RU2809374C1 - Method of plasmothermal processing of solid waste - Google Patents

Abstract

FIELD: waste disposal.

SUBSTANCE: invention can be used in industry and municipal services when processing waste of various compositions and physical states. A method of plasma-thermal processing of solid waste, in which there is a continuous supply of air into the upper working chamber of a furnace reactor, supply of raw materials for ignition into the upper working chamber onto the outer truncated-cone-shaped surface of the middle working chamber of the furnace reactor, ignition and heating of the middle working chamber. Subsequent feeding of waste into the upper working chamber, drying, heating and burning until flammable pyrolysis gases are formed, which are then directed through the gas outlet openings through recirculation pipes from the upper working chamber through the lower working chamber into the middle working chamber, limited by an internal truncated-cone-shaped space, inside which a plasma cloud is formed, heating the truncated cone-shaped surface from the inside. At the same time, the air continuously supplied through the lower working chamber is pushed into the internal truncated-cone-shaped space of the middle working chamber, under the pressure of which the plasma cloud is transferred through holes in the truncated-cone-shaped surface in the form of plasma jets into the upper working chamber, ensuring thermal destruction of waste throughout the truncated-cone-shaped area at the temperature of the superadiabatic combustion conditions. The resulting pyrolysis gases are additionally enriched with air along the perimeter of the truncated part of the cone, after which a flow of heated air-enriched pyrolysis gases is thrown into the lower working chamber, returning the upward gas flow to the operating cycle carried out in the furnace reactor. Downward flow of contaminated pyrolysis gases under pressure is directed into the afterburning chamber, where they are heated to the temperature at which harmful substances decompose into molecules, and the clean gases are cooled and discharged into the exhaust pipe.

EFFECT: increased efficiency of the separation process.

1 cl, 3 dwg

Description

The invention relates to the field of waste disposal and can be used in industry and municipal services when processing waste of various compositions and physical states.

In the 21st century, the problem of landfills threatens to develop into a global catastrophe. Landfills occupy hundreds of hectares of land, smoke, smoke, pollute the land, air, water, and emit toxic and harmful substances resulting from spontaneous unorganized combustion and decomposition of garbage.

Burying garbage in the ground does not solve the problem, but aggravates it, because... It only allows you to hide waste without protecting the environment from it. Rotting waste can continue for decades, polluting groundwater and releasing toxic gases into the atmosphere.

Also, burning waste at waste treatment plants does not solve the problem, because... When waste is burned, tons of harmful substances are released into the atmosphere, including dioxins and furans, which pose a threat to all living things.

Currently, a promising area of waste processing and disposal is plasma processing of garbage rubble.

The key advantage of plasma technology is the high temperatures obtained during plasma combustion, ranging from 1200°C and above. The essence of this technology is the thermochemical decomposition of organic components to the atomic level and their ionization with the subsequent production of gas (a mixture of hydrogen, carbon monoxide with admixtures of other flammable gases), which can subsequently be used as pure fuel or as a primary product for organic synthesis. Toxin emissions are reduced by 99%. At the same time, the inorganic component - solid waste (slag) is an environmentally friendly material that can be used as a composite material in construction. Thus, plasma waste recycling allows you to completely decompose waste into safe and valuable compounds. Another important advantage of this technology is its practical versatility, i.e. wide range of processed materials: solid, liquid, gaseous.

Various methods of waste processing using plasma technologies are known from the prior art (RF patents for invention No. 2038537, 2108517, 2143086, 2183794, 2246072, 2716652).

As a rule, installations implementing known methods contain plasma generators (plasmatrons) or use third-party fuel and a gas purification system. They are highly efficient, but at the same time they are quite complex structures and also require high energy consumption, which leads to a significant increase in the cost of both the structures themselves and the waste recycling process.

There is a known method of fuel utilization in a superadiabatic mode (RF patent for invention No. 2305129, IPC C10L9/08, published on August 27, 2007) through two-stage filtration combustion with the formation of synthesis gas, followed by its utilization with an excess of oxidizer, characterized in that the process temperature is maintained at the level of 2000-2300 K by increasing the fuel heating temperature Tn within 350°C<Tn<500°C due to additional heat recovery with reaching the stage of water dissociation to produce hydrogen involved in the combustion process as fuel.

The disadvantage of the known solution is that the design features of the installation that implements the method do not allow waste to be processed without additional fuel costs, both without their preliminary preparation and beyond the strict limits of their moisture content and a narrow range of the ratio of organic and inorganic components, as well as taking into account environmental requirements.

There is a known method for plasma-thermal processing of solid waste (RF patent for invention No. 2772320, IPC F23G 5/027, F23G 5/24, publ. 05/18/2022), including continuous supply of air to the upper working chamber of the furnace reactor, supply of raw materials for ignition to the upper working chamber onto the outer cone-shaped contour of the grate, ignition and warming up of the grate, feeding waste into the upper working chamber, drying it, heating and burning until flammable pyrolysis gases are formed from the waste, their subsequent injection through the recirculation pipes under the influence of pressure created by the smoke exhauster and supplied air , a downward gas flow into the lower combustion chamber, in which a vortex ascending flow of gases heated to a high temperature is formed, which, rising, enters the internal cone-shaped space of the grate, forming a plasma cloud inside it, which heats the grate from the inside and enters the external contour of the grate waste grates until the temperature of thermal destruction is reached, after which the flow of heated pyrolysis gases through the recirculation pipes is again thrown into the lower working chamber, returning the upward flow of gas at elevated temperature to the working cycle of plasma-thermal processing in the furnace reactor, and the downward flow of contaminated pyrolysis gases at low temperature under pressure, created by a smoke exhauster, are directed to the upper part of the dozhit chamber, where they are heated to a temperature of 1200-1700 ° C, as a result of which all harmful substances disintegrate into molecules, and clean gases fall down to the bottom of the dozhit chamber, where they are cooled to 350 ° C and discharged into the exhaust pipe.

The disadvantages of this known method include the insufficient efficiency of the waste recycling process.

The problem solved by the invention is to create a method for plasma-thermal processing of solid waste, which significantly increases the efficiency of the process, while not requiring large energy consumption.

To solve this problem, a method of plasma-thermal processing of solid waste is proposed, in which air is continuously supplied to the upper working chamber of the furnace reactor, raw materials for ignition are supplied to the upper working chamber on the outer truncated-cone-shaped surface of the middle working chamber of the furnace reactor, ignition and heating of the middle working chamber , subsequent feeding of waste into the upper working chamber, drying, heating and burning until flammable pyrolysis gases are formed, which are then directed through the gas outlet openings through recirculation pipes from the upper working chamber through the lower working chamber into the middle working chamber, limited by an internal truncated-cone-shaped space , inside of which a plasma cloud is formed, heating the truncated-cone-shaped surface from the inside; in parallel, the air continuously supplied through the lower working chamber is pushed into the internal truncated-cone-shaped space of the middle working chamber, under the pressure of which the plasma cloud through the holes in the truncated-cone-shaped surface in the form of plasma jets transferred to the upper working chamber, ensuring thermal destruction of the waste over the entire truncated cone-shaped area at the temperature of the superadiabatic combustion regime, while the resulting pyrolysis gases are additionally enriched with air along the perimeter of the truncated part of the cone, after which a flow of heated air-enriched pyrolysis gases is thrown into the lower working chamber, returning the upward flow of gas to the operating cycle carried out in the furnace reactor, and the downward flow of contaminated pyrolysis gases under pressure is sent to the afterburning chamber, where they are heated to the temperature of the decomposition of harmful substances into molecules, and the clean gases are cooled and discharged into the exhaust pipe.

The essence of the invention is illustrated in detail by drawings, where:

- in Fig. 1 shows a diagram of the installation for implementing the method of plasma-thermal waste processing;

- in Fig. 2 - general view of the grate as part of the installation for implementing the method of plasma-thermal waste processing;

- in Fig. 3 - general view of the grate blade as part of the installation for implementing the method of plasma-thermal waste processing.

The proposed method is implemented through an installation for plasma-thermal waste processing (Fig. 1), which contains a furnace reactor (1), an afterburner chamber (2), a smoke exhauster (3) and an exhaust pipe (4) technologically connected in series by pipes. The furnace unit (1) is made in the form of a cylinder, vertically located inside a lined housing, equipped with a lid (5) and a door block (6) with a technological hole (7) for the intake of forced air. The furnace reactor body (1) is divided into the upper (8) and middle (9) working chambers by a truncated cone-shaped surface of the grate (10), as well as into the middle (9) and lower (11) working chambers by a rigidly fixed ring stand (12) with supporting elements (13), on which a grate (10) is installed.

The grate (10) (Fig. 2) is preferably made of heat-resistant steel 20Х25Н19С2Л or high-alloy cast iron ChYu22Sh and is a truncated cone with a round plate (14) located coaxially on top, forming the upper base, and a ring element (15) at the bottom, forming lower base, as well as hollow triangular blades (16) evenly installed around their circumferences. The blades (minimum 12) have a trapezoidal profile, with the angle of the trapezoidal planes from 25 to 30° to the radii of the bases. In this case, the adjacent trapezoidal faces (17), (18) (Fig. 3) of the blades (16), one of which (18) faces inward of the cone, and the other (17) (Fig. 2) faces outward, form the entrance edge (19) (Fig. 3), which is made at an angle to the plane of the lower base from 75 to 85°. The third face (20) (Fig. 2) faces outside the cone and forms the exit edge (21) (Fig. 3), which is located at an angle to the plane of the lower base from 50 to 70°. Each blade (16) is equipped with a through, limited by the internal cavity of the blade, longitudinal channel (Fig. 2) with a lower inlet (22) and an upper outlet (23) holes, as well as outlet slotted holes (24) (Fig. 3), made in a trapezoidal shape. facet (18).

The cover (5) of the furnace reactor body (1) can be equipped with a lifting mechanism (25). The cover has a hole with a fixed door for supplying liquid or gaseous waste (not shown in the drawings), including the exhaust gases of the installation. A door block with a technological hole for visual observation of the process (not shown in the drawings) can also be located on the body.

One of the preferred options for implementing the method of plasma-thermal waste processing is demonstrated below with an example.

To start the waste recycling process, pressing the corresponding button on the control panel (26) (Fig. 1) of the control unit (27) starts the lifting mechanism (25) for opening the cover (5) of the furnace reactor body (1). Then the raw materials for ignition are poured into the upper working chamber (8) onto the grate (10). The level of ignition material must completely cover the upper edge of the grate (3). Then, by pressing the corresponding button on the control panel (26), the starting mode is selected, which is carried out at a rotation speed of the fan (27) of the smoke exhauster (3) of 150 Hz. Next, the grate (10) is ignited, after which the lid (5) is closed by pressing the corresponding button on the control panel (26) and warmed up. After 20-40 minutes, the installation is switched to operating mode at a rotation speed of the fan (27) of the smoke exhauster (3) of 240-320 Hz and waste is loaded into the upper working chamber (8), which, falling onto the heated grate (10), goes through the drying stage and warming up. When burning waste, pyrolysis gas is formed, which, under the pressure created by the smoke exhauster (3) and the air entering through the technological opening (7) of the door block (6), is directed through the gas outlet openings (28) through the recirculation pipes (29) from the upper working chamber (8) through the lower working chamber (11) into the middle working chamber (9), limited by the inner part of the grate (10), forming a plasma cloud inside it. In parallel, due to the pressure of the smoke exhauster, air is sucked through the technological hole (7) of the door block (6) into the internal cavities of the blades (16) (Fig. 2) of the grate (10) through the lower inlet (triangular) holes (22). In this case, part of the air is pushed through the internal slotted openings (24) (Fig. 3) of the blades (16) into the inner part of the grate (10) (Fig. 2), under the pressure of which the plasma jets through the slotted gaps between the blades (16), bending around from the side of the inlet edges (19) (Fig. 3), trapezoidal edges (18), (17) (Fig. 2) and outlet edges (21) (Fig. 3), at an optimal angle, are transferred to the outer contour of the grate (10) (Fig. 2), ensuring uniform flow distribution over the entire surface of the external circuit, thereby maximizing the area of thermal destruction of waste and increasing the combustion temperature to 1700-3200 ° C in a superadiabatic combustion mode. In this case, part of the air sucked into the internal cavities of the blades (16) through the outlet holes (23) enriches the generated pyrolysis gases along the perimeter of the upper truncated conical part of the grate (10). Moreover, the energy of micro-discharges of static electricity is additionally used, formed during the dynamics of the movement of raw materials along the grate due to its design features, as well as due to the destruction of particles of recycled organic matter into hydrocarbons and carbon monoxide, which makes it possible to maximize the adiabatic characteristics of the combustion process, and, consequently, reduce time cycle of waste destruction, which ultimately makes it possible to work with a more complex morphological composition of incoming raw materials and waste.

Next, the flow of heated and air-enriched pyrolysis gases through the recirculation pipes (29) (Fig. 1) is again thrown into the lower working chamber (11), followed by the repetition of the cycle in the furnace reactor (1) for an upward flow of gas at an elevated temperature. In this case, a downward flow of contaminated pyrolysis gases at low temperature under pressure created by the smoke exhauster (3) flows through the pipe (30) into the upper part of the exhaust chamber (2) and twists in a spiral around the pipe (31). The temperature in the upper part of the chamber (2) reaches 1200-1700°C. At this temperature, all harmful substances (dioxins, furans) break down into molecules. Clean gases fall down the afterburning chamber (2), cooling to 350°C and through the inlet of the pipe (31) are discharged through the smoke exhauster (3) into the exhaust pipe (4).

The main advantages of the claimed method are:

- increasing the temperature of disposal of various organic wastes with a high content of non-combustible components without grinding them, without the use of additional fuel, and also without environmental restrictions on the use of bottom ash;

- use of static electricity energy, followed by recovery of the resulting heat;

- compliance with environmental requirements for emissions of pollutants into the atmosphere.

The submitted application materials do not exhaust the possible implementation options and do not limit in any way the scope of the proposed technical solution. Other options for execution and use are possible within the scope of the claimed formula.

Claims (1)

A method of plasma-thermal processing of solid waste, in which there is a continuous supply of air into the upper working chamber of a furnace reactor, supply of raw materials for ignition into the upper working chamber onto the outer truncated-cone-shaped surface of the middle working chamber of the furnace reactor, ignition and heating of the middle working chamber, subsequent supply of waste to the upper working chamber, their drying, heating and combustion until the formation of flammable pyrolysis gases, which are then directed through the gas outlet openings through recirculation pipes from the upper working chamber through the lower working chamber into the middle working chamber, limited by an internal truncated-cone-shaped space, inside which a plasma plasma is formed the cloud, heating the truncated-cone-shaped surface from the inside, in parallel ensures the pushing of air continuously supplied through the lower working chamber into the internal truncated-cone-shaped space of the middle working chamber, under the pressure of which the plasma cloud is transferred through holes in the truncated-cone-shaped surface in the form of plasma jets to the upper working chamber , providing thermal destruction of waste over the entire truncated cone-shaped area at the temperature of the superadiabatic combustion mode, while the resulting pyrolysis gases are additionally enriched with air along the perimeter of the truncated part of the cone, after which the flow of heated air-enriched pyrolysis gases is thrown into the lower working chamber, returning the upward flow of gas to operating cycle carried out in a furnace reactor, and a downward flow of contaminated pyrolysis gases under pressure is sent to the afterburning chamber, where they are heated to the temperature of the decomposition of harmful substances into molecules, and clean gases are cooled and discharged into the exhaust pipe.