RU2251483C2 - Worn tires processing method and a device of its realization - Google Patents

Abstract

FIELD: rubber industry; a fuel-and-power complex and enterprises of worn tires processing.

SUBSTANCE: the invention is pertinent to technologies of processing of industrial and a domestic rubber wastes and may be used in rubber industry, in a fuel-and-power complex and at enterprises processing worn auto tires. The method of processing of worn tires provides for their preparation and feeding through a sluice chamber into a reactor. Then conduct pyrolysis under pressure in the overheated steam medium, consequent separation of a solid phase, separation of a fluid phase and a steam-gas phase with incineration of the latter for maintenance of a process of the pyrolysis and removal from the reactor of the solid and liquid phases. Pyrolysis is carried out at a negative pressure in the reactor within the interval of 0.01-0.1 atm in a mode of a continuous loading of tires and unloading of a solid phase. Sluice chambers are filled in with water with a capability of loading (6) and unloading (7) of the reactor (3) and formation of a water check. The steam-gas phase is additionally exposed to a catalytic cracking. The liquid phase in amount of 25-30 % is incinerated in the reactor for maintenance of a process of pyrolysis. The device for processing of worn tires consists of a vertical reactor with a sluice chamber for loading of the worn tires, a tool for unloading of a solid phase and functionally linked with the reactor a steam-gas phase condenser and an accumulating container-settler of a liquid phase with a cock and a consumption indicator. The device is supplied with the sluice chamber of unloading. Sluice chambers of loading and unloading have the water checks capable to seal the reactor. The sluice chamber of loading is supplied with a loading conveyor, which at an inlet and an outlet of the water check is equipped with the pressure rolls. The reactor is additionally supplied with a cartridge of a catalytic cracking and is equipped with a furnace with burners. The furnace body is made conical in the form of a guiding mean for stringing tires onto a vertex of the cone from the loading conveyer. In the cone base of the furnace there is a ring-type infrared source made out of refractory steel. The invention allows to increase productivity of the process of the worn tires reprocessing and to reduce specific power inputs.

EFFECT: the invention ensures an increased productivity of the process of the worn tires reprocessing and reduction of specific power inputs.

7 cl, 3 dwg

Description

The invention relates to the field of ecology and is associated with the disposal of products of technogenic human activities, in particular, to the technology for processing industrial and household rubber waste, and can be used in the fuel and energy complex, in the rubber industry, as well as in enterprises for processing automobile tires.

The known technological complex (1) for non-waste processing of solid organic waste, including worn tires, aircraft and other tires to produce energy (gasoline fraction, fuel oil, pyrolysis gas), pyrocarbon (solid carbon residue) and metal. The method includes preparing the feedstock with its multi-stage grinding to a size of crumbs of the order of 20-25 mm and subsequent drying. The dried crumb enters the reactor, where at a temperature of about 950 ° C it undergoes degradation with the release of a vapor-gas mixture, and a solid carbon residue with metal inclusions under its own weight and pressure of the newly incoming raw material moves to the lower part of the reactor. Then, through a cooling system, it is sent to a two-roll crusher for preliminary grinding and separation of metal from “baked” carbon. From the crusher, the crushed solid residue is conveyed through a conveyor belt to a storage bin, and metal inclusions are previously extracted from it. From the storage bunker, the carbon residue is fed by a screw feeder into the micron grinder, where the final grinding to the desired fraction takes place. Pyrolysis gas is partially supplied to the heating of the reactor, the rest to the consumer. Butadiene, gasoline, toluene and benzene are isolated from liquid hydrocarbon vapors after petrochemical condensation and rectification.

The disadvantages of this method include the presence of highly energy-intensive processes of grinding tires and drying chips, as well as the cyclical nature of the reactor, due to the periodicity of the process of loading raw materials and unloading the solid residue from the reactor and the associated significant energy losses.

There is a method of recycling rubber waste in an inert coolant - quartz sand (2). The method includes pyrolysis of rubber waste in a reactor at a temperature of 500-700 ° C, separation of the solid phase, separation of the liquid and gaseous phases by condensation and burning of the latter to maintain the pyrolysis process.

The disadvantage of this method is the high energy intensity and low productivity due to the cyclical processes of loading and unloading in the reactor and the inevitable loss of thermal energy.

Also known is the technology for processing rubber waste by the method of steam thermolysis (3). The method includes the “digestion” of rubber in a working environment - superheated water vapor. Water vapor during cooling makes it easy to concentrate the decomposition products. In this case, a gas-vapor mixture is used, consisting of 98-85 wt.% Superheated to 300-1600 ° C water vapor and 2-15 wt.% Gas obtained from gaseous decomposition products. Before the thermal decomposition, rubber wastes are mixed with 3-40 wt.% Oil by passing gaseous decomposition products and the working medium through the waste layer at their mass ratio (0.05-1.62): 1. Solid decomposition products are mixed with 4-40% oil and pressed into briquettes while heating to 100-500 ° C by filtering gas obtained from gaseous decomposition products.

The disadvantages of the method include the high decomposition temperature of rubber waste, reaching 1600 ° C, and the cyclical nature of the processing process, which significantly increases energy costs.

Closest to the proposed invention is a method for the destruction of rubber waste by decomposition in a reactor in an environment of superheated steam (4), which is chosen as a prototype. The method includes the preliminary preparation and pyrolysis of worn tires under excess pressure in an environment of superheated water vapor. In this case, steam is taken in an amount of 18-110% by weight of the waste, and the resulting carbon solid phase is crushed to a particle size of 0.001-0.210 mm. The liquid phase is separated with steam and mixed with 23.0-55.8 wt.% Of the crushed carbon phase to obtain liquid fuel. The decomposition process includes the periodic loading of rubber waste into the reactor and unloading of the solid carbon phase from it through the lock chambers. Thermal destruction is carried out at a temperature of 400-500 ° C. Destruction gases are condensed together with water vapor, and non-condensable gases are sent to combustion in the furnace of the steam generator to maintain the pyrolysis process.

Liquid condensate after mixing with the crushed carbon residue to a homogeneous state is a fuel - an analogue of fuel oil brand M-40.

The disadvantage of this method is the cyclical process of processing rubber waste and, as a result, low productivity and large losses of thermal energy, inevitable during periodic loading of raw materials into the reactor and unloading of the solid phase from it.

A device (5) is known for the thermal decomposition of hydrocarbons, including old automobile tires. The device contains a pyrolysis chamber - a drive, which is placed in the furnace with its open end facing down. The furnace contains an upper part in the form of a cap with double walls and a lower part - a bottom connected to the upper part by a conical connector with seals. The drive forms a common gap with the side walls and ceiling of the furnace, connected by nozzles for supplying and discharging pyrolysis products.

The disadvantage of this device is its low productivity and efficiency, due to the cyclical nature of the decomposition process associated with the periodic loading of raw materials and unloading of the solid phase from the storage chamber.

Also known is a furnace for pyrolysis of car tires (6). The device comprises upper and lower parts connected by a conical connector to the sealing rings. In the cavity of the upper part of the furnace, a pyrolysis chamber is vertically mounted. The furnace is equipped with an annular tray with a pipe for the removal of liquid pyrolysis products. The device operates cyclically: lift the upper part of the furnace with a lifting device, load the tire packet into the pyrolysis chamber, then return the upper part to its place and fix the detachable joints. Next, hot gases are supplied from the combustion device between the walls of the furnace and the pyrolysis chamber, and the tires are decomposed according to a predetermined mode, followed by unloading in the reverse order of the solid residue from the pyrolysis chamber.

The disadvantage of the furnace design is the cyclical operation and high energy losses associated with the need for periodic heating of the furnace to operating temperature after the next loading of tires and subsequent cooling during unloading of the solid phase of the degradation products.

Closest to the proposed invention is a device for processing rubber waste by pyrolysis under excessive pressure in an environment of superheated water vapor, which is taken as a prototype (7). The device comprises a vertical reactor with an upper airlock with a hatch (shutter) for loading tires and a screw conveyor for unloading a solid phase. By means of a drive, the conveyor is kinematically connected to the lock hatch with a lower discharge chamber. The reactor through a pipeline with a tap and a flowmeter is functionally connected to a steam generator, as well as to a condenser and storage tank - a liquid phase settler.

Tires are periodically loaded into the reactor through the lock chamber, and the hatch shutter is closed. At the same time, superheated steam is supplied from the steam generator through a tap and a flow meter under excessive pressure and thermolysis is carried out according to a predetermined mode. The gaseous products of pyrolysis in a mixture with steam are condensed in a condenser. Non-condensable gases are sent through a faucet and a flow meter for combustion into the furnace of a steam generator. The condensate formed from the condenser is poured into the storage tank - sump. After completion of the decomposition process, the solid phase (carbon residue) is removed from the reactor by a screw conveyor through the airlock of the discharge chamber and sent to grinding. Next, the reactor is loaded with a new batch of tires and the pyrolysis cycle is resumed.

A disadvantage of the known method and device are large heat losses and low productivity due to the cyclical nature of the processes of loading the feedstock and unloading solid processed products.

The objective of the invention is to eliminate the noted drawbacks of the known method and device for processing rubber waste.

The aim of the invention is to increase productivity and reduce the energy intensity of the process of processing used tires.

This goal is achieved in that in a method for processing used tires, including preparing and supplying them to the reactor through a lock chamber, pressure pyrolysis in a medium of water vapor, subsequent separation of the solid phase, separation of the liquid and vapor-gas phases with combustion of the latter to maintain the pyrolysis process and removal from the reactor of solid and liquid phases, according to the invention, pyrolysis is carried out at a negative pressure in the range of 0.01-0.1 atm in the mode of continuous loading of tires and unloading of the solid phase, while the lock chambers olnyayut water to form a water seal, vaporous phase is further subjected to catalytic cracking, and the liquid phase in an amount of 25-30%, resulting in the decomposition, are burned in the reactor to sustain the pyrolysis process.

During preparation, the tires are cut in a transverse annular cross section in the radial direction, and during the pyrolysis, they are moved from top to bottom in the reactor and unbent into the tape when unloading at the outlet of the reactor.

This goal is also achieved by the fact that in a device for processing worn tires containing a vertical reactor with lock chambers for loading and unloading a solid phase, an unloading conveyor, a vapor-gas phase condenser and a liquid-phase storage tank with a tap and flow meter, functionally connected to the reactor, according to the invention , the lock chamber loading and unloading is made with water gates with the possibility of sealing the reactor, and the lock chamber of the boot is equipped with a conveyor boot, which at the inlet and outlet of the water lock, it is equipped with pressure rollers, the reactor is additionally equipped with a catalytic cracking cartridge and equipped with a furnace with burners, while the furnace body is conical in the form of a guide, the top of the cone of which is kinematically connected to the feed conveyor, and a ring infrared emitter is mounted in the base of the furnace cone from heat resisting steel.

The furnace body is hollow inside and equipped with a vertical partition with the possibility of the formation of a chimney, the latter being functionally connected with the annular gap between the outer surface of the reactor and its external heat-insulating wall, where a spiral chimney is additionally mounted.

The burners of the furnace through an additional intermediate tank are connected to the tank-settler of the liquid phase, while the bottom of the settler is connected to the discharge chamber of the solid phase through the water drain pipe, and the lid of the settler is connected to the condenser.

The condenser is equipped with an exhaust fan, which is configured to create negative pressure in the reactor and supply gaseous non-condensable decomposition products of the tires for combustion.

The loading conveyor is made of chain and equipped with hooks for gripping the tires, and the unloading conveyor is made of tape and equipped with a magnetic separator.

The invention is illustrated by drawings, where Fig. 1 shows a schematic diagram of a device for implementing the method, Fig. 2 is a diagram of a section of tires during their preparation, and Fig. 3 is a view of a tire in section BB.

The device contains a section 1 for preparing tires 2, a reactor 3 with a heat-insulating wall 4 and a catalytic cracking cartridge 5, lock chambers for loading 6 and unloading 7 with water locks 8, a chain loading conveyor 9 with grab hooks 10 and pressure rollers 11, a belt unloading conveyor 12 with a magnetic separator 13 for separating metal inclusions 14 and a hopper 15 for storing the carbon phase 16. Functionally connected to the reactor 3 is a capacitor 17 with an exhaust fan 18, the capacity of the sump 19 with taps 20, 21 and intermediate m tank 22, a pipe 23. The furnace 24 of the reactor 3 with a vertical partition 25, a chimney 26, a spiral chimney 27, an exhaust pipe 28, an annular infrared emitter 29 and burners 30.

The essence of the method and the distinctive features of the device for its implementation are as follows.

It has been established that the thermal decomposition of rubber and worn products from it, such as tires, in a water vapor medium is a typical diffusion process, the speed of which is limited by the rate of heat supply and the diffusion kinetics of volatile destruction components. Therefore, the engineering and technological solution to the problems of supply and reduction of heat loss is a key task to achieve effective indicators of the technological process of processing used tires. The developed method and device allow to conduct the process of steam thermolysis of rubber in a continuous mode, eliminating the cyclic shutdown of the reactor for the period of loading the feedstock and unloading solid decomposition products from the working zone. The continuity of the destruction process is achieved by cutting off the working zone of the reactor from the external environment by means of water gates in the lock chambers of loading and unloading, which allows the thermolysis process to be carried out in a stationary mode without stopping the decomposition reactor. In this case, the wetting of the tires with water, while passing through the water shutter of the loading chamber, favorably affects the kinetics of the subsequent heating of the rubber waste to the decomposition temperature (280-500 ° C). The operating temperature in the decomposition zone of the reactor, after entering the regime, is supported by its own energy source - burning of gas and part of the liquid waste decomposition products. In this case, the liquid phase of the destruction of rubber, for the purpose of energy supply of the decomposition process, is used in an amount of 25-30% of the obtained volume, and the gas component of the decomposition products is completely burned in the reactor furnace. Thus, high environmental safety and efficiency of the rubber waste disposal process is achieved.

It is significant that steam thermolysis is carried out at a negative pressure in the reactor working zone (0.01-0.1 atm), the latter provides efficient vaporization at a lower temperature in the reactor due to a shift in the equilibrium moisture content point and increases the safety and efficiency of the tire decomposition process.

In the process of degradation of rubber, together with the volatile vapor-gas phase, finely dispersed soot is recovered by means of a replaceable zeolite cartridge with which the reactor is additionally equipped. At the same time, the cartridge is impregnated with metal salts of variable valency (Ni, Co, Cr, Cu, etc.), which provides catalytic cracking of the organic component of the vapor-gas phase and increases the environmental safety of the process of disposal of used tires.

Efficient extraction and return of heat to the reactor from the exhaust flue gases is also achieved due to the spiral design of the chimney, which, in combination with the conical shape of the guide furnace of the reactor, provides uniform all-round heat supply to the tires and does not require preliminary grinding. This design of the reactor significantly reduces energy costs for the preliminary preparation of tires and saves energy due to heat recovery.

An important factor in the economical operation of the device is to optimize the conditions for supplying heat to the tires and the efficient use of the reaction volume of the reactor, which is achieved by orderly tight packing of the loaded tires by stringing them on the conical guide of the furnace. The tire rim is pre-cut before loading into the reactor, thereby ensuring their continuous smooth movement in the working zone of the reactor from top to bottom under their own weight due to the gradual opening of the tire along the cut and extension of the ring into the tape in the lower base of the cone, followed by removal of solid residue from the reactor.

The use of a water lock in the sluice chamber for unloading solid carbon residue, in addition to sealing the working zone of the reactor, eliminates the pollution of the working atmosphere of the workshop with particles of soot, which is trapped in the sluice chamber. Such a constructive solution of the device for implementing the method improves occupational health and increases the environmental safety of the process.

The invention is as follows.

In the preparatory section 1, tires 2 are sorted by size and cut according to the scheme, as shown in figure 2. Next, the tires 2 are captured by a loader (not shown in the drawing) and, oriented “up” to the section “C”, they are fed into the load lock chamber 6, where the rollers 11, at the entrance to the water lock 8, squeeze air out of the cavity (31) of the tire 2 and stacked on a chain conveyor 9. Then they are fed into the reactor 3 by their gripping hooks 10, while at the outlet of the water lock 8, the tires 2 are passed through the rollers 11 and water is squeezed out of the cavity 31 through section “C”, which is now oriented “down” . In the upper part of the working zone of the reactor 3, tires 2 are strung on the conical guide of the furnace body 24. As a result of the appropriate choice of the angle of the conical guide furnace 24 and softening of the rubber under the influence of high temperature, the tires 2 are deformed, open along section “C” and gradually under their own weight advance along the working zone of the reactor 3 from top to bottom. The height of the reactor 3 and the speed of advancement of tires 2 in it are selected based on the calculation of the time sufficient for complete decomposition of the rubber, which averages 2.5-3 hours. At the base of the conical guide furnace 24, in the zone of the infrared emitter 29 heated by the burners 30, the tires 2 are already straightened into the tape in the form of the carbon phase 16 (solid residue with the inclusion of metal) and enter the discharge lock chamber 7. Next, the carbon phase 16 through the water the shutter 8 enters the conveyor belt 12, through which it is fed to the magnetic separator 13, where it is freed from metal impurities 14 and then stored in the hopper 15. After placing the tires 2 in the reactor 3 with an exhaust fan 18 create a vacuum (negative pressure in the range of 0.01-0.1 atm), and then the destruction products are separated into carbon, liquid and vapor-gas phases, while the latter is removed by vacuum through a catalytic cracking cartridge and sent to a condenser 17. The vapor-gas phase is cleaned of fine soot and carry out catalytic cracking of the organics contained in it. The condensed liquid phase from the condenser 17 enters the settling tank 19, where liquid hydrocarbons are separated from the water. Pipeline 23 discharges water through a valve 20 into a water lock 8 of the discharge unloading chamber 7. A part of the hydrocarbon component of the liquid phase (in the amount of 25-30%) from the settling tank 19 is sent to the intermediate tank 22 and then burned to the burners 30 of the furnace 24. The remaining 70-75% of the liquid phase, as the finished fuel from the settling tank 19, is sent to the drain (arrow "A") in the storage (not shown in the drawing).

The non-condensable gas phase from the condenser 17 by an exhaust fan 18 is sent to the burners 30 for burning in the furnace 24 and maintaining the pyrolysis process in the reactor 3. The combustion products through the chimney 26 of the furnace 24 and the spiral chimney 27, between the heat-insulating wall 4 and the outer surface of the reactor 3, are removed through the chimney 28 into the atmosphere.

The process of destruction of worn tires is characterized by the following parameters.

Weight, kg / hour:

- Solid Carbon Phase - 900

- Gaseous products - 600

- Metal cord (5% by weight) - 75

Temperature, ° С:

- gas-vapor mixture - (350-450);

thermal conductivity of steam, W / (m • K) - 67.3 • 10 " ³ .

The obtained products of the processing of worn tires averaged have the following parameters (Table 1).

Table 1 Name Parameter 1. Solid phase: - Density, kg / m ³ 1780 - Ash content,% 5.2 - Sulfur content,% 0.31 - Calorific value, kJ / kg (kcal / kg) 35970 (8600) 2. The liquid phase: - Density at 20 ° C, kg / m ³ 920 - Ash content,% Is absent - Mass fraction of sulfur,% 0.83 - Flash point, ° С 51 (in a closed crucible); 96 (open crucible) - Lower calorific value, kJ / kg 41500 (9875) (kcal / kg)

According to their characteristics, the liquid phase corresponds to M-40 fuel oil, the solid carbon phase is an analogue of the carbon adsorbent, and metal inclusions are alloyed steel scrap.

The implementation of the method in continuous mode, unlike the prototype, allows 2-3 times to increase the productivity of the process of processing used tires, to reduce specific energy consumption by 25-30%.

The proposed method has been tested in laboratory conditions and at present the pilot plant is being prepared by the applicant for pilot tests.

Sources of information

1. Belavin V. “Production of technological complexes for utilization of solid organic waste”, NVF PE “PIROL” “Secondary resources. Alternative energy, petrochemistry ”-“ Utilization of organic waste ”, www.belizl.narod.ru: March, 2003

2. Palgunov P.P., Sumarokov M.V. “Disposal of industrial waste.” -M .: Stroyizdat, 1990.-pp. 165-166.

3. Aristarkhov D.V., Egorov N.N., Zhuravsky G.I. and others. “Steam thermolysis of organic waste”, Minsk-2001, p.86-94.

4. (72) Grebenkov A.Zh., Drozdov V.N., Novikov G.T. “Method of processing rubber waste”, Patent RU No. 2076501, (71) AOZT “Robentech”, (51) MPK6 V 29 V 17/00, C 08 J 11/10, 11/14; RU BI No. 9 dated 03/27/97.

5. Dipl.-Ing. Rudolf Seibrt, Rechtsanwait u. Patentanwalt. Tattenbachatrabe 9, 8000 MONCHEN, 22; “A device for producing hydrocarbons from automobile tires by heat treatment.” The application of Germany No. 2949983, Cl. C 10 V 53/00, 1991.

6. (72) Sadykov A.F., Takhautdinov Sh.F. et al. “Furnace for the pyrolysis of hydrocarbon feedstocks”, (71) (73) JSC Tatar NIPKI of petroleum engineering, JSC Tatneft, Patent RU No. 2078111, MPK6 C 10 V 1/04, C 10 G 1/10, S 10 B 53/08, BI No. 12 of 04/27/97.

7. (72) Zhuravsky G.I., Drozdov V.N., Mulyarchik V.V. et al. “Method for processing rubber waste”, (71) (73) NTPVC “TOKEMA”, Patent BY No. 862, (21) No. 1046A, (22) 12/9/93, (51) MPK5 C 08 J 11 / 14, C 10 L 1/00 (prototype).

Claims (7)

1. A method of processing used tires, including preparing and supplying them to the reactor through a lock chamber, pressure pyrolysis in an environment of superheated water vapor, subsequent separation of the solid phase, separation of the liquid and vapor-gas phases with combustion of the latter to maintain the pyrolysis process and removal of solid and liquid phase, characterized in that the pyrolysis is carried out at a negative pressure in the reactor in the range of 0.01-0.1 atm in the mode of continuous loading of tires and unloading of the solid phase, while the lock chambers are filled with water with the possibility of the formation of a water gate, the vapor-gas phase is additionally subjected to catalytic cracking, and the liquid phase in an amount of 25-30% is burnt in the reactor to maintain the pyrolysis process. 2. The method according to claim 1, characterized in that the tires during preparation are cut in a transverse annular cross section in the radial direction, and during the pyrolysis process they are moved from top to bottom in the reactor and unbent into the tape when unloading at the outlet of the reactor. 3. A device for processing used tires, comprising a vertical reactor with a lock chamber for loading tires, means for discharging a solid phase and a combined-cycle phase condenser and a storage tank for liquid phase with a tap and a flow meter, characterized in that the device is equipped with a lock chamber for unloading and the lock chamber for loading and unloading is made with water gates with the possibility of sealing the reactor, and the lock chamber of the boot is equipped with a conveyor loading, which is at the entrance and the outlet of the water lock is equipped with pressure rollers, the reactor is additionally equipped with a catalytic cracking cartridge and equipped with a furnace with burners, while the furnace body is conical in the form of a guide for stringing tires onto the top of the cone from the feed conveyor, and a ring infrared emitter made of heat-resistant is mounted at the base of the furnace cone steel. 4. The device according to claim 3, characterized in that the furnace body is hollow and provided with a vertical partition with the possibility of the formation of a chimney, the latter being functionally connected with an annular gap between the outer surface of the reactor and its external heat-insulating wall, in which a spiral chimney is additionally mounted. 5. A device according to any one of claims 3 and 4, characterized in that the burners of the furnace are connected through an additional intermediate tank to the liquid sump tank, while the bottom of the sump is connected to the discharge chamber of the solid phase through a water drain pipe and the lid of the sump is connected to the condenser . 6. The device according to any one of claims 3 to 5, characterized in that the condenser is equipped with an exhaust fan, which is configured to create negative pressure in the reactor and supply gaseous non-condensable decomposition products of the tires for combustion. 7. The device according to any one of claims 3 to 6, characterized in that the loading conveyor is made of chain and equipped with hooks for gripping the tires, and the unloading conveyor is made of tape and equipped with a magnetic separator.

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