EP1260571A2 - Process and plant for oil extraction from fruits and seeds - Google Patents

Abstract

Process to extract oil from a fruit e.g. olives or avocado pears, comprises crushing the fruit and either simultaneously or subsequently subjecting it to high pressure and then relaxed. The crushed and relaxed fluid is then processed in a full- mantle screw centrifuge. An Independent claims is also included for a commensurate assembly incorporating a crushing extruder (12) which subjects the crushed fruit to high pressure (7) with a pressure zone (7a) and a relaxation valve (7b) feeding the screw centrifuge (11). The high- pressure zone (7) crushes the fruit and incorporates a homogenisator. The centrifuge separates the crushed fruit into an first phase containing oil and a second 'Orujo' phase containing a mixture of solids and water.

Description

The invention relates to a method for extracting oil from fruits or seeds, preferably olives or avocados, with a solid-bowl screw centrifuge and a plant for oil production according to the preamble of claim 29.

A generic method and a generic system, which are at have proven particularly useful in olive oil production are known from EP 0 557 758. This process involves a two-phase separation in a solid bowl screw centrifuge performed in which the oil as the one phase directly from a solid / water mixture is separated as the second phase.

The olives are preprocessed after washing by chopping in a grinder, which the olives without the addition of water or at the Use of dried olives under a water additive, which the Restores the fresh water content of fresh olives, turns them into fruit pulp, which is disrupted in a Malaxeur downstream of the mill. This Digestion in the malaxeur is used to release the oil and then in the Malaxeur downstream solid bowl screw centrifuge in the oil components as well as being able to separate solid and water.

The efficiency of this known method is in itself very good. Still is it is desirable to provide alternative solutions to preprocessing the pulp to create entry into the solid bowl screw centrifuge and in particular to reduce the expenditure on equipment, the quality of the oil being as good as possible Should be compared to the operated apparatus structure. The solution to this problem in procedural terms as well as in terms of the plant for Olive oil production is the object of the invention.

The invention solves this problem on the one hand by a method for oil production, which is specified in feature 1. It also solves it through an oil production facility, whose features are specified in claim 29.

With the invention, the fruits or seeds are crushed and during or after subjected to high pressure crushing and subsequent relaxation, whereupon the chopped fruit pulp of the solid bowl screw centrifuge is fed.

The invention also provides a plant for extracting oil from fruit or seeds, preferably olives or avocados, with a chopper the fruits or seeds into a pulp, preferably a mill or a Extruder, one of the devices for comminuting - e.g. when using one Extruder - or downstream high pressure section to unlock the Fruit pulp, and a solid bowl screw centrifuge downstream of the high pressure section, preferably provided with a plunger for separation of the pulp in different phases, preferably in oil as the first phase and in a solid / water mixture as the second phase.

In the method according to the invention and in the system according to the invention each time the malaxeur necessary to unlock the pulp becomes replaced by the fruit pulp during or preferably after chopping is exposed to the high pressure and the subsequent relaxation. For example, it is conceivable to directly use an extruder for shredding and the Extruder prevailing pressure and a subsequent relaxation to unlock the fruit or seeds. Alternatively, crushing in one Mill conceivable, either in the mill or preferably after passing through the mill will go through the high pressure section.

A particular advantage of the invention is that preprocessing of the pulp when replacing the malaxer with a high pressure path relative can be done quickly. It has been found, for example, that there is a dwell time of just 6 minutes in the high-pressure section can suffice to achieve the Unlock olives enough to use in a solid bowl screw centrifuge to be able to process further. The quality of the oil is the same as in the processing comparable or even better with a quality that can be achieved with a malax. In addition to olives, avocados in particular are particularly good with the invention Processable.

To implement the high pressure line with a high pressure zone and the relief valve Various possibilities are available to the expert.

For example, the high-pressure section can be a pipe - with an upstream one designed accordingly Pumping device - which has a length of more than 10, preferably has a length of 10 to 30 meters.

It is for easier processing or for easier opening of the pulp also conceivable that the fruit pulp before entering the high pressure line and / or when passing through the high pressure section - heated by means of a heating device becomes. When processing olives, the fruit pulp is preferred to max. Heated to 40 ° C and when processing avocados to more than 40 ° C, especially 40 ° - 80 ° C.

The residence time of the fruit pulp in the high-pressure section is preferably 2 to 12, especially 4 to 8 minutes.

It has also proven to be advantageous if the pressure in the high-pressure section more than 10 bar, preferably more than 30 bar, in particular more than 50 bar. A pressure between 50 and 80 is very particularly preferred even more specifically chosen between 60 and 70 bar. So when using a relatively high pressure, the dwell time in the high-pressure section can be reduced to 6 min be lowered.

Before entering the high-pressure line, the fruits or seeds are preferred first washed and then crushed, preferably in a mill, in particular in a hammer mill.

It is conceivable that the pulp directly after chopping and / or from the first buffer tank via at least one pump in the high pressure line becomes.

The fruit pulp is preferably brought out of the high-pressure section with the help of a relief valve relaxed and then directly and / or after further relaxation fed to the solid bowl screw centrifuge in a further buffer tank becomes.

Finally, it is conceivable to process the pulp in a hermetic manner System, if necessary with the supply of an inert gas.

In summary, it can be said that with the replacement of the malaxer with a High pressure path created an alternative to preprocessing in a malaxeur which is the expenditure on equipment and in particular the processing time from the unwashed olive to the production of the oil. So is For example, it is possible to make a ready-made olive or avocado in just 30 minutes To produce oil. If necessary, this can be done from the solid bowl screw centrifuge escaping oil in a clarifier - if necessary with the addition of a few percent by weight in water - to be cleaned.

Further advantageous embodiments can be found in the remaining subclaims.

Exemplary embodiments are explained below with reference to the drawing.

It shows:

Figure 1

a flow diagram of a method for olive oil production,

Figure 2

2 shows a flow diagram of a second method for extracting olive oil,

Figure 3

3 shows a flow diagram of a third method for extracting olive oil, and

Figure 4

a table which test results of the oil production with the reproduces method according to the invention.

According to Figure 1, the washed olives are first a mill 1 (e.g. hammer mill) fed. No water is added to the olives, provided they are fresh Olives are processed. Only when processing dried olives So much water is added to the olives that the natural water content is fresher Olive is restored.

The olives are then transferred from the mill 1, preferably with a pump 2 a pipe 3 is fed to a first buffer tank 4. The first buffer tank 4 relieved the stable operation of the system. Alternatively, it is also conceivable that Buffer tank 4 and the fruit pulp produced in the mill directly above one or more pumps (feed pump 5, this downstream piston pump 6) to be fed to a high-pressure section 7. The high pressure section 7 comprises the pressure zone 7a and the expansion valve 7b. The pressure zone 7a can be, for example, as be designed as a simple pipeline or as another homogenizer.

The high pressure section 7 is to be designed such that in the pressure zone 7a and by means of the subsequent relaxation with an expansion valve 7b is sufficient The pulp is unlocked or the oil is released. This is preferred in the high pressure section 7 generates a pressure of more than 50 bar and the High-pressure section 7 or the delivery rate is designed such that the dwell time the fruit pulp in the high pressure section preferably 2 to 12, in particular Is 4 to 8 minutes. Particularly good results were obtained from one Lingering of the pulp in the high pressure section reached at 6 minutes.

It is particularly advantageous if the fruit pulp - e.g. in the buffer tank 4 - by means of a heating device, not shown here, is heated. The temperature of the Fruit pulp should, however, not exceed 40 ° C (production of a high quality Olive oil). The fruit pulp is preferably heated to 30 ° C in the buffer tank. It is also conceivable to heat directly when passing through the high-pressure section. When processing other products such as avocados, there is also a warming to more than 40 ° C - especially 40 - 80 ° C) conceivable.

From the high-pressure section 7, the fruit pulp is either directly or, for example via a further, preferably heatable buffer tank 8 and / or a feed pump 9 the inlet 10 of a solid bowl screw centrifuge (in the Drawing briefly "VS centrifuge") 11 supplied.

According to a particularly advantageous variant of the invention, it is set in such a way that that in the solid bowl screw centrifuge directly a separation of the digested Fruit pulp in a first phase of oil (cloudy oil) and in a second phase Orujo (water-solid mixture) takes place. However, three-phase processing is also conceivable with the addition of water.

2 reduces the method to just a few steps. After crushing in the Mill 1 and the passage of the pump 2 takes place directly in the out of the pressure zone 7a and the expansion valve 7b existing high-pressure section 7 unlocking of the olives before they enter the solid-bowl screw centrifuge 11, which separates the entering pulp into oil and orojo (water / solid mixture).

3, the pulp is crushed by means of an extruder 12, in which there is an increased pressure in relation to the environment, so that the Extruder 12 itself forms the high pressure section 7. The extruder 12 is the open pulp then directly or via one or more buffers 4 and / or a feed pump 5 is passed into the solid bowl screw centrifuge.

The test table of Fig. 4 illustrates that it is with the inventive Process is readily possible to produce an olive oil, in particular It should be borne in mind that the expenditure on equipment compared to the use of a malaxer is significantly reduced. As you can see, it decreases with increasing Temperature of the residual oil content in the Orujo. The experiments for Fig. 4 were carried out with a Structure carried out that corresponds to that of FIG. 1

reference numeral

1

hammer mill

2

pump

3

pipeline

4

buffer tank

5

feed pump

6

piston pump

7

pressure range

7a

pressure zone

7b

expansion valve

8th

buffer tank

9

feed pump

10

Intake

11

Solid bowl centrifuge Sehn corner

12

extruder

Claims (30)

Process for extracting oil from fruits or seeds, preferably olives or avocados, with a solid-bowl screw centrifuge, characterized in that the fruits or seeds are crushed and are subjected to high pressure and subsequent relaxation during or after the crushing, whereupon the crushed fruit pulp of the solid-skin Screw centrifuge is fed. A method according to claim 1, characterized in that an extruder (12) is used for crushing so that the fruits or seeds are subjected to the pressure prevailing in the extruder (12) during crushing. Method according to claim 1 or 2, characterized in that the chopped fruit pulp from the fruits or seeds is fed to a full-bowl screw centrifuge via a high-pressure section (7) with a pressure zone (7a) and a relief valve (7b). A method according to claim 3, characterized in that the high pressure section (7) has a homogenizer. Method according to one of the preceding claims, characterized in that the high-pressure section (7) is designed to disrupt the pulp. Method according to one of the preceding claims, characterized in that the chopped fruit pulp is separated in the solid-bowl screw centrifuge (11) in a two-phase separation process in oil as the first phase and in a solid / water mixture - orojo - as the second phase. Method according to one of the preceding claims, characterized in that the pressure zone (7a) has a tube. Method according to one of the preceding claims, characterized in that the pressure zone (7a) has a length of more than 10m. Method according to one of the preceding claims, characterized in that the pressure zone (7a) has a length of 10 to 30 m. Method according to one of the preceding claims, characterized in that the fruit pulp is heated before entering the solid bowl screw centrifuge. Method according to one of the preceding claims, characterized in that the fruit pulp when processing olives to a max. 40 ° C is heated. Method according to one of the preceding claims, characterized in that the fruit pulp is heated to more than 40 ° C when processing avocados. Method according to one of the preceding claims, characterized in that the fruit pulp is heated to 40 ° C to 80 ° C when processing avocados. Method according to one of the preceding claims, characterized in that the residence time of the fruit pulp in the high-pressure section (7) is at least two minutes. Method according to one of the preceding claims, characterized in that the residence time of the fruit pulp in the high-pressure section (7) is 2-12 min. Method according to one of the preceding claims, characterized in that the residence time of the fruit pulp in the high-pressure section (7) is 4-8 minutes. Method according to one of the preceding claims, characterized in that the pressure in the high-pressure section (7) is more than 10 bar. Method according to one of the preceding claims, characterized in that the pressure in the high-pressure section (7) is more than 30 bar. Method according to one of the preceding claims, characterized in that the pressure in the high-pressure section (7) is more than 50 bar. Method according to one of the preceding claims, characterized in that the pressure in the high-pressure section (7) is 50 to 80 bar. Method according to one of the preceding claims, characterized in that the pressure in the high-pressure section (7) is 60 to 70 bar. Method according to one of the preceding claims, characterized in that the fruits or seeds are first washed and then crushed. Method according to one of the preceding claims, characterized in that the crushing of the fruits or seeds into a pulp takes place in a mill (1). Method according to one of the preceding claims, characterized in that the fruit pulp is fed into a buffer tank (4) directly after the chopping or directly via a pump (2) and / or a pipeline. Method according to one of the preceding claims, characterized in that the fruit pulp, after the chopping, is passed directly and / or out of the first buffer tank (4) via at least one pump (5, 6) into the high-pressure section. Method according to one of the preceding claims, characterized in that the fruit pulp is expanded from the high-pressure section (7) with the aid of an expansion valve and then is fed directly and / or after further expansion in a further buffer tank to the solid bowl screw centrifuge (11). Method according to one of the preceding claims, characterized in that the processing of the fruit pulp takes place in a hermetic system. Method according to one of the preceding claims, characterized in that the processing of the fruit pulp takes place in a hermetic system with the supply of an inert gas. Plant for extracting oil from fruits or seeds, preferably olives or avocados, with: A) a device (1) for chopping the fruits or seeds into a fruit pulp, preferably a mill or an extruder (12), B) a high-pressure section (7) associated with the device for chopping or downstream for opening the pulp, and C) one of the high-pressure section (7) downstream solid bowl screw centrifuge (11), preferably provided with a plunger, for separating the pulp into different phases, preferably in oil as the first phase and in a solid / water mixture as the second phase. System according to claim 29, characterized in that the high-pressure section (7) has a pressure zone (7a) and an expansion valve (7b).

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