ES2288359A1 - Co-ordinated control system for lines used for the continuous extraction of virgin olive oil - Google Patents

Abstract

The invention relates to the virgin olive oil production process which is based on a deeper knowledge of the materials involved in the process for the production of oils from olives and for oils obtained by centrifugation of olive pomace. The invention is made possible through the use of a new generation of sensors for transmission using electromagnetic fields in the microwave range included between 1 and 10 Ghz. The aforementioned sensors, which are located at measuring points indicated in the invention, enable real optimisation of the process and the machinery used both in three- and two-phase systems.

Description

Coordinated control system for lines of Continuous extraction of virgin olive oil.

Object of the invention

The present invention is directed and focused to the process of making virgin olive oils, based on of a deeper knowledge of the subjects involved in the process of making oils from olives and for oils obtained by centrifugation of the pomace; them and achieved by using new generation of sensors by transmission from electromagnetic fields in the band of microwave between 1 and 10 Ghz.

Located at the measurement points indicated in the present invention, allow true process optimization and of the machinery used, both in systems of three and two phases Thanks to the microwave technology by transmission in the medium used for the first time to know the fraction hydro-molecular in oil processing lines olive, you get a complete characterization of the matter premium, allowing the truly automatic adaptation of parameters to which the machinery or industrial process is sensitive, regardless of the changing nature of the olive.

State of the art

In recent years, the only experiences of online measurement systems, in lines of continuous production of virgin olive oil, have been based solely on NIR type analyzers (near infrared) by reflection that offer readings in the same instrument, readings of fat and moisture content. These equipments, which only offer the measurement of moisture and fat content in the pomace resulting from the process, require a complex system of extraction and preparation of the sample and in the few existing facilities, have been used exclusively to monitor the level of losses of Oil in the manufacturing process.

If you analyze the behavior of these devices and based on studies conducted from the point of view of the oil content determination, it has been possible check the great difficulty in maintaining reliable calibrations in all olive varieties, in addition to the special care of maintenance and cleaning, they also offer only a vision of the outer layer of the sample and not inside the mass flow in the process, so they are not recommended for use in control systems.

On the other hand, if it is analyzed, from the point of view of the determination of humidity, it has been found that in certain varieties of olive, it is almost impossible to determine the humidity with the necessary precision and repeatability, in fact in many Sometimes erratic measures have been obtained, therefore and for the same reason as in the previous case, they are not recommended for use in control systems. These analyzers have additional drawbacks, derived from the measurement point in the process, as they have been commonly used for real-time analysis of the pomace at the exit of the horizontal centrifugal decanter, in which it is necessary to take into account that everything , or a part of the pomace is collected by the extraction system, where it is " compressed " causing the oily part to stick to the outer walls, distorting the absolute measurement and introducing a time delay that incapacitates it for use in systems Real-time control. These systems of continuous sample extraction of the pomace at the exit of the horizontal centrifugal decanter require auxiliary elements such as sample extraction, augers, pumps, etc., with the consequent complication, high cost and possibilities of installation failure. (horizontal centrifugal decanter stops, failures due to lack of cleaning, forgetfulness, etc.). To the above disadvantages, it is necessary to add the self-evaporation suffered by the wet sample that affects the determination of humidity, while it is transferred to the sensor, causing a distortion of the real and absolute measurement.

For these reasons, the measurement alternative in line of systems based on NIR technology, is ruled out for use in a reliable control system or solution. Test that is, since these systems began to be used for Process of elaboration of virgin olive oils, have been used in very few facilities and of course in none of them are being an integral control solution.

To all these inconveniences we must add some more, such as high acquisition costs and Mandatory periodic maintenance of its parameters calibration, which implies the need to have a reference laboratory These calibration procedures periodically, they must be performed with due rigor and present certain difficulties, due to the actual response time of the laboratories, after a previous sampling of the sample that never stops be punctual and therefore little representative of the state or situation of the elaboration process.

Finally and to complete the vision of the current scenario, there are other market solutions, which use a single NIR team for several production lines, using a whole set of transport elements of the type endless, thereby increasing the time of update of the measurements of each line, which make theoretical and virtually unusable for real use in systems or solutions Reliable control.

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On the use of systems for online determination of oil content and humidity, by means of NIR, the most important inconveniences are summarized detected that are detailed below:

They measure the surface of the sample, not the complete set in the process.

They are sensitive to olive varieties.

High cost of acquisition and of maintenance.

They require periodic calibrations with reference laboratories

They cannot be used in line with the process.

They require extraction and preparation systems of the sample.

They are delicate equipment, susceptible to decalibration

They only solve part of the problem (only measure, do not control).

We must highlight the substantial differences between the present invention and the patent ES 2190330, as the same is based on the indirect determination of the constant free water dielectric, present in the substances that they take part in the elaboration process, through devices based on capacitors or capacitors, so you can finally use this magnitude (only) to add water in the process, when necessary.

First, the big difference is the use of new specific sensors that use a field microwave electromagnetic going through the mainstream of the product to be measured, measuring directly, not the constant water dielectric but the "total fraction hydro-molecular ", which is equivalent to knowledge of the total water present in the olive paste, pomace, and oils. That is the free water, and the water embedded in the molecular structure of the fiber or solid part, which is called, "nuclear moisture." This helps to have a greater and deeper knowledge of the physical characteristics of those cited substances, which in the case of the process of making oils from virgin olive, it is of vital importance, given the changing nature of the olive.

Second, and given the greatest and deepest knowledge of the products involved due to the use of new sensors, the other important part of the present invention, as is the complete and coordinated control of all  the extraction line, from the mill exit, to the vertical centrifugal separator.

The performance scenario of this invention, is developed within the scope of an elaboration line complete composed of several sub-processes that go from crushing the olive in a hammer mill metallic, until the oil is cleaned in the centrifuge separator vertical.

In the first phase or grinding, they do not exist today in particular day measurement or control systems other than intuitive and visual own that the teacher performs, being Particularly important is the choice of the screen that determines the degree of grinding, in order to avoid the formation of fines and emulsions; that is why it is not recommended to add water in this point, since it is very easy the appearance of emulsions that complicate the process of beating and subsequent centrifugation.

In the whipping process today, and in In the best case, only control systems are available. Simple temperature, which try to keep this parameter inside of operating limits. As for the addition of adjuvants, microtalco or enzymes are usually added in amounts fixed, throughout a campaign and at the discretion and intuition of the master and in some areas water is added uncontrollably, in function to the low humidity contents that the olive, with the consequent added complication, since both additions, water and microtalco, should be added depending on technological parameters established based on the state of the paste at the entrance of the thermo-blender.

Currently, in the solutions of existing automation in the market, the addition of water in the thermo-whipping process, it is done uniquely and exclusively under machinery protection criteria, it is that is, water is added uncontrollably when there is a electrical overload in the agitation system of the mixer. Be has been able to verify that under normal operating conditions no there is a simple and clear relationship between the rheological value of the mass (visco-pasture, compactness, consistency, fluidity, etc.), and the electrical consumption of the drive of the blender, obtaining strongly non-linear responses, before low moisture content of olive paste, due mainly to the tendency to oversize the stirring systems

In the next separation process solid-liquid, the olive paste previously treated in the thermo-whipping process, it is conducted to the horizontal centrifugal decanter, by means of a pump positive displacement; in this centrifugation process, it they separate the oily fraction from the aqueous and solid fractions.

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The advantages in the olive sector are known of the two-phase horizontal centrifugal decanter where eliminates the discharge of the water phase or high water pollutant, incorporating it into the solid phase, called by some authors "alperujo", which is characterized by higher content moisture.

This two-phase system requires a greater and more critical control of humidity and other parameters technological, with more demand than in the separation process in three phases, hence the contribution of the present invention that based on a total and coordinated control of the process that involves more unit production, less oil losses in the pomace and less discharge of polluting waters.

Currently, the only controls used in this part of the process, they are the simple control of the regime of pasta feed to the horizontal centrifuge decanter, by a flow measuring device and a frequency inverter that acts on the volumetric mass pump. The amount of water to add is done entirely manually and at the criteria of teacher, which is far from what it should be, which is control a variable water flow, consistent with nature changing of the olive, to keep stable and controlled the separation levels in the horizontal centrifuge decanter and to be able to reduce both the losses of oils in the pomace and the dirt of the oil obtained, and finally the discharge of water pollutants

At the present time, there is no other type of online measurement, control, performance, or intervention in the own horizontal centrifugal decanter, although certain manufacturers have incorporated devices that allow you to adjust both speed  differential as the external adjustment of the regulation diaphragms. These settings, although they exist in some installations, are not used. in practice, mainly due to lack of training, difficulty and great complication in its handling, ignorance overall and finally the absence of online instruments that Indicate the results of the changes online.

In the final phase of the centrifugation process, the oil obtained, with a certain percentage of dirt and moisture, is conducted by a centrifugal pump, so discontinuous to a vertical centrifuge separator for cleaning final, subjecting it to strong centrifugal accelerations, with g values around 7,000.

This high centrifugation process eliminates part of the excess water resulting from the previous process, as well as the moisture that is trapped (nuclear moisture), in the fines that They have a density similar to oil. To do this, and according to current practices, a quantity of water is added in a way manual and teacher criteria, following visual controls newspapers, there is a general tendency to always add an amount of water greater than necessary, with the consequent increase in polluting spills.

Moreover, the added water temperature It is also controlled manually, being very difficult in the practice not exceeding 35 ° C.

The vertical centrifugal separator has a automatic cleaning system that acts on the machine, each certain time and at the discretion and criteria of the teacher, for not dispose of any device that indicates the degree of dirt internal machine or final oil.

Once thus centrifuged the oil and not exempt totally fine and moist, it is led to the deposits of Natural decantation before storage in the cellar.

This need to have to control all the oil mill machinery, through periodic visual checks and the need to perform analytical controls more or less frequent loss of oil in the pomace and in the waters of oil wash and if in addition to this joins that in the current mills exist on average at least two- three lines, it is easy understand, the great difficulty that the teacher has to attend to the entire installation, which makes the system of little effective process control work, within a changing scenario, caused by the variability of the raw material, which must also be controlled with all the necessary rigor following the new food safety regulations.

Finally, the obsession to recover until the last drop of extractable oil by centrifugation, has led to the sector to the need to have to install in the oil mills, what which is called second centrifugation operations, that is take the centrifuged masses of the first extraction and return them to go through another centrifugation process.

This has led to having to endure large investments in the purchase of machinery, which apart from the amortization must consider energy, personal and of maintenance to recover between 5% MG / S and 12% MG / S, already that this oil must be sold as pomace oil at a lower price. This post-process is what is normally performed in pomace extractors before the extraction process chemistry itself, to recover, part and not all of the residual oil indicated above.

To avoid the real inconveniences that have been detailed above when using NIR sensors and taking a great qualitative step towards other more innovative and reliable solutions, first of all, the strategy must be modified in the measurement of the most important key variable, which instead of "Search for the oil that is lost" due to an improved processing system, be that of "creating the best processing conditions and keeping them controlled at all times" using another variable or magnitude that does not require the use of any online analyzer to know in real time, the oil content that goes through the pomace. In the specific case of this invention, it has been found on the basis of the deepest and most representative knowledge of the total hydro-molecular fraction of the olive and the index of oil purity in the resulting oils. These parameters have proved to be of great importance in the process of making virgin olive oil by centrifugation, because in conjunction with other auxiliary variables it allows full control of the process.

The new sensor is designed to, with the help of at least one digital processor, control and optimize a complete line of elaboration in an integral and coordinated way, because Everything about her is interrelated. Below are the Features to present:

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A measurement system capable of evaluate online, the total fraction hydro-molecular at any point in the process, for so much that it is able to adapt to measure in ducts or pipes, in blender, in tank.

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The measurement system must be designed for truly online applications with the process, without the need to prepare the sample and analyze how  The same is evolving.

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Faculty of measuring a section cross section, and to be able to correctly measure the mainstream of the product, evaluating the process so relevant, indispensable condition for control or optimization reliable.

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A measurement system that does not need optical transparency of the medium, or based on properties optical reflective and independent of the degree of dirt or sensor embedding, indispensable condition as in the case previous.

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That the complete solution based on these new sensors, be able to keep under control and at all times all the processes involved in the line of elaboration in its right point of optimal work, with a minimal intervention by the teacher.

Explanation of the invention.

The present invention consists of a new control system coordinated by optimal points, for lines of elaboration of virgin olive oil and pomace oils by centrifugation It is based on a new procedure for online determination of the total fraction hydro-molecular from the interaction of water molecules present in the raw material and fluids resulting from centrifugation processes, with a field of microwave electromagnetic origin, using sensors Especially prepared for the process. This property of molecular interaction of water with microwaves, is used in the present invention for the online determination of a new parameter or concept that indicates the degree of cleanliness of the resulting oils in the manufacturing processes by centrifugation in both first and second centrifugation; East new parameter is called, "oil purity index", which is the key point to gain total control of the process of elaboration.

This new system offers more knowledge deep molecular properties of certain components present in the olive paste, as well as in the pomace and in the oils resulting from the industrial separation process.

This means being able to know, the free water of plant or added origin, and embedded water (nuclear moisture) strongly kidnapped by the pulp and bone (hydrophilic), which they are part of the solid fraction present in both the olive, as in the pomace. This better knowledge of the raw material and the incorporation of the oil purity index parameter, together with others auxiliary quantities involved in the manufacturing process, are the information entries for the control system, control the entire line in a coordinated and predictive way, adapting at all times to the changing nature of the olive to process and with minimal attention from the teacher of the oil mill.

All these functionalities are achieved through a system that with its corresponding elements of action and measure, act on the parameters most important technological-operational of all the processing line, from the exit of the mill, to the vertical centrifugal separator, to keep them within requirements of maximum production and quality.

Specifically, the purpose of this invention is a coordinated control system, for lines of continuous extraction of virgin olive oil, based on the continuous evaluation, at any point of the line, of the fraction total hydro-molecular, and characterized in that said evaluation is carried out, using field sensors electromagnetic in the microwave band. These sensors are from type of wave transmission, working in a frequency range between 1 to 10 Ghz, and are located in at least one of the following points of the extraction line:

to)

In the blender, particularly in the upper body at the entrance of the olive paste

b)

At outlet duct of the volumetric pump, which conducts the paste of olive towards the horizontal centrifugal decanter.

C)

At Outlet of centrifugal decanter oil horizontal.

d)

At oil outlet duct of centrifugal separator vertical.

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The extraction line on which the sensors, is virgin olive oil first or second centrifugation The system may additionally include meters auxiliary flow, temperature, level and electrical power. So much microwave sensors such as auxiliary meters transmit the information at least to a digital modular processor of control.

Said digital modular control processor, performs the following control and regulation actions in the mixer; continuous feeding of olive paste, Dosage of microtalco and / or enzymes, water addition and control of olive paste temperature.

In the horizontal centrifugal decanter, the digital modular processor performs the following actions of control and regulation: control of the feeding regime in Continuous whipped olive paste, final water addition, variation of the differential speed, action on diaphragms and regulation of cleaning periods, and in the separator Vertical centrifuge performs the following control actions and regulation: control of the continuous feeding regime of oil from the horizontal centrifuge decanter, speed addition of wash water, water temperature control of washing and regulation of cleaning periods.

Detailed description of the invention

In each of the processes of thermo-beating, oil extraction and cleaning a production line of virgin olive oil, that is from the exit of the mill or entrance to the thermo-blender and the vertical centrifuge separator, the present invention provides first of all a better knowledge of the behavior of fluids or materials present in each of the above processes and as a result, thanks to other physical quantities auxiliary, know what are the best technological conditions both the process and the machinery, which will be called "optimal work points" that go far beyond simple humidity control at a single point in the process. The objective is, through the coordinated control system object of this invention, control the conditions so that these optimal points of work are obtained and guaranteed at all times.

First of all and to understand why the need for a new solution to control the process of elaboration of virgin olive oils, it is necessary to make a small review on the constitution of the materials or products of the process, read, olive paste entrance to thermo-blender, olive paste at the entrance to horizontal centrifugal decanter, pomace as residual part of the manufacturing process and oils obtained.

The olive paste is composed of a part of solids (fraction of solids) and another of liquids, that is vegetable water (hydro-molecular fraction) and oil (oil fraction). The solid fraction in turn consists of endocarp ossicles plus the fibrous pulp resulting from grinding process of olive, mesocarp, pericarp and part of the endocarp. These solid components of the olive are normally "soaked" to a greater or lesser extent by water vegetable, that is water absorbed by the soil tree, along with other nutritional substances plus the oil that is intended separate in the process.

This presence of solids in the constitution of the olive paste makes it behave like a fluid not Newtonian, and we must take into account magnitudes such as the visco-pastosity, compactness, consistency, degree of fluidity, etc., that is its rheological value, which conditions and in sometimes prevents a normal elaboration of the olive paste, both in the process of shaking and in the centrifugal separation, (what are commonly called pastes difficult).

The solids content in the olive is distributes between 14-20% for the bone, of 1-3% for the seed or almond and the rest 8-10% for the epicarp and other pulp. The others two components, vegetable water and oil, constitute the fraction liquid composed of vegetation water (40-55%) and oil (18-33%), this one liquid fraction makes the olive paste flow and be handled with relative ease in the process. Necessary remember that this liquid phase comes from a fruit, as is the olive, with continuous changes in the proportions of its components, or the characteristics of any of them, affecting to the process, especially in the preparation of pasta.

These two components (water and oil), you have to treat them very carefully because at certain temperatures of work and in the presence of solids, they may appear during certain Shaking process phases, undesirable emulsions. These Emulsions may appear well during grinding by addition uncontrolled water and movement action at high speeds of the hammers of the mill, or even during the shake depending of the moisture of the olive, deteriorated fruits and / or times of excessive shake

Therefore, it is necessary to consider water original or vegetable and water added as a total fraction hydro-molecular olive paste though it is an exemption from the elaboration, it is also an adjuvant and can be used at your convenience to favor the purpose of your Correct separation in the horizontal centrifuge decanter.

This total fraction hydro-molecular is the most variable parameter e unpredictable in the manufacturing process being also a factor decisive in the proper functioning of both the process of thermo-shake, as extraction in the decanter Horizontal centrifuge and vertical centrifuge separator.

The milkshake process

In the first place and to create conditions for the characterization of the dough, from the beginning of the process, the total hydro-molecular fraction in the olive paste must be known at the entrance to the thermobatcher in the upper body, by means of a microwave sensor transmission. In this way, it is possible to know exactly under which conditions the raw material to be processed is entering, in order to adapt and control the most important operating parameters at their optimum point.

To keep the parameters of the thermo-whipped within the operating levels more convenient, the system object of the invention regulates in mode the diet of olive paste continued, to from the level of the thermo-mixer and modifying well be the speed of the paste feed pump of olive by means of a frequency inverter, or by any other means of proportional regulation is valve regulation or gate, or if the mill is just before the blender, modifying the feeding regime to it. All of it  in order to maintain the processing regime continued without cuts or arrests, as the extraction process In the horizontal centrifugal decanter it is also continuous.

By using this new sensor for microwave at the entrance of the blender, knowing the fraction total hydro-molecular (key magnitude) and the regime of elaboration, the present system object of invention, decides in what time to add water and in what exact amount, just to bring the key magnitude to the optimum working point or standard conditions

Similarly to the previous case with the knowledge of the total hydro-molecular fraction and the processing regime, the system object of invention decides in what time should add adjuvants (microtalco or enzymes) and in what quantity, modulating the dosing system according to of the operating parameter or optimum working point.

At the same time, knowing the total fraction hydro-molecular, the processing regime, the filling level of the thermo-blender, and the paste inlet and outlet temperatures plus the temperature of the heating water, the system object of the present invention, controls the temperature of the olive paste at the exit of the blender, within the preset value or optimum point of job.

Therefore, the new system object of the invention, through continuous and current evaluation principal of the total fraction process hydro-molecular and other auxiliary quantities, comprehensively and in a coordinated manner, controls the following points optimal work:

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Set the optimal point of Continuous feeding more adequate at all times.

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Decide the moment and point optimal microtalc or enzymes to be dosed.

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Decide the moment and point Optimum amount of water to add.

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Control the optimum point of olive paste temperature in the blender.

These four aspects are the most uncontrolled at this time, because their control and surveillance is based on the teacher's periodic visual controls.

From the controlled thermo whipping process at all times and considering the olive paste within the desired operational parameters, this is conducted to the decanter horizontal centrifuge, by means of a displacement pump positive, either double thyme or gears, lobular type or any other type driven by an electric motor to which adds a frequency converter for pump speed and therefore to vary the feeding regime at horizontal centrifugal decanter.

The centrifugal separation process

In this process and if it is a system of two phase processing, phase separation occurs oil or oil on the one hand and the rest of the components of the olive on the other, which is commonly called pomace or alperujos. But you have to keep in mind that the vast majority of horizontal centrifugal decanters working in two phases, no they have external regulation of the diaphragms, it is for that reason that it is very important to keep the optimal conditions controlled at all times, regardless of the type of olive to be made, although a large part of the standardization work was already done in the previous process, it is critical to be able to control this process thanks to the advantages of deeper knowledge, both of the olive paste when knowing the fraction accurately and precisely total hydro-molecular at the entrance to the decanter horizontal centrifuge and accurate and precise index knowledge of oily purity of the oil obtained, at its exit, thanks to the new transmission microwave sensor technology that reveals the status of the entire mainstream of the product such and how it evolves in the process itself. These two magnitudes they are key pieces, together with other auxiliary parameters, for control at all times the internal state of the rings that are form inside the horizontal centrifuge decanter or point Optimal work as seen below.

In a two-phase horizontal centrifugal decanter and based on a paste of determined characteristics, the solid-water-oil separation process is carried out, by the action of the centrifugal force caused by the angular velocity of the internal organs, subjecting the set of the paste at a gravity proportional to the centrifugal acceleration (w2 r) which is notoriously involved in the values (G) , a factor that determines the efficiency of the machine and is deduced from the following expression.

G = w 2 r / g

in which (w 2 r) is the centrifugal acceleration and (g) the acceleration of gravity, the normal values of (G) of a horizontal centrifugal decanter in the market are between 2,500 and 3,000.

Inside the decanter, there is a separation of the different components forming the rings, thanks to the centrifugal acceleration action seen above  and at the different densities of each of the components that for olive paste they are typically 1.2 to 1.3 g / cm3 for the heaviest element that is the solid fraction, 1.05 to 1.06 g / cm3 for the aqueous fraction, and finally the oily fraction with densities between 0.915 to 0.917 g / cm3. These components are placed inside the horizontal centrifuge decanter from outside towards inside in the same order, the separations not being clear between the phases but transition zones appear.

The total solid fraction is displaced within of the horizontal centrifugal decanter by the action of the auger that rotates at a different speed from the outer part of the rotor and evacuated through a suitable conduit, generating a byproduct called orujo, on which all the efforts of monitoring and surveillance and the point where the NIR sensors online.

The requirement to know the fat losses in the pomace, has been and is a real headache of machinery manufacturers, mill masters, engineers, and research centers, etc. For this reason it is easy to think that everyone is more worried about the oil that can be lose, that in creating conditions for total extraction and take the appropriate corrective actions before the losses occur

Starting from the condition that the paste of olive, has been conveniently prepared in the previous process thermo-beaten and brought to optimal conditions working, to be processed in the centrifuge decanter horizontal, the total fraction must be known hydro-molecular as a key variable in this part of process.

In this process, the knowledge of the total hydro-molecular fraction of the olive paste before entering the decanter centrifuge horizontal, as well as knowledge of the oil purity index of the oil leaving the same in the main stream of the process as it is evolving.

These two key quantities, in conjunction with other auxiliary variables, such as the flow of paste, the flow of water to be added, the differential speed and the electrical consumption of the main drive of the horizontal centrifugal decanter , are essential for the system subject to the In this invention, control the following optimal working points in a comprehensive and coordinated manner.

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Establish and control the pasta flow rate more convenient within values optimal.

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Establish and control the total hydro-molecular fraction more convenient for the decanter

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Decide the moment and flow Exact water to add to the process.

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Decide the differential speed of the most convenient decanter at all times.

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Check the output diaphragm of oil if the decanter has it incorporated.

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Control the interface of oil-water ring with respect to the position of the diaphragm.

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Regulation of the periods of decanter cleaning.

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Performance Detection irregular decanter.

The oil obtained at the outlet of the decanter horizontal centrifuge, in this phase of the process and controlled in every moment through the system, so that density impurities next to the resulting oil and nuclear moisture, always be below reasonable operational limits, it is conducted to fine separation sieve, and subsequently by a pump centrifuge is taken to the next final cleaning process before of its natural decantation, phase explained below.

The oil cleaning process

Starting from working conditions previously exposed and the processes of whipping and separation controlled at their optimum working points, the oil separated into the horizontal centrifugal decanter will be accompanied as has been cited above, of a certain amount of fine solids and water from the interface or transition zone, value that the system object of the present invention, as an index of purity Oily, always keeps controlled at all times, in order to separate the maximum oil and avoid losses in the pomace.

As a consequence of this situation the oil impurified has to undergo a debugging process that performs in a vertical centrifugal separator, in this process, the oil is usually mixed with a certain amount of hot water which is used as a means of purification, their intimate contact products, different densities and centrifugal acceleration which in these machines can reach values of (G) of up to 7,000, they make virgin olive oil with a state of purity that after rapid decantation is classified by quality and Store in warehouse.

This final stage of the process has its own critical points that must be controlled and maintained throughout time within the values or quality parameters more and more demanding. To do this, one of the most important news that provides the present invention, is the real-time knowledge of oil purity index, at the outlet of the centrifuge separator vertical, by means of a new suitable sensor based on a field microwave transmission, in order to know everything moment the quality of all the oil that comes out of the process of cleaning being the key magnitude for the control of this process.

With the knowledge of the key magnitude of the oil purity index, at the outlet of the centrifuge separator vertical, and other auxiliary variables, such as the flow rate of oil, water flow, water temperature, temperature of oil, and the integration of the machine cleaning system, The system object of the present invention controls comprehensive and coordinated, the following optimal points of job:

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Stabilize the oil flow to the separator

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Set the exact flow of water added to the separator

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Control the temperature of the water added to the separator

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Regulation of the periods of separator cleaning

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Performance Detection irregular separator

Finally, with the three controlled processes within the optimal work points (thermo-beating, separation and cleaning), with independence of the variations of the characteristics of the raw material and thanks to the knowledge of the total fraction hydro-molecular olive paste and index of oil purity of oils, the industrial application of system object of the present invention, offers the following advantages:

1.) Savings in the consumption of adjuvants (microtalco or enzymes) .- The saving in this input is easily demonstrable, since normally the work system that is being used today is to dose a fixed amount at the teacher's discretion . The present invention will dose the fair amount (between 1% and 3%) according to the processing regime and only when necessary.

2.) Lower water expenditure (only that required) .- With the system object of the invention, water saving is evident, since normally the current work system is to add an estimated amount and teacher criteria. That is not the right criteria to follow; The present system will dose the right amount of water and only when necessary depending on the changing nature of the olive and the state of the rings inside the horizontal centrifuge decanter.

3.) Optimization of the Shaking Process .- Through the online determination of the total hydro-molecular fraction, at the entrance of the olive paste in the blender, and therefore the power to decide when and how much adjuvant to add, as well as the total control over the water to be added, together with the improvement of the batch feed system from continuous to discontinuous, plus the temperature control, it can be said that the conditions of the whipping process, comparing it with the current situation or mode of This work presents all the possible advantages, especially from the point of view of obtaining virgin oils of the highest quality.

4.) Precise control of the horizontal centrifugal decanter .- To date, the machinery and the process are being controlled through periodic visual controls carried out by the oil mill master, as there are no sensors that indicate how the machine is evolving or the separation process, having to be aware of several machines at once and having to wait for the results of the analysis that when it receives them, the situation has changed again. With the system object of the present invention, he knows that the machine will always be at its optimum working point, even by varying the characteristics of the olive, losses are minimized and machinery is better controlled.

5.) Greater depletion of the pomace. - The advantages and benefits are evident in view of the results obtained in the evaluation phases in real facilities. The horizontal centrifugal decanter is always working at its right optimum working point, because once it is preset, it is always controlled without the need to be aware of the state of the pomace.

6.) Maximum possible extraction with the highest quality. - Through the performance of the system object of the present invention, it is known that all the oil or oily fraction is leaving where it should and that, despite the control, goes with the pomace, can only be extracted either in a second extraction partially, or else everything can be extracted by chemical procedures.

7.) Higher performance of the horizontal centrifugal decanter .- With the new system object of the present invention, the horizontal centrifugal decanter will always be operating to the maximum of its technological-operational possibilities, not as now that it takes a regime normally below that the manufacturer advises, not taking into account at all times (real time) the changing conditions of the olive.

8.) Less need for dedication by the teacher .- It has already been indicated that the machinery is under control, at all times adapting to the raw material, so minimal interventions by the teacher are necessary, leaving it free for others technological surveillance functions of the entire mill and with less pressure.

9.) Better control of the oil cleaning process .- Comparing the benefits obtained with the present invention, with the current controls of this process, the differences are substantial, since it is passed from the classic periodic visual controls of the centrifuge separator vertical, to a system that by means of real-time knowledge of the index of oily purity of the processed oil allows to regulate the flows of oil and water, as well as to control the cleaning cycles of the machine.

10.) Reduction of polluting effluents. - The knowledge of the oil purity index, of the oils both at the exit of the horizontal centrifuge decanter and the final oil at the exit of the vertical centrifuge separator, thanks to the new microwave sensors and their permanent control, allows a substantial reduction of the needs of cleaning water with the consequent decrease of the polluting spills.

11.) Lower investment cost. - With the new system fully installed in an oil mill, the investment of installing revision machinery with all its accessories, and derived costs, can be perfectly avoided to remove a very small portion of the mechanically extractable oil, comparing with the reasonable cost of an automation so understood.

12.) Lower maintenance cost. - Not having to use delicate sensors, which need periodic calibrations, which have delicate moving parts, and shock descaling, etc. maintenance costs are reduced, as there is no need for specialized technical personnel.

Brief description of the figures

Figure 1: Description of functional block 1

Figure 2: Description of functional block 2

Figure 3: Description of functional block 3

Figure 4: Diagram of the architecture of the modular digital control processor

Figure 5: Results obtained in the block functional 1

Figure 6: Results obtained in the block Functional 2 at the entrance to the horizontal centrifugal separator

Figure 7: Results obtained in the block Functional 2 at the output of the horizontal centrifugal separator

Figure 8: Results obtained in the block functional 3

Embodiment of the invention

There have been experiences in various facilities, experimental and commercial, of elaboration of virgin olive oil In the experience carried out in the Experimental oil mill of the CSIC Fat Institute they used sensors based on microwave technology by Transmission of the supplied µ-ICC series by the company | My | tec.

These sensors allow excellent control of the products involved in the manufacturing process, in the own mainstream of the process, obtaining measurements fully representative of the total fraction hydro-molecular (free water plus nuclear moisture or embedded water), in the olive paste, and the new parameter, oil purity index of the oils, indispensable condition for its use in a control solution.

An adequate selection of the measurement points of the previous variables, to obtain the maximum authority and representativeness controlling the process of elaboration automatically, reducing the workload to that the teacher of the mill is normally subjected.

Total, comprehensive and coordinated control of everything the manufacturing process is carried out by means of a processor Modular digital control, designed to control and optimize by separated each of the three parts of the manufacturing process, (preparation, separation and cleaning), intervening in each of them, a certain number of sensors for the determination of complementary variables and at least one new technology sensor microwave by transmission. This digital modular processor of control can be adapted to control and optimize so the entire processing line is coordinated, or separately in each of the parts of the process, called Blocks Functional, described below:

to)

Preparation or thermo-beating phase (Functional Block-1) .- This phase is composed of the elements involved in the process from the mill with its feeding system, the pumping system of the crushed olive paste and the thermos -batidora with all its accessory equipment to the outlet duct of the pasta already prepared.

b)

Phase of separation by centrifugation (Functional Block-2) .- This phase is composed of the elements that make up the process, from the olive paste pump to the outlet of the thermo-blender and the machinery that integrates the horizontal centrifugal decanter to the cleaning screen at the oil outlet of said decanter.

C)

Final cleaning phase (Functional Block-3) .- This phase is composed of the elements that make up the process, from the centrifugal pump of the sifted oil, the machinery that integrates the vertical centrifuge separator with all its cleaning automatisms and accessory equipment , and the oil transfer pump to the cellar or pre-settling tanks.

Each of the three parts of the process corresponds to a Functional Block , which consists of at least one new microwave sensor per transmission, operating in a frequency range between 1 to 10 Ghz., A series of standard sensors for measurement of auxiliary or complementary variables, such as: flow rates, levels, temperatures and electrical power and a modular digital control processor (PMDC), with its periphery of inputs and outputs and its operator management interface.

This modular digital control processor (PMDC) is broken down in turn, by three I / O sub-modules of inputs and outputs (sub-module-1, sub-module-2 and sub-module-3) corresponding to each of the three Functional Blocks, to allow their progressive installation separately, offering each of they their own functionalities according to the needs operational of each of the three Functional Blocks, obtaining maximum benefits when implementing the digital modular control processor (PMDC) completely, see (Figure 4).

Three block diagrams are presented, with the architecture of each of the three Functional Blocks where you can see the location of the different microwave sensors and the sensors that correspond to the auxiliary variables or complementary, as well as the different performances of each of the three sub-modules of the processor Modular digital control (PMDC) complete.

Description of functional block 1 (Figure 1)

The elements are described below. sensors and actuators with their corresponding correlations, which together with the PMDC digital modular control processor and the sub-module-1 periphery of inputs and outputs (see Figure 4), make up the first part of the present invention (control system), which controls and optimizes all operations inherent in the process of preparing pasta.

This Functional Block-1, has of a key magnitude for the paste characterization of olive consisting of a new microwave sensor by transmission [4] located at the top of the thermo-mixer [7] immediately after paste drop, allowing to know the value of the total fraction hydro-molecular paste, and depending on it, the control system decides the precise moment of adding the adequate amount of water by means of the flow sensor [13] and the modulator [3]. This action is combined by a special algorithm. with the power absorbed by the drive of the thermo-mixer [7] through the sensor [6], and with the  volumetric processing regime of olive paste by means of the sensor [10] and in coordination with the fraction sensor total hydro-molecular olive paste to the thermo-mixer output by means of the sensor [14], to ensure processing conditions for the Next phase of separation.

In the same way, and from the information of the total hydro-molecular fraction by sensor [4], and the volumetric flow of pulp processing of olive by means of the sensor [10], the control system, decides the precise moment of adding the right amount of adjuvants (either microtalc or enzymes) by means of dispenser [12].

To guarantee processing conditions stable and continuously, the control system, by means of level sensor [11], acts well on the power system from the hammer mill [1] or on the olive paste pump [2], which conducts the paste from the tank [15] to the thermo-mixer [7], to maintain a stable flow of pasta to it getting a continuous feed, improving conditions for process optimization. This action is combined by a special algorithm with the flow of volumetric processing of olive paste by means of the sensor of flow [10], pumped by means of the volumetric pump [8].

From the operating parameters, that the master proposes, the control system, by means of the sensor temperature [9], acts on the heat input system [5] to maintain the temperature of the paste at the exit of the thermo-mixer [7] in order to maintain the process temperature, below the levels required in function of quality and production requirements. This action is combines by means of a special algorithm with the filling level of the thermo-mixer [7] in order to improve the System dynamics

Description of functional block 2 (Figure 2)

The elements are described below. sensors and actuators with their corresponding correlations that, together with the digital modular control processor or system of control and the (sub-module-2) of periphery of inputs and outputs (see Figure 4), make up the phase solid-liquid separation process, which controls and optimizes the centrifugation process of the paste olive.

This functional block-2, has of two key quantities based on online determination and the mainstream of the process, of the total fraction hydro-molecular olive paste to the input to the horizontal centrifugal decanter and purity index oil of the processed oil, by means of microwave sensors by transmission, operating at frequencies between 1 to 10 Ghz., Which allow a greater knowledge of the nature of fluids involved in the manufacturing process.

From this consideration, the system of control, together with the operating parameters entered by the teacher, determine the total fraction hydro-molecular olive paste more convenient at all times at the entrance to the centrifuge decanter horizontal, by means of the sensor [11] installed in the pipe Main input, deciding if necessary, when to add water and the precise amount to be added, using the sensor flow [3] and modulator [2]. This action is performed in a way coordinated from the elaboration regime, which is also controlled by the control system, by means of the flow sensor [10] and the speed variation system of the pump pasta feed [1], in order to keep the more convenient working conditions at all times, with Independence of the changing characteristics of the olive.

These two magnitudes, processing regime or paste flow and the total hydro-molecular fraction, are permanently calculated and controlled by the system of control, depending on the state of the rings inside the horizontal centrifugal decanter [5].

To do this, the control system and from the second key magnitude, which indicates the oil purity index of the outgoing oil [7] through the evacuation ducts, through of the sensor [8] and a specific control algorithm, modifies from convenient way both the total fraction hydro-molecular as the processing regime more adequate, as well as the priority action or modulation on the external diaphragm adjustment device [12], if the machine It has such an adjustment. All in order to keep the rings at its just optimal point of work, regardless of changing characteristics of the olive.

In this way, maintaining the purity index Oily, always controlled and within appropriate parameters and precise, it is not necessary to be measuring or monitoring permanent oil loss level at the outlet of the duct of the pomace [6], because with this work system, you have the assurance that all extractable oil by centrifugation, out through the oil outlet ducts and not with the marc

In each processing regime and condition of Work, the control system, sets the differential speed of the horizontal centrifugal decanter, more convenient, by means of the differential speed sensor [13] acting on the system of variation [9], and taking into account the specific load of the decanter by means of the sensor [4], in order to achieve maximum oil extraction, by centrifugation, independently of the processing regime.

Description of functional block 3 (Figure 3)

The elements are described below. sensors and actuators with their corresponding correlations, which together with the digital modular control processor or system of control and the (sub-module-3) of periphery of inputs and outputs (see Figure 4), make up the phase for cleaning the oil produced in the previous phase of centrifugation, which controls and optimizes the purification process of the oil in the vertical centrifuge separator.

This Functional Block-3, has of a key magnitude based on online determination and mainstream of the process, of the oil purity index of the final oil as it is leaving the centrifuge separator vertical, by means of a microwave sensor by transmission, operating at frequencies between 1 to 10 Ghz., which It allows a better knowledge of the oil conditions.

In order to guarantee a regime of oil feed to the vertical centrifuge separator [11], the control system from the final oil flow sensor produced [10] and pumped by the pump [9] from the tank [8], stabilizes the flow of incoming oil to the separator, by means of the transfer pump regulating device [2] which transports the oil from the sifted oil tank to the separator  vertical centrifuge [11].

From the oil purity index of the oil final determined by the sensor [6], the control system, together with the operating parameters introduced by the teacher, first determine the fair amount of water to add, using the flow sensor [4] and the modulator [3] and secondly it establishes the orders to the cleaning system of the vertical centrifuge separator [11] and notifies the operator of irregularities in its operation.

In this way, and considering a better and more stable cleaning of the oils resulting from the process of solid-liquid centrifugal separation of the phase previous and a total and continuous control over the final oil by means of the oil purity index, less amount of washing water, and greater efficiency in the use of machinery at optimization time of the discharges of both the wash water as of the purges of solids.

The control system, starting from the temperature of the oil at the outlet of the vibrotamiz [1] and from the sensor of temperature [12], sets the most appropriate water temperature of cleaning by means of the water temperature sensor [15] and the heat modulator [14], keeping the water temperature at a value not less than 35 ° C and not more than the safety value that Estimate the teacher.

Description of the control system (Figure 4)

The blocks are described below. functional features of the digital modular control processor or control system, which is composed of the unit of interface with the operator [1] and the communications module [7].

The central processing unit [2] or module main is where calculations, correlations and control algorithms, for each of the Functional Blocks [5], based on the operating parameters stored in the storage block [6].

The control system, in turn has three sub-modules of inputs and outputs [4] where locate the elements of conversion, and adaptation of signals; every one of them, is designed and sized for the management of each one of the three areas of the process, separately or independent, so that they can be implemented in a way gradual or complete

Results obtained with the new sensors Function Block 1

The results are shown in Figure 5 derived from the operation of the sensor used for the analysis in continuous of the total hydro-molecular fraction of the pasta in the blender, for different varieties and qualities of olive (arbequina, chamomile, picual, hojiblanca, etc. ...) in various process conditions (grinding grade, temperature of milkshake, etc ...).

The results obtained for the 526 samples, indicate the existence of a clear correlation (R2 = 91.84 and Standard Error = 1.44) between the online measurements performed by the sensor and laboratory values, being, by therefore, a valid sensor for the online analysis of the total hydro-molecular fraction in the paste of olive in blender and can be used in the control system for the characterization of the mass.

Function block 2. Horizontal centrifugal separator input

The results are shown in Figure 6 derived from the operation of the pipe sensor, used to the analysis of the total hydro-molecular fraction in Continuous olive paste injected into the centrifugal separator horizontal for the different varieties (arbequina, chamomile, picual, hojiblanca, etc. ..) in various process conditions (degree of grinding, shake temperature, etc. ...).

The results obtained for 1,387 samples, indicate the existence of a clear correlation (R2 = 99.13 and Standard Error = 0.726) between measurements online made by the sensor and the values of laboratory, therefore, being the fully valid sensor for the online analysis of the total fraction hydro-molecular olive paste that is injected into the horizontal centrifugal separator and can be used in the  control system for good process regulation.

Function block 2. Horizontal centrifugal separator output

The results are shown in Figure 7 derived from the operation of the sensor used for the analysis online of the oil purity index of the oil at horizontal centrifugal separator output for different olive varieties and in various process conditions.

The results obtained for the 420 samples of oil, indicate the existence of a clear correlation (R2 = 99.01 and Standard Error = 0.27) between measurements online made by the sensor and the values of laboratory, validating in this way for analysis online of the oil purity index of the oil at horizontal centrifugal separator output, being able therefore be approved for process control for your safety Operation and efficiency

Function block 3. Vertical centrifugal separator output

The results are shown in Figure 8 derived from the operation of the pipe sensor used to the continuous analysis of the oil purity index of the oil at vertical centrifuge output.

These results come from the measurements contributed by the sensors with different varieties (arbequina, chamomile, picual, hojiblanca, ...) and olive qualities, in Various process conditions.

The results obtained for the 218 samples of oil, indicate the existence of a clear correlation (R2 = 98.21 and Standard Error = 0.056) between measurements online made by the sensor and the values of laboratory, this being valid for analysis online of the oil purity index at the exit of the vertical centrifuge.

Claims (10)

1. Coordinated control system for continuous extraction lines of virgin olive oil, based on the continuous evaluation, at any point of the line, of the total hydro-molecular fraction, and characterized in that said evaluation is carried out, by means of sensors of electromagnetic fields in the microwave band. 2. Coordinated control system for continuous extraction lines of virgin olive oils according to claim 1, characterized in that the sensors are of the type of wave transmission, working in a frequency range between (1 to 10 Ghz.). 3. Coordinated control system for continuous extraction lines of virgin olive oils, according to claims 1 and 2, characterized in that the sensors are located in at least one of the following points of the extraction line:

to)

In the blender, particularly in the upper body at the entrance of the olive paste

b)

At outlet duct of the volumetric pump, which conducts the paste of olive towards the horizontal centrifugal decanter.

C)

At Outlet of centrifugal decanter oil horizontal.

d)

At oil outlet duct of centrifugal separator vertical.

4. Coordinated control system for continuous extraction lines of virgin olive oil, according to claims 1 to 3, characterized in that the extraction line on which the sensors are located is virgin olive oil of first centrifugation. 5. Coordinated control system for continuous extraction lines of virgin olive oil, according to claims 1 to 3, characterized in that the extraction line in which the sensors are located is virgin olive oil of second centrifugation. 6. Coordinated control system for continuous extraction lines of virgin olive oil, according to claims 1 to 5, characterized in that the system additionally includes auxiliary flow, temperature, level and electrical power meters. 7. Coordinated control system for continuous extraction lines of virgin olive oil, according to claims 1 to 6, characterized in that the auxiliary sensors and meters transmit the information to at least one modular digital control processor. 8. Coordinated control system for continuous extraction lines of virgin olive oil, according to claim 7, characterized in that the digital modular control processor performs the following control and regulation actions in the mixer; continuous feeding of the olive paste, dosing of microtalco and / or enzymes, addition of water and temperature control of the olive paste. 9. Coordinated control system for continuous extraction lines of virgin olive oil, according to claim 7, characterized in that the digital modular control processor performs the following control and regulation actions in the horizontal centrifugal decanter: feeding regime in continuous paste of whipped olive paste, final addition of water, variation of the differential speed, action on the diaphragms and regulation of cleaning periods. 10. Coordinated control system for continuous extraction lines of virgin olive oil, according to claim 7, characterized in that the digital modular control processor performs the following control and regulation actions, in the vertical centrifugal separator: feeding regime in oil continuous from the horizontal centrifugal decanter, rate of addition of wash water, temperature control of the wash water and regulation of cleaning periods.