Solutions for metering blast furnace gas

Project Overview

As an important by-product in the steel production process, blast furnace gas’s accurate measurement is crucial to an enterprise’s production management and economic benefits. However, blast furnace gas has the characteristics of high water and dust content, low pressure, low flow rate, low density, and large pipe diameter, making its accurate measurement difficult. Therefore, formulating a scientific and reasonable measurement plan is of great significance to ensure the accuracy of blast furnace gas measurement data.

1. Selection of blast furnace gas measurement methods There are various measurement methods for blast furnace gas, including coefficient method, coke coefficient method, nitrogen balance method, etc. Each of these methods has advantages and disadvantages and needs to be selected according to the actual conditions of the blast furnace. The coefficient method is a simple and practical method, which is calculated based on the proportional relationship between the hourly blast flow rate of the blast furnace and the amount of blast furnace gas generated. However, the accuracy of this method is affected by many factors, such as blast furnace operating conditions, raw material quality, etc. Therefore, when using the coefficient method, the coefficient needs to be revised regularly to improve the accuracy of measurement. The coke coefficient law calculates the amount of blast furnace gas generated based on the amount of coke consumed per hour of blast furnace production. This method is relatively accurate, but the impact of coal injection and other factors on coke consumption needs to be taken into account. Therefore, when using the coke coefficient method, coal powder needs to be converted into coke and added for calculation.

The nitrogen balance method is the most accurate measurement method. It calculates the amount of blast furnace gas by analyzing the nitrogen content in the blast furnace blast and blast furnace gas. This method requires sampling and analysis of blast furnace blast and blast furnace gas, so the operation is relatively complex, but it can ensure the accuracy of measurement data. 2. Optimization of blast furnace gas measurement plan In order to ensure the accuracy of blast furnace gas measurement data, we need to optimize the measurement plan. This mainly includes the following aspects: First, for large-diameter gas measurement pipelines, due to the low gas flow rate and pipeline pressure, we can use insertion flow meters for measurement. At the same time, in order to avoid inaccurate measurements caused by clogging of the throttling parts, a maintenance ball valve can be installed between the plug-in flow meter and the pipeline so that the flow meter can be pulled out online for dredging when necessary. In addition, depending on the site conditions, a purge valve can also be installed for online backflushing to prevent minor blockage of the throttling part.

Secondly, for low-flow blast furnace gas, the disadvantages of gas interception by orifice plates and other throttling parts are more obvious. In order to solve this problem, we can use a reasonable diameter reduction method to improve the gas flow rate and measurement accuracy. At the same time, in order to ensure the stability of measurement data, we also need to calibrate and maintain the flow meter regularly.

Finally, we also need to consider the impact of blast furnace operating conditions on gas metering. Changes in blast furnace operating conditions will lead to changes in gas composition and flow, thus affecting the accuracy of measurement. Therefore, we need to collect blast furnace operating condition data in real time, such as air volume entering the furnace, blast humidity, coal injection volume, etc., and correct the measurement results based on these data.