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Why do we need to measure and control the dewpoint of protecting gas in the furnace?

- Dec 07, 2018 -

Why do we need to measure and control the dewpoint of protecting gas in the furnace?

Because the dewpoint of furnace atmosphere is the mark of moisture content in protecting atmosphere inside furnace, and the height of dewpoint can affect the reduction of oxide scale on the surface of strip steel, so, in production practice, we must pay attention to the dewpoint test of furnace atmosphere.

Principle of location of dew point test in continuous annealing furnace of galvanizing unit?

In the continuous annealing furnace of galvanizing unit, at least one dew-point measuring sampling hole shall be set in each section.In addition, dew point test points should be set on the rapid cooler that is most prone to air leakage.For each test point, infrared gas analyzer is generally used for continuous automatic determination.

How does an infrared dew point analyzer work?

Infrared gas analyzer is the basis of infrared radiation measurement.The structure is composed of radiator, measuring chamber receiver, thin film wafer and other components.During measurement, the radiator emits uniform infrared ray to the measurement room. The receiver has two entrances, one of which passes through the measurement gas and the other passes through the standard gas.If the measured gas contains water, the intensity of infrared ray passing through it will be weakened. From its weakened intensity, it can be converted into the dew point of the measured gas and displayed automatically.

Maintenance of infrared gas analyzer?

In order to check whether the measuring points work normally, portable dew-point tester should be used frequently to check each point.Especially when the dew point measured by a certain measuring point suddenly becomes abnormal, all kinds of calibration work should be carried out in time to carefully analyze the reasons for the change of dew point.

Generally speaking, there are three reasons for the change of dew point: first, the instrument itself may be abnormal;Second, the stove may be the cause of air leakage;Third, it may be that the dehydration system that produces the protective gas is out of order.