ES2937151T3 - Continuous pressing device and operating procedure thereof - Google Patents

Abstract

A continuous pressing device (100) for products containing a solid part and a liquid part, where the device comprises: a tubular body (405) having a side wall at least partly perforated; a piston (485, 600) slidably inserted into a first end of the tubular body; a pressure chamber (510) defined internally of the tubular body (405) between an end face of the piston (485, 600) and the second axial end of the tubular body (405); at least one inlet (525) provided in the body of the piston (485, 600) and opening into the pressure chamber (510) through the front face of the piston (485, 600); a pump (200) connected to the inlet (525) to supply the product to be pressed into the pressing chamber (510); and sealing means (430) to oppose the exit of the product from the second axial end of the tubular body (405), (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Continuous pressing device and operating procedure thereof

technique field

The present invention relates to a continuous pressing device for products that contain a solid part and a liquid part, and to a method of operation thereof.

In particular, the device and the method of the present invention are intended for the pressing of plant products, typically for pressing grapes in the oenological field, without however excluding the possibility of their advantageous use for pressing other products, including waste. organic animal husbandry or other pulps of various kinds in which it is required to separate the liquid part from the solid part.

prior art

As is known, the oenological processes include bunches of grapes that arrive from the harvest that undergo a first stage of squeezing, whose function is to break and squeeze the grapes, so as to obtain a product that contains juice (must), skins , seeds, pulp residues, as well as scrapes, in case the latter have not been completely eliminated in a previous stage of destemming.

The product obtained by squeezing is then subjected to a pressing stage that has the purpose of separating the liquid part, that is, the must, from the solid parts such as the skins, seeds and stems.

The pressing stage can be carried out by discontinuous oenological presses that comprise a pressing element, for example a sliding piston or an inflatable membrane, which is capable of pressing the product inside a chamber with a perforated wall, in such a way that the juice obtained from the pressing comes out of the holes in the walls while the solid parts are contained inside.

Typically, the product to be processed is pressed a plurality of times, with a mixing step after each pressing step, the solid parts inside the press chamber being mixed in the mixing step to obtain a squeeze. Fuller than the grapes.

In general, the must obtained with the first stages of pressing is of better quality and, therefore, is used for higher quality products with respect to the must obtained in subsequent pressings.

Once the total exhaustion of the grape has been achieved, the completely crushed solid parts (orujo) are discharged from the press chamber, which is filled with new product to be pressed.

Although efficient and functional, this type of press suffers from the disadvantage that it can only work discontinuously, which significantly limits production capacity.

To counteract this drawback, continuous cycle oenological presses have been disclosed, the most widespread of which includes a perforated cylinder in which a rotating screw is housed.

The product to be processed is loaded from an inlet located at a first end of the perforated cylinder, and advanced by the screw towards an outlet located at the opposite end. The screw normally has a variable pitch that gradually decreases from the inlet to the outlet, so that it subjects the product to progressive compression as it gradually advances through the perforated cylinder.

The must obtained from this progressive squeezing leaves continuously through the perforated walls of the cylinder, while the exhausted skins are discharged continuously through the outlet.

As the quality of the must obtained with this system is generally better near the inlet and progressively decreases towards the outlet, it is usually collected in a container located below the perforated cylinder and subdivided into sectors capable of keeping the different varieties separate. must qualities. Thanks to this continuous cycle operation, screw presses have the important advantage of having a higher production capacity compared to discontinuous presses.

A disadvantage of these continuous presses is that they present a certain difficulty in adapting their pressing parameters, especially the squeezing pressure, to the changing conditions of the product to be processed. In addition, continuous presses usually subject the grapes to significant mechanical stresses, derived from contact with the moving screw, stresses that can give rise to undesirable dregs caused, for example, by the partial destruction of the skins, or even by the breaking of pips or scrapes, with the possible release of unwanted substances.

For example, the document FR 2701816 describes a discontinuous extractor press, in particular for pressing grapes with a view to making cognac. The discontinuous extractor press comprises a tank with a horizontal longitudinal axis and equipped with means for feeding grapes, said tank being provided at its upstream end with a piston comprising a pressing head and a mobile rod in translation along said axis. longitudinal of the vat, and at its downstream end there is a flange equipped with closing means with adjustable closing pressure, and with means for draining the juices obtained. The discontinuous extractor press further comprises means that make the pressing head rotate around the longitudinal axis of the vat.

US 6,123,018 discloses a method and apparatus for extracting liquid from a liquid-containing suspension. The apparatus includes a plurality of interconnected press assemblies, the output of one press assembly being connected to the input of a successive press assembly. Each press assembly is provided with a cylindrical ported container and a two-part piston assembly that is movable between extended and retracted positions within the ported container. During operation, a pump continuously feeds the pressurized slurry through the inlet of the first press assembly to cause liquid in the first stage slurry upstream of the two-part piston assembly to drain radially through the leaky container. After a suitable amount of liquid has been extracted from the first stage suspension, batch processing of the partially dried suspension will begin.

Disclosure of the invention

Therefore, one purpose of the present invention is to provide a pressing device and an operating method thereof that does not present the drawbacks of the prior art and, thanks to this, an efficient pressing can be carried out in a continuous cycle that It allows adequate regulation of the pressing parameters based on the characteristics of the products to be processed and it does not subject the product to excessive mechanical stress.

Another purpose of the present invention is to achieve the aforementioned objective with a solution that is simple, rational and relatively moderate in cost.

These and other purposes are achieved with the features of the invention that are listed in independent claims 1 and 10.

The dependent claims describe preferred or specifically advantageous aspects of the invention.

In particular, a device for the continuous pressing of products comprising at least one liquid part and one solid part is disclosed, in particular for plant products such as grapes, comprising:

- a tubular body that has a side wall that is at least partially perforated,

- a piston slidably inserted into a first end of the tubular body,

- at least one inlet associated with the piston and opening into a pressing chamber defined inside the tubular body between the piston and the second axial end of the tubular body,

- a pump connected to the inlet to supply the product to be pressed inside the pressing chamber, and

- sealing means to oppose the exit of the product from the second axial end of the tubular body, the sealing means being able to move between a position of complete closure of the pressing chamber, in which the sealing means prevent the outlet of the product, and a fully open position of the pressing chamber, in which they allow the free outlet of the product.

According to the invention, the continuous pressing device is provided with an electronic control system programmed to carry out the operating procedure set forth later in this description.

As will become clear from the discussion below, thanks to this solution it is advantageously possible to carry out an efficient continuous cycle pressing process, for example grapes, without using any rotating screw inside the chamber. pressing, and thus reducing the risk of destruction and breakage of the solid parts of the product, such as the skins, seeds and stems of the grapes.

In one aspect of the invention, the sealing means may comprise a hatch leaf door hinged to the second axial end of the tubular body.

With this solution, the hatch door in its completely closed position engages with the end of the tubular body, completely closing the pressing chamber and the product to be processed inside. As the hatch door rotates in an outward direction, the hatch door tilts away from the end of the tubular body, defining a discharge outlet through which the product contained in the pressing chamber can exit to the outside. The dimensions of said discharge outlet orifice increase as the inclination of the hatch door with respect to the axis of the tubular body increases.

The hatch door reaches the fully open position when it reaches a position parallel to the axis of the tubular body, that is to say when it leaves the cross section of the passage of the tubular body completely clear. In each intermediate position between the fully closed position and the fully open position, the hatch door continues to exert a certain opposing action on the outlet of the product, which, however, decreases as the dimensions of the discharge outlet orifice increase.

The face of the hatch door facing the inside of the baling chamber (when the hatch door is in the fully closed position) can be perfectly flat, that is, it can be shaped to improve the shape of the exit hole of download. For example, the face of the hatch door may be convex, or it may be conical, wedge-shaped, or more generally it may be defined by one or more inclined surfaces that protrude into the bale chamber.

In an alternative embodiment, the sealing means may comprise an additional piston that can be slidably inserted into the second axial end of the tubular body. In this way, when the piston is inserted at least partially into the second end of the tubular body, the pressing chamber is completely closed. As the piston is retracted outward, it moves away from the second end of the tubular body, creating a discharge outlet for product to exit. However, the piston continues to exert a certain opposition action to the output of the product. This counteracting action decreases with the distance between the piston and the tubular body, that is, gradually as the dimensions of the discharge outlet increase, until reaching a fully open position in which the piston is so far from the body tubular that the product that comes out of the second end of the same can no longer reach it.

Also in this case, the face of the piston facing the inside of the pressing chamber can be perfectly flat, or it can be shaped in such a way as to improve the shape of the discharge outlet orifice, for example, it can have a convex shape, a conical, wedge-shaped or, in general, formation can be defined by one or more inclined surfaces that protrude inward.

In another aspect of the invention, the pump may be a peristaltic pump.

A peristaltic pump is, in general, a variable displacement volumetric pump that applies the principle of peristalsis, according to which the product to be pumped is pushed towards the supply by a shutter that runs along an elastic tube.

The use of a peristaltic pump is particularly advantageous for this type of application, since it does not involve direct contact between the product to be processed and the rotating parts of the pump. However, it is possible that the peristaltic pump could be replaced by other types of adjustable displacement volumetric pumps.

According to the invention, the device comprises a scraper ring, which is coaxially inserted into the tubular body and which is capable of reciprocating both with respect to the tubular body and the piston.

The presence of this scraper ring is important in order to be able to periodically clean at least a part of the perforated wall of the tubular body, whose holes tend to be clogged by the product that is being pressed, obstructing and sometimes making the outflow totally impossible. of the must.

In one embodiment, the wiper ring can be shaped as a hollow cylinder, which is interposed coaxially between the piston and the tubular body and is movable with respect to both in a reciprocating motion, typically between the piston and the tubular body, and is movable with respect to both in a reciprocating motion, typically between a retracted position in which it is substantially flush with the piston and an advanced position in which it projects axially with respect to the piston into the pressing chamber.

In another embodiment, the wiper ring can flank the piston inside the pressing chamber, in such a way that it can be moved from a position close to a position remote from the piston.

In another aspect of the invention, the device may comprise a device for scraping the external surface of the tubular body.

This aspect of the invention has the advantage of preventing the holes in the perforated wall of the tubular body from being blocked by product residues that sometimes adhere to the outer surface.

In particular, this device may comprise one or more rotating brushes and movement means capable of translating the rotating brushes in a reciprocating movement along the direction of the axis of the tubular body. The present invention makes available an operating procedure for the device described above, which comprises a start-up stage comprising:

- set the sealing means in a fully closed position,

- starting the pump to load the pressing chamber, forming a compact agglomeration of pressed product at the second axial end of the tubular body,

- move the sealing means to a position of at least partial opening of the pressing chamber,

and then a successive stage of pressing in a continuous cycle comprising:

- keeping the pump in constant operation, so that it continuously supplies the product to be pressed inside the pressing chamber and causes the consequent output of the pressed product from the second end of the tubular body.

Due to this start-up stage, when the sealing means are opened, the product loaded into the pressing chamber does not come out freely, but is retained internally by the friction that the cake of pressed product exerts against the side walls of the body. tubular, possibly with the addition of the counteracting action that the sealing means in a partially open position may continue to exert on the cake.

In this way, during the next pressing stage in a continuous cycle, the product to be pressed that is continuously dispensed into the pressing chamber by the volumetric pump pushes the product already present in it so that it slides in the opposite direction. axial towards the second end of the tubular body. With this thrust, the final part of the cake comes out and is discharged outside the pressing chamber, while the product already present in the chamber is progressively compacted towards the discharge, re-forming the discharged part of the cake, and while the newly introduced product begins to be squeezed in the initial section immediately downstream of the piston.

As the dispensing of the product by means of the pump is continuous, the overall effect obtained is a continuous pressing of the product, with the liquid part (for example, the must) coming out continuously from the perforated walls of the tubular body, and with the solid parts completely crushed (for example, pomace) that are continuously discharged from the second end of the tubular body.

The pressing is carried out in the total absence of mechanical actions, solely due to the effect of the pressure supply of the product to be processed inside the pressing chamber.

In addition, the degree of pressing to which the product is subjected generally increases progressively in the axial direction towards the cake, so the quality of the liquid part (for example, must) obtained with this system is normally better in the vicinity of the piston. and progressively decreases towards the second end of the tubular body, allowing separate collection thereof.

In a preferred aspect of the invention, the step of loading the pressing chamber comprises in particular: - predisposing the piston in an initial position inside the tubular body,

- monitor the pressure in the pressing chamber until it reaches a predetermined value, that is, a preset value, or previously programmed, and then

- progressively moving the piston towards the first end of the tubular body until reaching a predetermined working position, that is to say, a preset, predetermined or programmed position.

In this way, the start-up stage makes it possible to immediately make a fairly dense cake of completely pressed solid parts (for example, the pomace) at the second axial end of the tubular body.

To achieve this effect, the piston can be kept in the initial position until the pressure in the pressing chamber reaches a sufficiently high pressure, for example between 2 and 8 bar, so as to ensure that the solid parts of the cake present a degree of compaction high enough for the subsequent stages.

By progressively retracting the piston towards the first end of the tubular body, the length of the pressing chamber is increased until reaching the predetermined working position for the next continuous cycle pressing cycle.

The working position of the piston generally depends on the characteristics of the product to be pressed and the type of work. As a general rule, this position is established so that the final length of the pressing chamber is high enough to obtain, during the continuous cycle pressing stage, the complete exhaustion of the product to be pressed (that is, substantially complete squeezing of the solids), but not so high as to cause excessive cake consolidation.

By progressively retracting the piston, a progressive differentiation of the characteristics of the product that accumulates in the pressing chamber is also obtained, that is to say, more solid and compact towards the sealing means and progressively more liquid and less compact towards the piston.

In more detail, the stage of loading the pressing chamber can comprise moving the piston towards the working position through a predetermined stage, that is, a pre-established, preset or previously programmed stage, for example, between 30 and 300 mm, each time. that the pressure inside the pressing chamber reaches a predetermined value, that is to say preset, preset or previously programmed, for example, between 2 and 8 bar.

This retraction through successive stages is advantageous since it has been found to be particularly effective for consolidating the cake and for differentiating in the axial direction the degree of compaction of the product that progressively accumulates in the tubular body.

In another aspect of the invention, the continuous cycle pressing step comprises:

- monitor the pressure in the pressing chamber, and

- regulating at least one operating parameter of the device so as to maintain a predetermined value, that is to say, preset, preset or previously programmed, of the pressure in the pressing chamber, for example, between 2 and 8 bar.

In other words, this aspect of the invention can generally comprise:

- monitor the pressure in the pressing chamber, and

- calculate the difference between the monitored value and the predetermined value of the pressure in the pressing chamber, and

- regulating (ie varying) at least one operating parameter of the device so as to reduce the difference.

By keeping the pressure in the pressing chamber substantially constant, advantageously, it is possible to preserve the dynamic equilibrium that makes it possible to constantly recreate a quantity of cake equal to the quantity discharged during the same period, thus avoiding both an excessive consolidation of the cake, which could lead to blockage of the device, and excessive softening of the same, which could cause it to break and, therefore, the immediate emptying of the pressing chamber.

In a preferred aspect of the invention, the operating parameter that is regulated to maintain the desired pressure is selected between: the position of the sealing means, the delivery rate to the pump and the position of the piston.

This choice is advantageous to the extent that these parameters are the ones that usually have the most influence on the balance of the cake and therefore on the pressure in the pressing chamber.

In detail, in the embodiment of the invention, all these operating parameters can be regulated, it is even possible to do it sequentially, one after the other.

For example, if the pressure in the pressing chamber drops (i.e. the cake softens), the procedure may include:

- moving the shuttering means to a fully closed position, so as to increase the opposing action on the cake and, therefore, the counter-pressure acting on it,

- reduce the flow rate of the supply pump, so as to increase the compaction of the solid parts (pomace) that make up the cake,

- moving the piston towards the first end of the tubular body, so as to increase the length of the pressing chamber and, consequently, increase the exhaustion level of the solid parts (pomace) that make up the cake.

If all these interventions fail to increase the pressure in the pressing chamber up to the predetermined pressure, the shuttering means can be brought to the fully closed position and the start-up step of the device can be repeated.

If, on the contrary, the pressure in the chamber increases (which means that the cake is hardening), the procedure can include:

- displacing the sealing means to a fully open position of the pressing chamber, so as to reduce the counterpositioning action at the exit of the cake and, therefore, the counterpressure acting on it,

- increase the flow rate of the supply pump, so as to reduce the compaction of the solid parts (pomace) that make up the cake,

- moving the piston towards the second end of the tubular body, so as to reduce the length of the pressing chamber, consequently reducing the level of exhaustion of the solid parts (pomace) that make up the cake.

If all these interventions do not achieve the effect of lowering the pressure in the pressing chamber to the predetermined value, an unblocking procedure can be carried out which consists in pushing the hardened cake towards the discharge.

This maneuver can be carried out by advancing the piston towards the second end of the tubular body in successive stages, individually comprised, for example, between 30 and 300 mm. At the completion of each stage, conditions can be checked and, if ideal conditions have not been achieved, an additional push stage can be carried out.

It should be noted that, although the main parameter to be controlled is the pressure in the pressing chamber, the procedure could also include the control of other process parameters, such as the pressure exerted by the cake on the sealing means and/or the flow rate of the liquid part (must) collected (including the separate collection of musts of different qualities).

In another aspect of the invention, the continuous cycle pressing step may also include:

- alternately move the piston from the working position.

This maneuver can be continuously repeated one or more times with a predetermined periodic frequency. In this way, during the retraction path towards the first end of the tubular body, the pressing chamber expands and a suction effect is obtained that is added to the flow rate of the pump, facilitating the dispensing of the product to be pressed. On the other hand, during the advance path towards the second end of the tubular body, a compression effect is obtained. In this way, the advance path of the piston contributes to the advancement of the entire cake and, thanks to the scraping of the sealing rings of the piston against the side wall of the tubular body, also contributes to removing the product that could clog the drainage holes. provided for in the first section of the pressing chamber and which are essential for the collection of the must.

The stroke of the piston during these maneuvers can have a predetermined length, that is to say preset, predetermined or previously programmed, for example, between 30 and 300 mm from the working position for the continuous cycle pressing stage.

In the event that the device is provided with the aforementioned scraper cylinder, the step of cleaning the drain holes can also be carried out by actuating the scraper cylinder to move relative to the tubular body and the piston, which are located stationary.

In another aspect of the invention, the step of pressing in a continuous cycle may comprise modifying the position of the piston as a function of a change in the characteristics of the product to be pressed.

This aspect of the invention has the advantage of adapting the operation of the device to a variation in the characteristics of the product to be processed, without interrupting the continuous cycle pressing stage.

In another aspect of the invention, the operating procedure further comprises a termination step of work that includes:

- stop the bomb,

- move the shutter means to a fully closed position,

- moving the piston in a direction of approximation to the second end of the tubular body, applying a constant thrust of a predetermined amount, that is to say, preset, predetermined or previously programmed for the same.

This leads to a static pressing that has the effect of completely exhausting the product still contained in the pressing chamber, retaining only the exhausted solid parts (pomace).

The thrust applied to the piston should preferably be such that the piston exerts a constant pressure on the product equal to the ideal pressure calculated for continuous cycle pressing.

In another aspect of the invention, the work completion step further comprises:

- monitoring the displacement of the piston while it is subject to thrust, and when the monitored displacement of the piston is zero,

- moving the sealing means to a fully open position of the pressing chamber, and - continuing to advance the piston towards the second end of the tubular body.

With this solution, once the total exhaustion of the residual product has been achieved, the product is finally and completely discharged outside the tubular body.

In another aspect of the invention, during the work completion stage, the piston advances until it is completely outside the pressing chamber, leaving the second end of the tubular body open.

In this way, after having been emptied of the completely exhausted solid parts (pomace), it is easy to carry out a complete internal cleaning and disinfection of the pressing chamber, as well as the piston and the respective scraper cylinder (if present). This is a great advantage over screw presses that are difficult to clean and cannot be easily restarted when empty.

Brief description of the drawings

Other features and advantages of the invention will become clear from reading the following description, given by way of non-limiting example, with the help of the figures illustrated in the attached figures of the drawings.

Figure 1 is a perspective view of a press according to an embodiment of the present invention. Figure 2 is a side view of the press of Figure 1.

Figure 3 is a top view of a loading piston belonging to the press of Figure 1, shown with the scraper cylinder sectioned and in a retracted position.

Figure 4 is the view of Figure 3 shown with the doctor roll in the advanced position.

Figure 5 is a schematic side view of a pressing device according to an embodiment of the present invention, showing the press in section.

Figures 6 to 10 show the device of figure 5 in 5 different operating stages during the pressing process.

Figures 11 and 12 show a press according to an alternative embodiment of the present invention, comprising a wiper ring shown respectively in a retracted and advanced position.

Figures 13 and 14 are a perspective elevation of the loading group of the press of Figures 11 and 12, respectively with the scraper ring in the retracted and advanced position.

Figures 15 to 17 show three views of the wiper ring of Figures 13 and 14.

Figures 18 to 20 show three views of a wiper ring according to an alternative embodiment.

Figure 21 is a side view of a press in another embodiment of the present invention, which is provided with an external scraper device.

Figure 22 is the section along the line XXII-XXII of Figure 21, in which some details have been hidden to reveal the characteristics of the external scraper device.

Best Mode for Carrying Out the Invention

Figure 5 illustrates a device 100 for the continuous cycle pressing of food products, in the example for pressing grapes in the oenological field.

The device 100 schematically comprises a pump 200 intended to collect the product to be pressed from a squeezer 300 and to supply the product under pressure into a press 400.

The 300 crusher is a device capable of processing whole bunches of grapes, destemmed or partially destemmed, with the purpose of opening and squeezing the grapes, so as to obtain a product that contains a liquid part (must) and a solid part (skins). , seeds, remains of pulp and also scrapes, in case the scrapes have not been completely eliminated in a previous destemming stage).

The crusher 300 can generally comprise a loading hopper 305, by means of which the product to be squeezed is transported between two grooved rollers that rotate in the opposite direction 310, whose function is to break and squeeze the grapes. The product that passes through the grooved rollers 310 is collected in a lower tray 315, inside which is a screw 320. The screw 320 is driven by an electric motor 325 positioned on the outside of the tray 315, so that it is advanced the squeezed product to the pump 200.

In some embodiments, a juice separator (not shown) may be interposed between the juicer 300 and the pump 200, for example, a vibrating screen separator, to separate the liquid from the solid parts of the fermented grapes and skins. .

The 200 pump is generally a variable flow displacement pump. In the illustrated example, pump 200 is a peristaltic pump. In particular, the pump 200 comprises a flexible and elastic tube 205, for example made of silicone, PVC or other polymers, the ends of which respectively define the inlet 210 and the outlet 215 of the pump.

The pump 200 further comprises a rotor 220, which is driven in rotation by a respective motor (not illustrated). The rotor 220 supports two diametrical rollers 225, which can rotate in contact with the flexible tube 205, so as to define a shutter that moves in the direction of the length of the tube itself. In this way, the shutter continuously pushes discrete amounts of product from the inlet 210 to the outlet 215. The flow rate of the pump 200 can be regulated by varying the speed of rotation of the rotor 220 by means of the motor.

The use of the peristaltic pump 200 is advantageous, since the pumping is carried out without any direct contact between the product and the moving parts of the pump. However, it is possible that in other embodiments the peristaltic pump 200 can be replaced by a volumetric pump of any other type as long as it is of variable flow.

The press 400 comprises a tubular body 405, in the example an internally hollow cylinder. Said tubular body 405 is supported by a support frame 410, in the example a carriage, on which the tubular body 405 is arranged, preferably with its X axis oriented horizontally. The side wall of the tubular body 405 is perforated, that is, it has a plurality of through holes for drainage.

In the illustrated example, the drain holes are evenly distributed over the entire side wall of the tubular body 405, but in other embodiments, they may be distributed over a limited part of the side wall, for example, only at the bottom.

The tubular body 405 has two axial ends, including a first loading end and a second discharge end. A loading mouth 415 and a discharge mouth 420 are coaxially fixed respectively to the ends, whose mouths have substantially the same diameter as the tubular body 405. The loading mouth 415 is perfectly cylindrical, while the discharge mouth 420 It has a dovetail shape.

Sealing means are associated with the discharge outlet 420, designated in its entirety with the number 425, which are capable of completely closing the second axial end of the tubular body 405 and opening it progressively and exerting in a continuous manner an action of opposition to the exit of the product, until reaching a fully open position, in which the product can freely exit the tubular body 405.

In other words, the sealing means 425 are movable, that is, they can be moved or can be configured to move between the fully closed position and the fully open position of the second end of the tubular body 405. In particular, they can be provide activation means capable of moving the shutter means 425 between the fully closed position and the fully open position. In the illustrated example, said shuttering means 425 comprise a hatch door 430 that is hinged to the discharge mouth 420 according to a rotation axis Y perpendicular to the X axis of the tubular body 405. The rotation axis Y is located close to the second axial end of the tubular body 405, but outside the cross section thereof.

In this way, the hatch door 430 in the fully closed position obstructs the discharge mouth 420 (as can be seen in Figure 6), completely closing the second end of the shaft of the tubular body 405. Rotating outward, the The hatch door slopes away from the edge of the tubular body 405, and rises with respect to the bottom wall of the spout 420. In this way, the hatch door 430 progressively defines a spout through which the product contained in the tubular body 405 can come out, encountering more or less resistance depending on the dimension of the discharge opening itself. In particular, the dimensions of the discharge opening increase progressively until the hatch door 430 reaches the raised position shown in Figure 5. In this position, the hatch door 430 is substantially parallel to the X axis of the tubular body 405. , leaving its cross section completely clear and thus allowing the product to exit without encountering any obstacles.

It is observed that, in order to improve the conformation of the discharge mouth profile, the face of the hatch door 430 facing towards the product at the outlet, has a bulged profile whose convexity protrudes towards the inside of the tubular body 405 (when the hatch is in the fully closed position). However, it is possible that in other embodiments the face of the hatch door 430 is perfectly flat or conical, wedge-shaped or generally has sloped walls. The movements of the hatch door 430 between the previously mentioned fully closed and fully open positions are performed by means of a double-acting, hydraulically actuated cylinder/piston group 435, the ends of which are articulated respectively to a horizontal support 440 fixed above the hatch. tubular body 405 and a pair of fasteners 445 attached to the hatch door 430 and able to rotate securely with it about the Y-axis like a rocker. Thus, the lengthening and shortening of the cylinder/piston assembly 435 allows the movement and stopping of the hatch door 430 in the fully closed, fully open, and any other position in between.

As illustrated in Figure 1, the loading spout 415 and the discharge spout 420 are attached to two longitudinal members 450 that are parallel and positioned on diametrically opposite sides of the tubular body 405. Said longitudinal members 450 protrude axially with respect to to the loading mouth 415, on the opposite side with respect to the tubular body 405, so that they function as guides for a slider 455. In the illustrated example, the slider 455 comprises a central body 460 interposed between the longitudinal members 450, and two roller skates 465 fixed to the central body 460 and individually slidably coupled to a respective longitudinal member 450. In this way, the slider 455 can slide on the longitudinal members 450 in the direction of the X axis of the tubular body 405, approaching and moving away from the loading mouth 415. The displacements of the slider 455 are actuated by two piston groups Double-acting, hydraulically-acting, long-stroke/cylinder 470, each being attached to a respective longitudinal member 450, while the piston end 475 thereof is attached to a respective roller skate 465.

A loading group is firmly fixed to the central group 460 of the slider 455, indicated in its entirety by the number 480 and visible in detail in Figures 3 and 4. The loading group 480 comprises a piston 485, generally shaped cylindrical, which is located at the end of a coaxial shaft 490 (partially visible in figure 1), the opposite end of which is fixed to the central body 460 of the slider 455, so that the piston 485 can slide firmly with the slider 455 along the X axis of the tubular body 405.

In the illustrated example, piston 485 is inserted coaxially into a scraper cylinder 495 that has an axial length that is greater than the length of piston 485. In practice, the scraper cylinder has a substantially tubular body shape that is coaxially inserted into the outside of the piston 485 and inside the tubular body 405.

The scraper roll 495 is supported at the end of a cylindrical sleeve 500 (partially visible in Fig. 1) which is slidably inserted into the shaft 490. In this way, the scraper roll 495 can be moved firmly with the slider. 455, but is also capable of moving independently on board the slider 455 in the direction of the X axis of the tubular body 405, between a retracted position shown in Figure 3, in which the end is level with the piston end face 485, and an advanced position shown in Figure 4, in which the end thereof passes past the piston end face 485. This movement of the scraper cylinder 495 is accomplished by two piston/cylinder groups 505, with hydraulic action and double effect, the ends of each of which are fixed respectively to the central body 460 of the slider 455 and to a respective rib that protrudes from the cylindrical sleeve 500.

As illustrated in Figure 5, piston 485 and scraper cylinder 495 cross spout 415 and fit tightly, coaxially, and slide into tubular body 405 so as to close off the first end. This seal is made hermetic by one or more sealing rings that are applied to the skirt of the piston 485, so as to be interposed coaxially between the skirt and the scraper cylinder 495, and by one or more sealing rings that are applied to the cylinder wiper 495, so that they are interposed coaxially between the cylinder 495 and the tubular body 405.

It follows from the foregoing that the scraper cylinder 495 is movable, that is, capable of moving or configured to move with a reciprocating movement both with respect to the piston 485 and with respect to the tubular body 405. In other words, generally some means for moving the scraper cylinder 495 reciprocating both with respect to the piston 485 and with respect to the tubular body 405. It is noted that, in other embodiments, the scraper cylinder 495 might not be present, in which case the piston 485 it will be sized so that it alone occupies the entire cross section of the tubular body 405, with the interposition of one or more sealing rings.

In either case, a press chamber 510 with perforated walls is defined between the end face of the piston 485 and the second end of the tubular body 405. The press chamber 510 can be fully closed, partially open, or fully open based on the position of the hatch door 430, while the internal volume is variable depending on the axial position occupied by the piston 485.

Lastly, the loading unit 480 comprises a supply tube 515 for the product to be pressed, which is positioned eccentrically above the shaft 490 and is integrally connected to the slider 455. A first end of said supply tube 515 is connected to the outlet 215 of the pump 200 through a flexible conduit 520 or, in any case, an extensible conduit that can follow the movements of the slider 455. The second end of the delivery tube 515 is coupled to a dispensing port 525 which is provided on the body of the piston 485 and which opens into the pressing chamber 510 through the end face of the piston.

Below the tubular body 405, the device 100 is provided with a collection tray 530 for the must obtained by pressing. Said tray 530 develops along the entire length of the tubular body 405 and can be internally subdivided into sectors by means of a plurality of dividing walls 535 arranged in succession in the direction of its length. Each of the sectors can be associated with a respective discharge conduit 540 for collecting the must.

Finally, the device 100 is completed with an electronic control system (not illustrated), which generally comprises at least one electronic processing unit connected to the different hydraulic actuators and electric motors of the pump 200 and the squeezer 300. , which is programmed in such a way that it carries out the steps of the operating procedure described below.

In general terms, the operating procedure of the device 100 includes a start-up stage, a pressing stage in a continuous cycle, and a successive stage for finishing work.

Referring to Figure 6, the start-up stage comprises, firstly, prearranging the hatch door 430 in a completely closed position of the pressing chamber 510 and then bringing the piston 485 closer to the door of hatch 430 until reaching an initial position in which it is closest to the second end of the tubular body 405, that is, a position in which the volume of the pressing chamber 510 is the smallest.

From this configuration, the start-up stage consists of putting the squeezer 300 and the pump 200 in motion, so that the squeezed product begins to be supplied into the pressing chamber 510. In this way, the must it flows from the perforated walls of the tubular body 405, while the solid parts of the product thicken and progressively compact against the hatch door 430, thus beginning to form a rather dense agglomeration known as a cake.

During this stage of forming the cake, the procedure comprises that the pump 200 operates at a constant flow, while the pressure in the pressing chamber 510 is monitored, that is, the pressure with which the pump 200 pushes the product inside. of the pressing chamber 510.

This pressure can be measured directly, for example, by means of appropriate pressure sensors located in the pressing chamber 510 or in the connection conduits 515 and 520, or it can be measured indirectly, for example, by measuring the value of the torque developed by the electric motor to rotate the rotor 220 of the pump 200, or by measuring the thrust exerted by the product against the hatch door 430.

When the pressure in the pressing chamber 510 reaches a preset value, for example a value between 2 and 8 bar, this means that the cake is sufficiently compact.

Upon reaching this condition, the start-up stage comprises a stage of retraction of the piston 485 towards the first end of the tubular body 405, keeping the pump 200 in constant flow operation. This retraction stage can be of a predetermined amount, for example between 30 and 300 mm. In this way, the volume of the pressing chamber 510 increases while the pressure decreases.

While keeping the pump 200 running at a constant flow rate, the start-up step comprises retracting the piston 485 through an additional retraction step each time the pressure in the pressing chamber 510 reaches the preset value again.

In this way, a progressive retraction of the piston 485 is obtained, and a progressive increase in the length of the pressing chamber 510, thanks to which it is advantageously possible to consolidate the cake and axially differentiate the degree of compaction of the product that progressively accumulates. in the tubular body 405. In practice, the solid part of the grapes accumulated in the pressing chamber 510 is more solid and compact towards the hatch door 430 and progressively more liquid and less compact towards the piston 485 (as can be see in figure 7).

The retraction of the piston 485 ends when it reaches a predetermined working position for the successive step of pressing in a continuous cycle. The working position of the piston 485 generally depends on the characteristics of the product to be pressed and the type of work. As a general rule, this position is established in such a way that the final length of the pressing chamber 510 is long enough to obtain, during the continuous cycle pressing stage, the complete exhaustion of the product to be pressed (that is, , a substantially complete pressing of the solid parts), but not so high as to cause excessive consolidation of the cake.

When the piston 485 reaches the predetermined working position, the pump 200 is kept running at a constant flow, with the hatch door 430 still in the fully closed position, until the pressure in the baling chamber 510 again reaches the set point. predetermined value, after which, the start-up stage concludes with the full opening or at least partial opening of the hatch door 430, thus giving rise to the start of the continuous cycle pressing stage (such as as can be seen in figure 8).

When the hatch door 430 is open, the product that is already contained in the pressing chamber 510 cannot come out freely, but is retained inside by the friction exerted by the cake of crushed grapes against the side walls of the tubular body. 405 and possibly with the addition of the opposing action that the hatch door 430 in the partially open position can continue to exert on the cake.

Thanks to the presence of the cake, during the successive step of pressing in a continuous cycle, the hatch door 430 is thus kept in a fully or partially open position and the pump 200 is kept constantly in operation, so that continuously supplies the product to be pressed inside the pressing chamber 510.

In this way, the product to be pressed that is continuously dispensed in the pressing chamber 510 through the dosing mouth 525 pushes the product already present so that it slides in the axial direction towards the second end of the tubular body 405. This thrust also means that the final part of the cake comes out and is discharged outside the pressing chamber 510, while the solid part of the product already present in the chamber is progressively compacted towards the discharge, again forming the discharged part of the cake. the cake, and while squeezing the product just introduced into the initial section immediately downstream of the piston 485.

The global effect obtained is a continuous pressing of the product, carried out in the total absence of mechanical actions and solely due to the effect of the pressurized supply of the product to be processed inside the pressing chamber 510, the must continuously coming out of the perforated walls of the body. tubular 405 and with the exhausted skins discharged progressively through the discharge mouth 420.

The degree of pressing to which the solid part of the product is subjected generally decreases in the axial direction towards the discharge mouth 420, so that the quality of the must obtained with the system is normally better near the piston 485 and decreases progressively towards the second end of the tubular body 405, thus allowing separate collection along the various sectors of the underlying collection tray 530.

In order to maintain the dynamic balance that allows to constantly recreate an amount of cake that is substantially equal to the cake discharged during the same period, the pressure in the pressing chamber 510 is preferably kept constant at a predetermined value, that is, a preset or previously established value. programmed, during the whole of the continuous cycle pressing stage, for example, a value between 2 and 8 bar.

To achieve this purpose, during the continuous cycle pressing stage, the procedure comprises continuing to monitor the pressure in the pressing chamber 510 and, therefore, regulating in a closed cycle at least one operating parameter of the device 100, so that the error between the measured pressure value and the predetermined value is minimized.

In particular, the method includes regulating, either simultaneously or sequentially, the position of the hatch door 430, the delivery rate of the pump 200 (for example, by regulating the speed of the rotor 220) and the working position. of the 485 piston.

For example, if during continuous cycle pressing the pressure in the pressing chamber 520 drops (meaning the cake becomes softer), the procedure may comprise:

- move the hatch door 430 towards the fully closed position, so as to reduce the dimension of the discharge opening and thus increase the back pressure acting on the outgoing cake,

- reduce the flow rate of the pump 200, so as to increase the time available for compacting the marc of the cake,

- retracting the piston 485 towards the first end of the tubular body 405, so as to increase the length of the pressing chamber 510 and, consequently, increase the degree of exhaustion of the pomace that forms the cake.

If all these interventions do not produce the effect of increasing the pressure in the pressing chamber 510 up to the predetermined value, the hatch door 430 can be brought to the fully closed position and the start-up step of the device 100 can be repeated. .

If, on the other hand, during continuous cycle pressing, the pressure in the pressing chamber 510 increases (meaning that the cake becomes harder), the process comprises:

- move the hatch door 430 towards the fully open position, so as to increase the dimension of the discharge outlet hole and therefore reduce the back pressure acting on the outgoing cake,

- increase the flow of the pump 200, so as to reduce the time available to compact the pomace in the cake,

displacing the piston 485 towards the second end of the tubular body 405, in such a way that the length of the pressing chamber 510 is reduced and, consequently, the degree of exhaustion of the pomace that forms the cake is reduced.

If all these interventions do not produce the effect of lowering the pressure in the pressing chamber 510 to the predetermined value, an unblocking process can be carried out, which consists in strongly pushing the hardened cake towards the discharge.

This maneuver can be carried out by advancing the piston 485 towards the second end of the tubular body 405 in successive stages, each one comprising, for example, between 30 and 300 mm. At the completion of each stage, conditions can be checked and, if ideal conditions have not been restored, an additional push stage is performed.

During the continuous cycle pressing stage, an additional possibility is to make the piston 485, preferably integral with the scraper cylinder 495, systematically carry out one or more alternate movements starting from the working position.

In this way, during the retraction path of the piston 485 towards the first end of the tubular body 405, the pressing chamber 510 expands and a suction effect is obtained that can be added to the supply of the pump 200, facilitating the dispensing of the product to be pressed. During the advance path towards the second end of the tubular body 405 a compression effect is achieved. In this way, the advance path of the piston 485 contributes to the total advance of the cake and, thanks to the scraping of the sealing rings of the scraper cylinder 495 against the side wall of the tubular body 405, to remove the product that could clog the holes. drainage in the first section of the pressing chamber 510 and which are essential for the collection of the must.

The stroke of the piston 485 during these maneuvers can cover a predetermined distance between 30 and 300 mm, starting from the working position for the continuous cycle pressing stage.

To improve the cleaning of the first section of the press chamber 510, from time to time the scraper cylinder 495 is activated to move in an alternating motion between the retracted and advanced positions of the press. same, so as to clear the drainage holes without moving the piston 485 and, therefore, without modifying the dimensions of the pressing chamber 510.

During the continuous cycle pressing stage, the possibility of modifying the working position of piston 485 according to a variation in the characteristics of the product to be pressed is also included. This adjustment of the working position can be carried out manually or automatically with the help of suitable sensors that must be able to detect the characteristics of the product being worked on.

When the product to be pressed is finished, the step of continuous pressing ends and the step of finishing work begins.

Referring to Figure 9, the completion step of the job comprises firstly stopping the operation of the pump 200 and bringing the hatch door 430 to the fully closed position.

After having completed these maneuvers, the work completion stage includes bringing the piston 485 closer to the second end of the tubular body 405, regulating the activation of the piston/cylinder groups 470 so that they generate 485 a constant thrust of a predetermined value on the piston. , preferably a value equal to the ideal value calculated for continuous cycle pressing operation. In this way, a static pressing is carried out which has the effect of completely exhausting the residual product still contained in the pressing chamber 510.

While the piston/cylinder groups 470 exert the aforementioned constant thrust, the work completion step also comprises monitoring the displacement of the piston 485. When the displacement of the piston 485 is zero, the work completion step finally comprises displacing the hatch door 430 to the fully open position of the press chamber 510, thereby further advancing the piston 485 toward the second end of the tubular body 405, to discharge the final cake residue outside of the press chamber. pressing 510, as illustrated in Figure 10.

It has been observed that the piston 485 advances until it reaches a position in which it advances far enough to be completely out of the pressing chamber 510, also leaving open the second end of the tubular body 405. In this way, after being emptied of exhausted skins, the 400 press can be easily washed and disinfected. In particular, it is easily possible to carry out a complete internal cleaning of the pressing chamber 510, as well as, obviously, of the piston 485 and of the respective scraper cylinder 495.

In Figures 11 and 12, a variant embodiment of the press 400 described above is illustrated, which differs from the previous one only in the aspects that will be described below. Unless an indication of explicit difference is given, it is understood that all of the characteristics described above for the first embodiment are repeated identically, even for the second embodiment, and are designated with the same part numbers. reference.

In the second embodiment, the loading group 480 comprises a piston 600, generally cylindrical, which is closely inserted directly into the tubular body 405. One or more sealing rings can be applied to the skirt of the piston 600, whose rings are interposed coaxially between the piston 600 and the tubular body 405, to make a hermetic seal. The piston 600 is located at the end of a coaxial shaft 605, the opposite end of which is attached to the central body 460 of the slider 455 (not fully illustrated in ^{Figures 11 and 12), so that the piston} 600 ^{is can slide firmly with the piston 600 along the X axis} of the tubular body 405.

The supply tube 515 of the product to be pressed is fixed to the piston 600, which is positioned offset on the axis 605 and is in communication with a dispensing mouth 610, which is arranged in the center of the end face of the piston. 600, so that it opens into the pressing chamber 510 (as can be seen in Figure 14).

The loading group 470 also includes a scraper ring 615, which is inserted coaxially inside the tubular body 405, so that the flank of the piston 600 is placed inside the pressing chamber 510. This scraper ring 615, whose outer diameter is substantially equal to the internal diameter of the tubular body 405, it is supported by a central support hub 620, to which it is attached by a plurality of spokes 625. The central hub 620 is made by means of a hollow tubular body, so as to allow the passage of the products coming from the dispensing mouth 610 of the piston 600.

Two guide rods 630 are fixed at two diametrically opposed points of the central hub 620, each of which is slidably inserted into a through hole made in the piston 600. The free end of each guide rod 630 protrudes externally from the chamber of pressing 510 and is fixed to a respective double-acting hydraulic cylinder 635, which is rigidly connected to the slider 455 by means of a fastening 640. In this way, whatever the relative position of the load group 480 with respect to the tubular body 405, wiper ring 615 is capable of moving with an independent movement in the direction of the X axis of the body tubular 405, between a retracted position shown in Figure 13, in which it is in the position of piston 600, and an advanced position shown in Figure 14, in which it is separated from piston 600 by some distance.

The operation of the press 400 is identical to that described above for the first embodiment. During this operation, from time to time the scraper ring 615 is activated to alternate between the retracted and forward positions of the scraper ring 615 in order to clear the drain holes of the tubular body 405 without having to displace the piston 600 and, therefore, Therefore, without modifying the dimensions of the pressing chamber 510.

As illustrated in Figures 15 to 17, the scraper ring 615 can have a slightly concave shape, so that its opposite axial ends have slightly sharp edges capable of scrubbing substantially in contact with the internal surface of the tubular body 405. Thus In this way, the two extreme edges can act as two scrapers that rub against the internal surface of the tubular body 405, both during its advancement and during its retraction.

According to the alternative embodiment shown in figures 18 to 20, the wiper ring 615 may have a slightly smaller diameter than that of the tubular body 405, and the lateral surface thereof may be lined with an external annular strip 645 provided with bristles, for example, of a plastic material. In this way, the scraper ring 615 can act substantially as a brush that sweeps in contact with the internal surface of the tubular body 405.

In addition or alternatively to the above, the device 100 can also be equipped with an auxiliary device 650 capable of scraping the external surface of the tubular body 405.

As illustrated in figures 21 and 22, this device 650 can comprise a set of brushes 655 capable of coming into contact with the external surface of the tubular body 405, as well as movement means (not illustrated) capable of moving the 655 brushes with reciprocating movement in a direction parallel to the X axis.

In particular, the brushes 655 can be positioned in a circumferential arrangement to globally form an annular structure that can be coaxially inserted into the exterior of the tubular body 405 and that can be moved from one side to the other as a single element.

The brushes 655 of this device 655 are preferably roller brushes, which are associated with activation means capable of making them rotate around their axes during translation, in order to increase the scraping effect.

For example, the 655 brushes can be connected to each other by universal joints so that they can be driven to spin together by a single motor.

Naturally, a person skilled in the art could carry out numerous modifications of a technical and application nature to the device 100 described above and to the respective operating procedure, without detracting from the scope of protection of the invention as claimed below.

Claims (10)

1. Operating procedure for a continuous pressing device (100) for products that contain a solid part and a liquid part, in which the device comprises: - a tubular body (405) having a side wall of which at least one part is perforated, - a piston (485, 600) slidingly inserted into a first end of the tubular body, - a pressing chamber (510) defined inside the tubular body (405) between an end face of the piston (485, 600) and a second axial end of the tubular body (405); - at least one inlet (525) provided in the body of the piston (485, 600) and opening into the pressing chamber (510) through the end face of the piston (485, 600); - a pump (200) connected to the inlet (525) to supply the product to be pressed into the pressing chamber (510) and - sealing means (430) to oppose the exit of the product from the second axial end of the tubular body (405), the sealing means (430) being able to move between a position of complete closure of the pressing chamber ( 510), in which the sealing means (430) prevent the exit of the product, and a completely open position of the pressing chamber (510), in which the sealing means (430) allow the free exit of the product. , - a scraper ring or scraper cylinder (495, 615), which is coaxially inserted into the tubular body (405) and which is capable of reciprocating both with respect to the tubular body (405) and the piston (485, 600) , in which the operating procedure comprises a start-up step comprising: - setting the shutter means (430) in a fully closed position, - starting the pump (200) so as to load the product to be pressed into the pressing chamber (510) until it forms a compact agglomeration of pressed product at the second axial end of the tubular body (405), - moving the sealing means (430) to a position of at least partial opening of the pressing chamber (510), and then a successive stage of pressing in a continuous cycle comprising: - Keep the pump (200) in constant operation, so as to continuously supply the product to be pressed into the pressing chamber (510) and cause the consequent output of the pressed product from the second end of the tubular body ( 405). The method of claim 1, wherein the step of loading the press chamber (510) comprises: - prearrange the piston (485, 600) in an initial position inside the tubular body (405), - monitoring the pressure in the pressing chamber (510) until reaching a predetermined value, - Progressively moving the piston (485, 600) towards the first end of the tubular body (405) until reaching a predetermined working position. Method according to claim 2, in which the step of loading the pressing chamber (510) comprises moving the piston towards the working position by a predetermined step, each time the pressure in the pressing chamber (510) reaches a predetermined value. Process according to any one of claims 1 to 3, in which the step of pressing in a continuous cycle comprises: - monitoring the pressure in the pressing chamber (510), and - calculating a difference between the monitored value and a predetermined value of the pressure in the pressing chamber, and - regulating at least one operating parameter of the device (100) in such a way as to reduce the difference. The method of claim 4, wherein the operating parameter is selected from: the position of the sealing means (430), the delivery rate of the pump (200) and the position of the piston (485). Process according to any one of claims 1 to 5, in which the step of pressing in a continuous cycle comprises: - alternately move the piston (485, 600) starting from the working position. Method according to any one of claims 1 to 6, comprising a step for finishing the work comprising: - stop the pump (200), - move the shutter means (430) to a fully closed position, - moving the piston (485, 600) in a direction of approach to the second end of the tubular body (405), applying a constant thrust of a predetermined amount to it. The method of claim 7, wherein the step of finishing the work further comprises: - monitoring the displacement of the piston (485, 600) while it is subject to thrust and, when the monitored displacement of the piston (485) is zero, - moving the sealing means (430) to a position of complete opening of the pressing chamber (510), and - advancing the piston (485, 600) further towards the second end of the tubular body (405). The method according to claim 8, in which the piston is advanced until it is completely outside the pressing chamber (510), leaving the second end of the tubular body (405) open. 10. Device (100) for the continuous pressing of products containing a solid part and a liquid part comprising: - a tubular body (405) having a side wall of which at least one part is perforated, - a piston (485, 600) slidably inserted into a first end of the tubular body, - a pressing chamber (510) defined inside the tubular body (405) between an end face of the piston (485, 600) and a second axial end of the tubular body (405); - at least one inlet (525) provided in the body of the piston (485, 600) and opening into the pressing chamber (510) through the end face of the piston (485, 600); - a pump (200) connected to the inlet (525) to supply the product to be pressed inside the pressing chamber (510) and - Sealing means (430) to oppose the exit of the product from the second axial end of the tubular body (405), the sealing means (430) being able to move between the completely closed position of the pressing chamber ( 510), in which said sealing means (430) prevent the exit of the product, and a fully open position of the pressing chamber (510), in which they allow the free exit of the product, - a scraper ring or scraper cylinder (495, 615), which is coaxially inserted into the tubular body (405) and which is capable of reciprocating both with respect to the tubular body (405) and the piston (485, 600) , and an electrical control system programmed to carry out a start-up stage comprising: - prearranging the shutter means (430) in a fully closed position, - starting the pump (200) so as to load the product to be pressed into the pressing chamber (510) until it forms a compact agglomeration of pressed product at the second axial end of the tubular body (405), - moving the sealing means (430) to a position of at least partial opening of the pressing chamber (510), and then a successive stage of pressing in a continuous cycle comprising: - keeping the pump (200) in constant operation, so as to continuously supply the product to be pressed inside the pressing chamber (510) and causing the consequent output of the pressed product from the second end of the tubular body (405).