Untitled record

The present invention relates to an apparatus and a method for the production of defatted proteins and, more particularly, to a device for the continuous extraction of fats and oils contained in organic materials, such as fish and aquatic animals, using one or more organic solvents.

As is well known, it is of the utmost importance, when extracting con fats held in organic matter, that almost all of these fats are eliminated due to the fact that the phospholipids that they contain give an unpleasant characteristic odor and taste to the product obtained, if any remains in it. Solvent extraction is also an important condition

J with a view to obtaining an acceptable final product, this due to the fact that an ill-suited treatment during this extraction reduces the protein yield and can leave a residue of solvent. Even traces of solvent, although not toxic by themselves, f₆ often give the product an unpleasant taste.

Several different types of apparatus for the continuous extraction of fats contained in organic matter have been proposed. In such a known device, the material is introduced into the upper end ff of an extractor in the form of a slightly inclined tube and is driven downward through this juque extractor in a second extractor which is arranged at acute angle to the first. The material is then brought upwards into the second extractor while the solvent is pumped into it and is forced to go back through the two extractors. The manner is then introduced into a horizontal dryer in which the water and the solvent are evaporated before complete extraction if of the solvent in a horizontal counter-current evaporator comprising an open drive screw.

In a second device known for extraction - continuous against the current of the oil contained in fish and fish waste, these fish or fish waste are first boiled in two boilers

J o tubular screw type arranged horizontally to evaporate the water contained in the material subjected to extraction, after which it is saturated with a solvent before being introduced into the lower part of an extractor slightly inclined screw type counter current, in which the extraction takes place. The extraction can be either of the dipping type or of the impregnation type depending on the level of the solvent contained in the extractor. The material is then entrained in a series of driers in which this material is exposed to heat in order to extract the solvent and dry it.

These two devices have several drawbacks. They are both intended to be used with heavy halogenated hydrocarbons such as trichlorethylene and perchlorethylene. It has been found that such solvents do not adequately dissolve the phospholipids and are toxic. In addition, the angle of inclination of the extractors is small, in l₀ both cases, hence an elongated ramp reducing the extraction of the product. Both devices are also equipped with a type of evaporation and drying devices involving a long journey of the material to be transported along the hot surfaces, making

2 ^ thus run the risk of protein destruction. In addition, none of these devices is provided with a device for the primary evaporation of the solvent. The first of the devices described does not have a device forcing the solvent to move towards the center of the

2 # drive screw, which causes this solvent to flow along the surface of the extractor. The most important drawback of the second device is that the drive screw is eccentrically supported and is arranged in such a way that a gap is formed between this screw and the surface of the extractor facing upwards. , where it follows that the solvent finds its way into this gap and that the extraction power is thus reduced. In addition, evaporation in tubular boilers poses the risk of protein destruction.

In a third known device, the extraction is carried out in a counter-current, in which the material is shaken to fall through a vertical rectangular extractor, and is then driven upward (4 upwards by means of a bucket pump in passing through an inclined rectangular drum.

In the third device described, there is the disadvantage that the solvent can not pass through the material present in the inclined drum, but hole2_e ve its way along the top side of the drum.

In the extractor arranged vertically the solvent also finds its way along the sides of the extractor, because there is no device forcing this solvent to pass through the material. In addition, the extraction

K cannot be carried out without other problems arising from the fact that the materials and solvents used have only a slight difference in density, and that the organic matter is forced to move down during shaking, while that the solvent is constrained

J at the same time to move up

Consequently, one of the objects of the invention is the production of a continuous running apparatus which performs an almost complete degreasing of an organic matter containing fat, and a complete elimination of the solvent used for the extraction, so that one obtains a final product suitable for use in food and free from fats and oils, unpleasant tastes and odors.

It is possible to eliminate the drawbacks! T> of the devices described above and to achieve the objects of the invention by means of the device or of the following process. The material is subjected to a first extraction in at least one pre-extractor arranged vertically and provided with a stirring device, the said / Z pre-extractor being connected to a counter-current extractor equipped with a screw d drive, which may have openings in the blades and drive rods, if desired. The counter-current extractor is connected to separation and evaporation devices in order to extract the solvent. Such devices include one or more centrifuges and one or more counter-current or simple evaporators.

According to a preferred embodiment of the invention, several pre-extractors, preferably two, are linked together in series and used for a first extraction.

The process proposed by the invention can be implemented in continuous service, and comprises the supply of organic matter and a solvent for the fat to at least one pre-extractor arranged vertically and

I provided with an agitator device. The material subjected to a first extraction is transferred to an inclined counter-current extractor by means of a centrifuge if desired. The practically pure solvent is continuously added against the current in the counter-current extractor, and is forced to move from this extractor into the pre-extraction containers. The fat-rich solvent continuously extracted from organic matter is replaced by fresh solvent. The material flows from the countercurrent extractor into one or more centrifuges and one or more countercurrent evaporators which effectively remove the remaining solvent from the organic product.

The invention will be described in relation to several preferred embodiments of extraction apparatus, ffa with reference to the appended drawings, in which:

Fig. 1 shows a first extraction device.

Fig. 2 shows a turn of the blade of the drive screw arranged in the counter-current extractor of FIG. 1, which is provided with passage openings.

Fig. 3 shows a modified embodiment of the device which is the subject of FIG. 1; and

Fig. 4 shows a second particular embodiment of the device.

Figure 1 shows a cylindrical pre-extractor 10 having a conical lower part and arranged vertically. The upper part of the pre-extractor 10 is provided with a supply circuit 11, capable of being moved vertically, through which the material containing grease can be introduced into this pre-extractor 10. An agitator device 12, having radially directed fins or blades 13, 14 is "

f arranged in the lower part of the pre-extractor 10.

The pallets 13 arranged in the conical part are constituted by horizontal blades whose planar surfaces are inclined relative to the vertical, and the pallets arranged in the cylindrical part have the / ô planar part of their blades 14 arranged vertically.

The upper part of the pre-extractor 10 is connected to a condenser 15 from which the condensed solvent is again supplied to this pre-extractor 10.

The pre-extractor 10 is provided, at different levels, with discharge pipes 16 for the extraction of the organic solvent loaded with grease.

The bottom of the pre-extractor 10 is connected to the lower part of an extractor 17 with an inclined counter-current in the form of a tube provided with an outer casing, "higher". The extractor 17 against the current is fitted with a drive screw 18 which conveys the material into a transparent monitoring chamber 1-9. The extractor 17 inclined against the current, which is arranged at 45 preferably comprises conduits 20, 21 arranged in groups at different levels for the introduction of the solvent.

FIG. 2 shows a pallet 22 of the drive screw 18 arranged in the extractor 17 against the current, this pallet comprising a number of openings 23 which, in the lower part of the drive screw, are arranged in four concentric circles. As the circles move away from the central shaft of the drive screw 18, the number of openings 23 of each circle increases while the diameter of the openings decreases, that is to say say, for example, that the number of openings per circle goes from 6 to 12, then to 24 and to 36, while the diameter of these openings 23 goes from 8 to 6, then to 4 and 3 mm, respectively. In the upper part of the drive screw 18, there are only six openings 24 of 8 nm in diameter arranged in a single inner circle.

FIG. 1 shows the monitoring chamber 19 equipped with a slurry pump 25, connected to a worm screw centrifuge 26. The worm centrifuge 26 is provided with a line 27 which is connected to the lower group of lines 2 'for the introduction of the solvent into the extractor 17 against the current.

The centrifuge 26 is connected to the upper part of an inclined counter-current evaporator 28, equipped with a drive screw 29 and which is preferably presented at an angle of 30 ° relative to the horizontal plane. The drive screw 29 has, preferably, gaps 30 between turns so as to form the pallets 31 of this screw. The upper part of the countercurrent evaporator 28 is connected to a capacitor 32 collecting the vaporized mixture of solvent and water which has been formed in the countercurrent evaporator 28. The product which has been freed of solvent and grease in the evaporator 28 against the current, is introduced into a container 33 via a line 3-4 connected to the lower end of this evaporator 28. The pipe / is connected to a steam pipe F 35.

The process for extracting fats from organic materials implements the apparatus according to the invention in the following manner. When the pre-extractor 10 and the counter-extractor 17, which are connected to each other, have been filled with pure solvent up to any of the outlet conduits 16, the countercurrent extractor 17 is continuously supplied with solvent via the conduits 20, 21, at the same time as the organic material containing the grease is introduced into the pre-extractor 10 via the supply conduit 11, which is arranged vertically so that its lower part opens out below the surface of the solvent so as to facilitate sedimentation in

2 »the pre-extractor 10. The organic matter in suspension in the solvent slowly falls to the bottom of the pre-extractor 10 which is heated to the appropriate temperature, ie 70 to 80 ° C. Slow rotation of the paddles 13, 14 prevents channels from being formed in the slurry

2J * by the solvent rising through the conduit from the lower part of the extractor 17, at countercurrent. The solvent introduced into the extractor 17 against the current through the upper group of conduits 20 is pure solvent, the low-fat solvent being introduced via the group of lower conduits.

The inclined pallets IL, arranged in the conical part of the pre-extractor 10, press the slurry down towards the lower part of the extractor 17 against the current. The slurry f is transferred, by the screw 18 drive, through the extractor 17 against the current heated to the operating temperature of 70 to 80 ° C. This training can, of course, be obtained in another suitable manner.

/ 0 In the pre-extractor 10, a countercurrent extraction of the organic material containing the fat which is introduced continuously takes place as the solvent rises from the extractor 17 against the current and flows upwards inside the pre-extractor 10. The fat-rich solvent obtained by extraction is withdrawn via any one of the discharge conduits 16. When the organic matter with its content of solvent loaded with grease has been introduced into the exto tractor 17 against the current, the solvent loaded with grease is first replaced, preferably, by solvent poor in grease coming from the conduits. lower 21, and then, at the upper part of the extractor 17 against the current, with pres2 solvent (pure stink coming from the upper duct 20.

The pure solvent and the low-fat solvent which are introduced into the extractor 17 against the current via the conduits 20, 21 flow downwards from this extractor 17, due to the inclination

J "of it and of the preset difference between the liquid levels in the pre-extractor 10 and in the extractor 17 against the current. The solvent flows through the organic material, forced to move upward through the extractor 17 against the current * by the screw 18 drive.

By means of the openings 23 in the drive screw 18, a stream of solvent is directed radially towards the center of the screw 18 and ensures effective washing of the organic material.

tt> The fat-free material is then introduced, via the monitoring chamber 19, into the worm centrifuge 26 in which most of the solvent is extracted from this material. The remaining solvent is entrained by means of steam in the succeeding counter-current evaporator 28. The mixture of solvent and vapor is led to the condenser 32. Due to the presence of the intervals 30 in the drive screw 29, the organic material is perfectly mixed during the rotation of the screw, so that the contact between the vapor and the organic material is as large as possible.

The solvent stripped material is continuously fed from the evaporator 28 against the current to the container 33, after which it is transported to a device / device, not shown, for drying in a known manner.

The fat-rich solvent, drawn from the pre-extractor, is distilled in a device not shown, from which the distilled solvent is introduced into the extractor 17 against the current via the upper group of conduits20. The solvent separated in the worm centrifuge 26 and in the condenser 32 is recirculated, without prior purification, by being directed to the extractor 17 against the current via the / lower group of conduits 21.

If the raw organic material includes fishmeal, it is preferable to add one part of water to two parts of fishmeal so that the extraction is carried out under optimum conditions.

In the apparatus shown in FIG. 3, the connection between the lower part of the pre-extractor 40 and the lower part of the counter-extractor 4l is effected by means of a supply line 42 provided with 'A pump 43. The solvent is transferred from the extractor 41 against the current to the pre-extractor 4o via a line 44. For the rest, the device shown in Figure 3 corresponds to that making l object of figure 1 or the

I / figure 4 as follows.

In the apparatus shown in FIG. 4, a second pre-extractor 51 equipped with an agitator device 52 was connected in series after the first pre-extractor 50. A centrifuge 53 was added between

2 / the pre-extractor 51 and the extractor 54 against the current. According to this illustration, the solvent, the water and the raw material are mixed in the pre-extractor 50, and the main extraction is then carried out in the second pre-extractor 51. In order to maintain the solvent

I, in contact with the material for long periods of time, the agitator device 52 occurring in the. 13 pre-extractor 51 is provided with pallets 55 over its entire length, these pallets being spaced from one another and extending practically perpendicular to the shaft of this agitator device 52. The pallets / * tes 55 cause, in their respective horizontal plane, the necessary contact between the solvent and the material.

According to a modification made to the countercurrent extractor represented in FIGS. 1/0 and 5, the countercurrent extractor 54 shown in FIG. 4 works in reverse in the sense that the mass coming from pre extraction and centrifugation is introduced into the upper part of the extractor 54 against the current, and the solvent is introduced f / into the lower part of this extractor 54 against the current via a conduit 56. The solvent is evacuated from the upper part of the extraction 54 against the current by a pipe 57 which brings it to the pre-extractor 50. In order to prevent the

2 · mass slides downward along the inclined interior wall of the extractor 54 against the current, the drive screw 58 has been provided with coaches 59 which are arranged between the pallets of this screw 58, at a certain distance from his tree and practically

2 ^ parallel to this one. As a result of the arrangement of the coaches 59, the mass is perfectly agitated in order to maintain the desirable contact with the solvent.

From the counter-current extractor 54, the mass then containing practically pure solvent is brought into a centrifuge 60. The solvent recovered following the treatment with a centrifuge is conveyed to the extractor 54 & counter-current by driving 6l.

The mass is transferred via a line 62, provided with a drive screw 63, to the upper part

J * 1 * evaporator 64 against the current comprising, in the particular embodiment illustrated, a vertical container equipped with an agitator device 65 in the form of an open propeller having intervals 66. The steam is introduced, by the intermediary / 0 of a pipe 67, in the bottom of the evaporator 64,

The resulting solvent phase 68 is introduced into a distillation apparatus, and the water phase 69 can advantageously be used to wet the organic material in the pre-extractor 50, if necessary.

// In certain cases where high purity of the final product is required, a new extraction or a washing treatment can be carried out. As shown in FIG. 4, the product, freed of solvent, obtained at the bottom of the countercurrent evaporator 64 can be transferred, via a conduit 70 provided with a drive screw 71, to a mixing container 72 fitted with an agitating device 73. New solvent is added and mixed with the product, after treatment with the centrifuge 74, the solvent ii is again extracted in an evaporator 75. · against the current, and the pure product thus obtained can finally be dried from the known way.

The invention can be used for the production of proteins from fish, such as pressed fish or fish meal as well as from other organic matter. Those skilled in the art will understand that other embodiments than those described can be carried out without departing from the scope of the invention,