Technical Field of the Invention

The present invention relates to a device, which may be domestic, for malaxing and centrifuging olive pulp to produce olive oil. The device object of the present patent application allows to carry out both the malaxation step and the centrifugation step of the olive pulp to obtain an olive oil at home or wherever it is needed and whenever the oil is needed.

Background Art

Olive oil is obtained by pressing olives through mechanical or physical means, therefore without the need of any chemical intervention.

The conventional method involves crushing the olives in stone mills, thereby obtaining a paste of crushed olives, malaxing the paste to break up the emulsions, spreading the malaxed paste on fibre disks which are stacked on top of each other alternating disk and crushed and malaxed olive paste, pressing the disks stacked on top of each other on which the paste was distributed to expel the oil.

In recent years, the extraction technique has changed, and continuous cycle presses are used. Olives are crushed in mechanical knife or hammer crushers, the crushed olives are kneaded in malaxation tanks, the malaxed paste is centrifuged in a horizontal decanter in which three phases are separated: a solid phase containing pomace, water and oil.

In order to improve the quality of the extracted oil, another technique referred to as "sinolea" has been used, which is not very widespread and consists in that rows of metal rods are dipped into the malaxed olive paste, the oil wets the metal surfaces and, as a result of its surface tension, sticks to said metal surfaces, after which the rows of metal rods are allowed to drip to recover the collected oil.

Producing olive oil only in olive harvesting periods has been a shortcoming of the olive oil extraction techniques used so far. The olive tree is a biennial plant with a high yield of olives every two years, alternating with periods of much lower yield. All this has required the use of olive oil for two-year periods.

Olive oil is a natural product that deteriorates over time. When it is just produced, it is rich in all its organoleptic properties, which are lost over time.

Some companies have tried to build small plants to meet family consumption.

EP2796077A1 discloses an oil extraction device, the oil extraction device comprising: a malaxation and centrifugation vessel for malaxing and centrifuging milled olives having a hole in the lowest part of the malaxation and centrifugation vessel.

However, EP2796077A1 requires an additional container for the liquid produced during the centrifugation step, wherein a decanting tank is provided for separating oil from water.

The device described in EP2796077A1 has several drawbacks for domestic use, the first of which is the cleaning of its components. The device has several vessels which must be kept clean to ensure that the product is not contaminated by deteriorated residues.

The device described in EP2796077A1 provides for the use of two separate containers, a first container for the malaxation step and a second container for the centrifugation and decantation step, which increases production times.

WO 2017/051043A1 describes an automatic device for obtaining virgin olive oil by grinding, beating and centrifuging. The device comprises a grinding mill, a motor element, a frame where a removable container is mounted, inside which the olive paste is subjected to a low RPM beating process, generated by the rotation of the removable container and a heat source providing the required temperature, the centrifugation of the high RPM paste separates the virgin olive oil from the pomace that adheres to the walls of the removable container by centrifugal force. Lastly, the oil falls onto a tray through a valve situated at the lower part of the removable container.

Also the device described in WO2017/051043A1 has several drawbacks. First of all, said device is made to grind fresh olives and does not provide for the thawing step of the olive paste, whereby, even in the thawing step, the blades would spin in the frozen olive paste, thus risking breaking down.

Summary of the Invention

The main object of the present invention is to provide a device for producing extra virgin olive oil starting from frozen olive paste, so that the olive oil can be produced even when the olives have not been harvested.

The paste can be stored in the best way, e.g. by being frozen. Olive paste will be thereby available all the year round, 365 days a year. The production of oil can be carried out when needed and it will not be necessary to store oil for long periods, thus having an oil with the best organoleptic characteristics available.

The shortcomings and drawbacks present in the background art are overcome by the present invention, which embodies an olive pulp malaxing and centrifuging device for producing olive oil comprised of a cap, a containing drum, provided at the centre of its base with a discharge hole, in which a rotating drum driven by a motor is inserted, and a reel provided with blades, characterized in that said reel is arranged between a housing within the cap and the discharge hole formed at the centre of the base of the containing drum, said reel is mounted within the housing by means of a unidirectional bearing, being free to rotate in one direction and locked in the other direction, and said reel serves as a cap for the discharge hole.

Another feature is that said motor is provided with mechanisms for transmitting the rotation movement between the motor and the rotating drum.

Another feature is that the reel is comprised of a lower end and an upper end connected to each other by a screw and with the lower end free to rotate with respect to the upper end by means of an axial roller bearing.

Another feature is that said mechanisms for transmitting the rotation movement are operated by an electronic board which steers their speed and direction of rotation, and that said electronic board allows to monitor constantly the number of revolutions of the machine and keep them close to the values set for the various steps. Another feature is that said electronics operates the power of the motor by increasing it if the resistance of the pulp tends to decrease the number of revolutions by bringing them back to the desired ranges.

Another feature is that in the cap or in the containing drum or in the base there are a heating assembly and a fan.

Another feature is that the heating assembly is an electrical resistance provided with a temperature sensor.

Another feature is that said electronics, by exploiting the temperature sensor, operates the heating assembly and the fan to ensure that the temperatures suitable for the process are reached and subsequently maintained.

Another feature is that the electronics of the heating assembly is housed within the cap or the base.

Another feature is that, during the defrosting step, the rotating drum spins in one direction, and the reel stands still, when frozen olive pulp is used.

Another feature is that, during the malaxation step, the rotating drum spins in one direction, and the reel stands still.

Another feature is that, during the centrifugation step, the rotating drum spins in a direction opposite to that of the malaxation step, and the reel spins together with the rotating drum.

Another feature is that, during the centrifugation step, the rotating drum spins at a speed exceeding 2000 rpm.

Other features and advantages of the present invention will be evident from the following description of an embodiment of the present invention, given by way of a non-limiting example from Figures 1 to 8.

Brief Description of the Figures

Figure 1 shows a view of the device object of the present invention; Figure 2 shows an exploded view of the device object of the present invention;

Figure 3 shows a section of the reel of the device object of the present invention;

Figure 4 shows a view of the reel of the device object of the present invention;

Figure 5 shows an axonometric view of the cap of the device object of the present invention;

Figure 6 shows a top view of the cap of the device object of the present invention;

Figure 7 shows a section of the cap of the device object of the present invention;

Figure 8 shows a side view of the cap of the device object of the present invention.

Detailed description of an embodiment of the invention

With reference to the figures, the olive pulp malaxing and centrifuging device for producing olive oil consists of a containing drum 5, into which the rotating drum 3 is inserted. Within the containing drum 5, the motor 30 and the mechanisms for transmitting the rotation movement 31 between the motor 30 and the rotating drum 3, equipped with forward and reverse gear, are arranged. The start/stop button 6 is arranged outside the containing drum 5. At the centre of the base of the containing drum 5 there is a discharge hole 23 which can be provided with a discharge pipe 4. The lower end 9 of a reel 2, provided with a mechanism free to rotate in a rotating direction and blocked in the opposite direction, is inserted in the discharge hole 23 or in the discharge pipe 4. The lower end 9 of the reel 2 has, preferably but not exclusively, two slots for housing as many O-rings 10 to ensure the sealing of the discharge pipe 4 when the lower end 9 of the reel 2 is inserted in said discharge pipe. The reel 2 is provided with blades 8 needed for malaxing the olive pulp.

The lower end 9 of the reel 2 is connected to its upper end 7 by means of a screw 12 and free to rotate with respect to the upper end 7 by means of an axial roller bearing 1 1. The containing drum 5 is closed by a cap 1 . The cap contains a housing 17 for the upper end 7 of the reel 2.

The cap 1 is advantageously but not exclusively made of plastic and has means for monitoring the temperature which, advantageously but not exclusively, may be an OLED LCD (13).

Moreover, the cap 1 has in it a suction fan 14 conveying the air inside a duct 22, which, advantageously but not exclusively, may have a toroidal shape, by a heating assembly 15, which, advantageously not exclusively, can be an electrical resistance and by a temperature sensor 21 , which, advantageously but not exclusively, can be an infra-red temperature sensor allowing to monitor both the environmental temperature and the punctual temperature. In the cap 1 , a unidirectional bearing 16 is mounted on the base of the heating assembly 15, preferably radially with the housing 17 advantageously but not exclusively provided with a conveyor 17 to allow an easier insertion of the shaft of the reel 2 in the bearing itself, upon completion of the loading step of the machine. In the upper part of the cap, a compartment has been created to house the electronics 18 of the heating assembly 15.

For a better understanding of the operation of the machine, its operation has been divided into five steps:

STEP 1 : MACHINE LOADING

Removing the cap (1 ), inserting the drum (2) into the counter drum (5), inserting the reel (2) where appropriate, that is into the discharge hole (23), and possibly providing it with a discharge pipe (4), and loading the amount of desired pulp and closing the cap.

STEP 2: PROGRAMME STARTING

Starting the programme. By briefly pressing the start button (6) the normal mode programme, which will last about 45 minutes and will allow to yield about 170g of oil out of 900g of pulp oil, will be started. By exerting a prolonged pressure until the confirmation beep of the machine, the speed mode, which will last about 22 min and will allow to yield about 130 g out of 900g of pulp, will be started.

STEP 3: DEFROSTING

When frozen olive pastes are used, the machine starts the defrosting step. During this step, the drum 3 rotates clockwise and the reel 2 is idle in order to prevent it from being damaged due to the still frozen pulps. During the defrosting, the heating assembly 15 integrated in the cap 1 heats the pulps while constantly checking the temperature thereof by means of an infra-red temperature sensor and modulating the air temperature so as to avoid burning the pulps through the electric resistance and the fan for ensuring that the temperatures suitable for the process are reached and subsequently maintained. The temperature never exceeds 27 ° C. The air is not sucked from the outside, but it is taken from the inside the drum itself through a recirculation system to prevent oxidation.

STEP 4: MALAXATION

Once the constant temperature of 24 ° C is reached, the machine leaves the defrosting step behind and starts the malaxation.

During this step, the drum rotates in an anti-clockwise direction and the reel (2), this time, stands still, allowing the pulp to be processed at a speed of 45rpm. The duration of this step varies according to the choice of the type of programme and, specifically:

• NORMAL MODE: 20 min long. During this step, the heater is still on for 10 minutes in order to keep the temperature constant.

• SPEED MODE: 7 min. During this step, the heater is on.

STEP 5: COALESCENCE

Upon completion of the malaxation step, the machine proceeds to the coalescence step, which is practically identical to the malaxation step, but the speed drops to 40 rpm. The duration of this step varies according to the choice of the type of programme and, specifically:

• NORMAL MODE: 7 min long. During this step, the heater is off

• SPEED MODE: 2 min. During this step, the heater is off.

The operation of the device for producing oil starting from olive paste is simple. The operation of the device is based on two principles: first, the solid part is placed on the side surface of a container that is caused to spin at very high speed, exceeding 2000 revolutions per minute, and then at very high speed, exceeding 2000 revolutions per minute, the oil separates from the water and, since the oil is lighter than water, settles as a layer over the water layer.

The device object of this invention is operated by an electronic board which steers it speed and direction of rotation, and allows to monitor constantly the number of revolutions of the machine and keep them close to the values set for the various steps. In addition, said electronics operates the power of the motor by increasing it if the resistance of the pulp tends to decrease the number of revolutions by bringing them back to the desired ranges.

The device with said technical solutions which consider the proportion between oil and water extracted from a known quantity of olive paste is able to perfectly separate the two liquids, making it possible to produce extra virgin olive oil with a device that can be used at home.

The device is completely automatic and the only things that are up to the user is to insert the right amount of olive paste and extract the vessel with the produced extra virgin olive oil.

The invention, as it is well understood, is not limited to the disclosed embodiment, but can be subjected to improvements and modifications from the skilled person without parting from the scope of the patent.

The present invention provides many advantages and allows to overcome issues which could not be overcome with the systems currently available on the market.