A high-quality nut shelling process and equipment

Abstract

The present invention discloses a high-quality nut shelling process and equipment. The process includes a soaking process, a cryogenic quick-freezing process, and a shelling process carried out successively. Before the soaking process, it further includes: a polishing process: polishing the outer surface of the nuts to expose the woody layer of the nuts. The equipment includes: a polishing device arranged successively, which is used to polish the outer surface of the nuts to expose the woody layer of the nuts; a soaking device, which is used to soak the nuts; a cryogenic quick-freezing device, which is used to carry out cryogenic quick-freezing on the soaked nuts; a shelling device, which is used to shell the nuts after the quick-freezing treatment. The high-quality nut shelling process and equipment of the present invention, by adding a polishing process before the soaking process and polishing the outer shell of the nuts by the grinding wheel of the peeling machine, can grind off the outer surface to expose the woody layer with lower density and poor waterproofness. When the nuts are soaked subsequently, the soaking time can be greatly reduced, and the shelling efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural and sideline product processing, and particularly to a high-quality nut shelling process and equipment. Background Art

[0002] Nut shelling is a prerequisite for the primary processing of such shelled crops. However, due to the significant differences in the physical properties between the nut shell and the kernel, the shell is usually relatively hard, while the kernel is relatively fragile. During the shelling process, breakage and damage are likely to occur. The damaged kernels are prone to breeding bacteria, aflatoxins, etc., which affect the quality of nuts, resulting in significant losses and waste. Especially for nuts with a relatively complex internal structure like walnuts, it is even more difficult to ensure the whole kernel rate. Therefore, it is necessary to develop a nut shelling process and equipment that can achieve high-quality shelling.

[0003] In the prior art, Patent CN107897822A discloses a method for quickly shelling chestnuts, which discloses a process of first soaking chestnuts in brine, then making incisions in the chestnuts, and finally shelling them; Patent CN101791142A discloses a method for freezing and peeling almonds or peach kernels, which includes a process of soaking in warm water, cryogenic freezing, soaking again, and mechanical peeling. In the above patents, both disclose a process of first soaking and then performing post-treatment such as grooving and freezing. These two solutions have the following problems: The outer surface of the nut shell is generally relatively dense and has good water resistance. Soaking it requires a long time to penetrate, which will greatly affect the shelling efficiency. Patent CN103535839A discloses a walnut hard shell shelling machine, which directly squeezes walnuts through the extrusion gap between the stripper housing and the conical barrel. It is difficult to achieve a good shelling effect. During the shelling process, the diaphragm inside the walnut will affect the timely removal of the kernel. The kernel that is not removed in time will continue to be squeezed and damaged as the shell continues to be squeezed. Therefore, the whole kernel rate is low and the shelling efficiency is low. Summary of the Invention

[0004] Object of the Invention: In order to overcome the deficiencies in the prior art, the present invention provides a high-quality nut shelling process and equipment that can accelerate the soaking process and thus improve the shelling efficiency.

[0005] Technical Solution: To achieve the above object, the high-quality nut shelling process of the present invention includes a soaking process, a cryogenic quick-freezing process, and a shelling process that are carried out successively. Before the soaking process, it further includes:

[0006] Polishing Process: Polishing the outer surface of the nut to expose the woody layer of the nut.

[0007] Furthermore, before the soaking process, it further includes:

[0008] Grooving Process: Making grooves on the outer shell of the nut.

[0009] Further, in the grooving process, grooves with a preset depth are respectively formed in the length direction, width direction, and thickness direction of the nuts.

[0010] Further, the soaking process is specifically as follows:

[0011] Soak the nuts in normal-temperature water for 1 hour.

[0012] Further, the cryogenic quick-freezing process is specifically as follows:

[0013] Quick-freeze the soaked nuts in an environment of -45°C for 3 hours.

[0014] Further, the shelling process is carried out in multiple stages, specifically including:

[0015] Perform multi-point impact on the nut shell;

[0016] Exert extrusion on the nuts after multi-point impact so that at least part of the shell of the nuts falls off;

[0017] Screen the nuts to screen out the nuts whose shell falling-off degree meets the conditions;

[0018] Knead and impact the screened nuts to make the kernels come out.

[0019] A high-quality nut shelling equipment, which includes successively arranged:

[0020] Soaking equipment, which is used to soak the nuts;

[0021] Cryogenic quick-freezing equipment, which is used to perform cryogenic quick-freezing on the soaked nuts;

[0022] Shelling equipment, which is used to shell the nuts after quick-freezing treatment;

[0023] It further includes:

[0024] Grinding equipment, which is used to grind the outer surface of the nuts to expose the wood layer of the nuts.

[0025] Further, it also includes grooving equipment located before the soaking equipment, and the grooving equipment is used to groove the outer surface of the nuts.

[0026] Further, the shelling equipment includes a stationary roller and a moving roller, and the moving roller is rotatably installed inside the stationary roller;

[0027] The stationary roller has an inner conical surface that is wider at the top and narrower at the bottom;

[0028] The moving roller has an upper conical surface and a lower conical surface arranged up and down;

[0029] A primary annular space and a secondary annular space are respectively formed between the upper conical surface and the inner conical surface and between the lower conical surface and the inner conical surface;

[0030] A blocking ring placed between the primary annular space and the secondary annular space is fixed in the middle of the inner conical surface; a shell-breaking needle located above the blocking ring and a shell-breaking rib located below the blocking ring are also fixed on the inner conical surface;

[0031] Therefore, leakage grooves are formed on the blocking ring;

[0032] A strip-shaped plate is fixed on the upper conical surface.

[0033] Furthermore, the leakage grooves are D-shaped grooves and are arranged on the inner side of the blocking ring.

[0034] Beneficial effects: In the high-quality nut shelling process and equipment of the present invention, by adding a grinding process before the soaking process and grinding the outer shell of the nuts with the grinding wheel of the peeling machine, the outer surface can be ground to expose the wood layer with lower density and poorer waterproofness. When the nuts are soaked subsequently, the soaking time can be greatly reduced and the shelling efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a process schematic diagram of a high-quality nut shelling process;

[0036] Figure 2 is a schematic diagram of the composition of high-quality nut shelling equipment;

[0037] Figure 3 is a structural diagram of the shelling equipment;

[0038] Figure 4 is a structural diagram of the stationary roller;

[0039] Figure 5 is a positional relationship diagram of the nut with the lower end placed in the leakage groove and the moving roller;

[0040] Figure 6 is a state diagram of the nut on the upper end surface of the blocking ring;

[0041] In the figures: A - grinding equipment; B - grooving equipment; C - soaking equipment; C1 - soaking pool; C2 - stirring device; D - low-temperature quick-freezing equipment; E - shelling equipment; a - primary annular space; a1 - first space; a2 - second space; b - secondary annular space; 1 - stationary roller; 11 - inner conical surface; 2 - moving roller; 21 - lower conical surface; 22 - upper conical surface; 3 - blocking ring; 31 - leakage groove; 4 - shell-breaking needle; 5 - shell-breaking rib; 6 - strip-shaped plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] The present invention will be further described below with reference to the accompanying drawings.

[0043] As Figure 1 shown in the high-quality nut shelling process, which includes the following steps carried out successively:

[0044] Step S1, grinding process: Grind the outer surface of the nut to expose the wood layer of the nut. Generally, the outer surface of the nut has a relatively high density and good water impermeability. After grinding off the outer surface to expose the wood layer, since the wood layer has a relatively soft texture and poor water impermeability, the water seepage efficiency of the subsequent soaking process can be greatly increased, and the shell can be fully soaked.

[0045] Step S2, grooving process: Grooves are made on the shell of the nut. After making grooves on the nut shell, the water immersion speed of the shell during subsequent soaking can also be increased at the groove positions. Therefore, it is more reasonable to set the grooving process before the soaking process. The advantage of setting the grooving process after the grinding process is that after the nut is ground, the exposed wood layer is relatively rough and soft, which is convenient for grooving, and the nut is not easy to slide open during grooving. In this embodiment, the grooving depth is 1 mm, and a groove with a preset depth is made in each of the length direction, width direction, and thickness direction of the nut. Here, the groove can be a closed circular groove or a non-closed arc groove, and the length direction, width direction, and thickness direction involved here are referenced with the coordinate system of the grooving device.

[0046] Step S3, soaking process: Soak the nuts in normal temperature water for 1 hour. The purpose of soaking is to supplement water to the shell, so that when subsequent quick-freezing is carried out, there is enough water to freeze and act on the internal fibers of the shell microscopically.

[0047] Step S4, low-temperature quick-freezing process: Place the soaked nuts in an environment of -45°C and quick-freeze them for 3 hours. When low-temperature quick-freezing the fully water-soaked nuts, since the volume of water increases during the freezing process, a tensile effect is exerted on the fibers inside the shell. Since the shell is relatively brittle and the fibers inside it have poor toughness, the fibers will break when stretched, causing fine cracks on the outer surface and inside of the shell, which can effectively change the mechanical properties of the nut shell and is more conducive to subsequent shelling. In addition, for nuts with the kernel tightly attached to the shell, due to the different shrinkage rates of the kernel and the shell during quick-freezing, the kernel can be separated from the shell, facilitating the subsequent dropping of the kernel from the shell during shelling.

[0048] Step S5, shelling process: Use a shelling device to shell the quick-frozen nuts. The nuts processed through the above low-temperature quick-freezing process immediately enter the shelling process. The shell in the frozen state is more brittle and easier to break and fall off. Moreover, for some nuts with a not-hard-enough shell, in the frozen state, its shell also becomes hard and brittle and can be shelled by the same shelling device.

[0049] Preferably, the shelling process described in step S5 is carried out in multiple stages, specifically including:

[0050] Step S5.1, perform multi-point impact on the nut shell; by performing multi-point impact on the shell, broken pits or cracks will be formed at or near the positions of the points on the shell that are impacted. Subsequently, the cracks can extend around these impacted points and cooperate with the grooves pre-opened on the shell, making it easy for the shell to decompose into small fragments.

[0051] Step S5.2, extrude the nuts after multi-point impact to cause at least part of the shell of the nuts to fall off;

[0052] Step S5.3, screen the nuts to screen out the nuts whose degree of shell shedding meets the preset conditions; here, the nuts are screened by setting screening elements and setting shaped holes on the screening elements, and the preset condition is that the nuts can pass through the above-mentioned shaped holes.

[0053] Step S5.4, knead and impact the screened nuts to extract the kernels.

[0054] The above steps S5.1 - S5.4 can effectively shell general nuts, and can also shell nuts with complex internal structures such as walnuts with high quality. Inside the walnut shell, in addition to the kernels, there are also gaps embedded in the kernels and diaphragms connecting the shell. The diaphragms will prevent the kernels from falling out of the damaged walnut shell. In the above step S5.1, first perform multi-point impact on the nut shell, and many broken pits or cracks can be formed around the shell. Under the extrusion effect in the subsequent step S5.2 and the kneading and impact effects in step S5.4, the broken pits or cracks on the shell will spread, causing the walnut shell to break into many fine fragments. The fragments will fall off one after another under the above extrusion, kneading, and impact effects, and some of the connections between the diaphragms and the shell will be disconnected, and some diaphragms will fall off with the fragments, thus effectively solving the problem of the diaphragm blocking the kernels. In addition, during the process of the above fragments falling off one after another, the fragments around the kernel fall randomly, and the fragments that have not fallen are still distributed around the kernel, playing a protective role for the kernel. In this way, the kernel can be protected to the greatest extent, the direct impact on the kernel during the shelling process can be reduced, and the whole kernel rate can be improved.

[0055] The present invention also provides a high-quality nut shelling equipment, as Figure 2 shown, which includes successively arranged:

[0056] Grinding equipment A, which is used to grind the outer surface of the nuts to expose the woody layer of the nuts; here, the grinding equipment is a peeling machine, and the outer shell of the nuts can be ground by the grinding wheel of the peeling machine.

[0057] Grooving equipment B, which is used to groove the outer surface of the nuts.

[0058] Soaking device C, which is used for soaking nuts; in this embodiment, the soaking device C is a soaking pool C1, and a stirring device C2 can be arranged in the soaking pool C1 to stir the nuts in the pool, so as to avoid uneven water immersion caused by the upper and lower backlogs of nuts in the same batch after entering the pool, and also increase the processing capacity of nuts that can be soaked at one time.

[0059] Low-temperature quick-freezing device D, which is used for low-temperature quick-freezing of the soaked nuts;

[0060] Shelling device E, which is used for shelling the nuts after quick-freezing treatment; the nuts quick-frozen by the above-mentioned low-temperature quick-freezing device D immediately enter the shelling device E for shelling. The shell in the frozen state is more brittle and easier to break and fall off. Moreover, for some nuts with a not-hard enough shell, in the frozen state, its shell also becomes hard and brittle and can be shelled by the same shelling device E.

[0061] The above-mentioned sequence of each device can be the actual position sequence or the arrangement sequence on the transfer route of the material. No matter which sequence, for the same batch of nut materials, the nut materials are processed by the above-mentioned devices in turn. The subsequent device receives the materials processed by the previous device and further processes them.

[0062] The grooves opened by the grooving device B are beneficial to breaking the nut shell into small pieces during the subsequent shelling process. The grooving device B is arranged before the soaking device C because the grooves can also increase the water penetration of the shell and accelerate the soaking speed of the shell.

[0063] The above-mentioned grooving device B is arranged between the grinding device A and the soaking device C. The shell of the nut polished by the grinding device A is easier to groove, and it is not easy to slip during the grooving process.

[0064] Preferably, as Figure 3 shown, the shelling device E includes a stationary roller 1 and a moving roller 2, and the moving roller 2 is rotatably installed in the stationary roller 1; the stationary roller 1 has an inner conical surface 11 that is wider at the top and narrower at the bottom; the moving roller 2 has an upper conical surface 22 and a lower conical surface 21 arranged up and down; a first-stage annular space a and a second-stage annular space b are respectively formed between the upper conical surface 22 and the lower conical surface 21 and the inner conical surface 11; as Figure 4 shown, a blocking ring 3 placed between the first-stage annular space and the second-stage annular space is fixed in the middle of the inner conical surface 11; a shell-breaking needle 4 located above the blocking ring 3 and a shell-breaking rib 5 located below the blocking ring 3 are also fixed on the inner conical surface 11. The shell-breaking rib 5 is strip-shaped and extends along the generatrix of the inner conical surface 11; so a leakage groove 31 is formed on the blocking ring 3; a strip-shaped plate 6 is fixed on the upper conical surface 22, and the strip-shaped plate 6 extends along the generatrix of the upper conical surface 22 (the generatrix is a straight line that extends along the surface of the upper conical surface 22 and intersects with the central axis of the upper conical surface 22).

[0065] The above leakage groove 31 is a D-shaped groove, which is arranged inside the blocking ring 3 and penetrates the inside of the blocking ring 3.

[0066] With the above structure, a four-stage structure configuration from top to bottom is formed between the static roller 1 and the moving roller 2, and the nuts can be processed in four stages. The first-stage annular space a is divided into a first space a1 and a second space a2 arranged vertically according to the distance between the strip plate 6 and the shell-breaking needle 4. The four-stage structure configuration and the corresponding processing stages are as follows:

[0067] The first space a1 where the first structure configuration is located is located above the first-stage annular space a. The first structure configuration includes the strip plate 6 and the shell-breaking needle 4 in the first space a1, and is used to complete the process of the above step S5.1. In the first space a1, when the edge of the strip plate 6 is aligned with the end of the shell-breaking needle 4, the distance ( Figure 3 d) in it is greater than the maximum diameter of the nut, that is, the strip plate 6 and the shell-breaking needle 4 cannot squeeze the nut. When the moving roller 2 rotates, the nuts in the first space a1 are knocked out by the strip plate 6 or thrown out by the centrifugal force. The nuts fly and hit the inner conical surface 11 or the shell-breaking needle 4, and the shell-breaking needle 4 plays a major role in the nuts. The shell-breaking needle 4 forms a point impact on the nut shell. Due to the high pressure, pits and cracks spreading from the pits will be formed at the impacted positions on the nut shell. When the moving roller 2 rotates, each nut in the first space a1 will be thrown out or knocked out multiple times. The nut will collide with the tip of the shell-breaking needle 4 many times. Due to the randomness of the collision, the impact positions are evenly distributed around the nut shell, that is, many pits and cracks will be evenly distributed on the nut shell. In the subsequent process, as the nut is further squeezed, rubbed, and impacted, the pits and cracks distributed around the shell will spread, making the shell covered with fine cracks, and the shell will break into many small pieces and gradually fall off.

[0068] The second space a2 where the second structural configuration is located is located at the lower side of the primary annular space a. The second structural configuration includes the strip plate 6 and the shell-breaking needle 4 in the first space a1, which are used to complete the process of the above-mentioned step S5.2. In the second space a2, when the edge of the strip plate 6 is aligned with the end of the shell-breaking needle 4, the distance between the two is less than the maximum diameter of the nut. In this way, the strip plate 6 and the shell-breaking needle 4 squeeze the nut. With the basis of the above-mentioned multi-point impact and groove, the strip plate 6 and the shell-breaking needle 4 cooperate to squeeze the nut, which can make the cracks formed by the multi-point impact on the shell of the nut spread, and make the shell break along the groove, so that at least part of the shell is decomposed into small fragments. In the process of the nut moving downward, since the distance between the strip plate 6 and the shell-breaking needle 4 becomes smaller and smaller, the squeezing force of the two on the nut becomes greater and greater, so that the nut is gradually broken, and some fragments will be peeled off from the nut. When the strip plate 6 and the shell-breaking needle 4 squeeze the nuts, since the shell-breaking needle 4 is thinner and shorter, the nuts will slip and bypass the shell-breaking needle 4 when squeezed to a certain extent, thereby avoiding excessive squeezing and injuring the kernels.

[0069] The third structural configuration is the above-mentioned blocking ring 3. The blocking ring 3 plays a screening role, blocking the complete nuts on its upper side, while at least half of the nuts that have fallen in pieces can enter the secondary annular space b through the leakage groove 31, that is, completing the process of the above-mentioned step S5.3. Since the leakage groove 31 is not a full circle and it penetrates the inner side of the blocking ring 3, if the nut fails to pass through the leakage groove 31 at one time, the lower side of the nut is trapped in the leakage groove 31, and the nut contacts the moving roller 2 (such as Figure 5 As shown in the figure, when the moving roller 2 rotates, it drives the nuts to adjust their posture, so that the nuts that meet the conditions can leak out after adjusting their posture, effectively improving the screening efficiency. The nuts whose lower ends have been placed in the leakage groove 31 but have not leaked out of the leakage groove 31 will be knocked out of the leakage groove 31 by the strip plate and continue to be shelled in the primary annular space a until the leakage conditions are met. Figure 6 As shown, at the upper end surface of the barrier ring 3, since the distance between the inner conical surface 11 and the upper conical surface 22 is small, only one circle of nuts can be arranged on the upper end surface of the barrier ring 3, and the arranged circle of nuts is divided into multiple pieces by the strip plate 6. The strip plate 6 pushes the circle of nuts to move, and the needle tip of the lowest shell breaking needle 4 on the inner conical surface 11 acts on the shell of the nut passing by to peel off the broken shell, but the length of the shell breaking needle 4 is moderate so that it will not hurt the kernel, so that a part of the broken shell can be quickly peeled off so that the nuts can leak out from the leakage groove 31.

[0070] The fourth structure is configured as the inner conical surface 11, the lower conical surface 21 and the shell-breaking ribs 5 within the above-mentioned secondary annular space b, and is used to complete the process of the above step S5.4. The cone angle of the inner conical surface 11 is greater than that of the lower conical surface 21. Therefore, an annular space that is wider at the top and narrower at the bottom is formed between the inner conical surface 11 and the lower conical surface 21. After the nut enters the annular space, it falls to a position with an appropriate width and is stuck. The interaction between the inner conical surface 11 and the lower conical surface 21 rubs it, causing the broken outer shells to disconnect from each other and fall off. In addition, the rotation of the moving roller 2 enables the nuts within the secondary annular space b to perform a circumferential movement relative to the static roller 1, causing the nuts to impact the shell-breaking ribs 3. The shell-breaking ribs 3 can effectively break the large pieces of the outer shell on the nuts, accelerating the extraction of the kernels. Preferably, there is a certain distance between the upper end of the shell-breaking rib 5 and the blocking ring 3, so that a rubbing section is formed at the upper end of the secondary annular space b. Nuts with less shell shedding can be fully rubbed in the rubbing section, causing the fruit shells to be fully broken and fall off one after another. Many kernels of the nuts can directly fall out at this stage. Nuts whose kernels do not fall out can continue to be shelled in the subsequent annular space with the shell-breaking ribs 5.

[0071] It can be seen that the innovation of the above-mentioned shelling device E lies in the setting and arrangement of the shelling elements. With the above structure, before the nuts enter the secondary annular space b, they have experienced multi-point impact and the extrusion of the strip plate 6 and the shell-breaking needles 4. Coupled with the grooves previously opened on the nut shells, the nut shells can be fully broken. Then, through rubbing and supplementary impact in the secondary annular space b, the above process can first break the outer shell of the nuts into small pieces and then gradually fall off, effectively ensuring the integrity of the kernels.

[0072] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A nut shelling equipment, which includes the following components arranged in sequence: Soaking equipment, which is used for soaking nuts; Low-temperature quick-freezing equipment, which is used for quickly freezing the soaked nuts at low temperature; Shelling equipment, which is used for shelling the nuts after being quick-frozen; It is characterized in that It also includes: Grinding equipment, which is placed before the soaking equipment and is used for grinding the outer surface of the nuts to expose the woody layer of the nuts; The shelling equipment includes a stationary roller and a rotating roller, and the rotating roller is rotatably installed inside the stationary roller; The stationary roller has an inner conical surface that is wider at the top and narrower at the bottom; The rotating roller has an upper conical surface and a lower conical surface arranged vertically; A first annular space and a second annular space are respectively formed between the upper conical surface and the lower conical surface and the inner conical surface; A blocking ring is fixed in the middle of the inner conical surface and is located between the first annular space and the second annular space; A shell-breaking needle is also fixed on the inner conical surface above the blocking ring, and a shell-breaking rib is fixed below the blocking ring; The shell-breaking rib is strip-shaped and extends along the generatrix of the inner conical surface; Leakage grooves are formed on the blocking ring; A strip-shaped plate is fixed on the upper conical surface; The strip-shaped plate extends along the generatrix of the upper conical surface; The cone angle of the inner conical surface is greater than the cone angle of the lower conical surface.

2. The nut shelling equipment according to claim 1, characterized in that, It also includes grooving equipment located before the soaking equipment. The grooving equipment is used for grooving the outer surface of the nuts; The grooving equipment is arranged before the soaking equipment and after the grinding equipment.

3. The nut shelling equipment according to claim 1, characterized in that, The leakage groove is a D-shaped groove and is arranged on the inner side of the blocking ring.

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