RU2807829C1 - Inductor - grate of reactor installation for plasmothermal waste processing - Google Patents

Abstract

FIELD: waste treatment.

SUBSTANCE: devices for thermal neutralization (combustion) of solid household and municipal waste, sludge from biological sewage treatment plants and other solid waste, as well as vapor-gas, liquid waste, including low-energy waste in terms of the content of combustible components. To solve the problem, we propose a reactor grate for a plasma-thermal waste treatment plant, equipped with support elements and made in the form of a truncated cone with a round plate located coaxially on top, forming the upper base, and a ring element on the bottom, forming the lower base, as well as evenly installed along their circumferences hollow triangular blades having a trapezoidal profile, with an angle of location of the trapezoidal planes from 25 to 30° to the radii of the bases, while adjacent trapezoidal faces, one of which faces inward of the cone, and the other outward, form the leading edge of the blade at the point of convergence, made under an angle to the plane of the lower base from 75 to 85°, and the other face facing outward of the cone, which is the generatrix of the cone, forms the outlet edge of the blade, made at an angle to the plane of the lower base from 50 to 70°, and each blade is equipped with a through, limited by the internal cavity blades with a longitudinal channel with lower inlet and upper outlet holes, as well as outlet slotted holes made in a trapezoidal face facing the inside of the cone and oriented towards the inlet edge of the blade.

EFFECT: increasing the functionality of the grate and enhancing the efficiency of the plasma-thermal waste processing.

6 cl, 4 dwg

Description

The invention relates to devices for thermal neutralization (combustion) of solid household and municipal waste, sludge from biological sewage treatment plants and other solid waste, as well as vapor-gas, liquid waste, including low-calorie waste in terms of the content of combustible components.

From the existing level of technology, various installations for waste processing using plasma technologies are known (RF patents No. 2038537, 2108517, 2143086, 2183794, 2246072).

As a rule, all known installations contain plasma generators (plasmatrons) 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.

The closest in its technical essence to the claimed invention is the well-known grate of the reactor of an installation for plasma-thermal waste processing (RF patent No. 2772320, IPC F23G 5/027; F23G 5/24, publ. 05/18/2022), made in the form of a truncated cone , consisting of at least 12 blades with a vertical angle of inclination from 8 to 24°, rigidly fixed at the top on the upper round plate covering the truncated part of the grate, and at the bottom closed in a metal lower hoop, to which the blades have an extension, with the grate at the bottom The grille is equipped with a support stand with supports.

The process of plasma-thermal waste treatment using a known grate is carried out as follows.

First, raw materials for ignition are poured onto the grate, which is rigidly fixed in the upper working chamber of the furnace unit on a stand. The level of ignition material must completely cover the upper edge of the grate. The grate is ignited and warmed up. Next, waste is loaded into the furnace unit, which, falling onto a heated grate, goes through the stage of drying and heating. When waste is burned, pyrolysis gas is formed, which, under pressure created by the smoke exhauster and continuously supplied air, is directed through the gas outlet openings through special channels from the upper working chamber of the furnace unit through the lower working chamber into the inner part of the grate, forming a plasma cloud inside it. Plasma jets, passing through the slot gaps between the blades, heat the waste to a temperature of 1700-3200°C. Next, the contaminated pyrolysis gases, under pressure created by the smoke exhauster, flow through a special channel into the upper part of the afterburner chamber, where all harmful substances (dioxins, furans) disintegrate into molecules, and clean gases fall down the afterburner chamber, are cooled and then discharged through the smoke exhauster into the exhaust pipe .

The disadvantages of the known grate, chosen as a prototype, include limited functionality, as well as insufficient waste processing efficiency associated with the impossibility of transferring the plasma flow to the outer contour of the grate.

The problem solved by the invention is to increase the functionality of the grate and increase the efficiency of the plasma-thermal waste processing process.

To solve the problem, we propose a reactor grate for a plasma-thermal waste treatment plant, equipped with support elements and made in the form of a truncated cone with a round plate located coaxially on top, forming the upper base, and a ring element on the bottom, forming the lower base, as well as evenly installed along their circumferences hollow triangular blades having a trapezoidal profile, with an angle of location of the trapezoidal planes from 25 to 30° to the radii of the bases, while adjacent trapezoidal faces, one of which faces inward of the cone, and the other outward, form the leading edge of the blade at the point of convergence, made at an angle to the plane of the lower base from 75 to 85°, and the other face facing the outside of the cone, which is the generatrix of the cone, forms the outlet edge of the blade, made at an angle to the plane of the lower base from 50 to 70°, and each blade is equipped with a through, limited by the internal cavity of the blade a longitudinal channel with a lower inlet and an upper outlet, as well as outlet slotted holes made in a trapezoidal face facing the inside of the cone and oriented towards the inlet edge of the blade.

This technical solution allows, due to the design of the grate, to effectively transfer the plasma flow from its inner lower part to the entire surface area of the outer contour, thereby increasing the area of thermal destruction, as well as the combustion temperature. In addition, the enrichment along the perimeter of the grate of pyrolysis gases obtained from waste supplied to its external circuit is ensured, which significantly increases the functionality of the grate and increases the efficiency of the plasma-thermal waste processing process.

At the same time, in parallel with the performance of the functions of the grate, the generation of discharges of static electricity is also ensured due to the dynamics of the movement of raw materials along the grate and the turbulence of ascending gas flows, entraining particles of recycled organics that have the corresponding electrical resistivity. As a result, static electricity is generated, which forms microdischarges that promote both the dissociation of water into hydrogen and oxygen, and the thermal destruction of particles of recycled organic matter into hydrocarbons and carbon monoxide, which increase the adiabatic characteristics of the combustion process to a superadiabatic combustion mode with increasing temperature.

In this case, in the preferred design, the grate includes at least twelve all-metal blades.

To simplify the design of the grate, reduce its cost and increase functionality, the blades are attached to the mentioned round plate and ring element with welds, thereby forming a single supporting frame that does not require additional supporting elements, except for the supporting ones, for installation in the reactor vessel.

For ease of maintenance of the furnace unit, the round plate of the grate can be equipped with rigging fasteners.

In this case, the supporting elements of the grate can be made in the form of a ring support with supports spaced apart around the circumference or in the form of horizontal protrusions in the reactor vessel.

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

- in Fig. 1 shows a general view of the grate;

- in Fig. 2 – general view of the grate blade;

- in Fig. 3 – cross-section of the grate blade;

- in Fig. 4 – installation diagram for plasma-thermal waste processing

The design of the grate (1) (Fig. 1) in the preferred embodiment is made of heat-resistant steel 20Х25Н19С2Л or high-alloy cast iron ChYu22Sh in the form of a truncated cone with all-metal blades (2), closed from below into a metal lower ring element (3) with a stand (4) (Fig. 4), rigidly attached to the reactor vessel (15). From above, the blades are attached by welds to a plate (5) (Fig. 1) with a rigging ring (not shown in the drawings). The blades (2) have a hollow volume with a trapezoidal expansion to the annular element (3), which is attached to the blades by welded seams, and are triangular elements with trapezoidal edges (6), (7) (Fig. 3), forming an inlet at the point of convergence edge (8), and an intermediate edge (9), forming the exit edge (10) (Fig. 3). The blades are also equipped with lower inlet (11) and upper outlet (12) holes (Fig. 1), made in the form of triangular-shaped end sections, as well as technological slotted holes (13) (Fig. 2, 3) for outputting the plasma flow to the external contour of the grate (1).

One of the preferred options for implementing the proposed grate as part of an installation for plasma-thermal waste processing is demonstrated below with an example.

To start the waste processing process, open the lid (14) (Fig. 4) of the furnace reactor body (15) and pour raw materials for ignition into the upper working chamber on the grate (1). The level of ignition material must completely cover the upper edge of the grate (1). Then the grate (1) is ignited and warmed up. Then, after 20-40 minutes, waste is loaded into the upper working chamber (16) and the lid (14) is closed. The waste, falling onto the heated grate (1), goes through the stage of drying and heating. When burning waste, pyrolysis gas is formed, which, under pressure created by the smoke exhauster (17) and air entering through the technological adjustable hole (18) of the door block (19) of the housing (15), is directed through the gas outlet holes (20) through the recirculation pipes (21 ) from the upper working chamber (16) through the lower working chamber (22) to form an ascending gas flow into the middle working chamber (23), limited by the internal cone-shaped part of the grate (1), forming a plasma cloud inside it. In parallel, due to the pressure of the smoke exhauster (17), air is sucked through the technological hole (18) of the door block (19) into the internal cavities of the blades (2) (Fig. 2) of the grate (1) (Fig. 1) through the lower inlet (triangular) holes (11). In this case, part of the air is pushed through the internal slotted openings (13) (Fig. 2) of the blades (2) into the inner part of the grate (1) (Fig. 1), under the pressure of which the plasma jets through the slotted gaps between the blades (2), bending around from the side of the inlet edges (8) (Fig. 3), trapezoidal edges (6), (7) and outlet edges (10) (Fig. 3) are transferred at an optimal angle to the outer contour of the grate (1) (Fig. 1) , 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 (2) through the outlet holes (12) enriches the generated pyrolysis gases along the perimeter of the plate (5) of the grate (1). 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 (1) due to its design features, as well as due to the destruction of particles of recycled organic matter into hydrocarbons and carbon monoxide, which allows to maximize the adiabatic characteristics of the combustion process, and, Consequently, to reduce the 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 rising vortex flow of heated and air-enriched pyrolysis gases through the recirculation pipes (21) (Fig. 4) is again thrown into the lower working chamber (22), followed by the repetition of the cycle in the furnace reactor (15) for the upward flow of gas at elevated temperatures. In this case, a downward flow of contaminated pyrolysis gases of low temperature under pressure created by the smoke exhauster (17) flows through the pipe (24) into the upper part of the afterburning chamber (25) and twists in a spiral around the pipe (26). The temperature in the upper part of the afterburning chamber (25) reaches 1200-1700°C. At this temperature, all harmful substances (dioxins, furans) break down into molecules. Clean gases fall down the afterburning chamber (25), cooling to 350°C and through the inlet of the pipe (26) are discharged through the smoke exhauster (17) into the exhaust pipe (27).

The proposed design of the grate has expanded combustion functions, which makes it possible to work with a more complex morphological composition of incoming raw materials and reduces the time cycle of waste destruction (incineration).

The main advantages of the claimed invention 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 with subsequent recovery of the resulting heat;

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

Claims (6)

1. Grate of the reactor of the installation for plasma-thermal waste processing, equipped with supporting elements and made in the form of a truncated cone with a round plate located coaxially on top, forming the upper base, and on the bottom, a ring element forming the lower base, as well as hollow trihedral blades evenly installed along their circumferences , having a trapezoidal profile, with an angle of location of the trapezoidal planes from 25 to 30° to the radii of the bases, while adjacent trapezoidal edges, one of which faces the inside of the cone, and the other outside, form the leading edge of the blade at the point of convergence, made at an angle to the plane of the lower base from 75 to 85°, and the other face facing the outside of the cone, which is the generatrix of the cone, forms the outlet edge of the blade, made at an angle to the plane of the lower base from 50 to 70°, and each blade is equipped with a through, limited by the internal cavity of the blade longitudinal channel with lower inlet and upper outlet holes, as well as outlet slotted holes made in a trapezoidal face facing the inside of the cone and oriented towards the inlet edge of the blade. 2. The grate according to claim 1, characterized in that it is made of heat-resistant steel 20Х25Н19С2Л or high-alloy cast iron ChYu22Sh. 3. The grate according to claim 1, characterized in that the supporting elements are made in the form of an annular stand with supports spaced around the circumference or in the form of horizontal protrusions in the reactor vessel. 4. The grate according to claim 1, characterized in that it includes at least twelve all-metal blades. 5. The grate according to claim 1 or 3, characterized in that the blades have at least three longitudinally located slotted holes. 6. The grate according to claim 1, characterized in that the round plate is equipped with rigging fasteners.