A low temperature grinding device for whole grains and food products and a production process

Abstract

The application belongs to the field of food processing, and discloses a low-temperature grinding device for whole grains and food and a production process. The material of the upper grinding disc is silicon nitride, the material of the lower grinding disc is silicon carbide, the bottom surface of the upper grinding disc is a concave inverted cone shape, the top surface of the lower grinding disc is a concave inverted cone shape, the bottom surface of the upper grinding disc cooperates with the top surface of the lower grinding disc, the top surface of the upper grinding disc is provided with an upper grinding disc water channel, a water outlet and a water inlet are arranged on the upper grinding disc shell, and the water outlet and the water inlet are both in communication with the inside of the upper grinding disc water channel. A plurality of upper grinding disc grooves are arranged on the bottom surface of the upper grinding disc. Through the device, the upper grinding disc and the lower grinding disc can be cooled during the grinding process, and vitamins can be preserved during the grinding process, so that the flavor and nutrition of the flour are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of food processing, and particularly relates to a low-temperature grinding device for whole grains and food and a production process. BACKGROUND

[0002] In the process of grinding grains, green tea and cocoa coffee, a grinding head, a stone mill or a flour mill is usually used to grind them.

[0003] Among them, the stone mill is not only very slow in use, but also easy to drop residues, and easy to cause oxidation of wheat flour during grinding. Therefore, the grinding method by stone mill is gradually eliminated.

[0004] However, the traditional flour mill generally drives the metal grinding disc to rotate by the motor to grind the wheat. However, while the grinding speed is improved, the temperature rises to 45-85℃ during high-speed grinding, which causes denaturation of plant proteins, oxidation of vitamins and enzymes in flour, and chemical reaction between metal grinding disc and phytic acid and abscisic acid in wheat, resulting in metal corrosion. In addition, after long-term use, the iron mill is easy to wear, so that during use, the ground flour carries a small amount of metal particles, which is not conducive to the quality of flour. At the same time, the grooves of the grinding disc are easy to breed bacteria during long-term use. In addition, the rotating iron mill will produce iron filings during rotation, which will oxidize at high temperature.

[0005] In order to improve the hardness of the grinding disc and reduce the residues during grinding, researchers have developed and designed silicon nitride and silicon carbide engineering ceramic grinding discs by referring to the existing technology of ceramic cutters of precision machine tools. However, ordinary silicon carbide engineering ceramics have many microcracks on the surface, which are easy to break when impacted at high speed. Since the hardness is high and very sharp, the broken residues mixed in the flour will cause serious safety accidents when eaten by people.

[0006] In addition, due to the high hardness of silicon carbide engineering ceramics, which is only second to the hardness of diamond, the sintered grinding disc still has the problems of difficulty in carving and high cost in the carving process. Although some people use isostatic pressing to produce a blank, and then sinter after carving, the blank is easy to crack during subsequent sintering due to different stresses on the outside, resulting in a large number of microcracks, which will break due to stress problems during use.

[0007] In addition, in Japan, researchers have developed a sintering process using a grinding wheel, which mixes granular silicon carbide with a ceramic binder for sintering. However, the density and toughness of the grinding disc sintered in this way are not enough to support it as a grinding disc material, which is easy to break during rotation. In addition, its thermal conductivity efficiency is only 15-18W·m -1·K -1 Between these two materials, which are similar to stainless steel, the high temperatures generated during rotation can also cause the flour to oxidize.

[0008] In addition, the flour currently on the market is whitened by adding strong oxidizing agents, but this causes the loss of vitamins and minerals in the flour, leaving only refined carbohydrates, which is the refined flour on the market. However, the root cause of the lack of promotion of whole wheat flour is that the backward food grinding process results in a rough texture and poor flavor. Summary of the Invention

[0009] In order to overcome the shortcomings of the prior art, the present invention aims to provide a low-temperature grinding apparatus and production process for whole grains and food, so as to solve the problems mentioned in the background art.

[0010] The technical solution adopted by this low-temperature grinding device and production process for whole grains and food to solve its technical problems is as follows:

[0011] On one hand, a low-temperature grinding device for whole grains and food is provided, including an upper grinding disc and a lower grinding disc. The upper grinding disc is made of silicon nitride, and the lower grinding disc is made of silicon carbide. The bottom surface of the upper grinding disc is an upwardly concave inverted cone, and the top surface of the lower grinding disc is a downwardly concave inverted cone. The bottom surface of the upper grinding disc and the top surface of the lower grinding disc fit together. The top surface of the upper grinding disc is provided with an upper grinding disc water channel, and the outer shell of the upper grinding disc has an upper grinding disc water outlet and an upper grinding disc water inlet. The upper grinding disc's outlet and inlet are both connected to the interior of the upper grinding disc's water channel. Several upper grinding disc grooves are opened on the bottom surface of the upper grinding disc, dividing the bottom surface of the upper grinding disc into several upper grinding disc teeth. An upper grinding disc opening is provided in the middle of the upper grinding disc. The lower grinding disc's bottom surface is provided with a lower grinding disc water channel, and several lower grinding disc grooves are opened on the top surface of the lower grinding disc, dividing the top surface of the lower grinding disc into several lower grinding disc teeth. Mounting holes are provided on the lower grinding disc.

[0012] Furthermore, an upper grinding disc shell is fitted onto the upper grinding disc, forming a water flow path between the upper grinding disc shell and the upper grinding disc water channel. The upper grinding disc shell has an outlet and an inlet, both of which are connected to the interior of the upper grinding disc water channel. The middle of the upper grinding disc shell has an opening corresponding to the upper grinding disc opening. A lower grinding disc shell is fitted onto the lower grinding disc, forming a water flow path between the lower grinding disc shell and the lower grinding disc water channel. The lower grinding disc shell has an outlet and an inlet, both of which are connected to the interior of the lower grinding disc water channel. The middle of the lower grinding disc shell has a mounting hole corresponding to the mounting hole.

[0013] Furthermore, a first sealing groove is formed on the inner wall of the upper grinding disc shell and the lower grinding disc shell respectively, and a first sealing ring is installed in the first sealing groove. A second sealing groove is formed in the water outlet of the upper grinding disc, the water inlet of the upper grinding disc, the water outlet of the lower grinding disc, and the water inlet of the lower grinding disc respectively, and a second sealing ring is installed in the second sealing groove.

[0014] Furthermore, the upper and lower grinding disc teeth are rectangular racks.

[0015] Furthermore, trapezoidal chamfers are provided on both the upper and lower grinding disc teeth.

[0016] Furthermore, the upper grinding disc housing is provided with an upper grinding disc mounting threaded hole.

[0017] Furthermore, a lower grinding disc mounting threaded hole is provided on the lower grinding disc housing.

[0018] Furthermore, both the upper and lower grinding disc water channels are provided with microchannel embossing.

[0019] On the other hand, a production process for a low-temperature grinding device for any of the above-mentioned whole grains and foods is also provided. The first step is to prepare the blanks of the upper grinding disc and the lower grinding disc by isostatic pressing. The blank of the upper grinding disc is made of silicon nitride, and the blank of the lower grinding disc is made of silicon carbide. At the same time, a sintering aid with a volume fraction of 1.8-3% is uniformly doped in the silicon carbide blank. The sintering aid is alumina and yttrium oxide micro powder with a diameter of 0.3-0.5μm. The blank of the silicon nitride is uniformly doped with a sintering aid with a volume fraction of 1.8-3%. The novel aid adopts YB2C2 with a two-dimensional layered structure. In addition to effectively promoting densification and improving thermal conductivity, the YB2C2 nanosheets partially embedded in the Si3N4 matrix can play an inhibitory role such as deflection and bridging of relative crack propagation, which significantly improves the mechanical properties of Si3N4 ceramics.

[0020] Step 2: Using a 3D planar engraving machine, carve the shapes of the upper and lower grinding discs on the blank, and reserve a shrinkage allowance of 17-20%;

[0021] Step 3: Take out two sets of molds that correspond to the upper and lower grinding discs respectively. The molds include an upper mold and a lower mold. The upper mold and the lower mold are made of graphite that can withstand high temperatures of 2100℃. The upper mold has a centering cone surface in the middle of the bottom surface, and the lower mold has a centering cone surface in the middle of the bottom surface.

[0022] Step 4: Place carbon paper inside the upper and lower molds, with the carbon paper thickness between 0.5-0.7mm;

[0023] Step 5: Place the carved blanks into their respective molds;

[0024] Step 6: Clamp the molds in the corresponding sintering furnaces, apply pressure, vibrate, and heat at the same time, so that the sintering temperature of the silicon nitride blank is between 1800-1950℃ and the sintering temperature of the silicon carbide blank is between 1900-2050℃, and a dense upper and lower grinding disc can be obtained.

[0025] Step 7: Remove the corresponding upper and lower grinding discs from the corresponding molds, and embed them into the corresponding upper and lower grinding disc shells respectively. Specifically, the embedding method is as follows: heat the corresponding upper and lower grinding disc shells to 180-250℃, and then pneumatically press the upper and lower grinding discs into the corresponding upper and lower grinding disc shells. After cooling, there is a shrinkage allowance of 30-50 microns between the upper and lower grinding discs and the corresponding upper and lower grinding disc shells respectively.

[0026] Furthermore, after completing the fourth step, a PET or PE polymer organic solution is sprayed onto the carbon paper.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. The present invention provides a low-temperature grinding device for whole grains and food. By injecting cooling water into the water inlets of the upper and lower grinding discs, the device absorbs the heat generated during the rotation of the lower grinding disc, thereby cooling the upper and lower grinding discs. This device can cool the upper and lower grinding discs during the grinding process, preserve vitamins, and improve the flavor and nutrition of the flour.

[0029] 2. The low-temperature grinding device for whole grains and food according to the present invention can protect the upper grinding disc and the lower grinding disc respectively through the upper grinding disc shell and the lower grinding disc shell, and at the same time, the upper grinding disc shell and the lower grinding disc shell can fix the upper grinding disc and the lower grinding disc.

[0030] 3. The low-temperature grinding device for whole grains and food according to the present invention can seal the gaps between the upper grinding discs and between the lower grinding discs through the first sealing groove and the first sealing ring, respectively, to prevent coolant from flowing out from the gaps. The sealing groove and sealing ring in the water outlet, water inlet, water outlet and water inlet of the upper grinding disc can seal the pipeline when installing the cooling water pipeline to prevent leakage.

[0031] 4. The low-temperature grinding device for whole grains and food according to the present invention can improve the grinding effect and form a high-density, non-porous, sharp grinding particle size by means of a fixed grinding disc tooth and a moving grinding disc tooth in the shape of a rectangular toothed rack during grinding.

[0032] 5. A low-temperature grinding device for whole grains and food, as exemplified by the present invention, can form fine and smooth paste-like microparticles during the grinding process by opening a trapezoidal chamfer.

[0033] 6. A low-temperature grinding device for whole grains and food according to an example of the present invention has mounting holes on the upper grinding disc corresponding to the mounting thread holes of the upper grinding disc. The upper grinding disc can be fixed to the upper grinding disc shell by means of pins, and the upper grinding disc can be protected by the upper grinding disc shell.

[0034] 7. A low-temperature grinding device for whole grains and food according to an example of the present invention has mounting holes on the lower grinding disc corresponding to the mounting threaded holes of the lower grinding disc. The lower grinding disc can be fixed to the lower grinding disc housing by means of pins, and the lower grinding disc can be protected by the lower grinding disc housing.

[0035] 8. The low-temperature grinding device for whole grains and food, as exemplified by the present invention, can generate turbulence through embossing, thereby accelerating heat exchange.

[0036] 9. An example of the present invention describes a production process for a low-temperature grinding device for whole grains and food products. The upper and lower grinding discs produced by this process are first prepared as blanks using isostatic pressing. After carving, the blanks are sintered. During the sintering process, the upper grinding disc 110 is sintered at a high temperature of 1800-1950℃, and the lower grinding disc 210 is sintered at a high temperature of 1900-2050℃. This reduces the difficulty of subsequent processing. Furthermore, by simultaneously heating, vibrating, and sintering, the produced upper and lower grinding discs are made more dense, preventing the formation of micro-cracks during production. The theoretical density can reach 3.18 grams per cubic centimeter, and the fracture toughness of the upper grinding disc 110 can reach 7 MPa·m. 1 / 2 Compared to the current common 4MPa·m 1 / 2 The silicon carbide ceramic material content is close to 50% to 60%, making the produced grinding discs less prone to breakage, and the thermal conductivity of the produced grinding discs can reach 90 W·m. -1 ·K -1 It is 5 times stronger than stainless steel; the fracture toughness of the lower grinding disc 210 can exceed 6 MPa·m. 1 / 2 Compared to the current common 4MPa·m 1 / 2 Significant improvements have been made to the silicon carbide ceramic material used in the production of grinding discs, making them less prone to breakage, and the resulting grinding discs can achieve a thermal conductivity of 140 W·m. -1 ·K -1It is 8 times more heat-efficient than stainless steel, which can accelerate heat exchange efficiency during use and facilitate the rapid removal of heat by cooling water. By doping with sintering aids, it can promote sintering densification. By reserving 17-20% shrinkage before sintering, the volume of the blank can reach the standard volume after shrinkage during pressure sintering. The setting of carbon paper can prevent the blank from sintering together with the mold during sintering, making it easy to remove the sintered grinding disc after sintering.

[0037] 10. An example of the production process of a low-temperature grinding device for whole grains and food according to the present invention, through the engagement between the upper mold centering cone surface and the lower mold centering cone surface, the upper mold centering cone surface can slide into the lower mold centering cone surface along the inclined surface of the lower mold centering cone surface, which can automatically center the upper and lower molds, making the centering more accurate and thus reducing damage to the mold. Attached Figure Description

[0038] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 This is a schematic diagram of the structure of the present invention;

[0040] Figure 2 This is a schematic diagram of the upper grinding disc;

[0041] Figure 3 This is a front view of the upper grinding disc;

[0042] Figure 4 This is a cross-sectional view of the upper grinding disc;

[0043] Figure 5 This is a top view of the upper millstone;

[0044] Figure 6 This is a schematic diagram of the upper grinding disc housing;

[0045] Figure 7 This is a top view of the lower millstone;

[0046] Figure 8 This is a bottom view of the lower millstone;

[0047] Figure 9 This is a cross-sectional view of the lower grinding disc;

[0048] Figure 10 This is a schematic diagram of the lower grinding disc housing;

[0049] Figure 11 This is a downward-angled view of the mold;

[0050] Figure 12 This is an upward angled view of the mold;

[0051] Figure 13 This is a schematic diagram of the upper mold structure;

[0052] Figure 14 This is a schematic diagram of the lower mold structure.

[0053] In the diagram: 101, upper mold; 102, upper mold centering cone surface; 110, upper grinding disc; 111, upper grinding disc outlet; 112, upper grinding disc inlet; 114, upper grinding disc water channel; 150, upper grinding disc outer shell; 151, upper grinding disc mounting threaded hole; 152, first sealing groove; 153, first sealing ring; 154, second sealing groove; 155, second sealing ring; 201, lower mold; 202, lower mold centering cone surface; 210, lower grinding disc; 211, lower grinding disc outlet; 212, lower grinding disc inlet; 214, lower grinding disc water channel; 250, lower grinding disc outer shell; 251, lower grinding disc mounting threaded hole. Detailed Implementation

[0054] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0055] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0056] like Figure 1 As shown, this embodiment provides a low-temperature grinding device for whole grains and food, including an upper grinding disc 110 and a lower grinding disc 210. The upper grinding disc 110 is made of silicon nitride, and the lower grinding disc 210 is made of silicon carbide. The bottom surface of the upper grinding disc 110 is an upwardly concave inverted cone shape, and the top surface of the lower grinding disc 210 is a downwardly concave inverted cone shape. The bottom surface of the upper grinding disc 110 and the top surface of the lower grinding disc 210 cooperate with each other, as shown in the figure. Figures 2-5 As shown, the top surface of the upper grinding disc 110 is provided with an upper grinding disc water flow channel 114, and an upper grinding disc water flow passage is formed between the upper grinding disc outer shell 150 and the upper grinding disc water flow channel 114. Several upper grinding disc grooves are opened on the bottom surface of the upper grinding disc 110, dividing the bottom surface of the upper grinding disc into several upper grinding disc teeth. An upper grinding disc opening is provided in the middle of the upper grinding disc 110, which facilitates material feeding during grinding. Figures 6-8 As shown, the bottom surface of the lower grinding disc 210 is provided with a lower grinding disc water channel 214, and the top surface of the lower grinding disc 210 is provided with several lower grinding disc grooves. Through the several lower grinding disc grooves, the top surface of the lower grinding disc is divided into several lower grinding disc teeth. The lower grinding disc 210 is provided with mounting holes, through which the lower grinding disc can be easily installed on the working shaft.

[0057] In this embodiment, an upper grinding disc housing 150 is fitted onto the upper grinding disc 110. A water flow path is formed between the upper grinding disc housing 150 and the upper grinding disc water channel 114. The upper grinding disc housing 150 has an upper grinding disc outlet 111 and an upper grinding disc inlet 112, both of which communicate with the interior of the upper grinding disc water channel 114. The middle of the upper grinding disc housing 150 is provided with an upper grinding disc opening corresponding to the upper grinding disc opening. The grinding disc outer shell has an opening; the lower grinding disc outer shell 250 is installed on the lower grinding disc 210, and a water flow passage is formed between the lower grinding disc outer shell 250 and the lower grinding disc water flow channel 214. The lower grinding disc outer shell 250 has a lower grinding disc water outlet 211 and a lower grinding disc water inlet 212. Both the lower grinding disc water outlet 211 and the lower grinding disc water inlet 212 are connected to the interior of the lower grinding disc water flow channel 214. The middle part of the lower grinding disc outer shell has a lower grinding disc outer shell mounting hole corresponding to the mounting hole.

[0058] In this embodiment, a first sealing groove 152 is respectively opened on the inner wall of the upper grinding disc shell 150 and the lower grinding disc shell 250, and a first sealing ring 153 is respectively installed in the first sealing groove 152. A second sealing groove 154 is respectively opened in the upper grinding disc outlet 111, the upper grinding disc inlet 112, the lower grinding disc outlet 211 and the lower grinding disc inlet 212, and a second sealing ring 155 is respectively installed in the second sealing groove 154.

[0059] In this embodiment, the upper and lower grinding disc teeth are rectangular racks.

[0060] In this embodiment, trapezoidal chamfers are provided on both the upper and lower grinding disc teeth.

[0061] In this embodiment, the upper grinding disc housing 150 has an upper grinding disc mounting threaded hole.

[0062] In this embodiment, the lower grinding disc housing 250 has a lower grinding disc mounting threaded hole 251.

[0063] In this embodiment, both the upper grinding disc water channel 114 and the lower grinding disc water channel 214 are provided with microchannel embossing.

[0064] In this embodiment, as Figures 9-12As shown, a production process for a low-temperature grinding device for any of the above-mentioned whole grains and foods is also provided, including the following step: making blanks of the upper grinding disc 110 and the lower grinding disc 210 by isostatic pressing. The blank of the upper grinding disc 110 is made of silicon nitride, and the blank of the lower grinding disc 210 is made of silicon carbide. At the same time, a sintering aid with a volume fraction of 1.8-3% is uniformly doped in the silicon carbide blank. The sintering aid is alumina and yttrium oxide micro powder with a diameter of 0.3-0.5μm. The blank of the silicon nitride is uniformly doped with a sintering aid with a volume fraction of 1.8-3%. The novel aid adopts YB2C2 with a two-dimensional layered structure. In addition to effectively promoting densification and improving thermal conductivity, the YB2C2 nanosheets partially embedded in the Si3N4 matrix can play an inhibitory role such as reinforcing the deflection and bridging of relative crack propagation, and significantly improving the mechanical properties of Si3N4 ceramics.

[0065] Step 2: Using a 3D planar engraving machine, carve the shapes of the upper grinding disc 110 and the lower grinding disc 210 into the blank respectively, and reserve a shrinkage allowance of 17-20%;

[0066] Step 3: Take out two sets of molds that correspond to the upper grinding disc 110 and the lower grinding disc 210 respectively. The molds include an upper mold 101 and a lower mold 201. The upper mold 101 and the lower mold 201 are made of graphite that can withstand high temperatures of 2100℃. The upper mold 101 has an upper mold centering cone surface 102 in the middle of its bottom surface, and the lower mold 201 has a lower mold centering cone surface 202 in the middle of its bottom surface.

[0067] Step 4: Place carbon paper inside the upper mold 101 and the lower mold 201. The thickness of the carbon paper should be between 0.5-0.7mm.

[0068] Step 5: Place the carved blanks into their respective molds;

[0069] Step 6: Clamp the molds in the corresponding sintering furnaces, apply pressure, vibrate, and heat at the same time, so that the sintering temperature of the silicon nitride blank is between 1800-1950℃ and the sintering temperature of the silicon carbide blank is between 1900-2050℃, and a dense upper grinding disc 110 and lower grinding disc 210 can be obtained.

[0070] Step 7: Remove the corresponding upper grinding disc 110 and lower grinding disc 210 from the corresponding molds, and embed the upper grinding disc 110 and lower grinding disc 210 into the corresponding upper grinding disc shell 150 and lower grinding disc shell 250 respectively. Specifically, the embedding method is as follows: after heating the corresponding upper grinding disc shell 150 and lower grinding disc shell 250 to 180-250℃, pneumatically press the upper grinding disc 110 and lower grinding disc 210 into the corresponding upper grinding disc shell 150 and lower grinding disc shell 250. After cooling, the upper grinding disc 110 and lower grinding disc 210 have a shrinkage allowance of 30-50 microns with the corresponding upper grinding disc shell 150 and lower grinding disc shell 250 respectively.

[0071] In this embodiment, after completing the fourth step, a PET or PE polymer organic solution is sprayed onto the carbon paper.

[0072] In the production process, this product uses isostatic pressing to create the blank, which is then carved and placed into a mold. The upper mold 101 and lower mold 201 automatically align themselves during engagement via the upper mold centering cone 102 and the lower mold centering cone 202. The mold is then clamped in a sintering furnace for firing. During firing, the upper grinding disc 110 is sintered at a high temperature of 1800-1950℃, and the lower grinding disc 210 is sintered at a high temperature of 1900-2050℃, while simultaneously undergoing high-frequency vibration and frontal pressure. By allowing for a shrinkage allowance of 17-20%, the blank shrinks during the sintering process to obtain a standard-sized grinding disc. After sintering, only minor machining is required on the grinding disc. During the process, carbon paper with a thickness of 0.5-0.7 mm is placed between the mold and the ceramic grinding disc. A PET or PE polymer organic solution is sprayed onto the carbon paper. This carbon paper separates the mold and the grinding disc during sintering. Furthermore, if cracks appear in the carbon paper during sintering, the PET or PE polymer organic solution can repair these cracks, effectively separating the mold and the grinding disc. Grinding discs produced using this method have a theoretical density of 3.18 g / cm³, and the fracture toughness of the upper grinding disc (110) can reach 7 MPa·m¹ / ², which is nearly 50% to 60% higher than the commonly used silicon carbide ceramic materials (around 4 MPa·m¹ / ²). This makes the produced grinding discs less prone to breakage. Furthermore, the produced grinding disc has a thermal conductivity of 90 W·m⁻¹·K⁻¹, which is 5 times that of stainless steel; the lower grinding disc 210 has a fracture toughness exceeding 6 MPa·m¹ / ², a significant improvement compared to the currently common silicon carbide ceramic material of around 4 MPa·m¹ / ², making the produced grinding disc less prone to breakage. The produced grinding disc also has a thermal conductivity of 140 W·m⁻¹·K⁻¹, which is 8 times that of stainless steel. In use, the device produced in this way fixes the upper grinding disc 110 to the upper grinding disc shell 150, and the lower grinding disc 210 is fixedly mounted on the working shaft to the lower grinding disc shell 250. The lower grinding disc 210 is rotated by a motor-driven working shaft. This device allows for direct feeding or screw conveying from the opening of the upper grinding disc. The upper and lower grinding discs, with their rectangular toothed surfaces and trapezoidal chamfers, subject the material to intense shearing, friction, impact, and high-frequency vibration, resulting in crushing, dispersion, grinding, and refining. Under the centrifugal force of the rotating lower grinding disc 210, the ground particles are ejected from the gap between the upper and lower grinding discs 110 and 210. By controlling the distance between the upper and lower grinding discs 110 and 210, the particle size and fineness of the output powder can be controlled. This device enables ultra-fine grinding of flour, effectively removing the bran from grains, thus reducing the impact of bran on the texture of the whole wheat flour.Cooling water at 0-5℃ is injected into the upper grinding disc inlet 112 and the lower grinding disc inlet 212, respectively. Since the upper grinding disc 110 is stationary, its outlet 111 and inlet 112 are located on its outer periphery. The lower grinding disc 210 is a rotating component, therefore its outlet 211 and inlet 212 are both located on its bottom surface. Cooling water is injected into the lower grinding disc inlet 212 via a slip ring system. The water flows in the upper grinding disc water channel 114 and the lower grinding disc water channel 214 respectively. The embossing in both channels generates turbulence, accelerating heat exchange and keeping the grinding disc temperature below 35℃ during rotation. This prevents high-temperature oxidation of the flour, keeping it below the 42℃ oxidation temperature of vitamin C, thus preserving vitamins, enzymes, and carotene during grinding. Furthermore, silicon carbide is a bio-inert material with the fastest thermal conductivity. This material, silicon nitride, has a thermal conductivity eight times that of stainless steel. Utilizing its bio-inert properties, it does not chemically react with food, making it safer. Furthermore, as a natural low-temperature infrared material, silicon nitride possesses inherent infrared properties, exhibiting antibacterial and bacteriostatic effects, enhancing food flavor, and improving its antioxidant properties. Compared to metals, it is more inert and will not react with phytic acid or abscisic acid in food, preventing corrosion of the grinding disc. Additionally, using silicon nitride as the grinding disc material leverages its self-lubricating properties, reducing sliding resistance between friction surfaces during high-speed rotation. Therefore, the device produced using this process is more robust, preventing slag shedding during grinding. It also allows for temperature control of the grinding disc itself during rotation, reducing heat generation and effectively preserving nutrients in grains, achieving antibacterial and bacteriostatic effects during grinding.

[0073] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

[0074] Apart from the technical features described in the specification, the other technical features are known to those skilled in the art. To highlight the innovative features of this invention, the other technical features will not be described in detail here.

Claims

1. A production process for a low-temperature grinding device for whole grains and food, characterized in that, Step 1: The blanks for the upper and lower grinding discs are made by isostatic pressing. The blank for the upper grinding disc is made of silicon nitride, and the blank for the lower grinding disc is made of silicon carbide. At the same time, sintering aids with a volume fraction of 1.8-3% are uniformly doped into the silicon carbide blanks. The sintering aids are alumina and yttrium oxide micro powders with a diameter of 0.3-0.5μm. The blanks for the silicon nitride are also uniformly doped with sintering aids with a volume fraction of 1.8-3%. The sintering aids are YB2C2 with a two-dimensional layered structure. Step 2: Using a 3D planar engraving machine, carve the shapes of the upper and lower grinding discs on the blank, and reserve a shrinkage allowance of 17-20%; Step 3: Take out two sets of molds that correspond to the upper and lower grinding discs respectively. The molds include an upper mold and a lower mold. The upper mold and the lower mold are made of graphite that can withstand high temperatures of 2100℃. The upper mold has a centering cone surface in the middle of the bottom surface, and the lower mold has a centering cone surface in the middle of the bottom surface. Step 4: Place carbon paper inside the upper and lower molds, with the carbon paper thickness between 0.5-0.7mm; Step 5: Place the carved blanks into their respective molds; Step 6: Clamp the molds in the corresponding sintering furnaces, apply pressure, vibrate, and heat at the same time, so that the sintering temperature of the silicon nitride blank is between 1800-1950℃ and the sintering temperature of the silicon carbide blank is between 1900-2050℃, and a dense upper and lower grinding disc can be obtained. Step 7: Remove the corresponding upper and lower grinding discs from the corresponding molds. Embed the upper and lower grinding discs into their respective upper and lower grinding disc housings. The embedding method is as follows: After heating the corresponding upper and lower grinding disc housings to 180-250℃, the housings expand due to heat, and the upper and lower grinding discs are pneumatically pressed into their respective housings. After cooling, there will be a shrinkage allowance of 30-50 microns between the upper and lower grinding discs and their respective housings. The low-temperature grinding device for whole grains and food includes an upper grinding disc and a lower grinding disc. The upper grinding disc is made of silicon nitride, and the lower grinding disc is made of silicon carbide. The bottom surface of the upper grinding disc is an inverted cone shape that is concave upwards, and the top surface of the lower grinding disc is an inverted cone shape that is concave downwards. The bottom surface of the upper grinding disc and the top surface of the lower grinding disc cooperate with each other. The top surface of the upper grinding disc is provided with an upper grinding disc water channel. Several upper grinding disc grooves are opened on the bottom surface of the upper grinding disc. Through the several upper grinding disc grooves, the bottom surface of the upper grinding disc is divided into several upper grinding disc teeth. The middle part of the upper grinding disc is provided with an upper grinding disc opening. The bottom surface of the lower grinding disc is provided with a lower grinding disc water channel, and the top surface of the lower grinding disc is provided with several lower grinding disc grooves. Through these grooves, the top surface of the lower grinding disc is divided into several lower grinding disc teeth. The lower grinding disc is provided with mounting holes.

2. The production process of a low-temperature grinding device for whole grains and food according to claim 1, characterized in that, The upper grinding disc housing is fitted onto the upper grinding disc, and a water flow passage is formed between the upper grinding disc housing and the upper grinding disc water flow channel. The upper grinding disc housing has an upper grinding disc water outlet and an upper grinding disc water inlet, both of which are connected to the interior of the upper grinding disc water flow channel. The middle part of the upper grinding disc housing has an upper grinding disc housing opening corresponding to the upper grinding disc opening. The lower grinding disc housing is installed on the lower grinding disc. A water flow passage is formed between the lower grinding disc housing and the lower grinding disc water flow channel. The lower grinding disc housing has a lower grinding disc water outlet and a lower grinding disc water inlet. Both the lower grinding disc water outlet and the lower grinding disc water inlet are connected to the inside of the lower grinding disc water flow channel. The lower grinding disc housing has a mounting hole in the middle that corresponds to the mounting hole.

3. The production process of a low-temperature grinding device for whole grains and food according to claim 1, characterized in that, The inner walls of the upper and lower grinding disc shells are respectively provided with first sealing grooves, and first sealing rings are respectively installed in the first sealing grooves. The water outlet, water inlet, water outlet and water inlet of the upper grinding disc are respectively provided with second sealing grooves, and second sealing rings are respectively installed in the second sealing grooves.

4. The production process of a low-temperature grinding device for whole grains and food according to claim 1, characterized in that, Both the upper and lower grinding disc teeth are rectangular racks.

5. The production process of a low-temperature grinding device for whole grains and food according to claim 1, characterized in that, Both the upper and lower grinding disc teeth have trapezoidal chamfers.

6. The production process of a low-temperature grinding apparatus for whole grains and food according to claim 1, characterized in that, The upper grinding disc housing has a threaded hole for mounting the upper grinding disc.

7. The production process of a low-temperature grinding device for whole grains and food according to claim 1, characterized in that, The lower grinding disc housing has a threaded hole for mounting the lower grinding disc.

8. The production process of a low-temperature grinding device for whole grains and food according to claim 1, characterized in that, Both the upper and lower grinding disc water channels are provided with microchannel embossing.

9. The production process of the low-temperature grinding apparatus for whole grains and food according to claim 1, characterized in that, After completing the fourth step, a PET or PE polymer organic solution is sprayed onto the carbon paper.

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