CN111394136B - Transport bed coal water slurry pyrolysis reaction device - Google Patents

Abstract

The utility model provides a transport bed coal slurry pyrolytic reaction device, includes: the system comprises a transport bed pyrolysis reaction device body, a spray gun for spraying coal water slurry and an ignition device for system ignition, which are arranged in the transport bed pyrolysis reaction device body, a gas-solid separation device and a material return device which are connected with the transport bed pyrolysis reaction device body, and a combustion-supporting air inlet which is arranged on the transport bed pyrolysis reaction device body and is used for providing combustion-supporting air; the reaction device is divided into a combustion area and a pyrolysis area, the coal water slurry can be pyrolyzed by setting reasonable residence time of the combustion area and the pyrolysis area and utilizing self combustion of fuel, and the higher gas yield of the coal water slurry pyrolysis is ensured by controlling the oxygen content in flue gas and adopting an anti-oxidation spray gun; meanwhile, the invention can also adopt the recirculated flue gas as the combustion-supporting gas, realize returning to the partial heat recovery of the system while facilitating to control oxygen amount; the gas-solid separation device is arranged at the outlet of the pyrolysis reaction device, so that the coke which is not burnt out is separated and returned to the pyrolysis device for continuous combustion, the heat utilization maximization is realized, and the energy consumption of the whole system is reduced. The device has the advantages of simple structure, scientific and reasonable structure, reliable work and long effective service life, and can meet the use requirement of conveniently providing the coal water slurry pyrolysis gas as the reducing gas in the low-nitrogen combustion transformation.

Description

Transport bed coal water slurry pyrolysis reaction device

technical field

The invention relates to a technology in the field of environmental protection, in particular to a transport bed coal-water slurry pyrolysis reaction device.

Background technique

At present, China's environmental protection department has put forward a minimum standard requirement for the concentration of nitrogen oxides contained in the exhaust gas of power boilers to be less than 50mg/Nm ³ . technological transformation methods to deal with it. At present, it is more commonly used to spray ammonia reducing agents such as urea and ammonia into the flue gas to be discharged in the tail flue of the boiler, so that it can be mixed with the flue gas and reduce part of the NOx nitrogen oxides, thereby reducing the amount of exhausted smoke. The method of NOx concentration in the air is realized. Although it has achieved certain results, there are problems such as the limitation of the reaction temperature window, serious ammonia escape, high investment and operating costs, and serious secondary pollution of the catalyst. Therefore, it is not ideal from the perspective of economy, practicability, and boiler low-nitrogen emission compliance. . However, the commonly used fuel-type reducing gases such as natural gas, coke oven gas, blast furnace gas and other gases are restricted by regions in application, and most boiler factories lack gas sources. Coal-water slurry pyrolysis gas contains a large amount of active reducing components (such as CH ₄ , H ₂ , CO, etc.) and can be used as a reducing agent to reduce nitrogen oxides in flue gas. Restricted by the origin of the reducing agent, it has attracted widespread attention from scholars. However, in industrial applications, pyrolysis devices are mostly used for pyrolysis of solid fuels (such as coal powder, biomass, etc.) The existing equipment for the pyrolysis of coal-based solid-liquid mixed fuel such as coal slurry cannot meet the requirements. Therefore, the current industrial application of coal-water slurry pyrolysis gas as a reducing agent has not been promoted. It is of great practical significance to develop a pyrolysis device suitable for coal-water slurry as raw material to promote the development of low-nitrogen combustion technology.

Contents of the invention

The purpose of the present invention is to overcome the technical problem that the coal-water slurry pyrolysis device encountered in the development of low-nitrogen combustion technology is not applicable, and propose a transport bed coal-water slurry pyrolysis reaction device, which can realize high-efficiency pyrolysis of coal-water slurry, Maintain high gas production rate and reduce production energy consumption.

The present invention is achieved through the following technical solutions:

The present invention includes: a transport bed pyrolysis reaction device body, a coal-water slurry spray gun arranged in the transport bed pyrolysis reaction device body, an ignition device for system ignition, a combustion-supporting air inlet for providing combustion-supporting air, and a transport bed. The gas-solid separation device and the feeding device connected to the main body of the bed pyrolysis reaction device.

The main body of the transport bed pyrolysis reaction device is cylindrical, and its outer shell is made of heat-resistant metal material, and the interior includes a pyrolysis section for coal-water slurry pyrolysis gasification reaction connected in sequence by split flanges, The combustion section and the ash section used for fuel combustion to provide heat for the entire device, among which: the lining of the combustion section and the pyrolysis section is made of refractory materials, and the inner lining uses 1500-2000 external threaded top belt wires per square meter The claw nails of the button are fixed to improve the high temperature resistance strength, and several manholes are set along the height direction for observing the reaction in the furnace and the pressure relief of the device; The outlet of the circulating flue gas and the return device are connected; several coal-water slurry spray guns are symmetrically arranged on both sides of the pyrolysis section, and their outlets are connected with the inlet of the gas-solid separation device for pyrolysis gas purification and material circulation; The bottom of the slag section is provided with an ash discharge port, and the ash and slag section is arranged in a cone shape.

The upper outlet of the gas-solid separation device is connected to the pyrolysis gas pipeline for transporting the purified pyrolysis gas from the body of the transport bed pyrolysis reaction device, and the lower outlet of the gas-solid separation device is connected to the inlet of the feeding device. The interior of the solid separation device is equipped with an axially offset central cylinder with high separation efficiency. The axially offset central cylinder is made of heat-resistant and wear-resistant materials, and its lining is made of refractory materials, which is more suitable for processing from The high temperature pyrolysis mixed flue gas of the pyrolysis separation device body.

The ignition device adopts a plasma ignition method, and the control system of the ignition device is automatically put into operation and cut off according to the temperature of the combustion section, so as to ensure a continuous and stable heat source for the pyrolysis reaction device.

The coal-water slurry spray gun is made of anti-wear and heat-resistant materials, the atomization angle of the nozzle is 30°～60°, the adjustment range between the nozzle and the wall is +/-15°, the center of the coal-water slurry spray gun The tube outputs atomized steam, the middle layer outputs coal water slurry, and the outermost layer outputs protective steam. In the present invention, steam is used instead of compressed air as the atomizing medium, which can prevent the coal-water slurry from being oxidized during the spraying process, thereby improving the pyrolysis efficiency.

The pipeline of the material return device is provided with a fluidizing air for preventing pipeline blockage, that is, two streams of high-momentum air with a small flow area are blown into it from the connection between the material return pipeline and the gas-solid separation device, and are continuously replenished. Into this place for fluidization.

An L-shaped control valve is arranged at the outlet of the returning material device to adjust and control the returning material flow.

The present invention relates to a transport bed coal-water slurry pyrolysis reaction method based on the above-mentioned device. The fuel injected into the combustion section is ignited and burned by an ignition device. The fuel is coal-water slurry or coal powder used to prepare the coal-water slurry. The combustion residence time is within 0.3s, and the excess air coefficient during combustion is 1 to 1.05. The combustion-supporting air can be heated air (at a temperature of about 300°C), or the circulating smoke from the boiler system used in conjunction with the device. Generally, the flue gas temperature is 300°C to 400°C, and the oxygen content in the flue gas is 5-8%. The burned ash is discharged through the ash outlet at the bottom of the ash section, and the high-temperature rising flue gas after combustion is fully mixed with the coal-water slurry sprayed through the spray gun with waterproof coal slurry oxidation in the pyrolysis section. The coal slurry undergoes pyrolysis reaction, and the water vapor as the protective steam is also pyrolyzed into +OH with reducing active components at high temperature, which greatly improves the pyrolysis gas production rate. The residence time of the pyrolysis reaction is 0.5-1s to ensure that the coal-water slurry is fully pyrolyzed, and the temperature in the pyrolysis section is always maintained above 950°C to ensure that the tar generated during the pyrolysis gasification reaction is fully pyrolyzed and effectively prevents tar Precipitation clogged pipes. At the same time, when the spray gun is arranged with a downward slope of 10°, it is beneficial for the airflow to swirl up in the device, increase the residence time, and make the pyrolysis reaction fully proceed. The mixed flue gas containing pyrolysis gas components output from the outlet of the transport bed pyrolysis device enters the separation device for gas-solid separation, and the separated and purified pyrolysis gas enters the pyrolysis gas pipeline through the upper outlet of the separation device, and For production, the separated particles containing unburned carbon are sent back to the combustion section through the return device to continue burning, so as to maximize heat utilization and reduce the energy consumption of the entire system, and finally realize high-efficiency and low-energy coal-water slurry pyrolysis. consumption effect.

technical effect

The present invention skillfully adopts the structure and working principle of the transport bed, divides the body of the pyrolysis reaction device into a combustion section and a pyrolysis section, and designs the functional configuration of different sections and a reasonable residence time so that the combustion generated in the lower part of the device body The high-temperature flue gas just provides heat for the pyrolysis of the coal-water slurry injected in the middle, and the high-efficiency pyrolysis of the coal-water slurry can be realized by using the fuel itself. Advanced spray gun ensures high gas production rate of coal water slurry pyrolysis. In the design of the present invention, medium-temperature circulating flue gas can also be used as combustion-supporting air. On the one hand, the medium-temperature flue gas increases the temperature of the combustion zone, which is more conducive to ignition and combustion stability. On the other hand, the oxygen content in the flue gas is low, which can effectively control the oxygen content in the combustion zone. , in order to form a reducing atmosphere in the pyrolysis section, which is beneficial to the pyrolysis of the injected coal-water slurry, and ensures a high pyrolysis gas production rate on the basis of realizing heat recovery. At the same time, in the pyrolysis reaction device The outlet is equipped with a gas-solid separation device, which separates the unburned air coke and returns it to the pyrolysis device to continue burning, providing heat for pyrolysis, maximizing the energy utilization of the system, and finally achieving a high gas production rate of the transport bed coal-water slurry pyrolysis device , The expected effect of low energy consumption.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of coal-water slurry spray gun;

In the figure: 1 transport bed pyrolysis reaction device body, 2 coal water slurry spray gun, 3 ignition device, 4 gas pipeline, 5 gas-solid separation device, 6 feeding device, 7 combustion air inlet, 11 refractory lining, 12 Pyrolysis section, 13 connecting flange, 14 combustion section, 15 manhole, 16 ash section, 17 pyrolysis gas outlet, 21 atomizing steam channel, 22 coal water slurry channel, 23 protection steam channel, 24 nozzle, 51 inlet Material port, 52 gas outlet, 53 central tube, 61 fluidized air duct, 62 outlet of feeding device.

Detailed ways

As shown in Figures 1 and 2, this embodiment includes: a transport bed pyrolysis reaction device body 1 connected to each other, a gas-solid separation device 5 and a feeding device 6, and a transport bed pyrolysis reaction device body 1 The ignition device 3 inside, wherein: the transport bed pyrolysis reaction device body 1 is connected to the gas-solid separation device inlet 51 through the pyrolysis gas outlet 17, and the transport bed pyrolysis reaction device body 1 is connected to the gas-solid separation device 5 The bottom is connected by a return device 6.

The transport bed pyrolysis reaction device body 1 includes: successively connected pyrolysis section 12, combustion section 14 and ash section 16, wherein: each section is connected by split connecting flanges, pyrolysis section, pyrolysis gas A plurality of manholes 15 are provided in both the chemicalization section and the combustion section, a plurality of coal-water slurry spray guns 2 are evenly distributed on both sides of the pyrolysis section and the combustion section B, and a combustion air inlet 7 is provided in the combustion section.

The inner lining of the transport bed pyrolysis reaction device body 1 is made of refractory material 11, and the inner lining is fixed by 1500-2000 claw nails with external threads and threaded buckles per square meter to improve the high temperature resistance strength.

The ignition device 3 adopts the plasma ignition method, uses intelligent system control, and automatically puts into operation and cuts off according to the temperature of the combustion section, so as to ensure that a continuous and stable heat source is provided for the operation of the transport bed pyrolysis reaction device body 1, and avoid failures caused by other equipment. causing the system to stop functioning.

The bottom of the ash and slag section 16 is provided with an ash discharge port, and the ash and slag section is arranged in a cone shape, which can reduce the risk of slag clogging and improve the ash discharge efficiency.

The interior of the gas-solid separation device 5 is provided with an axially offset center cylinder 53 .

The coal-water slurry spray gun 2 is connected to the middle wall of the transport bed pyrolysis reaction device body 1, wherein an atomizing steam channel 21, a coal-water slurry channel 22, a protection steam channel 23 and a nozzle 24 arranged in rotation are provided, wherein : The adjustment range between the nozzle 24 and the wall of the coal-water slurry spray gun 2 is +/-15°.

The nozzle 24 is made of anti-wear material to increase its service life. When the coal-water slurry spray gun 2 is atomized by steam, the atomization angle is 30°～60°, and the outer layer is added with protective steam to avoid the coal-water slurry Exposure to too much oxygen during the injection process ensures that the pyrolysis reaction of the coal-water slurry is fully carried out.

The excess air coefficient of the combustion section is 1-1.05, the bottom combustion residence time is within 0.3s, and the pyrolysis section residence time is 0.5-1s to ensure sufficient pyrolysis of the coal-water slurry.

The gas-solid separation device 5 separates the unburned coke and purifies the pyrolysis gas entering the furnace at the same time. The separated coke enters the transport bed pyrolysis reaction device body 1 through the feeding device 6 for combustion, and through the combustion-supporting The air inlet 7 inputs heating air in the furnace or medium-temperature flue gas as a combustion-supporting gas.

This embodiment relates to the transport bed coal-water slurry pyrolysis reaction method of the above-mentioned device: the coal-water slurry enters the transport bed pyrolysis reaction device body 1 through the coal-water slurry spray gun 2 for pyrolysis, and the ignition device 3 is ignited when it starts to operate. The coal water slurry or the pulverized coal fuel used to make the coal water slurry is burned to provide heat for the pyrolysis of the coal water slurry injected into the pyrolysis section, and the pyrolysis product enters the gas-solid separation device 5 through the pyrolysis gas outlet and through the feed port 17 The separated pyrolysis gas is output through the gas outlet 52 for production use, and the unpyrolyzed coke enters the combustion section 14 of the transport bed pyrolysis reaction device through the return device 6 to continue to participate in combustion, and passes through the The combustion-supporting air inlet 7 provides the amount of oxygen required for combustion, so as to prevent the excessive oxygen amount in the body 1 of the transport bed pyrolysis reaction device from affecting the pyrolysis gas rate, and the ignition device 3 stops operating after the coke at the bottom of the pyrolysis gas burns stably.

The method preferably further creates a high temperature and reducing atmosphere for the reaction zone of the pyrolysis section by controlling the amount of oxygen in the combustion flue gas of the combustion section 14, so as to provide favorable conditions for the pyrolysis of the coal-water slurry.

The above control, by using steam instead of traditional compressed air as the atomizing medium, can avoid the coal-water slurry from being exposed to too much oxygen during the spraying process, and the outermost layer of the coal-water slurry spray gun is further equipped with protective steam. On the one hand The high-speed jet steam can penetrate the rotating and rising flue gas to ensure the full mixing of the coal water slurry and the flue gas. On the other hand, the water vapor pyrolyzes OH ions at high temperature, which increases the reducing active components in the pyrolysis gas and improves the thermal efficiency. The gas production rate of the solution process and the fuel utilization rate.

Compared with the prior art, the present invention has the advantages that: the present invention realizes the efficient conversion of pyrolysis gas by strictly controlling the residence time and oxygen amount of the combustion section and the pyrolysis section, and the unburned pyrolysis products are separated by a gas-solid separation device. The carbon is separated, and then sent back to the transport bed pyrolysis reaction device body 1 for combustion through the return device 6, and the hot air or circulating flue gas provides the oxygen required for coke combustion, which can not only fully recycle the heat, but also avoid overheating. A large amount of oxygen enters the main body of the transport bed pyrolysis reaction device to oxidize the coal-water slurry to realize high-efficiency and low-energy-consumption coal-water slurry pyrolysis.

After specific practical experiments, under the condition that the concentration of coal-water slurry is above 60%, the pyrolysis reaction device operates normally, and the experimental data that can be obtained by using bituminous coal is: the reducing components in the pyrolysis gas at the outlet of the pyrolysis reaction device reach 40% above.

The above specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The scope of protection of the present invention is subject to the claims and is not limited by the above specific implementation. Each implementation within the scope is bound by the invention.

Claims (1)

1. A transport bed coal-water slurry pyrolysis reaction method based on a transport bed coal-water slurry pyrolysis reaction device, characterized in that, the transport bed coal-water slurry pyrolysis reaction device comprises: transport bed pyrolysis reaction The device body, the coal-water slurry spray gun arranged in the body of the transport bed pyrolysis reaction device, the ignition device for system ignition and the combustion air inlet for providing combustion air, the air connection connected with the body of the transport bed pyrolysis reaction device Solid separation device, return device; The main body of the transport bed pyrolysis reaction device is cylindrical, and its outer shell is made of heat-resistant metal material, and the interior includes a pyrolysis section for coal-water slurry pyrolysis gasification reaction connected in sequence by split flanges, The combustion section and the ash section used for fuel combustion to provide heat for the entire device, among which: the lining of the combustion section and the pyrolysis section is made of refractory materials, and the inner lining uses 1500-2000 external threaded top belt wires per square meter The claw nails of the button are fixed to improve the high temperature resistance strength, and several manholes are set along the height direction for observing the reaction in the furnace and the pressure relief of the device; The outlet of the circulating flue gas and the return device are connected; several coal-water slurry spray guns are symmetrically arranged on both sides of the pyrolysis section, and their outlets are connected with the inlet of the gas-solid separation device for pyrolysis gas purification and material circulation; The bottom of the slag section is provided with an ash outlet, and the ash and slag section is arranged in a cone ring; The upper outlet of the gas-solid separation device is connected to the pyrolysis gas pipeline for transporting the purified pyrolysis gas from the body of the transport bed pyrolysis reaction device, and the lower outlet of the gas-solid separation device is connected to the inlet of the feeding device. The interior of the solid separation device is equipped with an axially offset central cylinder with high separation efficiency. The axially offset central cylinder is made of heat-resistant and wear-resistant materials, and its lining is made of refractory materials, which is more suitable for processing from High-temperature pyrolysis mixed flue gas from the body of the pyrolysis separation device; The ignition device adopts a plasma ignition method, and the control system of the ignition device is automatically put into operation and cut off according to the temperature of the combustion section, so as to ensure that a continuous and stable heat source is provided for the pyrolysis reaction device; The coal-water slurry spray gun is made of anti-wear and heat-resistant materials, the atomization angle of the nozzle is 30°～60°, the adjustment range between the nozzle and the wall is +/-15°, the center of the coal-water slurry spray gun The tube outputs atomized steam, the middle layer outputs coal water slurry, and the outermost layer outputs protective steam; The interior of the gas-solid separation device is provided with an axially offset central cylinder with high separation efficiency. The axially offset central cylinder is made of heat-resistant and wear-resistant materials, and its lining is made of refractory materials; The pipeline of the material return device is provided with a fluidizing air for preventing pipeline blockage, that is, two streams of high-momentum air with a small flow area are blown into it from the connection between the material return pipeline and the gas-solid separation device, and are continuously replenished. into the place for fluidization; The outlet of the return device is equipped with an L-shaped control valve to adjust and control the return flow, that is, by using steam instead of traditional compressed air as the atomization medium, the coal-water slurry can be prevented from contacting too much oxygen during the spraying process. The outermost layer of the coal water slurry spray gun is further equipped with protective steam. On the one hand, the high-speed jet steam can penetrate the rotating and rising flue gas to ensure the full mixing of the coal water slurry and the flue gas. On the other hand, the water vapor is pyrolyzed at high temperature. OH ions, increase the reducing active components in the pyrolysis gas, improve the gas production rate and fuel utilization rate in the pyrolysis process; In the transport bed coal-water slurry pyrolysis reaction method, the fuel injected into the combustion section is ignited and burned by an ignition device. The residence time is within 0.3s, the excess air coefficient during combustion is 1-1.05, the combustion-supporting air comes from the medium-temperature flue gas extracted from the inlet of the circulating flue gas, the temperature is 300°C-400°C, and the oxygen content in the flue gas is 5-8% The burned ash is discharged through the ash outlet at the bottom of the ash section, and the high-temperature rising flue gas after combustion is fully mixed with the coal-water slurry injected through the spray gun with waterproof coal slurry oxidation in the pyrolysis section. The coal-water slurry is subjected to pyrolysis reaction, and the residence time of the pyrolysis reaction is 0.5-1s to ensure that the coal-water slurry is fully pyrolyzed. The temperature in the pyrolysis section is always maintained above 950°C so that the tar generated during the pyrolysis and gasification reaction Full pyrolysis; the mixed flue gas containing pyrolysis gas components output from the outlet of the transport bed pyrolysis device enters the separation device for gas-solid separation, and the separated and purified pyrolysis gas enters the pyrolysis gas pipeline through the upper outlet of the separation device For production purposes, the separated particles containing unburned carbon are sent back to the combustion section through the return device to continue combustion.

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