RU129429U1 - INSTALLATION OF CONCRETE DISPOSAL AFTER DISMANTLING OF TEMPORARY ACCOMMODATION POINTS OF THE POPULATION AFFECTED IN EMERGENCY - Google Patents

Abstract

Installation of concrete recycling after dismantling of temporary accommodation points for the population affected by an emergency, containing three technological chains: the first chain is preparatory and consists of bunkers for storing mixtures, concrete, bricks, asphalt brought by vehicles, the second chain is a technological one and contains an installation for screening heavy metal , an electromagnet for catching it, an installation for sifting out sand and storing it in a bunker as an aggregate, a crusher for separating pieces of concrete from reinforcement connected to the second electromagnet, the third chain is a finishing one and consists of a reserve bunker connected to an impact mill connected with a third electromagnet, and also contains two screens connected to a water treatment system, including a mixer with a supply unit for chips and organic components, then a fractionation unit, from where the processed products are sent to the secondary aggregates warehouse, characterized in that others the upholstery is made of a jaw and contains an electric motor with a pulley, an eccentric, movable and fixed cheeks and an unloading window.

Description

The utility model relates to the processing of concrete scrap resulting from the dismantling of buildings and structures, the accumulation of substandard products at prefabricated reinforced concrete enterprises, as well as during the destruction of buildings and structures in emergency situations.

Recycling of concrete scrap is currently aimed mainly at obtaining secondary aggregates and the release of reinforcing steel. The technology has become widespread when equipment for the production of aggregate from concrete scrap is installed at the site of dismantling, and the aggregate obtained is used mainly for the construction of crushed stone preparation of pavement and foundations. Effective is the technology, which provides for the production of fractionated gravel and its use in the factory production of concrete and reinforced concrete structures.

The closest technical solution to the claimed object is the installation of concrete recycling according to the patent of the Russian Federation No. 2437722, which includes three technological chains: the first chain is preparatory and consists of bunkers for storing mixtures of concrete, brick, asphalt brought by vehicles, the second chain is technological and contains an installation for screening heavy metal, an electromagnet for trapping it, an installation for screening sand and storing it in a hopper as a filler, a crusher for If concrete pieces are removed from reinforcement connected with the second electromagnet, the third chain is finishing and consists of a backup hopper connected to a shock-reflective mill connected to the third electromagnet, and also contains two screens connected to a water treatment system, including a mixer with a chip supply unit and organic components, then the fractionation unit, from where the processed products are sent to a secondary aggregate warehouse (prototype).

The disadvantages of the known method and device include the fact that from recycled scrap only one group of materials is obtained, and the rest goes to waste. Due to the formation of many wastes, this method and device cannot be classified as environmentally friendly.

EFFECT: increased efficiency of recycling concrete scrap and improvement of environmental conditions.

This is achieved by the fact that the concrete recycling plant, which includes three technological chains: the first chain is preparatory and consists of bunkers for storing mixtures of concrete, brick, asphalt transported by vehicles, the second chain is technological and contains a heavy metal screening plant, an electromagnet for trapping it, a plant for screening sand and storing it in a hopper as a filler, an impact crusher to separate pieces of concrete from reinforcement connected with the second ele a thromagnet, the third chain is finishing and consists of a backup hopper connected to a shock-reflective mill connected to the third electromagnet, and also contains two screens connected to a water treatment system, including a mixer with a chip and organic components supply unit, then a fractionation unit, from where processed products are sent to a warehouse of secondary aggregates.

The crusher is made jaw and contains an electric motor with a pulley, an eccentric, a movable and fixed cheeks and an unloading window.

The crusher can be made centrifugal shock and containing the source hole, bucket, high-speed rotor, emitter, swirl chamber, the impeller and the outlet.

As a radiator of vibrational energy, a vibrator of various operating principles is used, for example, eccentric, electromagnetic, etc.

Figure 1 presents a General diagram of the installation, figure 2 is a General view of a jaw crusher, figure 3 is a General view of a centrifugal crusher.

The volume of concrete waste of all types (cellular, dense, with metal fittings) in the form of industrial defects, products of demolition of buildings and temporary pavements, log cabins pile heads, etc. in the Russian Federation and the CIS countries it is estimated at millions of tons per year. Increased use of such waste can reduce the burden on the environment. In addition, recycled waste is a reserve of material and energy resources in the construction industry and related industries.

A variety of concrete material requires the use of various processing techniques.

Aerated concrete in accordance with GOST 25495-89 "Aerated concrete, technical conditions" are divided into two main types - non-autoclaved foam concrete and autoclaved aerated concrete. The differences in these concretes from the point of view of recycling are very significant - the first has predominantly closed porosity, and the second is through.

Non-autoclaved foam concrete scrap can be put into production of blocks after two-stage crushing. Moreover, in the first stage of crushing, it is recommended to use lightweight crusher designs with a complex swing of the cheek. In our practice, a similar crusher is used with an elongated cheek and an unloading slot, adjustable within 5 ÷ 20 mm. The crusher allows crushing fragments of foam concrete with a particle size of up to 350 ÷ 400 mm in two dimensions with a reduction ratio of 20 ÷ 25. The crusher mass is 60 kg without a bed, the installed drive power is 3 ÷ 4 kW. The performance of lightweight jaw crushers in the processing of cellular concrete waste is 0.5 ÷ 0.8 m3 / h.

The second stage of crushing is carried out in a high-speed roller crusher, which allows to obtain 70% of the product with a particle size smaller than 0.4 mm with a maximum size of single grains of 1.2 mm. Such a product can also be directly used in the production of foam concrete according to the classical scheme.

Due to the simplicity of design and low weight, both of these crushers are characterized by high maintainability; they are easy to operate even in a small business system in the absence of a specialized mechanical service. One of the most serious issues in their operation is the lubrication of crusher bearing assemblies. Even with the relatively low strength of the crushed material, these units operate in dusty and high energy conditions due to the high degree of reduction of the crushed material. This requires special attention to the selection of lubricants.

A somewhat more complicated technology is the utilization of cellular autoclaved aerated concrete, which is determined by the physical properties of the raw materials. Two types of marketable products can be obtained from aerated concrete waste: crushed stone (-50 ÷ + 5 mm) and small-sized (-12 ÷ + 1 mm).

The fraction of -50 ÷ + 5 mm is used as a heat insulating backfill, which is not very cost-effective, since it can only be implemented in the price category of expanded clay. The fraction of -12 ÷ + 1 mm is used as an absorbent carrier for cleaning and conditioning domestic and industrial wastewater. After removal of the pulverulent fraction and the corresponding modification of the surface, the absorbent carrier can be used both in a single-use (replaceable) product mode and in a regenerated product mode. This fraction has a higher added value and ensures the profitability of processing.

Crushed sand of autoclaved aerated concrete on physical and chemical properties is not suitable for re-manufacturing aerated concrete. However, it can be effectively used in the production of non-autoclaved foam concrete as a substitute for building sand with some activity. The sand fraction is also used as a component of building mixtures for the manufacture of bulk floors. However, from an economic point of view, the above ways of utilizing the sand fraction can ensure only break-even.

To increase the profitability of the utilization of the sand fraction, it would be logical to use it as a component of dry construction mixtures (CCC). A very light, almost white color of this fraction gives additional appeal to this direction. However, the direct use of the sand fraction in the composition of the CCC is hindered by the high humidity of this product, reaching 12–18%. A product with such humidity can be used only if the enterprise itself carries out construction work. At high drying costs, the production of ordinary-grade CCC using a sand fraction is also unprofitable. At the same time, the production of tile adhesives based on them in the premium price class is quite cost-effective. To increase the strength and rheological properties of CCC, polymer modifying additives are introduced into the sand-cement mixture.

Nevertheless, an economic analysis of the production of crushed stone product and sand product from waste aerated concrete for CCC shows the preference for increasing the yield of crushed stone product. In order to increase its yield, various crushing schemes of the initial aerated concrete scrap were tested. It has been established that the best is the combination of the head low-speed roller-gear crusher, which takes a piece up to 400 mm, and the jaw crushers mentioned earlier with an elongated cheek in the second stage with a closed crushing cycle. Option 1. Roller-gear crusher in an open cycle, unloading gap of 70 mm. Jaw crusher in a closed cycle (not shown in the drawing).

Option 2. Roller-gear crusher in an open cycle, unloading gap of 40 mm. Jaw crusher in a closed cycle (not shown in the drawing).

Option 3. Roller-gear crusher in a closed cycle, unloading gap of 40 mm. Jaw crusher in a closed cycle (not shown in the drawing).

Tests were carried out on identical feedstock. According to the tested options, the yield of the fraction -12 + 1 mm was respectively according to the schemes: 1 ÷ 55%, 2 ÷ 50% and 3 ÷ 43%. Thus, in the framework of the task, a variant of scheme 1 was preferable.

Double-screen vibrating resonant screens and half-screen with rigid kinematics of the loading edge of the deck and the spring support of the unloading edge were used as classifying apparatuses. With equal sieve areas, the vibrating screen has an undoubted advantage in performance. However, according to the complete balance of products compiled using photoplanimetric and laser dispersion analysis, the formation of an additional class of 1 mm on a semi-gyration screen is 2-3% less, apparently due to less abrasion of aerated concrete on the screening surface. Therefore, the choice of the type of screen should depend on the given technical and economic criteria for the effectiveness of a particular production.

Full commercial processing of cellular concrete waste from enterprises of the North-West Region (defective blocks and wall panels, combat, etc.) using the Mechanobra technology was implemented in St. Petersburg.

A much more complex task is the processing of solid reinforced concrete waste, as well as destroyed building structures containing metal inclusions. For this purpose, crushers are needed which, without damaging the mechanism, are capable of processing multicomponent and highly durable materials with a high degree of reduction.

The VSChD * vibroshake crushers created by Mekhanobr-Tekhnika OJSC possess the properties required for this task. They are able to crush materials of any strength;

thanks to the dynamic drive of crushing cheeks they do not require a safety mechanism when large pieces of metal get in; have a degree of crushing from 8 to 15, which allows you to combine two stages of crushing.

The reason for this choice was the successful long-term operation of a vibroscale crusher with a receiving hole size of 440 × 1200 mm in the United States, where carborundum plates 400 mm thick and 1100 mm wide are crushed in one pass to 50 mm at a capacity of 60 t / h. Prior to this, spent refractory carborundum slabs were stored, since not one of the traditional crushers was capable of destroying materials of such high strength.

The technological capabilities of vibratory jaw crushers interested the Japanese company IHI, which acquired a vibratory jaw crusher with a feed opening size of 130 × 300 mm. Another Japanese company, Sankyo Frontier, purchased a vibratory jaw crusher with a suction hole size of 440 × 800 mm for the disposal of reinforced concrete. The crusher provided the passport characteristics: the product is smaller than 50 mm, productivity 35 t / h. Since concrete is a less durable material compared to natural rocks, one of the vibration exciters was turned off in order to reduce overgrinding and reduce energy consumption. In this case, the cheek with the exciter switched off acts as a mobile inertial anvil, performing synchronous antiphase movement with the movable cheek.

Due to the vibration effect on pieces of reinforced concrete (slabs, poles, piles, sleepers), the reinforcement is destroyed at the welds and is well cleaned of concrete. Then it goes to the compaction and goes to remelting. Crushed stone from concrete has a strength of almost half that of granite. This should be taken into account when planning its future use. If necessary, such crushed stone can be crushed to obtain particles of cement fineness. Recycled cement, having received newly formed surfaces, becomes active and can be used as grade 100 for the zero cycle or as a 30% additive in cements of grade 300 or 500.

For processing waste reinforced concrete and other building materials, vibration jaw crushers with a capacity of up to 300 t / h can be used (Table 2).

The drawing shows a diagram of the installation of concrete recycling

The concrete recycling plant includes three process chains. The first chain is preparatory and consists of bunkers for storing 1 mixture of mixes 2, concrete 3, brick 4, asphalt 5. The second chain is technological and contains installation 6 for screening heavy metal, an electromagnet 8 for trapping it, installation 9 for screening sand and storing it in the hopper 7 as a filler, an impact crusher 10 for separating pieces of concrete from the reinforcement connected with the second electromagnet 11. The third chain is finishing and consists of a backup hopper 12, connected first with a shock-reflecting mill 14, connected with the third electromagnet 13, and also contains two screens 15 and 16 connected to a water treatment system 17, including a mixer 18 with a block for supplying wood chips and organic components, then a fractionation unit 20, from where the processed products are sent to a warehouse of 21 secondary aggregates.

Jaw crusher (figure 2) is mainly used for crushing various ores and large bulk materials, the tensile strength of which does not exceed 250 MPa, in medium granules.

The crusher (figure 2) is made jaw and contains an electric motor with a pulley, an eccentric, movable and fixed cheeks and an unloading window.

This crusher is widely used in mines, in smelting, in the production of building materials, in the construction of highways, railways, water facilities and the chemical industry, etc. In the field of design and production, a large jaw crusher has no analogues in the world. A distinctive feature of jaw crushers is the ability to set the required slot width, this ensures that at the output you get exactly the size of the material that is required.

During operation, the electric motor drives the eccentric by means of a pulley so that the movable cheek periodically approaches the fixed cheek and moves away from the fixed cheek, thereby materials are squeezed out, crushed until they are forced out of the discharge window.

Benefits:

1. A large degree of crushing of a jaw crusher, equal fineness of the material.

2. High degree of maintainability.

3. Rugged construction and ease of operation and cleaning.

4. Reliable operation, low cost of operation.

5. Free slit width adjustment.

Installation recycling concrete works as follows.

Destruction of structures during the disposal of concrete scrap can be carried out by shock methods, splitting, cutting, crushing. The first chain is preparatory and consists of bunkers for storing 1 mixture of mixes 2, concrete 3, brick 4, asphalt 5. The second chain is technological and contains installation 6 for screening heavy metal, an electromagnet 8 for trapping it, installation 9 for screening sand and storing it in the hopper 7 as a filler, an impact crusher 10 for separating pieces of concrete from the reinforcement connected with the second electromagnet 11. The third chain is finishing and consists of a backup hopper 12, connected first with a shock-reflecting mill 14, connected to the third electromagnet 13, and also contains two screens 15 and 16 connected to a water treatment system 17, including a mixer 18 with a block for supplying wood chips and organic components, then a fractionation unit 20, from where the processed products are sent to a warehouse of 21 secondary aggregates. Hydraulic and pneumatic hammers are used from destruction means by shock methods, hydroclines are cracked by splitting; sharp - diamond wheels, equipment for plasma cutting, etc .; crushing - concrete breakers with movable straight or curved teeth, suspended on an excavator instead of a bucket. When large structures are destroyed, the energy of explosion and expansion can be used. The use of expanding reagents can reduce noise, vibration and the release of construction debris during the destruction of structures. A number of expanding reagents are developed based on lime.

A number of primary crushing plants for substandard concrete and reinforced concrete have been developed using crushing and screening equipment used in the processing of broken stone from quarries. The efficiency of such plants is lower than stone crushing. For the destruction of reinforced concrete structures up to 12 m long, hydraulic presses are used that develop a pressure of up to 2 MPa.

Reinforcement from concrete is removed using magnetic separators. After the reinforcement is removed, the concrete scrap enters the jaw crusher to obtain secondary crushed stone. It has been established that the use of large aggregates from crushed concrete of classes B20 ÷ B40 allows you to get concrete the same or slightly (5 ÷ 10%) lower than the strength of concrete on natural aggregates. With a decrease in the size of the secondary aggregate (up to 3 ÷ 10 mm), ceteris paribus, the strength decreases significantly. The greatest decrease in strength is characteristic of concrete on secondary limestone aggregate (about 20%) and about half as much on granite. When replacing fine natural aggregate (of medium-sized quartz sand) with aggregate of crushed concrete (fractions less than 3 mm) at W / C-0.65, the strength decreases on average by 20% for concrete on secondary granite and 25% for concrete on secondary limestone aggregates. At the same time, workability of concrete mixtures significantly worsens. The use of secondary aggregates increases the deformability of concrete; it is greater, the smaller the size of the aggregate and the strength of the concrete subjected to crushing. The elastic modulus of concrete on secondary aggregates is reduced by 7–18% compared with concrete on natural aggregates. The deterioration of the strength properties of concrete on crushed concrete aggregates and the increase in their deformability under load can be compensated by the addition of superplasticizers to the mixture.

A centrifugal impact crusher (FIG. 3) can be used, which contains a feed hole, a bucket, a high-speed rotor, a radiator, a swirl chamber, an impeller forming a continuous material cladding, and an outlet.

Centrifugal impact crusher operates as follows.

The material completely enters the center of the initial hole, then falls into the material delivery bucket, falls onto the high-speed rotor through the material inlet, then due to acceleration the material is ejected from the emitter, first hits with free fall material, then together they hit the surrounding material lining in the swirl chamber . First, the material bounces to the upper part of the crushing chamber, then deviates and falls down, with the material, which from the impeller, forms a continuous material lining, eventually comes out of the outlet.

A number of primary crushing plants for substandard concrete and reinforced concrete have been developed using crushing and screening equipment used in the processing of broken stone from quarries. The efficiency of such plants is lower than stone crushing. For the destruction of reinforced concrete structures up to 12 m long, hydraulic presses are used that develop a pressure of up to 2 MPa.

Claims (1)

A concrete recycling installation after dismantling temporary accommodation centers for the affected populations, containing three technological chains: the first chain is preparatory and consists of bunkers for storing mixtures of concrete, brick, asphalt transported by vehicles, the second chain is technological and contains a heavy metal screening unit , an electromagnet for trapping it, an installation for screening sand and storing it in a hopper as a filler, a crusher to separate pieces of concrete from a matura associated with the second electromagnet, the third chain is finishing and consists of a backup hopper connected to a shock-reflective mill connected to the third electromagnet, and also contains two screens connected to a water treatment system, including a mixer with a chip supply unit and organic components, then the fractionation unit, from where the processed products are sent to a secondary aggregate warehouse, characterized in that the crusher is made jaw and contains an electric motor with a pulley, an eccentric, movable and fixed cheeks and discharge window.

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