This invention relates to a process for extracting solid, granular and/or crushed materials with a liquid, for a pretreat ent thereof to further extraction as well as an equipment for carrying out this process.

It is known that a previous mechanical and chemical decomposition of a solid is the precondition for obtaining an active agent from the solid (extraction). ("De¬ composition" means either chemical or me¬ chanical destruction or both in this descrip¬ tion.) The mechanical decomposition of a solid - e.g. a plant - is substantially car¬ ried out by crushing and grinding, where the walls of plant cells are loosened and the cutting up to small pieces of the solid occurs. Chemical decomposition is usually achieved by using a chemical containing one or more components and results in the dis¬ solution of the valuable substance (active agent) being present in the solid, chiefly in the cells.

The crushing (mechanical decomposition) is carried out by using various grinding apparatus (e.g. hammer mill, roll train and the like). The removal of substances (extrac¬ tion) can most favourably be effectuated from a material ground to a powder since the decomposition of cell walls occurs to the highest grade in this case. However,

the extent of grinding is limited thereby that the flow of liquid through the ground solid aggregate being in powder form proceeds only with holdback and can even be stopped in extreme cases. From this point of view, the continuously working (operating) counter- current solid/liquid extractors are particu¬ larly sensitive therefore, the optimization of the grade (extent) of grinding is necessary. It should be noted that the operation of grinding is usually not directly connected to the extractor; the grinding apparatus is located farther, eventually in a separate space.

An efficient chemical decomposition, i.e. dissolution of the valuable substance (active agent) substantially requires the getting of the decomposing (extracting) liquid to each solid particle and a sufficient residence time thereof together with the solid particle. In the Hungarian patent specification No. 148,662 an apparatus for decomposition of a solid to be extracted is described, to which a ground solid is fed in, to which a liquid possessing a pH value (acidic, alkaline or neutral) and chemical properties (composition) suitable to the extraction task given is added and intimately contacted therewith usually for about 2-3 hours under stirring. For this task of mixing Z-arm kneaders are commonly used, which play a role in the Hungarian patent specification cited, too; e.g. the decomposition of the

periwinkle (Vinca minor L.) plant material is traditionally carried out in an apparatus fitted with a Z-arm: the ground plant material is stirred (kneaded) together with the added decomposing organic solvent for 3 hours, then the wet solid kneaded with (decomposed by) the liquid is introduced to the extractor through the feeding in system.

The equipment described above is burdened by several unfavourable properties. The du¬ ration of the decomposition is long even in the case when the behaviour of the solid is extremely favourable from the point of view of extraction; the "Vinca minor L." mentioned above is also a material of such type. The kneading equipment is technically rather complicated. The solid grist of great mass and the decomposing liquid are difficult to be mixed and even in the case of stirring them together for several hours, it occurs that the liquid cannot get to all solid par¬ ticles whereby undeco posed particles are introduced to the extractor to result in a significant deterioration in the extraction efficiency thereof. Beside the continuously working extraction equipment, the use of a kneading equipment operating periodically is unfavourable and in addition, the kneader and the feeder have a rather high space de¬ mand.

An other decomposing equipment is known from the Hungarian patent specification No. 159,977, where the crushed dry solid is firstly

introduced in a feeding vessel from where it is transported to a screw feeder. Here, the composing liquid is sprayed onto the solid passing forwards, which is taken up by the solid material. The solid thus chemi¬ cally decomposed is fed into the extractor. According to this description the decomposing treatment effectuated in the screw feeder is substantially more efficient (effective) than the method using the Z-arm kneader de¬ scribed in the Hungarian patent specification No. 148,662 cited above.

A part of the granular solids to be extracted possesses unfavourable properties unpreferably influencing the process of ob¬ taining the active agents particularly in the case when the obtaining (recovery) of the active agent from the solid, is carried out in continuous operation by a countercurrent liquid. Such unfavourable material charac¬ teristics are e.g. as follows:

- a high fat content causing the aggluti¬ nation of particles during the countercurrent extraction whereby the passage of the extrac¬ ting liquid through the aggregation of par¬ ticles is impeded and even stopped in an extreme case (e.g. in the extraction of ergot)', the solid particle possesses a cell wall being impermeable to the liquid, which cannot be treated by the traditional mechanical and chemical decomposition and therefore, the efficiency of the extraction cannot be increased beyond a certain (defined) limit

value. The material transfer becomes slower and the extraction period is significantly increased (e.g. in the extraction of Ca- taranthus) , the capacity of the solid particles for taking up liquid is relatively low, i.e. the taking-up of liquid is slow and therefore, the swelling (deformation) demands a long time. For this reason disturbances occur in the operation of solid/liquid extractors, particularly of those having a bulk flow (conveyor) system since the deformation of the solid is continued after the begining of the extraction process, too; "a plug" can be formed and the flow of liquid may be interrupted (e.g. in an aqueous-acidic extraction); the capacity of the solid particles for taking up liquid and their capability of deformation are significant, which lead to the formation of a "plug" and in this way to inhibition of the liquid flow to result in a working disturbance in the solid/ /liquid extractors (the increase in the vol¬ ume of mallow is about 4-fold in an extraction using hot water).

The most severe drawback of solvings according to the Hungarian patent specifi¬ cations Nos. 148,662 and 159,977 consists therein that they are unsuitable to decompose and extract granular solids with such un¬ favourable properties, these can essentially be used in the cases of plant grists where

the decomposing liquid can unimpededly flow in to the inner part of the decomposed cell and flow out therefrom; or in the cases of grists with a very low fat content; as well as in the cases of grists having a not too high capacity of volume alteration and taking up a liquid.

The present invention is aimed to solve the pretreatment, i.e. decomposition for ex¬ tracting a solid with a liquid, whereby ma¬ terials having unfavourable properties from the viewpoint of extraction, e.g. fatty, diffusion-weakening cell walls or extreme swelling properties, can be extracted in the optimum (best) way namely, with an ef¬ ficiency over 95Λ, low liquid/solid ratio and a short time of residence in the extractor. The invention is based on the recogni¬ tion that materials disturbing the extraction process, chiefly fat, can be removed from the solid by wetting the solid to be extracted, pressing out a part of the wetting liquid from the solid while subjecting the solid to an influence mechanically decomposing the cell walls and subsequently again bringing liquid to the material thus treated; the cell walls weakening the diffusion in an undecomposed state become capable to let in and out the liquid; the formation of the cell liquor and the deformation of solid particles are already finished before their entry to the ' reactor; thus, the ideal con¬ ditions are ensured for a best extraction.

Based on this recognition, the aim of the invention has been achieved by a process including mixing the solid with a liquid resulting in a chemical decomposition thereof and pressing out the liquid mixed with the material (product) to be obtained from the solid, which comprises

- bringing the liquid resulting in a chemi¬ cal decomposition onto the solid while moving it forwards under agitation and achieving an intimate contect of the solid therewith,

- further conveying the wetted solid under a higher than atmospheric pressure increasing while moving it forwards, beside a continuous decrease in its volume, whereby the cell walls of the solid or a part thereof are cleft and removing by overpressure the liquid mixed with the material to be obtained from the wetted solid;

- further conveying the pressed and partly liquid-exempted solid while agitating it, meanwhile adding decomposing liquid thereto and intimately contacting it with the liquid, then portionwise adding (feeding) it into a reactor.

It should be emphasized that the term "granular and/or crushed material" means all ground, milled, granulated materials and the like, from which any useful ingredient (component) can be obtained by extraction. According to a preferred embodiment of the process, the solid pressed out by an overpressure is pressed through a slit before its transfer to the extractor and

by the edge of the wall bounding the slit an edge force is effected on the solid, which results in the mechanical destruction (de¬ composition) of the cells or a part thereof. Due to this measure, the further treatment of the material in the extractor can be car¬ ried out with a higher efficiency, particularly in the cases of materials possessing peculiar properties mentioned in the introduction of this description.

According to an other aspect of the invention, the decomposing liquid is applied by spraying onto the crushed solid being in movement; thus, the contact of the media can be made more uniform and effective.

A preferred embodiment of the process also consists therein that the pressure of the solid is continuously enhanced while continuously decreasing its volume during its transfer under an overpressure. This can be achieved by conveying the material by a screw, the threads of which have an increasing volume while passing from the site of feeding in up to the site of leaving.

It is characteristic of a further embodiment of the process that, before pressing the solid, the mixing thereof with liquid is carried out for 30-240 minutes during its transfer under an atmospheric pressure. Suitably, an edge force of 5.0-20.0 N/mm is effected on the solid for the mechanical decomposition of the cells, furthermore, before feeding in to the extractor, the pressed

and optionally mechanically decomposed solid is stirred with the decomposing liquid during its transfer for 10-60 minutes.

The equipment according to the invention has a screw conveyor for contacting the solid with the decomposing liquid as well as devices for removing the liquid containing also sub¬ stance obtained from the wetted solid. It is characteristic of this equipment that the screw conveyor is built in as a part of such a conveying-wetting unit to the casing thereof, which has an orifice connected with a conduit used for feeding in the extraction liquid, and a feeder joins the casing? the casing is in connection with a pressing- -decomposing unit possessing a screw press, the thread-volumes of which decrease in the passage direction of the material and the screw press is at least partially surrounded by a filter mantle, the screw press is sepa¬ rated from a chamber by a wall containing an orifice opposed to the screw press, into which a conic destructive body extends, which is movable parallelly with the longitudinal geometric central axis of the screw press against an elastic force; the destructive body toegether with the rim of the orifice bounds a material-transmitting slit; the chamber is in connection with a feeding- -charging unit having a screw conveyor; and into the casing at least partially surrounding it, an orifice leads, which is connected with a conduit used for feeding in extraction

liquid; this casing is connected with an extractor. Suitably, the longitudinal geometric central axis of the screw conveyor of conveying- -wetting unit closes with the horizontal an angle, which increases in the direction of conveyance of the material and is not higher than about 20 , preferably about 15°. According to an other characteristic of the invention, the conveying-wetting unit has a casing formed by a twin-trough with duplicate wall and a cover closing it; the inner side walls of the trough pieces (members) are lower than the outer side walls thus, a common space is present between the trough pieces (members) and the screw conveyors situated in the trough pieces (members) are mounted revolvably in a direction opposed one to the other.

According to an other preferred embodi¬ ment of the equipment of invention, the conveying-wetting unit contains: an upper fixed cover plate fitted with a feeding, material-transmitting inlet orifice leading to the region of one end of casing of the conveying-wetting unit; a lower fixed disk fitted with a material inlet orifice being displaced in relation to the said orifice; as well as a disk revolvably imbedded between the cover plate and the disk and fitting in thereto by the insertion of sealing; in the revolvable disk, several orifices are shaped which, during rotation of the disk, get to overlapping on the one hand with the

\

orifice of the upper cover plate and on the other hand, with the orifice of the lower disk; around these orifices, sealings are situated between the intermediate revolvable disk and the fixed lower disk.

According to an other embodiment of the equipment of the invention ram plates are fastened, which trend horizontally on two sides in the cylindric space bounded by the filter mantle surrounding the screw press in the region of the longitudinal geo¬ metric central axis and extend up to the outer outline of the threads of the screw press.

According to an other example of em¬ bodiment, the volume ratio of the first screw- -thread to the last one of the screw press (by considering the passage direction of the material) is 1.5:1 to 3:1, preferably about 2:1 whereas the volumes of the inter¬ mediate screw-threads gradually decrease while passing from the first one up to the last one. Suitably, the pitch is constant and the volume decrease is ensured by decrease in the thread-depth.

According to a further implementation of the equipment of the invention, a socket having a geometrical axis being identical with the longitudinal geometric central axis of the screw press, extending into the chamber joins the conic destructive body of the pressing-decomposing unit; a disk being perpendicular to the longitudinal geometric

central axis mentioned above is fastened to the socket; an axis fitted with bearings, being revolvable together with the screw press is led through the socket; a sleeve fitted with a base plate joins the axis fitted with bearings; the base plate can be moved in two directions and is fastened in an op¬ tional position within the range of its mo¬ bility ( ovability) ; and a helical spring led onto the axis, used for the elastic sup-" port of the desctructive body is situated between the base plate and the disk. The adjustment of the sleeve is made possible by its conveniently threaded formation and connection.

According to an other implementation of the invention, an inner wall being per¬ pendicular to the longitudinal geometric central axis of the screw press is built in to the chamber and the sleeve is placed in the central orifice thereof whereas at least three orifices fitted with bearings are formed in the circumferential region of the wall ^* , rods are led through these orifices in such a way that one end thereof is fastened to the disk connected with the socket and the other end thereof is fastened to an end disk, in which an orifice fitted with bearings is provided (formed) for re¬ ceiving the end of the axis.

Finally, it is preferable to incorporate the axis to a supporting bearing between the intermediate wall and the end disk.

The invention will hereinafter be de¬ scribed in detail on basis of the enclosed drawings showing a preferred embodiment of the equipment according to the invention and the solving of some structural details (parts) as well as demonstrating the process in connection with the extraction. In the drawings:

Figure 1 shows a preferred embodiment of the equipment in a schematic vertical longitudinal section, partly from a side- -view;

Figure 2 illustrates the feeding device and conveying-wetting unit on a higher scale;

Figure 3 shows the section taken along the line _j A-/\ signed in Figure 2;

Figure 4 shows the section taken along the line j^-J3 signed in Figure 2;

Figure 5 indicates the detail J) signed in Figure 2 on a higher scale;

Figure 6 illustrates the pressing-de¬ composing unit of the equipment according to Figure 1 on a higher scale in the section taken along the line L-I_ signed in Figure

7;

Figure 7 is a section taken along the line E_-E_ signed in Figure 6;

Figure 8 demonstrates the forces occurring in the decomposition process on the drawing containing the detail of higher scale signed in Figure 6;

Figure 9 shows a detail of the screw il¬ lustrated in Figure 6 on a higher scale;

Figure 10 illustrates the feeding-charging unit of the equipment according to Figure 1 on a higher scale,

Figure 11 is a section taken along the line j^-H signed in Figure 10,

Figure 12 illustrates the process according to the invention by the use of a combined equipment established by connecting the equip¬ ment according to Figure 1 with a solid/liquid extractor of bulk flow (conveyor) system. Main parts of the equipment according to Figure 1 are: the charger 1, the conveying- -wetting unit signed as a whole by the ref¬ erence number 2, the pressing-decomposing unit 13, as well as the feeding-charging unit 26 joining the extractor 30, which are connected in series in the order of succession mentioned above. It should be noted that the vertical arrangement according to Figure 1 is suitable but, depending on the given endowments of location, the connection of the main partial units may also be carried out on an identical level by inserting ma¬ terial-conveying equipment parts.

Main parts of the charger 1 are: throat 10, driving mechanism 11 and charging mechanism 12. In the present embodiment, the conveying- -wettiπg unit 2 contains the partial units 2a, 2b possessing 4a, 4b screw conveyors situated in casings 3a, 3b to which a common drive 5 is adapted. The casings 3a, 3b are contacted (connected) through the transmitting orifice 6 one with the other. The charger

1 mentioned above leads from above to the end of casing 3a being opposite to the drive 5 and the transmitting orifice 6. The long geometric central axes of screws 4a, 4b are signed by the reference letters _x- _ι and x_„ , respectively. The feeding in conduits 7a, 7a' lead from above into the casings 3a, 3b. These conduits serve for spraying in the wetting liquor (accordingly, nozzles /not illustrated/ are connected to the feeding orifices). A feeding in conduit 76 of the same kind leads to the casing 3b, too. Beneath the end of casing 3 being opposite to the transmitting orifice 6, an outlet 8 exists. To this, a transfer tube 9 joins, which leads to casing 14 of the pressing-decomposing unit 13, to one end thereof fitted with the drive 17 through the inlet 9a. In the casing 14, a screw 15 surrounded by the filter mantle 16 and connected to the drive 17 is formed, the longitudinal geometric central axis of which is signed by the reference letter I3 _* An outlet 18 leaves the casing 14 beneath. The end of the cylindric casing 14, which is opposite to inlet 9a, is closed by the wall 19 being perpendicular to the longitudinal geometric central axis JK, containing a central orifice 20. The wall 19 is one bounding wall of front-side of the chamber 21. In this chamber 21, the decomposing (destructive) mechanism signed as a whole by the reference number 31 is situated, which will be described in detail hereinafter. A feeding in conduit

22 leads to chamber 21 from above whereas an outlet 24 is in its lower part. To this outlet a transfer tube 23 is connected, which leads through the inlet 25 from above to the end opposed to extractor 30 of the feeding-charging unit signed as a whole by the reference number 26. The feeding-charging unit 26 has a cylindric casing 27, wherein a screw 28 possessing the longitudinal geo¬ metric central axis _x. is situated? this is connected with the drive 29.

As shown in Figure 1, the longitudinal geometric central axes _x_ _{ι »} 21 _? °^ the screw conveyors 4a, 4b close an oblique angle o , , e(~ with the horizontal line. The longitudinal geometric central axis L _ι °f the upper screw 4a trends from below upwards in the direction, where the solid passes according to the arrow the value of this angle _β ⁽ _, is between 0° and 20°, conventiently about 10 . The angle ^„ of the longitudinal geometric central axis °f the lower screw 4b is also between 0° and 20°, and its slope is similarly in the direction of passing of the material signed by arrow e _^ therefore, it extends with a descent and is not ascent (as the longitudi¬ nal geometric central axis 2τ) • However, there is no difficulty to form also the lon¬ gitudinal geometric central axis x. _? -*-" ^aπ ascent position. The ascent position deviating from the horizontal makes possible the devel¬ opment of a fluidized bed in the casing 3a or 3b, respectively.

The conveying-wetting unit 2 according to Figure 1 as well as charger 1 are shown in Figures 2 to 5 in more detail by using the reference numbers of Figure 1 for signing the identical structural elements.

Figures 2, 4 and 5 contain the solvings for the parts of charger 1. To the charging mechanism signed as a whole by the reference number 12, a throat 10 and chamber 40 are connected from above and from beneath, res¬ pectively. The chamber 40 leads to casing 3a of the partial unit 2a of the wetting- -conveying unit 2 (see also Figure 1). From a view from above, the charging mechanism 12 has a circular cover plate 35, wherein a similarly circular orifice 33 is shaped; the throat 10 mentioned above used for intro¬ ducing the solid joins this orifice 33. The cover plate 35 has a fixed position: it is rigidly fastened to the rim extending outwards of chamber 40 by the means of screws 39. Beneath the cover 35, a circular revolvable disk 36 is situated, from which a verticular axis 37 led through the cover 35 extends upwards; this axis 37 is bound with drive 11 being capable in this way to revolve the disk 36 according to arrow _rκ (Figures 2 and 4). As shown particularly clearly in Figure 4, in the disk 36 three lengthy radial orifices 36a are formed in the identical side interspaces one from another (separated by an angle of 120 each) are shaped. (In Figure 4, the position of the feeding orifice

33 is also demonstrated by a dotted line, which is formed in the fixed cover 35.) Beneath the revolvable disk 36, a further similarly circular fixed disk 34 is situated, which is rigidly fastened to the rim 38 simi¬ larly mentioned above, by the aid of screws 39 mentioned above by inserting ^* the sealing 41c. There is a material outlet orifice 42 in the disk 34. Sealing rings 41a, 41b fit into the revolvable disk 36 above and beneath; the former one is adapted to the surface of disk 34, the latter one to the surface of the cover 35 while revolving of the disk 36. Around the orifices 36a, separate sealings (sealing rings) 41d moving together with the orifice 36a are placed between the disks 34 and 36. In Figures 2 and 5, the disks 36 and 34 are in such a position in relation of one to the other that an orifice 36a is covered by the outlet 42.

A preferred example of embodiment of the conveying-wetting unit 2 will hereinafter be described on the basis of Figures 2 and 3. In this case, the casings 3a, 3b are formed by duplicate-wall, curved twin-troughs 43a, 43b wherein the screw conveyors 4a, 4a' and 4b, 4b' are situated one beside the other. The duplicate wall is necessary because it is suitable for carrying out the process of the invention in several cases over room tem¬ perature and the duplicate walls can be heated e.g. by hot water or by introducing saturated steam when it is required by the task given.

The direction of rotation of the screws signed by the arrows are opposite one to the other in the trough pieces of the twin- -troughs 43a, 43b; i.e. one of the screws is always right-handed, the other screw is left-handed. Each of the screw conveyors is in functional connection with the drive 5. The outer walls 46a, 46b of the twin- -troughs 43a, 43b as well as their frontal wall extend over the screw conveyors whereas the inner wall of the trough pieces are lower, extend only up to the longitudinal geometric central axes jx, , jx _? °f the screws according to the example of embodiment; thus, the screw pairs possess a common space 44a, 44b each, where they are in contact one with the other. These common places 44a, 44b are closed by the covers 45a, 45b. Thus each screw pair rotates in the direction signed by arrows n_ , _n ₇ in a closed space in the casings 3a, 3b as clearly shown in Figure 3*, in the same Figure the tubes used for feeding in a heating or cooling medium to the duplicate walls of the twin-troughs are signed by the refer¬ ence numbers 48, 48a, whereas the tubes serving to lead out these media are signed by the reference numbers 49, 49a.

It should be noted that, in this example of embodiment, the screws 4a, 4a' and 4b, 4b' are structurally formed in such a way that the steel plate streak forming the screw leaves 51 prepared from steel are helically rolled up on the axes 50 rotating during

operation. Of course, screw structures of other sort may also be used.

The pressing-decomposing unit signed as a whole by the reference number 13 in Figure 1 is described in detail in Figures 6 to 9; the structural elements previously discussed are signed by the reference numbers previously used. As shown in Figure 6, the pressing-decomposing unit 13 has sections I and II built together one with the other; the compression is carried out in the section I whereas section II is provided for decompo¬ sing the cells.

The pressing-decomposing unit 13 is shaped in such a manner that, depending on the demands given, it can be operated in two different modes of working. Section I provided for compression can be operated alone or together with section II provided for the decomposing procedure by forming an operation series. The desired mode of working can be accomplished by adjusting the decomposing mechanism 31 dependently on the properties of the given raw material (grist) to be processed (see hereinafter). To the inlet orifice 9a of pressing section I, the stump 52 is connected, which represents a part of the transfer-tube 9 shown in Figure 1. The main structural element of section I is the rotating screw press 15 surrounded by a cylindric skeleton 53, this is covered by the filter mantle 16 men¬ tioned above in relation to Figure 1, which is suitably prepared from screening cloth.

The pitch of the screw press 15 is constant, however, the thread-depth gradually decreases in the passage direction signed by arrow of the solid as it can clearly be seen in Figures 6 and 9. The horizontal ram plates 54 extending up to the outer outline of the screw leaves lead from both sides into the inner space of the skeleton 53 covered by the filter mantle 16. The intended purpose of the ram plates 54 will be described herein¬ after. These ram plates are situated on a horizontal plane passing through the longi¬ tudinal geometric central line x.- _? ^an ^ are fastened to skeleton 53, which latter is fixed to the cylindric casing 14. The trun¬ cated conic-shaped, hollow desctructive body 57, which can move back and forth according to the double arrow _ , in the direction of the longitudinal geometric central axis .x, , fits to the central orifice 20, which is situated oppositely to the screw press 15 in the wall 19 formed by the flat plate and closing the cylindrical casing 14 on its frontal side opposed to the inlet orifice 9a. As mentioned above, the screw press 15 is shaped in such a manner that the mean thread-depth of the first screw-thread 55 being at the feeding in orifice 9a and the volume element _v, , respectively corresponding to the area bounded by the thread-depth and stretched by hatching in Figure 9, are essen¬ tially greater than the volume element _v of the last screw-thread 56; besides, the

volumes of the screw-threads between these two screw-threads 55, 56 gradually decrease while passing from screw-thread 55 to the screw-thread 56. It is suitable to bring the volume element ratio —vu/—v1, between the following values:

1.5 *- v _χ ^ 3

The optimum value of —vu/—v1, is about 1/2.

Returning now to the destructive body 57 mentioned above, this element which is an unconditionally important partial unit of the section II (Figure 6) and decomposing mechanism 31, respectively together with a socket 58, which the axis 61 fastened to the screw press 15 is led through, the centre line of axis 61, socket 58 and screw press 15 is the same, i.e. the longitudinal geometric central axis S.- ₅ - The conic destructive body

57 mentioned above joins the end of socket

58 situated towards the screw press 15 whereas the circular disk 59 is fastened to the oppo¬ site end thereof. Thus, the destructive body 57 and disk 59 move together according to the double arrow J , . One end of rods 62, preferably at least three or four rods being parallel to the longitudinal geometric central axis x, _J is fastened to the edge of disk 59; the other end thereof is rigidly fastened to an end disk 68 where the central orifice 67 fitted with bearings is present; the end of axis 61 mentioned above joins this orifice

67 fitted with bearings in a manner allowing the free movement according to the double arrow k, (Figure 6). In the chamber 21, an intermediate wall 63 prepared from plate is also incorporated in a fixed manner, which divides the inner space of the chamber to two parts. Near to the circumferential region of the wall 63, orifices 64 fitted with bearings are provided for leading through the rods 62 mentioned above. In the inter¬ mediate wall 63, a central orifice 69 is present, with a threaded sleeve 70, thus being adjustable to the direction signed by the double arrow Ik, . Through the sleeve 70, the axis 61 is led on the other hand, the supporting plate 65 being perpendicular to the longitudinal geometric central axis _x, is fastened to the edge thereof lying towards the disk 59. Between this supporting plate and disk 59, a prestressed helical spring 60 surrounding the axis 61 is situated; the supporting plate 65 mentioned above, which is mobile and can be fastened in an optional position between the terminal po¬ sitions of its movement, is actually provided for supporting and prestressing the helical spring 60 on its one side. The transverse bearing 66 shown in Figure 6 serves to support the axis 61. The feeding in conduit 22 previ¬ ously mentioned in relation to Figure 1 leads to the frontal part of the cylindric chamber 21, which is between the walls 63 and 19. The outlet orifice 24 also leads out from this frontal part of the chamber.

The dimensions of the helical spring are selected and the grade of its prestress is adjusted in such a way that the edge force (indicated in Figure 8) occurring in the contact line of the wall 19 and the trun¬ cated destructive body 57 falls into the following range of values:

5.0 N/mm P _E 20.0 N/mm

The optimum value of the edge force is:

E 10.0 N/mm

The spring force should be adjusted in such a way that the outer conic mantle surface of the conic destructive body 57 be capable to extend by 5 to 10 mm from the edge of orifice 20 beside the operation of the edge force j and thus, the solid be capable to leave while being decomposed by the slit (see later, Example 2). In this time, a surface overpressure of total 8 to 10 bar acts on the solid passing through the slit.

When the treated material is not wanted to be subjected to cell-decomposing process, i.e. the compression thereof is sufficient (see later, Example I), the adjustment of the decomposing mechanism 31 is carried out as follows.

The threaded socket 70 and the mobile supporting rate 65 moving therpwith are ad¬ justed to the right starting position in order to stop the support of the helical spring 60 by the supporting plate. Thus,

it bacomes unloaded, the outer conic mantle surface of the conic destructive body is removed from the edge of orifice 20 by about 30 mm and in this way the solid compressed in the section I, where it is under the effect of about 0.5-4.0 bar overpressure along the screw press 15, can freely leave through the "open slit" without any functioning of section II, i.e. the value of the edge force j is zero in this case.

Namely, the edge force j outlined in Figure 8 on a higher scale, arises from the prestress of the helical spring 60 when the conic destructive body 57 is stretched to the edge of orifice with a diameter D, of the disk-like wall 19. When signing the spring force by —Pr- E D, ^" ► ^" II

This edge force j is illustrated in the usual resolution along geometry in Figure 8, where

— Pcs r —P_E sinft

— Pcs is the sliding (shear) force, against which the material leaves the material-trans¬ mitting slit of measure _^ * sin opening along the mantle of the conic destructive body 57 as a result of the displacement X_ occurring during the compression.

The shear force P_ - P_ _F • cos/3 "cuts" the solid particles along the edge of the orifice having a D, diameter.

The feeding-charging unit 26 shown in Figure 1 is illustrated on a higher scale in Figures 10 and 11 while using the reference numbers and signs previously employed according to the sense. In this case the longitudinal geometric central axis x_. of screw 28 and therefore, the trough 71 with duplicate wall forming the casing 27 as well as its sealing cover are also horizontal. The feeding conduit 32 mentioned in relation to Figure 1 leads through the cover 72 near to the inlet orifice 25 into the inner part of casing 27. The trough 72 is connected to the extractor 30 (not shown here separatedly) , more precisely to the stump thereof introducing the solid, by the aid of the rim 77 of trough 72 and screws 78. As shown in Figure 11, a feeding conduit 75 used for introducing a heating or cooling medium leads into the space between the walls of trough 71 having duplicate walls and an outlet conduit 76 used for removing this medium leaves.

In the case of this example of embodiment the screw leaves are formed by the plate streak helically rolled up to the revolvable axis 73.

Based on Figures 1 to 11, the equipment discussed above in detail works as follows. The material, e.g. plant material pre¬ viously decomposed mechanically, e.g. by

grinding and thus being in a coarse-granular state is fed in according to arrow JΪ signed in Figure 2 by the conveying mechanism (not illustrated) through the throat 10 by the means of the charging mechanism 12 through the chamber 40 into the conveying-wetting unit 2. As it is clearly seen from Figures 4 and 5, a closed charging can be accomplished by using the charger 1 according to the in¬ vention since portions of identical volume are introduced through the orifices 33, 36a and 42 into the conveying-wetting unit 2 while the disk 36 rotates in such a way due also to the sealing rings 41a, 41b and 41d (Figure 5), it is completely inhibited that through the orifices turned away one from the other, vapours arising from the liquid(s) introduced to the conveying-wetting unit 2 continuously get to the conveying mechanism joining the throat 10, which could be very dangerous when using e.g. liquid organic solvents.

The air-dry solid grist fed in through chamber 40 according to arrow b_ is conveyed (transferred) in a free transportation by the rotating screws 4a, 4a' (Figure 3) in the upper partial unit 2a of the conveying- -wetting unit 2 in the direction of arrow towards the transmitting orifice 6 (Figures 1 and 2) while a liquid is sprayed onto the moving solid from above through the feeding conduits 7a, i.e. at various sites according to the arrows k. The solid moved-conveyed

in a rotating state gets to intimate contact with the liquid and takes up a significant part thereof. The wetted solid falls through the transmitting orifice 6 according to arrow d into the partial unit 2b onto the rotating screws 4b, 4b' where, while passing under stirring (arrow _e) , the taking up -of moisture is finished; when necessary, an additional amount of liquid can be introduced into the solid mass through the feeding conduit 7b (arrow _1) . Due to the moisture uptake a de¬ formation, e.g. swelling, may occur in some kinds of solids. The wet, optionally swollen solid gets from the partial unit 2b through the outlet orifice 8, transfer-tube 9 and inlet orifice 9a, according to arrow _ (Fig¬ ures 1 and 2) to the pressing-decomposing space 13.

As a result of the operations described above, a part of the liquid directly penetrates through the destroyed cell wall into the ground solid moved and contacted with the liquid in the closed system, an other part thereof osmotically gets through the intact cell walls to the inner space of the cells containing the valuable substance. Thus, there is formed a so-called cell liquor in the solid.

According to those discussed above, the solid pretreated by wetting and stirring for a relatively long time (which can be controlled by the number of revolutions of the screws) is led to the fore-part of section I (Figure 6), more particularly into the

first 55 threads of the screw press 15 of changing thread-depth within the pressing- -deco posing unit 13. While rotating, the screw press 15 conveys the material towards the orifice 20, i.e. the destructive body 57 (Figure 6) according to arrow (Figures 1 and 6). While passing forwards in the space in the direction of arrow under an over¬ pressure, the granular wet material is pressed into a continuously decreasing volume since, as it has formerly been discussed in detail, the volume of screw-threads continuously decreases from the inlet orifice 9a towards the orifice 20. Under the effect of the higher and higher surface pressure on the material having a given aggregation volume, the liquid phase being in the wetted solid flows through the cylindric filter mantle 16 (screen), gets to the bottom of casing 14 and leaves it through the outlet conduit 18 according to arrow jn.

Under effect of the force of pression exerted by the screw 15 in casing 14, which is induced by the significant volume change between the screw-threads, optionally a fat- -containing liquid usually containing also the active agent leaves the solid, which is led to further processing (into a collecting vessel) chiefly for isolating the active agent. The efficiency of liquid exemption achieved by the screw press 15 is enhanced by the horizontal ram plates 54 (Figures 6 and 7) built into the cylindric space bounded by the filter mantle 16. These ram plates

divide this space to two halves: namely, due to the presence of these ram plates (ribs), the whole mass of the wetted solid is forced to a passing movement without rotation.

The conic destructive body 57 (ram cone) is braced by the controllable compressive force displayed by the chemical spring 60. By the extent of prestress of the helical spring 11 the surface force can be controlled, which acts for achieving the needed decomposi¬ tion of the cell wall on the aggregation of particles pressed through the slit between the wall 19 and the conic destructive body 57 extending into the orifice 20 being in the wall 19.

At the slit mentioned a significant edge force j develops, which exerts a pression on the walls of intact cells. Due to the incompressibility of liquids, under this effect the cells containing a liquid are explosion-likely ruptured (split), their wall is decomposed (destroyed) and becomes permeable to the extraction liquid to be fed in later.

Accordingly, the wet solid, which has been pressed through along the destructive body 57 and exempted from the major part of its liquid content, and contains cells decomposed in their most part, falls down in the direction of arrow , leaves the press¬ ing-decomposing unit 13 under effect of gravity through the outlet orifice 24 according to arrow h _^ (Figures 1 and 6) and, as clearly shown in Figures 1 and 10, after falling

into the feeding-charging unit 26 it gets to the screw 28 thereof through the inlet orifice 25. Then, this screw conveys the material into the extractor 30 according to arrow _i. The granular solid can additionally be treated in the feeding-charging unit 26 with a liquid introduced through the feeding conduit 32 (arrow o ) ; usually, an extraction liquid is fed into casing 27 by spraying. The material being well mixed with this liquid during its screw conveyance (the residence time should usually be at least a few minutes, preferably about 15 minutes) gpts to the extractor 30 according arrow j_. It is of purpose to select the amount of the sprayed in extraction liquid in such a manner that it be identical or nearly identical with the amount of liquid removed from the solid in the pressing-decomposing unit 13. According to our experience the solid pretreated in this way can well be extracted e.g. in a countercurrent solid/liquid extractor. If a material is treated in the equipment accord¬ ing to the invention, which shows a slow uptake of liquid and cannot advantageously be influenced by grinding (mechanical de¬ composition), it can be observed that its capacity of taking up liquid preferably de¬ velops, the deformation (swelling) of the material ceases within a short time and thus, no further deformation has to be considered for the extractor.

When treating in the equipment according to the invention a solid showing a significant

deformation, e.g. being capable to swell to several fold of its original dry volume on effect of moisture, it is observed that this material does not change its volume during its treatment or in the extractor, i.e. it does not swell and becomes easy to be extracted.

Hereinafter, the invention will be described on the basis of Figure 12, showing the pretreating equipment illustrated schema¬ tically in connection with a countercurrent solid/liquid extractor and demonstrating the most important working steps of the pro¬ cess. In Figure 12, the structural parts previously discussed are signed by the ref¬ erence numbers formerly used and the arrows indicating the direction of inlet and outlet are signed by the same reference letters. The pretreating equipment shown on the left side of Figure 12 as a whole signed by the reference number 80 is identical with the equipment according to Figures 1 to 11 whereas on the right side of Figure 12 an U-shaped, countercurrent solid/liquid extractor of bulk flow (conveyor) system is indicated signed as a whole by the reference number 30 used also in Figures 1 and 10. (Such an extractor is known e.g. from the United States patent specification No. 3,279,890.) In the U-shaped casing 79 of the extractor 30, per¬ forated disks attached onto a drag chain pass in the direction of arrow. r_. The neigh¬ bouring disks bound cells one with the other,

which are provided to receive the solid to be extracted. After compression and decom¬ position of the cells, the solid to be extrac¬ ted arrives from the pretreating equipment

80 according to the invention to the site

81 of feeding in (here, the feeding-charging unit 26 shown in Figures 1 and 10 leads to the extractor 30) and smoothly passes in casing 79 up to the outlet 82 (arrow _t) . The extraction liquid passes in a counterflow (arrows TL ) against the solid in casing 79, the extraction o.f solid occurs as a result of contact (intensified by the vibrator or pulsator 105) with the liquid and the active agent is transferred from the solid to the liquid. The solid exempted from the active agent and containing liquid gets to the screw press 83 according to arrow j , where the liquid is pressed out from the solid and the major part of liquid leaves through the filter mantle 84, i.e. the solid loses a significant part of its liquid content. Ac¬ cording to arrow v_, the solid falls into the liquid-exempting unit 85 (e.g. drier, evaporator and the like). The solid here fully exempted from liquid is led through the conduit 92 to the conveying device 86, wherefrom it gets to vessel 87 according to arrow _, . If the liquid pressed out is valuable, i.e. not water, it is led through the conduit 106 into the vessel 88 supplying the system with extraction liquid. A conduit 89 containing the charging pump 90 leads out from the bottom of vessel 88. One conduit

89a branched off therefrom feeds the extraction liquid to the upper end of one shank of the U-shaped casing 79; through the other conduit 32 (previously mentioned in connection with Figures 1 and 6) branched off from conduit 89, and extraction liquid can be introduced by spraying from above into the feeding- -charging unit 26 of the pretreating equipment 80. Finally, in the carrying out of many extraction tasks, it is suitable to feed a little portion of the extraction liquid into the pressing-decomposing unit 13 of the pretreating equipment 80, which the conduit 22 is provided for. It should be noted that it may be convenient from a technological point of view to spray an extraction liquid into the feeding-charging unit 2, too, this becomes possible by using the conduits 7a, 7a' (with cross-connections not illustrated). The vessel 88 is supplied with fresh extraction liquid through the conduit 91.

The extract containing the active agent is separated from the wet solid in the filter chamber 93 of the extractor 79. From here, the extract is led by a pump through the conduits 94, 96 and 96a into the vessel 97 collecting the extract; however the totel amount or a part of the extract may be fed through the conduits 96 and 97a into the partial unit 2a of the previously discussed conveying-wetting unit of the pretreating equipment 80 (see also Figure 1). In this case, the extract is led to further processing

(isolation of the active agent) through the conduit 18 leaving section I signed in Figure 6 of the pressing-decomposing unit 13 as well as through the conduit 18a into the vessel 97 mentioned above, wherefrom it can be conveyed by the pump 98 through conduit 102 to the site of isolation of the active agen .

The decomposing liquid required to the chemical pretreatment is sprayed from vessel 99 by the pump 100 into the partial units 2a, 2b of the conveying-wetting unit 2 through the conduits 7, 7a', 7b (described in connection with Figures 1 and 2). The conduit 100 leading to vessel 99 is provided for supplying the decomposing liquid.

If the solid to be extracted contains a contamination interfering with the further processing of the extract, the liquid leaving the pressing-decomposing unit 13 through the conduit 18 is led not into the extract- -collecting vessel 97 but through the conduit 18b into the vessel 103, and conveyed further by the pump 104 for annihilation.

The invention will be illustrated in detail by the following non limiting Examples. In these Examples the establishment shown in Figure 12 and the general technological process demonstrated therein will be referred to.

Example 1

The active agent is ¹ extracted from dried ergot plant material ("drug"). In the

course of this complex procedure, the dried plant material is pretreated by using the process of the invention. It is known that the alkaloid content of the sorts of dried ergot plant materials ("drugs") (containing ergotamine, ergocristine, ergocornine-ergo- cryptine and ergocryptine) varies between 4 g/kg and 6 g/kg.

The dried plant material is ground to a material of 2 to 3 mm particle size on a roller mill. The grist is fed through the charger 1 of the pretreating equipment 80 into the conveying-wetting unit 2 by the means of a suitable conveyor. The charging of the dried plant material is controlled (regulated) in such a manner as to introduce 8D to 90 kg/hour of grist into the equipment. Into the conveying-wetting unit 2, 80 litres of ethyl acetate per hour as "first" extraction liquid and 40 litres of concentrated ammonium hydroxide per hour as chemically decomposing liquid are charged. The plant material is treated, i.e. wetted, stirred and conveyed in the partial units 2a, 2b of the wetting-conveying equipment 2, while being forced to a swirling movement, at room temperature (20 to 25 C) under atmospheric pressure for about 60 minutes. During the very intimate contact, the liquids are kneaded into the plant material and the particles of the plant material are swollen.

The swollen plant material is led into the pressing-decomposing unit 13, where the

major part of the cells are ruptured under the effect of the overpressure, which then continuously increases meanwhile the material passes forwards to result in about 80 litres of press liquor per one hour ("first" extract). The press liquor contains about 30 to 35? of the alkaloid content of the dried plant material together with strange substances, e.g. fat, which interfere with the further extraction. This "first" extract is introduced to the vessel 97 shown in Figure 12. It should be noted that, in a case according to the present Example namely, in the pretreatment and partial extraction of ergot, the decomposi¬ tion of cell walls is not unconditionally required, the plant material pressed out in a screw with decreasing thread-depth is decomposed to a suitable degree for efficient¬ ly carrying out its extraction in the ex¬ tractor 79 (Figure 12).

After leaving the pressing-decomposing unit 13, the partially extracted plant material is conveyed by the means of the feeding- -charging unit 26 into the extractor 30. Into the feeding unit 26, 80 litres of ethyl acetate per hour are fed in as "second" ex¬ traction liquid and the residence time of the material is adjusted here to 15 minutes. An intimate contact occurs also here between the solid and the secondary extraction liquid during the conveyance by screw.

In the extractor 30 the passage rate of the solid is adjusted (by suitably selecting

the rate of chain carrying the perforated cells) in such a way as to achieve a residence time of 120 minutes of the plant material in the extractor". As a "third" extraction liquid 240 litres of ethyl acetate per hour are charged into the extractor 30 on its side opposite to the feeding in of the plant material. The extraction liquid passes in a counterflow against the solid (see arrows and z_ on Figure 12). The extraction is carried out at room temperature (20 to 25 C). The extract ("secondary" extract) leaves the extractor 30 through the conduit 94 and gets to the vessel 97. The total amount of the "first" and "second" extractions is 230 to 240 litres per hour and contains about 95 to 985- of the alkaloid content of the dried plant material.

The solid extracted is removed from the extractor 30 through the press 83.

Example 2

Vinblastine is extracted from the dried Cataranthus plant material by using the process according to the invention. It is known that Cataranthus plant material is ground to a solid aggregation consisting of particles of 3 to 4 mm in size on a roller mill. The grist is fed in an amount of 50 to 60 kg per hour through the charger 1 into the con¬ veying-wetting unit 2 of the equipment ac¬ cording to Figure 12. Into the same unit 70 litres of 5% aqueous tartaric acid solution and 90 litres of water per hour are charged

as "first" extraction liquid through the conduits 7a and 7b. The residence time in the conveying-wetting unit 2 of the material is adjusted to 1 hour. The pretreatment is carried out at 50 C. During this period, the material becomes completely wetted, the gel stock of cells takes up the water, the material particles swell and the diffusion starts.

The swollen plant material is introduced to the pressing-decomposing unit 13, where the cells are ruptured under the decomposing effect of overpressure occurring in the section I (screw press period) as well as the edge force occurring at the beginning of section II; here, about 110 litres per hour of press liquor ("first" extract) are obtained, which contains 55-60?ό of the vinblastine content of the dried plant material. (The JP__ edge force has previously adjusted to 12.0 N/mm; in the section I, the pressure developed cor¬ responding thereto that the thread-depth of the screw press decreased to its half value from the first thread to the last one by considering the passage direction of the material.) This press liquor is introduced to the vessel signed by the reference number 97 in Figure 12, the pressed plant material is led to the feeding-charging unit 26, where 120 litres per hour of water are sprayed onto the material through the conduit 22, of course in the environment of feeding in of the pressed solid (Figure 12). This wet,

pretreated plant material is fed into the extractor 30 of bulk flow (conveyor) system. In the casing 79 of extractor 30, the rate of drag chain is adjusted so as to achieve a residence time of about 60 minutes of the plant material in the extractor 30. As a "second" extraction liquid 110 litres per hour of water and 20 litres per hour of 5% aqueous tartaric acid are fed into the ex¬ tractor 30 through the conduit 89a drawn in Figure 12, which passes (moves) counter- currently against the plant material. The amount of tartaric acid solution has been so selected as to obtain a pH value of 3 to 3.2 for both the "first" and "second" press liquors. The "second" press liquor (extract) leaves the filter unit 93 of ex¬ tractor 30 and is conveyed by the pump 95 through the conduit 94 into the collecting vessel 97. The total amount of the "first" and "second" extracts is 210 - to 220 litres per hour, which contains 95 to 97?≤ of the vinblastine content of the dried plant material (35 to 3750 of which are extracted in the extractor 30). The plant material extracted is removed from extractor 30 by the means of press 83 drawn in Figure 12.

The advantageous effects of the invention can be summarized as follows.

A substantially important advantage of the invention lies therein that substances possessing unfavourable properties from the viewpoint of extraction, e.g. high fat content,

propensity to strong swelling, can also be extracted with a high efficiency and by their pretreatment the factors unfavourably influ¬ encing the extraction can be eliminated or at least essentially decreased by using the invention. The equipment according to the invention can be either connected to an ex¬ isting extractor or built in as a partial unit of a novel establishment.

It is of course that the invention is not restricted to the working Examples described or to the embodiments of the equip¬ ment described and illustrated, but it can be accomplished in several ways falling within the scope of protection defined by the claims. It should be emphasized that the equipment has here been described only schematically; it should be appreciated that it contains several structures, e.g. locking devices, instruments, sensing and controlling devices and the like, the planning and incorporation of which are obvious for one skilled in the art.