CN110883056A - Screening system and method for recycled aggregate recovery - Google Patents

Abstract

The invention discloses a screening system and method for recycling recycled aggregates, comprising: a pre-screening device: screening concrete wastes according to different required specifications; a jet-grinding device: jet-grinding recycled aggregates; Screening device: Screen the blasted aggregate according to different specifications required; the pre-screening device, blasting device and fine screening device are successively undertaken according to the production process of recycled aggregate; it can solve the problem of construction waste concrete concrete The wastes are complex, diverse and wet, and the screening problems such as the initial crushing are difficult to screen and the mesh is easy to block; the dust and residual mortar on the surface of the finished aggregate can be further cleaned to obtain high-quality recycled aggregate; the present invention proposes The advanced screening method of recycled aggregate recovery system can not only achieve high-quality recovery of cement concrete aggregates, but also solve the problem that recycled asphalt fine materials are sticky and difficult to screen. Screening of particles and asphalt fine particles below 5mm, compact structure.

Description

A screening system and method for recycling recycled aggregates

technical field

The invention relates to the technical field of recycling of recycled aggregates, in particular to a screening system and method for recycling recycled aggregates.

Background technique

In recent years, with the continuous increase in the amount of cement concrete and asphalt concrete waste, the shortage of primary aggregates has caused problems such as soaring aggregate prices. It has become an important topic that the society needs to study and solve urgently.

As we all know, the current method of recycling the aggregate in the concrete waste is to obtain the raw materials required by the aggregate regeneration system after primary crushing on site. The raw materials are further processed, such as re-crushing (or blasting, shot blasting) and other processes to remove the mortar, dust, soil and other attachments attached to the surface of the aggregate, and then sieving and grading to obtain high-quality recycled materials. Coarse aggregates and fine aggregates.

Because the concrete waste is complex, diverse, wet, and contains debris such as slag, a large amount of mortar powder will be generated during the primary crushing process. If this part of the fine material is not screened out in advance, it will enter the aggregate regeneration system for re-crushing (or spraying). In the grinding and shot peening device, it not only reduces the output, but also aggravates the loss of the internal parts of the grinding device, and the moisture content of this part of the fine material is high, which is easy to lead to re-crushing (or blasting, shot peening) of the inner cavity device. , causing unnecessary effects.

Due to the high moisture content of this part of the fine material, especially the asphalt content and viscosity of the reclaimed asphalt below 5mm, if the conventional screening technology is used for the screening operation, the screening efficiency is low, the output is low, and the screen is easy to block. , The problem that is not easy to clean is the bottleneck of aggregate regeneration technology.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above deficiencies and provide a screening system and method for recycling recycled aggregates.

In order to achieve the above-mentioned purpose, the technical solution of the present invention is: a screening system for reclaimed aggregate recovery, comprising:

Pre-screening device: screen the concrete waste according to different specifications required;

Jet grinding device: jet grinding the recycled aggregate;

Fine screening device: screen the aggregate after jet grinding according to different specifications required;

The pre-screening device, the jet-milling device and the fine-screening device are successively undertaken according to the production process of recycled aggregate.

Preferably, the pre-screening device is any one of a relaxation screen, a multi-frequency vibrating screen, a circular vibrating screen, a trommel screen and a linear vibrating screen.

Preferably, the fine screening device is any one of an air screening mechanism, an elliptical screen mechanism, and a multi-stage combined screening mechanism.

Preferably, the relaxation screen is provided with a toothed screen mechanism, toothed screen bars and a relaxation screen structure.

Preferably, the air screening mechanism includes an air selection chamber, a blower, a recovery filter, a dispersion device, and a vibrating screen, the blower is arranged on one side of the air selection chamber, and the recovery filter is arranged on the side of the air selection chamber. On the other side, the dispersing device is arranged at the feed port of the air-sorting chamber, and is used to distribute the aggregate evenly. The vibrating screen is placed at the bottom of the air-selection chamber to screen the aggregate. Several layers of screen meshes are arranged in sequence from top to bottom, and the mesh size of each screen mesh decreases sequentially from top to bottom.

Preferably, the bottom of the vibrating screen is provided with an anti-clogging device to prevent clogging.

Preferably, the elliptical screen mechanism includes a bracket, an elastic body and a driving unit arranged on the bracket, a screen box arranged on the upper end of the elastic body, and a vibration exciter arranged on one side of the bracket, and the elastic body supports the screen box horizontally The drive unit is connected with the vibration exciter in a transmission, and can drive each vibration exciter to vibrate synchronously, so that the screen box moves in an elliptical trajectory under the cooperation of the elastic body.

Preferably, the multi-stage combined screening mechanism includes a first screen box and a second screen box arranged from top to bottom, the first screen box is a circular vibrating screen, and the coarse aggregate is screened, and the first screen box is a circular vibrating screen. The second screen box is a high-frequency screen, which screens fine aggregates and easily-bonded aggregates, and the sieve size of the first screen box and the second screen box decreases in turn.

A screening method for recycling recycled aggregates, using the above-mentioned screening system for recycling recycled aggregates, comprising the following steps in sequence:

S1, pre-screening treatment: the concrete waste is screened according to the different specifications required by the pre-screening device;

S2, jet mill treatment: the pre-screened aggregate is jet milled by a jet mill device;

S3, fine screening treatment: the aggregates after jet grinding are screened by a fine screening device according to different specifications required.

Preferably, after step S3, the finished aggregate needs to be humidified.

By adopting the above technical scheme, the beneficial effects of the present invention are: through the relaxation screen, it can solve the screening problems that the construction waste concrete waste is complex and diverse, wet, and the initial crushing contains a lot of powder, which is difficult to screen and easy to block the screen; Screening by air screening mechanism, combined with air selection and vibrating screening, separates the powder in the crushing process in advance, and further cleans the dust and residual mortar on the surface of the finished aggregate to obtain high-quality recycled aggregate; oval The screen mechanism has a compact structure, which can solve the problems that the linear vibrating screen is easy to block, the size of the circular vibrating screen is large, and the screening accuracy is low, and high-quality regenerated finished sand can be obtained. Separation method, through the recycled aggregate recycling system, not only can the high-quality recycling of cement concrete aggregates be realized, but also the problem that the recycled asphalt concrete recycled fine materials are sticky and difficult to be screened can be solved. Screening of large particles and asphalt fine particles below 5mm, compact structure.

Description of drawings

Fig. 1 is the structural representation of the screening system of the first embodiment of the present invention;

Fig. 2 is the structural representation of the sieving system of embodiment 2 of the present invention;

Fig. 3 is the enlarged view of A place in Fig. 2 of the present invention;

Fig. 4 is the structural representation of the sieving system of embodiment 3 of the present invention;

Fig. 5 is the schematic flow chart of the screening method of the present invention;

Description of main reference numerals: 1 relaxation screen, 2 air screening mechanism, 21 air separation chamber, 22 blower, 23 recovery filter, 24 dispersion device, 25 vibrating screen, 3 anti-blocking device, 4 elliptical screen mechanism, 41 bracket , 42 screen box, 43 elastomer, 44 drive unit, 45 exciter, 5 multi-frequency vibrating screen, 6 probability screen, 7 multi-stage combined screening mechanism, 71 first screen box, 72 second screen box, A as Pre-screening device, B as jet mill device, C as fine screening device.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

The screening system for recycling the recycled aggregate of the present invention

As shown in Figures 1-4, a screening system for recycled aggregate recovery includes:

Pre-screening device A: Screen the concrete waste according to different specifications required;

Jet-grinding device B: jet-grind the recycled aggregate;

Fine screening device C: screen the aggregate after jet grinding according to different specifications required;

Pre-screening device A, jet mill B and fine screening device C are successively undertaken according to the production process of recycled aggregate.

The pre-screening device A is any one of a relaxation screen 1, a multi-frequency vibrating screen 5, a circular vibrating screen, a trommel screen and a linear vibrating screen.

The fine screening device C is any one of the air screening mechanism 2 , the elliptical screening mechanism 4 and the multi-stage combined screening mechanism 7 .

The relaxation screen 1 is provided with a toothed screen mechanism, toothed screen bars and a relaxation screen structure.

The air screening mechanism 2 includes an air selection chamber 21, a blower 22, a recovery filter 23, a dispersing device 24, and a vibrating screen 25. The blower 22 is arranged on one side of the air selection chamber 21, and the recovery filter 23 is arranged on the side of the air selection chamber 21. On the other side of the winnowing chamber 21, the dispersing device 24 is arranged at the feed port of the winnowing chamber 21 to distribute the aggregate evenly, and the vibrating screen 25 is arranged at the bottom of the For screening, the vibrating screen 25 includes several layers of screen meshes arranged in sequence from top to bottom, and the mesh size of each screen mesh decreases sequentially from top to bottom.

The bottom of the vibrating screen 25 is provided with an anti-clogging device 3 to prevent clogging.

The elliptical screen mechanism 4 includes a bracket 41, an elastic body 43 and a drive unit 44 arranged on the bracket 41, a screen box 42 arranged on the upper end of the elastic body 43, and a vibration exciter 45 arranged on one side of the bracket. The screen box 42 is supported horizontally, and the drive unit 44 is connected with the exciter 45 in a driving manner, and can drive each exciter 45 to vibrate synchronously, so that the screen box 42 moves in an elliptical trajectory with the cooperation of the elastic body 43 .

The multi-stage combined screening mechanism 7 includes a first screen box 71 and a second screen box 72 arranged from top to bottom, the first screen box 71 is a circular vibrating screen, and the coarse aggregate is screened. The sieve box 72 is a high-frequency sieve, which sieves the fine aggregate and the easily-bonded aggregate, and the mesh size of the first sieve box 71 and the second sieve box 72 decreases in turn.

The screening method for recycling recycled aggregate of the present invention

As shown in Figure 5, a screening method for recycling of recycled aggregates, using the above-mentioned screening system for recycling of recycled aggregates, comprises the following steps in sequence:

S1, pre-screening treatment: the concrete waste is screened according to the different specifications required by the pre-screening device A;

S2, jet mill treatment: the pre-screened aggregate is jet milled by jet mill B;

S3, fine screening treatment: the aggregate after jet grinding is screened by fine screening device C according to different specifications required.

After step S3, the finished aggregate needs to be humidified.

Example 1

This embodiment is aimed at the recovery of cement concrete recycled aggregate

As shown in Figure 1, according to the characteristics of construction waste that is complex and diverse, wet, and contains slag and other debris, the pre-screening device A for raw materials can use a relaxation screen 1 suitable for screening construction waste, and the preliminarily crushed concrete The waste is screened into the raw material specifications required by the recycled aggregate recycling system: such as recycled aggregate raw materials (5-40mm), abrasive particles (0-5mm), oversized materials (>40mm) and debris returned to the primary through the return system The crushing machine is used for re-crushing or separation; the relaxation screen 1 is equipped with a toothed screen mesh mechanism suitable for the screening of large aggregates of construction waste, toothed screen bars and a relaxation screen mesh structure suitable for the screening of wet fine materials; The fine materials screened by sieve 1, such as (0-5mm) abrasive particles can be further selected by a well-known powder sorting equipment to remove a part of the fine powder, and then feed the abrasive particles to the blasting device B; if the concrete waste is dried , contains less debris, the pre-screening device A can also use the well-known circular vibrating screen, trommel screen, linear vibrating screen 25 and other conventional screening equipment for screening; fine screening of recycled aggregate products, fine screening according to needs The sorting device C can use the air screening mechanism 2 for screening; the air screening mechanism 2 includes a blower 22, a recovery filter 23, a dispersion device 24, an air separation chamber 21, and a vibrating screen 25. The finished product processed by the jet mill B The mixture is fed into the air screening mechanism 2 through the dispersing device 24, and the combination of the air separation and the vibrating screen 25 is realized through the action of the fan, the air separation chamber 21, the vibrating screen 25, and the recovery filter 23 connected to the negative pressure dust removal device. The powder is separated in advance, and the dust and residual mortar on the surface of the finished aggregate are further cleaned to obtain high-quality recycled aggregate; the air selection chamber 21 is provided with a blower 22 on the side, and the other side is connected to the recovery filter connected to the negative pressure dust collector. The dispersing device 24 is installed at the feed port of the air selection chamber 21 to achieve uniform distribution of materials; the air selection chamber 21 is provided with a vibrating screen 25 at the bottom, and the vibrating screen 25 is composed of several layers of screen meshes from top to bottom. It is set at the bottom, and multi-stage screening is carried out through multi-layer screen meshes. The size of the screen holes decreases from top to bottom in order to meet the screening of different amounts of aggregates and improve the screening quality. The same vibrating screen 25 can obtain several specifications. The bottom of the vibrating screen 25 screen is provided with an anti-blocking device 3 (for example: an anti-blocking screen); the finished fine material after being screened by the air screening mechanism 2 can be partially returned to the jet mill B as The supplement of the abrasive particles can also be stored in the storage system separately from other materials; the finished fine particles can also be humidified by a humidifier, so that the recycled fine aggregates contain appropriate moisture and are convenient for transportation.

Example 2

This embodiment is aimed at the recovery of cement concrete recycled aggregate

As shown in Figures 2 and 3, in view of the characteristics of construction wastes that are complex and diverse, wet, and contain dregs and other debris, the pre-screening device A for raw materials can use a relaxation screen 1 suitable for screening construction wastes. The crushed concrete waste is screened into the raw material specifications required by the recycled aggregate recycling system: such as recycled aggregate raw materials (5-40mm), abrasive particles (0-5mm), oversized materials (>40mm) and debris through the return material The system returns to the primary crusher for re-crushing or separation; the relaxation screen 1 has a toothed screen mechanism suitable for the screening of large aggregates of construction waste, a toothed screen bar and a relaxation screen structure suitable for the screening of wet fine materials; The fine materials sieved by the sieve 1, such as (0-5mm) abrasive particles can be further selected by a well-known powder sorting equipment to remove a part of the fine powder, and then the abrasive particles are fed into the blasting device B; if the concrete waste is Dry and contain less debris, the pre-screening device A can also use conventional screening equipment such as well-known circular vibrating screen, trommel screen, linear vibrating screen 25 for screening; the fine screening device C of the finished recycled aggregate can be used for screening Elliptical screen mechanism 4. The elliptical screen mechanism 4 includes a screen box 42, a vibration exciter 45 and a drive unit 44. The screen box 42 is supported and connected to the floor bracket 41 through an elastic body 43 and is horizontal, and the drive unit 44 drives the The vibration exciter 45 is connected to drive the vibration exciter 45 to vibrate synchronously, and the vibration exciter 45 vibrates synchronously and cooperates with the elastic body 43 to make the motion track of the screen box 42 be an elliptical track; The recycled aggregate is screened into several specifications of finished coarse aggregate and fine aggregate, which solves the problems that the linear vibrating screen 25 screen is easy to block, the output is low, the size of the circular vibrating screen is large, and the screening accuracy is low; the ellipse The finished fine aggregates screened by the sieve mechanism 4 can be further screened by the probability sieve 6 or the above-mentioned air screening mechanism 2 to obtain high-quality regenerated finished sand; the regenerated finished sand can also be humidified by a humidifier. Make the recycled fine aggregate contain appropriate moisture for easy transportation.

Example 3

This embodiment is aimed at the recovery of recycled aggregate of asphalt concrete

Asphalt pavement regeneration is to excavate and mill the old asphalt pavement, recycle the old material and further crush and screen it for mixing new asphalt mixture. The wear device strips the recycled aggregate from the asphalt on the surface of the aggregate by blasting and other processes. This part of the fine material and the asphalt milling material below 5mm have high asphalt content and can be used for the regeneration of the asphalt pavement surface, which has special economic value, but Difficult to sift.

As shown in Figure 4, in view of the characteristics of high viscosity and difficult screening of fine asphalt materials, multi-frequency vibrating screen 5 can be used for pre-screening of raw materials, and the initially milled recycled materials are screened into recycled aggregate recovery systems as needed. Required raw material specifications: For example: 40-100mm, 20-40mm, 5-10mm, 0-5mm and other grades of materials, qualified materials enter the blast mill B for further processing, and unqualified materials return to the primary crushing host for re-crushing ;Multi-frequency vibrating screen 5 equipment combines the advantages of circular vibrating screen and high-frequency screen. The circular vibrating screen is suitable for the screening of coarse particles and other easy-to-screen materials, and the high-frequency exciter 45 of the high-frequency screen is suitable for asphalt recycling materials. The screening of difficult-to-screen materials such as fine materials and special viscous materials can effectively solve the screening problems of special viscous materials; the pre-screening of raw materials in the asphalt concrete aggregate recovery system can also be screened by the above-mentioned relaxation screen 1; According to the characteristics of the recycled asphalt material, the fine screening of the finished product can be accurately screened by a multi-stage combined screening mechanism 7; the multi-stage combined screening mechanism 7 includes a first screen box 71 and a second screen box 72: the first screen The box 71 can be a circular vibrating screen suitable for the screening of large materials, and the second screen box 72 can be a high-frequency screen suitable for the screening of fine materials and easily-bonded materials; Set to the bottom, the screen holes decrease from top to bottom in order to meet the screening of different amounts of aggregates and improve the screening quality. The same screening equipment can obtain recycled aggregates of several finished specifications; the precision of the finished asphalt recycled aggregates Screening can also be carried out by using the above-mentioned multi-layer relaxation screen 1 structure. The relaxation screen 1 is composed of several layers of screen meshes. According to actual needs, a toothed screen mesh mechanism suitable for large aggregate screening and suitable for wet fine mesh can be set up. The number of layers of 1 mesh structure of the relaxation screen for material screening is combined.

In summary, through the relaxation screen 1, it can solve the screening problems that the construction waste concrete waste is complex, diverse, wet, and the initial crushing contains a lot of powder, which is difficult to screen and easy to block; The vibrating screen 25 separates the powder in the crushing process in advance, and further cleans the dust and residual mortar on the surface of the finished aggregate, so as to obtain high-quality recycled aggregate; the elliptical screen mechanism 4 has a compact structure, which can solve the problem of using linear The screen mesh of the vibrating screen 25 is easy to block, the size of the circular vibrating screen is large, and the screening accuracy is low, and high-quality recycled finished sand can be obtained; the screening method of the recycled aggregate recovery system proposed by the present invention , not only can achieve high-quality recycling of cement concrete aggregates, but also solve the problem that asphalt concrete recycled fine materials are sticky and difficult to screen. Screening, compact structure.

The above are only preferred embodiments of the present invention, and cannot limit the scope of the present invention. All equivalent changes and decorations made according to the scope of the patent application of the present invention should still fall within the scope of the present invention.

Claims (10)

1. A screening system for recycled aggregate recovery, comprising:

pre-screening device: screening the concrete waste according to different required specifications;

and (3) a jet milling device: carrying out abrasive blasting on the recycled aggregate;

fine screening device: screening the milled aggregate according to different required specifications;

and the pre-screening device, the abrasive blasting device and the fine screening device are sequentially connected according to the production flow of the recycled aggregate.

2. A screening system for recycled aggregate recovery according to claim 1, wherein said pre-screening device is any one of a relaxation screen, a multi-frequency vibrating screen, a circular vibrating screen, a drum screen and a linear vibrating screen.

3. The screening system for recycled aggregate recovery of claim 1, wherein the fine screening device is any one of an air screening mechanism, an elliptical screening mechanism and a multi-stage combined screening mechanism.

4. A screening system for recycled aggregate recovery as recited in claim 2, wherein said relaxation screen is provided with a toothed screening mechanism, toothed rider bars and a relaxation screen structure.

5. The system of claim 3, wherein the air screening mechanism comprises an air separation chamber, an air blower, a recovery filter, a dispersing device and a vibrating screen, the air blower is arranged at one side of the air separation chamber, the recovery filter is arranged at the other side of the air separation chamber, the dispersing device is arranged at a feed inlet of the air separation chamber and is used for uniformly distributing the aggregates, the vibrating screen is arranged at the bottom of the air separation chamber and is used for screening the aggregates, the vibrating screen comprises a plurality of layers of screens which are sequentially arranged from top to bottom, and the screen mesh sizes of the screens are sequentially reduced from top to bottom.

6. A screening system for recycled aggregate recovery according to claim 5, wherein the bottom of the vibrating screen is provided with anti-blocking means to prevent clogging.

7. The screening system for recycled aggregate recovery according to claim 3, wherein the elliptical screening mechanism comprises a bracket, an elastic body and a driving unit which are arranged on the bracket, a screening box arranged at the upper end of the elastic body, and a vibration exciter arranged on one side of the bracket, wherein the elastic body horizontally supports the screening box, the driving unit is in transmission connection with the vibration exciter and can drive the vibration exciters to synchronously vibrate, and the screening box moves in an elliptical track under the cooperation of the elastic body.

8. The screening system for recycled aggregate recovery according to claim 3, wherein the multistage combined screening mechanism comprises a first screening box and a second screening box which are arranged from top to bottom, the first screening box is a circular vibrating screen and is used for screening coarse aggregates, the second screening box is a high-frequency screen and is used for screening fine aggregates and easily-bonded aggregates, and the screen mesh sizes of the first screening box and the second screening box are sequentially reduced.

9. A screening method for recycled aggregate recovery using a screening system for recycled aggregate recovery according to any one of claims 1 to 8, wherein: comprises the following steps which are carried out in sequence:

s1, pre-screening treatment: screening the concrete waste material according to different required specifications through a pre-screening device;

s2, abrasive blasting: carrying out abrasive blasting on the aggregate subjected to the pre-screening treatment by an abrasive blasting device;

s3, fine screening treatment: and screening the milled aggregate through a fine screening device according to different required specifications.

10. The screening method for recycled aggregate recycling according to claim 9, wherein the finished aggregate is subjected to a humidification treatment after step S3.

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