Method for extracting herbal medicine

Abstract

A method for extracting herbal medicine includes: step one, spray extraction; step two, pressure filtration and concentration; step three, spray and countercurrent precipitation; and step four, concentrating reduced pressure and drying.

Claims

1. A method for extracting an herbal medicine comprising: step one, spray extraction: pulverizing herbs to 100 to 120 mesh fine powder, adding the fine powder and an extracting solvent, in a ratio of 6-7 L extracting solvent/1 kg fine powder, to an agitation tank (1), stirring a mixture of the fine powder and extracting solvent at 80-100 r/min for 1-1.5 hours, spraying the mixture to an extraction tank (3) at a spraying speed of 400 to 600 L/h, adding first additional extracting solvent to fill two-thirds to three-fourths of the extraction tank (3), the mixture being sprayed 2-3 cm below a surface of the extracting solvent in the extraction tank (3), spraying countercurrently second additional extracting solvent from a bottom of the extraction tank (3) at a speed of 1000-1600 L/h to form an extraction solution, the second additional extracting solvent being pumped from an extracting solvent tank (6) at a pump pressure of 3.0-5.0 MPa, the step one, spray extraction being conducted at room temperature; step two, pressure filtration and concentration: discharging the extraction solution from step one to a filter press (4) to remove insoluble waste at a speed of 400-600 L/h and a pressure of 0.4-0.7 MPa to store at an extraction storage tank (5), pumping the extraction solution from the extraction storage tank (5) to a vacuum concentration tank (10), concentrating the extraction solution in the vacuum concentration tank (10) under 0.08 MPa to 0.1 MPa and at 60-80° C. to form a concentrated extraction solution with a solution density of 1.0-1.3, the extracting solvent being recycled to the extracting solvent tank (6); step three, spray and countercurrent precipitation: spraying the concentrated extraction solution to a tube centrifuge (12) at a speed of 200-400 L/h, adding a precipitation solvent to fill two-thirds to three-fourths of the tube centrifuge (12), the concentrated extraction solution being sprayed 2-3 cm below a surface of the precipitation solvent in the tube centrifuge (12), spraying countercurrently additional precipitation solvent from a bottom of the tube centrifuge (12) at a speed of 1000-1400 L/h and a pressure of 2.0-4.0 MPa to form a precipitation solution, centrifuging the precipitation solution and discharging a supernatant through an overflow outlet (20) of the tube centrifuge (12) to a resting tank (17) at a speed of 600-900 L/h, the supernatant being stored in the resting tank (17) for 24 hours; and step four, concentrating reduced pressure and drying: concentrating the supernatant from the resting tank (17) under reduced pressure, drying by vacuum spray and freeze-dry to obtain the herbal medicine.

2. The method of claim 1, wherein the extracting solvent is water or 10% ethanol aqueous solution containing 0.5% ammonia.

3. The method of claim 1, wherein the precipitation solvent is 60% ethanol aqueous solution, 85% ethanol aqueous solution, anhydrous ethanol, or 98% sulfuric acid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

(2) In the drawings:

(3) FIG. 1 shows a device for high pressure spray and counter-current precipitation extraction of herbal medicine.

(4) FIG. 2 shows a tube centrifuge (12) of the device for high pressure spray and counter-current precipitation extraction of herbal medicine.

REFERENCE NUMERALS

(5) (1) agitation tank; (2) plunger pump; (3) extraction tank; (4) filter press; (5) extraction storage tank; (6) extracting solvent tank; (7) plunger pump; (8) centrifugal pump; (9) centrifugal pump; (10) vacuum concentration tank; (11) plunger pump; (12) tube centrifuge; (13) rotating tube; (14) spiral scraper; (15) extraction waste discharge outlet; (16) differential; (17) resting tank; (18) precipitation solvent storage tank; (19) plunger pump; (20) overflow outlet; and (21) inner tube.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(6) Reference will now be made in detail to embodiments of the present invention, example of which is illustrated in the accompanying drawings.

(7) Referring to FIG. 1, a device for high pressure spray and counter-current precipitation extraction of herbal medicine includes an agitation tank (1); a first plunger pump (2); an extraction tank (3); a filter press (4); an extraction storage tank (5); an extracting solvent tank (6); a second plunger pump (7); a first centrifugal pump (8); a second centrifugal pump (9); a vacuum concentration tank (10); a third plunger pump (11); a tube centrifuge (12); a resting tank (17); a precipitation solvent storage tank (18); a fourth plunger pump (19); and an extraction waste discharge device. A bottom outlet of the agitation tank (1) is connected to a top inlet of the extraction tank (3) via the first plunger pump (2); an outlet of the extracting solvent tank (6) is connected to a lower solvent inlet of the extraction tank (3) via the second plunger pump (7); a bottom outlet of the extraction tank (3) is connected to an inlet of the filter press (4); an outlet of the filter press (4) is connected to an inlet of the extraction storage tank (5); an outlet of the extraction storage tank (5) is connected to an inlet of the vacuum concentration tank (10) via the first centrifugal pump (8); a solvent outlet of the vacuum concentration tank (10) is connected to an inlet of the extracting solvent tank (6) via the second centrifugal pump (9); an outlet of the vacuum concentration tank (10) is connected to a top inlet of the tube centrifuge (12) via the third plunger pump (11); a bottom inlet of the tube centrifuge (12) is connected to an outlet of the precipitation solvent storage tank (18) via the fourth plunger pump (19); an overflow outlet (20) of the tube centrifuge (12) is connected to an inlet of the resting tank (17); the extraction waste discharge device includes a spiral scraper (14), a differential (16), an inner tube (21), and an extraction waste discharge outlet (15); and a rotating tube (13) of the tube centrifuge (12) is connected to the differential (16), and the differential (16) is connected to the spiral scraper (14) via a shaft.

(8) Referring to FIG. 2, the tube centrifuge (12) includes the rotating tube (13) that is connected the differential (16). The extraction waste discharge device includes the spiral scraper (14), the differential (16), the inner tube (21), and the extraction waste discharge outlet (15). The differential (16) is connected to the spiral scraper (14) via a shaft. The rotating tube (13) has a column shape at one end (and a truncated cone shape at the other end, and a half cone angle of 10 to 12°. The overflow outlet (20) has a diameter of 60 to 100 mm and has a center line that is perpendicular to a rotary axis of the rotating tube (13). The inner tube (21) has a double truncated cone shape, a bottom half cone angle α1 that is the same as the half cone angle of the rotating tube (13), a top half cone angle α2 of 60-65°, and a length that is one third of the length of the rotating tube (13). The spiral scraper (14) is a single-headed spiral made of a wear-resistant steel and has a blade thickness of 6-8 mm and a blade height of 30-35 mm, and a distance between the spiral scraper (14) and the rotating tune (13) is 1.5 mm to 2 mm.

Example 1

(9) The extraction of flavonoids from herb Pogonatherum crinitum includes the following steps:

(10) Step one, spray extraction: 200 kg of herb Pogonatherum crinitum was pulverized to 100 to 120 mesh fine powder. The fine powder and water, in a ratio of 7 L water/1 kg fine powder, to an agitation tank (1). The mixture was stirred at 90 r/min for 1 hour, was pumped by a first plunger pump (2), and was sprayed into an extraction tank (3) at a spraying speed of 500 L/h. Three-fourths of the extraction tank (3) was filled with water, and the mixture was sprayed 2 cm below the surface of water. Water was pumped from a second plunger pump (7) from an extracting solvent tank (6) and sprayed countercurrently from the bottom of the extraction tank (3) at a speed of 1200 L/h to conduct extraction and form an extraction solution. The pressure of the second plunger pump (7) is 3.5 MPa. The extraction is conducted at 25° C.

(11) Step two, pressure filtration and concentration: the extraction solution from step one was discharged to a filter press (4) at a speed of 500 L/h and a pressure of 0.5 MPa via the outlet at the bottom of the extraction tank (3) to remove insoluble waste. The filtered extraction solution was stored in an extraction storage tank (5), and subsequently, pumped by a first centrifugal pump (8) to a vacuum concentration tank (10). The extraction solution was concentrated under −0.08 MPa and at 60° C. in the vacuum concentration tank (10) to form a concentrated extraction solution with a solution density of 1.2. Water was recycled to the extracting solvent tank (6) by a second centrifugal pump (9).

(12) Step three, spray and countercurrent precipitation: the concentrated extraction solution was pumped by a third plunger pump (11) to a tube centrifuge (12) at a speed of 300 L/h. The rotating tube (13) has a column shape (diameter: 600 mm; height: 700 mm) at one end a truncated cone shape (half cone angle: 10°; height: 600 mm) at the other end. The overflow outlet (20) has a diameter of 80 mm. The inner tube (21) has a double truncated cone shape, a bottom half cone angle α1 of 10°, a top half cone angle α2 of 65°. The spiral scraper (14) has a blade thickness of 6 mm and a blade height of 30 mm, and a distance between the spiral scraper (14) and the rotating tune (13) is 1.5 mm. The rotating speed of the rotating tube (13) is 3000 r/min. Three-fourths of the tube centrifuge (12) was filled with 60% ethanol aqueous solution. The concentrated extraction solution was sprayed 2 cm below the surface of 60% ethanol aqueous solution. 60% ethanol aqueous solution was pumped from a precipitation solvent storage tank (18) by the fourth plunger pump (19) and sprayed countercurrently from the bottom of the tube centrifuge (12) at a speed of 1200 L/h and a pressure of 3.0 MPa to form a precipitation solution. The tube centrifuge (12) was spun at 3000 r/min. The supernatant was discharged via an overflow outlet (20) to a resting tank (17) at a speed of 600-900 L/h. The supernatant was stored in the resting tank (17) for 24 hours. The extraction waste was discharged through an extraction waste discharge outlet (15) by a spiral scraper (14).

(13) Step four, concentrating reduced pressure and drying: the supernatant from the resting tank (17) was concentrated under reduced pressure to a solution of density of 1.3. The solution was dried by vacuum spray to obtain flavonoids at a yield of 93%.

Example 2

(14) The extraction of phenolic compounds and nonpolar diterpenoid compounds from herb Salvia miltiorrhiza includes the following steps:

(15) Same steps as Example 1 except that the rotating tube (13) has a column shape (diameter: 600 mm; height: 600 mm) at one end a truncated cone shape (half cone angle: 12°; height: 550 mm) at the other end; the overflow outlet (20) has a diameter of 100 mm; the inner tube (21) has a double truncated cone shape, a bottom half cone angle α1 of 12°, a top half cone angle α2 of 60°; the spiral scraper (14) has a blade height of 35 mm; and 85% ethanol aqueous solution was used precipitation solvent.

(16) The phenolic compounds and nonpolar diterpenoid compounds were extracted at a yield of 90.2%.

Example 3

(17) The extraction of saponins from herb Panax notoginseng includes the following steps:

(18) Same steps as Example 1 except that the rotating tube (13) has a column shape (diameter: 600 mm; height: 600 mm) at one end a truncated cone shape (half cone angle: 12°; height: 550 mm) at the other end; the inner tube (21) has a double truncated cone shape, a bottom half cone angle α1 of 12°, a top half cone angle α2 of 60°; the spiral scraper (14) has a blade thickness of 8 mm and a distance between the spiral scraper (14) and the rotating tune (13) is 2 mm; and 70% ethanol aqueous solution was used precipitation solvent.

(19) The saponins were extracted at a yield of 89.4%.

Example 4

(20) The extraction of glycyrrhinic acid from herb Glycyrrhiza uralensis includes the following steps:

(21) Same steps as Example 1 except that 10% ethanol aqueous solution containing 0.5% ammonia was used as extracting solvent; and 98% sulfuric acid was used as precipitation solvent.

(22) The glycyrrhinic acid was extracted at a yield of 91.3%.

Example 5

(23) The extraction of ginkgo polysaccharide from herb Ginkgo biloba includes the following steps:

(24) Same steps as Example 1 except that anhydrous ethanol was used as precipitation solvent.

(25) The ginkgo polysaccharide was extracted at a yield of 92.7%.

(26) It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.