HK1055069B - A press for separating cocoa mass, a method for operating the press and a method for modifying a press - Google Patents

Description

Press for separating cocoa mass, method for operating press and method for improving press

The invention relates to a press for separating cocoa mass into cocoa cake and cocoa butter, comprising a frame in which a plurality of pressure elements are arranged and means for compressing the pressure elements; each pressure element comprising a cavity for receiving cocoa mass to be pressed, the cavity having at least one juicer therein; a filter is disposed in front of the juicer and on a side of the cavity opposite the juicer. The invention also relates to a press operating method and a press improving method.

Such a press is known, for example, from international patent application WO 92/12853. This press is used to separate cocoa mass into cocoa butter (which is liquid at high temperature) on the one hand and a solid cocoa cake which can be processed into cocoa powder on the other hand. Typically, a hydraulic cylinder is provided, which is formed in a cylinder block that is connected to a stop device by two tie rods. In the cylinder there is a plunger, and between the plunger and the stop means there is arranged a series of pressure elements. Each pressure element comprises a so-called pot defining a (generally cylindrical) cavity in which there is a juicer and, for example, two filters. The spacing between the filters is provided to receive an appropriate amount of cocoa mass to be pressed.

During the pressure cycle, the tanks are filled with hot cocoa mass through supply lines, and they are subsequently compressed. The cocoa butter is thus pressed out through the filter and discharged.

In many cases, the cocoa industry requires that the resulting cocoa butter cake contain less than 10% (by weight) cocoa butter. In order to meet this requirement with hydraulic presses according to the prior art, it is necessary to extend the pressing time at very high pressures.

The object of the present invention is to provide a press which enables a significant reduction in the duration of the pressure cycle and/or a reduction in the pressure, and preferably without excessive changes to the press compared to prior art presses.

To achieve this object, the press according to the invention is characterized in that: in the filling position of the juicer, the spacing between the filters is in the range 40-90 mm. Preferably, the above-mentioned spacing is in the range of 60-90mm, preferably in the range of 60-76 mm.

Surprisingly, it is apparent that the production capacity of the present press can be significantly increased in this way, as will be discussed in more detail below.

The invention further relates to a method for operating a press, wherein the position of the squeezer is selected such that the spacing between the filters is in the range of 40-90mm during the step of filling the cavity with cocoa mass.

This method makes it possible to (partly) utilize the advantages of the invention in existing presses. Furthermore, the pressure elements of existing presses can be modified such that the spacing between the above-mentioned filters in the filling position of the juicer is in the range of 40-90 mm.

For the sake of completeness, it should be noted that german patent application 1109501 discloses a press comprising a can having a filling height of about 20mm, and the filling height should not exceed 30 mm.

The invention will now be explained in more detail with reference to the figures, which show an exemplary embodiment of a hydraulic machine according to the invention.

Fig. 1 is a perspective view of a hydraulic press for pressing cocoa mass according to the invention.

Figure 2 is a cross-sectional view of the hydraulic press of figure 1 in a filling position.

Fig. 3 is a sectional view corresponding to fig. 2, showing the end of the pressure state.

The figures show a hydraulic press according to the invention suitable for pressing cocoa mass in which cocoa cakes to be processed into cocoa powder and cocoa butter pressed from the above-mentioned cocoa mass are formed. Such pressing processes and pressure elements and pressure devices associated therewith are known per se and will therefore only be briefly discussed.

The hydraulic machine 1 as shown is mounted in a frame (not shown) and comprises two tie rods 2, 2 ', which two tie rods 2, 2' are fixed in the cylinder liners 3 of the hydraulic cylinders 4 on the left side of the hydraulic machine 1 in the figure. Present in the hydraulic cylinder 4 is a plunger 5, which plunger 5 can be moved to and fro in the hydraulic cylinder 4. The plunger 5 can exert a pressure on a series of 16 (in this embodiment) pressure elements 6, which pressure elements 6 are supported at the end remote from the plunger 5 by a stop 7. The stop device 7 and the cylinder liner 3 are connected by tie rods 2, 2'.

As shown in fig. 2 and 3, each pressure element 6 comprises a tank 8, which tank 8 comprises a cylindrical cavity 9 which is bounded at the end faces by disc filters 10, 10 ', which disc filters 10, 10' have a diameter of 450mm and are known per se. The left hand filter 10 is supported by a so-called press plate which abuts the juicer 11, which juicer 11 fits precisely into the cylindrical cavity 9. The right filter 10' is also supported by a pressure plate which abuts the rear of the juicer forming part of a pressure element arranged to the right of the tank 8. The round tie rods 2, 2' are mounted to the cans and the juicers through round holes 12, the round holes 12 being formed in side portions of the cans and the juicers. In addition the tank comprises a supply line for cocoa mass, while the press plate and the juicer comprise a discharge line for discharging cocoa butter which has been pressed through the filter.

Fig. 2 shows the hydraulic press 1 in the filling position. In this position, the hydraulic plunger 5 occupies the far left position of the hydraulic machine 1 and the spacing between the disc filters 10, 10' and hence the volume of the cavity 9 in each pressure element 6 is at its maximum. According to the invention, all or nearly all points of the cavity 9 must be spaced from an imaginary plane through the filter or through one of the filters by a distance of less than 45 mm. For the cavity 9 to be provided with two flat parallel filters 10, 10 'at both ends, this means that the distance between the filters 10, 10' must not exceed 90 mm. In this exemplary embodiment, it was found that the optimum spacing between the filters 10, 10' present in each pressure element 6 in the filling position is 71 mm. In another embodiment of the invention (not shown) the hydraulic machine consists of a series of 18 pressure elements, each cavity also being cylindrical and having a diameter of 600 mm. In this particular embodiment, the optimum spacing was found to be 67 mm.

Fig. 3 shows how the pressure elements 6 of the hydraulic machine according to fig. 1 are compressed uniformly by moving the plunger 5 to the right until the pressure reaches a certain limit value and the spacing between the filters is reduced to, for example, 36 mm. In this position, a larger portion of the cocoa butter present in the cocoa mass has been pressed through the filter 10, 10'. The plunger 5 can be moved to the left again, after which the resulting cocoa cake can be removed from the cavity 9.

As already mentioned above, in many cases, the cocoa industry requires that the resulting cocoa cake contain less than 10% cocoa butter. To accomplish this task, in the hydraulic press according to the prior art, the spacing between the two filters in the filling position is chosen to be greater than 92 mm. A typical pressure cycle lasts 20-25 minutes (min) and requires a pressure of 550 bar. For the prior art press comprising 14 tanks, this means that 200-250kg (e.g., 220kg) of cocoa mass is processed per cycle.

Surprisingly, it is apparent that with the hydraulic machine according to the invention as described above, the pressure cycle duration can be reduced to 5-10 minutes in some cases, while the required pressure can be reduced by about 10%. According to the hydraulic press of the invention comprising 16 pots, each pressure cycle can process as many cocoa mass as the prior art press having the same length comprising 14 pots. However, the capacity of the hydraulic machine according to the invention is about 25-50% higher, since the pressure cycle can be carried out for much less time.

Furthermore, it is clear that the resulting cocoa cake composition is more uniform; the cocoa butter content in the cocoa butter cake is in the range of 9.5-10.5% compared to 9-13% for cocoa butter cakes obtained with prior art hydraulic presses. As a result, the cocoa cakes obtained by the present invention belong to a higher quality class and their economic value is higher.

A significant advantage from the point of view of process technology is moreover the fact that the risk of so-called "opening" of the hydraulic machine is smaller. In some cases, some of the pressure elements remain fixed during the pressing operation, while on the other hand other pressure elements are forced aside, as a result of which one or more cans can open and considerable damage to the press can result. This phenomenon appears to be less frequent in the press according to the invention, which may be related to the enhanced homogeneity of the cocoa cake.

The stresses in the frame will also be lower due to the lower pressure in the hydraulic cylinder, as a result of which cheaper materials, in particular steel, can be used and no refining or less special methods are required for the material. This makes it possible to use a cheaper frame structure.

From the above, it is clear that the invention has important advantages over the prior art presses, while at the same time the measures taken are relatively simple. The invention can be used on existing presses by the following method: or by cooperating with the control or manipulation of the press, in particular by opening the cavity in the pressure element less far during filling; or by modifying the press and providing it with narrower pressure elements, in particular cans, juicers, or pressboards.

The invention is not limited to the above-described embodiments, which can of course be varied in several ways without departing from the scope of the claims. The press can therefore also be used for products whose pressing and filtering behaviour can be compared with that of cocoa mass. Furthermore, a spacing of more than 45mm may be used between the cavity and some point in the filter, for example as a result of the presence of a partition for fixing the filter or as a result of the shape of the juicer or the cavity wall. Such a change in the spacing will not prevent a sufficient operation of the press according to the invention.

Claims (8)

1. A press (1) for separating cocoa mass into cocoa cake and cocoa butter, comprising a frame in which a plurality of pressure elements (6) are arranged, and means (4, 5) for compressing the pressure elements (6), wherein each pressure element (6) comprises a cavity (9) for receiving cocoa mass to be pressed, and wherein in the cavity (9) at least one squeezer (11) is present; a filter (10, 10') arranged in front of the juicer (11) and on the side of the cavity (9) opposite said juicer (11), characterised in that: the spacing between the filters (10, 10') in the filling position of the juicer (11) is in the range 40-90 mm.

2. The press (1) according to claim 1, characterized in that: the above-mentioned spacing is in the range of 60-90mm, preferably in the range of 60-76 mm.

3. The press (1) according to claim 1 or 2, characterized in that: the cavity is cylindrical and the filter is flat or substantially flat.

4. Method for operating a press (1) according to the preamble of claim 1, characterized in that: in the step of filling the cavity (9) with cocoa mass, the spacing between the filters (10, 10') is in the range of 40-90 mm.

5. Method for improving a press (1) according to the preamble of claim 1, characterized in that: in the filling position of the juicer (11), the spacing between the filters (10, 10') is in the range 40-90 mm.

6. The method of claim 5, wherein: furthermore, the number of pressure elements (6) increases.

7. Method according to one of the claims 4 to 6, characterized in that: the above-mentioned spacing is in the range of 60-90mm, preferably in the range of 60-76 mm.

8. Method according to one of the claims 4 to 6, characterized in that: said cavity (9) is cylindrical; while the filter (10, 10') is flat or substantially flat.