A purification device for supercritical essential oil extracts

Abstract

This utility model relates to the field of essential oil purification technology, and discloses a purification device for supercritical essential oil extracts. It includes a material tank for storing supercritical essential oils and a purification component connected to the material tank. The purification component includes a shell and a filter cylinder mounted on top of the shell. The top of the filter cylinder is connected to an opening at the bottom of the material tank. A pressure plate can be installed inside the filter cylinder, and a filter element is detachably installed at the bottom of the filter cylinder. A filter membrane is installed inside the shell, and a discharge port is provided at the bottom of the shell. This utility model achieves a synergistic effect of coarse and fine filtration through the multi-stage filtration synergy of the pressure plate, filter element, and filter membrane, significantly improving purification accuracy.

Description

Technical Field

[0001] This utility model relates to the field of essential oil purification technology, specifically to a purification device for supercritical essential oil extracts. Background Technology

[0002] Essential oils are indispensable substances in the pharmaceutical, food, and cosmetic industries. Especially in the cosmetics field, essential oils are often used in the development of perfumes, balms, massage oils, and other products. Their market price is high and supply cannot meet demand. Currently, essential oils on the market are mainly obtained through water distillation extraction. Although this method has the advantages of simple process and low cost, it has obvious drawbacks, such as low yield of volatile components with high boiling points and easy deterioration of heat-sensitive active substances.

[0003] Supercritical carbon dioxide extraction has gained increasing attention due to its advantages such as low extraction temperature, high extraction efficiency, and no organic solvent residue. However, existing supercritical extraction devices still face two major bottlenecks in practical applications: Firstly, the purity of the target product is insufficient: Under low-temperature extraction conditions, SC-CO2 has a strong solubility for low-molecular-weight impurities such as colloids and pigments, causing them to precipitate simultaneously with the active ingredients of the essential oil. Subsequent conventional filtration methods (such as centrifugation and diatomaceous earth adsorption) are difficult to effectively separate coexisting substances with similar molecular weights, and the final product often requires secondary purification, significantly increasing the process cost.

[0004] Secondly, the lack of sterile control: Although the high-pressure, sealed environment of the supercritical system can inhibit the growth of microorganisms, the extract is easily exposed to unclean air during the depressurization and collection stage, causing secondary pollution. Traditional filter membranes (such as cellulose membranes) have low mechanical strength and poor pressure resistance, making it impossible to directly integrate sterilization-grade filter units into high-pressure pipelines, resulting in a significant reduction in the shelf life of essential oils. Utility Model Content

[0005] The present invention aims to provide a purification device for supercritical essential oil extracts to filter out colloids and pigments in essential oils, thereby initially improving the purity of essential oils.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a purification device for supercritical essential oil extract, comprising a material tank for storing supercritical essential oil and a purification component connected to the material tank. The purification component includes a shell and a filter cylinder installed on the top of the shell. The top of the filter cylinder is connected to an opening at the bottom of the material tank. A pressure plate is installed inside the filter cylinder. A filter element is detachably installed at the bottom of the filter cylinder. A filter membrane is installed inside the shell. A discharge port is provided at the bottom of the shell.

[0007] Beneficial effects: 1. Synergistic effect of multi-stage filtration: pressure plate, filter element and filter membrane: The pressure plate in the filter cartridge can initially divide the incoming essential oil extract, so that the material is evenly distributed and flows through the filter element. The pressure plate can first remove larger particulate impurities or mechanical impurities. After the initial filtration, the essential oil enters the outer shell and is finely filtered through the filter membrane, which further intercepts small molecule impurities, colloids or residual trace solid particles, achieving the synergistic effect of coarse filtration and fine filtration, and significantly improving the purification accuracy.

[0008] 2. The pressure-distributing plate design can buffer and reduce the pressure of a large amount of essential oil in the upper part, preventing the essential oil from falling directly onto the filter element and causing damage: When the upper part receives a large amount of essential oil from the material tank, the pressure-distributing plate can effectively buffer and reduce the pressure of the essential oil under high pressure. Through its own structure, it disperses the concentrated impact of the fluid into a uniform distribution state, avoiding the essential oil from directly impacting the surface of the filter element at high speed due to gravity or delivery pressure. This prevents the filter element from being damaged due to excessive instantaneous force, significantly extending the service life of the filter element. At the same time, the essential oil after being distributed by the pressure-distributing plate can more evenly cover the effective filtration area of ​​the filter element, avoiding the decrease in filtration efficiency caused by material accumulation in local areas.

[0009] 3. Detachable structure for easy replacement and cleaning: The filter element at the bottom of the filter cartridge is designed to be detachable. When the filter element is clogged or reaches the end of its service life, it can be quickly disassembled and replaced without the need for complicated disassembly of the entire device. In addition, the filter membrane inside the outer shell can also be flexibly replaced with different pore sizes or material types according to purification needs, to adapt to the purification needs of different essential oil components.

[0010] Preferably, as a further improvement, the filter cartridge includes an upper part and a lower part, the bottom end of the upper part and the top end of the lower part both extend radially to form a first mounting part and a second mounting part, and the pressure dividing plate is installed between the first mounting part and the second mounting part.

[0011] Beneficial effects: The first and second mounting sections form a horizontal load-bearing platform, with the pressure-distributing plate tightly clamped between them. This ensures stability under continuous impact from essential oils and vibrations during equipment operation, preventing displacement or loosening of the pressure-distributing plate from affecting the pressure reduction effect and ensuring the reliable buffering and pressure reduction function for essential oils. The split structure design of the upper and lower sections facilitates maintenance of the pressure-distributing plate without disassembling the entire filter cartridge or interrupting the overall operation of the equipment, significantly reducing the difficulty and time cost of daily maintenance.

[0012] Preferably, as a further improvement, the filter element includes a honeycomb element, the outer edge of the honeycomb element extends outward to form a fixing part, and the lower bottom end extends radially to form a third mounting part, the third mounting part being connected to the fixing part.

[0013] Beneficial effects: The fixed part extending from the outer edge of the honeycomb element and the third mounting part extending radially from the bottom end form a precise connection structure. Through the tight connection between the two, the honeycomb element can be firmly fixed to the bottom of the filter cartridge, avoiding the honeycomb element from loosening, shifting or even falling off due to the continuous impact of essential oils, and ensuring that the filter element maintains a stable filtration posture during long-term operation. At the same time, the honeycomb element itself has the structural characteristics of being porous and having regular channels, which can effectively intercept larger particulate impurities in essential oils.

[0014] Preferably, as a further improvement, the honeycomb component is provided with a plurality of through holes, and the filter component further includes a filler that fills each through hole.

[0015] Beneficial effects: The numerous through-holes within the honeycomb filter element can intercept larger particulate impurities. However, after filling these through-holes with filler, a secondary filtration barrier is essentially constructed on top of the existing channels. This transforms the initial filtration process into a composite filtration mode of fine and coarse screening, significantly improving the purity of the essential oil before it enters the filter membrane and reducing the pressure on subsequent fine filtration. Secondly, the filler forms uniformly distributed micro-filtration channels within the through-holes, guiding the essential oil to fully contact the filter medium during flow. This avoids inadequate filtration in certain areas due to excessively high flow rates within the through-holes. Compared to filtration relying solely on the through-hole structure, the presence of filler slows down the fluid flow rate, prolonging the residence time of the essential oil within the filter element. This ensures that impurities are fully retained, reducing fluctuations in purification effects caused by the direct passage of insufficiently filtered fluid and improving the stability and consistency of the initial filtration process.

[0016] Preferably, as a further improvement, the upper diameter of each through hole is larger than the lower diameter.

[0017] Beneficial effects: The large-diameter through-hole structure at the top naturally guides the essential oil flowing down from the pressure plate, expanding the initial contact area of ​​the material and avoiding localized turbulence caused by concentrated impact on a certain area. As the diameter of the through-hole gradually decreases downwards, the fluid accelerates smoothly during flow, reducing energy loss caused by sudden changes in flow velocity. This allows the essential oil to penetrate more evenly into the packing, ensuring full contact between the filter medium and the material, improving filtration efficiency while reducing impact damage to the packing. Secondly, the larger diameter space at the top can accommodate more initial material, and the loose structure of the packing first traps larger particles of impurities. The smaller diameter space at the bottom, through the dense structure of the packing, deeply intercepts fine impurities, avoiding blockage caused by excessive impurities in the lower small diameter area. Furthermore, the gradient filtration enhances the targeted trapping effect on impurities of different particle sizes, improving the overall purification accuracy.

[0018] Preferably, as a further improvement, the lower part includes an inner cylinder and an outer cylinder sleeved outside the inner cylinder, the bottom of the inner cylinder is connected to the outer cylinder, the filler is installed between the inner cylinder and the outer cylinder, and multiple through holes are provided on both the inner cylinder and the outer cylinder.

[0019] Beneficial effects: The double-layer structure of the inner and outer cylinders significantly increases the contact area between the filter medium and the essential oil. Compared with a single cylindrical structure, the double-layer through-hole design makes the material flowing through the filling material more evenly distributed per unit time. The increase in filtration area directly increases the throughput per unit time, effectively avoiding the problems of material retention or low purification efficiency caused by insufficient filtration area.

[0020] Preferably, as a further improvement, the diameter of the inner cylinder is equal to the diameter of the upper inner circumference.

[0021] Beneficial effects: When essential oils flow from the upper space into the lower inner cylinder, the equal diameter design eliminates the steps or abrupt changes in diameter at the connection between the two, allowing the fluid to flow naturally along the continuous inner wall surface. This avoids turbulence and eddies caused by local reduction in diameter, significantly reducing fluid flow resistance and minimizing the problem of decreased flow rate due to energy loss. It ensures that essential oils enter the filtration area between the inner and outer cylinders at a stable flow rate, guaranteeing the continuity of filtration efficiency.

[0022] Preferably, as a further improvement, the pressure plate has a plurality of pressure dividing holes.

[0023] Beneficial effects: When a large amount of essential oil flows from the material tank into the filter cartridge, the pressure dividing holes can disperse the concentrated high-pressure fluid into multiple low-pressure streams. The flow-limiting effect of the channels reduces the impact pressure of the fluid on the lower filter elements. Compared with a solid plate without holes, the pressure dividing holes can achieve precise control of fluid pressure by controlling the flow rate of a single hole and the total flow area. This avoids problems such as damage to the filter elements and deformation of the pore size caused by excessive instantaneous pressure, significantly extending the service life of the filter components and reducing equipment maintenance costs.

[0024] Preferably, as a further improvement, it also includes a retaining tray, in which the filter membrane is installed, and a buckle is formed on the outer periphery of the retaining tray in the radial direction, and a retaining groove is formed on the inner wall of the outer shell, wherein the buckle engages with the retaining groove.

[0025] Beneficial effects: The snap-fit ​​structure between the clip and the slot provides a convenient way to replace the filter membrane. When the filter membrane becomes clogged due to long-term use, its flux decreases, or it needs to be replaced with a filter membrane of different pore size and material according to purification requirements, the clip and slot can be separated manually by pressing or rotating the snap-fit ​​plate without the need for tools. This allows for quick removal of the old filter membrane and installation of the new one. This design significantly reduces maintenance downtime and simplifies operation.

[0026] Preferably, as a further improvement, the top of the outer shell extends axially to form a connecting portion, which is fixedly connected to the outer periphery of the filter cartridge.

[0027] Beneficial effects: The fixed connection between the connecting part and the outer periphery of the filter cylinder forms a rigid integral structure between the outer shell and the filter cylinder, which effectively disperses the fluid impact force and material gravity load during equipment operation, avoids relative displacement or vibration caused by loose connection between the outer shell and the filter cylinder, and reduces structural fatigue wear during long-term use. Attached Figure Description

[0028] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present utility model.

[0029] Figure 2 This is a cross-sectional view of the filter cylinder in Embodiment 1 of this utility model.

[0030] Figure 3 In Embodiment 1 of this utility model Figure 1 A magnified portion of the local area.

[0031] Figure 4 This is a cross-sectional view of the filter cylinder in Embodiment 2 of this utility model.

[0032] Figure 5 This is a schematic diagram of the outer shell and filter cylinder in Embodiment 3 of this utility model.

[0033] The reference numerals in the accompanying drawings include: material tank 1, outer shell 2, discharge port 21, support platform 22, connecting part 23, filter cylinder 3, upper part 31, first mounting part 311, lower part 32, second mounting part 321, third mounting part 322, inner cylinder 33, outer cylinder 34, filter hole 35, pressure dividing plate 4, pressure dividing hole 41, filter element 5, honeycomb element 51, fixing part 511, filling element 52, filter membrane 6, snap-fit ​​plate 7, buckle 71, rubber stopper 8, clamp 9. Detailed Implementation

[0034] The following detailed description illustrates the specific implementation method: Example 1 like Figures 1-3 As shown, this embodiment provides a purification device for supercritical essential oil extract, including a material tank 1 for storing supercritical essential oil and a purification component connected to the material tank 1. The top of the material tank 1 can be connected to the supercritical essential oil extraction device. The purification component includes a shell 2 and a filter cylinder 3 welded to the top of the shell 2. The top of the filter cylinder 3 is connected to an opening at the bottom of the material tank 1 via a pipe. A rubber stopper 8 is installed at the connection point at the top of the filter cylinder 3, and a switch valve is provided on the pipe to control the opening and closing of the opening of the material tank 1.

[0035] A pressure-distributing plate 4 is detachably installed inside the filter cartridge 3. The filter cartridge 3 includes an upper part 31 and a lower part 32. The bottom end of the upper part 31 and the top end of the lower part 32 both extend radially to form a first mounting part 311 and a second mounting part 321. The pressure-distributing plate 4 is installed between the first mounting part 311 and the second mounting part 321 and connected by bolts and nuts. To ensure the sealing of the filter cartridge 3, sealing rings are provided at the connection between the first mounting part 311 and the second mounting part 321. The pressure-distributing plate 4 has several pressure-distributing holes 41, and the side of the pressure-distributing plate 4 closest to the upper part 31 is recessed downwards to facilitate the rapid flow of essential oil out of the pressure-distributing plate 4. A filter element 5 is detachably installed at the bottom of the filter cartridge 3. The filter element 5 includes a stainless steel honeycomb element 51 with several through holes. It is worth noting that the upper diameter of each through hole is larger than the lower diameter. The filter element 5 also includes a filler 52, specifically diatomaceous earth. Diatomaceous earth can absorb pigments and metallic substances in essential oils. Before use, the diatomaceous earth needs to be mixed with the filtrate, and then the diatomaceous earth mixed with the filtrate is filled into each through-hole. Due to the irregular shape, porous structure, and rough surface of the diatomaceous earth particles, when these particles are tightly packed together to form a filter cake, their irregular shape and rough surface will generate significant mechanical interlocking and inter-particle friction, making it difficult for the diatomaceous earth to be easily peeled off or dispersed by the fluid. The outer edge of the honeycomb element 51 extends outward to form a fixing part 511, and the bottom end of the lower part 32 extends radially to form a third mounting part 322. The third mounting part 322 is connected to the fixing part 511 by bolts. Specifically, the first mounting part 311, the second mounting part 321, the third mounting part 322, and the fixing part 511 are all flanged connections.

[0036] The bottom of the outer casing 2 is conical, and a filter membrane 6 is installed on top of the cone. This filter membrane 6 is specifically made of nylon or polytetrafluoroethylene ultrafiltration membrane and is used to filter the essential oil after it has passed through the stainless steel honeycomb mesh, in order to filter out colloids within the essential oil. The specific installation method of the filter membrane is as follows: Figure 3 As shown, this embodiment also includes a retaining plate 7, which includes a base plate 71 and a cover plate 72 for retaining the filter membrane 6. The filter membrane 6 is placed between the base plate 71 and the cover plate 72. The end of the base plate 71 near the filter membrane 6 is recessed downward to form a retaining groove. The side of the cover plate 72 near the filter membrane 6 extends downward to form a retaining block. The retaining block engages in the retaining groove, and at this time, part of the filter membrane 6 is pressed into the retaining groove along with the retaining block, thereby realizing the installation of the filter membrane 6. The inner wall of the outer shell 2 extends radially to form a support platform 22, and the retaining plate 7 with the filter membrane 6 installed is placed on the support platform 22. The bottom of the outer shell 2 is provided with a discharge port 21, and a switch valve is provided on the discharge port 21. A storage tank is placed at the bottom of the discharge port 21. To avoid contamination of the essential oil by contact with air, a rubber stopper 8 is provided at the connection between the discharge port 21 and the tank opening.

[0037] The usage process in this embodiment is as follows: 1. Pretreatment: First, pretreatment is performed on filter element 5: diatomaceous earth is mixed with a small amount of supercritical essential oil sample to be filtered, and after stirring evenly, the mixture is filled into each through hole of the stainless steel honeycomb element 51; then, the fixing part 511 of the honeycomb element 51 is connected and fixed to the third mounting part 322 of the lower part 32 of the filter cylinder using bolts (flange connection), completing the installation of filter element 5. Simultaneously, the installation of filter membrane 6 is checked: a nylon filter membrane or polytetrafluoroethylene ultrafiltration membrane is spread on the base plate 71. When the cover plate 72 is pressed down, the locking blocks on the cover plate 72 engage with the locking grooves on the base plate 71. At this time, part of the filter membrane 6 is pressed into the locking groove along with the locking blocks, thus achieving the installation of filter membrane 6.

[0038] 2. Filtration Process: Open the valve at the bottom of material tank 1. The essential oil flows into filter cylinder 3 through the pipe. The essential oil first contacts the pressure plate 4. The pressure plate 4 is fixed inside filter cylinder 3 via the first mounting part 311 and the second mounting part 321 (flange connection). Its side near the upper part 31 is recessed downwards, engaging with the pressure-distributing holes 41 on its surface, allowing the essential oil to quickly disperse and flow through the pressure plate 4, entering the filter element 5 area. Deep Purification and Fine Filtration: The essential oil flowing through the pressure plate 4 enters filter element 5. The diatomaceous earth filled in the through-holes of the stainless steel honeycomb element 51 adsorbs pigments and metallic substances in the essential oil through its porous structure, rough surface, and mechanical interlocking, completing preliminary purification. The essential oil treated by filter element 5 enters the outer shell 2 and flows through the filter membrane 6. The filter membrane 6 further filters and removes colloidal substances from the essential oil, achieving fine filtration.

[0039] 3. Collection of Preliminary Purified Essential Oil: The purified essential oil, after being filtered through filter membrane 6, collects in the conical area at the bottom of the outer shell 2. Open the valve of outlet 21, and the essential oil flows into the storage tank below through the outlet. After collection, close the outlet valve to complete one purification operation.

[0040] Example 2 like Figure 4 As shown, the difference between this embodiment and Embodiment 1 lies in the filtration structure of the lower part 32 of the filter cylinder 3. In this embodiment, the lower part 32 includes an inner cylinder 33 and an outer cylinder 34 sleeved outside the inner cylinder 33. The bottoms of the inner cylinder 33 and the outer cylinder 34 are connected, and a filler 52 is installed between the inner cylinder 33 and the outer cylinder 34. Both the inner cylinder 33 and the outer cylinder 34 are provided with multiple filter holes 35. The diameter of the inner cylinder 33 is equal to the inner circumference diameter of the upper part 31.

[0041] The usage process in this embodiment is as follows: When a large amount of essential oil flows into the lower part 32 through the pressure plate 4, the essential oil accumulates in the inner cylinder 33 of the lower part 32. As the essential oil continues to accumulate, the liquid level gradually rises, and the essential oil will permeate through the filter holes 35 on the inner cylinder 33 to the area between the inner cylinder 33 and the outer cylinder 34. At this time, the filler 52 (such as diatomaceous earth) installed between the inner cylinder 33 and the outer cylinder 34 will adsorb and filter the essential oil, further removing impurities such as pigments and metallic substances. Since both the inner cylinder 33 and the outer cylinder 34 are provided with filter holes 35, the essential oil filtered by the filler 52 will permeate through the filter holes 35 on the outer cylinder 34 and enter the interior of the outer shell 2. Subsequently, the essential oil continues to flow downward, is filtered by the filter membrane 6 to remove colloidal substances, and finally collects in the conical area at the bottom of the outer shell 2. The valve of the outlet 21 is opened, and the purified essential oil flows into the storage tank, completing the entire purification process.

[0042] Example 3 like Figure 5 As shown, the difference between this embodiment and embodiment one is that the connection method between the outer shell 2 and the filter cartridge 3 is different. In this embodiment, the top of the outer shell 2 extends in the axial direction to form a connecting part 23. The connecting part 23 is fixedly connected to the outer periphery of the upper part 31 of the filter cartridge 3. Specifically, the outer periphery of the connecting part 23 is recessed inward to form a groove. When the filter cartridge 3 is installed on the connecting part 23, the upper part 31 and the connecting part 23 need to be clamped together by the clamp 9.

[0043] The above are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A purification apparatus for supercritical essential oil extracts, characterized in that: The device includes a material tank for storing supercritical essential oils and a purification assembly connected to the material tank. The purification assembly includes a shell and a filter cylinder mounted on top of the shell. The top of the filter cylinder is connected to an opening at the bottom of the material tank. A pressure plate is detachably connected inside the filter cylinder. A filter element is detachably installed at the bottom of the filter cylinder. A filter membrane is installed inside the shell. A discharge port is provided at the bottom of the shell.

2. The purification apparatus for supercritical essential oil extract according to claim 1, characterized in that: The filter cartridge includes an upper part and a lower part. The bottom end of the upper part and the top end of the lower part both extend radially to form a first mounting part and a second mounting part. The pressure plate is installed between the first mounting part and the second mounting part.

3. The purification apparatus for supercritical essential oil extract according to claim 2, characterized in that: The filter element includes a honeycomb element, the outer edge of which extends outward to form a fixing part, and the lower bottom end extends radially to form a third mounting part, which is connected to the fixing part.

4. The purification apparatus for supercritical essential oil extract according to claim 3, characterized in that: The honeycomb component has several through holes, and the filter component also includes a filler that fills each through hole.

5. The purification apparatus for supercritical essential oil extract according to claim 4, characterized in that: The upper diameter of each through hole is larger than the lower diameter.

6. The purification apparatus for supercritical essential oil extract according to claim 5, characterized in that: The lower part includes an inner cylinder and an outer cylinder sleeved outside the inner cylinder. The bottom of the inner cylinder is connected to the outer cylinder. The filler is installed between the inner cylinder and the outer cylinder, and multiple filter holes are provided on both the inner cylinder and the outer cylinder.

7. The purification apparatus for supercritical essential oil extract according to claim 6, characterized in that: The diameter of the inner cylinder is equal to the diameter of the upper inner circumference.

8. The purification apparatus for supercritical essential oil extract according to claim 1, characterized in that: The pressure plate has several pressure dividing holes.

9. The purification apparatus for supercritical essential oil extract according to claim 8, characterized in that: It also includes a snap-fit ​​tray, in which the filter membrane is installed. The snap-fit ​​tray has a buckle formed on its outer periphery in the radial direction, and a slot is formed on the inner wall of the outer shell. The buckle engages with the slot.

10. The purification apparatus for supercritical essential oil extract according to claim 9, characterized in that: The top of the outer shell extends axially to form a connecting portion, which is fixedly connected to the outer periphery of the filter cartridge.

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