RU2281834C2 - Method for magnesium casting and plant for performing the same - Google Patents

Abstract

FIELD: metallurgy, namely magnesium casting systems.

SUBSTANCE: plant includes conduction electromagnetic pump, mixer, supply pipe mounted in mixer and communicated with pump. Chamber rigidly joined with supply pipe is arranged in mixer. In said chamber there is opening for mounting pipe whose one end is communicated with chamber and whose other end is communicated with gas source. After heating up active zone of pump, magnesium is fed from mixer through supply pipe to active zone due to cyclic feed of gas into chamber and magnesium is cast into casting molds. Relation of volumes of chamber and supply pipe is equal to 3 : 1. It allows create lifting effort and provides rapid starting of pump.

EFFECT: enhanced efficiency, lowered cost of plant.

3 cl, 1 dwg, 1 ex

Description

The invention relates to ferrous metallurgy, in particular to the casting of molten non-ferrous metals, mainly magnesium.

A known method and installation for casting metal (the book. Technology of electromagnetic transportation of light metals. Mishchenko VD, Mikelson AE, Krumin Yu.K. - M .: Metallurgy / Problems of non-ferrous metallurgy. - 1980. - p. 128 ; Art. Testing a submersible electromagnetic conductive electromagnetic pump for magnesium. - I.P. Vyatkin, G.I. Kabakov, S.V. Mushkov et al. - Non-ferrous metals. - 1970, No. 10, pp. 51-52 ) The method includes heating the pump in a salt bath. Installing it in a mixer, heating the pipeline and supplying current to the pump core.

The installation consists of a mixer and a submersible pump, the active zone of which is constantly below the metal level in the mixer. The pump is installed in a metal casing to prevent contact of the pump components with magnesium. In the casing there are copper tires, a magnetic circuit.

The disadvantage of such an installation and method is that the current supply buses placed in the molten magnesium quickly fail due to oxidation, which leads to high material costs and low plant service life and method productivity.

A known method and installation for casting magnesium (st. Industrial development of casting magnesium using a conductive electromagnetic pump. - IP Vyatkin, GI Kabakov, SV Mushkov and others J. Non-ferrous metals. - 1970, No. 4. - p. 57-59), by the number of common features adopted for the closest analogue prototype. The method includes supplying current from the workshop AC network to the active zone of the pump, heating the metal path to 700-750 ° C, creating a vacuum through the suction pipe and supplying metal from the mixer through the feed pipe and the pump through the conveying pipe to the molds. By creating a vacuum of about 500 mm water column liquid metal through the inlet pipe enters the active zone of the pump and the pump is switched to operating mode.

The installation consists of a mixer in which a feed pipe is placed, connected to a conductive electromagnetic pump, an alternating current network, a vacuum system, conveying pipes, and molds.

The disadvantage of the data of the method and device is the complexity of the installation and method due to the need to create a vacuum in the mixer. In addition, starting the pump leads to an increased danger of the staff. This installation does not allow the supply of metal in a closed volume.

The technical result is aimed at eliminating the disadvantages of the prototype, to increase the productivity of the installation and the safety of the pump.

The technical result is achieved by the fact that the proposed method of casting magnesium using a conductive electromagnetic pump, including heating the active zone of the pump, supplying magnesium to the active zone of the pump from the mixer by means of a feed pipe installed in it and connected to the conductive electromagnetic pump, and casting magnesium into casting molds by means of a conveyor pipes, it is new that the supply of magnesium to the active zone of the pump is carried out by periodic supply of gas to the chamber placed in the mixer and connected to the supply pipe, and the creation of increased pressure in it, while the ratio of the chamber volume to the volume of the supply pipe is set equal to 3: 1.

In addition, inert gas or compressed air is used as the gas.

To implement the method, there is proposed a facility for casting magnesium using a conductive electromagnetic pump, comprising a mixer, a supply pipe installed in the mixer and connected to a pump, a conveying pipe and molds for magnesium, it is new that it is equipped with a chamber installed in the mixer connected to the supply pipe, a gas supply pipe, one end of which is connected to the chamber, and the other to the gas supply source, with an opening made in the lower part of the chamber, and the ratio of the chamber volume to The height of the feed pipe is 3: 1.

The gas supply to the chamber is necessary to start the conductive pump into operation, i.e. it is supplied with one impulse of such a force to cause the vertical movement of magnesium along the supply pipe to the pump. In this case, the gas is divided into two parts: one part together with magnesium leaves through the feed pipe, and the other part leaves the chamber through the chamber opening into the mixer. Then, after starting the pump, magnesium constantly enters the hole for casting into molds.

The hole in the chamber serves two purposes — to remove gas from the chamber and to fill the magnesium into the chamber.

Maintaining the ratio of the chamber volume to the volume of the supply pipe equal to 3: 1 allows you to create a lifting force and direct the magnesium into the supply pipe. All this allows you to quickly start up the pump and thereby increase the performance of the method and device, reduce the cost of starting the pump into operation.

The claimed group of inventions meets the requirement of unity of invention, since the claimed method of casting magnesium and installation for its implementation form a single inventive concept.

The drawing shows the installation for casting magnesium, consisting of a mixer 1, a pump 2, a supply pipe 3, output pipes 4, a magnetic circuit 5, an active zone 6, a chamber 7 with an opening 8 mounted on a supply pipe 3, a pipe for supplying gas 9, transporting pipes 10 and molds 11.

Device operation example

The supply of liquid metal to the active zone of the pump channels 4 are as follows.

A conductive electromagnetic pump 2 is installed on the mixer 1 with molten magnesium, and the feed pipe 3 with the chamber 7 with the hole 8 is placed in the mixer 1, while the chamber 7 is completely lowered into the molten magnesium. In the chamber 7, a hole is made for installing the pipe 9, the other part of the pipe 9 is connected to a compressed air supply system or to an inert gas cylinder. The ratio of the volume of the chamber to the volume of the feed pipe is 3: 1. To heat the parts of the supply pipe 3 and the conveying pipe 10, a voltage of ~ 30 V is applied and an alternating current of ~ 1.5 kA is generated. Then the core 6 with the outlet pipes 4 of the pump 2 is heated to a temperature of 700-750 ° C, applying voltage from the main source of alternating current U = 2-3 V, I = 4-8 kA. Then both current sources are turned off and gas, for example compressed air or inert gas, is supplied into the chamber 7 through the pipe 9. The gas supplied under pressure is divided into two parts, most of it enters the feed pipe 3 and supplies magnesium to the active zone 6 of the pump 2, the other part exits through the hole 8. When the core 6 is filled, the gas supply is stopped, the current and magnesium are turned on again the action of the electromagnetic force Lorensa rushes into the conveying pipe 10 and the mold 11, the pump turned on.

Thus, this group of inventions will eliminate the disadvantages of the prototype and increase the productivity of the installation, increase the safety of the pump, and also provide continuous casting of magnesium in casting molds.

Claims (3)

1. The method of casting magnesium using a conductive electromagnetic pump, including heating the active zone of the pump, supplying magnesium to the active zone of the pump from the mixer by means of a feed pipe installed in it and connected to the conductive electromagnetic pump and casting magnesium into casting molds by means of a conveying pipe, characterized in that the supply of magnesium to the active zone of the pump is carried out by periodic supply of gas to the chamber placed in the mixer and connected to the supply pipe, and creating an increased pressure in it tions, the ratio of chamber volume to the volume of the feed pipe is set to 3: 1. 2. The method according to claim 1, characterized in that inert gas or compressed air is used as the gas. 3. Installation for casting magnesium using a conductive electromagnet pump, containing a mixer, a supply pipe installed in the mixer and connected to the pump, a conveying pipe and molds for magnesium, characterized in that it is equipped with a chamber mounted in the mixer and rigidly attached to the feed a pipe, a gas supply pipe, one end of which is connected to the chamber, and the other to a gas supply source, while an opening is made in the lower part of the chamber, and the ratio of the chamber volume to the volume of the supply pipe is 3: 1.