WO1986004786A1

WO1986004786A1 - Conveyor and heat treatment device

Info

Publication number: WO1986004786A1
Application number: PCT/SE1986/000061
Authority: WO
Inventors: Lennart STENSTRÖM
Original assignee: Alfastar Ab
Priority date: 1985-02-18
Filing date: 1986-02-14
Publication date: 1986-08-28
Also published as: SE8500753D0; SE446931B; SE8500753L; AU5545586A; EP0213170A1

Abstract

A device for transport and heat treatment of products under well controllable conditions. The device comprises a conveyor (18), a driving device (27a) and preferably a sluice (13) for the passage of the conveyor through zones having different environmental conditions. The device includes a unit (11) for input and output of products to respectively from the conveyor. The conveyor is formed by substantially horizontal parts which are joined by a reversing arrangement (26) and form a first treatment path in a forward direction (16) and a second treatment path in a return direction (17). Each conveyor part is encapsuled in an confinement formed by several straight module units (12, 14), and the reversing arrangement is formed as a turning around unit having a guide (25) for reversing the conveyor to the return direction.

Description

CONVEYOR AND HEAT TREATMENT DEVICE

TECHNICAL FIELD OP THE INVENTION

The present invention relates to a device for transport and heat treatment of products under well controllable conditions. Products of a specific interest in this context are products requiring heat stabilization, for instance food stuff and pharmaceutical compounds.

BACKGROUND OF THE INVENTION

The term heat stabilization is thought to include a number of general processes as stabilization, pasteurization, cooling, etc.

The heat stabilization thought at the first hand in the present context includes known concepts for refining and improving the efficiency of general processes.

In the stabilization process there may for instance be included a method for fast preheating to a temperature distribution within the product suited for microwave treatment. A two-step process comprising contact with a hot medium directly followed by a short time contact with a cooler medium may precede or start the microwave treatment.

It is also possible to adjust the temperature profile in advance such that the microwave treatment gives a uniform temperature profile within the product.

A further possibility is to carry out the microwave treatment in water or other liquid and control the water temperature such that the temperature increase at the surface Ls depressed.

Heat stabilization according to the present concept implies a qualified process technology and it is of importance that the physical requisites for the stabilization/process are the proper ones. OBJECT OF THE INVENTION

The problem according to the invention is to provide a device for transport and heat treatment of products where the transport device may be used in a qualified process environment and is adaptable to the desired process conditions and also manufacturable by using a rational production. Such stipulations do also mean flexibility as far as the structure of the process line is concerned and requirements for simple rebuilding and adjustment to increased capacity of an existing line on a given or minimum floor space at a lowest possible total cost.

The object of the invention is to offer a transport and heat treatment device which meets the stipulations of the problem definition.

SUMMARY OF THE INVENTION

The invention provides a device for transport and heat treatment of products under well controllable condi- tions, comprising a conveyor, driving means and preferably an arrangement for passing the conveyor through at least two zones having different environmental conditions, and a device for input and output, respectively, of the product to the conveyor and from the conveyor. The device is distinguished in that the conveyor comprises substantially horizontal conveyor parts in the process active portions of the device, the conveyor parts forming by means of a reversing arrangement a first treatment path in the forward direction and a second treatment path in the return direction, and each conveyor part being encasal in a confinement formed by several straight module units, and the reversing arrangement being arranged as a turning around unit having a guide for reversing the conveyor to the return direction.

In one embodiment of the invention the conveyor comprises several mutually pivotably connected links. In said embodiment the double length of each module unit preferably corresponds to a certain integral number multiple of the length of each link.

The device according to the invention preferably is arranged such that the reversing or turning around unit as well as adjacent module units, at least partly, contain a fluid in a liquid phase, and such that said conveyor guide and at least portions of adjacent conveyor parts are arranged in the fluid.

At least certain of the module units preferably are equipped with means for individual temperature control.

At least some of the module units preferably have microwave transferring windows of a dielectric material.

At least some of the module units suitably are equipped with a device for measuring the temperature in the product.

The object of reducing the necessary floor surface is obtained by arranging several conveyor parts forming a number of forward and return paths above each other such that several closed treatment paths are obtained.

In that case where a sluice device Is arranged the module units preferably are arranged at both sides of the sluice device, and the modules are dimensioned for a high pressure at one side of the sluice and dimensioned for a lower pressure at the other side of the sluice.

Preferably the sluice device is arranged with a rotor which forms a passage for the conveyor and the product between an opening in the housing of the sluice and the rotor, and the rotor is provided with means for driving the conveyor via a drive motor driving the rotor.

Preferably the conveyor comprises a cassette device having means for encasing the product with a predetermined section during the transport thereof in the device.

Suitably the cassette is formed as a link of the conveyor.

BAD ORI BRIEF DESCRIPTION OP THE DRAWINGS

Fig. 1 in a perspective view shows an example of a heat stabilization line where the device for transport and heat treatment according to the invention is included,

Fig. 2 in a perspective view shows another example of a line where the inventive idea is realized,

Fig. 3 in a perspective view shows a first type of a module unit according to the invention,

Fig. 4 in a perspective view shows a so called reversing or turning around unit,

Fig. 4a shows another type of reversing unit,

Fig. 5 in a perspective view shows another type of module unit, a so called connection housing according to the inventive idea,

Fig. 6 in a perspective view shows a microwave module,

Fig. 7 in a perspective view shows a microwave applicator,

Fig. 8 in a perspective view shows a product cassette representing the parts of which the conveyor of the system is constructed,

Fig. 9 is a radial partial section through the sluice,

Fig. 10 is an axial partial section through the sluice,

Fig. 11 shows an arrangement of several complete treatment lines arranged vertically above each other,

Fig. 12 shows a process line without a sluice, and

Fig. 13 shows an example of a layout for a factory.

SPECIFIC DESCRIPTION

The reference numeral 10 in Fig. 1 generally denotes a heat stabilization system comprising an input and output unit 11, the input of which is arranged at the upper side, module units 12 of the low pressure type arranged at two levels above each other, a sluice device 13 and high pressure modules 14 arranged above each other. Some of the latter modules have microwave devices 15, if necessary at both levels.

Basically the module units 12 and 14 consist of straight elements of the same length which if necessary may be provided with angled connection flanges for obtaining for instance a bump in the path, and when the modules are interconnected into a system, for instance as in Fig. 1, there is formed a first process path substantially in the direction 16 and a second path in the opposite direction 17.

In Fig. 1 said paths are parallel to each other and located right above each other, but it is of course possible to have a lateral displacement between the paths as well as the bumps, etc.

The module units encase a conveyor system 18 comprising cassettes 18a (Fig. 8). At the input and output unit 11 the conveyor system is not encased and is therefor visable at 18. Further on, the cassette comprises the device surrounding the product. The side elements 19 of the cassette are formed as links comprising joint elements 20, 20a at each corner and dog members 21 for cooperation with driving means on a drum 37 forming part of the rotor of the sluice device.

In the actual case the active conveyor parts are arranged at both sides of the sluice 13, but it is of course possible to use such conveyor parts only at one side of the sluice.

Fig. 2 for instance shows one embodiment where the input unit 11 is directly connected to the sluice.

The module units 12, 14 basically have the same exterior dimension and shape, respectively, but may be dimensioned for different pressures and may be supplemented by insulation of different thickness depending on the process requirements and the construction of the system that has been chosen.

It is the intention that the confinement by using module units i.a. shall allow the product to be completely or partly surrounded by a fluid, preferably in a liquid phase (water). It is also possible to provide the module unit with a restriction acting as a "mini-sluice" (see 22 in Fig. 3) in order to delimit specific treatment zones in excess to what is obtained by the actual sluice.

In simplier embodiments the sluice 13 may be eliminated in which case one or several of the mentioned restrictions delimit zones having different environment conditions along the treatment path. In this case the sluice as a driving means may be replaced by a simple driving device without any sluice function or the driving function may be arranged at a wheel 27 according to Fig. 4a or at a corresponding wheel 27a adjacent to the input and output unit 11. Then the process line will have the appearance as for instance in Fig. 12.

The length of a module unit is selected such that the double module unit length corresponds to an integral number multiple of the length of the cassette 18a, meaning that the operative length of the process line will be easily adjustable by mounting/demounting a number of module units and cassettes, respectively, corresponding to the mentioned length ratio.

The module unit 12 (14) in Fig. 3 basically has an internal cross section defined by the shape of the cassette and the desired environment in an actual section. The reference numeral 22 indicates for instance a restriction for use as a mini-sluice between environments disclosing for instance different temperatures and/or somewhat different pressures.

Means 24 for individual temperature sensing in the product may be arranged in each module unit 12, 14, 30, 32.

The longitudinal internal grooves 25 are guide grooves wherein the pins 21 of the cassettes slide.

In Fig. 4 there is shown a reversing unit 26 which reverses or turns around the conveyor from the forward direction 16 to the return direction 17. The unit has guide grooves 25 for the conveyor but it is also possible as appears from Fig. 4a to use a driving or free running wheel 27 engaging the conveyor in order to reverse the direction. The simplified alternative according to Fig. 4 is especially well suited when the medium in the two horizontal conveyor parts moves in a direction substantially towards the reversing units, i.e. in the direction of the arrows 28, 29. In such case the flow of the medium contributes to a placement of the conveyor in the flow in the "natural loopshape", meaning that friction, necessary driving force and strength requirements of the eassettes may be reduced. The embodiment according to Fig. 4a is especially well suited when the medium in the horizontal parts moves differently, as the tension in the conveyor and therefore also the requirement of a low friction in the reversing unit will be higher.

In Fig. 5 there is shown a module unit formed as a connecting house 30 to be inserted at a desired location in the line and which is provided with an opening 31 for facilitating service and facilitate connection of a conduit for the actual fluid, for instance water, vapour or air to the process active internal region of said housing and for facilitating the mounting of devices 24 for temperature measurement in said fluid and in the product that is transported and processed in the cassettes. The connection is obtained in a suitable cover used for covering the opening 31. As an alternative the connection may be made by using openings 31a in the sides of the module unit.

In Fig. 6 there is shown a microwave module 32 having openings 33 for mounting microwave applicators 34 (Fig. 7). The openings 33 are provided with a microwave transferring window having a suitable dielectric constant. Openings 33 alternatively may be provided with devices for temperature measurement (as 24 in Fig. 5) or may simply be covered by a cover.

All module units 12, 14, 30, 32 have a double length related to the length of each cassette lδa corresponding to an integral number ratio, and the module units may be provided with flanges 35 which if necessary may be some-what angled from the normal perpendicular connection plane of a respective module. In Figs. 9 and 10 there is shown an embodiment of a sluice 13 having radially displacable flaps 36. Such flaps are journalled in a flange 37 on the drum 38 and are uniformally spaced around the periphery of the drum.

Each flap has a radially outer sealing portion 39 designed for abutting the inside of the housing 40. There may be a need for addition of a material in the region of the outer sealing having favourable characteristics from a friction and sealing point of view.

At the side of the flap 36 facing the drum there is a longitudinal groove 41 extending in the generatrix direction of the drum. A flexible sealing list 42 is arranged in the groove and may be moved between end positions determined by the width of the groove 41.

The pressure difference between the spaces on both sides of the flap causes abutment of the sealing list against either wall of the groove walls. The net torque obtained causes the flap 36 into sealing abutment against the inside of the housing regardless positive or negative pressure difference. The force acting against the house has a predetermined relation relative the pressure difference and may be determined by the shape of the groove.

In the flaps 36 there are recesses 43 for the joints 20, 20a of the cassettes. The joints are dimensioned and arranged to seal within the recesses. The driving of the conveyor 18 comprising the cassettes 18a is obtained by driving the drum 38. Pins 21 on the cassettes act as dogs for the cassettes and are driven by members (not shown) on the two flanges 37 of the drum when the drum is rotated by a drive motor (not shown). The driving members are mounted pairwise in front of each other on said flanges between the flaps. The number of member pairs correspond to the number of flaps.

In Fig. 11 there is shown an arrangement comprising complete process lines arranged vertically above each other and having an input unit 11, module units 12, 14 and a sluice 13. The compact and simple construction of the system into a desired configuration highly contributes to a flexible line design.

If for instance the capacity of the line has to be doubled it is possible to either double the number of modules 12 and 14 in the line or place a similar line beside the first or place a similar line above the same, basically according to Fig. 1, which however shows three lines above each other.

The first measure is the best when the length of the floor space so allows.

The second measure is preferable when a marginally increased width of the floor space is made available for the plant. This extra width is small thanks to a straight and narrow process line.

If this small extra width is not available the third measure is suitable. This measure is possible as the line is straight and occupies a small space in the height direction.

In all embodiments the units (not shown) for control, datalogging and signal processing are effected very little or not at all by the change of capacity of the plant.

In all embodiments the convenient service facility of all elements 11, 12, 13, 14, 18 and 26 of each process line is maintained, as such elements all are available at an operation level which for each (horizontal and straight) process line generally is uniform and ergonometrically correct.

An advantage of the device according to the invention is that it allows a continous supply and removal of products from one and the same place in the device, meaning that the connection to machinery for packaging before the heat treatment and for packaging in for instance capsules after the heat treatment may be accomplished by one and the same conveyor belt or similar, or may be accomplished by several conveyor belts placed adjacent to each other and parallel and which like one single conveyor belt require a minimum of space and simplifies the plant layout compared to process lines having the input at one end and the output at the other.

This is exemplified in Fig. 13 where 44 shows the process line according to the invention, 45 shows the packaging machinery for the product to be processed, 46 shows the cartonning machinery for the ready processed products, 47 a conveyor for the transport functions to and from the process lines 44, and 48 units for supplying power and treatment fluid to the line 44.

A further advantage of the invention is that the straight and identical module units are cheap to manufacture regardless they fulfil several functions.

Although a limited number of embodiments have been described by reference to the drawings it is realized that modifications and alternatives are possible within the scope of the invention as per the accompanying claims.

Claims

1. A device for transport and heat treatment of products under well controllable conditions, comprising a conveyor (18, 18a) , a driving device (37, 21, 27, 27a) and preferably an arrangement (13) for the passage of the conveyor through at least two zones having different environmental conditions, and a device (11) for input and output, respectively, of the product to and from the conveyor, c h a r a c t e r i z e d in that the conveyor, in the treatment active parts of the device, generally comprises substantially horizontal conveyor parts which are joined through a reversing arrangement (26) and form a first treatment path in the forward direction (16) and a second treatment path in the return direction (17), in that each conveyor part is encapsuled in a confinement formed by several straight module units (12, 14, 30, 32), and in that the reversing arrangement is formed as a turning around unit (26) having a guide (25; 27) for reversing the conveyor to the return direction.

2. A device according to claim 1, c h a r a c t e r i z e d in that the conveyor is formed by a number of identical pivotably connected links (18a).

3. A device according to claim 2, c h a r a c t e r i z e d in that the double length of each module unit (12, 14, 30, 32) corresponds to a certain integral number ratio relative the length of each link (18a).

4. A device according to claim 1, c h a r a c t e r i z e d in that at least the reversing unit (26) as well as the adjacent module units, at least partly, contain a fluid in a liquid phase, and that said conveyor guide (25; 27) and at least parts of adjacent conveyor parts are arranged in the fluid.

5. A device according to claim 4, c h a r a c t e r i z e d in that a fluid is arranged to flow in a direction substantially towards the reversing unit, and that said unit forms a curved part of the process path.

6. A device according to anyone of claims 1 to 5, c h a r a c t e r i z e d in that at least some of the module units are equipped with means (31a) for temperature setting individually for each module unit or for a group of interconnected module units.

7. A device according to anyone of claims 1 to 6, c h a r a c t e r i s e d in that at least some of the module units have openings (33) provided with a microwave transferring window of a dielectric material.

8. A device according to anyone or any of the preceding claims, c h a r a c t e r i z e d in that at least someone of the module units is equipped with a device (24) for temperature measurement in the product.

9. A device according to claim 1, c h a r a c t e r i z e d in that several conveyor parts forming forward and return paths are arranged above each other sueh that several closed process paths are obtained (Fig. 11).

10. A device according to anyone or any of the preceding claims, c h a r a c t e r i z e d by a sluice device (13) allowing passage of the conveyor (18) and the product between zones having different environmental conditions and which is connected to at least one module unit (12, 14, 30, 32) in the forward direction and one module in the return direction.

11. A device according to claim 10, c h a r a c t e r i z e d in that the module units (12, 14, 30, 32) are arranged at both sides of the sluice device, and that said units are formed as high pressure modules (14) at one side of the sluice and as low pressure modules (12) at the other side of the sluice.

12. A device according to claim 10, c h a r a c t e r i z e d in that a rotor (38) is arranged in the housing of the sluice device and forms a passage for the conveyor (18, 18a) and the product between an opening in the housing and the rotor, and that the rotor which is driven by a motor is provided with means for driving the conveyor.

13. A device according to anyone or any of the preceding claims, c h a r a c t e r i z e d in that the conveyor (18) comprises a cassette device (18a) having means for surrounding the product with a predetermined section during the transport in the device.

14. A device according to claim 13, c h a r a c t e r i z e d in that each cassette forms a link of the conveyor.