GB2317840A - Refining chocolate in a stationary drum with a rotor carrying a series of grinding bars - Google Patents

Abstract

A chocolate refining machine or conche 5 comprises a control wheel (40, Figure 2) having pegs 35 that can vary the pressure exerted by grinding bars 50 on drum lining bars 55. The drum 10 has a shaft driven rotor 20 on which are pivoted arms 25 that are supported by the pegs. The control wheel can rotate relative to the rotor so that the pegs can adjust the tilt of the arms and thereby vary the pressure exerted by the grinding bars on the lining bars. Additional refining is carried out by a pair of contra rotating rollers 180 supplied with chocolate substances from the conche via a piping system 175.

Description

Improvements in or Relating to Chocolate Refining Machinery The present invention relates to the refining of substances to manufacture chocolate, chocolate compounds and substitutes for use in the confectionery, biscuit and ice cream industries.

Chocolate, chocolate compounds and substitutes may be produced by refining a mixture of cocoa liquor and, depending on the final product required, cocoa butter, sugar, milk powders and/or vegetable fats. The refining operation may be undertaken by a device known in this particular art as a conche comprising a stationary cylindrical drum with an axial rotor provided therein. The rotor is provided with a plurality of radial arms each carrying at its free end a grinding bar while the interior of the drum is lined with similarly constructed lining bars. In use, rotation of the rotor causes the raw materials within the drum to be ground between the grinding bars and the lining bars. The clearance between the grinding and lining bars, and hence the forces exerted upon the raw materials by the bars, may be varied by moving the grinding bars relative to the rotor. The present applicants patent no. GB 2 025 675 B discloses such a conche.

A drawback of this method of refining is that it can take a considerable period of time, in the region of 24 hours, to produce refined product. Furthermore deflection of the grinding bars can lead to the finished product being of less than ideal quality.

It is an object of the present invention to obviate or mitigate at least some of the aforementioned disadvantages.

According to a first aspect of the present invention there is provided a conche for the refining of substances to manufacture chocolate, chocolate compounds and substitutes comprising a drum within which is rotatably mounted a drive shaft carrying a plurality of rotors, the interior of said drum being lined with a plurality of lining bars, said plurality of rotors being provided with a plurality of grinding bars which contact or may be brought into contact with said lining bars, and means to vary the pressure exerted by the grinding bars upon the lining bars.

Preferably the grinding bars may be mounted upon carrier plates, said carrier plates being rigidly attached to a first end of at least one plate-form arm.

A second end of said plate-form arms may preferably be rotatably mounted upon said rotor(s) Preferably the conche may be provided with two rotors and the carrier plates may be provided with two plate-form arms.

The means to vary the pressure exerted by the grinding bars against the lining bars may comprise at least one control wheel provided concentric to the at least one rotor, said control wheel being provided on one side with a plurality of spaced pegs engagable with said plate-form arms.

The pressure exerted by the pegs upon the plate-form arms and hence by the grinding bars upon the lining bars may be varied by rotating the control wheel relative to the rotor.

Where two or more rotors, and hence two or more control wheels, are used there may be provided means to synchronise the movement of the control wheels relative to the rotors.

According to a second aspect of the present invention there is provided machinery for the refining of substances to manufacture chocolate, chocolate compounds and substitutes comprising a conche, apparatus to further refine the above noted substances, and a piping system to transfer said substances between the conche and the apparatus.

The apparatus may comprise one or more roll refiners.

The one or more roll refiners may be mounted atop the conche.

The piping system may include insulated pipe work, at least one pump, and valve means to control the flow through the pipe work.

Preferably product may be cycled through the piping system from the conche to the roll refiner before being passed back to the conche.

The piping system may be provided with a an over flow path such that any product not entering the roll refiner may be returned the conche.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings which show: Fig 1 A partially cut-away perspective view of an existing chocolate refining conche; Fig 2 A simplified representation of the grinding bar adjustment mechanism; Fig 3 A fully sectioned representation of a refining conche in accordance with a first aspect of the present invention; Fig 4 A side view of a refining conche in accordance with a second aspect of the present invention; Fig 5 A plan view of the conche shown in Fig 4; Fig 6 A first end view of the conche shown in Fig 4 in the direction of arrow A; and Fig 7 A second end view of the conche shown in Fig 4 in the direction of arrow B.

Referring firstly to Figs 1 and 2 there is shown a conche 5 of the type known in this particular art and covered by GB patent 2 052 675 B. The conche 5 comprises a drum 10, a drive shaft 15 projecting axially into the drum 10 and carrying thereupon a rotor or spiderwheel 20. The spiderwheel 20 carries a plurality of substantially tangentially extending plate-form arms 25 which, due to the internal diameter of the drum 10, surround the spiderwheel 20 in a trailing arrangement. The drive shaft 15 runs in bearings 30 provided at each end of the drum 10 and is driven via suitable gearbox means (not shown) from an electric motor (not shown).

The arms 25 are rotatably mounted upon the spiderwheel 20 and are supported by pegs 35 present upon a control wheel 40 concentric with the spiderwheel 20. The arms 25 are each provided at their free end with a carrier plate 45 upon which is mounted a grinding bar 50. The grinding bars 50 may be manufactured from hardened (molybdenum) steel and the interior of the drum 10 is provided with lining bars 55 manufactured from a similar hardened material. The control wheel 40, and hence the pegs 35, may be rotated relative to the spiderwheel 20 by a means later described and thus the angle of the arms 25 relative to the spiderwheel 20, and accordingly the pressure exerted on the lining bars 55 by the grinding bars 50, may be varied.

In use, raw materials such as sugar, cocoa liquor, vegetable fats and milk solids may be loaded into the drum 10 via hoppers 60 provided in an upper portion thereof. Once the drum 10 is filled with the required volume and proportions of the raw materials the drive shaft 15 is rotated and hence the grinding bars 50 are caused to move relative to the lining bars 55. The aims of the refining operation are to reduce the sugar to a maximum particle size of between 20 to 25 microns depending on the quality required, and to wet all the dry sugar surfaces with fat, to obtain maximum surface exposure to permit volatilization of undesired flavours, and to permit oxidation of astringent substances. To keep the raw materials at an adequate working temperature the conche 5 is fitted with heating means such as a hot water jacket 65 and a heated sump 70.

Referring now to Fig 3 there is shown a chocolate refining machine or conche 5 in accordance with the present invention comprising a drum 10, a drive shaft 15 supporting a pair of spiderwheels 20, means to rotate the drive shaft 75, a pair of control wheels 40 provided with pegs 35 and means 80 to rotate the control wheels 40 relative to the spiderwheels 20. The drum 10 is further provided with lining bars 55, grinding bars 50 provided upon carrier plates 45, and supported by arms 25 mounted upon the spiderwheels 20. The control wheels 40 are supported upon brackets 85 which in turn are mounted upon shafts 90 which are rotatably mounted within the spider wheels 20. The control wheels 40 are further mounted upon rollers 95 provided between the outer edges of the spiderwheels 20 and the inner edges of the control wheels 40. An end 100 of each of the shafts 90 is connected to a lever 105 which in turn is attached to the first end 110 of a connecting damper 115. The second ends 120 of the dampers 115 are connected to a carrier 125. A conche 5 in accordance with the present invention may be provided with two or more bracket 85/shaft 90/lever 105/connecting damper 115 assemblies depending on the volume of product it is intended to handle.

The conche 5 is further provided with a control shaft 130 slidably mounted within the drive shaft 15 and connected to the carrier 125, and means 135 to displace the control shaft 130 along a longitudinal axis relative to the drive shaft 15.

Said means 135 comprise a worm shaft 140, a worm wheel 145, a shaft 150 threadably mounted within the worm wheel 145, and a thrust coupling 155 connecting the shaft 150 to the control shaft 130. The shaft 130 is prevented from rotating by virtue if a key and keyway assembly 132.

In use, rotation of the worm shaft 140, and hence the worm wheel 145, results in the axial displacement of the shaft 150 relative to the worm wheel 145. This displacement is transmitted to the control shaft 130 via the thrust coupling 155. Movement of the control shaft 130 is transmitted to the carrier 125 which is permitted to move relative to the drive shaft 15 and spiderwheels 20 by the provision of a pair of bushes 160.

Movement of the carrier 125 results in either a tensile or compressive acting force being transmitted via the connecting dampers 115 to the levers 105. The connecting dampers 115 are eccentrically mounted to the levers 105 with respect to the shafts 90 and thus a force applied to the levers 105 by the connecting dampers 115 results in the rotation of the shafts 90. Such rotation is transmitted by the brackets 85 to the control wheels 40 and subsequently the pressure exerted by the pegs 35 against the arms 25, and hence between the grinding and lining bars 50, 55, may be varied.

The use of two or more spiderwheels 20 with the grinding bars 50 within the drum 10 leads to an even distribution of pressure over the width of the grinding bars 50 and thus in turn leads to an improvement in the quality of the refined product. The arrangement enables two or even more sets of arms and associated control wheels 40 to be actuated from a single set of dampers 115.

Referring now to Figs 4 to 7 there is shown a chocolate refining machine in accordance with a second aspect of the present invention comprising a conche 5, a roll refiner 165 mounted atop the conch 5, a pump 170, and a piping system 175 to permit product to be passed between the conche 5 and the roll refiner 165. The roll refiner 165 comprises a pair of contra-rotating rollers 180 which are each driven via a belt 185 by an electric motor 190. The rollers 180 are displacable relative to one another and hence the clearance C between the rollers 180 may be varied.

In use, raw materials such as sugar, cocoa liquor, vegetable fats and milk solids may be loaded into the conche 5 via hoppers 60 provided in an upper portion thereof and the refining operation may be commenced. Once the product has been subjected to an initial period within the conche 5 it may be passed from the conche 5 to the roll refiner 165 via the pump 170 and piping system 175. The rollers 180 are manufactured from hardened steel and serve to further reduce the particle size of the raw materials. The roller clearance may be set at, for example, 70 to 75 microns.

The flowrate of product into the roll refiner 165 is regulated by a valve 195 provided at the inlet 200 to the roll refiner 165, while the outlet 205 of the roll refiner 165 is provided directly above an inlet hopper 60 of the conche 5.

The piping system 170 includes a by-pass path 210 to permit product not entering the roll refiner 165 to return to the conche 5, the proportion of product passing via the path 210 may be controlled by the valve 195.

The roll refiner 165 may be provided with automatic sensing means to control the inlet flowrate of product. Such sensing means may be connected to the pump 170 and/or the valve 195 in order to regulate the inlet flow.

The product may be circulated through the conche 5 and roll refiner 165 until the desired product consistency is achieved. Valve controlled outlet means can be provided on the roll refiner 165 to permit the escape of undesirable gases and/or vapours liberated from the raw materials.

The provision of a conche 5 fitted one or more roll refiners 165 to provide the above described product recycling operation will reduce the time needed to refine a given mass of product to the desired quality.

The embodiments of the present invention hereinbefore described are given by way of example only, and are not meant to limit the scope of the invention in any way.

Claims (16)

1. A conche for the refining of substances to manufacture chocolate, chocolate compounds and substitutes comprising a drum within which is rotatably mounted a drive shaft carrying a plurality of rotors, the interior of said drum being lined with a plurality of lining bars, said plurality of rotors being provided with a plurality of grinding bars which contact or may be brought into contact with said lining bars, and means to vary the pressure exerted by the grinding bars upon the lining bars.

2. A conche as claimed in claim 1, wherein the grinding bar is mounted upon carrier plates, said carrier plates being rigidly attached to a first end of at least one plate-form arm.

3. A conche as claimed in claim 2, wherein a second end of said plate-form arms is rotatably mounted upon said rotor(s).

4. A conche as claimed in any one of the preceding claims, wherein the conche is provided with two rotors and the carrier plates may be provided with two plateform arms.

5. A conche as claimed in any one of the preceding claims, wherein the means to vary the pressure exerted by the grinding bars against the lining bars comprises at least one control wheel provided concentric to the at least one rotor, said control wheel being provided on one side with a plurality of spaced pegs engagable with said plate-form arms.

6. A conche as claimed in claim 5, wherein the pressure exerted by the pegs upon the plate-form arms and hence by the grinding bars upon the lining bars is varied by rotating the control wheel relative to the rotor.

7. A conche as claimed in claim 5 or 6, wherein two or more rotors, and hence two or more control wheels, are provided together with means to synchronise the movement of the control wheels relative to the rotors.

8. A conche as claimed in any one of the preceding claims, wherein the grinding bars are made of hardened metal.

9. Machinery for the refining of substances to manufacture chocolate, chocolate compounds and substitutes comprising a conche, apparatus to further refine the above noted substances, and a piping system to transfer said substances between the conche and the apparatus.

10. Machinery as claimed in claim 9, including one or more roll refiners.

11. Machinery as claimed in claim 10, wherein the one or more roll refiners are mounted atop the conche.

12. Machinery as claimed in any one of claims 9 to 11, wherein the piping system includes insulated pipe work, at least one pump, and valve means to control the flow through the pipe work.

13. Machinery as claimed in any one of claims 9 to 12, wherein product is cycled through the piping system from the conche to the roll refiner before being passed back to the conche.

14. Machinery as claimed in any one of claims 9 to 13, wherein the piping system is provided with an over flow path such that any product not entering the roll refiner may be returned the conche.

15. A conche substantially as hereinbefore described with reference to and as illustrated in Figs 2 and 3 of the accompanying drawings.

16. Machinery for refining a substance substantially as hereinbefore described with reference to and as illustrated in Figs 4 to 7 of the accompanying drawings.