End point judgment device and method for distillation process for preparing sponge titanium by magnesiothermy

Abstract

The invention provides an end point judgment device and method for a magnesiothermy method sponge titanium distillation process, the device comprises a shell, the shell is installed on the pipe wall of a steam pipeline between a distillation furnace and a condensing furnace of magnesiothermy method sponge titanium equipment or the outer wall of the condensing furnace through a connecting flange, a valve is arranged between the connecting flange and the shell, and the valve is connected with the shell through a connecting flange. The valve is used for controlling the communication or isolation between the inner cavity of the shell and the steam pipeline, a measuring probe connected with a measuring instrument is arranged in the inner cavity of the shell, a quartz crystal oscillator is arranged on the measuring probe, and the measuring instrument is used for measuring the resonant frequency of the quartz crystal oscillator / the resonant frequency time change rate / the thickness of a deposited film of the quartz crystal oscillator. Magnesium and magnesium chloride impurity steam in the pipeline is captured and condensed on the quartz crystal oscillator of the measuring probe, and the change of the frequency of the quartz crystal oscillator or the impurity deposition amount is measured to directly represent the content of magnesium and magnesium chloride impurities in the pipeline, so that the progress degree of the distillation process stage is reflected, and the end point judgment is realized.

Description

technical field [0001] The invention belongs to the field of measurement and control instruments in the production process of sponge titanium, and in particular relates to an end point judging device and method for the distillation process of sponge titanium produced by magnesia method. Background technique [0002] The magnesium thermal method is one of the most important methods for producing sponge titanium. The main purpose of the distillation stage in the magnesium thermal method is to evaporate and separate the magnesium and magnesium chloride impurity components present in the sponge titanium lump under vacuum conditions. The specific process is: the impurity components in the sponge titanium lump first evaporate into steam, diffuse out of the sponge titanium lump, and then enter the condensation furnace along the pipeline connecting the distillation furnace and the condensation furnace, and condense into a solid in the condensation furnace. In the actual distillation...

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Problems solved by technology

[0004] Combined with the actual production experience of the sponge titanium distillation process by the magnesia method, it can be found that although the existing pressure detection method and temperature detection method can reflect the degree of the distillation stage to a certain extent, they have some common defects: ( 1) Theoretical inaccuracy: Although the pressure detection method and the temperature detection method have a certain theoretical basis in principle, they are both indirect detection methods, and there is a lack of direct measurement of physical quantities - pressure and temperature - and the evaporation of impurities. Quantitative Theoretical Relationships

And in practical application, the method of interference time is often used to ensure the complete distillation. Therefore, when the distillation is actually stopped, the titanium sponge may have met the requirements of the impurity content index for a long time, resulting in a waste of resources.

(2) Differences in working conditions: the actual production equipment, process and environmental conditions are very complicated, and there are many factors affecting the pressure and temperature measurement in the condensation furnace. Under such conditions, the pressure detection method or temperature detection method is adopted To measure whether the distillation has reached the end, it cannot truly reflect the true progress of the distillation process in the furnace

Therefore, using the same pressure and temperature endpoint judgment criteria, there are differences in the sponge titanium produced at different times, different equipment, different sizes, and even different locations in the same plant. The final result is that the quality of the final sponge titanium product varies greatly.

(3) Randomness of errors: There are a large number of randomly occurring uncertain influencing factors in actual production, which will directly affect the measurement of pressure and temperature in the condensing furnace, such as condensation blockage in the pipeline between the distillation furnace and the condensing furnace, furnace body When the seal of the furnace cover leaks, the vacuum system fails, etc., the pressure change in the condensing furnace will be abnormal; the thickness of the impurity components deposited on the surface of the temperature sensor changes, the external cooling conditions of the condensing furnace are different, and the cooling system fails, etc. , it will cause abnormal temperature changes in the condensation furnace, which will bring unpredictable errors to the pressure detection method and temperature detection method as the end point of the distillation process

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