阅读说明：本技术 一种lt干法除尘系统及lt干法除尘方法 (LT dry dedusting system and LT dry dedusting method ) 是由 沈志军 樊云飞 李水 周志盟 武东亮 于 2019-11-14 设计创作，主要内容包括：本发明公开了一种LT干法除尘系统及LT干法除尘方法；一种LT干法除尘系统,包括顺次通过管道连接的活动烟罩、汽化冷却烟道、蒸发冷却塔、静电除尘器、风机、煤气柜和/或放散烟囱,其中活动烟罩连接转炉以收集烟尘,蒸发冷却塔内设有能够喷出细小水滴的雾化喷嘴,蒸发冷却塔的出口连接有双层卸灰阀,双层卸灰阀下部连接有储灰仓；LT干法除尘系统还包括降温除尘脱水一体塔,降温除尘脱水一体塔的进口管道连接风机,降温除尘脱水一体塔的出口管道通过三通阀分别连接煤气柜和/或放散烟囱；一种LT干法除尘方法,使用LT干法除尘系统,利用声波团聚原理,脱除烟气中的细小颗粒,烟气排放浓度不高于10mg/Nm<Sup>3</Sup>,到达超低排放标准。(The invention discloses an LT dry dedusting system and an LT dry dedusting method; an LT dry dedusting system comprises a movable smoke hood, an evaporative cooling flue, an evaporative cooling tower, an electrostatic precipitator, a fan, a gas holder and/or a diffusion chimney which are sequentially connected through pipelines, wherein the movable smoke hood is connected with a converter to collect smoke dust, an atomizing nozzle capable of spraying fine water drops is arranged in the evaporative cooling tower, an outlet of the evaporative cooling tower is connected with a double-layer ash discharge valve, and the lower part of the double-layer ash discharge valve is connected with an ash storage bin; the LT dry dedusting system also comprises a cooling, dedusting and dehydrating integrated tower, wherein an inlet pipeline of the cooling, dedusting and dehydrating integrated tower is connected with a fan, and an outlet pipeline of the cooling, dedusting and dehydrating integrated tower is respectively connected with a gas cabinet and/or a diffusing chimney through a three-way valve; an LT dry dedusting method uses an LT dry dedusting system, and utilizes the sound wave agglomeration principle to remove fine particles in flue gas, and the emission concentration of the flue gas is not higher than 10mg/Nm 3 And reaching the ultra-low emission standard.)

1. An LT dry dedusting system comprises a movable smoke hood, an evaporative cooling flue, an evaporative cooling tower, an electrostatic precipitator, a fan, a gas holder and/or a diffusion chimney which are sequentially connected through a pipeline, wherein the movable smoke hood is connected with a converter to collect smoke dust, an atomizing nozzle capable of spraying atomized water drops is arranged in the evaporative cooling tower, a lower outlet of the evaporative cooling tower is connected with a double-layer ash discharge valve, and the lower part of the double-layer ash discharge valve is connected with an ash storage bin; the LT dry dedusting system is characterized by further comprising a cooling, dedusting and dehydrating integrated tower, wherein an inlet pipeline of the cooling, dedusting and dehydrating integrated tower is connected with the fan, and an outlet pipeline of the cooling, dedusting and dehydrating integrated tower is respectively connected with the gas cabinet and/or the diffusing chimney through a three-way valve.

2. The LT dry dedusting system of claim 1, wherein the temperature reduction, dedusting and dehydration integrated tower comprises a washing and cooling section, an acoustic agglomeration section and a dehydration section, and the dehydration section is provided with a cyclone blade capable of collecting water mist water drops.

3. The LT dry dedusting system according to claim 1, wherein a servo valve is installed on the inlet pipe of the electrostatic precipitator, a micro differential pressure device is installed on the evaporative cooling flue, and the servo valve is interlocked with the micro differential pressure device provided at the furnace mouth on the evaporative cooling flue.

4. The LT dry dedusting system according to claim 1, wherein a water seal check valve and a shut-off valve are installed on the inlet pipeline of the gas tank.

5. A LT dry dedusting method, comprising the following steps:

(1) flue gas generated by the converter passes through the movable smoke hood and the vaporization cooling flue, and the vaporization cooling flue carries out primary cooling on the flue gas while recovering heat energy;

(2) the flue gas subjected to primary cooling in the step (1) is subjected to secondary cooling through an evaporative cooling tower, atomized water drops sprayed by an atomizing nozzle of the evaporative cooling tower cool the high-temperature flue gas, the atomized water drops after cooling the flue gas are completely evaporated, and the atomized water drops cool the flue gas and simultaneously perform conditioning treatment on the flue gas;

(3) the flue gas subjected to secondary cooling and conditioning treatment in the step (2) enters an electrostatic dust collector for electrostatic dust collection;

(4) enabling the flue gas subjected to electrostatic dust removal treatment in the step (3) to enter a cooling, dust removing and dewatering integrated tower through a fan, enabling fine particles in the flue gas to collide to reduce the number concentration of the particles and increase the average particle size by utilizing a sound wave agglomeration demisting technology in a sound wave agglomeration section of the cooling, dust removing and dewatering integrated tower, and enabling the flue gas subjected to sound wave agglomeration to pass through a dewatering section of the cooling, dust removing and dewatering integrated tower to be collected by a cyclone blade to remove fine particles in the flue gas;

(5) and (4) diffusing the flue gas treated in the steps (1) to (4) through a diffusing chimney or entering a gas cabinet for gas recovery.

6. The LT dry dedusting method according to claim 5 and the step (2) is characterized in that the atomized water drops sprayed by the atomizing nozzle of the evaporative cooling tower cool the high temperature flue gas to 200 ℃.

7. The LT dry dedusting method according to claim 5, characterized in that in the step (3), the dust content of the flue gas entering the electrostatic precipitator is reduced to 25mg/m after electrostatic dedusting³。

8. The LT dry dedusting method according to claim 5, wherein in the step (4), the concentration of the discharged flue gas treated by the cooling, dedusting and dewatering integrated tower is not higher than 10mg/Nm³。

9. The LT dry dedusting method according to claim 5, characterized in that the flue gas treated in the steps (1) to (4) is switched to the emission chimney through a three-way valve for emission or enters the gas tank for gas recovery.

Technical Field

The invention belongs to the field of converter flue gas purification, and particularly relates to an LT dry dedusting system and an LT dry dedusting method.

Background

At present, there are two main methods for purifying flue gas of a large converter: OG wet purification system and "LT" dry purification system. Converter LT dry dedusting systems have been rapidly developed since their success in German trials in 1983. With the stricter emission standard, the emission concentration of the flue gas discharged from the top station reaches 10mg/Nm³The requirement of ultralow emission standard, but no matter which process treatment method, the fine particles in the flue gas are difficult to remove, and the ultralow emission requirement is difficult to achieve. Therefore, the LT dry dedusting process is in urgent need of upgrading and reconstructing on the basis of the original system.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The invention aims to provide an LT dry dedusting system and an LT dry dedusting method, which can remove fine particles in flue gas and achieve the purpose that the emission concentration of the flue gas is not higher than 10mg/Nm³Ultra-low emission requirements.

In order to achieve the purpose, the LT dry dedusting system provided by the invention comprises a movable smoke hood, an evaporative cooling flue, an evaporative cooling tower, an electrostatic precipitator, a fan, a gas holder and/or a diffusing chimney which are sequentially connected through a pipeline, wherein the movable smoke hood is connected with a converter to collect smoke dust, an atomizing nozzle capable of spraying atomized water droplets is arranged in the evaporative cooling tower, a lower outlet of the evaporative cooling tower is connected with a lower outlet, a double-layer ash discharge valve is connected, and the lower part of the ash discharge valve is connected with an ash storage bin; LT dry process dust pelletizing system still includes the integrative tower of cooling dust removal dehydration, the inlet pipeline of the integrative tower of cooling dust removal dehydration connects the fan, the outlet conduit of the integrative tower of cooling dust removal dehydration passes through the three-way valve and connects respectively gas chamber and/or diffuse the chimney.

Further, the cooling, dedusting and dewatering integrated tower comprises a washing and cooling section, a sound wave agglomeration section and a dewatering section, wherein the dewatering section is provided with a rotational flow blade capable of collecting water mist and water drops.

Furthermore, a servo valve is installed on an inlet pipeline of the electrostatic dust collector, a micro differential pressure device is installed on the vaporization cooling flue, and the servo valve is interlocked with the micro differential pressure device arranged at a furnace mouth on the vaporization cooling flue.

Furthermore, a water seal check valve and a stop valve are installed on an inlet pipeline of the gas tank.

The invention also provides an LT dry dedusting method, which comprises the following steps:

(1) flue gas generated by the converter passes through the movable smoke hood and the vaporization cooling flue, and the vaporization cooling flue carries out primary cooling on the flue gas while recovering heat energy;

(2) the flue gas subjected to primary cooling in the step (1) is subjected to secondary cooling through an evaporative cooling tower, atomized water drops sprayed by an atomizing nozzle of the evaporative cooling tower cool the high-temperature flue gas, the atomized water drops after cooling the flue gas are completely evaporated, and the atomized water drops cool the flue gas and simultaneously perform conditioning treatment on the flue gas;

(3) the flue gas subjected to secondary cooling and conditioning treatment in the step (2) enters an electrostatic dust collector for electrostatic dust collection;

(4) enabling the flue gas subjected to electrostatic dust removal treatment in the step (3) to enter a cooling, dust removing and dewatering integrated tower through a fan, enabling fine particles in the flue gas to collide to reduce the number concentration of the particles and increase the average particle size by utilizing a sound wave agglomeration demisting technology in a sound wave agglomeration section of the cooling, dust removing and dewatering integrated tower, and enabling the flue gas subjected to sound wave agglomeration to pass through a dewatering section of the cooling, dust removing and dewatering integrated tower to be collected by a cyclone blade to remove fine particles in the flue gas;

(5) and (4) diffusing the flue gas treated in the steps (1) to (4) through a diffusing chimney or entering a gas cabinet for gas recovery.

Preferably, in the step (2), the atomized water drops sprayed by the atomizing nozzle of the evaporative cooling tower cool the high-temperature flue gas to 200 ℃.

PreferablyIn the step (3), the dust content of the flue gas entering the electrostatic dust collector is reduced to 25mg/m after electrostatic dust collection³。

Preferably, in the step (4), the emission concentration of the flue gas treated by the cooling, dedusting and dehydrating integrated tower is not higher than 10mg/Nm³。

Preferably, the flue gas treated in the steps (1) to (4) is switched to the diffusing chimney for diffusing through a three-way valve or enters the gas tank for gas recovery.

The LT dry dedusting system and the LT dry dedusting method provided by the invention have the following beneficial effects:

1. the device has the advantages of water saving, electricity saving, small system resistance and small occupied area;

2. the fine particles in the smoke are easy to be caught and collected, and the emission concentration of the treated smoke is not higher than 10mg/Nm³And the requirement of ultra-low emission can be met.

Drawings

Fig. 1 is a schematic structural diagram of a LT dry dedusting system in a specific embodiment.

In the figure:

1. the movable smoke hood 2, the vaporization cooling flue 3, the evaporation cooling tower 4, the servo valve 5, the electrostatic dust collector 6, the fan 7, the cooling, dust removing and dewatering integrated tower 8, the three-way valve 9, the gas tank 10, the emission chimney 11, the water seal check valve 12, the stop valve 13 and the ash storage bin.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments in order to make the technical field better understand the scheme of the present invention.

As shown in fig. 1, an LT dry dedusting system comprises a movable smoke hood 1, an evaporative cooling flue 2, an evaporative cooling tower 3, an electrostatic precipitator 5, a fan 6, a cooling, dedusting and dewatering integrated tower 7, a gas holder 9 and a diffusing chimney 10 which are connected in sequence through pipelines. The movable smoke hood 1 is connected to a converter to collect smoke dust, a double-layer ash discharge valve is connected to an outlet at the lower part of the evaporative cooling tower 3, an ash storage bin 13 is connected to the lower part of the ash discharge valve, and ash in the ash storage bin 13 is transported away by a transportation vehicle. Be equipped with the atomizing nozzle that can spout atomizing water droplet in the evaporative cooling tower 3, atomizing nozzle spun atomizing water droplet can cool off high temperature flue gas, and the water spray can carry out accurate control according to the flue gas caloric content, and the atomizing water droplet after the cooling flue gas evaporates completely, and the atomizing water droplet still carries out quenching and tempering to the flue gas when cooling down to the flue gas, makes the specific resistance of dust be favorable to electrostatic precipitator 5's entrapment. Install servo valve 4 on the inlet pipe of electrostatic precipitator 5, install the differential pressure device on the vaporization cooling flue, this servo valve 4 interlocks with the differential pressure device of the fire door that sets up on vaporization cooling flue 2, and when the flue gas volume of converter fire door produced undulant, the servo valve 4 of interlocking differential pressure device can make the reaction fast, and then guarantees the pressure-fired state of converter fire door, guarantees that the converter fire door can not a large amount of excessive flue gas. The cooling, dedusting and dewatering integrated tower 7 replaces a coal gas cooling tower in the original LT dry dedusting process, and the cooling, dedusting and dewatering integrated tower 7 is arranged behind a fan 6 and is used for carrying out fine dedusting on the flue gas passing through an electrostatic precipitator 5; the cooling, dedusting and dewatering integrated tower 7 consists of a washing and cooling section, an acoustic agglomeration section and a dewatering section, wherein the dewatering section comprises a rotational flow blade capable of collecting water mist and water drops; the integrative tower 7 of cooling dust removal dehydration utilizes the sound wave reunion defogging technique, makes the fine particle in the flue gas bump to make granule number concentration reduce, average particle diameter increase, become easily caught, make the water smoke water droplet in the flue gas more easily collected by whirl blade when passing through the dehydration section, later the tiny granule in the exhaust flue gas, thereby reach the requirement of ultralow emission. Install three-way valve 8 on the export pipeline of integrative tower 7 of cooling dust removal dehydration, the chimney 10 is diffused in the one end intercommunication of three-way valve 8 export, and the other end intercommunication gas chamber 9 of three-way valve 8 export installs water seal check valve 11 and trip valve 12 on the inlet pipeline of gas chamber 9, prevents the flue gas refluence in the gas chamber 9.

The LT dry dedusting method comprises the following steps:

(1) the flue gas generated by the converter passes through the movable smoke hood 1 and the vaporization cooling flue 2, and primary cooling is carried out on the flue gas while heat energy is recovered;

(2) the flue gas through the cooling of vaporization cooling flue 2 carries out the secondary cooling through evaporative cooling tower 3, and the atomizing water droplet of evaporative cooling tower 3's atomizing nozzle spun can be with high temperature flue gas cooling, and the water spray can carry out accurate control according to the flue gas caloric content, and the atomizing water droplet after the cooling flue gas evaporates completely, and the flue gas can be cooled to 200 ℃, and the atomizing water droplet still carries out quenching and tempering to the flue gas when cooling down the flue gas, makes the specific resistance of dust be favorable to electrostatic precipitator 5's entrapment.

(3) The smoke after the secondary cooling and conditioning treatment of the evaporative cooling tower 3 enters an electrostatic dust collector 5 for electrostatic dust collection, and the dust content (standard state) of the smoke is reduced to 25mg/m after the electrostatic dust collection³；

(4) The flue gas after electrostatic dust removal treatment enters a cooling, dust removal and dehydration integrated tower 7 through a fan 6, a sound wave agglomeration demisting technology is utilized, appropriate acoustic frequency and intensity are selected according to actual conditions on site, fine particles in the flue gas are collided, the number concentration of the particles is reduced, the average particle size is increased, the particles are easy to capture, water mist droplets in the flue gas are collected by a cyclone blade when passing through a dehydration section, then the fine particles in the flue gas are removed, and the emission concentration of the flue gas after being treated by the cooling, dust removal and dehydration integrated tower 7 is not higher than 10mg/Nm³Reaching the ultra-low emission standard;

(5) and (4) switching the flue gas treated in the steps (1) to (4) to a diffusion chimney 10 through a three-way valve 8 for diffusion or carrying out coal gas recovery.

The LT dry dedusting system has the advantages of water saving, electricity saving, small system resistance and small occupied area, on the basis of the original LT dry dedusting process, a rear bell valve of a fan 6 is removed, a gas cooler is changed into a cooling, dedusting and dewatering integrated tower 7, the sound wave agglomeration demisting technology is utilized to collide fine particles in the flue gas, so that the particle number concentration is reduced, the average particle size is increased, the particles are easy to capture, water mist and water drops in the flue gas are easier to be collected by a cyclone blade when passing through a dewatering section, then the fine particles in the flue gas are discharged, and the discharge concentration of the treated flue gas is not higher than 10mg/Nm³Thereby meeting the requirement of ultra-low emission.

The inventive concept is explained in detail herein using specific examples, which are given only to aid in understanding the core concepts of the invention. It should be understood that any obvious modifications, equivalents and other improvements made by those skilled in the art without departing from the spirit of the present invention are included in the scope of the present invention.