CN112146110A

CN112146110A - Operation method of waste tire pyrolysis gas combustion kiln

Info

Publication number: CN112146110A
Application number: CN202011068251.5A
Authority: CN
Inventors: 杨松
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-08
Filing date: 2020-10-08
Publication date: 2020-12-29

Abstract

The invention relates to the technical field of environmental protection, in particular to an operation method of a waste tire pyrolysis gas combustion kiln. The method is characterized in that: because the enthalpy value of the pyrolysis gas is changed greatly, natural gas with stable low calorific value is used as preheating fuel when the furnace is ignited, mixed gas of the natural gas and air is ignited through an ignition rod, at the moment, a flow control valve at the outlet end of a diffusion tube of a pyrolysis gas combustion kiln is opened ¼, a pyrolysis gas combustor is in a closed state, high-temperature flame flows into the furnace through a burner, the temperature of a combustion chamber begins to rise, after a flame stabilizing wall and a gas distribution wall in the combustion chamber reach the designed ignition temperature of the pyrolysis gas of 400-450 ℃, a waste gas turbine runs at full load and drives a gas compressor turbine to convey compressed air to the pyrolysis gas combustor through a planetary speed increaser, the pyrolysis gas is sprayed out through a gas bag assembly, mixed with the air, then is intensively rotated and disturbed through a swirl disc to realize uniform mixing and then is conveyed to the burner, and the flame.

Description

Operation method of waste tire pyrolysis gas combustion kiln

Technical Field

The invention relates to the technical field of environmental protection, in particular to an operation method of a waste tire pyrolysis gas combustion kiln.

Background

Waste tires are common solid waste pollutants, people recycle the waste tires through a plurality of ways to realize harmless treatment, wherein the preparation of fuel oil and carbon black through pyrolysis of the waste tires is one of the solutions, and pyrolysis gas of one of byproducts of the preparation of the fuel oil and the carbon black through pyrolysis of the waste tires is good gas fuel and can provide heat energy required by pyrolysis reaction of the waste tires. The Chinese invention patent (patent application number 200610114090.2, with the name of a method for continuously pyrolyzing waste tires by using a gas furnace) discloses a method for continuously pyrolyzing waste tires by using a gas furnace, which is characterized by comprising the following steps: (1) cleaning and airing the waste tire, and then simply cutting the waste tire in the radial direction; the common trolley tire does not need to be cut; (2) putting the waste tire treated in the step (1) into a pyrolysis container (303), and adding a catalyst into the pyrolysis container (303) at the same time; the pyrolysis container (303) is placed on a push plate (103) and pushed into a furnace body (105) through a feeding sealed cabin (102) by a hydraulic pushing device (101); (3) the hearth (302) is sealed by sealed cabins (102, 106) at two ends and is kept in a micro-negative pressure state, a pyrolysis container (303) moves on a roller rod (104) under the pushing of a subsequent push plate along with the placed push plate, and is pushed out of the discharging sealed cabin (106) by a hydraulic pushing device (101) after being preheated by a preheating section (201), pyrolyzed by a pyrolyzing section (202) and cooled by a cooling section (203), wherein the preheating temperature of the preheating section (201) is 80-250 ℃, the pyrolyzing temperature of the pyrolyzing section (202) is 250-550 ℃, and the cooling temperature of the cooling section (203) is 550-100 ℃; the pyrolysis time, namely the retention time, is 1-4 hours; (4) an air inducing device at the top of the kiln at the pyrolysis section pumps out gaseous products generated by pyrolysis, liquid and gaseous products are obtained through a condenser, the liquid is mixed fuel oil, oil products such as fractionated gasoline and diesel oil can be continuously processed, and non-condensable gaseous products are returned to the kiln to be combusted to serve as heat sources; (5) the residual pyrolytic carbon residue in the pyrolysis container after pyrolysis is discharged after the temperature is reduced to below 100 ℃ through a cooling section, and the pyrolytic carbon residue can be used for preparing carbon black filler or activated to prepare activated carbon. The Chinese invention patent (patent application number 201310387596.0, the patent name is a waste tire cracking gas recycling device) discloses a waste tire cracking gas recycling device, which is characterized in that: including firing burning furnace, pyrolysis furnace, connecting pipe, be connected with gas collection device and gas purifier behind the pyrolysis furnace, its characterized in that: the gas collecting device comprises a gas storage tank and a buffer tank, wherein a gas inlet of the gas storage tank is connected with the cracking furnace, and a gas outlet of the gas storage tank is connected with an external discharge device and a gas purifying device through a tee joint; the back of the gas purification device is connected with a full-pressure fan and a buffer tank; the gas outlet of the buffer tank is connected with the combustion furnace; the fuel gas recycling device also comprises an electronic control device arranged in the full-pressure fan of the gas storage tank and the buffer tank; the electronic control device comprises a PLC controller and a touch pad input device; the PLC is connected with the gas liquid level measuring meter, the pressure detecting meter and the electromagnetic control valve; the fuel gas liquid level measuring meter is one of a servo liquid level meter, a radar liquid level meter or a double-flange liquid level meter; the buffer tank is a constant-pressure buffer tank, and a fuel gas liquid level gauge and a pressure gauge are arranged in the constant-pressure buffer tank; a low-pressure alarm device is arranged on the constant-pressure buffer tank; the gas purification device comprises a desulfurization device and a dust removal and dehumidification device; the desulfurization device is a desulfurization tower adopting wet desulfurization, and lime slurry in the desulfurization tower is used as a desulfurizing agent for desulfurization.

In the prior art, a technical scheme that a non-condensable gaseous product (pyrolysis gas) obtained by pyrolyzing waste tires is returned to a kiln to be combusted to serve as a heat source is provided, but details of a pyrolysis gas combustion device are not disclosed; in the second prior art, a pyrolysis gas collecting device obtained by pyrolyzing waste tires is provided, which comprises a gas storage tank and a buffer tank, and details of a pyrolysis gas combustion device are not disclosed.

Disclosure of Invention

Aiming at the problems, the invention aims to provide an operation method of a waste tire pyrolysis gas combustion kiln, which is characterized by comprising the following steps:

firstly, because the enthalpy value of the pyrolysis gas is changed greatly, natural gas with stable low calorific value is adopted as a preheating fuel when igniting the furnace, a mixed gas of the natural gas and air is ignited by an ignition rod, at the moment, a flow control valve at the outlet end of a diffusion pipe of a pyrolysis gas combustion kiln is opened ¼, a pyrolysis gas combustor is in a closed state, high-temperature flame flows into the furnace through a burner, a combustion chamber starts to be heated, high-temperature flue gas directly flows into a waste gas turbine of a waste gas turbine pressurization system through a temperature regulating chamber, the waste gas turbine starts a heat engine and starts low-load operation, after a flame stabilizing wall and a gas distribution wall in the combustion chamber reach the designed ignition temperature of the pyrolysis gas of 400-450 ℃, the flow control valve at the outlet end of the diffusion pipe of the pyrolysis gas combustion kiln is completely opened, the waste gas turbine runs in full load and drives the permeation gas to horizontally convey compressed air to the pyrolysis gas combustor through a planetary speed increaser, the pyrolysis gas is sprayed, the shape of the flame is adjusted by the flame stabilizing wall to realize the continuous and stable combustion of the pyrolysis gas, the high-temperature flue gas flow field of the combustion chamber is uniformly distributed by the gas distribution wall, and then the high-temperature flue gas flow field is conveyed to the vertical pyrolysis tower body and the rotary harrow roller to start working through the nozzle, the throat pipe and the diffusion pipe.

Step two, the high-temperature flue gas output by the pyrolysis gas combustion kiln is subjected to heat exchange through a vertical pyrolysis tower body and a rotary rake roller, the oxygen content of the discharged waste gas is reduced to be below 3%, the temperature is 410-420 ℃, the absolute pressure is 105kPa, the waste gas enters a stationary blade grid through a waste gas inlet shell and an air inlet cone, the waste gas expands in a nozzle in a stationary blade flow passage of the stationary blade grid to convert heat energy and pressure energy into kinetic energy, the flow velocity of the waste gas is correspondingly increased, the waste gas is sprayed to movable blades from the stationary blade at a high speed and in a 16-18-degree-angle direction of the inclination angle of the center line of the nozzle flow passage, in a movable blade flow passage of a movable blade wheel, the waste gas flows along the blade root in a-18-20-degree-angle direction, the flow direction of the flow passage is continuously changed along the shape of the flow passage, and the movable blade inevitably generates circumferential component force to push the movable blade wheel, the component force of the movable blade in the axial direction is borne by an axial thrust bearing of the bearing box, so that overlarge axial displacement is avoided, in order to improve the efficiency of converting the thermal potential energy of the waste gas into mechanical work on the rotor assembly, the section of a waste gas through flow channel formed by the waste gas inlet shell, the gas inlet cone, the transition shell and the movable blade shroud is in a Venturi tube form which is gradually reduced and then gradually enlarged, and in order to prevent the waste gas turbine from stalling and surging, the back pressure of the outlet shell is kept at 50-55 kPa absolute pressure.

And step three, designing a performance curve of the compression turbine according to an intake flow value of 1.3-1.5 times, accelerating the rotating speed output by a rotor assembly of the exhaust gas turbine through a planetary speed increaser, so that the rotating speed of a compression turbine of the compression turbine is increased to 3000-7500 r/min, the compression turbine always works in a large-flow stable working condition area, an output shaft of the planetary speed increaser drives the compression turbine to suck air from an air inlet channel, the air radially enters a diffuser channel at a high speed through centrifugal force, airflow is decelerated in the diffuser, kinetic energy is converted into pressure energy, the air is pressurized and enters a pyrolysis gas combustor through an outlet of a compression volute, and a blower required by premixed air conveyed by the pyrolysis gas combustor is replaced.

Fourthly, the steam with the working pressure of 0.35-0.4 MPa is accelerated in the Laval nozzle to form supersonic jet flow, the steam passes through a mixing chamber between an outlet of the nozzle and an inlet of a diffuser pipe, a negative pressure area appears due to the high speed of the steam flow, so that the exhaust gas discharged by a waste gas turbine is ejected, the outlet pressure of the exhaust gas is reduced to 50-55 kPa, the pressure difference between an inlet and an outlet of the waste gas turbine reaches 52-57 kPa, a movable impeller can reliably work, the ejected exhaust gas is sucked into the mixing chamber to be mixed with the working steam, then a single uniform mixed fluid is gradually formed, the mixed fluid is decelerated and compressed to a certain back pressure through the diffuser pipe and then discharged, and the compression stage of the mixed fluid is that two fluids in the diffuser pipe continue to exchange energy while being gradually compressed, the kinetic energy is converted into pressure energy, and the mixed fluid is discharged out of a steam jet pump, so that the steam jet pump can regulate the mixed gas and the source gas of the pyrolysis gas combustion kiln according to the requirements of Different pressure mixed fluids are saved, the mixed fluids are collected and sent into an expansion tank, one path of inert tail gas conveyed out by the expansion tank can be directly used as mixed gas for a heat supply and gas decomposition burner, and the other path of inert tail gas is condensed and then used as cold source gas for a heat supply and gas decomposition combustion kiln.

And fifthly, a flow sensor is connected to the outlet of the compression volute to monitor the output air flow, the air flow is ensured to fall in a stable working area of a compression turbine performance curve, the air flow output by the compression turbine is 1.3-1.5 times of the designed air flow limit value of the pyrolysis gas combustor, and the lower calorific value of the mixed pyrolysis gas is 17-54 MJ/Nm³The variation range is large, and the air flow of the part needs to be shunted by the emptying valve according to the variation of the low-level heat value of the input pyrolysis gasThe feeding air flow sensor and the discharged tail gas oxygen content sensor feed value are calculated to calculate a control value and transmit the control value to the servo motor, the servo motor drives the vent valve, the vent valve comprises a valve rod assembly and an arc valve plate, the servo motor drives the arc valve plate to rotate through the valve rod assembly, the arc valve plate enlarges the flow area of the auxiliary air chamber and reduces the flow area of the main air chamber at the same time, part of air conveyed by the compression turbine is vented through the auxiliary air chamber, therefore, the air quantity required by the premixing of the air delivery pipe is obtained through the adjustment of the vent valve, the working pressure of compressed air input by the compression turbine is 112-118 kPa, the air bag assembly is coaxial with the air delivery pipe, the pyrolysis gas is sprayed out through the air bag assembly and mixed with the air, the uniform mixing is realized through the strong rotary disturbance of the rotary flow disc, the working pressure of inert tail gas output by the expansion tank is 112-118 kPa, the temperature is, the inert tail gas is diffused by a secondary air volute body to be fully mixed with the pyrolysis gas and the air, the excess air coefficient is adjusted while part of heat energy is recycled, and NO is reduced_XAnd (4) pollutant discharge.

The inventor finds that the tire consists of an outer tire, an inner tire and a cushion belt, the outer tire consists of three main parts, namely a tire body, a tire tread and a tire bead, the tire body is formed by attaching a plurality of layers of rubberized cord fabrics according to a certain angle, and the cord fabrics are usually made of high-strength steel wires and synthetic fiber rubberized fabrics; the tread contacts with the ground and is made of heat-resistant and shear-resistant rubber materials; the tyre bead is used for tightly fixing the tyre on a wheel rim, and mainly comprises a steel wire ring, triangular filling rubber and steel wire ring wrapping cloth. The pneumatic tire can be classified into a car tire, a truck tire, an agricultural tire, an engineering tire, a special vehicle tire, an aircraft tire, a motorcycle tire and a bicycle tire according to the application of the pneumatic tire, and the recycled waste tire is generally a car tire, a truck tire, an agricultural tire, a motorcycle tire and a bicycle tire, and the structure of the waste tire is generally an oblique tire and a radial tire. The recovered waste tires are used for building fillers, highway fillers, regenerated rubber preparation, fuel oil and carbon black preparation by pyrolysis and the like.

The inventor finds that the waste tire pyrolysis mainly aims at recovering pyrolysis oil and pyrolysis carbon to further prepare products such as fuel oil, carbon black and the like, and the pyrolysis gas is mainly usedThe product is uneconomical undoubtedly, because the pyrolysis oil chain hydrocarbon with larger molecular weight can be cracked to generate pyrolysis gas mainly containing methane, ethane, ethylene, propylene and other components with smaller molecular weight only by increasing the yield of the pyrolysis gas (550-600 ℃), a part of energy is wasted on damaging a molecular chain due to the higher pyrolysis temperature, and the pyrolysis gas generated by degrading the pyrolysis oil is flammable and explosive and is difficult to store and transport; in order to reduce the manufacturing cost of the pyrolysis reaction furnace and meet the requirements of mechanical processing, Q345R steel is selected as a furnace body material, the allowable stress requirement of the Q345R steel at high temperature is considered, namely the steel is used at the temperature of not more than 475 ℃, the comprehensive consideration of the factors is taken, the pyrolysis process temperature of the waste tires is designed to be 350-400 ℃, the heat source for pyrolyzing the waste tires is high-temperature flue gas generated by recycling pyrolysis gas, the pyrolysis gas is non-condensable combustible gas after pyrolysis oil is condensed at normal temperature, and the low-grade heat value is 17-54 MJ/Nm³. Due to the requirements of heat transfer efficiency and heat transfer temperature difference, the temperature of flue gas from the outlet of the waste tire pyrolysis gas combustion kiln to the jacket of the vertical pyrolysis tower body and the inlet of the rotary rake roller is controlled to be 550-560 ℃, the temperature of flue gas after heat exchange of the vertical pyrolysis tower body and the rotary rake roller is 410-420 ℃, and the average temperature difference of heat transfer is 140 ℃, so that the pyrolysis gas combustion kiln can regulate and control the temperature of high-temperature flue gas generated by pyrolysis gas combustion, a cold source is required to be introduced to be mixed with the high-temperature flue gas, and the temperature required by a pyrolysis process is achieved by regulating the component ratio of.

The inventor finds that high-temperature flue gas generated by pyrolysis gas combustion of a pyrolysis gas combustion kiln provides a heat source for pyrolysis of waste tires, a burner is a key device of the pyrolysis gas combustion kiln, the glue content of the waste tires is greatly different, the heat value of the pyrolysis gas of the waste tires is greatly different, and the range of the low-level heat value of the pyrolysis gas is 17-54 MJ/Nm³The range of adjusting the thermal load output by the burner is also large, and in order to ensure the necessary thermal strength of the hearth, the burner needs to realize continuous and stable combustion, have flame with certain shape and length and stable without extinguishing, avoid backfire and fire dropping, have small excess air coefficient, and reduce NO_XThe design requirements of pollutant discharge and the like are met, so the advantages of premixed type and diffusion type are absorbed, and primary air intake adoptsThe air and fuel gas are premixed, the oxygen content of the combustion air is adjusted by adding inert tail gas into the secondary air, and in a word, the premixed type and the diffusion type are serially connected to adjust the mixing ratio of the pyrolysis gas, the air and the inert tail gas through the secondary air to meet the design requirements.

The inventor finds that in the waste tire pyrolysis process, the requirements of material balance, water (steam) balance and energy balance and the total targets of saving energy, reducing emission and recycling, the oxygen content of the exhaust gas after the high-temperature flue gas output by the pyrolysis gas combustion kiln is subjected to heat exchange through the vertical pyrolysis tower body and the rotary rake roller is reduced to be less than 3%, the temperature is 410-420 ℃, the pressure bearing of the rotary rake roller under the dynamic seal high-temperature working condition is limited, and the designed absolute pressure is not more than 105kPa, so that the pressure index of the exhaust gas is lower than the pressure requirements of a secondary air inlet of a combustor and a cold source at an inlet of the pyrolysis gas combustion kiln of 112-118 kPa, and the exhaust gas cannot be directly recycled. According to the operating principle of turbocharging, considering that the pressure of the discharged waste gas is low, selecting an axial air inlet and vertical upward exhaust mode with small pressure loss at the air inlet end, and using a cantilever type rotor structure, the discharged waste gas is expanded through a static blade grid and a movable blade wheel to do work, the heat energy is converted into mechanical energy for rotating the movable blade wheel, the movable blade wheel drives a planetary speed increaser to drive the air turbine, the air turbine pumps the air to pressurize and enter a combustor, a blower required by premixed air conveyed by the combustor is replaced, but the absolute pressure of an inlet of the discharged waste gas is 105kPa, an outlet of the discharged waste gas is directly communicated with a chimney, namely, the backpressure of a waste gas turbine is 101 kPa, the pressure difference of the inlet and the outlet is not enough to overcome the pressure loss of a flow passage of the static blade grid and the movable blade wheel to cause the rotation, the outlet pressure of the discharged waste gas is reduced to 50-55 kPa, the pressure difference between the inlet and the outlet of the waste gas turbine reaches 52-57 kPa, and the movable impeller can work reliably. The steam source of the steam jet pump is saturated steam generated by condensation of pyrolysis oil, the pressure is 0.35-0.4 MPa, the exhaust gas and steam mixed gas at the outlet of the steam jet pump are sent to an expansion tank, non-condensable gas in the expansion tank is inert tail gas, the inert tail gas has three purposes, one of the inert tail gas serves as a cold source for adjusting the temperature of the pyrolysis gas combustion kiln, the other inert tail gas serves as an air source for adjusting the coefficient of excess air of a pyrolysis gas combustor, and the third inert tail gas serves as inert protective gas required by purging of a middle-section bell jar storage bin.

The inventor finds that the temperature of pyrolysis oil produced by a waste tire pyrolysis reaction furnace is 350-400 ℃, the pyrolysis oil needs to be condensed and fractionated and then is utilized, the condensation is generally realized through a dividing wall type heat exchanger, a cold source generally selects cooling water, the cooling water absorbs heat energy and converts the heat energy into steam, the steam with different qualities generated by multistage condensation is utilized, the steam can be used as a working fluid source with different pressure levels in a multistage steam ejector (pump) and can also be used as cooling steam of an exhaust turbine, and the total targets of material balance, water (steam) balance and energy balance in the waste tire pyrolysis process are achieved, and the total targets of energy conservation, emission reduction and cyclic utilization are achieved.

The inventor finds that the left side of a stable working condition area of the gas turbine is a surge working condition area, when the air flow introduced from an air inlet channel is lower than a surge boundary, the air flow in the area is strongly pulsed and periodically vibrated, the gas turbine is severely vibrated, the dynamic stress of the gas turbine is greatly increased, the noise is increased, the right side of the stable working condition area of the gas turbine is a blocking working condition area, the air flow speed on the narrowest section of the gas turbine and a diffuser blade channel reaches the sound speed, and the flow cannot be increased. The exhaust gas turbine has a large variation range of the inlet flow of the exhaust gas due to the influence of the enthalpy value of the pyrolysis gas, the variation range of the rotating speed output by the rotor assembly is large, the gas turbine is difficult to keep working in a stable working condition area, the structure of the rotatable inlet guide vane adjustment, the rotatable diffuser blade adjustment and the like is complex and limited in effect, the gas turbine can design a performance curve according to the 1.3-1.5 times of the inlet flow value, namely the exhaust gas turbine is driven by a planetary speed increaser, the rotating speed of the gas turbine is improved, so that the gas turbine always works in a large-flow stable working condition area, if a combustor needs small-flow air, a venting method can be adopted, namely a flow sensor and an anti-surge venting valve are connected at the outlet of a gas compression volute, the venting valve is driven by a servo motor, a signal is transmitted to the servo.

The inventor finds that steam with the working pressure of 0.35-0.4 MPa is accelerated in a Laval nozzle to form supersonic jet flow, the steam passes through a mixing chamber between an outlet of the nozzle and an inlet of a diffuser pipe, a negative pressure area appears due to the fact that the steam flow is at high speed, exhaust gas of an exhaust gas turbine is ejected, the outlet pressure of the exhaust gas is reduced to 50-55 kPa, the pressure difference between an inlet and an outlet of the exhaust gas turbine reaches 52-57 kPa, and a movable impeller can work reliably. The ejected exhaust gas is sucked into the mixing chamber to be mixed with the working steam, then a single uniform mixed fluid is gradually formed, the mixed fluid is compressed to a certain back pressure through the diffuser pipe in a speed reducing mode and then is discharged, and the compression stage of the mixed fluid is that two streams of fluid in the diffuser pipe continue to exchange energy and gradually compress at the same time, the kinetic energy is converted into pressure energy, and the mixed fluid is discharged out of the steam jet pump. Therefore, the steam jet pump can adjust different pressure mixed fluids according to the requirements of the mixed gas of the pyrolysis gas burner and the cold source gas of the pyrolysis gas combustion kiln, the mixed fluids are collected and sent into the expansion tank, one path of inert tail gas conveyed by the expansion tank can be directly used as the mixed gas for the pyrolysis burner, and the other path of inert tail gas is condensed and then used as the cold source gas for the pyrolysis gas combustion kiln.

The inventor finds that the outlet of the compression volute is connected with a flow sensor for monitoring the output air flow, the air flow is ensured to fall in a stable working area of a compression turbine performance curve, the air flow output by the compression turbine is 1.3-1.5 times of the design air flow limit value of a pyrolysis gas combustor, and the lower calorific value of the mixed pyrolysis gas is 17-54 MJ/Nm³The variable range is large, the variation of the low-level heat value of input pyrolysis gas is matched, partial air flow of the vent valve is required to be shunted, the control value is calculated by an input air flow sensor and the feedback value of an oxygen content sensor of exhaust tail gas and is transmitted to a servo motor, the vent valve is driven by the servo motor and comprises a valve rod assembly and an arc valve plate, the servo motor drives the arc valve plate to rotate through the valve rod assembly, the arc valve plate reduces the flow area of a main air chamber while enlarging the flow area of an auxiliary air chamber, partial air conveyed by a compression turbine is discharged through an auxiliary air chamber, and therefore the air quantity required by premixing of an air delivery pipe is obtained through the adjustment of the vent valve, the compressed air is compressedThe working pressure of compressed air input by a turbine is 112-118 kPa, an air bag assembly is coaxial with an air delivery pipe, pyrolysis gas is sprayed out through the air bag assembly to be mixed with air and then is uniformly mixed through strong rotation disturbance of a cyclone disc, the working pressure of inert tail gas output by an expansion tank is 112-118 kPa, the temperature is 200-250 ℃, the inert tail gas is fully mixed with the pyrolysis gas and the air through diffusion of a secondary air volute body according to the feedback value of an oxygen content sensor of the exhaust tail gas, the excess air coefficient is adjusted while part of heat energy is recovered, and NO is reduced_XAnd (4) pollutant discharge.

The inventor finds that the pyrolysis gas combustion kiln is divided into a combustion chamber and a temperature adjusting chamber, the combustion chamber and the temperature adjusting chamber are arranged in series, the combustion chamber comprises an ignition rod, a burner, a furnace shell, a flame stabilizing wall, a gas distribution wall and a nozzle, the flame stabilizing wall is built by refractory bricks, the heat storage effect is realized for keeping the temperature level of the hearth, the pyrolysis gas is continuously and stably combusted, the shape of the flame is set, the phenomenon that local cold and hot unevenness is caused by flame spread along the inner wall of the furnace shell from the burner is avoided, the gas distribution wall is built into a grid by the refractory bricks, the temperature field of the combustion chamber is kept stable as heat storage filler, the flame is continuously and stably combusted, the flow field distribution of the combustion chamber is also uniform, the opening ratio and the thickness of the gas distribution wall are adjusted to increase the pressure of the furnace shell and the nozzle, and the. The temperature adjusting chamber comprises a cold source inlet, a throat pipe and a diffusion pipe, according to the working principle of a jet pump, high-temperature flue gas which expands sharply after pyrolysis gas combustion is taken as a pressure working carrier and is sprayed into the throat pipe through a nozzle, inert tail gas of the cold source is sucked from the cold source inlet, the inert tail gas can be uniformly mixed with the high-temperature flue gas and then is sent into the diffusion pipe through the throat pipe, the cold source inlet is designed into a volute shape, the on-way resistance of the inert tail gas is reduced, the pyrolysis gas combustion kiln can obtain higher pressure ratio and flow ratio, and the high-efficiency area can work.

The inventor finds that because the enthalpy value of the pyrolysis gas is changed greatly, natural gas with stable low calorific value is used as preheating fuel when ignition is carried out, mixed gas of the natural gas and air is ignited through an ignition rod, at the moment, a flow control valve at the outlet end of a diffusion pipe of a pyrolysis gas combustion kiln is opened ¼, a pyrolysis gas combustor is in a closed state, high-temperature flame flows into the kiln through a burner, a combustion chamber starts to be heated, high-temperature flue gas directly flows into a waste gas turbine of a waste gas turbocharging system through a temperature adjusting chamber, the waste gas turbine starts a heat engine and starts low-load operation, after a flame stabilizing wall and a gas distribution wall in the combustion chamber reach the designed ignition temperature of the pyrolysis gas of 400-450 ℃, the flow control valve at the outlet end of the diffusion pipe of the pyrolysis gas combustion kiln is completely opened, the waste gas turbine runs in full load, the permeation gas is driven by a planetary speed increaser to convey compressed air to the pyrolysis gas combustor, the pyrolysis The shape of the flame is adjusted by the flame stabilizing wall to realize the continuous and stable combustion of the pyrolysis gas, the high-temperature flue gas flow field of the combustion chamber is uniformly distributed by the gas distribution wall, and then the high-temperature flue gas flow field is conveyed to the vertical pyrolysis tower body and the rotary harrow roller to start working through the nozzle, the throat pipe and the diffusion pipe.

Compared with the prior art, the invention at least has the following advantages: firstly, the change range of the inlet flow of the waste gas is large due to the influence of the enthalpy value of the pyrolysis gas, the change range of the rotating speed output by a rotor assembly is also large, the gas turbine is difficult to keep working in a stable working condition area, the structure is complex and the effect is limited due to the adoption of rotatable inlet guide vane adjustment, rotatable diffuser blade adjustment and the like, the gas turbine can design a performance curve according to the inlet flow value of 1.3-1.5 times, namely the waste gas turbine is driven by a planetary speed increaser, the rotating speed of the gas turbine is improved, so that the gas turbine always works in a large-flow stable working condition area, if a combustor needs small-flow air, a venting method can be adopted, namely a flow sensor and an anti-surge venting valve are connected to the outlet of a gas compression volute, the venting valve is driven by a servo motor, a signal is transmitted to the servo motor by; secondly, the exhaust gas turbine selects an axial air inlet mode with small pressure loss at an air inlet end and a vertical upward air exhaust mode, a cantilever type rotor structure is adopted, the exhausted exhaust gas is expanded through a static blade grid and a movable impeller to do work, heat energy is converted into mechanical energy for rotating the movable impeller, the movable impeller drives a planetary speed increaser to drive the air turbine, and the air turbine pressurizes and pressurizes air to enter a combustor, so that a blower required by premixed air conveyed by the combustor is replaced; thirdly, according to the working principle of the jet pump, high-temperature flue gas which expands sharply after pyrolysis gas combustion is taken as a pressure working carrier and is sprayed into the throat pipe through the nozzle, cold source inert tail gas is sucked from a cold source inlet, the inert tail gas can be uniformly mixed with the high-temperature flue gas and then is sent into the diffusion pipe through the throat pipe, the cold source inlet is designed into a volute shape, the on-way resistance of the inert tail gas is reduced, and the pyrolysis gas combustion kiln furnace can obtain higher pressure ratio and flow ratio and can work in a high-efficiency area.

Drawings

Fig. 1 is a schematic structural view of a front view of an operation method of a waste tire pyrolysis gas combustion kiln.

Fig. 2 is a partial enlarged structural schematic diagram of a part a of the operation method of the waste tire pyrolysis gas combustion kiln.

Fig. 3 is a partial enlarged structural schematic diagram of a B operation method of the junked tire pyrolysis gas combustion kiln of the present invention.

Fig. 4 is a schematic view of the structure of the direction C of the operation method of the waste tire pyrolysis gas combustion kiln.

Fig. 5 is a schematic structural diagram of a large sample D of the operation method of the waste tire pyrolysis gas combustion kiln.

Fig. 6 is a schematic structural diagram of a large sample E of the operation method of the waste tire pyrolysis gas combustion kiln.

Fig. 7 is a schematic structural diagram of a large sample F of the operation method of the waste tire pyrolysis gas combustion kiln.

Fig. 8 is a partial enlarged structural schematic diagram of G of the operation method of the waste tire pyrolysis gas combustion kiln of the invention.

Fig. 9 is a schematic view of the arrangement structure of the H-H section of the operation method of the waste tire pyrolysis gas combustion kiln of the invention.

Fig. 10 is a schematic structural diagram of a large sample I of the operation method of the waste tire pyrolysis gas combustion kiln.

Fig. 11 is a schematic view of the arrangement structure of a J-J section of the operation method of the waste tire pyrolysis gas combustion kiln furnace of the invention.

Fig. 12 is a schematic view of the arrangement structure of the K-K section of the operation method of the waste tire pyrolysis gas combustion kiln furnace of the invention.

I-waste gas turbocharging system II-pyrolysis gas burner III-pyrolysis gas combustion kiln

1-compressor turbine 2-planet speed increaser 3-exhaust gas turbine 4-steam jet pump

5-expansion tank 6-waste gas inlet shell 7-air inlet cone 8-movable impeller cooling steam assembly

9-stationary blade cascade 10-movable impeller 11-rotor component 12-transition shell

13-moving blade shroud 14-outlet shell 15-bearing box 16-air inlet channel

17-compressor turbine 18-diffuser 19-compressor volute outlet 20-nozzle

21-mixing chamber 22-diffuser pipe 23-auxiliary air chamber 24-emptying valve 25-main air chamber

26-secondary air volute 27-servo motor 28-air transmission pipe 29-air bag assembly

30-cyclone disk 31-arc valve plate 32-valve rod assembly 33-ignition rod 34-burner

35-furnace shell 36-flame stabilizing wall 37-air distribution wall 38-nozzle 39-cold source inlet

40-throat pipe 41-diffusion pipe 42-combustion chamber 43-temperature adjusting chamber.

Detailed Description

The invention is further described with reference to the following detailed description of embodiments and drawings.

As shown in fig. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12, the method for operating a pyrolysis gas combustion kiln for junked tires is characterized in that:

firstly, because the enthalpy value of the pyrolysis gas is changed greatly, natural gas with stable low calorific value is used as preheating fuel when igniting the furnace, the mixed gas of the natural gas and air is ignited through an ignition rod 33, at the moment, a flow control valve at the outlet end of a diffusion pipe 41 of a pyrolysis gas combustion kiln III is opened ¼, a pyrolysis gas burner II is in a closed state, high-temperature flame flows into the furnace through a burner 34, a combustion chamber 42 starts to be heated, high-temperature flue gas directly flows into an exhaust gas turbine 3 of an exhaust gas turbine pressurization system I through a temperature adjusting chamber 43, the exhaust gas turbine 3 starts to heat up and starts to run at low load, a flame stabilizing wall 36 and a gas distribution wall 37 in the combustion chamber 42 reach the designed ignition temperature of the pyrolysis gas of 400-450 ℃, the flow control valve at the outlet end of the diffusion pipe 41 of the pyrolysis gas combustion kiln III is completely opened, the exhaust gas turbine 3 runs at full load and drives a gas compression turbine 1 to convey, the pyrolysis gas is sprayed out through the gas bag assembly 29 to be mixed with air, then is intensively rotated and disturbed through the cyclone disk 30 to be uniformly mixed and sent into the burner 34, the flame shape is adjusted through the flame stabilizing wall 36 to realize continuous and stable combustion of the pyrolysis gas, the high-temperature flue gas flow field of the combustion chamber 42 is uniformly distributed through the gas distribution wall 37, and then the pyrolysis gas is conveyed to the vertical pyrolysis tower body and the rotary harrow roller through the nozzle 38, the throat pipe 40 and the diffusion pipe 41 to start working.

Step two, the high-temperature flue gas output by the pyrolysis gas combustion kiln III is subjected to heat exchange by a vertical pyrolysis tower body and a rotary rake roller to discharge waste gas, the oxygen content is reduced to be below 3%, the temperature is 410-420 ℃, the absolute pressure is 105kPa, the waste gas enters a static blade grid 9 through a waste gas inlet shell 6 and an air inlet cone 7, the waste gas expands in a nozzle in a static blade flow channel of the static blade grid 9 to convert heat energy and pressure energy into kinetic energy, the flow velocity of the waste gas is correspondingly increased, the waste gas is sprayed to movable blades from the static blade at a high speed and in the direction of 16-18 degrees of inclination angle of the central line of the nozzle flow channel, in a movable blade flow channel of a movable blade wheel 10, the waste gas flow is bent at an attack angle of-18-20 degrees along the blade root, the flow direction of the movable blade continues to change along the shape of the flow channel, and the movable blade inevitably generates circumferential component force due to the, mechanical work is output through the rotor assembly 11, axial component force generated by the movable blades is borne by an axial thrust bearing of the bearing box 15, so that overlarge axial displacement is avoided, in order to improve the efficiency of converting thermal potential energy of waste gas into mechanical work on the rotor assembly 11, the section of a waste gas through flow passage formed by the waste gas inlet shell 6, the gas inlet cone 7, the transition shell 12 and the movable blade shroud 13 is in a Venturi tube form which is gradually reduced and then gradually enlarged, and in order to prevent the waste gas turbine 3 from stalling and surging, the back pressure of the outlet shell 14 is kept at 50-55 kPa.

And step three, because the compressor turbine 1 designs a performance curve according to an intake flow value of 1.3-1.5 times, the rotating speed output by a rotor assembly 11 of the exhaust gas turbine 3 is accelerated by the planetary speed increaser 2, so that the rotating speed of a compressor turbine 17 of the compressor turbine 1 is increased to 3000-7500 r/min, the compressor turbine 1 always works in a large-flow stable working condition area, an output shaft of the planetary speed increaser 2 drives the compressor turbine 17 to suck air from an air inlet channel 16, the air enters a diffuser 18 channel from the radial direction at high speed by centrifugal force, in the diffuser 18, airflow is decelerated, kinetic energy is converted into pressure energy, the air is pressurized and fed into a pyrolysis gas combustor II through a compressor volute outlet 19, and an air blower required by premixed air conveyed by the pyrolysis gas combustor II is replaced.

Fourthly, the steam with the working pressure of 0.35 to 0.4MPa is accelerated in the Laval nozzle 20 to form supersonic jet flow, the steam passes through a mixing chamber 21 between an outlet of the nozzle 20 and an inlet of a diffuser 22, a negative pressure area appears due to the high speed of the steam flow, so that the exhaust gas discharged by the exhaust gas turbine 3 is ejected, the outlet pressure of the exhaust gas is reduced to 50 to 55 kPa, the pressure difference between an inlet and an outlet of the exhaust gas turbine 3 reaches 52 to 57 kPa, the movable impeller 10 can reliably work, the ejected exhaust gas is sucked into the mixing chamber 21 to be mixed with the working steam, then a single uniform mixed fluid is gradually formed, the mixed fluid is decelerated and compressed to a certain back pressure through the diffuser 22 and then is discharged, and the compression stage of the mixed fluid is that two fluid in the diffuser 22 continuously carry out energy exchange and gradually compress at the same time, the kinetic energy is converted into pressure energy, and the mixed fluid is discharged out of the steam jet pump 4, therefore, the steam jet pump 4 can adjust different pressure mixed fluids according to the requirements of the pyrolysis gas burner II for mixing gas and the pyrolysis gas combustion kiln III for cold source gas, the mixed fluids are collected and sent into the expansion tank 5, one path of inert tail gas sent out by the expansion tank 5 can be directly used as the mixed gas for the pyrolysis gas burner II, and the other path of inert tail gas is condensed and then used as the cold source gas for the pyrolysis gas combustion kiln III.

Step five, a flow sensor is connected to the outlet 19 of the compression volute to monitor the output air flow, the air flow is ensured to fall in a stable working area of a performance curve of the compression turbine 1, the air flow output by the compression turbine 1 is 1.3-1.5 times of the limit value of the designed air flow of the pyrolysis gas combustor, and the mixed heat is proportionedThe low calorific value of the decomposed gas is 17-54 MJ/Nm³The variation range is large, the variation of the low-level heat value of input pyrolysis gas is matched, partial air flow is required to be shunted by the emptying valve, a control value calculated by the feedback value of an input air flow sensor and a discharged tail gas oxygen content sensor is transmitted to the servo motor 27, the servo motor 27 drives the emptying valve 24, the emptying valve 24 comprises a valve rod assembly 32 and an arc valve plate 31, the servo motor 27 drives the arc valve plate 31 to rotate through the valve rod assembly 32, the arc valve plate 31 enlarges the flow area of the auxiliary air chamber 23 and simultaneously reduces the flow area of the main air chamber 25, partial air conveyed by the compression turbine 1 is emptied through the auxiliary air chamber 23, therefore, the air quantity required by the air delivery pipe 28 is obtained through the adjustment of the emptying valve 24, the working pressure of compressed air input by the compression turbine 1 is 112-118 kPa, the air bag assembly 29 is coaxial with the air delivery pipe 28, the pyrolysis gas is sprayed out through the air bag assembly 29 and mixed with the air and then is intensively rotated, the working pressure of the inert tail gas output by the expansion tank 5 is 112-118 kPa, the temperature is 200-250 ℃, according to the feedback value of the oxygen content sensor of the exhaust tail gas, the inert tail gas is diffused by the secondary air volute body 26 to be fully mixed with the pyrolysis gas and the air, the excess air coefficient is adjusted while part of heat energy is recovered, and NO is reduced_XAnd (4) pollutant discharge.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. The operation method of the waste tire pyrolysis gas combustion kiln is characterized by comprising the following steps: firstly, because the enthalpy value of the pyrolysis gas is changed greatly, natural gas with stable low-grade heat value is adopted as preheating fuel when igniting the furnace, the mixed gas of the natural gas and air is ignited by an ignition rod, at the moment, a flow control valve at the outlet end of a diffusion tube of a pyrolysis gas combustion kiln is opened ¼,the pyrolysis gas burner is in a closed state, high-temperature flame flows into the furnace through the burner, the temperature of the combustion chamber begins to rise, high-temperature flue gas directly flows into a waste gas turbine of a waste gas turbocharging system through a temperature adjusting chamber, the waste gas turbine starts to heat up and starts low-load operation, after a flame stabilizing wall and a gas distribution wall in the combustion chamber reach the designed ignition temperature of pyrolysis gas of 400-450 ℃, a flow control valve at the outlet end of a diffusion pipe of a pyrolysis gas combustion kiln is completely opened, the waste gas turbine runs at full load, a planetary speed increaser drives a gas compressor to flatly convey compressed air to the pyrolysis gas burner, the pyrolysis gas is ejected through a gas bag assembly, mixed with air and then is intensively disturbed through a swirl disc to realize uniform mixing and conveying to the burner, the flame shape is adjusted through the flame stabilizing wall to realize continuous and stable combustion of the pyrolysis gas, the flow distribution of the high-temperature, The diffusion tube is conveyed to the vertical pyrolysis tower body and the rotary harrow roller to start working; step two, the pyrolysis gas combustion kiln outputs high-temperature flue gas, the oxygen content of the discharged waste gas is reduced to be below 3%, the temperature is 410-420 ℃, the absolute pressure is 105kPa, and the axial component force generated by the movable blades is borne by an axial thrust bearing of the bearing box so as to avoid generating overlarge axial displacement; driving a compressed air turbine to suck air from an air inlet channel by an output shaft of the planetary speed increaser, enabling the air to radially enter a diffuser channel at a high speed by centrifugal force, reducing the speed of air flow in the diffuser, converting kinetic energy into pressure energy, and pressing and conveying the air to enter a pyrolysis gas burner through an outlet of a compressed air volute so as to replace a blower required by premixed air conveyed by the pyrolysis gas burner; fourthly, the steam with the working pressure of 0.35-0.4 MPa is accelerated in a Laval nozzle to form supersonic jet flow, the steam passes through a mixing chamber between an outlet of the nozzle and an inlet of a diffuser pipe, a negative pressure area appears due to the high speed of the steam flow, so that the exhaust gas discharged by an exhaust gas turbine is ejected, the outlet pressure of the exhaust gas is reduced to 50-55 kPa, the pressure difference between an inlet and an outlet of the exhaust gas turbine reaches 52-57 kPa, a movable impeller can reliably work, the ejected exhaust gas is sucked to the mixing chamber to be mixed with the working steam, then a single uniform mixed fluid is gradually formed, and the single uniform mixed fluid is discharged after being subjected to deceleration compression to a certain back pressure through the diffuser pipe,the compression stage of the mixed fluid, namely, two streams of fluid in the diffuser pipe continue to exchange energy and gradually compress the fluid at the same time, the kinetic energy is converted into pressure energy, and the mixed fluid is discharged out of the steam jet pump; fifthly, the air bag assembly is coaxial with the air delivery pipe, the pyrolysis gas is sprayed out through the air bag assembly to be mixed with air, then uniform mixing is achieved through strong rotating disturbance of the spinning disk, the working pressure of inert tail gas output by the expansion tank is 112-118 kPa, the temperature is 200-250 ℃, according to the fed value of an exhaust tail gas oxygen content sensor, the inert tail gas is diffused through the secondary air volute body to be fully mixed with the pyrolysis gas and the air, the excess air coefficient is adjusted while part of heat energy is recycled, and NO is reduced_XAnd (4) pollutant discharge.

2. The method for operating a scrap tire pyrolysis gas combustion kiln according to claim 1, wherein the method comprises the following steps: waste gas enters the stationary blade cascade through the waste gas inlet shell and the air inlet cone, the waste gas expands in the nozzle in a stationary blade flow passage of the stationary blade cascade to convert heat energy and pressure energy into kinetic energy, the flow velocity of the waste gas is correspondingly increased, the waste gas is sprayed to movable blades from the stationary blade at a high speed and in the direction of 16-18 degrees of inclination angle of the central line of the nozzle flow passage, the waste gas flow is bent along the movable blade root in the direction of-18-20 degrees of attack angle in the movable blade flow passage of the movable blade wheel, the flow direction of the waste gas is continuously changed along the shape of the flow passage, and the movable blades inevitably generate circumferential component force due to the turning of the gas flow, so that the movable blade wheel is pushed to continuously rotate, and mechanical work.

3. The method for operating a scrap tire pyrolysis gas combustion kiln according to claim 1, wherein the method comprises the following steps: in order to improve the efficiency of converting the thermal potential energy of the waste gas into mechanical work on the rotor assembly, the section of a waste gas through flow channel formed by the waste gas inlet shell, the gas inlet cone, the transition shell and the movable blade shroud is in a Venturi tube form which is gradually reduced and then gradually enlarged, and in order to prevent the waste gas turbine from stalling and surging, the back pressure of the outlet shell is kept at 50-55 kPa absolute pressure.

4. The method for operating a scrap tire pyrolysis gas combustion kiln according to claim 1, wherein the method comprises the following steps: because the performance curve of the compressor turbine is designed according to the intake flow value of 1.3-1.5 times, the rotating speed output by the rotor assembly of the exhaust gas turbine is accelerated by the planetary speed increaser, so that the rotating speed of the compressor turbine is increased to 3000-7500 r/min, and the compressor turbine always works in a large-flow stable working condition area.

5. The method for operating a scrap tire pyrolysis gas combustion kiln according to claim 1, wherein the method comprises the following steps: the steam jet pump can adjust different pressure mixed fluid according to the requirement of pyrolysis gas combustor mixed gas and pyrolysis gas burning kiln stove cold source gas, collects the mixed fluid and sends into the expansion tank, and the inert tail gas that the expansion tank carried out can directly supply heat to the gas burning ware and use as mixed gas all the way, and the heat is supplied to the gas burning kiln stove and is used as cold source gas after another way condensation.

6. The method for operating a scrap tire pyrolysis gas combustion kiln according to claim 1, wherein the method comprises the following steps: the outlet of the compression volute is connected with a flow sensor for monitoring the output air flow, the air flow is ensured to fall in a stable working area of a compression turbine performance curve, the air flow output by the compression turbine is 1.3-1.5 times of the limit value of the designed air flow of the pyrolysis gas combustor, and the lower calorific value of the mixed pyrolysis gas is 17-54 MJ/Nm³The variation range is large, the air flow of a part needs to be shunted by the emptying valve in accordance with the variation of the low-level heat value of the input pyrolysis gas, the feedback values of the input air flow sensor and the exhaust tail gas oxygen content sensor are used for calculating a control value and transmitting the control value to the servo motor, and the servo motor drives the emptying valve.

7. The method for operating a scrap tire pyrolysis gas combustion kiln according to claim 1, wherein the method comprises the following steps: the emptying valve comprises a valve rod assembly and an arc valve plate, the servo motor drives the arc valve plate to rotate through the valve rod assembly, the arc valve plate reduces the flow area of the main air chamber while expanding the flow area of the auxiliary air chamber, part of air conveyed by the compression turbine is emptied through the auxiliary air chamber, therefore, the air quantity required by premixing of the air delivery pipe is obtained through adjustment of the emptying valve, and the working pressure of compressed air input by the compression turbine is 112-118 kPa.