat. No. 4,646,629 which issued on Mar. 3, 1987. However, it will be understood that other drive systems may be used. Also, it will be understood that the system within the several retorts for heating and thereafter cooling the containers may be of any well known type used in retorts which raise the temperature of the product within the containers in the cars to the sterilizing temperature, maintain the temperature a sufficient length of time until the product within the sterilizer is sterilized, and thereafter cool the product to reduce the pressure within the containers to a pressure below atmospheric pressure before opening the door 36 of the associated retort 32. 
     The batch sterilization system of the present invention is preferably under the control of a computer or programmable controller and a plurality of sensors. The control system will allow for independent control of each retort thereby enabling the several retorts to handle different products under different sterilizing pressures, temperatures and time. 
     A modification of the batch sterilization system 30a is illustrated in FIG. 9. Components of the system 30a which are equivalent to those of the first embodiment will be assigned the same numerals followed by the letter &#34;a&#34;. 
     The system 30a comprises an unloader 20a which directs empty cars Ca onto conveyors 22a, 24a and 26a into a loader 28a which loads a new batch of product filled containers to be processed into cars Ca. The loader 28a moves the cars Ca onto a carrier 74a of a first elevator 42a which is vertically and transversely movable for moving one or more cars over a bridge 100a into horizontal and vertical alignment with a selected retort 32a. Each retort includes an inlet door 36a operated by a power means such as a hydraulic cylinder 40a and an outlet door 120 operated by a second power means 122. When the bridge 100a is lowered into transport position as shown in FIG. 9 and the inlet door 36a is opened, one or more container filled cars are moved into the retort and the door 36a is closed. With both doors 36a and 120 closed, a sterilizing medium is directed into the selected retort to sterilize the product being processed; and thereafter the product is cooled by a cooling medium such as cold water. The outlet door 120 is then opened and the car or cars Ca with processed products therein are conveyed over an outlet bridge 124 of a second elevator 126 and onto a second transversely and vertically movable carrier 128. The carrier 128 is then moved to the level of one of a plurality of discharge conveyors 130 (only two being shown) which transfers the cars with processed containers therein onto a cross conveyor 132. A hydraulic pusher 134 then pushes the car into the unloader 20a which unloads containers (not shown) with processed products therein from the cars Ca and moves the cars onto the conveyor 22a thereby completing a cycle of operation. All of the above described components are preferably controlled by a computer CPa. 
     It will be noted that the modified batch sterilization system 30a (FIG. 9) positions the unloader 20a closely adjacent to the discharge of the second elevator 126 thereby unloading the cars Ca as soon as possible so that empty cars can be returned to the loader 28a thus saving considerable energy. 
     In case of mechanical, electrical, or hydraulic problems or the like in one or more retorts, the control systems preferably will also allow bypassing of the defective retorts to allow continued operation of the other retorts while the defective retorts or controls are being repaired. 
     From the foregoing description it will be apparent that a batch sterilizer system has been disclosed. The system uses conventional loaders and unloaders and conveying systems for selectively loading and unloading a plurality of retorts, each of which are under the control of a computer or programmable controller, thereby enabling a plurality of cars to be loaded with containers, to be moved into selected ones of the retorts for sterilization and subsequent discharge from the several retorts. When the system is used to handle more than one type of product to be sterilized, batches of containers having a first type of product therein would be loaded into a first batch of cars and first groups of retorts; and other products would be loaded into a second batch of cars and second group of retorts. The computer would be programed to provide the desired sterilizing and cooling times for the particular product in each group of retorts. A plurality of vertical rows and a plurality of horizontal rows of retorts in excess of that illustrated in the drawings would be used when sterilizing large volumes of containers. 
     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.