阅读说明：本技术 一种不停产倒开二次吸收浓酸泵的方法 (Method for turning on secondary absorption concentrated acid pump without stopping production ) 是由 张学兵 周尚� 李雪琼 李劲林 赵飞 金之涛 张彩绍 李云松 杨国林 王鑫海 吴 于 2021-08-12 设计创作，主要内容包括：本发明涉及一种不停产倒开二次吸收浓酸泵的方法,属于冶炼烟气制酸技术领域。本发明通过调整冶炼炉生产负荷,同时增加预转化吸收、一次转化吸收生产负荷,达到二次转化吸收不承担生产负荷时倒开备用泵,确保生产组织持续稳定运行,备用泵运行正常即可逐渐恢复冶炼炉生产负荷,保障生产系统作业率,杜绝设备空转及系统升温电能消耗目的,满足清洁生产、节能降耗相关规范要求。(The invention relates to a method for turning on a secondary absorption concentrated acid pump without stopping production, belonging to the technical field of acid preparation by smelting flue gas. According to the invention, the production load of the smelting furnace is adjusted, and the production loads of pre-conversion absorption and primary conversion absorption are increased simultaneously, so that the backup pump is turned over when the production load is not born by secondary conversion absorption, the continuous and stable operation of production organization is ensured, the production load of the smelting furnace can be gradually recovered when the backup pump operates normally, the operation rate of a production system is ensured, the purposes of equipment idling and system temperature rise electric energy consumption are avoided, and the requirements of relevant standards of clean production, energy conservation and consumption reduction are met.)

1. A method for turning on a secondary absorption concentrated acid pump without stopping production is characterized in that: the method comprises the following steps:

1) when the vibration value of the secondary concentrated acid absorption main pump exceeds 4.5mm/s, judging that the operation abnormality of the main pump cannot reach the normal operation condition, and determining that a secondary concentrated acid absorption standby pump needs to be turned over;

2) the production load of the smelting furnace is reduced to be within 60 percent of the normal load;

3) acid making system SO₂Regulation of main fan speed, SO₂The rotating speed of the fan is reduced to 38HZ, the opening degree of the pre-conversion air inlet valve and the pre-conversion air return valve is opened to 80%, the opening degree of the pre-conversion return valve is closed to 20%, and the rotating speed of the booster fan is increased to 30-35 HZ;

4) the temperature of the flue gas at the inlet of pre-conversion and primary conversion is ensured to be between 410 and 420 ℃, and the conversion rate is ensured to be in the optimal state; meanwhile, the normal operation of the concentrated acid pump for pre-absorption and primary absorption is confirmed, and the converted SO is ensured₃The smoke is completely absorbed;

5) the secondary absorption concentrated acid standby pump is checked and confirmed before starting the machine, and the standby pump is started;

6) closing an outlet valve of a secondary concentrated acid absorption main pump to 50%, stopping the main pump when the pump is reversed, quickly closing the outlet valve of the main pump completely, opening an outlet valve of a standby pump to 30%, starting the standby pump, and slowly opening the opening of the outlet valve to a required position according to the running current of the standby pump;

7) after the standby pump operates stably, the production load is gradually increased to a production state.

2. The method for turning on the secondary absorption concentrated acid pump without stopping production according to claim 1, characterized in that: the concrete time of the pump reversing is determined according to the production period of the converter, and one of the two converters is in the discharging period, and the other converter is in the blowing-off sampling or feeding period.

3. A method of non-stop switching over a secondary absorption concentrated acid pump according to claim 1 or 2, characterized in that: the operation time of turning back the secondary absorption concentrated acid pump is controlled within 10 min.

4. A method of non-stop switching over a secondary absorption concentrated acid pump according to claim 1 or 2, characterized in that: in the step 2), the reduction of the production load of the smelting furnace to be within 60% of the normal load means that the quantity of the pizza burden is reduced to be within 60% of the normal production quantity.

Technical Field

The invention belongs to the technical field of acid preparation by smelting flue gas, and particularly relates to a method for turning on a secondary absorption concentrated acid pump without stopping production.

Background

The smelting flue gas acid making system adopts the pre-conversion pre-absorption and two-stage conversion two-stage absorption process to produce the sulfuric acid, and each stage of conversion absorption bears the production load under the normal production state. According to the production practice in recent years, the secondary absorption concentrated acid pump of the acid making system needs to be turned over for about 2 times per year during normal production due to the fault that the vibration value of equipment exceeds the standard. During the period of turning back the standby pump, the production system is required to stop production on the whole line, the standby pump is turned back after the reflux is opened in the acid making process so as to ensure the safety of the absorption tower equipment and the aim of controlling the tail gas to reach the standard stably, but the method needs to stop the production on the whole line for 0.8h during smelting, and the equipment idles, starts an electric furnace for heat preservation or raises the temperature during the period of stopping the production again, so that the production cost and the cost are increased, and the comprehensive competitiveness of enterprises are influenced.

Disclosure of Invention

The invention provides a method for turning over a secondary absorption concentrated acid pump without stopping production, which can turn over a standby pump when the production load is not borne by secondary conversion absorption by adjusting the production load of a smelting furnace and increasing the pre-conversion absorption production load at the same time, thereby ensuring that the production organization continuously and stably operates and simultaneously achieving the aim of stably controlling the tail gas emission index.

In order to realize the purpose, the invention is realized by the following technical scheme:

the method for turning over the secondary absorption concentrated acid pump without stopping production comprises the following steps:

1) when the vibration value of the secondary concentrated acid absorption main pump exceeds 4.5mm/s, judging that the operation abnormality of the main pump cannot reach the normal operation condition, and determining that a secondary concentrated acid absorption standby pump needs to be turned over;

2) the production load of the smelting furnace is reduced to be within 60 percent of the normal load;

3) acid making system SO₂Regulation of main fan speed, SO₂The rotating speed of the fan is reduced to 38HZ, the opening degree of the pre-conversion air inlet valve and the pre-conversion air return valve is opened to 80%, the opening degree of the pre-conversion return valve is closed to 20%, and the rotating speed of the booster fan is increased to 30-35 HZ;

4) the temperature of the flue gas at the inlet of pre-conversion and primary conversion is ensured to be between 410 and 420 ℃, and the conversion rate is ensured to be in the optimal state; meanwhile, the normal operation of the concentrated acid pump for pre-absorption and primary absorption is confirmed, and the converted SO is ensured₃The smoke is completely absorbed;

5) the secondary absorption concentrated acid standby pump is checked and confirmed before starting the machine, and the standby pump is started;

6) closing an outlet valve of a secondary concentrated acid absorption main pump to 50%, stopping the main pump when the pump is reversed, quickly closing the outlet valve of the main pump completely, opening an outlet valve of a standby pump to 30%, starting the standby pump, and slowly opening the opening of the outlet valve to a required position according to the running current of the standby pump;

7) after the standby pump operates stably, the production load is gradually increased to a production state.

Further preferably, the specific time of the pump reversing is determined according to the production cycle of the converter, and the selection is based on that one converter is in the discharging period, and the other converter is in the blowing-off sampling or feeding period.

Further preferably, the operation time of turning on the secondary absorption concentrated acid pump is controlled within 10 min.

Further preferably, in the step 2), the reduction of the production load of the smelting furnace to within 60% of the normal load means that the amount of the pizza burden is reduced to within 60% of the amount of the normal production burden.

The principle of the invention lies in fully evaluating the production load adaptability of the acid making system and utilizing the production efficiency of the pre-conversion absorption and primary conversion absorption systems, and fully playing the roles of pre-conversion absorption and primary conversion absorption by adjusting the production load of the front-stage smelting system to be reduced to be within 60 percent of the normal loadReceive equipment efficiency and realize SO₂The flue gas is completely converted and absorbed in the front section system, and more than 99.5 percent of SO is absorbed₂The flue gas is converted and absorbed into sulfuric acid in the front section system, the production task is not carried out in the second section conversion and absorption, the normal desulfurization load of the tail absorption system is guaranteed, and basic conditions are provided for stable standard-reaching emission control of tail gas. And controlling the back-off time of the secondary absorption concentrated acid pump within 10min, namely, holding part of residual acid in the secondary absorption tower in the period of time, and uniformly distributing a liquid film on the acid-resistant ceramic ring, so that the direct contact of high-temperature flue gas with the ceramic ring is avoided, and the damage of the high-temperature flue gas to equipment in a short time is avoided.

The invention has the advantages that:

1. the existing mode of turning back a secondary absorption concentrated acid standby pump needs that an Isa furnace and a converter are both in a production stop state, an acid making system is operated by pumping back, the secondary absorption concentrated acid pump is turned back, and the production stop of the whole production line is influenced by 0.8 h. The invention properly reduces the production load of the Isa furnace and the converter, fully exerts the production efficiency of pre-conversion absorption and primary conversion absorption to implement the back-opening work of the secondary absorption concentrated acid pump, can complete the back-opening operation only by reducing the load of the smelting furnace for 0.3h, and effectively shortens the back-opening operation time.

2. By the method, the standby pump is turned upside down, the whole production line is in a continuous production state, the operation rate of production equipment is improved, and the production cost is reduced. The secondary absorption concentrated acid standby pump can gradually recover the production load of the smelting furnace when running normally, the operation rate of a production system is guaranteed, the purposes of equipment idling and system temperature rise electric energy consumption are avoided, and the requirements of relevant specifications of clean production, energy conservation and consumption reduction are met.

3. The method has better adaptability to the original equipment, does not involve large transformation, does not need to invest excessive transformation cost, and can realize the quick and continuous production and the back-off work of the secondary absorption concentrated acid pump.

Drawings

FIG. 1 is a process flow diagram;

in the figure, the air inlet valve is pre-converted, the air return valve is pre-converted, and the reflux valve is pre-converted.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the following detailed description of the embodiments of the present invention is provided to facilitate the understanding of the skilled person.

Examples

The method for turning on the secondary absorption concentrated acid pump without stopping production comprises the following steps:

1) confirming that the vibration value of the secondary absorption concentrated acid main pump exceeds 4.5mm/s, judging that the operation abnormality of the main pump cannot reach the normal operation condition, and turning on the secondary absorption standby concentrated acid pump;

2) determining the pump reversing time: one of the two converters is in a discharging period, and the other converter is in a blowing-stopping sampling or feeding period;

3) the amount of the pizza burden is reduced to be within 60 percent of the amount of the normal production burden;

4) acid making system SO₂Regulation of main fan speed, SO₂The rotating speed of the fan is reduced to 38HZ from 46HZ, the opening degrees of the pre-conversion air inlet valve and the pre-conversion air return valve are opened from about 50% to 80%, the opening degree of the pre-conversion air return valve is closed from about 50% to 20%, and the rotating speed of the booster fan is increased to 30-35 HZ from about 25 HZ;

5) observing the temperature of flue gas at the inlet of pre-conversion and primary conversion between 410 and 420 ℃, ensuring the conversion rate to be in the optimal state, and simultaneously confirming the normal operation of pre-absorption and primary absorption concentrated acid pumps to ensure the total absorption of the converted SO3 flue gas;

6) the secondary absorption standby concentrated acid pump is checked and confirmed before starting the machine, and the standby concentrated acid pump is started;

7) closing an outlet valve of a secondary concentrated acid absorption main pump to 50%, stopping the main pump when the pump is reversed, quickly closing the outlet valve of the main pump completely, opening an outlet valve of a standby pump to 30%, starting the standby pump, and slowly opening the opening of the outlet valve to a required position according to the running current of the standby pump; the pump reversing operation should be fully organized and planned, and the operation time is controlled within 10 min.

8) After the standby pump operates stably, the production load is gradually increased to a production state.

The invention fully evaluates the production load adaptability of the acid making system and utilizes the production efficiency of the pre-conversion absorption and primary conversion absorption systems, and fully exerts the pre-conversion absorption and the primary conversion absorption by adjusting the production load of the front-stage smelting system to be reduced to be within 60 percent of the normal loadReceive equipment efficiency and realize SO₂The flue gas is completely converted and absorbed in the front section system, and more than 99.5 percent of SO is absorbed₂The flue gas is converted and absorbed into sulfuric acid in the front section system, the production task is not carried out in the second section conversion and absorption, the normal desulfurization load of the tail absorption system is guaranteed, and basic conditions are provided for stable standard-reaching emission control of tail gas. And controlling the back-off time of the secondary absorption concentrated acid pump within 10min, namely, holding part of residual acid in the secondary absorption tower in the period of time, and uniformly distributing a liquid film on the acid-resistant ceramic ring, so that the direct contact of high-temperature flue gas with the ceramic ring is avoided, and the damage of the high-temperature flue gas to equipment in a short time is avoided.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.