US2649380A

US2649380A - Method of batch processing discrete articles

Info

Publication number: US2649380A
Application number: US263551A
Authority: US
Inventors: George M Flynn
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-12-27
Filing date: 1951-12-27
Publication date: 1953-08-18
Anticipated expiration: 1970-08-18

Description

Aug. 18, 1953 G. M. FLYNN METHOD OF BATCH PROCESSING DISCRETE ARTICLES Filed Dec. 2'7, 1951 Zez/eb Z Z j 1 2 5 n LL" T fl 5?; E A4\ u nrrr itl J9 INVENTOR.

Geog-9815f. F9222, BY

i atentecl Aug. 18, 195 3 UNITED STATES PATENT OFFICE METHOD OF BATCH PROCESSING DISCRETE ARTICLES 2 Claims. 1

This invention relates to the processing of various products or articles and, in certain of its aspects, is particularly suited to the processing of canned products, though in its broader aspects it may be used to advantage in processing various other products and discrete articles in industrial operations.

In the method of my invention, the articles or products are treated in a body of liquid within a suitable receptacle and, after treatment, are discharged from the receptacle through a continuous column of liquid extending from the interior of the receptacle to the exterior thereof. That expedites handling of the treated articles, an important consideration in many industrial operations, and also guards the articles against injury when they are of a character to be bruised or otherwise injured by contact one with the other if discharged from the receptacle downward through the air. articles through a continuous column of liquid, as above stated, is of the essence of the method of my invention and, so far as I am aware, is fundamentally new.

In the processing of canned foods it is the usual practice to exhaust as much air as practicable from the cans by thermal or mechanical means, before they are closed and hermetically sealed. The filled and closed cans, after they leave the closing machine, are manually placed in receptacles known as retort baskets or crates. The baskets are mechanically hoisted and lowered into vertical retorts. After a retort has been loaded with baskets of cans, the cover of the retort is closed and sealed and steam under suitable pressure is admitted to the retort for an appropriate time for effecting sterilization of the filled and closed cans. Upon completion of the sterilizing operation it is necessary in many instances to partially cool the cans in water, to reduce the pressure therein to a sufliciently low value, before the retort can be opened to the atmosphere preparatory to removing the cans therefrom. Such pressure cooling is usually necessary for cans of sizes two and one half or larger, but is not usually necessary for cans of the smaller sizes. In either case. the baskets of cans are mechanically withdrawn from the retorts and passed through an elongated tank or cooling canal containing cooling water in which the baskets are immersed. After cooling sufficiently the cans are removed from the baskets individually by hand. Handling of the cans .in the manner above. described necessitates con- The discharge of the siderable manual labor and the use of a large number of baskets. Those baskets occupy considerable floor space which would otherwise be available for processing equipment. That is objectionable for obvious reasons. The potential productive capacity of the retorts is reduced by the space occupied by the individual baskets and allowed between the several baskets included in each retort load or batch. Under the present practice, in handling the sealed cans, both before and after sterilization, there is risk that the cans may be dropped, or forcefully struck one against the other, with the result that a slight opening may be sprung in the cans. When the cans are passed through the water of the cooling canal, the resultant cooling of the contents of the cans causes a partial vacuum therein, and if any of the cans have slight openings sprung in them unsterile cooling water will be drawn through those openings into the cans, contaminating the contents thereof. Also, and for analogous reasons, there is risk that unsterile water adhering to the cans will be drawn into the cans after they pass out of the cooling canal. In either case spoilage of the contents of such cans will result. It is known, as a labor saving operation in the processing of small and exceptionally sturdy cans, such as flat sardine cans, to deliver automatically the individual filled and closed cans into a body of water within a vertical retort, after which the water is discharged from the retort, the cans are steam sterilized, and the bottom of the retort is opened and the cans are discharged through the atmosphere onto a, suitable conveyor or the like. This latter procedure is not used with cans of larger sizes and less resistant structure, since the amount of spoilage attending this abusive can discharging operation would render it prohibitive.

I shall first describe the method of my invention, by way of example only, as used for processing canned food products. In the method of my invention, as used for the processing of canned products, the objections to the presently known methods, above briefly referred to, are avoided. The individual filled and closed cans are delivered automatically from the closing machine into a retort containing a column of water of considerable depth which serves to cushion the cans and prevent injury thereto, after which the cans are steam sterilized in the retort and, upon completion of the sterilizing operation, are discharged from the retort to a point exterior thereof 7 and downward through a continuous retort are steam sterilized, the steam is shut Lair 7 and cooling water is admitted to .the retortproviding therein a water column of appropriate depth effective for cooling the cans and,'upon completion of the cooling operation, the :bottom of the retort is opened and the cans are .discharged therefrom while the water column within the retort is maintained, the cans moving downward through a body of water which is continuous and extends to a point exterior of the retort, this body of water comprising the water column maintained within the retort. After discharge of the cans from the retort, the bottom of the retort is again closed, with the water column remaining therein, it being noted that the water of this column has been heated to a substantial extent by heat abstracted from the cans cooled thereby, and a further charge of filled and closed cans is delivered to the retort, such cans being heated to some extent by the water then in the retort. Further objects and advantages of my invention will appear from the detail description.

The single figure of the drawing is a View partly in section and partly in elevation, somewhat diagrammatic, of one means for practicing the method of my invention.

This application is a continuation-in-part of my copending application for Method of Batch ?rocessing Articles, Serial No. 36,682, filed July 2, 1948, now abandoned.

The means or apparatus shownin the drawing comprises a receptacle or retort I having a cylindrical body 2 provided with upper and lower frusto-conical heads 3 and 4, respectively. The upper head 3 is provided with an upwardly extending cylindrical inlet neck '5 controlled 'by a gate valve 6, of suitable known type, interposed therein. A track i, of known type, which may lead from a can closing machine, extends at a downward inclination to the upper end of'neck 5 for delivering thereto filled and-closed cans c. A steam supply pipe 8, leading from a suitable source of supply of steam under pressure, opens into neck 5 adjacent and below the gate valve'6. Pipe 8 is provided with a control valve -9, shown as a manually operated valve of known type. A suitable pressure gauge I is mounted on steam supply pipe 8, in communication with the interior of the retort.

A cylindrical discharge neck II extends downward from head 4 and is provided with a gate valve I2 of suitable known type interposed therein. A pipe I3 opens into the neck I I, above valve I2, and is provided, at its outerend, with a T i l to which are connected two pipes I5 and H5 provided with manually operated control valves i1 and I8, respectively, of known type. Pipe may be connected to a suitable source of supply of cooling water and pipe l6 may bea drain pipe connected to a suitable .point of discharge. The discharge neck II extends downward a material distance into a tank I9 of elongated rectangular or oblong shape in planzfor containing .cooling water, commonly termed a cooling canal. The tank I9 extends a considerable distance to one side of neck II and receives, at its side remote from neck II, the upper run 20a of an endless belt conveyor 20 of known type, which enters the tank I9 at one end thereof and passes upward out of the tank at the other end thereof. A deflector 2| is secured to the other side of tank I9, in underlying relation t'o neck I I, and extends at an inclination downward to the upper run 26a of conveyor 26, for directing onto upper run 20a cans discharged through neck I I.

A pipe 22 connects tank I9, at a oint a substantial'distance below discharge neck II, to the intake of a pump 23 of suitable known type. The

discharge of pump 23 is connected by a pipe 24 to pipeB, between valve 9 thereof and the inlet neck"5 of thereceptacle or retort I. The pipe .24.:is" provided with a manually operated control valve 25, of suitable known type, similar to the .valves 9, I1 and I8. In the use of the apparatus for the handling or treatment of articles or products which are heavier than the treating liquid, the valve 25'is closed and the pump 23 is not operated, as will be explained more fully later.

The apparatus shown in the drawing is by way of example onlyand may be varied considerably in detail without departing from my invention. In practicing the method of my invention,

with the apparatus illustrated, with the lower gate valve I2 closed and valve9 closed and the upper gate valve 6 open, valve I! is opened and water under appropriate pressure is admitted to the retort I so as to provide therein a water column of appropriate height. It may be assumed, for example, that the water level, before delivery of cans to the retort, is that indicated in the drawing, the water is controlled to a desired temperature, and the water volume is such that,

"when thepro'per number of cans have been delivered to the retort, the water level will be at the top of the retort, as indicated. The filled and closed cans c are then delivered from track I downward into retort I, in suitable number, after which the upper gate valve 6 is closed, the lower gate valve I2 remaining closed, and the valves I? and I8 being closed, it being understood that 'valve I1 is closed when the proper amount of water has been supplied to the retort. After closing-gate valve 6, the drain valve I8 is opened and the control valve 9 in the steam pipe 8 is opened, admitting steam under proper pressure to the interior of the retort. The water is then "discharged from the retort through pipes I3 and I6, by gravity and by the steam pressure exerted on the water column. After the water has been discharged from the retort, valve I8 is closed and the filled and closed cans within the retort are steam processed at appropriate pressure and for an appropriate length of time to effect sterlizing thereof. When the cans are delivered to the retort, they drop into the water column therein and sink gently and slowly through the water,

which effectively-guards the cans against injury. During the sterilizing operation, the cans remain quiescent within the retort, so that there is no risk of injury to the cansat that time. It will be to the retort and sterilizing them, they are ef- Upon completion of the sterilizing operation,

"valve I! is opened and cooling water, under appropriate pressure, is supplied to the retort I so as to provide therein a water column in which the cans are immersed. The entering cooling water condenses the steam within the retort and/or volumetrically displaces the steam through valve 9, which is closed when the retort is properly filled with water. As will be explained more fully presently, a controlled partial vacuum is formed within the retort when the cans are discharged therefrom. This controlled negative pressure within the retort above the water column may be indicated by the gauge It and is controllable such that the atmospheric pressure effective upon the water in thecooling canal will support the water column at the de sired height within the retort I, when the lower or discharge gate valve I2 is open. After the cans have been properly cooled, the gate valve I2 is opened and the cooled cans pass downward through neck ll into the tank or cooling canal l9 and are deflected, by the deflector 21, onto the upper run 200. of the conveyor 20, which removes the cans from the cooling canal and conveys them to a suitable point, such as a labeling machine. During discharge of the cans from the retort, they pass downward through a continuous body of water comprising the water column within the retort and the body of water exterior to the retort, within the tank or canal Hi, this latter body of water being in free communication with and constituting an extension of the water column within the retort. The cans being discharged from the retort sink gently and slowly through the water and are thus effectively guarded against injury,

After all of the cans have been dischrged from the retort, the lower gate valve I2 is closed so as to retain the water column within the retort. The Water of that column has absorbed considerable heat from the cans cooled thereby. The upper gate valve 6 is then opened and a succeeding batch of filled and closed cansis delivered to the retort downward into the water column therein. Since the water has been heated to a controlled degree by the cans of the preceding batch, it does not exert any objectionable chilling effect upon the entering cans.

Referring further to the controlled negative pressure which is essential to the maintaining of the designated water column in the retort during discharge of the cans, it may be assumed, by way of example, that the cans are cooled until the water within the retort is at a temperature of 200 F., that the water level of the filled retort is 11.5 feet above the surface of the water in the cooling canal, and the water in the cooling canal i9 is at a temperature of 70 F., when the gate valve I2 is opened. The vapor pressure above the water at 200 F., within the retort is 11.5 pounds per square inch, and assuming the prevailing atmospheric pressure on the water in the canal l9 to be 14.7 pounds per square inch, the pressure differential is 3.2 pounds per square inch, which will support a 7.5 foot column of water. Therefore as the cans are discharged from the retort, the level of the water column within the retort will fall to the desired height of 7.5 feet above the level of the water in the cooling canal l9. As the cans sink in the cooling canal [9, because they are heavier than the water within the system, so also is the lighter 200 F. water within retort l retained substantially separate from the heavier 70 F., water within cooling canal l9. When all of the cans have been discharged from the retort, the gate valve I2 may be closed and the cycle repeated.

It will be seen, from the above, that by the ing tanks or receptacles.

" method of my invention I have eliminated considerable manual handling of the cans and the use of a large number of retort crates or baskets and the basket transferring mechanism, required under the present practice above mentioned. I have thereby reduced the manpower requirements, effected a substantial saving in required manufacturing floor space and, by increasing the productive capacity of the retorts through the elimination of retort baskets and the reduction in essential retort cooling time peculiar to my method, have materially increased the retort output, while providing a comparatively simple processing apparatus which is highly flexible, in respect to the range of can sizes which can be processed therein, compared to the known and presently used automatic can retorting systems.

In the above description of my invention I have referred to the use of water and steam as the heat transfer media, because those are the ones commonly used in the food canning and analogous industries. It Will be understood, however, that my invention comprehends the use of any suitable fluid heat transfer medium and that the appropriate negative pressure within the receptacle or retort, for maintaining the desired liquid column therein, may be established in any suitable manner. While the method of my invention is particularly suitable, in certain of its aspects, for the processing'of canned foods and the like, it is not limited to that use and, in the broader aspects of my invention,'may be used for processing any products adaptable to treatment in the manner above described. The apparatus is shown semi-diagrammatically and is subject to variations such as may be required in practice.

It is well known to' subject many food products to preparatory treatment under liquids preliminary to canning, preserving or other processing. Apples are usually blanched before canning by being placed in brine or water and subjected to a high vacuum, or by heating in water for several hours at F. Potatoes, after peeling, are immersed in an 0.5% sodium bisulfite solution to prevent browning. Hominy is treated with boiling lye solution, followed by bleaching, and leaching with water. Dry beans may be soaked in water for as long as sixteen hours to obtain optimum quality, before blanching and canning. Fish, after dressing, are immersed in strong brine for as long as two hours to extract moisture from the tissue. In walnut shelling operations, small pieces of nut meats are-separated and recovered from intermingled shell fragments by immersing the mixture in water under vacuum to effect an increase in the apparent specific gravity of the shell fragments, sufficient to obtain subsequent flotation separation of the meats from the shells.

The common practice, in accumulating or treating fruits and vegetables and analogous products in batches under liquids, preparatory to canning or other processing thereof, is to place the articles or products in baskets for transfer into and subsequent removal from suitable treat- That is time consuming and necessitates equipment for handling the baskets. An alternative common practice is to place the articles directly into the treating receptacle, which subsequently entails either manual or mechanical upward removal of the articles, or their downward discharge from the receptacle through the atmosphere. The depth in the receptacle of articles which can be discharged downward through the atmosphere is z igeiaeso dimited by pr 'actical consideratidns, as isf'also the deptn of a receptacle; which can zbeiunloaded "manuallyj 'the complexity of upward mechanical removal 'of the treated articles "being obvious,

fi llla'rly from batteries or '-'receptacle's "of maximum depth and miriimum' floorzspac pared "with downward discharge of the treated articlesfrom the receptacle.

In the method of my Y invention, i'tll'e fruits, vegetables or other products, are delivered directly into the :"liq'uid filled treating or Fholding receptacle without I the use of baskets or other conta'iners. Atft'he end 'ofthe treatment period, the bottom of there'ceptac-le is opened, the receptacle "being "otherwise aclos'erl to "atmosphere,

and' the treated 'prddu'ctsare discharged'from" the receptacle downward through a continuous *column of liquid, in the same manner as described above with're'ferenceto cannedproducts. That 1 eiifec'ts a substantiarsaving "in time' and i equipment inhandling fruits and vegetables and other 'uncanned articles, *while also guarding Fagainst bruising 'of' or injury to "articles'of a character subject "to bruising or "injury by striking "one againstthe othefland at the same time making it possible "to handle such products or articles in greater depth than isp'racticable by conventional batch handling practices.

It is"wel1*known'inindustrial processes/to treat articlesfboth metallic and non-metallic, in baths "or soliitionsior'various purposes. For example, metallic articles may be immersed pickling baths or inpxi'dizing baths, in suitable receptacles. 'Also"'non=rnetallic articles maybe im- "mersed in bath-s for I cleaningpcoloring, coating or other "purposes. In many cases the articles to be treated are rather small and thei-present 1 practice is to place them in baskets "or containerslfor immersion and removal from the bath.

"Such articles are well suited 'for handling :in

"accordancewith the method ofmy'invention.

' They may be-"delivered directly into the'bath, in

a suitable receptacle, without the useof baskets or otherponta'iners. At theend'o'f the treatment periodf the bottom of the receptacle "is opene'd,

the -receptacle "being "otherwise 'closed to atif they'are fragile'or ofla'character 'to be injured by striking-one againstthe other.

In thelabove' description itrhas'beemassii-medv that the articles 'or products treated are heavier, or of greater specific gravity,=than thetreating liquid, "and are discharged from the receptacle 'by f gravity downward through :the sustained 'column 'of' liquid, the valve -'25 remaining :closed 1 and the pump-23 not being operated. The method of -my--invention may also be used to advantage 1 in the handling and treatment of articles or :products which are lighter, or of less specific gravity,-than the treatingliq-uid. For -exarnple,ap--

.ples which have not been blanched asabove, peaches and I pears, after peeling and preparatory to further-processing thereof, *are immersed in water-or brine, to prevent oxidation and browning, in which theytend to float. Tomatoes,

- which may be'advantageously heldin=water,; preparatory to canning, tend to float in the bath. Also, in'industrial' operations, there maybe-articles formed'of wood or other "light-materials "which it is desirable to treat in a liquidbath: for

fh'vi-the' bottom of the receptacle after treatment of the receptacle I various purposes :and which tend to float in" the bath. 'In order to discharge downward through the sustained column of liquid articles or products of less specific gravity than" the treating liquids, when the-lower end of the receptacle is opened, the valve 425 is'op'ened and the'pump 23 isaset into operation. The pump 23 withdraws liquid from tank I9 and dischargesit into thetop of The water or other'liquid thus flows in a closed circuit and downward through the sustained column of liquid extending from the interiorofreceptacle I into tank I9. That does not disturb the continuity of the column of liquid, due tothe fact that the water or other liquid'is returned to'the receptacle I at the same rate at'which it is withdrawn from'the tank I9. The liquid 'flowing downward through the sustained liquid column creates a currentflowing downward from the upper surface of the-liquid into tank I9. That downwardly flowing current entrains the treated articles and carries them downward into tank l9, so that they are rapidly discharged from the receptacle I downward through the sustained column of liquidin much the same manner as the heavier articles or products, previously referred to, thoughnot by gravity alone. If desired, in'handling or treating articles or products of reater specific gravity than the treating liquid, the valve'25 may be opened and the pump 23 operated tocreate a down current for expediting the discharge of such articles, though ordinarily that is not necessary. Within the broader aspects of my invention, a down current through the sustained water column, to assist in discharging the treated articles as above explained, maybe created in any suitable manner.

It will be clear from the above, that the method of my invention, while particularly suitable in certain of its aspects for the handling or processing of canned products, is, in its broader aspects, well fitted'for the handling or treatment of any suitable discrete articles in" industrial operations, including 'both edible and inedible articles, as well as metallic andnon-metallic articles. As previously noted, the method of my invention, inits' broader aspects, is not limited to the treatmentor handling of food stuffs and may be used in connection 'with any discrete articles susceptible to treatment by that method.

'It will be understoodthat changes, bothas to the method and'theapparatus, may-be resorted to without departing from the'fieldand scope of my invention, andI intend to include I'claim: :1. The method of batch processing canned products, which comprises delivering 1 the filled and closed cans into a body of water within a retort, draining-thewaterfromthe retort and t'hereaftersteam processingthe cans in the retort,

cooling the cans by refilling the retort with water, and discharging the cans downward from the retort by gravity through a continuous column of water by opening the bottom of the retort to a connecting underlying body of water subject to atmospheric pressure while maintaining the retort :otherwise closed to the atmosphere.

.2. In a methodlof batch processing :discrete articles by treating the'articles in a liquid bath within a receptacle, the novelfsteps of opening 9 the articles, to a connecting underlying body of liquid subject to atmospheric pressure while maintaining the receptacle otherwise closed to the atmosphere, thereby providing a continuous sustained column of liquid extending from the interior of the receptacle to said underlying body of liquid, and discharging the treated articles from said receptacle downward through said liquid column.

GEORGE M. FLYNN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Smith Jan. 2, 1900 Donnellan Aug. 15, 1922 Hansen Dec. 18, 1923 Fooks Apr. 20, 1926 Thomas Dec. 23, 1941

Claims

1. THE METHOD OF BATCH PROCESSING CANNED PRODUCTS, WHICH COMPRISES DELIVERING THE FILLED AND CLOSED CANS INTO A BODY OF WATER WITHIN A RETORT, DRAINING THE WATER FROM THE RETORT AND THEREAFTER STEAM PROCESSING THE CANS IN THE RETORT, COOLING THE CANS BY REFILLING THE RETORT WITH WATER, AND DISCHARGING THE CANS DOWNWARD FROM THE RETORT BY GRAVITY THROUGH A CONTINOUS COLUMN OF WATER BY OPENING THE BOTTOM OF TH RETORT TO A CONNECTING UNDERLYING BODY OF WATER SUBJECT TO ATMOSPHERIC PRESSURE WHILE MAINTAINING THE RETORT OTHERWISE CLOSED TO THE ATMOSPHERE.