A novel cold press with low residual oil content in the dry cake and a method for cooling the pressing chamber.

Abstract

This invention proposes a novel cold-pressing machine with low residual oil content in the pressed cake. The press cage includes several cage plates, with heat exchange channels on the inner walls of the cage plates and several pressing bars arranged on the side walls of the heat exchange channels. The root circle diameter of the pressing section of the screw shaft gradually increases along the axial direction towards the cake outlet. The tooth surface pitch and tooth back pitch of the screw teeth are two unequal pitches, with the tooth surface pitch being greater than the tooth back pitch. The width and depth of the screw groove gradually decrease along the axial direction towards the cake outlet. A cooling water chamber is provided inside the screw shaft. This invention significantly reduces the pressing temperature inside the pressing chamber by designing a water-cooled structure for the press cage and a water-cooled structure for the screw shaft. The screw shaft adopts a double-pitch design for both the tooth surface and tooth back, combined with a truncated cone-shaped tooth root circle, reducing the amount of oilseeds retained in the pressing chamber and significantly increasing the unit pressure of the oilseeds in the pressing chamber. This improves the oil quality and oil extraction efficiency while reducing the residual oil content in the pressed cake.

Description

Technical Field

[0001] This invention relates to the field of screw oil press technology, and in particular to a novel cold press with low residual oil content in the dry cake and a method for cooling the pressing chamber. Background Technology

[0002] Low-temperature cold pressing of oilseeds is a new pressing technology that emerged at the end of the last century and the beginning of this century. Unlike the traditional high-temperature hot pressing process of screw oil presses, the pressing temperature of the pressing chamber in a low-temperature cold press must be below 65℃ throughout the entire pressing process, from the time the material enters the chamber to the time the press cake leaves the chamber. Therefore, the low-temperature cold pressing process has the advantages of fully preserving various nutrients, producing high-quality cold-pressed oil, minimizing protein denaturation in the cold-pressed cake, increasing its comprehensive utilization and development value, and being green, environmentally friendly, and pollution-free. As a result, the research and development of low-temperature cold presses has received widespread attention and participation from scientists and engineers both domestically and internationally. For example, the double-screw oil press developed in my country emerged during this wave of research and development in low-temperature cold pressing. Unfortunately, this model lacks any cooling design, and its pressing temperature still reaches around 90℃, far below the process design requirements for low-temperature cold pressing. The Kp series low-temperature cold press, developed and manufactured by the German company Kemeria-Skätter, meets the requirements of low-temperature cold pressing technology in terms of pressing chamber temperature. However, the residual oil content of the cold-pressed cake is as high as 10% to 14%, which is much lower than the 6% to 7% residual oil content of the traditional high-temperature hot pressing process. This results in low oil extraction efficiency and excessive oil loss. If secondary pressing is adopted, the processing cost will increase, and the degree of protein denaturation in the pressed cake will also increase, reducing the value of protein development and utilization in the pressed cake.

[0003] The reasons why the Kp series low-temperature cold press is unsatisfactory can be mainly attributed to the following aspects:

[0004] Firstly, the cooling measures for the pressing chamber are simplistic and ineffective.

[0005] Secondly, it only adopts a hollow shaft water-cooled design for the transmission shaft of a traditional screw oil press, without considering that the total wall thickness of the cooling system, which indirectly cools the screw components (such as the screw, bushing, and sleeve) above it, is too large. The wall thickness of the hollow transmission shaft plus the wall thickness of the screw and sleeve combination is at least 50mm to 60mm. The larger the machine, the larger the wall thickness that needs to be cooled, and the worse the cooling effect. Therefore, the Kp series low-temperature cold press has reduced and controlled the pressure in the pressing chamber. The pressing chamber pressure is directly proportional to the pressing chamber temperature and inversely proportional to the residual oil content of the cold-pressed cake. It is precisely this "low-pressure, low-temperature" design of the pressing chamber that leads to the excessively high residual oil content and excessive oil loss in the cold-pressed cake.

[0006] Thirdly, its screw shaft still adopts the conventional method of ordinary screw oil press, which is composed of multiple sections of screw, multiple bushings and other pressing components connected to the main transmission shaft through an internal key. This results in too many screw rotations in the pressing chamber and too much oil content in the pressing chamber, which makes the unit pressure of the oil in the pressing chamber too low. The insufficient unit pressure will inevitably increase the residual oil rate of the dry cake and oil loss, and seriously affect the oil output efficiency of the low temperature cold press.

[0007] In summary, the key to solving the problem lies in how to improve the current "low pressure, low temperature" working conditions to "high pressure, low temperature" conditions, while ensuring the quality of the oil produced, and maximizing the oil extraction efficiency and reducing the residual oil rate of the dry cake. This requires the design and development of cooling systems for the pressing cage and screw shaft, as well as the design and development of the screw pressing teeth. Summary of the Invention

[0008] This invention proposes a novel cold press with low residual oil content in the dry cake and a cooling method for the pressing chamber, which solves the problem that existing cold presses cannot simultaneously meet the working conditions of "high pressure and low temperature", resulting in the inability to guarantee high oil quality, high oil extraction efficiency and low residual oil content in the dry cake.

[0009] The technical solution of this invention is implemented as follows:

[0010] The first aspect of the present invention provides a novel cold press with low residual oil content in dry cake, comprising a frame, on which a controller, a drive component and a press cage are mounted, a feeding hopper is mounted at the feed end of the press cage, and a single spiral shaft or multiple spiral shafts are mounted inside the press cage.

[0011] The pressing cage includes several cage plates arranged at intervals along the axial direction. The opposite side edges of the cage plates are fixedly connected by a first connecting plate and a second connecting plate, respectively. The inner wall of the inner hole of the cage plate is provided with a heat exchange channel along the circumferential direction. Several pressing bars are arranged adjacent to each other along the circumferential direction on the side wall of the heat exchange channel. The pressing bars surround to form the pressing chamber. The heat exchange channel is connected to the external circulation pipeline through a corresponding flow channel.

[0012] The spiral shaft includes a feeding section spiral shaft and a pressing section spiral shaft. The root circle diameter of the pressing section spiral shaft gradually increases along the axial direction towards the cake discharge end. The tooth surface pitch S1 and tooth back pitch S2 of the spiral pressing teeth of the pressing section spiral shaft are two unequal pitches, and the tooth surface pitch S1 is greater than the tooth back pitch S2. The spiral groove width and spiral groove depth of the pressing section spiral shaft both gradually decrease along the axial direction towards the cake discharge end.

[0013] The spiral shaft has a cooling water chamber inside, which is connected to the first water inlet pipe and the first water outlet pipe on the outside.

[0014] Optionally, the heat exchange channel includes a cooling water tank, in which a heat exchange tube is embedded, and several of the pressing bars are arranged adjacent to each other along the side wall of the heat exchange tube. The heat exchange tube is connected to the external circulation pipeline through a corresponding flow channel.

[0015] Preferably, the heat exchange channel includes a cooling water tank, a sealing sleeve is welded to the open side of the cooling water tank, and a plurality of the pressing bars are arranged adjacent to each other along the side wall of the sealing sleeve. The cooling water tank is connected to the external circulation pipeline through a corresponding flow channel.

[0016] Preferably, the external circulation pipeline includes a branch pipe and a collection pipe, which are respectively installed on the first connecting plate and the second connecting plate. The branch pipe is connected to the heat exchange channel of each cage plate through a corresponding first flow channel, and the collection pipe is connected to the heat exchange channel of each cage plate through a corresponding second flow channel. The branch pipe and the collection pipe are connected to the second inlet pipe and the second outlet pipe, respectively. Low-temperature coolant is introduced into the branch pipe through the second inlet pipe. After being branched by the branch pipe, the coolant enters the heat exchange channel through the first flow channel of each cage plate and exchanges heat with the pressing bars in the pressing chamber. Then, it is collected in the collection pipe through the second flow channel of each cage plate and finally discharged from the second outlet pipe. By connecting the circulation pipelines of the heat exchange channels of multiple cage plates in parallel, the pipeline layout cost can be saved, the pipeline layout space can be reduced, and on-site installation and use can be facilitated.

[0017] Optionally, the external circulation pipeline includes several sets of independent second inlet pipes and second outlet pipes. Each set of second inlet pipes and second outlet pipes is connected to the heat exchange channel of the corresponding cage plate through a first flow channel and a second flow channel. By setting the circulation pipeline of the heat exchange channel of each cage plate independently, the medium temperature, flow rate and other parameters of each circulation pipeline can be adjusted independently, and the temperature of different parts in the pressing chamber can be precisely controlled.

[0018] Optionally, the cage plate is formed by two semi-annular plates enclosing each other, and the two semi-annular plates are detachably connected by a connector. This detachable cage plate structure is more suitable for installation in large and medium-sized machines.

[0019] Specifically, each of the inner holes of the semi-annular plate is fixedly installed with a pressure plate at both ends, and several of the pressing bars are arranged close to each other between the two pressure plates. The pressing plates at both ends can tightly press the several pressing bars onto the inner wall of the sealing sleeve corresponding to the inner hole of the semi-annular plate.

[0020] Furthermore, the heat exchange channel and the sealing sleeve are both two-section split structures, and both ends of the heat exchange channel are equipped with sealing plugs; the first connecting plate, the second connecting plate, the diversion pipe, the water collection pipe, the first flow channel, and the second flow channel are each provided with two sets, which are used for circulating water in the heat exchange channels inside the two semi-annular plates respectively; since pressure plates are installed at both ends of the inner hole of the semi-annular plate, the original integral annular heat exchange channel and the sealing sleeve are separated into two independent structures by the pressure plates. Therefore, by setting two sets of independent circulation pipelines to introduce coolant into the heat exchange channels inside the two semi-annular plates respectively, the circulating cooling of the split cage plate is realized.

[0021] Specifically, the connector includes bolts, pins, and lugs. The sides of both first and second connecting plates are provided with through holes for installing bolts. Lugs are installed at both ends of the bottom surface of the two second connecting plates. The pins pass through the shaft holes of the four lugs in sequence. The two second connecting plates at the bottom of the two semi-annular plates are hinged by the lugs and pins to facilitate automatic alignment when the two semi-annular plates are closed. The two first connecting plates at the upper part of the two semi-annular plates are locked by bolts, and the two second connecting plates at the lower part of the two semi-annular plates are locked by bolts to achieve locking and fixing of the two semi-annular plates.

[0022] Furthermore, the water collection pipe has a notch at the position where it passes through the ear plate. The notch is sealed and welded to the ear plate, which can prevent the ear plate from affecting the layout path of the water collection pipe without affecting the sealing of the water collection pipe.

[0023] Furthermore, the bolts are installed at positions between two adjacent cage plates on the first connecting plate and between two adjacent cage plates on the second connecting plate, thus staggering the bolt's penetration path from the first flow channel within the first connecting plate and the second flow channel within the second connecting plate. This avoids the bolt installation affecting the first and second flow channels.

[0024] Preferably, the width of the spiral press teeth gradually increases along the axial direction towards the cake discharge end. The purpose of this design is to minimize the axial length of the spiral press teeth and the total number of spiral turns. Under the conditions of constant oil input, constant input power, constant spiral shaft speed, and constant total compression ratio, on the one hand, it can increase the unit pressure of the oilseeds being pressed in the pressing chamber and improve the oil extraction efficiency; on the other hand, it can shorten the pressing time of the oilseeds in the pressing chamber, thereby reducing the pressing temperature and improving the oil quality.

[0025] Specifically, the difference between the beginning and end widths of any spiral groove is Δl = S1 - S2.

[0026] Specifically, the length L of the pressing section spiral shaft is L = S2 × n + b2, where n represents the number of spiral teeth and b2 represents the axial width at the end of the spiral teeth.

[0027] Specifically, the end width l of the spiral groove is L = S2 × n - b1 - S1 × (n - 1), where n represents the number of spiral teeth and b1 represents the axial width of the beginning of the spiral teeth.

[0028] Specifically, the two ends of the spiral shaft are respectively connected to a power input shaft and a rotating support shaft, and the spiral teeth are integrally machined with the spiral shaft; the rotating support shaft is a hollow shaft, and its shaft hole communicates with the cooling water chamber; the first water inlet pipe and the first water outlet pipe are installed at the ends of the rotating support shaft. By setting a cooling water chamber inside the spiral shaft and introducing a cooling medium into the cooling water chamber through the shaft hole of the rotating support shaft, rapid cooling of the spiral shaft is achieved.

[0029] Furthermore, a bearing assembly is installed on the outside of the rotating support shaft, and a cover is sealed on the outer end face of the bearing assembly; one end of the first water inlet pipe is located outside the cover, and the other end is located inside the cover and extends into the cooling water chamber; the first water outlet pipe is installed on the outer side of the bottom of the cover; by sealing the cover on the outer end face of the bearing assembly and installing the first water inlet pipe and the first water outlet pipe on the cover, the external low-temperature cooling medium can be introduced into the cooling water chamber through the first water inlet pipe to exchange heat with the spiral shaft, and the cooled medium after heat exchange can be discharged into the cover through the shaft hole of the rotating support shaft, and finally discharged through the first water outlet pipe at the bottom of the cover, thereby realizing the circulating cooling of the spiral shaft.

[0030] Furthermore, the bearing assembly includes a bearing sleeve fixedly fitted outside the rotating support shaft, a roller bearing fitted outside the bearing sleeve, a bearing housing fitted outside the roller bearing, bearing caps at both the front and rear ends of the bearing housing, and the open end of the housing sealed and welded to the bearing cap at the front end of the bearing housing, with an oil seal element between the inner side of the bearing cap and the bearing sleeve; through the mutual cooperation of the bearing sleeve, roller bearing, bearing housing, bearing cap and oil seal element, the sealing performance of the bearing assembly can be ensured, preventing the cooling medium from seeping into the bearing assembly or protruding outside the housing.

[0031] Furthermore, the roller bearing is a self-aligning roller bearing, and an adjusting nut is provided at the front end of the self-aligning roller bearing. The adjusting nut is used to adjust the axial clearance of the roller bearing to ensure the stability of the rotation of the rotating support shaft.

[0032] Furthermore, the side of the cover is provided with a mounting hole, and a threaded joint is sealed and installed in the mounting hole. The first water inlet pipe is fixedly installed on the cover through the threaded joint.

[0033] Specifically, both ends of the spiral shaft are provided with threaded holes, and the thread direction of the threaded holes is opposite to that of the spiral shaft. The power input shaft, the rotary support shaft and the spiral shaft are connected by threads. By screwing the spiral shaft to the power input shaft and the rotary support shaft at both ends, the machining and assembly of the spiral shaft are facilitated, and the power input shaft, the spiral shaft and the rotary support shaft can be machined separately.

[0034] Furthermore, annular grooves are provided on both ends of the spiral shaft, and sealing rings are embedded in the annular grooves, which can improve the sealing performance of the connection between the spiral shaft and the power input shaft and the rotary support shaft.

[0035] Specifically, the root circle diameter of the screw shaft in the feeding section is constant, and the cooling water chamber is located inside the screw shaft in the pressing section. Since the volume between the pressing chamber and the screw shaft in the feeding section is fixed, less heat is generated. However, in the pressing section, the root circle diameter of the screw shaft gradually increases, resulting in a gradual decrease in the volume between the pressing chamber and the screw shaft, and more heat is generated. Therefore, it is only necessary to open a cooling water chamber inside the screw shaft in the pressing section for cooling.

[0036] A second aspect of the present invention provides a method for cooling a pressing chamber, comprising the following steps:

[0037] Real-time monitoring of operating temperature data within the pressing chamber;

[0038] Based on the monitored temperature data, the external circulation pipeline is controlled to circulate and deliver cooling medium into the heat exchange channel of the cage plate, while the first inlet pipe and the first outlet pipe are controlled to circulate and deliver cooling medium into the cooling water chamber inside the spiral shaft.

[0039] The higher the operating temperature inside the pressing chamber, the greater the flow rate and the faster the flow speed of the cooling medium circulation.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] (1) This invention sets up a heat exchange channel on the inner wall of the inner hole of the cage plate. During operation, coolant is circulated into the heat exchange channel through an external circulation pipe. The heat on the pressing bar is transferred to the heat exchange channel and then carried away by the coolant, thereby rapidly reducing the pressing temperature in the pressing chamber. This realizes the design concept of "low temperature and high pressure" in the pressing chamber and achieves true low temperature pressing. Under the premise of ensuring the quality of the oil and low denaturation of the protein in the cake, the oil extraction efficiency is maximized.

[0042] (2) This invention improves the pressing section of the traditional spiral shaft. The invention adopts a double pitch design on the tooth surface and tooth back, combined with a truncated cone tooth root circle. The purpose of this design is: on the one hand, to make the feed end of the spiral groove wide and deep, and the cake end narrow and shallow. During the movement of the oil from the beginning to the end of the spiral groove, the oil is continuously subjected to the double squeezing effect of the spiral groove narrowing and shallowing at every moment; on the other hand, to reduce the number of spiral calculation turns in the pressing chamber, and correspondingly reduce the amount of oil in the pressing chamber, so that the unit pressure of the oil in the pressing chamber is greatly improved. This advantage of the invention can improve the oil output efficiency of the low temperature cold press and reduce oil loss.

[0043] (3) Traditional spiral shafts are composed of a number of screws, bushings, and smooth sleeves, and rotate together with the main drive shaft through an internal key connection. When cooling the spiral shaft, the cooling thickness includes the thickness of the screws plus the wall thickness of the main drive shaft, resulting in poor cooling effect. This invention uses a truncated cone spiral shaft to replace the original main drive shaft design, changing the indirect cooling of the spiral shaft by the main drive shaft to direct cooling. This not only reduces the cooling wall thickness of the main drive shaft but also increases the cross-sectional area of ​​the cooling water chamber, greatly improving the cooling effect of the spiral shaft. Thus, it can maintain a low pressing temperature without sacrificing the pressing chamber pressure, achieving true high-pressure low-temperature pressing, reducing the residual oil rate of the dry cake, and improving the oil extraction efficiency. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the overall structure of a novel cold press with low residual oil content in dry cake according to the present invention.

[0046] Figure 2 This is a schematic diagram of the internal structure of the integrated cage plate in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the internal structure of the split-type cage plate in an embodiment of the present invention;

[0048] Figure 4 This is a schematic diagram of the structure of the split cage plate after it is opened in an embodiment of the present invention;

[0049] Figure 5 This is a front view of the pressing cage in an embodiment of the present invention;

[0050] Figure 6This is a top view of the press cage in an embodiment of the present invention;

[0051] Figure 7 This is a bottom view of the pressing cage in an embodiment of the present invention;

[0052] Figure 8 This is a schematic diagram of the structure of the screw shaft in the pressing section of this invention.

[0053] Figure 9 This is a schematic diagram of the internal structure of the spiral shaft in an embodiment of the present invention;

[0054] Figure 10 for Figure 9 Enlarged view of section A;

[0055] Figure 11 This is a schematic diagram of the external structure of the spiral shaft in an embodiment of the present invention;

[0056] Figure 12 These are the morphological diagrams of the dried cakes corresponding to the four sets of test data in this embodiment of the invention;

[0057] In the diagram: 1. Frame; 2. Controller; 3. Drive unit; 4. Press cage; 5. Feed hopper; 6. Cage loading plate; 7. First connecting plate; 8. Second connecting plate; 9. Cooling water tank; 10. Sealing sleeve; 11. Press bar; 12. Diverter pipe; 13. Water collecting pipe; 14. First flow channel; 15. Second flow channel; 16. Second water inlet pipe; 17. Second water outlet pipe; 18. Semi-annular plate; 19. Pressure plate; 20. Sealing plug; 21. Bolt; 22. Pin; 23. Ear plate; 24. Notch; 5. Spiral press teeth; 26. Feeding section spiral shaft; 27. Pressing section spiral shaft; 28. Spiral groove; 29. ​​Tooth surface; 30. Tooth back; 31. Cooling water chamber; 32. First water inlet pipe; 33. First water outlet pipe; 34. Power input shaft; 35. Rotary support shaft; 36. Shaft hole; 37. Cover; 38. Bearing sleeve; 39. Roller bearing; 40. Bearing seat; 41. Bearing cover; 42. Oil seal element; 43. Adjusting nut; 44. Threaded joint; 45. Threaded hole; 46. Sealing ring. Detailed Implementation

[0058] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0059] Reference Figures 1 to 11The first aspect of the present invention provides a novel cold press with low residual oil content in dry cake, including a frame 1, on which a controller 2, a drive component 3 and a press cage 4 are installed. A feeding hopper 5 is installed at the feed end of the press cage 4, and a single spiral shaft or multiple spiral shafts are installed inside the press cage 4.

[0060] The pressing cage 4 includes several cage plates 6 arranged at intervals along the axial direction. The opposite side edges of the cage plates 6 are fixedly connected by a first connecting plate 7 and a second connecting plate 8, respectively. The inner wall of the inner hole of the cage plate 6 is provided with a heat exchange channel along the circumferential direction. Several pressing bars 11 are arranged adjacent to each other along the circumferential direction on the side wall of the heat exchange channel. The pressing bars 11 surround to form a pressing chamber. The heat exchange channel is connected to the external circulation pipeline through a corresponding flow channel.

[0061] The spiral shaft includes a feeding section spiral shaft 26 and a pressing section spiral shaft 27. The root circle diameter of the pressing section spiral shaft 27 gradually increases along the axial direction towards the cake discharge end. The pitch S1 of the tooth surface 29 and the pitch S2 of the tooth back 30 of the spiral pressing tooth 25 of the pressing section spiral shaft 27 are two unequal pitches, and the pitch S1 of the tooth surface 29 is greater than the pitch S2 of the tooth back 30. The width and depth of the spiral groove 28 of the pressing section spiral shaft 27 both gradually decrease along the axial direction towards the cake discharge end.

[0062] The spiral shaft is provided with a cooling water chamber 31, which is connected to the first water inlet pipe 32 and the first water outlet pipe 33 on the outside.

[0063] In the specific implementation process, several temperature sensors are installed on the pressing cage 4. The temperature sensors can be installed on the cage plate 6 and the pressing bars 11. By monitoring the temperature of the cage plate 6 and the pressing bars 11, the temperature of the oil in the pressing chamber is indirectly measured. The controller 2 uses circulating water to cool the pressing cage 4 and the screw shaft according to the monitored temperature data to ensure that the oil is in a low-temperature pressing environment.

[0064] The driving component 3 includes a motor and a reducer. The motor drives the reducer to rotate the screw shaft, which works in conjunction with the pressing mill to transport and compress the oil.

[0065] Optionally, the heat exchange channel includes a cooling water tank 9, in which a heat exchange tube (not shown in the figure) is embedded. Several of the pressing bars 11 are arranged adjacent to each other along the side wall of the heat exchange tube. The heat exchange tube is connected to the external circulation pipeline through a corresponding flow channel.

[0066] Preferably, such as Figure 2 As shown, the heat exchange channel includes a cooling water tank 9, and a sealing sleeve 10 is welded to the open side of the cooling water tank 9. Several pressing bars 11 are arranged close to each other along the side wall of the sealing sleeve 10. The cooling water tank 9 is connected to the external circulation pipeline through a corresponding flow channel.

[0067] In this embodiment, a closed annular heat exchange channel is obtained by opening a cooling water tank 9 on the inner wall of the inner hole of the cage plate 6 and welding a sealing sleeve 10. In the specific implementation process, it is not limited to using the method of embedding a heat exchange copper tube in the cooling water tank 9. Cooling liquid can be circulated in the heat exchange copper tube to achieve rapid cooling of the pressing chamber.

[0068] In this embodiment, the sealing sleeve 10 is made of a metal material with welding performance similar to that of the cage plate 6, and the thickness of the sealing sleeve 10 should not be too thick (too thick will reduce the heat transfer efficiency); the width of the sealing sleeve 10 is greater than the width of the cooling water tank 9, thereby ensuring the welding sealing effect.

[0069] In the specific implementation process, the cooling water tank 9 is not limited to the processing method, and its cross-section is not limited to being designed as a semi-circle, rectangle or other shape; the coolant is not limited to water, cooling oil or other heat-conducting media.

[0070] In this embodiment, cooling water tanks 9 can be provided in all the cage plates 6 along the entire axial length of the pressing cage 4 to achieve full cooling of the pressing cage 4 along the axial length. Alternatively, cooling water tanks 9 can be provided in some of the cage plates 6 along the axial length of the pressing cage 4 to achieve local cooling of the pressing cage 4 along the axial length.

[0071] Preferably, such as Figures 2 to 4 As shown, the external circulation pipeline includes a branch pipe 12 and a collection pipe 13, which are respectively installed on the first connecting plate 7 and the second connecting plate 8; the branch pipe 12 is connected to the cooling water tank 9 of each cage plate 6 through the corresponding first flow channel 14, and the collection pipe 13 is connected to the cooling water tank 9 of each cage plate 6 through the corresponding second flow channel 15; the branch pipe 12 and the collection pipe 13 are respectively connected to the second inlet pipe 16 and the second outlet pipe 17; through the first Low-temperature coolant is introduced into the diversion pipe 12 through the second inlet pipe 16. After being diverted by the diversion pipe 12, the coolant enters the cooling water tank 9 through the first flow channel 14 of each cage plate 6 and exchanges heat with the pressing bars 11 in the pressing chamber. Then, it is collected in the water collection pipe 13 through the second flow channel 15 of each cage plate 6, and finally discharged from the second outlet pipe 17. By connecting the circulation pipes of the cooling water tank 9 of multiple cage plates 6 in parallel, the cost of pipe layout can be saved, the pipe layout space can be reduced, and the on-site installation and use can be facilitated.

[0072] In this embodiment, as Figures 2 to 4As shown, the first connecting plate 7 is located on the upper part of the cage plate 6, and the second connecting plate 8 is located on the lower part of the cage plate 6. The first connecting plate 7 and the second connecting plate 8 can be integrally cast or welded with the cage plate 6. The first flow channel 14 extends from the top surface of the first connecting plate 7 into the cooling water tank 9 inside the cage plate 6, and the second flow channel 15 extends from the bottom surface of the second connecting plate 8 into the cooling water tank 9 inside the cage plate 6.

[0073] Furthermore, in this embodiment, as Figures 2 to 4 As shown, the cross-section of the diversion pipe 12 and the water collection pipe 13 is semi-circular, which can well adapt to the surface shape of the first connecting plate 7 and the second connecting plate 8; in the specific implementation process, their cross-sectional shape can also be flexibly selected according to the actual situation.

[0074] In this embodiment, the diversion pipe 12 and the water collection pipe 13 are obtained by cutting a circular pipe axially from the end face. The side of the diversion pipe 12 is sealed and welded to the top surface of the first connecting plate 7 to form a semi-circular cavity. All the inlets of the first flow channels 14 on the top surface of the first connecting plate 7 are connected in parallel in the semi-circular cavity corresponding to the diversion pipe 12. The side of the water collection pipe 13 is sealed and welded to the bottom surface of the second connecting plate 8 to form a semi-circular cavity. All the outlets of the second flow channels 15 on the bottom surface of the second connecting plate 8 are connected in parallel in the semi-circular cavity corresponding to the water collection pipe 13. Plugs are welded to both ends of the diversion pipe 12 and the water collection pipe 13.

[0075] Optionally, the external circulation pipeline includes several sets of independent second inlet pipes 16 and second outlet pipes 17. Each set of second inlet pipes 16 and second outlet pipes 17 is connected to the cooling water tank 9 of the corresponding cage plate 6 through the first flow channel 14 and the second flow channel 15. By setting the circulation pipeline of the cooling water tank 9 of each cage plate 6 independently, the medium temperature, flow rate and other parameters of each circulation pipeline can be adjusted independently, and the temperature of different parts in the pressing chamber can be precisely controlled.

[0076] Optionally, such as Figure 3 , 4 As shown, the cage plate 6 is formed by two semi-annular plates 18. The two semi-annular plates 18 are detachably connected by connectors. This detachable cage plate 6 structure is more suitable for the installation of large and medium-sized machines.

[0077] In this embodiment, the cage plate 6 can be a non-openable, one-piece structure. When the cage plate 6 is a one-piece structure, its internal cooling water tank 9 is a continuous annular groove, and there is no need to use a sealing plug 20. Alternatively, the cage plate 6 in this embodiment can be an openable, split structure. When the cage plate 6 is a split structure, its internal cooling water tank 9 consists of two discontinuous semi-annular grooves. If both ends of the semi-annular groove penetrate the opening and closing end face of the semi-annular plate 18, then sealing plugs 20 need to be welded to both ends of the semi-annular groove for sealing. If both ends of the semi-annular groove do not penetrate the opening and closing end face of the semi-annular plate 18, then there is no need to weld sealing plugs 20 to both ends of the semi-annular groove for sealing.

[0078] Specifically, such as Figure 3 , 4 As shown, pressure plates 19 are fixedly installed at both ends of the inner hole of each semi-annular plate 18, and several pressing bars 11 are arranged close to each other between the two pressure plates 19. The pressure plates 19 at both ends can tightly press the several pressing bars 11 onto the inner wall of the sealing sleeve 10 corresponding to the inner hole of the semi-annular plate 18.

[0079] Further, if Figure 3 , 4 As shown, the cooling water tank 9 and the sealing sleeve 10 are both two-section split structures, and both ends of the cooling water tank 9 are provided with sealing plugs 20; the first connecting plate 7, the second connecting plate 8, the diversion pipe 12, the water collection pipe 13, the first flow channel 14, and the second flow channel 15 are each provided with two sets, which are respectively used for the circulation of cooling water tanks 9 inside the two semi-annular plates 18; since pressure plates 19 are installed at both ends of the inner hole of the semi-annular plate 18, the original integral annular cooling water tank 9 and the sealing sleeve 10 are separated into two independent structures by the pressure plates 19. Therefore, by setting two sets of independent circulation pipes to introduce coolant into the cooling water tanks 9 inside the two semi-annular plates 18, the circulation cooling of the split cage plate 6 is realized.

[0080] Specifically, such as Figures 3 to 7 As shown, the connector includes bolts 21, pins 22, and ear plates 23. Through holes for mounting bolts 21 are provided on the sides of both first connecting plates 7 and second connecting plates 8. Ear plates 23 are respectively installed at both ends of the bottom surface of the two second connecting plates 8. The pins 22 pass through the shaft holes 36 of the four ear plates 23 in sequence. The two second connecting plates 8 at the bottom of the two semi-annular plates 18 are hinged together by the ear plates 23 and pins 22, facilitating automatic alignment when the two semi-annular plates 18 are closed. The two first connecting plates 7 at the upper part of the two semi-annular plates 18 are locked by bolts 21, and the two second connecting plates 8 at the lower part of the two semi-annular plates 18 are locked by bolts 21, thus achieving the locking and fixing of the two semi-annular plates 18.

[0081] Further, if Figure 7As shown, the water collection pipe 13 has a notch 24 at the position where it passes through the ear plate 23. The notch 24 is sealed and welded to the ear plate 23, which can avoid the ear plate 23 from affecting the layout path of the water collection pipe 13 without affecting the sealing of the water collection pipe 13.

[0082] Furthermore, such as Figures 5 to 7 As shown, the bolt 21 is installed between two adjacent cage plates 6 on the first connecting plate 7 and between two adjacent cage plates 6 on the second connecting plate 8. The penetration path of the bolt 21 is staggered from the path of the first flow channel 14 in the first connecting plate 7 and the second flow channel 15 in the second connecting plate 8, which can avoid the impact of the installation of the bolt 21 on the first flow channel 14 and the second flow channel 15.

[0083] In specific implementation, the internal structure of the press cage 4 in this embodiment can be adaptively adjusted according to the number of spiral shafts to adapt to the cooling of the press cage 4 of the multi-spiral cold press; the cooling press cage 4 in this embodiment is not limited to use with a single spiral shaft or a double spiral shaft.

[0084] The water cooling process of the press cage 4 in this embodiment is as follows:

[0085] Low-temperature coolant is introduced into the semi-circular cavity corresponding to the diversion pipe 12 through the second inlet pipe 16. The low-temperature coolant is diverted from the diversion pipe 12 into the first flow channel 14 of each cage plate 6, and flows into the cooling water tank 9 of each cage plate 6 from the outlet at the bottom of each first flow channel 14. The coolant exchanges heat with the sealing sleeve 10 in the cooling water tank 9, quickly removing the heat generated by the friction between the material and the pressing bar 11 in the pressing chamber, thereby achieving rapid cooling of the pressing chamber. The coolant after heat exchange flows from each second flow channel 15 into the semi-circular cavity corresponding to the water collection pipe 13, and is finally discharged through the second outlet pipe 17. The discharged coolant is cooled and then introduced into the cooling water tank 9 through the second inlet pipe 16 to achieve water-cooled circulation heat dissipation of the pressing chamber.

[0086] Preferably, such as Figure 8 As shown, the width of the spiral pressing teeth 25 gradually increases along the axial direction towards the cake discharge end. The purpose of this design is to ensure that, under the conditions of constant oil input, constant input power, constant spiral shaft speed, and constant total compression ratio, the length and number of spiral pressing teeth 25 are shortened as much as possible. On the one hand, this increases the unit pressure of the oilseeds being pressed in the pressing chamber and improves the oil extraction efficiency; on the other hand, it shortens the pressing time of the oilseeds in the pressing chamber, thereby reducing the pressing temperature and improving the oil quality.

[0087] Specifically, such as Figure 8 As shown, the difference between the beginning width and the end width of any spiral groove 28 is Δl = S1 - S2.

[0088] Specifically, such as Figure 8As shown, the length L of the pressing section spiral shaft 27 is S2×n+b2, where n represents the number of spiral teeth 25 turns and b2 represents the axial width of the end of the spiral teeth 25.

[0089] Specifically, such as Figure 8 As shown, the end width l of the spiral groove 28 is S2×n-b1-S1×(n-1), where n represents the number of spiral teeth 25 turns and b1 represents the axial width of the beginning of the spiral teeth 25.

[0090] Specifically, such as Figure 9 As shown, the two ends of the spiral shaft are respectively connected to a power input shaft 34 and a rotating support shaft 35. The spiral teeth 25 are integrally formed with the spiral shaft. The rotating support shaft 35 is a hollow shaft, and the shaft hole 36 of the rotating support shaft 35 communicates with the cooling water chamber 31. The first water inlet pipe 32 and the first water outlet pipe 33 are installed at the ends of the rotating support shaft 35. By setting a cooling water chamber 31 inside the spiral shaft and introducing a cooling medium into the cooling water chamber 31 through the shaft hole 36 of the rotating support shaft 35, rapid cooling of the spiral shaft is achieved.

[0091] In this embodiment, the spiral shaft is machined using a CNC lathe. The spiral shaft is made of 20CrMnTi, with surface carburizing and quenching, the carburized layer depth is 1.5-2mm, and the heat treatment hardness is HRc58-62. The power input shaft 34 is made of 40Cr, with quenching and tempering treatment, and the hardness is HB260-310. The rotating support shaft 35 is made of 45# seamless steel pipe, with quenching and tempering treatment, and the hardness is HB190-240.

[0092] Furthermore, such as Figure 9 As shown, a bearing assembly is mounted on the outside of the rotating support shaft 35, and a cover 37 is sealed on the outer end face of the bearing assembly. One end of the first water inlet pipe 32 is located outside the cover 37, and the other end is located inside the cover 37 and extends into the cooling water chamber 31. The first water outlet pipe 33 is installed on the outer side of the bottom of the cover 37. By sealing the cover 37 on the outer end face of the bearing assembly and installing the first water inlet pipe 32 and the first water outlet pipe 33 on the cover 37, the external low-temperature cooling medium can be introduced into the cooling water chamber 31 through the first water inlet pipe 32 to exchange heat with the spiral shaft. The cooled medium after heat exchange is discharged into the cover 37 through the shaft hole 36 of the rotating support shaft 35, and finally discharged through the first water outlet pipe 33 at the bottom of the cover 37, thereby achieving circulating cooling of the spiral shaft. Since the cover 37 is sealed and welded to the outer end face of the bearing assembly, the cover 37 is not affected by the rotation of the spiral shaft.

[0093] In the specific implementation process, in addition to being installed on the bearing assembly through the cover 37, the first water inlet pipe 32 and the first water outlet pipe 33 can also be directly installed on the end of the rotating support shaft 35 by means of a rotary joint. The structure and installation method of the rotary joint are conventional methods in this field.

[0094] Furthermore, such as Figure 10 As shown, the bearing assembly includes a bearing sleeve 38 fixedly sleeved on the outside of the rotating support shaft 35. A roller bearing 39 is sleeved on the outside of the bearing sleeve 38. A bearing housing 40 is sleeved on the outside of the roller bearing 39. Bearing covers 41 are provided at both the front and rear ends of the bearing housing 40. The open end of the cover 37 is sealed and welded to the bearing cover 41 at the front end of the bearing housing 40. An oil seal element 42 is provided between the inner side of the bearing cover 41 and the bearing sleeve 38. Through the mutual cooperation of the bearing sleeve 38, roller bearing 39, bearing housing 40, bearing cover 41 and oil seal element 42, the sealing performance of the bearing assembly can be guaranteed, preventing the cooling medium from seeping into the bearing assembly or protruding outside the cover 37. During the rotation of the rotating support shaft 35, the bearing sleeve 38 rotates together with the rotating support shaft 35, while the bearing housing 40 and the bearing caps 41 at its front and rear ends remain stationary. The bearing housing 40 and the bearing sleeve 38 are rotatably connected by the roller bearing 39. The bearing caps 41 at both ends of the bearing housing 40, together with the oil seal element 42, play a sealing role for the bearing assembly.

[0095] Furthermore, such as Figure 10 As shown, the roller bearing 39 is a self-aligning roller bearing 39. The front end of the self-aligning roller bearing 39 is provided with an adjusting nut 43. The adjusting nut 43 is used to adjust the axial clearance of the roller bearing 39 to ensure the stability of the rotation of the rotating support shaft 35.

[0096] Furthermore, such as Figure 9 , 11 As shown, the side of the cover 37 is provided with a mounting hole, and a threaded connector 44 is sealed and installed in the mounting hole. The first water inlet pipe 32 is fixedly installed on the cover 37 through the threaded connector 44.

[0097] Specifically, such as Figure 9 As shown, both ends of the spiral shaft are provided with threaded holes 45, and the thread direction of the threaded holes 45 is opposite to the thread direction of the spiral shaft. The power input shaft 34, the rotating support shaft 35 and the spiral shaft are connected by threads. By screwing the spiral shaft to the power input shaft 34 and the rotating support shaft 35 at both ends, it is convenient to process and assemble the spiral shaft. The power input shaft 34, the spiral shaft and the rotating support shaft 35 can be processed separately.

[0098] Furthermore, such as Figure 9As shown, annular grooves are provided on both ends of the spiral shaft, and sealing rings 46 are embedded in the annular grooves, which can improve the sealing performance of the connection between the spiral shaft and the power input shaft 34 and the rotary support shaft 35.

[0099] Specifically, the root circle diameter of the feeding section screw shaft 26 is constant, and the cooling water cavity 31 is opened inside the pressing section screw shaft 27. Since the volume between the pressing chamber and the screw shaft in the feeding section is fixed, less heat is generated. However, in the pressing section, because the root circle diameter of the screw shaft gradually increases, the volume between the pressing chamber and the screw shaft in the pressing section gradually decreases, resulting in more heat being generated. Therefore, it is only necessary to open a cooling water cavity 31 inside the pressing section screw shaft 27 for cooling.

[0100] Preferably, the inner wall of the cooling water chamber 31 and the inner wall of the shaft hole 36 can be provided with spiral guide vanes (not shown in the figure, similar to the stirring vanes provided on the inner wall of a concrete mixing tank). On the one hand, the cooling medium in the cooling water chamber 31 can be discharged into the cover 37 by the rotation of the spiral guide vanes and the spiral shaft, thereby improving the flow efficiency of the cooling medium in the cooling water chamber 31 and thus improving the heat exchange efficiency. On the other hand, the spiral guide vanes greatly increase the contact area between the cooling medium and the spiral shaft, thereby further improving the heat exchange efficiency.

[0101] A second aspect of the present invention provides a method for cooling a pressing chamber, comprising the following steps:

[0102] Real-time monitoring of operating temperature data within the pressing chamber;

[0103] Based on the monitored temperature data, the external circulation pipeline is controlled to circulate and deliver cooling medium into the heat exchange channel of the cage plate 6, while the first water inlet pipe 32 and the first water outlet pipe 33 are controlled to circulate and deliver cooling medium into the cooling water chamber 31 inside the spiral shaft.

[0104] The higher the operating temperature inside the pressing chamber, the greater the flow rate and the faster the flow speed of the cooling medium circulation.

[0105] The water cooling process for the spiral shaft in this embodiment is as follows:

[0106] The spiral shaft rotates inside the pressing chamber, causing it to squeeze and rub against the raw material inside, generating a large amount of heat. Cooling medium is introduced into the cooling water chamber 31 inside the spiral shaft through the first water inlet pipe 32. The cooling medium directly exchanges heat with the spiral shaft, absorbing the heat of the spiral shaft. As the spiral shaft rotates, the cooling medium covers the entire inner wall of the cooling water chamber 31, rapidly reducing the temperature of the spiral shaft. The cooled medium after heat exchange flows into the cover 37 through the shaft hole 36 of the rotating support shaft 35, and finally flows out from the first water outlet pipe 33 at the bottom of the cover 37, thereby realizing the circulating water cooling of the spiral shaft.

[0107] In the design of this embodiment, the cross-sectional area between the root circle of the spiral shaft and the cooling water cavity can be adjusted to be slightly larger than or equal to the cross-sectional area of ​​the corresponding part of the original drive shaft. This maximizes the cooling effect of the spiral shaft while ensuring the structural reliability of the spiral shaft.

[0108] Traditional screw oil presses consist of a drive shaft, multiple screw components with different pitches, several bushings, and a smooth sleeve connected by a key. Although a cooling design is incorporated into the drive shaft, the combined wall thickness of the water-conducting section of the drive shaft, along with the wall thickness of the screw and other assembly components, reaches approximately 60mm. Such a large thickness results in only moderate cooling effectiveness. In contrast, this invention eliminates the traditional hollow drive shaft, reducing the cooling thickness of the screw shaft by about 50% while increasing the cooling area of ​​the cooling water. Consequently, the cooling effect is significantly improved, creating more room for further increasing the pressing chamber pressure, reducing the residual oil content in the dried cake, and minimizing oil loss.

[0109] The design process of the helical shaft in this embodiment is as follows:

[0110] According to the design task and the traditional design calculation method for screw oil presses, after determining the empty volume V1 and related dimensions of the screw shaft 26 in the feeding section, a suitable total compression ratio for the low-temperature cold pressing process is selected. Based on the total compression ratio, the screw shaft 27 in the pressing section is designed as follows:

[0111] 1) The root diameter of the front end of the screw shaft 27 in the pressing section is equal to the root diameter of the end of the screw shaft 26 in the feeding section;

[0112] 2) The front section of the screw shaft 27 in the pressing section has the same geometry and dimensions as the rear section of the screw shaft 26 in the feeding section;

[0113] 3) Preliminarily determine the pitch S1 of tooth surface 29, the pitch S2 of tooth back 30, and the number of turns n of spiral pressing tooth 25;

[0114] 4) Calculate the axial length of the spiral press tooth 25 = S2×n+10 (10 represents the width of the acute angle of the tooth back reserved at the end of the spiral press tooth 25).

[0115] 5) Preliminarily determine the root circle diameter of the back of the end tooth of the spiral press tooth 25;

[0116] 6) Calculate the empty volume V2 of the last spiral groove 28 in the pressing section;

[0117] 7) Calculate the actual total compression ratio = V1 ÷ V2;

[0118] 8) Compare the calculated total compression ratio with the selected total compression ratio, and adjust the design parameters according to the error until the error between the calculated total compression ratio and the selected total compression ratio meets the requirements.

[0119] In this embodiment, at least one spiral shaft is installed inside the spiral cold press. When a double spiral shaft is used, the two spiral shafts rotate in opposite directions and are combined and installed inside the pressing chamber of the spiral cold press.

[0120] Traditional screw shafts employ a multi-section assembly design, with a large pitch and small root circle diameter at the front end, and a gradually decreasing pitch and increasing root circle diameter at the rear end. Adjacent sections with different root circle diameters are connected by tapered bushings, resulting in a large number of screw teeth and tapered bushings, and a large axial dimension—sometimes reaching 9 screw sections (i.e., screw teeth) and 6 tapered bushings. This leads to excessively long pressing time and high temperatures of the oilseeds inside the pressing chamber, which is extremely detrimental to low-temperature cold pressing of oilseeds. In this embodiment, the pressing section screw shaft 27 uses a tooth surface 2... The 9-tooth back 30 double pitch design, combined with the conical root circle of the tooth, makes the spiral groove 28 wider at the front and narrower at the back, and deeper at the front and shallower at the back. During the movement of the oil material from the beginning to the end of the spiral groove 28, it is continuously subjected to the double squeezing effect of the narrowing and shallowing of the spiral groove 28 at every moment. This reduces the number of spiral calculation turns in the pressing chamber, and correspondingly reduces the amount of oil material retained in the pressing chamber. This greatly increases the unit pressure of the oil material in the pressing chamber. This advantage of the present invention can improve the oil extraction efficiency of the low temperature cold press and reduce oil loss.

[0121] The operating parameters of the domestically developed SLZ30 double-screw oil press are as follows:

[0122] The daily processing capacity is 28 tons of peanut kernels, using a hot-pressing and roasting process. The main motor has a power of 37 kW, the screw shaft speed is 11 rpm, and the space volume of the screw shaft in the feeding section is 0.002655 m³. 3 The total number of spiral turns inside the pressing chamber is calculated to be 16.2, and the bulk density of peanut kernels is 570 kg / m³. 3 The peanut kernel content in the pressing chamber is g = 0.002655m³. 3 ×0.6×2×16.2×570kg / m 3 =29.42kg (0.6 in the formula is the oil filling coefficient of the screw shaft in the feeding section), the axial thrust generated by the screw shaft is 36836Kgf, and the pressure borne by each kilogram of peanut kernel in the pressing chamber is 36836kgf÷29.42kg=1252kgf.

[0123] The formula for calculating the total number of spiral turns N inside the pressing chamber of the SLZ30 twin-screw oil press is as follows:

[0124] N=L1÷d1+L2÷d2+(L3+C3)÷d3+(L4+C4)÷d4+(L5+C5)÷d5+(L6+C6)÷d6+(L7+C7)÷d7+(L8+C8)÷d8+L9÷d9

[0125] Among them, Li Let d represent the length of the i-th screw. i C represents the pitch of the i-th screw, where i = 1, 2, ..., 9; j Let L1, L2, ..., L9 represent the length of the bushing corresponding to the j-th screw, where j = 3, 4, ..., 8. In this embodiment, L1, L2, ..., L9 are 42mm, 170mm, 160mm, 150mm, 140mm, 120mm, 110mm, 90mm, and 78mm, respectively. The length of screw 1 is 42mm, which is its length inside the pressing chamber. The total length of screw 1 is 364mm. The remaining lengths are the lower end of the feed inlet, located outside the pressing chamber, and are not included in the calculation. d1, d2, ..., d9 are 208mm, 114mm, 128mm, 112mm, 96mm, 80mm, 72mm, 64mm, and 64mm, respectively. C3, C4, ..., C8 are 60mm, 60mm, 70mm, 70mm, 80mm, and 90mm, respectively. Substituting the above parameters into the above formula, we get N = 16.2 rings.

[0126] Under the conditions of constant oil input, constant input power, constant screw shaft speed, and constant overall compression ratio, if the pressing section screw shaft 27 of this embodiment is configured in the SLZ30 double screw oil press, the total length of the screw shaft can be shortened from the original 1812mm to 976mm, and the total number of screw teeth 25 in the pressing chamber can be reduced from the original 16.2 turns to 7.59 turns; the achieved effects include:

[0127] Firstly, the amount of oilseeds in the pressing chamber is reduced from 29.42 kg to 13.78 kg, while the pressure per kilogram of peanut kernels increases from 1252 kgf to 2712.465 kgf, representing a 116.65% increase in unit pressure. If the main motor power is reduced to 22 kW, the pressure per kilogram of peanut kernels will be 1589.4 kgf. This increases the unit pressure of the pressed oilseeds in the pressing chamber while reducing the motor output power, thus achieving the goal of energy saving and consumption reduction.

[0128] Secondly, it shortens the pressing time of oilseeds in the pressing chamber from the original 88.36 seconds to 41.4 seconds, a reduction of 53.1%, thereby effectively reducing the pressing temperature in the pressing chamber.

[0129] This embodiment uses rapeseed as the oilseed and conducts four sets of tests on the operating conditions of the screw oil press. The change in the main motor power consumption can be directly reflected by the magnitude of the main motor current. The larger the main motor current, the higher the operating pressure and temperature inside the pressing chamber, the greater the motor power consumption, and the lower the residual oil rate of the pressed cake. In addition, the residual oil rate of the pressed cake is also related to the moisture content of the oilseed. The lower the moisture content of the oilseed, the lower the residual oil rate of the pressed cake. Therefore, this embodiment indirectly reflects the effect of the water-cooled structure design of the screw oil press's cage plate and screw shaft on improving the operating temperature inside the pressing chamber, and the effect of the dual-pitch design of the screw shaft's tooth surface and back on improving the residual oil rate of the pressed cake by collecting data on oilseed moisture content, main motor current during the operation of the screw oil press, corresponding internal operating temperature data of the pressing chamber, and residual oil rate of the pressed cake. The test results are shown in Table 1 below.

[0130] Table 1. Test Results of Screw Press Operation Conditions

[0131] Serial Number Oilseed moisture content (%) Main motor current (A) Press chamber operating temperature (°C) Residual oil content of dried cake (%) 1 10.05±0.4 14 50～55 8.12±0.5 2 5.02±0.4 17 60～65 6.22±0.2 3 6.64±0.2 16 55～60 6.98±0.3 4 6.21±0.5 15 52～60 6.60±0.2

[0132] The biscuit forms corresponding to the above four test groups are as follows: Figure 12 As shown, Figure 12 (a) Figure 12 (b) Figure 12 (c) Figure 12 (d) Corresponding to the morphology of the dry cakes in the four test groups in Table 1; based on Table 1 above and Figure 12 As can be seen, the improved screw oil press of this embodiment greatly reduces the operating temperature inside the pressing chamber, with the maximum operating temperature inside the pressing chamber not exceeding 65°C, ensuring that the pressing temperature inside the pressing chamber is always kept below 65°C in the cold pressing process range, thereby greatly improving the quality of cold-pressed oil. On the other hand, under the condition of ensuring that the pressing temperature inside the pressing chamber is below 65°C in cold pressing, the residual oil rate of the dry cake is greatly reduced, which can be reduced to about 7%, thereby improving the oil extraction efficiency and reducing oil loss.

[0133] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel cold press with low residual oil content in dry cake, comprising a frame (1), wherein a controller (2), a drive component (3), and a pressing cage (4) are mounted on the frame (1), a feeding hopper (5) is mounted at the feed end of the pressing cage (4), and a single or multiple spiral shafts are mounted inside the pressing cage (4); characterized in that: The pressing cage (4) includes several cage plates (6) arranged at intervals along the axial direction. The opposite side edges of the cage plates (6) are fixedly connected by a first connecting plate (7) and a second connecting plate (8). The inner wall of the inner hole of the cage plate (6) is provided with a heat exchange channel along the circumferential direction. Several pressing bars (11) are arranged adjacent to each other along the circumferential direction on the side wall of the heat exchange channel. The pressing bars (11) together form a pressing chamber. The heat exchange channel is connected to the external circulation pipeline through a corresponding flow channel. The heat exchange channel includes a cooling water tank (9), and a sealing sleeve (10) is welded to the open side of the cooling water tank (9). Several of the pressing bars (11) are arranged close together along the side wall of the sealing sleeve (10). The cooling water tank (9) is connected to the external circulation pipeline through a corresponding flow channel. The external circulation pipeline includes a branch pipe (12) and a collection pipe (13), which are respectively installed on the first connecting plate (7) and the second connecting plate (8); the branch pipe (12) is connected to the heat exchange channel of each cage plate (6) through the corresponding first flow channel (14), and the collection pipe (13) is connected to the heat exchange channel of each cage plate (6) through the corresponding second flow channel (15); the branch pipe (12) and the collection pipe (13) are respectively connected to the second inlet pipe (16) and the second outlet pipe (17); The cage plate (6) is formed by two semi-annular plates (18) enclosing each other. The two semi-annular plates (18) are detachably connected by connectors. Each semi-annular plate (18) has a pressure plate (19) fixedly installed at both ends of its inner hole. Several pressing bars (11) are arranged close to each other between the two pressure plates (19). The heat exchange channel and the sealing sleeve (10) are both two-section split structures, and the openings at both ends of the heat exchange channel are provided with sealing plugs (20). The first connecting plate (7), the second connecting plate (8), the diversion pipe (12), the water collection pipe (13), the first flow channel (14), and the second flow channel (15) are each provided with two sets, which are used for circulating water in the heat exchange channels inside the two semi-annular plates (18). The spiral shaft includes a feeding section spiral shaft (26) and a pressing section spiral shaft (27). The root circle diameter of the pressing section spiral shaft (27) gradually increases along the axial direction towards the cake discharge end. The pitch of the spiral teeth (25) of the pressing section spiral shaft (27) is as follows: S 1 and tooth back (30) pitch S 2 represents two unequal pitches, and the pitch of the tooth surface (29) is... S 1 is greater than the tooth back (30) pitch S 2. The width and depth of the spiral groove (28) of the spiral shaft (27) of the pressing section gradually decrease along the axial direction towards the cake discharge end; The spiral shaft is provided with a cooling water chamber (31), which is connected to the first water inlet pipe (32) and the first water outlet pipe (33) on the outside.

2. The novel cold press with low residual oil content in dry cake as described in claim 1, characterized in that, The connector includes bolts (21), pins (22), and ear plates (23). The sides of the two first connecting plates (7) and the two second connecting plates (8) are provided with through holes for installing bolts (21). The through holes are located between two adjacent cage plates (6). The two first connecting plates (7) and the two second connecting plates (8) are connected by bolts (21). Ear plates (23) are installed at both ends of the bottom surface of the two second connecting plates (8). The pins (22) pass through the shaft holes (36) of the four ear plates (23) in sequence.

3. The novel cold press with low residual oil content in dry cake as described in claim 1, characterized in that, The length of the screw shaft (27) of the pressing section L = S 2× n + b 2, of which, n This indicates the number of spiral teeth (25) turns. b 2 indicates the axial width at the end of the spiral press teeth (25).

4. A novel cold press with low residual oil content in dry cake as described in claim 1, characterized in that, The end width of the spiral groove (28) l = S 2× n - b 1- S 1×( n -1), where, n This indicates the number of spiral teeth (25) turns. b 1 indicates the axial width of the beginning of the spiral press tooth (25).

5. A novel cold press with low residual oil content in dry cake as described in claim 1, characterized in that, The two ends of the spiral shaft are respectively connected to a power input shaft (34) and a rotating support shaft (35). The spiral teeth (25) are integrally formed with the spiral shaft. The rotating support shaft (35) is a hollow shaft, and the shaft hole (36) of the rotating support shaft (35) is connected to the cooling water chamber (31). The first water inlet pipe (32) and the first water outlet pipe (33) are installed at the end of the rotating support shaft (35). A bearing assembly is installed on the outside of the rotating support shaft (35). A cover (37) is sealed on the outer end face of the bearing assembly. One end of the first water inlet pipe (32) is located outside the cover (37), and the other end is located inside the cover (37) and extends into the cooling water chamber (31). The first water outlet pipe (33) is installed on the outer side of the bottom of the cover (37).

6. A novel cold press with low residual oil content in dry cake as described in claim 5, characterized in that, The bearing assembly includes a bearing sleeve (38) fixedly sleeved on the outside of the rotating support shaft (35), a roller bearing (39) sleeved on the outside of the bearing sleeve (38), a bearing housing (40) sleeved on the outside of the roller bearing (39), a bearing cover (41) provided at both the front and rear ends of the bearing housing (40), the opening end of the cover (37) is sealed and welded to the bearing cover (41) at the front end of the bearing housing (40), and an oil seal element (42) is provided between the inner side of the bearing cover (41) and the bearing sleeve (38).

7. A method for cooling the pressing chamber, based on the novel cold-press machine according to any one of claims 1 to 6, characterized in that, Includes the following steps: Real-time monitoring of operating temperature data within the pressing chamber; Based on the monitored temperature data, the external circulation pipeline is controlled to circulate and deliver cooling medium into the heat exchange channel of the cage plate (6), while the first water inlet pipe (32) and the first water outlet pipe (33) are controlled to circulate and deliver cooling medium into the cooling water chamber (31) inside the spiral shaft. The higher the operating temperature inside the pressing chamber, the greater the flow rate and the faster the flow speed of the cooling medium circulation.

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