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CN113680460A - Sand powder roller mill for efficiently preparing waste concrete regenerated sand powder and using method thereof - Google Patents

Sand powder roller mill for efficiently preparing waste concrete regenerated sand powder and using method thereof Download PDF

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Publication number
CN113680460A
CN113680460A CN202110954267.4A CN202110954267A CN113680460A CN 113680460 A CN113680460 A CN 113680460A CN 202110954267 A CN202110954267 A CN 202110954267A CN 113680460 A CN113680460 A CN 113680460A
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China
Prior art keywords
sand
grinding
waste concrete
powder
slurry
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Granted
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CN202110954267.4A
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Chinese (zh)
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CN113680460B (en
Inventor
叶卫东
张永龙
郑青
刘福永
倪明星
张伟丽
杨成刚
刘畅
王宇
迟源
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Hefei Zhongya Building Material Equipment Co ltd
Hefei Cement Research and Design Institute Co Ltd
Original Assignee
Hefei Zhongya Building Material Equipment Co ltd
Hefei Cement Research and Design Institute Co Ltd
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Priority to CN202110954267.4A priority Critical patent/CN113680460B/en
Publication of CN113680460A publication Critical patent/CN113680460A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C15/00—Disintegrating by milling members in the form of rollers or balls co-operating with rings or discs
    • B02C15/06—Mills with rollers forced against the interior of a rotary ring, e.g. under spring action
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C23/00—Auxiliary methods or auxiliary devices or accessories specially adapted for crushing or disintegrating not provided for in preceding groups or not specially adapted to apparatus covered by a single preceding group
    • B02C23/02—Feeding devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C23/00—Auxiliary methods or auxiliary devices or accessories specially adapted for crushing or disintegrating not provided for in preceding groups or not specially adapted to apparatus covered by a single preceding group
    • B02C23/18—Adding fluid, other than for crushing or disintegrating by fluid energy
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
    • F26B21/001—Drying-air generating units, e.g. movable, independent of drying enclosure
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/91—Use of waste materials as fillers for mortars or concrete

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Crushing And Grinding (AREA)

Abstract

The invention discloses a sand powder roller mill for efficiently preparing waste concrete recycled sand powder and a using method thereof.A waste concrete sand-slurry particle heating and feeding device heats sand-slurry particles before grinding and regulates the throughput of the sand powder to perform continuous feeding; the waste concrete sand-slurry particle stripping and shaping mechanism selectively crushes material layers of the heated waste concrete sand-slurry particle groups, phase splitting and stripping the cement slurry wrapped on the surface of sand particles, then grinds the granular cement slurry into fine powder, grinds the protruded edges and corners on the sand particles, and selects regenerated coarse sand, regenerated medium sand, regenerated fine sand and regenerated fine powder through screening. The invention is of a totally enclosed structure, operates under micro negative pressure, and has no dust during the production process; the intelligent production equipment can be realized, the large-scale production is facilitated, the production energy consumption is reduced, and the economic benefit of enterprises is improved.

Description

Sand powder roller mill for efficiently preparing waste concrete regenerated sand powder and using method thereof
Technical Field
The invention relates to the technical field of regeneration and recycling of solid wastes of buildings, in particular to a sand powder roller mill for efficiently preparing waste concrete regenerated sand powder and a using method thereof.
Background
China actively promotes the recycling of waste concrete and obtains certain effect, but the recycling of the waste concrete in the past is focused on recycled aggregate, the technology and equipment for crushing, screening and processing coarse and fine aggregates of the waste concrete are mature, and the accepted process mainly comprises two-stage crushing and one-step shaping. The first-stage crushing mainly adopts a jaw type or rotary type crusher, the second-stage crushing mainly adopts a cone type or impact type crusher, and the shaping machine adopts vertical shaft impact crushing. The by-products generated in the processing process, namely, the reclaimed sand has poor gradation, poor sphericity, more edges and corners and rough surface, the components contain hardened cement mortar, the reclaimed concrete prepared by using the hardened cement mortar has larger water consumption, low strength and low elastic modulus, and the durability of impermeability, frost resistance, carbonization resistance, shrinkage, creep, chloride ion permeability resistance and the like is lower than that of common concrete, and a great amount of microcracks are generated in the interior of the reclaimed sand due to damage accumulation in the crushing process of waste concrete blocks, so that the reclaimed sand has large porosity, large water absorption, small stacking density, high crushing index value and obviously inferior performance to natural sand; the byproduct, namely the regenerated micro powder generated in the processing process has large fluctuation of components, low activity and difficult dispersion, and is not effectively utilized in the cement concrete industry. The regenerated sand powder is mainly used for roadbed backfill, filling materials, concrete bricks, building blocks and the like at present, is simple and extensive, and is a resource waste substantially.
With the continuous and intensive research on recycling of waste concrete, the difficulty that about 30-40% of waste concrete sand powder generated in the process of crushing and processing recycled aggregate is not effectively utilized due to low quality is gradually noticed. Around the recycling of all components of the waste concrete, partial crushing, grinding and sorting processes and equipment are introduced from the industries of ore processing, cement grinding and the like, such as an impact type and hammer crusher used for crushing the waste concrete in Hazemag of Germany; the ultrafine crushing cone crusher of babbittless (babbittless) in france and the top horizontal bar cone crusher of the castanet of japan (Kurimoto) are mainly used for finely crushing sand. The existing equipment is mainly suitable for impact/impact crushing of homogeneous materials, so that a large amount of microcracks are generated on aggregates, the activity of the regenerated sand powder is low, the water absorption of the regenerated sand powder is strong, the strength of the aggregates is low, the environmental pollution is serious and other problems are caused, and technical innovation and improvement of equipment functions are not performed from the angle of effective separation of all components of waste concrete. Meanwhile, the surface of the reclaimed sand powder is wrapped by part of residual cement slurry, so that the reclaimed sand has the defects of high water absorption, poor grading, low density, low activity of reclaimed micro powder and poor product quality, and the technology and equipment for efficiently stripping and shaping the waste concrete sand-slurry particles are lacked.
In recent years, the building industry in China is vigorously developed, and the demand of building materials is sharply increased. In the concrete raw material, the aggregate accounts for about 75 percent of the total weight of the concrete, and the source of the aggregate is mainly mountain-opening stone-taking, sand and stone are formed by processing, or sand, pebbles and gravels in a river channel are directly dug, so that the natural environment is seriously damaged. In addition, natural sandstone resources in China are not uniformly distributed, and sandstone in partial areas is extremely deficient. Therefore, with the national emphasis on environmental protection and urban mineral resources, the recycling of the waste concrete sand powder is an important content of the layout of the urban mineral resources, and it is urgently needed to develop a high-efficiency preparation technology and equipment for the waste concrete recycled sand powder, so as to realize green, energy-saving and large-scale production, promote the utilization of all components and high quality of the waste concrete, effectively alleviate the shortage of sand and mineral admixture resources for construction engineering, and meet the major requirements of national sustainable development.
The vertical mill is used as a high-efficiency energy-saving material layer grinding device, is widely applied to the industries of cement, electric power, non-mine and the like and the aspect of industrial waste residue treatment, adopts a grinding disc to drive grinding rollers to move mutually, and after particles form a material layer on the grinding disc and are subjected to extrusion force, the particles are crushed by extrusion and shearing force, the materials are repeatedly ground in the rolling process of the grinding rollers, the particle roundness is better, the utilization efficiency of the crushing and grinding energy of the vertical mill is higher than that of the material layer crushing of a cone crusher and that of single particles of the ball mill, so that the vertical mill is widely accepted and applied as a grinding device for producing fine powder. However, as a more efficient and energy-saving grinding device, the device is used for efficiently preparing high-quality recycled sand powder of waste concrete, the principle analysis of selective grinding of a material layer is feasible, the original vertical mill needs to be innovated in principle, and innovated in structure and function, and the problems of poor grading of the recycled sand, poor sphericity, large self porosity, large water absorption, small stacking density, high crushing index value, large fluctuation of components of the recycled micro powder, low activity, difficult dispersion and the like are solved.
Disclosure of Invention
The invention aims to make up the defects of the prior art, provides a sand powder roller mill for efficiently preparing waste concrete regenerated sand powder and a using method thereof, replaces the traditional crushing modes (such as jaw crushing, impact crushing, vertical shaft impact crushing, conical crushing, double-roller crushing, ball mill and the like), can realize large-scale production of high-quality regenerated sand and high-activity regenerated micro powder by adopting the device, has the advantages of high stability, low energy consumption, long service life and the like, can meet the requirements of different sand for construction engineering, can replace part of mineral admixtures, relieves the shortage of natural river sand and mineral admixture resources, and improves the recycling level of waste concrete resources.
According to the invention, the cement slurry wrapped on the sand surface is heated to dehydrate and embrittle to generate cracks by fully utilizing the physical property difference of the sand powder surface, such as hardness, brittleness, grindability, thermal expansion coefficient and the like, according to the bonding strength of the sand-slurry interface and based on the material layer selective crushing principle under the action of a multidimensional force field and by adopting the methods of heating, crushing, stripping, grinding, shaping, scattering and the like; extrusion force is directly applied to material particles, large materials are directly crushed due to the transmission of crushing force among the materials, and fine and broken materials are extruded to form a material bed for crushing among particle groups; further applying extrusion force and shearing force to the compacted material layer, crushing the material with low hardness in the material layer particle group, and forming regenerated sand by the hardest material; and further applying friction force to the stripped particle group for grinding and shaping to realize the efficient stripping of the waste concrete sand-slurry particles, wherein the sand-slurry stripping efficiency reaches over 90 percent, the apparent density of the reclaimed sand is improved, the water absorption rate of the reclaimed sand is reduced, and the quality of the reclaimed sand and the reclaimed micro powder is improved.
The invention is realized by the following technical scheme:
a sand powder roller mill for efficiently preparing waste concrete recycled sand powder comprises a waste concrete sand-slurry particle heating and feeding device and a waste concrete sand-slurry particle stripping and shaping mechanism;
the waste concrete mortar-slurry particle heating and feeding device heats the mortar-slurry particles before grinding, and continuously feeds by regulating and controlling the throughput of sand powder;
the waste concrete sand-slurry particle stripping and shaping mechanism selectively crushes material layers of heated waste concrete sand-slurry particle groups, phase splitting and stripping cement slurry wrapped on the surfaces of sand particles, grinds the granular cement slurry into fine powder, grinds the protruded edges and corners on the sand particles, and selects regenerated coarse sand, regenerated medium sand, regenerated fine sand and regenerated fine powder through screening.
The waste concrete sand-slurry particle heating and feeding device comprises a reverse baffling efficient heater and a feeder, wherein the reverse baffling efficient heater is positioned above the feeder and is connected with the feeder through a flange;
the reverse baffling efficient heater comprises a heating chamber shell, a bulk material stepped grate plate, a movable baffle plate and a heat insulation layer; the top of the heating chamber shell is provided with a feeding port and a first air outlet, the bottom of the heating chamber shell is provided with a material collecting hopper, the middle of the heating chamber shell is provided with an inclined air inlet, and two connecting lines of the feeding port and the material collecting hopper and the centers of the air inlet and the first air outlet are distributed in an X shape; the plurality of bulk material stepped grate plates are uniformly arranged below the feeding port and close to the side of the air inlet of the heating chamber shell from top to bottom, and each bulk material stepped grate plate forms a certain included angle with the horizontal plane and is connected to the heating chamber shell by adopting an insertion method; the movable baffle plate is arranged below the air outlet, a plurality of baffle plates are uniformly distributed from top to bottom and form a whole with the side plates at two sides, each baffle plate forms a certain included angle with the horizontal plane, the inclined direction is opposite to the bulk material stepped grate plate and forms 75-105 degrees of included angles in a one-to-one correspondence mode, and the side plates at two sides are connected with a plurality of groups of horizontal groove-shaped holes in the heating chamber shell through bolts; the heat-insulating layer is laid outside the heating chamber shell;
the feeder comprises a feeding pipe, a discharging pipe and an adjusting bolt; the feeding pipe is arranged below the collecting hopper of the heating chamber shell and is connected with the collecting hopper through a flange; the blanking pipe is sleeved on the lower part of the feeding pipe and is connected with the flange through a plurality of adjusting bolts.
The waste concrete sand-slurry particle stripping and shaping mechanism comprises an integral base, a main transmission device, a frame, a lower shell, a grinding disc, a plurality of grinding rollers, a transmission arm, a pressurizing device, a limiting device and an upper shell.
The integral base comprises a main speed reducer base and a rack base, and the main speed reducer base and the rack base are connected or welded into a whole in pairs through bolts; the integral base is positioned on a concrete foundation and is embedded into a foundation hole by adopting foundation bolts to be fixed by grouting;
the main transmission device comprises a main motor base, a main motor, a coupler, a main speed reducer and a frequency converter, wherein the main motor base is positioned on a concrete foundation and is embedded in a foundation hole by adopting a foundation bolt for grouting and fixing; the main motor is arranged on a main motor base, and an output shaft of the main motor is axially connected with an input shaft of the main speed reducer through a coupler in the horizontal direction; the main speed reducer is positioned on a main speed reducer base, and an output thrust disc in the vertical direction of the main speed reducer is connected with the lower plane of the grinding disc through a flange; and the frequency converter is connected with the main motor through a cable.
The number of the racks is at least three, the racks are positioned on the rack base and fixed on the concrete foundation through foundation bolts; the lower shell is positioned on the upper plane of the frame and is connected with the upper plane of the frame through lower shell supporting legs, and an annular groove with an upward notch is formed in the bottom edge of the lower shell; and a discharge hole is formed in the bottom surface of the annular groove of the lower shell.
The grinding disc comprises a disc seat, a lining plate, a movable cone, a material blocking ring, a material scraping frame and a material scraping plate, and is positioned above the annular groove in the lower shell and the output thrust disc of the main speed reducer; the disc seat is a rotating body, a plurality of wear-resistant lining plates with low inside and high outside are fixed on the inner concave surface of the upper part of the disc seat, the wear-resistant lining plates surround to form a disc-shaped grinding track, the lower part of the disc seat penetrates through an annular hole surrounded by an annular groove of the lower shell, and the bottom surface of the lower part of the disc seat is fixedly connected with an output thrust disc of the main speed reducer; the movable cone is positioned on the side surface of the upper part of the disc seat and fixedly connected with the outer convex surface of the upper part of the disc seat, the movable cone is integrated or split, the conical angle of the movable cone is 30-60 degrees, the surface of the movable cone is compounded with a wear-resistant lining, and the stop ring is positioned on the upper plane of the movable cone and connected with the movable cone; the scraping frame is positioned below the lower plane of the upper part of the disc seat and is fixedly connected with the disc seat, and the scraping plates are connected with the scraping frame; the feeder is positioned above the grinding disc.
Each grinding roller is positioned above the grinding disc, the inclination angle of the axial center line of each grinding roller and the horizontal plane is not more than 12 degrees, and each grinding roller is arranged on the horizontal plane at equal angles and intervals; a grinding body roller sleeve is fixed at one end of the grinding roller, the grinding surface of the roller sleeve is arc-shaped, and a wear-resistant lining is compounded on the outer surface of the arc shape; the other end of the grinding roller is fixedly connected with the transmission arm; the total projection area of the grinding roller on the grinding disc is 60-70% of the area of the grinding track;
the transmission arm is arranged on the upper plane of the frame and comprises a rocker arm, a movable arm, a cross shaft, a bearing seat, a bearing and a thrust device, wherein the rocker arm and the movable arm are connected through the cross shaft and a pin, the cross shaft is supported on the bearing seat through 2 bearings, the bearing seat is connected with the upper plane of the frame and a lower shell supporting leg into a whole, one part of the thrust device is fixed on one end face of the cross shaft, and the other part of the thrust device is fixed on one end face of the bearing seat;
the pressurizing device comprises an oil cylinder, a pressurizing base, a hydraulic system, an energy accumulator and a pipeline, the pressurizing device is positioned below the transmission arm, a head lug of the oil cylinder is connected with a lower hole of the movable arm through a pin shaft, a cylinder body of the oil cylinder is connected with the pressurizing base through a pin shaft, the pressurizing base is positioned on the frame base and fixed on a concrete foundation through anchor bolts, a pressurizing oil path of the hydraulic system is connected with a rod cavity of the oil cylinder through the energy accumulator and the pipeline, and a roller lifting oil path is connected with a rodless cavity of the oil cylinder through the pipeline;
the limiting device is positioned on the outer side of the movable arm and is arranged on a vertical plate in the rack, and a plurality of groups of disc springs are arranged in the limiting device;
the upper shell comprises a shell, a grinding roller door, a cover plate and a fixed cone, the shell is positioned above the lower shell, is cylindrical and is connected with the lower shell, the shell is provided with the grinding roller door for the grinding roller to freely turn in and out, the cover plate is positioned above the shell and is connected with the shell to support the reverse deflection efficient heater and the feeder, and the cover plate is provided with a second air outlet; the fixed cone is arranged on the lower portion of the upper shell and surrounds the periphery of the movable cone of the grinding disc, the fixed cone is split, the position of the fixed cone is adjustable up and down, the distance between the split fixed cone sections is 40-80 mm, and the grinding surface of the fixed cone is compounded with a wear-resistant lining.
In the main transmission device, the rotating speed of the grinding disc is controlled by adjusting the working frequency of the main motor through a frequency converter; the height of the material blocking ring is 5-40 mm and is adjustable, and the detention time of the waste concrete sand powder on the grinding disc is controlled to reach 30-60 seconds.
The use method of the sand powder roller mill for efficiently preparing the waste concrete regenerated sand powder comprises the following steps:
step one, heating and feeding: introducing hot air of 100-300 ℃ into an air inlet of the reverse baffling efficient heater, feeding crushed waste concrete sand-slurry particles into the heating chamber shell from top to bottom, uniformly distributing the crushed waste concrete sand-slurry particles on the bulk material stepped grate plate, introducing the hot air into the hot air furnace from bottom to top, feeding the crushed waste concrete sand-slurry particles into the heating chamber shell, enabling sand powder and the hot air to flow in an X-shaped crossed reverse direction between the bulk material stepped grate plate and the movable baffle plate, rapidly heating the ground sand-slurry particles, evaporating the surface moisture of the particles, dehydrating and embrittling cement slurry wrapped on the surface of the sand to generate cracks, adjusting the distance between a discharging pipe and a grinding disc to regulate the throughput of the sand powder, and continuously feeding the sand powder;
step two, crushing and stripping: starting a main motor, driving the grinding disc to rotate through a main speed reducer, adjusting the rotating speed of the main motor and the rotating speed of the grinding disc through a frequency converter, stopping adjustment when the rotating speed of the grinding disc meets the requirement, and keeping the rotating speed of the grinding disc constant; the lower end of the movable arm is pulled by a hydraulic oil cylinder of the grinding roller pressurizing device to drive the grinding roller to rotate, so that an extrusion area and a stripping area which are reasonably distributed in a multi-dimensional force field are formed between a grinding roller sleeve and a grinding disc lining plate;
the heated waste concrete mortar-slurry particles fall at the center of the grinding disc, move towards the edge of the grinding disc under the action of centrifugal force generated by the rotary grinding disc and enter a grinding track to form a material layer; waste concrete sand-slurry particles enter a sand-slurry stripping device, particle groups are selectively crushed under the actions of extrusion, shearing and friction of a multidimensional force field of a grinding roller sleeve and a grinding disc lining plate, and as the original sand is high in hardness and cement slurry wrapped on the surface of the sand particles is heated, the cement slurry is dehydrated, embrittled and cracked, the cement slurry wrapped on the surface of the sand particles is subjected to phase splitting and stripping by optimally regulating and controlling the thickness of a material layer, the pressure of a grinding roller and the rotating speed of a grinding disc by utilizing the speed difference generated during layered movement of the particle groups in the material layer and the difference of hardness, brittleness and grindability and physical property of each component to form coarse sand (2.36-4.75 mm), medium sand (1.18-2.36 mm), fine sand (0.075-1.18 mm) and fine powder (less than 0.075mm), the stripped materials continuously move to the edge of the grinding disc under the action of centrifugal force, and enter a grinding and shaping process;
step three, grinding and shaping: the stripped coarse sand (2.36-4.75 mm), medium sand (1.18-2.36 mm) and fine sand (0.075-1.18 mm) still contain a part of granular cement slurry and are not ground into fine powder, the surfaces of some sand grains still wrap a part of the cement slurry, the movable cone and the fixed cone form a concentric grinding cavity, the concentric grinding cavity is divided into a wedge-shaped area and a parallel area, the minimum meshing angle of the wedge-shaped area is 20-22 degrees, and the vertical distance of the parallel area is 10-35 mm and is adjustable; the materials selectively crushed from the sand-slurry stripping device enter a concentric grinding cavity under the action of centrifugal force and gravity, are subjected to the extrusion, shearing and friction effects of a moving cone rotating at a medium speed (4-8 m/s), and meanwhile, sand grains with different grain sizes are used as grinding bodies to carry out inter-grain friction on the material layers of the sand-slurry and the cement slurry again, so that part of cement slurry wrapped on the surfaces of the sand grains is ground, and meanwhile, the granular cement slurry is ground into fine powder; because the sand grains with different grain sizes are rubbed with each other, the protruded edges and corners on the sand grains are ground off, and the sand grains are shaped;
step four, scattering and discharging: the stripped and shaped regenerated sand powder falls into an annular material collecting groove, agglomerated materials are loosened under the centrifugal impact action of a rotary scraping plate, fine powder adhered to the surface of sand grains is further removed, all the fine powder is discharged from a discharge hole, then the regenerated coarse sand (2.36-4.75 mm), regenerated middlings (1.18-2.36 mm), regenerated fine sand (0.075-1.18 mm) and regenerated fine powder (less than 0.075mm) are sorted by winnowing and screening, and the sand-pulp particles larger than 4.75mm continue to be returned to a sand powder roller mill for crushing and stripping.
The invention has the advantages that:
1. the invention effectively solves the problems of poor grading, high water absorption, low activity and other performances of the reclaimed sand powder produced by an impact crusher preparation system based on a non-selective single-particle crushing principle. The sand powder roller mill is designed based on the principle of selective material layer crushing under the action of a multidimensional force field, the sand-slurry surface moisture of the waste concrete sand powder is removed through heating, and the cement slurry wrapped on the sand surface is dehydrated and embrittled to generate cracks; after the sand powder enters the sand powder roller mill, the grinding gap between a movable cone and a fixed cone and the like are adjusted simultaneously by adjusting the material throughput in the mill, the grinding speed of the grinding disc, the pressure of the roller mill and the height of a material retaining ring, and sand-slurry particles are subjected to the actions of multi-dimensional force fields such as extrusion, shearing, friction and the like in a material layer for multiple times, so that the sand and the slurry are stripped, and meanwhile, regenerated sand and fine powder are generated, thereby realizing that the sand-slurry stripping efficiency reaches more than 90 percent, improving the reshaping effect of the regenerated sand and greatly reducing the wrapping amount of cement slurry on the surface of the regenerated sand;
2. the invention adopts the principle design of selective material layer crushing under the action of a multidimensional force field, the crushing and stripping energy efficiency utilization rate of sand-slurry particles is higher than that of single particle impact crushing of a ball mill, the energy consumption can be saved by 30-40%, and the energy-saving effect is obvious;
3. the reclaimed sand produced by the method has high apparent density, low water absorption, good sphericity, less microcracks, low crushing index value and extremely small physical property difference with primary sand, and the reclaimed sand directional grading regulation and control system of the next procedure can meet the fineness modulus requirements of different engineering products and replace part of natural river sand; the fine powder produced by the invention is supplied to a regenerated micro powder activation preparation system of the next procedure for continuous grinding, and the regenerated micro powder with high activity is produced to replace part of mineral admixture;
4. the invention can realize the intellectualization of production equipment, is beneficial to large-scale production, reduces the production energy consumption and improves the economic benefit of enterprises; the invention is of a totally enclosed structure, operates under micro negative pressure, and has no dust during the production process;
5. the product produced by the method has high quality, can realize high cost performance utilization of the waste concrete reclaimed sand powder, is beneficial to improving the comprehensive utilization rate of reclaimed resources, is beneficial to improving the performance of reclaimed sand powder premixed mortar, reclaimed sand powder concrete and products, and is beneficial to engineering quality. The invention has excellent popularization value.
Drawings
Fig. 1 is an axial side view of a sand-powder roller mill provided by an embodiment of the present invention.
Fig. 2 is a top view of a sand powder roller mill according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a sand powder roller mill according to an embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a grinding disc of the sand powder roller mill provided by the embodiment of the invention.
Fig. 5 is a schematic structural view of a driving arm of the sand-powder roller mill according to the embodiment of the invention.
Fig. 6 is a schematic structural view of a waste concrete mortar-slurry particle heating and feeding device according to an embodiment of the present invention.
FIG. 7 is an enlarged view of a portion of the configuration of a waste concrete grit-slurry remover and a grinding device according to an embodiment of the present invention.
FIG. 8 is an enlarged view of the scattering and discharging structure provided in the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the following embodiments and accompanying drawings.
In the description of the present invention, the terms "connected," "combined," "formed," "combined," and "enclosed" should be interpreted broadly, and may be, for example, fixedly connected or detachably connected; can be mechanically or electrically connected; the connection may be direct or indirect through an intermediate medium, or the connection may be internal to the two components. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description of the present invention, the waste concrete sand powder to be described is sand-slurry particles with a particle size of less than 10mm, which are produced by crushing and sorting waste concrete blocks, and the components comprise hardened cement mortar.
According to the invention, hot air is required to be introduced for heating when the comprehensive moisture content of the waste concrete sand powder is more than 2.5%, and hot air is not required to be introduced when the comprehensive moisture content of the waste concrete sand powder is less than 2.5%.
In the present invention, the waste concrete sand powder is not restricted to contain iron impurities such as steel bars, iron nuggets, alloy steels, etc., and the details thereof are not described in the examples.
Example 1
Referring to fig. 1 to 8, a sand powder roller mill for efficiently preparing waste concrete recycled sand powder comprises a waste concrete sand-slurry particle heating and feeding device 100 and a waste concrete sand-slurry particle stripping and shaping mechanism 200.
The waste concrete sand-slurry particle heating and feeding device 100 is positioned above an upper shell of the sand powder roller mill, is connected with an upper cover plate of the upper shell, and comprises a reverse baffling efficient heater 110 and a feeder 120, wherein the reverse baffling efficient heater 110 is positioned above the feeder 120 and is connected with the feeder through a flange, and the feeder 120 is positioned inside the sand powder roller mill and above a grinding disc;
the reverse baffling efficient heater 110 comprises a heating chamber 111, a bulk material stepped grate plate 112, a movable baffle 113 and an insulating layer 114; the top of the shell of the heating chamber 111 is provided with a feeding port 115 and a first air outlet 116, the bottom is provided with a heated material collecting hopper, the middle part is provided with an air inlet 117 which forms a certain angle with the horizontal plane, and two connecting lines of the feeding port and the collecting hopper as well as the centers of the air inlet and the first air outlet are distributed in an X shape; the plurality of bulk cargo stepped grate plates 112 are uniformly arranged below the feeding port from top to bottom and close to the side of the shell air inlet, and each bulk cargo stepped grate plate forms a certain included angle with the horizontal plane and is connected to the shell through a flange by adopting an insertion method; the group of movable baffle plates 113 are arranged below the air outlet, are uniformly distributed from top to bottom by a plurality of baffle plates and are integrated with the side plates at two sides, each baffle plate forms a certain included angle with the horizontal plane, the inclination direction of each baffle plate is opposite to that of the bulk material stepped grate plate, the baffle plates at two sides are in one-to-one correspondence to form included angles of 75-105 degrees, and the side plates at two sides are connected with a plurality of groups of horizontal groove-shaped holes on the shell through bolts; the insulating layer 114 is laid outside the heating chamber;
the feeder 120 comprises a feeding pipe 121, a discharging pipe 122 and an adjusting bolt 123; the feeding pipe 121 is arranged below the heating chamber collecting hopper and is connected with the heating chamber collecting hopper through a flange; the blanking pipe 122 is sleeved on the lower part of the feeding pipe and is connected with the flange through the plurality of adjusting bolts 123.
The waste concrete sand-pulp particle stripping and shaping mechanism 200 structurally comprises an integral base 210, a main transmission device 220, a frame and lower shell 230, a grinding disc 240, a grinding roller 250, a transmission arm 260, a pressurizing device 270, a limiting device 280 and an upper shell 290;
the integral base 210 is a steel structural member and comprises a main speed reducer base 211 and a rack base 212, and every two of the main speed reducer base and the rack base are connected or welded into a whole through bolts; the integral base 210 is located on a concrete foundation and is embedded in a foundation hole by anchor bolts and fixed by grouting. The arrangement of the integral base 210 improves the stability of the equipment during operation;
the main transmission device 220 comprises a main motor base 221, a main motor 222, a coupling 223, a main reducer 224 and a frequency converter 225. The main motor base 221 is positioned on a concrete foundation and is embedded in a foundation hole by adopting foundation bolts to be grouted and fixed; the main motor 222 is installed on the main motor base through bolt connection, and an output shaft of the main motor 222 is axially connected with an input shaft of the main speed reducer through a coupler in the horizontal direction; the main reducer 224 is positioned on the main reducer base 211, and a vertical output thrust disc of the main reducer 224 is connected with the lower plane of the grinding disc 240 through a flange; the frequency converter 225 is connected with the main motor through a cable, and the frequency of the main motor 222 is adjustable. The main motor 222 and the main reducer 224 are both provided with a lubricating system;
the frame and the lower shell 230 are steel structural members and comprise at least three frames 231, a lower shell 232 and a discharge hole 233, wherein the frames are positioned on the frame base 212 and fixed on a concrete foundation through foundation bolts; the lower shell 232 is positioned on the upper plane of the frame and is connected with the upper plane of the frame 231 through lower shell supporting legs, and an annular groove with an upward notch is formed in the inner part of the bottom edge of the lower shell; the discharge hole 233 is arranged on the bottom surface of the annular groove of the lower shell; a composite wear-resistant lining plate is laid in the annular groove;
the grinding disc 240 comprises a disc seat 241, a lining plate 242, a movable cone 243, a material stop ring 244, a material scraping frame 245 and a material scraping plate 246, and the grinding disc is positioned above an annular groove in the lower shell 232 and an output thrust disc of the main speed reducer 224; the disc seat 241 is a rotating body, a plurality of wear-resistant lining plates 242 with low inner parts and high outer parts are fixed on the inner concave surface of the upper part of the disc seat 241, the wear-resistant lining plates 242 surround to form a disc-shaped grinding track, the lower part of the disc seat 241 penetrates through an annular hole surrounded by an annular groove of the lower shell, and the bottom surface of the lower part of the disc seat 241 is fixedly connected with an output thrust disc of the main speed reducer 224; the movable cone 243 is positioned on the side surface of the upper part of the disc seat 241 and fixedly connected with an outer convex surface flange of the upper part of the disc seat 241, the movable cone 243 is integral or split, the conical angle of the movable cone 243 is 30-60 degrees, the surface is compounded with a wear-resistant lining, and the material blocking ring 244 is positioned on the upper plane of the movable cone 243 and connected with the movable cone 243; the scraping frame 245 is positioned below the lower plane of the upper part of the disc seat 241 and is fixedly connected with the disc seat 241, the scraping plates 246 are connected with the scraping frame 245, and the collision surfaces of the scraping plates and the materials are designed by adopting a composite wear-resistant steel plate, so that the service life of the scraping frame is prolonged;
each grinding roller 250 is positioned above the grinding disc 240, the inclination angle between the axial center line of each grinding roller 250 and the horizontal plane is not more than 12 degrees, and each grinding roller is arranged on the horizontal plane at equal angles and intervals; a grinding body roller sleeve 251 is fixed at one end of the grinding roller 250, the grinding surface of the roller sleeve 251 is in a circular arc shape, a wear-resistant lining is compounded on the outer surface of the circular arc shape, and a wear-resistant welding wire can be adopted for on-line surfacing; the other end of the grinding roller 250 is fixedly connected with a transmission arm 260;
each transmission arm 260 is installed on the upper plane of the frame 231 and comprises a rocker arm 261, a movable arm 262, a transverse shaft 263, a bearing seat 264, a bearing 265 and a thrust device 266, wherein the rocker arm 261 and the movable arm 262 are connected through the transverse shaft 263 and a pin, the transverse shaft 263 is supported on the bearing seat 264 through 2 bearings 265, the bearing seat 264 is integrally connected with the upper plane of the frame 231 and the supporting legs of the lower shell 232, and a part of the thrust device 266 is fixed on one end face of the transverse shaft 263 and a part of the thrust device 266 is fixed on one end face of the bearing seat 264. The lower part of the movable arm 262 is connected with an oil cylinder 271 through a pin shaft; the sand powder roller mill of the embodiment adopts a rocker arm roller turning mechanism, and the grinding roller can be turned out of the mill for maintenance;
each pressurizing device 270 comprises an oil cylinder 271, a pressurizing base 272, a hydraulic system 273, an energy accumulator 274 and a pipeline, the pressurizing device 270 is positioned below the transmission arm 260, a head lug of the oil cylinder 271 is connected with a lower hole of the movable arm 262 through a pin shaft, a cylinder body of the oil cylinder 271 is connected with the pressurizing base 272 through a pin shaft, the pressurizing base 272 is positioned on the frame base 212 and fixed on a concrete foundation through anchor bolts, a pressurizing oil path of the hydraulic system 273 is connected with a rod cavity of the oil cylinder 271 through the energy accumulator 274 and the pipeline, a roller lifting oil path is connected with a rodless cavity of the oil cylinder 271 through the pipeline, and the loading and the roller lifting of the grinding roller can be realized;
each limiting device 280 is positioned at the outer side of the movable arm 262 and is arranged on a vertical plate in the frame 231, and a plurality of groups of disc springs are arranged in the limiting devices and are used for adjusting the gap between the grinding roller and the grinding disc;
the upper shell 290 comprises a shell 291, a grinding roller door 292, a cover plate 293 and a fixed cone 294, wherein the shell 291 is positioned above the lower shell 232, is cylindrical and is connected with the lower shell 232 through a flange, the shell 291 is provided with the grinding roller door 292 so that a grinding roller can freely turn in and turn out, the cover plate 293 is positioned above the shell 291 and is connected with the shell 291 through a flange to support the reverse deflection efficient heater 110 and the feeder 120, and an air outlet two 295 is formed in the cover plate 293; the fixed cone 294 is arranged at the lower part of the upper shell and surrounds the movable cone 243 of the grinding disc, the fixed cone 294 is split, the position of the fixed cone 294 can be adjusted up and down, the distance between the sections of the split fixed cones is 40-80 mm, and the fixed cone 294 is favorable for discharging mixed non-breakable iron impurities; the fixed cone 294 is compounded with a wear-resistant lining.
Example 2
Referring to fig. 1 to 8, when the invention works, if the comprehensive moisture content of the waste concrete sand powder is more than 2.5%, hot air with the temperature of 100 ℃ to 300 ℃ is introduced into an air inlet 117 of the reverse baffling efficient heater 110, the waste concrete sand powder after being crushed and removed of iron impurities mixed in materials enters the heating chamber 111 from top to bottom, is uniformly distributed on the bulk material stepped grate plate 112, the hot air is introduced from the hot air furnace to enter the heating chamber 111 from bottom to top, and the sand powder and the hot air flow between the bulk material stepped grate plate 112 and the movable baffle plate 113 in an X-shaped cross reverse flow mode. The distance between the bulk material stepped grate plate 112 and the movable baffle plate 113 is adjustable, so that the sand powder heating effect is ensured, and the smooth flowing of the sand powder is also ensured.
In the invention, when the main transmission device 220 works, the rotating speed of the grinding disc 240 is controlled by adjusting the working frequency of the main motor 222 through the frequency converter 225; meanwhile, the height of the material blocking ring 244 is adjusted, and the retention time of the waste concrete sand powder on the grinding track of the grinding disc is controlled to reach 30-60 seconds, so that the sand-slurry stripping effect is guaranteed.
In the invention, the waste concrete sand-slurry particle stripping and shaping mechanism 200 functionally comprises a sand-slurry stripping device 201 and a sand-slurry grinding device 202; the preparation of the waste concrete recycled sand powder is mainly finished by a sand-slurry stripping device 201, and a sand-slurry grinding device 202 plays a role in auxiliary stripping and shaping;
the sand-pulp stripping device 201 comprises a grinding disc 240 and at least three grinding rollers 250, wherein a plurality of wear-resistant lining plates with low inside and high outside are paved on the inner concave surface of the upper part of the grinding disc 240 and enclose a disc-shaped grinding track, and the radius of the inner surface of the track is R1(ii) a Each grinding roller 250 is provided with a tyre-shaped wear-resistant roller sleeve 251, the grinding surface of the roller sleeve 251 is arc-shaped, and the radius of the outer surface of the arc-shaped surface is R2(ii) a Radius R of inner surface of grinding track1Greater than the radius R of the circular outer surface of the roller sleeve2The distance between the extension line of the connecting line of the centers of the two arcs and the intersection point of the two arcs is a minimum gap, the minimum gap is positioned at the upper part of the climbing section of the grinding track, the minimum gap L is 10-25 mm, the position and the size of the minimum gap are designed to be beneficial to avoiding jumping and stopping due to overlarge vibration under the condition that a material layer is too thin, meanwhile, high-efficiency and stable grinding roller pressure can be applied, and the sand-slurry particle stripping efficiency is improved; the total projected area of the grinding roller 250 on the grinding disc 240 is 60-70% of the area of the grinding track, and the projection area is increased, so that sand-slurry particles can be acted by a multi-dimensional force field for many times in a material layer, and the stripping efficiency of sand and slurry is improved; the hydraulic loading force of each grinding roller 250 is provided by a transmission arm 260 and a pressurizing oil cylinder 271, and the hydraulic loading is carried outThe force is equal and adjustable, the pressure of the grinding roller is reasonably controlled, the sand-slurry stripping can be realized, the requirements of stable, safe and economic operation of the mill are met, the pressure of the grinding roller is low, the stripping efficiency is low, the hydraulic pressure of the grinding roller is high, and the sand is easy to crush; the minimum gap between each grinding roller sleeve 251 and the grinding disc lining plate 242 is set to be 5-10 mm for the first time, and the limiting is adjusted through the limiting device 280, so that the grinding rollers are prevented from being in direct contact with the lining plate and generating strong vibration;
the abrasive grit-slurry grinding device 202 includes a moving cone 243 and a set of fixed cones 294. The movable cone 243 is positioned on the side surface of the upper part of the disk seat 241, and the conical angle of the movable cone 243 is 30-60 degrees; the fixed cone 294 is positioned at the lower part of the upper shell 290 and surrounds the periphery of the movable cone 243 on the grinding disc, the fixed cone 294 is split, the position of the fixed cone 294 can be adjusted up and down, the distance between the sections of the split fixed cones is 40-80 mm, and the mixed non-crushable iron impurities can be discharged conveniently; the movable cone and the fixed cone form a concentric grinding cavity, the concentric grinding cavity is divided into a wedge-shaped area and a parallel area, the minimum meshing angle of the wedge-shaped area is 20-22 degrees, and sand-slurry particles can smoothly enter the wedge-shaped area to form a stable material layer; the vertical distance of the parallel area is 10-35 mm, the length of the parallel area is 60-200 mm, the size of the gap is adjustable, reasonable gaps and the length of the parallel area are set, the high-efficiency stripping of sand-slurry particles is realized through the regulation and control of the rotating speed of the grinding disc, and cement slurry is ground into fine powder.
In the invention, the grinding cavity of the sand powder roller mill is surrounded by the lower shell 232, the grinding disc 240, the upper shell 290 and the reverse baffling efficient heater 110 to form a fully-closed structure, and the air outlet II 295 is arranged above the cover plate 293 of the upper shell, so that micro negative pressure is formed in the grinding cavity, no dust overflows, and the requirements of green production are met; the bottom edge of the lower shell 232 is internally provided with an annular groove with an upward notch, the bottom surface of the annular groove is provided with a discharge hole 233, the scraping frame 245 is positioned in the annular groove with the upward notch and is connected with the grinding disc into a whole, the plurality of scraping plates 246 are connected with the scraping frame 245, the material cake from the grinding device 202 loosens the material under the centrifugal impact action of the rotating scraping plates, the fine powder adhered to the surface of sand grains is further removed, and the fine powder is completely discharged from the discharge hole 233.
Example 3
Referring to fig. 1-8, a use method of a sand powder roller mill for efficiently preparing waste concrete reclaimed sand powder comprises the following steps:
step one, heating and feeding: when the invention works, if the comprehensive moisture content of the waste concrete sand powder is more than 2.5 percent, hot air at 100-300 ℃ is introduced into the air inlet 117 of the reverse baffling efficient heater 110, the crushed waste concrete sand-slurry particles enter the heating chamber 111 from top to bottom and are uniformly distributed on the bulk material stepped grate plate 112, the hot air is introduced from the hot air furnace into the heating chamber 111 from bottom to top, the sand powder and the hot air flow in an X-shaped cross reverse direction between the bulk material stepped grate plate 112 and the movable baffle plate 113, and the frosted-slurry particles are rapidly heated, thereby improving the heat exchange efficiency of the sand-slurry particles, evaporating the moisture on the surfaces of the particles, and dehydrating and embrittling the cement slurry wrapped on the surfaces of the sand to generate cracks. The distance between the blanking pipe 122 and the grinding disc 240 is adjusted to regulate the throughput of the sand powder, and continuous feeding is carried out.
Step two, crushing and stripping: when the grinding disc rotating speed control device works, the main motor 222 is started, the main motor drives the grinding disc to rotate through the main speed reducer 224, the rotating speed of the main motor and the rotating speed of the grinding disc 240 are adjusted through the frequency converter 225, the adjustment is stopped when the rotating speed of the grinding disc meets the requirement, and the rotating speed of the grinding disc is kept constant. The lower end of the movable arm 262 is pulled by a hydraulic oil cylinder 271 of the grinding roller pressurizing device 270 to drive the grinding roller 250 to rotate, so that an extrusion area and a stripping area which are reasonably distributed in a multi-dimensional force field are formed between the grinding roller sleeve 251 and the grinding disc lining plate 242, the clearance between the extrusion area, namely a disc and a roller curved surface is large, the linear speed is equivalent, and the material is mainly subjected to the action of extrusion force; in the stripping area, the clearance between the curved surfaces of the disc and the roller is small, the linear velocity difference is larger and larger, and the material layer is acted by not only extrusion force but also shearing force and friction force; the crush zone provides a dense and stable bed of material for the stripping zone. The heated waste concrete mortar-slurry particles fall at the center of the grinding disc 240, move towards the edge of the grinding disc under the action of centrifugal force generated by the rotation of the grinding disc driven by the main motor 222, and enter a grinding track to form a material layer beneficial to sand-slurry stripping. Waste concrete sand-slurry particles enter the sand-slurry stripping device 210, a material layer is selectively crushed under the action of a multidimensional force field such as extrusion, shearing, friction and the like of a grinding roller sleeve 251 and a grinding disc lining plate 242 under the action of hydraulic pressure generated by an oil cylinder, and as the raw sand has high hardness and cement slurry wrapped on the surface of the sand particles is heated, dehydrated, embrittled and cracked, the cement slurry wrapped on the surface of the sand particles is subjected to phase splitting and stripping by optimally regulating and controlling the thickness of the material layer, the grinding pressure of a grinding roller 250, the rotating speed of a grinding disc 240 and the like and by utilizing the speed difference generated during the movement of the particles and the particles in the material layer and the physical property difference of the hardness, brittleness, grindability and the like of each component, so that coarse sand (2.36-4.75 mm), medium sand (1.18-2.36 mm), fine sand (0.075-1.18 mm) and fine powder (less than 0.075mm) are formed. Meanwhile, the possibility of particle shape damage and microcrack generation and further crushing of sand grains is reduced by regulating and controlling the multi-dimensional force field. The stripped material continues to move under centrifugal action toward the edge of the disc into the grinding device 202.
Step three, grinding and shaping: the stripped coarse sand (2.36-4.75 mm), medium sand (1.18-2.36 mm) and fine sand (0.075-1.18 mm) contain a part of granular cement slurry and are not ground into fine powder, and the surface of some sand grains is still covered with a part of the cement slurry. In the present invention, the abrasive grit-slurry grinding apparatus includes a moving cone 243 and a set of fixed cones 294. The movable cone 243 rotates along with the disc seat 241, the fixed cone 294 surrounds the movable cone on the grinding disc, the movable cone and the fixed cone form a concentric grinding cavity, the concentric grinding cavity is divided into a wedge area and a parallel area, the minimum meshing angle of the wedge area is 20-22 degrees, and the vertical distance of the parallel area is 10-35 mm and is adjustable. The material after carrying out the selectivity crushing from sand-thick liquid stripping off device gets into the concentric intracavity of grinding under centrifugal force and the effect of gravity, through setting up the reasonable clearance of moving awl and fixed cone, parallel zone length and regulation and control mill rotational speed, the material layer of the intracavity of grinding concentrically receives the extrusion of the rotatory moving awl 243 of intermediate speed (4 ~ 8m/s), cut and the frictional force effect, carry out the inter-particle friction of material layer once more to sand-thick liquid and cement slurry with the sand grain of different particle sizes as the rinding body simultaneously, make the part grout integument of parcel on the sand grain surface ground, the graininess cement slurry is ground into the farine simultaneously. Because the mutual grinding between the sand grain of different particle sizes, comparatively outstanding edges and corners and edge are ground off on the sand grain, realize the sand grain plastic, improve the performance of reclaimed sand.
Step four, scattering and discharging: in the operation of the invention, the stripped and shaped regenerated sand powder falls into the annular collecting groove, the agglomerated material is loosened under the centrifugal impact action of the rotary scraper 246, the fine powder adhered to the surface of the sand is further removed, and the sand powder is completely discharged from the discharge port 233 to enter the next process. And the next procedure is to sort out the regenerated coarse sand (2.36-4.75 mm), the regenerated medium sand (1.18-2.36 mm), the regenerated fine sand (0.075-1.18 mm) and the regenerated fine powder (less than 0.075mm) by air separation and screening, and continuously returning the sand-pulp particles larger than 4.75mm to the sand powder roller mill for crushing and stripping.
The invention has the following principle outline: the invention relates to a sand powder roller mill for efficiently preparing high-quality recycled waste concrete sand powder, which is designed by adopting the methods of heating-feeding, crushing-stripping, grinding-shaping, scattering-discharging according to the effective separation angle of each component of the waste concrete sand powder and the selective material layer crushing principle under the action of a multidimensional force field based on the sand-slurry interface bonding strength and the multi-dimensional force field based on the physical and chemical characteristics of each component in the waste concrete sand powder in different regions and different ages and the physical property difference of hardness, grindability and the like caused by the residual cement slurry wrapped on the surface of the recycled sand.
Table 1 shows the comparison between the present invention and the conventional equipment:
Figure RE-GDA0003314864430000141
Figure RE-GDA0003314864430000151
table 2 shows a comparison of the basic properties of reclaimed and natural sands produced after grinding according to the invention with C40:
Figure RE-GDA0003314864430000152
the effects listed are shown in tables 1 and 2. As can be seen from the table 1, the invention has good effect and better solves the defect of poor performance of the waste concrete sand powder prepared by the traditional equipment. As can be seen from Table 2, compared with natural sand, the reclaimed sand prepared by the invention has higher water absorption, other indexes such as apparent density, bulk density and porosity are not much different from those of the natural sand, and the apparent density and bulk density of some reclaimed sand are even better than those of the natural sand, thereby achieving the purpose of the invention.
While there have been shown and described what are at present considered the fundamental principles of the invention, its essential features and advantages, it will be understood by those skilled in the art that the invention is not limited by the embodiments described above, which are given by way of illustration of the principles of the invention, but rather are intended to be covered by the scope of the invention which is defined by the appended claims.

Claims (10)

1. The utility model provides a waste concrete regeneration sand powder high efficiency preparation is with sand powder roller mill which characterized in that: comprises a waste concrete sand-slurry particle heating and feeding device and a waste concrete sand-slurry particle stripping and shaping mechanism;
the waste concrete mortar-slurry particle heating and feeding device heats the mortar-slurry particles before grinding, and continuously feeds by regulating and controlling the throughput of sand powder;
the waste concrete sand-slurry particle stripping and shaping mechanism selectively crushes material layers of heated waste concrete sand-slurry particle groups, phase splitting and stripping cement slurry wrapped on the surfaces of sand particles, grinds the granular cement slurry into fine powder, grinds the protruded edges and corners on the sand particles, and selects regenerated coarse sand, regenerated medium sand, regenerated fine sand and regenerated fine powder through screening.
2. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 1, which is characterized in that: the waste concrete sand-slurry particle heating and feeding device comprises a reverse baffling efficient heater and a feeder, wherein the reverse baffling efficient heater is positioned above the feeder and is connected with the feeder through a flange;
the reverse baffling efficient heater comprises a heating chamber shell, a bulk material stepped grate plate, a movable baffle plate and a heat insulation layer; the top of the heating chamber shell is provided with a feeding port and a first air outlet, the bottom of the heating chamber shell is provided with a material collecting hopper, the middle of the heating chamber shell is provided with an inclined air inlet, and two connecting lines of the feeding port and the material collecting hopper and the centers of the air inlet and the first air outlet are distributed in an X shape; the plurality of bulk material stepped grate plates are uniformly arranged below the feeding port and close to the side of the air inlet of the heating chamber shell from top to bottom, and each bulk material stepped grate plate forms a certain included angle with the horizontal plane and is connected to the heating chamber shell by adopting an insertion method; the movable baffle plate is arranged below the air outlet, a plurality of baffle plates are uniformly distributed from top to bottom and are integrated with the side plates at two sides, each baffle plate forms a certain included angle with the horizontal plane, the inclination direction of each baffle plate is opposite to that of the bulk material stepped grate plate, the baffle plates at two sides are in one-to-one correspondence to form included angles of 75-105 degrees, and the side plates at two sides are connected with a plurality of groups of horizontal groove-shaped holes in the heating chamber shell through bolts; the heat-insulating layer is laid outside the heating chamber shell;
the feeder comprises a feeding pipe, a discharging pipe and an adjusting bolt; the feeding pipe is arranged below the collecting hopper of the heating chamber shell and is connected with the collecting hopper through a flange; the blanking pipe is sleeved on the lower part of the feeding pipe and is connected with the flange through a plurality of adjusting bolts.
3. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 1, which is characterized in that: the waste concrete sand-slurry particle stripping and shaping mechanism comprises an integral base, a main transmission device, a frame, a lower shell, a grinding disc, a plurality of grinding rollers, a transmission arm, a pressurizing device, a limiting device and an upper shell.
4. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 3, which is characterized in that: the integral base comprises a main speed reducer base and a rack base, and the main speed reducer base and the rack base are connected or welded into a whole in pairs through bolts; the integral base is positioned on a concrete foundation and is embedded into a foundation hole by adopting foundation bolts to be fixed by grouting;
the main transmission device comprises a main motor base, a main motor, a coupler, a main speed reducer and a frequency converter, wherein the main motor base is positioned on a concrete foundation and is embedded in a foundation hole by adopting a foundation bolt for grouting and fixing; the main motor is arranged on a main motor base, and an output shaft of the main motor is axially connected with an input shaft of the main speed reducer through a coupler in the horizontal direction; the main speed reducer is positioned on a main speed reducer base, and an output thrust disc in the vertical direction of the main speed reducer is connected with the lower plane of the grinding disc through a flange; and the frequency converter is connected with the main motor through a cable.
5. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 4, which is characterized in that: the number of the racks is at least three, the racks are positioned on the rack base and fixed on the concrete foundation through foundation bolts; the lower shell is positioned on the upper plane of the frame and is connected with the upper plane of the frame through lower shell supporting legs, and an annular groove with an upward notch is formed in the bottom edge of the lower shell; and a discharge hole is formed in the bottom surface of the annular groove of the lower shell.
6. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 5, which is characterized in that: the grinding disc comprises a disc seat, a lining plate, a movable cone, a material blocking ring, a material scraping frame and a material scraping plate, and is positioned above the annular groove in the lower shell and the output thrust disc of the main speed reducer; the disc seat is a rotating body, a plurality of wear-resistant lining plates with low inside and high outside are fixed on the inner concave surface of the upper part of the disc seat, the wear-resistant lining plates surround to form a disc-shaped grinding track, the lower part of the disc seat penetrates through an annular hole surrounded by an annular groove of the lower shell, and the bottom surface of the lower part of the disc seat is fixedly connected with an output thrust disc of the main speed reducer; the movable cone is positioned on the side surface of the upper part of the disc seat and fixedly connected with the outer convex surface of the upper part of the disc seat, the movable cone is integrated or split, the conical angle of the movable cone is 30-60 degrees, the surface of the movable cone is compounded with a wear-resistant lining, and the stop ring is positioned on the upper plane of the movable cone and connected with the movable cone; the scraping frame is positioned below the lower plane of the upper part of the disc seat and is fixedly connected with the disc seat, and the scraping plates are connected with the scraping frame; the feeder is positioned above the grinding disc.
7. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 6, which is characterized in that: each grinding roller is positioned above the grinding disc, the inclination angle of the axial center line of each grinding roller and the horizontal plane is not more than 12 degrees, and each grinding roller is arranged on the horizontal plane at equal angles and intervals; a grinding body roller sleeve is fixed at one end of the grinding roller, the grinding surface of the roller sleeve is arc-shaped, and a wear-resistant lining is compounded on the outer surface of the arc shape; the other end of the grinding roller is fixedly connected with the transmission arm; the total projection area of the grinding roller on the grinding disc is 60-70% of the area of the grinding track;
the transmission arm is arranged on the upper plane of the frame and comprises a rocker arm, a movable arm, a cross shaft, a bearing seat, a bearing and a thrust device, wherein the rocker arm and the movable arm are connected through the cross shaft and a pin, the cross shaft is supported on the bearing seat through 2 bearings, the bearing seat is connected with the upper plane of the frame and a lower shell supporting leg into a whole, one part of the thrust device is fixed on one end face of the cross shaft, and the other part of the thrust device is fixed on one end face of the bearing seat;
the pressurizing device comprises an oil cylinder, a pressurizing base, a hydraulic system, an energy accumulator and a pipeline, the pressurizing device is positioned below the transmission arm, a head lug of the oil cylinder is connected with a lower hole of the movable arm through a pin shaft, a cylinder body of the oil cylinder is connected with the pressurizing base through a pin shaft, the pressurizing base is positioned on the frame base and fixed on a concrete foundation through anchor bolts, a pressurizing oil path of the hydraulic system is connected with a rod cavity of the oil cylinder through the energy accumulator and the pipeline, and a roller lifting oil path is connected with a rodless cavity of the oil cylinder through the pipeline.
8. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to claim 7, which is characterized in that: the limiting device is positioned on the outer side of the movable arm and is arranged on a vertical plate in the rack, and a plurality of groups of disc springs are arranged in the limiting device;
the upper shell comprises a shell, a grinding roller door, a cover plate and a fixed cone, the shell is positioned above the lower shell, is cylindrical and is connected with the lower shell, the shell is provided with the grinding roller door for the grinding roller to freely turn in and out, the cover plate is positioned above the shell and is connected with the shell to support the reverse deflection efficient heater and the feeder, and the cover plate is provided with a second air outlet; the fixed cone is arranged on the lower portion of the upper shell and surrounds the movable cone of the grinding disc, the fixed cone is split, the position of the fixed cone is adjustable up and down, the distance between the split fixed cone sections is 40 mm-80 mm, and the fixed cone grinding surface is compounded with a wear-resistant lining.
9. The sand powder roller mill for efficiently preparing the reclaimed sand powder of the waste concrete according to the claims 4 and 6, which is characterized in that: in the main transmission device, the rotating speed of the grinding disc is controlled by adjusting the working frequency of the main motor through a frequency converter; the height of the material blocking ring is 5-40 mm and is adjustable, and the detention time of the waste concrete sand powder on the grinding disc is controlled to reach 30-60 seconds.
10. The use method of the sand powder roller mill for efficiently preparing the waste concrete regenerated sand powder is characterized by comprising the following steps of: the method specifically comprises the following steps:
step one, heating and feeding: introducing hot air at 100-300 ℃ into an air inlet of the reverse baffling efficient heater, introducing crushed waste concrete sand-slurry particles into the heating chamber shell from top to bottom, uniformly distributing the crushed waste concrete sand-slurry particles on the bulk material stepped grate plate, introducing the hot air into the hot air furnace from bottom to top, introducing the hot air into the heating chamber shell, enabling sand powder and the hot air to flow in an X-shaped crossed reverse direction between the bulk material stepped grate plate and the movable baffle plate, rapidly heating the ground sand-slurry particles, evaporating the surface moisture of the particles, dehydrating and embrittling cement slurry wrapped on the surface of the sand to generate cracks, adjusting the distance between a discharging pipe and a grinding disc to adjust the throughput of the sand powder, and continuously feeding the sand powder;
step two, crushing and stripping: starting a main motor, driving the grinding disc to rotate through a main speed reducer, adjusting the rotating speed of the main motor and the rotating speed of the grinding disc through a frequency converter, stopping adjustment when the rotating speed of the grinding disc meets the requirement, and keeping the rotating speed of the grinding disc constant; the lower end of the movable arm is pulled by a hydraulic oil cylinder of the grinding roller pressurizing device to drive the grinding roller to rotate, so that an extrusion area and a stripping area which are reasonably distributed in a multi-dimensional force field are formed between a grinding roller sleeve and a grinding disc lining plate;
the heated waste concrete mortar-slurry particles fall at the center of the grinding disc, move towards the edge of the grinding disc under the action of centrifugal force generated by the rotary grinding disc and enter a grinding track to form a material layer; waste concrete sand-slurry particles enter a sand-slurry stripping device, particle groups are selectively crushed under the actions of extruding, shearing and rubbing a multidimensional force field by a grinding roller sleeve and a grinding disc lining plate, and as the original sand is high in hardness and cement slurry wrapped on the surface of sand particles is heated, the cement slurry is dehydrated, embrittled and cracked, the cement slurry wrapped on the surface of the sand particles is subjected to phase splitting and stripping by optimally regulating and controlling the thickness of a material layer, the hydraulic pressure of a grinding roller and the rotating speed of a grinding disc by utilizing the speed difference generated during layered movement of the particle groups in the material layer and the hardness, brittleness and grindability physical property difference of each component to form coarse sand, medium sand, fine sand and fine powder, the stripped material continuously moves to the edge of the grinding disc under the action of centrifugal force, and enters a grinding and shaping process;
step three, grinding and shaping: the stripped coarse sand, medium sand and fine sand still contain a part of granular cement slurry which is not milled into fine powder, the surfaces of some sand grains still wrap part of the cement slurry, the movable cone and the fixed cone form a concentric grinding cavity, the concentric grinding cavity is divided into a wedge-shaped area and a parallel area, the minimum meshing angle of the wedge-shaped area is 20-22 degrees, and the vertical distance of the parallel area is 10-35 mm and can be adjusted; the materials after being selectively crushed from the sand-slurry stripping device enter a concentric grinding cavity under the action of centrifugal force and gravity, are extruded, sheared and subjected to the action of friction force by a moving cone rotating at a medium speed, and meanwhile, sand grains with different grain sizes are used as grinding bodies to carry out inter-grain friction on the sand-slurry and the cement slurry again, so that part of cement slurry wrapped on the surfaces of the sand grains is ground off, and meanwhile, the granular cement slurry is ground into fine powder; because the sand grains with different grain sizes are rubbed with each other, the protruded edges and corners on the sand grains are ground off, and the sand grains are shaped;
step four, scattering and discharging: the stripped and shaped regenerated sand powder falls into an annular collecting groove, agglomerated materials are loosened under the centrifugal impact action of a rotary scraper, fine powder adhered to the surface of sand grains is further removed and is completely discharged from a discharge port, then the regenerated coarse sand, the regenerated medium sand, the regenerated fine sand and the regenerated fine powder are sorted by winnowing and screening, and sand-slurry particles larger than 4.75mm are continuously ground and stripped by a sand-powder roller mill.
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