EA006345B1 - Method for processing of old worn-out tires and device therefor - Google Patents

Abstract

The invention relates to a method and device for processing old tires and other industrial rubber products and polymer materials. The aim of the invention for processing old tires is characterized by steps of sorting tires, cutting them across to one or several parts in unfolded state for reinforced tread rubber strips and not reinforced side rubber strips and further producing therefrom standard granules to be additionally crushed in a gap between two surfaces of a tool with variable cross-section, wherein one of the surfaces rotates around vertical or inclined axis causing a cyclically changing character of zone's loads at which the material is being crushed during compression and at expansion separation of fraction to fine pieces directed downwards to the outlet and to a coarse pieces entrained into the compression zone for crushing. A set of mills arranged in parallel, each having its size-crushing range, is used for processing the material from granules to powder, total capacity of all mills covers crushing range and being united into a uniform mechanism of a ring system of separation, which provides separate dimensional feed of mills and separation of the resulted powder. The crushing device comprises a housing with a drive, a vertically or obliquely arranged shaft with removable crushing cups having narrowing downwards expanding cavities, grooves or other elements mounted above the main screw profile providing cyclic gap change between their walls. The device has a feeder with a drive adjustable by a working shaft load, which makes it possible to operate the device in optimum zone of load and crushing abilities. The design permits to assemble and operate up to eight devices, different in purpose and dimensions, thus providing simple service, setup and repair ensuring uniform distribution and effective crushing of rubber crumbs. The inventive advantage of the method and device: no wastes of own production process, gas pollution, dustiness and noise; availability of automated drive control system; low transport and operation costs due to lesser production area, initial equipment cost and power consumption.

Description

The invention relates to a method of processing worn pneumatic tires and other products from polymers with similar properties, including conveyor belts, hoses, linoleum, in order to extract materials suitable for reuse.

Originating in the sixties, the processing of worn tires developed mainly in the direction of mechanical grinding and was intended to utilize them. Obtained during the processing of rubber crumb was used as additives in asphalt, bitumen, simple rubber products. Technically feasible was considered to receive crumbs with sizes of 1-5 mm. Moreover, in most countries, processing was subsidized by their consumers or the state.

In recent years, the need for fine powders has increased dramatically in order to return materials to rubber and other industries for the production of new materials. The cost of fine powders approached the cost of the vulcanizate, but the requirements for the quality of powders dramatically increased, in terms of size these were powders from 0.02 to 0.1 mm, in terms of impurity content not more than 0.1%. Such high requirements of mechanical grinding technology, as a rule, do not provide.

A known line for the disposal of worn tires, containing a vehicle connected to the vehicle for radially splitting tires, with machines for producing large and finely dispersed chips with a magnetic device and a device for sifting chips (1).

The method of processing tires for crumb realized by the line includes the following technological operations:

cutting tires onto sidewalls and tread tracks on a boring machine; grinding tread tracks and sidewalls with disc mills into fragments; grinding fragments with mills with paired friction cylindrical rollers and interchangeable armor.

The disadvantages of the method implemented by the line include the fact that the fragments after the disc mill have a variation in configuration and weight, which in the absence of their size distribution in the mills reduces the productivity and quality of grinding; complex design of mills, crumbs distribution systems and lines in general.

It is known and is the closest in design and technology to a device for producing a powder from a polymeric material (2). The device is intended for processing waste rubber products, reinforced with a metal or fabric cord. The device includes a housing, a sealing screw, an annular prechamber with an annular protuberance and a working annular channel. The housing has openings for loading and unloading, a sealing zone and a grinding zone. Inside the housing is placed a sealing screw with spiral grooves. In the grinding zone, an annular recess is made on the inner surface with the formation of an annular chamber of preliminary destruction. Executive working body grinding is made in the form of an annular protrusion. The working body grinding is installed with the formation of an annular slotted channel relative to or to the inner surface of the annular recess, or to the lateral surface of the rotor. The device has a means of cooling the screw, housing and rotor.

Considering the fact that crumb crushing is carried out in a slit gap, without regulating the material supply, the load on the drive shaft, on the limited surface of the pre-chamber and the annular channel, the compression does not implement the stresses necessary for the separation of rubber and cord, and that heating material in the process of compression - it is energy costs and a powerful drive - it can be concluded that the efficiency of the process and the quality of the product can be improved.

Taking into account the difference of the loaded materials, for the prototype these are tire fragments, and in our case it is a dimensional granule or crumb, as well as processes in the mills — the installation (prototype) compresses the material and feeds it to the grinding zone, where grinding of the fragments accompanied by the heating of the material due to mass punching through the prechamber and the grinding zone, and the vertical cyclic mill crushes the crumb between the surfaces of the screw and the glass under relative conditions O but the free shredded crumb from the grinding zone, which is a large part of the chamber, and installation methods of grinding have little similarity.

The closest in nature of the process, an integrated approach to solving the problem and the quality of the product obtained is a method of mechanical processing of worn tires (3).

The method involves sorting, high-speed milling, stamping, cutting of waste into appropriate sizes, crushing of rubber crumb, magnetic separation and sifting. The method provides a sufficiently high quality of the materials, however, the removal of material for a 0.5-1 mm tooth cutter indicates that the process does not have high productivity with significant system complexity, and technological operations, starting with the installation of the tire in the device, then milling and removal of residues, it is difficult to automate.

The objective of the invention is to create a waste-free and cost-effective method and device for processing worn tires with the aim of obtaining a powder with high consumer properties.

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The essence of the invention is a method of processing worn tires, including sorting, cutting, grinding, vibrating sieving and cleaning, characterized in that the tire is cut across into one or more parts, which are cut in the unfolded state on the edge of the metal cord and bead ring (only rubber) on the metal-reinforced tread strips and not reinforced sidewalls with separate cutting them into dimensional granules, which are crushed in the gap between the tool surfaces with variable cross-section that when rotating one of them around a vertical or inclined axis leads to cyclically changing the nature of the load zones, where under maximum compression, under the action of friction forces, torsional, tensile and shear stresses occur, leading to the destruction of the material gravity and conical cavities made along the common screw profile of the instrument, to the division of the fraction into small ones in the downward and coarse directions, distributed in accordance with its dimensions by instrument levels.

Optimal process conditions in the gap are provided by grinding the crumb from a large, conventionally 20 mm to a small, conventionally 0.1 mm, a complex of 4-8 vertically or obliquely located mills, operating in parallel in their size range, totally overlapping the entire grinding range, combined in a single mechanism of the ring system of transportation and separation, which provides separate feeding of mills with a crumb of a given size and separation of the commodity crumb at the place of its formation.

Moreover, the whole process of preparing dimensional granules is carried out without crushing, only by cutting.

A device for implementing this method, including a housing, loading and unloading openings, a working chamber, a grinding tool and a drive, has a vertical or inclined shaft with removable grinding screws having expansion cavities, grooves or other elements made over the main profile.

The support, the supporting structure and the element for attachment to the metered-feed system is a housing with a drive and grinding cups. Glasses have a variable profile, which during rotation of the screw provides a cyclic change in the gap between the walls of the screw and the glasses.

All the mills of the complex, having the same design and dimensions, provide the necessary conditions for assembling into the complex and grinding different fractions due to the installation of screws and glasses of the required size and profile, which are technologically and structurally assigned to the instrument class and made in the form of removable parts providing manual replacement without disassembling device or complex.

The mills are suspended and mounted on the frame of the upper separator by the housing pad and have a feeder with an adjustable drive that ensures the stable operation of the mill according to the load current of the drive of the working shaft. The shaft, in turn, is equipped with an adjustable drive and maintains optimal modes of performance and degree of grinding.

The number of mills depends on the performance of the line given by the design of the grinding degree and technological feasibility.

One or two mills cannot work effectively over the entire size range, moreover, the crumb obtained in one cycle of grinding or powder is heterogeneous in fractional composition and after sieving a significant part of it requires re-grinding.

In relation to the prototype, which performs destruction due to forceful compression, heating and forcing material through a die, the method and device claimed by the invention ensures the destruction of crumb in a variety of periodically occurring zones, practically over the entire surface of the outer glasses, except for extensions, and in more rational conditions of tension and torsion. The regulation of the gaps when receiving fine powders is carried out by an easy-cone tool and a set of gaskets. Pockets for fine powder are made in the form of grooves along the normal to the direction of the main screw. The number of grooves when grinding powders can be up to 30, and the number of screw visits is up to 6.

In real conditions, the process should be considered in dynamics, since the length of the grinding zone in the mill is more than 600 mm, and the crumb at the outlet is 2-3 times smaller than at the entrance, therefore the screw profile has a number of design features, including variable pitch , the angle of elevation of the coil (in accordance with the size of the crumb), the depth of the grooves, gaps, longitudinal risks on the ribbon.

The cutting of tires across perform mechanical or hydraulic shears with quick-release knives, having a shaped profile or other device that provides performance up to 100 pcs / h.

Cutting into ribbons 150-250 mm wide is carried out by a device for cutting tires and conveyor belts, providing an adjustable feed of the unfolded tire or conveyor belt between the drive rollers, one of which has two or more knives for obtaining a given width or on the table.

Cutting tapes into a measured, large crumb is carried out by feeding the tape between the drive rollers, on one of which or on the table there are three or more knives that cut the tape into strips, which are fed under the rotating side knife of the device. The speed of the longitudinal feed and side knife, and, consequently, the linear dimensions of the crumb is regulated by frequency drives.

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The technical efficiency of the claimed method of processing is achieved by eliminating the traditional method of grinding tires, fragments or chips with crushers, double-sheared disk shears from the process of processing, with the transition to cutting with a single-blade tool, followed by grinding the crumb to powder with complexes of several parallel mills.

A distinctive feature of the method is the grinding of the crumb by the size and separation of the product fraction at the education stage, since the presence of the small fraction is harmful to the grinding of larger ones. At the same time, the whole grinding process is considered as two technologically related processes first - obtaining large dimensional crumbs by cutting tires and other similar products and materials, most of which, in order to reduce transportation costs, should be carried out outside the main production - at service stations or mobile units;

the second is to obtain a powder of 0.5-0.05 mm or less by grinding the granules with cyclic mills under the conditions of primary production.

The technical result is achieved due to the exclusion of crushers from the grinding process, which, due to their technical capabilities, cannot effectively work both on the 0-0-0-0 mm cord and rubber from 1 to 40 mm thick, due to the fact that the necessary cutting condition - the gaps between the knives B = K8, where B - the gap between the knives; 8 - thickness of the material being cut; k - coefficient depending on the properties of the material; for steel, k = 0.08; B = 0.08 x 0.2 = 0.0016 mm; for rubber, k = 0.02; B = 0.02 x 1 = 0.02 mm, - not technically provided by the crusher design.

Due to the fact that the gaps between the blades for tires with steel cord are structurally higher than the calculated ones, the process of destruction has the character of a gap, not a cut, photo 5-6. As a result, the energy costs per 1 ton of crumbs with a size of 1-3 mm are more than 500 kW / h and increase with an increase in the degree of grinding. In addition, despite the complex cleaning system, the presence of impurities and fractional composition, the quality of the crumb remains low, which significantly reduces the scope of its use.

The technical result is achieved through the use of single-edged sharply sharpened tools and special equipment, which provide a significant reduction in cutting forces, as well as time for replacement and sharpening, which, combined with a rational way of carrying it out, provides a multiple decrease in power consumption, increases productivity and process culture.

The technical result is achieved by introducing into the process of cutting a productive method and device for producing dimensional chips, the peripheral speed of the side knife of which is several times higher than the speed of the pressing tools and provides productivity up to 400 kg / h. Obtaining dimensional chips is a prerequisite for providing productive and high-quality grinding.

The technical result is achieved by obtaining a powder in a manner that is carried out by a complex of three or more mills equipped with an instrument with a profile corresponding to the size of the grinded fraction, which ensures optimal crumb grinding regimes for each mill and efficient operation of the complex as a whole.

In order to maintain optimum grinding conditions, the mills are equipped with variable-drive feeders, and the main drives - asynchronous electric motors with frequency regulation and torque control on the shaft, which, if increased beyond the specified, decreases the crumb feed and vice versa.

The constancy of the operating mode of the load current is a necessary condition for the process.

The technical result is achieved due to the characteristic features of the process of grinding the crumb into powder, which are provided by the design features of the mill and the tool.

The main ones are:

vertical or inclined arrangement of the tool, which provides conditionally unobstructed (under its own weight), the passage is a failure of a crumb, the dimensions of which are smaller than the gap between the outer cup and the inner screw, conical tapered to the bottom straight or inclined cavities both along the outer cup and the inner screw .

The presence of cavities during the rotation of the screw forms a cyclical change in the cross sections of the working chamber and the impact of the tool on the material, provides batch reception of crumbs and feed under the screw in the upper part, and further along the screw with the formation of threads - fine down, and large and medium screw at its level . The number and size of cavities depend on the size of the crumbs. In addition, the surface of the glasses has grooves directed opposite to the direction of movement of the main flow, which create in the compression zones effective stresses between the screw and the glass, necessary for fracture, and contribute to the separation of the material in the expansion zones.

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The technical result is achieved due to the ring distribution system of the crumb, in which the upper separators size scatter the crumb through the bunkers of the mills, and the lower, together with magnetic and pneumatic separators, ensure the cleaning of the fraction from metal inclusions, the removal of yarn and fluff, the sifting of marketable powder and the return of non-milled and newly arrived crumbs by an elevator on the upper separators of the complex. The complex is made on the basis of a typical unit, the supporting structure of which is elevator racks, connected to a spatial frame by a beam or a frame of an upper separator or auger, on which the number of mills required by the performance conditions is hung. Installation of mills is carried out without modification of the line.

The installation location of additional devices: magnetic separators, suction strands, spike picking, gravel inclusions is determined by the design of these devices and can be performed both on the bottom and on the upper separator or on transitions. The number of separators can be reduced to one top with additional conveying devices, with one separator and transport devices should provide the same basic functions - sifting, distribution in mills and screenings of the product fraction, as two.

Studies and works confirm the effectiveness of the method.

The invention is illustrated in FIG. 1-10 and photo 1-6. FIG. 1 shows a removable screw with a central hole 1 for mounting on a shaft with a keyway 2, a single or multiple thread screw groove 3, a ribbon at the edge of the groove 4 and pockets tapering towards the bottom at an angle of 1-3 °.

FIG. 2 shows an outer glass having a cavity tapering downwards at an angle of 1-3 ° — pockets 1 and a helical groove 2.

FIG. 3 shows screw 1 and cup 2 in several positions of the screw. In position A, the pockets of the screw and the glass are on the same axis and form the maximum expansion along the axes of the pockets, and the maximum compression along the axes of the projections; in position B, when the screw pockets are located at an angle of 30 ° with respect to the glass, a decrease in the deformation is observed due to a decrease in the loaded section; in position B, when the protrusions of the screw are opposite the pockets of the glass, there is a decrease in the load across all sections, which, with a further turn of the screw, begins to increase. The change in cross-section during the rotation of the screw forms the cyclical nature of the load and crumb destruction.

FIG. 4 shows screw 2 and glass 1 with the distribution of crumb 3 according to levels 8; Ό; WITH; Ν; when the screw is rotated, the crumb is distributed according to its size — small at the bottom, and the largest at the top, and the middle one takes its level along the cone.

FIG. 5 shows the main elements of a vertical circulation mill. The drive is located vertically of the working shaft of the mill 1, on which are mounted prefabricated screws 2, is carried out by a gear motor 3, which is installed on the supporting housing 4 with the shaft bearings 5.

The support body is the basic and supporting structure of the machine on which the external quick-detachable cups are mounted 6. The clearance between the light-angle screws and the cups is adjusted when the mill is set up for fine grinding by installing a smaller tool or installing the measuring pads 10 between the cups. The support body is attached to the frame of the separator 7, which combines the mill into a single complex. A typical complex allows completing from two to four mills. For an adjustable feed of crumbs, the mill includes a feeder 8, and for removal of crumbs - a device or a tray 9. The system is equipped with frequency converters for adjustable material feed and operating modes of the drives.

Fig. 6 shows the main elements of the device for producing large measuring chips from tapes. The device consists of a bed 1 with blocks of feed rollers located on it - the top 2, with knives cutting the tape into strips, the bottom 3 and the end cutting block 4, the cutting strip into granules of the required format. Regulation of cutting speed and feed is carried out by frequency converters.

FIG. 7 shows single-blade knives: 1 - flat; 2 - disk; 3 - side used for granulation.

FIG. 8 shows the crushing complex of four mills, the left supporting structure and simultaneously the lifting and transporting device of which is an elevator 1 feeding the crumb to the upper separator 2, linking its frame resting on the right stand 3, the upper part of the structure to a spatial framework.

Vertical mills 4 are suspended on the frame of the upper 2 separators. If it is necessary to increase the number of mills to a maximum of 8, the complex can be assembled from two consecutive blocks, with the right pillar 3 being completed as an elevator. The material crushed by the mills falls on the tray of the lower separator 5, the frame of which connects the elevator and the rack along the bottom, completing the rigid spatial framework for the design, and the technological process - according to a closed ring pattern.

FIG. 9 shows a variant of the complex of fine grinding with one upper separator 2. There are no fundamental differences in the method of grinding, however, the use of a drum-type separator with a built-in magnetic separator, a metering device 7 and a system for cleaning from thread and down allows, in the absence of increased powder requirements , dispense with the ventilation system and from -4 a separate fine-cleaning complex, while the separator 2 separates the product fraction into the bunker above the dosing device 7, on the inclined trays of which a magnetic a second drum type separator 8 and a pneumatic intake 9, directing the flow of light particles into a cyclone or filter.

Vertical mills 4.1-4.4 are assembled on the cases of the top 5 and bottom 6 screws in the amount of 3-4 according to the process conditions. The material ground by the mills is fed by the lower screw into the elevator 1, then to the separator 2, which weeds out, cleans and feeds the product fraction into the hopper of the dosing device for packing into bags, and nedomol and the newly received fraction for grinding into the screw 5 feeding the mills.

An example of the implementation of the method and operation of the device, Fig 10.

Cleaned tires (2) are conveyed by conveyor 1 to hydraulic shears 3, where they are cut with shaped shears across to one for small, two or more parts for large ones.

The cut tire or its parts are transported to the device 4 for cutting into tapes, which with the feed rollers unrolls and cuts the tire into tread and sideband, which are transported to the devices 5; 6

The tread band is fed to the receiving rollers of the device 5 for longitudinal cutting and grinding, and the side tape is fed to the rollers of the device 6 of a similar design, which is equipped with a rotary device for cutting ring blanks.

Received large dimensional crumb by screw 7 is fed to the elevator 8 of the grinding complex and distributed to the mills by the feeder 9. After grinding by the mills 10.1-10.4, the crumb is fed to the table of the vibration separator 11 for separating and cleaning the metal cord with a magnetic separator 12, and from the fabric cord by a pneumatic system 13 , and then goes to the elevator 14, which feeds the crumb to the table of the upper separator 15, and the separator disperses it according to the specified sizes into the mills' hoppers 16.1-16.4.

Optimal conditions for productivity and degree of grinding are ensured only if the balance between size, amount of crumb fed to the mill, degree of grinding, condition of the tool, time and degree of impact is maintained. The fulfillment of these conditions is ensured by variable frequency drives of feeders, which ensure the stable operation of the mills by the load current of the drives of the working shafts. The moment on the shaft of the mill, and accordingly the load current is maintained within 0.8 1N., By changing which the feeders of the mills proportionally decrease or increase the flow of material.

Crushed crumb from all mills goes to the bottom separator pos. 17, which separates the remnants of the metal with a magnetic separator 18, separates the commodity powder and the ventilation system 13 or other device, feeds it to a typical fine-cleaning complex, and returns to the grain elevator tray 14.

The supply of granules delivered to the grinding of the places of reception is carried out by a separate transport system into the chute of the elevator 8.

The method of processing worn tires and the device for its implementation make it possible to obtain a powder with high-quality fractional composition and the presence of impurities, which is clearly confirmed by the attached photos.

Photo 1 shows the tread strip, from which the granules are obtained, captured in photo 2.

Photo 3 shows the powder and metal cord obtained after grinding the granules. The powder compares favorably with crushed chips, it is much smaller and less polluted.

Photo 4 depicts a clean metal cord, obtained after grinding the granules, confirming the achievement of our task, it is easily separated and is a homogeneous mass of wires, which has a large bulk weight that can be pressed for transportation and reuse, it differs favorably from the shapeless and polluted cord after crushers imprinted on photo 6.

Photo 5 (copies of the advertising brochure L1rte LkIyideke Shsjay, page 77) shows a fragment of the tire after the crusher, which with its torn edges confirms that the crushers are tearing, not cutting the material.

Profitability of production is ensured by excluding energy-intensive crushing equipment from the process;

an annular arrangement of separators, mills and elevators, providing a compact, easy-to-maintain, minimum in footprint, initial cost and power consumption of the system;

reducing transport costs by placing relatively simple equipment for cutting and producing pellets in tire fitting organizations, reception points or mobile stations;

reducing operating costs - the cost of equipment, the occupied area is much lower, and the ability to effectively load equipment is higher.

Sources of information taken into account in the examination

1. Patent VI 2198788, class B 29B 17/00, 08/23/2000.

2. Patent VI 2213657, class B 29B 17/00, 11/14/2002.

3. Patent VI 2160664, class B 29B 17/00, 02.27.1998.

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Claims (4)

CLAIM 1. A method of processing worn tires, including sorting, cutting, grinding, vibrating sieving and cleaning, characterized in that the tire is cut across into one or more parts, which are cut in the unfolded state on the edge of the metal cord and side ring (rubber only) into metal reinforced tread strips and unreinforced sidewalls with separate cutting them into dimensional granules, which are crushed in the gap between the surfaces of the instrument with a variable cross-section, which during rotation of one and around them, a vertical or inclined axis leads to the appearance of zones that cyclically change the nature of the load, where the material is destroyed under compression, and when expanded under the action of gravity and the profile of the tool, it is divided into fractions. 2. A method according to claim 1, characterized in that the granulation process of the granules is carried out by several concurrently located and operating in its size range mills, totally covering the entire grinding range, united in a single mechanism by an annular separation system, which provides separate feeding of mills with a crumb of a given size and separation of commodity powder at the place of its formation. 3. A device for processing, including a housing, loading and unloading openings, a working chamber, a grinding tool and a drive, characterized in that it has a vertical or inclined shaft with removable screws and grinding cups having expansion cavities, grooves or other elements made over the main screw profile. 4. The device according to claim 3, characterized in that, having the same design and dimensions, provides the necessary conditions for assembling into a complex and grinding different fractions by installing screws and glasses of the required profile, which are classified as tools, which are manually changed without disassembling device or complex.