Process and device for the continuous conveyance of confections

[0001] 1. Field of the Invention

[0002] In the industrial manufacture of sweets, continuously operating plants are well known. These plants generally include a cooker, in which confections (for example candy) are produced by mixing according to predetermined recipes, and a subsequent processing line in which the material, in certain cases mixed with additional ingredients, is cooled and then subsequently shaped into individual candies.

[0003] 2. Description of the Related Art

[0004] The continuous conveyance of the material, in particular from the cooker or, as the case may be, an evaporation room downstream of the cooker, to a cooling line usually occurs by means of a discharge screw conveyor which has the form of a helical rotor rotating within a static housing. The rotor has until now been mounted on both ends of the static housing, and includes a discharge column extending out approximately perpendicular to the rotor axes. The stator housing at the same time is provided with supply columns, through which the possible ingredients such as coloring agents, aromas or medicinally active agents, which could be gaseous, liquid, pasty, granular or in powder form, can be continuously added or dosed.

[0005] It has been found, in the plants operating today, that the required consistency of treatment of the material cannot always be guaranteed. This has now been found to be a consequence of the fact that different portions of the material can have different dwell times, particularly at the end of the screw rotor, and the material in each case experiences a sharp detour during discharge, whereby temperature and viscosity differences in the material or other disadvantages result, for example an undesired recrystallization could occur in the material.

[0006] The present invention provides relief for this problem. It is the object of the invention to guarantee a consistent and gentle treatment of the material on the way from cooker to the cooling-line, and this objective is achieved in that the material is conveyed along a flow path which is essentially free of abrupt detours or sharp bends.

[0007] Regarding the equipment aspect of the invention, this is achieved in that the discharge screw conveyor and/or the mixer are provided with helical rotors mounted or supported only on the inlet side, and in that the outlet columns of these devices are oriented essentially along the axial direction of the helical rotors. Thereby it is achieved in simple and very elegant manner, that at the exit end of the helical rotor uncontrolled dwell times or abrupt deflectors or detours are avoided, which results in an even and gentle handling of the material.

[0010] In the schematically illustrated equipment, a confectionary material such as for example a candy substance B moves continuously from a cooker (not shown in greater detail) to an evaporation space 1 and from there further to a vacuum space 2. From this vacuum space the material is discharged by means of a discharge helix A, comprised of a helical rotor 3 and a stationary housing 4. The rotor 3 as well as the stionary housing 4 and in certain cases the helix blades 9 are heatable.

[0011] The rotor 3 is supported only on the inlet side in a bearing 6 and is there driven via a motor 5. The supply of steam 7 and the withdrawal of condensate 8 from the internal space and in certain cases the heated blades 9 of the rotor occurs via the shaft end 6a of the rotor at the mounted end. These blades can be simple or compound or multi-helical and exhibit a constant or a non-constant pitch, depending upon the type and composition of the candy substance B to be conveyed and taking into consideration the possible change in volume of the mass when leaving the vacuum or low pressure area 2. The same applies for the diameter of the shaft of the rotor 3, which can be constant, stepped or continuously increasing. The discharge area 10 of the discharge screw conveyor A is shown in the drawing as being conical and coaxial to the rotor 3, which is the preferred embodiment. The discharge area can also be designed to be eccentric-conical, that is, displaced to the axis of the rotor 3 or in certain cases also at a slight angle thereto; it need merely be ensured, that the discharge end of the rotor 3 does not cause any abrupt change in direction of the mass.

[0012] Downstream of the discharge screw conveyor A is one or more helical mixers, of which one mixer M is represented. This mixer (and also every subsequent mixer, in the case that multiple mixers are provided) includes a static housing 12 and a rotor 11. This rotor 11 is also mounted only on the inlet side in a bearing 13 and is there driven by a motor 14. Besides this, the internal space of the rotor 11 and in certain cases its blades 19 as well as the rotor 3 are heatable, whereby here also the supply of steam 15 and the withdrawal of condensate 16 out of the internal space and in certain cases the heated blades 19 occurs via the end of the shaft 13a on the bearing side. Further, the mixture includes dosing columns 17 and 18.1–18.4 for introducing ingredients, wherein particular care is to be taken, that the rotor 11 can produce a zone free of over-pressurization 17a, which makes possible the addition of for example particulate and powdery ingredients via gravity. Further, here also the discharge area 20 of the mixer M is preferably designed to be coaxial-conical, but could however also be eccentric-conical, as was already described for the discharge screw conveyor A. From this discharge area 20 the material is available for further processing, which need not be described herein in greater detail.

[0013] The one sided—that is, cantilevered or flying—supporting of the helical rotors of the discharge conveyor A and the mixer M make possible, as has already been indicated many times above, a flow path design free of changes in direction in the discharge area 10 or as the case may be 20. A further important advantage is to be seen herein, that there is no storage or dwell time under pressure, and thus leaks can be advantageously avoided, which might occur under conditions such as continuous pressurization of the confections being conveyed. This is particularly significant with abrasive materials and/or high temperatures. Further, the absence of abrupt detours of the material is particularly advantageous for a reduction in the mechanical stressing of the devices themselves.

[0014] It has already been mentioned, that the rotor 11 of the mixer M can produce a pressure-free zone. This applies naturally also for the rotor 3 of the discharge conveyor A. In general, both rotors can be so designed and operated, that during conveyance of the material a pressure differential is produced, which for example produces a pressure reduction or vacuum on the suction side and a pressure increase at the pressure side.