A cottonseed processing extraction method and apparatus

Abstract

The present application relates to a cottonseed processing leaching method and equipment, the cottonseed processing leaching method comprises the steps of pretreatment, rolling, pre-pressing, crushing and leaching, the pretreatment step is to remove the cottonseed ginning, shelling and softening to obtain soft cotton kernel, the rolling is to roll the soft cotton kernel in the pretreatment step into a sheet, then drying, to obtain sheet cotton kernel, the pre-pressing step is to cold press the sheet cotton kernel, to obtain cotton cake and primary crude oil, the crushing step is to crush the cotton cake, to obtain cotton kernel powder, the leaching step is to use pure solvent for continuous soaking and flushing during the upward conveying of the cotton kernel powder, the solvent containing oil is evaporated to obtain secondary crude oil, the primary crude oil is removed after removing impurities such as gum and gossypol, and the secondary crude oil is removed after removing impurities such as solvent, gum and gossypol, which is cottonseed oil, and the cottonseed processing leaching equipment is used to realize the cottonseed processing leaching method.

Description

Technical Field

[0001] This invention belongs to the field of cottonseed processing technology, specifically relating to a cottonseed processing leaching method and equipment. Background Technology

[0002] Cottonseed is an important vegetable oilseed. The kernel of cottonseed contains not only 35% to 45% oil but also 39% protein, making it the world's second most important oilseed and protein crop after soybeans. In addition to producing cottonseed oil, the remaining material can be used as protein-rich feed. Currently, cottonseed oil is usually produced by pressing or solvent extraction. Compared with pressing, solvent extraction has greater advantages in terms of lower cost, simpler operation, higher extraction rate, and less residual oil.

[0003] In oil extraction using leaching methods, soaking and spraying extraction are commonly employed. However, due to the small processing capacity and lack of continuous production capability of soaking methods, spraying extraction is now more commonly carried out using equipment such as annular leaching devices and drag chain leaching devices. These leaching devices have advantages such as continuous production, large processing capacity, and small footprint. Their leaching principle involves repeatedly spraying a solvent, allowing the solvent to contact the material and extract oil from cottonseed. For example, Chinese patent application number CN201610712865.X discloses a method for extracting cottonseed oil with a yield of 94%–96%. The journal "Research Progress in Rapeseed Oil Processing Technology" (Chinese Cereals and Oils Journal), Vol. 38, No. 3, March 2023, records a comparison of oil yields from different extraction processes, with leaching yielding approximately 90%–98%. However, industrial leaching oil extraction processes are often limited by cost and profitability, making it difficult to achieve high leaching yields. Further improvements to the process are still possible. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a cottonseed processing leaching method and equipment. By employing a special leaching process and equipment, the oil yield in industrial production is increased, solvent usage is reduced, costs are lowered, and the oil yield is improved.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A cottonseed processing and leaching method includes pretreatment, rolling, pre-pressing, crushing and leaching steps, wherein the pretreatment step involves delinting, dehulling and softening the cottonseed to obtain softened cotton kernels.

[0007] The rolled blank is made by rolling the softened cotton kernels in the pretreatment step into sheets with a thickness of 0.3 mm to 0.4 mm, and then drying them to obtain sheet cotton kernels;

[0008] The pre-pressing step involves cold pressing the flake cottonseed to obtain cotton cake and primary crude oil.

[0009] The pulverizing step involves pulverizing the cotton cake to obtain cotton kernel powder;

[0010] The leaching step involves continuously soaking and rinsing cottonseed powder with a pure solvent while it is being transported from bottom to top. After the solvent containing oil evaporates, secondary crude oil is obtained. After removing impurities such as gum and gossypol from the primary crude oil, and after removing impurities such as solvent, gum and gossypol from the secondary crude oil, cottonseed oil is obtained.

[0011] In laboratory settings, leaching can achieve high extraction efficiency for oils because it allows for multiple leaching cycles and long leaching times. For example, the study "Research on Extraction Technology of Cottonseed Oil in Xinjiang" (Food Science and Technology, Vol. 34, No. 9, 2009, pp. 168-171) states that, with other factors remaining constant, the extraction rate increases with the number of leaching cycles, the extraction rate increases with the soaking time, and the extraction rate increases significantly with the increase of the solvent ratio. However, this is only under experimental conditions. Actual industrial production requires comprehensive consideration of production costs and benefits, and usually only a limited number of leaching cycles are performed. Furthermore, it is necessary to minimize the solvent ratio and shorten the leaching time to achieve the best benefits. Therefore, it is difficult to achieve a relatively high extraction rate in industrial production, resulting in a certain amount of oil remaining in the cottonseed meal after leaching, causing waste. In addition, the high-temperature treatment of cottonseed before leaching in existing technologies will cause gossypol to combine with protein, reducing the effective utilization of cottonseed protein.

[0012] This invention eliminates steaming and roasting in the pre-pressing step, instead using direct cold pressing. The resulting crude oil is then treated to remove impurities such as gums and gossypol, yielding cottonseed oil for use as edible oil. The purpose of not steaming and roasting is to reduce the binding effect of gossypol with protein, preventing the protein in cottonseed meal from combining with gossypol to form indigestible protein components. This fully protects the effective nutritional components of cottonseed protein, resulting in high protein content in subsequent processes, improving the utilization rate of cottonseed, providing feed and aquaculture enterprises with a new type of high-quality feed plant protein, and serving as a supplement and substitute for soybean meal and fishmeal.

[0013] In the leaching step of this invention, a pure solvent is used for continuous soaking and rinsing. After pre-pressing and soaking, the cottonseed has very little residual oil. The pure solvent can quickly leach out the residual oil from the cottonseed. After leaching, the solvent is immediately distilled, and the distilled solvent is condensed and then added back into the soaking process. The solvent that has been soaking for a period of time overflows, forming a cycle. This method allows the cottonseed powder to be soaked and rinsed for a sufficient amount of time. As the cottonseed powder is transported upward, the solvent it comes into contact with becomes increasingly pure, resulting in a better leaching effect. Compared with the multiple spraying in the prior art, this method has a better extraction effect and uses less solvent. Furthermore, because the solvent is repeatedly distilled and leached, the same batch of solvent can be enriched with more oil, resulting in higher utilization. In the later processing, only a small amount of solvent needs to be removed to obtain pure oil. Compared with the prior art, the solvent of this invention has a high degree of oil enrichment, and the energy consumption for later purification is low.

[0014] Furthermore, in the pretreatment step, the softening temperature is 60°C and the moisture content is controlled at 10% to 12%. In the rolling step, the drying process uses hot air at 60°C to 70°C for fluidized drying, and at the end of drying, the moisture content of the flaky cotton kernels is controlled at 2% to 4%.

[0015] This invention strictly limits the softening and drying temperatures of cottonseeds because steaming and roasting are not performed. The softening of cottonseeds is mainly to enable the cottonseeds to form better flaky kernels during the rolling process, and to avoid the cottonseeds' condition being affected by rolling when the moisture content is low. After rolling, drying is performed, and the low moisture content can improve the oil yield of the cottonseeds.

[0016] Furthermore, the pre-pressing stage extracts 60% to 70% of the total oil, which can obtain as much primary crude oil as possible without wasting too much energy on the pressing equipment. This stage is the optimal stage for energy consumption and efficiency of the pressing equipment. If the remaining 30% to 40% of the oil is pressed, the energy consumption will be high and the efficiency will be low.

[0017] Furthermore, in the leaching step, the solvent temperature is 45℃~55℃, and the solvent used to soak the cottonseed powder is distilled to evaporate the solvent and then condensed. The condensed solvent is used to repeatedly rinse and soak the cottonseed powder.

[0018] At this temperature, cottonseed proteins do not denature even after prolonged soaking, and their binding ability with gossypol is weak, which can prolong the leaching time and better preserve cottonseed protein, providing high-quality raw materials for subsequent processing.

[0019] Furthermore, the solvent is petroleum ether with a boiling range of 30°C to 60°C.

[0020] The appropriate solvent is selected based on the leaching temperature. Petroleum ether with a boiling range of 30℃ to 60℃ is used under normal pressure. If hexane is used, negative pressure operation is required, which will increase costs. Therefore, petroleum ether is preferred as the leaching solvent. The advantage of choosing petroleum ether as the solvent is that distillation does not waste energy excessively. Since the boiling point of the solvent is also close to the leaching temperature, the solvent separation process is achieved during the process of keeping the leaching temperature. This ensures that the solvent used for rinsing and leaching is a pure solvent that has evaporated and then condensed, rather than a solvent containing oils or with poor leaching effect. When the solvent is reused, its extraction efficiency does not decrease.

[0021] A cottonseed processing leaching device includes a shell, an leaching chamber, a conveying section, a feeding section, and a condenser. The upper end of the shell is connected to the condenser, and the lower part is provided with a heating jacket. The leaching chamber inside the shell includes a carrying tank and an overflow tank, wherein both the carrying tank and the overflow tank are cylindrical bodies with open ends. The bottom plate of the carrying tank has filter mesh holes. The overflow tank is sleeved on the outside of the carrying tank, and the upper end of the overflow tank is lower than the upper end of the carrying tank. The conveying section is located inside the carrying tank. The drive shaft of the conveying section passes through the leaching chamber and the shell and is connected to a motor located outside the shell. The conveying section pushes the material in the carrying tank upward. The feeding section is located outside the shell. The lower end of the feeding section passes through the shell and the overflow tank and connects to the lower part of the carrying tank. The connection between the lower end of the feeding section and the carrying tank is lower than the upper end of the overflow tank. The upper end of the carrying tank is connected to a discharge trough, which passes through the shell and connects to a storage chamber outside the shell.

[0022] This invention relates to an industrial cottonseed leaching device that solves the problem of low cottonseed leaching rate without increasing costs, and may even reduce production costs in some aspects. Its principle lies in a special leaching chamber. The chamber's supporting tank holds cottonseed powder, which is slowly conveyed upwards by a conveyor and discharged through a discharge trough at the top of the supporting tank. The lower part of the casing holds and heats the solvent, causing it to vaporize. The vaporized solvent moves upwards and condenses in a condenser, becoming pure solvent that falls back into the supporting tank, rinsing the cottonseed powder above. The rinsed solvent flows downwards into the supporting tank, causing the solvent that had already soaked the cottonseed powder in the supporting tank to flow into an overflow tank and overflow for reheating. Because the overflow tank is located outside the supporting tank, the liquid level in the supporting tank is flush with the top of the overflow tank, thus the solvent in the supporting tank also soaks and extracts the cottonseed powder. Compared to existing technologies, the solvent extraction of oils in this invention is more thorough and has a higher extraction rate. It enables continuous leaching of cottonseed, with cottonseed powder moving upwards along the conveyor. The soaking time of the cottonseed powder can be adjusted by controlling the speed of the conveyor. Compared to existing technologies, it has a higher extraction rate and a smaller solvent ratio. This invention can form a pure solvent within the shell, which can improve the mass transfer speed of oil in the soaked cottonseed powder. Its extraction capacity is higher than that of existing technologies. The leaching and soaking leaching extraction effect is also stronger than that of existing technologies. Furthermore, because this invention can refresh the solvent within the shell, the solvent ratio is reduced, and the cost is decreased. The heat source for heating the solvent in this invention is actually a heat source for keeping the solvent warm, without adding a heat source. Only the heating power is increased, so it does not significantly increase the cost. Therefore, the cottonseed leaching equipment for industrial production of this invention can achieve effects that existing technologies do not have.

[0023] Furthermore, the bottom of the housing is provided with a drain pipe with a shut-off valve, and the side wall of the housing is provided with an injection pipe with a shut-off valve, the injection pipe being lower than the upper end of the overflow tank.

[0024] The drain and injection tubes can refresh the solvent, draining oil-rich solvent and replenishing it with new solvent.

[0025] Furthermore, the conveying section includes a first helical blade and a second helical blade, both of which are connected to the drive shaft. The first and second helical blades have the same direction of rotation, and the pitch of the first helical blade is greater than that of the second helical blade. The lower end of the first helical blade is connected to the upper end of the second helical blade, and the connection point between the first and second helical blades is lower than the connection point between the lower end of the feeding section and the bearing trough.

[0026] The function of the first spiral blade is to move the cottonseed powder upwards, while the function of the second spiral blade is to prevent the cottonseed powder from moving downwards, but not to prevent the solvent from flowing downwards, so that the cottonseed powder can be successfully leached out.

[0027] Furthermore, the outer edges of both the first and second helical blades are lower than the connection points between the first and second helical blades and the drive shaft.

[0028] This setup allows cottonseed powder to move smoothly upwards and be evenly extracted, before being transferred to the discharge trough at the top of the carrying tank.

[0029] Furthermore, the discharge trough includes a collection trough and a downwardly inclined chute. The outer diameter of the collection trough is larger than the outer diameter of the bearing trough. A scraper is connected to the drive shaft. The scraper slides in contact with the inner side of the collection trough. The chute extends through the housing into the storage chamber. The lower end of the storage chamber has a closable valve.

[0030] The scraper can concentrate the cottonseed powder that has been leached out in the collection tank. As the scraper rotates, the leachated cottonseed powder is discharged from the chute into the storage chamber. Because the solvent contains a certain degree of toxicity, the lower end of the storage chamber needs to have a sealable valve to prevent the solvent from evaporating into the workshop, or the lower end of the storage chamber can be directly connected to other processing equipment, such as extrusion equipment or storage containers.

[0031] Furthermore, the feeding section includes a storage hopper and a conveying pipe, and a rotary unloader is provided between the storage hopper and the conveying pipe, through which the storage hopper discharges material into the conveying pipe.

[0032] The rotary unloader has both unloading function and separation function between the storage hopper and the conveying pipe to prevent solvent evaporation from entering the workshop environment.

[0033] The beneficial effects of the present invention through the above technical solution are as follows:

[0034] This invention employs a unique leaching process. Instead of steaming or roasting in the pre-pressing step, it involves direct cold pressing followed by leaching. During leaching, a pure solvent is used for continuous soaking and rinsing. This pure solvent rapidly extracts oil from the cottonseed. Furthermore, the solvent is immediately distilled after leaching, ensuring a constant supply of pure solvent in the carrier tank. This allows the cottonseed powder to undergo sufficient soaking and rinsing time. As the cottonseed powder is transported upwards, the solvent it comes into contact with becomes increasingly pure, resulting in increasingly better leaching effects. Compared to the multiple leaching processes in existing technologies, this invention offers superior extraction efficiency. Because the solvent is repeatedly distilled and leached, the same batch of solvent can concentrate more oil, leading to higher utilization. Only a small amount of solvent needs to be removed in the later stages to obtain pure oil. Compared to existing technologies, this results in higher oil concentration and lower energy consumption for later purification, increasing the oil yield in industrial production, reducing solvent usage, lowering costs, and improving oil yield.

[0035] This invention strictly limits the softening and drying temperature of cottonseed. Because steaming and roasting are not carried out, the processing and extraction temperatures are low. After soaking for a long time, the protein in cottonseed does not denature and has a weak binding ability with gossypol. This can prolong the leaching time, better preserve the cottonseed protein, and provide high-quality raw materials for subsequent processing.

[0036] The cottonseed processing and leaching equipment of the present invention can solve the problem of low cottonseed leaching rate without increasing costs. It forms a pure solvent in the shell, and its extraction capacity is higher than that of the prior art. The leaching and extraction effect formed by rinsing and soaking is also stronger than that of the prior art. Furthermore, because the present invention can refresh the solvent in the shell, less solvent is required, so the solvent ratio is reduced and the cost is reduced. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a cottonseed processing and leaching device according to the present invention;

[0038] Figure 2 This is a cross-sectional front view of a first embodiment of a cottonseed processing and leaching device according to the present invention;

[0039] Figure 3 This is a cross-sectional front view of a second embodiment of a cottonseed processing and leaching device of the present invention;

[0040] Figure 4 yes Figure 2 Sectional view along axis AA;

[0041] Figure 5 This is a structural diagram of the conveyor section;

[0042] Figure 6 This is a sectional front view of the conveyor section.

[0043] The attached diagram is labeled as follows: 1. Shell; 2. Leaching chamber; 3. Conveying section; 4. Feeding section; 5. Condenser; 6. Heating jacket; 7. Support tank; 8. Overflow tank; 9. Filter mesh; 10. Pad; 11. Grille; 12. Motor; 13. First spiral blade; 14. Second spiral blade; 15. Storage hopper; 16. Conveying pipe; 17. Rotary unloader; 18. Discharge chute; 19. Collection chute; 20. Sluice; 21. Scraper; 22. Storage chamber; 23. Drain pipe; 24. Injection pipe; 25. Closing ring. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0045] Example 1:

[0046] like Figure 1 , Figure 2 and Figure 4As shown, a cottonseed processing leaching device includes a shell 1, an leaching chamber 2, a conveying section 3, a feeding section 4, and a condenser 5. The shell 1 is a cylindrical body with upper and lower end caps. The upper end of the shell 1 has a condenser 5, and the lower end has a heating jacket 6. The outlet of the condenser 5 is connected to a negative pressure pipeline or a waste gas treatment pipeline. The space inside the shell 1 is the leaching chamber 2, which includes a carrying tank 7 and an overflow tank 8. Both the carrying tank 7 and the overflow tank 8 are cylindrical bodies with open upper ends. The bottom plate of the carrying tank 7 has a through hole, which is covered with a filter screen, so that the bottom plate of the carrying tank 7 has filter screen holes 9 for solvent outflow, preventing cottonseed powder from falling to the bottom of the carrying tank 7 and causing blockage. The overflow tank 8 is sleeved on the outside of the carrying tank 7. The inner wall of the overflow tank 8 is connected to the outer wall of the carrying tank 7 by a pad 10 or a connecting rod, so that there is a gap between the inner wall of the overflow tank 8 and the outer wall of the carrying tank 7, which allows the carrying tank 7 to... The overflow trough 8 is stably connected internally and is fixed inside the housing 1 using a grid 11, crossbeams, etc. It has gaps that allow the oily solvent inside the housing 1 to descend and allow the solvent to evaporate. The upper end of the overflow trough 8 is lower than the upper end of the carrying tank 7. The overflow trough 8 allows the solvent to overflow, while the higher upper end of the overflow trough 8 allows the solvent to form a higher liquid level in the carrying tank 7 for soaking cottonseed powder, improving the leaching effect. However, this soaking cannot completely submerge all the cottonseed powder to prevent the solvent from being quickly mixed with the oily solvent when it flows downwards, reducing the leaching effect. The conveying unit 3 is located inside the carrying tank 7. The drive shaft of the conveying unit 3 passes through the carrying tank 7, the overflow trough 8, and the housing 1 and is connected to a motor 12 located outside the housing 1. The connection between the drive shaft and the housing 1, and the connection between the drive shaft and the overflow trough 8, are equipped with mechanical seals to prevent solvent and oil from overflowing. Figure 5 and Figure 6As shown, the conveying unit 3 includes a first helical blade 13 and a second helical blade 14. Both the first helical blade 13 and the second helical blade 14 are connected to the drive shaft. The outer edges of both the first helical blade 13 and the second helical blade 14 are in sliding contact with the inner wall of the bearing groove 7. The outer edges of both the first helical blade 13 and the second helical blade 14 are lower than the connection points between the first helical blade 13 and the second helical blade 14 and the drive shaft. The first helical blade 13 and the second helical blade 14 have the same rotation direction. The pitch of the first helical blade 13 is greater than the pitch of the second helical blade 14. The lower end of the first helical blade 13 is connected to the upper end of the second helical blade 14 and the connection is smooth. The connection between the first helical blade 13 and the second helical blade 14 is lower than the connection between the lower end of the feeding section 4 and the bearing trough 7. The first helical blade 13 pushes the material in the bearing trough 7 upwards, while the second helical blade 14 prevents the cottonseed powder from moving downwards. The feeding section 4 is located outside the housing 1 and includes a storage hopper 15 and a conveying pipe 16. A rotary unloader 17 is provided between the storage hopper 15 and the conveying pipe 16. The storage hopper 15 discharges material into the conveying pipe 16 via the rotary unloader 17. The lower end of the conveying pipe 16 penetrates the housing 1 and the overflow trough 8, connecting to the lower part of the bearing trough 7. The connection between the lower end of the conveying pipe 16 and the bearing trough 7 is lower than the upper end of the overflow trough 8. Figure 4 As shown, the upper end of the bearing tank 7 is connected to a discharge tank 18. The discharge tank 18 includes a collection tank 19 and a downwardly inclined chute 20. The collection tank 19 is an annular tank with a certain inclination on its bottom surface, allowing the cottonseed powder accumulated in the collection tank 19 to drain the solvent and facilitate the solvent to flow back into the bearing tank 7 along the inclination angle. The outer diameter of the collection tank 19 is larger than the outer diameter of the bearing tank 7. A scraper 21 is connected to the drive shaft, and the scraper 21 slides in contact with the inner side of the collection tank 19. The side wall of the collection tank 19 has a notch that connects to the downwardly inclined chute 20. The chute 20 penetrates the housing 1 and extends into the storage chamber 22 outside the housing 1. Inside, the lower end of the storage chamber 22 has a sealable valve. The collection tank 19 can concentrate the cottonseed powder and drain the solvent in the cottonseed powder, avoiding excessive solvent in the discharged cottonseed powder, which facilitates subsequent processing. After the solvent absorbs more oil, its volume increases. The bottom of the shell 1 is provided with a drain pipe 23 with a stop valve, and the side wall of the shell 1 is provided with an injection pipe 24 with a stop valve. The injection pipe 24 is lower than the upper end of the overflow tank 8 and is used to extract the solvent with more oil and add new solvent. The lower end of the condenser 5 is provided with a closing ring 25 with a large upper diameter and a small lower diameter. The closing ring 25 makes the condensed solvent more concentrated and sprayed onto the cottonseed powder in the carrying tank 7.

[0047] Example 2:

[0048] This embodiment is basically the same as Embodiment 1, and the similarities will not be repeated. The differences are as follows:

[0049] like Figure 3As shown, the lower end of the overflow trough 8 is close to the lower end of the shell 1. The distance between the lower end of the overflow trough 8 and the lower end of the shell 1 is closer than that in Embodiment 1. The height of the bearing trough 7 and the overflow trough 8 is higher. When the lower part of the shell 1 is filled with solvent, the solvent submerges the lower part of the overflow trough 8, but there is a gap between the liquid surface and the upper end of the overflow trough 8.

[0050] This allows the carrying tank 7 to be deeper, resulting in a longer time for cottonseed powder to be transported from bottom to top. With a longer leaching time, the extraction effect is better. The overflow tank 8 occupies a certain volume of solvent. When using the same volume of solvent, the liquid level in Example 2 is higher and the liquid level change is more obvious. A viewing window is provided on the shell 1, which makes it easy to confirm the proportion of oil in the solvent in the shell 1 by observing the liquid level change, and to conveniently control the timing of solvent replacement. When the liquid level is consistent, the volume of solvent used in Example 2 is less than that in Example 1, which not only improves the leaching effect but also further reduces the solvent ratio.

[0051] A cottonseed processing and leaching method includes pretreatment, rolling, pre-pressing, crushing and leaching steps. The pretreatment step involves delinting, dehulling and softening the cottonseed to obtain softened cotton kernels. The softening temperature is 60°C and the moisture content is controlled at 10% to 12%.

[0052] The rolling process involves rolling the softened cotton kernels from the pretreatment step into sheets with a thickness of 0.3 mm to 0.4 mm, followed by drying. The drying process uses hot air at 60°C to 70°C for fluidized drying, and the moisture content is controlled at 2% to 4% at the end of drying to obtain sheet cotton kernels.

[0053] The pre-pressing step involves cold pressing the flaky cottonseeds to extract 60% to 70% of the oil, yielding cottonseed cake and primary crude oil.

[0054] The crushing step involves crushing the cotton cake to obtain cotton kernel powder;

[0055] The leaching step involves adding cottonseed powder into the carrier tank 7 via the feeding section. During the upward conveying of the cottonseed powder, it is continuously soaked and rinsed with a pure solvent, which is petroleum ether or n-hexane with a boiling range of 30℃ to 60℃. In the leaching step, the solvent temperature is 45℃ to 55℃. The solvent used to soak the cottonseed powder is directly distilled in the shell 1, causing the solvent to evaporate and then condense in the condenser 5, flowing back into the carrier tank 7. The cottonseed powder is rinsed and soaked repeatedly. The solvent in the carrier tank 7 is squeezed into the overflow tank 8 by the rinsed solvent. The solvent in the original overflow tank 8 overflows from the upper end of the overflow tank 8 and is re-evaporated in the lower part of the shell 1. The solvent containing oil is extracted from the shell 1. After the solvent is evaporated, secondary crude oil is obtained. After removing impurities such as gum and gossypol from the primary crude oil, and after removing impurities such as solvent, gum and gossypol from the secondary crude oil, cottonseed oil is obtained.

[0056] A trial production was conducted using a cottonseed processing and leaching method according to the present invention, with a production capacity of 5 tons of cottonseed. In the pretreatment stage, 2850 kg of softened cottonseed kernels were obtained (the oil content of the cottonseed was measured to be 30.62%). After drying in the rolling stage, 2644 kg of flaky cottonseed kernels were obtained. In the cold pressing stage, 567.2 kg of primary crude oil and 2068.4 kg of cottonseed cake were obtained (the oil content was measured to be 14.77%). After pulverization, cottonseed powder was obtained. Leaching was performed using a cottonseed processing and leaching device according to Example 1 of the present invention, with a leaching temperature of 45℃~55℃. When the operation was stable, the leaching temperature was maintained at 50℃. After solvent removal at ±2℃, 287.5 kg of secondary crude oil and 2145.2 kg of cottonseed meal containing 17% solvent were obtained. The weight of cottonseed after solvent removal was 1774.7 kg. The oil content was measured to be 0.83%, and the weight of unextracted oil was approximately 14.7 kg, accounting for 0.52% of the softened cottonseed. That is, this invention extracts 30.1% of the oil from cottonseed containing 30.62% oil, with an oil extraction rate of 98.3%. Furthermore, because no steaming or roasting was performed before pre-pressing, the extracted cottonseed meal is yellow instead of the brown color of the prior art, which is significantly different from the cottonseed meal in the prior art.

[0057] The above data does not strictly conform to the calculated amounts. For example, the calculated amount of oil should be 872.67 kg, but the weight of primary crude oil plus the weight of secondary crude oil plus the amount of unextracted oil is 869.4 kg. Furthermore, the primary and secondary crude oils are in a state where gossypol and impurities have not been removed. The actual amount of oil obtained is lower than the calculated amount because only a small amount of raw materials are used in the pilot-scale test. Various losses and residues occur during the start-up, shutdown, interruption, and material collection and weighing processes. However, these losses will be averaged to a negligible level by the large volume of raw materials in actual industrial production. Therefore, this invention only compares the initial oil content and the final oil content, obtaining an oil extraction rate of 98.3%, which is close to the experimental data. This means that this invention can achieve a high oil extraction rate in industrial production, extracting as much oil as possible without excessively increasing production costs, or even reducing them. The preferred embodiments of this invention have been described in detail above with reference to the accompanying drawings. However, this invention is not limited to the above embodiments. Various modifications to the technical solutions of this invention can be made without departing from the spirit of this invention, i.e., within the scope of disclosure.

Claims

1. A cottonseed processing and leaching device for realizing a cottonseed processing and leaching method, the method comprising pretreatment, rolling, pre-pressing, crushing and leaching steps, wherein the pretreatment step is to delint, dehull and soften the cottonseed to obtain softened cotton kernels; The rolled blank is made by rolling the softened cotton kernels in the pretreatment step into sheets with a thickness of 0.3 mm to 0.4 mm, and then drying them to obtain sheet cotton kernels; The pre-pressing step involves cold pressing the flake cottonseed to obtain cotton cake and primary crude oil. The crushing step involves crushing the cotton cake to obtain cotton kernel powder; The leaching step involves continuously soaking and rinsing cottonseed powder with a pure solvent while it is being transported from bottom to top. After the solvent containing oil evaporates, secondary crude oil is obtained. After removing gum and gossypol impurities from the primary crude oil, the secondary crude oil is further purified by removing solvent, gum, and gossypol impurities to obtain cottonseed oil. Its features are, The cottonseed processing leaching equipment includes a shell (1), an leaching chamber (2), a conveying section (3), a feeding section (4), and a condenser (5). The upper end of the shell (1) is connected to the condenser (5), and the lower part is provided with a heating jacket (6). The leaching chamber (2) is located inside the shell (1). The leaching chamber (2) includes a support tank (7) and an overflow tank (8). The bottom plate of the support tank (7) has filter mesh holes (9). The overflow tank (8) is fitted on the outside of the support tank (7), and the upper end of the overflow tank (8) is lower than the upper end of the support tank (7). The conveying section (3) is located inside the support tank (7). The drive shaft passes through the leaching chamber (2) and the shell (1) and is connected to the motor (12) located outside the shell (1). The conveying part (3) pushes the material in the carrying tank (7) upward. The feeding part (4) is located outside the shell (1). The lower end of the feeding part (4) passes through the shell (1) and the overflow tank (8) and connects to the lower part of the carrying tank (7). The lower end of the feeding part (4) is connected to the carrying tank (7) at a point lower than the upper end of the overflow tank (8). The upper end of the carrying tank (7) is connected to the discharge tank (18). The discharge tank (18) passes through the shell (1) and connects to the storage chamber (22) outside the shell (1).

2. The cottonseed processing and leaching equipment according to claim 1, characterized in that, The bottom of the housing (1) is provided with a drain pipe (23) with a shut-off valve, and the side wall of the housing (1) is provided with an injection pipe (24) with a shut-off valve. The injection pipe (24) is lower than the upper end of the overflow tank (8).

3. The cottonseed processing and leaching equipment according to claim 1, characterized in that, The conveying part (3) includes a first helical blade (13) and a second helical blade (14). The first helical blade (13) and the second helical blade (14) are both connected to the drive shaft. The first helical blade (13) and the second helical blade (14) have the same direction of rotation. The pitch of the first helical blade (13) is greater than the pitch of the second helical blade (14). The lower end of the first helical blade (13) is connected to the upper end of the second helical blade (14). The connection between the first helical blade (13) and the second helical blade (14) is lower than the connection between the lower end of the feeding part (4) and the bearing groove (7).

4. The cottonseed processing and leaching equipment according to claim 3, characterized in that, The outer edges of the first helical blade (13) and the second helical blade (14) are both lower than the connection between the first helical blade (13) and the second helical blade (14) and the transmission shaft.

5. The cottonseed processing and leaching equipment according to claim 1, characterized in that, The discharge trough (18) includes a collection trough (19) and a downwardly inclined chute (20). The outer diameter of the collection trough (19) is larger than the outer diameter of the bearing trough (7). A scraper (21) is connected to the drive shaft. The scraper (21) slides in contact with the inner side of the collection trough (19). The chute (20) penetrates the housing (1) and extends into the storage chamber (22). The lower end of the storage chamber (22) has a closable valve.

6. The cottonseed processing and leaching equipment according to claim 1, characterized in that, The feeding section (4) includes a storage hopper (15) and a conveying pipe (16). A rotary unloader (17) is provided between the storage hopper (15) and the conveying pipe (16). The storage hopper (15) discharges material into the conveying pipe (16) through the rotary unloader (17).

7. The cottonseed processing and leaching equipment according to claim 1, characterized in that, In the pretreatment step, the softening temperature is 60℃ and the moisture content is controlled at 10% to 12%. In the rolling step, the drying process uses hot air at 60℃ to 70℃ for fluidized drying, and the moisture content of the flaky cotton kernels is controlled at 2% to 4% at the end of drying.

8. The cottonseed processing and leaching equipment according to claim 1, characterized in that, In the leaching step, the solvent temperature is 45℃~55℃, and the solvent used to soak the cottonseed powder is distilled to evaporate the solvent and then condensed. The condensed solvent is used to repeatedly rinse and soak the cottonseed powder.

9. The cottonseed processing and leaching equipment according to claim 1, characterized in that, The solvent is petroleum ether with a boiling range of 30°C to 60°C.

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