RU2416520C1 - Method of cutting worn-out tires into cord and rubber chips - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to destruction of structures by blasting and may be used in disposal of industrial rubber goods, e.g. worn-out tires. Proposed method consists in placing explosive contact charge on tire surface and its blasting. Note here that said charge represents a flat layer with width corresponding to tire width and is placed on outer tread surface all over tire length.

EFFECT: direct division into cords and rubber chips.

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Description

Technical field

The invention relates to the field of destruction of explosive methods and can be used for the disposal of rubber products, such as worn tires.

State of the art

A known method of destroying worn-out tires and a device for its implementation, which consists in placing a noncontact elongated explosive charge (BB) in the armored chamber along the symmetry axis of the tire package and its undermining [1].

The essence of the known method and device for its implementation is that in the first phase of the explosion, the whole tires are destroyed into relatively large fragments, and in the second, as a result of the formation of a directed, repeatedly circulating in the annular space flow of energy of the explosion, grinding of the fragments formed upon their collision with destructive elements in the pipeline chamber. In this case, when preparing tires for destruction by an explosion, it is supposed to cut the side rings and treat the tires with high-frequency currents or by heating the wire with an inductor, or by cooling.

The specified method of tire destruction has the following disadvantages:

- tire pretreatment;

- the use of a non-contact explosive charge leads to an increase in the size of the fragments obtained in the first phase of the explosion;

- the consequence of this is the second phase of the explosion, which consists in the effect of high-speed gas flows of the products of subsequent explosions on large fragments, which should lead to crushing into smaller ones (grains) during multiple collisions with destructive elements when moving in a chamber of a pipe looped over an armored camera;

- subsequent grinding of the obtained grains and separation of the rubber crumb from the metal wire cord.

In general, we can conclude that the energy of the explosion is used inefficiently.

A known method of destruction of rubber products [2], adopted for the prototype, which produce the placement of the contact charge on the surface of the material, mainly the tire, in places of destruction and charge detonation, additionally, the contact charge is made in the form of rings interconnected for simultaneous dynamic loading, and place it on the inner wall of the tire so that the plane of each ring is perpendicular to the surface of the tire and coincides with its radius.

Although in this method the explosive charge is made contact with placement on the inner surface of the tire, but its representation in the form of connected rings, the plane of which is perpendicular to the surface of the tire, only leads to the destruction of the tire into separate fragments along the lines of contact with charges. Therefore, there will also have to carry out additional grinding of the obtained fragments and the separation of rubber crumb from a metal wire cord.

The disadvantages of this method are determined by the fact that only a small part of the explosion energy is used, since the explosive charge contacts the bus only along the contact lines, and the bulk of the explosion energy is dissipated in the space inside the tire.

Disclosure of invention

The object of the present invention is to provide a more efficient way to use the energy of the explosion for the direct separation of used tires into cord and crumb rubber without pre-treatment of tires and without subsequent regrinding.

This task is achieved by the fact that in the method of cutting worn tires into cord and rubber crumb, which consists in placing the explosive contact charge on the tire surface and undermining it, the charge is made in the form of a flat layer with a width corresponding to the tire width and placed on the outer tread surface tires along the entire circumference. In a particular case, the width of the explosive layer may be equal to the width of the tire.

New features that have significant differences in the method is the following set of operations.

1. The contact charge is performed in the form of a flat explosive layer with a width corresponding to the width of the tire, to ensure maximum contact area, which, in turn, will provide maximum voltage in the loaded part of the tire.

2. The contact charge is placed on the outer tread surface of the tire so that during the movement of the part of the tire loaded by the explosion towards the center, compressive stresses arise that differ in magnitude in the cord and rubber, and therefore, at the interface between them for their effective separation and high-quality crushing rubber.

List of drawings

Figure 1 - diagram of a device for implementing the proposed method.

Figure 2 - layout of the charge of the explosive and detonator on the bus.

The implementation of the invention

The proposed method can be implemented in the device schematically depicted in figures 1 and 2, in which the numbers denote:

1 - armored car (or armored camera);

2 - tires;

3 - flat charges (layers) of explosives;

4 - detonator;

5 - cord.

The device comprises an armored car (or armored car) 1, a stack of destructible tires 2, contact charges BB 3, made in the form of a flat thin layer with a width corresponding to the width of the tire, a detonator 4 for initiating detonation. Charges 3 can be connected with each other to transfer detonation from one charge to another (for example, detonation cords) or undermine each from its own detonator.

The execution of the explosive contact charge in the form of a flat layer and its placement on the outer surface of the tire leads to the fact that after the detonation of the charge, the loaded part of the tire begins to move toward the center under the influence of detonation products. At the same time, compressive stresses appear in the rubber and cord 5, which increase in magnitude during movement. Since materials (cord and rubber) differ significantly in their mechanical properties, the stresses arising in them will differ. As soon as the difference between the stresses reaches a critical value equal to the tensile strength in the cord-adhesive-rubber system, the rubber will detach from the cord. Further, each of these materials will move independently in the form of separate arrays.

If the cord is metallic (or from synthetic fibers), then at the end of the movement, a tangled lump of wire (fibers) is formed on the tire's axis of symmetry, completely free of rubber, which can immediately be sent for further processing.

As for rubber, in the process of independent movement to the center, compressive stresses arise in it, increasing many times at the moment of collapse on the axis of symmetry. Since rubber works well in tension and much worse in compression, as a result of exposure to these stresses, large fragments of rubber will break down into crumb rubber.

Thus, after the explosion from each tire we will have the following end products:

1. a clump of wire (fibers);

2. rubber crumb from the explosion-loaded part of the tire;

3. two rubber sides with side rings, which can then be easily disposed of by known mechanical methods.

The method is as follows.

A stack of several rows of tires 2 with charges 3 on the external tread surface is laid (fed) into the armored chamber (armored chamber) 1. The charges are connected with each other by detonation cords for the transmission of detonation or install detonators 4 for each charge. Then the armored car (armored camera) 1 is closed with a protective cover (door), after which they undermine the charges 3.

After undermining, the protective cover (door) is removed (opened) and the obtained cutting products are removed.

Example: According to the proposed method, explosive cutting of spent metal cord tires from a ZIL-130 truck was carried out. As an explosive, an elastic explosive was used, which is a strip 3 ... 4 mm thick, which is freely wound on the outer surface in one layer. Initiation was carried out by one detonator.

After the explosion, they got a tangled ball of wire, completely free of rubber; crumb rubber with a characteristic size of <1 mm (almost the rubber of the loaded part of the tire was crushed into dust); two rubber sides with rings.

The tests confirmed the efficiency and high efficiency of the proposed method for the destruction of ring-shaped rubber products, such as aircraft and automobile tires.

Information sources

1. Patent RU 2057014, 02.15.1994.

2. Patent RU 2338642, 05/07/2007.

Claims (1)

The method of cutting worn tires into cord and rubber crumb, which consists in placing a contact charge of an explosive on the tire surface and its blasting, characterized in that the charge is made in the form of a flat layer with a width corresponding to the width of the tire, and placed on the outer tread surface of the tire the entire circumference.

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