High-efficiency incineration hearth for PTA (pure terephthalic acid) oxidation residue waste liquid

Abstract

The invention relates to a PTA oxidation residue waste liquid efficient incineration hearth, and relates to the technical field of chemical waste residue waste liquid treatment, the PTA oxidation residue waste liquid efficient incineration hearth comprises a heat insulation hearth, the heat insulation hearth is internally provided with a preheating section, a high-temperature incineration section, a quenching section, a cooling section and an ash hopper in sequence from top to bottom; the preheating section, the high-temperature burning section, the quenching section, the cooling section and the ash hopper are all lined with alkali-resistant fireproof layers with the thickness of 200 mm and heat insulation layers with the thickness of 150 mm. The device operation condition can be improved, the blocking risk is reduced, and long-period stable operation of the system is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical waste residue and waste liquid treatment technology, and particularly relates to a PTA oxidation residue and waste liquid efficient incineration hearth. BACKGROUND

[0002] Purified terephthalic acid (PTA) is a basic raw material for producing polyester fiber and PET resin. PTA oxidation residue and waste liquid is complex in composition (containing benzene series, acetic acid, cobalt / manganese catalyst, etc.). The existing incineration technology mostly adopts a membrane water-cooled wall hearth for incineration. The waste liquid is sprayed into the hearth by a spray gun and is atomized and incinerated under the accompanying combustion of fuel gas. The incineration generates salts such as sodium carbonate and sodium bromide. The hearth temperature is about 1300-1400 DEG C. The sodium carbonate and sodium bromide are in a molten state at this temperature. The salt is taken to the bottom of the incinerator by the flue gas and is discharged by a bottom sluice. The membrane water-cooled wall hearth is externally lined with about 50-60 mm thick refractory material. The boiler cools the refractory material.

[0003] However, in the actual production process, the existing membrane water-cooled wall furnace incineration technology has the following defects: (1) Furnace refractory coking and corrosion: PTA oxidation residue waste liquid incineration will generate more sodium carbonate and sodium bromide. The mixed salt is in a molten state at high temperature, which is easy to react with alumina in the refractory material to form sodium metaaluminate, causing alkali explosion, and the refractory material is easy to break off. The thickness of the refractory material is only 50-60mm thick. After a period of corrosion, the membrane water-cooled wall will be exposed to the flue gas, and the salt in the flue gas will cause serious corrosion of the pipe wall, causing the boiler to leak and shut down, affecting the service life of the equipment; (2) Strong ash adhesion: PTA oxidation residue waste liquid incineration will generate more sodium carbonate and sodium bromide. The mixed salt is in a molten state at high temperature, even if the flue gas temperature is reduced in the membrane water-cooled wall passage, the ash temperature cannot be truly reduced, and the center hot core temperature of the ash in the flue gas is still high, in a molten state, when encountering the cold part of the boiler convection tube bundle and the ash bucket, coking and blocking will occur, causing the heating surface and the ash discharge channel to be blocked, and the boiler cannot continue to operate in severe cases; (3) Uneven heat load: The membrane water-cooled wall mainly uses radiation heat transfer. When waste liquid and fuel gas are mixed and burned, the water-cooled wall will cool and heat the flue gas, and the temperature field distribution on the furnace cross section is uneven, and the local temperature may be lower than 1100℃, causing incomplete combustion of part of the organic matter in the waste liquid; (4) Nitrogen oxide emission exceeds the standard: The membrane water-cooled wall furnace needs to ensure that the outlet temperature is above 1100℃, and the high-temperature combustion section needs to reach 1300℃-1400℃. This temperature range is the interval for the generation of a large amount of high-temperature thermal NOx, so the membrane water-cooled wall furnace generates more NOx than other furnaces, which puts a lot of pressure on flue gas emission; (5) Energy waste: The main component of PTA oxidation residue waste liquid is water, which needs a lot of heat during incineration. Due to the high-temperature combustion of the membrane water-cooled wall furnace, the furnace temperature needs to reach 1300℃-1400℃, which requires more energy absorption than adiabatic furnaces, so the fuel gas consumption requirement is higher, causing energy waste. SUMMARY

[0004] In order to improve the operation of the equipment, reduce the risk of blockage, and realize long-period stable operation of the system, the present application provides a PTA oxidation residue waste liquid efficient incineration furnace.

[0005] The PTA oxidation residue waste liquid efficient incineration furnace provided by the present application adopts the following technical solution: A PTA oxidation residue waste liquid efficient incineration furnace, comprising an adiabatic furnace, the adiabatic furnace is sequentially provided with a preheating section, a high-temperature incineration section, a quenching section, a cooling section and an ash bucket from top to bottom, and the preheating section, the high-temperature incineration section, the quenching section, the cooling section and the ash bucket are all lined with a 200mm thick refractory layer and a 150mm thick insulation layer; The preheating section is vertical and cylindrical, and a burner is fixedly installed at the top of the preheating section, which is used to continuously generate high-temperature stable flue gas in the preheating section, and the flue gas generated by the burner has a temperature higher than 1100 DEG C and lower than 1300 DEG C. The high-temperature incineration section is vertical and cylindrical, and has an inner diameter larger than that of the preheating section, and a shoulder-shaped slope section is formed at one end of the high-temperature incineration section close to the preheating section, and a plurality of waste liquid spray guns are fixedly installed on the shoulder-shaped slope section, the waste liquid spray guns are arranged at equal intervals on the shoulder-shaped slope section, a fuel gas spray gun is installed beside each waste liquid spray gun, and the waste liquid spray gun and the fuel gas spray gun are both arranged in an inclined downward manner; an annular combustion-supporting air tank is fixedly installed on the outside of the high-temperature incineration section, and a cyclone generating mechanism is arranged at each waste liquid spray gun; The quenching section is vertical and cylindrical, and annular flue gas distribution tanks are installed on the outer sidewall of the quenching section at equal intervals along the axial direction, a plurality of inlet smoke tanks are uniformly arranged on the flue gas distribution tank along the circumferential direction, low-temperature circulating flue gas flows in the flue gas distribution tank, the flue gas distribution tank is in communication with the inner cavity of the quenching section, and a layered quenching structure for quenching and cooling the outer layer, the middle layer and the inner layer of high-temperature waste gas is installed on the flue gas distribution tank; The cooling section is vertical and cylindrical, and an outlet for discharging the cooled flue gas is formed in the sidewall of the cooling section; The ash hopper is funnel-shaped, and a slag discharge port for discharging the ash slag is formed in the bottom of the ash hopper, and a slag removing machine is connected to the slag discharge port.

[0006] By adopting the above technical scheme, the preheating section is adopted, the stable flame is generated by the burner, the high-temperature stable flue gas is continuously maintained, the stable temperature environment is provided for the combustion of the waste liquid, the waste liquid is quickly ignited after being atomized, and the combustion effect of the waste liquid is improved; the PTA waste liquid enters the inner cavity of the high-temperature incineration section in the form of waste liquid spray after being atomized by the waste liquid spray gun arranged in multiple zones, the particle size of the waste liquid can be reduced, the benzene series, acetic acid, cobalt / manganese catalyst and other organic matters in the waste liquid are ignited by the high-temperature stable flue gas sprayed by the burner, and the fuel gas spray gun is used in cooperation, the fuel gas can be continuously supplemented, heat is generated after the fuel gas is ignited, the heat consumed by the supplemented waste liquid incineration can be made, the temperature in the high-temperature incineration section is stably maintained at 1100-1300 DEG C, a stable temperature is provided for the waste liquid incineration, and the consumption of the fuel gas can be reduced, thereby saving the use cost of the incinerator. At the same time, since the waste liquid and the fuel gas are atomized and sprayed in multiple zones, the heating surface of the waste liquid and the fuel gas can be increased, the incineration rate of the waste liquid and the fuel gas can be effectively guaranteed, and the content of toxic and harmful substances in the waste gas generated by the waste liquid combustion can be reduced. In addition, the waste liquid spray gun is arranged in an inclined downward manner, the contact area between the atomized waste liquid and the high-temperature flue gas generated by the burner can be further increased, and the incineration effect of the waste liquid can be improved. Since the temperature in the inner cavity of the high-temperature incineration section is always stably maintained at 1100-1300 DEG C, the good incineration rate of the waste liquid can be guaranteed, and the NOx gas generated due to high temperature can be reduced. After the high-temperature waste gas generated by the waste liquid combustion enters the inner cavity of the quenching section, the low-temperature circulating flue gas in the flue gas distribution box enters the inner cavity of the quenching section through the quenching layered structure, the outer layer, the middle layer and the inner layer of the high-temperature waste gas generated by the waste liquid combustion can be subjected to layered cooling treatment by the low-temperature circulating flue gas, the high-temperature waste gas generated by the waste liquid combustion can be subjected to zoned and layered cooling treatment, the high-temperature waste gas generated by the waste liquid combustion can be quickly cooled in each region, the sodium carbonate and sodium bromide molten salt generated in the high-temperature waste gas can be cooled and solidified, and then subjected to gravity settling in the ash bucket, thereby preventing the molten salt in the molten state from falling to the inner wall of the ash bucket to cause the bottom ash discharge port of the ash bucket to be blocked, and reducing the reaction between the molten salt adhered to the surface of the refractory layer and the alumina in the refractory layer, thereby prolonging the service life of the refractory layer. The ash in the flue gas is settled by gravity and falls into the ash bucket, and is discharged after being cooled by the ash discharge machine.

[0007] Preferably, the refractory layer is composed of a composite Al-Si-Mg series alkali-resistant refractory brick, and the refractory layer has an apparent porosity of 10% or less.

[0008] By adopting the technical scheme, the Al-Si-Mg series alkali-resistant refractory brick has a crystal phase structure different from traditional corundum bricks, has good alkali resistance and corrosion resistance, and has a porosity of less than 10%, so that the molten salt is less likely to penetrate into the refractory layer and react with the aluminum oxide in the refractory layer to cause the refractory layer to break and fall off, thereby prolonging the service life of the incinerator.

[0009] Preferably, the burner is a high-efficiency low-nitrogen burner, and the high-efficiency low-nitrogen burner uses high-calorific-value fuel as fuel.

[0010] By adopting the technical scheme, the low-nitrogen oxide burner refers to a burner with low nitrogen oxide emissions during fuel combustion. The use of a low-nitrogen oxide burner can reduce nitrogen oxide emissions during combustion.

[0011] Preferably, the cyclone generating mechanism includes cyclone devices and a fairing, a plurality of installation holes are formed in the shoulder-shaped slope section, and the plurality of cyclone devices are sealingly installed in the installation holes. The cyclone devices are coaxially sealingly arranged on the waste liquid injection lance, and the cyclone blades of the cyclone devices are coaxially and uniformly arranged on the periphery of the waste liquid injection lance. The fairing is fixedly installed on the outer side wall of the shoulder-shaped slope section, the fairing is coaxially arranged outside the installation hole, and a plurality of groups of air holes are formed in the fairing and are uniformly arranged in a circumferential array.

[0012] By adopting the technical scheme, the high-pressure combustion air in the combustion air box is uniformly distributed by the fairing, and then guided by the cyclone piece, so that the high-pressure combustion air forms a cyclone and enters the inner cavity of the high-temperature incineration section. The cyclone combustion air carries the atomized waste liquid, which can increase the turbulence of the atomized waste liquid, further contact the atomized waste liquid particles, fuel gas and high-temperature flue gas in the high-temperature incineration section, and further improve the incineration rate of the waste liquid.

[0013] Preferably, the low-temperature circulating flue gas flowing in the flue gas distribution box is the flue gas after the waste liquid is burned after being cooled.

[0014] By adopting the technical scheme, the low-temperature flue gas is the flue gas after the waste liquid is burned after being cooled. By recycling the flue gas after the waste liquid is burned, the cost of cooling the high-temperature flue gas after combustion is saved, and since the cooling medium and the high-temperature flue gas after combustion have the same composition, the cooling medium and the high-temperature flue gas after combustion can be prevented from reacting.

[0015] Preferably, the temperature of the circulating flue gas is 200-250 DEG C.

[0016] Preferably, the layered quenching structure comprises a plurality of outer-layer quenching nozzles, a plurality of middle-layer quenching nozzles and a plurality of inner-layer quenching nozzles, which are arranged in layers from top to bottom, and the lengths of the outer-layer quenching nozzles, the middle-layer quenching nozzles and the inner-layer quenching nozzles extending into the inner cavity of the quenching section gradually increase along the flow direction of the exhaust gas after combustion, and the time length of the high-temperature exhaust gas generated after combustion of the waste liquid passing through the outer-layer quenching nozzles, the middle-layer quenching nozzles and the inner-layer quenching nozzles is 0.2s.

[0017] By adopting the above technical scheme, the outer layer of the high-temperature exhaust gas generated after combustion of the exhaust gas can be cooled by the outer-layer quenching nozzle; the middle layer of the high-temperature exhaust gas generated after combustion of the exhaust gas can be cooled by the middle-layer quenching nozzle; and the middle layer of the high-temperature exhaust gas generated after combustion of the exhaust gas can be cooled by the inner-layer quenching nozzle. By mutual matching and use of the outer-layer quenching nozzle, the middle-layer quenching nozzle and the inner-layer quenching nozzle, the high-temperature exhaust gas after combustion of the waste liquid can be cooled in zones and layers, so that the molten salt in each region of the high-temperature exhaust gas can be cooled and solidified into solid particles.

[0018] Preferably, a cooling nozzle is mounted on the ash bucket, and a nozzle opening of the cooling nozzle is in communication with the inner cavity of the ash bucket.

[0019] By adopting the above technical scheme, the ash settled in the ash bucket can be further cooled by the cooling nozzle, which facilitates the subsequent ash discharging machine to discharge the ash in the ash bucket.

[0020] Preferably, an adjusting cover is rotatably mounted on the fairing, a plurality of waist-shaped holes are formed through the adjusting cover, the plurality of waist-shaped holes are respectively arranged with a group of air holes, and the width of the waist-shaped hole is the same as the diameter of the air hole. An adjusting gear ring is integrally formed on the outer side wall of the adjusting cover, a plurality of servo motors are fixedly installed on the outer side wall of the shoulder-shaped slope section, a driving gear is fixedly installed on the driving end of the plurality of servo motors through a shaft coupling, and the driving gear is engaged with the adjusting gear ring.

[0021] By adopting the above technical scheme, the adjusting cover can be driven to rotate by the driving gear through the servo motor, so as to realize the technical effect of adjusting the exposed area of the air hole. By adjusting the exposed area of the air hole, the rotational flow intensity of the rotational flow combustion-supporting wind generated by the rotational flow device can be adjusted to meet the needs of different working conditions.

[0022] In summary, the PTA oxidation residue waste liquid high-efficiency incinerator furnace has at least one of the following beneficial technical effects: 1The preheating section is adopted, the stable flame is generated by the burner, the high-temperature stable flue gas is continuously maintained, the stable temperature environment is provided for the combustion of the waste liquid, the waste liquid is quickly ignited after atomization, and the combustion effect of the waste liquid is improved; the PTA waste liquid is atomized by the waste liquid spray gun arranged in several zones, and then enters the inner cavity of the high-temperature incineration section in the form of waste liquid spray, which can reduce the particle size of the waste liquid, the benzene series, acetic acid, cobalt / manganese catalyst and other organic matters in the waste liquid are ignited by the high-temperature stable flue gas sprayed by the burner, and the fuel gas spray gun is used, the fuel gas can be continuously supplemented, the heat is generated after the fuel gas is ignited, the heat consumed by the supplemented waste liquid incineration can make the temperature in the high-temperature incineration section stable between 1100~1300℃, which can provide a stable temperature for the waste liquid incineration, and can reduce the consumption of fuel gas and save the use cost of the incinerator; at the same time, since the waste liquid and fuel gas are atomized and sprayed in zones, the heating surface of the waste liquid and fuel gas can be increased, which can effectively guarantee the incineration rate of the waste liquid and fuel gas, and reduce the content of toxic and harmful substances in the waste gas generated by the waste liquid combustion; in addition, the waste liquid spray gun is arranged obliquely downward, which can further increase the contact area between the atomized waste liquid and the high-temperature flue gas generated by the burner, and improve the incineration effect of the waste liquid. Since the temperature in the inner cavity of the high-temperature incineration section is always stable between 1100~1300℃, the good incineration rate of the waste liquid can be guaranteed, and the generation of NOx gas caused by high temperature can be reduced; 2After the high-temperature waste gas generated by the waste liquid combustion enters the quenching section, the low-temperature circulating flue gas in the flue gas distribution box enters the inner cavity of the quenching section through the quenching layered structure, which can perform layered cooling treatment on the outer layer, middle layer and inner layer of the high-temperature waste gas generated by the waste liquid combustion through the low-temperature circulating flue gas, and can perform zoned and layered cooling treatment on the high-temperature waste gas generated by the waste liquid combustion, so that the high-temperature waste gas generated by the waste liquid combustion can be quickly cooled in each region, the sodium carbonate and sodium bromide molten salt generated in the high-temperature waste gas can be solidified and then settled in the ash bucket under the action of gravity, so that the molten salt in the molten state cannot fall to the inner wall of the ash bucket to cause the blockage of the residue discharge port at the bottom of the ash bucket, and the molten salt adhered to the surface of the refractory layer and penetrated into the refractory layer can be reduced, so that the reaction between the molten salt and the alumina in the refractory layer can be avoided to cause the fracture and falling of the refractory layer, and the service life of the refractory layer can be prolonged; 3The cyclone device and the fairing are matched and used, the high-pressure combustion air in the combustion air box can be uniformly distributed by the fairing, and then guided by the cyclone vane, so that the high-pressure combustion air forms a cyclone and enters the inner cavity of the high-temperature incineration section, the atomized waste liquid is wrapped and carried by the cyclone combustion air, the turbulence of the atomized waste liquid can be increased, the atomized waste liquid particles, fuel gas and high-temperature flue gas in the high-temperature incineration section can be further contacted and ignited, and the incineration rate of the waste liquid can be further improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the whole structure of the incinerator.

[0024] Figure 2 is a schematic diagram for showing the incineration process of the incinerator according to an embodiment of the present application.

[0025] Figure 3 is a schematic diagram for showing the overall structure of the fairing according to an embodiment of the present application.

[0026] Figure 4 is a schematic diagram for showing the connection relationship among the fairing, the adjusting cover and the servo motor according to an embodiment of the present application.

[0027] Figure 5 is a schematic diagram for showing the positional relationship between the waist-shaped hole and the air hole according to an embodiment of the present application.

[0028] Legend: 1, preheating section; 11, burner; 2, high-temperature incineration section; 21, shoulder-shaped slope section; 22, waste liquid injection lance; 23, mounting hole; 24, cyclone device; 25, fairing; 251, air hole; 26, adjusting cover; 261, waist-shaped hole; 262, gear ring; 27, servo motor; 28, mounting seat; 29, combustion air box; 3, quenching section; 31, flue gas distribution box; 32, inlet flue gas box; 33, outer layer quenching injection pipe; 34, middle layer quenching injection pipe; 35, inner layer quenching injection pipe; 4, cooling section; 41, outlet; 411, waste gas purification device; 412, waste gas cooling device; 5, ash bucket; 51, ash discharge port; 52, cooling injection pipe; 53, ash discharging machine; 6, refractory layer; 7, heat insulation layer. DETAILED DESCRIPTION

[0029] The following will be described in detail in combination with Figures 1-5 The present application is further described in detail.

[0030] Embodiment 1 The present application discloses a PTA oxidation residue waste liquid high-efficiency incinerator hearth. Referring to Figures 1-3 , which mainly comprises an adiabatic hearth, the adiabatic hearth is sequentially provided with a preheating section 1, a high-temperature incineration section 2, a quenching section 3, a cooling section 4 and an ash bucket 5 in the direction from top to bottom, the preheating section 1, the high-temperature incineration section 2, the quenching section 3, the cooling section 4 and the ash bucket 5 are all lined with a 200mm-thick alkali-resistant refractory layer 6 and a 150mm-thick heat insulation layer 7, and the alkali-resistant refractory layer 6 is located on the inner side of the heat insulation layer 7.

[0031] The refractory layer 6 is composed of composite Al-Si-Mg alkali-resistant refractory bricks. The apparent porosity of the traditional corundum-based refractory bricks is between 20% and 30%, and the Al-Si-Mg alkali-resistant refractory bricks have a crystal phase structure different from that of the traditional corundum bricks, and have good alkali resistance and corrosion resistance. In addition, the Al-Si-Mg alkali-resistant refractory bricks have an apparent porosity of less than 10%. Therefore, the molten salt can further reduce the penetration of the molten salt into the refractory layer 6 and the reaction of the molten salt with the aluminum oxide in the refractory layer 6, thereby prolonging the service life of the incinerator.

[0032] The preheating section 1 is a vertical cylinder, and a burner 11 is fixedly installed at the top of the preheating section 1. The burner 11 is used to continuously generate high-temperature stable flue gas in the preheating section 1. The flue gas generated by the burner 11 has a temperature higher than 1100°C and lower than 1300°C.

[0033] The preheating section 1 is used to generate stable flame by the burner 11, continuously maintain high-temperature stable flue gas, and provide a stable temperature environment for the combustion of waste liquid, thereby ensuring the rapid ignition of the atomized waste liquid and improving the combustion effect of the waste liquid.

[0034] The burner 11 is a high-efficiency low-nitrogen burner 11, and the high-efficiency low-nitrogen burner 11 uses high-calorific-value fuel as fuel. The low-nitrogen-oxide burner 11 refers to a burner 11 with low nitrogen oxide emissions during fuel combustion. The use of the low-nitrogen-oxide burner 11 can reduce the emission of nitrogen oxides during combustion.

[0035] Since the flue gas generated by the burner 11 has a temperature of 1100°C or higher and 1300°C or lower, the organic matter and harmful substances in the waste liquid can be completely incinerated, and the content of NOx in the flue gas after combustion can be further reduced, thereby avoiding the generation of a large amount of thermal NOx.

[0036] Referring to Figure 1 The high-temperature incineration section 2 is a vertical cylinder, and the inner diameter of the high-temperature incineration section 2 is greater than that of the preheating section 1. A shoulder-shaped slope section 21 is formed at one end of the high-temperature incineration section 2 close to the preheating section 1. A plurality of waste liquid lances 22 are fixedly installed on the shoulder-shaped slope section 21. The waste liquid lances 22 are arranged at equal intervals on the shoulder-shaped slope section 21. Fuel gas lances are installed beside the waste liquid lances 22. The waste liquid lances 22 and the fuel gas lances are both inclined downward. In this embodiment, the atomized waste liquid stays in the high-temperature incineration section 2 for more than 2 seconds.

[0037] The PTA waste liquid is atomized by the waste liquid spray gun 22 arranged in several sections and enters the inner cavity of the high-temperature incineration section 2 in the form of waste liquid spray, which can reduce the particle size of the waste liquid. The benzene series, acetic acid, cobalt / manganese catalyst and other organic matters in the waste liquid are ignited by the high-temperature stable flue gas sprayed by the burner 11, and the fuel gas spray gun is used to continuously supplement the fuel gas. After the fuel gas is ignited, heat is generated, which can make up for the heat consumed by the incineration of the waste liquid, stabilize the temperature in the high-temperature incineration section 2 at 1100-1300℃, provide a stable temperature for the incineration of the waste liquid, and reduce the consumption of fuel gas, saving the use cost of the incinerator. At the same time, since the waste liquid and fuel gas are atomized and sprayed in sections, the heating surface of the waste liquid and fuel gas can be increased, which can effectively guarantee the incineration rate of the waste liquid and fuel gas and reduce the content of toxic and harmful substances in the waste gas generated by the combustion of the waste liquid. In addition, the waste liquid spray gun 22 is arranged obliquely downward, which can further increase the contact area between the atomized waste liquid and the high-temperature flue gas generated by the burner 11, and improve the incineration effect of the waste liquid. Since the temperature in the inner cavity of the high-temperature incineration section 2 is always stable at 1100-1300℃, the good incineration rate of the waste liquid can be guaranteed, and the generation of NOx gas caused by high temperature can be reduced.

[0038] Referring to Figure 1 In this embodiment, in order to further improve the incineration rate of the waste liquid, an annular combustion-supporting air box 29 is fixedly installed on the outside of the high-temperature incineration section 2, and a cyclone generating mechanism is arranged at each of the several waste liquid spray guns 22.

[0039] The cyclone generating mechanism includes a cyclone device 24 and a fairing 25. A plurality of installation holes 23 are formed in the shoulder-shaped slope section 21, and the cyclone devices 24 are sealingly installed in the installation holes 23. The cyclone device 24 is coaxially sealingly arranged on the waste liquid spray gun 22, and the cyclone blades of the cyclone device 24 are coaxially and uniformly arranged on the periphery of the waste liquid spray gun 22. The fairing 25 is fixedly installed on the outer wall of the shoulder-shaped slope section 21, and the fairing 25 is coaxially arranged outside the installation hole 23. A plurality of groups of air holes 251 are formed in the fairing 25, and the air holes 251 are uniformly arranged in a circumferential array.

[0040] Referring to Figure 3 In this embodiment, the fairing 25 has six groups of air holes 251, and each group has three air holes 251. The six groups of air holes 251 are uniformly distributed along the axis of the fairing 25.

[0041] The quenching section 3 is a vertical cylinder, and annular flue gas distribution boxes 31 are mounted on the outer wall of the quenching section 3 at equal intervals in the axial direction. Low-temperature circulating flue gas flows in the flue gas distribution boxes 31, and inlet flue gas boxes 32 are mounted on the flue gas distribution boxes 31. The flue gas distribution boxes 31 are provided with a layered quenching structure for quenching and cooling the outer layer, the middle layer and the inner layer of the high-temperature flue gas. After heat exchange with the three layers of low-temperature circulating flue gas, the high-temperature flue gas after waste liquid combustion is cooled to a temperature of 550-650°C after passing through the quenching section 3.

[0042] It should be noted that in the present embodiment, the low-temperature flue gas is the flue gas after waste liquid combustion after cooling to a temperature of 200-250°C. By recycling the flue gas after waste liquid combustion, the cost of cooling the high-temperature flue gas after combustion is saved. At the same time, since the cooling medium and the high-temperature flue gas after combustion have the same composition, the reaction between the cooling medium and the high-temperature flue gas can be avoided.

[0043] Referring to Figure 1 , the layered quenching structure includes a plurality of outer layer quenching nozzles 33, a plurality of middle layer quenching nozzles 34 and a plurality of inner layer quenching nozzles 35. The outer layer quenching nozzles 33, the middle layer quenching nozzles 34 and the inner layer quenching nozzles 35 are arranged in layers in the direction from top to bottom, and the lengths of the outer layer quenching nozzles 33, the middle layer quenching nozzles 34 and the inner layer quenching nozzles 35 extending into the inner cavity of the quenching section 3 gradually increase in the flow direction of the flue gas after combustion. The high-temperature flue gas after waste liquid combustion passes through the outer layer quenching nozzles 33, the middle layer quenching nozzles 34 and the inner layer quenching nozzles 35 for a time of 0.2s.

[0044] The outer layer of the high-temperature flue gas after waste liquid combustion can be cooled by the outer layer quenching nozzles 33. The middle layer of the high-temperature flue gas after waste liquid combustion can be cooled by the middle layer quenching nozzles 34. The inner layer of the high-temperature flue gas after waste liquid combustion can be cooled by the inner layer quenching nozzles 35. By using the outer layer quenching nozzles 33, the middle layer quenching nozzles 34 and the inner layer quenching nozzles 35 together, the high-temperature flue gas after waste liquid combustion can be cooled in zones and layers, so that the molten salt in each zone of the high-temperature flue gas can be solidified into solid particles by cooling, and the molten salt in the molten state can be prevented from falling onto the inner wall of the ash bucket 5 to cause the bottom discharge port 51 of the ash bucket 5 to be blocked. At the same time, the molten salt can be prevented from adhering to the surface of the refractory layer 6, penetrating into the refractory layer 6 and reacting with the alumina in the refractory layer 6 to cause the refractory layer 6 to break and fall off, thereby prolonging the service life of the refractory layer 6.

[0045] It should be noted that in some other embodiments, according to the actual needs of use, the number of quenching nozzles can be increased, and the lengths of the quenching nozzles extending into the inner cavity of the quenching section 3 can be adjusted, which are not limited and described here.

[0046] In addition, the contact area of the flue gas with the refractory layer 6 is increased at the outer layer quenching nozzle 33, the middle layer quenching nozzle 34 and the inner layer quenching nozzle 35.

[0047] The high-temperature flue gas passing through the quenching section 3 continues to be cooled in the cooling section 4. The side wall of the cooling section 4 is provided with an outlet 41 for the flue gas after the waste liquid is burned. The outlet 41 is connected to the flue gas purification device 411 and the flue gas cooling device 412 through a flue gas pipeline.

[0048] In the embodiment, the passing time of the flue gas in the inner cavity of the cooling section 4 is 2s, which can completely debond the ash in the flue gas to ensure smooth ash and slag discharge and prevent the ash and slag from adhering to the inner wall of the hearth and blocking the slag discharge port 51. The ash in the flue gas is settled by gravity and falls into the ash hopper 5. After cooling, the ash is discharged through the slagging machine 53.

[0049] Through the cooperation and use of the burner 11, the waste liquid spray gun 22 and the fuel gas spray gun, the organic matter in the waste liquid can be incinerated at a temperature of 1100-1300℃. This can ensure complete combustion of the organic matter, reduce the content of the organic matter and harmful components in the flue gas after combustion, and avoid the generation of a large amount of high-temperature thermal NOx.

[0050] It should be noted that in the embodiment, the low-temperature flue gas circulating in the flue gas distribution box 31 is the flue gas after the waste liquid is burned after being cooled. The temperature of the circulating flue gas is 200-250℃.

[0051] The low-temperature flue gas is the flue gas after the waste liquid is burned after being cooled. The flue gas can be recycled, which saves the cost of cooling the high-temperature flue gas after combustion. In addition, since the composition of the cooling medium and the high-temperature flue gas after combustion is the same, the cooling medium and the high-temperature flue gas after combustion can be prevented from reacting.

[0052] Referring to Figure 1 The ash hopper 5 is provided with a cooling spray pipe 52, and the nozzle of the cooling spray pipe 52 communicates with the inner cavity of the ash hopper 5. Through the cooling spray pipe 52, the ash in the ash hopper 5 can be further cooled, and the cooling of the ash in the ash hopper 5 is accelerated, which facilitates the subsequent discharge of the ash by the slagging machine 53.

[0053] The implementation principle of the high-efficiency incineration furnace for PTA oxidation residue waste liquid in this application embodiment is as follows: A preheating section 1 is used, where a burner 11 generates a stable flame and continuously maintains high-temperature and stable flue gas, providing a stable temperature environment for the combustion of the waste liquid, ensuring rapid ignition of the atomized waste liquid, and improving the combustion effect. The PTA waste liquid is atomized by waste liquid spray guns 22 arranged in several sections and enters the inner cavity of the high-temperature incineration section 2 in the form of a waste liquid spray, which can reduce the particle size of the waste liquid. Organic substances such as benzene compounds, acetic acid, and cobalt / manganese catalyst in the waste liquid are ignited by the high-temperature and stable flue gas sprayed from the burner 11. In conjunction with a fuel gas spray gun, fuel gas can be continuously replenished. The ignition of the fuel gas generates heat. The increased temperature of the high-temperature incineration section 2 replenishes the heat consumed in the incineration of waste liquid, stabilizing the temperature between 1100 and 1300°C. This provides a stable temperature for waste liquid incineration and reduces fuel gas consumption, saving on incinerator operating costs. Simultaneously, the atomized waste liquid and fuel gas are sprayed in separate zones, increasing their surface area for heating and ensuring a high incineration rate, while reducing the content of toxic and harmful substances in the exhaust gas. Furthermore, the downward tilt of the waste liquid spray gun 22 further increases the contact area between the atomized waste liquid and the high-temperature flue gas generated by the burner 11, improving the incineration effect. Because the temperature inside the high-temperature incineration section 2 remains stable between 1100 and 1300°C, a good incineration rate is ensured while reducing NOx gas emissions associated with high temperatures. After the high-temperature exhaust gas generated from the combustion of waste liquid enters the quenching section 3, the low-temperature circulating flue gas in the flue gas distribution box 31 enters the inner cavity of the quenching section 3 through the quenching layered structure. This low-temperature circulating flue gas can perform layered cooling treatment on the outer, middle, and inner layers of the high-temperature exhaust gas generated from the combustion of waste liquid. This allows for zoned and layered cooling of the high-temperature exhaust gas, ensuring that all areas of the high-temperature exhaust gas generated from the combustion of waste liquid can be rapidly cooled. This allows the sodium carbonate and sodium bromide molten salts generated in the high-temperature exhaust gas to cool and solidify, and then settle into the ash hopper 5 under gravity. This prevents the molten salts in the molten state from falling onto the inner wall of the ash hopper 5 and clogging the bottom slag discharge port 51 of the ash hopper 5. Simultaneously, it reduces the adhesion of molten salts to the surface of the refractory layer 6, reducing the possibility of them penetrating into the interior of the refractory layer 6 and reacting with the alumina inside the refractory layer 6, which could lead to breakage and detachment of the refractory layer 6, thus extending the service life of the refractory layer 6. The ash in the flue gas settles down by gravity and falls into the ash hopper 5, and after cooling, is discharged by the slag discharger 53.

[0054] Example 2 Reference Figure 4 and Figure 5In the embodiment, the outer coaxial cover of the fairing 25 is provided with and rotationally connected with an adjusting cover 26, six waist-shaped holes 261 are formed through the adjusting cover 26, the six waist-shaped holes 261 are respectively matched with the six groups of air holes 251, the width of the waist-shaped hole 261 is the same as the diameter of the air hole 251, when the adjusting cover 26 is rotated to the position where the waist-shaped holes 261 are respectively coincided with the six groups of air holes 251, the six groups of air holes 251 are completely exposed, when the adjusting cover 26 is rotated to the position where the waist-shaped holes 261 are dislocated with the air holes 251 on the fairing 25, the exposed area of the air holes 251 can be changed. In the case that the air pressure inside the combustion air box 29 is stable, the reduction of the area of the air holes 251 can result in the reduction of the rotational flow intensity generated in the inner cavity of the high-temperature incineration section 2.

[0055] In order to achieve the technical effect of adjusting the rotational flow intensity, in the embodiment, the outer sidewall of the adjusting cover 26 is integrally provided with an adjusting gear ring 262, the outer sidewall of the shoulder-shaped slope section 21 is fixedly provided with a plurality of mounting seats 28, and the plurality of mounting seats 28 are respectively located on the sides of the adjusting cover 26.

[0056] The mounting seat 28 is provided with a servo motor 27, the driving shaft end of the servo motor 27 is provided with a driving gear, the driving gear is engaged with the adjusting gear ring 262, the servo motor 27 can drive the adjusting cover 26 to rotate through the driving gear, the exposed area of the air hole 251 can be automatically adjusted, and the technical effect of automatically adjusting the rotational flow intensity can be achieved.

[0057] Embodiment 3 In the actual production and processing process, the content of organic matter and harmful substances in the waste liquid will have a certain fluctuation range, the higher the content of water in the waste liquid, the higher the heat required for the waste liquid combustion, and the higher the usage amount of the fuel gas required for the complementary combustion, in the embodiment, in order to dynamically adjust the fuel gas injection amount of the fuel gas lance, a fuel gas control module is arranged on the incinerator.

[0058] The fuel gas control module comprises a temperature sensor, a data processor and a controller, the temperature sensor is fixedly installed on the high-temperature incineration section, the sensing end of the temperature sensor extends into the inner cavity of the high-temperature incineration section, and the temperature sensor is used for detecting the temperature of the inner cavity of the high-temperature incineration section and outputting the incineration temperature data.

[0059] The data input end of the data processor is connected with the data output end of the temperature sensor through data wires, the signal output end of the data processor is connected with the signal input end of the controller, and the controller is connected with the fuel gas lance arranged on the high-temperature incineration section.

[0060] The data processor judges the adjustment of the fuel gas lance based on the temperature data collected by the temperature sensor, increases the fuel gas flow of the fuel gas lance when the temperature in the inner cavity of the high-temperature incineration section is low, and reduces the fuel gas flow of the fuel gas lance when the temperature in the inner cavity of the high-temperature incineration section is high.

[0061] The data processor calculates the fuel gas flow adjustment amount according to the following formula: ; In the formula, K represents the fuel gas flow adjustment amount; L represents the reference flow of the fuel gas lance; T represents the current temperature of the high-temperature incineration section, in degrees Celsius; T0 represents the standard temperature of the high-temperature incineration section, in degrees Celsius; d represents the main nozzle diameter of the nozzle of the waste liquid lance, in meters; and Q represents the flow of the waste liquid lance, in cubic meters per second. In the formula, T0 represents the standard temperature of the high-temperature incineration section, in degrees Celsius; d represents the main nozzle diameter of the nozzle of the waste liquid lance, in meters; and Q represents the flow of the waste liquid lance, in cubic meters per second.

[0062] In addition, in order to further improve the incineration rate of the waste liquid, the rotational flow intensity corresponding to different rotational angles of the servo motor driven adjusting cover is calculated by a pre-test method, and a correlation curve between the rotational angle of the servo motor and the intensity value of the rotational flow intensity is constructed. While adjusting the replenishment amount of the fuel gas, the rotational flow intensity is adjusted by rotating the servo motor driven adjusting cover, the turbulence degree of the atomized waste liquid is adjusted by the rotational flow intensity of different intensities, and the incineration rate of the atomized waste liquid is ensured.

[0063] Embodiment 4 In the embodiment, the inner side wall of the refractory layer of the cooling section is provided with turbulence lines, and the turbulence lines are arranged alternately. The high-temperature flue gas after combustion and the low-temperature circulating flue gas injected through the flue gas injection pipe are further mixed, the cooling effect on the high-temperature flue gas after combustion is improved, the molten salt is solidified into small particles and discharged together with the ash, and the molten salt is prevented from adhering to the inner wall surface of the ash bucket or the pipeline connected with the ash discharge port of the ash bucket.

[0064] The above are preferred embodiments of the present application, and are not sequentially limited to the protection scope of the present application. Therefore, equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.​

Claims

1. A high-efficiency incineration furnace for PTA oxidation residue waste liquid, characterized in that, The furnace includes an insulated furnace chamber, which is arranged in sequence from top to bottom as a preheating section (1), a high-temperature incineration section (2), a rapid cooling section (3), a cooling section (4), and an ash hopper (5). The preheating section (1), the high-temperature incineration section (2), the rapid cooling section (3), the cooling section (4), and the ash hopper (5) are all lined with a 200mm thick refractory layer (6) and a 150mm thick heat insulation layer (7). The preheating section (1) is a vertical cylindrical shape, and a burner (11) is fixedly installed on the top of the preheating section (1). The burner (11) is used to continuously generate high-temperature and stable flue gas in the preheating section (1). The flue gas temperature generated by the burner (11) is higher than 1100℃ and lower than 1300℃. The high-temperature incineration section (2) is a vertical cylindrical shape, and the inner diameter of the high-temperature incineration section (2) is larger than the inner diameter of the preheating section (1). The high-temperature incineration section (2) has a shoulder-shaped slope section (21) formed at one end near the preheating section (1). Several waste liquid spray guns (22) are fixedly installed on the shoulder-shaped slope section (21). Several waste liquid spray guns (22) are arranged at equal intervals on the shoulder-shaped slope section (21). Fuel gas spray guns are installed on the sides of each waste liquid spray gun (22), and both the waste liquid spray guns (22) and the fuel gas spray guns are inclined downwards. An annular combustion-supporting air box (29) is fixedly installed on the outside of the high-temperature incineration section (2), and a swirl generation mechanism is provided at each of the several waste liquid spray guns (22). The quench section (3) is a vertical cylindrical shape. Annular flue gas distribution boxes (31) are installed at equal intervals along the axial direction on the outer wall of the quench section (3). Several inlet flue gas boxes (32) are evenly arranged along the circumference of the flue gas distribution box (31). Low-temperature circulating flue gas flows inside the flue gas distribution box (31). The flue gas distribution box (31) is connected to the inner cavity of the quench section (3). The flue gas distribution box (31) is equipped with a layered quench structure that performs quench cooling on the outer, middle, and inner layers of the high-temperature exhaust gas. The cooling section (4) is a vertical cylindrical shape, and an outlet (41) is provided on the side wall of the cooling section (4) for the exhaust of the cooled flue gas. The ash hopper (5) is funnel-shaped, and the bottom of the ash hopper (5) is provided with a slag discharge port (51) for ash and slag discharge. The slag discharge port (51) is connected to a slag removal machine.

2. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 1, characterized in that, The refractory layer (6) is composed of composite Al-Si-Mg alkali-resistant refractory bricks, and the refractory layer (6) has an apparent porosity of less than 10%.

3. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 2, characterized in that, The burner (11) is a high-efficiency low-NOx burner (11), and the high-efficiency low-NOx burner (11) uses high-calorific-value fuel as fuel.

4. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 3, characterized in that, The swirling mechanism includes a swirling device (24) and a shroud (25). A plurality of mounting holes (23) are provided on the shoulder-shaped slope section (21). A plurality of the swirling devices (24) are sealed and installed in the mounting holes (23). The swirling devices (24) are coaxially sealed on the waste liquid spray gun (22). The swirling blades of the swirling devices (24) are coaxially and evenly arranged on the periphery of the waste liquid spray gun (22). The fairing (25) is fixedly installed on the outer wall of the shoulder-shaped slope section (21). The fairing (25) is coaxially covered on the outside of the mounting hole (23). The fairing (25) has several sets of ventilation holes (251) arranged in a circular array.

5. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 4, characterized in that, The low-temperature circulating flue gas flowing in the flue gas distribution box (31) is the flue gas after the waste liquid has been burned after circulating cooling.

6. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 5, characterized in that, The temperature of the circulating flue gas is 200~250℃.

7. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 6, characterized in that, The layered quenching structure includes several outer quenching nozzles (33), several middle quenching nozzles (34), and several inner quenching nozzles (35). The outer quenching nozzles (33), middle quenching nozzles (34), and inner quenching nozzles (35) are arranged in layers evenly from top to bottom. The length of the outer quenching nozzles (33), middle quenching nozzles (34), and inner quenching nozzles (35) extending into the inner cavity of the quenching section (3) gradually increases along the flow direction of the exhaust gas after combustion. The time for the high-temperature exhaust gas generated after the combustion of the waste liquid to pass through the outer quenching nozzles (33), middle quenching nozzles (34), and inner quenching nozzles (35) is 0.2s.

8. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 1, characterized in that, A cooling nozzle (52) is installed on the ash hopper (5), and the nozzle of the cooling nozzle (52) is connected to the inner cavity of the ash hopper (5).

9. The high-efficiency incineration furnace for PTA oxidation residue waste liquid according to claim 4, characterized in that, An adjustment cover (26) is rotatably mounted on the fairing (25). A plurality of waist-shaped holes (261) are provided through the adjustment cover (26). The plurality of waist-shaped holes (261) are respectively set with a group of vent holes (251). The width of the waist-shaped holes (261) is the same as the diameter of the vent holes (251). An adjustment gear ring (262) is integrally formed on the outer wall of the adjustment cover (26), and a number of servo motors (27) are fixedly installed on the outer wall of the shoulder-shaped slope section (21). The drive ends of the servo motors (27) are fixedly installed with drive teeth through a coupling, and the drive teeth mesh with the adjustment gear ring (262).

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