CN113502191A

CN113502191A - Method for extracting volatile oil from houttuynia cordata

Info

Publication number: CN113502191A
Application number: CN202110896739.5A
Authority: CN
Inventors: 蓝峻峰; 王小明
Original assignee: Guangxi Science and Technology Normal University
Current assignee: Guangxi Science and Technology Normal University
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2021-10-15

Abstract

The invention discloses a method for extracting volatile oil from houttuynia cordata, which comprises the steps of firstly crushing houttuynia cordata raw materials to obtain crushed houttuynia cordata, then carrying out ultrasonic extraction treatment to obtain houttuynia cordata extract, then putting the houttuynia cordata extract into a heating device of volatile oil extraction equipment, introducing high-temperature water vapor into the heating device to heat the houttuynia cordata extract to obtain high-temperature volatile oil-containing vapor, finally introducing the volatile oil-containing vapor into an oil-water separation device of the volatile oil extraction equipment, introducing cold water into the oil-water separation device to condense the volatile oil-containing vapor to obtain oil-water mixed liquid, and separating the volatile oil from the top of the separation device by utilizing the principle of light oil and heavy water to obtain the volatile oil. According to the invention, the houttuynia cordata is subjected to ultrasonic extraction treatment, so that volatile oil components in the houttuynia cordata are easy to extract, and the houttuynia cordata extract with high volatile oil content is obtained.

Description

Method for extracting volatile oil from houttuynia cordata

Technical Field

The invention relates to the technical field of extraction of plant volatile oil, and particularly relates to an extraction method of volatile oil in houttuynia cordata.

Background

The herba houttuyniae is a wild plant with homology of medicine and food, has the efficacies of clearing away heat and toxic material, reducing swelling and expelling pus, relieving cough and reducing sputum and the like, and has the inhibiting effect on various bacteria. The volatile oil is the main functional substance of houttuynia cordata, and has good curative effects on upper respiratory tract infection, bronchitis, pneumonia, chronic bronchitis, pertussis and the like.

In the prior art, the extraction method of volatile oil in houttuynia cordata mainly comprises a steam distillation method, a grease absorption method, an organic solvent extraction method, a supercritical fluid extraction method, a cold pressing method and the like. The steam distillation method has the characteristics of simple equipment, safe operation, no pollution, low cost, capability of avoiding the influence of organic solvent residue on the quality of the volatile oil in the extraction process and the like, so the steam distillation method is widely applied to the industry at present. However, the yield of volatile oil extracted from the houttuynia cordata by the steam distillation method in the prior art is low, and the water resource consumption is high.

Disclosure of Invention

The invention provides a method for extracting volatile oil from houttuynia cordata.

The invention adopts the following technical scheme:

a method for extracting volatile oil from houttuynia cordata mainly comprises the following steps:

the method comprises the following steps: firstly, cleaning and airing the houttuynia cordata raw material, and crushing the aired houttuynia cordata raw material by using a crusher to obtain a crushed houttuynia cordata material;

step two: putting the crushed houttuynia cordata into a pretreatment device of volatile oil extraction equipment, adding distilled water for ultrasonic extraction treatment, and filtering to obtain a houttuynia cordata leaching solution;

step three: putting the houttuynia cordata leaching liquor into a heating device of volatile oil extraction equipment, and introducing high-temperature water vapor into the heating device to heat the houttuynia cordata leaching liquor to obtain high-temperature volatile oil-containing vapor;

step four: introducing the vapor containing volatile oil into an oil-water separation device of volatile oil extraction equipment, introducing cold water into the oil-water separation device, condensing the vapor containing volatile oil to obtain oil-water mixed liquid, and separating from the top of the separation device by utilizing the principle of light oil and heavy water to obtain the volatile oil.

According to a preferable technical scheme of the invention, in the second step, the ratio of the distilled water to the ground houttuynia cordata is 2-4: 1 in parts by weight, and the ultrasonic treatment time is 20-40 min.

As a preferred technical scheme of the invention, the water vapor pressure in the third step is 2.0-2.5 MPa, and the temperature is 350-400 ℃.

As a preferred technical scheme of the invention, the volatile oil extraction equipment comprises a pretreatment device, a heating device and an oil-water separation device which are sequentially connected through a pipeline, wherein the pretreatment device comprises a tank body I, a screen, an ultrasonic generator and a stirrer, a feed inlet and a discharge outlet are respectively arranged at the top and the bottom of the tank body I, a water inlet is arranged on the side wall of the lower part of the tank body I, the screen is movably connected at the upper part of the tank body I, the ultrasonic generator is arranged on the side wall of the lower part of the tank body I, the stirrer is arranged at the bottom of the tank body I, the heating device comprises a tank body II, a steam generator and a steam uniform distributor, a liquid inlet and a gas outlet are respectively arranged at two sides of the upper part of the tank body II, the steam uniform distributor is arranged at the bottom of the tank body II, a plurality of exhaust holes are uniformly distributed on the steam uniform distributor, the steam generator is positioned outside the tank body II and is connected with the steam uniform distributor through the pipeline I, the oil-water separator comprises an outer tank, an inner tank and a cold water coil pipe, the inner tank is sleeved in the outer tank, an air inlet and a liquid outlet are respectively arranged on two sides of the bottom of the inner tank, the air inlet is connected with a gas outlet through a pipeline III, a check valve is arranged on the liquid outlet and communicated with the outer tank, an oil outlet and a water outlet are respectively arranged on the upper portion and the lower portion of the outer tank, the cold water coil pipe is arranged in the inner tank, and the cold water coil pipe is connected with an external cold water pool through the cold water pipe.

As a preferred technical scheme of the invention, the first tank body is cylindrical, the side wall of the upper part of the first tank body is provided with an annular groove which surrounds the first tank body by one circle, the groove is internally provided with a plurality of connecting rods, the screen is circular and is matched with the first tank body, the edge of the screen is provided with an annular clamping plate, the clamping plate is provided with connecting holes with the number corresponding to the number of the connecting rods, the connecting rods are sleeved in the connecting holes, the outer part of the connecting rod between the top surface of the clamping plate and the upper inner top surface of the groove is sleeved with an upper spring, and the outer part of the connecting rod between the bottom surface of the clamping plate and the lower inner bottom surface of the groove is sleeved with a lower spring.

As a preferred technical scheme of the invention, a support frame is welded on the inner side walls of the two tank bodies at the liquid inlet, a filter basket is placed in the support frame, and a slag discharge port is arranged at the top of the two tank bodies right above the support frame.

As a preferred technical scheme of the invention, the diameter of the outer tank is gradually reduced from the middle part to the top part to form an outer narrow neck, the top part of the outer narrow neck is provided with an exhaust pipe, the upper part of the outer narrow neck is provided with an oil outlet, the diameter of the inner tank is gradually reduced from the middle part to the top part to form an inner narrow neck matched with the outer narrow neck, the top end of the inner narrow neck penetrates through the top end of the outer narrow neck and is hermetically connected with an elastic membrane cover, the upper part of the inner narrow neck is provided with an air return pipe, the lower end of the air return pipe extends to the inner bottom part of the outer tank, and the lower end of the air return pipe is provided with a bubbler.

As a preferred technical scheme of the invention, the cold water coil is a spiral coil, the bottom of the cold water coil is provided with an atomizing nozzle, the cold water coil is provided with a plurality of layers according to the height of the inner tank, the side wall of the inner tank between the two layers of cold water coils is provided with an annular guide plate, and the guide plate is arranged downwards in an inclined manner towards the center of the inner tank.

As a preferable technical scheme of the invention, a water outlet pipe is arranged at the water outlet, a pipeline IV is connected to the water outlet pipe, and the other end of the pipeline IV is connected with the inlet end of the steam generator.

The invention has the beneficial effects that:

according to the invention, the houttuynia cordata is subjected to ultrasonic extraction treatment, so that volatile oil components in the houttuynia cordata are easy to extract, and the houttuynia cordata extract with high volatile oil content is obtained.

Drawings

FIG. 1 is a front view of the present invention;

FIG. 2 is an enlarged schematic view of the structure at A;

fig. 3 is a schematic diagram of a screen structure.

The symbols in the drawings illustrate that:

1: jar body one, 2: screen mesh, 3: ultrasonic generator, 4: stirrer, 5: feed inlet, 6: discharge port, 7: water inlet, 8: a second tank body 9: steam generator, 10: steam uniform distributor, 11: liquid inlet, 12: outlet, 13: exhaust hole, 14: the first pipeline, 15: a second pipeline, 16: pump body, 17: outer vessel, 18: an inner tank: 19: cold water coil, 20: air inlet, 21: liquid outlet, 22: pipeline three, 23: check valve, 24: oil outlet, 25: water outlet, 26: cold water pipe, 27: groove, 28: connecting rod, 29: a splint, 30: connection hole, 31: upper spring, 32: lower spring, 33: support frame, 34: filter basket, 35: slag discharge port, 36: outer narrow neck, 37: exhaust pipe, 38: inner narrow neck, 39: elastic film cover, 40: muffler, 41: bubbler, 42: connecting pipe, 43: deflector, 44: water outlet pipe, 45: and a fourth pipeline.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings.

Example 1

step two: putting the crushed houttuynia cordata into a pretreatment device of volatile oil extraction equipment, adding distilled water for ultrasonic extraction treatment, filtering to obtain houttuynia cordata extract, and performing ultrasonic extraction treatment to enable organic components in the houttuynia cordata to be separated more easily;

Further, in the second step, the ratio of the distilled water to the ground houttuynia cordata is 2:1 in parts by weight, and the ultrasonic treatment time is 40 min.

Further, the water vapor pressure in the third step is 2.0MPa, and the temperature is 350 ℃.

Further, as shown in fig. 1 to 3, the volatile oil extraction equipment comprises a pretreatment device, a heating device and an oil-water separation device which are sequentially connected through a pipeline, wherein the pretreatment device comprises a tank body 1, a screen 2, an ultrasonic generator 3 and a stirrer 4, a feed inlet 5 and a discharge outlet 6 are respectively arranged at the top and the bottom of the tank body 1, the feed inlet 5 is used for feeding the crushed houttuynia cordata into the tank body 1, the discharge outlet 6 is used for discharging the suspension of the houttuynia cordata subjected to ultrasonic leaching treatment, a water inlet 7 is arranged on the side wall of the lower part of the tank body 1, and the water inlet 7 is used for introducing distilled water into the tank body 1. The screen 2 is movably connected to the upper portion of the tank body I1, the ultrasonic generator 3 is arranged on the side wall of the lower portion of the tank body I1, the ultrasonic generator 3 can adopt a wiring mode in the prior art, and the wiring mode can refer to the wiring mode of ultrasonic waves in the prior art, and details are not repeated herein. The stirrer 4 is arranged at the bottom of the tank body 1, the stirrer 4 can adopt a conventional stirrer in the prior art, the stirrer is arranged at the bottom in the embodiment, and the function of the stirrer is not special or changed, so that the detailed structure and the connection mode of the stirrer 4 are not described herein. The heating device comprises a tank body II 8, a steam generator 9 and a steam uniform distributor 10, wherein both sides of the upper part of the tank body II 8 are respectively provided with a liquid inlet 11 and a gas outlet 12, the liquid inlet 11 is used for introducing houttuynia cordata leaching liquor into the tank body II 8, and the gas outlet 12 is used for discharging volatile oil-containing steam generated in the tank body II 8. Steam uniform distributor 10 locates jar body two 8 bottoms, is equipped with a plurality of exhaust holes 13 of evenly arranging on steam uniform distributor 10, and steam uniform distributor 10 can adopt the conventional steam uniform distributor among the prior art, and its main function is the vapor dispersion that will let in jar body two 8 evenly for the inside houttuynia cordata thunb leaching liquor of jar body two 8 is heated evenly, improves the volatile oil extraction rate. The steam generator 9 is located outside the second tank 8 and connected with the steam uniform distributor 10 through the first pipe 14, and the steam generator 9 can be a conventional steam generator in the prior art, and specific structures and use principles thereof are not described herein again. The discharge port 6 is connected with the liquid inlet 11 through a second pipeline 15, a pump body 16 is arranged on the second pipeline 15, and the houttuynia cordata suspension in the tank body 1 is pumped into the tank body 8 through the pump body 16. The oil-water separation device comprises an outer tank 17, an inner tank 18 and a cold water coil pipe 19, wherein the inner tank 18 is sleeved in the outer tank 17, and the shape of the inner tank 18 is matched with that of the outer tank 17. An air inlet 20 and a liquid outlet 21 are respectively arranged at two sides of the bottom of the inner tank 18, the air inlet 20 is connected with the air outlet 12 through a third pipeline 22, and the volatile oil-containing steam enters the inner tank 18 through the third pipeline 22 and the air inlet 20. The liquid outlet 21 is provided with a one-way valve 23 and communicated with the outer tank 17, and the condensed oil-water mixed liquid enters the outer tank 17 through the liquid outlet 21. The upper part and the lower part of the outer tank 17 are respectively provided with an oil outlet 24 and a water outlet 25, the oil outlet 24 is used for collecting volatile oil floating on the upper layer of the outer tank 17, and water separated from the volatile oil is discharged out of the outer tank 17 from the water outlet 25. The cold water coil 19 is arranged in the inner tank 18, and the cold water coil 19 is connected with an external cold water pool through a cold water pipe 26.

Further, the tank body 1 is cylindrical, the side wall of the upper part of the tank body 1 is provided with an annular groove 27 surrounding the periphery of the tank body 1, specifically, the opening of the groove 27 faces the center of the tank body 1, and the bottom opposite to the opening of the groove 27 is the side wall of the tank body 1. Be equipped with a plurality of connecting rods 28 in the recess 27, connecting rod 28 upper end fixed connection is on the top surface of recess 27, and the lower extreme fixed connection of connecting rod 28 is in the lower bottom surface of recess 27, and connecting rod 28 evenly distributed is in recess 27, and in this embodiment, connecting rod 28 is equipped with 4. The screen cloth 2 is circular with jar body 1 adaptation, and the border of screen cloth 2 is equipped with annular splint 29, and splint 29 is used for pressing from both sides the border of tight fixed screen cloth 2, be equipped with the connecting hole 30 that corresponds with connecting rod 28 figure on the splint 29, connecting hole 30 evenly arranges on splint 29, and connecting hole 30 is equipped with 4 specifically. The clamping plate 29 is nested in the groove 27, the connecting rod 28 penetrates through the connecting hole 30, so that the screen 2 is fixed on the inner side wall of the upper part of the tank body I1, the outer part of the connecting rod 28 between the top surface of the clamping plate 29 and the upper inner top surface of the groove 27 is sleeved with an upper spring 31, and the outer part of the connecting rod 28 between the bottom surface of the clamping plate 29 and the lower inner bottom surface of the groove 27 is sleeved with a lower spring 32. Therefore, when the crushed houttuynia cordata thrown from the feed inlet 5 falls on the screen 2, houttuynia cordata particles with the particle size smaller than the meshes of the screen 2 can smoothly fall to the bottom of the tank body I1, and some houttuynia cordata particles with larger particle size are intercepted on the screen 2; in addition, when the ground houttuynia cordata falls onto the screen 2 from above, a certain impact force is applied to the screen 2, this causes the clamp plate 29 to compress the lower spring 32 downward due to the force, and the crushed houttuynia cordata falling into the screen 2 from above has different weight and more time and less time, so that the force of impact on the screen 2 is not always equally great, which makes the force pressing on the lower spring 32 unbalanced, thereby causing the lower spring 32 to be compressed at times, and to be sprung up at times by its own restoring force, which in turn causes compression of the upper spring 31, so that the clamping plate 29 moves up and down between the upper spring 31 and the lower spring 32, thereby driving the screen 2 to vibrate up and down, which has the advantages that the screen 2 can spread the crushed houttuynia cordata falling on the screen by self vibration, so that the particulate matter of the houttuynia cordata with small particle size is shaken off quickly, and the blockage of the meshes of the crushed houttuynia cordata due to the excessive crushed houttuynia cordata accumulated on the screen 2 is avoided.

Further, the welding has a support frame 33 on the two 8 inside walls of jar body of inlet 11 department, and the bottom of support frame 33 is equipped with the support bar, and the support frame 33 side is equipped with the rail, place filter basket 34 in the support frame 33, filter basket 34 is made by the fine and close filter screen, and inlet 11 is located filter basket 34 open-ended top, is equipped with row cinder notch 35 just to the jar body two 8 tops of support frame 33 top. Specifically, the houttuynia cordata suspension enters the second tank 8 through the liquid inlet 11, firstly passes through the filter basket 34, the crushed houttuynia cordata residues in the houttuynia cordata suspension are intercepted through the filter basket 34, then the residue discharge port 35 is opened, the filter basket 34 is lifted out, the crushed houttuynia cordata residues can be put into the first tank 1 again for ultrasonic leaching, the crushed houttuynia cordata residues are filtered to obtain the houttuynia cordata leaching liquor, the houttuynia cordata leaching liquor directly falls into the bottom of the second tank 8 and is heated through high-temperature steam, the volatile oil is heated, gasified and separated from the houttuynia cordata leaching liquor, mixed with the steam to form volatile oil-containing steam, and finally discharged through the gas outlet 12 and enters the inner tank 18 for condensation.

Further, the diameter of the outer tank 17 is gradually reduced from the middle to the top to form an outer narrow neck 36, so that a small amount of volatile oil is easier to enrich and convenient to collect, an exhaust pipe 37 is arranged at the top of the outer narrow neck 36, the exhaust pipe 37 is used for exhausting gas in the outer tank 17, an oil outlet 24 is arranged at the upper part of the outer narrow neck 36, and the volatile oil enriched and collected at the upper layer of the outer narrow neck 36 is collected from the oil outlet 24. The diameter of the inner tank 18 is gradually reduced from the middle to the top to form an inner narrow neck 38 matched with the outer narrow neck 36, the top end of the inner narrow neck 38 penetrates through the top end of the outer narrow neck 36 and is connected with an elastic membrane cover 39 in a sealing mode, the elastic membrane cover 39 is used for buffering the pressure in the inner tank 18 to avoid burst of the inner tank 18 caused by overlarge instantaneous pressure, an air return pipe 40 is arranged at the upper portion of the inner narrow neck 38, the lower end of the air return pipe 40 extends to the inner bottom of the outer tank 17, and a bubbler 41 is arranged at the lower end of the air return pipe 40.

Furthermore, the cold water coil pipe 19 is a spiral coil pipe, the bottom surface of the cold water coil pipe 19 is provided with an atomizing nozzle, the cold water coil pipe 19 is provided with a plurality of layers according to the height of the inner tank 18, the cold water coil pipes 19 are communicated through a connecting pipe 42, the side wall of the inner tank 18 between the two layers of cold water coil pipes 19 is provided with an annular guide plate 43, the guide plate 43 is arranged downwards and slantwise towards the center of the inner tank 18, and the guide plate 43 can prevent the steam containing volatile oil from rising along the side wall of the inner tank 18, so that the steam cannot be contacted with atomized water vapor, the steam rises along the center of the inner tank 18 as much as possible, and the condensation dead angle is reduced; secondly, the condensed oil-water mixed liquid can drop to the center of the inner tank 18 along the guide plate 43, so that the condensed oil-water mixed liquid is further contacted with the atomized water vapor and is fully condensed.

Furthermore, a water outlet pipe 44 is arranged at the water outlet 25, a fourth pipeline 45 is connected to the water outlet pipe 44, and the other end of the fourth pipeline 45 is connected with an inlet end of the steam generator 9.

Specifically, the volatile oil-containing vapor enters from the bottom of the inner tank 18, then rises along the height of the inner tank 18, meets atomized water vapor sprayed from the upper part in the process of rising continuously, the volatile oil-containing vapor is quickly condensed into oil-containing liquid after meeting the atomized water vapor with lower temperature, the rising layer is cooled layer by layer, most of the volatile oil-containing vapor is condensed, a small amount of volatile oil is introduced into the outer tank 17 through the air return pipe 40, bubbles are generated through the bubbler 41, the oil-containing liquid enters the outer tank 17 through the liquid outlet 21, according to the principle of light oil and heavy water, the volatile oil floats to the upper layer, as the volatile oil mainly forms small oil droplets, the viscosity is high, the volatile oil is not easy to separate from the water, the bubbles discharged through the air return pipe 40 can destroy the surface tension of the small oil droplets of the volatile oil, the volatile oil is aggregated into large oil droplets, the volatile oil rapidly floats to the upper layer after being separated from the volatile oil, and is discharged from the water outlet 25, one part enters the steam generator 9 through a pipe IV 45 to be used as water source supplement, so that water resources are saved.

Example 2

Further, in the second step, the ratio of the distilled water to the ground houttuynia cordata is 3:1 in parts by weight, and the ultrasonic treatment time is 30 min.

Further, the water vapor pressure in the third step is 2.3 MPa, and the temperature is 380 ℃.

The structure of the volatile oil extraction apparatus is the same as in example 1.

Example 3

Further, in the second step, the ratio of the distilled water to the ground houttuynia cordata is 4:1 in parts by weight, and the ultrasonic treatment time is 20 min.

Further, the water vapor pressure in the third step is 2.5 MPa, and the temperature is 400 ℃.

Finally, it should be noted that: these embodiments are merely illustrative of the present invention and do not limit the scope of the present invention. In addition, other variations and modifications will be apparent to persons skilled in the art based on the foregoing description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.

Claims

1. A method for extracting volatile oil from houttuynia cordata is characterized by comprising the following steps: the method mainly comprises the following steps:

2. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 1, wherein the method comprises the following steps: in the second step, the distilled water and the ground houttuynia cordata are mixed in a weight ratio of 2-4: 1, and the ultrasonic treatment time is 20-40 min.

3. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 1, wherein the method comprises the following steps: the water vapor pressure in the third step is 2.0-2.5 MPa, and the temperature is 350-400 ℃.

4. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 1, wherein the method comprises the following steps: the volatile oil extraction equipment comprises a pretreatment device, a heating device and an oil-water separation device which are sequentially connected through a pipeline, wherein the pretreatment device comprises a tank body I (1), a screen (2), an ultrasonic generator (3) and a stirrer (4), the top and the bottom of the tank body I (1) are respectively provided with a feed inlet (5) and a discharge outlet (6), the lower side wall of the tank body I (1) is provided with a water inlet (7), the screen (2) is movably connected to the upper part of the tank body I (1), the ultrasonic generator (3) is arranged on the lower side wall of the tank body I (1), the stirrer (4) is arranged at the bottom of the tank body I (1), the heating device comprises a tank body II (8), a steam generator (9) and a steam uniform distributor (10), both sides of the upper part of the tank body II (8) are respectively provided with a liquid inlet (11) and a gas outlet (12), and the steam uniform distributor (10) is arranged at the bottom of the tank body II (8), a plurality of exhaust holes (13) which are uniformly distributed are formed in the steam uniform distributor (10), the steam generator (9) is positioned outside the tank body II (8) and is connected with the steam uniform distributor (10) through a pipeline I (14), the discharge hole (5) and the liquid inlet (11) are connected through a pipeline II (15), a pump body (16) is arranged on the pipeline II (15), the oil-water separation device comprises an outer tank (17), an inner tank (18) and a cold water coil pipe (19), the inner tank (18) is sleeved in the outer tank (17), an air inlet (20) and a liquid outlet (21) are respectively arranged on two sides of the bottom of the inner tank (18), the air inlet (20) is connected with the air outlet (12) through a pipeline III (22), a check valve (23) is arranged on the liquid outlet (21) and is communicated with the outer tank (17), an oil outlet (24) and a water outlet (25) are respectively arranged on the upper portion and the lower portion of the outer tank (17), the cold water coil pipe (19) is arranged in the inner tank (18), and the cold water coil pipe (19) is connected with an external cold water pool through a cold water pipe (26).

5. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 4, wherein the method comprises the following steps: the jar body (1) is cylindrical, and jar body (1) upper portion lateral wall is equipped with annular groove (27) of its a week of ring, be equipped with a plurality of connecting rods (28) in recess (27), screen cloth (2) for with the circular of jar body (1) adaptation, the border of screen cloth (2) is equipped with annular splint (29), be equipped with connecting hole (30) that correspond with connecting rod (28) figure on splint (29), connecting rod (28) cover is worn in connecting hole (30), and connecting rod (28) outside cover that is located on splint (29) top surface and recess (27) between the interior top surface is equipped with spring (31), and connecting rod (28) outside cover that is located under splint (29) bottom surface and recess (27) between the bottom surface is equipped with down spring (32).

6. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 4, wherein the method comprises the following steps: a support frame (33) is welded on the inner side wall of the tank body II (8) at the liquid inlet (11), a filter basket (34) is placed in the support frame (33), and a slag discharge port (35) is arranged right at the top of the tank body II (8) above the support frame (33).

7. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 4, wherein the method comprises the following steps: outer jar (17) diameter is reduced gradually to the top by the middle part and is formed outer narrow neck (36), outer narrow neck (36) top is equipped with blast pipe (37), and outer narrow neck (36) upper portion is equipped with oil-out (24), interior jar (18) diameter is reduced gradually by the middle part to the top and is formed interior narrow neck (38) with outer narrow neck (36) adaptation, the top of outer narrow neck (36) is run through on interior narrow neck (38) top and sealing connection has elastic membrane cover (39), and interior narrow neck (38) upper portion is equipped with muffler (40), muffler (40) lower extreme extends to outer jar (17) bottom in, and muffler (40) lower extreme is equipped with bubbler (41).

8. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 4, wherein the method comprises the following steps: the cold water coil pipe (19) is spiral coil pipe, and cold water coil pipe (19) bottom surface is equipped with atomizing nozzle, and cold water coil pipe (19) highly is provided with a plurality of layers according to inner tank (18), is equipped with annular guide plate (43) on inner tank (18) lateral wall between two-layer cold water coil pipe (19), guide plate (43) are towards inner tank (18) center slope and set up downwards.

9. The method for extracting the volatile oil from the houttuynia cordata as claimed in claim 4, wherein the method comprises the following steps: a water outlet pipe (44) is arranged at the water outlet (25), a fourth pipeline (45) is connected to the water outlet pipe (44), and the other end of the fourth pipeline (45) is connected with the inlet end of the steam generator (9).