Dry-method corn flour making process

Abstract

The invention provides a dry-method corn flour making process. The dry-method corn flour making process comprises the following steps: sequentially carrying out rough grain cleaning, clean grain conditioning, slag breaking and separating, primary grading, primary winnowing, embryo selecting, peeling, secondary grading, secondary winnowing, color sorting, endosperm crushing, grinding and screening on raw corn grains to obtain standard corn flour; wherein the clean grain conditioning adopts a corn conditioning conveyor to construct a constant-temperature and constant-humidity closed environment for the clean grains to continuously pass through, and the clean grains form a conditioned corn material with a target water specific gravity after passing through the corn conditioning conveyor; a corn ballast breaking machine is adopted for ballast breaking and separation, the corn ballast breaking machine is provided with a pre-pressing cavity and a ballast breaking cavity which are communicated up and down, and the pre-pressing cavity is connected with a discharging port of the corn conditioning and conveying mechanism and used for fracturing the conditioned corn materials and enabling the fractured conditioned corn materials to fall into the ballast breaking cavity at a constant speed to be broken. The corn dry-method pulverizing process provided by the invention has the advantages of water saving, emission reduction and low energy consumption, and can improve the corn flour yield and reduce the fat content of corn flour.

Description

Technical Field

[0001] The invention belongs to the technical field of corn deep processing, and in particular relates to a corn dry milling process. Background Art

[0002] The existing common methods for processing and milling corn include the following: 1. Processing of whole corn kernels: After the corn is cleaned, it is directly processed into corn flour for consumption using a hammer mill or a grinding machine, which is often seen in rural areas. 2. Processing by grinding and peeling: After the corn is cleaned, it is first peeled by a sand roller peeling machine and then by an iron roller degerminator to finally obtain the endosperm. The endosperm is then purified and enters a crusher to make grits and extract powder. 3. Processing of corn grits and extracting germs: After the corn is cleaned, it enters a corn grits crusher after being moistened, and then a germ selection machine modified from a stone removal machine or a seed selection machine is used to extract the germ. The corn grits are then made into grits and flour. 4. Corn starch processing technology: The cleaning, soaking, crushing and separation processes are used to obtain separated clean corn germ, corn fiber, starch and corn protein.

[0003] The first three corn processing methods are all dry processing, especially the grinding and threshing process, which is the mainstream process of corn processing plants. Its disadvantages are low finished product yield (60~65%), high power consumption (electricity consumption per ton of corn is 90~110kw), especially the effect of corn germ and grit separation is poor, and it is difficult to obtain low-fat corn flour that meets the requirements; the fourth processing method belongs to wet processing technology, and its disadvantage is that a large amount of sewage is generated during the production process, which puts great pressure on environmental protection and high operating costs. It is bound to be gradually eliminated in the industry. Summary of the invention

[0004] The embodiment of the present invention provides a corn dry flour milling process, which aims to promote water saving, consumption reduction and emission reduction in the corn processing and flour milling process, improve the flour yield and reduce the fat content of corn flour.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a corn dry milling process, including: subjecting the corn raw grains to raw grain cleaning, clean grain conditioning, slag separation, primary classification, primary air separation, germ selection, peeling, secondary classification, secondary air separation, color selection, endosperm crushing, grinding, and screening to obtain standard corn flour; wherein, the clean grain conditioning adopts a corn conditioning conveyor to construct a closed environment with constant temperature and humidity for the clean grain to pass continuously, and the clean grain forms a tempered corn material with a target moisture content after passing through the corn conditioning conveyor; the slag separation adopts a corn slag crusher, and the corn slag crusher has a pre-compression chamber and a slag breaking chamber connected up and down, and the pre-compression chamber is connected to the discharge port of the corn conditioning conveyor mechanism, which is used to fracture the tempered corn material and make the fractured tempered corn material fall into the slag breaking chamber at a uniform speed for crushing.

[0006] In a possible implementation, the corn conditioning conveyor includes: The casing has a closed-air feeder on the top wall at one end and a closed-air discharger on the bottom wall at the other end; The stirring and conveying assembly is arranged in the casing, and has a high-speed stirring section and a low-speed conditioning section. The high-speed stirring section is close to the closed-air feeder and is used to continuously stir and convey the clean grain fed by the closed-air feeder. The low-speed conditioning section is connected to the high-speed stirring section and is used to continuously stir and convey the clean grain to the closed-air discharger. The time for the clean grain to pass through the low-speed conditioning section is controlled to be 12~30min; The steam pipe group is connected to the casing and used to pass water vapor to the high-speed stirring section. The amount of water vapor introduced is related to the feeding amount of the closed air feeder to control the clean grain temperature at 45~70℃; The water injection pipe group is connected to the casing and is used to inject clean water at room temperature into the high-speed stirring section. The injection amount of clean water at room temperature is related to the feeding amount of the closed-air feeder to control the wetting degree of the clean grain, thereby controlling the moisture content of the tempered corn material at 17~19%.

[0007] In some embodiments, a casing is provided with a drain valve at the bottom of one end of a closed air discharger; the top wall of the casing has an air layer, the bottom surface of the air layer has an air hole array connected to the inner cavity of the casing, and a steam hood is provided above the air hole array, the steam hood is located directly above the high-speed stirring section and is connected to the steam pipe group; a spray pipe is provided in the casing, the spray pipe is located on the side of the steam hood away from the low-speed tempering section and is connected to the water injection pipe group.

[0008] Exemplarily, the stirring and conveying assembly includes a first rotating shaft and a second rotating shaft, each of which is configured with an independent driving unit; the first rotating shaft and the second rotating shaft are connected to each other and rotated together, and the ends of the two rotating shafts that are far away from each other are respectively rotatably connected to the end walls of the casing; wherein, a plurality of stirring blades are spirally distributed on the first rotating shaft to form a high-speed stirring section; a plurality of feeding blades and a plurality of stirring fins are spirally distributed on the second rotating shaft to form a low-speed tempering section, and the feeding blades are distributed between the stirring blades and the stirring fins.

[0009] For example, the stirring blade is provided with a first connecting rod, which passes through the first rotating shaft along the radial direction of the first rotating shaft to form a rotational fit; the feeding blade and the stirring wing are both provided with a second connecting rod, which passes through the second rotating shaft along the radial direction of the second rotating shaft to form a rotational fit; wherein the first connecting rod and the second connecting rod are both screwed with locking parts for locking their respective rotation angles.

[0010] In a possible implementation, two grinding rollers are arranged horizontally in pairs in the pre-pressing chamber, with a grinding gap between the two grinding rollers; a slag breaking roller is provided in the slag breaking chamber; the slag breaking roller and the grinding roller are respectively provided with independent power units; wherein the two grinding rollers rotate synchronously in opposite directions at a linear speed of 0.5-2 m / s and form a flexible grinding pressure, and the flexible grinding pressure is used to fracture the tempered corn material falling into the grinding gap; the slag breaking roller crushes the endosperm of the fractured tempered corn material at a rotational linear speed of 13-19 m / s to allow the corn embryo to fall off completely.

[0011] In some embodiments, pressure-adjusting and distance-adjusting mechanisms are provided at both ends of the frame of the corn crusher, and both ends of the two material-grinding rollers are rotatably connected to the pressure-adjusting and distance-adjusting mechanisms; wherein the pressure-adjusting and distance-adjusting mechanisms are used to form a material-grinding gap and a flexible material-grinding pressure between the two material-grinding rollers, and to adjust the material-grinding gap and the flexible material-grinding pressure.

[0012] Exemplarily, the pressure and distance adjusting mechanism includes a base for fixedly connecting to a frame, a first axle seat fixedly connected to the base, a second axle seat hinged at the bottom to the base, and a traction assembly connected to the tops of the first axle seat and the second axle seat; wherein the first axle seat and the second axle seat are respectively used to connect two material-grinding rollers, and an elastic pushing member is arranged between the first axle seat and the second axle seat to form a material-grinding gap between the two material-grinding rollers; the traction assembly is used to apply an elastic tensioning force to the first axle seat and the second axle seat to form a flexible grinding force between the two material-grinding rollers.

[0013] For example, the traction assembly includes a distance-adjusting rod and a spring-loaded head; wherein, the elastic force of the spring-loaded head is adjustable, one end of the distance-adjusting rod passes through the first axle seat and is threadedly connected to the distance-adjusting lock nut, and the other end of the distance-adjusting rod passes through the second axle seat and is threadedly engaged with the spring-loaded head.

[0014] In some embodiments, the spring head includes: A sleeve head is slidably sleeved on the distance adjusting rod and abuts against a side of the second shaft seat away from the first shaft seat, and a threaded sleeve is arranged inside the sleeve head; The pressure regulating rod has a stop step at one end, and the other end is inserted into the sleeve and threadedly matched with the screw sleeve. The end of the pressure regulating rod inserted into the screw sleeve has an internal threaded hole, which is threadedly connected with the distance adjusting rod, and the pitch of the internal threaded hole is equal to the pitch of the screw sleeve; The disc spring is sleeved on the pressure regulating rod and located between the stop step and the sleeve head, and is used to enable the distance regulating rod to obtain elastic tensioning force.

[0015] The beneficial effects of the corn dry milling process provided by the present invention are as follows: compared with the prior art, the corn dry milling process of the present invention can reduce water consumption and sewage discharge by adopting dry milling, and at the same time, a clean grain conditioning process is arranged before slag breaking and separation, which can greatly reduce the power consumption of slag breaking and separation, and promote energy saving in production; the corn conditioning conveyor adopted for the clean grain conditioning can construct a closed environment of constant temperature and humidity, so that the clean grain can be conditioned during the transportation process to obtain the target water content, and can make the corn embryo absorb water to fill and toughen while avoiding the softening of the endosperm due to water absorption, thereby forming a tempered corn material with high-toughness corn embryo and dry and hard endosperm, and on this basis, the corn conditioning conveyor can directly and continuously feed the tempered corn material into the corn slag crusher, by This can prevent the endosperm of the tempered corn material from absorbing water and softening during the transportation and unloading process; after the tempered corn material enters the corn slag crusher, it is first pre-pressed in the pre-pressing chamber to fracture the dry and hard endosperm part, and then falls into the slag crushing chamber at a uniform speed from the pre-pressing chamber, where the fractured dry and hard endosperm is crushed, so that the toughened corn embryo can be completely fallen off. Since the tempered corn material is pre-cracked before slag breaking, not only the uniformity of endosperm crushing can be improved, but also the force of the crushing chamber on the tempered corn material can be reduced, thereby improving the shedding integrity of the corn embryo, and then reducing the difficulty of separating the corn embryo and endosperm, and improving the endosperm purification rate, thereby reducing the fat content of the final standard corn flour and improving the flour yield of the standard corn flour. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flowchart of a corn dry milling process provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the corn conditioning conveyor used in the embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the corn conditioning conveyor used in an embodiment of the present invention; Figure 4 A schematic cross-sectional view of a corn slag crusher used in an embodiment of the present invention; Figure 5 It is a front view schematic diagram of the pressure and distance regulating mechanism of the corn slag crusher adopted in the embodiment of the present invention; Figure 6 For along Figure 5 Schematic diagram of the cross-sectional structure along line AA.

[0017] In the figure: 10, corn conditioning conveyor; 11, housing; 111, air-tight feeder; 112, air-tight discharger; 113, drain valve; 114, air interlayer; 1141, air hole array; 1142, steam cover; 115, spray pipe; 12, stirring and conveying assembly; 1201, high-speed stirring section; 1202, low-speed conditioning section; 121, first rotating shaft; 1211, stirring blade; 1212, first connecting rod; 122, second rotating shaft; 1221, feeding blade; 1222, stirring fin; 1223 , second connecting rod; 13, steam pipe group; 14, water injection pipe group; 20, corn slag crusher; 21, pre-pressure chamber; 211, grinding roller; 22, slag crushing chamber; 221, slag crushing roller; 23, pressure and distance adjustment mechanism; 231, base; 232, first axle seat; 233, second axle seat; 234, traction assembly; 2341, distance adjustment rod; 2342, spring pressure head; 2343, distance adjustment lock nut; 2344, sleeve; 2345, screw sleeve; 2346, pressure regulating rod; 2347, disc spring; 235, elastic push piece. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be noted that when an element is referred to as being "disposed on" or "connected to" another element, it may be directly on the other element or indirectly on the other element. It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meanings of "multiple" and "several" are two or more, unless otherwise clearly and specifically defined.

[0020] Please also read Figures 1 to 6, the corn dry milling process provided by the present invention is now described. The corn dry milling process comprises: subjecting the raw corn to raw grain cleaning, clean grain conditioning, slag separation, primary classification, primary air separation, germ selection, peeling, secondary classification, secondary air separation, color selection, endosperm crushing, grinding, and screening to obtain standard corn flour; wherein, the clean grain conditioning adopts a corn conditioning conveyor 10 to construct a closed environment with constant temperature and humidity for the clean grain to pass continuously, and the clean grain forms a tempered corn material with a target moisture content after passing through the corn conditioning conveyor 10; the slag separation adopts a corn slag crusher 20, and the corn slag crusher 20 has a pre-compression chamber 21 and a slag breaking chamber 22 connected up and down, and the pre-compression chamber 21 is connected to the discharge port of the corn conditioning conveyor 10, which is used to fracture the tempered corn material and make the fractured tempered corn material fall into the slag breaking chamber 22 at a uniform speed for crushing.

[0021] Here we explain each of the above steps one by one: Raw grain cleaning: The raw corn grains are sequentially passed through a vibrating screen, an air suction duct, a suction stone remover, a gravity grading stone remover, a corn color sorter, and a flat rotary screen to obtain clean grains; among them, the vibrating screen is used to remove large and small impurities; the air suction duct is used to remove light impurities; the two stone removers are used to remove side stones (and the gravity grading stone remover can remove corn cobs); the color sorter can remove moldy grains and other colored impurities to reduce the toxin content of corn; the flat rotary screen is used to grade corn to make the particle size of the clean grain uniform. When the particle size difference is large, the small-particle clean grain and the large-particle clean grain will enter the clean grain conditioning and slag breaking and separation processes respectively after grading. After the slag breaking and separation is completed, the subsequent processes can be carried out simultaneously.

[0022] Clean grain conditioning: A corn conditioning conveyor 10 is used to work in conjunction with a corn crusher 20. The clean grain is continuously and evenly fed into the high-speed stirring section 1201 through a closed-air feeder 111. At the same time, clean water and water vapor are injected into the high-speed stirring section 1201 according to the clean grain feeding speed. The clean grain, clean water and water vapor are evenly mixed through high-speed stirring. The introduction of water vapor is used to control the temperature of the clean grain to keep the clean grain in a constant temperature environment. At the same time, the introduction amount of clean water is related to the feeding speed of the closed-air feeder 111, that is, when the feeding speed increases, the injection amount of clean water should increase accordingly, and vice versa, the injection amount of clean water should decrease accordingly, thereby ensuring that the wetness of the clean grain is always in a stable range. Of course, the change in the introduction amount of water vapor also has a certain influence on the humidity of the clean grain, but it is very small and can be ignored here; in the high-speed stirring section 12 01 The evenly moistened clean grain enters the low-speed conditioning section 1202, which has both low-speed stirring and conveying functions. The function of low-speed stirring is to maintain the uniformity of wetting of the clean grain, thereby improving the uniformity of water absorption of the corn kernels, and the purpose of conveying is to ensure the accuracy of the conditioning time. The moistened clean grain can be directly conveyed to the corn crusher 20 within the required time, thereby eliminating the transit transportation step. The purpose of doing so is, on the one hand, that the corn embryo absorbs water before the endosperm, so it is necessary to ensure the accuracy of the conditioning time. Within the target time, the corn kernels can reach the state where the corn embryo is full of water and toughness, while the endosperm is still in a dry and hardened state. If there is a transit transportation process, the endosperm will absorb the moisture of the corn embryo, causing the corn embryo to dehydrate and shrink, and the endosperm to absorb water and soften, thereby affecting the subsequent crushing effect.

[0023] Crushing and separation: Separating the corn from the quenched corn material when the corn embryo absorbs water and is tough, and the endosperm remains dry and hard. The pre-pressing chamber 21 directly receives the quenched corn material from the corn quenching conveyor 10, and then pre-presses the quenched corn material. By controlling the pre-pressing force, the hard endosperm is cracked and the corn embryo remains intact. After pre-pressing, the corn enters the crushing chamber 22, and the cracked endosperm can be broken into petals by a small external force. At the same time, the corn embryo falls off completely from the broken endosperm, and then the petal-shaped endosperm and the intact corn embryo are separated. They are separated by a special corn separator. Due to the pre-fracturing, the proportion of whole uncrushed corn particles after crushing can be less than 0.5%. At the same time, after pre-fracturing, the force of the crushing chamber 22 on the corn particles can be reduced, so that the powder produced by crushing is less than 10%, while ensuring the integrity of the corn embryo. The above process can avoid the situation that the corn embryo cannot be completely separated from the endosperm after being crushed, thereby improving the purity of the endosperm, which is also the key to reducing the fat content of the final standard corn flour.

[0024] Initial classification: materials above 5880 microns (4 mesh) are returned to the corn slag crusher 20; materials between 3630 microns (6 mesh) and 5880 microns (4 mesh) are sent to the embryo selection machine; materials between 2160 microns (10 mesh) and 3630 microns (6 mesh) are selected by wind and sent to the first embryo mill; materials between 930 microns and 2160 microns are selected by wind and sent to the embryo mill; materials between 110 microns and 930 microns are sent to the second embryo mill; materials below 110 microns are standard corn flour.

[0025] Primary air separation: Separate corn fiber from heavy materials by taking advantage of the different specific gravities of the materials.

[0026] Germ selection: The materials with the size of 3630 microns (6 mesh) to 5880 microns (4 mesh) are mainly divided into two types: endosperm, germ, a small amount of corn fiber, and the adhesion of germ and endosperm. Based on the different specific gravity of germ and endosperm, the materials are divided into four categories in the germ selection machine: pure endosperm, germ-grist mixture (high specific gravity of corn germ), grist-germ mixture (high specific gravity of corn grist), and germ; among them, pure endosperm directly enters the crusher.

[0027] Dehulling: For the germ-grist mixture, grist-germ mixture, and germ sorted by the germ selector, a dehulling machine is used to separate the adhered corn fiber from the material.

[0028] Secondary classification: After dehulling, the germ-grist mixture, grist-germ mixture, and germ enter the grading screen to separate the materials broken during the dehulling process. The broken materials enter the first germ press mill. The dehulled and classified materials undergo secondary air separation to remove the corn fiber.

[0029] Color sorting: After peeling, secondary classification and secondary air separation, the germ-grass mixture, the grain-germ mixture and the germ enter the color sorter to separate the endosperm and germ. Among them, the endosperm enters the crusher, the germ is put into the warehouse for packaging, and the mixture that cannot be separated enters the first germ pressing mill.

[0030] Crushing: In order to facilitate the feeding of the mill and improve the efficiency of the mill, the pure endosperm is designed to be crushed before grinding to make the material smaller and produce part of the standard corn flour.

[0031] Grinding: Different materials enter the corresponding grinding system according to their properties, state and quality. Pure endosperm needs to be ground continuously for multiple times and enter the grading screen for grading after each grinding. Endosperm containing germ uses different grinding systems according to the particle size of the material and the amount of germ contained.

[0032] Screening: The ground materials enter the screening system; among them, qualified standard corn flour enters the collection system, and unqualified materials enter the next grinding system; in this process, the corresponding grading screen can be designed according to the requirements of standard corn flour to separate the materials containing skin and germ, and reduce the fat content and fiber content in the standard corn flour.

[0033] Through the above process, the final standard corn flour yield is: 76~79% dry basis; fat content ≤0.9% dry basis; germ yield: 7.5~9% dry basis; corn fiber yield: 2~5% dry basis; corn feed yield: 7~14.5% dry basis; the above standard corn flour can be used directly to produce syrup, and can also be used in corn processing plants to produce corn grits and corn flour, or used in other corn deep processing industries, such as alcohol plants.

[0034] From the perspective of water conservation, consumption reduction and emission reduction, the process is compared with the current starch factory process as follows: A 100,000-ton wet starch plant produces corn flour by wet method, consuming 160,000 tons of corn per year, processing about 480-500 tons of corn per day, with a total investment of about 60 million yuan. It uses 5 tons of water per ton of starch, consumes 150 degrees of electricity, and consumes 4.5 million tons of water per year. Every day, more than 1,000 tons of wastewater with a COD value of 3,000 mg / L need to be treated. The wastewater treatment device has an investment of 20 million yuan to achieve the standard discharge of COD value below 100 mmg / L. The operating fee is 4-6 yuan per ton, a total of 5,000 yuan per day, and an annual expenditure of 1.65 million yuan. There are also about 300 tons of corn soaking water with a concentration of 9-10% per day with no outlet. Each ton of starch uses 2.1 tons of water vapor, which is equivalent to 0.284 tons of standard coal consumption. One ton of coal burns about 2.7 tons of carbon dioxide. The production of one ton of starch will emit 0.77 tons of carbon dioxide, and 77,000 tons of carbon dioxide will be emitted throughout the year.

[0035] The corn dry milling process provided in this embodiment is used to produce 100,000 tons of standard corn flour, with a total production investment of 15 to 20 million yuan. Each ton of standard corn flour uses 80 kg of water, consumes about 90 degrees of electricity, consumes about 60 kg of water vapor, and consumes about 8,000 tons of water per year, and no sewage is generated. It can be seen that from the perspective of using standard corn flour to produce starch sugar, the corn dry milling process provided in this embodiment can greatly reduce investment and save energy and water resources, reduce carbon dioxide emissions, and eliminate a large number of liquid pollution sources caused by wet production, which is of great significance to reducing costs and improving benefits in starch sugar production.

[0036] The corn dry milling process provided in this embodiment, compared with the prior art, can reduce water consumption and sewage discharge by adopting dry milling. At the same time, a clean grain conditioning process is set before slag separation, which can greatly reduce the power consumption of slag separation and promote energy saving in production. The corn conditioning conveyor 10 used for the clean grain conditioning can construct a closed environment with constant temperature and humidity, so that the clean grain can be conditioned during the transportation process to obtain the target moisture content, and can make the corn embryo absorb water to fill and toughen while avoiding the endosperm absorbing water and softening, thereby forming a tempered corn material with high-toughness corn embryo and dry and hard endosperm. On this basis, the corn conditioning conveyor 10 can directly and continuously feed the tempered corn material into the corn slag crusher 20, thereby avoiding the transfer and unloading process. The endosperm of the tempered corn material absorbs water and softens; after the tempered corn material enters the corn slag crusher 20, it is first pre-pressed in the pre-pressing chamber 21 to fracture the dry and hard endosperm part, and then falls into the slag crushing chamber 22 at a uniform speed from the pre-pressing chamber 21, and the fractured dry and hard endosperm is crushed in the slag crushing chamber 22, so that the toughened corn embryo is completely fallen off. Since the tempered corn material is pre-cracked before slag breaking, not only the uniformity of endosperm crushing can be improved, but also the force of the crushing chamber on the tempered corn material can be reduced, thereby improving the shedding integrity of the corn embryo, and then reducing the difficulty of separating the corn embryo and endosperm, and improving the endosperm purification rate, thereby reducing the fat content of the final standard corn flour and improving the flour yield of the standard corn flour.

[0037] In some embodiments, see Figure 2 and Figure 3 The corn conditioning conveyor 10 includes a casing 11, a stirring and conveying assembly 12, a steam pipe group 13 and a water injection pipe group 14; a closed-air feeder 111 is provided on the top wall of one end of the casing 11, and a closed-air discharger 112 is provided on the bottom wall of the other end; the stirring and conveying assembly 12 is arranged in the casing 11, and has a high-speed stirring section 1201 and a low-speed conditioning section 1202, the high-speed stirring section 1201 is close to the closed-air feeder 111 and is used for continuously stirring and conveying the clean grain fed by the closed-air feeder 111, the low-speed conditioning section 1202 is connected to the high-speed stirring section 1201 and is used to continuously stir and convey the clean grain to the closed-air discharger 112, and the clean grain passes through the low-speed conditioning section 1 The duration of 202 is controlled at 12~30min; the steam pipe group 13 is connected to the casing 11 and is used to pass water vapor into the high-speed stirring section 1201, and the amount of water vapor introduced is related to the feeding amount of the air-tight feeder 111 (the amount of water vapor introduced is 0.8~1.1% of the specific gravity of the clean grain feeding amount, preferably 1% specific gravity) to control the clean grain temperature at 45~70℃; the water injection pipe group 14 is connected to the casing 11 and is used to inject normal temperature clean water into the high-speed stirring section 1201, and the injection amount of normal temperature clean water is related to the feeding amount of the air-tight feeder 111 to control the wetting degree of the clean grain, thereby controlling the water content of the tempered corn material at 17~19%.

[0038] The casing 11 is provided with an airtight feeder 111 and an airtight discharger 112 to form a closed environment inside, which is conducive to ensuring the stability of the internal temperature and humidity. Water is injected into the high-speed stirring section 1201 through the water injection pipe group 14, and then the high-speed stirring section 1201 is used to stir the clean grain to make the clean grain uniformly moistened. At the same time, water vapor is introduced into the high-speed stirring section 1201 through the steam pipe group 13, and the water vapor is mixed with the moistened clean grain to keep the clean grain temperature in the range of 45-70°C. On this basis, it enters the low-speed tempering section 1202, and the rotation speed of the low-speed tempering section 1202 is adjusted to control the time length of the clean grain passing through the low-speed tempering section 1202, thereby making the tempering time of the clean grain more accurate, and the low-speed tempering section 1202 can be used to moisten the clean grain. It has a stirring effect, so as to avoid that the clean grain can always maintain a uniform wetting degree during the process of passing through the low-speed conditioning section 1202. Specifically, in this embodiment, the time for the clean grain to pass through the low-speed conditioning section 1202 can be controlled to be 12-30 minutes according to actual conditions. At this time, the corn embryo is full of water and has toughness, and the endosperm is still in a dry and hard state, and the tempered corn material in this state can directly enter the corn slag crusher 20, thereby accurately controlling the clean grain conditioning time, and avoiding the situation that the water of the tempered corn kernels is lost from the corn embryo to the endosperm before the slag is broken and separated, which causes the endosperm to soften and affects the slag breaking effect.

[0039] In some embodiments, see Figure 3 The casing 11 is provided with a closed air discharge device 112, and a drain valve 113 is provided at the bottom of one end thereof; the top wall of the casing 11 is provided with an air interlayer 114, and the bottom surface of the air interlayer 114 is provided with an air hole array 1141 which is connected to the inner cavity of the casing 11, and a steam cover 1142 is provided above the air hole array 1141, and the steam cover 1142 is located directly above the high-speed stirring section 1201 and is connected to the steam pipe group 13; a spray pipe 115 is provided in the casing 11, and the spray pipe 115 is located on the side of the steam cover 1142 away from the low-speed tempering section 1202 and is connected to the water injection pipe group 14.

[0040] The purpose of setting the air hole array 1141 and the spray pipe 115 is to ensure that water vapor and clean water can evenly contact the clean grain, so as to improve the wetting uniformity and temperature balance of the clean grain under the action of high-speed stirring; specifically, clean water is sprayed downward through the spray pipe 115 at the top of the casing 11 to fully mix the clean water with the clean grain entering the high-speed stirring section 1201. At the same time, in order to avoid water stagnation at the bottom of the casing 11 which may cause the endosperm of some clean grain to be soaked and softened, a drain valve 113 is arranged at the bottom of the high-speed stirring section 1201 to drain water outward at a regular time. The position setting of the spray pipe 115 and the steam hood 1142 allows the clean grain to be mixed with clean water first and then with water vapor, thereby preventing the clean grain from being burned by high-temperature water vapor. In other words, the clean grain is first wetted with clean water and then with water vapor, and the temperature of the clean grain is evenly increased to 45-70°C by using water vapor during the stirring process.

[0041] As a specific embodiment of the stirring and conveying assembly 12, please refer to Figure 3 The stirring and conveying assembly 12 includes a first rotating shaft 121 and a second rotating shaft 122, each of which is equipped with an independent driving unit; the first rotating shaft 121 and the second rotating shaft 122 are connected to each other and rotated together, and the ends of the two shafts that are far away from each other are respectively rotatably connected to the end walls of the casing 11 at both ends; wherein, a plurality of stirring blades 1211 are spirally distributed on the first rotating shaft 121 to form a high-speed stirring section 1201; a plurality of feeding blades 1221 and a plurality of stirring fins 1222 are spirally distributed on the second rotating shaft 122 to form a low-speed tempering section 1202, and the feeding blades 1221 are distributed between the stirring blades 1211 and the stirring fins 1222.

[0042] The rotation speeds of the first rotating shaft 121 and the second rotating shaft 122 can be independently regulated, so that the high-speed stirring section 1201 can be used to fully and evenly mix the clean grains with the clean water and water vapor and then enter the low-speed conditioning section 1202, and the time for the clean grains to pass through the low-speed conditioning section 1202 can be controlled by controlling the speed of the second rotating shaft 122; on this basis, the stirring blades 1211 on the first rotating shaft 121 stir the clean grains, and the spiral distribution method can make the clean grains move in the spiral direction before the low-speed conditioning section 1202 during the stirring process; in order to avoid Driven by the stirring fins 1222, the clean grain moves too fast towards the air-locking discharger 112, which affects the conditioning time. Therefore, the surface area of ​​the stirring fins 1222 is made as small as possible. At the same time, in order to ensure that the material in the high-speed stirring section 1201 can be smoothly transferred to the low-speed conditioning section 1202, a plurality of feeding blades 1221 are arranged between the stirring fins 1222 and the stirring blades 1211. The feeding blades 1221 are used to smoothly push the evenly moistened clean grain to the stirring fins 1222, thereby avoiding blockage of the clean grain between the high-speed stirring section 1201 and the low-speed conditioning section 1202.

[0043] Specifically, in this embodiment, please refer to Figure 3 The stirring blade 1211 is provided with a first connecting rod 1212, and the first connecting rod 1212 passes through the first rotating shaft 121 along the radial direction of the first rotating shaft 121 to form a rotational fit; the feeding blade 1221 and the stirring wing 1222 are both provided with a second connecting rod 1223, and the second connecting rod 1223 passes through the second rotating shaft 122 along the radial direction of the second rotating shaft 122 to form a rotational fit; wherein the first connecting rod 1212 and the second connecting rod 1223 are both screwed with locking members for locking their respective rotation angles.

[0044] The stirring blade 1211 can achieve angle adjustment through the cooperation of the first connecting rod 1212 and the first rotating shaft 121. After adjustment, it is locked by a locking member such as a nut. Similarly, the feeding blade 1221 and the stirring fin 1222 can be adjusted in angle by rotating the second connecting rod 1223, thereby achieving the adjustment of the clean grain conveying speed of the high-speed stirring section 1201 and the low-speed tempering section 1202 without changing the rotation speed.

[0045] As a specific embodiment of the corn crusher 20, please refer to Figures 4 to 6 Two material-grinding rollers 211 are arranged horizontally in pairs in the pre-pressing chamber 21, and a material-grinding gap is provided between the two material-grinding rollers 211; a material-grinding roller 221 is provided in the slag-breaking chamber 22; the slag-breaking roller 221 and the material-grinding roller 211 are respectively provided with their own independent power units; wherein, the two material-grinding rollers 211 rotate synchronously in opposite directions at a linear speed of 0.5-2 m / s and form a flexible grinding pressure, and the flexible grinding pressure is used to fracture the tempered corn material falling into the material-grinding gap; the slag-breaking roller 221 crushes the endosperm of the fractured tempered corn material at a rotational linear speed of 13-19 m / s to make the corn embryo fall off completely.

[0046] After the quenched corn material enters the pre-pressing chamber 21, it falls into the gap between two synchronously counter-rotating grinding rollers 211 to form a grinding gap. In the process of passing through the grinding gap, the endosperm is fractured by the two grinding rollers 211 and falls into the slag breaking chamber 22. The slag breaking roller 221 rotates and hits the corn grains with the fractured endosperm, so that the endosperm is broken into petals and the corn embryo falls off completely from the endosperm. The pre-pressing can make the slag breaking roller 221 rotate at a rotational linear speed of 13-19 m / s, which is lower than the normal rotation speed, to break the endosperm into petals. In addition, since the endosperm is still in The corn kernels are in a dry and hard state, thus improving the uniformity of the endosperm being crushed into petals after pre-compression; the low speed can also reduce the force of the crushing roller 221 on the corn embryo, and the corn embryo is in a tough and impact-resistant state at this time, thus improving the integrity rate of the corn embryo, and facilitating the subsequent separation of the corn embryo from the endosperm, thereby improving the flour yield and reducing the fat content of the standard corn flour; in addition, the tempered corn kernels pass through the grinding gap and fall into the crushing chamber 22 at a continuous and uniform speed, thereby avoiding frequent changes in the amount of material in the crushing chamber 22 and affecting the crushing uniformity.

[0047] On the basis of the above, the force between the two grinding rollers 211 is a flexible grinding force, thereby ensuring that the tempered corn material with different particle sizes (the raw grain cleaning is followed by corn grading, but the grading is interval grading, so there are still certain particle size differences between the tempered corn materials entering at the same time) can basically squeeze the endosperm part of corn grains of different sizes and break them after entering the grinding gap, while preventing the grinding roller 211 from grinding the corn grains too hard and causing the corn embryo to break.

[0048] For some possible implementations, see Figures 4 to 6 Both ends of the frame of the corn crusher 20 are provided with pressure-adjusting and distance-adjusting mechanisms 23, and both ends of the two material-grinding rollers 211 are rotatably connected to the pressure-adjusting and distance-adjusting mechanisms 23; wherein, the pressure-adjusting and distance-adjusting mechanisms 23 are used to form a material-grinding gap and a flexible material-grinding pressure between the two material-grinding rollers 211, and to adjust the material-grinding gap and the flexible material-grinding pressure.

[0049] The same ends of the two grinding rollers 211 are connected by a set of pressure-adjusting and distance-adjusting mechanisms 23. By adjusting the grinding gap and the flexible grinding force, it is possible to avoid the situation where the grinding rollers 211 excessively squeeze the tempered corn material, causing damage to the corn embryo and breakage, or the grinding rollers 211 squeeze the tempered corn material too little, resulting in the inability to crush corn kernels with smaller particle sizes, thereby improving the corn kernel crushing effect and the crushing adaptability to corn kernels with different particle sizes.

[0050] In addition, pressure-adjusting and distance-adjusting mechanisms 23 are respectively provided at both ends of the grinding roller 211, which can enable the two ends of the grinding gap to expand or contract independently based on the flexible grinding force, so that corn particles with different particle sizes at different positions entering the grinding gap can all be crushed, thereby improving the fracturing rate of the tempered corn material, and further improving the slag breaking uniformity and germ removal rate of the tempered corn material.

[0051] In some embodiments, the voltage and distance regulating mechanism 23 is as follows: Figure 5 The structure shown includes a base 231 for fixedly connecting to a frame, a first axle seat 232 fixedly connected to the base 231, a second axle seat 233 hinged at the bottom to the base 231, and a traction assembly 234 connected to the top of the first axle seat 232 and the second axle seat 233; wherein the first axle seat 232 and the second axle seat 233 are respectively used to connect two material-grinding rollers 211, and an elastic pushing member 235 is arranged between the first axle seat 232 and the second axle seat 233 to form a material-grinding gap between the two material-grinding rollers 211; the traction assembly 234 is used to apply an elastic tensioning force to the first axle seat 232 and the second axle seat 233 to form a flexible grinding force between the two material-grinding rollers 211.

[0052] The bottom of the second axle seat 233 is hinged to the base 231, and the top is connected to the first axle seat 232 through a traction assembly 234. An elastic jacking force is applied between the first axle seat 232 and the second axle seat 233 through an elastic jacking member 235 such as a spring, thereby reducing the movement resistance of the second axle seat 233 to the greatest extent, thereby improving the response sensitivity of the second axle seat 233 to force, and then enabling the grinding gap to change sensitively according to the difference in corn particle size, thereby improving the fracturing rate of tempered corn material; the size of the grinding gap can be adjusted by adjusting the distance between the traction assembly 234 acting on the first axle seat 232 and the second axle seat 233, and the flexible grinding force can be adjusted by adjusting the elastic tension force of the traction assembly 234 itself. The structure is simple and compact, and the adjustment is convenient.

[0053] Alternatively, if Figure 5 and Figure 6 As shown, the traction assembly 234 used in this embodiment includes a distance-adjusting rod 2341 and a spring-pressing head 2342; wherein, the elastic force of the spring-pressing head 2342 is adjustable, one end of the distance-adjusting rod 2341 passes through the first axle seat 232 and is threadedly connected to the distance-adjusting lock nut 2343, and the other end of the distance-adjusting rod 2341 passes through the second axle seat 233 and is threadedly engaged with the spring-pressing head 2342.

[0054] By rotating the distance adjustment lock nut 2343, the effective length of the distance adjustment rod 2341 acting on the first shaft seat 232 and the second shaft seat 233 can be changed, thereby adjusting the size of the grinding gap. By adjusting the elastic force of the spring-pressing head 2342, the elastic tension force can be changed, thereby adjusting the flexible grinding force. The adjustment method is simple and the overall structure is stable.

[0055] For an example, see Figure 6 The above-mentioned spring head 2342 includes a sleeve 2344, a pressure regulating rod 2346 and a disc spring 2347; wherein the sleeve 2344 is slidably sleeved on the distance adjusting rod 2341 and abuts against the side of the second shaft seat 233 away from the first shaft seat 232, and a threaded sleeve 2345 is arranged in the sleeve 2344; one end of the pressure regulating rod 2346 is provided with a stop step, and the other end is inserted into the sleeve 2344 and threadedly matched with the threaded sleeve 2345, and one end of the pressure regulating rod 2346 inserted into the threaded sleeve 2345 has an internal threaded hole, the internal threaded hole is threadedly connected to the distance adjusting rod 2341, and the pitch of the internal threaded hole is equal to the pitch of the threaded sleeve 2345; the disc spring 2347 is sleeved on the pressure regulating rod 2346 and is located between the stop step and the sleeve 2344, and is used to enable the distance adjusting rod 2341 to obtain elastic tensioning force.

[0056] By rotating the pressure-adjusting rod 2346, the stop step can be moved closer to or away from the sleeve 2344, so that one or more disc springs 2347 clamped between the stop step and the sleeve 2344 are compressed or stretched. When the compression degree of the disc spring 2347 increases, the distance-adjusting pull rod 2341 needs to transmit a greater resistance force to the disc spring 2347 through the pressure-adjusting rod 2346 to drive the disc spring 2347 to further compress, thereby achieving an increase in the flexible rolling force. Conversely, when the pre-compression degree of the disc spring 2347 is smaller, the flexible rolling force also decreases accordingly. ; On the basis of the above, during the rotation of the pressure regulating rod 2346, since the pitch of the internal threaded hole and the threaded sleeve 2345 are equal, the change in the distance between the stop step and the sleeve 2344 can be consistent with the change in the length of the distance adjusting rod 2341 screwed into the internal threaded hole, thereby ensuring that the grinding gap remains unchanged during the adjustment of the flexible grinding force; that is to say, the structural method of the above-mentioned spring pressure head 2342 can achieve the adjustment of the grinding gap and the flexible grinding force without affecting each other, thereby improving the convenience of adjustment.

[0057] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A corn dry flour production process, characterized in that: include: The corn raw grains are sequentially subjected to the steps of cleaning the raw grains, conditioning the clean grains, separating the dregs from the grains, primary classification, primary air separation, embryo selection, peeling, secondary classification, secondary air separation, color selection, endosperm crushing, milling and screening to obtain standard corn flour; Among them, the clean grain conditioning adopts a corn conditioning conveyor to construct a closed environment with constant temperature and humidity for the clean grain to pass continuously, and the clean grain forms a tempered corn material with a target moisture content after passing through the corn conditioning conveyor; the corn slag separation adopts a corn slag crusher, and the corn slag crusher has a pre-compression chamber and a slag crushing chamber connected up and down, and the pre-compression chamber is connected to the discharge port of the corn conditioning conveyor mechanism, which is used for fracturing the tempered corn material and making the fractured tempered corn material fall into the slag crushing chamber at a uniform speed for crushing.

2. The corn dry milling process according to claim 1, characterized in that: The corn conditioning conveyor comprises: The casing has a closed-air feeder on the top wall at one end and a closed-air discharger on the bottom wall at the other end; A stirring and conveying assembly is arranged in the housing, and comprises a high-speed stirring section and a low-speed conditioning section. The high-speed stirring section is close to the air-tight feeder and is used to continuously stir and convey the clean grain fed by the air-tight feeder. The low-speed conditioning section is connected to the high-speed stirring section and is used to continuously stir and convey the clean grain to the air-tight discharger. The time for the clean grain to pass through the low-speed conditioning section is controlled to be 12 to 30 minutes. A steam pipe group, connected to the casing and used to pass water vapor into the high-speed stirring section, wherein the amount of water vapor passed is related to the feeding amount of the air-tight feeder to control the clean grain temperature at 45-70° C.; A water injection pipe group is connected to the casing and is used to inject clean water at room temperature into the high-speed stirring section. The injection amount of the clean water at room temperature is related to the feeding amount of the closed-air feeder to control the wetting degree of the clean grain, thereby controlling the water content of the tempered corn material to be between 17 and 19%.

3. The corn dry flour milling process according to claim 2, characterized in that: The casing is provided with a drain valve at the bottom of one end of the air-locking discharger; the top wall of the casing is provided with an air layer, the bottom surface of the air layer is provided with an air hole array connected to the inner cavity of the casing, and a steam hood is provided above the air hole array, the steam hood is located directly above the high-speed stirring section and is connected to the steam pipe group; a spray pipe is provided in the casing, the spray pipe is located on the side of the steam hood away from the low-speed tempering section and is connected to the water injection pipe group.

4. The corn dry flour production process according to claim 2, characterized in that: The stirring and conveying assembly includes a first rotating shaft and a second rotating shaft, each of which is equipped with an independent driving unit; the first rotating shaft and the second rotating shaft are connected to each other and rotated together, and the ends of the two shafts that are far away from each other are respectively rotatably connected to the end walls of the casing; wherein, a plurality of stirring blades are spirally distributed on the first rotating shaft at intervals to form the high-speed stirring section; a plurality of feeding blades and a plurality of stirring fins are spirally distributed on the second rotating shaft at intervals to form the low-speed tempering section, and the feeding blades are distributed between the stirring blades and the stirring fins.

5. The corn dry flour production process according to claim 4, characterized in that: The stirring blade is provided with a first connecting rod, which passes through the first rotating shaft along the radial direction of the first rotating shaft to form a rotational fit; the feeding blade and the stirring wing are both provided with a second connecting rod, which passes through the second rotating shaft along the radial direction of the second rotating shaft to form a rotational fit; wherein, the first connecting rod and the second connecting rod are both screwed with locking parts for locking their respective rotation angles.

6. The corn dry flour milling process according to claim 1, characterized in that: Two material-grinding rollers are arranged horizontally in pairs in the pre-pressing chamber, and a material-grinding gap is provided between the two material-grinding rollers; a slag-breaking roller is provided in the slag-breaking chamber; the slag-breaking roller and the material-grinding roller are respectively provided with independent power units; wherein the two material-grinding rollers rotate synchronously in opposite directions at a linear speed of 0.5-2 m / s and form a flexible grinding force, and the flexible grinding force is used to fracture the tempered corn material falling into the material-grinding gap; the slag-breaking roller crushes the endosperm of the fractured tempered corn material at a rotational linear speed of 13-19 m / s to make the corn embryo fall off completely.

7. The corn dry flour milling process according to claim 6, characterized in that: Both ends of the frame of the corn crusher are provided with pressure and distance adjusting mechanisms, and both ends of the two material-grinding rollers are rotatably connected to the pressure and distance adjusting mechanisms; wherein the pressure and distance adjusting mechanisms are used to form the material-grinding gap and the flexible material-grinding pressure between the two material-grinding rollers, and to adjust the material-grinding gap and the flexible material-grinding pressure.

8. The corn dry milling process according to claim 7, characterized in that: The pressure and distance adjusting mechanism includes a base for fixedly connecting to a frame, a first axle seat fixedly connected to the base, a second axle seat hinged to the base at the bottom, and a traction assembly connected to the top of the first axle seat and the second axle seat; wherein, the first axle seat and the second axle seat are respectively used to connect the two material grinding rollers, and an elastic pushing member is arranged between the first axle seat and the second axle seat to form the material grinding gap between the two material grinding rollers; the traction assembly is used to apply an elastic tensioning force to the first axle seat and the second axle seat to form the flexible grinding force between the two material grinding rollers.

9. The corn dry milling process according to claim 8, characterized in that: The traction assembly includes a distance-adjusting rod and a spring-loaded head; wherein, the elastic force of the spring-loaded head is adjustable, one end of the distance-adjusting rod passes through the first axle seat and is threadedly connected to the distance-adjusting lock nut, and the other end of the distance-adjusting rod passes through the second axle seat and is threadedly engaged with the spring-loaded head.

10. The corn dry flour milling process according to claim 9, characterized in that: The spring pressing head comprises: A sleeve head is slidably sleeved on the distance-adjusting pull rod and abuts against a side of the second shaft seat away from the first shaft seat, and a threaded sleeve is arranged in the sleeve head; A pressure regulating rod, one end of which is provided with a stop step, and the other end of which penetrates into the sleeve and is threadedly engaged with the screw sleeve, and one end of the pressure regulating rod that penetrates into the screw sleeve has an internal threaded hole, the internal threaded hole is threadedly connected with the distance adjusting rod, and the pitch of the internal threaded hole is equal to the pitch of the screw sleeve; The disc spring is sleeved on the pressure regulating rod and located between the stop step and the sleeve head, and is used to enable the distance regulating rod to obtain the elastic tensioning force.

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