RU2700614C1 - Apparatus for heat treatment of solid municipal wastes by pyrolysis - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to devices for thermal processing of municipal solid waste and can be used in housing and communal services for the disposal and destruction of waste with the simultaneous production of gaseous fuels. Plant for thermal processing of solid municipal wastes by pyrolysis in form of tunnel furnace for pyrolysis, which during operation operates in continuous mode, at one end thereof with loading device equipped with dosing unit at inlet and equalizing plate at outlet, belt conveyor and ash residue unloading device on its other end, equipped with pipes for pyrolysis gas formed in the furnace pyrolysis gas discharge pipes, contains a rectangular metal housing with a heat-insulated flat arch, lined inside from inside, under which there is a metal recuperative chamber, in which radiation tubes with diameter D are installed, which are installed horizontally along the furnace at distance L≥D from each other, such that their parts protrude from the recuperative chamber into the furnace working space by 0.5*D, on the side of the nozzle in each radiation tube there are radial holes for supply of combustion air from the recuperative chamber equipped with an inlet branch pipe from the opposite side, wherein the collector for gaseous products of processing of solid municipal wastes is communicated with pipes for discharge of pyrolysis gas from the working space of the furnace, with a pipe for subsequent supply of gas to external consumers and with a branch for supply of gas for combustion into nozzles of radiation tubes.

EFFECT: higher energy efficiency of processing solid municipal wastes.

1 cl, 2 dwg

Description

The invention relates to a device for thermal processing of solid municipal waste (MSW) and can be used in housing and communal services for the disposal and destruction of waste with the simultaneous production of gaseous fuel.

Known devices for the disposal and destruction of unsorted and pre-sorted MSW, which represent a shaft-type furnace (reactor), containing a loading device, a lined housing with zones for drying, pyrolysis and gasification of the MSW layer, equipped with openings for outputting gaseous products of processing, devices for preparation and supply of combustible gas to an external consumer and devices for removing unprocessed inorganics (patent for invention RU No. 2089786, IPC F23G 5 / 00.1997, patent for invention RU No. 2089787, M To F23G 5 / 00.1997, patent for invention RU No. 2201552, IPC F23G5 / 027, F23G 5/14, 2003, patent for invention RU No. 2282788, IPC F23G 5/027, 5/24, 2006 ., patent for invention RU No. 2433344, IPC F23G 5/027, 5/14, 5/24, 2010).

The disadvantages of these devices are: low reliability due to freezing of the processed waste in the upper part of the gasification chamber, associated with the release of resins from the waste by pyrolysis gas rising from the bottom of the gasification chamber; the dependence of the thermal processing process on the gas permeability of the MSW layer; the need for devices for loosening the MSW layer during sintering; design complexity due to the presence of additional energy-intensive devices for producing a gasification agent.

Known devices for the thermal processing of MSW, operating in the combustion mode. The most common are direct-burning furnaces of the MSW layer in the air stream on fixed or moving grates of a special design, placed in a lined case equipped with gas burner devices (US patent No. 5265587, IPC F23H 07/04, 1993, patent for invention RU No. 2114357 , IPC F23G 5/00, 1998, patent for invention RU No. 2265773, IPC F23G 5/00, F23B 1/16, С04В 2/10, 2003).

The disadvantages of these devices are the obligatory presence of a complex and expensive system of secondary purification of flue gases, due to the content of dioxins and furans in them, as well as the rapid wear of the grate and their pollution by dust and resin particles. The burning of MSW is associated not only with the difficulties of neutralizing the toxic components of flue gases, but also with the utilization of the generated heat. Incinerator filters are usually comparable in value to the furnace itself. The energy received in such furnaces does not compensate for the costs of burning MSW.

Known devices for the thermal destruction of solid waste, which are cyclone furnaces decompressed and fluidized bed with a stream of heated air pre-sorted and crushed MSW, containing a lined housing with burner devices (patent for invention RU No. 224976, IPC F23G 5/00, 2002 ., patent for invention RU No. 2226468, IPC F23G 5/30, 2004).

The disadvantages of such devices are: the use of additional nodes and mechanisms for the implementation of the processes of separation and grinding of MSW; creation of high speeds (not lower than 28 m / s) of the flow of the mixture of air and waste to organize a more complete combustion process.

Known mobile plants for the thermal processing of municipal solid waste directly in landfills and landfills. The most common are rotary kilns operating in the combustion mode, equipped with gas burners and mounted on a tractor (patent for invention RU No. 2292515, IPC F23G 5/00, F23G 5/20, 2005, patent for invention RU No. 2456507, IPC F23G 5/20, 2011, patent for invention RU No. 2442931, IPC F23G 5/40, 2012).

The disadvantages of the plants are: low productivity of the incinerated waste, complexity and cumbersome equipment used.

The well-known "Portable installation module for the thermal processing of municipal solid waste at the landfill" (patent for the invention of the Russian Federation No. 2617230, IPC F23G 5/40, 2017), containing a metal lined inside a rectangular case with a flat arch, equipped with mounting loops for transportation, framed by a metal frame with a vertical tape support installed in the lower part along the outer perimeter of the cap body and forming a channel for collecting gaseous products of processing solid household waste, connected to the pipeline the house for supplying gas to the consumer is equipped with radiation pipes installed horizontally under the dome of the hood, so that the distance from the radiation pipes to the layer of municipal solid waste does not exceed 0.5 m, connected by pipelines to the channel for collecting gaseous waste products and a pipeline for supplying starting gaseous fuel, while the number of radiation pipes and their relative position are determined from the condition of ensuring uniform and stable heating and thermal decomposition of waste due to radiant heat.

The disadvantages of the known installation are: uneven heating of the MSW layer due to its heterogeneity and different dispersion, significant loss of thermal energy through the arch, which reduces the efficiency of MSW processing; the complexity and cumbersomeness of auxiliary equipment, the difficulties of operation in the winter.

The well-known "Tunnel furnace" (Utility Model Patent No. 149053, IPC F27B 9/12, F27B 9/14, F23G 5/027, C10B 53/02, C10J 3/00, B09B 3/00, C10L 5/00, 2014 d.), adopted for the prototype, containing a hopper, agitators, propulsion unit, a drying section equipped with IR lamps, a pyrolysis section equipped with microwave generators and gas atomizers, a storage hopper equipped with gas atomizers.

The disadvantages of this device are the lack of applicability for thermal MSW processing, the complexity of the design, the use of microwave radiation as thermal radiation, which reduces the yield of pyrolysis products during processing and reduces the environmental friendliness of the process.

The technical task is to create a simple, reliable and efficient device for the thermal processing of municipal solid waste by pyrolysis.

The technical result of the invention is to increase the energy efficiency of MSW processing.

The technical result is achieved by the fact that the installation for the thermal processing of municipal solid waste by the pyrolysis method in the form of a tunnel pyrolysis furnace, which operates continuously during operation, at one end with a loading device equipped with a dispenser at the input and an equalizing plate at the output, tape a conveyor and an ash residue unloading device at its other end, equipped with nozzles for discharging the pyrolysis gas generated in the furnace, contains a straight metal lined from the inside a casing with a thermally insulated flat arch, under which there is a metal recuperative chamber, in which radiation pipes of diameter D are installed, installed horizontally along the furnace at a distance L≥D from each other, so that their parts protrude from the recuperative chamber into the working space of the furnace 0.5 * D, on the nozzle side in each radiation pipe there are made radial openings for supplying combustion air from a regenerative chamber equipped with an inlet pipe on the opposite side, while p for gaseous products of processing municipal solid waste communicated with pipes for the removal of pyrolysis gas from the working space of the furnace, with a pipe for subsequent supply of gas to an external consumer and with a pipe for supplying gas for combustion in the nozzles of radiation pipes.

The proposed technical solution is illustrated by drawings, where in FIG. 1 shows a view of a plant for the thermal processing of municipal solid waste by pyrolysis in longitudinal section; in FIG. Figure 2 shows the type of installation for the thermal processing of municipal solid waste by pyrolysis in cross section.

The plant for the thermal processing of municipal solid waste by the pyrolysis method in the form of a tunnel pyrolysis furnace contains a metal lined rectangular inside 1 with a thermally insulated flat arch 2. At one end, the tunnel furnace is equipped with a loading device 3, equipped with a dispenser 4 at its entrance and an equalizing plate at the output (not shown in the drawing). At the other end, the tunnel kiln is equipped with an ash discharge unloading device 5. In the working space of the furnace, a conveyor belt 6 is installed, equipped with a cleaning tool 7 of the conveyor belt, made, for example, in the form of a scraper. Under the arch 2 there is a metal recuperative chamber 8, in which radiation tubes 9 of diameter D are installed, installed horizontally along the furnace at a distance L≥D from each other, in order to ensure uniform and stable heating and thermal decomposition of MSW due to radiant heat. The recuperative chamber 8 is designed to heat combustion air, which is carried out in the radiation pipes 9. The radiation pipes 9 are installed in such a way that their parts protrude from the regenerative chamber 8 into the working space of the furnace by 0.5 * D. On the nozzle side 10, in each radiation pipe 9 there are made radial openings 11 for supplying combustion air from a regenerative chamber 8 provided with an inlet pipe 12 from the opposite side. In the side walls of the furnace, nozzles for pyrolysis gas removal 14 (gaseous products of MSW processing) from the furnace working space communicated with the collector 13 for collecting pyrolysis gas are evenly located. The collector 13 for gaseous products of processing municipal solid waste is also in communication with a pipe for subsequent supply of gas to an external consumer 15 and with a pipe for supplying gas for combustion 16 to the nozzles 10 of the radiation pipes 9.

Installation for thermal processing of solid municipal waste works as follows. Through the loading device 3, equipped with a dispenser 4, a continuous batch loading of pre-prepared MSW onto an endless belt conveyor 6 is performed so that the height of the MSW layer does not exceed 0.5 m. Dispenser 4 has at the output a leveling plate with which to regulate the thickness of the MSW layer . Transportation of MSW throughout the entire production process is carried out by a conveyor belt 6 ensuring the continuity of the process of thermal decomposition of MSW and the production of pyrolysis gas. The speed of the conveyor 6 is selected taking into account the rate of thermal decomposition of the waste.

The radiation pipes 9 are ignited by supplying starting gaseous fuel into them through nozzles 10 and air through openings 11 from the regenerative chamber 8 to improve fuel-air mixture formation and ensure stable combustion. Atmospheric air enters the recuperative chamber 8 through the nozzle 13. Radiation tubes 9 isolate the flame of the fuel burned in them from the working space of the furnace and provide radiant heat transfer in the working space from the heat transfer surfaces. The placement of the radiation pipes 9 in such a way that their parts protrude from the regenerative chamber 8 into the working space of the furnace by 0.5 * D allows the radiation pipes 9 to transfer heat by radiation in its upper part - the air moving in the regenerative chamber 8, heating it, and in its lower part - a layer of MSW placed on the conveyor belt 6. Heating the air directed to combustion in the regenerative chamber 8 improves the combustion conditions of the fuel, increasing the combustion temperature and the efficiency of the process. The resulting combustion products are removed into the atmosphere through the pipe 17.

A recuperative chamber 8 filled with air creates an air gap between the thermally insulated arch 2 and the radiation tubes 9, which can significantly reduce the heat loss from the radiation tubes 9 through the arch 2, and therefore, reduce fuel consumption, as well as create directed thermal radiation fluxes to the layer MSW, intensifying the pyrolysis of waste and increasing the energy efficiency of the process.

Organized radiant fluxes of directed action acting on the MSW layer lead to its thermal decomposition at a temperature of at least 550 ° C with the formation of gaseous products (pyrogas) and a solid carbon residue. Pyrogas is removed from the furnace working space through nozzles 14 to a collector 13 for collecting pyrogas and then through nozzle 15 for subsequent supply to an external consumer and through nozzle 16 for burning radiation pipes 9 into nozzles 10. The solid carbon residue remaining on the conveyor belt after the process is collected by the device unloading 5 ash residue for subsequent use for technological purposes.

After the installation for thermal processing of solid municipal waste to the operating mode, the supply of starting gaseous fuel to the radiation pipes 9 is turned off, which will subsequently work on pyrogas.

Thus, the use of the claimed invention improves the energy efficiency of the processing of previously prepared solid municipal waste.

Claims (1)

The installation for the thermal processing of municipal solid waste by the pyrolysis method in the form of a tunnel pyrolysis furnace, which operates continuously during operation, at one end with a loading device equipped with an inlet dispenser and an output leveling plate, a conveyor belt and an ash residue unloading device at its other end, equipped with nozzles for discharging the pyrolysis gas generated in the furnace, characterized in that it contains a metal lined rectangular inside with heat an insulated flat arch, under which there is a metal recuperative chamber, into which radiation pipes with a diameter D are installed, installed horizontally along the furnace at a distance L≥D from each other, so that their parts protrude from the regenerative chamber into the furnace working space by 0.5 * D, on the nozzle side, in each radiation pipe, radial openings are made for supplying combustion air from a regenerative chamber equipped with an inlet pipe on the opposite side, while the collector for gaseous of municipal solid waste processing products, it was connected with nozzles for discharging pyrolysis gas from the furnace working space, with a nozzle for subsequent gas supply to an external consumer, and with a nozzle for supplying gas for combustion to the nozzles of radiation pipes.

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