阅读说明：本技术 一种电解质高温烟气的处理装置 (Processing apparatus of electrolyte high temperature flue gas ) 是由 黄海辉 孙留根 袁朝新 常耀超 靳冉公 徐晓辉 王为振 高崇 于 2019-08-27 设计创作，主要内容包括：本发明公开了一种电解质高温烟气的处理装置,所述装置包括集液罐、高温表冷器、高温脱硝管道、二次燃烧室、旋风收尘器、中温脱硝塔、二级表冷器、高温布袋收尘器、引风机和填料塔,待处理的电解质高温烟气经过集液罐-高温表冷器-高温脱硝管道-二次燃烧室-旋风收尘器-中温脱硝塔-二级表冷器-高温布袋除尘器-填料塔洗涤处理后达标排放。上述装置能够在对烟气进行有效降温、回收电解质的同时脱除烟气中的氮氧化物,避免了湿法处理过程中溶液对设备、管道的腐蚀及堵塞的问题。(The invention discloses a device for treating electrolyte high-temperature flue gas, which comprises a liquid collecting tank, a high-temperature surface cooler, a high-temperature denitration pipeline, a secondary combustion chamber, a cyclone dust collector, a medium-temperature denitration tower, a secondary surface cooler, a high-temperature cloth bag dust collector, an induced draft fan and a packed tower, wherein the electrolyte high-temperature flue gas to be treated is washed by the liquid collecting tank, the high-temperature surface cooler, the high-temperature denitration pipeline, the secondary combustion chamber, the cyclone dust collector, the medium-temperature denitration tower, the secondary surface cooler, the high-temperature cloth bag dust collector and the packed tower and then is discharged after reaching the standard. The device can effectively cool the flue gas, recover the electrolyte and simultaneously remove the nitrogen oxide in the flue gas, thereby avoiding the problems of corrosion and blockage of the solution to equipment and pipelines in the wet treatment process.)

1. The utility model provides a processing apparatus of electrolyte high temperature flue gas, a serial communication port, the device is including collection fluid reservoir, high temperature surface cooler, high temperature denitration pipeline, afterburning room, cyclone dust collector, medium temperature denitration tower, second grade surface cooler, high temperature cloth bag dust collector, draught fan and packed tower, wherein:

The electrolyte high-temperature flue gas to be treated enters the liquid collecting tank through a pipeline, and alumina and aluminosilicate substances in the flue gas are changed into liquid from gas state in the cooling process, settled at the bottom of the liquid collecting tank and periodically discharged;

the flue gas treated by the liquid collection tank enters the high-temperature surface cooler through a pipeline of the lining, the surface temperature of the high-temperature surface cooler is 250-350 ℃, partial heat is dissipated through radiation and air convection heat exchange, and the temperature of the flue gas out of the high-temperature surface cooler is controlled to be 950-1100 ℃;

the outlet of the high-temperature surface cooler is connected with the secondary combustion chamber through the high-temperature denitration pipeline, the high-temperature denitration component is cylindrical or square equipment, the outer surface of the high-temperature surface cooler is carbon steel or stainless steel, refractory bricks or castable are lined inside the high-temperature surface cooler, a urea sprayer connector, a temperature detection port and a pressure detection port are reserved, the length of the high-temperature denitration pipeline is not less than 3m, and high-temperature denitration is completed in the pipeline by using an SNCR (selective non-catalytic reduction) denitration technology;

Enabling the flue gas subjected to high-temperature denitration treatment to enter the secondary combustion chamber, reacting with oxygen in introduced air in the secondary combustion chamber, completely combusting residual carbon and carbon monoxide in the flue gas, and introducing excessive air into the secondary combustion chamber to further cool the combusted flue gas, wherein the temperature of the flue gas at an outlet of the secondary combustion chamber is 350-500 ℃;

the flue gas treated by the secondary combustion chamber enters the cyclone dust collector through a steel pipe, and the cyclone dust collector is used for collecting coarse dust in the flue gas as much as possible, so that subsequent medium-temperature denitration is prevented from being influenced;

the flue gas collected by the cyclone dust collector enters the medium-temperature denitration tower, a catalyst is filled in the medium-temperature denitration tower, a urea solution is sprayed inwards, nitrogen oxides in the flue gas are reduced into nitrogen under the action of the catalyst, and the temperature of the flue gas in the medium-temperature denitration tower is 300-400 ℃;

The temperature of the flue gas treated by the medium-temperature denitration tower is 250-350 ℃, the flue gas enters the secondary surface air cooler through a pipeline, and is treated by the secondary surface air cooler to be cooled to 100-150 ℃;

the flue gas subjected to the temperature reduction treatment by the secondary surface cooler enters the high-temperature cloth bag dust collector through a steel pipe, the high-temperature cloth bag dust collector is used for collecting fine electrolyte in the flue gas, and one-stage or multi-stage cloth bag recovery is arranged according to the electrolyte content of the flue gas;

The flue gas treated by the high-temperature cloth bag dust collector enters the packed tower through the induced draft fan, and the packed tower is further sprayed and washed by alkali liquor or lime milk to remove dust and SO in the flue gas₂so that the smoke can reach the standard and be discharged outside.

2. the electrolyte high-temperature flue gas treatment device according to claim 1,

The liquid collection tank is made of steel lining insulating bricks, refractory bricks or anticorrosive bricks and specifically comprises a flue gas inlet, a flue gas outlet, a liquid discharge port, a manhole, a flue gas temperature and pressure measurement port and an air supplementing port.

3. The electrolyte high-temperature flue gas treatment device according to claim 1,

The bottom of the high-temperature surface cooler is provided with a smoke dust discharge port and a cleaning port, and the smoke outlet is provided with an air supplement port, so that if the temperature of the smoke at the outlet is too high, the smoke can be supplemented with air for cooling.

4. The electrolyte high-temperature flue gas treatment device according to claim 1,

The secondary combustion chamber is cylindrical or square equipment, the outer surface of the secondary combustion chamber is made of carbon steel or stainless steel, refractory bricks or castable are lined inside the secondary combustion chamber, and the bottom of the secondary combustion chamber is provided with a smoke exhaust port and a cleaning port.

5. The electrolyte high-temperature flue gas treatment device according to claim 1,

the secondary surface cooler is made of steel pipes/steel materials, the bottom of the secondary surface cooler is provided with a dust bin and a dust discharge port, and hot flue gas is radiated by the surface of the secondary surface cooler and cooled by air convection;

an air interface is arranged on a flue gas outlet pipeline of the secondary surface cooler, if the temperature of flue gas at the outlet of the secondary surface cooler is too high, the air interface is automatically opened, air is supplemented for cooling, and a cloth bag is prevented from being burnt by hot flue gas.

6. the electrolyte high-temperature flue gas treatment device according to claim 1,

the electrolyte high-temperature flue gas to be treated is flue gas generated by calcining waste cathodes of electrolytic aluminum at ultrahigh temperature, the flue gas temperature is 1400-1600 ℃, and the flue gas components contain NOx, C, CO, NaF, aluminosilicate and Fe₂O₃、Al₂O₃。

7. The electrolyte high-temperature flue gas treatment device according to claim 1,

and the electrolytes collected by the high-temperature surface cooler, the secondary combustion chamber, the medium-temperature denitration tower, the cyclone dust collector, the secondary surface cooler and the high-temperature cloth bag dust collector are collected by a scraper conveyor or a spiral conveyor and packaged after being cooled.

Technical Field

the invention relates to the technical field of pyrometallurgical smelting, in particular to a device for treating electrolyte high-temperature flue gas.

background

The amount of the waste electrolytic aluminum cathode discharged every year in China is about 40 ten thousand tons. The waste aluminum cathode contains NaF and AlF₃、Al₂O₃、Na₂CO₃and NaCN, wherein the fluorine-containing compound accounts for 20-40 percent, and the cyanide accounts for-100 ppm, and belongs to dangerous waste according to the national records of dangerous waste. At present, no feasible waste cathode harmless disposal technology exists in China. Most enterprises adopt a landfill or storage mode for disposal, but due to the solubility and high corrosivity of fluoride, the disposal cost is very high for preventing secondary pollution; enterprises also adopt a combustion method, but the fluoride is easy to cause secondary pollution and is difficult to meet the requirement of environmental protection. Under the new environment-friendly situation, the electrolytic aluminum enterprises urgently need the technology suitable for the harmless disposal and resource utilization of the waste cathode.

In view of the above, a method for calcining waste cathode at ultrahigh temperature has been developed in recent years, for example, the prior art has mentioned a method of wet cooling and dust collection, i.e. a high-efficiency atomizing spray device and two-stage packed tower collection. The main drawbacks of this flue gas collection: the electrolyte enters the solution and contains fluoride, so that the corrosion to equipment is serious, the circulating liquid is easy to block pipelines and equipment, the electrolyte is difficult to filter, and the drying treatment is also needed.

Disclosure of Invention

the invention aims to provide a device for treating electrolyte high-temperature flue gas, which can effectively cool the flue gas, recover the electrolyte and simultaneously remove nitrogen oxides in the flue gas, and avoid the problems of corrosion and blockage of solution to equipment and pipelines in the wet treatment process.

the purpose of the invention is realized by the following technical scheme:

The utility model provides a processing apparatus of electrolyte high temperature flue gas, the device is including album fluid reservoir, high temperature surface cooler, high temperature denitration pipeline, postcombustion room, cyclone dust collector, medium temperature denitration tower, second grade surface cooler, high temperature cloth bag dust collector, draught fan and packed tower, wherein:

the electrolyte high-temperature flue gas to be treated enters the liquid collecting tank through a pipeline, and alumina and aluminosilicate substances in the flue gas are changed into liquid from gas state in the cooling process, settled at the bottom of the liquid collecting tank and periodically discharged;

The flue gas treated by the liquid collection tank enters the high-temperature surface cooler through a pipeline of the lining, the surface temperature of the high-temperature surface cooler is 250-350 ℃, partial heat is dissipated through radiation and air convection heat exchange, and the temperature of the flue gas out of the high-temperature surface cooler is controlled to be 950-1100 ℃;

the outlet of the high-temperature surface cooler is connected with the secondary combustion chamber through the high-temperature denitration pipeline, the high-temperature denitration component is cylindrical or square equipment, the outer surface of the high-temperature surface cooler is carbon steel or stainless steel, refractory bricks or castable are lined inside the high-temperature surface cooler, a urea sprayer connector, a temperature detection port and a pressure detection port are reserved, the length of the high-temperature denitration pipeline is not less than 3m, and high-temperature denitration is completed in the pipeline by using an SNCR (selective non-catalytic reduction) denitration technology;

enabling the flue gas subjected to high-temperature denitration treatment to enter the secondary combustion chamber, reacting with oxygen in introduced air in the secondary combustion chamber, completely combusting residual carbon and carbon monoxide in the flue gas, and introducing excessive air into the secondary combustion chamber to further cool the combusted flue gas, wherein the temperature of the flue gas at an outlet of the secondary combustion chamber is 350-500 ℃;

the flue gas treated by the secondary combustion chamber enters the cyclone dust collector through a steel pipe, and the cyclone dust collector is used for collecting coarse dust in the flue gas as much as possible, so that subsequent medium-temperature denitration is prevented from being influenced;

the flue gas collected by the cyclone dust collector enters the medium-temperature denitration tower, a catalyst is filled in the medium-temperature denitration tower, a urea solution is sprayed inwards, nitrogen oxides in the flue gas are reduced into nitrogen under the action of the catalyst, and the temperature of the flue gas in the medium-temperature denitration tower is 300-400 ℃;

the temperature of the flue gas treated by the medium-temperature denitration tower is 250-350 ℃, the flue gas enters the secondary surface air cooler through a pipeline, and is treated by the secondary surface air cooler to be cooled to 100-150 ℃;

The flue gas subjected to the temperature reduction treatment by the secondary surface cooler enters the high-temperature cloth bag dust collector through a steel pipe, the high-temperature cloth bag dust collector is used for collecting fine electrolyte in the flue gas, and one-stage or multi-stage cloth bag recovery is arranged according to the electrolyte content of the flue gas;

The flue gas treated by the high-temperature cloth bag dust collector enters the packed tower through the induced draft fan, and the packed tower is further sprayed and washed by alkali liquor or lime milk to remove dust and SO in the flue gas₂So that the smoke can reach the standard and be discharged outside.

According to the technical scheme provided by the invention, the device can effectively cool the flue gas, recover the electrolyte and remove the nitrogen oxide in the flue gas, so that the problems of corrosion and blockage of the solution to equipment and pipelines in the wet treatment process are solved.

drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

fig. 1 is a schematic structural diagram of a device for processing electrolyte high-temperature flue gas according to an embodiment of the present invention.

Detailed Description

the technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

The following will describe an embodiment of the present invention in further detail with reference to the accompanying drawings, and as shown in fig. 1, is a schematic structural diagram of an apparatus for processing electrolyte high-temperature flue gas provided by the embodiment of the present invention, the apparatus includes a liquid collecting tank, a high-temperature surface cooler, a high-temperature denitration pipeline, a secondary combustion chamber, a cyclone dust collector, a medium-temperature denitration tower, a secondary surface cooler, a high-temperature bag dust collector, an induced draft fan, and a packed tower, wherein:

the electrolyte high-temperature flue gas to be treated enters the liquid collecting tank through a pipeline, and alumina and aluminosilicate substances in the flue gas are changed into liquid from gas state in the cooling process, settled at the bottom of the liquid collecting tank and periodically discharged;

The flue gas treated by the liquid collection tank enters the high-temperature surface cooler through a pipeline of the lining, the surface temperature of the high-temperature surface cooler is 250-350 ℃, partial heat is dissipated through radiation and air convection heat exchange, and the temperature of the flue gas out of the high-temperature surface cooler is controlled to be 950-1100 ℃;

The outlet of the high-temperature surface cooler is connected with the secondary combustion chamber through the high-temperature denitration pipeline, the high-temperature denitration component is cylindrical or square equipment, the outer surface of the high-temperature surface cooler is carbon steel or stainless steel, refractory bricks or castable are lined inside the high-temperature surface cooler, a urea sprayer connector, a temperature detection port and a pressure detection port are reserved, the length of the high-temperature denitration pipeline is not less than 3m, and high-temperature denitration is completed in the pipeline by using an SNCR (selective non-catalytic reduction) denitration technology; specifically, the method comprises the following steps: urea with a certain concentration is sprayed into the high-temperature denitration pipeline, and ammonia generated by decomposition of the urea at high temperature selectively reduces nitrogen oxides in the flue gas into nitrogen, so that denitration is realized;

enabling the flue gas subjected to high-temperature denitration treatment to enter the secondary combustion chamber, reacting with oxygen in introduced air in the secondary combustion chamber, completely combusting residual carbon and carbon monoxide in the flue gas, and introducing excessive air into the secondary combustion chamber to further cool the combusted flue gas, wherein the temperature of the flue gas at an outlet of the secondary combustion chamber is 350-500 ℃;

The flue gas treated by the secondary combustion chamber enters the cyclone dust collector through a steel pipe, and the cyclone dust collector is used for collecting coarse dust in the flue gas as much as possible, so that subsequent medium-temperature denitration is prevented from being influenced;

The flue gas collected by the cyclone dust collector enters the medium-temperature denitration tower, a catalyst is filled in the medium-temperature denitration tower, a urea solution is sprayed inwards, nitrogen oxides in the flue gas are reduced into nitrogen under the action of the catalyst, and the temperature of the flue gas in the medium-temperature denitration tower is 300-400 ℃;

the temperature of the flue gas treated by the medium-temperature denitration tower is 250-350 ℃, the flue gas enters the secondary surface air cooler through a pipeline, and is treated by the secondary surface air cooler to be cooled to 100-150 ℃;

the flue gas subjected to the temperature reduction treatment by the secondary surface cooler enters the high-temperature cloth bag dust collector through a steel pipe, the high-temperature cloth bag dust collector is used for collecting fine electrolyte in the flue gas, and one-stage or multi-stage cloth bag recovery is arranged according to the electrolyte content of the flue gas;

the flue gas treated by the high-temperature cloth bag dust collector enters the packed tower through the induced draft fan, and the packed tower is further sprayed and washed by alkali liquor or lime milk to remove dust and SO in the flue gas₂So that the smoke can reach the standard and be discharged outside.

In the concrete implementation, the liquid collection tank is made of steel lining insulating bricks, refractory bricks or anticorrosive bricks, and specifically comprises a flue gas inlet, a flue gas outlet, a liquid discharge port, a manhole, a flue gas temperature and pressure measurement port and an air supplementing port.

The bottom of the high-temperature surface cooler is provided with a smoke dust discharge port and a cleaning port, and the smoke outlet is provided with an air supplement port, so that if the temperature of the smoke at the outlet is too high, the smoke can be supplemented with air for cooling.

The secondary combustion chamber is cylindrical or square equipment, the outer surface of the secondary combustion chamber is made of carbon steel or stainless steel, refractory bricks or castable are lined inside the secondary combustion chamber, and the bottom of the secondary combustion chamber is provided with a smoke exhaust port and a cleaning port.

the secondary surface cooler is made of steel pipes/steel materials, the bottom of the secondary surface cooler is provided with a dust bin and a dust discharge port, and hot flue gas is radiated by the surface of the secondary surface cooler and cooled by air convection;

An air interface is arranged on a flue gas outlet pipeline of the secondary surface cooler, if the temperature of flue gas at the outlet of the secondary surface cooler is too high, the air interface is automatically opened, air is supplemented for cooling, and a cloth bag is prevented from being burnt by hot flue gas.

The electrolyte high-temperature flue gas to be treated is flue gas generated by calcining the waste cathode of the electrolytic aluminum at ultrahigh temperature, the flue gas temperature is 1400-1600 ℃, and the flue gas components contain NOx, C, CO, NaF, aluminosilicate and Fe₂O₃、Al₂O₃。

In addition, the electrolytes collected by the high-temperature surface cooler, the secondary combustion chamber, the medium-temperature denitration tower, the cyclone dust collector, the secondary surface cooler and the high-temperature cloth bag dust collector are collected by a scraper conveyor or a spiral conveyor, and are packaged after being cooled.

For example, the high-temperature calcination project of a waste cathode has the treatment scale of 10t/d and the high-temperature flue gas volume of the electrolyte of 350Nm³the temperature of the flue gas is 1500 ℃.

by utilizing the treatment device disclosed by the embodiment of the invention, the electrolyte high-temperature flue gas to be treated sequentially passes through the processes of a liquid collecting tank, a high-temperature surface air cooler, high-temperature denitration, a secondary combustion chamber, a cyclone dust collector, an intermediate-temperature denitration tower, a secondary surface air cooler, a high-temperature cloth bag dust collector, a fan and a packed tower. After treatment, the laying rate of electrolyte and smoke dust reaches more than 99.9%, smoke is discharged after reaching the standard, and the dust collection efficiency of the device can reach more than 99.9%.

it is noted that those skilled in the art will recognize that embodiments of the present invention are not described in detail herein.

in summary, the apparatus according to the embodiment of the present invention has the following advantages:

(1) The device mainly collects dust by a dry method, avoids the corrosion of solution in the dust collection by the wet method to pipelines and equipment, avoids the blockage of the equipment and the pipelines by the dust collection liquid by the wet method, and improves the running rate of the equipment;

(2) The device adopts two sections denitration techniques, has improved the desorption rate of nitrogen oxide in the flue gas greatly.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.