Liquid waste incineration device for waste lye, distillation residues, organic waste solvents and like

Abstract

The invention discloses a waste liquid incineration device for waste lye, distillation residues, organic waste solvents and the like, and relates to the technical field of chemical hazardous waste treatment, the waste liquid incineration device comprises an incineration part, a waste heat recovery part, a flue gas up-to-standard emission treatment part and an incineration residue recovery part; the organic waste solvent, distillation residues and waste alkali liquor are burnt out together, and due to the fact that the calorific value of the organic waste solvent is high, auxiliary fuel natural gas is needed for starting and baking a furnace and an incandescent light, and the auxiliary fuel natural gas is not needed under the normal working condition; the heat insulation incinerator is arranged above one side of a cooling chamber of the waste heat boiler with the U-shaped membrane type wall structure, the membrane type wall tube panel with the Z-shaped structure penetrates through the two cooling chambers of the waste heat boiler with the U-shaped membrane type wall structure, and high-temperature flue gas with the temperature higher than 1100 DEG C can be cooled to the temperature lower than 300 DEG C; according to the incinerator, the U-shaped membrane wall structure waste heat boiler and the Z-shaped structure membrane wall tube panel structure, NaOH matter state change and adhesion in waste alkali liquid are fully considered, it is ensured that the system can reliably, safely and stably run, and the system has the characteristics of being environmentally friendly, capable of saving energy and capable of achieving resource utilization and energy regeneration.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical hazardous waste treatment, and particularly to a liquid waste incineration device for waste alkali liquor, distillation residue, organic waste solvent, etc. Background Art

[0002] Liquid wastes such as waste alkali liquor, distillation residue, and organic waste solvent are hazardous wastes generated during the chemical engineering production process. The waste alkali liquor has a pungent and foul smell and strong alkalinity. If not properly pretreated, when high-concentration waste alkali liquor enters the sewage biochemical treatment system, it will inhibit the growth and reproduction of microorganisms, and in severe cases, it can cause a large number of microorganisms to die, thus affecting the normal operation of the sewage treatment plant and the compliance discharge of the total discharged wastewater. The generation of distillation residue is mainly due to the fact that during the distillation process, some substances cannot be vaporized and distilled out, thus concentrating in the liquid phase to form residue. The components of distillation residue usually include inorganic salts, glycerol, gum, pigments, soaps, and polymerized glycerol, etc. Waste solvents usually refer to those solvents that have been used and lost their effectiveness, or some solvents that have not reacted completely during chemical reactions. The harmful substances contained in liquid wastes such as waste alkali liquor, distillation residue, and organic waste solvent pose a great threat to the ecological environment and human health. How to safely, effectively, harmlessly, resourcefully, and energy-efficiently treat chemical hazardous wastes has always been a thorny problem faced by chemical enterprises.

[0003] The advantages of treating waste alkali liquor, distillation residue, and organic waste solvent by incineration method lie in its high efficiency, thorough harmlessness, and environmental friendliness. By this method, not only can the volume of waste alkali liquor, distillation residue, and organic waste solvent be greatly reduced, reducing the risks and costs of storage, transportation, and disposal, but also the maximum recovery or reuse can be achieved, reducing emissions to the environment. Due to the relatively high calorific value of organic waste solvent, its combustion process is similar to that of liquid fuel. As long as good atomization effect is ensured and sufficient combustion air is supplied, stable combustion conditions can be obtained, providing heat energy for incinerating waste alkali liquor and distillation residue, realizing the energy-efficient function, and achieving the purpose of "treating waste with waste".

[0004] During the incineration process, a series of chemical reactions occur during the incineration of waste alkali liquor, distillation residues, and organic solvents. The corrosive and irritating substances involved can erode and corrode the refractory materials of the incinerator, affecting the long-term stable operation of the incineration equipment. For example, the excessive presence of sodium hydroxide in the waste alkali liquor during incineration can cause erosion of the refractory materials, especially in the middle of the reaction zone where the alkali liquor erodes the refractory materials most severely. To solve this problem, refractory materials with erosion and corrosion resistance need to be introduced, such as corundum refractory materials with added chromium materials, to improve the erosion and corrosion resistance of the refractory materials. When the system recovers the waste heat of the flue gas and incineration residues, due to the low melting point of sodium hydroxide (melting point temperature 318 °C), the coking problem is an important difficulty. During the incineration of waste alkali liquor, distillation residues, and organic solvents, molten salts and alkalis will form in the furnace, and coking occurs at low temperatures. This not only affects the incineration efficiency but may also cause equipment damage, increasing the difficulty and cost of treatment.

[0005] In summary, waste alkali incineration not only poses a threat to the environment and human health but also damages the incineration system. Therefore, corresponding safety measures and treatment technologies need to be taken to reduce its harm.

[0006] Measures to solve these difficulties are to optimize the structural forms of the incinerator and the waste heat boiler. That is, the refractory material of the furnace wall uses dense corundum-chrome refractory castables resistant to molten salt and alkali corrosion, and the waste heat boiler uses a U-shaped membrane wall structure waste heat boiler and a Z-shaped membrane wall tube screen. The temperature of the molten salts and alkalis in the waste heat boiler should be reduced below the melting point as much as possible to achieve the complete conversion of the molten salts and alkalis into solid salts and alkalis. Steam soot blowers are arranged in the waste heat boiler to effectively soot blow the membrane wall of the waste heat boiler and the Z-shaped membrane wall tube screen, which can effectively avoid equipment accidents such as coking and salt accumulation, and improve the incineration efficiency of the incinerator, the thermal efficiency of the waste heat boiler, and the stability, reliability, and safety of the system operation.

[0007] Publication No. CN 114543102 A, an integrated boiler for waste alkali liquor incineration and waste heat recovery, comprising: a furnace, a flue and a steam drum; a spout is provided at the top of the furnace; a refractory reflux cooling device is provided at the spout at the top of the furnace; it comprises: a ring-shaped refractory ring formed by circumferentially splicing a plurality of refractory blocks in the spout, the lower section of the ring-shaped refractory ring extends into the bottom of the spout and hermetically covers the water-cooled wall around the spout, the ring-shaped refractory ring is fixed on the water-cooled wall at the top of the furnace through a mounting seat circumferentially arranged on its outer periphery, a reflux cooling space is provided in the ring-shaped refractory ring, the reflux cooling space is communicated with the inner cavity of a reflux hood covering the upper part of the ring-shaped refractory ring, a burner is fixed on the reflux hood, the nozzle of the burner passes through the reflux hood and then extends downward into the central through hole of the ring-shaped refractory ring, and an air inlet is further provided on the reflux hood. The refractory reflux cooling device is easy to transport and install, can better protect the water-cooled wall at the spout and is not easily damaged. Disadvantages of this patent: First, the structure is complex. During the flue gas cooling process, it passes through multiple flues and evaporators and superheaters with the flue gas flowing horizontally across the heating surfaces inside the flues. Molten salt and alkali are prone to adhesion and bridging on the back side of the heating surfaces, blocking the heating surfaces. At the same time, both the furnace slag outlet and the flue gas slag outlet are prone to blockage, resulting in the system being unable to operate normally. In addition, the equipment cost and construction cost are greatly increased, etc.

[0008] Publication No. of Application (43) CN 115164216 A A resource utilization system for waste gas, waste oil, and waste lye, comprising a pretreatment unit, an incineration unit, a heat energy recovery unit, a flue gas treatment unit, and a crude salt refining unit. The incineration unit includes an incinerator. The pipelines for transporting waste gas, waste oil, and waste lye are connected to the incinerator through the pretreatment unit. The incinerator incinerates waste oil, waste gas, and waste lye. The high-temperature superheater and the low-temperature superheater constitute the heat energy recovery unit. The flue gas treatment unit includes a quenching tower, an air preheater, a economizer, an electrostatic precipitator, a bag filter, a denitration reactor, and a chimney connected in sequence. The crude salt refining unit includes a stirring dissolver, a filter, and an evaporator connected in sequence. The salts at the bottom of the incinerator, the sodium carbonate crude salts collected by the electrostatic precipitator and the bag filter are refined through the crude salt refining unit. The present invention constitutes a system for burning chemical organic waste gas, waste oil, and producing by-products of steam and carbonate from waste sodium hydroxide lye, so as to achieve the purpose of resource utilization of waste. This patent describes that its incinerator adopts a waste liquid incineration boiler with a single drum and a π-shaped layout. The incinerator is surrounded by a membrane water wall. The bottom of the furnace is a high-temperature combustion zone, and the upper-middle part of the furnace is a high-temperature oxidation zone. The waste lye atomizing spray gun is located above the gas burner and the oil burner, and the waste lye atomizing spray gun is arranged in layers. At the same time, this patent is for liquid salt collection, that is, the molten inorganic salts at the bottom of the furnace flow out of the furnace, and the high-temperature flue gas rises and enters each heating surface. The defects of this patent are: (1) Side spraying of waste liquid and side burning of auxiliary fuel are likely to cause "dripping water" of the waste liquid. Large pieces of inorganic salts will accumulate on the furnace wall under the spray gun, affecting the normal operation of the atomizing spray gun and the auxiliary burner. At the same time, the waste liquid is easily sprayed onto the opposite furnace wall, causing large pieces of inorganic salts to accumulate on the opposite furnace wall, affecting the stable operation of the system; (2) The molten material chute at the bottom of the furnace is easily blocked by unmolten inorganic salts or turns into a solid state during the cooling process of flowing out, blocking the molten material chute. At the same time, the molten material chute is easily damaged by the erosion of high-temperature inorganic salts. Summary of the Invention

[0009] The purpose of the present invention is to provide a waste lye, distillation residue, organic waste solvent and other liquid waste incineration device to achieve "treating waste with waste" and solve the problems such as "inorganic salt blockage" and "inorganic salt wall hanging" in the above-mentioned background technology that affect the safe and reliable operation of the device system.

[0010] To achieve the above object, the present invention provides the following technical solution: A liquid waste incineration device for waste alkali liquor, distillation residues, organic waste solvents, etc., includes an incineration section, a waste heat recovery section, an incineration residue recovery section, and a flue gas up-to-standard discharge treatment section. The incineration section, the waste heat recovery section, the incineration residue recovery section, and the flue gas up-to-standard discharge treatment section are sequentially connected through a flue, and the incineration section and the waste heat recovery section are jointly connected to the incineration residue recovery section; the incineration section includes an adiabatic incinerator and a combined burner at its top, and the bottom outlet of the adiabatic incinerator is directly connected to the waste heat recovery section; the waste heat recovery section includes a U-shaped membrane wall structure waste heat boiler and an economizer connected through a flue, the flue gas discharged from the economizer enters the flue gas up-to-standard discharge treatment section, and the bottoms of the U-shaped membrane wall structure waste heat boiler and the economizer are respectively connected to the incineration residue recovery section through ash discharge pipes; the flue gas up-to-standard discharge treatment section includes a bag filter, and its flue gas outlet is connected to an acid removal tower through an induced draft fan, the top of the acid removal tower is directly connected to a wet electrostatic precipitator and then connected to a chimney, and the bottom of the bag filter is connected to the incineration residue recovery section through an ash discharge pipe; the incineration residue recovery section includes a coarse crusher connected to the U-shaped membrane wall structure waste heat boiler, and a water-cooled scraper conveyor is arranged below the coarse crusher, the economizer and the bag filter and then connected to a fine crusher and a roller slag cooler.

[0011] Preferably, the adiabatic incinerator is of a vertical cylindrical structure and is connected with an SNCR denitration spray gun at the flue gas outlet end of its side wall; a blowdown port is arranged at the bottom of the waste liquid buffer tank and is connected with a blowdown collection bucket through a pipeline.

[0012] Preferably, the combined burner is respectively connected to a combustion-supporting fan, a natural gas pipeline and a waste liquid booster pump, and the inlet of the waste liquid booster pump is connected to a waste liquid buffer tank.

[0013] Preferably, the U-shaped membrane wall structure waste heat boiler includes a first cooling chamber, a second cooling chamber and a bottom channel. The U-shaped membrane wall structure waste heat boiler adopts a Z-shaped membrane wall tube screen to penetrate through the two cooling chambers of the U-shaped membrane wall structure waste heat boiler. The adiabatic incinerator is arranged above one side of the cooling chamber. The flue gas outlet temperature of the first cooling chamber is below 300 °C; the flue gas outlet at the upper part of the side wall of the second cooling chamber is connected to the economizer; a plurality of groups of steam soot blowers are arranged from top to bottom at the side wall of the first cooling chamber of the U-shaped membrane wall structure waste heat boiler, and the plurality of groups of steam soot blowers are jointly connected to a steam header; a conical ash hopper is formed at the bottom channels of the first cooling chamber and the second cooling chamber of the U-shaped membrane wall structure waste heat boiler, and the bottom of the cone is connected to the coarse crusher through an ash discharge pipe; the upper and lower headers of the U-shaped membrane wall structure waste heat boiler and the Z-shaped membrane wall tube screen are connected to the steam drum through connecting pipes. The steam outlet of the steam drum is connected to the steam header, and the water inlet is connected to the outlet header of the economizer. A blowdown port is arranged at the bottom of the steam drum and is connected to a blowdown expander; the steam header is respectively connected to a steam transmission pipeline and a steam soot blower.

[0014] Preferably, the bottom of the bag filter is connected to the water-cooled scraper conveyor through a dust dropping pipe; a multi-layer industrial water spray layer connected to an industrial water pipe is arranged at the inner top of the acid removal tower, and a multi-layer acid removal circulating spray layer is arranged below it. The multi-layer acid removal circulating spray layer is connected to the side wall pipe orifice at the bottom of the acid removal tower through an acid removal circulating pump; the side wall pipe orifice in the middle and lower part of the acid removal tower is connected to an alkali liquid tank through an alkali liquid pump.

[0015] Preferably, an industrial water nozzle connected to an industrial water pipe is arranged at the top of the wet electrostatic precipitator.

[0016] Preferably, the outer wall shell of the adiabatic incinerator is made of carbon steel, and three layers of furnace walls are laid inside the shell: an adiabatic layer made of aluminum silicate fiber felt close to the shell, a heat preservation layer made of light heat preservation castable in the middle, and a refractory layer made of chromic corundum refractory castable on the fire side; the combined burner adopts a top-spray waste liquid and top-burn auxiliary fuel form, includes a waste liquid atomizing spray gun and is equipped with a flame detector and a temperature monitor; the incineration temperature of the adiabatic incinerator is ≥1100 °C, and the residence time of the high-temperature flue gas in the incinerator is >2 s.

[0017] Preferably, the economizer adopts a vertical arrangement of finned tube convection tube bundles, and its flue gas outlet is connected to the bag filter through a flue; the inlet header of the economizer is connected to a boiler feed water tank through a pipeline via a boiler feed water pump, and the outlet header is connected to a steam drum through a pipeline; a low-pressure steam pipe is arranged at the top of the blowdown expander and connected to the boiler feed water tank, the bottom side wall of the blowdown expander is discharged into the sewer through a blowdown port via a blowdown heat exchanger, and circulating cooling water is introduced into the blowdown heat exchanger.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. The organic waste solvent has a relatively high calorific value. Together with the distillation residue and waste alkali liquid, after being ignited by an auxiliary fuel, it is burned out, providing energy for burning the distillation residue and waste alkali liquid, realizing "treating waste with waste" and the energy utilization of the organic waste solvent;

[0020] 2. The adiabatic incinerator is arranged above one side of the cooling chamber of the U-shaped membrane wall structure waste heat boiler. The Z-shaped membrane wall tube screen penetrates through the cooling chamber one and the cooling chamber two of the U-shaped membrane wall structure waste heat boiler, and the high-temperature flue gas above 1100 °C can be reduced to below 300 °C. The molten salts and alkalis after burning the organic waste solvent, distillation residue, and waste alkali liquid run downward in the incinerator, fall into the lower ash hopper of the U-shaped membrane wall structure waste heat boiler after being cooled by the cooling chamber one of the U-shaped membrane wall structure waste heat boiler, and are cooled into solids by exchanging heat with the Z-shaped membrane wall tube screen. This arrangement method can prevent the molten salts and alkalis from adhering and blocking the recovery equipment, and at the same time facilitate the recovery of solid salts and alkalis;

[0021] 3. The combined burner combustion method using the top spray waste liquid and top combustion auxiliary fuel can prevent the waste alkali liquid and distillation residue from being sprayed onto the furnace wall of the adiabatic incinerator, avoiding the occurrence of phenomena such as "dripping water" and "inorganic salt blockage" and "inorganic salt wall hanging" that affect the safe and reliable operation.

[0022] 4. The refractory material of the furnace wall of the adiabatic incinerator adopts corrosion-resistant chrome corundum castable. Chrome corundum castable has the advantages of corrosion resistance, high refractoriness, high strength, and high wear resistance, and can effectively resist the erosion, penetration, and corrosion of the molten incineration residue generated during the incineration of organic waste solvents, distillation residues, and waste alkali liquids, maintaining the integrity and service life of the furnace wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the present invention;

[0024] Figure 2 is a schematic system flow diagram of the present invention;

[0025] Figure 3 is a schematic elevation layout diagram of the present invention;

[0026] In the figure: incineration section - 1, adiabatic incinerator - 101, combined burner - 102, combustion air blower - 103, waste liquid booster pump - 104, waste liquid buffer tank - 105, SNCR denitration spray gun - 106, sewage collection bucket - 107, waste heat recovery section - 2, U-shaped membrane wall structure waste heat boiler - 201, economizer - 202, steam soot blower - 203, steam header - 204, steam drum - 205, blowdown expander - 206, boiler feed water pump - 207, boiler feed water tank - 208, blowdown heat exchanger - 209, flue gas compliance emission treatment section - 3, bag filter - 301, induced draft fan - 302, acid scrubber - 303, wet electrostatic precipitator - 304, chimney - 305, industrial water spray layer - 306, acid scrubbing circulating spray layer - 307, acid scrubbing circulating pump - 308, alkali liquid pump - 309, alkali liquid tank - 310, industrial water nozzle - 311, incineration residue recovery section - 4, coarse crusher - 401, water-cooled scraper conveyor - 402, fine crusher - 403, roller slag cooler - 404. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings and specific embodiments.

[0028] Please refer to Figures 1 - 3 , Figure 1 which is a schematic structural diagram of the present invention; Figure 2 which is a schematic system flow diagram of the present invention; Figure 3This is a schematic elevation view of the present invention.

[0029] The present invention provides a liquid waste incineration device for waste alkali liquor, distillation residues, organic waste solvents, etc., which includes an incineration section 1 for incinerating liquid wastes such as waste alkali liquor, distillation residues, and organic waste solvents. The incineration section 1 is sequentially connected with a waste heat recovery section 2 and a flue gas up-to-standard emission treatment section 3 through a flue. The incineration section 1 and the waste heat recovery section 2 are respectively connected with an incineration residue recovery section 4 for recovering incineration residues.

[0030] The incineration section 1 includes an adiabatic incinerator 101 and a combined burner 102 at its top. The bottom outlet of the adiabatic incinerator 101 is directly connected to the waste heat recovery section 2. The combined burner 102 is connected to a combustion-supporting fan 103, a natural gas pipeline, and a waste liquid booster pump 104 through pipelines. The inlet of the waste liquid booster pump 104 is connected with a waste liquid buffer tank 105, and the waste liquid to be treated is transported into the waste liquid buffer tank 105 through a pipeline for buffering and voltage stabilization.

[0031] The waste heat recovery section 2 includes a U-shaped membrane wall structure waste heat boiler 201 and is connected with an economizer 202 through a flue. The flue gas discharged from the economizer 202 enters the flue gas up-to-standard emission treatment section 3. The bottoms of the U-shaped membrane wall structure waste heat boiler 201 and the economizer 202 are respectively connected to the incineration residue recovery section 4 through ash dropping pipes.

[0032] The flue gas up-to-standard emission treatment section 3 includes a bag filter 301. The flue gas discharged from it is connected to an acid removal tower 303 through an induced draft fan 302. The top of the acid removal tower 303 is directly connected with a wet electrostatic precipitator 304. The flue gas after dust removal and fog droplet reduction in the wet electrostatic precipitator 304 is discharged into the air at a high altitude through a chimney 305 at its top. The bottom of the bag filter 301 is connected to the incineration residue recovery section 4 through an ash dropping pipe.

[0033] The incineration residue recovery section 4 includes a coarse crusher 401 connected to the U-shaped membrane wall structure waste heat boiler 201. A water-cooled scraper conveyor 402 is jointly arranged below the coarse crusher 401, the economizer 202, and the bag filter 301, and is sequentially connected with a fine crusher 403 and a roller slag cooler 404.

[0034] An SNCR denitration spray gun 106 is connected to the side wall of the adiabatic incinerator 101 near the flue gas outlet. A blowdown port is arranged at the bottom of the waste liquid buffer tank 105 and is connected with a blowdown collection bucket 107 through a pipeline.

[0035] The adiabatic incinerator 101 is of a vertical cylindrical structure. The outer wall shell is made of carbon steel and is lined with three layers of furnace walls inside: an adiabatic layer made of aluminosilicate fiber felt close to the shell, a heat-insulating layer made of lightweight heat-insulating castable in the middle, and a refractory layer made of chromic corundum refractory castable on the fire side. A combined burner 102 is installed at the top of the adiabatic incinerator 101, and the incineration method of top-spraying waste liquid and natural gas is adopted. The combined burner 102 includes a waste liquid atomizing spray gun and is equipped with advanced flame detection and temperature monitors to ensure the smooth progress of combustion. The incineration temperature of the adiabatic incinerator 101 is ≥1100°C, and the residence time of the high-temperature flue gas in the incinerator is >2 s. After the organic waste solvent, distillation residue, and waste alkali liquid are incinerated, part of them reacts to form sodium carbonate, and the melting point of sodium carbonate is 851°C. Part of the waste alkali liquid becomes molten sodium hydroxide, and the melting point of sodium hydroxide is 318°C. The molten salt and alkali are viscous and easily adhere when cooled. To prevent adhesion and blockage of the equipment, it is considered not to set an ash collection device at the bottom of the incineration furnace chamber, but to arrange the adiabatic incinerator 101 above the cooling chamber 1 of the U-shaped membrane wall structure waste heat boiler 201. The molten salt and alkali enter the U-shaped membrane wall structure waste heat boiler 201 with the flue gas for cooling.

[0036] The U-shaped membrane wall structure waste heat boiler 201 includes a cooling chamber 1 and a cooling chamber 2 that are connected at the bottom. The adiabatic incinerator 101 is arranged above one side of the cooling chamber of the U-shaped membrane wall structure waste heat boiler. The flue gas of the adiabatic incinerator 101 enters from the top of the cooling chamber 1 of the U-shaped membrane wall structure waste heat boiler 201, makes a 180° turn at the bottom, enters the cooling chamber 2, and then enters the economizer 202 through the flue gas outlet arranged at the upper part of the side wall of the cooling chamber 2. Multiple groups of steam soot blowers 203 are arranged vertically from top to bottom at the side wall of the cooling chamber 1 of the U-shaped membrane wall structure waste heat boiler 201, and the multiple groups of steam soot blowers 203 are jointly connected to a steam header 204 through pipelines. The bottom of the U-shaped membrane wall structure waste heat boiler 201 is a conical ash hopper, and the bottom of the cone is connected to a coarse crusher 401 through a dust fall pipe. The U-shaped membrane wall structure waste heat boiler 201 is connected to a steam drum 205 through upper and lower headers, and the blowdown ports of the steam drum 205 and the lower header are both connected to a blowdown expander 206 through pipelines.

[0037] The outlet flue of the U-shaped membrane wall structure waste heat boiler 201 is designed with an angle of 30° inclined downward along the flue gas direction, which can make the soot be carried out of the flue with the flue gas and prevent the soot from accumulating in the flue.

[0038] To reduce the adhesion and blockage of salt and alkali to the hopper of the U-shaped membrane wall structure waste heat boiler 201 in the molten state, a Z-shaped membrane wall tube screen is used to penetrate the two cooling chambers of the U-shaped membrane wall structure waste heat boiler, increasing the heat transfer area of the U-shaped membrane wall structure waste heat boiler and cooling the flue gas, so that the flue gas outlet temperature of the first cooling chamber is below 300 °C, lower than the melting point of sodium hydroxide; during the cooling process of the flue gas, the molten salt and alkali are quickly cooled into a solid state, and a small part of the molten salt and alkali will adhere to the heating surface of the Z-shaped membrane wall tube screen to form a solid brittle film attached to the metal surface of the heat transfer surface, which can fall off by itself due to gravity and cannot form a bridge to block the flue gas flow path due to the distance between the heating surfaces of the Z-shaped membrane wall tube screen; at the same time, multiple groups of steam soot blowers are used to regularly soot blow the heating surface to ensure that the salt and alkali deposits on the heating surface can be cleaned in time; the solid brittle salt and alkali will fall into the bottom cone hopper and enter the incineration residue recovery section 4 after being crushed by the coarse crusher 401.

[0039] The steam outlet of the steam drum 205 is connected to the steam header 204, and the water inlet is connected to the outlet header of the economizer 202. A blowdown pipe interface is provided at the bottom of the steam drum 205 and is connected to the blowdown expander 206; the steam header 204 is respectively connected to the steam transmission pipeline and the steam soot blower 203; the economizer 202 adopts a convection tube bundle structure with finned tubes, is arranged vertically, and is covered with aluminum silicate fiber felt on the outside of the shell. By laying a reasonable thickness, it is ensured that the external temperature of the economizer 202 during normal operation is not higher than 60 °C, and at the same time, two groups of steam soot blowers 203 are provided; the flue gas after heat exchange and cooling is introduced into the bag filter 301 through the flue; the inlet header of the economizer 202 is connected to the boiler feed water tank 208 through a pipeline via the boiler feed water pump 207, and the outlet header is connected to the steam drum 205 through a pipeline; an ash discharge pipe is provided at the bottom of the economizer 202 and is connected to the water-cooled scraper conveyor 402; a low-pressure steam pipe is provided at the top of the blowdown expander 206 and is connected to the boiler feed water tank 208 for discharging the secondary steam separated by the blowdown expander into the boiler feed water tank 208. The bottom side wall of the blowdown expander 206 is connected with a blowdown heat exchanger 209 through a pipeline, and circulating cooling water is introduced to cool the sewage in the blowdown heat exchanger 209 and then discharged through the trench.

[0040] The bottom of the bag filter 301 is connected to the incineration residue recovery section 4 through a dust dropping pipe for collecting the separated dust.

[0041] On the inner top of the deacidification tower 303, there are multiple industrial water spray layers 306 connected to industrial water pipes, and below it, there are multiple deacidification circulating spray layers 307. The multiple deacidification circulating spray layers 307 are connected to the pipe orifice on the bottom side wall of the deacidification tower 303 through a deacidification circulating pump 308, continuously sending the circulating alkali liquid in the tower into the deacidification circulating spray layers. The alkali liquid falling from the spray layers reacts with the acidic gases in the flue gas to neutralize and remove the acidic gases. The pipe orifice on the middle and lower side wall of the deacidification tower 303 is connected to an alkali liquid tank 310 through an alkali liquid pump 309 to appropriately supplement the alkali liquid, so that the pH value in the deacidification tower is maintained between 7 and 9. When the salt solution in the deacidification tower reaches a certain concentration, open the valve to discharge part of it to the sewage treatment plant. Monitor the liquid level of the deacidification tower and open the water replenishment valve in a timely manner to supplement clean water.

[0042] On the top of the wet electrostatic precipitator 304, there is an industrial water nozzle 311 connected to an industrial water pipe, which effectively removes small particles and sticky particulate matters through the flushing action of water. The flue gas at about 60 - 70 °C after deacidification enters the wet electrostatic precipitator 304, and after high-efficiency dust removal and white smoke elimination, it is discharged ultra-cleanly through the chimney. The wet electrostatic precipitator has the characteristics of high dust removal efficiency, the ability to purify harmful gases simultaneously, small floor area, simple structure, reduction of chimney corrosion problems, low operating cost, wide adaptability, and simple operation.

[0043] The coarse crusher 401 receives the incineration residues discharged from the U-shaped membrane wall structure waste heat boiler 201 and crushes them, and together with the incineration residues discharged from the economizer 202 and the bag filter 301, they are conveyed to the fine crusher 403 through a water-cooled scraper conveyor 402 for further crushing, and at the same time, heat exchange and cooling are carried out through circulating cooling water in the water-cooled scraper conveyor 402. After being crushed by the fine crusher 403, they directly fall into a drum slag cooler 404 for heat exchange and cooling, and after cooling, they are packaged for further treatment.

[0044] In the present invention, organic waste solvents with relatively high calorific value are incinerated until completely burned together with distillation residues and waste alkali liquor. After being ignited by auxiliary fuel, an adiabatic incinerator is used. Except for furnace startup and baking, under normal operating conditions, only a pilot light needs to be set, and no additional auxiliary fuel consumption is required to complete the incineration of waste, which is the most energy-saving; the refractory material of the furnace wall of the adiabatic incinerator is made of corrosion-resistant chrome corundum castable. Chrome corundum castable has the advantages of corrosion resistance, high refractoriness, high strength, and high wear resistance, and can effectively resist the erosion, penetration, and corrosion of the molten incineration residues generated during the incineration of organic waste solvents, distillation residues, and waste alkali liquor, maintaining the integrity and service life of the furnace wall; the adiabatic incinerator is arranged above the first cooling chamber of the U-shaped membrane wall structure waste heat boiler. The Z-shaped membrane wall tube screen penetrates through the two cooling chambers of the U-shaped membrane wall structure waste heat boiler, and the high-temperature flue gas above 1100 °C can be reduced to below 300 °C. The molten salts and alkalis after the incineration of organic waste solvents, distillation residues, and waste alkali liquor run downward in the incinerator and fall into the lower ash hopper of the U-shaped membrane wall structure waste heat boiler after being cooled by the first cooling chamber of the U-shaped membrane wall structure waste heat boiler, and are cooled from the liquid state to the solid state. This layout can prevent the molten salts and alkalis from sticking and blocking the recovery equipment. At the same time, not setting a molten salt receiving device at the lower part of the incinerator can also reduce the investment cost; during the process of a small part of the molten salts and alkalis descending with the flue gas in the first cooling chamber, they will adhere to the membrane wall heating surface. However, due to the sufficient distance between the heating surfaces, there is no situation where the flue gas scours the tube wall laterally. Moreover, a layer of film will form between the salts and alkalis adhered to the membrane wall and the membrane wall tubes during the rapid cooling process, and they can fall off by themselves relying on gravity. At the same time, multiple groups of steam soot blowers are added to ensure that the salt and alkali deposits on the heating surface can be cleaned in time, ensuring that the flue gas flow channel will not be blocked and enabling the system to operate reliably, safely, and stably; the outlet flue of the U-shaped membrane wall structure waste heat boiler is designed with an angle of 30° inclined downward along the flue gas direction. Selecting an appropriate flue gas flow velocity can enable the soot to be carried out of the flue by the flue gas, preventing the soot from accumulating in the flue. To prevent the soot from blocking the channels in the economizer and ensure the long-term stable operation of the equipment, two groups of steam soot blowers are also installed in the economizer flue gas channel.

[0045] Although the embodiments of the present invention have been shown and described, it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, for those of ordinary skill in the art, it can be understood that without departing from the principle and spirit of the present invention, all other embodiments obtained by making various changes, modifications, substitutions, and variations to these embodiments without creative work belong to the scope of protection of the present invention.

Claims

1. A device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc., characterized in that: The invention comprises an incineration section (1), a waste heat recovery section (2) and a flue gas emission treatment section (3) which are connected in sequence through a flue, wherein the incineration section (1) and the waste heat recovery section (2) are connected to an incineration residue recovery section (4); the incineration section (1) comprises an adiabatic incinerator (101) and a combined burner (102) at the top thereof, and the bottom outlet of the adiabatic incinerator (101) is directly connected to the waste heat recovery section (2); the waste heat recovery section (2) comprises a U-shaped membrane wall structure waste heat boiler (201) and an economizer (202) which are connected through a flue, and the flue gas discharged from the economizer (202) enters the flue gas emission treatment section (3), and the bottoms of the U-shaped membrane wall structure waste heat boiler (201) and the economizer (202) are respectively connected to the incineration section (101) through ash dropping pipes. The incineration residue recovery section (4) comprises a bag filter (301) and its smoke outlet is connected to a deacidification tower (303) through an induced draft fan (302); the top of the deacidification tower (303) is directly connected to a wet electrostatic precipitator (304) and then to a chimney (305); the bottom of the bag filter (301) is connected to the incineration residue recovery section (4) through an ash dropping pipe; the incineration residue recovery section (4) comprises a coarse crusher (401) connected to the U-shaped membrane wall structure waste heat boiler (201); a water-cooled scraper (402) is arranged below the coarse crusher (401), the economizer (202) and the bag filter (301) and then to a fine crusher (403) and a drum slag cooler (404).

2. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc. according to claim 1, characterized in that: The adiabatic incinerator (101) is a vertical cylindrical structure and is connected to a SNCR denitrification spray gun (106) on its side wall near the flue gas outlet; a sewage outlet is provided at the bottom of the waste liquid buffer tank (105) and is connected to a sewage collection bucket (107) through a pipeline.

3. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc. according to claim 2, characterized in that: The combined burner (102) is respectively connected to a combustion-supporting fan (103), a natural gas pipeline and a waste liquid booster pump (104); the liquid inlet of the waste liquid booster pump (104) is connected to a waste liquid buffer tank (105).

4. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc. according to claim 3, characterized in that: The U-shaped membrane wall structure waste heat boiler (201) comprises a cooling chamber 1, a cooling chamber 2 and a bottom channel. The U-shaped membrane wall structure waste heat boiler (201) adopts a Z-shaped membrane wall tube screen to penetrate the two cooling chambers of the U-shaped membrane wall structure waste heat boiler. The adiabatic incinerator (101) is arranged above one side of the cooling chamber. The flue gas outlet temperature of the cooling chamber 1 is below 300° C. The flue gas outlet at the upper part of the side wall of the cooling chamber 2 is connected to the economizer (202). Multiple groups of steam soot blowers (203) are arranged from top to bottom on the side wall of the cooling chamber 1 of the U-shaped membrane wall structure waste heat boiler (201). The multiple groups of steam soot blowers (203) are commonly connected to a steam cylinder (204). The bottom channels of cooling chamber 1 and cooling chamber 2 of the U-shaped membrane wall structure waste heat boiler (201) form a conical ash hopper and are connected to a coarse crusher (401) at the bottom of the cone through an ash dropping pipe; the upper and lower headers of the U-shaped membrane wall structure waste heat boiler (201) and the Z-shaped membrane wall tube screen are connected to the steam drum (205) through a connecting pipe, the steam outlet of the steam drum (205) is connected to the steam sub-cylinder (204), and the water inlet is connected to the outlet header of the economizer (202); a sewage outlet is provided at the bottom of the steam drum (205) and is connected to a sewage expansion device (206); the steam sub-cylinder (204) is respectively connected to a steam conveying pipeline and a steam soot blower (203).

5. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc. according to claim 4, characterized in that: The bottom of the bag filter (301) is connected to the water-cooled scraper (402) through an ash dropping pipe; a multi-layer industrial water spray layer (306) connected to an industrial water pipe is arranged on the inner top of the deacidification tower (303), and a multi-layer deacidification circulation spray layer (307) is arranged below the deacidification tower (303); the multi-layer deacidification circulation spray layer (307) is connected to the bottom side wall pipe opening of the deacidification tower (303) through a deacidification circulation pump (308); the middle and lower side wall pipe opening of the deacidification tower (303) is connected to an alkali liquid tank (310) through an alkali liquid pump (309).

6. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc. according to claim 5, characterized in that: An industrial water nozzle (311) connected to an industrial water pipe is arranged on the top of the wet electrostatic precipitator (304).

7. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, organic waste solvent, etc. according to any one of claims 1 to 6, characterized in that: The outer wall shell of the adiabatic incinerator (101) is made of carbon steel, and three layers of furnace walls are laid on the inner side of the shell: an insulating layer made of aluminum silicate fiber felt close to the shell, an insulating layer made of lightweight thermal insulation castable in the middle, and a refractory layer made of chrome corundum refractory castable on the fire side; the combined burner (102) adopts the form of top spraying waste liquid and top burning auxiliary fuel, includes a waste liquid atomizing spray gun and is equipped with a flame detection and temperature monitor; the incineration temperature of the adiabatic incinerator (101) is ≥1100°C, and the residence time of high-temperature flue gas in the incinerator is >2s.

8. The device for incinerating liquid waste such as waste alkali liquor, distillation residue, and organic waste solvent according to claim 7, characterized in that: The economizer (202) adopts a vertical arrangement of finned tube convection tube bundles and its flue gas outlet is connected to the bag filter (301) through a flue; the inlet header of the economizer (202) is connected to the boiler feed water tank (208) through a pipeline via a boiler feed water pump (207), and the outlet header is connected to the steam drum (205) through a pipeline; a low-pressure steam pipe is arranged on the top of the sewage expansion device (206) and is connected to the boiler feed water tank (208), and the bottom of the side wall of the sewage expansion device (206) is discharged into the ditch through the sewage outlet via the sewage heat exchanger (209), and circulating cooling water is introduced into the sewage heat exchanger (209).

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