WO1993009914A1

WO1993009914A1 - Process and device for triturating salvaged tyres and other objects made of rubber or plastics

Info

Publication number: WO1993009914A1
Application number: PCT/EP1992/002600
Authority: WO
Inventors: Walter Iten
Original assignee: Walter Iten
Priority date: 1991-11-12
Filing date: 1992-11-12
Publication date: 1993-05-27
Also published as: AU2915792A; DE4137173A1; DE4137173C2

Abstract

A process is disclosed for triturating salvage tyres (23) and other objects made of rubber or plastics. The salvage tyres (23) or other objects are triturated in their totality in a single dry grinding operation, after which the resulting product may be re-used. A device for carrying out this process is also disclosed.

Description

Method and device for pulverizing used tires and other rubber and plastic objects

The invention relates to a method for pulverizing old tires and other rubber or plastic objects, in which the old tires or other objects as a whole are pulverized in one operation by dry grinding and then fed to a further use, and a device for carrying out this method hrens. The constantly growing mountains of tires and plastics pose a great threat to the environment. Although there are possibilities for recovering the valuable raw materials contained therein, their technical application has hitherto failed due to economic viability. Multiple use of used tires and other plastic objects through all-round renewal makes sense, but does not serve an environmentally friendly solution in the long run.

As is known, only 2% of car tires and other rubber and plastic objects can be destroyed in waste incineration plants because of the high combustion temperature of about 2000 ° C. required for this and because of their high pollutant content. To a smaller extent, tires are cut into palm-sized pieces that can be burned more easily using conventional chips.

It is also already known to shred old tires in shredding plants with knife-like devices into larger pieces in order to be able to store them better in landfills.

Attempts have also already been made to supply old tires and other rubber and plastic objects for industrial processing. To date, however, high energy, wage, plant and construction costs have not allowed economic exploitation.

Since 1990, strict regulations have been in place for combustion plants in Germany with regard to the emissions of dioxin and furan, which must not exceed 0.1 ng per exhaust air. This new regulation requires extremely expensive flue gas cleaning systems and old systems have to be converted accordingly by 1993. The question of what happens to the highly toxic filters and their residues remains open. In order to get an idea of the environmental problems that arise as a result, one has to realize that in Germany alone in 1990 more than 550,000 metric tons of used tires were produced. Landfills and other disposal options are no longer available and intermediate deposits have long reached their capacity limits. In the USA, 1,200,000 tons of new tires are even produced annually, which are not biodegradable and have an extraordinarily high chemical resistance, so that their service life is almost unlimited.

From DE-OS 2 417 711 a method for pulverizing old tires is already known, in which the old tires are first shredded in a coarse chip machine and then comminuted again in a fine chip machine and freed from the metal parts by means of magnets. A pulverizing machine then processes the metal-free old tire into powder with the desired grain size.

The disadvantage of this method is that several machines arranged one behind the other are required, which require relatively high investment costs, require a lot of space and make complex controls necessary to ensure trouble-free operation of the machines connected in series.

From DE-OS 30 48 405 a method is known in which the tread of an old tire is converted into rubber flour by grinding, while the associated carcass is used as a reinforcement in the construction industry after separation. The tire must be cut before grinding and fed to a grinding machine. The carcass and the steel insert remain after the end of the procedure and must be recycled separately.

ER _SA TZBLATT The disadvantage of this process is that only a part of the old tire is pulverized for further use and that the carcass and steel insert have to be recycled separately for special purposes. In addition, this method is complicated and involves a great deal of effort.

From CH-PS 43 806 a device for crushing vulcanized rubber is known, in which pieces of rubber are crushed in a rotatable container, the inside of which has sharp projections. If you want to shred old tires in such a device, the metal parts must first be removed from the old tires with great technical and economic effort.

It was therefore an object of the invention to provide a method and a device for pulverizing used tires and other rubber or plastic objects, which is technical. are simple and economical and deliver reusable end products.

It has been found that this object can be achieved according to the invention by introducing the old tires or rubber or plastic objects under pressure into a process chamber with one or more grinding bodies oscillating and rotating therein by means of a delivery and delivery shaft. in which problem-free and trouble-free pulverization of the old tire or the plastic object takes place with cooling by means of cold air in a closed circuit even if it contains metal parts. Then the rubber or plastic parts and any existing textile and metal parts are separated from each other and sent for further technical use. The invention relates to a method for pulverizing old tires or other rubber or plastic objects, in which the old tires or other objects as a whole are pulverized in a single operation by dry grinding or grinding and then passed on for further use is characterized in that

a) the old tires or other objects are transported in a closed conveyor shaft and then in a narrowing delivery shaft on driven spiked rollers standing or lying upright or lying one by one or in series to a closed process chamber, each used tire or other object in the the feed chute narrowing towards the process chamber is increasingly deformed (compressed),

b) each pressed old tire or other object entering the process chamber is pressed against one or more cylindrical grinding wheels, preferably double grinding wheels, oscillating and rotating on one axis, preferably double grinding wheels, and cooled with cold air of e.g. -20 ° C is ground into a powder in a closed circuit,

c) the powder obtained in the process chamber is drawn off and in a separating device into rubber powder parts or plastic powder parts and, if appropriate

Metal powder parts and textile powder parts are separated by electrostatic means and by air sifting and transferred to silos for storing the different powder parts.

The delivery shaft used in stage (a) preferably has left and right or top and bottom Individually or jointly driven spiked rollers which extend over the entire width or the entire height of the conveyor shaft and which feed the feed material to the process chamber under pressure.

A chain drive by means of pinions is preferably used as the drive for the spiked rollers, or the individual spiked rollers are driven by electronically controllable electric motors.

The feed rate of the old tires or other objects is preferably continuously and continuously adjustable.

The grinding wheel (s) in the process chamber is (are) preferably rotatable on an axis of rotation and arranged to move laterally backwards and forwards perpendicular to the conveyor shaft and are designed as so-called oscillating rotating grinding wheels.

The cylindrical grinding wheel (s) used according to the invention preferably consists of several segments made of different materials, in particular sintered materials with a surface of silicon, electro-corundum, silicon carbide, cubic boron nitride and / or industrial diamonds and / or Segments have different surface grains for grinding different components of the old tire or the other objects.

The segments of the abrasive body (s) are preferably connected to one another via rubber seals, preferably neoprene dividers, arranged between them.

However, the abrasive bodies that can be used according to the invention can also consist of a cast metal or steel roller, which are arranged on their circumferential surface parallel to one another, interchangeable diamond grinding belts with preferably dovetail-shaped cross-section.

According to a preferred embodiment of the invention, the rubber or plastic powder particles and the metal powder particles are separated from one another by electrostatic means and by air separation in the separating device.

The invention further relates to a device for carrying out the method described above, which is characterized by

a closed conveyor and delivery shaft with driven spiked rollers for introducing the old tires or rubber or plastic objects under pressure into the process chamber,

a process chamber with one or more axially mounted, rotatable cylindrical grinding bodies arranged therein, which (are) oscillating perpendicularly to the conveyor shaft along the axis of rotation, and

a device for separating the rubber or plastic powder particles, the textile fabric powder particles and any metal powder particles from one another.

According to a preferred embodiment of the invention, the grinding body (s) in the process chamber consists of several cylindrical segments made of different materials and / or with different surface grain sizes, rubber seals, preferably neoprene discs, being arranged between the individual segments when the Seg¬ consist of a ceramic material.

In another embodiment of the invention, the grinding wheel (s) in the process chamber consist of one or more cylindrical, rotatably mounted, along the Rotating axis of oscillating metal cast or steel roller (s) that can be moved back and forth, on the circumferential surface of which interchangeable, interchangeable industrial diamond abrasive belts with dovetail cross-section are arranged horizontally or vertically parallel to each other.

According to the invention it is possible, even in small and medium-sized businesses, to recover the raw materials contained therein from used tires or rubber and plastic objects in a technically simple and economical manner, wherein according to the invention a precise separation of rubber, steel and textile particles is possible.

In the device according to the invention, car, truck and other special and extreme tires can be ground into their segments or into the finest segment powders with a particle diameter of about 0.1 mm by promechani drive. The heat generated during grinding is dissipated by cooling with cold air, for example at a temperature of -20 ° C., in a closed circuit. The cold air supplied from the outside is blown into the process chamber, in which it heats up, is withdrawn therefrom and cooled down again outside the process chamber to the initial temperature (for example -20 ° C.) before it is returned to the process circuit. came he is introduced.

The device according to the invention is extremely simple to operate and a monitoring person is sufficient to monitor it. The system according to the invention can be switched on and off continuously, so that it works economically even with very small quantities. On the other hand, the system according to the invention permits the pulverization of steel belt tires in an amount of up to 220 kg / min with a low expenditure of energy. The total energy consumption in a small system is less than 100 kW / h. With the system according to the invention, it is possible to completely recover the raw materials contained therein from old tires and other rubber and plastic objects in an environmentally friendly manner. Due to the particle fineness and purity of the material that can be achieved, the material obtained can be used again for technically high-quality products.

The powder obtainable according to the invention can be reused for the production of corresponding objects (tires, moldings). It is particularly well suited for the production of impact-resistant underbody protection in motor vehicles and for the production of elastic bumpers on vehicles, in particular the outside of ship's hulls.

The invention is explained in more detail below using the example of pulverizing old tires with reference to the accompanying drawings. Show it:

1 shows the sequence of the overall method according to the invention in a system according to the invention with its essential parts in a schematic representation;

2 shows the loading and pulverizing device of the overall system according to the invention in an enlarged view;

3 shows a schematic illustration of the conveying and delivery shaft of the device according to the invention in an enlarged illustration;

4 shows the schematic structure of the delivery shaft of the device according to the invention in a further enlarged illustration; 5 shows the essential parts of the process chamber of the device according to the invention, in which the rubber or plastic objects are pulverized;

6 shows an embodiment of the grinding bodies arranged in the process chamber in a schematic representation on an enlarged scale; and

7 shows a further embodiment of the grinding bodies arranged in the process chamber in a schematic illustration on an enlarged scale.

In the exemplary embodiment of the method according to the invention shown in FIG. 1 in the device according to the invention, the numbers 1 and 2 denote

(bordered part at the top left in FIG. 1) the device for introducing the old tires delivered by truck and the adjoining process chamber with grinding devices. The powder obtained in the process chamber 2 is, after being transported by means of the conveying devices 3 and 4, in the separating device 5 (magnetic separation) in metal or steel powder, on the one hand, which is collected in the containers 6, and in abrasive material, textile material powder and rubber powder, on the other hand, which are transported by means of the conveying device 7 into the container 8, from which after deduction of the heaviest particles (eg ceramic abrasion) at 10 and the light powder parts (eg textile parts) at 9 via the device 11 ( Wind sifting) are conveyed by means of a blower 12 into the loading silos 13, from which they are separated according to the material properties, e.g. as a rubber powder in the transport devices 14 and 15 are transported away for further use.

The order of the powder separation by magnetic separation and air separation can also be reversed. FIG. 2 shows an enlarged view of the charging device with subsequent pulverizing device according to the present invention in a schematic illustration on an enlarged scale.

In the embodiment shown, old tires 23 of different sizes are introduced from above through two separately feed chutes 21, 22 into two parallel infeed chutes 24, 25 in which the tires 23 are driven into the downward tapering infeed chutes 24, 25 by means of driven transport rollers Pressure and with increasing deformation are introduced into the process chamber 26 with one or more grinding wheels 27 arranged therein.

3, in which the conveyor shaft and delivery shaft are schematically shown on an enlarged scale in section, the conveyor device 30 can be seen, with the aid of which the tires 33 are transported in the conveyor shaft 31 to the end of the conveyor shaft 31, with suitable retaining devices 32 an undesired rolling back of the conveyed tires is prevented at suitable intervals. Arriving at the end of the conveying shaft 31, the tires are held back by means of a suitable sensor device (not shown) until the tires conveyed under pressure in the feed shaft 34 into the process chamber are rubbed by the two grinding bodies 37, 38 have been. The lock (not shown) by means of a suitable sensor device overall then dissolved at the end of the conveying shaft (31), so that further tire in the delivery chute 34 enter NEN ^'kön¬.

In the embodiment shown, the two cylindrical grinding bodies 37, 38 arranged in the process chamber are on axes arranged parallel to one another rotatably arranged, the two grinding bodies 37, 38 rotating in opposite directions to one another and in opposite directions to the tire fed into the infeed shaft 34. At the same time, the two grinding bodies 37 and 38 are displaced relative to one another in the axial direction, so that overall there is an oscillating rotational movement which ensures that the tire fed through the feed shaft 34 with constantly changing surfaces of the grinding bodies 37, 38 comes into contact.

4 shows the feed chute of the device according to the invention in an enlarged view. The illustrated infeed double shaft 41, 42 tapering in the direction of the process chamber has, on the opposite surfaces, spiked rollers 43 which are individually driven by electric motors and ensure the transport of the tire to be ground under pressure into the process chamber . In this case, too, the spiked rollers on the opposite surfaces of the feed chute 41, 42 rotate in opposite directions to one another in such a direction of rotation that the supplied tire is transported into the process chamber.

5a shows a schematic representation of the introduction of the tire to be ground into the space between the counter-rotating abrasive bodies 51, 52, of which the abrasive body 52 has the shape shown in FIG. 6.

5b shows the two grinding bodies 51, 52 shown in cross section in FIG. 5a in a representation in longitudinal section, from which the oscillating movement of the two grinding bodies 51 and 52 relative to one another can be seen.

5c shows one of the two grinding bodies 51, which is mounted on a rotatable axis 53 so as to be displaceable by means of a motor 54 which runs on rails. The grinding wheels which can be used according to the invention can be set in rotation with axis motors (not shown) and can be displaced in the axial direction with drive motors (also not shown). The

Abrasives can consist of a drum roller made of steel or cast metal, which can be made in one piece or in several parts. Such drum rollers usually have a diameter between 200 and 1000 mm, preferably about 800 mm. They can be constructed from 50 to 200 mm, preferably 100 to 150 mm, wide segments, a segment generally weighing about 120 kg. The individual segments can be connected to one another by suitable toothing or mortising so that they do not move against one another when the drum roller rotates.

The length of the drum roller is usually 300 to 3000 mm, preferably 1500 mm.

The cylindrical used according to the invention

Abrasive bodies can consist of a ceramic material with a suitable surface grain. In this case, the cylindrical grinding body can consist of individual block segments, between which rubber seals, preferably neoprene seals, with a thickness of preferably 2 mm are arranged in order to avoid undesired wear of the ceramic material by moving the individual block segments against one another. The surface of the grinding media made of ceramic material preferably consists of silicon, electro-corundum or silicon carbide. However, their surface can also be galvanically coated, for example with cubic boron nitride and / or industrial diamonds.

The two cylindrical grinding wheels, as are preferred according to the invention, generally rotate against one another at a surface speed of, for example, 5 to 30 m / s, preferably 10 to 15 m / s. The Oszil The length of the lation, ie the distance over which the two grinding wheels move relative to one another in the axial direction, is generally about 100 cm (measured from the center of the grinding wheel).

The distance between the opposing cylindrical grinding bodies is usually about 0.5 to 10 mm, preferably 1 to 3 mm, in particular 2 mm.

If the grinding wheels used according to the invention are made up of segments, their width is generally between 50 and 200 mm, preferably between 100 and 150 mm. A grinding wheel preferably consists of 3 to 15, particularly preferably 7, segments, rubber seals, preferably neoprene seals, with a thickness of preferably 2 mm being arranged between the individual segments if the grinding wheels consist of ceramic material.

The drum roller 61 shown in FIG. 6a can be made from

Steel or cast metal exist. It is usually hollow on the inside. Before it is used, it is surface-treated by galvanic plasma coating for spraying on industrial diamonds and / or cubic boron nitride to achieve a surface grain size of 4/10 to 8/10, preferably 8/10 (for cubic boron nitride) or 0.5 up to 1.5 carats, preferably 1 carat, when using a coating with industrial diamonds.

However, it is advisable not to coat the entire surface of the round roller 61, but to provide grooves 64 with a dovetail cross section in the surface into which strip-shaped tools 62 with a suitable surface coating 65 can be inserted, as shown in FIG. 6b . In this way, the coating of the surface of the drum roller 61 can be Rush damage can be repaired locally without having to remove the entire drum roller.

6c shows a ready-to-operate drum roller 63 with coated tools 62 inserted into the grooves.

Depending on the size, up to 100 strip-shaped tools 62 can be inserted into the grooves 64 in the surface of a drum roller 61, as shown in FIG. 6a, these strip-shaped tools 62 extending over the entire length of the drum 61 or can only extend over part of the same.

7 shows a cast steel wheel 71 with a special coating 72. In this case, the special coating of the highly stressed surfaces can be applied by galvanic coating, which is achieved by plasma spraying, powder flame spraying and / or Arcing can be amplified.

The cast steel wheel 71 with a galvanic surface coating 72 shown in section in FIG. 7 AA expediently consists of individual grinding wheels (FIG. 7 BB) which have been coated on their circumferential surface in a thickness of preferably 2 mm in the manner described above. The individual grinding wheel disks 73 shown in FIG. 7 BB are pushed onto the barrel axis 74 and are preferably toothed together by means of tongue and groove. The running axis 74 with the slid-on grinding disk 73 is then pushed onto the fixed axis 75, on which it is rotatably mounted. A preferred embodiment of the invention, namely a system for comminuting tires of any origin (private cars, buses, agricultural vehicles, industrial vehicles) and various dimensions up to a maximum of 1500 mm in diameter and 450 mm in width, is explained in more detail below. Such a system is shown schematically in FIG. 8.

When the system is loaded, the tires do not have to be sorted, since the system is able independently to recognize the calibers supplied, to insert them and to process them according to the program which ensures the maximum material output.

The system consists of a conveyor belt and a loading bunker, where the incoming tire is measured (diameter) before it reaches the processing line. This is followed by a roller conveyor with driven rollers, which brings the tires to the grinder. This consists of 2 grinding cylinders, which are specially designed to perform this task. They not only rotate about their own axis in the opposite sense at the same speed, but at the same time perform an opposite displacement in the horizontal plane.

The result of the processing is a fine powder that consists of the three basic materials of the tire: rubber, textile fibers and steel.

The granules obtained are fed to a sorting system (cf. FIG. 1). In this part of the plant, the resulting raw products are sorted out so that they can be marketed.

The diagram of FIG. 8 with the following essential elements serves to understand the system and its components: Hydraulic cylinders fl) have the following functions:

- Widening of the loading bay depending on the size of the tire that falls off the conveyor belt.

- Reduction of the passage of the loading bay as soon as the imported tire has fallen off.

Measure the tire diameter by determining the opening distance.

Microswitch (A. B and C)

- A interrupts the conveyor belt motor circuit. He gives the command to D so that the walls of the grinding funnel open.

- B simultaneously ends the opening process for the side walls of the feed and allows the walls of the grinding funnel to close again.

C ends the closing process of the walls of the grinding funnel and starts the conveyor belt again.

Hydraulic cylinder G

It stops the tire from falling on the last transport roller directly above the grinder.

Microswitch H

Starts cylinders E -. lets the movable part of the cylinder G, which supports the tire when it falls, retract, starts the feed rollers

- lowers the frame of the feed against the grinder closes the movable side walls (O) against the tire starts the nozzles for the low-temperature blowing, which are assigned to the tube Q. Hydraulic cylinder E

They serve to widen and compress the side walls of the feed and are equipped with transducers for controlling the speed of movement.

Microswitch D

- It is located on one of the two hydraulic cylinders E.

- It shows the end of each grinding cycle.

- He turns off the feed roller motors. - He lifts the scaffold with the feeder up.

- It releases the tappet of cylinder H.

- It widens the side walls (O).

- It briefly widens the walls of the feeder and the grinding funnel. - It cuts off the supply of cooling air.

Hydraulic cylinder L

At the top of the ram, they are equipped with transducers and limit switches.

They regularly check the wear of the grinder.

- They provide the necessary measurement data so that the reduction gear feeds the energy lost during processing back to the grinder.

You give the PLC control the necessary data so that it can select the adapted program with which the rollers of the feed, which lie directly above the grinder, always follow the profile of the stability distance.

- The same data of the PLC control also serve that the speed of the grinder is adjusted manually can be set when their diameter changes, which means that the peripheral speed always remains constant.

Reduction gear (N)

it drives the horizontal movement of the grinders - by evaluating the motor current consumed, the PLC changes the speed of the loading rollers.

Detailed description of the individual system components

Sponsor

This is of the belt conveyor type, with a base made of straight rollers and lateral guidance by means of empty vertical rollers which are fastened to the lateral holding profiles of the conveyor. This preferably has an inclination to the horizontal of approximately 30 degrees, a length of 11 and can serve a height of 6 m.

The supporting structure is rectangular with vertical supports made of HEA profiles, cross connectors made of UPN profiles with connecting plates.

The flanks of the conveyor are made of profiled special steel sheet, which is shaped in the form of a C with the outer ends bent back. These sheets are connected to one another with welded cross members, which makes the construction rigid.

drive

It is taken over by a torque converter with a self-braking 4kW motor and transmits the torque di- right onto the control roller in the top part of the conveyor. This roller has a convex shape so that the friction takes over the drive of the belt.

Clamping device

In the lower part of the conveyor, the support arm of the return roller is mounted by means of 2 holders running on guides, each of which is provided with a screw rod with which changes in tension due to the length changes of the belt can be compensated.

tape

This has a polyurethane covering with a

Protective layer for good sliding from a double braid made of polyester fibers in order to improve the resistance to abrasion and to keep the coefficient of friction on the rollers small.

The conveyor belt is used to transport the frost to the grinding funnel. It preferably has the following dimensions:

Length 11 m usable width 1.6 m

Inclination to the horizontal 30 degree conveyor speed about 0.5 m / s motor power about 4 kW

Loading bunker

It is located just below the conveyor belt and can pick up and save the incoming tire until the request for processing arrives.

The PLC determines the size of the opening between the side walls in order to increase the diameter of the tire determine as soon as it leaves the loading coil and falls into the feed.

The bunker has approximately the shape of a truncated cone, on the outside it consists of a framework structure made of HEA profiles, between which two walls made of sheet steel rest, which form the fixed anchor points for the lateral guides of the tires. There are also two movable walls made of electro-welded sheet steel, which are attached to the fixed walls and can be moved with trolleys on longitudinal rails, which are attached to the support structure.

These movable walls have a swinging wall (P) on the lower edge, onto which the tire arriving from the conveyor falls, moves the wall with its own weight and actuates the microswitches A and B, which switch off the conveyor belt.

The opening command for the side walls is given by the PLC to the hydraulic cylinders (I) which are intended for the movement of the above-mentioned walls. The cylinders have a built-in linear transducer, which enables the PLC to record the displacement path and to control the speed and uniformity of the displacement.

In addition, the side guide walls for the tires both themselves have an oscillating wall on the inside, which is held by a spring and serves to support tires of small diameter laterally, so that they remain vertical and do not stand between the fixed ones Jam walls.

The entire structure mentioned above consists of a single module which is supported and anchored on the supporting structure by means of retaining screws. Loading (feeding)

It consists of two movable side walls, each inclined 10 degrees from the vertical and running on horizontal Hoesch guides, which in turn are welded to a rectangular steel frame. This, in turn, is housed in a rectangular steel structure which also carries a second set of guides, but these are oriented vertically.

The inclined side walls each carry a series of rollers that are tapered in the middle and diverge outwards in the shape of a truncated cone. These rollers have a surface which is bordered in order to increase the attack on the tire while it is pressed against the grinder.

Compared to the walls mentioned above, there are two movable walls which move in the horizontal plane, but are at right angles to them. The whole

Equipment of this structure, i.e. Both the walls with the drag rollers and the side guide walls (0) are in contact with the processed tire. The movement of the walls, which is controlled by the feed, is carried out by hydraulic cylinders (E). These are all equipped with a control drive, which ensures that the individual positions are the same. A microswitch (D) indicates when a single work cycle has ended. The side walls (0) are also adjusted and controlled according to the same principle as the motorized walls.

One of the walls (0) carries a vibrating cylinder (G) perpendicular to the background, directly above the grinder, whose plunger stops the fall of the tire, which with its own weight pushed the cylinder down and thus triggered the limit switch (H>).

REPLACEMENT LEAF The outer, rectangular frame for the walls of the feed is raised and lowered vertically by the hydraulic cylinders (F), which, like the cylinders (E), are controlled in a crosswise manner.

The trailing rollers on the two movable walls are driven by two inverter-controlled motors, one for each roller conveyor. The first roller is driven directly and the others are driven by a chain drive.

The vertical displacement of the intermediate frame, which contains the feed and the longitudinal displacement of the driven walls, is ensured by a system of large-diameter C-profiles and shielded roller rolling carriages CRS. The play between the guide and the roller carriage is ± 0.1 mm.

The feed rollers preferably have a maximum diameter of 220 mm and a minimum diameter of 180 mm. Parallel to their axis, they have a fluting with a depth of 15 mm in order to improve the transport of the tire. The special, concave shape ensures good vertical guidance over the grinders.

The rollers are preferably made of stainless steel

CrNiMn (A4) with surface treatment to keep abrasion to a minimum.

It is driven by two reduction gears (one on each wall), each with an inverter-controlled motor of 7.5 kW for speed control from the control center.

Grinders

While the tire is being processed, each grinder rotates about its axis at the same speed, however

ERSA _T ZBLATT in the opposite direction of rotation (for example, the first grinder rotates counterclockwise, the second grinder rotates clockwise).

In addition, they move alternately in the horizontal plane, so that the wear of the grinders is uniform and the tire is not shifted in either direction.

Each individual grinder is housed in an extremely solid carriage, which consists of steel sheets with stiffeners and ribs, so that vibrations during processing are avoided.

The axis of each individual grinder rotates in appropriately dimensioned support bearings, which are enclosed in two supports at the top and contain two slide bearings. These supports run along the sides of the car in a 45 degree offset position. They are each driven by a motor group (M) consisting of a self-braking motor connected to an inverter set and encoder. They have screws with ball bearings and angled holding points so that the worn grinders can be lifted off by hand.

The bearings in the lower part are connected to each other with a rod that carries the hydraulic cylinder (L) in the middle. This is provided with a linear transducer and limit switch. The limit switch is used for periodic checking of the entire wear of the grinder and supplies the necessary data to the PLC so that the system automatically restores the lost order.

The mutual movement of the carriages is based on a system of supports and guides, some of which are attached to the bottom of the carriage and the others to the support structure of the plant.

EBSATZBLATT It is driven by a reduction gear (N), consisting of a motor and inverter set, which generates the necessary torque using a right-hand and left-hand screw.

Each individual grinder is rotated by an inverter-fed, self-braking motor of 20 kW. During the grinding process, low-temperature cooling air is introduced between the lower part of the grinder and the processed tire so that the processing time is optimized.

The functionality and performance of the system depend above all on the mechanical reliability that characterize a real grinding process. The following organs are exposed to major stresses and forces during the grinding process:

The grinders, the carriages carrying them, the axes of rotation, the support bearings and their supports, the power transmission. All of these components are calculated with generous safety factors (ratio 1:10), so that the safety guarantees also apply in the long term. The mechanical parts which are subject to greater wear apart from the grinders are the guides on which the carriages carrying the grinders are continuously moved around.

If one takes into consideration that each car travels about 25 km at a speed of 300 mm / s in a 24 hour operation, this results in about 6000 km per year. It carries a dynamic load of approximately 4000 kg, plus the torsional and tipping forces resulting from the processing, the acceleration and braking stress and all the unforeseen forces that occur in a system that performs repetitive operations with non-uniform materials , are inevitable, must be added.

Description of the grinding process of a tire When the system is started, the central control system automatically checks the individual components and their electrical connections in order to check their effectiveness.

Therefore, each individual command has at least two control systems: the first is the effective control command and the second is used to check whether the command has been carried out:

If the checkup has given a positive result, the electronics center checks the idle states of the following system components:

- conveyor stationary

- Loading bunker with closed side walls at least one tire in the loading bunker

- Feed completely raised against the upper end of the grinder

- Motorized walls totally closed

- The guide walls for the tire, which are at right angles to it, are fully open

- Roller conveyor stationary - Hydraulic cylinder fully extended to brake the falling tire

- Grinders stationary in the static arrangement for normal tire processing

If all of these tests are positive, the electronics center approves the start of the system. The first thing that starts is the motors that drive the grinders. These reach their normal number of wires after about 8 seconds. Then the motors for the reciprocating movement of the grinders and for the conveyor system, which feeds the system with one tire, start at the same time. This falls into the loading bunker and triggers the change with its own weight from microswitch A to B. In addition to switching off the conveyor belt motor, this results in the release of the command to widen the side walls of the loading bunker and feeder simultaneously by means of the hydraulic cylinders (I and E). The first command drops the tire, the second one catches it. As soon as the loading bunker is empty, the tire falls into the feeder. At the same time, the microswitches (A and B) in turn change their switching position, which causes the walls of the loading bunker to close again.

During the first phase, the control center uses the transducers in the hydraulic cylinders (I) to determine the position of the opening. After the electronic evaluation, the central unit is able to determine how large the diameter of the tire is for processing.

The closing of the walls of the loading bunker is controlled with the limit switch (C), which releases the motor of the conveyor belt. This starts and brings a new tire to the loading bunker.

The weight of the tire dropped into the feeder causes the cylinder (G) to vibrate, which catches the fall and in turn actuates the contact of the microswitch (H). This triggers the command that the side walls driven by the hydraulic cylinders (E) clamp the tire from the tread side between the side walls (0) of the lateral enclosure. This clamp along the flanks, at times even the entire framework that contains the feeder, shifts downwards against the grinder. The hydraulic cylinder (G) immediately withdraws its plunger and the feed rollers set in motion with a delay of about 2 seconds compared to the processes described above. At this moment the effective grinding process of the tire begins. The tire is driven by the feeder over the grinders and theirs

ERS ^A TZBLATT Exposed to abrasion. It quickly shrinks and turns into a type of flour that is discharged to the side from a convoyor outside the grinder. This part is designed as a tub. The theoretical production of the system is about 150 g / s.

As already described above, the grinders rotate in opposite directions at the same speed, so that the grinding action of the two works is opposite to the direction of the feed. For this reason it is important that the

Sidewalls of the feeder constantly exert a stable pressure on the tire, because otherwise it would be thrown back by the grinders and their mechanical effect.

Simultaneously with the rotation around its own axis, the grinders move parallel in the horizontal by crossing each other. This movement is important so that the wear on the surfaces is constant and even. In addition, the result is that the rubbed-off powder is better removed.

The pipe for the low-temperature cooling air (-20 ° C, quantity 6-7 m ³ / min) is located directly below the grinders in the middle parallel to their axis and in the axis of the feed. The cooling air is processed in a cooling system outside the shredding system. The distribution pipe has a length of about 500 mm and has a series of slots towards the top, from which the air currents emerge, which hit the surface of the grinder and, through the gaps in the tread, also the tire. This makes the surface of the tire being processed a little harder and therefore easier to machine. This supply of cooling air ceases when one grinding process has ended and starts again when the next begins.

Periodically (ie approximately every 200 work steps), the system switches itself off briefly at the end of processing so that the Hydraulic cylinders (L), which are provided for checking the diameter of the grinders, the total wear of which can determine.

Although the invention was explained in more detail above on the basis of preferred embodiments, it is in no way restricted to it. Rather, changes and modifications of any kind within the scope of specialist knowledge can be made without thereby departing from the scope of the present invention.

Claims

Patent claims

1. A method for pulverizing old tires or other rubber or plastic objects, in which the old tires or other objects as a whole are pulverized in a single operation by dry grinding and then fed to a further use, in that way that

a) the old tires or other objects are transported in a closed delivery shaft and then in a narrowing delivery shaft on driven spiked rollers, standing upright or lying down, individually or in series, are fed to a closed process chamber, each old tire or other object is increasingly deformed (compressed) in the delivery shaft narrowing towards the process chamber,

b) each pressed old tire or other object entering the process chamber is pressed against one or more cylindrical grinding wheels, preferably double grinding wheels, which oscillate and rotate on one axis in each case and are ground to a powder under cooling with cold air in a closed circuit,

c) the powder obtained in the process chamber is drawn off and separated in a separating device into rubber powder parts or plastic powder parts and optionally metal powder parts and textile powder parts by means of wind screening and electromagnetic sensor methods and transferred to silos for storing the different powder parts.

2. The method according to claim 1, characterized in that the feed shaft in stage (a) has left and right or top and bottom extending over the entire width or the entire height of the shaft driven spiked rollers, which the loading material of Feed process chamber.

3. The method according to claim 1 or 2, characterized gekenn¬ characterized in that the spiked rollers on pinions by chain drive are driven together or by electronically controllable electric motors individually.

4. The method according to any one of claims l to 3, characterized in that the feed rate of the old tires or other objects is continuously and continuously adjustable.

5. The method according to any one of claims 1 to 4, characterized in that the grinding wheel (s) in the process chamber are laterally moved back and forth on the axis of rotation perpendicular to the feed shaft and oscillate against one another.

6. The method according to any one of claims 1 to 5, characterized in that the grinding body (s) in the process chamber consists of several segments of different materials and / or with different surface grain size (for grinding) the different components of the Old tire or other objects.

7. The method according to any one of claims 1 to 6, characterized in that the segments of the grinding body consist of a sintered material with a surface of silicon, electro-corundum, silicon carbide, cubic boron nitride or industrial diamonds and are connected to one another in ceramic-bonded grinding wheels via neoprene discs .

8. The method according to any one of claims 1 to 6, characterized in that the grinding body has interchangeable industrial diamond grinding tools arranged parallel to one another on its circumferential surface.

9. The method according to any one of claims 1 to 8, characterized in that in the separating device, the rubber or plastic powder particles and the metal powder particles are separated from one another electrostatically and by air separation.

10. Apparatus for carrying out the method according to one of claims 1 to 9, characterized by

a closed delivery shaft with an adjoining delivery shaft with driven spiked rollers for introducing the used tires or rubber or plastic objects into the process chamber under pressure,

a process chamber with one or more axially mounted rotatable cylindrical abrasive bodies arranged therein, which can be displaced relative to one another perpendicular to the infeed shaft, and

a device for separating the rubber or plastic powder particles, the textile fabric powder particles and any metal powder particles, preferably by air separation and by electrostatic means.

11. The device according to claim 10, characterized gekennzeich¬ net that the feed shaft left and right or above and below extending over the entire width or the entire height of the shaft driven spiked rollers to supply the feed material under pressure of the process chamber Pro¬ .

12. The apparatus of claim 10 or 11, characterized ge indicates that the spiked rollers on pinions by chain drive are driven together or by electronically controllable electric motors individually.

13. Device according to one of claims 10 to 12, characterized in that the abrasive body (s) in the process chamber is (are) laterally reciprocally mounted on the axis of rotation perpendicular to the conveyor shaft and oscillate against one another.

14. Device according to one of claims 10 to 13, characterized in that the grinding body (s) in the process chamber consists of several segments made of different materials and / or with different surface grain sizes and that in the case of ceramic-bonded grinding wheels between the individual segments of neoprene plates are arranged.

15. Device according to one of claims 10 to 14, characterized in that the (the) grinding body in the process chamber on the circumferential surface horizontally or vertically parallel to each other, interchangeable industrial diamond grinding belts (have).