RU2003011C1 - Shaft furnace for producing melt aluminium from scrap - Google Patents

Abstract

SUBSTANCE: furnace consists of three lined sections for heating scrap, its melting and accumulation of melt. Inductors are installed on each section. Ultrasonic waveguides connected to an ultrasonic transducer are installed in the wall of the melting section with a deepening inside the section. A granular filter is placed between the sections for melting scrap and accumulating melt. The invention provides an increase in furnace productivity and melt quality 3 and

Description

I ljoCpcjiemiH relates to the field of non-ferrous metallurgy, in particular to devices and platinum aluminum scrap, and can; T with i -; /, ooFiaho for the production of zlumi,)

 from a mine having burners of a charge and electric furnace,

1 ,, C 1, UCXfCfl

j. , “Shmi /

, - even ne (ax coefficient of heat1oo. ,, -n og gas burner to the scrap is very

MIr, iro significantly restricts the production of these treatments.

 mg ln supplementation.p ml vipia

.-. .I,, g I1, ZY. H iVC, Is PPG & OZN NDKHO, LHbivi I wen1-, round foot K,). i (, JpC.V.

 / v r.v ionic pa 1lh heat sidereal- i, sf: 1.in h) f) {iri6 - Jcwriri -n- i

and. rj r which is the highest possible - i, i i & It was ne1 si.

. 4s J1 IO Champions League. T1 or joHi MCFa iachiori furnace

m- - si .1) 4i, nvKiopi, since the increase

, -, Э 1кНи1ЬМиС7И and СПЧЗ НЛ Basically with

 .,. The knowledge of Cherchengelsh is possible - 1 f / h -:., it i is about the order based on missile defense incn, -; in cree d |,) lg.- ec C i peujpT e solid. In addition to - th fired PUK in electric shafts and in induction furnaces, it is practically impossible to obtain aluminum of a given quality. Therefore, as a rule, the metal is refined in tundishes or in dispensing crucibles, thereby increasing the time to produce aluminum of a given quality, i.e. lowering productivity.

The closest in technical essence to the claimed solution is a shaft furnace, including a shaft for heating and supplying scrap covered by an inductor, and a melting crucible with an outlet located under the shaft, made in the form of lined sections interconnected, with inductors installed on each of them.

A disadvantage of the known device is that the increase in productivity can be achieved mainly due to the additional transfer of energy to the processed material, which is limited by the power, and therefore the size of the inductor. In this case, the thermodynamic capabilities of the solid metal-melt system itself (internal

energy, surface energy) is not used.

In addition, in the known furnace, products are obtained in the form of a semi-finished product, i.e. it is impossible to obtain aluminum of a given quality, therefore, the melt is refined with aluminum in intermediate ladles or in transfer crucibles. Those. the time required for the production of aluminum of a given quality increases, thereby decreasing the productivity of its production.

The aim of the invention is to increase the productivity of the furnace with obtaining a molten aluminum of a given quality.

The goal is achieved in that in a well-known shaft furnace containing three interconnected lined sections for

0 heating of the scrap, its melting and accumulation of the melt and inductors installed on each section, between the sections of melting and accumulation a granular filter is placed, in the circuit of the melting section with a recess

5 oiugr sections installed waveguides of ultrasonic vibrations connected to an ultra-sonic transducer,

Figure 1 shows a sectional view of a mine smelting night; Fig. 2 Q is a graph of the dependence of the reduction of the aluminum rod size on the smelting process at different frequencies of the cascaded ultrasonic vibrations; Fig. 3 is a graph of the variation in the melting rate in

5 melting process at different frequencies of superimposed ultrasonic vibrations.

The upper part of the claimed shaft furnace is a shaft (section) 1 for heating and supplying scrap 2, it is made

Q is made of refractory material and is surrounded by a spiral inductor 3 consisting of a small number of BITS used for pre-continuous heating of the dumped aluminum scrap 2.

5 Under the shaft (section) 1 there is a crucible 4, consisting of two lined sections; scrap melting sections 4 and melt accumulation sections 6. A grain filter 7 is installed between sections 5 and 6. Section

Melting Q 5 is surrounded by a more powerful inductor having a combined helical winding. When connecting the inductor 8 partially or to the total number of turns at various voltage levels

5, the scrap 2 can be heated to a melting point and subsequently melted. In the wall of the melting section 5 in the zone of formation of the liquid bath of the melt 9 with a deepening inside the section 5, waveguides of ultrasonic vibrations 10 are built in, which serve to transmit oscillations from

generator 11 of ultrasonic vibrations into the zone of formation of the liquid bath of the melt 9.

The accumulation sections of melt 6 are covered by an inductor 12 and have an outlet 13. This section is designed to heat the aluminum melt 14 to 720 ° C and maintain this temperature during its further processing.

In Fig. 2, dependences are plotted in the coordinate system where the abscissa shows the time of aluminum smelting, g, and the ordinate shows the decrease in the length of the aluminum rod (I). In this coordinate system, the dependences I f (t, f) 15,16,17,18,19 are shown, respectively, in the presence of ultrasonic vibrations with a frequency f 70, 60, 25, 100, 150 kHz in the claimed solution, and the curve 20 dependencies I f (g, at f 0) according to the prototype.

Fig. 3 shows the dependences in the coordinate system, where the abscissa axis shows the time (g} for aluminum smelting, and the ordinate axis shows the melting rate (UPL) of the aluminum rod in the melt in the inventive device (curves 21.22, 23,24,25} "in the prototype (curve 26). Curves 21, 22, 23, 24.25 show the melting speed of the rod at frequencies of 70.60.25, 100.150 kHz, respectively, and curve 26 shows the melting speed of the rod in the device- prototype at f 0.

The proposed shaft furnace operates as follows.

The prepared lump scrap is loaded into the shaft (section) 1 from above and, continuously heated from the inductor 3 to 400 ° C, is lowered by its own weight. Scrap 2 is melted in a molten liquid bath 9 formed above the granular filter 7. In order to intensify melting in the molten liquid bath 9, ultrasonic vibrations with a frequency of 60-70 kHz are introduced through the waveguides 10 from the ultrasonic oscillation generator 11. As a source of ultrasound, ultrasonic generators-IQ can be used. Under the influence of ultrasonic vibrations in the molten aluminum in the boundary layer, near the scrap pieces, Schlichting flows arise, which destroy this layer and thereby intensify the process of heat and mass transfer and, consequently, melting. Under the influence of ultrasonic vibrations, cavitation of the melt also takes place, which also intensifies the processes of heat and mass transfer and, in addition, partially refines the melt. The resulting melt is passed through a grain filter 7 with a thickness of 30-50 mm. which consists of corundum, polyethylene coke and alloys of calcium or magnesium fluorides with a grain size of +2 - (- 4). The filter 7 is covered by a stainless steel mesh at the top and bottom. Passing through the granular filter 7, the aluminum melt is cleaned of iron, copper, aluminum oxides, iron, alkali metals and other chemical compounds, and accumulates in the melt accumulation section. 8 it maintains a temperature of 720 ° C, which is most favorable for further refining of the aluminum melt 14. Refining is performed depending on the quality requirements of the metal. After refining is completed, the melt is discharged through the drain hole 13.

To confirm that the positive effect is higher than the prototype, experimental studies were carried out in an ultrasonic flaw detection laboratory.

Was aluminum smelted in the prototype device and in the proposed furnace. The experiment was carried out on a prototype device made in the form of a laboratory induction melting furnace with an industrial frequency of 50 Hz and a power of 2 kW. In steel crucibles of a prototype furnace placed in its working space, an aluminum melt superheated at 50 ° C above the melting temperature was prepared, into which an aluminum rod was lowered. By reducing the length of the I rod (Fig. 2, curve 20), the melting rate of the metal in the melt was determined (Fig. 3, curve 26). The melt temperature was measured by an HAev thermocouple, the readings of which were recorded on a diagram tape of the KSP-4 potentiometer

During the experiment, at the moment of immersion of the rod into the melt by a steel waveguide 10, ultrasonic vibrations of various frequencies were introduced through the side walls of the crucible 4. The source of ultrasound was serial flaw detectors DUK-20 and UKB-Sh, which provided the transmission of ultrasonic vibrations with a frequency of 2Ј, 60, 70, 100, 150 kHz. The results of the experiments are shown in figure 2 and 3.

The melting rate was calculated from the change in the length of the aluminum rod during the melting process (curves 15, 16, 17, 18, 19) at different frequencies of 70, 60, 25, 100, 150 kHz in the proposed solution and in the prototype (curve 20, frequency f 0) v ™ core in the melt (curves 21, 22, 23, 24, 25 for the proposed solution, 26 for the prototype).

i / b fsh 3 it can be seen that the melting rate of P / v о с,, т, of the device is higher than in the pro-LI R&D, and therefore the production rate of the furnace and the furnace are also higher.

... p, the highest melting rate is Ad barely; Slag performance 1, sl ih i, j4 is achieved with impact, i pac i iau by ultrasound at a frequency of 60-70 kN, which provides an increase

L- from: the odnnosti for the built-in furnace according to i Os-zchsmm-o with a prototype of 25%

П, о, yiai smoeusfois sho possesses pre- | M / n (astopm in comparison with the prototype, .a providing an increase in production, obtaining a melt, t about mi of a given quality. Availability c) rq. 1 m and f, gokspi ppav- with icini o / icri / e, t inward of the wave-wave in the center; m, of the acoustic vibrations of the state-of-the-art / ei image of the intrinsic

  - ABOUT . i 1LS n / IPBe, COTO, 7h SPOSOO. (jf p, uoHufO omstall speech -, l i / ic i «l1 a to the questionnaire

, L m, lOpr / jaTuiaaewoM melt

p V v t-, l st h s1 and current, which

i | s / i i, ouoi "v iccc leroio- n iassi

i U ill S iTnyUldlOl DEPTH LAYER,

r T OII L jp MS boundary of the separation Phase T) i dch l utill - melt and gasification - ier j.o.u hEsooOmen and accordingly

melting process, as confirmed by experimental studies. Along with the purification of the melt from impurities, a grain filter contributes to the formation of a liquid bath of aluminum melt above it. Due to the presence of a molten molten bath, pieces of aluminum scrap melt directly in the molten metal under the influence of ultrasonic vibrations, which

intensifies the melting process and partially refines the melt.

In the proposed furnace, the second section of the crucible is designed to accumulate molten aluminum, provides the possibility of simultaneously melting and refining, which makes it possible to obtain a molten aluminum of a given quality without further processing of the melt in other aggregates (in intermediate and casting ladles and

etc.) This provides a reduction in the time required to produce a melt of a given quality, i.e. leads to increased productivity of the furnace with obtaining a molten aluminum of a given quality in comparison with the prototype.

(56) Smirnov V.I. Metallurgists of copper, nickel and cobalt, M. Metallurgists, 1964, p. 158-159.

USSR copyright certificate No. 204355, cl. F 27 1/09, 1965.

Claims (1)

The claims A MINING FURNACE FOR PRODUCING MELT OF ALUMINUM FROM SCRAP, containing three interconnected lined sections for heating the scrap, its melting and accumulation of the melt and inductors installed on each section, characterized in that, in order to increase furnace performance and melt quality, it is equipped with a granular filter located between the melting and storage sections, and ultrasonic vibrating waveguides connected to the ultrasonic transducer mounted in the wall of the melting section with a recess inward to the section. i r b s § t y "w" / rt ( min