Physical refining method of flax shell oil

Abstract

The invention belongs to the field of vegetable oil refining, and particularly discloses a physical refining method of flax shell oil, which comprises the steps of pretreatment, flax shell crushing, cold pressing, high-frequency pulsed electric field treatment, adsorption resin filtration, pre-degassing, molecular distillation, ultrafiltration and the like. And the flax shell oil with high purity, strong oil fragrance, low acid value and peroxide value and high unsaturated fatty acid content is obtained. Wherein the pretreatment comprises the steps of drying, coarse grinding separation, vibration screening, electrostatic separation, winnowing and the like, and thorough separation of flax shells and seed kernels is ensured; impurities and bad components are effectively removed through the steps of cold pressing, high-frequency pulsed electric field treatment, adsorption resin filtration and the like. The pre-degassing and molecular distillation further improve the purity and quality of the oil, and the ultrafiltration step ensures the stability and uniformity of the final product. The waste flax shells in the prior art are used for oil pressing, waste is turned into wealth, and the flax shell oil product is high in quality and has wide application prospects.

Description

Technical Field

[0001] The invention belongs to the field of vegetable oil refining, and specifically discloses a physical refining method for flax shell oil. Background Art

[0002] In the traditional processing of refined linseed oil, a large amount of flax husks are produced as by-products. These flax husks are usually regarded as waste, which not only takes up a lot of storage space, but also may pollute the environment. Therefore, how to effectively utilize these flax husk wastes has become a problem that needs to be solved urgently.

[0003] Traditional methods of flax husk treatment mainly include landfill and incineration, but these methods not only waste resources, but may also have a negative impact on the environment. Landfill will occupy a large amount of land resources and is difficult to degrade; incineration may produce harmful gases and pollute air quality. According to statistics, flax husks also contain about 17%-20% oil, but the main problem is that flax husk oil is difficult to extract, the extraction cost is high, and the efficiency is low. Therefore, it is particularly important to develop an environmentally friendly and efficient physical refining method for flax husk oil. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a new physical refining method for flax husk oil. The method effectively separates the flax husk from the seed kernel through meticulous pretreatment steps, avoiding the interference of the oil in the seed kernel on the quality of the shell oil. At the same time, a low-temperature air flow mill is used to grind the flax husk, retaining the nutrients and natural aroma in the flax husk. In the pressing process, the present invention uses a spiral cold press and optimizes parameters such as the rotation speed of the screw, the humidity of the flax husk and the pressing temperature, further improving the extraction efficiency and quality of the oil.

[0005] The present invention includes the following technical solutions:

[0006] A physical refining method for linseed oil comprises the following steps:

[0007] S1 pretreatment: crushing flax seeds to separate flax kernels and flax husks;

[0008] S2 Flax husk crushing: Use a low-temperature airflow crusher to crush the separated flax husk;

[0009] S3 cold pressing: using a spiral cold press to press the crushed flax husk to obtain flax husk oil A;

[0010] S4 high-frequency pulse electric field treatment: flax shell oil A obtained by squeezing is treated with a high-frequency pulse electric field to obtain flax shell oil B;

[0011] S5: filtration with adsorption resin: filtration and purification of flax shell oil B through macroporous adsorption resin to obtain flax shell oil C;

[0012] S6 pre-degassing: flax shell oil C is placed into a molecular distiller and volatile components in the material are removed by heating and decompression;

[0013] S7 molecular distillation: Control the molecular distillation temperature, operation accuracy, distillation scraper speed and condensed water temperature to perform molecular distillation. Light molecules escape and are condensed and collected to obtain linseed shell oil D;

[0014] S8 ultrafiltration: linseed oil D is ultrafiltered to obtain a product.

[0015] Furthermore, in the above-mentioned physical refining method of linseed oil, step S1 comprises:

[0016] S11 dries the flax seeds to reduce the moisture content to between 0.5% and 3.0%;

[0017] S12: The dried flax seeds are sent into a separation chamber equipped with a coarse grinding rotor. When the flax seeds pass through the coarse grinding rotor, they are in contact with and rubbed against the coarse grinding rotor, and are broken and separated into flax husks and seed kernels.

[0018] S13 further screens the initially separated flax husks and kernels using a vibrating screening device;

[0019] S14 sends the screened mixture into an electrostatic separation device, and under the action of an electrostatic field, the difference in the charge properties of flax husks and kernels in the electric field is used to further separate the two; the distance between the electrostatic adsorption surface and the husk-kernel mixture is controlled at 35 cm, and the electrostatic voltage is set at 6000-11000 V;

[0020] S15 uses wind sorting equipment to completely separate the flax husks and kernels based on the weight difference between the two by adjusting the air flow speed and direction, and collects the flax husks.

[0021] Furthermore, in the above-mentioned physical refining method of flax shell oil, in the S3 cold pressing, the screw speed is 10-20rpm; the flax shell humidity is 5-10%; and the pressing temperature is 25-40°C.

[0022] Furthermore, in the above-mentioned physical refining method of flax shell oil, in the S4 high-frequency pulse electric field treatment, the electric field strength is 10-30 kV / cm, the pulse width is 8-12 μs, and the total number of pulses is 100-200.

[0023] Furthermore, in the above-mentioned physical refining method of flax shell oil, in the S5 adsorption resin filtration, HP20 macroporous adsorption resin is used as the adsorption filtration filler, the adsorption temperature is 20-30° C., and the adsorption time is: 1-3h.

[0024] Furthermore, in the above-mentioned physical refining method of flax shell oil, in the S6 pre-degassing, the temperature is 10-20° C. and the vacuum degree is 1-5 KPa.

[0025] Furthermore, in the above-mentioned physical refining method of flax shell oil, in the S7 molecular distillation, the molecular distillation conditions are evaporation pressure 5-8KPa, distillation temperature 85-95°C, and feed rate 50-100mL / min.

[0026] Furthermore, in the above-mentioned physical refining method of flax shell oil, the filtration parameters in the S8 ultrafiltration are: membrane pore size: 50-100nm, operating pressure: 0.4-0.6Mpa, temperature: 25-35°C, flow rate: 500-600L / h / m 2 .

[0027] The invention discloses flax shell oil, which is prepared by any one of the above methods.

[0028] The invention also discloses the application of the flax shell oil in the fields of food, health care products and cosmetics.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The physical refining method of flax shell oil of the present invention significantly improves the overall quality of the product, and its beneficial effects are mainly reflected in the following aspects:

[0031] First of all, through meticulous pretreatment steps, including drying, coarse grinding separation, vibration screening, electrostatic separation and air separation, the flax husk and kernel are effectively separated, laying a solid foundation for the subsequent refining process.

[0032] Secondly, the cold pressing technology is used, combined with a specific screw speed, flax shell humidity and pressing temperature, to maximize the retention of nutrients and natural aroma in flax shell oil. At the same time, high-frequency pulse electric field treatment further improves the quality of the oil, effectively removes undesirable components, and significantly reduces the acid value and peroxide value of flax shell oil.

[0033] Furthermore, through high-precision processing technologies such as adsorption resin filtration and molecular distillation, the present invention successfully removes small molecular impurities and volatile components in the oil, significantly improving the purity of flax shell oil. In particular, the application of molecular distillation technology greatly retains and improves the unsaturated fatty acid content of the final product.

[0034] Finally, the introduction of the ultrafiltration step further ensures the stability and uniformity of the flax shell oil, making the product more suitable for use in food, health products and cosmetics.

[0035] In summary, the flax shell oil physical refining method of the present invention turns waste into preservation, utilizes the flax shell waste in the flaxseed oil processing process for refining, improves the purity of the product, retains rich nutrients and natural aroma, significantly reduces the acid value and peroxide value, and increases the unsaturated fatty acid content. These advantages make the flax shell oil obtained by the present invention more competitive in the market and have a wider application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The purity comparison of linseed oil in the embodiment and the comparative example is shown;

[0037] Figure 2 The yield of linseed oil in the embodiment and the comparative example is compared;

[0038] Figure 3 The figure is a comparison of the acid value of the linseed shell oil of the embodiment and the comparative example;

[0039] Figure 4 is a comparison of the peroxide values ​​of the flax shell oils of the examples and the comparative examples;

[0040] Figure 5 Comparison of the α-linolenic acid content of the flax shell oil of the embodiment and the comparative example. DETAILED DESCRIPTION

[0041] A physical refining method for linseed oil comprises the following steps:

[0042] S1 pretreatment: crushing flax seeds to separate flax kernels and flax husks;

[0043] S2 Flax husk crushing: Use a low-temperature airflow crusher to crush the separated flax husk;

[0044] S3 cold pressing: using a spiral cold press to press the crushed flax husk to obtain flax husk oil A;

[0045] S4 high-frequency pulse electric field treatment: flax shell oil A obtained by squeezing is treated with a high-frequency pulse electric field to obtain flax shell oil B;

[0046] S5: filtration with adsorption resin: filtration and purification of flax shell oil B through macroporous adsorption resin to obtain flax shell oil C;

[0047] S6 pre-degassing: flax shell oil C is placed into a molecular distiller and volatile components in the material are removed by heating and decompression;

[0048] S7 molecular distillation: Control the molecular distillation temperature, operation accuracy, distillation scraper speed and condensed water temperature to perform molecular distillation. Light molecules escape and are condensed and collected to obtain linseed shell oil D;

[0049] S8 ultrafiltration: linseed oil D is ultrafiltered to obtain a product.

[0050] The step S1 comprises:

[0051] S11 dries the flax seeds to reduce the moisture content to between 0.5% and 3.0%;

[0052] S12: The dried flax seeds are sent into a separation chamber equipped with a coarse grinding rotor. When the flax seeds pass through the coarse grinding rotor, they are in contact with and rubbed against the coarse grinding rotor, and are broken and separated into flax husks and seed kernels.

[0053] S13 further screens the initially separated flax husks and kernels using a vibrating screening device;

[0054] S14 sends the screened mixture into an electrostatic separation device, and under the action of an electrostatic field, the difference in the charge properties of flax husks and kernels in the electric field is used to further separate the two; the distance between the electrostatic adsorption surface and the husk-kernel mixture is controlled at 35 cm, and the electrostatic voltage is set at 6000-11000 V;

[0055] S15 uses wind sorting equipment to completely separate the flax husks and kernels based on the weight difference between the two by adjusting the air flow speed and direction, and collects the flax husks.

[0056] In the S3 cold pressing, the screw speed is 10-20 rpm; the flax shell moisture is 5-10%; and the pressing temperature is 25-40°C.

[0057] In the S4 high-frequency pulse electric field treatment, the electric field strength is 10-30 kV / cm, the pulse width is 8-12 μs, and the total number of pulses is 100-200.

[0058] In the S5 adsorption resin filtration, HP20 macroporous adsorption resin is used as the adsorption filtration filler, the adsorption temperature is 20-30° C., and the adsorption time is 1-3 h.

[0059] In the S6 pre-degassing, the temperature is 10-20° C. and the vacuum degree is 1-5 KPa.

[0060] In the S7 molecular distillation, the molecular distillation conditions are evaporation pressure 5-8 KPa, distillation temperature 85-95° C., and feed rate 50-100 mL / min.

[0061] In the S8 ultrafiltration, the filtration parameters are: membrane pore size: 50-100nm, operating pressure: 0.4-0.6Mpa, temperature: 25-35°C, flow rate: 500-600L / h / m 2 .

[0062] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Example 1

[0064] A physical refining method for linseed oil comprises the following steps:

[0065] S1 pretreatment: crushing flax seeds to separate flax kernels and flax husks;

[0066] S2 Flax husk crushing: Use a low-temperature airflow crusher to crush the separated flax husk;

[0067] S3 cold pressing: using a spiral cold press to press the crushed flax husk to obtain flax husk oil A;

[0068] S4 high-frequency pulse electric field treatment: flax shell oil A obtained by squeezing is treated with a high-frequency pulse electric field to obtain flax shell oil B;

[0069] S5: filtration with adsorption resin: filtration and purification of flax shell oil B through macroporous adsorption resin to obtain flax shell oil C;

[0070] S6 pre-degassing: flax shell oil C is placed into a molecular distiller and volatile components in the material are removed by heating and decompression;

[0071] S7 molecular distillation: Control the molecular distillation temperature, operation accuracy, distillation scraper speed and condensed water temperature to perform molecular distillation. Light molecules escape and are condensed and collected to obtain linseed shell oil D;

[0072] S8 ultrafiltration: linseed oil D is ultrafiltered to obtain a product.

[0073] The step S1 comprises:

[0074] S11 dries the flax seeds to reduce the moisture content to between 0.5% and 3.0%;

[0075] S12: The dried flax seeds are sent into a separation chamber equipped with a coarse grinding rotor. When the flax seeds pass through the coarse grinding rotor, they are in contact with and rubbed against the coarse grinding rotor, and are broken and separated into flax husks and seed kernels.

[0076] S13 further screens the initially separated flax husks and kernels using a vibrating screening device;

[0077] S14 sends the screened mixture into an electrostatic separation device, and under the action of an electrostatic field, the difference in the charge properties of flax husks and kernels in the electric field is used to further separate the two; the distance between the electrostatic adsorption surface and the husk-kernel mixture is controlled at 35 cm, and the electrostatic voltage is set at 6000 V;

[0078] S15 uses wind sorting equipment to completely separate the flax husks and kernels based on the weight difference between the two by adjusting the air flow speed and direction, and collects the flax husks.

[0079] In the S3 cold pressing, the screw speed is 10 rpm; the flax shell moisture is 5%; and the pressing temperature is 25°C.

[0080] In the S4 high-frequency pulse electric field treatment, the electric field strength is 10 kV / cm, the pulse width is 8 μs, and the total number of pulses is 200.

[0081] In the S5 adsorption resin filtration, HP20 macroporous adsorption resin is used as the adsorption filtration filler, the adsorption temperature is 20° C., and the adsorption time is 3 h.

[0082] In the S6 pre-degassing, the temperature is 10° C. and the vacuum degree is 1 KPa.

[0083] In the S7 molecular distillation, the molecular distillation conditions are evaporation pressure 5 KPa, distillation temperature 85° C., and feed rate 50 mL / min.

[0084] In the S8 ultrafiltration, the filtration parameters are: membrane pore size: 50nm, operating pressure: 0.6Mpa, temperature: 25°C, flow rate: 500L / h / m 2 .

[0085] Example 2

[0086] A physical refining method for linseed oil comprises the following steps:

[0087] S1 pretreatment: crushing flax seeds to separate flax kernels and flax husks;

[0088] S2 Flax husk crushing: Use a low-temperature airflow crusher to crush the separated flax husk;

[0089] S3 cold pressing: using a spiral cold press to press the crushed flax husk to obtain flax husk oil A;

[0090] S4 high-frequency pulse electric field treatment: flax shell oil A obtained by squeezing is treated with a high-frequency pulse electric field to obtain flax shell oil B;

[0091] S5: filtration with adsorption resin: filtration and purification of flax shell oil B through macroporous adsorption resin to obtain flax shell oil C;

[0092] S6 pre-degassing: flax shell oil C is placed into a molecular distiller and volatile components in the material are removed by heating and decompression;

[0093] S7 molecular distillation: Control the molecular distillation temperature, operation accuracy, distillation scraper speed and condensed water temperature to perform molecular distillation. Light molecules escape and are condensed and collected to obtain linseed shell oil D;

[0094] S8 ultrafiltration: linseed oil D is ultrafiltered to obtain a product.

[0095] The step S1 comprises:

[0096] S11 dries the flax seeds to reduce the moisture content to between 0.5% and 3.0%;

[0097] S12: The dried flax seeds are sent into a separation chamber equipped with a coarse grinding rotor. When the flax seeds pass through the coarse grinding rotor, they are in contact with and rubbed against the coarse grinding rotor, and are broken and separated into flax husks and seed kernels.

[0098] S13 further screens the initially separated flax husks and kernels using a vibrating screening device;

[0099] S14 sends the screened mixture into an electrostatic separation device, and under the action of an electrostatic field, the difference in the charge properties of flax husks and kernels in the electric field is used to further separate the two; the distance between the electrostatic adsorption surface and the husk-kernel mixture is controlled at 35 cm, and the electrostatic voltage is set at 8500 V;

[0100] S15 uses wind sorting equipment to completely separate the flax husks and kernels based on the weight difference between the two by adjusting the air flow speed and direction, and collects the flax husks.

[0101] In the S3 cold pressing, the screw speed is 15 rpm; the flax shell moisture is 8%; and the pressing temperature is 35°C.

[0102] In the S4 high-frequency pulse electric field treatment, the electric field strength is 20 kV / cm, the pulse width is 10 μs, and the total number of pulses is 150.

[0103] In the S5 adsorption resin filtration, HP20 macroporous adsorption resin is used as the adsorption filtration filler, the adsorption temperature is 25° C., and the adsorption time is 2 h.

[0104] During the S6 pre-degassing, the temperature is 15° C. and the vacuum degree is 3 KPa.

[0105] In the S7 molecular distillation, the molecular distillation conditions are evaporation pressure 6.5 KPa, distillation temperature 90° C., and feed rate 75 mL / min.

[0106] In the S8 ultrafiltration, the filtration parameters are: membrane pore size: 75nm, operating pressure: 0.5Mpa, temperature: 30°C, flow rate: 550L / h / m 2 .

[0107] Example 3

[0108] A physical refining method for linseed oil comprises the following steps:

[0109] S1 pretreatment: crushing flax seeds to separate flax kernels and flax husks;

[0110] S2 Flax husk crushing: Use a low-temperature airflow crusher to crush the separated flax husk;

[0111] S3 cold pressing: using a spiral cold press to press the crushed flax husk to obtain flax husk oil A;

[0112] S4 high-frequency pulse electric field treatment: flax shell oil A obtained by squeezing is treated with a high-frequency pulse electric field to obtain flax shell oil B;

[0113] S5: filtration with adsorption resin: filtration and purification of flax shell oil B through macroporous adsorption resin to obtain flax shell oil C;

[0114] S6 pre-degassing: flax shell oil C is placed into a molecular distiller and volatile components in the material are removed by heating and decompression;

[0115] S7 molecular distillation: Control the molecular distillation temperature, operation accuracy, distillation scraper speed and condensed water temperature to perform molecular distillation. Light molecules escape and are condensed and collected to obtain linseed shell oil D;

[0116] S8 ultrafiltration: linseed oil D is ultrafiltered to obtain a product.

[0117] The step S1 comprises:

[0118] S11 dries the flax seeds to reduce the moisture content to between 0.5% and 3.0%;

[0119] S12: The dried flax seeds are sent into a separation chamber equipped with a coarse grinding rotor. When the flax seeds pass through the coarse grinding rotor, they are in contact with and rubbed against the coarse grinding rotor, and are broken and separated into flax husks and seed kernels.

[0120] S13 further screens the initially separated flax husks and kernels using a vibrating screening device;

[0121] S14 sends the screened mixture into an electrostatic separation device, and under the action of an electrostatic field, the difference in the charge properties of flax husks and kernels in the electric field is used to further separate the two; the distance between the electrostatic adsorption surface and the husk-kernel mixture is controlled at 35 cm, and the electrostatic voltage is set at 11000 V;

[0122] S15 uses wind sorting equipment to completely separate the flax husks and kernels based on the weight difference between the two by adjusting the air flow speed and direction, and collects the flax husks.

[0123] In the S3 cold pressing, the screw speed is 20 rpm; the flax shell moisture is 10%; and the pressing temperature is 40°C.

[0124] In the S4 high-frequency pulse electric field treatment, the electric field strength is 30 kV / cm, the pulse width is 12 μs, and the total number of pulses is 100.

[0125] In the S5 adsorption resin filtration, HP20 macroporous adsorption resin is used as the adsorption filtration filler, the adsorption temperature is 30° C., and the adsorption time is 1 h.

[0126] In the S6 pre-degassing, the temperature is 20° C. and the vacuum degree is 5 KPa.

[0127] In the S7 molecular distillation, the molecular distillation conditions are evaporation pressure 8 KPa, distillation temperature 95° C., and feed rate 100 mL / min.

[0128] In the S8 ultrafiltration, the filtration parameters are: membrane pore size: 100nm, operating pressure: 0.4Mpa, temperature: 35°C, flow rate: 600L / h / m 2 .

[0129] Comparative Example 1

[0130] This comparative example does not include the S4 high-frequency pulse electric field treatment, and the rest is the same as Example 2.

[0131] Comparative Example 2

[0132] This comparative example does not include S5 adsorption resin filtration, and the rest is the same as Example 2

[0133] Comparative Example 3

[0134] This comparative example does not include S6 pre-degassing and S7 molecular distillation, and the rest is the same as Example 2.

[0135] Comparative Example 4

[0136] This comparative example does not include S4-S7, and the rest is the same as Example 2.

[0137] Test Example 1

[0138] The flax shell oil prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to comparative tests. Test Example 1 mainly compared the purity and yield of flax shell oil (g / 100g shell raw material x 100%). The results are shown in Tables 1 and Figure 1-2 .

[0139] Table 1 Comparison of linseed oil purity and yield

[0140] purity Yield (%) Example 1 99.1 15.3 Example 2 99.3 16.5 Example 3 99.4 16.2 Comparative Example 1 97.4 11.7 Comparative Example 2 95.2 12.5 Comparative Example 3 91.7 11.3 Comparative Example 4 87.4 9.2

[0141] From the comparison results of Examples 1-3 and Comparative Examples 1-4 in Table 1, it can be seen that the purity of the flax husk oil prepared by the refining method used in the present invention is above 99%, meeting the standard of high-quality edible oil, and the yield is also above 15%, which is close to the theoretical oil content of flax husk.

[0142] Test Example 2

[0143] The flax shell oils prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to comparative tests. Test Example 2 mainly compared the acid value (mg KOH / g), peroxide value (mmol / kg) and α-linolenic acid content (wt%) of the flax shell oils. The results are shown in Tables 2 and Figure 3-5 shown.

[0144] Table 2 Flax shell oil quality test

[0145]

[0146]

[0147] From the comparison results of Examples 1-3 and Comparative Examples 1-4 in Table 2, it can be seen that the flax shell oil prepared by the refining method used in the present invention has a low acid value (lower than 0.60 mg KOH / g), a low peroxide value (lower than 1.5 mmol / kg), and a high α-linolenic acid content (higher than 60%).

[0148] In summary, the present invention proposes a new physical refining method for flax husk oil. The method effectively separates flax husk from seed kernel through meticulous pretreatment steps, avoiding the interference of oil in the seed kernel on the quality of oil in the husk. At the same time, a low-temperature airflow mill is used to grind the flax husk, retaining the nutrients and natural aroma in the flax husk. In the pressing process, the present invention uses a spiral cold press, and optimizes parameters such as the rotation speed of the screw, the humidity of the flax husk and the pressing temperature, further improving the extraction efficiency and quality of the oil.

[0149] The above are limited to several preferred embodiments of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A physical refining method for linseed oil, characterized in that: The following steps are involved: S1 pretreatment: crushing flax seeds to separate flax kernels and flax husks; S2 Flax husk crushing: Use a low-temperature airflow crusher to crush the separated flax husk; S3 cold pressing: using a spiral cold press to press the crushed flax husk to obtain flax husk oil A; S4 high-frequency pulse electric field treatment: flax shell oil A obtained by squeezing is treated with a high-frequency pulse electric field to obtain flax shell oil B; S5: filtration with adsorption resin: filtration and purification of flax shell oil B through macroporous adsorption resin to obtain flax shell oil C; S6 pre-degassing: flax shell oil C is placed into a molecular distiller and volatile components in the material are removed by heating and decompression; S7 molecular distillation: Control the molecular distillation temperature, operation accuracy, distillation scraper speed and condensed water temperature to perform molecular distillation. Light molecules escape and are condensed and collected to obtain linseed shell oil D; S8 ultrafiltration: linseed oil D is ultrafiltered to obtain a product.

2. A physical refining method for linseed oil according to claim 1, characterized in that: The step S1 comprises: S11 dries the flax seeds to reduce the moisture content to between 0.5% and 3.0%; S12: The dried flax seeds are sent into a separation chamber equipped with a coarse grinding rotor. When the flax seeds pass through the coarse grinding rotor, they are in contact with and rubbed against the coarse grinding rotor, and are broken and separated into flax husks and seed kernels. S13 further screens the initially separated flax husks and kernels using a vibrating screening device; S14 sends the screened mixture into an electrostatic separation device, and under the action of an electrostatic field, the difference in the charge properties of flax husks and kernels in the electric field is used to further separate the two; the distance between the electrostatic adsorption surface and the husk-kernel mixture is controlled at 35 cm, and the electrostatic voltage is set at 6000-11000 V; S15 uses wind sorting equipment to completely separate the flax husks and kernels based on the weight difference between the two by adjusting the air flow speed and direction, and collects the flax husks.

3. The physical refining method of linseed oil according to claim 1, characterized in that: In the S3 cold pressing, the screw speed is 10-20 rpm; the flax shell moisture is 5-10%; and the pressing temperature is 25-40°C.

4. The physical refining method of linseed oil according to claim 1, characterized in that: In the S4 high-frequency pulse electric field treatment, the electric field strength is 10-30 kV / cm, the pulse width is 8-12 μs, and the total number of pulses is 100-200.

5. The physical refining method of linseed oil according to claim 1, characterized in that: In the S5 adsorption resin filtration, HP20 macroporous adsorption resin is used as the adsorption filtration filler, the adsorption temperature is 20-30° C., and the adsorption time is 1-3 h.

6. A physical refining method for linseed oil according to claim 1, characterized in that: In the S6 pre-degassing, the temperature is 10-20° C. and the vacuum degree is 1-5 KPa.

7. A physical refining method for linseed oil according to claim 1, characterized in that: In the S7 molecular distillation, the molecular distillation conditions are evaporation pressure 5-8 KPa, distillation temperature 85-95° C., and feed rate 50-100 mL / min.

8. The physical refining method of linseed oil according to claim 1, characterized in that: In the S8 ultrafiltration, the filtration parameters are: membrane pore size: 50-100nm, operating pressure: 0.4-0.6Mpa, temperature: 25-35°C, flow rate: 500-600L / h / m 2 .

9. A linseed oil, characterized in that Obtained by the refining method according to any one of claims 1 to 8.

10. Use of the flaxseed oil as claimed in claim 9 in the fields of food, health products and cosmetics.

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