HU189374B - Furnace for thermal breaking down of used tires - Google Patents

Abstract

Furnace comprises (a) a furnace body adapted to receive the tyres in their initial form, the internal dia. of the body being larger than that of the outer dia. of the scrap tyres; (b) a feed appts. for charging the tyres into the furnace from above; (c) a fluidised bed section formed in the lower part of the body, provided with entrances in the side wall; (d) air ducts connected to the entry openings and communicating with a blower; (e) section forming a sealing bed beneath the fluidised bed section; (f) a transporter arranged beneath the sealing bed and at a distance from it; and (g) an opening at the lower end of the sealing bed, inclined so that the distance from the top surface of the transporter increases progressively int he advancing direction of the transporter. - The furnaces is used for mfr. of cement. The tyres can be incinerated whole, without being cut into pieces as in prior art. The ash enveloping the steel wires is agitated and crushed by the fluidising bed medium, released from the wires and carried out at the bottom onto the transporter.(0/5)

Description

BACKGROUND OF THE INVENTION The present invention relates to a furnace for the thermal dismantling of used tires.

Different types of furnaces, used tires, etc. are known. thermal decomposition, which, for example, heat the generated heat. It is used in cement production, for heating water boilers, for drying or for other purposes.

According to the state of the art many solutions have been developed for this purpose so far, but all have different shortcomings. In one embodiment, a deep fluidized bed oven was used to thermally dismantle used tires, but the non-combustible, steel cord fabric could not be removed from the furnace during continuous operation.

A further disadvantage of this solution is that the used tires had to be chopped before the thermal dismantling.

A further disadvantage of the prior art solution is that the thermal decomposition cannot be carried out periodically, continuously, and thus the heat content of the solid coals cannot be utilized without significant loss.

It is an object of the present invention to overcome the above disadvantages, that is, to improve the furnaces used for the thermal dismantling of used tires, which are substantially more efficient than the known solutions.

It is an object of the present invention to provide a continuous process of thermal dismantling of used tires without the need for splitting the tires during the pre-production operation and with improved thermal efficiency.

The invention is based on the discovery that the object of the present invention is solved by providing a furnace for the thermal dismantling of used tires which is capable of accommodating the original size of the tire and providing continuous operation, advantageous heat. remove the non-combustible axial cord fabric from the inside of the unit when used.

The object of the present invention is to provide a furnace of the type described in the introduction having an inner diameter greater than the outer diameter of the tires used in the vertical symmetrical axis, provided with a tire dispenser at the top of the furnace, a central part of the furnace the inlet openings are connected by pressure ducts connected to a pressure fan, the lower part of the furnace forming an insulating bed and having an opening at the bottom, below which is arranged a horizontal conveying device with a distance and an inclined plane of the opening at the bottom .

Preferably, the side wall of the central part of the furnace housing forming the fluidization bed has a downwardly tapering diameter.

From the viewpoint of simplifying the technology, an embodiment in which the portion of the furnace housing forming the lower insulating bed is substantially cylindrical is advantageous.

Furthermore, according to the invention, the object of the present invention has been solved in that the opening plane formed at the bottom of the insulating bed is preferably 15 ° to 30 ° with respect to the horizontal.

The invention will now be described in more detail by way of example with reference to the drawing. In the drawing it is

Figure 1 is a schematic longitudinal sectional view of a preferred embodiment of a furnace for thermally disassembling a used tire according to the invention,

Figure 2 is an enlarged view of a substantial part of the furnace of Figure 1, a

Figure 3 is a sectional view taken along line ΠΙ-ΙΙΙ in Figure 2, a

Fig. 4 is a sectional view taken along line IV-IV in Fig. 2;

Figure 5 is an enlarged view of another essential detail of the furnace of Figure 1.

Fig. 1 shows the furnace housing 1 of the thermal dismantling furnace, in which the used tires 2 are conveyed by the dispenser 3 to the dispensing chamber 4 and from there to the fluidization bed 5 for thermal dismantling. The fluid 11 (e.g. quartz sand, cement clinker) forming the fluidization bed 5 must be preheated to 600 ° C or higher to start the thermal decomposition furnace.

In order to heat the fluid 11, it is advantageous to heat and burn some of the used tires 2 in the fluidization bed 5 beforehand. Hereby the furnace is brought to a ready state.

The air needed to fluidize the fluid 11 is supplied to the inlets 9 (9a, 9b) formed in the sidewall 8 of the furnace 1 by means of air ducts 7 connected to the pressure blower 6.

By thermal decomposition, the gas generated from the used tires 2 is fed into a boiler (not shown) through a line 10 extending from the upper part of the furnace housing 1. The developed gas has high CO, H ₂ , CH ₄ and C% etc. because of its content burns well in the boiler _s

The thermal decomposition furnace is configured so that the upstream flow rate of the developed gas over the fluidization bed 5 is about 0.1-0.5 Nm ³ / sec, converted to normal.

The developed gas contains solid carbon particles with a maximum diameter of 1 mm. Therefore, for example, in the case of gas introduction into a boiler for water heating, it is advantageous to recycle the solid carbon particles to the gas-solid separator and then to the fluidization bed 5 for thermal decomposition.

The dosing chamber 4 is formed with a plurality of flue gas pistons (not shown) for proper insulation. With this metering chamber, the used tires 2 can be fed to the thermal disintegration furnace in continuous operation. The inlets 9 (9a, 9b) connected to the air ducts 7 are located on two different levels along the height of the furnace 1 as shown in Figures 1 and 2. Further, the lower inlets 9a are located radially with respect to the furnace 1 and the inlets 9b above are located tangentially (Figures 3 and 4),

AO / Nm / / min./flow required to supply the fluidization bed 5 at the lower inlets 9a; the amount of air blown at the upper inlet openings 9b / Am / Nm ³ / min./ is used to obtain the gas generated during the thermal dismantling of the used tires 2. The amount of air Aa is adjusted by a valve not shown here to regulate the amount of gas that can be developed from the amount of tire used through it.

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In order to maintain the operation of the thermal decomposition furnace, the thermal decomposition temperature of the fluidization bed 5 is preferably maintained between 600 ° C and 800 ° C, in part by controlling the amount of air passing through the upper inlets 9b. As described below, the medium 11 is circulated and replaced with a separator 16 located outside the furnace housing 1 and a return pipe 17. Furthermore, it is. The temperature of the fluidization bed 5 is controlled by the amount of fluid 11 exchanged. For a more advantageous effect, the symmetry axis of the inlets 9a and 9b is preferably 5 ^{° to} 20 ° to the horizontal in the direction of the lower part of the furnace 1.

Figures 2, 3 and 4 show the refractory lining la and the jacket lb. As shown in the drawing, the central part 13 of the furnace housing forming the fluidization bed 5 is formed by inclined side walls 8, which taper towards the lower part. The slanted sidewall design makes it easy to form a fluidized bed.

The insulating bed is formed with the medium 11 below the inlets 9a. The insulating effect is achieved by utilizing the bulking of the medium 11 to form the insulating bed 12. The insulating effect is satisfactory if the air creating the fluidization bed cannot be blown through the insulating bed 12. For this purpose, it is preferred that the insulating bed 12 has a longitudinal dimension parallel to the vertical axis of symmetry. 2 to 5 times the same longitudinal size of 5 fluidization beds.

Approx. It must be heat resistant at 1500 ° C. As a refractory material, cement kilns or quartz sand are preferably used. The ratio of the longitudinal dimensions of the central portion 13 and the lower portion 14 of the furnace housing parallel to the vertical axis of symmetry is equal to the ratio of the respective dimensions of the fluidization bed 5 and the insulating bed 12.

The fluid level 11 at the fluidization bed 5 is controlled such that the L / D ratio of the fluidization bed 5 to depth L and D is 1/2 to 2-2.

For proper operation, the position of the fluid 11 and the filling and emptying of the fluid 11 are controlled by the difference in pressure values measured at the top of the furnace and at some points in the fluidization bed 5. Medium 11 is changed at full volume 0.53 times per hour.

As soon as the used tire 2 is subjected to a thermal breakdown and passes through. On the fluidised bed 5, the smoldering material pieces covering the steel cord fabric 15 are detached from the steel cord fabric 15 by the resonant and refractory mechanical action of the fluidizing bed 5 and in small pieces are the gas produced. they go to the heat recovery boiler. At the same time, the steel cord fabric 15 is emptied together with the medium 11 passing through the insulating bed 12,

The medium 11 is composed of quartz sand or cement clinker particles having a diameter of 0.1 to 5 mm, preferably 0.2 to 1.2 mm.

All media and steel cord fabric 15 are separated in a separator 16 using a sieve and a magnetic separator and fed to the thermal decomposition furnace by the return tube 17.

The lower part of the furnace housing 4 is cooled with water 19 circulating in the cooling jacket 18, thereby reducing the temperature of the medium 11 and the steel cord fabric 15 and not causing thermal damage to the conveyor 20 and other components of the structure. The lower part 14 of the furnace housing, which forms the insulating bed 12, has an inner diameter smaller than the outer diameter of the used tire 2 and is substantially cylindrical in shape. In this way, it facilitates both the detachment of the tire from the steel cord 15 and the downward movement of the steel cord 15 towards the band opening.

The lower part 14 of the furnace housing forms an insulating bed 12 and has an opening 21 at its bottom, below which a conveying device (20) is arranged in a horizontal plane, spaced (h) and an inclined plane 21 of the opening 21 at the bottom of the insulating bed. 22 defines an increasing distance h from its upper surface.

If the inclination plane of the opening 21 coincides with the horizontal, the discharge of steel cord fabric 15 is difficult. If the angle is greater than the preferred 15 ° -30 °, the insulating effect of the insulating bed 12 will deteriorate.

An advantage of the present invention is that it allows continuous thermal decomposition of used tires of original size. Without the intermediate removal of steel cord fabric or solid tire residues, which requires a thermal interruption furnace operation, which would result in heat loss, the heat recovery boiler can be operated with the developed gas or solid fuel parts.

Claims (7)

Claims A furnace for the thermal dismantling of used tires, characterized in that the borehole (1) having a vertical symmetrical axis has an inner diameter greater than the outer diameter of the used tires (2), with a tire (2) used on the upper part of the furnace housing (1). provided, the central part (13) of the furnace forming a fluidization bed (5), whereby air ducts (7) connected to a pressure fan (6) connected to the inlets (9a, 9b) formed in the sidewall (8) of the furnace (1) and the furnace housing (1) its lower part (14) forming an insulating bed (12) and having at its bottom an opening (21) under which a conveying device (20) is arranged horizontally, spaced (h) and an opening (21) at the bottom of the insulating bed (12) with the conveying device (20) defines an increasing spacing (h) in its direction of transmission. Furnace according to Claim 1, characterized in that the central part (13) of the furnace housing forming the fluidization bed (5) has a downwardly narrowing inner diameter. Furnace according to Claim 1, characterized in that the lower part (14) of the furnace housing forming the insulating bed (12) has a substantially cylindrical shape. Furnace according to Claim 1, characterized in that the opening (21) at the bottom of the insulating bed (12) preferably has an inclination plane of 15 ° to 30 ° with respect to the horizontal. Furnace according to Claim 1, characterized in that the lower part (14) of the furnace housing (1) forming the insulating bed (12) has a length forming the fluidizing bed (5). preferably the middle part (13) has a length of 2-5 times, Furnace according to Claim 1, characterized in that the air ducts (7) are connected to a terminal 32 The inlet openings (9a, 9b) are arranged at two different levels along the height of the furnace housing (1), wherein the inlet openings (9a) below are formed radially with respect to the furnace housing (1). The furnace according to claim 1, characterized in that the inner diameter of the tires (2) of the furnace housing (1) is larger than the outer diameter and the inner diameter of the lower part (14) of the furnace housing (1) forming the insulating bed (12). (2) smaller than the outer diameter. 5 pieces of figure