System and method for coupling a replacement fuel vortex gasification to a cement production line

Abstract

This invention discloses a system and method for coupling alternative fuel vortex gasification with a cement production line. The system includes a vortex gasification device, a decomposition furnace, a flue gas chamber, and a distribution device. The outlet of the distribution device is connected to both the flue gas chamber and an ash cooling system. The vortex gasification device includes a vortex gasification section, a suspension section, a fluidized bed section, and a wind chamber section. The vortex gasification section is equipped with an air inlet pipe, and a flue gas outlet pipe is connected between the air inlet pipe and the flue gas chamber. The top of the suspension section is equipped with a flue gas outlet connected to the decomposition furnace. The vortex gasification device is equipped with an alternative fuel feed inlet, a difficult fuel feed inlet, and a bed material feed inlet. The fluidized bed section is equipped with a slag outlet connected to the distribution device. This invention uses a vortex gasification device for the pyrolysis and gasification of alternative fuels, which does not affect the stable operation of the cement clinker calcination system. The resulting combustible gas and carbonaceous fly ash are more easily combusted after entering the decomposition furnace, and the NOx concentration in the decomposition furnace can be reduced.

Description

Technical Field

[0001] This invention relates to a system and method for utilizing alternative fuels in cement kilns, and more particularly to a system and method for coupling alternative fuel vortex gasification with a cement production line. Background Technology

[0002] Currently, the use of alternative fuels has become an important technological path for carbon emission reduction and cost reduction and efficiency improvement in the cement industry. More and more cement plants are starting to use alternative fuels as fuel for cement decomposition furnaces, partially or completely replacing traditional fossil fuel coal.

[0003] There are many types of alternative fuels, with complex compositions, combustion characteristics, and large variations in calorific value. Directly feeding them into cement kilns can have a significant impact on kiln conditions. Existing cement kilns using alternative fuels are mostly direct combustion technologies, which involve feeding the alternative fuels directly into the decomposition furnace. In order to increase the amount of alternative fuels used, cement plants often adopt external pre-combustion furnace technology, such as FLSmidth's HOTDISC hot plate furnace, ThyssenKrupp's PREPOL-SC stepped furnace, and KHD's PYROROTOR@. Compared to cement decomposition furnaces, these are all external types. Furthermore, the use of external pre-combustion devices generally has the following problems: (1) RDF is mainly in a piled-up state in the pre-combustion device, resulting in a slow combustion rate and affecting the amount of RDF disposed of; (2) A separate tertiary air supply is required, which affects the air supply control and operational stability of the cement clinker calcination system; (3) The ash and slag produced after combustion enter the decomposition furnace in a discontinuous or streamed manner, which can easily cause fluctuations in the system's operating conditions; (4) The device has a complex structure, large weight and space requirements, and the system is complex and expensive. In addition, alternative fuel gasification technology, which converts alternative fuels into carbonaceous fly ash and combustible gas after pyrolysis and gasification in a gasifier, is also widely used due to its complete combustion of combustible gas and minimal impact on the decomposition furnace. Examples include Conch Cement's CKK gasifier and Jinyu Group's continuous pyrolysis gasifier. However, this technology also has certain problems: since pyrolysis gasification is an endothermic reaction, in order to maintain the reaction temperature inside the furnace (generally ≥550℃), low-calorific-value alternative fuels require a large air-fuel ratio, necessitating the introduction of more air. This results in lower calorific value of the combustible gas, lower heat utilization rate, and greater flue gas loss.

[0004] Existing technology discloses a method for removing NOx from a cement kiln using a biomass pyrolysis furnace. The flue gas from the decomposition furnace is drawn out by a fan. However, the flue gas temperature is high (≥1000℃) and the oxygen content is extremely low (<3.0%), placing extremely high demands on the high-temperature resistance of the fan. The flue gas is directly cooled by water in the cooling and dust removal chamber, resulting in some heat being carried away by the water and becoming unusable. Furthermore, the high dust content in the flue gas necessitates frequent water changes, leading to not only wasted dust but also significant heat absorption by the water. The evaporated water vapor enters the biomass pyrolysis furnace and ultimately the decomposition furnace. In addition, the temperature of the flue gas entering the biomass pyrolysis furnace is uncontrollable, and the low oxygen content also affects the pyrolysis efficiency. Existing technology also discloses a process using a denitrification pipe to handle alternative fuels. However, the denitrification pipe structure is similar to a thicker flue gas duct, suitable only for lightweight alternative fuels that can be supported by the flue gas. Heavier alternative fuels will fall into the flue gas chamber, affecting the stable operation of the combustion system. In addition, due to the influence of the flue gas flow field inside the denitrification tube and the alternative fuel feeding process, unlike pulverized coal conveyed by pneumatic conveying, it is impossible to achieve uniform mixing with high-temperature flue gas. The alternative fuel is prone to sticking to the wall, and the pyrolysis and gasification are unstable, which ultimately affects the stability of combustion and thus limits the amount of alternative fuel used. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a system that can effectively increase the amount of alternative fuel disposed of in cement kilns, improve the heat utilization rate of alternative fuels, and make full use of the high-temperature flue gas of cement kilns, and couple the alternative fuel vortex gasification with cement production lines using alternative fuels with low air-fuel ratio or zero air-fuel ratio.

[0006] A second objective of the present invention is to provide a method for performing alternative fuel vortex gasification using the aforementioned apparatus.

[0007] Technical Solution: The system for coupling alternative fuel vortex gasification with a cement production line according to the present invention includes a vortex gasification device, a decomposition furnace, a smoke chamber located at the bottom of the decomposition furnace, and a material distribution device connected to the vortex gasification device. The outlet of the material distribution device is connected to the smoke chamber and an ash cooling system, respectively. The vortex gasification device includes a vortex gasification section with a volute structure for suspending pyrolysis gasification of the alternative fuel, a suspension section connected to the upper part of the vortex gasification section, a fluidized bed section connected to the lower part of the vortex gasification section for fluidized combustion of refractory and heavy materials, and an air chamber section connected to the lower part of the fluidized bed section for supplying air to the fluidized bed section. The vortex gasification section is provided with an air inlet pipe, and a flue gas outlet pipe is connected between the air inlet pipe and the high-temperature kiln gas outlet of the smoke chamber. The top of the suspension section is provided with a flue gas outlet connected to the decomposition furnace. The vortex gasification device is provided with an alternative fuel feed inlet, a refractory material feed inlet, and a bed material feed inlet. The vortex gasification device is provided with a slag outlet connected to the material distribution device.

[0008] The material distribution device includes an ash discharge valve connected to the slag outlet and a tee connected to the outlet of the ash discharge valve. The outlets of the tee are respectively connected to the smoke chamber and the ash cooling and conveying system.

[0009] The flue gas outlet pipe is equipped with a first air volume regulating valve, and the pipe between the flue gas outlet and the decomposition furnace is equipped with a second air volume regulating valve; the first air volume regulating valve and the second air volume regulating valve are used to control the kiln gas volume and pressure entering the vortex gasification device.

[0010] The alternative fuel feeding inlet includes a first alternative fuel feeding inlet located on the top surface of the air inlet duct for feeding powdered, paste-like, or liquid alternative fuels; a second alternative fuel feeding inlet located on the side of the vortex chamber for feeding light alternative fuels; and a third alternative fuel feeding inlet located on the side of the suspension chamber for feeding heavy alternative fuels. This invention provides alternative fuel feeding inlets for different materials, enabling the processing of various forms of alternative fuels. With three types of alternative fuel feeding inlets, denser alternative fuels can be fed through the upper third alternative fuel feeding inlet to increase residence time; lighter alternative fuels can be fed through the second alternative fuel feeding inlet on the side of the vortex chamber, resulting in a more uniform distribution within the vortex chamber under the influence of the kiln gas vortex shearing; and powdered, paste-like, and liquid alternative fuels can enter the furnace through the first alternative fuel feeding inlet on the air inlet duct for easier material dispersion.

[0011] The vortex gasification section includes an upper constriction connected to the suspension section, a vortex chamber with a volute structure connected to the upper constriction, and a lower constriction connected to both the vortex chamber and the fluidized bed section. The air inlet pipe is located at the tangent of the volute structure and is used to connect to the high-temperature kiln gas from the cement kiln flue. The bed material feed inlet is located on the side of the upper constriction. The vortex gasification section of this invention features high temperature, strong turbulent pulsation, and a large space, which is beneficial for heat and mass transfer between the alternative fuel and the high-temperature gas. The initially reacted alternative fuel undergoes rapid pyrolysis and gasification under the scouring of the high-temperature, high-speed airflow. The resulting ash is dispersed and evenly discharged with the flue gas. Large, heavy, and difficult-to-burn particles, as well as mixed inorganic impurities, fall into the fluidized bed section for further reaction. This design is suitable for alternative fuels with high ash content and containing many impurities. The vortex gasification section of the vortex gasification device of the present invention adopts a volute structure with a large internal space, which introduces the high-temperature flue gas from the cement kiln flue into the vortex in the form of a vortex. The gasification temperature inside the vortex gasification section is high and the oxygen content is low. The alternative fuel is suspended in the vortex gasification section, which provides favorable conditions for maintaining the stable pyrolysis and gasification of the alternative fuel. The relatively stable high-temperature combustible gas produced is sent to the decomposition furnace, which is friendly to the operation of the kiln system.

[0012] The suspension section includes a suspension chamber located above and connected to the vortex gasification section, and the flue gas outlet is located at the top of the suspension chamber.

[0013] The fluidized bed section includes an air distribution plate and a bed material layer disposed on the upper part of the air distribution plate; the slag outlet is connected to the air distribution plate. The air chamber section includes an air chamber, which is provided with an air inlet connected to a blower. The fluidizing air in the fluidized bed section of this invention can be air or oxygen-enriched gas. For low-calorific-value alternative fuels, appropriately introducing a certain amount of fluidizing air can not only increase the gasification reaction temperature, but also allow heavy, difficult-to-burn alternative fuels to continue participating in the gasification reaction under the fluidization of the bed material, thereby improving their burnout rate. The fluidized bed section is provided with a slag discharge port, allowing impurities and ash to be discharged externally and not enter the decomposition furnace, thus reducing the impact on the kiln system operation and clinker quality. Since the high-temperature kiln gas can provide a certain amount of heat, the amount of oxygen required for the pyrolysis and gasification of alternative fuels is small. Consequently, the air volume required for the fluidized bed section of this invention is small, resulting in a small cross-section of the air distribution plate. The pyrolysis and gasification process of alternative fuels will have a low air-fuel ratio. With an appropriate amount of alternative fuel added, it may even be possible to not introduce fluidizing air, achieving a zero air-fuel ratio, and the entire system will have higher thermal efficiency.

[0014] The fire-retardant material feeding inlet is located on the top surface of the air inlet pipe and is used to connect with the fire-retardant material to reduce the temperature of the vortex gasification section; the fire-retardant material is preferably raw meal powder. This fire-retardant material feeding inlet of the present invention avoids excessively high temperatures within the vortex gasification section and can regulate the temperature of the vortex gasification section; after absorbing heat, the raw meal can directly enter the decomposition furnace, serving as a preheating and pre-decomposition function; while in the air chamber section, a certain amount of air or oxygen-enriched gas is blown into the vortex chamber to generate fluidizing air, which mixes with the high-temperature kiln gas, causing the alternative fuel to undergo an oxidation reaction and generate heat to maintain the temperature within the vortex chamber, ensuring that the temperature within the vortex chamber is always at the most suitable pyrolysis gasification temperature for various alternative fuels.

[0015] The method for coupling alternative fuel vortex gasification with a cement production line using the above-mentioned apparatus includes the following steps:

[0016] Alternative fuel is fed into the vortex gasification unit through the corresponding alternative fuel inlet. High-temperature kiln gas from the flue gas chamber enters the vortex gasification unit through the flue gas outlet pipe and air inlet pipe, forming a vortex. Under the influence of the vortex formed by the high-temperature kiln gas, the alternative fuel mixes with the kiln gas and undergoes drying, pyrolysis, and gasification reactions. The resulting combustible products and carbon-containing fly ash enter the decomposition furnace through the flue gas outlet, where they continue to burn upon contact with oxygen, thus fulfilling the role of alternative fuel. Impurities, non-combustible materials, and ash mixed into the alternative fuel fall into the fluidized bed section.

[0017] Impurities, flammable materials, and ash entering the fluidized bed section are further combusted and decomposed upon contact with the high-temperature fluidized bed material. Heavy non-combustible materials fall to the bottom of the fluidized bed section and enter the material distribution device through the slag outlet, from which they are sent to the decomposition furnace or ash cooling and conveying system.

[0018] When the temperature of the vortex gasification unit is too high, a non-combustible material is fed into the non-combustible material feed inlet to control the temperature in the vortex gasification section; conversely, air or oxygen-enriched gas is blown from the air chamber section into the fluidized bed section, and the resulting fluidizing air enters the vortex gasification section, causing the alternative fuel to undergo an oxidation reaction and generating heat to ensure the temperature in the vortex gasification section.

[0019] The kiln gas volume and pressure entering the vortex gasification device are controlled by adjusting the opening of the first and second air volume regulating valves.

[0020] The destination of the ash and slag from the feeding device is determined based on the amount produced, the composition, and the impact on the stable operation of the cement clinker calcination system, and is either sent to the decomposition furnace or the ash and slag cooling and conveying system.

[0021] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0022] (1) The system of the present invention uses a vortex gasification device to pyrolyze and gasify alternative fuels, which is suitable for various realities such as a wide variety of alternative fuels, complex sources, large fluctuations in composition, and large differences in physicochemical composition, and does not affect the stable operation of the cement clinker calcination system; the combustible gas and carbon-containing fly ash generated during the alternative fuel gasification process are not only easier to burn and replace part of the fuel coal after entering the decomposition furnace, but can also further reduce the NOx concentration in the decomposition furnace.

[0023] (2) The system of the present invention can effectively increase the amount of alternative fuel disposed of in cement kilns, improve the heat utilization rate of alternative fuels, and make full use of the high temperature kiln gas (>1000℃) in the flue as a heat source and reaction gas. The gasification temperature is high, so low air-fuel ratio or zero air-fuel ratio can be used. At the same time, the reducing components generated by the gasification of alternative fuels can be used to reduce the nitrogen oxide content in the high temperature kiln gas. The air volume of the high temperature kiln gas can also be adjusted to control the reaction temperature of alternative fuels, thereby minimizing the negative impact of unstable calorific value of alternative fuels on the cement kiln clinker calcination system.

[0024] (3) The slag outlet of the vortex gasification device is connected to a material distribution device, which can send the ash to the decomposition furnace or the ash cooling and conveying system. The ash is cooled by the cooling and conveying system and then transported to the raw material batching system or other places. It also has a certain adaptability to alternative fuels containing more non-combustible impurities.

[0025] (4) The high-temperature flue gas discharged from the smoke chamber has a high NOx content, and the reducing gases (CH4, C) produced by the pyrolysis and gasification of alternative fuels are also present. n H mThe system can remove NOx by using fuels such as H2 and CO. At the same time, the combustible gas generated by the vortex gasification device and the carbon-containing fly ash are not only easier to burn and replace part of the fuel coal after entering the decomposition furnace, but also reduce the NOx concentration. The system of this invention can greatly increase the types and proportions of alternative fuels used in cement kilns, and it is also adaptable to low-calorific-value alternative fuels and waste. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the system structure of the present invention, which couples alternative fuel vortex gasification with a cement production line.

[0027] Figure 2 This is a schematic diagram of the vortex gasification device of the present invention;

[0028] Figure 3 This is a top view of the vortex gasification device of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings.

[0030] like Figure 1 As shown, this invention provides a system for coupling alternative fuel vortex gasification with a cement production line, including a vortex gasification device 1, a decomposition furnace 2, a smoke chamber 3 located at the bottom of the decomposition furnace 2, and a material distribution device connected to the vortex gasification device 1. The outlet of the material distribution device is connected to the smoke chamber 3 and an ash cooling system 7, respectively. Figure 2 , 3 As shown, the vortex gasification device 1 includes a vortex gasification section 110, a suspension section 120, a fluidized bed section 130, and a wind chamber section 140 that are connected to each other.

[0031] The vortex vaporization section 110 includes an upper constriction 111, a middle vortex chamber 112, and a lower constriction 113. The upper constriction 111 has a conical structure and is connected to the suspension section 120. The vortex chamber 112 has a cylindrical structure with a volute shape. Figure 2As shown, the volute has a tangential air inlet pipe 114 at its tangential shear line, and the lower constriction 113 adopts a conical structure and is connected to the fluidized bed section 130; there can be two air inlet pipes 114; the air inlet pipe 114 is used to connect to the high-temperature kiln gas in the cement kiln smoke chamber 3; a flue gas outlet pipe is connected between the air inlet of the air inlet pipe 114 and the smoke chamber 3; a first air volume regulating valve 12 is provided on the flue gas outlet pipe; a flame-retardant material feeding inlet 115 and a... are provided on the top surface of the air inlet pipe 114. The first alternative fuel feed inlet 116; the flammable material feed inlet 115 is connected to the flammable material to reduce the temperature of the vortex gasification section. In this embodiment, the flammable material is raw material; the first alternative fuel feed inlet 116 is used to feed powdered alternative fuels, such as coal gangue, rice husks, sawdust, etc., paste-like alternative fuels, such as semi-solid sludge, oil sludge, and blended hazardous waste, etc., and liquid alternative fuels, such as waste engine oil and waste emulsion, etc.; the flammable material feed inlet 115 is connected to the flammable material unloading valve 11; the first alternative fuel feed... Inlet 116 is connected to a pneumatic conveying device or a pumping device, and is used to inject the alternative fuel into the air inlet duct 114 from the first alternative fuel feed inlet 116 via a pneumatic conveying device or pumping method; there can be multiple flame-retardant material feed inlets 115 and first alternative fuel feed inlets 116; a bed material feed inlet 117 is provided on the side of the upper constriction 111; the bed material feed inlet 117 is used to replenish the bed material of the fluidized bed section 130; the bed material feed inlet 117 is connected to the bed material discharge valve 9, and the bed material is sent into the bed material feed inlet 117 through the bed material discharge valve 9; there is a second alternative fuel feed inlet 118 on the side of the vortex chamber 112, and the second alternative fuel feed inlet 118 is used to feed light alternative fuels, such as biomass, waste textiles, etc.; the second alternative fuel feed inlet 118 is connected to a feeding device 8, and the second alternative fuel is sent into the second alternative fuel feed inlet 118 through the feeding device 8; the feeding device in this embodiment is a screw conveyor; there can be multiple second alternative fuel feed inlets 118, arranged circumferentially along the volute.

[0032] The suspension section 120 includes a suspension chamber 121, which is located above the vortex gasification section 110 and connected to its upper constriction 111. The suspension chamber 121 has a cylindrical structure. A third alternative fuel feed inlet 122 is located on the side of the suspension chamber 121, and a flue gas outlet 123 is located on the top surface of the suspension chamber 121. The third alternative fuel feed inlet 122 is connected to the rotary airlock feeder 10. The flue gas outlet 123 is connected to the upper part of the decomposition furnace 2, and a second airflow regulating valve 13 is provided on the connecting pipe between the flue gas outlet 123 and the decomposition furnace 2.

[0033] The fluidized bed section 130 is located at the bottom of the vortex gasification section 110 and connected to its lower constriction 113. The fluidized bed section 130 includes an air distribution plate 131 and a bed material layer 132 located on the upper part of the air distribution plate 131. The air distribution plate 131 is provided with a slag outlet 133, which is connected to a material distribution device. In this embodiment, the material distribution device includes an ash discharge valve 5 connected to the slag outlet 133 and a three-way valve 6 connected to the outlet of the ash discharge valve 5. The ash discharge valve 5 can discharge impurities and ash. The ash discharge valve 5 is preferably a heavy-duty flap valve, which can play a sealing role. The outlet of the three-way valve 6 is divided into two channels, one of which is connected to the smoke chamber 3 and the other of which is connected to the ash cooling and conveying system 7. The destination of ash is determined based on the amount produced, its composition, and its impact on the stable operation of the cement clinker calcination system: when the impact of directly feeding the ash into the decomposition furnace 2 on the stable operation of the cement clinker calcination system is acceptable, the tee 6 will send the ash into the decomposition furnace 2; otherwise, the tee 6 will send the ash into the ash cooling and conveying system 7; the ash cooling and conveying system 7 is used to cool the ash and convey it to the raw material batching station to participate in cement raw material batching or to other places for comprehensive utilization.

[0034] The air chamber section 140 includes an air chamber 141, which is located below the air distribution plate 132. The air chamber 141 is provided with an air inlet 142, which is connected to the blower 4.

[0035] like Figure 3 As shown, the process flow of the present invention is as follows:

[0036] When the vortex gasification device 1 is in use, different types of alternative fuels can be fed into the corresponding first alternative fuel feed port 116, second alternative fuel feed port 118, and third alternative fuel feed port 122 in proportion, or only one type of alternative fuel can be used at a time. However, it is necessary to ensure the overall stability of the calorific value of the added alternative fuels as much as possible. This can not only control the temperature stability in the vortex gasification section, but also ensure the stability of gas production, thereby ensuring the stability of the cement calcination system decomposition furnace 2. The bed material of the vortex gasification device 1 can be quartz sand, which is fed into the bed through the bed material feed port 117 by opening the bed material discharge valve 9.

[0037] Powdered alternative fuels, such as coal gangue, rice husks, and sawdust; paste-like alternative fuels, such as semi-solid sludge, oil sludge, and blended hazardous waste; and liquid alternative fuels, such as waste engine oil and waste emulsion, can all be injected into the air inlet pipe 114 of the vortex gasification device 1 through a pneumatic conveying device or pump. Light alternative fuels, such as biomass and waste textiles, can be fed into the vortex chamber 112 of the vortex gasification device 1 through the feeding device 8 from the second alternative fuel inlet 118. Then, they are uniformly introduced into the vortex chamber 112 under the drive of high-temperature kiln gas. Heavy alternative fuels, such as waste tire scraps and oil residue, can be fed into the suspension section 120 of the vortex gasification device 1 from the third alternative fuel inlet 122. Under the drive of high-temperature kiln gas, they slowly enter the vortex chamber 112.

[0038] The high-temperature kiln gas from the vortex gasification device 1 is drawn out from the flue gas outlet pipe of the smoke chamber 3 of the cement firing system, enters the air inlet pipe 114 through the first air volume regulating valve 12, and forms a vortex in the vortex chamber 112 under the drive of its volute structure; the flue gas generated by the vortex gasification device 1 enters the decomposition furnace 2 through the second air volume regulating valve 13. Since the negative pressure at the flue gas inlet of the decomposition furnace 2 is higher than the negative pressure at the outlet of the smoke chamber 3, the amount of high-temperature kiln gas entering the vortex gasification device 1 can be controlled by adjusting the opening of the first air volume regulating valve 12 and the second air volume regulating valve 13, thereby controlling the internal air volume, temperature and heat load of the vortex gasification device 1;

[0039] Various alternative fuels entering the vortex chamber 112 are first rapidly mixed with the kiln gas under the influence of the vortex formed by the high-temperature kiln gas, and undergo drying, pyrolysis, and gasification reactions. The resulting combustible products and carbon-containing fly ash enter the decomposition furnace 2 through the suspension section 121 and the flue gas outlet 123, where they continue to burn upon contact with oxygen, thus replacing part of the fuel coal. Impurities, refractory materials, and ash mixed in with the alternative fuels fall onto the fluidized bed. Based on the output of these heavy materials on the fluidized bed, the blower 4 is turned on to send air or oxygen-enriched gas into the air chamber 141, causing the bed material 132 of the fluidized bed section to fluidize, and the refractory materials will continue to burn. The ash discharge valve 5 is opened to discharge impurities and ash. The destination of the ash is determined based on the output, composition, and impact on the stable operation of the cement clinker calcination system: when the impact of directly sending the ash into the decomposition furnace 2 on the stable operation of the cement clinker calcination system is acceptable, the three-way valve 6 sends the ash into the decomposition furnace 2; otherwise, the material distribution device sends the ash into the ash cooling and conveying system 7.

[0040] Temperature control inside the vortex gasification device 1: When the temperature inside the vortex gasification section is too high, the temperature inside the vortex gasification section can be controlled by opening the non-flammable material discharge valve 11 and feeding raw material powder and other non-flammable materials through the non-flammable material feed inlet 115; when the temperature inside the vortex gasification section is too low, the blower 4 is turned on to blow a certain amount of air or oxygen-enriched gas into the fluidized bed section, so that the alternative fuel undergoes an oxidation reaction and generates heat to increase the temperature, so that the temperature inside the vortex gasification device 1 is always at the most suitable pyrolysis gasification temperature for various alternative fuels.

[0041] Pressure control inside the vortex gasification device 1: The flue gas inlet of the vortex gasification device 1 is connected to the upper part of the decomposition furnace 2 as much as possible. The kiln gas flow rate and pressure entering the vortex gasification device are controlled by adjusting the opening of the first air flow regulating valve 12 and the second air flow regulating valve 13.

Claims

1. A system for coupling alternative fuel vortex gasification with a cement production line, characterized in that, The system includes a vortex gasification device (1), a decomposition furnace (2), a smoke chamber (3) located at the bottom of the decomposition furnace (2), and a material distribution device connected to the vortex gasification device (1). The outlet of the material distribution device is connected to the smoke chamber (3) and the ash cooling and conveying system (7), respectively. The vortex gasification device (1) includes a vortex gasification section (110) with a volute structure for suspension pyrolysis gasification of alternative fuels, a suspension section (120) connected to the upper part of the vortex gasification section (110), a fluidized bed section (130) connected to the lower part of the vortex gasification section (110) for fluidized combustion of refractory and heavy materials, and a fluidized bed section (130) connected to the lower part of the vortex gasification section (110). The lower part of the fluidized bed section (130) is connected to the air chamber section (140) for supplying air to the fluidized bed section (130); the vortex gasification section (110) is provided with an air inlet pipe (114), and a flue gas outlet pipe is connected between the air inlet pipe (114) and the smoke chamber (3); the top of the suspension section (120) is provided with a flue gas outlet (123) connected to the decomposition furnace (2); the vortex gasification device (1) is provided with an alternative fuel feed inlet, a refractory material feed inlet (115) and a bed material feed inlet (117); the vortex gasification device (1) is provided with a slag outlet (133) connected to the material distribution device.

2. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The material distribution device includes an ash discharge valve (5) connected to the slag outlet and a tee (6) connected to the outlet of the ash discharge valve (5). The outlet of the tee (6) is connected to the smoke chamber (3) and the ash cooling and conveying system (7), respectively.

3. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The flue gas outlet pipe is provided with a first air volume regulating valve (12), and the pipe between the flue gas outlet (123) and the decomposition furnace (2) is provided with a second air volume regulating valve (13); the first air volume regulating valve (12) and the second air volume regulating valve (13) are used to control the kiln gas flow rate and pressure entering the vortex gasification device (1).

4. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The alternative fuel feeding inlet includes a first alternative fuel feeding inlet (116) on the air inlet duct (114) for feeding powdered, paste-like or liquid alternative fuel, a second alternative fuel feeding inlet (118) on the vortex gasification section (110) for feeding light alternative fuel, and a third alternative fuel feeding inlet (122) on the suspension section (120) for feeding heavy alternative fuel.

5. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The vortex gasification section (110) includes an upper constriction (111) connected to the suspension section (120), a vortex chamber (112) with a volute structure connected to the upper constriction (111), and a lower constriction (113) connected to the vortex chamber (112) and the fluidized bed section (130) respectively. The air inlet pipe (114) is connected to the vortex chamber (112).

6. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 5, characterized in that, The bed feed inlet (117) is located on the side of the upper constriction (111).

7. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The suspension section (120) includes a suspension chamber (121) located above the vortex gasification section (110) and connected to the vortex gasification section (110), and the flue gas outlet (123) is located at the top of the suspension chamber (121).

8. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The fluidized bed section (130) includes an air distribution plate (131) and a bed material layer (132) disposed on the upper part of the air distribution plate; the slag outlet (133) is connected to the air distribution plate (131).

9. The system for coupling alternative fuel vortex gasification with a cement production line according to claim 1, characterized in that, The air chamber section (140) includes an air chamber (141), which is provided with an air inlet (142) connected to the blower (4).

10. A method for coupling the alternative fuel vortex gasification system of claim 1 with a cement production line, characterized in that, Includes the following steps: The alternative fuel is fed into the alternative fuel inlet corresponding to the vortex gasification device (1). The high-temperature kiln gas from the smoke chamber (3) enters the vortex gasification device (1) through the flue gas outlet pipe and the air inlet pipe (114) to form a vortex. The alternative fuel is mixed with the kiln gas under the drive of the vortex formed by the high-temperature kiln gas and undergoes drying, pyrolysis and gasification reactions. The combustible gaseous products and carbon-containing fly ash produced enter the decomposition furnace (2) through the flue gas outlet (123) and continue to burn when they encounter oxygen, thereby playing the role of alternative fuel. The impurities, refractory materials and ash mixed in with the alternative fuel fall into the fluidized bed section (130). Impurities, flammable materials, and ash falling into the fluidized bed section (130) come into contact with the high-temperature fluidized bed material and are further burned and decomposed. Heavy non-combustible materials fall into the bottom of the fluidized bed section (130) and are discharged into the material distribution device through the slag outlet. The material distribution device then sends them into the smoke chamber (3) or the ash cooling and conveying system (7). When the temperature of the vortex gasification device (1) is too high, a fire-retardant material is fed into the vortex gasification section (110) through the fire-retardant material feed inlet (115) to control the temperature inside the vortex gasification section (110); conversely, air or oxygen-enriched gas is blown into the fluidized bed section (130) from the wind chamber section (140), and the resulting fluidizing air enters the vortex gasification section (110) to cause the alternative fuel to undergo an oxidation reaction and generate heat to ensure the temperature inside the vortex gasification section (110).

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