CN216614297U

CN216614297U - Continuous flocculation device for plant extraction

Info

Publication number: CN216614297U
Application number: CN202220049808.9U
Authority: CN
Inventors: 陈虎; 侯丽娟; 路付勇; 周保良; 李贵祯
Original assignee: Chenguang Biotech Group Co Ltd
Current assignee: Chenguang Biotech Group Co Ltd
Priority date: 2022-01-10
Filing date: 2022-01-10
Publication date: 2022-05-27
Anticipated expiration: 2032-01-10

Abstract

The utility model discloses a continuous flocculation device for plant extraction, which belongs to the field of flocculation equipment and comprises a second mixer for mixing extract liquor and a flocculating agent, a second group of separators, a first mixer, a first group of separators, a horizontal screw centrifuge, a plurality of valves, a plurality of liquid pumping pumps and communicated pipelines, wherein a liquid inlet of the second mixer is communicated with a liquid outlet of the second mixer; the first flocculated turbid liquid accumulated by the first group of separators flows back to the second mixer; and the clarified liquid separated by the first group of separators and the centrifuged clear liquid separated by the horizontal screw centrifuge enter the next procedure together, and the flocculated slag separated by the horizontal screw centrifuge is discharged outside. The treatment process of the utility model is convenient to control, simultaneously reduces the treatment time, improves the flocculation effect and is more suitable for industrial production.

Description

Continuous flocculation device for plant extraction

Technical Field

The utility model relates to the technical field of flocculation equipment, in particular to a continuous flocculation device for plant extraction, which is used for the plant extraction industry.

Background

Ferrous sulfate, calcium hydroxide + PAM's flocculation technique because of its low cost, handles simply, and the effect is obvious, by the miscellaneous in-process of removing of all kinds of system liquid of wide application in plant extraction trade, wherein the sugar process of carrying out of stevia rebaudiana leaf also uses this mode to carry out preliminary edulcoration to stevia rebaudiana leaf water extract, and concrete implementation is for adding ferrous sulfate, calcium hydroxide + PAM to stevia rebaudiana leaf extract, but still there is flocculating agent and extract and mixes the difficulty, and the processing time is long, the inhomogeneous scheduling problem of material structure.

In the liquid-liquid extraction separation equipment, the separator equipment is widely applied to the separation process due to the factors of simple principle, easy manufacture, good effect, energy conservation and the like, is particularly applied to the liquid-liquid extraction process with different densities, and is a device for excellent liquid-liquid separation and generation of molecular acting force. However, no continuous flocculation device which combines the liquid-liquid separation principle with the flocculation technology of ferrous sulfate, calcium hydroxide and PAM exists in the prior art.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is to provide a continuous flocculation device for plant extraction, which can effectively treat mixed liquid, fully react with a flocculant in the mixed liquid to generate precipitate, remove insoluble impurities in the mixed liquid, and mix and separate unreacted flocculant through a multi-stage separator, so that the flocculant fully flocculates impurities, and the yield and the economic benefit are improved.

In order to solve the technical problems, the technical scheme adopted by the utility model is as follows:

a continuous flocculation device for plant extraction comprises a second mixer for mixing extract liquor and a flocculating agent, a second group of separators, a first mixer, a first group of separators, a horizontal screw centrifuge, a plurality of valves, a plurality of liquid pumping pumps and a pipeline, wherein the liquid inlet of the second group of separators is communicated with the liquid outlet of the second mixer; the first flocculated turbid liquid accumulated by the first group of separators flows back to the second mixer; clear liquid separated by the first group of separators and centrifugal clear liquid separated by the horizontal screw centrifuge enter the next procedure together, and flocculated slag separated by the horizontal screw centrifuge is discharged; the first group of separators and the second group of separators are respectively composed of a plurality of separators which are sequentially connected in series, each separator is distributed in a step shape, a liquid outlet of the previous step separator is connected with a liquid inlet of the next step separator, and a slag discharging port of the next step separator is connected with a slag inlet of the previous step separator.

The technical scheme of the utility model is further improved as follows: the first group of separators comprises a No. 1 separator, a No. 2 separator and a No. 3 separator which are distributed in a step shape; a liquid inlet of the 1# separator is connected with a liquid outlet of the first mixer through a first liquid pouring pump, a liquid outlet of the 1# separator is connected with a liquid inlet of the 2# separator, a liquid outlet of the 2# separator is connected with a liquid inlet of the 3# separator, and a liquid outlet of the 3# separator is connected with equipment of the next working procedure; the slag notch of 3# separator bottom links to each other through the slag inlet of second liquid pump and 2# separator, and the slag notch of 2# separator bottom links to each other through the slag inlet of third liquid pump and 1# separator, and the slag outlet of 1# separator bottom links to each other through the slag inlet of fourth liquid pump and II blender.

The technical scheme of the utility model is further improved as follows: the second group of separators comprises a 4# separator, a 5# separator and a 6# separator which are distributed in a step shape; a liquid inlet of the No. 4 separator is connected with a liquid outlet of the second mixer through a fifth liquid pumping pump; the liquid outlet of the No. 4 separator is connected with the liquid inlet of the No. 5 separator, the liquid outlet of the No. 5 separator is connected with the liquid inlet of the No. 6 separator, and the liquid outlet of the No. 6 separator is connected with the mixed liquid adding port of the first mixer; the slag notch of 6# separator bottom links to each other through the slag inlet of sixth liquid pump and 5# separator, and the slag notch of 5# separator bottom links to each other through the slag inlet of seventh liquid pump and 4# separator, and the slag notch of 4# separator bottom links to each other through the slag inlet of eighth liquid pump and horizontal screw centrifuge.

The technical scheme of the utility model is further improved as follows: the top of the first mixer is provided with a mixed liquid adding port for adding the clarified mixed liquid flowing out of the liquid outlet of the 6# separator and a coagulant aid adding port for adding the coagulant aid, the bottom end of the first mixer is provided with a liquid outlet, and the first mixer is provided with a liquid outlet valve at the liquid outlet.

The technical scheme of the utility model is further improved as follows: during the continuous flocculation process, the feed in mixer I was maintained at 2/3 parts of the total volume of mixer I.

The technical scheme of the utility model is further improved as follows: an online pH meter for detecting the pH value of the feed liquid is arranged on a liquid outlet pipeline of the mixer I.

The technical scheme of the utility model is further improved as follows: an extract liquid adding opening and a flocculating agent adding opening for adding flocculating agent are formed in the top end of the second mixer; a slag inlet for injecting the first flocculation turbid liquid from the slag outlet of the No. 1 separator is also formed in the upper side end of the second mixer, and a tenth valve is arranged at the slag inlet; and a liquid outlet is formed in the bottom end of the second mixer, and a liquid outlet valve of the second mixer is arranged at the liquid outlet.

The technical scheme of the utility model is further improved as follows: during the continuous flocculation process, the feed in the second mixer was maintained at 2/3 parts of the total volume of the second mixer.

The technical scheme of the utility model is further improved as follows: the top end of the horizontal screw centrifuge is provided with a slag inlet for injecting second flocculation turbid liquid from a slag outlet of the No. 4 separator, and the slag inlet is provided with a nineteenth valve; the bottom end of the horizontal screw centrifuge is provided with a flocculation slag outlet for discharging flocculation slag and a centrifugal clear liquid outlet connected with equipment in the next process.

The technical scheme of the utility model is further improved as follows: the first mixer and the second mixer are internally provided with stirring devices for stirring feed liquid.

Due to the adoption of the technical scheme, the utility model has the technical progress that:

1. the utility model adopts 6 separators which are divided into two groups, the height of each separator is different, and the flocculated clear liquid flows from the top of the separator to the next separator step by step through pressure difference. The structure realizes the progressive clarification of flocculated clear liquid through the liquid level difference of different separators, and the lower-layer turbid liquid is conveyed through a feed liquid pump to realize the turbidness of a turbid person; enriching impurities in the flocculated turbid liquid through a 6-stage separator, finally, centrifugally separating the flocculated turbid liquid in a horizontal screw centrifuge, discharging flocculated slag, combining the centrifuged clear liquid with the clear liquid extracted from the upper part of the separator, and allowing the combined clear liquid to enter the next process for resin adsorption; the treatment process is convenient to control, reduces the treatment time, improves the flocculation effect and is suitable for industrial production.

2. The utility model has reasonable structure, stable and reliable operation and good effect, can effectively treat the mixed liquor, fully reacts with the flocculating agent in the mixed liquor to generate precipitate, removes insoluble impurities in the mixed liquor, and mixes and separates the unreacted flocculating agent through the multistage separator, so that the flocculating agent fully flocculates impurities, and the yield and the economic benefit are improved.

3. The utility model can effectively treat the extraction liquid, so that the transmittance of the system liquid reaches more than 70 percent, and the cost is reduced by 50 percent.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of the mixer of the present invention;

FIG. 3 is a schematic diagram of the separator of the present invention;

wherein, 1, the first mixer, 2, the first mixer outlet valve, 3, the first pumping pump, 4, the first valve, 5, the 1# separator, 6, the second valve, 7, the 2# separator, 8, the third valve, 9, the 3# separator, 10, the fourth valve, 11, the fifth valve, 12, the second pumping pump, 13, the sixth valve, 14, the seventh valve, 15, the third pumping pump, 16, the eighth valve, 17, the ninth valve, 18, the fourth pumping pump, 19, the tenth valve, 20, the second mixer, 21, the extract liquid filling opening, 22, the flocculant adding opening, 23, the second mixer outlet valve, 24, the fifth pumping pump, 25, the eleventh valve, 26, the 4# separator, 27, the twelfth valve, 28, the 5# separator, 29, the thirteenth valve, 30, the 6# separator, 31, the outlet valve, 32, the fourteenth valve, 33. a sixth liquid pumping pump 34, a fifteenth valve 35, a sixteenth valve 36, a seventh liquid pumping pump 37, a seventeenth valve 38, an eighteenth valve 39, an eighth liquid pumping pump 40, a nineteenth valve 41, a horizontal decanter centrifuge 42, a flocculated residue discharge port 43, a centrifuged clear liquid outlet 44, a coagulant aid adding port 45 and a mixed liquid adding port.

Detailed Description

The utility model is described in further detail below with reference to the accompanying drawings:

in the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" … …, and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Furthermore, the terms "first", "second" … … are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" … … may explicitly or implicitly include at least one such feature. In the description of the present invention, "a number" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

As shown in fig. 1 to 3, a continuous flocculation apparatus for plant extraction comprises a second mixer 20 for mixing an extract with a flocculant, a second group of separators having a liquid inlet communicated with a liquid outlet of the second mixer 20, a first mixer 1 for mixing a clarified mixed liquid separated by the second group of separators with a coagulant aid, a first group of separators having a liquid inlet communicated with a liquid outlet of the first mixer 1, a horizontal decanter centrifuge 41 for separating a second flocculated liquid accumulated by the second group of separators, a plurality of valves, a plurality of liquid pumping pumps and a pipeline for connection; the first flocculated turbidity accumulated in the first group of separators flows back to the II mixer 20; the clarified liquid separated by the first group of separators and the centrifuged clear liquid separated by the horizontal decanter centrifuge 41 enter the next process together, and the flocculated slag separated by the horizontal decanter centrifuge 41 is discharged outside; the first group of separators and the second group of separators are respectively composed of a plurality of separators which are sequentially connected in series, each separator is distributed in a step shape, a liquid outlet of the previous step separator is connected with a liquid inlet of the next step separator, and a slag discharging port of the next step separator is connected with a slag inlet of the previous step separator.

Specifically, the method comprises the following steps:

the first group of separators comprises a 1# separator 5, a 2# separator 7 and a 3# separator 9 which are distributed in a step shape; a liquid inlet of the 1# separator 5 is connected with a liquid outlet of the I-th mixer 1 through a first liquid beating pump 3, a liquid outlet of the 1# separator 5 is connected with a liquid inlet of a 2# separator 7, a liquid outlet of the 2# separator 7 is connected with a liquid inlet of a 3# separator 9, and a liquid outlet of the 3# separator 9 is connected with equipment of the next process; the slag hole of 3# separator 9 bottom links to each other through the slag inlet of second liquid pump 12 with 2# separator 7, and the slag hole of 2# separator 7 bottom links to each other through the slag inlet of third liquid pump 15 with 1# separator 5, and the slag hole of 1# separator 5 bottom links to each other through the slag inlet of fourth liquid pump 18 with II blender 20.

A second valve 6 is arranged at a liquid outlet at the upper end of the No. 1 separator 5, an eighth valve 16 is arranged at a slag inlet at the lower side end, and a ninth valve 17 is arranged at a slag outlet at the bottom end; a first valve 4 is arranged on a pipeline connecting the liquid outlet of the first mixer 1 and the liquid inlet of the 1# separator 5;

a third valve 8 is arranged at a liquid outlet at the upper end of the 2# separator 7, a sixth valve 13 is arranged at a slag inlet at the lower side end, and a seventh valve 14 is arranged at a slag outlet at the bottom end;

a fourth valve 10 is arranged at a liquid outlet at the upper end of the 3# separator 9, and a fifth valve 11 is arranged at a slag outlet at the bottom end.

The second set of separators includes a 4# separator 26, a 5# separator 28, and a 6# separator 30 in a stepped arrangement; the liquid inlet of the No. 4 separator 26 is connected with the liquid outlet of the II mixer 20 through a fifth liquid pumping pump 24; the liquid outlet of the No. 4 separator 26 is connected with the liquid inlet of the No. 5 separator 28, the liquid outlet of the No. 5 separator 28 is connected with the liquid inlet of the No. 6 separator 30, and the liquid outlet of the No. 6 separator 30 is connected with the mixed liquid adding port 45 of the mixer I1; the slag outlet at the bottom end of the 6# separator 30 is connected with the slag inlet of the 5# separator 28 through a sixth liquid pumping pump 33, the slag outlet at the bottom end of the 5# separator 28 is connected with the slag inlet of the 4# separator 26 through a seventh liquid pumping pump 36, and the slag outlet at the bottom end of the 4# separator 26 is connected with the slag inlet of a horizontal screw centrifuge 41 through an eighth liquid pumping pump 39.

An eleventh valve 25 is arranged at the liquid inlet at the upper part of the No. 4 separator 26, a twelfth valve 27 is arranged at the liquid outlet at the upper end, a seventeenth valve 37 is arranged at the slag inlet at the lower side end, and an eighteenth valve 38 is arranged at the slag outlet at the bottom end;

a thirteenth valve 29 is arranged at a liquid outlet at the upper end of the No. 5 separator 28, a fifteenth valve 34 is arranged at a slag inlet at the lower side end, and a sixteenth valve 35 is arranged at a slag outlet at the bottom end;

an outlet valve 31 is arranged at a liquid outlet at the upper end of the No. 6 separator 30, and a fourteenth valve 32 is arranged at a slag outlet at the bottom end.

In summary, six separators, namely the 1# separator 5, the 2# separator 7, the 3# separator 9, the 4# separator 26, the 5# separator 28 and the 6# separator 30, are divided into two groups, wherein the 1# separator 5, the 2# separator 7 and the 3# separator 9 are a first group of separators, the 4# separator 26, the 5# separator 28 and the 6# separator 30 are a second group of separators, the heights of the separators are different, flocculated clear liquid flows from the top of the separator to the next separator step by step through pressure difference, the structure realizes the step-by-step clarification of the flocculated clear liquid through different separator liquid level differences, and the lower turbid liquid is conveyed by a liquid pump to realize the turbidness of a turbid person.

As shown in FIG. 2, the top end of the first mixer 1 is provided with a mixed liquid adding port 45 for adding the clarified mixed liquid flowing out from the liquid outlet of the No. 6 separator 30 and a coagulant aid adding port 44 for adding the coagulant aid, the bottom end is provided with a liquid outlet, and the liquid outlet of the first mixer 2 is arranged at the liquid outlet. During the continuous flocculation process, the feed in mixer I1 was maintained at 2/3 of the total volume of mixer I1. An online pH meter for detecting the pH value of the feed liquid is arranged on a liquid outlet pipeline of the mixer 1I.

The top end of the second mixer 20 is provided with an extract liquid adding port 21 for adding extract liquid and a flocculant adding port 22 for adding flocculant; a slag inlet for injecting the first flocculation turbid liquid from the slag outlet of the No. 1 separator 5 is further formed in the upper side end of the second mixer 20, and a tenth valve 19 is arranged at the slag inlet; a liquid outlet is arranged at the bottom end of the second mixer 20, and a second mixer liquid outlet valve 23 is arranged at the liquid outlet. During the continuous flocculation process, the feed in the second mixer 20 is maintained at 2/3 of the total volume of the second mixer 20.

The inside of the first mixer 1 and the second mixer 20 is provided with a stirring device for stirring the feed liquid.

The top end of the horizontal screw centrifuge 41 is provided with a slag inlet for injecting the second flocculation turbid liquid from the slag outlet of the 4# separator 26, and the slag inlet is provided with a nineteenth valve 40; the bottom end of the horizontal screw centrifuge 41 is provided with a flocculation slag discharge port 42 for discharging flocculation slag and a centrifugal clear liquid outlet 43 connected with equipment of the next process.

The specific implementation mode is as follows: the extract liquor enters a second mixer 20 through an extract liquor feeding port 21 at the top of the second mixer 20, a flocculating agent ferrous sulfate enters a second mixer 20 through a flocculating agent feeding port 22 at the top of the second mixer 20, first flocculated turbid liquor which is not fully flocculated also enters the second mixer 20 through a tenth valve 19, feed liquor is fully stirred, mixed and flocculated in the second mixer 20 and then enters a fifth liquid pumping pump 24 through a second mixer liquid outlet valve 23, the feed liquor is pumped into a 4# separator 26 through an eleventh valve 25 by the fifth liquid pumping pump 24, after separation in the 4# separator 26, clarified liquor enters a 5# separator 28 through a twelfth valve 27, after separation in the 5# separator 28, the clarified liquor enters a 6# separator 30 through a thirteenth valve 29, after separation in the 6# separator 30, the clarified mixed liquor is discharged through an outlet valve 31, the clarified mixed liquor discharged through the outlet valve 31 enters the first mixer 1 through a mixed liquor feeding port 45, coagulant aid calcium hydroxide and PAM pass through coagulant aid filler port 44 and get into I blender 1, the feed liquid goes out liquid valve 2 through I blender after intensive mixing in I blender 1, first liquid pump 3, first valve 4 gets into 1# separator 5, after separating in 1# separator 5, clarified liquid gets into 2# separator 7 through second valve 6, after separating in 2# separator 7, clarified liquid gets into 3# separator 9 through third valve 8, after separating in 3# separator 9, clarified liquid gets into next step process through fourth valve 10 and carries out the resin adsorption.

After separation in the 3# separator 9, the turbid liquid enters the 2# separator 7 through the fifth valve 11, the second liquid pumping pump 12 and the sixth valve 13, after separation in the 2# separator 7, the turbid liquid enters the 1# separator 5 through the seventh valve 14, the third liquid pumping pump 15 and the eighth valve 16, and after separation in the 1# separator 5, the turbid liquid (the first flocculated liquid) enters the II-th mixer 20 through the ninth valve 17, the fourth liquid pumping pump 18 and the tenth valve 19.

After separation in the 6# separator 30, the turbid liquid enters the 5# separator 28 through the fourteenth valve 32, the sixth liquid pumping pump 33 and the fifteenth valve 34, after separation in the 5# separator 28, the turbid liquid enters the 4# separator 26 through the sixteenth valve 35, the seventh liquid pumping pump 36 and the seventeenth valve 37, after separation in the 4# separator 26, the turbid liquid (second flocculated liquid) enters the horizontal screw centrifuge 41 through the eighteenth valve 38, the eighth liquid pumping pump 39 and the nineteenth valve 40, the second flocculated liquid is separated by the horizontal screw centrifuge 41 to obtain flocculated slag, and the flocculated slag is discharged through a flocculated slag discharge port 42, and the centrifuged clear liquid enters the next process through a centrifuged clear liquid outlet 43 for resin adsorption.

And finally, centrifugally separating the second flocculated turbid liquid by a horizontal screw centrifuge 41, discharging flocculated slag from a flocculated slag discharge port 42, discharging separated clear liquid from a clear liquid outlet 43, and allowing the separated clear liquid and clear liquid collected by a fourth valve 10 on the upper part of the 3# separator 9 to enter the next process for resin adsorption.

The arrangement of the valves facilitates the control of the flow of the feed liquid.

The using method comprises the following steps:

1. the extract liquor enters the second mixer 20 through an extract liquor feeding port 21, ferrous sulfate serving as a flocculating agent is quantitatively added into the second mixer 20 through a flocculating agent feeding port 22 according to the flow rate of the extract liquor entering the second mixer 20, and the feed liquor and the flocculating agent are fully mixed in the second mixer 20. Controlling the flow rate of the extraction liquid and the first flocculation turbid liquid entering the II mixer 20, and simultaneously controlling the extraction flow rate of the feed liquid of the II mixer 20, so that the feed liquid in the II mixer 20 is kept at 2/3 of the total volume of the II mixer 20.

2. The clear mixed liquid enters the first mixer 1 through the mixed liquid adding port 45, the coagulant aid calcium hydroxide and PAM are quantitatively added through the coagulant aid adding port 44 according to the flow rate of the clear mixed liquid entering the first mixer 1, the clear mixed liquid enters the first mixer 1, and the feed liquid and the coagulant aid are fully mixed in the first mixer 1. The flow rate of the clarified mixed liquor entering the first mixer 1 is controlled, the feed liquor extraction flow rate of the first mixer 1 is controlled simultaneously, the feed liquor in the first mixer 1 is kept at 2/3 of the total volume of the first mixer 1, an online pH meter is additionally arranged on a pipeline of the extraction liquor of the first mixer 1 to detect the pH value of the feed liquor, and the addition amount of calcium hydroxide is controlled according to the pH value of the feed liquor.

3. The mixed feed liquid is separated by two groups of separators, the first group of separators consists of three separators, namely a 1# separator 5, a 2# separator 7 and a 3# separator 9, the three separators are different in height, the 1# separator 5, the 2# separator 7 and the 3# separator 9 are sequentially arranged from high to low, separated clear liquid gradually enters the next separator by pressure difference, and separated turbid liquid is gradually pumped into the previous separator by a liquid pumping pump.

The second group of separators consists of three separators, namely a 4# separator 26, a 5# separator 28 and a 6# separator 30, the three separators are different in height, the 4# separator 26, the 5# separator 28 and the 6# separator 30 are sequentially arranged from high to low, separated clear liquid enters the next separator step by step through pressure difference, and separated turbid liquid is pumped into the previous separator step by step through a liquid pumping pump.

The continuous flocculation device can effectively treat the extraction liquid, so that the transmittance of the system liquid reaches over 70 percent, and the cost is reduced by 50 percent.

Claims

1. A continuous flocculation device for plant extraction, characterized in that: the device comprises a II mixer (20) for mixing extract liquor and flocculating agent, a second group of separators, an I mixer (1) for mixing clarified mixed liquor separated by the second group of separators with coagulant aid, a first group of separators, a horizontal screw centrifuge (41) for separating second flocculated liquor accumulated by the second group of separators, a plurality of valves, a plurality of liquid pumping pumps and a pipeline for connecting the valves; the first flocculated turbidity accumulated in the first group of separators flows back to the II mixer (20); the clarified liquid separated by the first group of separators and the centrifuged clear liquid separated by the horizontal screw centrifugal machine (41) enter the next working procedure together, and the flocculated slag separated by the horizontal screw centrifugal machine (41) is discharged outside; the first group of separators and the second group of separators are respectively composed of a plurality of separators which are sequentially connected in series, each separator is distributed in a step shape, a liquid outlet of the previous step separator is connected with a liquid inlet of the next step separator, and a slag discharging port of the next step separator is connected with a slag inlet of the previous step separator.

2. A continuous flocculation apparatus for plant extraction according to claim 1, wherein: the first group of separators comprises a No. 1 separator (5), a No. 2 separator (7) and a No. 3 separator (9) which are distributed in a step shape; a liquid inlet of the 1# separator (5) is connected with a liquid outlet of the first mixer (1) through a first liquid beating pump (3), a liquid outlet of the 1# separator (5) is connected with a liquid inlet of the 2# separator (7), a liquid outlet of the 2# separator (7) is connected with a liquid inlet of the 3# separator (9), and a liquid outlet of the 3# separator (9) is connected with equipment of the next procedure; the slag hole of 3# separator (9) bottom links to each other through the slag inlet of second liquid pump (12) with 2# separator (7), and the slag hole of 2# separator (7) bottom links to each other through the slag inlet of third liquid pump (15) with 1# separator (5), and the slag hole of 1# separator (5) bottom links to each other through the slag inlet of fourth liquid pump (18) with II blender (20).

3. A continuous flocculation apparatus for plant extraction according to claim 1, wherein: the second set of separators comprises a 4# separator (26), a 5# separator (28) and a 6# separator (30) which are distributed in a step shape; a liquid inlet of the No. 4 separator (26) is connected with a liquid outlet of the second mixer (20) through a fifth liquid pumping pump (24); the liquid outlet of the No. 4 separator (26) is connected with the liquid inlet of the No. 5 separator (28), the liquid outlet of the No. 5 separator (28) is connected with the liquid inlet of the No. 6 separator (30), and the liquid outlet of the No. 6 separator (30) is connected with the mixed liquid adding port (45) of the mixer I (1); the slag outlet at the bottom end of the 6# separator (30) is connected with the slag inlet of the 5# separator (28) through a sixth liquid pumping pump (33), the slag outlet at the bottom end of the 5# separator (28) is connected with the slag inlet of the 4# separator (26) through a seventh liquid pumping pump (36), and the slag outlet at the bottom end of the 4# separator (26) is connected with the slag inlet of a horizontal screw centrifuge (41) through an eighth liquid pumping pump (39).

4. A continuous flocculation apparatus for plant extraction according to claim 1, wherein: the top of the first mixer (1) is provided with a mixed liquid adding port (45) for adding clarified mixed liquid flowing out of the liquid outlet of the 6# separator (30) and a coagulant aid adding port (44) for adding coagulant aid, the bottom is provided with a liquid outlet, and the liquid outlet is provided with a first mixer liquid outlet valve (2).

5. A continuous flocculation apparatus for plant extraction according to claim 4, wherein: during the continuous flocculation process, the feed liquid in the first mixer (1) is maintained at 2/3 of the total volume of the first mixer (1).

6. A continuous flocculation apparatus for plant extraction according to claim 4, wherein: an online pH meter for detecting the pH value of the feed liquid is arranged on a liquid outlet pipeline of the mixer (1).

7. A continuous flocculation apparatus for plant extraction according to claim 1, wherein: the top end of the second mixer (20) is provided with an extract liquid adding port (21) for adding extract liquid and a flocculant adding port (22) for adding flocculant; a slag inlet for injecting the first flocculation turbid liquid from the slag outlet of the No. 1 separator (5) is also formed in the upper side end of the second mixer (20), and a tenth valve (19) is arranged at the slag inlet; a liquid outlet is arranged at the bottom end of the second mixer (20), and a second mixer liquid outlet valve (23) is arranged at the liquid outlet.

8. A continuous flocculation apparatus for plant extraction according to claim 7, wherein: during the continuous flocculation process, the feed in the second mixer (20) is maintained at 2/3 of the total volume of the second mixer (20).

9. A continuous flocculation apparatus for plant extraction according to claim 1, wherein: the top end of the horizontal screw centrifuge (41) is provided with a slag inlet for injecting second flocculation turbid liquid from a slag outlet of the 4# separator (26), and a nineteenth valve (40) is arranged at the slag inlet; the bottom end of the horizontal screw centrifuge (41) is provided with a flocculation slag discharge port (42) for discharging flocculation slag and a centrifugal clear liquid outlet (43) connected with equipment in the next working procedure.

10. A continuous flocculation apparatus for plant extraction as claimed in any one of claims 1 to 8, wherein: the first mixer (1) and the second mixer (20) are internally provided with stirring devices for stirring feed liquid.