RU2815308C1 - Method and device for thermochemical recycling of combustible wastes in vertical two-shaft furnace for burning carbonate materials - Google Patents

Abstract

FIELD: destruction of wastes by burning.

SUBSTANCE: group of inventions relates to method and device of incinerators intended for destruction of specific wastes or specific low-grade fuels. Thermochemical recycling of combustible industrial wastes, halogen-containing wastes and polyvinyl chloride plastics, residues after sorting solid municipal wastes, plastics and polyethylenes, alternative fuels RDF, SRF, TDF are performed in vertical two-shaft furnace for calcination of lump carbonate material into lime. Charge is prepared in bunker trestle according to recipe. Fractional recycled wastes, additives and lumpy carbonate material with fraction of 20 mm to 120 mm are dosed from the feed bins. Charge is loaded into the first direct-flow shaft-gas generator through the first sealed conical loading device equipped with an aspiration unit of gasification products. Carbonate material is loaded with fraction from 20 mm to 120 mm into the second shaft of counterflow roasting through the second sealed conical loading device equipped with aspiration unit of gasification products. Charge is gasified in the first shaft-gas generator in the medium of limited supply of oxidizer with excess air coefficient α=0.5 to obtain gasification products from wastes in the form of a mixture of generator synthesis gas, consisting mainly of H₂ and CO, in the medium of alkali-earth metals CaCO₃ and CaO by heating from the upper combined burners at a temperature of more than +1,300 °C. Lump carbonate material CaCO₃ limestone is burnt in the second counterflow shaft for decomposition into gas CO₂ and commercial lime CaO. Wastes gasification products are evacuated by blowing into the second shaft through the transition channel, where gasification products are repeatedly afterburned in the medium of excess air by suction from bottom to top through a layer of incandescent lime CaO in the entire roasting and heating zone in the second shaft of counterflow roasting. Products of gasification leakage from mines are evacuated by rarefaction from both sluice loading devices and supplied to the transition channel-gas duct to the secondary afterburning tuyere with suction through the layer of incandescent lime CaO. Technical lime CaO mixed with recycled waste ash is unloaded from the first shaft-gas generator, and commercial lump lime CaO is discharged from the second counterflow calcination shaft. Waste flue gases are discharged from the two-shaft furnace for gas cleaning due to vacuum of the smoke exhauster from the upper part of the second firing shaft. Reacted finely dispersed CaO is trapped from flue gases by dust-gas cleaning filters. Flue gases are cleaned. After the furnace flue ash is deposited with coal-fabric and electric filters. Residual acid gases HCl, SO₂, HF are removed by dry or wet method. Nitrogen oxides — nitrogen monoxide NO and nitrogen dioxide NO₂ — are catalytically decomposed with ammonia solution at temperatures from +170 °C to +380 °C with formation of gaseous nitrogen and water vapor. In the first shaft-gas generator, gasification of wastes with oxidizer deficiency is performed, with excess air coefficient α=0.5, obtaining generator synthesis gas, which then enters the second carbonate annealing shaft for secondary afterburning, where it burns in excess air with α≥1.2 with heat release, thereby replacing the main fuel of the commercial lime production process. Additionally, incandescent commercial lime CaO in the burning zone of the second counterflow shaft is continuous, replaceable, adsorbing filtering bed for sucked in products of high-temperature gasification of utilized wastes of the first straight-flow shaft-gas generator. Required conditions of dioxins and furans thermochemical destruction are realized on CaO surface with provision of gasification products residence time in medium of alkali-earth metals CaCO₃ and CaO at temperature from +1,300 °C to +1,700 °C for more than 2 seconds with excess air α=1.08–1.2. CaO lime adsorbs on its surface and removes from both mines chlorine, fluorine, bromine and sulphur compounds converted into stable neutral compounds, thereby excluding reverse recombination of dioxins and furans, also binding heavy metals Pb, Zn, Cd, Hg with lime CaO, transforming into stable solid neutral compounds. Additionally, the charge composition provides gas permeability and mobility of the mixed-component charge, prevents the charge from hanging on the arches in the furnace shafts, recycled waste is crushed by grinding with lumpy carbonate material in the process of the charge layer descent in the gas generator shaft and the lining skull is cleaned from soot and crusts, gas, liquid fuel is used as fuel, and by transfer method and solid fuel. Method is carried out in a vertical two-shaft furnace containing service bins of recycled wastes, additives, lump carbonate material with fraction of 20 mm to 120 mm, bunker trestle with proportioners and conveyors for forming charge according to the recipe, charge feed conveyor, two upper loading devices with sealed sluices. Furnace comprises two vertical lined furnace shafts with heating, burning and cooling zones, connected by hollow lined transition channel-gas duct at the level between burning and cooling zones, two lower unloading devices, burners for natural gas, mixture of gases or liquid fuels, tuyere for secondary afterburning of gases of loading devices in transition channel, aspiration unit, smoke exhausters and air blowers, dust and gas cleaning facilities. Structurally, it combines two units: and second — shaft for counterflow calcination of lumpy carbonate material into commercial lime CaO and afterburning of generator synthesis gas, connected to each other by hollow lined transition channel-gas duct at the level between calcination and cooling zones. First shaft-gas generator is made with possibility of operation only in direct-flow mode of gas and charge movement from top to bottom, with upper arrangement of fuel and air supply burners, charge is loaded from above by transfer method and operation in combined mode of gasification of utilized wastes and burning of lump carbonate material included into composition of charge. Second shaft of counterflow firing is made with possibility of operation only in counterflow mode, loading from above by lumpy carbonate material with supply of fuel and air to its lower part by burners together with gasification products from upper loading devices, fed by the tuyere into the transition channel for mixing and secondary afterburning in the CaO layer of the second shaft. It has the possibility of overflow of products of gasification of wastes from the shaft-gas generator into the shaft of counterflow roasting through the hollow lined transitional channel-gas duct for supply of the entire volume of gasification products for secondary afterburning by suction in a layer of incandescent commercial lime CaO in the entire burning zone and heating of the second counterflow shaft. It has the possibility of evacuation of flue gases with dusty lime CaO reacted with pollutants by rarefaction of the smoke exhauster from the upper part of the second shaft of counterflow firing. It has the possibility of heating air supplied from below to the furnace shaft for lime cooling through unloading devices, and supply to the second shaft of counterflow firing for blowing.

EFFECT: improved environmental situation, cleaning of flue gases and elimination of recombination of dioxins and furans, high-efficiency recycling of halogen-containing wastes, simple design of a two-shaft furnace without the presence of moving parts in the high-temperature zone, recycling wastes by releasing commercial lime, which is a continuous replaceable filtering adsorbent, partial replacement of the main fuel with generator synthesis gas obtained from wastes during calcination of commercial lime, possibility of using gaseous or liquid fuel or solid fuel using an upper filling method.

3 cl, 4 dwg

Description

Field of technology

The claimed inventions relate to a method and design of waste incinerators specifically designed for the disposal of specific waste or specific low-grade fuels. The invention can be used for the production of marketable lime and joint thermochemical recycling of flammable industrial waste, halogen-containing waste and polyvinyl chloride plastics, residues after sorting municipal solid waste, plastics and polyethylenes, sewer cake, alternative fuels RDF, SRF, TDF, in particular, in a vertical two-shaft furnace for roasting carbonate materials. The invention can be used in the housing and communal services sector, pulp and paper and hydrolysis production, ferrous and non-ferrous metallurgy, chemical, oil and construction industries, and medical waste disposal.

Background for the creation of the proposed invention Currently, the problem of environmentally friendly disposal of flammable waste from civil and industrial sectors is widespread, especially those containing potentially dangerous elements in the form of halogen compounds (fluorine, chlorine, bromine, iodine), sulfur, nitrogen and heavy metals (zinc, copper, mercury, tin, lead, cadmium, etc.). There are four main technologies for recycling this waste: deposition (burial), composting (biochemical process of organic waste), recycling (reuse) and thermal disposal after sorting. Heat treatment has the main advantage that it disinfects and reduces the volume of waste by 10-100 times, but due to the presence of artificial materials and compounds in waste, during uncontrolled combustion in the presence of, for example, chlorine, supertoxicants are formed in the form of substances such as polychlorinated dibenzo- p-dioxins (PCDD), dibenzofurans (PCBs) and biphenyls (PCBs), phosgenes, which pose a particular danger to both humans and the environment. These compounds have not yet been fully, but sufficiently studied, and the conditions for their formation [1], thermal destruction, neutralization, and prevention of reverse recombination (reduction) upon cooling have been determined relatively recently. The entry of halides and other compounds of pollutants (pollutants) into massively burned waste is inevitable, due to unsatisfactory sorting of waste and a large amount of undetectable types of synthesized plastics and materials, therefore the occurrence of dioxins and furans in flue gases is inevitable.

Typically, in waste incineration plants, environmentally friendly combustion of sorted solid municipal waste is carried out on grates according to the following scheme [2]: unloading platform for garbage trucks, platform for transport of residues, receiving hopper, overhead crane with a grab bucket, receiving hopper of a boiler with a chute, feeder, roller grate grate, steam generator, slag and ash removal system, slag and ash bunker, crane for loading slag and ash waste, room for cooling water and sludge tanks, electrostatic filter, turbogenerator, chimney, air condenser. This technology is not intended for the use of waste that exceeds the standards for the content of halogen-containing elements for the production of alternative RDF fuel [3].

State of the art

There is a known method of burning organochlorine waste [RF Patent No. 2119125, published on September 20, 1998], a method of burning organochlorine waste, including its thermal decomposition, characterized in that the organochlorine waste is fed into the tuyere zone of a blast furnace for mixing with blast in a ratio of no more than 3000 mg of waste per 1 m3 of blast.

This method is accepted as analogous.

The disadvantage of this method is the violation of the technology of the blast furnace melting process according to a non-technological parameter - the content of hydrogen chloride HCl in the blast furnace gas. In the internal space of the blast furnace, the maximum concentration of chlorine is discretely exceeded, and its excess leaves with the blast furnace gas in the form of chlorine-carbon compounds. In the upper layer of the blast furnace charge in the temperature range +125°С…+150°С, carbon monoxide (CO) reacts with gaseous chlorine (Cl2), with the formation of CO+Cl2=COCl2 - phosgene, a chemical warfare agent [4] , and is evacuated from the upper part with blast furnace gas. The supply of PVC plastics and RDF fuel to the tuyere zone of a blast furnace is unacceptable due to the formation of ash deposits and deposits at the entrance of the supply tuyere. RDF and SRF fuels often contain excess sulfur and phosphorus content, which reduces the quality of cast iron.

There is a known method for the disposal of organochlorine waste in ferrous metallurgy [RF Patent No. 2502922, published on December 27, 2013], a method for the disposal of organochlorine waste, which includes supplying it with a blast stream to the combustion zone of a shaft-type furnace and thermal decomposition with subsequent passage through the charge materials, characterized in that that chlorine-binding additives are additionally introduced into the initial charge in an amount of 50-75 kg per 1 ton of smelted cast iron while maintaining the viscosity of the slag melt of 0.2-0.5 N⋅s/m2, while calcium compounds are used as chlorine-binding additives. 2. The method according to claim 1, characterized in that limestone is used as a chlorine-binding additive.

This method is accepted as analogous.

The disadvantage of this method is the violation of the technology of running and melting a blast furnace according to several non-technological parameters - the content of hydrogen chloride HCl in the blast furnace gas and the viscosity value of the slag melt. This method cannot be used everywhere due to the complexity and exclusivity of blast furnace production. Also, based on the work carried out [4], it is believed that halogen-containing materials (including PVC plastics) cannot be disposed of in blast furnaces, since this leads to the accumulation of halogens in the volume of the blast furnace shaft, and if their certain concentrations are exceeded, the halogens are removed from a blast furnace together with blast furnace gas in the form of organochlorine compounds. The same circumstances require careful chemical analysis of RDF fuel used as fuel additives in blast furnaces, including those made from municipal solid waste, which can affect the quality of commercial pig iron. (See Internet: https://metal2020.sfu.lipetsk.ru/files/Sbornik-SMNT2020.pdf).

There is a known method for processing solid household and industrial waste [RF Patent No. 2383822, published on March 10, 2010], a method for processing solid household and industrial waste, including their preparation and loading into a shaft furnace together with carbonate material, supplying the furnace with fuel and air for combustion, removal of flue gases and removal of the finished product from the lower part of the furnace, characterized in that a two-shaft kiln for calcining limestone is used as a shaft furnace, and prepared waste is loaded into one shaft, operating in direct flow mode, together with carbonate material and fed into its upper part fuel and air for combustion, carbonate material is loaded into another shaft, operating in counterflow mode, to produce lime, and fuel and combustion air are supplied to its lower part, and flue gases from the first shaft are sucked through the smoke channel into the second shaft and using a smoke exhauster removed from the top of the second shaft.

This method is adopted as a prototype.

The disadvantage of this method is the use of combustion and supply of flue gases for cleaning by suction on burnt lime, which is not entirely environmentally friendly and economical. After all, the use of gasification technology [5] of waste in an environment of limited supply of oxidizer to produce generator synthesis gas, consisting mainly of H2 and CO, is more economical due to the fact that the resulting generator synthesis gas from recycled waste can be supplied for partial replacement the main fuel for burning commercial lime. High-temperature gasification at a temperature of +1300°C eliminates the formation of tars in gasification products and promotes the gasification of volatile metals from the ash residue of the combustion process. This method does not provide for the evacuation of waste gasification products that exit the furnace when the upper loading devices are opened when loading materials into the furnace shafts, which can lead to the release of gasified compounds of dioxins and furans into the atmosphere, and it also does not provide for the removal of these gasification products back into the furnace , to the required location with preliminary turbulent mixing [10] with blast air from the cooling zone, for secondary thermal destruction with excess oxygen, neutralization and purification on a layer of calcined lime. There is no aspiration of gases from waste bins that contain methyl mercaptans and sulfur dioxide gases, and they must be cleaned and neutralized thermally in the same furnace. The burner devices of the second shaft for roasting carbonate rocks are located below the transition channel-gas duct connecting both shafts, which can provoke a wall effect, and the flue gases will pass from the transition channel upward along the wall of the roasting shaft of the furnace, bypassing the layer of hot lime and the zone of elevated firing temperature, including due to the absence of turbulent mixing of flue gases with blast air from the cooling zone.

A known device is a direct-counterflow furnace for firing carbonate rocks [USSR author's certificate No. 1663353 F27B 1/02, published on July 15, 1991, Bull. No. 26], the furnace in design and achieved result is accepted as an analogue, it belongs to devices for firing carbonate rocks (limestone, dolomite and magnesite), in particular for the production of high-quality metallurgical lime, and can be used in metallurgical, chemical, construction, food and other industries. The purpose of the invention is to increase the productivity of the furnace and the quality of the product. For this purpose, shafts 1 and 2 are divided into heating zones 4 with heat regeneration, firing 5 and cooling 6. At the border of firing zones 5 and cooling 6, the shafts are connected by a connecting channel 7. The cross-section of the shafts in the peripheral part is segment-shaped, and the base of the segment is directed to the side connecting channel 7. The peripheral part of the shaft segment can be made in the shape of a semicircle, and the inner part in the form of a rectangle. At the same time, there is an improvement in heat distribution across the cross-section of the shafts due to the elimination of stagnant zones, and the uniformity of distribution of the flow of furnace gases also increases.

This device is accepted as analog.

The disadvantage of this analogue is the functional purpose of the oven; it is not intended for working with waste. Structurally, the furnace operates in a heat recovery mode using a direct-counterflow scheme, and such blast modes are not suitable for waste gasification and secondary combustion with lime. Burner devices are located only in the upper part of both shafts to ensure firing of raw materials in direct-flow operating mode. There is no mine operating as a gas generator mine. There are no devices for afterburning gasification products from upper loading devices. The evacuation of exhaust flammable gases by a smoke exhauster occurs from the upper parts of two firing shafts, which does not ensure a guaranteed contact time of gases in the firing zone.

A known device is a cyclone furnace for firing fine materials [RF Patent No. 2791072, published 03/02/2023], where a cyclone furnace for heat treatment of finely ground material in the form of limestone, dolomite, gypsum, magnesite, pyrite cinders, slag, containing a housing with an upper loading device , tangentially located burner devices, a central gas exhaust pipe and a lower unloading device, characterized in that the burner devices are distributed along the height and circumference of the furnace, while the furnace is configured to introduce material into the furnace in doses, through the burner tunnel of the upper burner device. 3. The cyclone furnace according to claim 1, characterized in that the furnace is configured to simultaneously supply finely ground material and the addition of a gas phase of the pyrolysis or gasification process of alternative fuel - RDF, SRF, TDF or combustible waste - into the burner tunnel of the upper burner device.

This device is accepted as analog.

The disadvantage of this analogue is that it works only with finely ground fluxing limestone material of a pulverized fraction of 0...0.4 mm, or up to 15 mm of other materials, and lump crushed stone of quarry carbonate materials in the fraction range of 20...120 mm is not applicable to this analogue. This significantly reduces productivity for mass waste disposal. Also, based on the report on the research work [6], the original alternative RDF and SRF fuel had an ash residue [7, Fig. 2] when fed directly into the cyclone furnace along with the fired material, the mixture of ash and lime had a scatter in values due to the heterogeneity of the incoming alternative fuel and the presence of silicate inclusions [8], and when gasification in an external furnace of alternative RDF and SRF fuel with the supply of products gasification into the cyclone, an ash residue remains [7, Fig. 3], which, due to the absence of lime CaO, as an adsorber and neutralizer in the mixture formulation, has an increased hazard class and a high content of pollutants artificially synthesized by the thermal process.

A device for processing flammable solid waste consisting of two connected pyrolysis reactors is known [RF Patent No. 2316696, published 02/10/2008]. An installation for processing solid combustible waste, comprising a high-temperature reactor connected to a pyrolysis reactor having a heating chamber, characterized in that the pyrolysis reactor is vertically oriented and has two coaxially located pyrolysis chambers equipped with mixing devices, the first pyrolysis chamber has an external and internal coaxially located housings with a slotted annular channel between them, which is a heating chamber, which is connected to a high-temperature reactor, the outlet of the slotted annular channel is located inside the second pyrolysis chamber, the first pyrolysis chamber in the bottom part has a hopper with a lock chamber for collecting and removing coke ash residue, in In the upper part of the first pyrolysis chamber there is a pipe for supplying raw materials and a pipe for the outlet of pyrolysis products, equipped with a shut-off valve; in the axial zone of the first pyrolysis chamber there is at least one longitudinally oriented pipe, the inlet of which is located in the bottom part of the heating chamber, and the outlet of the pipe , equipped with a fine spray, is located in the bottom part of the second pyrolysis chamber, while in the upper part of the second pyrolysis chamber there is a pipe for supplying sorted raw materials and a pipe for exiting pyrolysis products, and in the bottom part of the second pyrolysis chamber there is a hopper for removing coke ash residue.

This device is accepted as analog.

The disadvantage of this analogue is the presence of movable mixing devices of pyrolysis chambers in the high-temperature zone of the pyrolysis reactors, which reduces the reliability of the design. Indirect heating of pyrolysis chambers, even with stirring, has zones where, due to coking, heat transfer is reduced and synthesized pollutants are formed. Because of this, the coke ash residue has particles that have not undergone complete thermal destruction, especially during continuous operation in the second chamber due to the reduced temperature. The temperature in the first chamber is +400°С…+500°С, and in the second chamber +390°С…+430°С, which contributes to the maximum formation of dioxins and furans in this temperature range [1], which are adsorbed on the surface of the coke ash residue and for commercial carbon black, and including for the resulting commercial liquid fuel with a high content of sulfur inclusions, since neutralization of halides and desulfurization are not provided for in this device. This device has a separation of the vapor-gas mixture, which creates an environmental burden due to the formation of by-products in the form of pyrolysis water containing phenols and organic acids. This device does not have high waste disposal capacity.

A device is known for a direct-counterflow furnace for firing carbonate materials [RF Patent No. 2729679, published 08/11/2020]. A direct-counterflow furnace for firing carbonate materials, containing two shafts with heating zones with heat regeneration, firing and cooling of the finished product, connected by a transition channel located at the border of the firing and cooling zones with a cross-section of the shafts at the level of the roof of the transition channel in the form of a semicircle in their peripheral part and the inner part in the form of a rectangle directed towards the transition channel, characterized in that the shafts from the top to the bottom of the firing zone are made internally with a circular cross-section, and in the lower part of the firing zone with a smooth transition from a round cross-section to a section at the level of the transition arch channel, and the angle of inclination of the walls inside the lower part of the firing zone is 75-90 degrees to the horizon, and at the level of the transition channel the width of the internal part of the section is equal to the radius of the semicircular section of the peripheral part.

This device is accepted as a prototype.

The disadvantage of this prototype is the functional purpose of the furnace; it is not designed to work with waste. Structurally, the furnace operates in the mode of a direct-counterflow regenerative CCR furnace, and such blast modes are not suitable for gasification of waste and its secondary combustion in a layer of hot lime. When the direction of the blast changes, the loaded and burning waste, as well as combustion products, will be evacuated by the blast from the furnace into the atmosphere and gas purification, which will create an emergency mode. Burner devices are located only in the upper part of both shafts to ensure the main firing of the material in direct-flow operating mode. There is no mine operating as a gas generator mine. The exhaust gas outlet is located in the upper part of each of the two shafts, which does not provide a guaranteed contact time of the gases in the high-temperature firing zone. There is no preparation of source materials in the form of waste, additives and carbonate materials, or charge supply. There is no bunker rack with supply bins and material dispensers for forming the mixture recipe, as well as ensuring the mobility and gas permeability of the mixture in the gas generator shaft. Loading devices do not ensure tightness and removal of furnace gasification products at the moment the loading gate is opened, which provokes the release of toxic gases into the atmosphere. There is no collection and re-burning in the furnace of gases from the top loading device and top gasification products emanating from the airlock chamber. There is no device for turbulent mixing of the injected gases for secondary combustion in the countercurrent of hot lime. Gas cleaning is not designed to work with ash and acid gases HCl, HF.

The main disadvantages of the above methods of waste neutralization and devices for their implementation include their insufficient efficiency in terms of safe thermal utilization and purification of gases, in particular, the inability to ensure the elimination of reverse recombination of dioxins and furans, as well as the elimination of the occurrence of phosgenes.

Disclosure of the Invention

The objectives of the proposed group of inventions are to reduce the likelihood of recombination of dioxins and furans in cooled flue gases during thermal disposal of chlorine-containing and halogen-containing combustible waste. Creation of an environmentally friendly, economical and high-performance industrial method for the thermochemical disposal of waste containing halides, sulfur and heavy metals, and in the creation of an industrial-type installation with high productivity, which, with its design and operating modes, implements the required method without reverse recombination of dioxins and furans, ensuring compliance flue gases to international emission standards [9].

The technical result consists in improving the environmental situation, cleaning flue gases and eliminating the recombination of dioxins and furans, in a high-performance method for recycling halogen-containing waste, in the simplicity of the design of a two-shaft furnace without the presence of moving parts in a high-temperature zone, in waste disposal due to the production of commercial lime, which is continuous replaceable filter adsorbent, partial replacement of the main fuel with generator synthesis gas obtained from waste during the burning of commercial lime, the possibility of using gaseous or liquid fuel, or solid fuel using the top pouring method.

These goals are achieved by forming the required composition of the charge of the supplied waste, depending on the morphological composition, and ensuring the required course of the process, ensuring the thermochemical and temporary regime of dioxin destruction [10], using a material in the charge that will act as an adsorbing agent to neutralize pollutants in its area. surface, which will ensure the elimination of the recombination of dioxins and furans and the further use of the spent adsorbing agent as a commercial product.

The invention is based on the following ideas. Combining the process of thermal waste disposal and chemical neutralization of pollutants with the main process of lime burning in a vertical two-shaft kiln to obtain the required conditions for high-temperature conditions for the destruction of dioxins and furans, the presence of a replaceable, continuously supplied adsorbing agent and an industrial device close to the required design.

Selection of adsorbing agent. As a continuous, replaceable commercial adsorbing agent, a carbonate material was selected, preferably limestone CaCO3, which after high-temperature firing is lime CaO, the decomposition reaction of which occurs when heated according to the scheme CaCO3 → CaO + CO2 -Q. Calcination of limestone into lime occurs in the temperature range +800°C...+1000°C to produce lime with high reactivity, the so-called soft-burnt lime [RF Patent No. 2712461, published 01/29/2020]. The production of another type of lime, high sintering, occurs at temperatures of, for example, about +1700°C. The firing process takes place in rotary kilns and in vertical single-shaft or double-shaft kilns. This range of operating temperatures is sufficient to meet the requirements for complete thermal destruction of dioxins and furans, which lie in the range of +1200°C and above, with a residence time of 2 seconds, subject to excess oxygen [1]. The adsorbing agent lime CaO binds and neutralizes on its surface the main pollutants from flue gases, the most toxic of which are sulfur compounds and elements of the halogen group, which at high temperatures and in the presence of gases are bound by lime according to the following reactions:

SO2+CaO+1/2O2→CaSO4+Q1 resulting in the resulting solid neutral compound CaSO4 gypsum, calcium sulfate (food additive E516);

2HCl+CaO→CaCl2+H2O+Q2 resulting in the resulting solid neutral compound CaCl2 calcium chloride, emulsifier (food additive E509);

2HF+CaO→CaF2+H2O+Q3 resulting in a solid neutral safe compound CaF2, which is a component of metallurgical fluxes.

In this way, on the surface of hot lump lime, neutralization and binding of toxic and corrosive acidic components is achieved, thereby preventing their reverse recombination during cooling, for example in the form of dioxins and furans. The absence of a circuit for sharp cooling (quenching) of flue gases to +200°C significantly reduces the energy consumption of the proposed method. Fine fractions of CaO that have reacted with pollutants are captured by standard dust sedimentation filters. Also, together with lime CaO and in the presence of other elements, heavy metals Pb, Zn, Cd, Hg transform into solid insoluble compounds.

The use of gasification of waste with a temperature not lower than +1300°C, since at this temperature the liquid fraction in the form of resins is no longer formed, but complete gasification of the waste occurs with a minimum solid residue, and this process is organized in a shaft furnace, which solves the problem of formation of deposits and coking of gas ducts.

Formation of the batch recipe. A charge is loaded into the gas generator shaft, including a mixture of recyclable waste according to the selected recipe, containing: the remains of combustible waste after sorting solid municipal waste (“sorting tails”), alternative fuel from solid municipal waste in the form of RDF (Refuse-derived fuel is translated from English as “fuel derived from waste”), SRF (Solid Recovered Fuel is translated from English as “solid recovered fuel”), TDF (Tire-Derived Fuel is translated from English as “fuel obtained from car tires”), polymers and plastics containing halides. The inclusion of liquid fractions (acid tar, paints, solvent, etc.) and paste fractions (dehydrated sewage cake and sludge, black liquor from pulp production, lignins, etc.) into the mixture composition is taken into account, which, when mixed with carbonate material, form a mixture and are fed into the furnace .

Device operation control. The mixture recipe is formed on the basis of the developed software of a mathematical model for controlling the operation of the device according to the specified method and is its inalienable part. Based on the energy and chemical indicators of the recycled waste and the fuel used, the dosing of materials from consumable bins and the supply of energy carriers are formed.

The implementation of guaranteed secondary combustion of the entire volume of gasification products of waste and flue gases is organized in the second limestone roasting shaft, by sucking through a layer of alkaline earth metals CaCO3 and CaO at a temperature of +1300°C with excess air α = 1.08-1.2 and contact time gases for more than 2 seconds. The passage of all gases is initiated by the formation of a model of gas movement in the furnace in one direction, using the vacuum of the smoke exhauster, through the only outlet gas duct in the upper flue part of the second countercurrent firing shaft.

Device design. By connecting the gas generator shaft and the carbonate material roasting shaft proposed above with a hollow transition channel-gas duct, a similar design of an industrial vertical two-shaft limestone roasting furnace is obtained. Typical two-shaft lime kilns operate using a co-current-countercurrent design with heat recovery. By changing the direction of the blast flows in the shafts, the proposed device changes the fundamental and functional purpose of the furnace, and the device is implemented as a two-shaft device that combines two units: the first is a direct-flow shaft-gas generator for combustible waste and calcination of technical lime, and the second is a counter-current burning shaft lump carbonate material into commercial lime CaO, connected to each other by a hollow transition channel-gas duct at the level between the firing and cooling zones. This design is the most economical and reliable in comparison with combustion on grates or in fluidized bed boilers, due to the absence of moving parts in the device in the form of screws, a cooled hearth with caps, movable grate bars with water cooling systems, heat exchangers and chemical water treatment systems and cooling towers.

The use of lump carbonate rocks in the composition of the charge. By forming a charge formulation in a bunker rack before loading it into a gas generator shaft, the variability of the fractional composition and thermal characteristics supplied for waste disposal is compensated. The addition of technical quicklime to the charge allows you to remove excess moisture from the charge before feeding it into the gas generator shaft. The addition of lump carbonate material to the charge ensures the mobility of the charge during transportation by conveyors and during top loading with a skip, and feeding into the shaft with a double-cone loading device. When the charge is in a mine with lump material, the layer is breathable for the passage of flammable gases, and hanging in the vaults is eliminated. The lump material also works as an abrasive and cleans the lining and mechanisms of the upper loading devices from deposits of resins and volatile metals, compensates for the formation of thickening of the skull on the lining, and also grinds and crushes waste during the process of the lime layer coming off.

The collection of gasification products, which are organized at the moment of depressurization of the upper loading devices, is carried out by aspiration and subsequent supply for secondary combustion through a tuyere into the transition channel for better turbulent mixing of gas mixtures. The said tuyere is also supplied with waste aspiration air from the bunker rack, which contains compounds of hydrogen sulfide and methyl mercaptans.

Providing the required blast conditions in the first gas generator shaft is achieved by placing burners and blowers at the top to ensure direct flow of downward gases and charge. In the second firing shaft, burners and blowers are installed from below, countercurrent to the movement of the limestone being fired.

Fuel used in the device: natural gas, fuel oil, including watered fuel, crude oil, pulverized coal and water-coal fuel. The furnace can be converted to operation using the pouring method using solid fuel or a combination of fuels, including liquid. Through the upper loading devices you can feed: coal and coke, used wooden railway sleepers impregnated with creosote, lignin from hydrolysis and cellulose production, tree bark and roots, black liquor from cellulose production, oils, auto plastics and filters, car tires and rubber products, medical packaging, syringes and mattresses, slack oil and acid tars, etc.

Versatility of work. In the event of a cessation of supplies of waste subject to thermochemical disposal, this device can switch to the production of only marketable lump lime by all two mines, using liquid, solid or gaseous fuel supplied either to the burners or through the top loading device in a pour-over method.

Flue gas cleaning. Well-known methods of complex flue gas purification are used. Includes cyclonic gas purification of the first stage, purification of fly ash with carbon-fabric and electrostatic precipitators with dry and wet removal of acid gases HCl, SO2, HF, as well as catalytic decomposition of nitrogen oxides (nitrogen monoxide NO and nitrogen dioxide NO2) with ammonia solution at temperatures from +170°C to +380°C with the formation of nitrogen gas and water vapor. Another combination of known gas purification methods can be carried out.

Application of the resulting products. After unloading the cooled ash residue of the charge from the first shaft-gas generator, metals, ash residue and industrial lime CaO are separated by separation, which can be used for dewatering waste in a bunker rack before feeding it into the furnace, for disinfection and dehydration of wastewater infiltrated from incoming waste. Dust removal from gas cleaning and sifted ash residue are suitable for partial replacement of raw materials in the production of gas silicate blocks by autoclaving, due to the complete afterburning of waste and the presence of impurities of ash, lime and silicates, which is given in the laboratory chemical analysis protocol [8] Samples No. 4 with mass content of SiO2 = 2 .9%, S=0.03% and P=0.01%.

The resulting burnt lump lime from the second roasting shaft is both a replaceable spent absorption filter agent for furnace gases and a commercial product in the form of construction lump lime with an activity of 88-92, the implementation of which generates payback and the economic effect of reducing the cost of waste disposal.

Based on the above ideas included in the claimed invention of the method and device, a comprehensive environmentally friendly processing of combustible waste, including halogen-containing waste, is implemented using the design of an industrial vertical two-shaft furnace for roasting carbonate materials.

Novelty

The proposed method and design of the device are novel, since the set of features of the invention formula have not been found in information and patent sources. The use of the design of an industrial two-shaft kiln for carbonate materials as a device for implementing the invention has not been determined, especially the operation of one of the shafts in the mode of a high-temperature direct-flow gas generator of combustible halogen-containing waste, including liquid.

Inventive step

The technical solution of a joint method and device declared as an invention has an inventive step, since the method and joint use of an industrial bunker rack for the formation of a complex charge formulation and the design of a two-shaft vertical furnace for roasting carbonate materials for the joint disposal of waste, including halogen-containing ones, is not obvious, and this leads to significant results in environmentally friendly flue gas purification and increased productivity of thermal disposal of combustible waste, including the use of industrial samples of standard equipment.

Industrial applicability

The group of claimed inventions of the method and device is at the stage of preliminary design of the furnace (Figure No. 3), and their use does not change the principle of construction of similar furnaces, since known equipment, materials and structures are used, and working industrial bunker racks and double-shaft kilns are close to according to the design of the invention, have been in industrial operation for a long time, for example, double-shaft kilns type PFR from Maerz Ofenbau AG (Switzerland), which have a capacity of up to 800 tons of lime per day, which can be comparable to the amount of recycled waste.

Brief description of the drawings of the device and method.

Figure 1. Design and schematic diagram of a vertical two-shaft furnace for firing carbonate materials for joint thermochemical recycling of combustible waste.

Figure 2. Functional diagram of the method for thermochemical disposal of combustible waste.

Figure 3. Sketch drawing of a vertical two-shaft furnace for firing carbonate materials for the joint disposal of combustible waste with charge feed bins.

Figure 4. Photo table of ongoing pilot tests of the method and device.

The inventive device is illustrated by the proposed design (Figure 1) of a vertical two-shaft furnace for firing carbonate material and joint thermochemical disposal of combustible waste. Composition: bunker rack - 1, consumable dosing waste hopper - 2, dosing hopper for additives and solid fuel - 3, dosing hopper for lump carbonate rocks - 4, charge feed conveyor - 5, feed conveyor for lump carbonate rocks - 6, aspiration installation of bunker rack - 7 , charge supply path - 8.1, carbonate raw material supply path - 8.2, charge lifting device - 9.1, carbonate raw material lifting device - 9.2, upper loading device of the first gas generator shaft -10, aspiration installation for collecting leakage of gasification products from the shaft -11, cone loading devices - 12, fuel and blast air supply paths - 13, upper burner devices of the first shaft - 14, first lined direct-flow gas generator shaft - 15, gasified charge and lump limestone CaCO3 for firing into technical lime CaO - 16, tuyere for secondary afterburning of aspiration gases leaks of the upper loading devices and aspiration air of the bunker rack - 17, lined hollow transition channel-gas duct - 18, cooler - 19, unloading device - 20, cooling and blowing fan - 21, metal and ash separator - 22, lower burner devices of the second shaft - 23, lump limestone CaCO3 for firing into commercial lime CaO - 24, second lined counterflow shaft for roasting commercial lime - 25, upper loading device of the second firing shaft - 26, solid gas purification residue bunker - 27, gas purification - 28, smoke exhauster - 29, chimney - 30, furnace flue gas outlet - 31, gasification products - 32, flue gases - 33.

The inventive method is illustrated in the diagram (Figure 2), where the accumulation of raw materials in supply bins and dosing of additives and technical lime for dehydration of raw materials occurs - [1], dosing of fractional combustible waste to be disposed of - [2], dosing of lump carbonate raw materials - [3] for joint supply and formation of the charge formulation in a bunker rack [4], dosing of lump carbonate raw materials for firing - [5], top supply of charge material into the first direct-flow gas generator shaft [7] of a vertical two-shaft furnace [6] and top supply of lump carbonate raw materials into the second firing shaft [10] of a two-shaft furnace [6], supplying gasification products from the first shaft to the second via a transition channel [8] for secondary afterburning, supplying aspiration air from the bunker rack and aspiration gases from the upper loading devices through the tuyere for secondary afterburning [9] , cooling of industrial lime and waste ash [11] with subsequent screening and separation [12] into metals [14] and industrial lime [15], and waste ash [13], cooling of commercial lime [17] with unloading of commercial lime [18] , gas purification [16] with the formation of fly ash [13], supply of energy resources [19].

The description of the operation of the claimed device and method is given according to the diagram (Figure 1), taking as initial data: fuel - natural gas, and recycled waste - “tails” after sorting solid municipal waste. The bunker rack [1] receives raw materials and additives of certain fractions, where, using conveyors, they are distributed from receiving bins to supply bins: lump carbonate rocks (preferably limestone CaCO3) [4], recyclable solid waste [2], additives (technical lime for dewatering of waste, solid and liquid fuels or reagents). Based on the types of waste being disposed of, a charge formulation is formed in the supply bins, and solid and liquid waste is supplied by bunker dispensers along a belt conveyor [5] to form a charge with the addition of carbonate raw materials from the supply bin [4] along a reversible conveyor [6]. Further transportation of the charge is ensured by the charge supply path [8.1] and lifting of the charge by a skip device or another [9.1] for reloading into the upper loading device of the first gas generator shaft [10] with subsequent loading into the gas generator shaft [15], through sealed locks of a double-cone loading device [12], equipped with an aspiration unit [11] for blowing off penetrated gasification products at the moment of opening the cones [12]. The carbonate stone included in the charge ensures the mobility of the charge for conveyor transfer and unloading from the skip, prevents the charge from hanging in the vaults during heating and gasification, ensures the gas permeability of the charge layer, abrasively cleans the cones of the loading device and the lining from carbon deposits and resins, grinds the waste at the time of removal layer and adsorbs on itself the pollutants formed in the gas generator shaft.

From the hopper of lump carbonate rocks [4], limestone is dosed onto the conveyor [6] for firing CaCO3 into commercial lime CaO. The carbonate raw material supply path [8.2] delivers material for subsequent lifting on a skip or other device [9.2] for pouring into the upper loading device of the second counter-flow commercial lime roasting shaft [25] with subsequent loading into the burning shaft, through sealed locks of a double-cone loading device [12 ], equipped with an aspiration unit [11] for blowing off the penetrated gasification products at the moment of opening the cones [12]. The loaded limestone, having entered the firing shaft [25], is heated by the heat of the exhaust flue gases [33], and the unburned particles that fall on its surface with the flue gases [33] are carried down for re-burning into the firing zone [23], thereby eliminating the removal of unburnt particles. ash from the wall effect.

In the gas generator shaft [15], sequential heating of the loaded charge [16] occurs, and then the process of waste gasification begins with the formation of gasification products [32] from burning fuel and air [13] on combustion devices [14] with air deficiency α = 0 ,5 and at a temperature of about +1300°C to prevent the formation of tars in the resulting gasification product [32] - gas generator gas (synthesis gas), consisting mainly of hydrogen H2 and carbon monoxide CO. Gasification products [32] in the first shaft [15] are sent down in a co-current flow with the limestone of the mine charge [15]. Having passed the firing zone of the first shaft, limestone CaCO3 is fired into technical lime CaO with the release of carbon dioxide CO2, the lime adsorbs halogens, sulfur and heavy metals onto its surface. The blowing in the furnace is organized in such a way that the gasification products [32] are evacuated by the vacuum of the smoke exhauster [29] into the second shaft [25] for firing carbonate material, passing through a hollow inter-shaft transition channel [18]. Next, gasification products [32] enter upward, in countercurrent to the hot calcined carbonate material [24] with a surface temperature from +1300°C to +1700°C, are sucked through a layer of hot calcined commercial lime with a contact time of more than 2 seconds and are re-burned in a torch burners [23] with excess oxygen α=1.2. Commercial lime CaO in the area of burner devices [23] at temperatures above +1300°C adsorbs and neutralizes on its surface into neutral compounds the main halogens Cl, F, which did not react with lime CaO in the first gas generator shaft [15], thereby excluding recombination dioxins and furans, and heavy metals Pb, Zn, Cd, Hg, transform into solid insoluble compounds, and sulfur S transforms into the solid neutral compound gypsum CaSO4. Commercial lime [24], having been fired and adsorbed pollutants onto its surface, cools and goes down into the cooling zone, like the technical lime [16] of the first mine [15]. Having been cooled by combustion air from fans [21], lime from two mines is unloaded by unloading devices [20], and technical lime is additionally separated [22] for the presence of metals, lump lime and bottom ash with fine lime.

Leakage without proper cleaning of gasification products [32] and flue gases [33] from mines [15, 25] at the moment of opening of the cones [12] is eliminated by aspiration units [11], which supply the resulting gas-air mixture with atmospheric air for secondary combustion in the tuyere [ 17], located in the intershaft transition channel [18], where the required turbulent mixing of cold and hot (about +1250°C) gases is ensured. The air of the bunker rack has a high content of odorants in the form of hydrogen sulfide compounds, methyl mercaptan and others, therefore the aspiration air [7] of the bunker rack is also supplied for secondary combustion through a tuyere [17] for disinfection and cleaning.

All flue gases [33] and gasification products [32] are guaranteed to undergo secondary afterburning in the zone of calcination of commercial limestone on burners [23] with the suction of flue gases [33] in a layer of hot lime [24] due to the forced organization of the movement of all gases in the furnace from the vacuum of the smoke exhauster [29], through one outlet of the furnace flue gases [31], located in the upper part of the firing shaft [25].

After exiting the furnace, the flue gases [33] are sent to complex gas purification [28] using known methods, and during the gas purification process, fly ash (fly ash) [27] containing pulverized limestone and lime is formed. The cooled and washed flue gases [33] are released by the smoke exhauster [29] through the chimney [30] into the atmosphere.

An example of a specific implementation confirming the possibility of introducing the proposed method and device into production is shown in the photo table Figure 4.

Example 1. Experimental tests were carried out on a pilot plant simulating the claimed method and device [7, Fig. 1]. The lining refractory layer of two shafts, the upper loading and lower unloading screw devices were manufactured. Lime was burned together with RDF fuel in one of the shafts, then a mixture of RDF fuel and lime was fed into both shafts. The ash residue of RDF fuel was recorded, the amount of supplied air, coefficient a, and laboratory analysis [8] of the resulting materials were determined. Only gasification products of RDF fuel were supplied from the remote furnace to the firing zone of the alkaline earth material of lime and dolomite. The obtained results of pilot tests confirmed the calculated and practical data given in this method and device.

Information sources:

1. Bernadiner M. N. Dioxins in pyrometallurgical processes and methods of their neutralization, Electrometallurgy. 2000 No. 1. pp. 12-17.

2. Guidelines for calculating emissions of pollutants into the atmosphere from waste incineration and waste processing plants, AKH im. K. D. Pamfilova Ministry of Housing and Communal Services of the RSFSR 123371, Moscow, 1989, fig. 1.

3. Interstate standard GOST 33516-2015, Solid fuel from household waste, Technical characteristics and classes, p. 4.

4. Korshikov V.D., Konev V.A., Konev M.V. On the issue of using RDF fuel in blast furnaces, Modern metallurgy of the new millennium (SMNT-2020), Lipetsk State Technical University, PJSC Novolipetsk Metallurgical Plant, October 2020, pp. 6-16.

5. Efimov N.N., Fedorova N.V., Mirgorodsky A.I., Kolomiytseva A.M. Gasification of organic fuels and biomass, Advances in modern natural science. - 2007. - No. 1. - P.15-21; Internet link URL: https://natural-sciences.ru/ru/article/view?id=10830

6. Report on research work on the topic: “Preparation and testing of a pilot cyclone-type kiln produced by NPO Science-Intensive Technologies LLC, with the preparation of a report on the results of the work carried out and issuance of recommendations”, Federal State Budgetary Educational Institution of Higher Education “Lipetsk State Technical University”, February 25, 2022, pp. 40-81.

7. Photo table of graphic test materials, also known as Figure 4.

8. Protocol for laboratory testing of samples.

9. EU Reference Document on Best Available Techniques for the Waste Incineration, 2019, pp. 143-145.

10. ITS 9-2020. Information technology guide to the best available technologies. Recycling and neutralization of waste by thermal methods, Federal Agency for Technical Regulation and Metrology, pp. 76, 79, 81.

11. RF Patent No. 2119125, published 09.20.1998

12. RF Patent No. 2502922, published on December 27, 2013.

13. RF Patent No. 2383822, published 03/10/2010

14. Copyright certificate of the USSR No. 1663353 F27B 1/02, published on July 15, 1991. Bull. No. 26.

15. RF Patent No. 2791072, published 03/02/2023

16. RF Patent No. 2316696, published 02/10/2008

17. RF Patent No. 2729679, published 08/11/2020

18. RF Patent No. 2712461, published 01/29/2020

19. Figure 1. Design and schematic diagram of a vertical two-shaft furnace for firing carbonate materials for joint thermochemical recycling of combustible waste.

20. Figure 2. Functional diagram of the method for thermochemical disposal of combustible waste.

21. Figure 3. Sketch drawing of a vertical two-shaft furnace for firing carbonate materials for joint recycling of combustible waste with charge feed bins.

22. Figure 4. Photo table of ongoing pilot tests of the method and device.

Claims (14)

1. A method for thermochemical recycling of flammable industrial waste, halogen-containing waste and polyvinyl chloride plastics, residues after sorting solid municipal waste, plastics and polyethylenes, alternative fuels RDF, SRF, TDF in a vertical two-shaft kiln for firing lump carbonate material into lime, including stages where (a) prepare the charge in the bunker rack according to the recipe, dose fractional recyclable waste, additives and lump carbonate material with a fraction from 20 mm to 120 mm from the supply bins; (b) top loading the prepared mixture is loaded into the first direct-flow gas generator shaft through the first sealed conical loading device equipped with an aspiration installation for gasification products; (c) top load carbonate material with a fraction from 20 mm to 120 mm into the second countercurrent firing shaft through a second sealed conical loading device equipped with an aspiration unit for gasification products; (d) gasify the charge in the first gas generator shaft in an environment of limited supply of oxidizer with an excess air coefficient α=0.5 to obtain gasification products from waste in the form of a mixture of generator synthesis gas, consisting mainly of H ₂ and CO, in an alkaline earth environment metals CaCO ₃ and CaO by heating from upper combined burners at a temperature of more than +1300°C for the destruction of dioxins and furans, as well as eliminating the formation of liquid fractions in the form of resins, with gases being sucked through a layer of technical lime CaO charge with the possibility of supplying additives; (e) calcining lump carbonate material, limestone CaCO _{3 ,} in a second counterflow shaft to decompose it into CO ₂ gas and commercial lime CaO; (f) evacuate by blowing the waste gasification products, mainly in the form of generator synthesis gas, from the first shaft to the second shaft through a transition channel, where the gasification products are re-burned in an environment of excess air by suction from bottom to top, through a layer of hot lime CaO throughout the entire firing zone and heating in the second counter-current firing shaft, due to which the gasification products release the energy of subsequent combustion to the burning of commercial lime, replacing the main fuel of the process; (g) gasification leakage products from the mines are evacuated by vacuum from both lock loading devices and fed into the transition channel-gas duct to the secondary combustion lance with suction through a layer of hot lime CaO; (h) commercial lime CaO mixed with ash from recycled waste is unloaded from the first gas generator shaft, and marketable lump lime CaO is unloaded from the second counterflow roasting shaft; (i) waste flue gases are removed from the two-shaft furnace for gas purification due to the vacuum of the smoke exhauster from the upper part of the second roasting shaft in order to ensure the suction mode of the entire volume of gasification products through the high-temperature calcination zone of commercial lime CaO in the second shaft, and the reacted fine CaO is collected from the flue gases dust and gas purification filters; (j) they clean the flue gases, after the furnace they precipitate fly ash with carbon-fabric and electric precipitators, remove residual acid gases HCl, SO ₂ , HF in a dry or wet way, and also catalytically decompose nitrogen oxides - nitrogen monoxide NO and nitrogen dioxide NO ₂ - ammonia solution at temperatures from +170°C to +380°C with the formation of nitrogen gas and water vapor; characterized by the fact that in the first gas generator shaft gasification of waste with a deficiency of oxidizer is carried out, with an excess air coefficient α = 0.5, due to which generator synthesis gas is obtained, which then flows into the second carbonate roasting shaft for secondary combustion, where it burns in excess air with α≥1.2 with the release of heat, thereby replacing the main fuel of the process of obtaining commercial lime, additionally hot commercial lime CaO in the firing zone of the second counter-flow shaft is a continuous, replaceable, adsorbing filter load for the sucked products of high-temperature gasification of recycled waste of the first direct-flow mine-gas generator, on the surface of CaO the required conditions for the thermochemical destruction of dioxins and furans are realized, ensuring the residence time of gasification products in the environment of alkaline earth metals CaCO ₃ and CaO at temperatures from +1300°C to +1700°C for more than 2 seconds with excess air α =1.08-1.2, and lime CaO adsorbs on its surface and removes from both mines the elements chlorine, fluorine, bromine and sulfur compounds converted into stable neutral compounds, thereby eliminating the reverse recombination of dioxins and furans, and also binds heavy metals Pb , Zn, Cd, Hg with lime CaO, turning into stable solid neutral compounds, additionally, the charge formulation ensures gas permeability and mobility of the mixed-component charge, eliminates the charge hanging on the roofs in the furnace shafts, and grinds the recyclable waste by grinding with lump carbonate material during the process of the charge layer draining in the mine - gas generator and clean the lining shell from carbon deposits and deposits; gas, liquid fuel, and solid fuel are used as fuel. 2. Vertical two-shaft kiln for firing lump carbonate material into lime with joint thermochemical recycling of flammable industrial waste, halogen-containing waste and polyvinyl chloride plastics, residues after sorting solid municipal waste, plastics and polyethylenes, alternative fuels RDF, SRF, TDF, containing consumable bins for recyclable waste , additives, lump carbonate material with a fraction from 20 mm to 120 mm, a bunker trestle with dispensers and conveyors for forming the charge according to the recipe, a charge conveyor, two upper loading devices with sealed locks, two vertical lined furnace shafts with heating, firing and cooling zones, connected a hollow lined transition channel-gas duct at the level between the firing and cooling zones, two lower unloading devices, burners for natural gas, a mixture of gases or liquid fuels, a lance for secondary combustion of gases from loading devices in the transition channel, an aspiration unit, smoke exhausters and blowers, means dust and gas purification, characterized by the fact that it structurally combines two units: the first is a direct-flow shaft-gas generator of combustible waste into generator synthesis gas and the second is a counter-current shaft for burning lump carbonate material into commercial lime CaO and afterburning generator synthesis gas, interconnected by a hollow a lined transition channel-gas duct at the level between the firing and cooling zones, despite the fact that the first shaft-gas generator is designed to operate only in a direct-flow mode of gas and charge movement from top to bottom, with an upper arrangement of fuel and air supply burners, loading the charge from above in a pour-over method and operation in a combined mode of gasification of recycled waste and firing of lump carbonate material included in the charge, and the second countercurrent roasting shaft is designed to operate only in countercurrent mode, loading from above in a pouring method with lump carbonate material with the supply of fuel to its lower part by burner devices and air together with gasification products from the upper loading devices fed by a lance into the transition channel for mixing and secondary combustion in the CaO layer of the second shaft, with the possibility of flowing waste gasification products from the gas generator shaft into the countercurrent firing shaft through a hollow lined transition channel-gas duct for supplying everything volume of gasification products for secondary combustion by sucking CaO into a layer of hot commercial lime throughout the firing and heating zone of the second countercurrent shaft, with the possibility of evacuating flue gases with pulverized lime CaO reacted with pollutants using a vacuum exhauster from the upper part of the second countercurrent burning shaft, with the possibility of heating the air, supplied from below into the kiln shafts for cooling the lime through unloading devices, and entering the blast into the second counter-current firing shaft. 3. The furnace according to claim 2, characterized in that it is designed with the ability to load solid fuel into the shaft by pouring method from above or supply pulverized coal, water-coal fuels, petroleum products, fuel oil, watered fuel oil, crude oil or gases by burner devices.

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