IE78617B1 - An egg processing apparatus and system - Google Patents

Description

An Egg Processing Apparatus and System This invention relates to an egg processing apparatus and system for producing hard-boiled eggs.

The invention particularly relates to the production of shelled hard-boiled eggs. Difficulties can arise in stripping a shelled, hard-boiled egg in that the egg can be damaged during stripping of the shell. Generally speaking, the thicker the shell, the more likely that the egg will be damaged during shelling. This can lead to considerable wastage and expense.

It is an object of this invention to provide an efficient system for producing hard-boiled eggs, the shells of which can be stripped without damage to the egg.

According to the invention, there is provided an egg processing system for producing hard-boiled eggs, comprising the steps :cracking the shells of raw eggs in a controlled manner for cracking the shells without breaking the shells; delivering the eggs to a boiler; boiling the eggs in the boiler at a preset temperature for a preselected time period to hardboil the eggs; discharging hard-boiled eggs from an outlet of the boiler; rapidly cooling the hard-boiled eggs; 7861 7 - 2 feeding the eggs through a shelling apparatus for breaking and removing the shell from each egg, and delivering the eggs to a packing station and packing the eggs in containers.

Advantageously, the controlled cracking of the egg shells prior to boiling facilitates the subsequent stripping of the egg shells which readily easily peel away from the eggs .

In a preferred embodiment, the system includes cracking 10 the egg shells by impacting the raw eggs in a controlled manner against a cracking surface.

In a particularly preferred embodiment, the system includes positioning the raw eggs at a preset height above the cracking surface, releasing and dropping the raw eggs for impacting the raw eggs against the cracking surface.

Conveniently, the system includes cracking the egg shells by locating the raw eggs above a feed conveyor for delivering the raw eggs to the boiler, positioning the raw eggs at a preset height above the feed conveyor, dropping the raw eggs and impacting the raw eggs against a surface of the conveyor for cracking the eggs.

In another embodiment, the system includes :delivering the raw eggs on trays to a loading station, picking up the raw eggs by means of a lifting device having a suction cup for engaging eggs on the tray, applying a vacuum to each cup for gripping the egg with the suction cups, moving the lifting device over the feed conveyor, positioning the lifting device at a preset height above the feed conveyor, and releasing the vacuum for dropping the eggs from each suction cup onto a surface of the feed conveyor.

Using the lifting device, a plurality of eggs can be readily easily and rapidly handled for transfer to the feed conveyor. Further, controlled cracking of the eggs is carried out in a simple and efficient manner by dropping them directly onto the feed conveyor.

Preferably, the system includes engaging the lifting device with an associated rest above the feed conveyor for locating the lifting device at a preset height above the feed conveyor surface.

In a further embodiment, at the packing station the system includes delivering a plurality of shelled hard-boiled eggs into a container, filling the container with a liquid preservative to a level above the eggs in the container.

In another embodiment, the system includes the step of monitoring the pH of the albumen of raw eggs and selecting eggs for boiling which have a pH within a desired range.

In a further embodiment, the system includes the step of rapidly cooling the hard-boiled eggs discharged from the boiler by delivering the hard-boiled eggs into a chilled water bath, maintaining the water temperature in the chilled water bath at about 2°C, retaining the hard-boiled egg in the chilled water bath for a preset time period to cool the eggs to about 5°C.

In a preferred embodiment, the system includes the step of turning the eggs continuously within the boiler during boiling of the eggs for centring the egg yolk within each egg during cooking of the egg.

Conveniently, the system includes carrying the eggs on a conveyor between an inlet and an outlet of the boiler, the conveyor having a plurality of spaced-apart rotatable rollers moving between the inlet and outlet, the rollers rotating on a support as they move between the inlet and the outlet, carrying each egg between an adjacent pair of rollers, the rotation of the rollers continuously rotating the egg as it is being moved between the inlet and the outlet of the boiler.

In another aspect, the invention provides an egg processing apparatus comprising means for impacting raw eggs in a controlled manner against a cracking surface for cracking but not breaking the egg shells, means for delivering raw eggs to a boiler, the boiler operable to hard-boil the eggs, a cooler mounted at an outlet of the boiler for reception and rapid cooling of hard-boiled eggs, a shelling apparatus at an outlet of the cooler for breaking and removing the shells of hard-boiled eggs, and means for delivering shelled eggs to a packing station.

In a preferred embodiment, the impacting means is a lifting device operable to simultaneously lift a plurality of raw eggs from a tray, the lifting device engageable with an associated rest to position the eggs at a preset height above a feed conveyor for feeding the raw eggs to the boiler, the lifting device operable to release the eggs for dropping and impacting the eggs against a surface of the feed conveyor for cracking the egg shells in a controlled manner.

In another embodiment, the boiler has a hot water bath, a conveyor movable through the bath between an inlet and an outlet of the boiler, the conveyor having a plurality of spaced-apart rollers for reception of eggs between adjacent rollers, the rollers being rotatably mounted on a support for rotation of the rollers as the rollers move between the inlet and the outlet.

The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:Fig. 1 is a perspective view showing a loading station used in an egg processing system according to the invention; Fig. 2 is a detail partially sectioned side elevational view showing portion of the loading station; Fig. 3 is a schematic sectional elevational view of a boiler used in the system; Fig. 4 is a detail perspective view of a cooler used in the egg processing system; Fig. 5 is a side sectional elevational view the cooler; Fig. 6 is a perspective view of an egg shelling apparatus used in the system; Fig. 7 is an end sectional elevational view of the egg shelling apparatus; and Fig. 8 is a view similar to Fig. 7 showing the apparatus in a different position of use.

Referring to the drawings, a system and apparatus for producing shelled hard-boiled eggs will be described.

Trays of raw eggs 25 are delivered to a loading station 10 (Fig. 1). At the loading station 10, a lifting device 11 engages and simultaneously lifts all the raw eggs 25 from a tray 26 for transfer onto a feed conveyor 12 for delivery of the raw eggs to a boiler 14.

The lifting device 11 comprises a manifold 15 formed by a number of interconnected tubes 16 arranged in a generally parallel array. A tubular handle 18 at a top side of the manifold 15 communicates by means of a flexible pipe 19 with a vacuum source (not shown). A valve 20 on the handle 18 is operable to connect the manifold 15 to either the vacuum source or to atmosphere. A plurality of flexible suction cups 22 are mounted on an underside of each tube 16 and extend downwardly therefrom for engagement with eggs 25. A height adjustable rest 28 is mounted at a preset distance above the feed conveyor 12.

In use, an operator grips the lifting device 11 by the handle 18 and engages the suction cups 22 with all the raw eggs 25 on a tray 26 of eggs delivered to the loading station 10. Upon operation of the valve 20 by means of a thumb or finger, a vacuum is applied to each suction cup 20 through the manifold 15 so that all the eggs 25 are firmly gripped by each suction cup 22 and then can be simultaneously lifted off the tray 26 for transfer onto the feed conveyor 12. The operative engages a front end of the manifold 15 with the rest 28 to position the eggs at a desired height above the conveyor 12 as shown in Fig. 2. Then, operating the switch 20, the vacuum is released and each suction cup 22 vented to atmosphere. Thus, the eggs 25 are dropped onto the conveyor 12 impacting against a top surface of the conveyor 12 to crack an end of each egg shell but not break the egg shell. The top surface of the conveyor 12 is sufficiently hard to cause the controlled cracking of the eggs when the eggs are dropped onto it from the preset height determined by the spacing of the rest 18 above the conveyor 12.

The eggs 25 are then delivered by means of the feed conveyor 12 into the boiler 14. Within the boiler 14 (Fig. 3), the eggs 25 are conveyed through a water bath 30. The water bath 30 is kept at a temperature of about 96.5°C. The transit time of the eggs through the water bath 30 is about 20.5 minutes. Each egg 25 is rolled continuously as it moves between an inlet 31 and an outlet 32 of the boiler 14. To achieve this, the eggs 25 are carried on a conveyor 33 comprising a plurality of spacedapart rollers 34, the spacing between adjacent rollers 34 being sufficient to support an egg 25 on its side therebetween. The rollers 34 rotate as they move through the boiler 14 between the inlet 31 and outlet 32 for continuously rolling the eggs 25 during cooking of the eggs. This advantageously centres the yolk within the egg during cooking of the egg.

Hard-boiled eggs discharged from the boiler 14 are delivered into a cooler 40 (Figs. 4 and 5) for rapidly cooling the cooked eggs. The cooler 40 has a chilled water bath 41 within which cooling water (not shown) is maintained at a temperature of approximately 2°C. At an inlet end of the cooler 40, a rotating drum 42 is mounted within the bath 41 for reception of the hot cooked eggs from the boiler 14. The drum 42 has a central drive shaft 43 (Fig. 4). Paddles 44, extending radially outwardly of the drive shaft 43 form together with end plates 45, a number of separate pockets 46 for reception of eggs. The speed of rotation of the shaft 43 can be regulated to determine the time spent by the eggs within the chilled water of the bath 41. To chill the eggs to a temperature of approximately 5°C, they typically spend approximately 30 minutes in the chilled water of the bath 41. As the drum 42 rotates, one of the pockets 46 is receiving newly boiled eggs from the boiler 14 and another pocket 46 is at the same time discharging cooled eggs onto a supply conveyor 50 which delivers the eggs to an egg shelling apparatus 60.

The supply conveyor 50 has a plurality of spaced-apart bars 52, eggs sitting between adjacent bars 52 for carriage along by the conveyor 50. Guide rods 53 mounted above the bars 52 on supports 54 separate the eggs into individual streams for feeding into the egg shelling apparatus 60.

In the shelling apparatus 60 (Figs. 6-8), eggs 25 are dropped into pockets 61 within which the egg shells are broken and the eggs are then delivered by a conveyor belt 64 between stripping rollers 65, 66 which strip the broken egg shell from the eggs, the shelled eggs being discharging onto a packing conveyor 70. The stripping rollers are mounted on pivot arms 67, 68 which lift (as shown in Fig. 8) to receive a cracked egg 25 and at the same time discharge a shelled egg 25a to the packing conveyor 70.

The packing conveyor 70 carries the eggs through a spray housing 71 within which water is sprayed onto the eggs to carry away any remaining pieces of egg shell. Downstream of the spray housing 71, the shelled eggs are delivered into a container. The container is then filled with a preservative, closed and sealed. the preservative has a pH in the range 3 to 8, thus curtailing bacterial growth on the eggs to improve shelf life of the eggs. The preservative also helps prevent discoloration of the yolk.

The invention provides a system and apparatus for the efficient production of high quality shelled hard-boiled eggs. By cracking the shells of raw eggs prior to boiling the raw eggs, this greatly facilitates the subsequent removal of the egg shell, allowing even relatively thick egg shells, such as are found in brown eggs, to be readily easily removed without damaging the egg. Further, rotation of the eggs within the boiler during cooking advantageously centres the egg yolk within the egg white maintaining a good thickness of egg white around the yolk. Also, rapid cooling of the eggs downstream of the boiler assists in preventing darkening and discoloration of an outermost part of the yolk within each egg. The preservative within the containers also helps to prevent discoloration of the yolk as well as extending the shelf life of the product.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims (5)

1. An egg processing system for producing hard-boiled eggs, comprising the steps :cracking the shells of raw eggs in a controlled 5 manner for cracking the shells without breaking the shells; delivering the eggs to a boiler; boiling the eggs in the boiler at a preset temperature for a preselected time period to 10 hard-boil the eggs; discharging hard-boiled eggs from an outlet of the boiler; rapidly cooling the hard-boiled eggs; feeding the eggs through a shelling apparatus 15 for breaking and removing the shell from each egg, and delivering the eggs to a packing station and packing the eggs in containers.

2. A system as claimed in claim 1 which includes 20 cracking the egg shells by impacting the raw eggs in a controlled manner against a cracking surface.

3. A system as claimed in claim 2 which includes positioning the raw eggs at a preset height above the cracking surface, releasing and dropping the raw eggs for impacting the raw eggs against the cracking surface. A system as claimed in claim 2 or 3 which includes cracking the egg shells by locating the raw eggs above a feed conveyor for delivering the raw eggs to the boiler, positioning the raw eggs at a preset height above the feed conveyor, dropping the raw eggs and impacting the eggs against a surface of the conveyor for cracking the eggs. A system as claimed includes :- in claim 4 wherein the system delivering the station, raw eggs on trays to a loading picking up the raw eggs by means of a lifting device having a suction cup for engaging eggs on the tray, applying a vacuum to each cup for gripping the eggs with the suction cups, moving the lifting device over the feed conveyor, positioning the lifting device at a preset height above the feed conveyor, and releasing the vacuum for dropping the eggs from each suction cup onto a surface of the feed conveyor. A system as claimed in claim 5 which includes engaging the lifting device with an associated rest above the feed conveyor for locating the lifting device at a preset height above the feed conveyor surface. 7. A system as claimed in any preceding claim wherein at the packing station the system includes delivering a plurality of shelled hard-boiled eggs into a container, filling the container with a liquid preservative to a level above the eggs in the container. 8. A system as claimed in claim 7 wherein the preservative has a pH in the range 3 to 8. 9. A system as claimed in any preceding claim including the step of monitoring the pH of the albumen of raw eggs and selecting raw eggs for boiling which have a pH within a desired range. 10. A system as claimed in any preceding claim including the step of rapidly cooling the hard-boiled eggs discharged from the boiler by delivering the hardboiled eggs into a chilled water bath, maintaining the water temperature in the chilled water bath at about 2°C, retaining the hard-boiled eggs in the chilled water bath for a preset time period to cool the eggs to about 5°C. 11. A system as claimed in any preceding claim including the step of turning the eggs continuously within the boiler during boiling of the eggs for centring the egg yolk within each egg during cooking of the egg. 12. A system as claimed in any preceding claim including the steps of carrying the eggs on a conveyor between an inlet and an outlet of the boiler, the conveyor having a plurality of spaced-apart rotatable rollers moving between the inlet and the outlet, the rollers rotating on a support as they move between the inlet and the outlet, carrying each egg between an adjacent pair of rollers between the inlet and the outlet of the boiler, the rotation of the rollers continuously rotating the egg as it is being moved between the inlet and the outlet of the boiler for centring the egg yolk within each egg during cooking of the egg. 13. A system for producing hard-boiled eggs substantially as hereinbefore described with reference to the accompanying drawings . 14. Hard-boiled eggs whenever produced according to the system as claimed in any preceding claim. 15. An egg processing apparatus comprising means for impacting raw eggs in a controlled manner against a cracking surface for cracking but not breaking the egg shells, means for delivering raw eggs to a boiler, the boiler operable to hard-boil the eggs, a cooler mounted at an outlet of the boiler for reception and rapid cooling of hard-boiled eggs, a shelling apparatus at an outlet of the cooler for breaking and removing the shells of hard-boiled eggs, and means for delivering shelled eggs to a packing station. 16. Apparatus as claimed in claim 15 wherein the impacting means is a lifting device operable to simultaneously lift a plurality of raw eggs from a tray, the lifting device engageable with an associated rest to position the eggs at a preset height above a feed conveyor for feeding the raw eggs to the boiler, the lifting device operable to release the eggs for dropping and impacting the eggs against a surface of the feed conveyor for cracking the egg shells in a controlled manner. 17. Apparatus as claimed in claim 15 or claim 16 wherein the boiler has a hot water bath, a conveyor movable through the bath between an inlet and an outlet of the boiler, the conveyor having a plurality of

4. 5 spaced-apart rollers for reception of eggs between adjacent rollers, the rollers being rotatably mounted on a support for rotation of the rollers as the rollers move between the inlet and the outlet. 18. An egg processing apparatus substantially as

5. 10 hereinbefore described with reference to the accompanying drawings .