CN113621083B

CN113621083B - Corn starch wet milling processing technology and primary concentration technology

Info

Publication number: CN113621083B
Application number: CN202010380457.5A
Authority: CN
Inventors: 裴成利; 刘泽龙; 宫巍; 赵永武; 于元德; 秦善杰; 杨佳
Original assignee: Cofco Biochemical Energy Hengshui Co ltd; Beijing Technology and Business University; Cofco Nutrition and Health Research Institute Co Ltd
Current assignee: Cofco Biochemical Energy Hengshui Co ltd; Beijing Technology and Business University; Cofco Nutrition and Health Research Institute Co Ltd
Priority date: 2020-05-08
Filing date: 2020-05-08
Publication date: 2022-12-06
Anticipated expiration: 2040-05-08
Also published as: CN113621083A

Abstract

The invention relates to a novel corn starch wet milling processing technology and a primary concentration technology, and a corn starch wet milling processing system for the technology. Compared with the traditional Dalton process, the primary concentration process and the corn starch wet-milling process and system classify materials with different concentrations from the process perspective and adopt corresponding equipment, so that the best use of the materials can be realized integrally, the operation loads of the pre-concentration process and the main centrifugal machine are greatly reduced, and a large amount of energy consumption is saved.

Description

Corn starch wet milling processing technology and primary concentration technology

Technical Field

The invention relates to a corn starch wet grinding processing technology and a material primary concentration technology for starch wet processing, belonging to the technical field of food processing.

Background

Wet milling is the basic process for corn starch production, and is used in essentially all corn starch production worldwide. As shown in figure 1, in the wet grinding section of the traditional corn wet processing technology, coarse crushing, embryo extraction and re-crushing are generally adopted, the 'thick pulp' is obtained from the part below a screen through a separating screen I, the substance above the screen is continuously ground and crushed, then the ground and ground liquid is washed and sieved to obtain 'thin pulp', the fibers in the substance above the screen are extracted, and the thick pulp and the thin pulp are mixed to obtain the coarse pulp. Then pre-concentrating the coarse pulp, performing main separation and gluten concentration to collect concentrated gluten liquid and obtain process water; the main separation bottom flow is washed by refined cyclone, and refined starch milk is collected.

In the process, the raw slurry (also called raw starch milk) still contains a large amount of insoluble proteins and soluble substances. Chemical composition of the dry matter of the raw starch milk (calculated on a dry basis): 89 to 92 percent of starch, 6 to 8 percent of protein (Nx 6.25), 0.5 to 1 percent of fat, 0.1 to 0.3 percent of soluble substances, 0.2 to 0.3 percent of ash content and the like. The content of these impurities, particularly insoluble proteins, in the crude starch milk is still high and needs to be further separated. The principle of separating starch and protein (gluten) is mainly to utilize the relative density and particle size of the two substances to carry out centrifugal separation, wherein the particle size of the starch is 3-30 mu m, the particle size of the gluten is 1-2 mu m, but the gluten has strong hydrophilicity and can form larger aggregates, and the size of the aggregates can reach 140-170 mu m; the relative density of starch was 1.61 and the relative density of gluten was 1.18.

The starch purification and protein concentration of the coarse pulp are mainly realized by centrifugal separation. The centrifugal separator for corn starch is divided into a starch milk pre-concentration separator, a main separator, a gluten concentration separator and the like. The pre-concentration separator can concentrate the starch milk from 6-7 DEG Be to 12-14 DEG Be. The main separator is mainly used for separating starch and gluten, and can separate out most insoluble and soluble protein and a small amount of fine granular starch, the substance separated out from the overflow is called gluten water, and the starch milk can be concentrated by 6-12 DEG Be to 17-19 DEG Be. The gluten concentration separator is used for concentrating the gluten water separated by the main separator, and the dry gluten water concentration can be concentrated to 120-130 g/L.

The concentration of the starch milk before pre-concentration and feeding is generally 10-14 degrees Bx (5.5-7.7 degrees Be), and the starch milk comprises 89-92 percent of starch, 6-8 percent of protein, 0.5-1 percent of fat, 0.1-0.3 percent of soluble substances and 0.2-0.3 percent of mineral substances. The underflow starch milk after the main separation has the concentration of 28-32 degrees Bx (15.3-17.5 degrees Be) and contains 1.5-2.5 percent of protein. 1-2% of overflow gluten water-dried substance after main separation, and the content of starch is less than 20%.

However, the wet processing of corn starch has been characterized by high energy and water consumption. Therefore, a simpler and lower-cost method is still required to be explored in the field, so that cost reduction and efficiency improvement, low carbon and environmental protection are realized.

Disclosure of Invention

Aiming at the technical problems, the inventor researches and discovers a corn starch wet-milling processing technology and a primary concentration technology, the technology adds a set of pressure curved screen (separation screen II) at the downstream of fine milling and adds a set of cyclone at the downstream of the separation screen I and the separation screen II, the milled liquid after the fine milling is separated into slurry through the separation screen II, the separated thick slurry does not enter a pre-concentration centrifugal machine any more, but enters the cyclone for primary concentration, and concentrated starch milk is obtained. The concentrated starch milk separated by the primary concentration process can bypass a centrifuge system and directly enter a starch refining cyclone group for refining (figure 2). This variation is relative to the conventional dalton process, which is referred to as the primary concentration process. In addition, the process may also divert a portion of the slurry in the fiber washing and screening system to a cyclone. The process can reduce the load of the centrifuge in the steps of pre-concentration, main separation and the like, thereby reducing the consumption of power energy of the centrifuge.

Accordingly, in a first aspect, the present invention provides a corn starch wet milling process comprising the steps of:

(1) After the corn is soaked and crushed, separating by a separating screen I to obtain separating screen I thick pulp and separating screen I oversize products;

(2) Fine grinding the oversize material of the separating screen I to obtain fine ground liquid;

(3) Separating the fine ground liquid by a separating screen II to obtain thick slurry of the separating screen II and oversize products of the separating screen II;

(4) Enabling oversize materials of the separating screen II to enter a fiber washing and screening system to obtain slurry a and oversize materials for extracting fibers; optionally, splitting at least a portion of said slurry a into slurry a1 and slurry a2;

(5) Enabling the separating screen I thick slurry, the separating screen II thick slurry and the optional thin slurry a1 to enter a cyclone for further concentration to obtain concentrated starch milk I of underflow and thin slurry b of overflow;

(6) Feeding the slurry a, slurry b and optionally slurry a2 to a preconcentration centrifuge to obtain a crude concentrate and produce process water;

(7) Feeding the crude concentrated solution into a main separation centrifuge to obtain concentrated starch milk II of bottom flow and gluten liquid of top flow;

(8) Subjecting the gluten liquid to gluten concentration to further obtain a concentrated gluten liquid while producing process water; and

(9) And (3) feeding the concentrated starch milk I and II into a washing and refining system for refining to obtain refined starch milk.

In a second aspect, the present invention provides a primary concentration process for wet processing of corn starch, the primary concentration process comprising the steps of:

(1) After the corn is soaked and crushed, separating by a separating screen I to obtain separating screen I thick slurry and oversize products of the separating screen I;

(4) Enabling oversize materials of the separating screen II to enter a fiber washing and screening system to obtain slurry a and oversize materials for extracting fibers; optionally, splitting at least a portion of slurry a into slurry a1 and slurry a2; and

(5) And (3) enabling the separating screen I concentrated slurry, the separating screen II concentrated slurry and the optional slurry a1 to enter a cyclone for further concentration, and obtaining concentrated starch milk I of underflow and slurry b of overflow for further concentration and/or refining.

In a third aspect, the present invention provides a corn starch wet milling processing system, wherein the system comprises:

a crushing system;

a separation screen I connected in fluid communication downstream of the crushing system;

a refining connected in fluid communication downstream of the screen I;

a separation screen II connected in fluid communication downstream of said refining;

a fiber washing and screening system connected in fluid communication downstream of the separating screen II;

a cyclone connected in fluid communication downstream of the separation screen I and the separation screen II;

a pre-concentration centrifuge connected in fluid communication downstream of the fiber washing screen system and the cyclone;

a primary centrifuge connected in fluid communication downstream of the preconcentration centrifuge;

a gluten concentration separator connected in fluid communication downstream of the primary centrifuge; and

a wash refinement system connected in fluid communication downstream of the main separation centrifuge and the cyclone.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) The invention provides a novel primary concentration process for wet processing of corn starch, which classifies materials with different concentrations from the process perspective, and then adopts adaptive equipment to make the best use of things on the whole, thereby achieving the purposes of optimizing the process, purifying the process and perfecting the process.

(2) The corn starch wet milling processing technology uses a primary concentration technology, and compared with the traditional Dalton technology, the technology of the invention enables the feed starch milk amount of a pre-concentration centrifugal machine to be reduced by 56-129 tons/hour, and reduced by 16.5% -35.5%; the feeding amount of the starch milk of the main centrifugal machine is reduced by 61-167 tons/hour, and reduced by 17% -45%, so that the operation load of the pre-concentration and the main centrifugal machine can be greatly reduced, and a large amount of energy consumption is saved.

(3) The primary concentration process of the invention adds a set of pressure curved screen (i.e. separating screen II) and cyclone, reduces the process dependence on high energy consumption equipment disc centrifuge, and in the process, the equipment investment of the centrifuge is saved by at least half with a small amount of investment, thereby obviously reducing the equipment investment. The separation screen II (pressure curved screen) specially arranged in the process can convert the fine grinding product into thick slurry as much as possible and then enters the cyclone, so that the liquid entering the pre-concentration and main separator is thin slurry as much as possible, the centrifugal load of a part of the centrifugal load is divided by the cyclone with lower energy consumption on the basis of the centrifuge with higher energy consumption, the energy consumption is reduced, the process dependence on a disc centrifuge with high energy consumption equipment is further reduced, the equipment investment of the centrifuge is saved by at least half of the equipment investment in the process by using small investment, and the equipment investment is obviously reduced.

(4) Generally, the quality of the acid making water when the corn is soaked in the soaking process is one of the factors influencing the quality of the soaked corn. The water used for acid production is mainly fresh water and process water produced in the gluten concentration process. Because the quality of the acid preparation water is different, the quality of the prepared sulfurous acid solution is different, the quality of the fresh water is good, the quality of the prepared sulfurous acid solution is clean and pure, and the osmotic pressure of the sulfurous acid solution is high. Different process technologies produce different quality of process water (different content of dry matter, suspended matter, soluble matter and the like), the quality of the produced sulfurous acid solution has certain difference, and the soluble matter has larger influence on osmotic pressure of the produced sulfurous acid solution. The content of dry matters, suspended matters, soluble matters and the like in the process water obtained by the traditional Dalton process is high, and ideal effects are difficult to realize when the process water is recycled for soaking corns.

The primary concentration process of the invention promotes the reduction of the dry matter content of the top flow of the centrifuge by reducing the load of the centrifuge, and correspondingly reduces the dry matter, suspended matter, soluble matter and other contents of the produced process water, thereby realizing the purification and quality improvement of the process water of the whole production process. Compared with the traditional process, the process water can be effectively recycled for soaking the corn, so that the acid-making soaking process is effectively improved, the indexes of soluble substance content and the like of the soaked corn are correspondingly improved, and the optimization and progress of the whole process are realized.

Drawings

Fig. 1 is a schematic view showing a process flow of a conventional corn wet processing process.

FIG. 2 is a schematic diagram showing the process flow of the corn wet processing process incorporating the primary concentration process of the present invention.

Fig. 3 is a schematic diagram showing the overall reduction of process water dryness in examples of the present invention relative to comparative examples.

FIG. 4 is a schematic showing the reduction in post-steeping corn solubles in examples of the invention relative to a comparative example.

Detailed Description

The inventor discovers that a set of pressure curved screen (separating screen II) and a set of swirler are additionally arranged, ground liquid after fine crushing is subjected to pulp separation through a screening device I and a screening device II, and separated thick pulp does not enter a pre-concentration centrifugal machine any more, but enters the swirler for primary concentration. The starch milk obtained by separation can bypass a centrifugal machine system and directly enter a starch refining cyclone group for refining, so that the equipment asset investment can be obviously reduced, the energy consumption is reduced, and the process water quality and the protein yield are improved.

In some embodiments, the present invention provides a corn starch wet milling process comprising the steps of:

(6) Feeding the slurry a, the slurry b and optionally the slurry a2 into a pre-concentration centrifuge to obtain a crude concentrate and produce process water;

(7) The crude concentrated solution enters a main separation centrifuge to obtain concentrated starch milk II of the bottom flow and gluten liquid of the top flow;

(9) And refining the concentrated starch milk I and II in a washing and refining system to obtain refined starch milk.

In some embodiments, the present invention provides a primary concentration process for wet processing of corn starch, the primary concentration process comprising the steps of:

(4) Enabling oversize materials of the separating screen II to enter a fiber washing and screening system to obtain slurry a and oversize materials for extracting fibers; optionally, splitting at least a portion of said slurry a into slurry a1 and slurry a2; and

In some embodiments, the crushing process in step (1) above is performed using a crowned tooth mill at a speed of 1450-1500 rpm, preferably 1460-1490 rpm. Preferably, the sieve pores of the separating sieve I are 45-60 μm, preferably 48-55 μm, and the operating pressure is 0.2-0.4 MPa, preferably 0.3-0.4 MPa. Preferably, the steeping of the corn is performed with an acid water having a pH of 3.3-3.5, preferably 3.35-3.45; preferably, the soaking time is 38-48 h, preferably 42-46 h.

In some embodiments, said refining in step (2) above is performed at a rotational speed of 2900-3100 rpm, preferably 2950-3050 rpm. Preferably, the obtained fine ground liquid comprises: 393-485 kg/min of starch, preferably 402-416 kg/min; the fiber is 92-141 kg/min, preferably 95-110 kg/min; 1241-1729 kg/min of water, preferably 1270-1420 kg/min.

In some embodiments, the separation screen II in the above step (3) may be a pressure curved screen. Preferably, the pore size of the pressure curved sieve is less than or equal to 60 μm, preferably less than or equal to 50 μm. Preferably, the operating pressure of the separating screen II is in the range of 0.2MPa to 0.4MPa, preferably 0.3MPa to 0.35MPa.

Preferably, the undersize thick stock of separating screen II comprises: 69-109 kg/min starch, preferably 93-101 kg/min; 239-350 kg/min of water. Preferably, the oversize of the separating screen II comprises: 285-410 kg/min, preferably 300-395 kg/min of starch; fiber 92-141 kg/min, preferably 95-141 kg/min; and water 923-1410 kg/min, preferably 952-1410 kg/min.

In some embodiments, the fiber washing and screening system in step (4) above has a mesh size of 70 μm to 80 μm, preferably 72 μm to 78 μm, and an operating pressure of 0.2MPa to 0.4MPa, preferably 0.25MPa to 0.35MPa. Preferably, the fiber washing and screening system obtains slurry a which comprises: 283-379 kg/min of starch, preferably 292-379 kg/min; 2812-3243 kg/min of water, preferably 2980-3243 kg/min.

The fiber washing and screening system in the step (4) adopts a countercurrent washing and screening method, the fiber, starch and protein mixed solution enters from the front end of the system, the washing process water enters from the rear end and is washed and separated step by step, so that the starch, protein and fiber are separated to the maximum extent, starch and protein slurry is separated and extracted from the front end of the system, and the fiber is separated from the rear end of the system.

In some embodiments, at least a portion of slurry a is split into slurry a1 and slurry a2 in step (4) above. Preferably, the whole of slurry a is split into slurry a1 and slurry a2. Preferably, the slurry a (slurry a1 component = slurry a2 component) comprises: 277-392 kg/min of starch, 292-379 kg/min is preferred; 2812-3243 kg/min of water.

In the present invention, the division of the slurry a into the slurry a1 and the slurry a2 does not change the compositions of the slurries before and after the division, and the slurry a, the slurry a1, and the slurry a2 are the same in composition. The inventors have found that the main centrifuge operating load can be further reduced by splitting slurry a in step (4) above, wherein slurry a1 is split to the cyclone and slurry a2 is split to the preconcentration centrifuge.

In some embodiments, the cyclone in step (5) is in 1 to 2 stages, preferably, the cyclone is in 1 stage. Preferably, the size of the cyclone is selected from

And

one or more of the above. Preferably, the number of tubes of the cyclone is 316-598, preferably 430-452. Preferably, the feed pressure of the cyclone is between 0.65 and 0.8MPa, preferably between 0.65 and 0.75MPa.

Preferably, the feed to the cyclone in the step (5) comprises: 413-864 kg/min starch, preferably 489-763 kg/min; 1858-5209 kg/min water, preferably 2182-4533 kg/min water. Preferably, the underflow concentrated starch milk I obtained in step (5) above contains 372-778 kg/min, preferably 440-662 kg/min starch; 790 to 1654 kg/min of water, preferably 935 to 1410 kg/min. Preferably, the overflow slurry b obtained in step (5) above contains 40-86 kg/min starch, preferably 49-75 kg/min starch; 1065-3555 kg/min of water, preferably 1245-3125 kg/min.

In some embodiments, the rotation speed of the preconcentration centrifuge in the above step (6) is 2700-3100 rpm, preferably 2900-3050 rpm. In further exemplary embodiments, the rotation speed of the preconcentration centrifuge in the above step (6) is 2050 to 3100 rpm, preferably 2700 to 2950 rpm. Preferably, the feed to the pre-concentration centrifuge in step (6) above comprises: 77-428 kg/min starch, preferably 144-351 kg/min starch; 3836-4353 kg/min of water, preferably 3773-4340 kg/min. Preferably, the amount of process water produced by the pre-concentration centrifuge in step (6) above is 2730-3552 kg/min, preferably 2930-3442 kg/min. Preferably, the crude concentrated solution (i.e. the pre-concentrated starch milk) obtained in step (6) above comprises: 258-602 kg/min starch, preferably 312-515 kg/min; 3210-4330 kg/min, preferably 3280-4115 kg/min. Preferably, the process water obtained in step (6) is recycled for the preparation of the acid making water in step (1).

In some embodiments, in step (7) above, the main separator centrifuge has a rotational speed of 2300 to 2500 rpm, preferably 2400 to 2480 rpm. Preferably, the underflow concentrated starch milk II obtained in step (7) above comprises: 269-612 kg/min starch, preferably 321-594 kg/min starch; water in 572-1305 kg/min, preferably 680-1262 kg/min. Preferably, the gluten liquid of the top stream obtained in the step (7) above comprises: 7.8-11 kg/min starch, preferably 7.8-9 kg/min starch; 2837-3268 kg/min, preferably 2878-3267 kg/min of water.

The invention makes the material to be separated enter the centrifuge (enter the pre-concentration centrifuge and the main separation centrifuge in turn), under the action of centrifugal force, starch with large specific gravity enters the solid phase collection cavity and is discharged intermittently from the underflow outlet, and protein with small specific gravity, soluble substance and a large amount of water are discharged from the overflow outlet, thereby further improving the separation and processing effect.

In some embodiments, in the above step (8), the gluten concentration is performed by a gluten concentration separator; preferably, the gluten concentration separator generates 2757-3177 kg/min, preferably 2798-3176 kg/min, of process water.

In some embodiments, in step (9) above, the washing and refining system is operated at a pressure of 0.7MPa to 0.9MPa, preferably 0.75MPa to 0.85MPa. Preferably, the refined starch milk obtained in the step (9) contains 758-823 kg/min starch, preferably 773-823 kg/min starch; 1096-1190 kg/min water, preferably 1118-1190 kg/min water.

In some embodiments, the present invention provides a corn starch wet milling processing system, wherein the system comprises:

a crushing system;

a refining connected in fluid communication downstream of the screen I;

a fiber washing and screening system connected in fluid communication downstream of the separation screen II;

a pre-concentration centrifuge connected in fluid communication downstream of the fiber wash screen system and the cyclone;

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples. The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials, devices and the like used in the following examples are commercially available or can be prepared by those skilled in the art according to the ordinary knowledge in the art, unless otherwise specified.

In the invention, the protein content in the product is determined according to the first Kjeldahl method in the national standard GB 5009.5-2016 for food safety, and the protein conversion coefficient is 6.25. The moisture content of the product was determined according to the method of GB/T5009.3-2016. The starch content in the product is determined according to the national food safety standard GB 5009.9-2016. The fiber content in the product is measured according to the method specified in GB/T6434-2006 filtration method for measuring the content of crude fiber in feed.

The following examples are directed to a process configuration based on a nominal corn moisture of 14% and a commercial capacity of 2000 tons/day. The method is characterized by preparing fine grinding liquid by a conventional Dalton wet grinding process, and comprises the following steps: soaking the corn raw material for 36-48 h by using acid-making water with pH of 3.6-4.2 to obtain soaked corn, crushing the soaked corn by using a convex tooth mill (Dalianshenglie fluid equipment plant, model: TCM 920), obtaining thick slurry of a separation sieve I and oversize of the separation sieve I by using a separation sieve I (Zhuhai Li Qi machinery plant, model: YQS710X 2), and finely crushing the oversize in a refining mill (LZM 1000-NA) to obtain refined milled liquid. The operation or configuration parameters of the partial equipment in the above process and the subsequent process are as follows:

TABLE 1

Example 1

(1) The fine grinding fluid obtained by fine crushing contains: 478 kg/min of starch (mass flow, the same below), 141 kg/min of fiber and 1649 kg/min of water;

(2) And (3) feeding the ground liquid into a pressure curved sieve (YDQS-585, jiangsu Yilau mechanical equipment Limited, the same except special statements below) of a separation sieve II to obtain an oversize product and an undersize thick slurry of the separation sieve II, wherein the aperture of the sieve surface of the separation sieve II is 50 mu m, and the operating pressure is 0.35MPa. The oversize comprises: 409 kg/min of starch, 141 kg/min of fiber and 1410 kg/min of water; the undersize thick liquid comprises: 69 kg/min of starch and 239 kg/min of water;

(3) The oversize from the separation sieve II in step 2 is fed to a fiber washing and screening system (Zhuhai Liqi mechanical plant, type: YQS710X4, same except for special statements, sieve opening: 75 μm, operating pressure: 0.3 MPa) to obtain the undersize slurry a and the oversize for fiber extraction. Wherein slurry a comprises: 392 kilograms/minute of starch and 3243 kilograms/minute of water;

(4) The thick slurry in step 2 and the thick slurry of the separating screen I are combined and enter a cyclone (1 level, the number of pipes: 415, clamshell)

Fluid-Quip, inc.), containing in the feed: 413 kg/min of starch, 1858 kg/min of water, feeding pressure: 0.65MPa. After further concentration, underflow concentrated starch milk I and overflow slurry b are obtained. Wherein slurry b comprises: 41 kg/min of starch and 1068 kg/min of water; the concentrated starch milk I comprises: 372 kg/min of starch and 790 kg/min of water;

(5) And merging the slurry a in the step 3 and the slurry b in the step 4, and then feeding the merged slurry into a pre-concentration centrifuge (German West Valley apparatus factory, model: SDA 300) to obtain pre-concentrated starch milk (namely crude concentrated solution) and generate process water. Wherein the combined slurry comprises: 428 kg/min of starch and 4311 kg/min of water. The amount of process water is 2731 kg/min. The pre-concentrated starch milk comprises: 602 kg/min of starch and 4330 kg/min of water;

(6) The pre-concentrated starch milk in the step 5 enters a main separation centrifuge (German West Valley plant, model: SDA 300) to obtain concentrated starch milk II of the bottom flow and gluten liquid of the top flow. Wherein the gluten liquid of the top flow comprises: 8.9 kg/min of starch and 3268 kg/min of water. The underflow concentrated starch milk II contains: 612 kg/min of starch and 1301 kg/min of water;

(7) Concentrating the top flow gluten liquid in the step 6 by a gluten concentration separator to further obtain concentrated gluten liquid and simultaneously generate process water; wherein the process water amount is 3177 kg;

(8) And (3) merging the concentrated starch milk I in the step (4) and the concentrated starch milk II in the step (6), and then refining in a washing and refining system (Daliangsheng Ruide fluid equipment factory, model: XDXL 480-I) to obtain the refined starch milk. The refined starch milk comprises: 773 kg/min starch and 1118 kg/min water.

Example 2

(1) The grinding fluid obtained by fine crushing contains: 395 kg/min of starch (mass flow, the same below), 92 kg/min of fiber and 1273 kg/min of water;

(2) The ground liquid enters a separation sieve II pressure curved sieve with the sieve surface aperture of 60 mu m, and the pressure is 0.2MPa, so that oversize products and undersize thick pulp of the separation sieve II are obtained. The oversize comprises: 287 kg/min starch, 92 kg/min fiber and 923 kg/min water; the undersize thick liquid comprises: 109 kg/min of starch and 350 kg/min of water;

(3) The oversize of the separating screen II in step 2 is fed into a fiber washing and screening system (screen opening: 72 μm, operating pressure: 0.35 MPa) to obtain undersize slurry a and oversize for fiber extraction. Wherein slurry a comprises: 277 kilograms/minute of starch and 2812 kilograms/minute of water;

(4) The thick slurry in the step 2 and the thick slurry of the separating screen I are merged and then enter a cyclone (1 level, the number of pipes is 598, clamshell)

Fluid-Quip, inc.), containing in the feed: 603 kg/min starch, 2680 kg/min water, feed pressure: 0.8MPa. After further concentration, underflow concentrated starch milk I and overflow slurry b are obtained. Wherein, slurry b comprises: 60 kg/min of starch and 1525 kg/min of water; the concentrated starch milk I comprises: 543 kg/min of starch and 1154 kg/min of water;

(5) And (4) merging the slurry a in the step (3) and the slurry b in the step (4), and then feeding the merged slurry into a pre-concentration centrifugal machine to obtain pre-concentrated starch milk, and generating process water. Wherein the combined slurry comprises: 317 kg/min of starch and 4338 kg/min of water. The amount of process water was 3167 kg/min. The pre-concentrated starch milk comprises: 496 kg/min of starch and 4096 kg/min of water;

(6) And (5) feeding the pre-concentrated starch milk in the step 5 into a main separation centrifuge to obtain concentrated starch milk II of the underflow and gluten liquid of the overflow. Wherein the gluten liquid of the top flow comprises: 11 kg/min of starch and 3265 kg/min of water. The underflow concentrated starch milk II contains: 503 kg/min of starch and 1070 kg/min of water;

(7) Concentrating the top flow gluten liquid in the step 6 through a gluten concentration separator to further obtain concentrated gluten liquid and simultaneously generate process water; wherein the amount of process water is 3174 kg;

(8) And (4) merging the concentrated starch milk I in the step (4) and the concentrated starch milk II in the step (6), and then feeding the merged starch milk into a washing and refining system for refining to obtain the refined starch milk. The refined starch milk comprises: 822 kg/min of starch and 1189 kg/min of water.

Example 3

(1) The grinding fluid obtained by fine crushing contains: 402 kg/min starch (mass flow, the same below), 95 kg/min fiber and 1270 kg/min water;

(2) The ground liquid enters a separating screen II with the screen surface aperture of 45 mu m and the pressure of 0.4MPa, and screen oversize products and undersize thick pulp of the separating screen II are obtained. The oversize comprises: 301 kg/min of starch, 95 kg/min of fiber and 952 kg/min of water; the undersize thick pulp comprises: 101 kg/min of starch and 318 kg/min of water;

(3) And (3) feeding oversize products of the separation screen II in the step (2) into a fiber washing and screening system (screen holes: 70 mu m, operating pressure: 0.4 MPa) to obtain undersize slurry a and oversize products for extracting fibers. Wherein slurry a comprises: 292 kg/min of starch and 2812 kg/min of water;

(4) The thick slurry in step 2 and the thick slurry of the separating screen I are combined and then enter a cyclone (1 level, the number of pipes: 316, clamshell)

Fluid-Quip, inc.), containing in the feed: 602 kg/min starch, 2678 kg/min water, feed pressure: 0.65MPa. After further concentration, underflow concentrated starch milk I and overflow slurry b are obtained. Wherein slurry b comprises: 60 kg/min of starch and 1527 kg/min of water; the concentrated starch milk I comprises: 541 kg/min of starch and 1151 kg/min of water;

(5) And (4) merging the slurry a in the step (3) and the slurry b in the step (4), and then feeding the merged slurry into a pre-concentration centrifugal machine to obtain pre-concentrated starch milk, and generating process water. Wherein the combined slurry comprises: 313 kg/min starch and 4339 kg/min water. The amount of process water was 3183 kg/min. The pre-concentrated starch milk comprises: 495 kg/min of starch and 4083 kg/min of water;

(6) And (5) feeding the pre-concentrated starch milk in the step 5 into a main separation centrifuge to obtain concentrated starch milk II of the underflow and gluten liquid of the overflow. Wherein the gluten liquid of the top flow comprises: 8 kg/min starch and 3247 kg/min water. The concentrated starch milk II of the underflow comprises: 505 kg/min of starch and 1074 kg/min of water;

(7) Concentrating the top flow gluten liquid in the step 6 by a gluten concentration separator to further obtain concentrated gluten liquid and simultaneously generate process water; wherein the process water amount is 3156 kg;

(8) And (4) merging the concentrated starch milk I in the step (4) and the concentrated starch milk II in the step (6), and then feeding the merged starch milk into a washing and refining system for refining to obtain the refined starch milk. The refined starch milk comprises: 823 kg/min of starch and 1190 kg/min of water.

Example 4

(1) The grinding fluid obtained by fine crushing contains: 416 kg/min starch (mass flow, the same applies below), 110 kg/min fiber and 1420 kg/min water;

(2) The ground liquid enters a separating screen II with the screen surface aperture of 50 mu m and the pressure of 0.3MPa, and screen oversize products and undersize thick pulp of the separating screen II are obtained. The oversize comprises: 322 kg/min of starch, 110 kg/min of fiber and 1102 kg/min of water; the undersize thick pulp comprises: 93 kg/min of starch and 318 kg/min of water;

(3) And (3) enabling oversize products of the separation screen II in the step (2) to enter a fiber washing and screening system (screen holes: 80 mu m, and operating pressure: 0.2 MPa), and obtaining undersize slurry a and oversize products for extracting fibers. Wherein slurry a comprises: 311 kg/min of starch and 2980 kg/min of water;

(4) The thick slurry in step 2 and the thick slurry of the separating screen I are combined and then enter a cyclone (1 level, the number of pipes: 452, clamshell)

Fluid-Quip, inc.), comprising in the feed: 489 kg/min starch, 2182 kg/min water, feed pressure: 0.75MPa. After further concentration, underflow concentrated starch milk I and overflow slurry b are obtained. Wherein, slurry b comprises: 49 jin/min of starch and 1247 kg/min of water; the concentrated starch milk I comprises: 440 kg/min of starch and 935 kg/min of water;

(5) And (4) merging the slurry a in the step (3) and the slurry b in the step (4), and then feeding the merged slurry into a pre-concentration centrifugal machine to obtain pre-concentrated starch milk, and generating process water. Wherein the combined slurry comprises: 351 kg/min of starch and 4227 kg/min of water. The process water amount is 2931 kg/min. The pre-concentrated starch milk comprises: 515 kg/min of starch and 3993 kg/min of water;

(6) And (5) feeding the pre-concentrated starch milk in the step 5 into a main separation centrifuge to obtain concentrated starch milk II of the underflow and gluten liquid of the overflow. Wherein the gluten liquid of the top flow comprises: 9 kg/min starch and 3117 kg/min water. The underflow concentrated starch milk II contains: 524 kg/min of starch and 1115 kg/min of water;

(7) Concentrating the top flow gluten liquid in the step 6 by a gluten concentration separator to further obtain concentrated gluten liquid and simultaneously generate process water; wherein, the amount of process water is 3029 kg;

(8) And (5) merging the concentrated starch milk I in the step (4) and the concentrated starch milk II in the step (6), and then feeding the merged concentrated starch milk into a washing and refining system for refining to obtain the refined starch milk. The refined starch milk comprises: 758 kg/min starch and 1096 kg/min water.

Example 5

(1) The grinding fluid obtained by fine crushing contains: 485 kg/min starch (mass flow, the same below), 141 kg/min fiber and 1729 kg/min water;

(2) The ground liquid enters a separation sieve II pressure curved sieve with the sieve surface aperture of 50 mu m, and the pressure is 0.35MPa, so that oversize products and undersize thick pulp of the separation sieve II are obtained. The oversize comprises: 395 kg/min of starch, 141 kg/min of fiber and 1410 kg/min of water; the undersize thick liquid comprises: 89 kg/min of starch and 318 kg/min of water;

(3) The oversize of the separating screen II in step 2 enters a fiber washing and screening system (screen hole: 78 μm, operating pressure: 0.25 MPa), and undersize slurry a and oversize for extracting fibers are obtained. Wherein slurry a comprises: 379 kg/min of starch and 3243 kg/min of water;

(4) The tanks of slurry a obtained in step 3 are connected to the cyclone and the preconcentration centrifuge with different pipes and valves, respectively, so that slurry a is divided into slurry a1 and slurry a2, respectively. Wherein the slurry a1 contains 303 kg/min of starch and 2595 kg/min of water;

(5) The thick slurry in the step 2, the thick slurry of the separating screen I and the thin slurry a1 are merged and then enter a cyclone (1 level, pipe number: 433, clamshell)

Fluid-Quip, inc.), comprising in the feed: 736 kg/min starch, 4533 kg/min water, feed pressure: 0.65MPa. After further concentration, underflow concentrated starch milk I and overflow slurry b are obtained. Wherein slurry b comprises: 74 kg/min of starch and 3124 kg/min of water; the concentrated starch milk I comprises: 662 kg/min of starch and 1408 kg/min of water;

(6) And (5) merging the slurry a2 and the slurry b in the steps 4 and 5, and then feeding the merged slurry into a pre-concentration centrifugal machine to obtain pre-concentrated starch milk, and generating process water. Wherein the combined slurry comprises: 144 kg/min of starch and 3773 kg/min of water. The amount of process water was 3242 kg/min. The pre-concentrated starch milk comprises: 312 kg/min of starch and 3281 kg/min of water;

(7) And (5) feeding the pre-concentrated starch milk obtained in the step (6) into a main separation centrifuge to obtain concentrated starch milk II of the underflow and gluten liquid of the overflow. Wherein the gluten liquid of the top flow comprises: 9 kg/min of starch and 2837 kg/min of water. The concentrated starch milk II of the underflow comprises: 321 kg/min of starch and 683 kg/min of water;

(8) Concentrating the top flow gluten liquid in the step 7 through a gluten concentration separator to further obtain concentrated gluten liquid and simultaneously generate process water; wherein, the amount of process water is 2757 kg;

(9) And (4) merging the concentrated starch milk I in the step (5) and the concentrated starch milk II in the step (7), and then feeding the merged concentrated starch milk into a washing and refining system for refining to obtain the refined starch milk. The refined starch milk comprises: 773 kg/min starch and 1118 kg/min water.

Example 6

(1) The grinding fluid obtained by fine crushing contains: 402 kg/min of starch (mass flow, the same below), 95 kg/min of fiber and 1270 kg/min of water;

(2) The ground liquid enters a separating screen II with the screen surface aperture of 50 mu m and the pressure of 0.4MPa, and screen oversize products and undersize thick pulp of the separating screen II are obtained. The oversize comprises: 301 kg/min of starch, 95 kg/min of fiber and 952 kg/min of water; the undersize thick pulp comprises: 101 kg/min of starch and 318 kg/min of water;

(3) And (3) enabling oversize products of the separation screen II in the step (2) to enter a fiber washing and screening system (screen holes: 75 mu m, operating pressure: 0.3 MPa), and obtaining undersize slurry a and oversize products for extracting fibers. Wherein slurry a comprises: 292 kg/min of starch and 2812 kg/min of water;

(4) The tanks of slurry a obtained in step 3 are connected to the cyclone and the preconcentration centrifuge with different pipes and valves, respectively, so that slurry a is divided into slurry a1 and slurry a2, respectively. Wherein the slurry a1 contains 263 kg/min of starch and 2531 kg/min of water;

(5) The thick slurry in step 2, the thick slurry of the separating screen I and the thin slurry a1 are merged and then enter a cyclone (1 stage, the number of pipes is 316, clamshell)

Fluid-Quip, inc.), comprising in the feed: 864 kg/min starch, 5209 kg/min water, feed pressure: 0.65MPa. After the further concentration, the mixture is concentrated,obtaining the concentrated starch milk I of the underflow and the thin slurry b of the overflow. Wherein, slurry b comprises: 86 kg/min of starch and 3555 kg/min of water; the concentrated starch milk I comprises: 778 kg/min starch and 1654 kg/min water;

(5) And (4) merging the slurry a in the step (3) and the slurry b in the step (4), and then feeding the merged slurry into a pre-concentration centrifugal machine to obtain pre-concentrated starch milk, and generating process water. Wherein the combined slurry comprises: 77 kg/min of starch and 3836 kg/min of water. The amount of process water is 3552 kg/min. The pre-concentrated starch milk comprises: 258 kg/min of starch and 3211 kg/min of water;

(6) And (5) feeding the pre-concentrated starch milk in the step 5 into a main separation centrifuge to obtain concentrated starch milk II of the underflow and gluten liquid of the overflow. Wherein the gluten liquid of the top flow comprises: 7.8 kg/min starch and 2878 kg/min water. The underflow concentrated starch milk II contains: 269 kg/min of starch and 572 kg/min of water;

(7) Concentrating the top flow gluten liquid in the step 6 by a gluten concentration separator to further obtain concentrated gluten liquid and simultaneously generate process water; wherein, the process water amount is 2798 kg;

(8) And (4) merging the concentrated starch milk I in the step (4) and the concentrated starch milk II in the step (6), and then feeding the merged starch milk into a washing and refining system for refining to obtain the refined starch milk. The refined starch milk comprises: starch 823 kg/min. 1190 kg/min of water.

The following comparative examples were conducted on equipment configurations based on a process of 14% moisture of a maize trade mark and 2000 tons/day of processing capacity. And similarly, enabling oversize materials passing through the separating screen I to enter fine grinding and crushing to obtain fine grinding liquid. The process from the fine grinding fluid to the refined starch milk then uses the process shown in fig. 1. Of these, comparative example 1 corresponds to examples 1 and 5, comparative example 2 corresponds to example 2, comparative example 3 corresponds to example 3, comparative example 4 corresponds to example 4, and comparative example 5 corresponds to example 6, and except for the difference between comparative example 1 and example 5, only the primary concentrated fraction differs between the above corresponding examples and comparative examples.

Comparative example 1

(1) A liquid after finish grinding was obtained by the same conditions as in example 1;

(2) The ground liquid enters a fiber washing and screening system for washing and screening to obtain slurry under a screen; wherein the slurry comprises 506 kg/min of starch and 4068 kg/min of water;

(3) And (3) mixing the thick slurry of the separating screen I with the thin slurry in the step (2), and then feeding the mixture into a pre-concentration centrifugal machine to obtain concentration, and generating process water and a crude concentrated solution. Wherein, the feed of the pre-concentration centrifugal machine contains 845 kg/min starch and 4863 kg/min water; the process water amount is 1746 kg/min; the crude concentrated solution contains 982 kg/min of starch and 4905 kg/min of water;

(4) And (4) feeding the crude concentrated solution in the step (3) into a main separation centrifuge to obtain concentrated starch milk of the underflow and gluten liquid of the overflow. Wherein, the concentrated starch milk of the underflow contains 983 kg/min of starch and 2091 kg/min of water; the top flow of the gluten liquid contains 8.85 kg/min of starch and 2951 kg/min of water;

(5) The gluten liquid in step 4 is further concentrated, and simultaneously process water is generated; wherein the process water amount is 2868 kg/min;

(6) And 4, refining the concentrated starch milk in the step 4 in a washing and refining system to obtain the refined starch milk. The refined starch milk contains 772 kilograms of starch per minute and 1118 kilograms of water per minute.

Comparative example 2

(1) A fine grinding fluid was obtained by the same conditions as in example 2;

(2) The ground liquid enters a fiber washing and screening system for washing and screening to obtain slurry under a screen; wherein the slurry contains 426 kg/min of starch and 3690 kg/min of water;

(3) And (3) mixing the thick slurry of the separating screen I with the thin slurry in the step (2), and then feeding the mixture into a pre-concentration centrifugal machine to obtain concentration, and generating process water and a crude concentrated solution. Wherein, the feed of the pre-concentration centrifuge contains 901 kg/min of starch and 5142 kg/min of water; the process water amount is 1819 kg/min; the crude concentrate contained 1046 kg/min of starch and 5224 kg/min of water.

(4) And (4) feeding the crude concentrated solution in the step (3) into a main separation centrifuge to obtain concentrated starch milk of the underflow and gluten liquid of the overflow. Wherein, the concentrated starch milk of the underflow contains 1046 kg/min of starch and 2224 kg/min of water; the gluten liquid of the top flow contains 11 kg/min of starch and 3146 kg/min of water;

(5) The gluten liquid in step 4 is further concentrated, and simultaneously process water is generated; wherein the process water amount is 3058 kg/min;

(6) And 4, refining the concentrated starch milk in the step 4 in a washing and refining system to obtain the refined starch milk. The refined starch milk contains 822 kg/min of starch and 1189 kg/min of water.

Comparative example 3

(1) A fine grinding fluid was obtained by the same conditions as in example 3;

(2) The ground liquid enters a fiber washing and screening system for washing and screening to obtain slurry under the screen; wherein the slurry contains 435 kg/min of starch and 3690 kg/min of water;

(3) And (3) mixing the thick slurry of the separating screen I with the thin slurry in the step (2), and then feeding the mixture into a pre-concentration centrifugal machine to obtain concentration, and generating process water and a crude concentrated solution. Wherein, the feed of the pre-concentration centrifugal machine contains 898 kg/min of starch and 5172 kg/min of water; the process water amount is 1860 kilograms per minute; the crude concentrated solution contains 1043 kg/min of starch and 5214 kg/min of water;

(4) And (4) feeding the crude concentrated solution in the step (3) into a main separation centrifuge to obtain concentrated starch milk of the underflow and gluten liquid of the overflow. Wherein, the concentrated starch milk of the underflow contains 1047 kg/min of starch and 2225 kg/min of water; the gluten liquid of the top flow contains 8 kg/min of starch and 3135 kg/min of water;

(5) The gluten liquid in step 4 is further concentrated, and meanwhile, process water is generated; wherein the process water amount is 3047 kg/min;

(6) And 4, refining the concentrated starch milk in the step 4 in a washing and refining system to obtain the refined starch milk. The refined starch milk contains 823 kg/min of starch and 1190 kg/min of water.

Comparative example 4

(1) A fine grinding fluid was obtained by the same conditions as in example 4;

(2) The ground liquid enters a fiber washing and screening system for washing and screening to obtain slurry under the screen; wherein the slurry comprises 441 kg/min of starch and 3789 kg/min of water;

(3) And (3) mixing the thick slurry of the separating screen I with the thin slurry in the step (2), and then feeding the mixture into a pre-concentration centrifugal machine to obtain concentration, and generating process water and a crude concentrated solution. Wherein, the feed of the pre-concentration centrifuge contains 829 kg/min of starch and 4844 kg/min of water; the process water amount is 1786 kg/min; the crude concentrated solution contains 963 kg/min of starch and 4811 kg/min of water;

(4) And (4) feeding the crude concentrated solution in the step (3) into a main separation centrifuge to obtain concentrated starch milk of the underflow and gluten liquid of the overflow. Wherein, the concentrated starch milk of the bottom flow contains 964 kg/min of starch and 2050 kg/min of water; the top flow of the gluten liquid contains 9 kg/min of starch and 2895 kg/min of water;

(5) The gluten liquid in step 4 is further concentrated, and simultaneously process water is generated; wherein, the process water amount is 2814 kg/min;

(6) And 4, refining the concentrated starch milk in the step 4 in a washing and refining system to obtain the refined starch milk. The refined starch milk contains 758 kg/min starch and 1096 kg/min water.

Comparative example 5

(1) A fine grinding fluid was obtained by the same conditions as in example 6;

(2) The ground liquid enters a fiber washing and screening system for washing and screening to obtain slurry under a screen; wherein the slurry contains 435 kg/min of starch and 3690 kg/min of water;

(3) And (3) mixing the thick slurry of the separating screen I with the thin slurry in the step (2), and then feeding the mixture into a pre-concentration centrifugal machine to obtain concentration, and generating process water and a crude concentrated solution. Wherein, the feed of the pre-concentration centrifugal machine contains 898 kg/min of starch and 5172 kg/min of water; the process water amount is 1860 kg/min; the crude concentrated solution contains 1043 kg/min starch and 5214 kg/min water;

(4) And (4) feeding the crude concentrated solution in the step (3) into a main separation centrifuge to obtain concentrated starch milk of the underflow and gluten liquid of the overflow. Wherein, the concentrated starch milk of the underflow contains 1047 kg/min of starch and 2225 kg/min of water; the gluten liquid of the top flow contains 7.8 kg/min of starch and 3135 kg/min of water;

(5) The gluten liquid in step 4 is further concentrated, and simultaneously process water is generated; wherein the process water amount is 3047 kg/min;

(6) And 4, refining the concentrated starch milk in a washing and refining system to obtain refined starch milk. The refined starch milk contains 823 kg/min of starch and 1190 kg/min of water.

As can be seen by comparison of the material balances (Table 2), using the primary concentration compared to the conventional Dalton process, the amount of starch fed to the preconcentration centrifuge was reduced by 429-821 kg/min (26-49 tons/hr), a reduced by 50.8% -91.4%; the water inflow is reduced by 510 to 1336 kilograms per minute (31 to 80 tons per hour), and reduced by 10.5 to 25.8 percent; the amount of the starch milk is reduced by 939 to 2156 kilograms per minute (56 to 129 tons per hour), and reduced by 16.5 to 35.5 percent. The feeding starch amount of the main centrifugal machine is reduced by 398 to 785 kg/min (24 to 47 tons/h), the reduced equivalent is 40.5 to 75.2 percent, the water inflow is reduced by 618 to 2003 kg/min (37 to 120 tons/h), and the reduced equivalent is 12.6 to 38.4 percent; the starch milk is reduced by 1016-2788 kg/min (61-167 tons/h), and the reduced conversion is reduced by 17-45%. Thereby greatly reducing the operation load of the pre-concentration and the main centrifugal machine. Correspondingly, compared with the traditional dalton process, the power energy of the pre-concentration centrifuge of the corn wet processing process comprising the primary concentration process is reduced by about 33-71%, and the power energy of the main centrifuge is reduced by 16-40%.

For a conventional dalton process with a capacity of 2000 tons/day, the pre-concentration, main separation and gluten concentration sections are typically configured with 2 centrifuges each. However, since the primary concentration process can greatly save the power energy of the pre-concentration centrifuge and the main separation section, even one centrifuge can be saved in the main separation section, which also greatly saves the cost of investment, operation and maintenance (table 3).

TABLE 3 comparison of conventional Dalton Process and Primary concentration Process Equipment configurations

Device configuration	Preconcentration centrifuge	Main centrifuge	Gluten concentration centrifuge
				Traditional dale process	2 bench	2 bench	2 table
Primary concentration process	2 table	1 table	2 bench

In addition, as can be seen from fig. 3, the reduction of the centrifuge load causes the reduction of the dry matter content of the process water of the centrifuge top flow, especially the concentrated centrifuge top flow (the reduction refers to that of each embodiment relative to the comparative example of the corresponding relation), so that the process water is purified, the quality of the process water is improved, the acid making and soaking processes are effectively improved, the indexes (soluble matter content, fig. 4) of the soaked corn are improved, and the optimization and progress of the whole process are realized.

Claims

1. A corn starch wet milling processing technology comprises the following steps:

(4) Enabling oversize materials of the separating screen II to enter a fiber washing and screening system to obtain slurry a and oversize materials for extracting fibers; optionally, splitting at least a portion of slurry a into slurry a1 and slurry a2;

2. The corn starch wet milling process as claimed in claim 1, wherein the steeping of the corn is performed with the antacid water having pH of 3.3-3.5 in the step (1).

3. The corn starch wet milling process of claim 2 wherein in step (1) the steeping of the corn is performed with an antacid water having a pH of 3.35-3.45.

4. The corn starch wet milling process of claim 1 wherein the soaking time in step (1) is 38-48 hours.

5. The corn starch wet milling process as claimed in claim 4, wherein the soaking time in the step (1) is 42h to 46h.

6. The corn starch wet milling process of claim 1 wherein in step (1) the crushing step is performed using a burr mill at 1450-1500 rpm.

7. The corn starch wet milling process of claim 6 wherein in step (1) the crushing step is performed using a lobed mill at a speed of 1460-1490 rpm.

8. The corn starch wet milling process of claim 1, wherein in step (1), the screen openings of the separating screen I are in the range of 45 μm to 60 μm and the operating pressure is in the range of 0.2MPa to 0.4MPa.

9. The corn starch wet milling process of claim 8 wherein in step (1) the screen openings of the separating screen I are in the range of 48 μm to 55 μm.

10. The corn starch wet milling process of claim 8 wherein in step (1) the operating pressure of the separating screen I is from 0.3MPa to 0.4MPa.

11. The corn starch wet milling process of claim 1 wherein in step (2) the refining is fine crushing at a rotational speed of 2900-3100 rpm.

12. The corn starch wet milling process of claim 11 wherein in step (2) said refining is fine crushing at a speed of 2950-3050 rpm.

13. The corn starch wet milling process of claim 1 wherein in step (2) the post-refiner grinding liquor comprises: 393-485 kg/min of starch; fiber 92-141 kg/min; 1241-1729 kg/min of water.

14. The corn starch wet milling process of claim 13 wherein in step (2) the post-refiner grinding liquor comprises 402-416 kg/min starch.

15. The corn starch wet milling process as claimed in claim 13, wherein in step (2) the post-refiner liquor comprises 95-110 kg/min fiber.

16. The corn starch wet milling process as claimed in claim 13, wherein in step (2), the post-refiner milling liquor comprises 1270-1420 kg/min water.

17. The corn starch wet milling process of claim 1 wherein in step (3) the separating screen II is a pressure trommel.

18. The corn starch wet milling process of claim 17 wherein in step (3) the pressure wire has a pore size of 60 μm or less.

19. The corn starch wet milling process of claim 18 wherein in step (3) the pressure wire has a pore size of 50 μm or less.

20. The corn starch wet milling process as claimed in claim 1, wherein the operating pressure of the separating screen II in step (3) is in the range of 0.2MPa to 0.4MPa.

21. The corn starch wet milling process of claim 20, wherein in step (3) the separating screen II is operated at a pressure in the range of 0.3MPa to 0.35MPa.

22. The corn starch wet milling process of claim 1 wherein in step (3) the screen II undersize concentrate comprises: 69-109 kg/min of starch; 239-350 kg/min of water.

23. The corn starch wet milling process of claim 22 wherein in step (3) the screen II undersize concentrate comprises 93-101 kg/min starch.

24. The corn starch wet milling process as claimed in claim 1, wherein in step (3) the separating screen II oversize comprises: 285-410 kg/min of starch; fiber 92-141 kg/min; 923 to 1410 kg/min of water.

25. The corn starch wet milling process of claim 24 wherein in step (3) the separation screen II oversize comprises 300-395 kg/min starch.

26. The corn starch wet milling process of claim 24 wherein in step (3) the separation screen II oversize comprises 95-141 kg/min fiber.

27. The corn starch wet milling process of claim 24 wherein in step (3) the separation screen II oversize comprises water 952-1410 kg/min.

28. The corn starch wet milling process of claim 1, wherein in step (4) the fiber wash screen system has a mesh size of 70 μm to 80 μm and an operating pressure of 0.2MPa to 0.4MPa.

29. The corn starch wet milling process of claim 28 wherein in step (4) the fiber wash screen system has a mesh size of 72 μm to 78 μm.

30. The corn starch wet milling process of claim 28 wherein in step (4) the operating pressure of the fiber wash screen system is from 0.25MPa to 0.35MPa.

31. The corn starch wet milling process of claim 1 wherein in step (4) slurry a comprises: 277-392 kg/min of starch; 2812-3243 kg/min of water.

32. The corn starch wet milling process as claimed in claim 31, wherein slurry a contains 292-379 kg/min starch in step (4).

33. The corn starch wet milling process as claimed in claim 1, wherein the whole of slurry a is divided into slurry a1 and slurry a2 in step (4).

34. The corn starch wet milling process of claim 1 wherein in step (5) the cyclone is from stage 1 to stage 2.

35. The corn starch wet milling process as claimed in claim 34, wherein in step (5) the cyclone is stage 1.

36. The corn starch wet milling process of claim 1 wherein in step (5) the cyclone is of a size selected from the group consisting of

And

or a combination of one or more thereof.

37. The corn starch wet milling process of claim 1, wherein in step (5) the cyclone has a pipe count of 316-598.

38. The corn starch wet milling process of claim 37, wherein in step (5), the cyclone has a tube count of 430-452.

39. The corn starch wet milling process of claim 1 wherein the feed pressure to the cyclone in step (5) is from 0.65 to 0.8MPa.

40. The corn starch wet milling process as claimed in claim 39, wherein the feed pressure to the cyclone in step (5) is 0.65 to 0.75MPa.

41. The corn starch wet milling process as claimed in claim 1, wherein in step (5) the feed to the cyclone comprises: 413-864 kg/min starch; 1858-5209 kg/min of water.

42. The corn starch wet milling process as claimed in claim 41 wherein the feed to the cyclone in step (5) comprises 489-763 kg/min starch.

43. The corn starch wet milling process as claimed in claim 41, wherein the feed to the cyclone in step (5) comprises 2182-4533 kg/min water.

44. The corn starch wet milling process of claim 1 wherein in step (5) the concentrated starch milk I comprises: 372-778 kg starch/min; 790-1654 kg/min of water.

45. The corn starch wet milling process of claim 44 wherein in step (5) the concentrated starch milk I contains 440-662 kg/min starch.

46. The corn starch wet milling process of claim 44, wherein in step (5), the concentrated starch milk I contains 935-1410 kg/min water.

47. The corn starch wet milling process of claim 1 wherein in step (5) slurry b comprises: 43-86 kg/min of starch; 1109 to 3555 kilograms/minute of water.

48. The corn starch wet milling process as claimed in claim 47, wherein in step (5) the slurry b comprises 49-75 kg/min starch.

49. The corn starch wet milling process of claim 47, wherein in step (5), the slurry b comprises 1245-3125 kg/min water.

50. The corn starch wet milling process of claim 1 wherein in step (6) the pre-concentration centrifuge is operated at 2700-3100 rpm.

51. The corn starch wet milling process of claim 50 wherein in step (6) the pre-concentration centrifuge rotates at 2900-3050 rpm.

52. The corn starch wet milling process as claimed in claim 1 wherein in step (6) the feed to the preconcentration centrifuge comprises: 77-428 kg/min of starch; 3836-4353 kg/min of water.

53. The corn starch wet milling process as claimed in claim 52 wherein in step (6) the feed to the preconcentration centrifuge comprises 144-351 kg/min starch.

54. The corn starch wet milling process of claim 52 wherein in step (6) the feed to the preconcentration centrifuge comprises water 3773-4340 kg/min.

55. The corn starch wet milling process of claim 1 wherein in step (6) the preconcentration centrifuge produces from 2730 to 3552 kg/min process water.

56. The corn starch wet milling process of claim 55 wherein in step (6) the preconcentration centrifuge produces an amount of process water in the range of 2930 to 3442 kg/min.

57. The corn starch wet milling process as claimed in claim 1, wherein in step (6) the crude concentrate comprises: 258-602 kg/min of starch; 3210-4330 kg/min of water.

58. The corn starch wet milling process as claimed in claim 57, wherein in step (6) the crude concentrate comprises 312-515 kg/min starch.

59. The corn starch wet milling process of claim 57 wherein in step (6) the crude concentrate comprises water 3280-4115 kg/min.

60. The corn starch wet milling process of claim 1 wherein in step (6) the process water obtained in step (6) is recycled for use in the preparation of acid making water in step (1).

61. The corn starch wet milling process of claim 1 wherein in step (7) the main separator centrifuge rotates at 2300 to 2500 rpm.

62. The corn starch wet milling process of claim 61 wherein in step (7) the main separator centrifuge rotates at 2400-2480 rpm.

63. The corn starch wet milling process of claim 1 wherein in step (7) the concentrated starch milk II comprises: 269-612 kg/min of starch; water 572-1305 kg/min.

64. The corn starch wet milling process of claim 63, wherein in step (7) said concentrated starch milk II contains 321-594 kilograms per minute of starch.

65. The corn starch wet milling process of claim 63, wherein in step (7) the concentrated starch milk II contains 680-1262 kg/min water.

66. The corn starch wet milling process of claim 1 wherein in step (7) the gluten liquid comprises: 7.8-11 kg/min of starch; 2837 to 3268 kg/min of water.

67. The corn starch wet milling process as claimed in claim 66, wherein in step (7) the gluten liquid comprises 7.8-9 kg/min starch.

68. The corn starch wet milling process of claim 66 wherein in step (7) the gluten liquid comprises water 2878-3267 kg/min.

69. The corn starch wet milling process of claim 1 wherein in step (8) the gluten concentration is performed by a gluten concentration separator.

70. The corn starch wet milling process of claim 69 wherein in step (8) the gluten concentration separator produces from 2757 to 3177 kg/min process water.

71. The wet milling process of corn starch as claimed in claim 70, wherein in step (8), said gluten concentration separator produces 2798-3176 kg/min of process water.

72. The corn starch wet milling process as claimed in claim 1, wherein the operating pressure of the washing and refining system in step (9) is 0.7MPa to 0.9MPa.

73. The corn starch wet milling process as claimed in claim 72, wherein in step (9) the operating pressure of the wash refining system is from 0.75MPa to 0.85MPa.

74. The corn starch wet milling process of claim 1 wherein in step (9) the refined starch milk comprises: 758-823 kg/min of starch; 1096-1190 kg/min of water.

75. The corn starch wet milling process of claim 74, wherein in step (9) the fine starch milk comprises 773-823 kg/min starch.

76. The corn starch wet milling process of claim 74 wherein in step (9) the refined starch milk comprises 1118 to 1190 kg/min water.

77. A primary concentration process for wet processing of corn starch, the primary concentration process comprising the steps of:

78. The primary concentration process of claim 77, wherein in step (1), the steeping of the corn is performed with an acid water having a pH of 3.3-3.5.

79. The primary concentration process of claim 78, wherein in step (1), the steeping of the corn is performed with an acid water having a pH of 3.35-3.45.

80. The primary concentration process of claim 77, wherein in step (1), the soaking time is 38-48 h.

81. The primary concentration process of claim 80, wherein in the step (1), the soaking time is 42-46 h.

82. The primary concentration process of claim 77, wherein, in step (1), the crushing process is performed at 1450-1500 rpm using a lobe mill.

83. The primary concentration process of claim 82, wherein, in step (1), the crushing process is performed using a lobed mill at a speed of 1460-1490 rpm.

84. The primary concentration process as claimed in claim 77, wherein, in the step (1), the sieve opening of the separation sieve I is 45 μm to 60 μm, and the operation pressure is 0.2MPa to 0.4MPa.

85. The primary concentration process as claimed in claim 84, wherein, in the step (1), the mesh size of the separation sieve I is 48 μm to 55 μm.

86. The primary concentration process of claim 84, wherein, in said step (1), the operating pressure of said separation screen I is between 0.3MPa and 0.4MPa.

87. The primary concentration process of claim 77, wherein in step (2), the refining is fine crushing at a rotational speed of 2900-3100 rpm.

88. The primary concentration process of claim 87, wherein, in said step (2), said refining is performed at a rotation speed of 2950-3050 rpm for fine crushing.

89. The primary concentration process of claim 77, wherein, in said step (2), said refiner-milled liquor comprises: 393-485 kg/min of starch; 92-141 kg/min of fiber; 1241-1729 kg/min of water.

90. The primary concentration process of claim 89, wherein, in step (2), the fine ground liquor comprises 402-416 kg/min starch.

91. The primary concentration process of claim 89, wherein, in step (2), the refiner-milled liquid comprises 95 to 110 kg/min of fibers.

92. The primary concentration process of claim 89, wherein, in said step (2), said refiner-milled liquor comprises 1270-1420 kg/min water.

93. The primary concentration process of claim 77, wherein, in said step (3), said separating screen II is a pressure bending screen.

94. The primary concentration process of claim 93, wherein, in the step (3), the pore size of the pressure curved sieve is ≤ 60 μm.

95. The primary concentration process of claim 94, wherein, in the step (3), the pore size of the pressure curved sieve is less than or equal to 50 μm.

96. The primary concentration process of claim 77, wherein, in said step (3), the operating pressure of said separating screen II is in the range of 0.2MPa to 0.4MPa.

97. The primary concentration process of claim 96, wherein, in said step (3), the operating pressure of said separating screen II ranges from 0.3MPa to 0.35MPa.

98. The primary concentration process of claim 77, wherein in said step (3), said separation screen II undersize thick stock comprises: 69-109 kg/min of starch; 239-350 kg/min of water.

99. The primary concentration process of claim 98, wherein in step (3), the undersize concentrate of sieve II comprises 93-101 kg/min starch.

100. The primary concentration process of claim 77, wherein in step (3), the separation screen II oversize comprises: 285-410 kg/min of starch; fiber 92-141 kg/min; 923-1410 kg/min water.

101. The primary concentration process of claim 100, wherein in step (3), the separation screen II oversize comprises 300-395 kg/min starch.

102. The primary concentration process of claim 100, wherein in said step (3), said separation screen II oversize comprises 95-141 kg/min fiber.

103. The primary concentration process of claim 100, wherein in said step (3), said separation screen II oversize comprises water 952-1410 kg/min.

104. The primary concentration process as claimed in claim 77, wherein in the step (4), the fiber washing and screening system has a mesh size of 70 μm to 80 μm and an operating pressure of 0.2MPa to 0.4MPa.

105. The primary concentration process of claim 104, wherein in step (4), the fiber washing and screening system has a mesh size of 72 μm to 78 μm.

106. The primary concentration process of claim 104, wherein, in said step (4), said fiber washing and screening system is operated at a pressure of 0.25MPa to 0.35MPa.

107. The primary concentration process of claim 77, wherein, in said step (4), said slurry a comprises: 277-392 kg/min of starch; 2812-3243 kg/min of water.

108. The primary concentration process of claim 107, wherein, in step (4), the slurry a comprises 292-379 kg/min of starch.

109. The primary concentration process of claim 77, wherein in step (4), the entire portion of slurry a is split into slurry a1 and slurry a2.

110. The primary concentration process of claim 77, wherein, in said step (5), said cyclone is from 1 stage to 2 stages.

111. The primary concentration process of claim 110, wherein, in said step (5), said cyclone is stage 1.

112. The primary concentration process of claim 77, wherein in step (5), the size of said cyclone is selected from the group consisting of

And

one or more of the above.

113. The primary concentration process of claim 77, wherein, in said step (5), the number of tubes of said cyclone is 316-598.

114. The primary concentration process of claim 113, wherein in said step (5), the number of tubes of said cyclone is 430-452.

115. The primary concentration process as claimed in claim 77, wherein, in said step (5), the feed pressure of said cyclone is 0.65-0.8MPa.

116. The primary concentration process as claimed in claim 115, wherein, in said step (5), the feed pressure of said cyclone is 0.65-0.75MPa.

117. The primary concentration process of claim 77, wherein in step (5), the feed to the cyclone comprises: 413-864 kg/min starch; 1858-5209 kg/min of water.

118. The primary thickening process of claim 117, wherein in step (5) the feed to the cyclone contains 489-763 kg/min starch.

119. The primary concentration process as claimed in claim 117, wherein in said step (5), the feed to said cyclone comprises 2182-4533 kg/min of water.

120. The primary concentration process of claim 77, wherein in step (5), the concentrated starch milk I comprises: 372-778 kg/min of starch; 790-1654 kg/min of water.

121. The primary concentration process of claim 120, wherein, in step (5), the concentrated starch milk I comprises 440-662 kg/min starch.

122. The primary concentration process of claim 120, wherein, in said step (5), said concentrated starch milk I contains 935-1410 kg/min of water.

123. The primary concentration process of claim 77, wherein, in said step (5), said slurry b comprises: 43-86 kg/min of starch; 1109 to 3555 kilograms of water per minute.

124. The primary concentration process of claim 123, wherein, in step (5), the slurry b contains 49-75 kg/min of starch.

125. The primary concentration process of claim 123, wherein, in step (5), the slurry b comprises 1245-3125 kg/min water.

126. A corn starch wet milling process system, wherein the system comprises:

a crushing system;

a refining connected in fluid communication downstream of the separating screen I;