Alternative fuel vortex gasification device

Abstract

The utility model discloses an alternative fuel vortex gasification device. The device comprises a vortex gasification section, a suspension section, a fluidized bed section and an air chamber section which are communicated with one another, the vortex gasification section is provided with an air inlet pipeline communicated with high-temperature flue gas, and the top of the suspension section is provided with a flue gas outlet and a flue gas delivery pipeline; and an alternative fuel feeding port, a difficult fuel feeding port, a bed material feeding port and a slag outlet are further formed. High-temperature flue gas is introduced in a vortex mode, alternative fuel is in a suspended state and is high in gasification temperature and low in oxygen content, heat and mass transfer between the alternative fuel and the high-temperature gas is facilitated, stable pyrolysis gasification of the alternative fuel is maintained, generated high-temperature combustible gas and carbon-containing fly ash are more prone to combustion, fluctuation influence on follow-up combustion equipment is small, and energy is saved. And meanwhile, the adopted air-fuel ratio is small, cold air brought by the system is small, the heat value of combustible gas is high, and the device has higher heat efficiency.

Description

Technical Field

[0001] The utility model relates to a device for gasifying an alternative fuel, in particular to a vortex gasification device for alternative fuel. Background Art

[0002] At present, the use of alternative fuels has become an important technical path for the cement industry to reduce carbon emissions, reduce costs and increase efficiency. More and more cement plants have begun to use alternative fuels as cement decomposition furnace fuel, partially or completely replacing traditional fossil fuel coal.

[0003] There are many types of alternative fuels, with complex components, large variations in combustion characteristics and calorific value. Directly feeding them into cement kilns will have a great impact on kiln conditions. Existing cement kilns use alternative fuel technologies mostly based on direct combustion technology, that is, feeding alternative fuels directly into the decomposition furnace. In order to increase the use of alternative fuels, cement plants mostly use external pre-combustion furnace technology, such as FLSmidth's HOTDISC hot plate furnace, ThyssenKrupp's PREPOL-SC step furnace, KHD's PYROROTOR@, etc. Compared with cement decomposition furnaces, they are all external, and the use of external pre-combustion devices generally has the following problems: (1) RDF is mainly in a piled state in the pre-combustion device, and the combustion speed is slow, which affects the amount of RDF disposal; (2) A separate tertiary air needs to be introduced, which affects the air control and operating stability of the cement clinker burning system; (3) The ash produced after combustion enters the decomposition furnace in a discontinuous or stranded manner, which can easily cause fluctuations in the system operating conditions; (4) The device has a complex structure, is heavy and occupies a large space, and the system is complex and the cost is high.

[0004] In addition, alternative fuel gasification technology is also widely used because it converts alternative fuels into carbon-containing fly ash and combustible gas after pyrolysis and gasification in the gasifier and feeds them into the decomposition furnace. The combustible gas burns fully and has little impact on the decomposition furnace. Such as Conch's CKK gasifier and Jinyu's continuous pyrolysis gasifier. However, this type of technology also has certain problems: since pyrolysis and gasification is an endothermic reaction, in order to maintain the reaction temperature in the furnace (generally ≥550℃), low calorific value alternative fuels require a larger air-fuel ratio and more air, resulting in low calorific value of combustible gas, low heat utilization, and large exhaust loss.

[0005] The prior art discloses a suspended combined incinerator, which can ensure the complete combustion of graphitized waste carbon poles in the overhaul slag of aluminum electrolytic cells through a two-stage combined cyclone and oxygen-enriched combustion process. However, the cyclone section of this technology feeds air or oxygen-enriched gas, which is a two-stage combined combustion technology with a high air-fuel ratio and complete combustion. If this technology is applied to cement kilns, it will cause problems such as overheating in the furnace and low thermal utilization of alternative fuels. The prior art also discloses a cement kiln using a biomass pyrolysis furnace to remove NOx system, including a decomposition furnace smoke chamber and a biomass pyrolysis furnace. Part of the hot air is drawn out from the decomposition furnace smoke chamber, and enters the biomass pyrolysis furnace after cooling and dust removal, and is mixed with water vapor, coal powder, biomass powder and other organic matter to react to generate CO, H2, CH i Reducing gas is used to reduce the remaining NOx in the reduction zone of the decomposition furnace. However, the flue gas from the smoke chamber of the decomposition furnace is drawn out by a fan. However, the temperature of the smoke chamber is high (≥1000℃) and the oxygen content is extremely low (<3.0%), which requires the high temperature resistance of the fan to be extremely high. The flue gas is directly cooled by water in the cooling and dust removal bin, resulting in part of the heat being taken away by the water and cannot be used. In addition, the dust content of the flue gas is high and the water is changed frequently. Not only is the smoke dust wasted, but most of the heat of the flue gas is also absorbed by the water, and the evaporated water vapor enters the biomass pyrolysis furnace and finally enters the decomposition furnace. In addition, the temperature of the flue gas entering the biomass pyrolysis furnace is also uncontrollable, and the low oxygen content of the flue gas will also affect the pyrolysis effect of the biomass pyrolysis furnace. Utility Model Content

[0006] Purpose of the utility model: The purpose of the utility model is to provide an alternative fuel vortex gasification device that can effectively improve the disposal capacity and thermal efficiency of the alternative fuel gasification device by utilizing high-temperature flue gas, and has strong adaptability to alternative fuel types, high calorific value of gas production and low air-fuel ratio;

[0007] Technical solution: The alternative fuel vortex gasification device described in the utility model includes a vortex gasification section with a volute structure for suspended pyrolysis and gasification of alternative fuels, 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 flame-retardant and heavy materials, and a wind 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 duct for communicating with high-temperature flue gas, the top of the suspension section is provided with a flue gas outlet, and the flue gas outlet is connected to a flue gas delivery pipeline; the alternative fuel vortex gasification device is also provided with an alternative fuel feeding inlet, a flame-retardant fuel feeding inlet, a bed material feeding inlet and a slag outlet.

[0008] Among them, the alternative fuel feeding inlet includes a first alternative fuel feeding inlet arranged on the top surface of the air inlet duct for feeding powdered, paste or liquid alternative fuel, a second alternative fuel feeding inlet arranged on the side of the vortex chamber for feeding light alternative fuel, and a third alternative fuel feeding inlet arranged on the side of the suspension chamber for feeding heavy alternative fuel.

[0009] Among them, the vortex gasification section includes an upper constriction connected to the suspension section, a vortex chamber in a volute structure connected to the upper constriction, and a lower constriction connected to the vortex chamber and the fluidized bed section respectively; the air inlet duct is arranged at the rotary cutting line of the volute structure for receiving high-temperature flue gas; the bed material feeding inlet is arranged on the side of the upper constriction.

[0010] Wherein, the suspension section comprises a suspension chamber located at the upper part of the vortex gasification section and connected with the vortex gasification section, and the smoke outlet is located at the top of the suspension chamber.

[0011] The fluidized bed section includes an air distribution plate and a bed material layer disposed on the upper portion of the air distribution plate; the slag outlet includes a first slag outlet connected to the air distribution plate; the first slag outlet is provided with a first ash discharge valve. The air chamber section includes an air chamber, the air chamber is provided with an air inlet connected to a blower; the slag outlet includes a second slag outlet connected to the bottom of the air chamber; the second slag outlet is provided with a second ash discharge valve.

[0012] The fluidizing air of the fluidized bed section of the utility model can be air and oxygen-rich gas. For alternative fuels with low calorific value, a certain amount of fluidizing air is appropriately introduced, which can not only increase the gasification reaction temperature, but also enable the heavy and difficult-to-burn alternative fuels to continue to participate in the gasification reaction through the fluidization effect of the bed material, thereby increasing their burnout rate. The fluidized bed section is provided with a first slag discharge port, through which impurities and ash can be discharged.

[0013] Wherein, the difficult fuel feeding port is arranged on the top surface of the air inlet duct, and is used to connect with the difficult fuel to reduce the temperature of the vortex gasification section; if the utility model is applied to the field of cement production, the difficult fuel can be raw material. The difficult fuel feeding port arranged in the utility model avoids the excessive temperature in the vortex gasification section, and can play a role in regulating the temperature of the vortex gasification section; the raw material can also directly enter the decomposition furnace after absorbing heat, and play a role in preheating and pre-decomposing the raw material; and the wind chamber section generates fluidizing wind by blowing a certain amount of air or oxygen-rich gas into the vortex chamber and mixing with the high-temperature flue gas, so that the alternative fuel undergoes an oxidation reaction, and generates heat to ensure the temperature in the vortex chamber, so that the temperature in the vortex chamber is always at the most suitable pyrolysis and gasification temperature for various alternative fuels.

[0014] The air inlet pipeline is provided with a first air volume regulating valve, and the flue gas delivery pipeline is provided with a second air volume regulating valve; the air volume and pressure of the flue gas entering the vortex gasification device are controlled by adjusting the opening of the first air volume regulating valve and the second air volume regulating valve.

[0015] Beneficial effects: Compared with the prior art, the utility model has the following significant effects:

[0016] (1) The vortex gasification section of the vortex gasification device of the utility model adopts a volute structure with a large internal space, and the high-temperature flue gas of the cement kiln smoke chamber is introduced in the form of a vortex. The gasification temperature inside the vortex gasification section is high, the turbulent pulsation is strong, and the oxygen content is low. The alternative fuel is in a suspended state in the vortex gasification section, which is conducive to the heat and mass transfer between the alternative fuel and the high-temperature gas, and provides favorable conditions for maintaining the stable pyrolysis and gasification of the alternative fuel. The alternative fuel of the initial reaction is rapidly pyrolyzed and gasified under the flushing of the high-temperature and high-speed airflow, and the generated ash is dispersed and evenly discharged with the flue gas. Large, heavy, difficult to burn and mixed inorganic debris will fall into the fluidized bed section to continue the reaction. It has a certain adaptability to low-quality alternative fuels with high ash content and containing more impurities; the generated high-temperature combustible gas and carbon-containing fly ash are relatively stable and easier to burn, and have little impact on the fluctuation of subsequent combustion equipment, and can be used to play the role of alternative fuel and denitrification;

[0017] (2) Since the high-temperature kiln gas can provide a certain amount of heat, the cross-section of the air distribution plate of the utility model is small, the required air volume is small, the alternative fuel pyrolysis and gasification process will have a smaller air-fuel ratio, the cold air brought into the system is small, the calorific value of the combustible gas is high, and under the condition of appropriate alternative fuel dosage, it is not even necessary to introduce fluidizing air, so that the device has a higher thermal efficiency;

[0018] (3) The utility model sets up alternative fuel feeding ports for different materials, and can process alternative fuels in various forms. There are three types of alternative fuel feeding ports. Alternative fuels with higher density can be fed from the third alternative fuel feeding port on the upper part to increase the residence time; light alternative fuels can be fed from the second alternative fuel feeding port on the side of the vortex chamber, and driven by the kiln gas cyclone, they will have a more uniform distribution in the vortex chamber; powdered, paste-like and liquid alternative fuels can be fed into the furnace from the first feeding point on the air inlet duct to facilitate the dispersion of the materials;

[0019] (4) Reducing gases (CH4, C n H m , H2, CO, etc.) can play a role in removing NOx. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic elevational structural diagram of the alternative fuel vortex gasification device of the utility model;

[0021] Figure 2 It is a schematic diagram of the top view of the structure of the alternative fuel vortex gasification device of the utility model;

[0022] Figure 3 The utility model is applied in the process flow chart of cement production. DETAILED DESCRIPTION

[0023] The utility model is described in further detail below.

[0024] like Figure 1-3 As shown, the utility model provides an alternative fuel vortex gasification device 1, comprising a vortex gasification section 110, a suspension section 120, a fluidized bed section 130, and a wind chamber section 140 which are connected.

[0025] The vortex gasification section 110 includes an upper constriction 111, a vortex chamber 112 in the middle, and a lower constriction 113. The upper constriction 111 adopts a conical structure and is connected to the suspension section 120. The vortex chamber 112 adopts a cylindrical structure with a volute structure. Figure 2 As shown, a tangential air inlet duct 114 is provided at the spiral tangent line of the volute, and the lower constriction 113 adopts a conical structure and is connected to the fluidized bed section 130; there can be two tangential air inlet ducts; the air inlet duct 114 is used to access the high-temperature kiln gas of the cement kiln smoke chamber 12; a smoke outlet pipeline is connected between the air inlet of the air inlet duct 114 and the cement kiln smoke chamber 12; the smoke outlet pipeline is provided with a first air volume regulating valve 9; the negative pressure at the outlet point of the smoke outlet pipeline is higher than the negative pressure at the high-temperature kiln gas outlet; the air inlet duct 114 is connected to the high-temperature kiln gas outlet of the cement kiln smoke chamber 12 ... The top surface is provided with a difficult fuel feed inlet 115 and a first alternative fuel feed inlet 116; the difficult fuel feed inlet 115 is connected to the raw material to reduce the temperature of the vortex gasification section; the first alternative fuel feed inlet 116 is used to feed powdered alternative fuels, such as coal gangue, rice husk, sawdust, etc., paste alternative fuels, such as semi-solid sludge, oil sludge, hazardous waste after matching, etc., liquid alternative fuels, such as waste engine oil, waste emulsion, etc.; the difficult fuel feed inlet 115 is connected to the difficult fuel discharge valve 5 to feed the raw material into the difficult fuel discharge valve 5. The fuel feed inlet 15; the first alternative fuel feed inlet 116 is connected to the pneumatic conveying device or the pumping device, and is used to spray the fuel from the first alternative fuel feed inlet 116 into the air inlet duct 114 through the pneumatic conveying device or the pumping method; the difficult fuel feed inlet 115 and the first alternative fuel feed inlet 116 can be multiple; 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 connect with the bed material; a bed material unloading valve 3 is provided between the bed material feed inlet 117 and the bed material, and the bed material The material is fed into the bed material feeding inlet 117 through the bed material unloading valve 3; a second alternative fuel feeding inlet 118 is provided on the side of the vortex chamber 112 and located on the top surface of the air inlet duct 114, and the second alternative fuel feeding inlet 118 is used to feed light alternative fuels, such as biomass, waste textiles, etc.; the second alternative fuel feeding inlet 118 is connected to the feeding device 2, and the light alternative fuel is fed into the second alternative fuel feeding inlet 118 through the feeding device 2; the second alternative fuel feeding inlet 118 can be multiple, arranged along the circumferential direction of the volute.

[0026] The suspension section 120 includes a suspension chamber 121, which is arranged above the vortex gasification section 110 and connected to the upper constriction 111 thereof. The suspension chamber 121 adopts a cylindrical structure, and a third alternative fuel feed inlet 122 is arranged on the side of the suspension chamber 121, and a smoke outlet 123 is arranged on the top surface of the suspension chamber 121, and the smoke outlet 123 is connected to a smoke delivery pipeline; the third alternative fuel feed inlet 122 is connected to the rotary air lock feeder 4, and the third alternative fuel feed inlet 122 is fed through the rotary air lock feeder 4. The air inlet pipeline is provided with a first air volume regulating valve, and the smoke delivery pipeline is provided with a second air volume regulating valve; the air inlet pipeline is connected to the high-temperature smoke, and the source of the high-temperature smoke can be the smoke chamber of the decomposition furnace, and the smoke delivery pipeline can be connected to the air inlet of the decomposition furnace, so as to play the role of alternative fuel; the air volume and pressure of the smoke entering the vortex gasification device are controlled by adjusting the opening of the first air volume regulating valve and the second air volume regulating valve.

[0027] The fluidized bed section 130 is located at the bottom of the vortex gasification section 110 and is connected to its lower constriction 113. The fluidized bed section 130 includes an air distribution plate 131 and a bed material layer 132 arranged on the upper part of the air distribution plate 131. The air distribution plate 131 is provided with a first slag outlet 133, and the first slag outlet 133 is provided with a first ash discharge valve 6.

[0028] 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 , and a second slag outlet 143 is provided at the bottom of the air chamber 141 . The second slag outlet 143 is provided with a second ash discharge valve 7 . The air inlet 142 is connected to the air blower 8 .

[0029] The gasification process of the utility model device is as follows:

[0030] like Figure 3 As shown, when the alternative fuel vortex gasification device 1 is used, different types of alternative fuels can be fed in proportion from the corresponding first alternative fuel feeding port 118, the second alternative fuel feeding port 116, and the third alternative fuel feeding port 122, or only one alternative fuel can be used at a time, but the overall stability of the calorific value of the added alternative fuel needs to be ensured as much as possible, so that not only the temperature of the vortex gasification section 120 can be controlled to be stable, but also the stability of gas production can be ensured, thereby ensuring the stability of the decomposition furnace 11 of the cement burning system; the bed material of the alternative fuel vortex gasification device 1 can be quartz sand, and the bed material is fed through the bed material feeding port 117 by opening the bed material unloading valve 3;

[0031] Light alternative fuels such as biomass, waste textiles, etc. can be fed into the vortex chamber 112 of the alternative fuel vortex gasification device 1 from the second alternative fuel feeding port 118 through the feeding device 2; powdered alternative fuels such as coal gangue, rice husks, sawdust, etc., paste alternative fuels such as semi-solid sludge, oil sludge, hazardous waste after matching, etc., liquid alternative fuels such as waste engine oil, waste emulsion, etc., can all be sprayed into the air inlet duct 114 of the alternative fuel vortex gasification device 1 from the first alternative fuel feeding port 116 through a pneumatic conveying device or a pumping method; and then evenly enter the vortex chamber 112 under the drive of the high-temperature kiln gas; heavy alternative fuels such as waste tire pieces, oil residue, etc. can be fed into the suspension section 121 of the alternative fuel vortex gasification device 1 from the third alternative fuel feeding port 122, and slowly enter the vortex chamber 112 under the drive of the high-temperature kiln gas;

[0032] The high-temperature flue gas is led out from the smoke chamber 12 of the cement burning system through the smoke outlet pipeline, enters the air inlet duct 114 through the first air volume regulating valve 9, and controls the air intake through the first air volume regulating valve 9, and forms a vortex in the vortex chamber 112 driven by its volute structure; the flue gas generated by the alternative fuel vortex gasification device 1 is sent out through the smoke outlet 123 and the smoke outlet pipeline, and enters the decomposition furnace 11 through the second air volume regulating valve 10. The negative pressure at the flue gas access point of the decomposition furnace 11 is higher than the negative pressure at the smoke chamber outlet. By adjusting the opening of the first air volume regulating valve 9 and the second air volume regulating valve 10, the amount of high-temperature flue gas entering the alternative fuel vortex gasification device 1 can be controlled, thereby controlling the temperature and heat load of the alternative fuel vortex gasification device 1;

[0033] The various alternative fuels entering the vortex chamber 112 are first driven by the vortex formed by the high-temperature flue gas, and are quickly mixed with the flue gas, and are dried, pyrolyzed, and gasified. The generated combustible gaseous products and carbon-containing fly ash are sent out through the suspension section 121, the flue gas outlet 123, and the flue gas delivery pipeline, and enter the decomposition furnace 11. They continue to burn when they meet oxygen, thereby replacing part of the fuel coal. The impurities, flame retardants, and ash mixed in the alternative fuel fall onto the fluidized bed. According to the amount of these heavy materials on the fluidized bed, the blower 8 is turned on to send air or oxygen-rich gas into the wind chamber 141, and the bed material 132 on the fluidized bed is fluidized, and the flame retardants will continue to burn. At the same time, the first ash discharge valve 6 is opened to discharge the impurities and ash. The ash falling into the wind chamber 141 can be discharged through the second ash discharge valve 7. The discharged ash can be used for cement raw material batching.

[0034] When the temperature in the vortex chamber 112 is too high, the temperature in the vortex gasification section can be controlled by opening the difficult fuel unloading valve 5 and feeding non-combustible materials such as raw meal through the difficult fuel feeding port 115 on the air inlet duct 114; when the temperature in the vortex gasification section is too low, the blower 8 is turned on, and a certain amount of air or oxygen-rich gas is blown into the air chamber 141 through the air inlet 142. The generated fluidizing wind enters the vortex chamber 112 and mixes with the high-temperature flue gas, causing the alternative fuel to undergo an oxidation reaction and generate heat to ensure the temperature in the vortex chamber 112, so that the temperature in the vortex chamber 112 is always at the most suitable pyrolysis gasification temperature for various alternative fuels.

Claims

1. An alternative fuel vortex gasification device, characterized in that: The invention comprises a vortex gasification section (110) in a volute structure for suspended pyrolysis and 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 flame-retardant and heavy materials, and a wind chamber section (140) connected to the lower part of the fluidized bed section (130) for supplying air to the fluidized bed section (130); the vortex gasification section (110) is provided with an air inlet duct (114) for communicating with high-temperature flue gas, the top of the suspension section (120) is provided with a flue gas outlet (123), and the flue gas outlet (123) is connected to a flue gas delivery pipeline; the alternative fuel vortex gasification device is also provided with an alternative fuel feed inlet, a flame-retardant fuel feed inlet (115), a bed material feed inlet (117) and a slag outlet.

2. The alternative fuel vortex gasification device according to claim 1, characterized in that: The alternative fuel feed inlet comprises a first alternative fuel feed inlet (116) disposed on the air inlet duct (114) for feeding powdered, paste-like or liquid alternative fuel, a second alternative fuel feed inlet (118) disposed on the vortex gasification section (110) for feeding light alternative fuel, and a third alternative fuel feed inlet (122) disposed on the suspension section (120) for feeding heavy alternative fuel.

3. The alternative fuel vortex gasification device according to claim 1, characterized in that: The vortex gasification section (110) comprises an upper constriction (111) connected to the suspension section (120), a vortex chamber (112) in a volute structure connected to the upper constriction (111), and a lower constriction (113) respectively connected to the vortex chamber (112) and the fluidized bed section (130); the air inlet duct (114) is connected to the vortex chamber (112).

4. The alternative fuel vortex gasification device according to claim 3, characterized in that: The bed material feeding port (117) is arranged on the side of the upper constriction (111).

5. The alternative fuel vortex gasification device according to claim 1, characterized in that: The suspension section (120) comprises a suspension chamber (121) located at the upper part of the vortex gasification section (110) and connected to the vortex gasification section (110), and the smoke outlet (123) is located at the top of the suspension chamber (121).

6. The alternative fuel vortex gasification device according to claim 1, characterized in that: The fluidized bed section (130) comprises an air distribution plate (131) and a bed material layer (132) arranged on the upper part of the air distribution plate (131).

7. The alternative fuel vortex gasification device according to claim 1, characterized in that: The wind chamber section (140) comprises a wind chamber (141), and the wind chamber (141) is provided with an air inlet (142) connected to the air blower (4).

8. The alternative fuel vortex gasification device according to claim 1, characterized in that: The slag outlet comprises a first slag outlet (133) connected to the fluidized bed section (130).

9. The alternative fuel vortex gasification device according to claim 1, characterized in that: The slag outlet comprises a second slag outlet (143) communicated with the wind chamber section (140).

Images