RU2448199C1 - Sampling device of molten metal in electrolysis unit - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: device consists of housing made from fire-resistant material to which metal holder equipped with horizontal level metre is attached. Housing is made in the form of a plate on which cavities for molten metal, which are isolated from each other, are located. For cavity sealing there provided is locking device made in the form of metal gate valve, which is brought into action by means of worm gear. Device allows sampling of electrolyte and metal throughout the height of molten metal, as well as at any point along the perimetre of electrolysis unit with fixation of sampling height.

EFFECT: simpler design; higher monitoring accuracy of process parametrers.

3 cl, 1 dwg

Description

The invention relates to metallurgy, and in particular to means for controlling the chemical composition of the melt of the electrolyzer, in particular aluminum.

It is known "Device for measuring the level of metal and electrolyte in the bath of an aluminum electrolyzer" (patent for m, RU No. 19835, published September 27, 2006), which includes a heat-resistant rod equipped with a clamp to which a semicircular disk with a plug is rigidly attached , pivotally attached to the disk, a latch is freely installed in the slot of the plug, contacting on one side with the disk, and on the other with a rod passed into the tube, equipped with a level gauge and connected at one end to the plug and the other threaded connection to the handle rigidly connected to the rod it.

The disadvantage of this device is its low functionality, since it is not possible to take samples of metal and electrolyte. This leads to an increase in labor costs and an increase in the wear of tools, as a result of which the quality of the metal produced deteriorates.

The well-known "Method of sampling electrolyte from an electrolyzer for aluminum production" (patent RU No. 2284377, published September 27, 2006), which consists in sampling an electrolyte with a preheated sampler, pouring a sample of liquid electrolyte into a mold and crystallizing it. The working capacity of the sampler is preheated to 200-250 ° C, and then to a temperature not less than the crystallization temperature of the alkaline component of the electrolyte, placing it in the molten electrolyte in this electrolyzer. The liquid electrolyte sample is poured from the working capacity of the sampler into the mold without residue.

The disadvantage of this method is the inability to control the level of the melt from which sampling is performed, therefore, there are problems in correctly determining the technological state of the electrolysis process.

The well-known "Method of sampling and device for its implementation" (patent RU No. 2026545, publ. 09.01.1995), adopted as a prototype and includes sealing isolated from each other device systems with sample receivers located at different levels, immersing the device in the melt, depressurization, filling receivers, re-sealing systems and extraction from the melt. It is carried out using a melt sampling device containing a housing with melt sample receivers, means for sealing cavities that are made in isolated systems in the lower part of the vertical channels below the level of their intersection with the horizontal channels into which the corundum tubes are inserted.

The disadvantage of this method and device for sampling is, firstly, the complex design, and secondly, the low accuracy of determining the level from which the sampling of the melt.

The structural disadvantages of this device include the means of sealing, which are autonomous and located outside the melt zone. Since the sealing is carried out by creating excess pressure, melt sampling is carried out after reaching equilibrium of pressure by depressurizing the internal volumes, while the start time of sampling is determined by the operation of the safety valve. This leads to an increase in the duration of the sampling operation, increased wear of the sampling device.

Accuracy of sampling from a certain level is carried out by strictly vertical installation of the silicon carbide plate in the melt and sequential depressurization of the receivers due to the creation of excess pressure. Since each electrolyzer has its own characteristics of the movement of the melt, while the speed of movement in certain areas of the bath can vary greatly, determining the level of sampling to create excess pressure cannot be reliable.

The basis of the invention is the task of developing a device for sampling melt in an aluminum electrolysis cell, which would allow sampling of metal and electrolyte at a given level and would be easy to use, which will improve the accuracy of monitoring the technological parameters of an aluminum electrolyzer.

The achievement of the technical result is ensured by the fact that in the device for sampling the melt in the electrolyzer, which includes a body with cavities isolated from each other, located along its entire height, and means for sealing the cavities, the body is made of refractory material and is attached to a metal holder equipped with horizontal level gauge, while the means of sealing the cavities is made in the form of a metal valve connected to the metal holder using a worm gear.

The body of refractory material can be made in the form of a plate to which a metal holder is attached at right angles.

The metal valve can be made in the form of metal plates mounted on rails.

The housing is made of refractory, chemically resistant fluoride melts, material with cavities isolated from each other, located along its entire height, provides melt sampling from a given height. As a result of the reduced reactivity of the refractory, chemically resistant fluoride melts, body material, the samples taken retain their chemical composition. The removable housing, resistant to the aggressive effects of fluoride melt, allows the device to be used with minimal wear.

A rigid metal holder to the body at a right angle, which allows more accurate fixation of the vertical position of the silicon carbide plate in the melt with less effort, is achieved through a threaded connection made on the end of the holder and on the upper part of the body.

The level gauge mounted on the holder allows you to vertically expose the sampler in the melt and take samples from a known distance from the bottom of the cell

The implementation of the means of sealing cavities in the form of a metal valve connected to the metal holder by means of a worm gear provides the mobility of the metal valve, sealing the cavities and allows you to take samples of the melt after installing the device in the working position. Sealing prevents melt mixing from various levels. The operator performing the sampling is located at a remote distance from the open surface of the melt, which minimizes the temperature and toxic effects on his body.

The essence of the technical solution is illustrated by the drawing. The melt sampling device consists of a body 3 made of refractory, chemically resistant fluoride melts, a plate material to which a metal holder 1 with a horizontal level gauge 2 is attached. Cavities 4. Isolated from each other, are located along the entire height of the body. the holder is rigidly attached with the opposite end to the level gauge to the upper part of the housing 3 at right angles using a threaded connection. To seal the cavities 4, a sealing means is provided, made in the form of a metal valve 5, driven by a worm gear 6.

A device for sampling melt works as follows. The metal holder 1 is fixed to the housing 3 at an angle of 90 ° using a threaded connection. The cavities 4 of the housing 3, isolated from each other, are sealed with a metal valve 5. The metal valve 5 is manually driven by means of a worm gear 6 by moving the horizontal part of the valve. Sampling is made by the assembled device after strictly vertical installation of the housing 3 in the molten aluminum electrolyzer. The vertical position is controlled using a level gauge 2. Then, manually using the horizontal part of the valve 5 and the worm gear 6, raise the metal valve to seal the cavities, 5 for 3-5 seconds. After sampling, the metal valve 5 is again lowered and the cavities 4 are sealed, the housing 3 is removed from the melt. The sampling level is fixed by measuring the height of the cavities before the device is immersed in the melt. After cooling the device, the samples are removed from the cavities 4 of the housing 3 and sent for chemical analysis.

The device for sampling allows you to take samples of metal and electrolyte along the entire height of the melt and at any point along the perimeter of the aluminum electrolyzer, with fixing the height of the sampling of the melt, which improves the accuracy of the control of technological parameters of the aluminum electrolyzer.

Claims (3)

1. A device for sampling a melt in an electrolyzer, comprising a housing with cavities isolated from each other, located along its entire height, and a cavity sealing means, characterized in that the housing is made of refractory material and is attached to a metal holder equipped with a horizontal level gauge, this means of sealing cavities is made in the form of a metal valve connected to a metal holder using a worm gear. 2. The device according to claim 1, characterized in that the body of refractory material is made in the form of a plate and is attached to the metal holder at a right angle. 3. The device according to claim 1 or 2, characterized in that the metal valve is made in the form of metal plates mounted on rails.

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