SU1574644A1 - Device for circulation vacuum-treatment of molten steel - Google Patents

Abstract

The invention relates to metallurgy, and more particularly to equipment for the secondary treatment of liquid metal. The aim of the invention is to increase processing efficiency, increase reliability and maintainability. The device is equipped with a suction nozzle, made with side openings and mounted with the possibility of axial movement. The lance for gas supply is located along the axis of the nozzle and is installed vacuum-tight in its upper part. The tuyere is made with a thickening at the end with a conical end surface. The response surface of the socket, made in the lower part of the nozzle, interacts with it. The lance is made in the form of concentrically arranged tubes. The inner tube is equipped with a nozzle that is directed downwards. The proposed device provides an increase in the durability of the lining, increases the productivity of the vacuum cleaner by 10 - 15%. 2 hp f-ly, 3 ill.

Description

The invention relates to metallurgy, in particular, equipment for out-of-furnace treatment of liquid metal.

The purpose of the invention is to increase processing efficiency, increase reliability and maintainability.

Fig. 1 shows a device, a slit, at the time of immersion into the melt; in fig. 2 - the same in the working position; in fig. 3 - the same, in the initial position.

The device contains concentrically arranged vacuum chamber 1 with an airtight lid 2, a suction nozzle 3 and a lance 4. The suction nozzle 3 is made with side openings 5, by means of a vacuum seal 6 is mounted with the possibility of axial movement on the lid 2 and connected to a movement mechanism 7, which is made in the form of a clip 8, connected to the pipe 3 and through three hydraulic cylinders 9 connected to the lid 2. The tuyere 4 is located along the vertical axis of the pipe 3, installed in its upper part by means of a vacuum Neni 10 and is connected with the mechanism 11, the vertical movement, which is designed as a yoke 12 connected to the lance 4, and by means of three cylinders 13 associated with the lid 2 of lance 4 is provided with a thickening 14 at its lower end with

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a conical end surface 15, interacting with the counter surface 16 of the socket 17, made in the lower part of the nozzle 3.

In addition, the lance 4 is made of two concentric tubes 18 and 19, forming the inner and outer channels 20 and 21 o The inner pipe 19 has a nozzle 22, directed vertically downwards and connected to the inner channel 20, and in the thickening 14 evenly spaced nozzles 23 are made, directed vertically up and connected to the outer channel 21.

The lance 4 is provided with a water cooled head 24 connected to it by means of a threaded joint 25.

On the nozzle 3, below the lateral openings 5, there is an annular protrusion 26 of a conical lower surface 27, which interacts with a counter conical surface 28 of the protrusion 29, made in the lower part of the vacuum chamber 1.

The nozzle 3 is made up of two parts: the top 30 is water-cooled and the bottom 31 is lined, interconnected by means of a quick-release flange connection 32.

Vacuum chamber 1 with its paws. 33 is mounted on the carriage 34 of the vertical movement mechanism (not shown) and connected by means of the pipe 35c with pumping equipment (not shown).

The inner channel 20 of the tuyere 4 is connected to a three-position flow switch 36 connected to inert gas, oxygen and gas-powder pipelines from a pneumo-chamber pump (not shown).

The outer channel 21 of the tuyere 4 is connected to the pipeline 37 inert gas. Each of the pipelines is equipped with the necessary control and porn control equipment.

The device works as follows.

In the initial position, the nozzle 3 and the lance 4 is lowered to the stop conical surfaces 15 and 16, 27 and 28.

After feeding, the bucket 38 with steel 39 and slag 40 includes purging the inert gas through the nozzle 22 and the vacuum chamber 1 is immersed in the metal to a depth sufficient to prevent air from being sucked into the vacuum.

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measure 1. At the same time, slag 40 is pushed aside to the periphery of the bucket 38.

If necessary, the bath is purged with oxygen or a gas-powder mixture, after which a vacuum is created in the vacuum chamber 1, the inert gas is purged through the nozzles 23 and the lance 4 and the nozzle 3 are raised.

Due to the pressure difference - atmospheric and inside the nozzle - and a decrease in density, the metal-gas mixture rises through the nozzle 3 and through the side openings 5 merges into the bucket 38 through the annular gap formed by the vacuum chamber 1 and the nozzle 3. Adjusting the depth of immersion of the tuyere 4 in the metal and the flow rate gas through the nozzles 22 and 23, as well as the size of the gap between the vacuum chamber 1 and the nozzle 3, regulate the rate of metal circulation. After 3-4 times the passage of metal through the vacuum chamber 1, the degassing process is completed, the pumping equipment is cut off and the vacuum cavity is filled with an inert gas to atmospheric pressure, after which the vacuum chamber 1 is lifted to the initial position and the ladle 38 with metal is sent to casting with

By making the nozzle with side openings and installing it on the lid independently of the vacuum chamber, the device maintainability is increased, since it eliminates the need to dismantle the entire vacuum chamber during the repair of the nozzle and creates the prerequisites for placing the inlet and outlet openings at a sufficient distance to allow intensive mixing. Placing the tuyere inside the nozzle increases the reliability of the device by eliminating its mechanical damage, and the possibility of vertical movement provides adjustment of the circulation rate. Together with the presence of a thickening at the end of the tuyere, this feature allows the slag to be cut off when the nozzle is immersed in metal 0

The presence of two independent channels of the tuyere provides enhanced functionality due to the deep purge of the bath with powdered reagents or oxygen, repulsion of small particles of slag or

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liquid pshak when the pipe is immersed in the metal, adjusting the intensity and direction of the gas flow.

The presence of an annular protrusion with a coaxial lower surface in contact with the counter conical surface of the protrusion made in the lower part of the vacuum chamber provides for the cut-off of the donkey and regulation of the cross-section of the drain hole, which contributes to an increase in the efficiency of process control.

The proposed device is characterized by improved maintainability by providing the possibility of separate repair of the lining, increased reliability due to the placement of the tuyere inside the nozzle and eliminating the possibility of mechanical damage, increased processing efficiency due to placing the inlet and outlet apertures at a sufficient distance from each other, flexible adjustment of the parameters of the vacuum chamber and technological process and exclusion of slag ingress, wider technological capabilities account for use of the lance for circulating metal tion also for deep blowing oxygen molten or powdered reagents.

In addition, the need to use manual labor and the presence of staff in the vicinity of the hot lining, i.e. service conditions are improved and labor safety is improved.

Due to the effective cut-off of the spike, the lining life is increased and the consumption of refractories is reduced.

Increasing the durability of the lining, reducing the duration of the process of evacuation, auxiliary

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and repair operations cause an increase in the productivity of the vacuum by 10–15%.

Claims (3)

1. A device for circulating vacuuming of liquid steel, containing a coccentric located vacuum chamber with a sealed lid and a suction nozzle, a lance for supplying gas to the suction nozzle, characterized in that in order to increase processing efficiency, increase reliability and maintainability, the suction nozzle is mounted with the possibility of axial movement and is made with side openings, annular protrusion located below the side openings and with a conical lower surface, and the lower part of the vacuum chamber has a protrusion with a mating conical surface, while the tuyere is vacuum tightly installed in the upper part of the nozzle coaxially with it. 2. The device according to claim 1, characterized by topics that at the end of the tuyere there is a thickening with a conical end surface, and in the lower part of the nozzle - a socket with a mating conical surface. 3. The device according to PP. 1 -2, about t - the fact that the lance is made of two concentric tubes forming the inner and outer channels, while the inner tube has a nozzle directed vertically downwards, and in a thickening evenly spaced peripheral nozzles directed vertically upwards and connected to outer channel. n t 2B 21 1B 17 23 38 FIG. one fff LЈ 9Ј  2 / 7tf 35 Fig.z Compiled by A. Scherbakov Editor A. Ogar Tehred M. Didyk Order 1758 Circulation 497 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology CQCP 113035, Moscow, Zh-35, 4/5, Raushsk nab. Production and Publishing Combine Patent, Uzhgorod, st. Gagarin, 101 Proofreader M.Samborsk Subscription