Method and apparatus for industrial production of an extract by solid-liquid extraction
The industrial production of an extract by means of solid-liquid extraction improves the exchange of substances during extraction and allows enhanced dehumidification of a raffinate with residual moisture to obtain additional valuable extract. The extraction is enhanced during a first dwell time by at least one of at least partially flooding a vessel in the form of at least one flow discharged in a planned and targeted manner with a secondary solvent or the obtained extract, swirling and keeping in suspension the primary mixture within the vessel by supplying the secondary solvent or the obtained extract via a foot area of the vessel through an upwardly directed fourth flow, or moving the vessel relative to the extraction container within the obtained extract; circulating the secondary solvent or the extract in the extraction container by a circulation guide incorporating the extraction container from top to bottom relative to the extraction container; and supplying the extract freed from raffinate with residual moisture obtained by dehumidification to the already separated or to be separated extract freed from raffinate with residual moisture.
1 . A method for industrial production of an extract by solid-liquid extraction by means of an extraction container, the method comprising:
(a) bringing a primary mixture consisting of a solid primary solvent and a transition component into contact with a secondary solvent located in the extraction container for a predetermined dwell time to obtain the extract and a complementary portion of raffinate, wherein:
the extract comprises the secondary solvent and the transition component,
the raffinate comprises the primary solvent and residual moisture, wherein the residual moisture comprises more of the extract,
the extraction container is initially filled with a predetermined first mass of the secondary solvent,
the primary mixture is enclosed in a liquid-permeable vessel within the extraction container and has a predetermined second mass, and
step (a) comprises sub-steps of:
(i) one of:
first locating the vessel in the extraction container and then introducing the primary mixture into the vessel, or
first filling the vessel with the primary mixture and then placing the vessel into the extraction container,
(ii) moving the vessel within the extract container in a reciprocating first translational movement relative to the extraction container to enhance solid-liquid extraction during a first dwell time of the predetermined dwell time,
(iii) circulating, by means of a circulation guide, at least one of the secondary solvent or the extract in the extraction container from a top of the extraction container to a bottom of the extraction container, and
(iv) filling the extraction container with a predetermined additional first mass of the secondary solvent, without removing any extract from the extraction container, after the first dwell time, and continuing the solid-liquid extraction during a second dwell time of the predetermined dwell time,
(b) separating the extract and the raffinate from each other after the predetermined dwell time,
(c) after separation from the raffinate, discharging the extract from the extraction container, and
(d) at least partially removing the residual moisture from the raffinate, after steps (b) and (c) have been completed, through dehumidification by mechanical pressing in the vessel, wherein the extract that was contained in the residual moisture and was obtained by dehumidification is supplied to the extract either after the extract is separated from the raffinate in step (b) or after the extract is discharged in step (c).
2 . The method according to claim 1 , wherein
the dehumidification of step (d) starts at an earliest when a first part of the raffinate has dried out.
3 . The method according to claim 1 , wherein,
after the extract has been separated from the raffinate, filtering the extract to remove undesirable particles, which undesirable particles pass through outlets in the vessel.
4 . The method according to claim 3 , wherein,
for preliminary clarification before filtering and after the extract has been separated from the raffinate, separating the extract from the raffinate in a centrifugal field to form a pre-clarified extract.
5 . The method according to claim 1 , wherein,
after the extract has been separated from the raffinate, an automatic or forced discharging of the extract occurs, wherein a gaseous propellant is applied to a surface of the extract inside the extraction container during the discharging of step (c).
6 . The method according to claim 1 , wherein
the extraction container is designed as a homogeneous batch reactor.
7 . The method according to claim 1 , wherein the extract comprises a tea concentrate.
8 . The method according to claim 1 , wherein enhancing the solid-liquid extraction during the first dwell time in step (a) comprises, in sub-step (ii), at least one of:
generating a flow within the extraction container to at least partially move the secondary solvent or the extract in a targeted manner, or
stirring up the primary mixture and keeping afloat the primary mixture by feeding at least one of the secondary solvent or the extract as an upwardly directed flow from a lower part of the vessel.
9 . The method according to claim 1 , wherein moving the vessel within the extract relative to the extraction container at sub-step (ii) also includes moving the vessel in a first rotational movement.