Device for preparing flavored vegetable oil

Abstract

The utility model relates to the field of edible oil preparation, and discloses a device for preparing flavored vegetable oil, which comprises a crude oil degassing unit, a flavor substance extraction unit and a flavored vegetable oil mixing unit which are communicated in sequence, wherein the flavor substance extraction unit comprises an evaporation system, and the evaporation system is used for separating a gas-phase material containing flavor substances from the degassed crude oil; and the vacuumizing system is used for providing a vacuum environment for the evaporation system and extracting the gas-phase material containing the flavor substances from the evaporation system. By adopting the device provided by the utility model, the oxygen concentration and the distillation temperature in the crude oil in the flavor substance extraction process can be reduced, the oxidation and thermal decomposition reaction of impurities such as phospholipid and free fatty acid in the crude oil at high temperature are inhibited, and the generation of secondary products is reduced; when the product is added into refined vegetable oil to produce refined vegetable oil rich in flavor, quality reduction of oil products caused by excessive increase of peroxide value and anisidine value can be avoided.

Description

Technical Field

[0001] The utility model relates to the field of edible oil preparation, in particular to a device for preparing flavored vegetable oil. Background Art

[0002] As people's living standards improve, consumers have higher requirements for the quality of vegetable oils and fats. They not only require that the physical and chemical indicators of the oils and fats meet national standards, but also hope that the oils and fats can have their own inherent natural flavor to satisfy the sensory enjoyment of flavor during cooking and eating.

[0003] The reason why flavored oils can bring people pleasure when cooking and eating is that they contain trace amounts of flavor substances. Although these flavor substances are present in very small amounts in oils, their molecular weight is much lower than that of triglycerides, the main substance of oils, so their normal pressure boiling points are much lower than those of triglycerides. For example, 2,6-dimethylpyrazine is a flavor substance contained in sunflower oil, which gives sunflower oil a roasted sunflower seed aroma. The normal pressure boiling point of this substance is 155.6°C, while the normal pressure boiling point of triglycerides, the main component of oils, is usually as high as about 800°C. When the flavor substances in oils are heated or even at room temperature, some of them will evaporate from the oils into the air, and after being inhaled into the nasal cavity, they will stimulate the olfactory cells, allowing people to feel the unique aroma of the oils. When producing refined vegetable oil, the crude oil raw material needs to be degummed, deacidified, decolorized and deodorized to remove the impurities such as colloid, fatty acid, odorous substances with bad flavor and excessive pigments in the oil, so as to improve the color of the oil, and more importantly, to ensure that the oil product will not go rancid and deteriorate during the shelf life. However, after the above-mentioned process treatment, the flavor substances contained in the oil are basically removed, so the common refined vegetable oils on the market have a relatively light fragrance or even basically no smell. In order to meet consumers' demand for oil flavor, oil production enterprises only degummed the crude oil obtained by the pressing process without deacidification, decolorization and deodorization to obtain a flavor oil base oil that still contains a certain amount of flavor substances, and then mixed it with refined vegetable oil that has been refined in a certain proportion to obtain a flavored vegetable oil containing a certain amount of flavor substances, so as to take into account consumers' demand for vegetable oil quality and flavor.

[0004] CN 108165363A discloses a preparation process of rapeseed oil with low color value and strong aroma. The process comprises the following steps: removing impurities from the raw rapeseed, frying the seeds, pressing to obtain crude rapeseed oil and rapeseed cake; then distilling the crude rapeseed oil at 160-180°C, collecting the volatiles distilled during the distillation process, and condensing them into condensate as the flavor components of rapeseed oil; refining the crude rapeseed oil after distillation to obtain rapeseed oil with low color value; and uniformly mixing the rapeseed oil flavor components with the low color value rapeseed oil to obtain rapeseed oil with low color value and strong aroma.

[0005] The flavored vegetable oil obtained by mixing crude oil that has only undergone degumming as the base oil with refined vegetable oil that has undergone refining treatment, because the base oil used has not been deacidified, decolorized and deodorized, it still contains a large amount of free fatty acids, pigments and odorous substances. Therefore, the quality indicators such as acid value, peroxide value, anisidine value and color are usually significantly inferior to those of the refined vegetable oil obtained after refining treatment.

[0006] Although the process disclosed in CN108165363A can recover some flavor substances in crude rapeseed oil, the process requires distillation of crude rapeseed oil at 160-180°C. Because crude oil contains more phospholipid colloids, phenols and free unsaturated fatty acids, these substances will undergo complex chemical reactions when heated to 160-180°C, which will not only significantly deepen the color of the oil, but also generate more secondary products such as aldehydes, ketones, and quinones, resulting in a significant increase in the anisidine value of the oil. The anisidine value characterizes the amount of secondary products such as aldehydes and ketones in the oil. The higher the value, the more serious the deterioration of the oil. The higher the temperature of the oil during distillation, the faster the chemical reaction rate of generating secondary products will be, and the more secondary products such as aldehydes, ketones, etc. will be generated. Moreover, the molecular weight of these secondary products is relatively small, and the boiling point is close to the flavor substances in the oil. During the distillation process, most of them will inevitably evaporate together with the flavor substances in the oil, and be recovered together with the flavor substances during the condensation process. When the recovered flavor substances are added to refined vegetable oil to prepare flavored vegetable oil, these secondary products that cause the anisidine value of the oil to increase will inevitably reduce the quality of the flavored vegetable oil product.

[0007] Therefore, there is an urgent need for a device for preparing flavored vegetable oil that can reduce the oxygen concentration and distillation temperature in crude oil during the extraction of flavor substances, thereby inhibiting the oxidation and thermal decomposition reactions of impurities such as phospholipids and free fatty acids in the crude oil at high temperatures. Utility Model Content

[0008] The purpose of the utility model is to overcome the problem that in the process of extracting flavor substances in the prior art, due to the high oxygen concentration and distillation temperature in the crude oil, more secondary products are generated and volatilized together with the flavor substances, so that when the flavor substances are added to the refined vegetable oil to prepare the flavor vegetable oil, these secondary products reduce the quality of the flavor vegetable oil product. A device for preparing flavor vegetable oil is provided, which can reduce the oxygen concentration and distillation temperature in the crude oil during the extraction of flavor substances, thereby reducing the generation of secondary products.

[0009] In order to achieve the above object, the utility model provides a device for preparing flavored vegetable oil, wherein the device comprises: a crude oil degassing unit, a flavor substance extraction unit and a flavored vegetable oil mixing unit which are connected in sequence; wherein the flavor substance extraction unit comprises:

[0010] An evaporation system, wherein the evaporation system is used to separate a gas phase material containing flavor substances from the crude oil obtained after degassing by the crude oil degassing unit;

[0011] A vacuum pumping system is used to provide a vacuum environment for the evaporation system and to extract the gas phase material containing flavor substances from the evaporation system.

[0012] Preferably, the evaporation system comprises a flash tank or an evaporator.

[0013] Preferably, the crude oil degassing unit comprises: a crude oil feed pump, a crude oil heat exchanger and a crude oil degassing tank; wherein the crude oil heat exchanger is used to cool the crude oil raw material fed by the crude oil feed pump and then feed it into the crude oil degassing tank.

[0014] The crude oil degassing unit further includes a degassing vacuum pump. The degassing vacuum pump can be any common vacuum pump such as a liquid ring vacuum pump, a steam jet pump, a water jet pump, a Roots vacuum pump or a screw vacuum pump. The degassing vacuum pump is used to provide a vacuum environment for the crude oil degassing tank. Preferably, a water ring vacuum pump is used to extract the gas phase material in the crude oil degassing tank and send it to a gas-water separation tank, where it is separated from the circulating water used as the working medium of the vacuum pump and discharged into the atmosphere.

[0015] Preferably, the vacuum pumping system comprises: at least one stage of liquid ring vacuum pump and at least one stage of oil-gas separation tank; wherein the oil-gas separation tank is used to remove liquid oil entrained in the gas phase material delivered by the liquid ring vacuum pump.

[0016] Preferably, the vacuum pumping system comprises: a primary liquid ring vacuum pump, a primary oil-gas separation tank, a secondary liquid ring vacuum pump and a secondary oil-gas separation tank which are connected in sequence.

[0017] Preferably, when the evaporation system comprises an evaporator, the evaporation system further comprises:

[0018] an evaporator feed pump, used for feeding the degassed crude oil into the evaporator;

[0019] The evaporator discharge pump is used to extract the liquid phase material from the evaporator after the flavor substances are removed.

[0020] Preferably, when the evaporation system includes an evaporator, the evaporation system further includes: an evaporator circulation pump, which is used to pump the liquid oil in the gas-liquid separation chamber of the evaporator into the heat exchanger of the evaporator for cyclic heating and evaporation.

[0021] Preferably, the flavored vegetable oil blending unit comprises an absorption tower for absorbing flavor substances into the refined vegetable oil;

[0022] Alternatively, the flavored vegetable oil mixing unit includes: a cooler, a gas-liquid separation tank and a mixing tank; wherein the cooler is used to condense the gaseous material containing flavor substances, the gas-liquid separation tank is used to separate the condensate containing the flavor substances and discharge the non-condensable gas, and the mixing tank is used to mix the condensate containing the flavor substances and the refined vegetable oil to form the flavored vegetable oil.

[0023] Preferably, the vacuum system comprises: a primary liquid ring vacuum pump, a primary oil-gas separation tank, a secondary liquid ring vacuum pump and a secondary oil-gas separation tank which are connected in sequence, and refined vegetable oil feed ports are respectively provided on the side wall of the primary oil-gas separation tank, the side wall of the secondary oil-gas separation tank, and the side wall of the absorption tower or the mixing tank, which are used to feed refined vegetable oil into the primary oil-gas separation tank, the secondary oil-gas separation tank and the absorption tower or the mixing tank, respectively.

[0024] Through the above technical solution, the beneficial effects of the utility model at least include:

[0025] By adopting the device provided by the utility model, the oxygen concentration and the distillation temperature in the crude oil can be reduced during the extraction of flavor substances, the oxidation and thermal decomposition reactions of impurities such as phospholipids and free fatty acids in the crude oil at high temperatures can be inhibited, and the generation of secondary products can be reduced. Therefore, the concentration of oxidation and thermal decomposition products contained in the flavor substances extracted from the crude oil by the device provided by the utility model is very low, and the flavor substances are added to refined vegetable oil to produce refined vegetable oil rich in flavor, which can effectively avoid the quality degradation of the oil due to excessive increase in peroxide value and anisidine value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a device for preparing flavored vegetable oil in a preferred embodiment of the utility model.

[0027] Description of Reference Numerals

[0028] 1Crude oil feed pump 2Crude oil heat exchanger 3Crude oil degassing tank 4Degassing vacuum pump

[0029] 5 Gas-water separation tank 6 Evaporator 7 Evaporator circulation pump

[0030] 8. First-stage liquid ring vacuum pump 9. First-stage oil and gas separation tank 10. Second-stage liquid ring vacuum pump

[0031] 11 Secondary oil and gas separation tank 12 Absorption tower 13 Evaporator feed pump

[0032] 14 Evaporator discharge pump 15 Degassing crude oil preheater DETAILED DESCRIPTION

[0033] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0034] The utility model provides a device for preparing flavored vegetable oil, wherein the device comprises: a crude oil degassing unit, a flavor substance extraction unit and a flavored vegetable oil mixing unit which are connected in sequence; wherein the flavor substance extraction unit comprises:

[0035] An evaporation system, wherein the evaporation system is used to separate a gas phase material containing flavor substances from the crude oil obtained after degassing by the crude oil degassing unit;

[0036] A vacuum pumping system is used to provide a vacuum environment for the evaporation system and to extract the gas phase material containing flavor substances from the evaporation system.

[0037] In the utility model, the edible vegetable oil crude oil can include various vegetable oil crude oils obtained by pressing, such as rapeseed crude oil, sunflower seed crude oil, peanut oil crude oil, corn germ oil crude oil, camellia seed crude oil, walnut oil crude oil, etc. The crude oil is degassed in the degassing unit to remove the air dissolved in the crude oil, and then enters the evaporation system of the flavor substance extraction unit for evaporation to separate the gas phase material containing the flavor substance. The vacuum system of the flavor substance extraction unit provides a vacuum environment for the evaporation system. Under vacuum conditions, most of the flavor substances contained in the degassed crude oil can be volatilized at an evaporation temperature below 120°C, and then in the flavor vegetable oil mixing unit, the refined vegetable oil after refining treatment is mixed with the flavor substances sucked out of the evaporation system by the vacuum system, so as to obtain high-quality fragrant vegetable oil (flavor vegetable oil). In the device provided by the utility model, the crude oil after extracting most of the flavor substances in the flavor substance extraction unit can be refined according to a conventional refining method to obtain refined vegetable oil.

[0038] By adopting the device of the utility model, the oxygen concentration and evaporation temperature in the crude oil can be reduced during the extraction of flavor substances, thereby effectively inhibiting the oxidation and thermal decomposition reactions of impurities such as phospholipids and free fatty acids in the crude oil at high temperatures, and reducing the generation of secondary products. Therefore, the concentration of oxidation and thermal decomposition products contained in the flavor substances extracted from the crude oil by the device of the utility model is very low. After being mixed with refined vegetable oil, refined vegetable oil rich in flavor is obtained, which can avoid the quality degradation of the oil product due to excessive increase in peroxide value and anisidine value.

[0039] According to a preferred embodiment of the utility model, the evaporation system includes a flash tank or an evaporator 6. When a flash tank is used to recover flavor substances in oil, a heat exchanger needs to be set to heat the degassed crude oil to below 120°C with steam or other heat sources before entering the flash tank for flash evaporation. The heat exchanger can be any conventional heat exchange equipment such as a conventional shell and tube heat exchanger, a serpentine tube heat exchanger, a gas heater, an electric heater, a corrugated plate heat exchanger or a welded plate heat exchanger. In order to improve the recovery efficiency of flavor substances in oil, the raw material oil can be dispersed into small droplets or droplets through a distributor or an atomizing nozzle during the flash evaporation process to increase the surface area of ​​the raw material evaporation. The degassed crude oil is sprayed into the flash tank through a distributor or an atomizing nozzle. Under vacuum conditions, the flavor substances with relatively small molecular weight in the crude oil flash into gas and are extracted from the flash tank by the vacuum equipment.

[0040] In the utility model, the flash tank can be an empty cylindrical flash tank without internal components, or a filler can be arranged in the flash tank, and the degassed crude oil can be sprayed on the filler to expand the evaporation area. In order to further improve the volatilization efficiency of flavor substances in the degassed crude oil, nitrogen, carbon dioxide gas or water vapor can be injected into the flash tank with fillers below the fillers as a stripping medium, so as to strip the degassed crude oil distributed on the fillers.

[0041] The evaporator 6 can be a rising film evaporator, a falling film evaporator or a wiped film evaporator.

[0042] According to a specific embodiment of the utility model, the evaporator 6 is a falling film evaporator, which includes a gas-liquid separation chamber and an evaporator heat exchanger; wherein the evaporator heat exchanger is used to control the preheating temperature of the crude oil in the evaporation system. The degassed crude oil is injected into the liquid distributor of the falling film evaporator from the top, and then heated by the steam injected into the shell side of the evaporator during the process of flowing downward along the falling film evaporation tube. The flavor substances evaporate into gas after being heated and are extracted from the exhaust pipe at the top of the evaporator by the vacuum system, while the unevaporated liquid oil flows into the gas-liquid separation chamber at the bottom of the evaporator along the tube wall. The volume in the gas-liquid separation chamber of the falling film evaporator should make the average residence time of the crude oil in the falling film evaporator reach at least 15 minutes. In order to improve the extraction rate of flavor substances in the crude oil, the liquid oil in the gas-liquid separation chamber can be transported to the feed pipeline of the evaporator through the evaporator circulation pump 7, mixed with the degassed crude oil, and then heated and evaporated multiple times. The flow rate of the evaporation circulation pump is usually 5-10 times the feed amount of the degassed crude oil.

[0043] The preheating temperature of crude oil in the evaporation system should be controlled at 60-120°C, and the preferred temperature range is 75-105°C. If the preheating temperature is too high, the oxidation reaction of phospholipids in the crude oil will be aggravated, the color of the crude oil will be deepened, and the difficulty of decolorization of the oil will be increased during subsequent processing. At the same time, it will also aggravate the oxidation and thermal decomposition of free fatty acids and phenols in the crude oil. The secondary products generated by these reactions will evaporate along with the flavor substances in the crude oil during the subsequent evaporation process. When refined vegetable oil is used to absorb the flavor substances extracted from crude oil to produce rich-flavor refined vegetable oil, if a large amount of the above-mentioned secondary products of oxidation and thermal decomposition are mixed into the flavor substances, the anisidine value of the oil will be significantly increased. If the preheating temperature of the crude oil is too low, the total amount of flavor substances volatilized will be relatively small during the evaporation process due to the slow volatilization rate of the flavor substances, which will affect the recovery efficiency of the flavor substances.

[0044] According to a preferred embodiment of the utility model, the crude oil degassing unit comprises: a crude oil feed pump 1, a crude oil heat exchanger 2 and a crude oil degassing tank 3; wherein the crude oil heat exchanger 2 is used to cool the crude oil raw material fed by the crude oil feed pump 1 and then feed it into the crude oil degassing tank 3.

[0045] During the degassing process of crude oil, the temperature of the crude oil should be ensured not to exceed 30°C, otherwise the crude oil will suffer excessive loss of flavor substances when degassed under vacuum. In order to more effectively reduce the loss of flavor substances during the degassing process, in a preferred case, the temperature of the crude oil is first reduced to below 15°C by cooling.

[0046] The crude oil degassing unit further includes: a degassing vacuum pump 4. The degassing vacuum pump can be any common vacuum pump such as a liquid ring vacuum pump, a steam jet pump, a water jet pump, a Roots vacuum pump or a screw vacuum pump. The degassing vacuum pump 4 is used to provide a vacuum environment for the crude oil degassing tank 3. Preferably, the degassing vacuum pump 4 is a water ring vacuum pump, which extracts the gas phase material in the crude oil degassing tank 3 and sends it to the gas-water separation tank 5, where it is separated from the circulating water used as the working medium of the vacuum pump and discharged into the atmosphere.

[0047] The vacuum degree in the degassing process should be 1-10kPa absolute pressure in the degassing tank, and the preferred pressure range is 3-5kPa. Too high pressure will lead to insufficient degassing of the air contained in the crude oil, while too low pressure will not only increase energy consumption, but also cause some of the aroma substances with lower boiling points in the crude oil to be vaporized at room temperature and then be drawn away with the degassing air, resulting in excessive loss of flavor substances.

[0048] In the utility model, the vacuum pump for sucking the flavor substances out of the evaporation system may be a liquid ring vacuum pump or a mechanical vacuum pump, such as a dry screw vacuum pump, a diaphragm vacuum pump, a Roots vacuum pump, etc. When a liquid ring vacuum pump is used, the working medium of the vacuum pump is preferably refined vegetable oil for absorbing flavor substances.

[0049] In a preferred embodiment of the utility model, the vacuum system includes: at least one stage of liquid ring vacuum pump and at least one stage of oil-gas separation tank; wherein the oil-gas separation tank is used to remove liquid oil entrained in the gas phase material delivered by the liquid ring vacuum pump.

[0050] The higher the vacuum degree when the crude oil evaporates, the easier it is for the flavor substances to evaporate from the oil. However, increasing the vacuum degree means an increase in the investment in vacuum system equipment and energy consumption, so excessively increasing the vacuum degree is not economical. In actual operation, it is appropriate to keep the absolute pressure in the range of 0.1kPa-1kPa, and the preferred absolute pressure range is 0.15-0.5kPa.

[0051] In a more preferred embodiment of the present invention, the vacuum pumping equipment adopts a liquid ring vacuum pump; the vacuum pumping system includes: a primary liquid ring vacuum pump 8, a primary oil-gas separation tank 9, a secondary liquid ring vacuum pump 10 and a secondary oil-gas separation tank 11 connected in sequence.

[0052] The vacuum system is provided with two-stage liquid ring vacuum pumps (primary liquid ring vacuum pump 8 and secondary liquid ring vacuum pump 10). Since the pressure at the inlet of the secondary liquid ring vacuum pump 10 is substantially the same as the pressure at the outlet of the primary liquid ring vacuum pump 8, the two-stage vacuum pumps need to be provided with oil-gas separation tanks (primary oil-gas separation tank 9 and secondary oil-gas separation tank 11) respectively. By providing two-stage liquid ring vacuum pumps, the evaporator can be operated at a higher vacuum degree, which is beneficial to improving the extraction rate of flavor substances in the degassed crude oil.

[0053] The working medium of the liquid ring vacuum pump is usually water or mineral oil. When the working medium is water or mineral oil, the gaseous flavor substances volatilized in the evaporation system must be condensed into liquid and collected before the inlet of the vacuum pump through the condenser to prevent these flavor substances from being absorbed or contaminated by the working medium (water or mineral oil) of the liquid ring pump. When water is used as the working medium of the liquid ring vacuum pump, due to the limitation of the saturated vapor pressure of water, low-temperature water must be used in order for the system to achieve a higher vacuum degree. The lower the water temperature, the higher the vacuum degree that the system can achieve. If the vacuum degree in the evaporation system is to reach an absolute pressure below 611Pa, the working medium of the liquid ring vacuum pump must use a refrigerant with a lower condensation point. For example, the ethylene glycol aqueous solution with a volume percentage of ethylene glycol of 50% has a condensation point of -35°C. The saturated vapor pressure of mineral oil at room temperature is very low, so using mineral oil as the working medium of the liquid ring vacuum pump can also enable the vacuum system to achieve a higher vacuum degree. However, when using high-boiling-point mineral oil as the working medium of the liquid ring vacuum pump, in order to prevent the flavor substances sucked out of the evaporation system from being absorbed by the mineral oil, the flavor substances must also be condensed into liquid by a condensing device before the liquid ring vacuum pump, and the flavor substances must be recovered by collecting these condensates. The main components of edible vegetable oil are mixed triglycerides, that is, a mixture of long-chain fatty acid triglycerides such as oleic triglycerides, linoleic triglycerides, linolenic triglycerides, and palmitic triglycerides. The normal pressure boiling points of these long-chain fatty acid triglycerides are all above 700°C, so the saturated vapor pressure of edible vegetable oil is very low at room temperature. Therefore, using refined vegetable oil as the working medium of the liquid ring vacuum pump can not only make the system reach a very high vacuum degree, but also in the process of the flavor substances sucked out of the evaporation system contacting with the refined vegetable oil in the liquid ring vacuum pump, part of the flavor substances will be absorbed by the refined vegetable oil, thus reducing the amount of gas that the liquid ring vacuum pump needs to suck. Because the flavor substances in the liquid ring vacuum pump have a short contact time with the refined vegetable oil used as the working medium of the vacuum pump, and the mixing is not sufficient, it is impossible for all the flavor substances sucked by the liquid ring vacuum pump to be absorbed by the refined vegetable oil used as the working medium of the liquid ring vacuum pump. These unabsorbed gaseous flavors carry part of the liquid refined vegetable oil with them and enter the oil and gas separation tank of the liquid ring vacuum pump from the exhaust pipe. The gas discharged from the oil and gas separation tank still contains a small amount of liquid oil. As the refined vegetable oil in the oil and gas separation tank is continuously taken away by the gas, when the liquid level in the separation tank is lower than the liquid level required for the normal operation of the liquid ring vacuum pump, the gas extraction volume of the liquid ring vacuum pump will decrease due to insufficient supply of the working medium, and it may even fail to work normally. Therefore, when the liquid level in the oil and gas separation tank drops, refined vegetable oil should be added to the tank in time.Preferably, refined vegetable oil feed ports are respectively arranged on the side walls of the primary oil-gas separation tank 9 and the secondary oil-gas separation tank 11. Refined vegetable oil feed ports are arranged on the side walls of the primary oil-gas separation tank and the secondary oil-gas separation tank, and a float-type liquid level control valve is arranged at the feed port. In this way, when the liquid level in the oil-gas separation tank drops slightly, the float-type liquid level control valve will automatically open, and refined vegetable oil will be injected into the oil-gas separation tank through the oil supply pipeline to restore the liquid level to normal. Then the float valve will automatically cut off the oil inlet, thereby maintaining the liquid level in the oil-gas separation tank stable.

[0054] Since the flavor substances sucked out by the liquid ring vacuum pump cannot be completely absorbed by the refined vegetable oil which is the working medium of the liquid ring vacuum pump, in order to improve the extraction rate of flavor substances, in the scheme where the liquid ring vacuum pump using refined vegetable oil as the working medium is used as the vacuum equipment, a flavor vegetable oil mixing unit is still provided to further absorb the flavor substances contained in the exhaust gas of the last stage of the liquid ring vacuum pump.

[0055] According to a preferred embodiment of the present utility model, the evaporation system further comprises:

[0056] An evaporator feed pump 13, used to feed the degassed crude oil into the evaporator 6;

[0057] The evaporator discharge pump 14 is used to extract the liquid phase material from the evaporator 6 after the flavor substances are removed.

[0058] As a preferred embodiment of the utility model, a degassed crude oil preheater 15 can be provided, and the oil with a higher temperature from which flavor substances are extracted pumped out by the evaporator discharge pump 14 is used as a heat source, and the degassed crude oil from the evaporator feed pump 13 is preheated by indirect heat exchange, and then the degassed crude oil is heated to the temperature required for the evaporation operation by heating steam, so that the consumption of heating steam in the evaporation process of the degassed crude oil can be reduced. The crude oil preheater 15 can be any conventional heat exchange equipment such as a conventional shell and tube heat exchanger, a serpentine tube heat exchanger, a corrugated plate heat exchanger or a welded plate heat exchanger, and preferably a corrugated plate heat exchanger with high heat transfer efficiency is used.

[0059] In the present invention, the evaporation system feed pump 13 can be a conventional centrifugal pump or a shielded pump, preferably a shielded pump, so as to prevent the degassed crude oil from leaking into the air from the mechanical seal of the pump during the transportation process.

[0060] According to a preferred embodiment of the utility model, when the evaporation system includes an evaporator 6, the evaporation system also includes: an evaporator circulation pump 7, which is used to draw the liquid oil in the gas-liquid separation chamber of the evaporator into the heat exchanger of the evaporator for multiple heating and evaporation, thereby improving the extraction rate of flavor substances in the liquid oil.

[0061] According to a preferred embodiment of the utility model, when the evaporation system includes a flash tank, the evaporation system also includes: a flash tank circulation pump, which is used to suck the liquid oil at the bottom of the flash tank into the heat exchanger of the flash tank for multiple heating and evaporation, thereby improving the extraction rate of flavor substances in the liquid oil.

[0062] According to a preferred embodiment of the utility model, the flavored vegetable oil mixing unit includes an absorption tower 12 for absorbing flavor substances into refined vegetable oil; an overflow port is provided on the side wall of the absorption tower 12 for flowing out the flavored vegetable oil;

[0063] Alternatively, the flavored vegetable oil mixing unit includes: a cooler, a gas-liquid separation tank and a mixing tank; wherein the cooler is used to condense the gaseous material containing flavor substances, the gas-liquid separation tank is used to separate the condensate containing flavor substances and discharge the non-condensable gas, and the mixing tank is used to mix the condensate containing flavor substances and refined vegetable oil to form the flavored vegetable oil.

[0064] According to a preferred embodiment of the utility model, a gas distributor is arranged at the bottom of the absorption tower 12. After the gas discharged from the last stage of the liquid ring vacuum pump is fully contacted with the refined vegetable oil in the absorption tower 12 through the gas distributor, the flavor substances therein are basically all absorbed, and the non-condensable gas is discharged through the exhaust pipe at the top of the absorption tower. After the flavor substances absorbed by the refined vegetable oil in the absorption tower reach a certain concentration, the refined vegetable oil rich in flavor can be discharged from the upper part of the absorption tower as a product. The operation of discharging the refined vegetable oil rich in flavor (flavored vegetable oil) and replenishing the refined vegetable oil can be intermittent or continuous. When the degassing crude oil evaporator is operated in a continuous feeding mode, it is preferred that the flavor substance absorption tower also adopts a continuous feeding and continuous discharging mode for operation, which is more conducive to the quality of the flavored vegetable oil discharged from the absorption tower to remain stable. Preferably, the refined vegetable oil is continuously replenished from the bottom of the absorption tower to the tower through the oil supply pipeline, and the flavored vegetable oil product is continuously discharged from the overflow port of the upper side wall of the absorption tower. According to the different flavor substances content in the crude oil and the requirements of the flavor concentration of the flavored vegetable oil products, the flow rate of the refined vegetable oil injected into the absorption tower can be 1-10 times the flow rate of the degassed crude oil injected into the evaporation system. Under the above flow rate, in order to ensure the absorption effect of the flavor substances from the evaporator by the absorption tower, the average residence time of the refined vegetable oil used to absorb the flavor substances in the absorption tower should be no less than 15 minutes. If the device adopts an intermittent operation mode, and the evaporation and absorption of the flavor substances in the crude oil are carried out in batches, according to the different flavor substances content in the crude oil and the requirements of the flavor concentration of the flavored vegetable oil products, the amount of refined vegetable oil injected into the flavor substance absorption tower in each batch can be 1-10 times the amount of crude oil processed by the evaporation unit. The degassed crude oil injected into the evaporation unit is circulated in the evaporation unit for at least 15 minutes by the evaporation circulation pump according to the circulation amount of 2-3 minutes in the evaporation unit, so that the flavor substances in the crude oil can be fully recovered.

[0065] According to the utility model, when the vacuum pumping device of the vacuum pumping system uses a steam jet pump or a compressed air jet pump, it is preferred to set a cooler between the evaporator (or flash tank) and the steam jet pump (or compressed air jet pump), that is, the flavor substances from the evaporator (or flash tank) are condensed upstream of the steam jet pump (or compressed air jet pump), and the non-condensable gas is extracted by the steam jet pump (or compressed air jet pump) and directly discharged into the atmosphere. At this time, because the condensation is carried out under a relatively high vacuum degree, in order to enable the flavor substances from the evaporator (or flash tank) to be fully recovered after condensation, the condensation temperature should be sufficiently low. For example, ethylene glycol aqueous solution can be used as a refrigerant to reduce the temperature of the gas from the evaporator (or flash tank) to below -20°C in the cooler, so that the flavor substances therein are fully condensed.

[0066] When the vacuum pumping equipment of the vacuum pumping system adopts a mechanical vacuum pump, the cooler can be installed downstream of the mechanical vacuum pump. In order to prevent the flavor substances sucked out of the vacuum pumping system from being contaminated by the lubricating oil of the mechanical vacuum pump, when the cooler is installed downstream of the mechanical vacuum pump, the lubricating oil or grease in the mechanical vacuum pump that may come into contact with the sucked materials must be food grade, or an oil-free lubricated mechanical vacuum pump must be used. After the gaseous materials containing flavor substances sucked out of the evaporation system are compressed by the mechanical vacuum pump, the pressure increases and the freezing point also increases accordingly. Therefore, when the cooler is installed downstream of the mechanical vacuum pump, the gaseous materials containing flavor substances sucked out of the vacuum pumping system and the water vapor can be condensed into liquid for recovery by using normal temperature circulating cooling water as the refrigerant. However, in order to improve the recovery efficiency, it is best to use low-temperature circulating water with a temperature below 10°C as the refrigerant to condense the flavor substances discharged from the vacuum pumping system.

[0067] The utility model has no special restriction on the type of the cooler. Preferably, the cooler is a corrugated plate cooler.

[0068] According to a preferred embodiment of the present invention, a refined vegetable oil feed port is provided on the side wall of the absorption tower 12 or the mixing tank, for feeding the refined vegetable oil into the absorption tower 12 or the mixing tank.

[0069] In the utility model, the refined vegetable oil can be the refined edible oil obtained by using the device provided by the utility model, and the crude oil from which the flavor substances are removed from the evaporation system is processed by degumming, deacidification, decolorization and deodorization according to the conventional refining process of edible vegetable oil, or it can be the commercially available refined edible oil processed by using the same type of oil as the crude oil raw material.

[0070] In the utility model, the mass ratio of the refined vegetable oil used to absorb the gas phase material containing flavor substances (or to mix with the condensate containing flavor substances) and the crude oil raw material used to extract these flavor substances, although there is no special restriction, when the amount of the refined vegetable oil used for absorption (or mixing) is on the small side, although the obtained strong-flavor refined edible oil has a stronger fragrance, the output is also on the low side, and the fragrance of the edible oil is not the stronger the better, and when the amount of the refined vegetable oil used for absorption (or mixing) is on the large side, the content of flavor substances in the obtained product is on the small side, and the fragrance is on the weak side. Therefore, in actual production, the refined vegetable oil with a mass of 1-10 times of the crude oil raw material is usually used to absorb (or mix) the gas phase material containing flavor substances (or the condensate containing flavor substances) sucked out, and what kind of mass ratio is specifically adopted can be determined according to the richness of the fragrance of the crude oil raw material itself and the flavor evaluation result of the flavored vegetable oil product obtained after absorption (or mixing).

[0071] Combination Figure 1The device for preparing flavored vegetable oil in a preferred embodiment of the utility model is described. The device comprises: a crude oil degassing unit, a flavor substance extraction unit and a flavored vegetable oil mixing unit which are connected in sequence; wherein:

[0072] The crude oil degassing unit includes: a crude oil feed pump 1, a crude oil heat exchanger 2, a crude oil degassing tank 3, a degassing vacuum pump 4 and a gas-water separation tank 5; wherein the crude oil heat exchanger is used to cool down the crude oil raw material fed by the crude oil feed pump, and the cooled crude oil enters the degassing tank. The degassing vacuum pump is used to provide a vacuum environment for the crude oil degassing tank and extract the gas phase material in the crude oil degassing tank and send it to the gas-water separation tank.

[0073] The flavor substance extraction unit includes: an evaporation system and a vacuum system. The evaporation system includes an evaporator 6, an evaporator circulation pump 7, an evaporator feed pump 13 and an evaporator discharge pump 14; wherein the evaporator circulation pump is used to draw the liquid oil in the gas-liquid separation chamber of the evaporator into the heat exchanger of the evaporator for circulation heating and evaporation, thereby improving the extraction rate of flavor substances in the liquid oil, the evaporator feed pump 13 is used to send the degassed crude oil into the evaporator 6, and the evaporator discharge pump 14 is used to extract the liquid phase material after the flavor substances are removed from the evaporator 6. The vacuum system includes: a primary liquid ring vacuum pump 8, a primary oil-gas separation tank 9, a secondary liquid ring vacuum pump 10 and a secondary oil-gas separation tank 11 connected in sequence; wherein the primary oil-gas separation tank and the secondary oil-gas separation tank are used to remove the oil in the gas phase material sent in by the primary liquid ring vacuum pump and the secondary liquid ring vacuum pump, respectively. Refined vegetable oil feed ports are respectively arranged on the side walls of the primary oil-gas separation tank and the secondary oil-gas separation tank, and are used to feed refined vegetable oil into the primary oil-gas separation tank and the secondary oil-gas separation tank respectively.

[0074] The flavor vegetable oil mixing unit includes an absorption tower 12, and a refined vegetable oil feed port is arranged at the bottom of the absorption tower or on the side wall near the bottom, which is used to feed refined vegetable oil into the absorption tower; an overflow port is also arranged on the side wall in the middle or upper part of the flavor substance absorption tower, which is used to flow out the flavor vegetable oil.

[0075] The present invention will be described in detail by way of examples. In the following examples, unless otherwise specified, all methods are conventional methods; and the reagents and materials used, unless otherwise specified, can be obtained from commercial sources.

[0076] The following examples are used to illustrate the use of Figure 1 The apparatus shown is a method for preparing flavored vegetable oil.

[0077] Example 1

[0078] The crude rapeseed oil obtained by pressing is pumped into the crude oil cooling heat exchanger through the crude oil feed pump, and the control system automatically adjusts the flow of low-temperature water flowing through the heat exchanger to reduce the crude oil temperature to 7°C before entering the vacuum degassing tank. The absolute pressure in the vacuum degassing tank is maintained at 3kPa by the degassing vacuum pump to remove most of the air dissolved in the crude oil. The degassed crude oil is then extracted from the bottom of the degassing tank by the evaporator feed pump and transported to the crude oil preheating heat exchanger. After heat exchange with the crude oil from the falling film evaporator discharge pump, it enters the falling film evaporator. COFCO Fortune Brand refined first-grade rapeseed oil is injected into the first-stage oil-gas separator and the second-stage oil-gas separator of the falling film evaporator vacuum system as the working medium of the first-stage oil ring vacuum pump and the second-stage oil ring vacuum pump. COFCO Fortune Brand refined first-grade rapeseed oil is injected into the flavor substance absorption tower to a liquid level close to the overflow port, and then the second-stage liquid ring vacuum pump and the first-stage liquid ring vacuum pump are turned on in sequence. When the liquid level in the gas-liquid separation chamber of the falling film evaporator reaches about 50% of the set value, the circulating pump of the evaporator is turned on, and then saturated water vapor at 150°C is injected into the shell side of the falling film evaporator, and the crude oil temperature in the falling film evaporator is controlled at 105°C through the automatic control system. When the liquid level in the gas-liquid separation chamber of the falling film evaporator is close to the set value, the evaporator discharge pump is turned on, and the crude oil in the evaporator, from which most of the flavor substances have been removed, is transported to the crude oil preheating heat exchanger, and after heat exchange with the crude oil from the crude oil degassing tank, enters the crude oil refining device (not shown in the figure), and is refined in the refining device according to the conventional rapeseed oil refining method through degumming, decolorization, dewaxing and deodorization processes. The liquid level height in the gas-liquid separation chamber of the falling film evaporator should make the average residence time of the crude oil in the falling film evaporator reach 30 minutes. The control system automatically adjusts the opening of the valve on the outlet pipeline of the evaporator discharge pump to keep the liquid level in the gas-liquid separation chamber of the evaporator stable. The pressure in the falling film evaporator is maintained at about 200Pa by the primary and secondary oil ring vacuum pumps. The gas extracted from the evaporator is discharged from the secondary oil and gas separation tank and enters the gas distributor at the bottom of the flavor substance absorption tower. The flavor substances therein are dissolved and absorbed by the refined first-grade rapeseed oil in the absorption tower, and the gas that cannot be absorbed (the main component is the air leaking into the system) is discharged into the atmosphere from the top of the absorption tower as tail gas. When the discharge pump of the falling film evaporator starts to discharge normally, COFCO Fortune brand refined first-grade rapeseed oil is injected into the bottom of the flavor substance absorption tower at the same flow rate as the crude oil processing volume. The refined first-grade rapeseed oil entering the absorption tower stays in the tower for an average of about 15 minutes, rises to the upper overflow port and flows out, and the resulting product is a concentrated flavor refined rapeseed oil stock solution. The concentrated flavor refined rapeseed oil stock solution is evenly mixed with 5 times the weight of COFCO Fortune brand refined first-grade rapeseed oil to obtain a concentrated flavor refined rapeseed oil product for analysis, testing and flavor evaluation.

[0079] Comparative Example 1

[0080] The same batch of crude rapeseed oil raw material as in Example 1 was used. The crude rapeseed oil raw material and a citric acid aqueous solution with a mass concentration of 0.5wt% were uniformly mixed at a mass ratio of 10:1, placed in a 70°C water bath and stirred for 15 minutes, and then centrifuged at 1021Xg for 15 minutes to remove the colloid in the crude oil to obtain a concentrated rapeseed oil stock solution. The concentrated rapeseed oil stock solution was mixed with 5 times the mass of COFCO Fortune brand refined first-grade rapeseed oil as in Example 1 to obtain a concentrated rapeseed oil product for analysis, testing and flavor evaluation.

[0081] Comparative Example 2

[0082] The same batch of crude rapeseed oil as in Example 1 was used as raw material. The crude rapeseed oil raw material was distilled at 170°C until no volatiles were distilled out. The distillate was condensed using 30°C cold water as a refrigerant, and the resulting condensate was collected; the crude rapeseed oil after distillation was subjected to hydration degumming, alkali refining deacidification and activated carbon decolorization in sequence using conventional rapeseed oil refining processes to obtain low color rapeseed oil. The condensate obtained in the distillation process and the low color rapeseed oil obtained after refining were then evenly mixed to obtain a low color and fragrant rapeseed oil stock solution. The low color and fragrant rapeseed oil stock solution was mixed with 5 times the mass of COFCO Fortune brand refined first-grade rapeseed oil that was the same as in Example 1 to obtain a low color and fragrant rapeseed oil product for analysis, testing and flavor evaluation.

[0083] Test Case

[0084] The results of the analysis and testing of various indicators and the flavor evaluation of the fragrant rapeseed oil obtained in the embodiment and the comparative example are shown in Table 1. Among them, the acid value detection is carried out according to the method provided in GB5009.229; the peroxide value detection is carried out according to the method provided in GB5009.227; the anisidine value detection is carried out according to the method provided in GB / T24304-2009; the color detection is carried out according to the method provided in GB / T5009.37; the flavor evaluation is conducted by 10 evaluators with oil flavor evaluation qualifications to smell and blindly evaluate the three samples, and the average score of each sample is taken as the flavor evaluation score.

[0085] Table 1

[0086]

[0087] The refined first-grade rapeseed oil obtained after degumming, deacidification, decolorization, dewaxing and deodorization has almost no aroma. From the results in Table 1, it can be seen that the flavored vegetable oil prepared by the device provided by the utility model in Example 1 not only has a strong rapeseed oil aroma, but also has a significantly better quality than the flavored rapeseed oil obtained by the conventional production process.

[0088] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A device for preparing flavored vegetable oil, characterized in that: The device comprises: a crude oil degassing unit, a flavor substance extraction unit and a flavor vegetable oil mixing unit which are connected in sequence; wherein the flavor substance extraction unit comprises: An evaporation system, wherein the evaporation system is used to separate a gas phase material containing flavor substances from the crude oil obtained after degassing by the crude oil degassing unit; A vacuum pumping system is used to provide a vacuum environment for the evaporation system and to extract the gas phase material containing flavor substances from the evaporation system.

2. The device according to claim 1, characterized in that The evaporation system comprises a flash tank or evaporator (6).

3. The device according to claim 1, characterized in that The crude oil degassing unit comprises: a crude oil feed pump (1), a crude oil heat exchanger (2) and a crude oil degassing tank (3); wherein the crude oil heat exchanger (2) is used to cool the crude oil raw material fed by the crude oil feed pump (1) and then feed it into the crude oil degassing tank (3).

4. The device according to claim 3, characterized in that The crude oil degassing unit further comprises: a degassing vacuum pump (4) and a gas-water separation tank (5); wherein the degassing vacuum pump (4) is used to provide a vacuum environment for the crude oil degassing tank (3) and to extract gaseous materials in the crude oil degassing tank (3) and send them to the gas-water separation tank (5).

5. The device according to claim 1, characterized in that The vacuum pumping system comprises: at least one stage of liquid ring vacuum pump and at least one stage of oil-gas separation tank; wherein the oil-gas separation tank is used to remove liquid oil entrained in the gas phase material delivered by the liquid ring vacuum pump.

6. The device according to claim 5, characterized in that The vacuum pumping system comprises: a primary liquid ring vacuum pump (8), a primary oil-gas separation tank (9), a secondary liquid ring vacuum pump (10) and a secondary oil-gas separation tank (11) which are connected in sequence.

7. The device according to claim 2, characterized in that When the evaporation system comprises an evaporator (6), the evaporation system further comprises: an evaporator feed pump (13), used for feeding the degassed crude oil into the evaporator (6); The evaporator discharge pump (14) is used to extract the liquid phase material from the evaporator (6) after the flavor substances are removed.

8. The device according to claim 2, characterized in that When the evaporation system includes an evaporator (6), the evaporation system further includes: an evaporator circulation pump (7) for pumping liquid oil in the gas-liquid separation chamber of the evaporator into a heat exchanger of the evaporator for circulation, heating and evaporation.

9. The device according to claim 1, characterized in that The flavored vegetable oil mixing unit comprises an absorption tower (12) for absorbing flavor substances into refined vegetable oil; Alternatively, the flavored vegetable oil mixing unit includes: a cooler, a gas-liquid separation tank and a mixing tank; wherein the cooler is used to condense the gaseous material containing flavor substances, the gas-liquid separation tank is used to separate the condensate containing the flavor substances and discharge the non-condensable gas, and the mixing tank is used to mix the condensate containing the flavor substances and the refined vegetable oil to form the flavored vegetable oil.

10. The device according to claim 9, characterized in that The vacuum pumping system comprises: a primary liquid ring vacuum pump (8), a primary oil-gas separation tank (9), a secondary liquid ring vacuum pump (10) and a secondary oil-gas separation tank (11) which are connected in sequence; a side wall of the primary oil-gas separation tank (9), a side wall of the secondary oil-gas separation tank (11), and a side wall of an absorption tower (12) or a mixing tank are respectively provided with refined vegetable oil feed ports for respectively feeding refined vegetable oil into the primary oil-gas separation tank (9), the secondary oil-gas separation tank (11) and the absorption tower (12) or the mixing tank.

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