IT201800002858A1 - PNEUMATIC PRESS TO PRESS A VEGETABLE PRODUCT - Google Patents

Description

Industrial invention entitled:

PNEUMATIC PRESS FOR PRESSING

A VEGETABLE PRODUCT

The invention relates to a pneumatic press to press a vegetable product, the control method for the press and software that implements the control. The following description will refer by way of example to winemaking, a sector in which the invention has proved particularly effective.

Pneumatic presses are known for pressing a vegetable product, e.g. as in EP2342071. In a rotating drum with a horizontal axis, the crushed grapes are loaded and then pressed with an inflatable membrane which separates the liquid part from the peel through perforated collection channels placed on the internal surface of the drum.

A first type of press comprises a single inflatable membrane to invade the entire cylindrical volume of the drum. The disadvantages are several, including a limited draining surface compared to the volume of the drum (since only half of the drum can act as a draining surface). In case of membrane breakage, the press is out of order with enormous problems during the harvest, and the mass to be filtered translates into high pressures to be applied to obtain a good pressing speed.

A second type of press inside the drum is equipped with two inflatable membranes applied on the two internal half-walls of the same which act simultaneously by pressing the mass towards draining channels that cross diametrically (in section) the drum. The disadvantages of this solution are the design complexity, especially for large capacity presses; limited draining surface compared to the volume of the press; the impossibility of applying cooling surfaces on the drum (since this is entirely occupied by the membranes); and high difficulty of automatic cleaning of the internal channels; low mechanical resistance to impacts of the central raceways which results in potential and dangerous breakages. Furthermore, in the event of a single membrane breakage, the press is completely out of order, and it is very difficult to empty the drum because the radial channels interfere strongly.

A third and last type of press (see for example EP0721836) is similar to the first, with the difference that the drainage channels are arranged on all or most of the internal surface of the cylinder and the tubular type inflatable membrane presses radially from axis of the drum towards the outside. Notable disadvantage of this configuration is the design complexity. To support the tubular membrane, a massive axial structure is needed inside the drum, which creates major problems both in the emptying phase and in the rotation phase during the pressing cycles. And the structure creates considerable organoleptic damage to the product being processed. The central membrane must have a surface equal to the internal one of the drum, therefore it is double in size with respect to the press of the first type, with the creation of considerable wrinkles in the suction phase of the membrane itself, which creates major problems even in the washing phase of the press. . To overcome the problem of membrane size and wrinkles, the few manufacturers of this type of press also offer elastic membranes, which, unlike traditional polyurethane plastic membranes, are very fragile, therefore easily subject to disastrous breakage during work. Not only is the cost higher, but the membrane entails enormous difficulties in assembly and disassembly in the event of maintenance or breakage. Consequently, in the event of a diaphragm rupture, the press is out of order for a long time.

The main purpose of the present invention is to improve this state of the art, and its particular purpose is to create a press that alleviates the aforementioned problems.

A first aspect of the invention is a press for vegetable product, e.g. crushed grapes, including:

a drum rotating around a horizontal axis and equipped with a draining sieve to separate the plant product into a solid part and a liquid part,

where the drum volume consists of two or more isolated load volumes,

an inflatable membrane is installed in each loading volume to press plant product against a respective draining sieve.

The invention includes the variant of a hollow rotating drum whose internal cavity is partitioned to obtain smaller and isolated load volumes. The press then comprises:

a hollow drum rotatable around a horizontal axis and equipped on its internal side surface with a draining sieve to separate the plant product into solid part and liquid part,

where the internal volume of the drum is partitioned by two or more isolated loading volumes,

an inflatable membrane is installed in each loading volume to press plant product against a respective draining sieve.

Preferably, the press comprises a single drum internally partitioned into sub-volumes. The invention is applicable both when the draining sieve is a perforated drum wall (so that the plant product pressed by the membrane pushes the liquid part directly outside the drum through the perforated wall), and when the draining sieve comprises o it consists of one or more draining channels (the drum is closed) from which the liquid part is conveyed towards the outside of the drum through one or more liquid collectors.

The invention also includes the variant of a rotating drum formed by smaller load sub-volumes (or shells), isolated and joined together. The smaller load sub-volumes are separate and separable parts, but juxtaposed and fixed together to form a composite drum. It follows that two loading sub-volumes of the composite drum are separated from each other by at least two respective adjacent walls, i.e. the walls that delimit the volume of each sub-volume (i.e. between two sub-volumes there is not a single shared wall and dividing). Said walls, in the composite drum, can be in contact, partially in contact or kept separate by the means which rigidly fix the load sub-volumes to each other to form the drum. Note that the construction with sub-volumes formed by closed shells makes the drum overall

Preferably, the composite drum has a cross section (taken with respect to a plane orthogonal to the longitudinal axis of rotation of the drum), given by the composition of the cross sections of the loading sub-volumes, which is e.g. substantially inscribed or contained in a circumference or ellipse. In particular, the load sub-volumes are arranged with polar symmetry around an axis, which will be the rotation axis of the overall drum.

In the case of the composite and non-partitioned drum, the load sub-volumes may or may not have walls in contact at the rotation axis of the overall drum. This is by virtue of the fact that the walls of the loading sub-volumes, in correspondence with the rotation axis of the overall drum, can be spaced apart, eg. to make room for reciprocal fastening means, or to touch each other in some points thanks to their curvature. In particular, the wall of each sub-volume that is closest to the rotation axis of the overall drum can be, with respect to a radius that starts from this axis towards the outside of the drum, concave or concealed or flat. In other words, said closest wall comprises a surface facing the rotation axis of the drum which has a concavity or a convexity. Since the inflatable membrane at rest is preferably stretched on said closest wall and when inflated it moves away from the rotation axis of the overall drum, the concavity or convexity is useful for distributing the reaction force discharged by the membrane on said wall. The symmetrical arrangement of the sub-volumes around the rotation axis of the overall drum also facilitates the cancellation of the thrusts (which are opposite) on the respective walls closest to said axis.

In the following, by sub-volumes we mean both load volumes derived from the partitioning of the internal volume of a single drum, and shells that form load volumes and which, when mounted juxtaposed, make up the press drum.

The two or more sub-volumes that divide or constitute the internal volume of the drum are independent and isolated from each other, and preferably equal to each other

Each sub-volume is equipped with its own pressing membrane which is inflatable to press the plant product against the draining sieve present in that sub-volume. In particular, the pressing membrane is inflatable to press the vegetable product towards the outside of the drum, that is, against the internal lateral surface of the drum. Other positions for the draining sieve are also possible.

Each sub-volume is equipped with a draining sieve to separate the plant product into a solid part and a liquid part.

Preferably the draining sieve or sieve of one or each sub-volume is comprised in the inner lateral surface of the drum, but other positions are also possible, e.g. the or a draining sieve of one or each sub-volume is included in the internal lateral surface of the sub-volume itself.

Preferably the draining sieve of each sub-volume is independent from the others, and is e.g. connected to a separate duct suitable for draining the liquid collected from the respective sieve.

Preferably the internal volume of the drum is partitioned into two or more circular sectors.

Preferably, the drum internally comprises at least one dividing partition, to partition its internal volume into the two or more isolated loading volumes. In particular, the dividing walls extend from separate and distinct points of the inner side surface of the drum, more particularly the dividing walls extend from diametrically opposite points of the inner side surface of the drum.

With the structure defined above, numerous advantages and various methods of use are obtained, including:

1. The press never stops: in the event of a membrane breakage, the press continues to operate with the remaining sub-volumes. This feature makes it very advantageous with respect to the three types of presses described above. which stop when a membrane breaks. Statistically it is very unlikely that the membranes of the sub-volumes will rupture at the same time. During the harvest, when the presses work day and night, it is essential to press the freshly harvested grapes as quickly as possible in order to prevent the product from degrading.

2. The draining surface is on the whole equal to all or almost all of the internal surface of the drum. This results in high draining speed.

3. The press can work at low load with a subset of sub-volumes, as if it were one or two smaller capacity presses. It benefits from the operational flexibility with the associated ability to be able to process different plants separately (in this case the drainage points of each sub-volume are drained into separate tanks).

4. Multiple processing speed: by equipping each Nth sub-volume with an outlet for the pressed solid part, N times can be discharged at each revolution of the drum; or a sub-volume of vegetable product can be loaded or unloaded while pressing takes place in another sub-volume.

5. Different pressing programs for each Nth sub-volume, which is loaded with its own vegetable product.

6. Easy washing of the inside of both the press and the draining channels, and this above all compared to traditional presses with double membrane and tubular central membrane.

7. Preferably, the press comprises independent thermoregulation pockets for each subvolume and / or on the entire internal surface of the drum, so as to be able to heat each subvolume independently.

In general, the drum comprises one or more dividing walls, e.g. diametrical or radial, to partition its internal volume into N independent and separate sub-volumes. Preferably N = 2, and the drum comprises a single diametrical dividing wall to divide its internal volume into two independent and separate sub-volumes. Or in general the drum is composed of R independent and separate sub-volumes, each preferably in the form of a shell which delimits a closed volume.

Preferably R = 2, and the drum is formed by the assembly of two independent and separate sub-volumes.

Preferably, the dividing walls extend from the axis of the drum towards its periphery, but walls that do not intersect the axis of rotation of the drum and / or even non-flat walls are also achievable.

An inflatable membrane is mounted in each of the N or R sub-volumes to push the vegetable product towards sieves or draining channels, which are preferably placed on the internal surface of the drum. In particular, the membrane is inflatable so as to press the vegetable product towards the fraction of the internal surface of the drum which belongs to that sub-volume. In particular, the membrane is inflatable starting from the center of the drum towards the outside. Preferably the membrane is inflatable starting from a position in which the membrane is lying on or near the dividing wall of the subvolume (e.g. the membrane is approximately extended) to a position in which the membrane is spaced from the dividing wall of the sub-volume and approached to the inner surface of the cylinder (e.g. the membrane takes the shape of a cap).

In each of the N or R sub-volumes the inflatable membrane is preferably mounted so that the edges of the membrane rest on the inner surface of the drum. In particular, in each of the N or R sub-volumes the inflatable membrane is preferably mounted so that the edges of the membrane coincide with the connecting portions between the inner surface of the drum and a dividing wall.

In general, the N or R sub-volumes do not necessarily have to be the same or of equal capacity. Preferably each N-th or R-th sub-volume comprises a loading / unloading door, to better evacuate the pressed solid part.

Preferably each N-th or R-th sub-volume comprises an independent input for the axial load (or not) of the vegetable product.

Preferably each N-th or R-th sub-volume comprises an independent fluid inlet for inflation and deflation of the respective membrane.

The membrane of each N-th or R-th sub-volume can be inflated and deflated, e.g. with compressors and blowers, regardless of the membranes of the other (N-1) or (R-1) sub-volumes. Advantageously, the same compressor and blower can be used for all or many membranes, if the press comprises flow deviation valves to selectively divert a flow of fluid coming from a compressor or aspirator towards two or more membranes to inflate or deflate them.

A second aspect of the invention is a method of controlling a press as defined here, in one or each of the variants described. The method has these preferred steps:

filling all the sub-volumes with the product to be pressed at the same time, and then simultaneously pressing the product loaded into the sub-volumes of the press; and / or

filling with the product to be pressed only a sub-group of the sub-volumes and then pressing the loaded product only in that sub-volume of the press; and / or

rotate the drum a total of 360 degrees and sequentially unload the pressed solid part present in all the sub-volumes; and / or

loading or unloading a sub-volume with vegetable product while in another sub-volume the pressing is carried out, inflating the respective membrane; and / or

adjust pressing pressures and / or pressing times and / or the temperature of each sub-volume independently.

A third aspect of the invention is another method of controlling a press as defined here, in one or each of the variants described. The method has the steps of:

fill all the sub-volumes of the press with the product to be pressed at the same time,

then simultaneously press the product loaded into the sub-volumes.

Preferably the steps of the method are carried out by means of the instructions of a program loaded and executed in a microprocessor.

In particular, the operation of the press is preferably managed by a programmable electronic unit, such as eg. a PLC.

In particular, the programmable electronic unit determines the pressing cycles and controls the various operating phases by controlling the components of the press, such as for example.

the engine that turns the drum,

one or more independent axial or non-sub-volume loads;

a compressor and an aspirator to inflate or deflate the membranes of the press independently,

flow deviation valves to divert fluid, put under pressure by the compressor and / or the aspirator, to and from one of the press membranes,

drain valves to release juice from each Nth sub-volume;

one or more product loading and unloading doors to / from each sub-volume.

Another aspect of the invention relates to a method for building the drum of a press for vegetable product, eg. crushed grapes, where the drum rotates around a horizontal axis and is equipped with a draining sieve to separate the vegetable product in solid part and liquid part, where the volume of the drum consists of two or more isolated loading volumes, in each loading volume there being an inflatable membrane to press plant product against a respective draining sieve,

with the phase of

construct the drum as a composition of smaller sub-volumes or load shells, isolated and joined together.

A preferred embodiment of the press will now be described with reference to the attached drawing, where

● fig.1 shows a side view of the press;

● fig.2-4 show transparent front views of the press in various operating configurations; ● fig.5 shows a variant of the press in a perspective view;

● fig.6 shows the variant of fig.5 in front view;

● fig.7 shows a top view of the variant of fig.5.

● fig.8 shows a second variant of the press in a perspective view;

● fig.9 shows the variant of fig.8 in front view;

● fig.10 shows a top view of the variant of fig.8.

In the drawings, like numerical references indicate like parts, and relative terms such as horizontal are understood to refer to the press as in use. In order not to crowd the drawings, some repeated elements are not always indicated.

An MC press comprises a closed hollow drum 10, e.g. cylindrical, raised from the ground by a frame. The drum 10 can rotate around a horizontal axis X in a known way driven by a motor 20.

As an alternative to the closed cylindrical 10 drum, you can have a perforated cylinder, then open, where the juice drains directly to the outside passing through the holes made in the wall of the cylinder itself. It is understood that only for the sake of brevity reference is made here to a closed cylinder, while all the variants and advantages illustrated here apply to the open cylinder.

Evenly distributed on the internal surface of the drum 10, there are longitudinal draining channels 12, which extend parallel to the X axis for a good part of the length of the drum 10. The draining channels 12 communicate with collector ducts 18 which carry the juice extracted from the pressing out of the drum 10, e.g. towards a collection tank 16.

The drum 10 is internally divided into two equal semi-cylindrical sub-volumes 42a, 42b by a diametrical flat wall 40 (fig. 2). This flat wall can be e.g. also composed of a double reinforced wall, a concave-convex wall, a double concave-convex wall or of another shape or concave or convex or other shape suitable to allow a correct subdivision of the internal volumes of the drum and their resistance to pressure.

The semi-cylindrical sub-volumes 42a, 42b can be loaded with the product to be pressed through two independent ducts 14, and each contain a membrane 50a, 50b which can be independently inflated by means of a compressor 22 and which can be deflated independently by means of an aspirator 24. The membranes 50a, 50b in the figures are drawn in hatching to better highlight them.

Each membrane 50a, 50b is mounted so that at rest (when deflated) it lies approximately extended against the respective face of the diametrical wall 40, while in action (when inflated) it expands from the diametrical wall 40 towards the portion of the internal wall of the drum 10 opposite the surface of the diametrical wall 40 from which it started. In fig. 3 illustrates the initial pressing phase, when each membrane 50a, 50b has moved away from the X axis and is moving towards the periphery of the drum 10 (see arrows F) by pressing the juice against the channels 12 of the vegetable product P. S thus generated is conveyed into the manifolds 18 and collected in the tank 16 under the press MC.

The inflation and deflation of each membrane, the working times and the pressures in each subvolume can be the same or different. In the first case the system works as a “push-pull”, where the pressures are counterbalanced without weighing on the dividing wall 40. In the second case the dividing wall is sized to resist the independent pressurization and depressurization of the sub-volumes.

In a known way, the rotation of the drum 10 around the axis X serves to crumble and expel the solid part T of the pressed vegetable product which has remained packed against the draining channels 12 (see fig. 4) or - in the case of an open cylinder - against its dripping perforated wall.

The operations of the MC press are preferably managed by a programmable electronic unit or a PLC. In particular, the programmable electronic unit or the PLC manage

engine 20,

the compressor 22 and the aspirator 24, and

all the valves of the MC press.

The longitudinal draining channels 12 can be of a different shape from that illustrated.

In general, the drum 10 can be

- divided internally into any number of sub-volumes, not necessarily just two; and / or - internally divided by any number of partitions, not necessarily flat in shape and not necessarily arranged radially with respect to the axis of the drum.

Figs. 5-8 show a variant MC2 of the press which has a drum, rotatable around a horizontal axis X, consisting of two isolated loading volumes. The press MC2 comprises a drum 100 which, like the drum 10, can rotate around a horizontal axis X in a known way driven by a motor.

The difference from the previous variant is that the drum 100 is formed by the mechanical union of two equal cylinders or smaller drums 110, isolated from each other and rigidly connected together by brackets 120.

In essence, each cylinder or drum 110 consists of a shell with rigid walls that enclose a closed volume, and these walls are rigidly fixed with respect to the walls of the adjacent cylinders or drums 110 to form the drum 100.

Each cylinder or drum 110 comprises on its internal surface longitudinal draining channels, which extend parallel to the X axis for a good part of the length of the drum 110. The draining channels communicate with collector ducts which carry the juice extracted from pressing out from each drum 110. Or each cylinder or drum 110 has a perforated lateral surface for draining the pressed juice.

The drums 110 each contain an independently inflatable membrane for pressing the product loaded therein. When said above for the management and operation of the sub-volumes 42a, 42b it is applicable to the drums 110, and is not repeated.

It is then understood that the MC2 press shares all the advantages of the MC press, since the separate and / or programmed use of the loading volumes constituted by the drums 110 provides the same effects and results.

The MC2 press can be easier to build when in certain cases the internal partition of the drum 10 is difficult, and can exploit the modularity of the drums 110 for serial assembly.

The drum 100 can be formed by the mechanical union of any number of (preferably the same) smaller cylinders or drums rigidly connected together. It is sufficient for the assembly formed by the mechanical union of the smaller cylinders or drums to form a compound drum.

For the reciprocal rigid connection of the aforesaid smaller cylinders or drums, other means can also be used, such as welding, riveting, or connecting frames or beams.

In the MC2 press, the cylinders or drums 110 contain an inflatable membrane which at rest is spread over a wall 150, the wall closest to the X axis. In the example of Figures 6-8, the connection means are anchored to the walls 150. The when inflated, the membrane moves radially away from the X axis towards the opposite wall of the cylinders or drums 110.

It can be noted that the wall 150 is convex with respect to an imaginary radius that from the X axis propagates towards the outside of the drum 100. In other words, the X axis extends into a space outside the cylinders or drums 110, because thanks to the convexities of each cylinder or drum 110, an empty space is formed in the center of the drum 100 around the axis X (and can be used for example to install the connecting means).

The convex walls 150 are useful for supporting the reaction thrust of the inflatable membrane.

Figures 8-10 show another MC3 variant of the press. As with the MC2 press, the MC3 press comprises a compound drum 200 similar to the drum 100. In essence, the drum 200 is composed of smaller cylinders or drums 210, each consisting of a shell with rigid walls enclosing a closed volume, and these walls are rigidly fixed relative to the walls of the adjacent cylinders or drums 210 to form the drum 200.

The construction details described for the MC2 press are valid for the MC3 press, and are not repeated.

The only difference between the MC2 and MC3 presses is the shape of the smaller cylinders or drums that make up the overall drum.

While in the cylinders or drums 110 the wall 150 closest to the X axis is convex (with respect to an imaginary radius that propagates from the X axis towards the outside of the overall drum), in the MC3 press the homologous wall 250 is concave.

The walls 250 of the cylinders or drums 210 can be in contact or separate.

In the first case, the X axis extends into a space outside the cylinders or drums 210, because between the concavities of each cylinder or drum 210 in the center of the drum 100, around the X axis, there is an empty space (and for eg usable to install the means of connection).

In the second case, the X axis extends touching or remaining inside the walls 250.

The concave walls 250 are useful in withstanding the reaction thrust of the inflatable membrane, and are likely to be simpler to construct.

Claims (10)

CLAIMS 1. Press (MC) for vegetable product, eg. crushed grapes, including: a drum (10) rotating around a horizontal axis (X) and equipped with a draining sieve (12) to separate the vegetable product into solid part and liquid part, where the volume of the drum (10) consists of two or more isolated loading volumes, an inflatable membrane (50a, 50b) is installed in each loading volume to press the vegetable loaded therein against a respective draining sieve. 2. Press (MC) according to claim 1, in which the rotating drum is formed by the juxtaposition of smaller sub-volumes or load shells, isolated from each other and connected to each other integrally. Press (MC) according to claim 1 or 2, in which the drum has a cross section, taken with respect to a plane orthogonal to the longitudinal axis of rotation of the drum, which is given by the additive composition of the cross sections of the sub-volumes or cargo shells. Press (MC) according to claim 1 or 2 or 3, in which the section given by the additive composition is substantially inscribed or contained in a circumference or an ellipse. Press (MC) for vegetable product according to claim 1, comprising: a hollow drum (10) rotatable around a horizontal axis (X) and equipped on the internal side surface with a draining sieve (12) to separate the vegetable product into a solid part and a liquid part, where the internal volume of the drum (10) it is partitioned into two or more isolated loading volumes, an inflatable membrane (50a, 50b) being installed in each loading volume to press the vegetable loaded therein against a respective draining sieve. 6. Press (MC) according to claim 5, comprising one or more partitions (40) for partitioning the internal volume of the drum (10) into the two or more isolated loading volumes, where the partitions extend from separate and distinct points of the inner side surface of the drum. Press (MC) according to claim 5 or 6, wherein the internal volume of the drum (10) is partitioned into two equal semi-cylindrical sub-volumes. Press (MC) according to any preceding claim, wherein one or each inflatable membrane is mounted so that at the start of inflation it moves from the center of the drum outwards or from the axis of rotation of the drum towards the external. Press (MC) according to any preceding claim, wherein one or each membrane is inflatable starting from a position in which the membrane rests on or near the sub-volume partition to a position in which the membrane is spaced from dividing septum of the sub-volume and approached the inner surface of the cylinder, or in which one or each membrane is inflatable starting from a position in which the membrane rests on a wall of the sub-volume, said wall being the closest to the rotation axis of the drum, towards a position in which the membrane is spaced from the axis of rotation of the drum and approached the opposite surface of the sub-volume. Press (MC) according to claim 9, wherein in each of the sub-volumes the inflatable membrane is mounted so that the edges of the membrane lie on the inner surface of the drum or on said nearest wall.