DE69525919T2 - Drainage elements for a pneumatic press, especially for pressing fruit, grapes and their products - Google Patents

Abstract

The present invention relates to the drainage channels of a pneumatic press, as utilized in particular for pressing fruit, grapes and grape derivatives, which comprises a tubular membrane and a rotating drum. Associated with the internal surface of the rotating drum are drainage channels of diverse shape and size, of which the arrangement on the internal surface of the drum can be semi-circumferential, circumferential, or single or multistart spiral. The press thus obtained is a totally enclosed vessel in which the product is forced by the tubular membrane against the drainage channels. <IMAGE>

Description

This application concerns the system of drainage channels inside pneumatic membrane presses used for the external drainage of liquids from the pressing of fruit, grapes and similar products.

At present, the most commonly used presses for pressing fruit, grapes and similar products consist of an elastic semi-tubular membrane made of a non-toxic material, which is placed in the inner radius of the drum and presses the product against the discharge channels arranged in the form of a semi-spiral (see document AT-A-350 913), or in the form of a semi-circular passage in the length of the press drum (see document DE-U-93 00 755).

However, these conventional solutions are not always without problems. Due to the semi-circular or semi-spiral flow limited in the cylinder line, the liquid obtained from the pressing of fruit, grapes and similar products cannot have any cleaning effect on the drainage channels, as the liquid does not flow quickly enough to eliminate the product waste generated by the pressing process during its passage to the outlet; this forces the user to frequently interrupt the pressing process in order to remove said waste and thus restore the drainage capacity of the drainage channels, which represents a considerable time and cost.

In order to maintain their conveying capacity, the drainage channels must be regularly removed from the system and thoroughly cleaned.

The main subject matter of the present application therefore aims at eliminating these disadvantages by developing drainage channels whose design and arrangement in the drum of the printing press enable thorough and complete self-cleaning.

Self-cleaning would be possible if the drainage channels within the cylindrical housing were allowed to describe a complete circular or spiral passage, with one or more turns; this means that the liquid must necessarily travel a certain distance to the drainage outlet, during which a speed can be reached that enables permanent and complete cleaning in the area of the drainage channels and thus prevents clogging or blockages of the inner surfaces of the channels due to processing-related residues during operation.

With this measure, the wastewater channels always remain in a state of optimal efficiency, their discharge capacity always remains the same over time, without the need for maintenance or return measures.

Another, no less important, aim is to create an invention that combines the above-mentioned properties with a reliable and safe-to-use material; the manufacturing costs for this system are very low.

This and the above objectives as well as other benefits explained in more detail below

are achieved by a membrane press according to requirement 1.

Further features and advantages of the invention are made clear by the special form of construction, for which I have attached purely informative drawings. The following applies:

Fig. 3 shows the drainage channels inside the printing press in a median longitudinal section;

In Fig. 4 these are shown in cross-sectional plane in the drum of the press described in Fig. 3;

Fig. 5, 7 and 9 show views corresponding to Fig. 3, but with additional solutions for the arrangement of the drainage channels inside the press, while

Figures 6, 8 and 10 show views corresponding to Figure 4 of the parts described in Figures 5, 7 and 9.

With reference to the above figures, number 3 shows the most common construction of a printing press for fruit, grapes and similar products, namely with a frame 4 as a support for a drum 5 to which an expandable tubular membrane 1 made of a non-toxic material is attached. Drum 5 consists of a cylinder shell 2, which is closed at both ends by a convex end 6; inside, the expandable tubular membrane is fixed at one end; on the cylinder shell 2, at the drainage channels 3,1 extending over a complete circular passage on the inner surface of the cylinder shell 2, in polygonal section, there are outlets 7 connected to a drainage pipe 8.

In a variation of Fig. 3, Fig. 5 shows another application solution in which the drainage channels 3,2 run in a polygonal section in a complete spiral passage, with one or more turns, on the inner surface of a cylindrical housing 2.

As a variation of Fig. 3, Fig. 7 shows another application solution in which each drainage channel 3, 3 in polygonal section extends inside a closed circular extruded compartment 9, also in polygonal section, which is constructed on the inner surface of a cylinder jacket 2.

In a variation of Fig. 3, Fig. 9 shows a further application solution in which each drainage channel 3, 4 in polygonal section extends inside a closed spiral-shaped extruded compartment 10 with one or more turns, also in polygonal section and constructed on the inner surface of a cylinder jacket 2.

Each of the figures above clearly shows, in the drainage channels, the elongated orifices 11 of appropriate dimensions, arranged at regular intervals so that only the liquid can circulate, blocking all processing residues.

The solutions of the invention shown here meet the defined objectives by maintaining the flow capacity of the drainage channels without requiring maintenance or return work.

In terms of construction, the invention is uncomplicated; materials and dimensions of the individual components must of course be adapted to the specific needs of the individual case.

Claims (4)

1. Pneumatic membrane press with discharge channels that have a polygonal cross-section and are arranged at regular intervals with equally sized, elongated openings over a perfectly round surface on the inner surface of the cylindrical housing of the press. 2. Press as in requirement 1, characterized in that the channels extend spirally with one or more starting points over the entire inner surface of the cylindrical housing. 3. Press as in requirement 1, characterized in that each individual channel is located in a circular, extruded element which, like the channels themselves, has a polygonal cross-section and is located on the inner surface of the cylindrical housing. 4. Press as in requirement 1, characterized in that each individual channel is located in a spiral-shaped, extruded element with one or more starting points, which, like the channels themselves, has a polygonal cross-section and extends over the inner surface of the cylindrical housing.