US 3220157 A
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Description (OCR text may contain errors)
N. BUCHNER Nov. 30, 1965 2 Sheets-Sheet 1 Filed June 22, 1962 ill ii Nov. 30, 1965 N. BUCHNER 3,220,157
CHAMBER FOR THE EVACUATION AND GAS TREATMENT OF PACKAGES Filed June 22, 1962 2 Sheets-Sheet 2 FIG. 3
United States Patent Ofiiice 3,223,157 Patented Nov. 30, 1965 5 Claims. Cl. 53-86) This invention relates to a chamber for the evacuation and gas treatment of packages of various kinds charged with appropriate commodities, for example foodstuffs and sweetmeats.
Chambers of this kind can either be used individually or grouped together as a plurality of chambers on a rotating drum or other rotor and evacuated, individually or in sequence, as appropriate, and filled with an inert gas or a protective gas, such as nitrogen or the like, 'whereby the oxygen from the air which is present in the package in the or each chamber is withdrawn and this chamber then filled with the inert gas. Experience has shown that in mechanical evacuation and gas-treating processes, it is frequently not possible to achieve the degree of oxygen reduction in the package which is desirable and indeed should theoretically be attainable. It has been confirmed that during the evacua tion and subsequent gas treatment the package, when at reduced pressure, draws in not only the protective gas which is supplied thereto, but also the mixture of this protective gas and residual air which forms in the chamber, as a result of which the residual content of oxygen in the package remains higher than would theoretically be expected and desired.
To avoid high residual oxygen content it has previously been proposed to pass the gas treating nozzle directly into the opening or mouth of the package so that the protective gas reaches the package with as little mixing as possible. Where higher machine operating rates are required and the gasification periods have thus to be very short, the gas flow which this necessitates is so powerful that it will blow out parts of the contents of the package. Moreover, capacious turbulence phenomena are set up and these further cause residual air to be driven from the chamber into the package.
The object of this invention is to avoid these shortcomings and to formulate the chamber and the gas supply means in such a Way that large turbulence phenomena are avoided during the gas treatment. A further object is to arrange for the protective gas to pass directly into the package opening in a practically unpressurized stream.
For this purpose, and in accordance with a further object of the present invention, the supply conduit for the protective gas is not only applied directly at the opening of the package, but the mouthpiece thereof is provided with a plurality of orifices for the passage of the protective gas over the package opening. These orifices are, for example, arranged in distributed or linear fashion, as a spray device, and by a further feature of the invention the outer shape of this nozzle Will substantially conform with the cross sectional shape of the opening of the package.
In order to preclude the formation of eddy phenomena in the remaining parts 'of the interior of the chamber, in accordance with another and special feature of the invention, the hollow areas defined between the inner walls of the chamber and the tools and the package in the chamber are jacketed with a gas-pervious foamed material as far as possible. This filling not only reduces the gas circulation space, but also cuts down the possibility of the formation of any significant turbulence, since the remaining volume is broken down into very small parts.
The foamed covering has moreover the important advantage that the pores of the foam material fill with protective gas during the gas treatment. During the short period in which the chamber is opened for the purpose of removing the gas treating package and introducing a new package, this protective gas is largely retained in these pores. During the next-following evacuation, however, the protective gas is drawn out of the pores into the free space of the chamber so that a residual mixture which is very rich in protective gas and correspondingly weak in oxygen content is formed even before the gasification takes place, without extra apparatus being involved in this respect.
This novel construction of an evacuating and gastreating chamber is found by experience to succeed in securing, without extra technical expenditure, substantially smaller residual oxygen contents in the packages, so that even very delicate and readily deteriorable food stuffs can be packaged in an economic and fully automatic fashion for storage.
A preferred embodiment of a chamber according to the present invention will now be described with reference to the accompanying drawings. In these drawings:
FIGURE 1 is a cross section through the chamber having a package disposed therein for evacuation and gas treatment.
FIGURE 2 is a perspective view of the gas treating spray means in association with part of a package openmg.
FIGURE 3 is an apparatus for evacuating and gastreating packages, incorporating a plurality of chambers of the kind illustrated in FIGURE 1.
The individual chambers in the accompanying drawings comprises substantially a head portion 1 with builtin sealing tools 2 and 2' and two feed pipes 3 and 4, respectively providing suction air and protective gas services. Further the chamber comprises a bell 5 which is adapted to be raised and lowered by means described below, this being arranged to encap and expose, at appropriate times, a package 7 mounted on a holder 6. In the encapped case the bell 5 forms with the head portion 1 a chamber which is airtightly closed. To ensure proper airtight sealing between the abutting surfaces of the head portion 1 and bell 5, the former has a groove machined therein to receive a resilient sealing ring 33. Mounted on the holder 6 are a pair of cranked bars 34, the function of which is to hold down side flaps on a package, as seen in FIGURE 1.
The interior of a package 7, which in the example illustrated is assumed to consist of a carton with an inner lining bag of flexible material, communicates with the interior of the chamber 1, 5 through a'slit opening 8 which is formed by spreading the mouth of the bag flat. The chamber contains a gassing tube 9 which, in use, extends in the longitudinal direction of the opening 8, and is provided with rows of small orifices or perforations v10, in an arrangement conforming with the shape and size of this opening, whereby the protective gas is uniformly distributed over the complete length of opening 8 and can pass out of tube 9 smoothly under low pressure. Preferably the openings 10 are directed downwards and laterally, as will be observed from FIGURES 1 and 2.
The free space between the sealing tools 2,2 and the package 7, on the one hand and the inner walls of the chamber housing 1, 5 on the other hand, are partly or entirely filled by a gas-permeable foamed material 11, which may, for example, be adherently secured to these walls, and it will be observed from FIGURE 1 that the feed pipes 3 and 4 pass through this foamed material lining.
The chamber 1, 5 as described above can be used separately, but quite conveniently it may be incorporated in a machine 01 the kind described in U.S. Patent No. 3,006,120. A case of this application of the chamber is more particularly illustrated in FIGURE 3 of the accompanying drawings.
In this application a plurality of chambers 1, 5 are arranged in a circle at the periphery of a rotary drum 15. The machine also includes a pusher device 16 for pushing packages successively into a position to be received on the bracket 6 of the chambers 1, 5 as they arrive at this station. At this station the chamber concerned will, of course, be opened for the package insertion and closed again, and for performance of this operation there is an air cylinder unit 17 associated with each chamber on a lower flange of the drum 15, this being arranged to raise and lower its hell 5 at required times at the packageinsertion station against the corresponding head portion 1, which is fixed in relation to drum 15. The cylinder units 17 are connected by conduits 19 to a sleeve 20 which turns, with the drum 15, around a fixed control head 21 by which the cylinders 17 are appropriately supplied with air to raise and lower the bell 5, and thereby open and close each of the chambers concerned, at required times.
During the further travel of each chamber, now closed, from the package-insertion station, the package therein is evacuated, gas-treated and closed. In pursuance of these operations the air is extracted from the chamber 1, 5 and inert gas introduced thereinto by a further means comprising a fixed control head 22 and a rotating sleeve 23.
For this purpose the head 23 is connected through a central conduit 25 and a pipe 24 with a vacuum pump '(not shown) and through a pipe 26 with a source of gas (also not shown).
To close the package 7 after it has been evacuated and gas-treated, the heat sealing jaws 2, 2' in the chamber concerned are pivoted together, whereby they press the mouth of the bag between them and heat seal the same.
To implement this arrangement, the sealing jaws 2, 2' are secured by means of arms 27, 28 to spindles 29, 30 which are mounted in the head portion 1 of the chamber, and these spindles have levers 31 at their leading ends projecting from the head portion 1. During the rotation of the drum 15, these levers 31 run, over a specific portion of the rotary travel, on a fixed cam rail 32 to cause the turning of the spindles 29, 30 and pivoting of the sealing jaws 2, 2'.
'ages, a treating chamber comprising a treating vessel comprising cooperatingly formed shells having walls adapted for being placed in sealing engagement, foamed material lining the walls of said shells, means for positioning a package in said vessel with the package having an upper longitudinally extending opening, first conduit means to connect the interior of said vessel to a suction source, a
gassing tube mounted in said vessel in relation to said positioning device to be located adjacent the opening of a package which is positioned within the vessel, said gassing tube having a nozzle with distributed outlet orifices, second conduit means to connect said gassing tube to a protective gas supply and heat sealing tools pivotally mounted in said vessel.
2. In a machine for evacuating and gas treating packages, a treating chamber comprising a treating vessel comprising a head portion and a bell, foamed material lining said head portion and bell, means for moving said bell relative to said head portion to open and close the treating vessel, a bracket carried by said head portion to support and position a package under the latter, said package having a longitudinally extending upper opening and being positioned by said bracket with the opening facing upwardly a suction conduit projecting through said foamed material to open into said head portion, a gassing tube mounted on said head portion, and having a nozzle extending in the direction of length of the upper opening of a package on said positioning device, said nozzle being shaped in conformity with this opening and being provided with a plurality of gas outlet orifices distributed in rows facing downwardly and laterally, and heat sealing tools pivotally mounted on said head portion.
3. In a machine for evacuating and gas treating packages, a treating chamber comprising a closable vessel in which a package is adapted for being supported, a suction pipe projecting into said chamber, a gas feed pipe projecting into said chamber, said package having an opening of particular size and shape throughwhich air is exhausted from the package with the suction pipe operative, a gassing tube coupled to the gas feed pipe located adjacent the opening of the package and having a plurality of orifices in an arrangement conforming with the shape and size of the opening to cause gas from the gas feed pipe to be uniformly distributed over the complete length of the opening during a gas filling operation, means supported in said chamber for sealing the opening in the package, and gas pervious foam material in said chamber adherently secured to the vessel and constituting a foam lining for the vessel for absorbing gas from the feed pipe to restrict turbulent gas flow in the chamber during a gas feed operation.
4. In a machine as claimed in claim 3 wherein said vessel includes an upper head portion and a lower bell portion, said gas pervious foam material being in said upper head portion as well as the lower bell portion and extending substantially along the entire free interior surface of the vessel.
5. In a machine as claimed in claim 3 wherein said orifices in the gassing tube are arranged in a plurality of rows, one of said rows being located at a lowermost portion of the tube directly above the opening in the package, the other'of the rows of orifices facing in a downwards and lateral direction whereby gas may be discharged from said tube smoothly at low pressure for entry into the opening in the package.
References Cited by the Examiner UNITED STATES PATENTS 2,604,247 7/1952 Andre '53 22 X 2,606,704 8/1952 Nichols 53-22 X 2,693,305 11/1954 Boydetal 53-22 2,918,767 12/1959 Grinstead et 61. 52 112 3,006,120 10/1961 Grafingholt- 53112X TRAVIS S. MCGEHEE, Primary Examiner.
FRANK E. BAILEY, Examiner.