SU760492A1 - Two-phase channel induction furnace - Google Patents

Description

The invention relates to non-ferrous metallurgy, in particular to the constructive implementation of the induction unit of the channel furnace for melting metals. five

Known induction unit two-phase channel furnace for melting copper alloys, containing two magnetic, two cylindrical inductors and a refractory lining. ”Channels are made in the refractory lining, the configuration of which strictly repeats the inductor geometry £ ΐ £.

The disadvantage of this unit is the chaotic and unstable movement of the metal in the channels of the unit, which leads to its overheating and premature destruction of the lining.

In melting furnaces with such an induction unit, there is a significant value-20 temperature difference between the metal in the bath and in the channels of the furnace.

Closest to that proposed by design features is a two-phase induction channel- ^2th furnace, containing a bath designed for molten metal and an induction unit located under its base, made in the form. two side vertical channels, 30

2

central vertical channel and connecting them horizontal, covered by two closed magnetic circuits, on which cylindrical induction coils are located, side vertical channels and part of the central vertical channel to the horizontal axis of the coils are concentric with the coils, part of the central channel above the horizontal axis is expanding upwards [2].

The disadvantage of this design lies in the fact that the configuration of the channel part of the submerged stone of the unit does not create conditions, which form the axial component of the electrodynamic forces that ensure the unidirectional movement of the metal, and therefore decrease the temperature drop of the metal in the bath and the furnace channels. This is achieved by supplying the induction furnace with electromagnetic devices, which greatly complicate and increase the cost of its construction.

The purpose of the invention is to reduce the temperature difference of the metal in the channel part and in the bath of the furnace by increasing 760492

“· '” ““ • “' h-” - * 'g ’2732 & ίΡδΡ

the intensity of the single motion of the metal. · ''

The goal is achieved in that izvestnoypechi expanding part of the central channel is formed in a funnel shape, and on the furnace hearth with each of the lateral sides of the vertical channels to the vertical axis of the bobbin is formed protrusions ⁴ · ~ pepper section of which has a form of, mu triangle, one from the sides of which is aligned with the inner surface of the lateral vertical channel, and the angle facing the bath is 70-85 °.

In order to stabilize the unidirectional movement of the metal, it is advisable to include coils in a three-phase current network with a phase angle between the supply voltages in the range from 0 to 60 el.grad.

The drawing shows schematically an induction unit of a two-phase channel furnace, section.

The induction unit of the furnace includes magnetic conductors 1, induction coils 2, refractory lining 3 furnace baths and lining 4 bottom stones, side channels 5, central channel = 6, horizontal bottom channel 7 and protrusions 8 of bottom stones adjoining the "" "" side of the stone inductor th turned to the van *** "Not a furnace. The channel part of the furnace is performed using a special template when packing the unit with a lining mass. - 10

15

20

25

thirty

making the upper part of the bottom stone in the form of a protrusion, adjacent "r0 to" An inductor with a bevel at an angle of 70-85 ° to the side channel, provides intensive unidirectional movement of the metal, which leads to a sharp decrease in the differential "Metal temperature in the bath and in the channel part of the furnace, and, consequently, to eliminate overheating of the metal in the channels. This improves the service condition of the lining, increases its durability, and also creates opportunities for increasing the power consumption of the furnace, and increase its watchmaker-.

'STEPS.

50

'The choice of the angle of the protrusion is 70-85 °; due to the need to obtain a component of electrodynamic forces directed upward along the axis of the side channel, which allows to obtain an intense through-flow of metal in the channels. ''' ^1:

The proposed configuration of the hearth stone allows the Unidirectional movement of the metal to be obtained by simpler means as compared with the known device, in which for this purpose special magnetic devices that complicate the design of the furnace are used.

55

60

65

The proposed induction unit of a two-phase channel furnace is mounted and works as follows.

After casting the template according to a pre-made model of wood, which exactly corresponds to the developed channel configurations, a bottom stone is packed. Hearthstone It is installed in the form of a furnace, inductors and magnetic circuits are being mounted, the furnace bath is fixed to the hearth stone. The prepared oven is installed in the working socket of the overpass, where the power is connected to the inductors, then the oven is turned on to warm up according to the "defrost" mode. After the molten flax of the template, channels are formed in the sintered lining of the hearth stone of the furnace, which exactly follow the geometry of the template. Make-up and surfacing of the metal in the furnace bath. Bake. perovoyYtyyu'na working voltage (500 V). The existing channel geometry creates directional metal movement according to the following scheme: the metal from the furnace bath enters the mouth of the central 6 channel, divides into two, flows in the lower part of the central channel, passes through the bottom channel '7', and enters the furnace bath from the side channels five.

On induction furnaces of the YLK-1,2 type, research was conducted on the effect of the ^7th channel configuration of the unit on the temperature distribution of me.tall ^{over the} height of the channels and on the identification of temperature gradients of the metal between the bath and the channel part of the furnace.

It has been established that on these furnaces during the smelting of bronze (brand BRAZHNMts 9-4-4-1) the temperature drop decreases to 20-40 ° С (in known induction units it is 250-400 ° С). When smelting copper (M2 grade), there is no practical temperature difference between the metal between the bath and the channel part of the furnace. The integral velocity of the metal in the furnace channels calculated by the heat balance equation for copper smelting is 0.74 m / s and bronze 0.59 m / s.

This configuration of channel channel units at the point of transition of the side channels into the furnace bath ^: dramatically enhances the unidirectional movement of liquid metal through the channel due to the appearance of significant electrodynamic force, the velocity component of which is directed along the channel axis up into the bath and the appearance of which is effective from from the viewpoint of magnetic hydrodynamics, the flow of the surface of the hearth stone adjacent to the inductor by an electric current that faces the bath of the furnace.

760492

Claims (1)

Claim Two-phase induction channel furnace containing a bath intended for molten metal and an induction unit located under its bottom, made in the form of two lateral vertical channels, a central vertical channel and a horizontal connecting them, covered by two closed magnetic cores,. ₀ on which are located cylindrical ^and cue. Induction coils, side vertical channels and part of the central vertical channel to the horizontal axis of the coils are made concentric to the coils, part of the central channel 15 above the horizontal axis is expanding towards the top, characterized in that, in order to reduce the temperature difference of the metal in the channel part and in the bath by increasing the intensity of the unidirectional movement of the metal, the expanding part of the central channel is made in the form of a funnel, and on the bottom of the furnace on each side of the side vertical channels to the vertical axis of the coil there are protrusions whose cross section the sides of which are aligned with the inner surface of the lateral vertical channel, and the angle facing the bath is 70 - 85 °.