CN-122010271-A - Method for controlling pH value of condensed water of blast furnace gas pipeline

Abstract

The application provides a method for controlling pH value of condensed water in a blast furnace gas pipeline, which comprises the following steps of setting a plurality of alkali liquor injection points along the blast furnace gas pipeline, setting alkali liquor injection points with alkali liquor injection devices, detecting whether each point generates condensed water, and opening the alkali liquor injection device from the previous point of the first point generating condensed water to the previous point of the last point generating condensed water so as to neutralize dissolved HCl in the condensed water between the first point generating condensed water and the last point generating condensed water. The application sets a plurality of points on the blast furnace gas pipeline, each point is provided with an alkali liquor injector capable of injecting alkali liquor, the alkali liquor injection is started at the previous point where condensed water begins to appear, the pipeline before the point where condensed water appears is prevented from being corroded by acid in advance, the alkali liquor injection is stopped at the last point where condensed water appears, and the corrosion aggravated by the pipeline blockage caused by alkali liquor waste and solute sedimentation is avoided.

Inventors

• SHAO JIUGANG
• MAO RUI
• SHI MENGYUAN
• ZHANG TAO

Assignees

• 江苏沙钢钢铁有限公司
• 江苏省沙钢钢铁研究院有限公司
• 江苏沙钢集团有限公司

Dates

Publication Date

20260512

Application Date

20260402

Claims (10)

1. 1. A method for controlling the pH value of condensed water in a blast furnace gas pipeline, comprising the steps of: Setting a plurality of alkali liquor injection points along a blast furnace gas pipeline, wherein alkali liquor injection points are provided with alkali liquor injectors; detecting whether each point generates condensed water, and opening an alkali liquor sprayer from the previous point to the last point to neutralize HCl dissolved in the condensed water.
2. 2. The method for controlling the pH value of condensed water of a blast furnace gas pipeline according to claim 1, wherein the alkaline liquor injection flow rate is: , Wherein V An is the flow rate of alkali required by the nth point, the unit is kg/h, a=1 or 2, c is the alkali liquor mass concentration, V n+1 is the flow rate of condensed water generated from the nth point to the (n+1) th point, the unit is kg/h, c HCl is the acid concentration, The unit is mol/kg of target acid concentration, and the unit is g/mol of relative molecular mass of alkali.
3. 3. The method for controlling pH value of condensed water in a blast furnace gas pipeline according to claim 2, Wherein T n is the gas temperature of the nth point, T n+1 is the gas temperature of the (n+1) th point, the units are all the temperature, e is natural logarithm, and V g is the blast furnace gas flow, and the unit is m 3 /h.
4. 4. A method of controlling pH of condensate in a blast furnace gas conduit according to claim 3, wherein a pH meter is provided at the first point of production of condensate for measuring pH of condensate.
5. 5. The method for controlling pH value of condensed water in a gas pipeline of a blast furnace according to claim 4, , = The pH is the pH value of the first point for generating condensed water, and the pH 0 is the target pH value.
6. 6. The method for controlling pH value of condensed water in a blast furnace gas pipe according to claim 4, wherein said alkali liquor sprayer is provided at a position before the first position for generating condensed water, and the alkali liquor spraying flow rate is gradually increased until the pH value of the first position for generating condensed water reaches the target pH value.
7. 7. A method of controlling the pH of condensate in a blast furnace gas conduit according to claim 3, wherein any alkali liquor injection site is provided with a temperature sensor to detect the gas temperature at that site.
8. 8. The method for controlling the pH value of condensed water in a blast furnace gas pipeline according to claim 1, wherein any alkali liquor injection point is provided with a condensed water discharging device.
9. 9. The method for controlling the pH value of condensed water of a blast furnace gas pipe according to claim 8, wherein the distance between adjacent alkali liquor injection points tends to increase in the flow direction of the blast furnace gas.
10. 10. The method for controlling pH value of condensed water in a blast furnace gas pipe according to claim 1, wherein a heat insulating member is provided outside the blast furnace gas pipe to reduce the amount of condensed water precipitated.

Description

Method for controlling pH value of condensed water of blast furnace gas pipeline Technical Field The application relates to the technical field of steelmaking byproduct treatment, in particular to a method for controlling pH value of condensate water of a blast furnace gas pipeline. Background The blast furnace gas contains HCl gas, and HCl can be condensed together with water in the gas to be separated out along with the reduction of temperature in the gas pipeline conveying process. The condensed water of the gas containing HCl is strong in acidity, and the lowest pH value of the condensed water can be lower than 1.0 if neutralization treatment is not carried out, so that the condensed water has strong corrosiveness to a gas pipeline. Therefore, in order to reduce the corrosion of blast furnace gas pipelines, a gas alkali spraying system is built in many enterprises, and the main purpose is to neutralize HCl in gas condensate water and improve the pH value. In the prior art, the alkali spraying process is mainly divided into two types, one is to construct an independent alkali spraying tower, and the other is to directly spray alkali liquor at a certain point of a blast furnace gas pipeline. For the first process, the problems are high construction cost, large occupied area, high operation cost and large pipe network resistance, meanwhile, as the distance between the pipeline position and the alkali spraying tower increases, acid gas and condensed water still can be continuously separated out, the pH value of the condensed water can be gradually reduced, and the corrosion risk still exists. For the second process, the main problem is that due to the sedimentation effect, the sprayed alkali liquor can only neutralize a section of area close to the spraying point, the neutralization effect is poorer and worse along with the extension of the distance, and meanwhile, when the alkali liquor is oversprayed, the sedimented alkali liquor solute is also very easy to cause pipeline blockage and aggravate corrosion. Both use single-point blowing alkali lye, lead to follow-up along with gas pipeline position distance to spout the extension of alkali point position, the pH value can reduce once more, aggravates the corruption. Disclosure of Invention The application aims to provide a method for controlling the pH value of condensed water of a blast furnace gas pipeline, which solves the problem that the pipeline far from the point position is still corroded in the prior art by arranging a plurality of point positions capable of blowing alkali liquor on the pipeline and starting to blow the alkali liquor before the condensed water appears. In order to achieve one of the above objects, an embodiment of the present application provides a method for controlling pH of condensed water in a blast furnace gas pipe, comprising the steps of: Setting a plurality of alkali liquor injection points along a blast furnace gas pipeline, wherein alkali liquor injection points are provided with alkali liquor injectors; detecting whether each point generates condensed water, and opening an alkali liquor sprayer from the previous point to the last point to neutralize HCl dissolved in the condensed water. In one embodiment of the application, the alkali liquor blowing flow rate is: , Wherein V An is the flow rate of alkali required by the nth point, the unit is kg/h, a=1 or 2, c is the alkali liquor mass concentration, V n+1 is the flow rate of condensed water generated from the nth point to the (n+1) th point, the unit is kg/h, c HCl is the acid concentration, The unit is mol/kg of target acid concentration, and the unit is g/mol of relative molecular mass of alkali. In one embodiment of the present application, Wherein T n is the gas temperature of the nth point, T n+1 is the gas temperature of the (n+1) th point, the units are all the temperature, e is natural logarithm, and V g is the blast furnace gas flow, and the unit is m 3/h. In one embodiment of the application, a pH meter is provided at the first point of production of the condensed water for measuring the pH of the condensed water. In one embodiment of the present application,,=The pH is the pH value of the first point for generating condensed water, and the pH 0 is the target pH value. In one embodiment of the application, the alkali liquor sprayer arranged at the previous point of the first point for generating condensed water gradually increases the alkali liquor spraying flow rate until the pH value of the first point for generating condensed water reaches the target pH value. In one embodiment of the application, any alkali liquor injection point is provided with a temperature sensor to detect the gas temperature of the point. In one embodiment of the application, any alkali liquor injection point is provided with a condensed water discharging device. In one embodiment of the application, the distance between adjacent alkali liquor injection points tends to increase in the