CN110732382A

CN110732382A - machine-made sand vertical mill and production process system thereof

Info

Publication number: CN110732382A
Application number: CN201911173510.8A
Authority: CN
Inventors: 聂文海; 宋留庆; 何小龙; 杜鑫; 柴星腾
Original assignee: China Material (tianjin) Powder Technology Equipment Co Ltd; Tianjin Cement Industry Design and Research Institute Co Ltd
Current assignee: China Material (tianjin) Powder Technology Equipment Co Ltd; Tianjin Cement Industry Design and Research Institute Co Ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2020-01-31

Abstract

The invention discloses an machine-made sand vertical mill and a production process system thereof, belonging to the technical field of vertical mill sand making, wherein the machine-made sand vertical mill comprises a millstone, at least two grinding rollers, a material blocking ring and an auxiliary discharge device, the conical angle of each grinding roller is not more than 20 degrees, the total projection area of the grinding rollers on the millstone is 20-35 percent of the area of the millstone, the material blocking ring is a through-type screening material blocking assembly or a cross-over material blocking ring, and the auxiliary discharge device comprises a pneumatic blowing device and/or a mechanical discharge device.

Description

machine-made sand vertical mill and production process system thereof

Technical Field

The invention belongs to the technical field of vertical-mill sand making, and particularly relates to an machine-made sand vertical mill and a production process system thereof.

Background

With the continuous development of economy, the consciousness of environmental protection is gradually deepened, in the field of building materials, concrete is which is a material used in a large scale, sand serves as an aggregate of the concrete and plays a role of a framework in the concrete, the aggregate is further divided into coarse aggregate and fine aggregate, the coarse aggregate refers to aggregate with the particle size larger than 5mm, mainly natural rock or pebble, the fine aggregate refers to aggregate with the particle size of below 4.75mm, mainly river sand and machine-made sand, , under the condition that the river sand or machine-made sand refers to fine sand with the particle size of 0.075-1.18 mm, medium sand with the particle size of 1.18-2.36 mm and coarse sand with the particle size of 2.36-4.75 mm, the dry-mixed mortar can meet the requirements of different products, for example, the dry-mixed mortar mainly uses the fine sand and the medium sand, the common concrete mainly uses the medium sand and the coarse sand, the common concrete mainly uses the medium sand and the medium sand as the common sand, the common concrete mainly uses 63sand and , the natural sand as the natural sand, the natural sand is developed to promote the market of the rapid mining.

The existing machine-made sand production technology mainly adopts equipment such as a jaw crusher, a cone crusher, a ball mill, a double-rotor sand making machine, a vertical shaft type impact crusher and the like as main crushing equipment, the machine-made sand production is realized through multi-stage crushing, but the jaw crusher and the cone crusher crush particles by means of impact force, the acting force on the particles is small, the particles are crushed selectively, the produced machine-made sand particles are poor in circularity and mostly in a needle shape, and the gold small crystal is researched in the influences of aggregate needle shape content on the strength of gelled sand gravel (the regulations of water conservancy and south water north in the south of the river and 76-7 pages in 6 years in 2018), the needle shape sand gravel in concrete is considered to be harmful particles, the fluidity and the strength of the concrete can be greatly reduced, the quality deviation of the machine-made sand is reduced to the greatest extent, therefore, the product quality deviation of the jaw crusher and cone crusher machine-made sand preparation machine-made sand is not beneficial to engineering application, the ball mill is adopted as crushing equipment, the produced machine-made sand particles are good in circularity, but the major function of grinding, the production of the grinding powder fine powder is considered to be high in the scale production process of the mechanical sand preparation machine-made sand production, the mechanical sand production is considered to be high in the research of the high-made by the high-made fine powder production of the ball mill 150, the ball mill, the wet sand production machine-made sand production, the wet sand production process of the wet sand production, the wet sand production machine.

From the current production process, the machine-made sand production system adopting the crusher only adopts the cyclone cylinder as dust collection equipment, has poor field dust collection effect, serious ash emission in production and does not meet the requirement of green production, so that novel machine-made sand equipment and process systems need to be developed urgently, the product quality of machine-made sand is improved, the environment-friendly quality of a machine-made sand production line is improved, and green, efficient and large-scale production is realized.

The vertical mill is used as energy-saving and efficient material bed grinding equipment, universal application is achieved in the aspects of cement grinding and metallurgical slag treatment, the grinding rolls and the grinding discs move mutually, after particles form a material bed on the grinding discs and are subjected to extrusion force, the particles are crushed by extrusion and shearing force, the materials are ground for multiple times in the rolling process of the grinding discs, the particle roundness is good, the energy utilization efficiency of crushing and grinding of the vertical mill is higher than that of selective crushing of a cone crusher and that of single particles of a ball mill, therefore, the vertical mill is used as grinding equipment to produce fine powder and is accepted and applied widely by , Chinese patent publication No. CN109277146A discloses vertical mill sand making machines, the vertical mill sand making machines comprise a transmission device, a grinding device, a pressurizing device, a limiting device, a feeding device, a lower shell and a discharging device, the technology can basically achieve production of machine-made sand, and the defects exist due to the adoption of a traditional vertical mill structure:

1. the content of fine powder (less than 0.075mm) in the manufacturing process is too high, so that the sand forming rate is low, the energy consumption is high, the resource waste is caused, and the efficiency is low;

2. the extension of the grinding disc has fine powder accumulation, excessive grinding is caused in an accumulation area, the operation stability of the vertical mill is poor, the reliability of equipment is poor, and the shutdown maintenance frequency is high;

3. in the existing vertical mill, the tire roller is adopted, and raised arc transition surfaces exist on a grinding disc of the grinding structure, so that the flowability of materials on the grinding disc is poor;

4. auxiliary discharge is not involved, resulting in too high a fine content in the machine-made sand.

As more efficient and energy-saving grinding equipment, the grinding equipment is feasible in principle when used for producing machine-made sand, but the granularity of a product is increased from less than 0.075mm to less than 4.75mm, the original vertical mill needs to be redesigned, and the problems of high fine powder content, poor product circularity and high production energy consumption of the traditional machine-made sand crushing equipment are solved.

Disclosure of Invention

The invention aims at providing a machine-made sand vertical mill, which has the advantages of high sand forming rate, low energy consumption, no resource waste and high production efficiency.

Another objective of the invention is to provide kinds of machine-made sand production process systems using the machine-made sand vertical mill.

The machine-made sand vertical mill comprises a grinding disc, at least two grinding rollers and a material blocking ring, wherein the conical angle of each grinding roller is not more than 20 degrees, and the total projection area of the grinding rollers on the grinding disc is 20-35% of the area of the grinding disc.

Preferably, the material blocking ring is a through-type screening material blocking assembly, the through-type screening material blocking assembly comprises a material blocking ring and a fastening support piece, the material blocking ring is fixed on the grinding disc through the fastening support piece, and a hollow structure is formed between the material blocking ring and the grinding disc.

, preferably, the duty ratio of the hollow structure is 1 (0.4-0.7).

, preferably, the height of the hollow structure is 30-200 mm, and the height of the material retaining ring is 5-100 mm.

, preferably, the total height of the through type screening material blocking assembly is 2-6% of the diameter of the grinding disc.

preferably, a protective sleeve is sleeved outside the fastening support in the hollow structure, and the protective sleeve supports the upper retaining ring.

Preferably, the material blocking ring is a cross material blocking ring, a plurality of discharge openings are formed in the upper portion of the cross material blocking ring, so that the material blocking ring forms a concave-convex structure, and the total area of the discharge openings is 40-60% of the total area of the cross material blocking ring.

, preferably, the height of the concave part of the striding type material stop ring is 55-95% of the height of the convex part.

, preferably, the space between two adjacent discharge ports is 100-800 mm.

Preferably, the grinding disc grinding device further comprises an auxiliary discharging device, the auxiliary discharging device is located behind each grinding roller along the rotation direction of the grinding disc, and the auxiliary discharging device comprises a pneumatic blowing device and/or a mechanical discharging device.

preferably, the pneumatic injection device is fixed on the vertical mill shell and used for discharging the fine powder generated after grinding in time, and a nozzle of the pneumatic injection device extends into the upper part of the grinding disc and faces the material stop ring side or the grinding disc side.

And , preferably, the height of a nozzle of the pneumatic blowing device from the surface of the grinding disc is 20-100 mm, and the radial distance of the nozzle from the material retaining ring is 5-80 mm.

preferably, the mechanical discharging device is a shovel plate which is arranged obliquely downwards towards the grinding disc and is used for timely discharging the ground materials, wherein the end of the shovel plate is fixed on the vertical mill housing, and the other end of the shovel plate extends to the upper part of the grinding disc.

Preferably, , the shovel plate includes a material guiding section and a material shoveling section, and the shovel plate is in arc transition at the connection of the material shoveling section and the material guiding section.

Preferably in step , the distance between the part of the shovel plate above the grinding disc and the grinding roller is 5-30 mm, the distance between the shovel plate and the grinding roller is 5-60 mm, and the distance between the shovel plate and the material retaining ring is 5-80 mm.

Adopt above-mentioned machine-made sand to immediately grind and carry out machine-made sand production process systems, including former feed bin, machine-made sand immediately mill, combination formula selection powder machine, shale shaker and gumming mechanism, gumming mechanism includes whirlwind section of thick bamboo and circulating fan, and former feed bin export links to each other with machine-made sand immediately grinds material inlet, and the material export that machine-made sand immediately milled links to each other with combination formula selection powder machine's material inlet, and combination formula selection powder machine's bottom discharge gate links to each other with the shale shaker, and the shale shaker returns the oversize thing to machine-made sand immediately mill, and combination formula selection powder machine's air outlet links to each other with the whirlwind section of thick bamboo, and.

Preferably, the outlet of the circulating fan is also sequentially provided with a dust collector and a tail exhaust fan.

Preferably, the materials from the raw material bin can be directly fed into the combined powder concentrator through a belt conveyor.

Preferably, a plurality of layers of screens with different apertures are arranged on the vibrating screen.

Preferably, the combined powder concentrator comprises a sand concentration mechanism and a powder concentration mechanism, and the sand concentration mechanism is positioned below the powder concentration mechanism and connected through an expansion joint;

the sand separation mechanism comprises an air inlet shell, a sand separation shell and a sand collection shell, wherein the air inlet shell, the sand separation shell and the sand collection shell are sequentially connected through flanges, a plurality of air distribution plates are distributed on the side, close to the sand separation shell, of the air inlet shell from top to bottom, and an air inlet flange port is formed on the side, far away from the sand separation shell, of the air inlet shell;

the powder selecting mechanism comprises a flow guide shell, a powder selecting shell, a powder discharging shell, a driving device, a transmission main shaft and a rotating cage, wherein the flow guide shell, the powder selecting shell and the powder discharging shell are sequentially arranged from bottom to top and are connected through flanges, the driving device is arranged above the powder discharging shell and drives the transmission main shaft to rotate, the transmission main shaft is inserted into the powder discharging shell from top to bottom, the lower portion of the transmission main shaft is connected with the rotating cage through a flange, the rotating cage is arranged in the center of the powder selecting shell, the bottom of the flow guide shell is connected with the other end of an expansion joint, a sand return cone is arranged on the inner side of the flow guide shell, a space is reserved between the sand return cone and the flow guide shell, sand return pipes leading to a sand outlet are arranged at the bottom of the sand return cone, a plurality of flow guide vanes are uniformly distributed around the rotating cage, the tops of the flow guide vanes are connected with the lower bottom plate of the powder discharging shell, the bottoms of the flow guide vanes.

Preferably, the middle lower part of the air inlet shell and the sand collecting shell is provided with a supporting flange for fixing the sand selecting mechanism on the bracket.

Preferably, a plurality of supporting flanges are arranged on the outer side of the flow guide shell and used for fixing the powder selecting mechanism on the support.

Preferably, the distribution of the rotating cage and the guide vanes is coaxial with the powder selecting shell and the guide shell.

Preferably, the sand return pipe is mounted on the inner wall plate of the sand collecting shell far away from the side of the sand selecting shell .

Preferably, the powder concentrator further comprises a lubricating device, and the lubricating device is fixed on the powder concentrating shell.

Preferably, a steady flow bin is further arranged between the raw material bin and the machine-made sand vertical mill.

Preferably, a pre-screening device is arranged between the machine-made sand vertical mill and the combined powder concentrator.

Preferably, the machine-made sand mixing system further comprises a weighing device, a mixing device, a conveying device and a storage device.

The invention has the following advantages and beneficial effects:

1. according to the machine-made sand vertical mill, the grinding roller and the grinding disc move relatively to crush particles, so that the energy efficiency utilization rate is higher than that of a traditional crusher, the energy consumption can be saved by 15-45%, and the machine-made sand vertical mill has an obvious energy-saving effect; the machine-made sand adopts a material bed grinding structure, the raw materials are crushed by extrusion and shearing acting forces in a machine-made sand vertical mill, the circularity of the crushed particles is higher than that of the crushed particles due to impact crushing of a crusher, and the finished product particles have fewer needle-shaped particles and are better in quality; the machine-made sand vertical mill is of a totally enclosed structure, operates under micro negative pressure, has no dust leakage in the production process, and has good production environmental protection effect; the system has simple process flow, convenient operation and maintenance and high equipment intelligence degree, and is beneficial to large-scale production.

2. The machine-made vertical sand mill adopts a structure that a mill disc rotates mainly and a grinding roller rotates secondarily, the mill disc rotates under the driving of a motor and a speed reducer, the grinding roller is extruded on the mill disc under the action of a constant load pressure, the rotation of the mill disc drives the grinding roller to rotate, a material falls onto the mill disc through a central blanking pipe, moves towards the outer edge of the mill disc under the action of the rotation centrifugal force of the mill disc, is crushed by extrusion and shearing force when passing through the grinding roller, is directly thrown out of the mill disc, enters a lifter through an air duct and then enters the next steps.

3. According to the material blocking ring of the machine-made vertical sand mill, the content of fine powder of the obtained mill material is only 10-20%, the content of fine powder is reduced, only 20-30% of large particles which are not ground enter the mill material, the energy consumption of an auxiliary machine is reduced by 5-10%, and the material blocking efficiency of the large particles is improved; and an auxiliary discharging device is additionally used, so that auxiliary discharging can be better performed.

4. The combined type powder concentrator can simultaneously separate sand and powder from fed materials, the coarse materials left after separation can return to a machine-made sand vertical mill, closed cycle of crushing-sand separation is realized, the sand grain deformation is good, the function of a vibrating screen and a powder removing machine is combined , the utilization rate of equipment is improved to the maximum extent, the investment of the equipment is saved, the power consumption of separation is reduced, and the machine-made sand with good grading is obtained by adjusting the parameters of the concentration of the powder of the sand concentrator, the linear speed of a rotating cage, the installation angle of a guide vane and the like.

Drawings

Figure 1 is a schematic structural view of a through screen dam assembly provided in accordance with an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a striding type tail ring provided in the second embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a pneumatic blowing device and a mechanical discharging device according to a third embodiment of the present invention;

FIG. 4 is a flow chart of a machine-made sand production process system provided by the fourth embodiment of the invention;

FIG. 5 is a flow chart of a machine-made sand production process system provided by the fifth embodiment of the invention;

FIG. 6 is a flow chart of a machine-made sand production process system provided by a sixth embodiment of the present invention;

FIG. 7 is a flow chart of a machine-made sand production process system provided by the seventh embodiment of the invention;

fig. 8 is a schematic structural diagram of a combined type powder concentrator provided by an eighth embodiment of the invention;

fig. 9 is a schematic structural view of a rotating cage and guide vanes of the combined powder concentrator at a-a according to an eighth embodiment of the present invention;

FIG. 10 is a flow diagram of a machine-made sand production process system provided by example nine of the present invention;

fig. 11 is a flow chart of a machine-made sand production process system provided in the tenth embodiment of the present invention.

In the figure: 100-machine-made sand vertical mill; 110-grinding rolls; 120-grinding disc; 130-through screening stop assemblies; 131-a material blocking ring; 132-a fastening support; 133-a protective sleeve; 134-a cap; 140-crossing material blocking ring; 141-a discharge port; 150-a pneumatic blowing device; 151-a nozzle; 152-a gas delivery pipe; 160-mechanical discharge device; 161-a material guiding section; 162-material shoveling section; 170-vertical mill shell;

200-a raw material bin;

300-combined powder concentrator; 310-a sand selecting mechanism; 311-air intake shell; 312-sand selecting shell; 313-sand collecting shell; 314-weight type airlock valve; 315-breaking up the step plate; 316-a flow guiding stepped plate; 317-air distribution plate; 318-sand return pipe; 320-powder selecting mechanism; 321-a flow guide shell; 322-selecting powder shell; 323-powder discharging shell; 324-a drive device; 325-a transmission main shaft; 326-rotating cage; 327-guide vanes; 328-a lubricating device; 329-sand return cone; 330-an expansion joint;

400-vibrating screen;

500-a pollen removal mechanism; 510-a cyclone; 520-a circulating fan;

600-a dust collector;

700-tail exhaust fan;

800-steady flow storehouse;

900-trommel screen;

1000-machine-made sand dispensing system; 1010-weighing device; 1020-a mixing device; 1030-conveying means.

Detailed Description

For purposes of making the objects, aspects and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments, which are to be considered together with the accompanying drawings.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "connected" and "connected" shall be construed , and for example, may be a fixed connection, a detachable connection, or physically connected, may be mechanically connected, may be electrically connected, may be directly connected, may be indirectly connected through an intermediate medium, and may communicate between two elements.

Example 1

Referring to fig. 1, the machine-made sand vertical mill 100 provided by the embodiment comprises a grinding disc 120, at least two grinding rollers 110 and a material blocking ring, wherein the conical angle of each grinding roller 110 is not more than 20 degrees, the total projection area of the grinding roller 110 on the grinding disc 120 is 20-35% of the area of the grinding disc, the increase of the projection area can increase the yield of grinding of the grinding roller times, and the yield of fine powder can be reduced by matching with the increase of the rotating speed and timely discharging the ground material out of the mill.

Preferably, referring to fig. 1, the material blocking ring is a through-type screening material blocking assembly 130, the through-type screening material blocking assembly 130 includes a material blocking ring 131 and a fastening support 132, the material blocking ring 131 is fixed on the grinding disc 120 through the fastening support 132, and a hollow structure is formed between the material blocking ring 131 and the grinding disc 120. The hollow structure of the lower layer ensures that the materials can be discharged in time after being extruded, reduces the excessive grinding of the vertical mill and reduces the generation amount of fine powder; the material blocking ring 131 of the upper solid structure effectively blocks large particles which are not ground, so that the large particles stay on the grinding disc, the large particles are guaranteed to be discharged outside the grinding machine after being ground, and the circulating load of the system and the production energy consumption are reduced.

, the duty ratio of the hollow structure is preferably 1 (0.4-0.7), in the embodiment, the height of the hollow structure is 30-200 mm, the height of the material retaining ring 131 is 5-100 mm, and the gap between every two fastening support pieces 132 is 20-600 mm, so that materials smaller than 50mm can pass through, and excessive grinding of the materials is prevented.

, preferably, the total height of the through-type screening material blocking assembly 130 is 2-6% of the diameter of the grinding disc 120, and reasonable matching is carried out according to the feeding amount.

100% of materials of the material blocking ring structure of the original vertical mill pass through the upper part of the material blocking ring, and the content of fine powder of the milled materials reaches 20-30%; 70-90% of materials pass through the hollow part at the lower part of the through type screening material blocking assembly 130, the content of fine powder of the ground materials is only 10-20%, and the content of the fine powder is reduced. In addition, in the material blocking ring structure of the original vertical mill, about 35-45% of large particles which are not ground enter the milled materials, so that the system load and the energy consumption are increased; by adopting the through-type screening material blocking assembly 130 structure, only 20-30% of large particles which are not ground enter a ground material, the energy consumption of an auxiliary machine is reduced by 5-10%, and the material blocking efficiency of the large particles is improved.

preferably, a protective sleeve 133 is sleeved outside the fastening support 132 in the hollow structure, and the protective sleeve 133 supports the material retaining ring 131 in the upper solid structure, the fastening support 132 in this embodiment is a bolt, and a cap 134 is sleeved on the bolt head above the material retaining ring 131, and the cap 134 and the protective sleeve 133 are sleeved up and down respectively to prevent the fastening support 132 from being worn and damaged due to long-term use, which results in difficulty in screwing.

In the process of producing machine-made sand, the main factors influencing the quality of the machine-made sand product are the grinding disc rotating speed of the machine-made sand vertical mill, the centrifugal force of materials on the grinding disc, the grinding pressure and the like.

Wherein, 1) the grinding disc rotating speed of the machine-made sand vertical mill is calculated by adopting the following formula:

wherein: n is the rotation speed of the grinding disc, r/min;

k is an empirical coefficient and is dimensionless, and the value of K is 48-60;

d is the diameter of the grinding disc of the vertical mill, m.

The grinding disc rotating speed of the machine-made sand vertical mill is 1.05-1.35 times of that of the traditional vertical mill, and the grinding disc rotating speed of the traditional vertical mill is 25-35 r/min. The increase of the rotating speed can shorten the retention time of material particles in the grinding disc, reduce the times of grinding the particles and reduce the generation of fine powder.

2) The centrifugal force of the material on the grinding disc is calculated by adopting the following formula:

F＝mV²/R

wherein: f is the centrifugal force on the grinding disc of the material, N;

m is the mass of the particles, kg;

v is the peripheral speed of the grinding disc, m/s;

radius of R-disc, m.

It can be seen that when V is larger, the centrifugal force applied to the material is larger, the residence time of the grinding disc is shorter, grinding times can be discharged out of the grinding disc in time, and the number and degree of over-grinding of the material are reduced.

3) The grinding pressure of the material is calculated by adopting the following formula:

P＝F×S₁÷S₂÷k

wherein: p is grinding pressure, MPa;

f is the grinding pressure of the hydraulic cylinder, and N is the grinding pressure of the hydraulic cylinder;

S₁is the effective area of the hydraulic oil in the hydraulic cylinder, m²；

S₂Is the projected area of a single grinding roller on the grinding disc, m²；

K is the rocker coefficient of the machine-made sand vertical mill, is dimensionless and is a structural space design value, and the value of K is 0.6-0.8.

It is clear that the greater the grinding pressure to which the material is subjected, the more easily it is crushed.

The diameter of the grinding disc is selected according to the actual yield and different raw materials, and the grinding disc is used as a traditional vertical mill for producing cement or raw material products, the traditional vertical mill cannot be directly used for producing machine-made sand, and the detailed description is given in the background art, so that the diameter of the grinding disc, the pressure and the rotating speed of the grinding roller and the design of the material stop ring of the vertical mill for producing the machine-made sand need to be redesigned and matched according to the characteristics of the machine-made sand products, the diameter of the grinding disc 120 of the vertical mill for producing the machine-made sand is preferably 1.2m, the pressure of the grinding roller 110 is preferably 5MPa, and the rotating speed of the grinding disc 120 is preferably 43.8 r/min; in order to prove that the invention can realize the production of the machine-made sand with the expected specification by using the vertical mill, the applicant takes limestone as a raw material to carry out experiments to produce the machine-made sand with the grain size specification of 0.15-2.36 mm, and the production machine-made sand experiments are carried out on the diameter of the grinding disc 120, the pressure of the grinding roller 110 and the rotating speed of the grinding disc 120 in the embodiment and are compared with the existing double-rotor sand making machine and a vertical shaft type impact crusher.

The specific contents are as follows: the limestone is used as a raw material for carrying out an experiment, a machine-made sand vertical mill with a grinding disc 120 and a diameter of 1.2m is adopted, the rotating speed of the grinding disc 120 is 43.8r/min, the grinding pressure is 5MPa, the through type screening material blocking assembly 130 is hollow and has a height of 30mm, the height of the material blocking ring 131 is 8mm, the grinding time is 50min, machine-made sand with a thickness of 0.15-2.36 mm is produced, and 6 tons of the machine-made sand are produced. The sphericity coefficient pair of the machine-made sand produced by the machine-made sand vertical mill of the invention and the machine-made sand prepared by the existing double-rotor sand making machine and the vertical shaft type impact crusher is shown in table 1:

TABLE 1 production test results

From the above table, the quality of the machine-made sand vertical mill is better than that of a double-rotor sand making machine and a vertical shaft type impact crusher.

Example 2

Different from the embodiment 1, referring to fig. 2, the material blocking ring of the embodiment is a striding type material blocking ring 140, the upper portion of the striding type material blocking ring 140 is provided with a plurality of material discharging openings 141, so that the striding type material blocking ring 140 forms a concave-convex structure, and the total area of the material discharging openings 141 is 40-60% of the total area of the striding type material blocking ring 140.

After the materials are ground for times by the grinding roller 110, fine powder is accumulated at the corner at the bottom of the material blocking ring to form slopes which can be used as stable material layers, and the ground materials can be discharged through the formed slopes after being ground.

, preferably, the height of the concave part of the striding type material stop ring 140 is 55-95% of the height of the convex part, and reasonable selection is carried out according to the feeding amount.

, preferably, the interval between two adjacent discharge ports 141 is 100-800 mm, and reasonable selection is carried out according to the feeding amount.

Example 3

Unlike the embodiments 1 and 2, the machine-made sand vertical mill of the present embodiment further includes an auxiliary discharging device, which is located behind each grinding roller 110 in the rotation direction of the grinding disc 120, and the auxiliary discharging device includes a pneumatic blowing device 150 and/or a mechanical discharging device 160.

When the auxiliary discharging device combining the pneumatic blowing device 150 and the mechanical discharging device 160 is adopted, the mechanical discharging device 160 is away from the grinding disc 120 for a certain height, so that the upper material is mainly scooped up, and the lower fine powder is blown out by the pneumatic blowing device 150, and the combination of the two can better perform auxiliary discharging.

preferably, referring to fig. 3, the air delivery pipe 152 of the air blowing device 150 is fixed on the vertical mill housing 170 for discharging the fine powder generated after grinding in time, the nozzle 151 of the air blowing device 150 extends above the grinding disc 120 and faces the material stop ring side or the grinding disc 120 side, the compressed air flow rate of the air blowing device 150 is 35-85 m/s, the air blowing device 150 is arranged inside the mill for discharging the fine powder generated after grinding in time, so that the fine powder is not ground again and the amount of the fine powder is reduced and increased.

Preferably in step , the height of the nozzle 151 of the pneumatic blowing device 150 from the surface of the grinding disc 120 is 20-100 mm, the radial distance of the nozzle 151 from the material stop ring is 5-80 mm, and reasonable selection is carried out according to the feeding amount.

preferably, referring to fig. 3, the mechanical discharging device 160 is a shovel plate disposed obliquely downward toward the grinding disc 120 for discharging the ground material in time, the end of the shovel plate is fixed to the housing 170 of the vertical mill, and the end of the shovel plate extends above the grinding disc 120. the mechanical discharging device 160 is disposed inside the mill for discharging the ground material in time, so as to reduce the retention time of the ground material in the grinding disc 120, prevent the material from being ground for a second time, reduce the generation of fine powder, and provide forces to the material with a shovel, so that the shoveled material is thrown out of the grinding disc 120.

preferably, the shovel plate includes a guiding section 161 and a shoveling section 162, the shovel plate is in arc transition at the junction of the shoveling section 162 and the guiding section 161, the shoveling section 162 is used to shovel the material and lead the material out of the mill through the guiding section 161.

Preferably, steps are further carried out, the distance between the part of the shovel plate above the grinding disc 120 and the grinding roller 110 is 5-30 mm, the distance between the shovel plate and the grinding disc 120 is 5-60 mm, the distance between the shovel plate and the material stop ring is 5-80 mm, and reasonable matching is carried out according to the feeding amount.

Example 4

Referring to fig. 4, the present embodiment provides types of production process systems for machine-made sand by using the above machine-made sand vertical mill, including a raw material bin 200, a machine-made sand vertical mill 100, a combined type powder concentrator 300, a vibrating screen 400 and a powder removing mechanism 500, where the powder removing mechanism 500 includes a cyclone 510 and a circulating fan 520, an outlet of the raw material bin 200 is connected to a material inlet of the machine-made sand vertical mill 100, a material outlet of the machine-made sand vertical mill 100 is connected to a material inlet of the combined type powder concentrator 300 through a hoisting machine, a bottom discharge port of the combined type powder concentrator 300 is connected to the vibrating screen 400, the vibrating screen 400 returns oversize material to the machine-made sand vertical mill 100, an air outlet of the combined type powder concentrator 300 is connected to the cyclone 510, and an air outlet of the cyclone 510.

The material is crushed and ground by the machine-made sand vertical mill 100 and enters the screening equipment such as the combined powder concentrator 300 and the vibrating screen 400, and the high-efficiency, low-energy-consumption and clean production of the machine-made sand is realized.

The raw material enters a machine-made sand vertical mill 100 from a raw material bin 200 through a conveying belt, the ground material is discharged out of the machine-made sand vertical mill 100 and enters a lifting machine, the material discharged from the lifting machine enters a combined type powder concentrator 300, fine powder smaller than 0.075mm passes through the combined type powder concentrator 300 and moves upwards under the driving of gas, coarse particles move downwards under the action of gravity, the fine powder passes through the combined type powder concentrator 300 and then is collected by a cyclone cylinder 510 and enters a lower working section, the material after powder removal enters a vibrating screen 400, the vibrating screen 400 is provided with screen holes with the size of , particles meeting the size requirement enter a finished product through the vibrating screen 400 to form finished sand, the vibrating screen 400 in the embodiment can be provided with screen holes with three sizes according to different requirements, for example, the screen hole diameter of the screen holes is 4.75mm, 2.36mm or 1.18mm, the corresponding particles smaller than or equal to 4.75mm, 2.36 or 1.18mm are used as finished sand, the particles larger than the required size of the vibrating screen 400 return to the machine-made to the sieve hole mechanism 100 for grinding again, the next step, the air circulation of the combined type sand mill , the air enters a chimney 510, the air circulation system, the air is returned to the cyclone cylinder 510, the air separation process of the combined type powder concentrator 300, and the air separation system, the air separation system is carried by the 365, the cyclone cylinder 510, the air separation system, the.

The method comprises the steps of producing machine-made sand by using a vertical mill, enabling ground materials to enter a combined type powder concentrator 300 through a lifting machine, enabling the combined type powder concentrator 300 to be composed of a dynamic powder concentrator on the upper portion and a static screening machine on the lower portion, enabling fine powder to move upwards under the driving of airflow, separating harmful fine powder under the action of the dynamic powder concentrator, enabling the fine powder to enter a next step, enabling coarse particles passing through the combined type powder concentrator 300 to move downwards under the action of gravity, discharging the coarse particles through a discharge port at the bottom of the combined type powder concentrator 300, enabling the coarse particles to enter a vibrating screen 400, and screening the coarse particles through the vibrating screen 400 to obtain a mixer-made sand.

The technology replaces the original cone crusher, a double-rotor sand making machine, a vertical shaft type impact crusher and the like, reduces the content of needle-shaped particles in a product, reduces the fine powder content of machine-made sand, improves the product quality of the machine-made sand, improves the energy utilization rate of the sand making, reduces the production energy consumption, is beneficial to large-scale production, improves the resource utilization rate, is beneficial to improving the performance of concrete, and is beneficial to the engineering quality.

Example 5

Different from embodiment 4, referring to fig. 5, the outlet of the circulation fan 520 of this embodiment is further provided with a dust collector 600 and a tail exhaust fan 700 in sequence.

Part of the gas after passing through the circulating fan 520 enters the dust collector 600, after dust removal by the dust collector 600, is exhausted to the atmosphere through the tail exhaust fan 700 and the chimney, the double-fan system consisting of the circulating fan 520 and the tail exhaust fan 700 is adopted to increase the field dust collection effect, and the dust collector 600 can reduce the dust emission concentration to 5mg/m³And the ultra-clean emission is realized, and the environment protection is facilitated. Meanwhile, the arrangement of the tail exhaust fan 700 is beneficial to the adjustment of the circulating air volume, and particularly when the moisture of the grinding material is more than 2.5%, the finished product has high requirement on the moisture content (for example, machine-made sand for dry powder mortar with the moisture of less than 0.5%), wet air can be discharged, the dewing of the wet air in a system is reduced, and the service life of a pipeline is prolonged. Hot air can be connected in series before separation, the materials ground by the vertical mill are dried, and the whole circulating system is prevented from being influenced by water vapor condensation.

Example 6

Unlike embodiment 4, referring to fig. 6, in this embodiment, the material from the raw material bin 200 can be directly fed into the combined powder concentrator 300 through a belt conveyor.

When the content of finished sand in the raw material is high, the raw material can directly enter the combined type powder concentrator 300 for powder separation, the grinding efficiency of the vertical mill is improved, the operation load of auxiliary machines in a system is reduced, the energy consumption of the auxiliary machines is saved, and the operation safety of auxiliary machine equipment is improved.

Example 7

Different from the embodiment 5, please refer to fig. 7, the vibrating screen 400 of the embodiment is provided with a plurality of layers of screens with different apertures, and the screens are set to layers or multiple layers, so that the step-by-step screening can be performed, and the requirement of multiple products can be met.

Three discharge ports of the combined powder concentrator 300 are arranged, namely a fine sand outlet, a medium sand and coarse sand outlet and a coarse particle discharge port, and particles with the medium sand fraction of more than 1.18 enter the vibrating screen 400 for secondary separation, the vibrating screen 400 of the embodiment is provided with two layers of screens, the aperture of the upper layer screen of the vibrating screen 400 is 4.75mm, the aperture of the lower layer screen is 2.36mm, and the particles with the size of more than 4.75mm above the upper layer screen return to the mill again for grinding; particles with the diameter of 2.36-4.75 mm are used as coarse sand products; products with the diameter of less than 2.36mm are used as medium sand and fine sand products. The technology has the advantages that the production of machine-made sand products with different grain sizes can be realized, the production efficiency is improved, and the operation cost of enterprises is reduced.

A steady flow bin 800 is also arranged between the raw material bin 200 and the machine-made sand vertical mill 100. The steady flow bin 800 ensures the stability of the materials to be ground, improves the crushing and grinding efficiency of the vertical mill, reduces the fluctuation of the system output, ensures the stable operation of the system, improves the energy utilization rate, reduces the production energy consumption, improves the operation safety of the equipment and reduces the operation failure rate.

In addition, the invention adds a dust collecting device of an auxiliary machine in the vertical sand mill 100, the hoister and the vibrating screen 400, the dust collecting device can adopt a bag type dust collector, the number of the dust collectors is set according to the requirement, the dust in the conveying process is removed by the dust collectors and is discharged into the atmosphere, and the removed dust is returned to a corresponding belt conveyor through a material outlet and is conveyed along with the system. The cleaning degree of the on-site environment can be improved, dust collection treatment is carried out on conveying and screening equipment containing dust, the cleaning production benefit is improved, and the environment is protected.

Example 8

Referring to fig. 8 and 9, the combined powder concentrator 300 provided in embodiment 7 includes a sand selecting mechanism 310 and a powder selecting mechanism 320, where the sand selecting mechanism 310 is located below the powder selecting mechanism 320 and connected by an expansion joint 330; the expansion joint 330 is used for compensating the manufacturing error and the deformation of the upper and lower two-part mechanism caused by the temperature change.

The sand selecting mechanism 310 comprises an air inlet shell 311, a sand selecting shell 312 and a sand collecting shell 313, the air inlet shell 311, the sand selecting shell 312 and the sand collecting shell 313 are sequentially connected through flanges, a plurality of air distribution plates 317 are distributed on the side, close to the sand selecting shell 312, of the air inlet shell 311 from top to bottom, an air inlet flange port is formed on the side, far away from the sand selecting shell 312, of the air inlet shell 312, a feeding port is formed in the top of the sand selecting shell 312, a coarse material discharging port is formed in the bottom of the sand selecting shell, a heavy hammer type air locking valve 314 is arranged at the coarse material discharging port and has the functions of discharging and locking air, a plurality of scattering stepped plates 315 are uniformly distributed on the side, close to the sand collecting shell 313, of the sand selecting shell 312, from top to bottom, each scattering stepped plate 315 and the horizontal line form an included angle , a plurality of flow guide stepped plates 316 are uniformly distributed on the side, the flow guide stepped plates 316 correspond to the scattering stepped plates 315 , each stepped flow guide plate 316 and the horizontal line form a fixed included angle , the inclined direction is opposite to the scattering stepped plates 315, the top of the sand collecting shell 313 is connected with an expansion joint 330 .

The powder selecting mechanism 320 comprises a flow guide shell 321, a powder selecting shell 322, a powder discharging shell 323, a driving device 324, a transmission main shaft 325 and a rotating cage 326, wherein the flow guide shell 321, the powder selecting shell 322 and the powder discharging shell 323 are sequentially arranged from bottom to top and connected through flanges, the driving device 324 is arranged above the powder discharging shell 323 and drives the transmission main shaft 325 to rotate, the transmission main shaft 325 is inserted into the powder discharging shell 323 from top to bottom, the lower part of the transmission main shaft 325 is connected with the rotating cage 326 through a flange, the rotating cage 326 is arranged in the center of the powder selecting shell 322, the bottom of the flow guide shell 321 is connected with an expansion joint 330 and an end , a sand return cone 329 is arranged on the inner side of the flow guide shell 321, a space is reserved between the sand return cone 329 and the flow guide shell 321 and can meet the passing of gas and materials, the effect of collecting sand is achieved at the same time, sand return pipes 318 leading to a sand outlet are arranged at the bottom of the sand return cone 329, a plurality of flow guide vanes 327 are uniformly distributed around the rotating cage, the top of the flow guide vanes 326 is connected with a lower bottom plate of the powder discharging shell 323, and an air outlet 323 of.

Preferably, the middle lower parts of the air inlet shell 311 and the sand collecting shell 313 are provided with supporting flanges for fixing the sand selecting mechanism 310 on a bracket, so as to ensure firm installation.

Preferably, a plurality of supporting flanges are arranged on the outer side of the flow guide shell 321, and are used for fixing the powder selecting mechanism 320 on the bracket, so as to ensure firm installation.

Preferably, the distribution of the rotating cage 326 and the guide vanes 327 is coaxial with the powder selecting shell 322 and the guide shell 321, so that the sorting efficiency is improved.

Preferably, the sand return pipe 318 is installed on the inner wall plate of the sand collecting shell 313 far away from the side of the sand selecting shell 312 , so that the space is saved and the flow of sand is not hindered.

Preferably, the powder concentrator further comprises a lubricating device 328, wherein the lubricating device 328 is fixed on the powder concentrator shell 322 and provides lubricating grease for bearing lubrication of the whole device.

The working process of the combined powder concentrator 300 is as follows:

s1, the materials crushed by the machine-made sand vertical mill 100 are fed into the equipment through a feeding port above the sand selecting shell 312, the materials can collide and break up the step plate 315 like going down stairs layer by layer in the falling process, the falling speed of the materials is slowed down in the aspect of breaking up the step plate 315 , the time for sorting the materials is prolonged, the materials are broken up, the distribution of the materials in the width direction of the equipment is more uniform, the sorting efficiency is improved, when the materials fall from the upper layer breaking up step plate 315 to the lower layer breaking up step plate 315, due to the existence of transverse wind, sand and powder can be brought to the side of the diversion step plate 316 and cross the diversion step plate 316 to reach the sand collecting shellAt body 313; part of the large materials (coarse materials) are scattered by the scattering stepped plate 315 and are rebounded to the flow guiding stepped plate 316 and are rebounded by the flow guiding stepped plate 316, and finally the large materials (coarse materials) are discharged from the discharge hole at the bottom of the sand selecting shell 312 and can be conveyed to the machine-made sand vertical mill 100 to be continuously crushed. The particle size of the sand can be adjusted by adjusting the concentration of the selected powder, which is 100-500g/m³。

S2, most of sand and small part of powder entering the sand collecting shell 313 are settled due to the change of wind speed and wind direction, and are output from a sand outlet at the bottom of the shell; most of the fines and a small portion of the sand are carried away by the gas flow.

S3, the sand and the powder carried away by the gas pass through the diversion shell 321, enter the powder separation shell 322 and pass through the gap between the diversion blades 327 along with the gas flow, in the embodiment, the installation angle α of the diversion blades 327 is 50-75 degrees (see FIG. 10), the sand and the powder reach the periphery of the rotating cage 326, the rotating cage 326 rotating at high speed drives the material to do circular motion, the linear speed of the rotating cage 326 is 8-20m/S, in the horizontal direction, the material is subjected to two opposite forces, namely pulling force and centrifugal force of the gas on the material, the particle size of the powder is small, the centrifugal force is smaller than the pulling force of the gas on the powder, the sand passes through the gap between the blades of the rotating cage 326, enters the powder outlet shell 323, is output from an air outlet flange, the sand is opposite, and is thrown out by the rotating cage 326, cannot pass through the rotating cage 326, finally falls into a sand return cone 329 below the rotating cage 326, and is conveyed to a sand outlet through a sand return pipe 327 at the bottom, and the linear speed of the return sand outlet can be adjusted.

The combined type powder concentrator 300 can simultaneously separate sand and powder from fed materials, the coarse materials left after separation can return to the machine-made sand vertical mill 100 to continue to be crushed, the closed cycle of crushing-sand separation is realized, the sand grain shape is good, the two-in-one of the vibrating screen 400 and the powder removing function is realized, the utilization rate of equipment is improved to the maximum extent, the investment of the equipment is saved, and the power consumption of separation is reduced, and the well-graded machine-made sand is obtained by adjusting the powder concentration of the powder concentrator during sand separation, the linear speed of the rotary cage 326, the installation angle of the guide vanes 327 and other parameters.

Example 9

Different from embodiment 7, referring to fig. 10, a pre-screening device is disposed between the machine-made sand vertical mill 100 and the combined type powder concentrator 300 of this embodiment. The pre-screening apparatus of this embodiment is a trommel 900.

The material after vertical milling is pre-screened before entering the combined type powder concentrator 300, large particles are screened out, the screened large particles are returned to the machine-made sand vertical mill 100 to be milled, and the screened material enters the combined type powder concentrator 300. The technology can reduce the system resistance by about 500-800 Pa, reduce the power consumption of the fan, reduce the material circulation load in the system, reduce the system energy consumption by 5-15%, improve the screening efficiency, improve the particle definition of screened products and improve the product quality.

Example 10

Different from embodiment 9, referring to fig. 11, the machine-made sand production process system of this embodiment further includes a machine-made sand blending system 1000, and the machine-made sand blending system 1000 includes a weighing device 1010, a mixing device 1020, a conveying device 1030, and a storage device.

On the basis of producing different machine-made sand products, a machine-made sand blending system 1000 is added, the production of high-quality machine-made sand is realized through a weighing device 1010, a mixing device 1020, a conveying device 1030 and a storage device (not shown in the figure), and machine-made sand meeting the requirements of any fineness modulus can be produced. The technology can improve the product quality, meet different product requirements, realize the multifunction of a production system, improve the production economic benefit, reduce the investment cost of enterprises and improve the resource utilization rate.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: it is to be understood that modifications may be made to the technical solutions described in the foregoing embodiments, or some or all of the technical features may be equivalently replaced, and the modifications or the replacements may not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

The machine-made sand vertical mill comprises a grinding disc, at least two grinding rollers and a material blocking ring, and is characterized in that the conical angle of each grinding roller is not more than 20 degrees, and the total projection area of the grinding rollers on the grinding disc is 20-35% of the area of the grinding disc.
2. The machine-made sand vertical mill according to claim 1, wherein the material blocking ring is a through-type screening material blocking assembly, the through-type screening material blocking assembly comprises a material blocking ring and a fastening support piece, the material blocking ring is fixed on the grinding disc through the fastening support piece, and a hollow structure is formed between the material blocking ring and the grinding disc.
3. The machine-made sand vertical mill of claim 2, wherein the duty cycle of the hollow structure is 1: (0.4-0.7).
4. The machine-made sand vertical mill according to claim 3, wherein the height of the hollow structure is 30-200 mm, and the height of the baffle ring is 5-100 mm.
5. The machine-made sand vertical mill according to claim 2, wherein the total height of the through-type screening material blocking assembly is 2-6% of the diameter of the grinding disc.
6. The machine-made sand vertical mill according to claim 2, wherein a protective sleeve is sleeved outside the fastening support member at the hollow structure, and the protective sleeve supports the upper material blocking ring.
7. The machine-made sand vertical mill according to claim 1, wherein the material blocking ring is a cross-over material blocking ring, a plurality of material discharging openings are formed in the upper portion of the cross-over material blocking ring, so that the material blocking ring forms a concave-convex structure, and the total area of the material discharging openings is 40-60% of the total area of the cross-over material blocking ring.
8. The machine-made sand vertical mill according to claim 7, wherein the height of the concave part of the striding type material blocking ring is 55-95% of the height of the convex part.
9. The machine-made sand vertical mill according to claim 7, wherein the interval between two adjacent discharge ports is 100-800 mm.
10. The machine-made sand vertical mill according to claim 1, further comprising an auxiliary discharge device, wherein the auxiliary discharge device is positioned behind each grinding roller along the rotation direction of the grinding disc, and the auxiliary discharge device comprises a pneumatic blowing device and/or a mechanical discharge device.
11. The machine-made sand vertical mill according to claim 10, wherein the pneumatic blowing device is fixed on the vertical mill housing and used for timely discharging fine powder generated after grinding, and a nozzle of the pneumatic blowing device extends into the upper part of the mill disc and faces the material blocking ring side or the mill disc side.
12. The machine-made sand vertical mill according to claim 11, wherein the height of a nozzle of the pneumatic blowing device from the surface of the grinding disc is 20-100 mm, and the radial distance of the nozzle from the material stop ring is 5-80 mm.
13. The machine-made sand vertical mill according to claim 10, wherein the mechanical discharging device is a shovel plate which is arranged obliquely downwards towards the grinding disc and is used for discharging the ground materials in time, the end of the shovel plate is fixed on the vertical mill shell, and the other end of the shovel plate extends to the position above the grinding disc.
14. The machine-made sand vertical mill of claim 13, wherein the shovel plate comprises a material guiding section and a material shoveling section, and the shovel plate is in circular arc transition at the joint of the material shoveling section and the material guiding section. The shoveling section is used for shoveling the materials and guiding the materials out of the mill through the guiding section.
15. The machine-made vertical sand mill according to claim 13, wherein the part of the shovel plate above the grinding disc is 5-30 mm away from the grinding roller, 5-60 mm away from the grinding disc and 5-80 mm away from the material retaining ring.
16, A production process system for machine-made sand by using the machine-made sand vertical mill of claim 1, which is characterized in that the system comprises a raw material bin, the machine-made sand vertical mill, a combined powder concentrator, a vibrating screen and a powder removing mechanism, wherein the powder removing mechanism comprises a cyclone and a circulating fan, the outlet of the raw material bin is connected with the material inlet of the machine-made sand vertical mill, the material outlet of the machine-made sand vertical mill is connected with the material inlet of the combined powder concentrator, the bottom discharge hole of the combined powder concentrator is connected with the vibrating screen, the vibrating screen returns oversize materials to the machine-made sand vertical mill, the air outlet of the combined powder concentrator is connected with the cyclone, and the air outlet of the cyclone is connected with the circulating fan.
17. The machine-made sand production process system according to claim 16, wherein the outlet of the circulating fan is further provided with a dust collector and a tail exhaust fan in sequence.
18. The machine-made sand production process system of claim 16, wherein material from the raw material bin can be directly fed to the combined powder concentrator through a belt conveyor.
19. The machine-made sand production process system according to claim 16, wherein the vibrating screen is provided with a plurality of layers of screens with different apertures.
20. The machine-made sand production process system according to claim 19, wherein the combined powder concentrator comprises a sand concentrating mechanism and a powder concentrating mechanism, and the sand concentrating mechanism is positioned below the powder concentrating mechanism and connected through an expansion joint;

the sand selecting mechanism comprises an air inlet shell, a sand selecting shell and a sand collecting shell, and the air inlet shell, the sand selecting shell and the sand collecting shell are sequentially connected through flanges;

the sand separation device comprises an air inlet shell, a sand separation shell, a plurality of air distribution plates, a plurality of hammer type air locking valves, a plurality of scattering stepped plates, a plurality of diversion stepped plates, a plurality of expansion joints, a sand outlet and a hammer type air locking valve, wherein the air distribution plates are distributed on the side, close to the sand separation shell, of the air inlet shell from top to bottom, the air inlet flange is arranged on the side, far away from the sand separation shell, the top of the sand separation shell is provided with a feeding port, the bottom of the sand separation shell is provided with a coarse material discharging port, the hammer type air locking valves are arranged on the side, close to the air inlet shell, of the sand separation shell, the scattering stepped plates are uniformly distributed from top to bottom, the diversion stepped plates correspond to the scattering stepped plates , the diversion stepped plates and the horizontal lines form an included angle of , and the inclination direction of the diversion stepped plates is opposite to;

the powder selecting mechanism comprises a flow guide shell, a powder selecting shell, a powder discharging shell, a driving device, a transmission main shaft and a rotating cage, wherein the flow guide shell, the powder selecting shell and the powder discharging shell are sequentially arranged from bottom to top and are connected through flanges;

the powder separation device comprises a powder outlet shell, a driving device, a diversion shell, an expansion joint, a sand return cone, a sand return pipe, a plurality of diversion blades, a plurality of guide vanes and a plurality of guide vanes, wherein the driving device is arranged above the powder outlet shell to drive a transmission main shaft to rotate, the transmission main shaft is inserted into the powder outlet shell from top to bottom, the lower part of the transmission main shaft is connected with the diversion cage through a flange, the diversion cage is arranged in the center of the powder separation shell, the bottom of the diversion shell is connected with the other end of the expansion joint, the inner side of the diversion shell is provided with the sand return cone, a space is reserved between the sand return cone and the diversion shell, the bottom of the sand return cone is provided with sand return pipes leading to a.
21. The machine-made sand production process system according to claim 20, wherein the lower middle parts of the air inlet shell and the sand collecting shell are provided with supporting flanges for fixing the sand selecting mechanism on a bracket.
22. The machine-made sand production process system according to claim 20, wherein a plurality of support flanges are arranged on the outer side of the flow guide shell and used for fixing the powder selecting mechanism on the support.
23. The machine-made sand production process system according to claim 20, wherein the distribution of the rotating cage and the guide vanes is coaxial with the powder selecting shell and the guide shell.
24. The machine-made sand production process system of claim 20, wherein the sand return pipe is mounted on an inner wall of the sand collection housing on a side remote from the sand separation housing .
25. The machine-made sand production process system of claim 20, further comprising a lubrication device, the lubrication device being fixed to the powder concentrator housing.
26. The machine-made sand production process system according to claim 16, wherein a steady flow bin is further arranged between the raw material bin and the machine-made sand vertical mill.
27. The machine-made sand production process system according to claim 16, wherein a pre-screening device is arranged between the machine-made sand vertical mill and the combined powder concentrator.
28. The manufactured sand production process system of claim 16, further comprising a manufactured sand blending system comprising a weighing device, a blending device, a conveying device, and a storage device.