DE1902690A1 - Process for the continuous extraction of soluble components from solids such as roast coffee or the like. In two stages - Google Patents

Description

Karlsruhe, January 2, 1969 H / Sv

IITDÜSIRIE-WERKE KARLSRUHE Corporation

75 Karlsrah e Gartenstrasse 71

Process for the continuous extraction of soluble components from solids, such as roasted coffee or the like., in two stages

- Addition to the patent ..... (patent application P 15 19 818.2) -

The main patent relates to a process for extracting soluble components from pesticides which the comminuted extraction material and a solvent into the trough of one with a mixing and conveying screw provided extraction system introduced and after Extraction in the form of solids or extraction lamb and enriched with soluble components, liquid extract can be withdrawn from this as well as the maximum to increase the extraction efficiency

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possible yield of the pesticides achieved with the shortest residence time in the extraction system is that the from the mixing and! conveyor screw moved forward within the trough of the extraction system Solids or solid particles together with the solvent through at least one comminution device routed, further crushed there and then together with the solvent in the hollow of the Extraction system back and in countercurrent to the ones that have not yet passed through the shredding device Solids are guided.

In the main patent, there is also a step-by-step comminution has been proposed in several successive stages of comminution, from stage to stage the degree of comminution is increased. Finally, a device for performing the Procedure with the subject of the main patent

When extracting soluble constituents from solids, the yield is essential as well on a small damage to the goods. Coffee has proven to be a particularly difficult extraction good.

In coffee extraction, "high yields" are known only achievable with thermal digestion.

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File, the extraction material in the extraction system is subjected to high pressure (up to 20 atmospheres) and high temperature (200 ⁰ G) for a long time. Apart from the fact that the usual long residence times of the extraction material in the extraction system make continuous operation difficult or at least very large-volume devices make necessary, coffee in particular suffers considerable damage to the product in this type of digestion. In the process according to the main patent, no such damage to the product occurs. However, the achievable yield is subject to limits that cannot be exceeded.

The object of the present invention is therefore essentially to further improve what has been proposed Process such that a two-stage continuous extraction in the first stage highly concentrated and, in the second stage, a less highly concentrated extract, each under optimal Yield, but avoiding a relatively high accumulation of sludge and fat, can be obtained. Another The object of the present invention is also one in construction, operation and maintenance to create simple and inexpensive apparatus for carrying out the method according to the invention.

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Based on the extraction process according to the main patent, in which the comminuted extraction material and a solvent in the trough one with a mixed and Conveyor screw provided extraction system introduced and after extraction in the form of solids or solid sludge and liquid extract enriched with soluble constituents withdrawn from this the aforementioned object is achieved according to the invention solved in that a pressureless first extraction stage has a wetting and filtering section upstream and a second extraction stage working with overpressure is connected downstream, the first from the The pulp extract withdrawn from the first stage is fed to the wetting and filtering section in such a way that both , the cloudy substances contained in the cloudy extract as well as the

\ D.rken fine fractions of the conces- an aroma-tight sluice) led extraction material as a continuous filter, in which a first, highly concentrated pure extract liquid consistency can be removed, while at the same time the wetted and transferred swollen extraction in the first extraction step and, in this while feeding a lösimgo - or extraction agent is subjected to a leaching process in countercurrent, whereupon the resulting residue is then transferred to an atmosphere under increased pressure

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and / or temperature-standing mixing and digestion vessel arrives in which it is fed with simultaneous feeding taken from au3 of the second extraction stage, adjusted in pressure and temperature by reduction Cloud extract subjected to a hydrolysis process and then with increasing pressure and temperature in the second extraction stage is transferred, from which, with a prior supply of a solvent or extractant in countercurrent, a pure extract compared to the first less highly concentrated second pure extract of liquid consistency can be obtained, while the again leached residue is discharged at the end of the second extraction stage.

In an advantageous embodiment, the invention provides that in the line in which the pulp extract from the first extraction stage is fed to the wetting and piltering section, one with the first Extraction stage for the purpose of regulating setting of the through the wetting and filtering section through-running cloud extract is provided in connection with branching.

One other essential characteristic suggests the Invention that the first extraction stage with a

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Temperature is operated just below the boiling point of water, preferably 95 ⁰ C, the temperature generated on the one hand by external heating and on the other hand by feeding in a heated solution or. Extraction agent is maintained, according to a further feature of the invention, the solution fed into both extraction stages. Extraction agent is water at a temperature just below the boiling point, preferably 95 ° C.

Essential to the invention importance is also the further features that the pressure prevailing in the second extraction stage pressure is about 10 ... 12 kp / cm, that discharged from the first extraction stage the extraction mixture transferred under at least partial Frembeheizung to about 17O ⁰ C in the second extraction stage and that an additional overpressure is constantly maintained in at least one of the two extraction stages by adding an inert gas, in particular to avoid oxidation processes that impair the aroma.

Finally, the further proposed method features are also of essential importance for the invention, which essentially consist in the fact that the or

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The pure extract obtained in the first extraction stage has a concentration in the order of magnitude of about 25 ... 30fa _f d . the pure extract obtained in the second extraction step has a concentration in the order of magnitude of about 7 ... 1255, and that the pure extracts obtained in both stages find separate recycling.

The proposed invention is not limited to creating an optimal one effective extraction process, but it also shows ways to structural and constructive design the device required to carry out the procedure: "

According to the invention it is then proposed that the wetting and filtering path essentially consist of consists of a tube whose upper end is limited by an aroma-tight input device for the extraction material, and that approximately in the middle of the Tube means are provided for shaking the extraction material located in the tube, while the tube Below the vibrating device, a rotatable slot filter and, if necessary, a device for tabletting of the extraction material mixed with cloudy extract is assigned, with the pipe being calibrated to another

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According to the invention, it is conical from top to bottom expanded.

To shorten the construction and thus ultimately also the length of the room, according to the following feature of the invention provided that the tube is assigned at right angles or approximately at right angles to the first extraction stage.

In a further advantageous embodiment of the device according to the invention it is provided that the tube of to be assigned to the first extraction stage in such a way that the extraction material emerging from the tube - possibly in tablets is fed to the beginning of the "mixing and conveying screw".

To avoid that that is with lees extract Staggered extraction material sticks in the pipe, there are means provided for shaking the extraction material from a known vibrator; the input device is according to a further feature of the invention an also arora-proof lock, such as a cellular wheel, is connected downstream.

Of importance for the invention is not only the feature that that associated with the first extraction stage

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Mixing and conveying screw with roughly the same structure is twice as long as the screw assigned to the second extraction stage, but also that, that the first extraction stage to achieve and maintain the operating temperature preferably externally heated Hoizmäntel are assigned.

Finally, the proposed device is expediently supplemented or perfected according to the invention in that a heat exchanger and, if necessary, a flow heater are switched on between the first and the second extraction stage, which bring the mixture exiting from the mixing and digestion tank and to be fed to the second extraction stage to one temperature bring from about 170 ⁰ C, and in that the second extraction stage is arranged in a pressure-tight container.

The advantages associated with the proposed invention are obvious and convincing at the same time:

Of particular importance is the fact that the first Extraktionsotufθ with its mixing and conveyor screw upstream a bonetting and filter section

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through which not only the entire length of the mixing and conveyor screw can be optimally used, but above all also the extraction material Entry into the screw is "already in an extractable state and not just now must be prepared for this in the first worm threads. The one upstream of the first extraction stage The wetting, swelling and filtering lines also ensure that, compared to a separate filtration process, for example in a centrifuge, there are no aromatic carriers get lost.

Of no less great advantage is that of the first - pressureless - extraction stage downstream, Second extraction stage operating under pressure and / or temperature: This makes it possible to use the to be optimally treated further extract obtained by hydrolysis in the mixing and digestion vessel, so that from this finally a second extraction stage Concentrated extract can be drawn off according to circumstances and circumstances.

The method provided for carrying out the inventive method also brings significant advantages

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Device includes:

Above all, here is the extremely simple and purposeful one Formation of the wetting, swelling and filtering path in the form of a top down to be mentioned below the conically widening pipe. The tube is thereby taking into account the swell properties dimensioned so that the extraction material can stay in it for a time that can be determined in advance, v / during which the extraction material in particular by the supply of the aii3 of the first extraction stage withdrawn sludge extract a unlocked and already is largely filtered, the turbid substances on the one hand and the newly supplied granulated extraction material on the other hand permanently serving as the actual filter layer. In this way it results - in Connection with a vibrator arranged on the tube creates a continuous filter vortex without the There is a risk that this type of filter has the disadvantages of otherwise common filters. e.g. clogging, subject.

Another advantage of the device according to the invention is the tabletting device arranged at the end of the tube, which G3 enables the granulate bodies

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with the fine powder of the extraction material, e.g. coffee, and the mining material to be filtered out Tablets can be molded. The tablets are kept from the disintegration for a certain time Extraction screw transported. Without this measure there would be the risk that both the resulting Enrich the sludge and the turbid content in such a way that the desired and desired filter effect is achieved fails to appear.

In the drawing, the invention is shown using an exemplary embodiment. It shows

Fig. 1 is the scheme of a continuously operating extraction system, the first, pressureless working stage a wetting, swelling and filter section upstream and one under pressure and / or temperature working second stage is connected downstream,

Fig. 2 shows the same scheme as in Fig. 1, but with the turbidity ext ralct as the driving force is used for a thick matter pump, and finally

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Pig. 3 the structural design of the

\
as a wetting, swelling and piling section serving pipe including the tableting device provided at the lower end of the pipe.

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The extraction material: for example coffee granules,

reaches from a - not shown - dosing device via the aroma-tight granulate sluice 1, for example a cellular wheel, in the wetting, swelling and piltering path formed as a tube 2. Under consideration of Due to the swelling properties of the extraction material, the tube 2 is designed as conical as possible, i.e. the lower one The end of the pipe has a larger diameter than the upper one. The tube is also dimensioned such that the granulate in the tube has a residence time of about 30 minutes. The granulate is transported by means of a suitable shaking device, such as a vibrator known per se.

At the upper end of the tube 2, the granules are fed via the line 3 pulp extract, which by means of the Slurry extract pump 7 from the sump 8a of the first, provided with a known mixing and conveying screw 9 Extraktora 8 withdrawn. The ones on line 3

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Provided branch 6 allows the running through the filter section, made of pulp extract and granules existing mixture tightness the respective operational requirements set accordingly.

When the pulp extract passes through the pipe 2 this is largely filtered, with the turbid substances themselves and the fine components of the granulate acting as a filter layer to serve. In this way a permanent filter is produced, which as a result of its continuous Loading cannot clog. At the lower end, the wetted and swollen granules become aroma-proof entered in the actual extractor 8. The filtered pure extract of this stage I is from the Pump 5 withdrawn via the annular channel 5a.

This first extraction stage is operated at a temperature of about 95 ⁰ G, wherein the temperature of suitably mounted heating jackets (not shown) and is maintained by the injection of solvent is water having a temperature of about 95 ⁰ O also. In the case of countercurrent extraction, a largely leached residue is obtained at the rear end of the extractor 8. This is either through

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an Auspreßsehneeke 11 "or by a corresponding sized thick matter pump 13. in a mixing and digestion tank 12 promoted.

Compared to the unpressurized first extraction stage v / ground in this container 12 under increased pressure and / or temperature, the previously undissolved constituents of the leached residue are subjected to a hydrolysis process subject. This is done in addition, that in the container 12 au3 the sump 16a of the extractor withdrawn sludge extract is fed.

In the scheme of Pig. 1 becomes the one coming from the sump 16a Turbidity extract reduced in pressure and temperature by means of the expansion valve 19; in the scheme of Pig. 2 serves the pulp extract itself as the driving force for the thick matter pump 13. This pump already works in itself a certain premixing effect, which, however, occurs afterwards can experience an additional "reinforcement" through the mixing and boiling-up vessel 12 resulting mixture is through the thick matter pump 13 in the extractor 16 of the second extraction stage, the

under higher pressure - for example newsise 12 kp / cm - is,

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pumped. A Wännewechsler 14 and, if necessary, a! Water heater 15 to ensure that the mixture reaches a temperature of about 170 ⁰ C in the extractor sixteenth

The residue, which is now finally leached, is discharged from a residue discharge corner 13. Of the from the Sunpf 16a of the extractor 16 by means of the Extract withdrawn from pump 20 has a lower concentration al3 the extract obtained in the first extraction stage: earth in the first extraction stage Depending on the use, correspondingly suitable extraction3good concentrations in the Reaches the order of magnitude of about 25 ... 30 ^, during which the consentration of the in the second Stage obtained extract in the order of about? ... $ 12 moves.

For reasons of taste, it is advisable not to mix the two extracts obtained, but to utilize them separately. The extract obtained in the second stage can, if necessary, before the further use by freeze concentration or vacuum concentration.

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Suitable solvents or extractants in the sweiten stage hot water boron extractor is used of about 17O ⁰ G ". Is housed in a pressure vessel. To avoid Oxydationavorgänge, an additional pressure is maintained constant by the addition of inert gas 22nd also takes place in the extractor 8 To avoid oxidation processes that could impair the coffee aroma, an inert gas blanket.

In the process orphan according to the invention, both Extraction snakes with fresh water as the solution or extraction agent operated. So Ea v / will not the extract obtained in the second stage is used as an extractant for the first stage. This learns even the extract obtained from the first stage is not adversely affected by the hydrolysis extract.

With the help of the so-called triangle diagram it can be shown that it is expedient to use the first extraction stage to build as large as possible in order to obtain both a high yield and a high concentration. Since the first, pressureless extraction stage is right is easy to build and maintain, follows from this

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also a not insignificant economic advantage.

From theoretical considerations it can also be deduced that the length of the first extraction screw is at otherwise the same geometric dimensions should be chosen twice as long as the second extraction screw,

Ψ In Fig. 3 is connected upstream of the sluice aromadiehte granules 1 the tube 2 designed as Benetsungs-, source and filter section. A vibrator 2a is arranged approximately halfway up the tube, which, if necessary, conveys the extraction material located in the tube 2, which has already been digested by the addition of turbid extract, in the direction of the extractor3 8. Downstream of the vibrator 2a is an annular channel 5a which contains a rotatable slit filter in order to avoid blockages when the extract obtained here is drawn off.

Finally, there is one between pipe 2 and extractor 8 Tableting device attached so that the granules together with the fine powder distribution of the goods and can be formed into tablets with the cloudy material to be filtered out. The tablets are supposed to be transported by the extraction screw for a while before disintegration. Without this measure, the would exist . There is a risk of the sludge settling and the turbid components experience an enrichment and thereby the desired filter effect remains.

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Claims (1)

1S02S90 Claims Method for extracting soluble components from solids, such as roasted coffee or the like., In which the comminuted extraction material as well as a solution or. Extractant in the well one with one Mixing and screw conveyor provided extraction system introduced and after extraction in the form of solids and with soluble components enriched liquid extract can be withdrawn from the extractor, according to patent ... (patent application P 15 19 818.2), characterized, that a pressureless first extraction stage a wetting uhd filter section upstream and a second extraction stage working with overpressure downstream is, with the first subtracted from the first stage. Cloud extract from the wetting and filtering section is supplied in such a way that both the cloudy substances contained in the cloudy extract and the Fine fractions of the extraction material fed in via an aroma-tight lock as a continuous filter 8AD OFUGlNAL 009835 / 1SÜ0 19025S0 act, from which a first, highly concentrated pure extract of liquid consistency can be pulled off, while at the same time the wetted and swollen extraction material is transferred to the first extraction stage and in this is subjected to a leaching process with the addition of a solvent or extractant in countercurrent, whereupon the resulting residue then into a mixing and digestion vessel which is under increased pressure and / or temperature in relation to the atmosphere arrives, in which it is removed from the second extraction stage with simultaneous feeding, in Pressure and temperature adjusted by reducing the pulp extract subjected to a hydrolysis process and is then transferred to the second extraction stage with increasing pressure and temperature, from which with prior addition of a solution or extraction ion by means of a countercurrent to the first pure extract less highly concentrated second pure extract of liquid consistency can be obtained, while the again exhausted the residue at the end of the second / 'Extraction stage, is discharged. 003835/1586 ORIGINAL INSPECTED 2. The method according to claim 1, characterized in that in the line in which the pulp extract from the first extraction stage of the wetting and Filter section is fed, one with the first extraction stage for the purpose of regulating Arranging the pulp extract passing through the wetting and filtering section in connection standing branch is provided. J5. Method according to claim 1, characterized, that the first Extraküonsstufe with a temperature just below the boiling point of water, preferably 95 ° C, with the temperature generated on the one hand by external heating and on the other hand by feeding in a heated solution or Extractant is maintained. 4. The method according to claim 1 and 3 * characterized in that the fed into both extraction stages, -eiste solution or. Extractant water with a temperature just below the boiling point, preferably 95 ° C. 009835/1886 / 1902890 5. The method according to claim 1, characterized, that the pressure prevailing in the second extraction stage is about 10 ... 12 kp / cra. 6. The method according to claim 1 and 5, characterized, that the discharged from the first extraction stage Extraction mixture is transferred to the second extraction stage with at least partial external heating to around 170 ° C. 7 · method according to claim 1 and 3 to 6, characterized,. - that in particular to. Avoidance of aroma-impairing Oxidation processes by adding an inert Gas constantly maintained an additional overpressure in at least one of the two extraction stages will. 8. The method according to claim 1 to 7 * characterized, that the one at the end of the wetting and filtering section extractable or pure extract obtained in the first extraction stage has a concentration of the order of magnitude of about 25 ... 20 # has. ■ - 5 - 009835/1588 1S02690 9. The method according to claim 1 to J, characterized, that the obtained in the second extraction stage Pure extract has a concentration in the range of about 7 ... 12 # 10. The method according to claim 1 to 9, characterized, that the pure extracts obtained in both stages are used separately. 11. Device for carrying out the method according to claims 1 to 10, characterized in that the wetting and .Filterweg essentially consists of a tube (2), the upper end of which is connected to an aroma-tight input device (1) for the extraction material is limited, and that approximately in the middle of the tube (2) means (2a) for shaking the im Tube (2) located extraction material are provided, while the tube (2) is below the vibrating device (2a) rotatable slotted filter (5a) and, if necessary, a device (21) for tabletting the pulp extract Extraction material is assigned. 003835/1586 12. The device according to claim 11, characterized in that that the tube (2) widens conically from top to bottom 13 · Device according to claim 11 and 12, characterized in that that the tube (2) at right angles or approximately at right angles is assigned to the first extraction stage (8). 14. Apparatus according to claim 13, characterized, that the tube (2) is assigned to the first extraction stage (8) in such a way is that the extraction material emerging from the tube (2) - possibly tabletted - to the beginning of the mixing and feed screw (9) is fed. 15 device according to claims 11 to 13 * characterized in that the means for shaking the extraction material from a per se known vibrator (20) 'exist. 16. The device according to claim 11 to 13> characterized in that the input device (1) is also aroma-dense Lock (la), such as a cellular wheel, is connected downstream. 0098 3 5/1586 originally inspected 1S02690 17. Apparatus for carrying out the method according to the Claims 1 to 10, characterized, that the mixing and conveying screw (9) assigned to the first extraction stage (8) has approximately the same structure is twice as long as the screw (17) assigned to the second extraction stage (16) 18. Device according to claim 17 *
characterized, that the first extraction stage (8) to achieve and maintain the operating temperature are preferably assigned externally heated heating jackets. 19 device according to claim 17, characterized in that between the first and the second extraction stage (8, 16) a heat exchanger (14) and optionally a flow heater (15) are switched on, the one emerging from the mixing and digestion tank (12) and the second Bring the mixture to be fed to extraction stage (16) to a temperature of about 170 ° C. 20. Device according to claim 17 * characterized in that the second extraction stage (16) in a pressure-tight Container is arranged. 009835/1586