RU2354724C2 - Plasma thermo-decarbonator reactor-separator (tdrs) - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: reactor-separator is outfitted by heat exchanging facilities of the first and the second stage for heat passing and recovery t the production process with heat exchanging facility at the first stage is implemented in the form of screw mixer for simultaneous drying and heating of rough charge up to 180-250°C by hot clinker, fed from ball mill and following passing of heated charge into heat exchanging facility of the second stage, and heat exchanging facility of the second stage is implemented in the form of cavity package, covering cylindrical chamber and heating the rough charge up to 400-800°C for its following passage into TDRS on surface of melt and into the hollow partition, and also by additional small electrodes, immersed into melt and installed in side walls of cylindrical chamber.

EFFECT: exception of heat losses into the environment, maximal usage of the exothermal reaction energy, minimal consumption of energy resources, required for clinker formation, improvement of cement clinkers.

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Description

The invention relates to electric arc plasma separator reactors for the simultaneous melt of refractory, metallic and non-metallic materials and sublimates, mainly special types of artificial binder clinkers having a high degree of melt viscosity and associated non-ferrous metals, and can be used in cement, chemical industries and metallurgy.

The invention can significantly reduce energy consumption due to drying and heating of the raw material mixture, using the heat of the reactor itself, maximizing the efficiency of all equipment, dramatically increasing the performance of the reactor separator and the quality of cement clinkers, eliminating the cyclical nature of the work.

The present invention relates to devices for the simultaneous production of refractory, metallic and non-metallic materials and sublimates, mainly special types of artificial binder clinkers, for example cement clinker, having a high degree of melt viscosity and related metal alloys, and can be used in the cement industry.

A device for melting a material, mainly cement clinker, containing a chamber, solid horizontal rod electrodes, openings for introducing waste and steam, an opening for discharging exhaust gases is known (RF Patent No. 157060 C2, Н05В 7/00 dated 12/15/1998, "Plasma-chemical reactor "(Author Predtechensky MR)).

The disadvantages of this device are the low resource of the plasmatron (erosion of the electrodes), low productivity of the unit when using industrial waste, the cyclical nature of the work and the high consumption of energy resources.

Known plasma reactor for melting a material, mainly cement clinker, including a cylindrical chamber, hollow rod electrodes passing into the chamber through its upper cover, holes for introducing reagents in the chamber vault and outlet in the hearth, two electromagnetic coils covering the chamber and located one above the other by its height (Patent No. 2213792, С22В 9/22, F27B 14/04 dated 10/10/2003 (authors Yu.A. Burlov et al.)).

The disadvantage of this method is the rapid wear of the electrodes and the need to stop the unit to replace them.

The closest in technical essence and the achieved result is a plasma reactor for melting the material, mainly cement clinker, including a water-cooled cylindrical chamber, rod hollow graphite electrodes passing into the chamber through the top cover, four side feeders and one upper feeder for introducing the raw material charge, an electromagnetic coil , a longitudinal hollow partition cooled from the inside by raw material, which divides the chamber into two equal parts and has horizontal slit openings for the exit of the material and create an additional skull and an opening for the arc located above the surface of the melt rotating in the horizontal plane to evacuate solid raw materials from under the electrodes and move it to the arc burning zone, openings for the outlet of the finished material (Patent No. 2277598, С22В 9 / 22, F27B 14/04 dated 11.11.2004 (authors Burlov Yu.A. et al.)).

The disadvantage of this invention is the high consumption of energy.

The basis of the present invention is the elimination of heat loss to the environment, the maximum use of the energy of exothermic reactions, the minimum energy consumption required for clinker formation, a significant increase in reactor productivity and the quality of cement clinkers.

According to the invention, the problem is solved in that a plasma thermal decarbonizer reactor-separator (TDRS) for simultaneously producing a melt of refractory non-metallic materials and metallic materials and sublimates, containing a cylindrical chamber, rod hollow electrodes with heat-exchange elements, a channel for evacuating exhaust gases and sublimates, an electromagnetic coil creating a rotation of the melt in the horizontal plane for the evacuation of raw materials from under the electrodes and moving it to the arc burning zone, side feeders with channels for introducing part of the heated raw material and / or creating a scull on the lining in the form of conical slopes at the boundary of the melt mirror, a longitudinal hollow interior cooled by raw material using two central feeders mounted in it, dividing the entire lower part of the chamber into two equal parts and passing between the hollow rod electrodes immersed in the melt, the hole for the arc in the partition located above the surface of the melt, the channel for the output of melts of non-metallic and metallic materials located in the bottom of the chamber, a granulator for cooling and granulating the melt of refractory non-metallic materials, two heat exchangers of the first and second stages for transferring and returning heat to the production process, the heat exchanging device of the first stage being made in the form of a screw mixer for simultaneous drying and heating the feed mixture to 180-250 ° C with a hot clinker coming from the granulator, and further transferring the heated charge to the WTO heat exchanger th stage and second-stage heat exchange device is designed as a hollow body enclosing a cylindrical chamber and heating the raw material charge to 400-800 ° C and additional small electrodes immersed in the melt and mounted in the side walls of the cylindrical chamber.

The plasma thermal decarbonizer reactor-separator (TDRS) includes (see Fig. 1) a second-stage heat exchanger 1, which is a hollow reactor vessel and consists of an internal bearing part, an external part of the lined case and a filler (raw material charge) of the cavity, which during continuous operation of the feeder 2 moves from the top to the bottom. The heat exchanger 1 of the second stage covers a cylindrical chamber around the outer casing of the continuous reactor for transferring heat from the reactor casing at a temperature of 400-800 ° C; a raw material charge; rod hollow electrodes 3 passing into the chambers through the top of the hollow casing; heat exchange elements in one of the electrodes 3 are made in the form of inclined overflow shelves 4, delaying the fall of raw material and mounted in the cavity of the electrodes 3, the heat exchange elements of the second electrode are made in the form of a screw 5, channel 6 for evacuation of waste sizing gases and sublimates, openings 7 in the bottom for withdrawing refractory metal materials from the chamber, an electromagnetic coil 8 that creates a rotation of the melt in a horizontal plane to evacuate raw materials from under the electrodes 3 and move it to the arc burning zone, channels 9 for outputting a lighter a binder (refractory non-metallic materials) located between the holes 7 for outputting the melt of refractory metal materials, seven side feeders 10 (1 ', 2', 3 ', 4', 5 ', 6', 7 ') with channels for input heated in awns second stage heat exchanger 1 the raw material in the combustion zone of the reactor and create a ledge 11 on the lining in the form of tapered slopes at the boundary of the melt mirror and optionally at reverse feeders, feeding the preheated material through the feed electrodes 3 in the reactor cavity. A hollow longitudinal cooled by a raw material charge with feeders 10 (7 ') mounted in it baffle 12, dividing the lower part of the reactor into two equal chambers and located between rod hollow electrodes 3 immersed in the melt with an arc hole 13 located above the melt surface, which is equipped with horizontal slotted holes 14 with guides for the exit of the material and create an additional skull 15 in the form of conical slopes at the boundary of the melt mirror.

The granulator 16 is mounted under the reactor for cooling and granulating the melt of refractory non-metallic materials, made in the form of metal cylinders cooled from the inside, rotating around their axis in opposite directions relative to each other, a crusher (not shown conventionally) and a screw mixer, which is a heat exchanger 17 of the first stage, for heat transfer and transfer from a pre-crushed cooling clinker with a temperature of 1000-1200 ° С to a raw material charge with simultaneous drying and heating to a temperature 180-250 ° С, which is separated by means of a vibrating screen and / or vibrating screen 18 from the hot clinker and fed through the feeder 2 to the cavity of the heat exchanger 1 of the second stage, fire-liquid slag with a temperature of up to 1800 ° С is fed by the feeder 19 through a channel located in the wall the casing, through the graphite windows 20 pass two rods 21, with which the reactor is started, additional small electrodes 22 perform the function of the main electrodes at the time of replacement of the latter.

Plasma thermal decarbonizer reactor-separator (TDRS) works as follows.

The reactor is powered through electrodes 3 by a raw material mixture heated to 400-800 ° C. The raw material charge is initially heated in the first stage heat exchanger 17, which is a continuous screw mixer, which serves to transfer heat from a pre-crushed cooling clinker with a temperature of 1000-1200 ° С to a raw material charge with a temperature of 5-20 ° С through full contact of materials. With the joint mixing of clinker and raw material mixture due to the temperature difference, the mixture is heated to 180-250 ° C. Clinker is obtained in the reactor from a clinker melt, which is poured into a granulator 16 for heat recovery and granulation. The granulator 16 is made in the form of metal cylinders, water-cooled from the inside, rotating around its axis in opposite directions from each other. Then, the mixture selected by means of a vibrating screen and / or vibrating screen 18, heated to 180-250 ° C, is continuously fed by a feeder 2 into the cavity of the reactor vessel, which serves as a heat exchanger 1 of the second stage. The feed mixture enters the hollow body through the feeder 2, cools the walls of the reactor, while it is heated to 400-800 ° C and side feeders 10 (1 ', 2', 3 ', 4', 5 ', 6', 7 ') is introduced through channels located in the walls of the body at an angle of 90 ° on one horizontal plane relative to each other, into the reactor on the melt surface to create a skull lining of the material itself at the boundary of the melt mirror, resulting in a skull 11 in the form of conical slopes on the melt mirror thereby excluding thermochemical corrosion of the footer wki. To cool it using a feeder 10 (7 '), a raw material charge heated to 400-800 ° C is also supplied to the hollow partition 12, the partition 12 is equipped with horizontal slotted holes 14 (see Fig. 3) with guides for feeding material and creating an additional skull 15 in the form of conical slopes at the boundary of the melt mirror. When reversing feeders 10 (1 ', 2', 3 ', 4', 5 ', 6', 7 '), the raw material charge heated to 400-800 ° C is fed through electrodes 3 to the reactor. The main power of the reactor is made through the electrodes 3 with a heated raw material charge (400-800 ° C). The raw material charge heated to 400-800 ° C, which is introduced, contains in the calculated amount chemical compounds that provide artificial binders, for example cement clinker, during their melting.

When using waste materials, for example, chemical industries, as well as metallurgical industry waste in the form of liquid-liquid slag, they contain a certain amount of non-ferrous metals. Flame-liquid slag with a temperature of up to 1800 ° C is fed by a feeder 19 through a channel located in the wall of the housing. At the same time, additional heat is supplied, sharply reducing energy costs and increasing the productivity of the reactor and the quality of cement clinkers.

The ends of the electrodes 3 inside the reactor, depending on the mode, are raised or immersed in the melt to a depth (+50 mm) ÷ (-50 mm) above or below the melt mirror.

To start the plasma reactor into the melting chamber, divided by a longitudinal partition 12 into two equal parts, through the graphite windows 20 mounted in the wall of the melting chamber, the rod 21 passes to the electrode 3 with a charge "+" and forms an electric arc. Then, in one chamber, feed material 10 (1 ′) is fed until a melt is obtained. The rod 21 is raised up to the level of the hole 13 in the partition 12, thereby stretching the arc. Feeders 10 (2 ', 3') are connected. Carry out the same with another camera, i.e. the rod 21 passes to the electrode 3 with a charge "-" and forms an electric arc. Feed 10 (6 ') of the raw material until a melt is obtained. Feeders 10 (4 ', 5') are connected. An arc is ignited between these chambers and passes through a cylindrical hole 13 in the partition 12, where the plasma-forming gas is supplied. Feeder 2 is connected to feed the raw material heated to 180-250 ° C into the cavity of the reactor vessel. To stabilize the arc discharge, a plasma-forming gas is imparted rotation with the formation of a vortex. The vortex should be such that between the electric arc and the wall of the discharge channel a layer of plasma-forming gas is formed with a lower temperature and, accordingly, more dense, which isolates from the high temperature of the arc of the channel wall. The plasma-forming gas enters the discharge channel tangentially and forms a vortex there. Due to this, the material in the chamber is heated to its melting point. When firing clinker, the melt temperature reaches 1600-2100 ° C.

When the melt rises above the coil 8, voltage is applied to its winding. The walls of the chamber are made of non-magnetic material, for example steel, containing a large amount of nickel, chromium and titanium. The electromagnetic field generated as a result of the passage of current through the coil acts on the melt, which in the liquid state becomes conductive. Due to this, the melt rotates (mixes) in a horizontal plane to evacuate solid raw materials from under the electrodes 3 and move it to the arc burning zone and to the channels 9 for removing the binder melt in one direction (arrows shown in Fig. 2) simultaneously in both parts of the camera. When gaining a certain mass of the melt and heating the electrodes 3 inside the chamber above 1000 ° C, the material is fed through the cavity of the electrodes. Moreover, in the electrode 3 with a charge "+" the material is poured from shelf to shelf, which are heated to a temperature close to the temperature of the electrode. With a relatively slow (compared to a vertical fall) movement of the material and direct contact with the heated surface of the shelves, heat is transferred from the shelves to the material, and the last (preheated), brought to the dissociation temperature of carbonates, enters the melt surface and melts at a higher rate, t .to. in this case, exothermal reactions are already taking place with heat evolution. In this case, the productivity of the melting chamber is increased. The same process of heating the raw material occurs in the electrode 3 with a charge "-", but in this case, heating occurs when the material moves along a helical surface. As a result of mixing the melt due to the rotating magnetic field created by the three-phase coil, the melt is homogenized, which actively contributes to an increase in reactor productivity and an increase in product quality. The mixing speed is set by changing the frequency of the alternating current and is regulated depending on the viscosity of the melt, and the latter on its temperature. When melting the mixture to obtain a cement clinker, which contains a small amount of rare metals, some of them, the melting point of which is slightly higher than the clinker melt (except for tungsten and molybdenum), settle in the bottom of the chamber above the valves and are periodically released into the molds. The deposition of metals is due to the fact that their density is at least two times higher than the clinker melt.

Pairs of easily combustible rare metals (for example, lithium), together with carbon dioxide released as a result of decarbonization of the carbonate components of the clinker charge, are evacuated by the vacuum created in channel 6 into special separation devices where metal oxide pairs condense and carbon dioxide can be used to receiving dry ice. Sublimates of metal oxides are transferred for further processing to obtain a conditioned product. For a continuous production process when replacing the main electrodes 3, the latter are replaced by small electrodes 22 and, using power switching equipment, include them in the work.

Thus, the proposed device due to its compactness, the use of a continuous production process, heating the raw material charge moving in the cavity of the housing and cooling the walls of the reactor, cooling the clinker with the same raw material charge, minimizes energy consumption, significantly increases the productivity of the reactor, and improves the quality of the clinker and along with this it allows to obtain by-products in the form of their melt and sublimates.

Claims (1)

Plasma thermal decarbonizer reactor-separator (TDRS) for simultaneous production of a melt of refractory non-metallic materials and metallic materials and sublimates, containing a cylindrical chamber, rod hollow electrodes with heat-exchange elements, a channel for evacuating exhaust gases and sublimates, an electromagnetic coil creating a rotation of the melt in a horizontal plane for evacuation of raw materials from under the electrodes and moving it to the arc burning zone, side feeders with channels for introducing part of the heated raw material of the material and / or creating a skull on the lining in the form of conical slopes at the boundary of the melt mirror, a longitudinal hollow interior cooled by raw materials using two central feeders mounted in it, a partition that divides the lower part of the chamber into two equal parts along the entire height and passes between immersed into the melt by rod hollow electrodes, an opening for an arc in a partition located above the surface of the melt, channels located in the bottom of the chamber for outputting refractory melts non-metal and metal materials, a granulator for cooling and granulating the melt of refractory non-metallic materials to produce clinker, characterized in that the TDS is equipped with additional small electrodes immersed in the melt and installed in the side walls of the cylindrical chamber, and heat exchangers of the first and second stages for heat transfer and return in the production process, and the first stage heat exchanger is made in the form of a screw mixer for simultaneous drying and heating of the raw material charge to 180-25 0 ° C with hot clinker coming from the granulator and further transfer of the heated charge to the second stage heat exchanger, and the second stage heat exchange device is made in the form of a hollow body, covering a cylindrical chamber and heating the raw material charge to 400-800 ° C for its further transfer to TDRS on the surface of the melt and in the hollow partition.

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