Researchers of the Mathematics Department of Kim Il Sung University developed a system of measuring slag level in the oxygen blast furnace.
“A layer of slag is generally formed as molten iron boils during the melting process. To maintain its thickness is very important in ensuring the stability of the furnace and putting production on a normal track,” said Ri Kwang Il, director of the information mathematics institute.
Many scientists had attempted to solve the problem in the past, but in vain.
It has been regarded as the Gordian knot for a long time.
Scientists of the institute buckled down to the research to put slag level measurement in an oxygen blast furnace on a scientific basis at the Hwanghae Iron and Steel Complex.
“At first, we tried to apply a monitoring camera for the measurement, but it was impossible to ensure its accuracy due to the unstable furnace conditions and flames. At that time, a veteran skilled worker told us that the vibration noise from the furnace keeps changing according to melting process,” said section chief Jo Chol Man.
Finding a clue from the information, they carried on in-depth research and scientifically corroborated that the vibration property of the furnace is related to the thickness of slag layer.
On the basis of that, they developed a vibration sensor, control program and a comprehensive system of communications and analysis.
In particular, they designed a device circuit afresh and made a sensor at the lowest cost possible before developing a real-time level measurement program which efficiently blocks out various kinds of noises in the melting workshop including the one that is produced when steam is discharged and which recognizes the vibration noise of the furnace alone.
They also confirmed a rational location of the sensor through dozens of experiments and perfected the standard operating method of the measuring system.
Last December, they applied the slag level measurement system to the oxygen blast furnace at the Hwanghae Iron and Steel Complex.
It has made it possible to ensure the normal operation of the furnace and turn out quality pig iron while increasing the amount of tapping per charge.
It was later introduced into the Kim Chaek Iron and Steel Complex.