NL2013549B1

NL2013549B1 - Processing apparatus for processing food products using a liquid, assembly and method for processing food products using a liquid.

Info

Publication number: NL2013549B1
Application number: NL2013549A
Authority: NL
Inventors: Marinus Quirinus Kools Johannes; Martinus Meulendijks Johannes; Willem Dekker Thomas
Original assignee: Marel Townsend Further Proc Bv
Priority date: 2014-09-30
Filing date: 2014-09-30
Publication date: 2016-10-03
Also published as: WO2016053095A2; WO2016053095A3

Abstract

The present invention relates to a processing apparatus for processing food products using a liquid with a processing vessel containing a processing liquid and a screw conveyor for moving the food products through the processing vessel. The present invention also relates to an assembly of such a processing apparatus, a food product feeder and a food product discharger. Furthermore the present invention relates to a method for processing food products using a liquid with such an apparatus.

Description

Processing apparatus for processing food products using a liquid, assembly and method for processing food products using a liquid

The present invention relates to an apparatus for processing food products using a liquid, the apparatus comprising: an elongate processing vessel having a first feed end and a second discharge end, the processing vessel containing a processing liquid and a rotatable screw conveyor for moving the food products through the processing vessel. The present invention also relates to an assembly of such a processing apparatus, a food product feeder and a food product discharger. Furthermore the present invention relates to a method for processing food products using a liquid, comprising the method steps: A) feeding the food products at a first feed end to an elongate liquid holding processing vessel; B) moving the food products with a screw conveyor through the elongate processing vessel; and C) discharging the food products at a second discharge end out of the elongate processing vessel.

In EP 2 413 703 a system, method and apparatus for processing food products is disclosed wherein a screw conveyor in the form of a rotatable drum with an inwardly extending helical screw that is placed within a processing vessel conveys the food product through a processing liquid.

It is an object of the present invention to provide an improved processing apparatus, assembly and method for processing food products using a liquid that pairs the advantages of the prior art techniques with enhanced effectivity and/or enhanced efficiency.

The invention provides for this purpose a processing apparatus for processing food products using a liquid, the apparatus comprising: an elongate processing vessel having a first feed end and a second discharge end, the processing vessel containing a processing liquid; a screw conveyor in the form of a helical screw extending outwardly from a central shaft; which screw conveyor is at least partially rotatably arranged in the processing vessel such that the helical screw closely fits the inner wall of the processing vessel; wherein the central shaft of the screw conveyor at the feed end is hollow, which hollow shaft has an opening outside the processing vessel for connection to a food product feeder and wherein the hollow central shaft at the feed end is provided with a helical opening inside the processing vessel. The pitch of the helical shaft opening may substantially correspond with the pitch of the helical screw blade.

An advantage of the processing apparatus according the present invention is that the a screw conveyor in the form of a helical screw extending outwardly from a central shaft provides an open structure that facilities easy access to the processing room resulting for instance in easier cleaning of the apparatus as well as easy process inspection. A further advantage of the open structure is that the apparatus is lighter and more specific the moving part of the apparatus is lighter than the prior art equipment. The wording “the helical screw closely fits the inner wall of the processing vessel” is to be understood as that the distance between the helical screw and the inner wall of the processing vessel is smaller than the food products to be processed, thus preventing the passage of the food products between the helical screw and the inner wall of the processing vessel, but the distance is also so that it is not impeding the rotation of the helical screw. For this reason the inner wall of the lower part of the processing vessel may have a half cylinder shape, essentially corresponding to an outside diameter of the curvature of the helical screw blade.

The hollow feed end of the shaft of the screw conveyor enables dual use of the shaft construction, not only as an element for carrying the screw conveyor blade but also as a part of the product infeed means. The dual function of the shaft feed end further simplifies the construction and the opening outside the processing vessel for connection to a food product feeder makes further passages through the processing vessel of other infeed means superfluous, which also supports the easy cleaning of the apparatus. Due to the helical opening of the shaft inside the processing vessel such that the pitch of the helical shaft opening substantially corresponds with the pitch of the helical screw blade the feed of the food products into the vessel will always be performed synchronously with the rotation of the helical screw blade. This is beneficial for a robust feed process control, i.e. depositing food products at predetermined locations at predetermined tmes within the processing vessel

As the feed end of the shaft is adapted to allow the passage of food products to be processed the drive for rotation of the screw conveyor may be located at the discharge end of the shaft, e.g. outside the processing vessel. This drive may be an electric motor.

As the food products will be removed from the hollow shaft after the products have undergone a maximum rotation of 360°, the helical opening in the hollow central shaft may have a length of substantially a single winding of the helical screw of the screw conveyor. To promote a forward movement of the food products in the hollow shaft and to support the flow of the food products out of the hollow shaft into the processing vessel the opened shaft may connect to a liquid feed. The liquid will in such a situation carry or at least assist in propelling the food products through the opened shaft and the helical opening into the processing vessel. For such liquid flow the processing liquid from the processing vessel may be used, which is easy to realise with a dedicated liquid loop (a connection to the processing vessel including a pump that feeds processing liquid into the hollo shaft).

The elongate processing vessel may also be provided with nozzles to feed a gas into the liquid in the elongate processing vessel. The presence of gas bubbles in the processing liquid may enhances the efficiency of for instance heat exchange of the food products with the processing liquid and also makes the food products move in the processing liquid preventing parts of (floating) food products being not (or less) in contact with the processing liquid. The food products are stirred about in the liquid, thus enhancing the heat transfer from the liquid to the food products (or vice versa).

The invention also provides a processing apparatus for processing food products using a liquid, the apparatus comprising: an elongate processing vessel having a first feed end and a second discharge end for containing a processing liquid; a screw conveyor in the form of a helical screw; which screw conveyor is rotatable located in the processing vessel; wherein the elongate processing vessel is provided with nozzles to feed a gas into the liquid in the elongate processing vessel. These nozzles may be distributed at various locations spread over the length of the elongate processing vessel. As already mentioned before the presence of gas bubbles has an influence on the interaction of the processing liquid at the food products to be processed which may be sought for. The gas blown in the processing liquid may be air but also any other gas mixture may be introduced dependent on the process requirements. As for the propelling of the gas a blower may be used but also any other propellants are acceptable. As has been discovered to create high exchange (transfer) rates larger bubbles may be used as larger bubbles rise relative quickly and create more speed in the liquid than smaller bubbles.

As different requirements in different stages of the processing using a liquid of the food products may be required the feed of the aeration nozzles may be individually controllable (or controllable in groups). For instance at the entrance of the processing vessel the food products may be more vulnerable than when they have stayed for some period in the processing vessel already and have thus travelled further from the feed end towards the discharge end. Dependent on the type of food product processing using a liquid the temperature of the liquid may be of relevance; e.g. liquid heating (“blanching’, “cooking”) or liquid cooling may be applied. For such temperature treatment the processing apparatus may be provided with liquid temperature influencing means, like a heater or a cooler/freezer. These liquid temperature influencing means may be located inside the processing vessel and/or outside the processing vessel. As an alternative it is also possible that the processing vessel is double walled which double walled processing vessel then acts as a heat exchanger. For temperature control of the processing liquid, for the prevention of contamination of the processing liquid and/or the environment or for any other reason the processing vessel may be provided with a lid so that the process environment can be closed off from ambient atmosphere. For process control and cleaning purposes the lid may advantageously be removable. Furthermore the processing vessel may also be provided with one or more fluid injectors to add any fluid (e.g. to spray at any floating food products or to clean the processing vessel).

In yet another embodiment of the processing apparatus the longitudinal axis of the screw conveyor may meet at an angle of less than 10°, or even less than 5°, with the horizontal. When the axis of the screw conveyor slopes slightly down the efficiency of the food processing using a liquid may positively be influenced while the feed of the food products in the processing vessel may not negatively be influenced.

At the discharge side the helical screw blade may be provided with apertures. When the last part of the helical screw (e.g. the last winding of the helical screw of the screw conveyor) at the discharge end of the elongate processing vessel is provided with apertures a fraction of the processing fluid may flow through the blade and creates an at least partial axial liquid flow which may assist/support the removal of the food products from the processing vessel. To prevent food products to get stuck at the discharge side of the processing vessel it may be provided with a central food product guide, like for instance an axial cone. Of further assistance for the product removal from the vessel use may be made of a chute connecting to an aperture at the discharge end of the elongate processing vessel. Such a chute may be used as a liquid overflow with the liquid passage also the food products to be removed are carried away. Furthermore it may be advantageous to fit the shape of the end part helical screw of the screw conveyor with using a chute as mentioned before to get an easy transfer of the food products out of the processing vessel.

The invention also provides an assembly of a processing apparatus as described above, a food product feeder connecting to the feed end of the processing apparatus, and a food product discharger connecting to the discharge end of the processing apparatus. The assembly may furthermore also comprise a second processing apparatus according the invention, wherein the food product discharger links the two processing apparatuses and a second food product discharger being provided that connects to the discharge end of the second processing apparatus. Especially when two processing apparatuses are combined the first processing apparatus may be provided with a liquid heater and the second processing apparatus may be provided with a liquid cooler. At the front side (that means before the food product feeder into the first processing apparatus) also a sausage co-extrusion unit including a pincher for individualising sausages from a larger sausage strand may be added to the assembly. With such a production unit a compact co-extrusion line for sausages may be realised where the vulnerable individualised sausage are first cooked in a processing vessel and subsequently cooled in a second processing vessel before final treatment of the food products, such a sorting and packaging.

The invention also provides a method for processing food products using a liquid, comprising the method steps: A) feeding the food products at a first feed end to an elongate liquid holding processing vessel; B) moving the food products with a screw conveyor through the elongate processing vessel; and C) discharging the food products at a second discharge end out of the elongate processing vessel; wherein at various locations spread over the length of the elongate processing vessel gas is blown into the liquid in the processing vessel and/or wherein the food products are fed to the processing vessel through a hollow central shaft of the screw conveyor.

For all embodiments of the invention the level of the liquid in the processing vessel may be varied dependent on process requirements but often a liquid level just below the central axis of the screw conveyor is used. The quantity of gas blown into the liquid in the processing vessel may vary on various locations varies along the length (and/or the width) of the processing vessel. In a specific method the quantity of gas blown into the liquid in the processing vessel closer to the feed end is lower than the quantity of gas blown into the liquid in the processing vessel closer to the discharge end. According to this method, the advantages may be realised which have been summarized above in relation to the apparatus and assembly according the present invention.

The invention will be further elucidated herein below on the basis of the non-limitative exemplary embodiments shown in the following figures. Herein: figure 1 shows a schematic side view of a processing apparatus according the present invention; figure 2 shows a schematic side view of an alternative embodiment of a processing apparatus according the present invention; figure 3 shows a perspective view of a processing apparatus according the present invention; and figure 4 shows a perspective view of a food production assembly according the present invention.

Figure 1 shows a processing apparatus 1 for processing food products 2 using a liquid. An elongate processing vessel 3 contains a processing liquid 4. Food products 2 are fed to the processing vessel 3 at a first feed end 5 of the processing vessel 3 according arrow Pi. Partially in the processing vessel 3 is rotatable located a screw conveyor 6 in the form of a helical screw blade 7 extending outwardly from a central shaft 8. The central shaft 8 of the screw conveyor 6 at the feed end 5 is hollow 9 and this hollow shaft end 9 is open to the outside and is used to feed the food products 2 in (see Pi). The hollow shaft end 9 inside the processing vessel 3 is provided with a helical opening 10, which helical opening 10 has a pitch that corresponds with the pitch of the helical screw blade 7. For feeding the food products 2 into the processing vessel 3 processing liquid 4 is pumped out of the processing vessel 3 via a pipe 11 and pump 12 and fed into the hollow shaft end 9. After the food products 2 are dropped into the processing liquid 4 in processing vessel 3 rotation of the screw conveyor 6 results in displacement of the food products 2 according arrow P2 toward a discharge side 13 of the processing vessel 3. At the discharge end 13 the food products 2 are ejected (see arrow P3) via a chute 14.

Figure 2 shows a processing apparatus 20 for processing food products 2 using a liquid that corresponds partially with the processing apparatus as shown in figure 1. Here however the food products 2 are fed to a processing vessel 21 at a first feed end 22 via the open top of the processing vessel (see arrow P4). Also here in the processing vessel 21 is rotatable located a screw conveyor 23 in the form of a helical screw blade 24 extending outwardly from a central shaft 25. The elongate processing vessel 21 contains a processing liquid 26 in which processing liquid 26 gas is blown through nozzles 27 that are located in the bottom of the processing vessel 21. The output of the gas nozzles 27 is individually controllable with valves 28 and the gas is supplied with a blower 29. After the food products 2 are dropped into the processing liquid 4 in processing vessel 21 (P4) rotation of the screw conveyor 23 results in displacement of the food products 2 according arrow P5 toward a discharge side 30 of the processing vessel 21. At the discharge end 30 the food products 2 are ejected (see arrow Pó) via a chute 14.

Figure 3 shows a perspective view of a processing apparatus 40 with a processing vessel 41 and a screw conveyor 42 with a hollow shaft end 43. An electric drive 44 is connected to a central shaft 45 of the screw conveyor 42 at the discharge end 46. In the last part of helical screw blade 47 of the screw conveyor 42 apertures 48 are provided to allow processing fluid (not depicted in this figure) to flow through the blade end 47 that results in an overflow of processing fluid in a discharge chute 49 along which route the food products will leave the processing apparatus 40. Also visible in this figure is a lid 50 for closing off the processing apparatus 40 during processing.

Figure 4 shows a food production assembly 60 of two processing apparatuses 61, 62 according the present invention arranged in line. The assembly 60 starts with two hoppers 63, 64, one for casing material and one for a food dough. The material from the hoppers 63, 64 is fed to a sausage co-extrusion unit 65 where a single encased food stand is created. The food stand subsequently passes a brining gutter 66 to reach a pinching unit 67 where the brined encased food stand is subdivided in separated sausages. The separated sausages are then fed to a first processing apparatuses 61, more particular a blancher, from where a food product discharger 68 forwards the sausages to the second processing apparatuses 62 where the sausages may be cooled. Via a second food product discharger 69 that connect to the discharge end of the second processing apparatus 62 the sausage may leave the assembly 60.

Claims

A processing device for processing food products using a liquid, comprising: - an elongated processing vessel with a first supply end and a second discharge end, wherein the processing vessel comprises a processing liquid; - a screw conveyor in the form of a spiral screw extending outwards from a central axis; which screw conveyor is arranged at least partially in a rotatable manner in the processing vessel, so that the spiral screw fits closely onto the inner wall of the processing vessel; wherein the central axis of the screw conveyor is hollow at the feed end, wherein the hollow shaft has an opening outside the processing vessel for connection to a feed device for the food product and wherein the hollow central shaft is provided with a spiral opening in the processing vessel at the feed end.

2. Processing device as claimed in claim 1, characterized in that the pitch of the spiral shaft opening substantially corresponds to the pitch of the spiral screw blade.

3. Processing device as claimed in claim 1 or 2, characterized in that the spiral-shaped opening in the hollow central axis has a length of substantially a single turn of the spiral screw of the screw conveyor.

Processing device according to one of the preceding claims, characterized in that the opened shaft is connected to a liquid supply.

Processing device according to one of the preceding claims, characterized in that the elongated processing vessel is provided with nozzles for supplying a gas to the liquid in the elongated processing vessel.

Processing device for processing food products using a liquid, comprising: - an elongated processing vessel with a first supply end and a second discharge end for containing a processing liquid; -a screw conveyor in the form of a spiral screw; which screw conveyor is rotatably arranged in the processing vessel; wherein the elongated processing vessel is provided with nozzles for supplying a gas to the liquid in the elongated processing vessel.

Processing device as claimed in claim 6, characterized in that the nozzles are distributed over different positions, spread over the length of the elongated processing vessel.

Processing device according to claim 6 or 7, characterized in that the supply of the aeration nozzles can be controlled separately.

9. Processing device as claimed in any of the foregoing claims, characterized in that the processing device is provided with fluid temperature influencing means.

Processing device according to one of the preceding claims, characterized in that a longitudinal axis of the screw conveyor makes an angle of less than 10 °, or even less than 5 °, with the horizontal.

Processing device according to one of the preceding claims, characterized in that the spiral screw is provided with openings at the discharge end of the elongated processing vessel.

An assembly of a processing device as claimed in any one of the preceding claims, a feed device for food products which is connected to the feed end of the processing device, and a feed device for the food product which is connected to the discharge end of the processing device.

An assembly according to claim 11, characterized in that the assembly further comprises a second processing device according to one of claims 1 to 11, wherein the discharge device for food products couples the two processing devices and wherein a second discharge device for food products is provided which is connected to the discharge end of the second processing device.

Assembly as claimed in claim 13, characterized in that the processing device is provided with a liquid heating and the second processing device is provided with a cooler.

An assembly according to claim 13 or 14, characterized in that the assembly is provided with a sausage co-extrusion unit including a squeezing device for individualizing sausages from a large sausage strand.

A method for processing food products using a liquid, comprising the method steps: A) supplying the food products at a first feed end to an elongated liquid-containing processing vessel; B) moving the food products with a screw conveyor through the elongated processing vessel; and C) discharging the food products at a second discharge end from the elongated processing vessel; wherein at various positions spread over the length of the elongated processing vessel, gas is blown into the liquid in the processing vessel, and / or wherein the food products are supplied through a hollow central axis of the screw conveyor to the processing vessel.

A method according to claim 16, characterized in that the amount of gas that is blown into the liquid in the processing vessel varies at different positions.

A method according to claim 16 or 17, characterized in that the amount of gas that is blown into the liquid in the processing vessel close to the supply end is smaller than the amount of gas that is blown into the liquid in the processing vessel close to the discharge end.